Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/drivers/usb/host/fotg210-hcd.c

  1 /* Faraday FOTG210 EHCI-like driver
  2  *
  3  * Copyright (c) 2013 Faraday Technology Corporation
  4  *
  5  * Author: Yuan-Hsin Chen <yhchen@faraday-tech.com>
  6  *         Feng-Hsin Chiang <john453@faraday-tech.com>
  7  *         Po-Yu Chuang <ratbert.chuang@gmail.com>
  8  *
  9  * Most of code borrowed from the Linux-3.7 EHCI driver
 10  *
 11  * This program is free software; you can redistribute it and/or modify it
 12  * under the terms of the GNU General Public License as published by the
 13  * Free Software Foundation; either version 2 of the License, or (at your
 14  * option) any later version.
 15  *
 16  * This program is distributed in the hope that it will be useful, but
 17  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 18  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 19  * for more details.
 20  *
 21  * You should have received a copy of the GNU General Public License
 22  * along with this program; if not, write to the Free Software Foundation,
 23  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 24  */
 25 #include <linux/module.h>
 26 #include <linux/device.h>
 27 #include <linux/dmapool.h>
 28 #include <linux/kernel.h>
 29 #include <linux/delay.h>
 30 #include <linux/ioport.h>
 31 #include <linux/sched.h>
 32 #include <linux/vmalloc.h>
 33 #include <linux/errno.h>
 34 #include <linux/init.h>
 35 #include <linux/hrtimer.h>
 36 #include <linux/list.h>
 37 #include <linux/interrupt.h>
 38 #include <linux/usb.h>
 39 #include <linux/usb/hcd.h>
 40 #include <linux/moduleparam.h>
 41 #include <linux/dma-mapping.h>
 42 #include <linux/debugfs.h>
 43 #include <linux/slab.h>
 44 #include <linux/uaccess.h>
 45 #include <linux/platform_device.h>
 46 #include <linux/io.h>
 47 
 48 #include <asm/byteorder.h>
 49 #include <asm/irq.h>
 50 #include <asm/unaligned.h>
 51 
 52 #define DRIVER_AUTHOR "Yuan-Hsin Chen"
 53 #define DRIVER_DESC "FOTG210 Host Controller (EHCI) Driver"
 54 static const char hcd_name[] = "fotg210_hcd";
 55 
 56 #undef FOTG210_URB_TRACE
 57 #define FOTG210_STATS
 58 
 59 /* magic numbers that can affect system performance */
 60 #define FOTG210_TUNE_CERR       3 /* 0-3 qtd retries; 0 == don't stop */
 61 #define FOTG210_TUNE_RL_HS      4 /* nak throttle; see 4.9 */
 62 #define FOTG210_TUNE_RL_TT      0
 63 #define FOTG210_TUNE_MULT_HS    1 /* 1-3 transactions/uframe; 4.10.3 */
 64 #define FOTG210_TUNE_MULT_TT    1
 65 
 66 /* Some drivers think it's safe to schedule isochronous transfers more than 256
 67  * ms into the future (partly as a result of an old bug in the scheduling
 68  * code).  In an attempt to avoid trouble, we will use a minimum scheduling
 69  * length of 512 frames instead of 256.
 70  */
 71 #define FOTG210_TUNE_FLS 1 /* (medium) 512-frame schedule */
 72 
 73 /* Initial IRQ latency:  faster than hw default */
 74 static int log2_irq_thresh; /* 0 to 6 */
 75 module_param(log2_irq_thresh, int, S_IRUGO);
 76 MODULE_PARM_DESC(log2_irq_thresh, "log2 IRQ latency, 1-64 microframes");
 77 
 78 /* initial park setting:  slower than hw default */
 79 static unsigned park;
 80 module_param(park, uint, S_IRUGO);
 81 MODULE_PARM_DESC(park, "park setting; 1-3 back-to-back async packets");
 82 
 83 /* for link power management(LPM) feature */
 84 static unsigned int hird;
 85 module_param(hird, int, S_IRUGO);
 86 MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");
 87 
 88 #define INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)
 89 
 90 #include "fotg210.h"
 91 
 92 #define fotg210_dbg(fotg210, fmt, args...) \
 93         dev_dbg(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
 94 #define fotg210_err(fotg210, fmt, args...) \
 95         dev_err(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
 96 #define fotg210_info(fotg210, fmt, args...) \
 97         dev_info(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
 98 #define fotg210_warn(fotg210, fmt, args...) \
 99         dev_warn(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
100 
101 /* check the values in the HCSPARAMS register (host controller _Structural_
102  * parameters) see EHCI spec, Table 2-4 for each value
103  */
104 static void dbg_hcs_params(struct fotg210_hcd *fotg210, char *label)
105 {
106         u32 params = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
107 
108         fotg210_dbg(fotg210, "%s hcs_params 0x%x ports=%d\n", label, params,
109                         HCS_N_PORTS(params));
110 }
111 
112 /* check the values in the HCCPARAMS register (host controller _Capability_
113  * parameters) see EHCI Spec, Table 2-5 for each value
114  */
115 static void dbg_hcc_params(struct fotg210_hcd *fotg210, char *label)
116 {
117         u32 params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
118 
119         fotg210_dbg(fotg210, "%s hcc_params %04x uframes %s%s\n", label,
120                         params,
121                         HCC_PGM_FRAMELISTLEN(params) ? "256/512/1024" : "1024",
122                         HCC_CANPARK(params) ? " park" : "");
123 }
124 
125 static void __maybe_unused
126 dbg_qtd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd)
127 {
128         fotg210_dbg(fotg210, "%s td %p n%08x %08x t%08x p0=%08x\n", label, qtd,
129                         hc32_to_cpup(fotg210, &qtd->hw_next),
130                         hc32_to_cpup(fotg210, &qtd->hw_alt_next),
131                         hc32_to_cpup(fotg210, &qtd->hw_token),
132                         hc32_to_cpup(fotg210, &qtd->hw_buf[0]));
133         if (qtd->hw_buf[1])
134                 fotg210_dbg(fotg210, "  p1=%08x p2=%08x p3=%08x p4=%08x\n",
135                                 hc32_to_cpup(fotg210, &qtd->hw_buf[1]),
136                                 hc32_to_cpup(fotg210, &qtd->hw_buf[2]),
137                                 hc32_to_cpup(fotg210, &qtd->hw_buf[3]),
138                                 hc32_to_cpup(fotg210, &qtd->hw_buf[4]));
139 }
140 
141 static void __maybe_unused
142 dbg_qh(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
143 {
144         struct fotg210_qh_hw *hw = qh->hw;
145 
146         fotg210_dbg(fotg210, "%s qh %p n%08x info %x %x qtd %x\n", label, qh,
147                         hw->hw_next, hw->hw_info1, hw->hw_info2,
148                         hw->hw_current);
149 
150         dbg_qtd("overlay", fotg210, (struct fotg210_qtd *) &hw->hw_qtd_next);
151 }
152 
153 static void __maybe_unused
154 dbg_itd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
155 {
156         fotg210_dbg(fotg210, "%s[%d] itd %p, next %08x, urb %p\n", label,
157                         itd->frame, itd, hc32_to_cpu(fotg210, itd->hw_next),
158                         itd->urb);
159 
160         fotg210_dbg(fotg210,
161                         "  trans: %08x %08x %08x %08x %08x %08x %08x %08x\n",
162                         hc32_to_cpu(fotg210, itd->hw_transaction[0]),
163                         hc32_to_cpu(fotg210, itd->hw_transaction[1]),
164                         hc32_to_cpu(fotg210, itd->hw_transaction[2]),
165                         hc32_to_cpu(fotg210, itd->hw_transaction[3]),
166                         hc32_to_cpu(fotg210, itd->hw_transaction[4]),
167                         hc32_to_cpu(fotg210, itd->hw_transaction[5]),
168                         hc32_to_cpu(fotg210, itd->hw_transaction[6]),
169                         hc32_to_cpu(fotg210, itd->hw_transaction[7]));
170 
171         fotg210_dbg(fotg210,
172                         "  buf:   %08x %08x %08x %08x %08x %08x %08x\n",
173                         hc32_to_cpu(fotg210, itd->hw_bufp[0]),
174                         hc32_to_cpu(fotg210, itd->hw_bufp[1]),
175                         hc32_to_cpu(fotg210, itd->hw_bufp[2]),
176                         hc32_to_cpu(fotg210, itd->hw_bufp[3]),
177                         hc32_to_cpu(fotg210, itd->hw_bufp[4]),
178                         hc32_to_cpu(fotg210, itd->hw_bufp[5]),
179                         hc32_to_cpu(fotg210, itd->hw_bufp[6]));
180 
181         fotg210_dbg(fotg210, "  index: %d %d %d %d %d %d %d %d\n",
182                         itd->index[0], itd->index[1], itd->index[2],
183                         itd->index[3], itd->index[4], itd->index[5],
184                         itd->index[6], itd->index[7]);
185 }
186 
187 static int __maybe_unused
188 dbg_status_buf(char *buf, unsigned len, const char *label, u32 status)
189 {
190         return scnprintf(buf, len, "%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
191                         label, label[0] ? " " : "", status,
192                         (status & STS_ASS) ? " Async" : "",
193                         (status & STS_PSS) ? " Periodic" : "",
194                         (status & STS_RECL) ? " Recl" : "",
195                         (status & STS_HALT) ? " Halt" : "",
196                         (status & STS_IAA) ? " IAA" : "",
197                         (status & STS_FATAL) ? " FATAL" : "",
198                         (status & STS_FLR) ? " FLR" : "",
199                         (status & STS_PCD) ? " PCD" : "",
200                         (status & STS_ERR) ? " ERR" : "",
201                         (status & STS_INT) ? " INT" : "");
202 }
203 
204 static int __maybe_unused
205 dbg_intr_buf(char *buf, unsigned len, const char *label, u32 enable)
206 {
207         return scnprintf(buf, len, "%s%sintrenable %02x%s%s%s%s%s%s",
208                         label, label[0] ? " " : "", enable,
209                         (enable & STS_IAA) ? " IAA" : "",
210                         (enable & STS_FATAL) ? " FATAL" : "",
211                         (enable & STS_FLR) ? " FLR" : "",
212                         (enable & STS_PCD) ? " PCD" : "",
213                         (enable & STS_ERR) ? " ERR" : "",
214                         (enable & STS_INT) ? " INT" : "");
215 }
216 
217 static const char *const fls_strings[] = { "1024", "512", "256", "??" };
218 
219 static int dbg_command_buf(char *buf, unsigned len, const char *label,
220                 u32 command)
221 {
222         return scnprintf(buf, len,
223                         "%s%scommand %07x %s=%d ithresh=%d%s%s%s period=%s%s %s",
224                         label, label[0] ? " " : "", command,
225                         (command & CMD_PARK) ? " park" : "(park)",
226                         CMD_PARK_CNT(command),
227                         (command >> 16) & 0x3f,
228                         (command & CMD_IAAD) ? " IAAD" : "",
229                         (command & CMD_ASE) ? " Async" : "",
230                         (command & CMD_PSE) ? " Periodic" : "",
231                         fls_strings[(command >> 2) & 0x3],
232                         (command & CMD_RESET) ? " Reset" : "",
233                         (command & CMD_RUN) ? "RUN" : "HALT");
234 }
235 
236 static char *dbg_port_buf(char *buf, unsigned len, const char *label, int port,
237                 u32 status)
238 {
239         char *sig;
240 
241         /* signaling state */
242         switch (status & (3 << 10)) {
243         case 0 << 10:
244                 sig = "se0";
245                 break;
246         case 1 << 10:
247                 sig = "k";
248                 break; /* low speed */
249         case 2 << 10:
250                 sig = "j";
251                 break;
252         default:
253                 sig = "?";
254                 break;
255         }
256 
257         scnprintf(buf, len, "%s%sport:%d status %06x %d sig=%s%s%s%s%s%s%s%s",
258                         label, label[0] ? " " : "", port, status,
259                         status >> 25, /*device address */
260                         sig,
261                         (status & PORT_RESET) ? " RESET" : "",
262                         (status & PORT_SUSPEND) ? " SUSPEND" : "",
263                         (status & PORT_RESUME) ? " RESUME" : "",
264                         (status & PORT_PEC) ? " PEC" : "",
265                         (status & PORT_PE) ? " PE" : "",
266                         (status & PORT_CSC) ? " CSC" : "",
267                         (status & PORT_CONNECT) ? " CONNECT" : "");
268 
269         return buf;
270 }
271 
272 /* functions have the "wrong" filename when they're output... */
273 #define dbg_status(fotg210, label, status) {                    \
274         char _buf[80];                                          \
275         dbg_status_buf(_buf, sizeof(_buf), label, status);      \
276         fotg210_dbg(fotg210, "%s\n", _buf);                     \
277 }
278 
279 #define dbg_cmd(fotg210, label, command) {                      \
280         char _buf[80];                                          \
281         dbg_command_buf(_buf, sizeof(_buf), label, command);    \
282         fotg210_dbg(fotg210, "%s\n", _buf);                     \
283 }
284 
285 #define dbg_port(fotg210, label, port, status) {                               \
286         char _buf[80];                                                         \
287         fotg210_dbg(fotg210, "%s\n",                                           \
288                         dbg_port_buf(_buf, sizeof(_buf), label, port, status));\
289 }
290 
291 /* troubleshooting help: expose state in debugfs */
292 static int debug_async_open(struct inode *, struct file *);
293 static int debug_periodic_open(struct inode *, struct file *);
294 static int debug_registers_open(struct inode *, struct file *);
295 static int debug_async_open(struct inode *, struct file *);
296 
297 static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
298 static int debug_close(struct inode *, struct file *);
299 
300 static const struct file_operations debug_async_fops = {
301         .owner          = THIS_MODULE,
302         .open           = debug_async_open,
303         .read           = debug_output,
304         .release        = debug_close,
305         .llseek         = default_llseek,
306 };
307 static const struct file_operations debug_periodic_fops = {
308         .owner          = THIS_MODULE,
309         .open           = debug_periodic_open,
310         .read           = debug_output,
311         .release        = debug_close,
312         .llseek         = default_llseek,
313 };
314 static const struct file_operations debug_registers_fops = {
315         .owner          = THIS_MODULE,
316         .open           = debug_registers_open,
317         .read           = debug_output,
318         .release        = debug_close,
319         .llseek         = default_llseek,
320 };
321 
322 static struct dentry *fotg210_debug_root;
323 
324 struct debug_buffer {
325         ssize_t (*fill_func)(struct debug_buffer *);    /* fill method */
326         struct usb_bus *bus;
327         struct mutex mutex;     /* protect filling of buffer */
328         size_t count;           /* number of characters filled into buffer */
329         char *output_buf;
330         size_t alloc_size;
331 };
332 
333 static inline char speed_char(u32 scratch)
334 {
335         switch (scratch & (3 << 12)) {
336         case QH_FULL_SPEED:
337                 return 'f';
338 
339         case QH_LOW_SPEED:
340                 return 'l';
341 
342         case QH_HIGH_SPEED:
343                 return 'h';
344 
345         default:
346                 return '?';
347         }
348 }
349 
350 static inline char token_mark(struct fotg210_hcd *fotg210, __hc32 token)
351 {
352         __u32 v = hc32_to_cpu(fotg210, token);
353 
354         if (v & QTD_STS_ACTIVE)
355                 return '*';
356         if (v & QTD_STS_HALT)
357                 return '-';
358         if (!IS_SHORT_READ(v))
359                 return ' ';
360         /* tries to advance through hw_alt_next */
361         return '/';
362 }
363 
364 static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh,
365                 char **nextp, unsigned *sizep)
366 {
367         u32 scratch;
368         u32 hw_curr;
369         struct fotg210_qtd *td;
370         unsigned temp;
371         unsigned size = *sizep;
372         char *next = *nextp;
373         char mark;
374         __le32 list_end = FOTG210_LIST_END(fotg210);
375         struct fotg210_qh_hw *hw = qh->hw;
376 
377         if (hw->hw_qtd_next == list_end) /* NEC does this */
378                 mark = '@';
379         else
380                 mark = token_mark(fotg210, hw->hw_token);
381         if (mark == '/') { /* qh_alt_next controls qh advance? */
382                 if ((hw->hw_alt_next & QTD_MASK(fotg210)) ==
383                     fotg210->async->hw->hw_alt_next)
384                         mark = '#'; /* blocked */
385                 else if (hw->hw_alt_next == list_end)
386                         mark = '.'; /* use hw_qtd_next */
387                 /* else alt_next points to some other qtd */
388         }
389         scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
390         hw_curr = (mark == '*') ? hc32_to_cpup(fotg210, &hw->hw_current) : 0;
391         temp = scnprintf(next, size,
392                         "qh/%p dev%d %cs ep%d %08x %08x(%08x%c %s nak%d)",
393                         qh, scratch & 0x007f,
394                         speed_char(scratch),
395                         (scratch >> 8) & 0x000f,
396                         scratch, hc32_to_cpup(fotg210, &hw->hw_info2),
397                         hc32_to_cpup(fotg210, &hw->hw_token), mark,
398                         (cpu_to_hc32(fotg210, QTD_TOGGLE) & hw->hw_token)
399                                 ? "data1" : "data0",
400                         (hc32_to_cpup(fotg210, &hw->hw_alt_next) >> 1) & 0x0f);
401         size -= temp;
402         next += temp;
403 
404         /* hc may be modifying the list as we read it ... */
405         list_for_each_entry(td, &qh->qtd_list, qtd_list) {
406                 scratch = hc32_to_cpup(fotg210, &td->hw_token);
407                 mark = ' ';
408                 if (hw_curr == td->qtd_dma)
409                         mark = '*';
410                 else if (hw->hw_qtd_next == cpu_to_hc32(fotg210, td->qtd_dma))
411                         mark = '+';
412                 else if (QTD_LENGTH(scratch)) {
413                         if (td->hw_alt_next == fotg210->async->hw->hw_alt_next)
414                                 mark = '#';
415                         else if (td->hw_alt_next != list_end)
416                                 mark = '/';
417                 }
418                 temp = snprintf(next, size,
419                                 "\n\t%p%c%s len=%d %08x urb %p",
420                                 td, mark, ({ char *tmp;
421                                  switch ((scratch>>8)&0x03) {
422                                  case 0:
423                                         tmp = "out";
424                                         break;
425                                  case 1:
426                                         tmp = "in";
427                                         break;
428                                  case 2:
429                                         tmp = "setup";
430                                         break;
431                                  default:
432                                         tmp = "?";
433                                         break;
434                                  } tmp; }),
435                                 (scratch >> 16) & 0x7fff,
436                                 scratch,
437                                 td->urb);
438                 if (size < temp)
439                         temp = size;
440                 size -= temp;
441                 next += temp;
442                 if (temp == size)
443                         goto done;
444         }
445 
446         temp = snprintf(next, size, "\n");
447         if (size < temp)
448                 temp = size;
449 
450         size -= temp;
451         next += temp;
452 
453 done:
454         *sizep = size;
455         *nextp = next;
456 }
457 
458 static ssize_t fill_async_buffer(struct debug_buffer *buf)
459 {
460         struct usb_hcd *hcd;
461         struct fotg210_hcd *fotg210;
462         unsigned long flags;
463         unsigned temp, size;
464         char *next;
465         struct fotg210_qh *qh;
466 
467         hcd = bus_to_hcd(buf->bus);
468         fotg210 = hcd_to_fotg210(hcd);
469         next = buf->output_buf;
470         size = buf->alloc_size;
471 
472         *next = 0;
473 
474         /* dumps a snapshot of the async schedule.
475          * usually empty except for long-term bulk reads, or head.
476          * one QH per line, and TDs we know about
477          */
478         spin_lock_irqsave(&fotg210->lock, flags);
479         for (qh = fotg210->async->qh_next.qh; size > 0 && qh;
480                         qh = qh->qh_next.qh)
481                 qh_lines(fotg210, qh, &next, &size);
482         if (fotg210->async_unlink && size > 0) {
483                 temp = scnprintf(next, size, "\nunlink =\n");
484                 size -= temp;
485                 next += temp;
486 
487                 for (qh = fotg210->async_unlink; size > 0 && qh;
488                                 qh = qh->unlink_next)
489                         qh_lines(fotg210, qh, &next, &size);
490         }
491         spin_unlock_irqrestore(&fotg210->lock, flags);
492 
493         return strlen(buf->output_buf);
494 }
495 
496 /* count tds, get ep direction */
497 static unsigned output_buf_tds_dir(char *buf, struct fotg210_hcd *fotg210,
498                 struct fotg210_qh_hw *hw, struct fotg210_qh *qh, unsigned size)
499 {
500         u32 scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
501         struct fotg210_qtd *qtd;
502         char *type = "";
503         unsigned temp = 0;
504 
505         /* count tds, get ep direction */
506         list_for_each_entry(qtd, &qh->qtd_list, qtd_list) {
507                 temp++;
508                 switch ((hc32_to_cpu(fotg210, qtd->hw_token) >> 8) & 0x03) {
509                 case 0:
510                         type = "out";
511                         continue;
512                 case 1:
513                         type = "in";
514                         continue;
515                 }
516         }
517 
518         return scnprintf(buf, size, "(%c%d ep%d%s [%d/%d] q%d p%d)",
519                         speed_char(scratch), scratch & 0x007f,
520                         (scratch >> 8) & 0x000f, type, qh->usecs,
521                         qh->c_usecs, temp, (scratch >> 16) & 0x7ff);
522 }
523 
524 #define DBG_SCHED_LIMIT 64
525 static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
526 {
527         struct usb_hcd *hcd;
528         struct fotg210_hcd *fotg210;
529         unsigned long flags;
530         union fotg210_shadow p, *seen;
531         unsigned temp, size, seen_count;
532         char *next;
533         unsigned i;
534         __hc32 tag;
535 
536         seen = kmalloc_array(DBG_SCHED_LIMIT, sizeof(*seen), GFP_ATOMIC);
537         if (!seen)
538                 return 0;
539 
540         seen_count = 0;
541 
542         hcd = bus_to_hcd(buf->bus);
543         fotg210 = hcd_to_fotg210(hcd);
544         next = buf->output_buf;
545         size = buf->alloc_size;
546 
547         temp = scnprintf(next, size, "size = %d\n", fotg210->periodic_size);
548         size -= temp;
549         next += temp;
550 
551         /* dump a snapshot of the periodic schedule.
552          * iso changes, interrupt usually doesn't.
553          */
554         spin_lock_irqsave(&fotg210->lock, flags);
555         for (i = 0; i < fotg210->periodic_size; i++) {
556                 p = fotg210->pshadow[i];
557                 if (likely(!p.ptr))
558                         continue;
559 
560                 tag = Q_NEXT_TYPE(fotg210, fotg210->periodic[i]);
561 
562                 temp = scnprintf(next, size, "%4d: ", i);
563                 size -= temp;
564                 next += temp;
565 
566                 do {
567                         struct fotg210_qh_hw *hw;
568 
569                         switch (hc32_to_cpu(fotg210, tag)) {
570                         case Q_TYPE_QH:
571                                 hw = p.qh->hw;
572                                 temp = scnprintf(next, size, " qh%d-%04x/%p",
573                                                 p.qh->period,
574                                                 hc32_to_cpup(fotg210,
575                                                         &hw->hw_info2)
576                                                         /* uframe masks */
577                                                         & (QH_CMASK | QH_SMASK),
578                                                 p.qh);
579                                 size -= temp;
580                                 next += temp;
581                                 /* don't repeat what follows this qh */
582                                 for (temp = 0; temp < seen_count; temp++) {
583                                         if (seen[temp].ptr != p.ptr)
584                                                 continue;
585                                         if (p.qh->qh_next.ptr) {
586                                                 temp = scnprintf(next, size,
587                                                                 " ...");
588                                                 size -= temp;
589                                                 next += temp;
590                                         }
591                                         break;
592                                 }
593                                 /* show more info the first time around */
594                                 if (temp == seen_count) {
595                                         temp = output_buf_tds_dir(next,
596                                                         fotg210, hw,
597                                                         p.qh, size);
598 
599                                         if (seen_count < DBG_SCHED_LIMIT)
600                                                 seen[seen_count++].qh = p.qh;
601                                 } else
602                                         temp = 0;
603                                 tag = Q_NEXT_TYPE(fotg210, hw->hw_next);
604                                 p = p.qh->qh_next;
605                                 break;
606                         case Q_TYPE_FSTN:
607                                 temp = scnprintf(next, size,
608                                                 " fstn-%8x/%p",
609                                                 p.fstn->hw_prev, p.fstn);
610                                 tag = Q_NEXT_TYPE(fotg210, p.fstn->hw_next);
611                                 p = p.fstn->fstn_next;
612                                 break;
613                         case Q_TYPE_ITD:
614                                 temp = scnprintf(next, size,
615                                                 " itd/%p", p.itd);
616                                 tag = Q_NEXT_TYPE(fotg210, p.itd->hw_next);
617                                 p = p.itd->itd_next;
618                                 break;
619                         }
620                         size -= temp;
621                         next += temp;
622                 } while (p.ptr);
623 
624                 temp = scnprintf(next, size, "\n");
625                 size -= temp;
626                 next += temp;
627         }
628         spin_unlock_irqrestore(&fotg210->lock, flags);
629         kfree(seen);
630 
631         return buf->alloc_size - size;
632 }
633 #undef DBG_SCHED_LIMIT
634 
635 static const char *rh_state_string(struct fotg210_hcd *fotg210)
636 {
637         switch (fotg210->rh_state) {
638         case FOTG210_RH_HALTED:
639                 return "halted";
640         case FOTG210_RH_SUSPENDED:
641                 return "suspended";
642         case FOTG210_RH_RUNNING:
643                 return "running";
644         case FOTG210_RH_STOPPING:
645                 return "stopping";
646         }
647         return "?";
648 }
649 
650 static ssize_t fill_registers_buffer(struct debug_buffer *buf)
651 {
652         struct usb_hcd *hcd;
653         struct fotg210_hcd *fotg210;
654         unsigned long flags;
655         unsigned temp, size, i;
656         char *next, scratch[80];
657         static const char fmt[] = "%*s\n";
658         static const char label[] = "";
659 
660         hcd = bus_to_hcd(buf->bus);
661         fotg210 = hcd_to_fotg210(hcd);
662         next = buf->output_buf;
663         size = buf->alloc_size;
664 
665         spin_lock_irqsave(&fotg210->lock, flags);
666 
667         if (!HCD_HW_ACCESSIBLE(hcd)) {
668                 size = scnprintf(next, size,
669                                 "bus %s, device %s\n"
670                                 "%s\n"
671                                 "SUSPENDED(no register access)\n",
672                                 hcd->self.controller->bus->name,
673                                 dev_name(hcd->self.controller),
674                                 hcd->product_desc);
675                 goto done;
676         }
677 
678         /* Capability Registers */
679         i = HC_VERSION(fotg210, fotg210_readl(fotg210,
680                         &fotg210->caps->hc_capbase));
681         temp = scnprintf(next, size,
682                         "bus %s, device %s\n"
683                         "%s\n"
684                         "EHCI %x.%02x, rh state %s\n",
685                         hcd->self.controller->bus->name,
686                         dev_name(hcd->self.controller),
687                         hcd->product_desc,
688                         i >> 8, i & 0x0ff, rh_state_string(fotg210));
689         size -= temp;
690         next += temp;
691 
692         /* FIXME interpret both types of params */
693         i = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
694         temp = scnprintf(next, size, "structural params 0x%08x\n", i);
695         size -= temp;
696         next += temp;
697 
698         i = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
699         temp = scnprintf(next, size, "capability params 0x%08x\n", i);
700         size -= temp;
701         next += temp;
702 
703         /* Operational Registers */
704         temp = dbg_status_buf(scratch, sizeof(scratch), label,
705                         fotg210_readl(fotg210, &fotg210->regs->status));
706         temp = scnprintf(next, size, fmt, temp, scratch);
707         size -= temp;
708         next += temp;
709 
710         temp = dbg_command_buf(scratch, sizeof(scratch), label,
711                         fotg210_readl(fotg210, &fotg210->regs->command));
712         temp = scnprintf(next, size, fmt, temp, scratch);
713         size -= temp;
714         next += temp;
715 
716         temp = dbg_intr_buf(scratch, sizeof(scratch), label,
717                         fotg210_readl(fotg210, &fotg210->regs->intr_enable));
718         temp = scnprintf(next, size, fmt, temp, scratch);
719         size -= temp;
720         next += temp;
721 
722         temp = scnprintf(next, size, "uframe %04x\n",
723                         fotg210_read_frame_index(fotg210));
724         size -= temp;
725         next += temp;
726 
727         if (fotg210->async_unlink) {
728                 temp = scnprintf(next, size, "async unlink qh %p\n",
729                                 fotg210->async_unlink);
730                 size -= temp;
731                 next += temp;
732         }
733 
734 #ifdef FOTG210_STATS
735         temp = scnprintf(next, size,
736                         "irq normal %ld err %ld iaa %ld(lost %ld)\n",
737                         fotg210->stats.normal, fotg210->stats.error,
738                         fotg210->stats.iaa, fotg210->stats.lost_iaa);
739         size -= temp;
740         next += temp;
741 
742         temp = scnprintf(next, size, "complete %ld unlink %ld\n",
743                         fotg210->stats.complete, fotg210->stats.unlink);
744         size -= temp;
745         next += temp;
746 #endif
747 
748 done:
749         spin_unlock_irqrestore(&fotg210->lock, flags);
750 
751         return buf->alloc_size - size;
752 }
753 
754 static struct debug_buffer
755 *alloc_buffer(struct usb_bus *bus, ssize_t (*fill_func)(struct debug_buffer *))
756 {
757         struct debug_buffer *buf;
758 
759         buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);
760 
761         if (buf) {
762                 buf->bus = bus;
763                 buf->fill_func = fill_func;
764                 mutex_init(&buf->mutex);
765                 buf->alloc_size = PAGE_SIZE;
766         }
767 
768         return buf;
769 }
770 
771 static int fill_buffer(struct debug_buffer *buf)
772 {
773         int ret = 0;
774 
775         if (!buf->output_buf)
776                 buf->output_buf = vmalloc(buf->alloc_size);
777 
778         if (!buf->output_buf) {
779                 ret = -ENOMEM;
780                 goto out;
781         }
782 
783         ret = buf->fill_func(buf);
784 
785         if (ret >= 0) {
786                 buf->count = ret;
787                 ret = 0;
788         }
789 
790 out:
791         return ret;
792 }
793 
794 static ssize_t debug_output(struct file *file, char __user *user_buf,
795                 size_t len, loff_t *offset)
796 {
797         struct debug_buffer *buf = file->private_data;
798         int ret = 0;
799 
800         mutex_lock(&buf->mutex);
801         if (buf->count == 0) {
802                 ret = fill_buffer(buf);
803                 if (ret != 0) {
804                         mutex_unlock(&buf->mutex);
805                         goto out;
806                 }
807         }
808         mutex_unlock(&buf->mutex);
809 
810         ret = simple_read_from_buffer(user_buf, len, offset,
811                         buf->output_buf, buf->count);
812 
813 out:
814         return ret;
815 
816 }
817 
818 static int debug_close(struct inode *inode, struct file *file)
819 {
820         struct debug_buffer *buf = file->private_data;
821 
822         if (buf) {
823                 vfree(buf->output_buf);
824                 kfree(buf);
825         }
826 
827         return 0;
828 }
829 static int debug_async_open(struct inode *inode, struct file *file)
830 {
831         file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);
832 
833         return file->private_data ? 0 : -ENOMEM;
834 }
835 
836 static int debug_periodic_open(struct inode *inode, struct file *file)
837 {
838         struct debug_buffer *buf;
839 
840         buf = alloc_buffer(inode->i_private, fill_periodic_buffer);
841         if (!buf)
842                 return -ENOMEM;
843 
844         buf->alloc_size = (sizeof(void *) == 4 ? 6 : 8)*PAGE_SIZE;
845         file->private_data = buf;
846         return 0;
847 }
848 
849 static int debug_registers_open(struct inode *inode, struct file *file)
850 {
851         file->private_data = alloc_buffer(inode->i_private,
852                         fill_registers_buffer);
853 
854         return file->private_data ? 0 : -ENOMEM;
855 }
856 
857 static inline void create_debug_files(struct fotg210_hcd *fotg210)
858 {
859         struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
860 
861         fotg210->debug_dir = debugfs_create_dir(bus->bus_name,
862                         fotg210_debug_root);
863         if (!fotg210->debug_dir)
864                 return;
865 
866         if (!debugfs_create_file("async", S_IRUGO, fotg210->debug_dir, bus,
867                         &debug_async_fops))
868                 goto file_error;
869 
870         if (!debugfs_create_file("periodic", S_IRUGO, fotg210->debug_dir, bus,
871                         &debug_periodic_fops))
872                 goto file_error;
873 
874         if (!debugfs_create_file("registers", S_IRUGO, fotg210->debug_dir, bus,
875                         &debug_registers_fops))
876                 goto file_error;
877 
878         return;
879 
880 file_error:
881         debugfs_remove_recursive(fotg210->debug_dir);
882 }
883 
884 static inline void remove_debug_files(struct fotg210_hcd *fotg210)
885 {
886         debugfs_remove_recursive(fotg210->debug_dir);
887 }
888 
889 /* handshake - spin reading hc until handshake completes or fails
890  * @ptr: address of hc register to be read
891  * @mask: bits to look at in result of read
892  * @done: value of those bits when handshake succeeds
893  * @usec: timeout in microseconds
894  *
895  * Returns negative errno, or zero on success
896  *
897  * Success happens when the "mask" bits have the specified value (hardware
898  * handshake done).  There are two failure modes:  "usec" have passed (major
899  * hardware flakeout), or the register reads as all-ones (hardware removed).
900  *
901  * That last failure should_only happen in cases like physical cardbus eject
902  * before driver shutdown. But it also seems to be caused by bugs in cardbus
903  * bridge shutdown:  shutting down the bridge before the devices using it.
904  */
905 static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
906                 u32 mask, u32 done, int usec)
907 {
908         u32 result;
909 
910         do {
911                 result = fotg210_readl(fotg210, ptr);
912                 if (result == ~(u32)0)          /* card removed */
913                         return -ENODEV;
914                 result &= mask;
915                 if (result == done)
916                         return 0;
917                 udelay(1);
918                 usec--;
919         } while (usec > 0);
920         return -ETIMEDOUT;
921 }
922 
923 /* Force HC to halt state from unknown (EHCI spec section 2.3).
924  * Must be called with interrupts enabled and the lock not held.
925  */
926 static int fotg210_halt(struct fotg210_hcd *fotg210)
927 {
928         u32 temp;
929 
930         spin_lock_irq(&fotg210->lock);
931 
932         /* disable any irqs left enabled by previous code */
933         fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
934 
935         /*
936          * This routine gets called during probe before fotg210->command
937          * has been initialized, so we can't rely on its value.
938          */
939         fotg210->command &= ~CMD_RUN;
940         temp = fotg210_readl(fotg210, &fotg210->regs->command);
941         temp &= ~(CMD_RUN | CMD_IAAD);
942         fotg210_writel(fotg210, temp, &fotg210->regs->command);
943 
944         spin_unlock_irq(&fotg210->lock);
945         synchronize_irq(fotg210_to_hcd(fotg210)->irq);
946 
947         return handshake(fotg210, &fotg210->regs->status,
948                         STS_HALT, STS_HALT, 16 * 125);
949 }
950 
951 /* Reset a non-running (STS_HALT == 1) controller.
952  * Must be called with interrupts enabled and the lock not held.
953  */
954 static int fotg210_reset(struct fotg210_hcd *fotg210)
955 {
956         int retval;
957         u32 command = fotg210_readl(fotg210, &fotg210->regs->command);
958 
959         /* If the EHCI debug controller is active, special care must be
960          * taken before and after a host controller reset
961          */
962         if (fotg210->debug && !dbgp_reset_prep(fotg210_to_hcd(fotg210)))
963                 fotg210->debug = NULL;
964 
965         command |= CMD_RESET;
966         dbg_cmd(fotg210, "reset", command);
967         fotg210_writel(fotg210, command, &fotg210->regs->command);
968         fotg210->rh_state = FOTG210_RH_HALTED;
969         fotg210->next_statechange = jiffies;
970         retval = handshake(fotg210, &fotg210->regs->command,
971                         CMD_RESET, 0, 250 * 1000);
972 
973         if (retval)
974                 return retval;
975 
976         if (fotg210->debug)
977                 dbgp_external_startup(fotg210_to_hcd(fotg210));
978 
979         fotg210->port_c_suspend = fotg210->suspended_ports =
980                         fotg210->resuming_ports = 0;
981         return retval;
982 }
983 
984 /* Idle the controller (turn off the schedules).
985  * Must be called with interrupts enabled and the lock not held.
986  */
987 static void fotg210_quiesce(struct fotg210_hcd *fotg210)
988 {
989         u32 temp;
990 
991         if (fotg210->rh_state != FOTG210_RH_RUNNING)
992                 return;
993 
994         /* wait for any schedule enables/disables to take effect */
995         temp = (fotg210->command << 10) & (STS_ASS | STS_PSS);
996         handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, temp,
997                         16 * 125);
998 
999         /* then disable anything that's still active */
1000         spin_lock_irq(&fotg210->lock);
1001         fotg210->command &= ~(CMD_ASE | CMD_PSE);
1002         fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
1003         spin_unlock_irq(&fotg210->lock);
1004 
1005         /* hardware can take 16 microframes to turn off ... */
1006         handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, 0,
1007                         16 * 125);
1008 }
1009 
1010 static void end_unlink_async(struct fotg210_hcd *fotg210);
1011 static void unlink_empty_async(struct fotg210_hcd *fotg210);
1012 static void fotg210_work(struct fotg210_hcd *fotg210);
1013 static void start_unlink_intr(struct fotg210_hcd *fotg210,
1014                               struct fotg210_qh *qh);
1015 static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
1016 
1017 /* Set a bit in the USBCMD register */
1018 static void fotg210_set_command_bit(struct fotg210_hcd *fotg210, u32 bit)
1019 {
1020         fotg210->command |= bit;
1021         fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
1022 
1023         /* unblock posted write */
1024         fotg210_readl(fotg210, &fotg210->regs->command);
1025 }
1026 
1027 /* Clear a bit in the USBCMD register */
1028 static void fotg210_clear_command_bit(struct fotg210_hcd *fotg210, u32 bit)
1029 {
1030         fotg210->command &= ~bit;
1031         fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
1032 
1033         /* unblock posted write */
1034         fotg210_readl(fotg210, &fotg210->regs->command);
1035 }
1036 
1037 /* EHCI timer support...  Now using hrtimers.
1038  *
1039  * Lots of different events are triggered from fotg210->hrtimer.  Whenever
1040  * the timer routine runs, it checks each possible event; events that are
1041  * currently enabled and whose expiration time has passed get handled.
1042  * The set of enabled events is stored as a collection of bitflags in
1043  * fotg210->enabled_hrtimer_events, and they are numbered in order of
1044  * increasing delay values (ranging between 1 ms and 100 ms).
1045  *
1046  * Rather than implementing a sorted list or tree of all pending events,
1047  * we keep track only of the lowest-numbered pending event, in
1048  * fotg210->next_hrtimer_event.  Whenever fotg210->hrtimer gets restarted, its
1049  * expiration time is set to the timeout value for this event.
1050  *
1051  * As a result, events might not get handled right away; the actual delay
1052  * could be anywhere up to twice the requested delay.  This doesn't
1053  * matter, because none of the events are especially time-critical.  The
1054  * ones that matter most all have a delay of 1 ms, so they will be
1055  * handled after 2 ms at most, which is okay.  In addition to this, we
1056  * allow for an expiration range of 1 ms.
1057  */
1058 
1059 /* Delay lengths for the hrtimer event types.
1060  * Keep this list sorted by delay length, in the same order as
1061  * the event types indexed by enum fotg210_hrtimer_event in fotg210.h.
1062  */
1063 static unsigned event_delays_ns[] = {
1064         1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_ASS */
1065         1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_PSS */
1066         1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_DEAD */
1067         1125 * NSEC_PER_USEC,   /* FOTG210_HRTIMER_UNLINK_INTR */
1068         2 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_FREE_ITDS */
1069         6 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_ASYNC_UNLINKS */
1070         10 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_IAA_WATCHDOG */
1071         10 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_DISABLE_PERIODIC */
1072         15 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_DISABLE_ASYNC */
1073         100 * NSEC_PER_MSEC,    /* FOTG210_HRTIMER_IO_WATCHDOG */
1074 };
1075 
1076 /* Enable a pending hrtimer event */
1077 static void fotg210_enable_event(struct fotg210_hcd *fotg210, unsigned event,
1078                 bool resched)
1079 {
1080         ktime_t *timeout = &fotg210->hr_timeouts[event];
1081 
1082         if (resched)
1083                 *timeout = ktime_add(ktime_get(), event_delays_ns[event]);
1084         fotg210->enabled_hrtimer_events |= (1 << event);
1085 
1086         /* Track only the lowest-numbered pending event */
1087         if (event < fotg210->next_hrtimer_event) {
1088                 fotg210->next_hrtimer_event = event;
1089                 hrtimer_start_range_ns(&fotg210->hrtimer, *timeout,
1090                                 NSEC_PER_MSEC, HRTIMER_MODE_ABS);
1091         }
1092 }
1093 
1094 
1095 /* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
1096 static void fotg210_poll_ASS(struct fotg210_hcd *fotg210)
1097 {
1098         unsigned actual, want;
1099 
1100         /* Don't enable anything if the controller isn't running (e.g., died) */
1101         if (fotg210->rh_state != FOTG210_RH_RUNNING)
1102                 return;
1103 
1104         want = (fotg210->command & CMD_ASE) ? STS_ASS : 0;
1105         actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_ASS;
1106 
1107         if (want != actual) {
1108 
1109                 /* Poll again later, but give up after about 20 ms */
1110                 if (fotg210->ASS_poll_count++ < 20) {
1111                         fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_ASS,
1112                                         true);
1113                         return;
1114                 }
1115                 fotg210_dbg(fotg210, "Waited too long for the async schedule status (%x/%x), giving up\n",
1116                                 want, actual);
1117         }
1118         fotg210->ASS_poll_count = 0;
1119 
1120         /* The status is up-to-date; restart or stop the schedule as needed */
1121         if (want == 0) {        /* Stopped */
1122                 if (fotg210->async_count > 0)
1123                         fotg210_set_command_bit(fotg210, CMD_ASE);
1124 
1125         } else {                /* Running */
1126                 if (fotg210->async_count == 0) {
1127 
1128                         /* Turn off the schedule after a while */
1129                         fotg210_enable_event(fotg210,
1130                                         FOTG210_HRTIMER_DISABLE_ASYNC,
1131                                         true);
1132                 }
1133         }
1134 }
1135 
1136 /* Turn off the async schedule after a brief delay */
1137 static void fotg210_disable_ASE(struct fotg210_hcd *fotg210)
1138 {
1139         fotg210_clear_command_bit(fotg210, CMD_ASE);
1140 }
1141 
1142 
1143 /* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
1144 static void fotg210_poll_PSS(struct fotg210_hcd *fotg210)
1145 {
1146         unsigned actual, want;
1147 
1148         /* Don't do anything if the controller isn't running (e.g., died) */
1149         if (fotg210->rh_state != FOTG210_RH_RUNNING)
1150                 return;
1151 
1152         want = (fotg210->command & CMD_PSE) ? STS_PSS : 0;
1153         actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_PSS;
1154 
1155         if (want != actual) {
1156 
1157                 /* Poll again later, but give up after about 20 ms */
1158                 if (fotg210->PSS_poll_count++ < 20) {
1159                         fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_PSS,
1160                                         true);
1161                         return;
1162                 }
1163                 fotg210_dbg(fotg210, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
1164                                 want, actual);
1165         }
1166         fotg210->PSS_poll_count = 0;
1167 
1168         /* The status is up-to-date; restart or stop the schedule as needed */
1169         if (want == 0) {        /* Stopped */
1170                 if (fotg210->periodic_count > 0)
1171                         fotg210_set_command_bit(fotg210, CMD_PSE);
1172 
1173         } else {                /* Running */
1174                 if (fotg210->periodic_count == 0) {
1175 
1176                         /* Turn off the schedule after a while */
1177                         fotg210_enable_event(fotg210,
1178                                         FOTG210_HRTIMER_DISABLE_PERIODIC,
1179                                         true);
1180                 }
1181         }
1182 }
1183 
1184 /* Turn off the periodic schedule after a brief delay */
1185 static void fotg210_disable_PSE(struct fotg210_hcd *fotg210)
1186 {
1187         fotg210_clear_command_bit(fotg210, CMD_PSE);
1188 }
1189 
1190 
1191 /* Poll the STS_HALT status bit; see when a dead controller stops */
1192 static void fotg210_handle_controller_death(struct fotg210_hcd *fotg210)
1193 {
1194         if (!(fotg210_readl(fotg210, &fotg210->regs->status) & STS_HALT)) {
1195 
1196                 /* Give up after a few milliseconds */
1197                 if (fotg210->died_poll_count++ < 5) {
1198                         /* Try again later */
1199                         fotg210_enable_event(fotg210,
1200                                         FOTG210_HRTIMER_POLL_DEAD, true);
1201                         return;
1202                 }
1203                 fotg210_warn(fotg210, "Waited too long for the controller to stop, giving up\n");
1204         }
1205 
1206         /* Clean up the mess */
1207         fotg210->rh_state = FOTG210_RH_HALTED;
1208         fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
1209         fotg210_work(fotg210);
1210         end_unlink_async(fotg210);
1211 
1212         /* Not in process context, so don't try to reset the controller */
1213 }
1214 
1215 
1216 /* Handle unlinked interrupt QHs once they are gone from the hardware */
1217 static void fotg210_handle_intr_unlinks(struct fotg210_hcd *fotg210)
1218 {
1219         bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
1220 
1221         /*
1222          * Process all the QHs on the intr_unlink list that were added
1223          * before the current unlink cycle began.  The list is in
1224          * temporal order, so stop when we reach the first entry in the
1225          * current cycle.  But if the root hub isn't running then
1226          * process all the QHs on the list.
1227          */
1228         fotg210->intr_unlinking = true;
1229         while (fotg210->intr_unlink) {
1230                 struct fotg210_qh *qh = fotg210->intr_unlink;
1231 
1232                 if (!stopped && qh->unlink_cycle == fotg210->intr_unlink_cycle)
1233                         break;
1234                 fotg210->intr_unlink = qh->unlink_next;
1235                 qh->unlink_next = NULL;
1236                 end_unlink_intr(fotg210, qh);
1237         }
1238 
1239         /* Handle remaining entries later */
1240         if (fotg210->intr_unlink) {
1241                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
1242                                 true);
1243                 ++fotg210->intr_unlink_cycle;
1244         }
1245         fotg210->intr_unlinking = false;
1246 }
1247 
1248 
1249 /* Start another free-iTDs/siTDs cycle */
1250 static void start_free_itds(struct fotg210_hcd *fotg210)
1251 {
1252         if (!(fotg210->enabled_hrtimer_events &
1253                         BIT(FOTG210_HRTIMER_FREE_ITDS))) {
1254                 fotg210->last_itd_to_free = list_entry(
1255                                 fotg210->cached_itd_list.prev,
1256                                 struct fotg210_itd, itd_list);
1257                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_FREE_ITDS, true);
1258         }
1259 }
1260 
1261 /* Wait for controller to stop using old iTDs and siTDs */
1262 static void end_free_itds(struct fotg210_hcd *fotg210)
1263 {
1264         struct fotg210_itd *itd, *n;
1265 
1266         if (fotg210->rh_state < FOTG210_RH_RUNNING)
1267                 fotg210->last_itd_to_free = NULL;
1268 
1269         list_for_each_entry_safe(itd, n, &fotg210->cached_itd_list, itd_list) {
1270                 list_del(&itd->itd_list);
1271                 dma_pool_free(fotg210->itd_pool, itd, itd->itd_dma);
1272                 if (itd == fotg210->last_itd_to_free)
1273                         break;
1274         }
1275 
1276         if (!list_empty(&fotg210->cached_itd_list))
1277                 start_free_itds(fotg210);
1278 }
1279 
1280 
1281 /* Handle lost (or very late) IAA interrupts */
1282 static void fotg210_iaa_watchdog(struct fotg210_hcd *fotg210)
1283 {
1284         if (fotg210->rh_state != FOTG210_RH_RUNNING)
1285                 return;
1286 
1287         /*
1288          * Lost IAA irqs wedge things badly; seen first with a vt8235.
1289          * So we need this watchdog, but must protect it against both
1290          * (a) SMP races against real IAA firing and retriggering, and
1291          * (b) clean HC shutdown, when IAA watchdog was pending.
1292          */
1293         if (fotg210->async_iaa) {
1294                 u32 cmd, status;
1295 
1296                 /* If we get here, IAA is *REALLY* late.  It's barely
1297                  * conceivable that the system is so busy that CMD_IAAD
1298                  * is still legitimately set, so let's be sure it's
1299                  * clear before we read STS_IAA.  (The HC should clear
1300                  * CMD_IAAD when it sets STS_IAA.)
1301                  */
1302                 cmd = fotg210_readl(fotg210, &fotg210->regs->command);
1303 
1304                 /*
1305                  * If IAA is set here it either legitimately triggered
1306                  * after the watchdog timer expired (_way_ late, so we'll
1307                  * still count it as lost) ... or a silicon erratum:
1308                  * - VIA seems to set IAA without triggering the IRQ;
1309                  * - IAAD potentially cleared without setting IAA.
1310                  */
1311                 status = fotg210_readl(fotg210, &fotg210->regs->status);
1312                 if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
1313                         COUNT(fotg210->stats.lost_iaa);
1314                         fotg210_writel(fotg210, STS_IAA,
1315                                         &fotg210->regs->status);
1316                 }
1317 
1318                 fotg210_dbg(fotg210, "IAA watchdog: status %x cmd %x\n",
1319                                 status, cmd);
1320                 end_unlink_async(fotg210);
1321         }
1322 }
1323 
1324 
1325 /* Enable the I/O watchdog, if appropriate */
1326 static void turn_on_io_watchdog(struct fotg210_hcd *fotg210)
1327 {
1328         /* Not needed if the controller isn't running or it's already enabled */
1329         if (fotg210->rh_state != FOTG210_RH_RUNNING ||
1330                         (fotg210->enabled_hrtimer_events &
1331                         BIT(FOTG210_HRTIMER_IO_WATCHDOG)))
1332                 return;
1333 
1334         /*
1335          * Isochronous transfers always need the watchdog.
1336          * For other sorts we use it only if the flag is set.
1337          */
1338         if (fotg210->isoc_count > 0 || (fotg210->need_io_watchdog &&
1339                         fotg210->async_count + fotg210->intr_count > 0))
1340                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_IO_WATCHDOG,
1341                                 true);
1342 }
1343 
1344 
1345 /* Handler functions for the hrtimer event types.
1346  * Keep this array in the same order as the event types indexed by
1347  * enum fotg210_hrtimer_event in fotg210.h.
1348  */
1349 static void (*event_handlers[])(struct fotg210_hcd *) = {
1350         fotg210_poll_ASS,                       /* FOTG210_HRTIMER_POLL_ASS */
1351         fotg210_poll_PSS,                       /* FOTG210_HRTIMER_POLL_PSS */
1352         fotg210_handle_controller_death,        /* FOTG210_HRTIMER_POLL_DEAD */
1353         fotg210_handle_intr_unlinks,    /* FOTG210_HRTIMER_UNLINK_INTR */
1354         end_free_itds,                  /* FOTG210_HRTIMER_FREE_ITDS */
1355         unlink_empty_async,             /* FOTG210_HRTIMER_ASYNC_UNLINKS */
1356         fotg210_iaa_watchdog,           /* FOTG210_HRTIMER_IAA_WATCHDOG */
1357         fotg210_disable_PSE,            /* FOTG210_HRTIMER_DISABLE_PERIODIC */
1358         fotg210_disable_ASE,            /* FOTG210_HRTIMER_DISABLE_ASYNC */
1359         fotg210_work,                   /* FOTG210_HRTIMER_IO_WATCHDOG */
1360 };
1361 
1362 static enum hrtimer_restart fotg210_hrtimer_func(struct hrtimer *t)
1363 {
1364         struct fotg210_hcd *fotg210 =
1365                         container_of(t, struct fotg210_hcd, hrtimer);
1366         ktime_t now;
1367         unsigned long events;
1368         unsigned long flags;
1369         unsigned e;
1370 
1371         spin_lock_irqsave(&fotg210->lock, flags);
1372 
1373         events = fotg210->enabled_hrtimer_events;
1374         fotg210->enabled_hrtimer_events = 0;
1375         fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
1376 
1377         /*
1378          * Check each pending event.  If its time has expired, handle
1379          * the event; otherwise re-enable it.
1380          */
1381         now = ktime_get();
1382         for_each_set_bit(e, &events, FOTG210_HRTIMER_NUM_EVENTS) {
1383                 if (now >= fotg210->hr_timeouts[e])
1384                         event_handlers[e](fotg210);
1385                 else
1386                         fotg210_enable_event(fotg210, e, false);
1387         }
1388 
1389         spin_unlock_irqrestore(&fotg210->lock, flags);
1390         return HRTIMER_NORESTART;
1391 }
1392 
1393 #define fotg210_bus_suspend NULL
1394 #define fotg210_bus_resume NULL
1395 
1396 static int check_reset_complete(struct fotg210_hcd *fotg210, int index,
1397                 u32 __iomem *status_reg, int port_status)
1398 {
1399         if (!(port_status & PORT_CONNECT))
1400                 return port_status;
1401 
1402         /* if reset finished and it's still not enabled -- handoff */
1403         if (!(port_status & PORT_PE))
1404                 /* with integrated TT, there's nobody to hand it to! */
1405                 fotg210_dbg(fotg210, "Failed to enable port %d on root hub TT\n",
1406                                 index + 1);
1407         else
1408                 fotg210_dbg(fotg210, "port %d reset complete, port enabled\n",
1409                                 index + 1);
1410 
1411         return port_status;
1412 }
1413 
1414 
1415 /* build "status change" packet (one or two bytes) from HC registers */
1416 
1417 static int fotg210_hub_status_data(struct usb_hcd *hcd, char *buf)
1418 {
1419         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
1420         u32 temp, status;
1421         u32 mask;
1422         int retval = 1;
1423         unsigned long flags;
1424 
1425         /* init status to no-changes */
1426         buf[0] = 0;
1427 
1428         /* Inform the core about resumes-in-progress by returning
1429          * a non-zero value even if there are no status changes.
1430          */
1431         status = fotg210->resuming_ports;
1432 
1433         mask = PORT_CSC | PORT_PEC;
1434         /* PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND */
1435 
1436         /* no hub change reports (bit 0) for now (power, ...) */
1437 
1438         /* port N changes (bit N)? */
1439         spin_lock_irqsave(&fotg210->lock, flags);
1440 
1441         temp = fotg210_readl(fotg210, &fotg210->regs->port_status);
1442 
1443         /*
1444          * Return status information even for ports with OWNER set.
1445          * Otherwise hub_wq wouldn't see the disconnect event when a
1446          * high-speed device is switched over to the companion
1447          * controller by the user.
1448          */
1449 
1450         if ((temp & mask) != 0 || test_bit(0, &fotg210->port_c_suspend) ||
1451                         (fotg210->reset_done[0] &&
1452                         time_after_eq(jiffies, fotg210->reset_done[0]))) {
1453                 buf[0] |= 1 << 1;
1454                 status = STS_PCD;
1455         }
1456         /* FIXME autosuspend idle root hubs */
1457         spin_unlock_irqrestore(&fotg210->lock, flags);
1458         return status ? retval : 0;
1459 }
1460 
1461 static void fotg210_hub_descriptor(struct fotg210_hcd *fotg210,
1462                 struct usb_hub_descriptor *desc)
1463 {
1464         int ports = HCS_N_PORTS(fotg210->hcs_params);
1465         u16 temp;
1466 
1467         desc->bDescriptorType = USB_DT_HUB;
1468         desc->bPwrOn2PwrGood = 10;      /* fotg210 1.0, 2.3.9 says 20ms max */
1469         desc->bHubContrCurrent = 0;
1470 
1471         desc->bNbrPorts = ports;
1472         temp = 1 + (ports / 8);
1473         desc->bDescLength = 7 + 2 * temp;
1474 
1475         /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
1476         memset(&desc->u.hs.DeviceRemovable[0], 0, temp);
1477         memset(&desc->u.hs.DeviceRemovable[temp], 0xff, temp);
1478 
1479         temp = HUB_CHAR_INDV_PORT_OCPM; /* per-port overcurrent reporting */
1480         temp |= HUB_CHAR_NO_LPSM;       /* no power switching */
1481         desc->wHubCharacteristics = cpu_to_le16(temp);
1482 }
1483 
1484 static int fotg210_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
1485                 u16 wIndex, char *buf, u16 wLength)
1486 {
1487         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
1488         int ports = HCS_N_PORTS(fotg210->hcs_params);
1489         u32 __iomem *status_reg = &fotg210->regs->port_status;
1490         u32 temp, temp1, status;
1491         unsigned long flags;
1492         int retval = 0;
1493         unsigned selector;
1494 
1495         /*
1496          * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
1497          * HCS_INDICATOR may say we can change LEDs to off/amber/green.
1498          * (track current state ourselves) ... blink for diagnostics,
1499          * power, "this is the one", etc.  EHCI spec supports this.
1500          */
1501 
1502         spin_lock_irqsave(&fotg210->lock, flags);
1503         switch (typeReq) {
1504         case ClearHubFeature:
1505                 switch (wValue) {
1506                 case C_HUB_LOCAL_POWER:
1507                 case C_HUB_OVER_CURRENT:
1508                         /* no hub-wide feature/status flags */
1509                         break;
1510                 default:
1511                         goto error;
1512                 }
1513                 break;
1514         case ClearPortFeature:
1515                 if (!wIndex || wIndex > ports)
1516                         goto error;
1517                 wIndex--;
1518                 temp = fotg210_readl(fotg210, status_reg);
1519                 temp &= ~PORT_RWC_BITS;
1520 
1521                 /*
1522                  * Even if OWNER is set, so the port is owned by the
1523                  * companion controller, hub_wq needs to be able to clear
1524                  * the port-change status bits (especially
1525                  * USB_PORT_STAT_C_CONNECTION).
1526                  */
1527 
1528                 switch (wValue) {
1529                 case USB_PORT_FEAT_ENABLE:
1530                         fotg210_writel(fotg210, temp & ~PORT_PE, status_reg);
1531                         break;
1532                 case USB_PORT_FEAT_C_ENABLE:
1533                         fotg210_writel(fotg210, temp | PORT_PEC, status_reg);
1534                         break;
1535                 case USB_PORT_FEAT_SUSPEND:
1536                         if (temp & PORT_RESET)
1537                                 goto error;
1538                         if (!(temp & PORT_SUSPEND))
1539                                 break;
1540                         if ((temp & PORT_PE) == 0)
1541                                 goto error;
1542 
1543                         /* resume signaling for 20 msec */
1544                         fotg210_writel(fotg210, temp | PORT_RESUME, status_reg);
1545                         fotg210->reset_done[wIndex] = jiffies
1546                                         + msecs_to_jiffies(USB_RESUME_TIMEOUT);
1547                         break;
1548                 case USB_PORT_FEAT_C_SUSPEND:
1549                         clear_bit(wIndex, &fotg210->port_c_suspend);
1550                         break;
1551                 case USB_PORT_FEAT_C_CONNECTION:
1552                         fotg210_writel(fotg210, temp | PORT_CSC, status_reg);
1553                         break;
1554                 case USB_PORT_FEAT_C_OVER_CURRENT:
1555                         fotg210_writel(fotg210, temp | OTGISR_OVC,
1556                                         &fotg210->regs->otgisr);
1557                         break;
1558                 case USB_PORT_FEAT_C_RESET:
1559                         /* GetPortStatus clears reset */
1560                         break;
1561                 default:
1562                         goto error;
1563                 }
1564                 fotg210_readl(fotg210, &fotg210->regs->command);
1565                 break;
1566         case GetHubDescriptor:
1567                 fotg210_hub_descriptor(fotg210, (struct usb_hub_descriptor *)
1568                                 buf);
1569                 break;
1570         case GetHubStatus:
1571                 /* no hub-wide feature/status flags */
1572                 memset(buf, 0, 4);
1573                 /*cpu_to_le32s ((u32 *) buf); */
1574                 break;
1575         case GetPortStatus:
1576                 if (!wIndex || wIndex > ports)
1577                         goto error;
1578                 wIndex--;
1579                 status = 0;
1580                 temp = fotg210_readl(fotg210, status_reg);
1581 
1582                 /* wPortChange bits */
1583                 if (temp & PORT_CSC)
1584                         status |= USB_PORT_STAT_C_CONNECTION << 16;
1585                 if (temp & PORT_PEC)
1586                         status |= USB_PORT_STAT_C_ENABLE << 16;
1587 
1588                 temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
1589                 if (temp1 & OTGISR_OVC)
1590                         status |= USB_PORT_STAT_C_OVERCURRENT << 16;
1591 
1592                 /* whoever resumes must GetPortStatus to complete it!! */
1593                 if (temp & PORT_RESUME) {
1594 
1595                         /* Remote Wakeup received? */
1596                         if (!fotg210->reset_done[wIndex]) {
1597                                 /* resume signaling for 20 msec */
1598                                 fotg210->reset_done[wIndex] = jiffies
1599                                                 + msecs_to_jiffies(20);
1600                                 /* check the port again */
1601                                 mod_timer(&fotg210_to_hcd(fotg210)->rh_timer,
1602                                                 fotg210->reset_done[wIndex]);
1603                         }
1604 
1605                         /* resume completed? */
1606                         else if (time_after_eq(jiffies,
1607                                         fotg210->reset_done[wIndex])) {
1608                                 clear_bit(wIndex, &fotg210->suspended_ports);
1609                                 set_bit(wIndex, &fotg210->port_c_suspend);
1610                                 fotg210->reset_done[wIndex] = 0;
1611 
1612                                 /* stop resume signaling */
1613                                 temp = fotg210_readl(fotg210, status_reg);
1614                                 fotg210_writel(fotg210, temp &
1615                                                 ~(PORT_RWC_BITS | PORT_RESUME),
1616                                                 status_reg);
1617                                 clear_bit(wIndex, &fotg210->resuming_ports);
1618                                 retval = handshake(fotg210, status_reg,
1619                                                 PORT_RESUME, 0, 2000);/* 2ms */
1620                                 if (retval != 0) {
1621                                         fotg210_err(fotg210,
1622                                                         "port %d resume error %d\n",
1623                                                         wIndex + 1, retval);
1624                                         goto error;
1625                                 }
1626                                 temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
1627                         }
1628                 }
1629 
1630                 /* whoever resets must GetPortStatus to complete it!! */
1631                 if ((temp & PORT_RESET) && time_after_eq(jiffies,
1632                                 fotg210->reset_done[wIndex])) {
1633                         status |= USB_PORT_STAT_C_RESET << 16;
1634                         fotg210->reset_done[wIndex] = 0;
1635                         clear_bit(wIndex, &fotg210->resuming_ports);
1636 
1637                         /* force reset to complete */
1638                         fotg210_writel(fotg210,
1639                                         temp & ~(PORT_RWC_BITS | PORT_RESET),
1640                                         status_reg);
1641                         /* REVISIT:  some hardware needs 550+ usec to clear
1642                          * this bit; seems too long to spin routinely...
1643                          */
1644                         retval = handshake(fotg210, status_reg,
1645                                         PORT_RESET, 0, 1000);
1646                         if (retval != 0) {
1647                                 fotg210_err(fotg210, "port %d reset error %d\n",
1648                                                 wIndex + 1, retval);
1649                                 goto error;
1650                         }
1651 
1652                         /* see what we found out */
1653                         temp = check_reset_complete(fotg210, wIndex, status_reg,
1654                                         fotg210_readl(fotg210, status_reg));
1655                 }
1656 
1657                 if (!(temp & (PORT_RESUME|PORT_RESET))) {
1658                         fotg210->reset_done[wIndex] = 0;
1659                         clear_bit(wIndex, &fotg210->resuming_ports);
1660                 }
1661 
1662                 /* transfer dedicated ports to the companion hc */
1663                 if ((temp & PORT_CONNECT) &&
1664                                 test_bit(wIndex, &fotg210->companion_ports)) {
1665                         temp &= ~PORT_RWC_BITS;
1666                         fotg210_writel(fotg210, temp, status_reg);
1667                         fotg210_dbg(fotg210, "port %d --> companion\n",
1668                                         wIndex + 1);
1669                         temp = fotg210_readl(fotg210, status_reg);
1670                 }
1671 
1672                 /*
1673                  * Even if OWNER is set, there's no harm letting hub_wq
1674                  * see the wPortStatus values (they should all be 0 except
1675                  * for PORT_POWER anyway).
1676                  */
1677 
1678                 if (temp & PORT_CONNECT) {
1679                         status |= USB_PORT_STAT_CONNECTION;
1680                         status |= fotg210_port_speed(fotg210, temp);
1681                 }
1682                 if (temp & PORT_PE)
1683                         status |= USB_PORT_STAT_ENABLE;
1684 
1685                 /* maybe the port was unsuspended without our knowledge */
1686                 if (temp & (PORT_SUSPEND|PORT_RESUME)) {
1687                         status |= USB_PORT_STAT_SUSPEND;
1688                 } else if (test_bit(wIndex, &fotg210->suspended_ports)) {
1689                         clear_bit(wIndex, &fotg210->suspended_ports);
1690                         clear_bit(wIndex, &fotg210->resuming_ports);
1691                         fotg210->reset_done[wIndex] = 0;
1692                         if (temp & PORT_PE)
1693                                 set_bit(wIndex, &fotg210->port_c_suspend);
1694                 }
1695 
1696                 temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
1697                 if (temp1 & OTGISR_OVC)
1698                         status |= USB_PORT_STAT_OVERCURRENT;
1699                 if (temp & PORT_RESET)
1700                         status |= USB_PORT_STAT_RESET;
1701                 if (test_bit(wIndex, &fotg210->port_c_suspend))
1702                         status |= USB_PORT_STAT_C_SUSPEND << 16;
1703 
1704                 if (status & ~0xffff)   /* only if wPortChange is interesting */
1705                         dbg_port(fotg210, "GetStatus", wIndex + 1, temp);
1706                 put_unaligned_le32(status, buf);
1707                 break;
1708         case SetHubFeature:
1709                 switch (wValue) {
1710                 case C_HUB_LOCAL_POWER:
1711                 case C_HUB_OVER_CURRENT:
1712                         /* no hub-wide feature/status flags */
1713                         break;
1714                 default:
1715                         goto error;
1716                 }
1717                 break;
1718         case SetPortFeature:
1719                 selector = wIndex >> 8;
1720                 wIndex &= 0xff;
1721 
1722                 if (!wIndex || wIndex > ports)
1723                         goto error;
1724                 wIndex--;
1725                 temp = fotg210_readl(fotg210, status_reg);
1726                 temp &= ~PORT_RWC_BITS;
1727                 switch (wValue) {
1728                 case USB_PORT_FEAT_SUSPEND:
1729                         if ((temp & PORT_PE) == 0
1730                                         || (temp & PORT_RESET) != 0)
1731                                 goto error;
1732 
1733                         /* After above check the port must be connected.
1734                          * Set appropriate bit thus could put phy into low power
1735                          * mode if we have hostpc feature
1736                          */
1737                         fotg210_writel(fotg210, temp | PORT_SUSPEND,
1738                                         status_reg);
1739                         set_bit(wIndex, &fotg210->suspended_ports);
1740                         break;
1741                 case USB_PORT_FEAT_RESET:
1742                         if (temp & PORT_RESUME)
1743                                 goto error;
1744                         /* line status bits may report this as low speed,
1745                          * which can be fine if this root hub has a
1746                          * transaction translator built in.
1747                          */
1748                         fotg210_dbg(fotg210, "port %d reset\n", wIndex + 1);
1749                         temp |= PORT_RESET;
1750                         temp &= ~PORT_PE;
1751 
1752                         /*
1753                          * caller must wait, then call GetPortStatus
1754                          * usb 2.0 spec says 50 ms resets on root
1755                          */
1756                         fotg210->reset_done[wIndex] = jiffies
1757                                         + msecs_to_jiffies(50);
1758                         fotg210_writel(fotg210, temp, status_reg);
1759                         break;
1760 
1761                 /* For downstream facing ports (these):  one hub port is put
1762                  * into test mode according to USB2 11.24.2.13, then the hub
1763                  * must be reset (which for root hub now means rmmod+modprobe,
1764                  * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
1765                  * about the EHCI-specific stuff.
1766                  */
1767                 case USB_PORT_FEAT_TEST:
1768                         if (!selector || selector > 5)
1769                                 goto error;
1770                         spin_unlock_irqrestore(&fotg210->lock, flags);
1771                         fotg210_quiesce(fotg210);
1772                         spin_lock_irqsave(&fotg210->lock, flags);
1773 
1774                         /* Put all enabled ports into suspend */
1775                         temp = fotg210_readl(fotg210, status_reg) &
1776                                 ~PORT_RWC_BITS;
1777                         if (temp & PORT_PE)
1778                                 fotg210_writel(fotg210, temp | PORT_SUSPEND,
1779                                                 status_reg);
1780 
1781                         spin_unlock_irqrestore(&fotg210->lock, flags);
1782                         fotg210_halt(fotg210);
1783                         spin_lock_irqsave(&fotg210->lock, flags);
1784 
1785                         temp = fotg210_readl(fotg210, status_reg);
1786                         temp |= selector << 16;
1787                         fotg210_writel(fotg210, temp, status_reg);
1788                         break;
1789 
1790                 default:
1791                         goto error;
1792                 }
1793                 fotg210_readl(fotg210, &fotg210->regs->command);
1794                 break;
1795 
1796         default:
1797 error:
1798                 /* "stall" on error */
1799                 retval = -EPIPE;
1800         }
1801         spin_unlock_irqrestore(&fotg210->lock, flags);
1802         return retval;
1803 }
1804 
1805 static void __maybe_unused fotg210_relinquish_port(struct usb_hcd *hcd,
1806                 int portnum)
1807 {
1808         return;
1809 }
1810 
1811 static int __maybe_unused fotg210_port_handed_over(struct usb_hcd *hcd,
1812                 int portnum)
1813 {
1814         return 0;
1815 }
1816 
1817 /* There's basically three types of memory:
1818  *      - data used only by the HCD ... kmalloc is fine
1819  *      - async and periodic schedules, shared by HC and HCD ... these
1820  *        need to use dma_pool or dma_alloc_coherent
1821  *      - driver buffers, read/written by HC ... single shot DMA mapped
1822  *
1823  * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
1824  * No memory seen by this driver is pageable.
1825  */
1826 
1827 /* Allocate the key transfer structures from the previously allocated pool */
1828 static inline void fotg210_qtd_init(struct fotg210_hcd *fotg210,
1829                 struct fotg210_qtd *qtd, dma_addr_t dma)
1830 {
1831         memset(qtd, 0, sizeof(*qtd));
1832         qtd->qtd_dma = dma;
1833         qtd->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
1834         qtd->hw_next = FOTG210_LIST_END(fotg210);
1835         qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
1836         INIT_LIST_HEAD(&qtd->qtd_list);
1837 }
1838 
1839 static struct fotg210_qtd *fotg210_qtd_alloc(struct fotg210_hcd *fotg210,
1840                 gfp_t flags)
1841 {
1842         struct fotg210_qtd *qtd;
1843         dma_addr_t dma;
1844 
1845         qtd = dma_pool_alloc(fotg210->qtd_pool, flags, &dma);
1846         if (qtd != NULL)
1847                 fotg210_qtd_init(fotg210, qtd, dma);
1848 
1849         return qtd;
1850 }
1851 
1852 static inline void fotg210_qtd_free(struct fotg210_hcd *fotg210,
1853                 struct fotg210_qtd *qtd)
1854 {
1855         dma_pool_free(fotg210->qtd_pool, qtd, qtd->qtd_dma);
1856 }
1857 
1858 
1859 static void qh_destroy(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
1860 {
1861         /* clean qtds first, and know this is not linked */
1862         if (!list_empty(&qh->qtd_list) || qh->qh_next.ptr) {
1863                 fotg210_dbg(fotg210, "unused qh not empty!\n");
1864                 BUG();
1865         }
1866         if (qh->dummy)
1867                 fotg210_qtd_free(fotg210, qh->dummy);
1868         dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
1869         kfree(qh);
1870 }
1871 
1872 static struct fotg210_qh *fotg210_qh_alloc(struct fotg210_hcd *fotg210,
1873                 gfp_t flags)
1874 {
1875         struct fotg210_qh *qh;
1876         dma_addr_t dma;
1877 
1878         qh = kzalloc(sizeof(*qh), GFP_ATOMIC);
1879         if (!qh)
1880                 goto done;
1881         qh->hw = (struct fotg210_qh_hw *)
1882                 dma_pool_alloc(fotg210->qh_pool, flags, &dma);
1883         if (!qh->hw)
1884                 goto fail;
1885         memset(qh->hw, 0, sizeof(*qh->hw));
1886         qh->qh_dma = dma;
1887         INIT_LIST_HEAD(&qh->qtd_list);
1888 
1889         /* dummy td enables safe urb queuing */
1890         qh->dummy = fotg210_qtd_alloc(fotg210, flags);
1891         if (qh->dummy == NULL) {
1892                 fotg210_dbg(fotg210, "no dummy td\n");
1893                 goto fail1;
1894         }
1895 done:
1896         return qh;
1897 fail1:
1898         dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
1899 fail:
1900         kfree(qh);
1901         return NULL;
1902 }
1903 
1904 /* The queue heads and transfer descriptors are managed from pools tied
1905  * to each of the "per device" structures.
1906  * This is the initialisation and cleanup code.
1907  */
1908 
1909 static void fotg210_mem_cleanup(struct fotg210_hcd *fotg210)
1910 {
1911         if (fotg210->async)
1912                 qh_destroy(fotg210, fotg210->async);
1913         fotg210->async = NULL;
1914 
1915         if (fotg210->dummy)
1916                 qh_destroy(fotg210, fotg210->dummy);
1917         fotg210->dummy = NULL;
1918 
1919         /* DMA consistent memory and pools */
1920         dma_pool_destroy(fotg210->qtd_pool);
1921         fotg210->qtd_pool = NULL;
1922 
1923         dma_pool_destroy(fotg210->qh_pool);
1924         fotg210->qh_pool = NULL;
1925 
1926         dma_pool_destroy(fotg210->itd_pool);
1927         fotg210->itd_pool = NULL;
1928 
1929         if (fotg210->periodic)
1930                 dma_free_coherent(fotg210_to_hcd(fotg210)->self.controller,
1931                                 fotg210->periodic_size * sizeof(u32),
1932                                 fotg210->periodic, fotg210->periodic_dma);
1933         fotg210->periodic = NULL;
1934 
1935         /* shadow periodic table */
1936         kfree(fotg210->pshadow);
1937         fotg210->pshadow = NULL;
1938 }
1939 
1940 /* remember to add cleanup code (above) if you add anything here */
1941 static int fotg210_mem_init(struct fotg210_hcd *fotg210, gfp_t flags)
1942 {
1943         int i;
1944 
1945         /* QTDs for control/bulk/intr transfers */
1946         fotg210->qtd_pool = dma_pool_create("fotg210_qtd",
1947                         fotg210_to_hcd(fotg210)->self.controller,
1948                         sizeof(struct fotg210_qtd),
1949                         32 /* byte alignment (for hw parts) */,
1950                         4096 /* can't cross 4K */);
1951         if (!fotg210->qtd_pool)
1952                 goto fail;
1953 
1954         /* QHs for control/bulk/intr transfers */
1955         fotg210->qh_pool = dma_pool_create("fotg210_qh",
1956                         fotg210_to_hcd(fotg210)->self.controller,
1957                         sizeof(struct fotg210_qh_hw),
1958                         32 /* byte alignment (for hw parts) */,
1959                         4096 /* can't cross 4K */);
1960         if (!fotg210->qh_pool)
1961                 goto fail;
1962 
1963         fotg210->async = fotg210_qh_alloc(fotg210, flags);
1964         if (!fotg210->async)
1965                 goto fail;
1966 
1967         /* ITD for high speed ISO transfers */
1968         fotg210->itd_pool = dma_pool_create("fotg210_itd",
1969                         fotg210_to_hcd(fotg210)->self.controller,
1970                         sizeof(struct fotg210_itd),
1971                         64 /* byte alignment (for hw parts) */,
1972                         4096 /* can't cross 4K */);
1973         if (!fotg210->itd_pool)
1974                 goto fail;
1975 
1976         /* Hardware periodic table */
1977         fotg210->periodic = (__le32 *)
1978                 dma_alloc_coherent(fotg210_to_hcd(fotg210)->self.controller,
1979                                 fotg210->periodic_size * sizeof(__le32),
1980                                 &fotg210->periodic_dma, 0);
1981         if (fotg210->periodic == NULL)
1982                 goto fail;
1983 
1984         for (i = 0; i < fotg210->periodic_size; i++)
1985                 fotg210->periodic[i] = FOTG210_LIST_END(fotg210);
1986 
1987         /* software shadow of hardware table */
1988         fotg210->pshadow = kcalloc(fotg210->periodic_size, sizeof(void *),
1989                         flags);
1990         if (fotg210->pshadow != NULL)
1991                 return 0;
1992 
1993 fail:
1994         fotg210_dbg(fotg210, "couldn't init memory\n");
1995         fotg210_mem_cleanup(fotg210);
1996         return -ENOMEM;
1997 }
1998 /* EHCI hardware queue manipulation ... the core.  QH/QTD manipulation.
1999  *
2000  * Control, bulk, and interrupt traffic all use "qh" lists.  They list "qtd"
2001  * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
2002  * buffers needed for the larger number).  We use one QH per endpoint, queue
2003  * multiple urbs (all three types) per endpoint.  URBs may need several qtds.
2004  *
2005  * ISO traffic uses "ISO TD" (itd) records, and (along with
2006  * interrupts) needs careful scheduling.  Performance improvements can be
2007  * an ongoing challenge.  That's in "ehci-sched.c".
2008  *
2009  * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
2010  * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
2011  * (b) special fields in qh entries or (c) split iso entries.  TTs will
2012  * buffer low/full speed data so the host collects it at high speed.
2013  */
2014 
2015 /* fill a qtd, returning how much of the buffer we were able to queue up */
2016 static int qtd_fill(struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd,
2017                 dma_addr_t buf, size_t len, int token, int maxpacket)
2018 {
2019         int i, count;
2020         u64 addr = buf;
2021 
2022         /* one buffer entry per 4K ... first might be short or unaligned */
2023         qtd->hw_buf[0] = cpu_to_hc32(fotg210, (u32)addr);
2024         qtd->hw_buf_hi[0] = cpu_to_hc32(fotg210, (u32)(addr >> 32));
2025         count = 0x1000 - (buf & 0x0fff);        /* rest of that page */
2026         if (likely(len < count))                /* ... iff needed */
2027                 count = len;
2028         else {
2029                 buf +=  0x1000;
2030                 buf &= ~0x0fff;
2031 
2032                 /* per-qtd limit: from 16K to 20K (best alignment) */
2033                 for (i = 1; count < len && i < 5; i++) {
2034                         addr = buf;
2035                         qtd->hw_buf[i] = cpu_to_hc32(fotg210, (u32)addr);
2036                         qtd->hw_buf_hi[i] = cpu_to_hc32(fotg210,
2037                                         (u32)(addr >> 32));
2038                         buf += 0x1000;
2039                         if ((count + 0x1000) < len)
2040                                 count += 0x1000;
2041                         else
2042                                 count = len;
2043                 }
2044 
2045                 /* short packets may only terminate transfers */
2046                 if (count != len)
2047                         count -= (count % maxpacket);
2048         }
2049         qtd->hw_token = cpu_to_hc32(fotg210, (count << 16) | token);
2050         qtd->length = count;
2051 
2052         return count;
2053 }
2054 
2055 static inline void qh_update(struct fotg210_hcd *fotg210,
2056                 struct fotg210_qh *qh, struct fotg210_qtd *qtd)
2057 {
2058         struct fotg210_qh_hw *hw = qh->hw;
2059 
2060         /* writes to an active overlay are unsafe */
2061         BUG_ON(qh->qh_state != QH_STATE_IDLE);
2062 
2063         hw->hw_qtd_next = QTD_NEXT(fotg210, qtd->qtd_dma);
2064         hw->hw_alt_next = FOTG210_LIST_END(fotg210);
2065 
2066         /* Except for control endpoints, we make hardware maintain data
2067          * toggle (like OHCI) ... here (re)initialize the toggle in the QH,
2068          * and set the pseudo-toggle in udev. Only usb_clear_halt() will
2069          * ever clear it.
2070          */
2071         if (!(hw->hw_info1 & cpu_to_hc32(fotg210, QH_TOGGLE_CTL))) {
2072                 unsigned is_out, epnum;
2073 
2074                 is_out = qh->is_out;
2075                 epnum = (hc32_to_cpup(fotg210, &hw->hw_info1) >> 8) & 0x0f;
2076                 if (unlikely(!usb_gettoggle(qh->dev, epnum, is_out))) {
2077                         hw->hw_token &= ~cpu_to_hc32(fotg210, QTD_TOGGLE);
2078                         usb_settoggle(qh->dev, epnum, is_out, 1);
2079                 }
2080         }
2081 
2082         hw->hw_token &= cpu_to_hc32(fotg210, QTD_TOGGLE | QTD_STS_PING);
2083 }
2084 
2085 /* if it weren't for a common silicon quirk (writing the dummy into the qh
2086  * overlay, so qh->hw_token wrongly becomes inactive/halted), only fault
2087  * recovery (including urb dequeue) would need software changes to a QH...
2088  */
2089 static void qh_refresh(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
2090 {
2091         struct fotg210_qtd *qtd;
2092 
2093         if (list_empty(&qh->qtd_list))
2094                 qtd = qh->dummy;
2095         else {
2096                 qtd = list_entry(qh->qtd_list.next,
2097                                 struct fotg210_qtd, qtd_list);
2098                 /*
2099                  * first qtd may already be partially processed.
2100                  * If we come here during unlink, the QH overlay region
2101                  * might have reference to the just unlinked qtd. The
2102                  * qtd is updated in qh_completions(). Update the QH
2103                  * overlay here.
2104                  */
2105                 if (cpu_to_hc32(fotg210, qtd->qtd_dma) == qh->hw->hw_current) {
2106                         qh->hw->hw_qtd_next = qtd->hw_next;
2107                         qtd = NULL;
2108                 }
2109         }
2110 
2111         if (qtd)
2112                 qh_update(fotg210, qh, qtd);
2113 }
2114 
2115 static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
2116 
2117 static void fotg210_clear_tt_buffer_complete(struct usb_hcd *hcd,
2118                 struct usb_host_endpoint *ep)
2119 {
2120         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
2121         struct fotg210_qh *qh = ep->hcpriv;
2122         unsigned long flags;
2123 
2124         spin_lock_irqsave(&fotg210->lock, flags);
2125         qh->clearing_tt = 0;
2126         if (qh->qh_state == QH_STATE_IDLE && !list_empty(&qh->qtd_list)
2127                         && fotg210->rh_state == FOTG210_RH_RUNNING)
2128                 qh_link_async(fotg210, qh);
2129         spin_unlock_irqrestore(&fotg210->lock, flags);
2130 }
2131 
2132 static void fotg210_clear_tt_buffer(struct fotg210_hcd *fotg210,
2133                 struct fotg210_qh *qh, struct urb *urb, u32 token)
2134 {
2135 
2136         /* If an async split transaction gets an error or is unlinked,
2137          * the TT buffer may be left in an indeterminate state.  We
2138          * have to clear the TT buffer.
2139          *
2140          * Note: this routine is never called for Isochronous transfers.
2141          */
2142         if (urb->dev->tt && !usb_pipeint(urb->pipe) && !qh->clearing_tt) {
2143                 struct usb_device *tt = urb->dev->tt->hub;
2144 
2145                 dev_dbg(&tt->dev,
2146                                 "clear tt buffer port %d, a%d ep%d t%08x\n",
2147                                 urb->dev->ttport, urb->dev->devnum,
2148                                 usb_pipeendpoint(urb->pipe), token);
2149 
2150                 if (urb->dev->tt->hub !=
2151                                 fotg210_to_hcd(fotg210)->self.root_hub) {
2152                         if (usb_hub_clear_tt_buffer(urb) == 0)
2153                                 qh->clearing_tt = 1;
2154                 }
2155         }
2156 }
2157 
2158 static int qtd_copy_status(struct fotg210_hcd *fotg210, struct urb *urb,
2159                 size_t length, u32 token)
2160 {
2161         int status = -EINPROGRESS;
2162 
2163         /* count IN/OUT bytes, not SETUP (even short packets) */
2164         if (likely(QTD_PID(token) != 2))
2165                 urb->actual_length += length - QTD_LENGTH(token);
2166 
2167         /* don't modify error codes */
2168         if (unlikely(urb->unlinked))
2169                 return status;
2170 
2171         /* force cleanup after short read; not always an error */
2172         if (unlikely(IS_SHORT_READ(token)))
2173                 status = -EREMOTEIO;
2174 
2175         /* serious "can't proceed" faults reported by the hardware */
2176         if (token & QTD_STS_HALT) {
2177                 if (token & QTD_STS_BABBLE) {
2178                         /* FIXME "must" disable babbling device's port too */
2179                         status = -EOVERFLOW;
2180                 /* CERR nonzero + halt --> stall */
2181                 } else if (QTD_CERR(token)) {
2182                         status = -EPIPE;
2183 
2184                 /* In theory, more than one of the following bits can be set
2185                  * since they are sticky and the transaction is retried.
2186                  * Which to test first is rather arbitrary.
2187                  */
2188                 } else if (token & QTD_STS_MMF) {
2189                         /* fs/ls interrupt xfer missed the complete-split */
2190                         status = -EPROTO;
2191                 } else if (token & QTD_STS_DBE) {
2192                         status = (QTD_PID(token) == 1) /* IN ? */
2193                                 ? -ENOSR  /* hc couldn't read data */
2194                                 : -ECOMM; /* hc couldn't write data */
2195                 } else if (token & QTD_STS_XACT) {
2196                         /* timeout, bad CRC, wrong PID, etc */
2197                         fotg210_dbg(fotg210, "devpath %s ep%d%s 3strikes\n",
2198                                         urb->dev->devpath,
2199                                         usb_pipeendpoint(urb->pipe),
2200                                         usb_pipein(urb->pipe) ? "in" : "out");
2201                         status = -EPROTO;
2202                 } else {        /* unknown */
2203                         status = -EPROTO;
2204                 }
2205 
2206                 fotg210_dbg(fotg210,
2207                                 "dev%d ep%d%s qtd token %08x --> status %d\n",
2208                                 usb_pipedevice(urb->pipe),
2209                                 usb_pipeendpoint(urb->pipe),
2210                                 usb_pipein(urb->pipe) ? "in" : "out",
2211                                 token, status);
2212         }
2213 
2214         return status;
2215 }
2216 
2217 static void fotg210_urb_done(struct fotg210_hcd *fotg210, struct urb *urb,
2218                 int status)
2219 __releases(fotg210->lock)
2220 __acquires(fotg210->lock)
2221 {
2222         if (likely(urb->hcpriv != NULL)) {
2223                 struct fotg210_qh *qh = (struct fotg210_qh *) urb->hcpriv;
2224 
2225                 /* S-mask in a QH means it's an interrupt urb */
2226                 if ((qh->hw->hw_info2 & cpu_to_hc32(fotg210, QH_SMASK)) != 0) {
2227 
2228                         /* ... update hc-wide periodic stats (for usbfs) */
2229                         fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs--;
2230                 }
2231         }
2232 
2233         if (unlikely(urb->unlinked)) {
2234                 COUNT(fotg210->stats.unlink);
2235         } else {
2236                 /* report non-error and short read status as zero */
2237                 if (status == -EINPROGRESS || status == -EREMOTEIO)
2238                         status = 0;
2239                 COUNT(fotg210->stats.complete);
2240         }
2241 
2242 #ifdef FOTG210_URB_TRACE
2243         fotg210_dbg(fotg210,
2244                         "%s %s urb %p ep%d%s status %d len %d/%d\n",
2245                         __func__, urb->dev->devpath, urb,
2246                         usb_pipeendpoint(urb->pipe),
2247                         usb_pipein(urb->pipe) ? "in" : "out",
2248                         status,
2249                         urb->actual_length, urb->transfer_buffer_length);
2250 #endif
2251 
2252         /* complete() can reenter this HCD */
2253         usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
2254         spin_unlock(&fotg210->lock);
2255         usb_hcd_giveback_urb(fotg210_to_hcd(fotg210), urb, status);
2256         spin_lock(&fotg210->lock);
2257 }
2258 
2259 static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);
2260 
2261 /* Process and free completed qtds for a qh, returning URBs to drivers.
2262  * Chases up to qh->hw_current.  Returns number of completions called,
2263  * indicating how much "real" work we did.
2264  */
2265 static unsigned qh_completions(struct fotg210_hcd *fotg210,
2266                 struct fotg210_qh *qh)
2267 {
2268         struct fotg210_qtd *last, *end = qh->dummy;
2269         struct fotg210_qtd *qtd, *tmp;
2270         int last_status;
2271         int stopped;
2272         unsigned count = 0;
2273         u8 state;
2274         struct fotg210_qh_hw *hw = qh->hw;
2275 
2276         if (unlikely(list_empty(&qh->qtd_list)))
2277                 return count;
2278 
2279         /* completions (or tasks on other cpus) must never clobber HALT
2280          * till we've gone through and cleaned everything up, even when
2281          * they add urbs to this qh's queue or mark them for unlinking.
2282          *
2283          * NOTE:  unlinking expects to be done in queue order.
2284          *
2285          * It's a bug for qh->qh_state to be anything other than
2286          * QH_STATE_IDLE, unless our caller is scan_async() or
2287          * scan_intr().
2288          */
2289         state = qh->qh_state;
2290         qh->qh_state = QH_STATE_COMPLETING;
2291         stopped = (state == QH_STATE_IDLE);
2292 
2293 rescan:
2294         last = NULL;
2295         last_status = -EINPROGRESS;
2296         qh->needs_rescan = 0;
2297 
2298         /* remove de-activated QTDs from front of queue.
2299          * after faults (including short reads), cleanup this urb
2300          * then let the queue advance.
2301          * if queue is stopped, handles unlinks.
2302          */
2303         list_for_each_entry_safe(qtd, tmp, &qh->qtd_list, qtd_list) {
2304                 struct urb *urb;
2305                 u32 token = 0;
2306 
2307                 urb = qtd->urb;
2308 
2309                 /* clean up any state from previous QTD ...*/
2310                 if (last) {
2311                         if (likely(last->urb != urb)) {
2312                                 fotg210_urb_done(fotg210, last->urb,
2313                                                 last_status);
2314                                 count++;
2315                                 last_status = -EINPROGRESS;
2316                         }
2317                         fotg210_qtd_free(fotg210, last);
2318                         last = NULL;
2319                 }
2320 
2321                 /* ignore urbs submitted during completions we reported */
2322                 if (qtd == end)
2323                         break;
2324 
2325                 /* hardware copies qtd out of qh overlay */
2326                 rmb();
2327                 token = hc32_to_cpu(fotg210, qtd->hw_token);
2328 
2329                 /* always clean up qtds the hc de-activated */
2330 retry_xacterr:
2331                 if ((token & QTD_STS_ACTIVE) == 0) {
2332 
2333                         /* Report Data Buffer Error: non-fatal but useful */
2334                         if (token & QTD_STS_DBE)
2335                                 fotg210_dbg(fotg210,
2336                                         "detected DataBufferErr for urb %p ep%d%s len %d, qtd %p [qh %p]\n",
2337                                         urb, usb_endpoint_num(&urb->ep->desc),
2338                                         usb_endpoint_dir_in(&urb->ep->desc)
2339                                                 ? "in" : "out",
2340                                         urb->transfer_buffer_length, qtd, qh);
2341 
2342                         /* on STALL, error, and short reads this urb must
2343                          * complete and all its qtds must be recycled.
2344                          */
2345                         if ((token & QTD_STS_HALT) != 0) {
2346 
2347                                 /* retry transaction errors until we
2348                                  * reach the software xacterr limit
2349                                  */
2350                                 if ((token & QTD_STS_XACT) &&
2351                                                 QTD_CERR(token) == 0 &&
2352                                                 ++qh->xacterrs < QH_XACTERR_MAX &&
2353                                                 !urb->unlinked) {
2354                                         fotg210_dbg(fotg210,
2355                                                 "detected XactErr len %zu/%zu retry %d\n",
2356                                                 qtd->length - QTD_LENGTH(token),
2357                                                 qtd->length,
2358                                                 qh->xacterrs);
2359 
2360                                         /* reset the token in the qtd and the
2361                                          * qh overlay (which still contains
2362                                          * the qtd) so that we pick up from
2363                                          * where we left off
2364                                          */
2365                                         token &= ~QTD_STS_HALT;
2366                                         token |= QTD_STS_ACTIVE |
2367                                                  (FOTG210_TUNE_CERR << 10);
2368                                         qtd->hw_token = cpu_to_hc32(fotg210,
2369                                                         token);
2370                                         wmb();
2371                                         hw->hw_token = cpu_to_hc32(fotg210,
2372                                                         token);
2373                                         goto retry_xacterr;
2374                                 }
2375                                 stopped = 1;
2376 
2377                         /* magic dummy for some short reads; qh won't advance.
2378                          * that silicon quirk can kick in with this dummy too.
2379                          *
2380                          * other short reads won't stop the queue, including
2381                          * control transfers (status stage handles that) or
2382                          * most other single-qtd reads ... the queue stops if
2383                          * URB_SHORT_NOT_OK was set so the driver submitting
2384                          * the urbs could clean it up.
2385                          */
2386                         } else if (IS_SHORT_READ(token) &&
2387                                         !(qtd->hw_alt_next &
2388                                         FOTG210_LIST_END(fotg210))) {
2389                                 stopped = 1;
2390                         }
2391 
2392                 /* stop scanning when we reach qtds the hc is using */
2393                 } else if (likely(!stopped
2394                                 && fotg210->rh_state >= FOTG210_RH_RUNNING)) {
2395                         break;
2396 
2397                 /* scan the whole queue for unlinks whenever it stops */
2398                 } else {
2399                         stopped = 1;
2400 
2401                         /* cancel everything if we halt, suspend, etc */
2402                         if (fotg210->rh_state < FOTG210_RH_RUNNING)
2403                                 last_status = -ESHUTDOWN;
2404 
2405                         /* this qtd is active; skip it unless a previous qtd
2406                          * for its urb faulted, or its urb was canceled.
2407                          */
2408                         else if (last_status == -EINPROGRESS && !urb->unlinked)
2409                                 continue;
2410 
2411                         /* qh unlinked; token in overlay may be most current */
2412                         if (state == QH_STATE_IDLE &&
2413                                         cpu_to_hc32(fotg210, qtd->qtd_dma)
2414                                         == hw->hw_current) {
2415                                 token = hc32_to_cpu(fotg210, hw->hw_token);
2416 
2417                                 /* An unlink may leave an incomplete
2418                                  * async transaction in the TT buffer.
2419                                  * We have to clear it.
2420                                  */
2421                                 fotg210_clear_tt_buffer(fotg210, qh, urb,
2422                                                 token);
2423                         }
2424                 }
2425 
2426                 /* unless we already know the urb's status, collect qtd status
2427                  * and update count of bytes transferred.  in common short read
2428                  * cases with only one data qtd (including control transfers),
2429                  * queue processing won't halt.  but with two or more qtds (for
2430                  * example, with a 32 KB transfer), when the first qtd gets a
2431                  * short read the second must be removed by hand.
2432                  */
2433                 if (last_status == -EINPROGRESS) {
2434                         last_status = qtd_copy_status(fotg210, urb,
2435                                         qtd->length, token);
2436                         if (last_status == -EREMOTEIO &&
2437                                         (qtd->hw_alt_next &
2438                                         FOTG210_LIST_END(fotg210)))
2439                                 last_status = -EINPROGRESS;
2440 
2441                         /* As part of low/full-speed endpoint-halt processing
2442                          * we must clear the TT buffer (11.17.5).
2443                          */
2444                         if (unlikely(last_status != -EINPROGRESS &&
2445                                         last_status != -EREMOTEIO)) {
2446                                 /* The TT's in some hubs malfunction when they
2447                                  * receive this request following a STALL (they
2448                                  * stop sending isochronous packets).  Since a
2449                                  * STALL can't leave the TT buffer in a busy
2450                                  * state (if you believe Figures 11-48 - 11-51
2451                                  * in the USB 2.0 spec), we won't clear the TT
2452                                  * buffer in this case.  Strictly speaking this
2453                                  * is a violation of the spec.
2454                                  */
2455                                 if (last_status != -EPIPE)
2456                                         fotg210_clear_tt_buffer(fotg210, qh,
2457                                                         urb, token);
2458                         }
2459                 }
2460 
2461                 /* if we're removing something not at the queue head,
2462                  * patch the hardware queue pointer.
2463                  */
2464                 if (stopped && qtd->qtd_list.prev != &qh->qtd_list) {
2465                         last = list_entry(qtd->qtd_list.prev,
2466                                         struct fotg210_qtd, qtd_list);
2467                         last->hw_next = qtd->hw_next;
2468                 }
2469 
2470                 /* remove qtd; it's recycled after possible urb completion */
2471                 list_del(&qtd->qtd_list);
2472                 last = qtd;
2473 
2474                 /* reinit the xacterr counter for the next qtd */
2475                 qh->xacterrs = 0;
2476         }
2477 
2478         /* last urb's completion might still need calling */
2479         if (likely(last != NULL)) {
2480                 fotg210_urb_done(fotg210, last->urb, last_status);
2481                 count++;
2482                 fotg210_qtd_free(fotg210, last);
2483         }
2484 
2485         /* Do we need to rescan for URBs dequeued during a giveback? */
2486         if (unlikely(qh->needs_rescan)) {
2487                 /* If the QH is already unlinked, do the rescan now. */
2488                 if (state == QH_STATE_IDLE)
2489                         goto rescan;
2490 
2491                 /* Otherwise we have to wait until the QH is fully unlinked.
2492                  * Our caller will start an unlink if qh->needs_rescan is
2493                  * set.  But if an unlink has already started, nothing needs
2494                  * to be done.
2495                  */
2496                 if (state != QH_STATE_LINKED)
2497                         qh->needs_rescan = 0;
2498         }
2499 
2500         /* restore original state; caller must unlink or relink */
2501         qh->qh_state = state;
2502 
2503         /* be sure the hardware's done with the qh before refreshing
2504          * it after fault cleanup, or recovering from silicon wrongly
2505          * overlaying the dummy qtd (which reduces DMA chatter).
2506          */
2507         if (stopped != 0 || hw->hw_qtd_next == FOTG210_LIST_END(fotg210)) {
2508                 switch (state) {
2509                 case QH_STATE_IDLE:
2510                         qh_refresh(fotg210, qh);
2511                         break;
2512                 case QH_STATE_LINKED:
2513                         /* We won't refresh a QH that's linked (after the HC
2514                          * stopped the queue).  That avoids a race:
2515                          *  - HC reads first part of QH;
2516                          *  - CPU updates that first part and the token;
2517                          *  - HC reads rest of that QH, including token
2518                          * Result:  HC gets an inconsistent image, and then
2519                          * DMAs to/from the wrong memory (corrupting it).
2520                          *
2521                          * That should be rare for interrupt transfers,
2522                          * except maybe high bandwidth ...
2523                          */
2524 
2525                         /* Tell the caller to start an unlink */
2526                         qh->needs_rescan = 1;
2527                         break;
2528                 /* otherwise, unlink already started */
2529                 }
2530         }
2531 
2532         return count;
2533 }
2534 
2535 /* high bandwidth multiplier, as encoded in highspeed endpoint descriptors */
2536 #define hb_mult(wMaxPacketSize) (1 + (((wMaxPacketSize) >> 11) & 0x03))
2537 /* ... and packet size, for any kind of endpoint descriptor */
2538 #define max_packet(wMaxPacketSize) ((wMaxPacketSize) & 0x07ff)
2539 
2540 /* reverse of qh_urb_transaction:  free a list of TDs.
2541  * used for cleanup after errors, before HC sees an URB's TDs.
2542  */
2543 static void qtd_list_free(struct fotg210_hcd *fotg210, struct urb *urb,
2544                 struct list_head *head)
2545 {
2546         struct fotg210_qtd *qtd, *temp;
2547 
2548         list_for_each_entry_safe(qtd, temp, head, qtd_list) {
2549                 list_del(&qtd->qtd_list);
2550                 fotg210_qtd_free(fotg210, qtd);
2551         }
2552 }
2553 
2554 /* create a list of filled qtds for this URB; won't link into qh.
2555  */
2556 static struct list_head *qh_urb_transaction(struct fotg210_hcd *fotg210,
2557                 struct urb *urb, struct list_head *head, gfp_t flags)
2558 {
2559         struct fotg210_qtd *qtd, *qtd_prev;
2560         dma_addr_t buf;
2561         int len, this_sg_len, maxpacket;
2562         int is_input;
2563         u32 token;
2564         int i;
2565         struct scatterlist *sg;
2566 
2567         /*
2568          * URBs map to sequences of QTDs:  one logical transaction
2569          */
2570         qtd = fotg210_qtd_alloc(fotg210, flags);
2571         if (unlikely(!qtd))
2572                 return NULL;
2573         list_add_tail(&qtd->qtd_list, head);
2574         qtd->urb = urb;
2575 
2576         token = QTD_STS_ACTIVE;
2577         token |= (FOTG210_TUNE_CERR << 10);
2578         /* for split transactions, SplitXState initialized to zero */
2579 
2580         len = urb->transfer_buffer_length;
2581         is_input = usb_pipein(urb->pipe);
2582         if (usb_pipecontrol(urb->pipe)) {
2583                 /* SETUP pid */
2584                 qtd_fill(fotg210, qtd, urb->setup_dma,
2585                                 sizeof(struct usb_ctrlrequest),
2586                                 token | (2 /* "setup" */ << 8), 8);
2587 
2588                 /* ... and always at least one more pid */
2589                 token ^= QTD_TOGGLE;
2590                 qtd_prev = qtd;
2591                 qtd = fotg210_qtd_alloc(fotg210, flags);
2592                 if (unlikely(!qtd))
2593                         goto cleanup;
2594                 qtd->urb = urb;
2595                 qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
2596                 list_add_tail(&qtd->qtd_list, head);
2597 
2598                 /* for zero length DATA stages, STATUS is always IN */
2599                 if (len == 0)
2600                         token |= (1 /* "in" */ << 8);
2601         }
2602 
2603         /*
2604          * data transfer stage:  buffer setup
2605          */
2606         i = urb->num_mapped_sgs;
2607         if (len > 0 && i > 0) {
2608                 sg = urb->sg;
2609                 buf = sg_dma_address(sg);
2610 
2611                 /* urb->transfer_buffer_length may be smaller than the
2612                  * size of the scatterlist (or vice versa)
2613                  */
2614                 this_sg_len = min_t(int, sg_dma_len(sg), len);
2615         } else {
2616                 sg = NULL;
2617                 buf = urb->transfer_dma;
2618                 this_sg_len = len;
2619         }
2620 
2621         if (is_input)
2622                 token |= (1 /* "in" */ << 8);
2623         /* else it's already initted to "out" pid (0 << 8) */
2624 
2625         maxpacket = max_packet(usb_maxpacket(urb->dev, urb->pipe, !is_input));
2626 
2627         /*
2628          * buffer gets wrapped in one or more qtds;
2629          * last one may be "short" (including zero len)
2630          * and may serve as a control status ack
2631          */
2632         for (;;) {
2633                 int this_qtd_len;
2634 
2635                 this_qtd_len = qtd_fill(fotg210, qtd, buf, this_sg_len, token,
2636                                 maxpacket);
2637                 this_sg_len -= this_qtd_len;
2638                 len -= this_qtd_len;
2639                 buf += this_qtd_len;
2640 
2641                 /*
2642                  * short reads advance to a "magic" dummy instead of the next
2643                  * qtd ... that forces the queue to stop, for manual cleanup.
2644                  * (this will usually be overridden later.)
2645                  */
2646                 if (is_input)
2647                         qtd->hw_alt_next = fotg210->async->hw->hw_alt_next;
2648 
2649                 /* qh makes control packets use qtd toggle; maybe switch it */
2650                 if ((maxpacket & (this_qtd_len + (maxpacket - 1))) == 0)
2651                         token ^= QTD_TOGGLE;
2652 
2653                 if (likely(this_sg_len <= 0)) {
2654                         if (--i <= 0 || len <= 0)
2655                                 break;
2656                         sg = sg_next(sg);
2657                         buf = sg_dma_address(sg);
2658                         this_sg_len = min_t(int, sg_dma_len(sg), len);
2659                 }
2660 
2661                 qtd_prev = qtd;
2662                 qtd = fotg210_qtd_alloc(fotg210, flags);
2663                 if (unlikely(!qtd))
2664                         goto cleanup;
2665                 qtd->urb = urb;
2666                 qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
2667                 list_add_tail(&qtd->qtd_list, head);
2668         }
2669 
2670         /*
2671          * unless the caller requires manual cleanup after short reads,
2672          * have the alt_next mechanism keep the queue running after the
2673          * last data qtd (the only one, for control and most other cases).
2674          */
2675         if (likely((urb->transfer_flags & URB_SHORT_NOT_OK) == 0 ||
2676                         usb_pipecontrol(urb->pipe)))
2677                 qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
2678 
2679         /*
2680          * control requests may need a terminating data "status" ack;
2681          * other OUT ones may need a terminating short packet
2682          * (zero length).
2683          */
2684         if (likely(urb->transfer_buffer_length != 0)) {
2685                 int one_more = 0;
2686 
2687                 if (usb_pipecontrol(urb->pipe)) {
2688                         one_more = 1;
2689                         token ^= 0x0100;        /* "in" <--> "out"  */
2690                         token |= QTD_TOGGLE;    /* force DATA1 */
2691                 } else if (usb_pipeout(urb->pipe)
2692                                 && (urb->transfer_flags & URB_ZERO_PACKET)
2693                                 && !(urb->transfer_buffer_length % maxpacket)) {
2694                         one_more = 1;
2695                 }
2696                 if (one_more) {
2697                         qtd_prev = qtd;
2698                         qtd = fotg210_qtd_alloc(fotg210, flags);
2699                         if (unlikely(!qtd))
2700                                 goto cleanup;
2701                         qtd->urb = urb;
2702                         qtd_prev->hw_next = QTD_NEXT(fotg210, qtd->qtd_dma);
2703                         list_add_tail(&qtd->qtd_list, head);
2704 
2705                         /* never any data in such packets */
2706                         qtd_fill(fotg210, qtd, 0, 0, token, 0);
2707                 }
2708         }
2709 
2710         /* by default, enable interrupt on urb completion */
2711         if (likely(!(urb->transfer_flags & URB_NO_INTERRUPT)))
2712                 qtd->hw_token |= cpu_to_hc32(fotg210, QTD_IOC);
2713         return head;
2714 
2715 cleanup:
2716         qtd_list_free(fotg210, urb, head);
2717         return NULL;
2718 }
2719 
2720 /* Would be best to create all qh's from config descriptors,
2721  * when each interface/altsetting is established.  Unlink
2722  * any previous qh and cancel its urbs first; endpoints are
2723  * implicitly reset then (data toggle too).
2724  * That'd mean updating how usbcore talks to HCDs. (2.7?)
2725 */
2726 
2727 
2728 /* Each QH holds a qtd list; a QH is used for everything except iso.
2729  *
2730  * For interrupt urbs, the scheduler must set the microframe scheduling
2731  * mask(s) each time the QH gets scheduled.  For highspeed, that's
2732  * just one microframe in the s-mask.  For split interrupt transactions
2733  * there are additional complications: c-mask, maybe FSTNs.
2734  */
2735 static struct fotg210_qh *qh_make(struct fotg210_hcd *fotg210, struct urb *urb,
2736                 gfp_t flags)
2737 {
2738         struct fotg210_qh *qh = fotg210_qh_alloc(fotg210, flags);
2739         u32 info1 = 0, info2 = 0;
2740         int is_input, type;
2741         int maxp = 0;
2742         struct usb_tt *tt = urb->dev->tt;
2743         struct fotg210_qh_hw *hw;
2744 
2745         if (!qh)
2746                 return qh;
2747 
2748         /*
2749          * init endpoint/device data for this QH
2750          */
2751         info1 |= usb_pipeendpoint(urb->pipe) << 8;
2752         info1 |= usb_pipedevice(urb->pipe) << 0;
2753 
2754         is_input = usb_pipein(urb->pipe);
2755         type = usb_pipetype(urb->pipe);
2756         maxp = usb_maxpacket(urb->dev, urb->pipe, !is_input);
2757 
2758         /* 1024 byte maxpacket is a hardware ceiling.  High bandwidth
2759          * acts like up to 3KB, but is built from smaller packets.
2760          */
2761         if (max_packet(maxp) > 1024) {
2762                 fotg210_dbg(fotg210, "bogus qh maxpacket %d\n",
2763                                 max_packet(maxp));
2764                 goto done;
2765         }
2766 
2767         /* Compute interrupt scheduling parameters just once, and save.
2768          * - allowing for high bandwidth, how many nsec/uframe are used?
2769          * - split transactions need a second CSPLIT uframe; same question
2770          * - splits also need a schedule gap (for full/low speed I/O)
2771          * - qh has a polling interval
2772          *
2773          * For control/bulk requests, the HC or TT handles these.
2774          */
2775         if (type == PIPE_INTERRUPT) {
2776                 qh->usecs = NS_TO_US(usb_calc_bus_time(USB_SPEED_HIGH,
2777                                 is_input, 0,
2778                                 hb_mult(maxp) * max_packet(maxp)));
2779                 qh->start = NO_FRAME;
2780 
2781                 if (urb->dev->speed == USB_SPEED_HIGH) {
2782                         qh->c_usecs = 0;
2783                         qh->gap_uf = 0;
2784 
2785                         qh->period = urb->interval >> 3;
2786                         if (qh->period == 0 && urb->interval != 1) {
2787                                 /* NOTE interval 2 or 4 uframes could work.
2788                                  * But interval 1 scheduling is simpler, and
2789                                  * includes high bandwidth.
2790                                  */
2791                                 urb->interval = 1;
2792                         } else if (qh->period > fotg210->periodic_size) {
2793                                 qh->period = fotg210->periodic_size;
2794                                 urb->interval = qh->period << 3;
2795                         }
2796                 } else {
2797                         int think_time;
2798 
2799                         /* gap is f(FS/LS transfer times) */
2800                         qh->gap_uf = 1 + usb_calc_bus_time(urb->dev->speed,
2801                                         is_input, 0, maxp) / (125 * 1000);
2802 
2803                         /* FIXME this just approximates SPLIT/CSPLIT times */
2804                         if (is_input) {         /* SPLIT, gap, CSPLIT+DATA */
2805                                 qh->c_usecs = qh->usecs + HS_USECS(0);
2806                                 qh->usecs = HS_USECS(1);
2807                         } else {                /* SPLIT+DATA, gap, CSPLIT */
2808                                 qh->usecs += HS_USECS(1);
2809                                 qh->c_usecs = HS_USECS(0);
2810                         }
2811 
2812                         think_time = tt ? tt->think_time : 0;
2813                         qh->tt_usecs = NS_TO_US(think_time +
2814                                         usb_calc_bus_time(urb->dev->speed,
2815                                         is_input, 0, max_packet(maxp)));
2816                         qh->period = urb->interval;
2817                         if (qh->period > fotg210->periodic_size) {
2818                                 qh->period = fotg210->periodic_size;
2819                                 urb->interval = qh->period;
2820                         }
2821                 }
2822         }
2823 
2824         /* support for tt scheduling, and access to toggles */
2825         qh->dev = urb->dev;
2826 
2827         /* using TT? */
2828         switch (urb->dev->speed) {
2829         case USB_SPEED_LOW:
2830                 info1 |= QH_LOW_SPEED;
2831                 /* FALL THROUGH */
2832 
2833         case USB_SPEED_FULL:
2834                 /* EPS 0 means "full" */
2835                 if (type != PIPE_INTERRUPT)
2836                         info1 |= (FOTG210_TUNE_RL_TT << 28);
2837                 if (type == PIPE_CONTROL) {
2838                         info1 |= QH_CONTROL_EP;         /* for TT */
2839                         info1 |= QH_TOGGLE_CTL;         /* toggle from qtd */
2840                 }
2841                 info1 |= maxp << 16;
2842 
2843                 info2 |= (FOTG210_TUNE_MULT_TT << 30);
2844 
2845                 /* Some Freescale processors have an erratum in which the
2846                  * port number in the queue head was 0..N-1 instead of 1..N.
2847                  */
2848                 if (fotg210_has_fsl_portno_bug(fotg210))
2849                         info2 |= (urb->dev->ttport-1) << 23;
2850                 else
2851                         info2 |= urb->dev->ttport << 23;
2852 
2853                 /* set the address of the TT; for TDI's integrated
2854                  * root hub tt, leave it zeroed.
2855                  */
2856                 if (tt && tt->hub != fotg210_to_hcd(fotg210)->self.root_hub)
2857                         info2 |= tt->hub->devnum << 16;
2858 
2859                 /* NOTE:  if (PIPE_INTERRUPT) { scheduler sets c-mask } */
2860 
2861                 break;
2862 
2863         case USB_SPEED_HIGH:            /* no TT involved */
2864                 info1 |= QH_HIGH_SPEED;
2865                 if (type == PIPE_CONTROL) {
2866                         info1 |= (FOTG210_TUNE_RL_HS << 28);
2867                         info1 |= 64 << 16;      /* usb2 fixed maxpacket */
2868                         info1 |= QH_TOGGLE_CTL; /* toggle from qtd */
2869                         info2 |= (FOTG210_TUNE_MULT_HS << 30);
2870                 } else if (type == PIPE_BULK) {
2871                         info1 |= (FOTG210_TUNE_RL_HS << 28);
2872                         /* The USB spec says that high speed bulk endpoints
2873                          * always use 512 byte maxpacket.  But some device
2874                          * vendors decided to ignore that, and MSFT is happy
2875                          * to help them do so.  So now people expect to use
2876                          * such nonconformant devices with Linux too; sigh.
2877                          */
2878                         info1 |= max_packet(maxp) << 16;
2879                         info2 |= (FOTG210_TUNE_MULT_HS << 30);
2880                 } else {                /* PIPE_INTERRUPT */
2881                         info1 |= max_packet(maxp) << 16;
2882                         info2 |= hb_mult(maxp) << 30;
2883                 }
2884                 break;
2885         default:
2886                 fotg210_dbg(fotg210, "bogus dev %p speed %d\n", urb->dev,
2887                                 urb->dev->speed);
2888 done:
2889                 qh_destroy(fotg210, qh);
2890                 return NULL;
2891         }
2892 
2893         /* NOTE:  if (PIPE_INTERRUPT) { scheduler sets s-mask } */
2894 
2895         /* init as live, toggle clear, advance to dummy */
2896         qh->qh_state = QH_STATE_IDLE;
2897         hw = qh->hw;
2898         hw->hw_info1 = cpu_to_hc32(fotg210, info1);
2899         hw->hw_info2 = cpu_to_hc32(fotg210, info2);
2900         qh->is_out = !is_input;
2901         usb_settoggle(urb->dev, usb_pipeendpoint(urb->pipe), !is_input, 1);
2902         qh_refresh(fotg210, qh);
2903         return qh;
2904 }
2905 
2906 static void enable_async(struct fotg210_hcd *fotg210)
2907 {
2908         if (fotg210->async_count++)
2909                 return;
2910 
2911         /* Stop waiting to turn off the async schedule */
2912         fotg210->enabled_hrtimer_events &= ~BIT(FOTG210_HRTIMER_DISABLE_ASYNC);
2913 
2914         /* Don't start the schedule until ASS is 0 */
2915         fotg210_poll_ASS(fotg210);
2916         turn_on_io_watchdog(fotg210);
2917 }
2918 
2919 static void disable_async(struct fotg210_hcd *fotg210)
2920 {
2921         if (--fotg210->async_count)
2922                 return;
2923 
2924         /* The async schedule and async_unlink list are supposed to be empty */
2925         WARN_ON(fotg210->async->qh_next.qh || fotg210->async_unlink);
2926 
2927         /* Don't turn off the schedule until ASS is 1 */
2928         fotg210_poll_ASS(fotg210);
2929 }
2930 
2931 /* move qh (and its qtds) onto async queue; maybe enable queue.  */
2932 
2933 static void qh_link_async(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
2934 {
2935         __hc32 dma = QH_NEXT(fotg210, qh->qh_dma);
2936         struct fotg210_qh *head;
2937 
2938         /* Don't link a QH if there's a Clear-TT-Buffer pending */
2939         if (unlikely(qh->clearing_tt))
2940                 return;
2941 
2942         WARN_ON(qh->qh_state != QH_STATE_IDLE);
2943 
2944         /* clear halt and/or toggle; and maybe recover from silicon quirk */
2945         qh_refresh(fotg210, qh);
2946 
2947         /* splice right after start */
2948         head = fotg210->async;
2949         qh->qh_next = head->qh_next;
2950         qh->hw->hw_next = head->hw->hw_next;
2951         wmb();
2952 
2953         head->qh_next.qh = qh;
2954         head->hw->hw_next = dma;
2955 
2956         qh->xacterrs = 0;
2957         qh->qh_state = QH_STATE_LINKED;
2958         /* qtd completions reported later by interrupt */
2959 
2960         enable_async(fotg210);
2961 }
2962 
2963 /* For control/bulk/interrupt, return QH with these TDs appended.
2964  * Allocates and initializes the QH if necessary.
2965  * Returns null if it can't allocate a QH it needs to.
2966  * If the QH has TDs (urbs) already, that's great.
2967  */
2968 static struct fotg210_qh *qh_append_tds(struct fotg210_hcd *fotg210,
2969                 struct urb *urb, struct list_head *qtd_list,
2970                 int epnum, void **ptr)
2971 {
2972         struct fotg210_qh *qh = NULL;
2973         __hc32 qh_addr_mask = cpu_to_hc32(fotg210, 0x7f);
2974 
2975         qh = (struct fotg210_qh *) *ptr;
2976         if (unlikely(qh == NULL)) {
2977                 /* can't sleep here, we have fotg210->lock... */
2978                 qh = qh_make(fotg210, urb, GFP_ATOMIC);
2979                 *ptr = qh;
2980         }
2981         if (likely(qh != NULL)) {
2982                 struct fotg210_qtd *qtd;
2983 
2984                 if (unlikely(list_empty(qtd_list)))
2985                         qtd = NULL;
2986                 else
2987                         qtd = list_entry(qtd_list->next, struct fotg210_qtd,
2988                                         qtd_list);
2989 
2990                 /* control qh may need patching ... */
2991                 if (unlikely(epnum == 0)) {
2992                         /* usb_reset_device() briefly reverts to address 0 */
2993                         if (usb_pipedevice(urb->pipe) == 0)
2994                                 qh->hw->hw_info1 &= ~qh_addr_mask;
2995                 }
2996 
2997                 /* just one way to queue requests: swap with the dummy qtd.
2998                  * only hc or qh_refresh() ever modify the overlay.
2999                  */
3000                 if (likely(qtd != NULL)) {
3001                         struct fotg210_qtd *dummy;
3002                         dma_addr_t dma;
3003                         __hc32 token;
3004 
3005                         /* to avoid racing the HC, use the dummy td instead of
3006                          * the first td of our list (becomes new dummy).  both
3007                          * tds stay deactivated until we're done, when the
3008                          * HC is allowed to fetch the old dummy (4.10.2).
3009                          */
3010                         token = qtd->hw_token;
3011                         qtd->hw_token = HALT_BIT(fotg210);
3012 
3013                         dummy = qh->dummy;
3014 
3015                         dma = dummy->qtd_dma;
3016                         *dummy = *qtd;
3017                         dummy->qtd_dma = dma;
3018 
3019                         list_del(&qtd->qtd_list);
3020                         list_add(&dummy->qtd_list, qtd_list);
3021                         list_splice_tail(qtd_list, &qh->qtd_list);
3022 
3023                         fotg210_qtd_init(fotg210, qtd, qtd->qtd_dma);
3024                         qh->dummy = qtd;
3025 
3026                         /* hc must see the new dummy at list end */
3027                         dma = qtd->qtd_dma;
3028                         qtd = list_entry(qh->qtd_list.prev,
3029                                         struct fotg210_qtd, qtd_list);
3030                         qtd->hw_next = QTD_NEXT(fotg210, dma);
3031 
3032                         /* let the hc process these next qtds */
3033                         wmb();
3034                         dummy->hw_token = token;
3035 
3036                         urb->hcpriv = qh;
3037                 }
3038         }
3039         return qh;
3040 }
3041 
3042 static int submit_async(struct fotg210_hcd *fotg210, struct urb *urb,
3043                 struct list_head *qtd_list, gfp_t mem_flags)
3044 {
3045         int epnum;
3046         unsigned long flags;
3047         struct fotg210_qh *qh = NULL;
3048         int rc;
3049 
3050         epnum = urb->ep->desc.bEndpointAddress;
3051 
3052 #ifdef FOTG210_URB_TRACE
3053         {
3054                 struct fotg210_qtd *qtd;
3055 
3056                 qtd = list_entry(qtd_list->next, struct fotg210_qtd, qtd_list);
3057                 fotg210_dbg(fotg210,
3058                                 "%s %s urb %p ep%d%s len %d, qtd %p [qh %p]\n",
3059                                 __func__, urb->dev->devpath, urb,
3060                                 epnum & 0x0f, (epnum & USB_DIR_IN)
3061                                         ? "in" : "out",
3062                                 urb->transfer_buffer_length,
3063                                 qtd, urb->ep->hcpriv);
3064         }
3065 #endif
3066 
3067         spin_lock_irqsave(&fotg210->lock, flags);
3068         if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
3069                 rc = -ESHUTDOWN;
3070                 goto done;
3071         }
3072         rc = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
3073         if (unlikely(rc))
3074                 goto done;
3075 
3076         qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
3077         if (unlikely(qh == NULL)) {
3078                 usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
3079                 rc = -ENOMEM;
3080                 goto done;
3081         }
3082 
3083         /* Control/bulk operations through TTs don't need scheduling,
3084          * the HC and TT handle it when the TT has a buffer ready.
3085          */
3086         if (likely(qh->qh_state == QH_STATE_IDLE))
3087                 qh_link_async(fotg210, qh);
3088 done:
3089         spin_unlock_irqrestore(&fotg210->lock, flags);
3090         if (unlikely(qh == NULL))
3091                 qtd_list_free(fotg210, urb, qtd_list);
3092         return rc;
3093 }
3094 
3095 static void single_unlink_async(struct fotg210_hcd *fotg210,
3096                 struct fotg210_qh *qh)
3097 {
3098         struct fotg210_qh *prev;
3099 
3100         /* Add to the end of the list of QHs waiting for the next IAAD */
3101         qh->qh_state = QH_STATE_UNLINK;
3102         if (fotg210->async_unlink)
3103                 fotg210->async_unlink_last->unlink_next = qh;
3104         else
3105                 fotg210->async_unlink = qh;
3106         fotg210->async_unlink_last = qh;
3107 
3108         /* Unlink it from the schedule */
3109         prev = fotg210->async;
3110         while (prev->qh_next.qh != qh)
3111                 prev = prev->qh_next.qh;
3112 
3113         prev->hw->hw_next = qh->hw->hw_next;
3114         prev->qh_next = qh->qh_next;
3115         if (fotg210->qh_scan_next == qh)
3116                 fotg210->qh_scan_next = qh->qh_next.qh;
3117 }
3118 
3119 static void start_iaa_cycle(struct fotg210_hcd *fotg210, bool nested)
3120 {
3121         /*
3122          * Do nothing if an IAA cycle is already running or
3123          * if one will be started shortly.
3124          */
3125         if (fotg210->async_iaa || fotg210->async_unlinking)
3126                 return;
3127 
3128         /* Do all the waiting QHs at once */
3129         fotg210->async_iaa = fotg210->async_unlink;
3130         fotg210->async_unlink = NULL;
3131 
3132         /* If the controller isn't running, we don't have to wait for it */
3133         if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING)) {
3134                 if (!nested)            /* Avoid recursion */
3135                         end_unlink_async(fotg210);
3136 
3137         /* Otherwise start a new IAA cycle */
3138         } else if (likely(fotg210->rh_state == FOTG210_RH_RUNNING)) {
3139                 /* Make sure the unlinks are all visible to the hardware */
3140                 wmb();
3141 
3142                 fotg210_writel(fotg210, fotg210->command | CMD_IAAD,
3143                                 &fotg210->regs->command);
3144                 fotg210_readl(fotg210, &fotg210->regs->command);
3145                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_IAA_WATCHDOG,
3146                                 true);
3147         }
3148 }
3149 
3150 /* the async qh for the qtds being unlinked are now gone from the HC */
3151 
3152 static void end_unlink_async(struct fotg210_hcd *fotg210)
3153 {
3154         struct fotg210_qh *qh;
3155 
3156         /* Process the idle QHs */
3157 restart:
3158         fotg210->async_unlinking = true;
3159         while (fotg210->async_iaa) {
3160                 qh = fotg210->async_iaa;
3161                 fotg210->async_iaa = qh->unlink_next;
3162                 qh->unlink_next = NULL;
3163 
3164                 qh->qh_state = QH_STATE_IDLE;
3165                 qh->qh_next.qh = NULL;
3166 
3167                 qh_completions(fotg210, qh);
3168                 if (!list_empty(&qh->qtd_list) &&
3169                                 fotg210->rh_state == FOTG210_RH_RUNNING)
3170                         qh_link_async(fotg210, qh);
3171                 disable_async(fotg210);
3172         }
3173         fotg210->async_unlinking = false;
3174 
3175         /* Start a new IAA cycle if any QHs are waiting for it */
3176         if (fotg210->async_unlink) {
3177                 start_iaa_cycle(fotg210, true);
3178                 if (unlikely(fotg210->rh_state < FOTG210_RH_RUNNING))
3179                         goto restart;
3180         }
3181 }
3182 
3183 static void unlink_empty_async(struct fotg210_hcd *fotg210)
3184 {
3185         struct fotg210_qh *qh, *next;
3186         bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);
3187         bool check_unlinks_later = false;
3188 
3189         /* Unlink all the async QHs that have been empty for a timer cycle */
3190         next = fotg210->async->qh_next.qh;
3191         while (next) {
3192                 qh = next;
3193                 next = qh->qh_next.qh;
3194 
3195                 if (list_empty(&qh->qtd_list) &&
3196                                 qh->qh_state == QH_STATE_LINKED) {
3197                         if (!stopped && qh->unlink_cycle ==
3198                                         fotg210->async_unlink_cycle)
3199                                 check_unlinks_later = true;
3200                         else
3201                                 single_unlink_async(fotg210, qh);
3202                 }
3203         }
3204 
3205         /* Start a new IAA cycle if any QHs are waiting for it */
3206         if (fotg210->async_unlink)
3207                 start_iaa_cycle(fotg210, false);
3208 
3209         /* QHs that haven't been empty for long enough will be handled later */
3210         if (check_unlinks_later) {
3211                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_ASYNC_UNLINKS,
3212                                 true);
3213                 ++fotg210->async_unlink_cycle;
3214         }
3215 }
3216 
3217 /* makes sure the async qh will become idle */
3218 /* caller must own fotg210->lock */
3219 
3220 static void start_unlink_async(struct fotg210_hcd *fotg210,
3221                 struct fotg210_qh *qh)
3222 {
3223         /*
3224          * If the QH isn't linked then there's nothing we can do
3225          * unless we were called during a giveback, in which case
3226          * qh_completions() has to deal with it.
3227          */
3228         if (qh->qh_state != QH_STATE_LINKED) {
3229                 if (qh->qh_state == QH_STATE_COMPLETING)
3230                         qh->needs_rescan = 1;
3231                 return;
3232         }
3233 
3234         single_unlink_async(fotg210, qh);
3235         start_iaa_cycle(fotg210, false);
3236 }
3237 
3238 static void scan_async(struct fotg210_hcd *fotg210)
3239 {
3240         struct fotg210_qh *qh;
3241         bool check_unlinks_later = false;
3242 
3243         fotg210->qh_scan_next = fotg210->async->qh_next.qh;
3244         while (fotg210->qh_scan_next) {
3245                 qh = fotg210->qh_scan_next;
3246                 fotg210->qh_scan_next = qh->qh_next.qh;
3247 rescan:
3248                 /* clean any finished work for this qh */
3249                 if (!list_empty(&qh->qtd_list)) {
3250                         int temp;
3251 
3252                         /*
3253                          * Unlinks could happen here; completion reporting
3254                          * drops the lock.  That's why fotg210->qh_scan_next
3255                          * always holds the next qh to scan; if the next qh
3256                          * gets unlinked then fotg210->qh_scan_next is adjusted
3257                          * in single_unlink_async().
3258                          */
3259                         temp = qh_completions(fotg210, qh);
3260                         if (qh->needs_rescan) {
3261                                 start_unlink_async(fotg210, qh);
3262                         } else if (list_empty(&qh->qtd_list)
3263                                         && qh->qh_state == QH_STATE_LINKED) {
3264                                 qh->unlink_cycle = fotg210->async_unlink_cycle;
3265                                 check_unlinks_later = true;
3266                         } else if (temp != 0)
3267                                 goto rescan;
3268                 }
3269         }
3270 
3271         /*
3272          * Unlink empty entries, reducing DMA usage as well
3273          * as HCD schedule-scanning costs.  Delay for any qh
3274          * we just scanned, there's a not-unusual case that it
3275          * doesn't stay idle for long.
3276          */
3277         if (check_unlinks_later && fotg210->rh_state == FOTG210_RH_RUNNING &&
3278                         !(fotg210->enabled_hrtimer_events &
3279                         BIT(FOTG210_HRTIMER_ASYNC_UNLINKS))) {
3280                 fotg210_enable_event(fotg210,
3281                                 FOTG210_HRTIMER_ASYNC_UNLINKS, true);
3282                 ++fotg210->async_unlink_cycle;
3283         }
3284 }
3285 /* EHCI scheduled transaction support:  interrupt, iso, split iso
3286  * These are called "periodic" transactions in the EHCI spec.
3287  *
3288  * Note that for interrupt transfers, the QH/QTD manipulation is shared
3289  * with the "asynchronous" transaction support (control/bulk transfers).
3290  * The only real difference is in how interrupt transfers are scheduled.
3291  *
3292  * For ISO, we make an "iso_stream" head to serve the same role as a QH.
3293  * It keeps track of every ITD (or SITD) that's linked, and holds enough
3294  * pre-calculated schedule data to make appending to the queue be quick.
3295  */
3296 static int fotg210_get_frame(struct usb_hcd *hcd);
3297 
3298 /* periodic_next_shadow - return "next" pointer on shadow list
3299  * @periodic: host pointer to qh/itd
3300  * @tag: hardware tag for type of this record
3301  */
3302 static union fotg210_shadow *periodic_next_shadow(struct fotg210_hcd *fotg210,
3303                 union fotg210_shadow *periodic, __hc32 tag)
3304 {
3305         switch (hc32_to_cpu(fotg210, tag)) {
3306         case Q_TYPE_QH:
3307                 return &periodic->qh->qh_next;
3308         case Q_TYPE_FSTN:
3309                 return &periodic->fstn->fstn_next;
3310         default:
3311                 return &periodic->itd->itd_next;
3312         }
3313 }
3314 
3315 static __hc32 *shadow_next_periodic(struct fotg210_hcd *fotg210,
3316                 union fotg210_shadow *periodic, __hc32 tag)
3317 {
3318         switch (hc32_to_cpu(fotg210, tag)) {
3319         /* our fotg210_shadow.qh is actually software part */
3320         case Q_TYPE_QH:
3321                 return &periodic->qh->hw->hw_next;
3322         /* others are hw parts */
3323         default:
3324                 return periodic->hw_next;
3325         }
3326 }
3327 
3328 /* caller must hold fotg210->lock */
3329 static void periodic_unlink(struct fotg210_hcd *fotg210, unsigned frame,
3330                 void *ptr)
3331 {
3332         union fotg210_shadow *prev_p = &fotg210->pshadow[frame];
3333         __hc32 *hw_p = &fotg210->periodic[frame];
3334         union fotg210_shadow here = *prev_p;
3335 
3336         /* find predecessor of "ptr"; hw and shadow lists are in sync */
3337         while (here.ptr && here.ptr != ptr) {
3338                 prev_p = periodic_next_shadow(fotg210, prev_p,
3339                                 Q_NEXT_TYPE(fotg210, *hw_p));
3340                 hw_p = shadow_next_periodic(fotg210, &here,
3341                                 Q_NEXT_TYPE(fotg210, *hw_p));
3342                 here = *prev_p;
3343         }
3344         /* an interrupt entry (at list end) could have been shared */
3345         if (!here.ptr)
3346                 return;
3347 
3348         /* update shadow and hardware lists ... the old "next" pointers
3349          * from ptr may still be in use, the caller updates them.
3350          */
3351         *prev_p = *periodic_next_shadow(fotg210, &here,
3352                         Q_NEXT_TYPE(fotg210, *hw_p));
3353 
3354         *hw_p = *shadow_next_periodic(fotg210, &here,
3355                         Q_NEXT_TYPE(fotg210, *hw_p));
3356 }
3357 
3358 /* how many of the uframe's 125 usecs are allocated? */
3359 static unsigned short periodic_usecs(struct fotg210_hcd *fotg210,
3360                 unsigned frame, unsigned uframe)
3361 {
3362         __hc32 *hw_p = &fotg210->periodic[frame];
3363         union fotg210_shadow *q = &fotg210->pshadow[frame];
3364         unsigned usecs = 0;
3365         struct fotg210_qh_hw *hw;
3366 
3367         while (q->ptr) {
3368                 switch (hc32_to_cpu(fotg210, Q_NEXT_TYPE(fotg210, *hw_p))) {
3369                 case Q_TYPE_QH:
3370                         hw = q->qh->hw;
3371                         /* is it in the S-mask? */
3372                         if (hw->hw_info2 & cpu_to_hc32(fotg210, 1 << uframe))
3373                                 usecs += q->qh->usecs;
3374                         /* ... or C-mask? */
3375                         if (hw->hw_info2 & cpu_to_hc32(fotg210,
3376                                         1 << (8 + uframe)))
3377                                 usecs += q->qh->c_usecs;
3378                         hw_p = &hw->hw_next;
3379                         q = &q->qh->qh_next;
3380                         break;
3381                 /* case Q_TYPE_FSTN: */
3382                 default:
3383                         /* for "save place" FSTNs, count the relevant INTR
3384                          * bandwidth from the previous frame
3385                          */
3386                         if (q->fstn->hw_prev != FOTG210_LIST_END(fotg210))
3387                                 fotg210_dbg(fotg210, "ignoring FSTN cost ...\n");
3388 
3389                         hw_p = &q->fstn->hw_next;
3390                         q = &q->fstn->fstn_next;
3391                         break;
3392                 case Q_TYPE_ITD:
3393                         if (q->itd->hw_transaction[uframe])
3394                                 usecs += q->itd->stream->usecs;
3395                         hw_p = &q->itd->hw_next;
3396                         q = &q->itd->itd_next;
3397                         break;
3398                 }
3399         }
3400         if (usecs > fotg210->uframe_periodic_max)
3401                 fotg210_err(fotg210, "uframe %d sched overrun: %d usecs\n",
3402                                 frame * 8 + uframe, usecs);
3403         return usecs;
3404 }
3405 
3406 static int same_tt(struct usb_device *dev1, struct usb_device *dev2)
3407 {
3408         if (!dev1->tt || !dev2->tt)
3409                 return 0;
3410         if (dev1->tt != dev2->tt)
3411                 return 0;
3412         if (dev1->tt->multi)
3413                 return dev1->ttport == dev2->ttport;
3414         else
3415                 return 1;
3416 }
3417 
3418 /* return true iff the device's transaction translator is available
3419  * for a periodic transfer starting at the specified frame, using
3420  * all the uframes in the mask.
3421  */
3422 static int tt_no_collision(struct fotg210_hcd *fotg210, unsigned period,
3423                 struct usb_device *dev, unsigned frame, u32 uf_mask)
3424 {
3425         if (period == 0)        /* error */
3426                 return 0;
3427 
3428         /* note bandwidth wastage:  split never follows csplit
3429          * (different dev or endpoint) until the next uframe.
3430          * calling convention doesn't make that distinction.
3431          */
3432         for (; frame < fotg210->periodic_size; frame += period) {
3433                 union fotg210_shadow here;
3434                 __hc32 type;
3435                 struct fotg210_qh_hw *hw;
3436 
3437                 here = fotg210->pshadow[frame];
3438                 type = Q_NEXT_TYPE(fotg210, fotg210->periodic[frame]);
3439                 while (here.ptr) {
3440                         switch (hc32_to_cpu(fotg210, type)) {
3441                         case Q_TYPE_ITD:
3442                                 type = Q_NEXT_TYPE(fotg210, here.itd->hw_next);
3443                                 here = here.itd->itd_next;
3444                                 continue;
3445                         case Q_TYPE_QH:
3446                                 hw = here.qh->hw;
3447                                 if (same_tt(dev, here.qh->dev)) {
3448                                         u32 mask;
3449 
3450                                         mask = hc32_to_cpu(fotg210,
3451                                                         hw->hw_info2);
3452                                         /* "knows" no gap is needed */
3453                                         mask |= mask >> 8;
3454                                         if (mask & uf_mask)
3455                                                 break;
3456                                 }
3457                                 type = Q_NEXT_TYPE(fotg210, hw->hw_next);
3458                                 here = here.qh->qh_next;
3459                                 continue;
3460                         /* case Q_TYPE_FSTN: */
3461                         default:
3462                                 fotg210_dbg(fotg210,
3463                                                 "periodic frame %d bogus type %d\n",
3464                                                 frame, type);
3465                         }
3466 
3467                         /* collision or error */
3468                         return 0;
3469                 }
3470         }
3471 
3472         /* no collision */
3473         return 1;
3474 }
3475 
3476 static void enable_periodic(struct fotg210_hcd *fotg210)
3477 {
3478         if (fotg210->periodic_count++)
3479                 return;
3480 
3481         /* Stop waiting to turn off the periodic schedule */
3482         fotg210->enabled_hrtimer_events &=
3483                 ~BIT(FOTG210_HRTIMER_DISABLE_PERIODIC);
3484 
3485         /* Don't start the schedule until PSS is 0 */
3486         fotg210_poll_PSS(fotg210);
3487         turn_on_io_watchdog(fotg210);
3488 }
3489 
3490 static void disable_periodic(struct fotg210_hcd *fotg210)
3491 {
3492         if (--fotg210->periodic_count)
3493                 return;
3494 
3495         /* Don't turn off the schedule until PSS is 1 */
3496         fotg210_poll_PSS(fotg210);
3497 }
3498 
3499 /* periodic schedule slots have iso tds (normal or split) first, then a
3500  * sparse tree for active interrupt transfers.
3501  *
3502  * this just links in a qh; caller guarantees uframe masks are set right.
3503  * no FSTN support (yet; fotg210 0.96+)
3504  */
3505 static void qh_link_periodic(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
3506 {
3507         unsigned i;
3508         unsigned period = qh->period;
3509 
3510         dev_dbg(&qh->dev->dev,
3511                         "link qh%d-%04x/%p start %d [%d/%d us]\n", period,
3512                         hc32_to_cpup(fotg210, &qh->hw->hw_info2) &
3513                         (QH_CMASK | QH_SMASK), qh, qh->start, qh->usecs,
3514                         qh->c_usecs);
3515 
3516         /* high bandwidth, or otherwise every microframe */
3517         if (period == 0)
3518                 period = 1;
3519 
3520         for (i = qh->start; i < fotg210->periodic_size; i += period) {
3521                 union fotg210_shadow *prev = &fotg210->pshadow[i];
3522                 __hc32 *hw_p = &fotg210->periodic[i];
3523                 union fotg210_shadow here = *prev;
3524                 __hc32 type = 0;
3525 
3526                 /* skip the iso nodes at list head */
3527                 while (here.ptr) {
3528                         type = Q_NEXT_TYPE(fotg210, *hw_p);
3529                         if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
3530                                 break;
3531                         prev = periodic_next_shadow(fotg210, prev, type);
3532                         hw_p = shadow_next_periodic(fotg210, &here, type);
3533                         here = *prev;
3534                 }
3535 
3536                 /* sorting each branch by period (slow-->fast)
3537                  * enables sharing interior tree nodes
3538                  */
3539                 while (here.ptr && qh != here.qh) {
3540                         if (qh->period > here.qh->period)
3541                                 break;
3542                         prev = &here.qh->qh_next;
3543                         hw_p = &here.qh->hw->hw_next;
3544                         here = *prev;
3545                 }
3546                 /* link in this qh, unless some earlier pass did that */
3547                 if (qh != here.qh) {
3548                         qh->qh_next = here;
3549                         if (here.qh)
3550                                 qh->hw->hw_next = *hw_p;
3551                         wmb();
3552                         prev->qh = qh;
3553                         *hw_p = QH_NEXT(fotg210, qh->qh_dma);
3554                 }
3555         }
3556         qh->qh_state = QH_STATE_LINKED;
3557         qh->xacterrs = 0;
3558 
3559         /* update per-qh bandwidth for usbfs */
3560         fotg210_to_hcd(fotg210)->self.bandwidth_allocated += qh->period
3561                 ? ((qh->usecs + qh->c_usecs) / qh->period)
3562                 : (qh->usecs * 8);
3563 
3564         list_add(&qh->intr_node, &fotg210->intr_qh_list);
3565 
3566         /* maybe enable periodic schedule processing */
3567         ++fotg210->intr_count;
3568         enable_periodic(fotg210);
3569 }
3570 
3571 static void qh_unlink_periodic(struct fotg210_hcd *fotg210,
3572                 struct fotg210_qh *qh)
3573 {
3574         unsigned i;
3575         unsigned period;
3576 
3577         /*
3578          * If qh is for a low/full-speed device, simply unlinking it
3579          * could interfere with an ongoing split transaction.  To unlink
3580          * it safely would require setting the QH_INACTIVATE bit and
3581          * waiting at least one frame, as described in EHCI 4.12.2.5.
3582          *
3583          * We won't bother with any of this.  Instead, we assume that the
3584          * only reason for unlinking an interrupt QH while the current URB
3585          * is still active is to dequeue all the URBs (flush the whole
3586          * endpoint queue).
3587          *
3588          * If rebalancing the periodic schedule is ever implemented, this
3589          * approach will no longer be valid.
3590          */
3591 
3592         /* high bandwidth, or otherwise part of every microframe */
3593         period = qh->period;
3594         if (!period)
3595                 period = 1;
3596 
3597         for (i = qh->start; i < fotg210->periodic_size; i += period)
3598                 periodic_unlink(fotg210, i, qh);
3599 
3600         /* update per-qh bandwidth for usbfs */
3601         fotg210_to_hcd(fotg210)->self.bandwidth_allocated -= qh->period
3602                 ? ((qh->usecs + qh->c_usecs) / qh->period)
3603                 : (qh->usecs * 8);
3604 
3605         dev_dbg(&qh->dev->dev,
3606                         "unlink qh%d-%04x/%p start %d [%d/%d us]\n",
3607                         qh->period, hc32_to_cpup(fotg210, &qh->hw->hw_info2) &
3608                         (QH_CMASK | QH_SMASK), qh, qh->start, qh->usecs,
3609                         qh->c_usecs);
3610 
3611         /* qh->qh_next still "live" to HC */
3612         qh->qh_state = QH_STATE_UNLINK;
3613         qh->qh_next.ptr = NULL;
3614 
3615         if (fotg210->qh_scan_next == qh)
3616                 fotg210->qh_scan_next = list_entry(qh->intr_node.next,
3617                                 struct fotg210_qh, intr_node);
3618         list_del(&qh->intr_node);
3619 }
3620 
3621 static void start_unlink_intr(struct fotg210_hcd *fotg210,
3622                 struct fotg210_qh *qh)
3623 {
3624         /* If the QH isn't linked then there's nothing we can do
3625          * unless we were called during a giveback, in which case
3626          * qh_completions() has to deal with it.
3627          */
3628         if (qh->qh_state != QH_STATE_LINKED) {
3629                 if (qh->qh_state == QH_STATE_COMPLETING)
3630                         qh->needs_rescan = 1;
3631                 return;
3632         }
3633 
3634         qh_unlink_periodic(fotg210, qh);
3635 
3636         /* Make sure the unlinks are visible before starting the timer */
3637         wmb();
3638 
3639         /*
3640          * The EHCI spec doesn't say how long it takes the controller to
3641          * stop accessing an unlinked interrupt QH.  The timer delay is
3642          * 9 uframes; presumably that will be long enough.
3643          */
3644         qh->unlink_cycle = fotg210->intr_unlink_cycle;
3645 
3646         /* New entries go at the end of the intr_unlink list */
3647         if (fotg210->intr_unlink)
3648                 fotg210->intr_unlink_last->unlink_next = qh;
3649         else
3650                 fotg210->intr_unlink = qh;
3651         fotg210->intr_unlink_last = qh;
3652 
3653         if (fotg210->intr_unlinking)
3654                 ;       /* Avoid recursive calls */
3655         else if (fotg210->rh_state < FOTG210_RH_RUNNING)
3656                 fotg210_handle_intr_unlinks(fotg210);
3657         else if (fotg210->intr_unlink == qh) {
3658                 fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
3659                                 true);
3660                 ++fotg210->intr_unlink_cycle;
3661         }
3662 }
3663 
3664 static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
3665 {
3666         struct fotg210_qh_hw *hw = qh->hw;
3667         int rc;
3668 
3669         qh->qh_state = QH_STATE_IDLE;
3670         hw->hw_next = FOTG210_LIST_END(fotg210);
3671 
3672         qh_completions(fotg210, qh);
3673 
3674         /* reschedule QH iff another request is queued */
3675         if (!list_empty(&qh->qtd_list) &&
3676                         fotg210->rh_state == FOTG210_RH_RUNNING) {
3677                 rc = qh_schedule(fotg210, qh);
3678 
3679                 /* An error here likely indicates handshake failure
3680                  * or no space left in the schedule.  Neither fault
3681                  * should happen often ...
3682                  *
3683                  * FIXME kill the now-dysfunctional queued urbs
3684                  */
3685                 if (rc != 0)
3686                         fotg210_err(fotg210, "can't reschedule qh %p, err %d\n",
3687                                         qh, rc);
3688         }
3689 
3690         /* maybe turn off periodic schedule */
3691         --fotg210->intr_count;
3692         disable_periodic(fotg210);
3693 }
3694 
3695 static int check_period(struct fotg210_hcd *fotg210, unsigned frame,
3696                 unsigned uframe, unsigned period, unsigned usecs)
3697 {
3698         int claimed;
3699 
3700         /* complete split running into next frame?
3701          * given FSTN support, we could sometimes check...
3702          */
3703         if (uframe >= 8)
3704                 return 0;
3705 
3706         /* convert "usecs we need" to "max already claimed" */
3707         usecs = fotg210->uframe_periodic_max - usecs;
3708 
3709         /* we "know" 2 and 4 uframe intervals were rejected; so
3710          * for period 0, check _every_ microframe in the schedule.
3711          */
3712         if (unlikely(period == 0)) {
3713                 do {
3714                         for (uframe = 0; uframe < 7; uframe++) {
3715                                 claimed = periodic_usecs(fotg210, frame,
3716                                                 uframe);
3717                                 if (claimed > usecs)
3718                                         return 0;
3719                         }
3720                 } while ((frame += 1) < fotg210->periodic_size);
3721 
3722         /* just check the specified uframe, at that period */
3723         } else {
3724                 do {
3725                         claimed = periodic_usecs(fotg210, frame, uframe);
3726                         if (claimed > usecs)
3727                                 return 0;
3728                 } while ((frame += period) < fotg210->periodic_size);
3729         }
3730 
3731         /* success! */
3732         return 1;
3733 }
3734 
3735 static int check_intr_schedule(struct fotg210_hcd *fotg210, unsigned frame,
3736                 unsigned uframe, const struct fotg210_qh *qh, __hc32 *c_maskp)
3737 {
3738         int retval = -ENOSPC;
3739         u8 mask = 0;
3740 
3741         if (qh->c_usecs && uframe >= 6)         /* FSTN territory? */
3742                 goto done;
3743 
3744         if (!check_period(fotg210, frame, uframe, qh->period, qh->usecs))
3745                 goto done;
3746         if (!qh->c_usecs) {
3747                 retval = 0;
3748                 *c_maskp = 0;
3749                 goto done;
3750         }
3751 
3752         /* Make sure this tt's buffer is also available for CSPLITs.
3753          * We pessimize a bit; probably the typical full speed case
3754          * doesn't need the second CSPLIT.
3755          *
3756          * NOTE:  both SPLIT and CSPLIT could be checked in just
3757          * one smart pass...
3758          */
3759         mask = 0x03 << (uframe + qh->gap_uf);
3760         *c_maskp = cpu_to_hc32(fotg210, mask << 8);
3761 
3762         mask |= 1 << uframe;
3763         if (tt_no_collision(fotg210, qh->period, qh->dev, frame, mask)) {
3764                 if (!check_period(fotg210, frame, uframe + qh->gap_uf + 1,
3765                                 qh->period, qh->c_usecs))
3766                         goto done;
3767                 if (!check_period(fotg210, frame, uframe + qh->gap_uf,
3768                                 qh->period, qh->c_usecs))
3769                         goto done;
3770                 retval = 0;
3771         }
3772 done:
3773         return retval;
3774 }
3775 
3776 /* "first fit" scheduling policy used the first time through,
3777  * or when the previous schedule slot can't be re-used.
3778  */
3779 static int qh_schedule(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
3780 {
3781         int status;
3782         unsigned uframe;
3783         __hc32 c_mask;
3784         unsigned frame; /* 0..(qh->period - 1), or NO_FRAME */
3785         struct fotg210_qh_hw *hw = qh->hw;
3786 
3787         qh_refresh(fotg210, qh);
3788         hw->hw_next = FOTG210_LIST_END(fotg210);
3789         frame = qh->start;
3790 
3791         /* reuse the previous schedule slots, if we can */
3792         if (frame < qh->period) {
3793                 uframe = ffs(hc32_to_cpup(fotg210, &hw->hw_info2) & QH_SMASK);
3794                 status = check_intr_schedule(fotg210, frame, --uframe,
3795                                 qh, &c_mask);
3796         } else {
3797                 uframe = 0;
3798                 c_mask = 0;
3799                 status = -ENOSPC;
3800         }
3801 
3802         /* else scan the schedule to find a group of slots such that all
3803          * uframes have enough periodic bandwidth available.
3804          */
3805         if (status) {
3806                 /* "normal" case, uframing flexible except with splits */
3807                 if (qh->period) {
3808                         int i;
3809 
3810                         for (i = qh->period; status && i > 0; --i) {
3811                                 frame = ++fotg210->random_frame % qh->period;
3812                                 for (uframe = 0; uframe < 8; uframe++) {
3813                                         status = check_intr_schedule(fotg210,
3814                                                         frame, uframe, qh,
3815                                                         &c_mask);
3816                                         if (status == 0)
3817                                                 break;
3818                                 }
3819                         }
3820 
3821                 /* qh->period == 0 means every uframe */
3822                 } else {
3823                         frame = 0;
3824                         status = check_intr_schedule(fotg210, 0, 0, qh,
3825                                         &c_mask);
3826                 }
3827                 if (status)
3828                         goto done;
3829                 qh->start = frame;
3830 
3831                 /* reset S-frame and (maybe) C-frame masks */
3832                 hw->hw_info2 &= cpu_to_hc32(fotg210, ~(QH_CMASK | QH_SMASK));
3833                 hw->hw_info2 |= qh->period
3834                         ? cpu_to_hc32(fotg210, 1 << uframe)
3835                         : cpu_to_hc32(fotg210, QH_SMASK);
3836                 hw->hw_info2 |= c_mask;
3837         } else
3838                 fotg210_dbg(fotg210, "reused qh %p schedule\n", qh);
3839 
3840         /* stuff into the periodic schedule */
3841         qh_link_periodic(fotg210, qh);
3842 done:
3843         return status;
3844 }
3845 
3846 static int intr_submit(struct fotg210_hcd *fotg210, struct urb *urb,
3847                 struct list_head *qtd_list, gfp_t mem_flags)
3848 {
3849         unsigned epnum;
3850         unsigned long flags;
3851         struct fotg210_qh *qh;
3852         int status;
3853         struct list_head empty;
3854 
3855         /* get endpoint and transfer/schedule data */
3856         epnum = urb->ep->desc.bEndpointAddress;
3857 
3858         spin_lock_irqsave(&fotg210->lock, flags);
3859 
3860         if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
3861                 status = -ESHUTDOWN;
3862                 goto done_not_linked;
3863         }
3864         status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
3865         if (unlikely(status))
3866                 goto done_not_linked;
3867 
3868         /* get qh and force any scheduling errors */
3869         INIT_LIST_HEAD(&empty);
3870         qh = qh_append_tds(fotg210, urb, &empty, epnum, &urb->ep->hcpriv);
3871         if (qh == NULL) {
3872                 status = -ENOMEM;
3873                 goto done;
3874         }
3875         if (qh->qh_state == QH_STATE_IDLE) {
3876                 status = qh_schedule(fotg210, qh);
3877                 if (status)
3878                         goto done;
3879         }
3880 
3881         /* then queue the urb's tds to the qh */
3882         qh = qh_append_tds(fotg210, urb, qtd_list, epnum, &urb->ep->hcpriv);
3883         BUG_ON(qh == NULL);
3884 
3885         /* ... update usbfs periodic stats */
3886         fotg210_to_hcd(fotg210)->self.bandwidth_int_reqs++;
3887 
3888 done:
3889         if (unlikely(status))
3890                 usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
3891 done_not_linked:
3892         spin_unlock_irqrestore(&fotg210->lock, flags);
3893         if (status)
3894                 qtd_list_free(fotg210, urb, qtd_list);
3895 
3896         return status;
3897 }
3898 
3899 static void scan_intr(struct fotg210_hcd *fotg210)
3900 {
3901         struct fotg210_qh *qh;
3902 
3903         list_for_each_entry_safe(qh, fotg210->qh_scan_next,
3904                         &fotg210->intr_qh_list, intr_node) {
3905 rescan:
3906                 /* clean any finished work for this qh */
3907                 if (!list_empty(&qh->qtd_list)) {
3908                         int temp;
3909 
3910                         /*
3911                          * Unlinks could happen here; completion reporting
3912                          * drops the lock.  That's why fotg210->qh_scan_next
3913                          * always holds the next qh to scan; if the next qh
3914                          * gets unlinked then fotg210->qh_scan_next is adjusted
3915                          * in qh_unlink_periodic().
3916                          */
3917                         temp = qh_completions(fotg210, qh);
3918                         if (unlikely(qh->needs_rescan ||
3919                                         (list_empty(&qh->qtd_list) &&
3920                                         qh->qh_state == QH_STATE_LINKED)))
3921                                 start_unlink_intr(fotg210, qh);
3922                         else if (temp != 0)
3923                                 goto rescan;
3924                 }
3925         }
3926 }
3927 
3928 /* fotg210_iso_stream ops work with both ITD and SITD */
3929 
3930 static struct fotg210_iso_stream *iso_stream_alloc(gfp_t mem_flags)
3931 {
3932         struct fotg210_iso_stream *stream;
3933 
3934         stream = kzalloc(sizeof(*stream), mem_flags);
3935         if (likely(stream != NULL)) {
3936                 INIT_LIST_HEAD(&stream->td_list);
3937                 INIT_LIST_HEAD(&stream->free_list);
3938                 stream->next_uframe = -1;
3939         }
3940         return stream;
3941 }
3942 
3943 static void iso_stream_init(struct fotg210_hcd *fotg210,
3944                 struct fotg210_iso_stream *stream, struct usb_device *dev,
3945                 int pipe, unsigned interval)
3946 {
3947         u32 buf1;
3948         unsigned epnum, maxp;
3949         int is_input;
3950         long bandwidth;
3951         unsigned multi;
3952 
3953         /*
3954          * this might be a "high bandwidth" highspeed endpoint,
3955          * as encoded in the ep descriptor's wMaxPacket field
3956          */
3957         epnum = usb_pipeendpoint(pipe);
3958         is_input = usb_pipein(pipe) ? USB_DIR_IN : 0;
3959         maxp = usb_maxpacket(dev, pipe, !is_input);
3960         if (is_input)
3961                 buf1 = (1 << 11);
3962         else
3963                 buf1 = 0;
3964 
3965         maxp = max_packet(maxp);
3966         multi = hb_mult(maxp);
3967         buf1 |= maxp;
3968         maxp *= multi;
3969 
3970         stream->buf0 = cpu_to_hc32(fotg210, (epnum << 8) | dev->devnum);
3971         stream->buf1 = cpu_to_hc32(fotg210, buf1);
3972         stream->buf2 = cpu_to_hc32(fotg210, multi);
3973 
3974         /* usbfs wants to report the average usecs per frame tied up
3975          * when transfers on this endpoint are scheduled ...
3976          */
3977         if (dev->speed == USB_SPEED_FULL) {
3978                 interval <<= 3;
3979                 stream->usecs = NS_TO_US(usb_calc_bus_time(dev->speed,
3980                                 is_input, 1, maxp));
3981                 stream->usecs /= 8;
3982         } else {
3983                 stream->highspeed = 1;
3984                 stream->usecs = HS_USECS_ISO(maxp);
3985         }
3986         bandwidth = stream->usecs * 8;
3987         bandwidth /= interval;
3988 
3989         stream->bandwidth = bandwidth;
3990         stream->udev = dev;
3991         stream->bEndpointAddress = is_input | epnum;
3992         stream->interval = interval;
3993         stream->maxp = maxp;
3994 }
3995 
3996 static struct fotg210_iso_stream *iso_stream_find(struct fotg210_hcd *fotg210,
3997                 struct urb *urb)
3998 {
3999         unsigned epnum;
4000         struct fotg210_iso_stream *stream;
4001         struct usb_host_endpoint *ep;
4002         unsigned long flags;
4003 
4004         epnum = usb_pipeendpoint(urb->pipe);
4005         if (usb_pipein(urb->pipe))
4006                 ep = urb->dev->ep_in[epnum];
4007         else
4008                 ep = urb->dev->ep_out[epnum];
4009 
4010         spin_lock_irqsave(&fotg210->lock, flags);
4011         stream = ep->hcpriv;
4012 
4013         if (unlikely(stream == NULL)) {
4014                 stream = iso_stream_alloc(GFP_ATOMIC);
4015                 if (likely(stream != NULL)) {
4016                         ep->hcpriv = stream;
4017                         stream->ep = ep;
4018                         iso_stream_init(fotg210, stream, urb->dev, urb->pipe,
4019                                         urb->interval);
4020                 }
4021 
4022         /* if dev->ep[epnum] is a QH, hw is set */
4023         } else if (unlikely(stream->hw != NULL)) {
4024                 fotg210_dbg(fotg210, "dev %s ep%d%s, not iso??\n",
4025                                 urb->dev->devpath, epnum,
4026                                 usb_pipein(urb->pipe) ? "in" : "out");
4027                 stream = NULL;
4028         }
4029 
4030         spin_unlock_irqrestore(&fotg210->lock, flags);
4031         return stream;
4032 }
4033 
4034 /* fotg210_iso_sched ops can be ITD-only or SITD-only */
4035 
4036 static struct fotg210_iso_sched *iso_sched_alloc(unsigned packets,
4037                 gfp_t mem_flags)
4038 {
4039         struct fotg210_iso_sched *iso_sched;
4040         int size = sizeof(*iso_sched);
4041 
4042         size += packets * sizeof(struct fotg210_iso_packet);
4043         iso_sched = kzalloc(size, mem_flags);
4044         if (likely(iso_sched != NULL))
4045                 INIT_LIST_HEAD(&iso_sched->td_list);
4046 
4047         return iso_sched;
4048 }
4049 
4050 static inline void itd_sched_init(struct fotg210_hcd *fotg210,
4051                 struct fotg210_iso_sched *iso_sched,
4052                 struct fotg210_iso_stream *stream, struct urb *urb)
4053 {
4054         unsigned i;
4055         dma_addr_t dma = urb->transfer_dma;
4056 
4057         /* how many uframes are needed for these transfers */
4058         iso_sched->span = urb->number_of_packets * stream->interval;
4059 
4060         /* figure out per-uframe itd fields that we'll need later
4061          * when we fit new itds into the schedule.
4062          */
4063         for (i = 0; i < urb->number_of_packets; i++) {
4064                 struct fotg210_iso_packet *uframe = &iso_sched->packet[i];
4065                 unsigned length;
4066                 dma_addr_t buf;
4067                 u32 trans;
4068 
4069                 length = urb->iso_frame_desc[i].length;
4070                 buf = dma + urb->iso_frame_desc[i].offset;
4071 
4072                 trans = FOTG210_ISOC_ACTIVE;
4073                 trans |= buf & 0x0fff;
4074                 if (unlikely(((i + 1) == urb->number_of_packets))
4075                                 && !(urb->transfer_flags & URB_NO_INTERRUPT))
4076                         trans |= FOTG210_ITD_IOC;
4077                 trans |= length << 16;
4078                 uframe->transaction = cpu_to_hc32(fotg210, trans);
4079 
4080                 /* might need to cross a buffer page within a uframe */
4081                 uframe->bufp = (buf & ~(u64)0x0fff);
4082                 buf += length;
4083                 if (unlikely((uframe->bufp != (buf & ~(u64)0x0fff))))
4084                         uframe->cross = 1;
4085         }
4086 }
4087 
4088 static void iso_sched_free(struct fotg210_iso_stream *stream,
4089                 struct fotg210_iso_sched *iso_sched)
4090 {
4091         if (!iso_sched)
4092                 return;
4093         /* caller must hold fotg210->lock!*/
4094         list_splice(&iso_sched->td_list, &stream->free_list);
4095         kfree(iso_sched);
4096 }
4097 
4098 static int itd_urb_transaction(struct fotg210_iso_stream *stream,
4099                 struct fotg210_hcd *fotg210, struct urb *urb, gfp_t mem_flags)
4100 {
4101         struct fotg210_itd *itd;
4102         dma_addr_t itd_dma;
4103         int i;
4104         unsigned num_itds;
4105         struct fotg210_iso_sched *sched;
4106         unsigned long flags;
4107 
4108         sched = iso_sched_alloc(urb->number_of_packets, mem_flags);
4109         if (unlikely(sched == NULL))
4110                 return -ENOMEM;
4111 
4112         itd_sched_init(fotg210, sched, stream, urb);
4113 
4114         if (urb->interval < 8)
4115                 num_itds = 1 + (sched->span + 7) / 8;
4116         else
4117                 num_itds = urb->number_of_packets;
4118 
4119         /* allocate/init ITDs */
4120         spin_lock_irqsave(&fotg210->lock, flags);
4121         for (i = 0; i < num_itds; i++) {
4122 
4123                 /*
4124                  * Use iTDs from the free list, but not iTDs that may
4125                  * still be in use by the hardware.
4126                  */
4127                 if (likely(!list_empty(&stream->free_list))) {
4128                         itd = list_first_entry(&stream->free_list,
4129                                         struct fotg210_itd, itd_list);
4130                         if (itd->frame == fotg210->now_frame)
4131                                 goto alloc_itd;
4132                         list_del(&itd->itd_list);
4133                         itd_dma = itd->itd_dma;
4134                 } else {
4135 alloc_itd:
4136                         spin_unlock_irqrestore(&fotg210->lock, flags);
4137                         itd = dma_pool_alloc(fotg210->itd_pool, mem_flags,
4138                                         &itd_dma);
4139                         spin_lock_irqsave(&fotg210->lock, flags);
4140                         if (!itd) {
4141                                 iso_sched_free(stream, sched);
4142                                 spin_unlock_irqrestore(&fotg210->lock, flags);
4143                                 return -ENOMEM;
4144                         }
4145                 }
4146 
4147                 memset(itd, 0, sizeof(*itd));
4148                 itd->itd_dma = itd_dma;
4149                 list_add(&itd->itd_list, &sched->td_list);
4150         }
4151         spin_unlock_irqrestore(&fotg210->lock, flags);
4152 
4153         /* temporarily store schedule info in hcpriv */
4154         urb->hcpriv = sched;
4155         urb->error_count = 0;
4156         return 0;
4157 }
4158 
4159 static inline int itd_slot_ok(struct fotg210_hcd *fotg210, u32 mod, u32 uframe,
4160                 u8 usecs, u32 period)
4161 {
4162         uframe %= period;
4163         do {
4164                 /* can't commit more than uframe_periodic_max usec */
4165                 if (periodic_usecs(fotg210, uframe >> 3, uframe & 0x7)
4166                                 > (fotg210->uframe_periodic_max - usecs))
4167                         return 0;
4168 
4169                 /* we know urb->interval is 2^N uframes */
4170                 uframe += period;
4171         } while (uframe < mod);
4172         return 1;
4173 }
4174 
4175 /* This scheduler plans almost as far into the future as it has actual
4176  * periodic schedule slots.  (Affected by TUNE_FLS, which defaults to
4177  * "as small as possible" to be cache-friendlier.)  That limits the size
4178  * transfers you can stream reliably; avoid more than 64 msec per urb.
4179  * Also avoid queue depths of less than fotg210's worst irq latency (affected
4180  * by the per-urb URB_NO_INTERRUPT hint, the log2_irq_thresh module parameter,
4181  * and other factors); or more than about 230 msec total (for portability,
4182  * given FOTG210_TUNE_FLS and the slop).  Or, write a smarter scheduler!
4183  */
4184 
4185 #define SCHEDULE_SLOP 80 /* microframes */
4186 
4187 static int iso_stream_schedule(struct fotg210_hcd *fotg210, struct urb *urb,
4188                 struct fotg210_iso_stream *stream)
4189 {
4190         u32 now, next, start, period, span;
4191         int status;
4192         unsigned mod = fotg210->periodic_size << 3;
4193         struct fotg210_iso_sched *sched = urb->hcpriv;
4194 
4195         period = urb->interval;
4196         span = sched->span;
4197 
4198         if (span > mod - SCHEDULE_SLOP) {
4199                 fotg210_dbg(fotg210, "iso request %p too long\n", urb);
4200                 status = -EFBIG;
4201                 goto fail;
4202         }
4203 
4204         now = fotg210_read_frame_index(fotg210) & (mod - 1);
4205 
4206         /* Typical case: reuse current schedule, stream is still active.
4207          * Hopefully there are no gaps from the host falling behind
4208          * (irq delays etc), but if there are we'll take the next
4209          * slot in the schedule, implicitly assuming URB_ISO_ASAP.
4210          */
4211         if (likely(!list_empty(&stream->td_list))) {
4212                 u32 excess;
4213 
4214                 /* For high speed devices, allow scheduling within the
4215                  * isochronous scheduling threshold.  For full speed devices
4216                  * and Intel PCI-based controllers, don't (work around for
4217                  * Intel ICH9 bug).
4218                  */
4219                 if (!stream->highspeed && fotg210->fs_i_thresh)
4220                         next = now + fotg210->i_thresh;
4221                 else
4222                         next = now;
4223 
4224                 /* Fell behind (by up to twice the slop amount)?
4225                  * We decide based on the time of the last currently-scheduled
4226                  * slot, not the time of the next available slot.
4227                  */
4228                 excess = (stream->next_uframe - period - next) & (mod - 1);
4229                 if (excess >= mod - 2 * SCHEDULE_SLOP)
4230                         start = next + excess - mod + period *
4231                                         DIV_ROUND_UP(mod - excess, period);
4232                 else
4233                         start = next + excess + period;
4234                 if (start - now >= mod) {
4235                         fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
4236                                         urb, start - now - period, period,
4237                                         mod);
4238                         status = -EFBIG;
4239                         goto fail;
4240                 }
4241         }
4242 
4243         /* need to schedule; when's the next (u)frame we could start?
4244          * this is bigger than fotg210->i_thresh allows; scheduling itself
4245          * isn't free, the slop should handle reasonably slow cpus.  it
4246          * can also help high bandwidth if the dma and irq loads don't
4247          * jump until after the queue is primed.
4248          */
4249         else {
4250                 int done = 0;
4251 
4252                 start = SCHEDULE_SLOP + (now & ~0x07);
4253 
4254                 /* NOTE:  assumes URB_ISO_ASAP, to limit complexity/bugs */
4255 
4256                 /* find a uframe slot with enough bandwidth.
4257                  * Early uframes are more precious because full-speed
4258                  * iso IN transfers can't use late uframes,
4259                  * and therefore they should be allocated last.
4260                  */
4261                 next = start;
4262                 start += period;
4263                 do {
4264                         start--;
4265                         /* check schedule: enough space? */
4266                         if (itd_slot_ok(fotg210, mod, start,
4267                                         stream->usecs, period))
4268                                 done = 1;
4269                 } while (start > next && !done);
4270 
4271                 /* no room in the schedule */
4272                 if (!done) {
4273                         fotg210_dbg(fotg210, "iso resched full %p (now %d max %d)\n",
4274                                         urb, now, now + mod);
4275                         status = -ENOSPC;
4276                         goto fail;
4277                 }
4278         }
4279 
4280         /* Tried to schedule too far into the future? */
4281         if (unlikely(start - now + span - period >=
4282                         mod - 2 * SCHEDULE_SLOP)) {
4283                 fotg210_dbg(fotg210, "request %p would overflow (%d+%d >= %d)\n",
4284                                 urb, start - now, span - period,
4285                                 mod - 2 * SCHEDULE_SLOP);
4286                 status = -EFBIG;
4287                 goto fail;
4288         }
4289 
4290         stream->next_uframe = start & (mod - 1);
4291 
4292         /* report high speed start in uframes; full speed, in frames */
4293         urb->start_frame = stream->next_uframe;
4294         if (!stream->highspeed)
4295                 urb->start_frame >>= 3;
4296 
4297         /* Make sure scan_isoc() sees these */
4298         if (fotg210->isoc_count == 0)
4299                 fotg210->next_frame = now >> 3;
4300         return 0;
4301 
4302 fail:
4303         iso_sched_free(stream, sched);
4304         urb->hcpriv = NULL;
4305         return status;
4306 }
4307 
4308 static inline void itd_init(struct fotg210_hcd *fotg210,
4309                 struct fotg210_iso_stream *stream, struct fotg210_itd *itd)
4310 {
4311         int i;
4312 
4313         /* it's been recently zeroed */
4314         itd->hw_next = FOTG210_LIST_END(fotg210);
4315         itd->hw_bufp[0] = stream->buf0;
4316         itd->hw_bufp[1] = stream->buf1;
4317         itd->hw_bufp[2] = stream->buf2;
4318 
4319         for (i = 0; i < 8; i++)
4320                 itd->index[i] = -1;
4321 
4322         /* All other fields are filled when scheduling */
4323 }
4324 
4325 static inline void itd_patch(struct fotg210_hcd *fotg210,
4326                 struct fotg210_itd *itd, struct fotg210_iso_sched *iso_sched,
4327                 unsigned index, u16 uframe)
4328 {
4329         struct fotg210_iso_packet *uf = &iso_sched->packet[index];
4330         unsigned pg = itd->pg;
4331 
4332         uframe &= 0x07;
4333         itd->index[uframe] = index;
4334 
4335         itd->hw_transaction[uframe] = uf->transaction;
4336         itd->hw_transaction[uframe] |= cpu_to_hc32(fotg210, pg << 12);
4337         itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, uf->bufp & ~(u32)0);
4338         itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(uf->bufp >> 32));
4339 
4340         /* iso_frame_desc[].offset must be strictly increasing */
4341         if (unlikely(uf->cross)) {
4342                 u64 bufp = uf->bufp + 4096;
4343 
4344                 itd->pg = ++pg;
4345                 itd->hw_bufp[pg] |= cpu_to_hc32(fotg210, bufp & ~(u32)0);
4346                 itd->hw_bufp_hi[pg] |= cpu_to_hc32(fotg210, (u32)(bufp >> 32));
4347         }
4348 }
4349 
4350 static inline void itd_link(struct fotg210_hcd *fotg210, unsigned frame,
4351                 struct fotg210_itd *itd)
4352 {
4353         union fotg210_shadow *prev = &fotg210->pshadow[frame];
4354         __hc32 *hw_p = &fotg210->periodic[frame];
4355         union fotg210_shadow here = *prev;
4356         __hc32 type = 0;
4357 
4358         /* skip any iso nodes which might belong to previous microframes */
4359         while (here.ptr) {
4360                 type = Q_NEXT_TYPE(fotg210, *hw_p);
4361                 if (type == cpu_to_hc32(fotg210, Q_TYPE_QH))
4362                         break;
4363                 prev = periodic_next_shadow(fotg210, prev, type);
4364                 hw_p = shadow_next_periodic(fotg210, &here, type);
4365                 here = *prev;
4366         }
4367 
4368         itd->itd_next = here;
4369         itd->hw_next = *hw_p;
4370         prev->itd = itd;
4371         itd->frame = frame;
4372         wmb();
4373         *hw_p = cpu_to_hc32(fotg210, itd->itd_dma | Q_TYPE_ITD);
4374 }
4375 
4376 /* fit urb's itds into the selected schedule slot; activate as needed */
4377 static void itd_link_urb(struct fotg210_hcd *fotg210, struct urb *urb,
4378                 unsigned mod, struct fotg210_iso_stream *stream)
4379 {
4380         int packet;
4381         unsigned next_uframe, uframe, frame;
4382         struct fotg210_iso_sched *iso_sched = urb->hcpriv;
4383         struct fotg210_itd *itd;
4384 
4385         next_uframe = stream->next_uframe & (mod - 1);
4386 
4387         if (unlikely(list_empty(&stream->td_list))) {
4388                 fotg210_to_hcd(fotg210)->self.bandwidth_allocated
4389                                 += stream->bandwidth;
4390                 fotg210_dbg(fotg210,
4391                         "schedule devp %s ep%d%s-iso period %d start %d.%d\n",
4392                         urb->dev->devpath, stream->bEndpointAddress & 0x0f,
4393                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out",
4394                         urb->interval,
4395                         next_uframe >> 3, next_uframe & 0x7);
4396         }
4397 
4398         /* fill iTDs uframe by uframe */
4399         for (packet = 0, itd = NULL; packet < urb->number_of_packets;) {
4400                 if (itd == NULL) {
4401                         /* ASSERT:  we have all necessary itds */
4402 
4403                         /* ASSERT:  no itds for this endpoint in this uframe */
4404 
4405                         itd = list_entry(iso_sched->td_list.next,
4406                                         struct fotg210_itd, itd_list);
4407                         list_move_tail(&itd->itd_list, &stream->td_list);
4408                         itd->stream = stream;
4409                         itd->urb = urb;
4410                         itd_init(fotg210, stream, itd);
4411                 }
4412 
4413                 uframe = next_uframe & 0x07;
4414                 frame = next_uframe >> 3;
4415 
4416                 itd_patch(fotg210, itd, iso_sched, packet, uframe);
4417 
4418                 next_uframe += stream->interval;
4419                 next_uframe &= mod - 1;
4420                 packet++;
4421 
4422                 /* link completed itds into the schedule */
4423                 if (((next_uframe >> 3) != frame)
4424                                 || packet == urb->number_of_packets) {
4425                         itd_link(fotg210, frame & (fotg210->periodic_size - 1),
4426                                         itd);
4427                         itd = NULL;
4428                 }
4429         }
4430         stream->next_uframe = next_uframe;
4431 
4432         /* don't need that schedule data any more */
4433         iso_sched_free(stream, iso_sched);
4434         urb->hcpriv = NULL;
4435 
4436         ++fotg210->isoc_count;
4437         enable_periodic(fotg210);
4438 }
4439 
4440 #define ISO_ERRS (FOTG210_ISOC_BUF_ERR | FOTG210_ISOC_BABBLE |\
4441                 FOTG210_ISOC_XACTERR)
4442 
4443 /* Process and recycle a completed ITD.  Return true iff its urb completed,
4444  * and hence its completion callback probably added things to the hardware
4445  * schedule.
4446  *
4447  * Note that we carefully avoid recycling this descriptor until after any
4448  * completion callback runs, so that it won't be reused quickly.  That is,
4449  * assuming (a) no more than two urbs per frame on this endpoint, and also
4450  * (b) only this endpoint's completions submit URBs.  It seems some silicon
4451  * corrupts things if you reuse completed descriptors very quickly...
4452  */
4453 static bool itd_complete(struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
4454 {
4455         struct urb *urb = itd->urb;
4456         struct usb_iso_packet_descriptor *desc;
4457         u32 t;
4458         unsigned uframe;
4459         int urb_index = -1;
4460         struct fotg210_iso_stream *stream = itd->stream;
4461         struct usb_device *dev;
4462         bool retval = false;
4463 
4464         /* for each uframe with a packet */
4465         for (uframe = 0; uframe < 8; uframe++) {
4466                 if (likely(itd->index[uframe] == -1))
4467                         continue;
4468                 urb_index = itd->index[uframe];
4469                 desc = &urb->iso_frame_desc[urb_index];
4470 
4471                 t = hc32_to_cpup(fotg210, &itd->hw_transaction[uframe]);
4472                 itd->hw_transaction[uframe] = 0;
4473 
4474                 /* report transfer status */
4475                 if (unlikely(t & ISO_ERRS)) {
4476                         urb->error_count++;
4477                         if (t & FOTG210_ISOC_BUF_ERR)
4478                                 desc->status = usb_pipein(urb->pipe)
4479                                         ? -ENOSR  /* hc couldn't read */
4480                                         : -ECOMM; /* hc couldn't write */
4481                         else if (t & FOTG210_ISOC_BABBLE)
4482                                 desc->status = -EOVERFLOW;
4483                         else /* (t & FOTG210_ISOC_XACTERR) */
4484                                 desc->status = -EPROTO;
4485 
4486                         /* HC need not update length with this error */
4487                         if (!(t & FOTG210_ISOC_BABBLE)) {
4488                                 desc->actual_length =
4489                                         fotg210_itdlen(urb, desc, t);
4490                                 urb->actual_length += desc->actual_length;
4491                         }
4492                 } else if (likely((t & FOTG210_ISOC_ACTIVE) == 0)) {
4493                         desc->status = 0;
4494                         desc->actual_length = fotg210_itdlen(urb, desc, t);
4495                         urb->actual_length += desc->actual_length;
4496                 } else {
4497                         /* URB was too late */
4498                         desc->status = -EXDEV;
4499                 }
4500         }
4501 
4502         /* handle completion now? */
4503         if (likely((urb_index + 1) != urb->number_of_packets))
4504                 goto done;
4505 
4506         /* ASSERT: it's really the last itd for this urb
4507          * list_for_each_entry (itd, &stream->td_list, itd_list)
4508          *      BUG_ON (itd->urb == urb);
4509          */
4510 
4511         /* give urb back to the driver; completion often (re)submits */
4512         dev = urb->dev;
4513         fotg210_urb_done(fotg210, urb, 0);
4514         retval = true;
4515         urb = NULL;
4516 
4517         --fotg210->isoc_count;
4518         disable_periodic(fotg210);
4519 
4520         if (unlikely(list_is_singular(&stream->td_list))) {
4521                 fotg210_to_hcd(fotg210)->self.bandwidth_allocated
4522                                 -= stream->bandwidth;
4523                 fotg210_dbg(fotg210,
4524                         "deschedule devp %s ep%d%s-iso\n",
4525                         dev->devpath, stream->bEndpointAddress & 0x0f,
4526                         (stream->bEndpointAddress & USB_DIR_IN) ? "in" : "out");
4527         }
4528 
4529 done:
4530         itd->urb = NULL;
4531 
4532         /* Add to the end of the free list for later reuse */
4533         list_move_tail(&itd->itd_list, &stream->free_list);
4534 
4535         /* Recycle the iTDs when the pipeline is empty (ep no longer in use) */
4536         if (list_empty(&stream->td_list)) {
4537                 list_splice_tail_init(&stream->free_list,
4538                                 &fotg210->cached_itd_list);
4539                 start_free_itds(fotg210);
4540         }
4541 
4542         return retval;
4543 }
4544 
4545 static int itd_submit(struct fotg210_hcd *fotg210, struct urb *urb,
4546                 gfp_t mem_flags)
4547 {
4548         int status = -EINVAL;
4549         unsigned long flags;
4550         struct fotg210_iso_stream *stream;
4551 
4552         /* Get iso_stream head */
4553         stream = iso_stream_find(fotg210, urb);
4554         if (unlikely(stream == NULL)) {
4555                 fotg210_dbg(fotg210, "can't get iso stream\n");
4556                 return -ENOMEM;
4557         }
4558         if (unlikely(urb->interval != stream->interval &&
4559                         fotg210_port_speed(fotg210, 0) ==
4560                         USB_PORT_STAT_HIGH_SPEED)) {
4561                 fotg210_dbg(fotg210, "can't change iso interval %d --> %d\n",
4562                                 stream->interval, urb->interval);
4563                 goto done;
4564         }
4565 
4566 #ifdef FOTG210_URB_TRACE
4567         fotg210_dbg(fotg210,
4568                         "%s %s urb %p ep%d%s len %d, %d pkts %d uframes[%p]\n",
4569                         __func__, urb->dev->devpath, urb,
4570                         usb_pipeendpoint(urb->pipe),
4571                         usb_pipein(urb->pipe) ? "in" : "out",
4572                         urb->transfer_buffer_length,
4573                         urb->number_of_packets, urb->interval,
4574                         stream);
4575 #endif
4576 
4577         /* allocate ITDs w/o locking anything */
4578         status = itd_urb_transaction(stream, fotg210, urb, mem_flags);
4579         if (unlikely(status < 0)) {
4580                 fotg210_dbg(fotg210, "can't init itds\n");
4581                 goto done;
4582         }
4583 
4584         /* schedule ... need to lock */
4585         spin_lock_irqsave(&fotg210->lock, flags);
4586         if (unlikely(!HCD_HW_ACCESSIBLE(fotg210_to_hcd(fotg210)))) {
4587                 status = -ESHUTDOWN;
4588                 goto done_not_linked;
4589         }
4590         status = usb_hcd_link_urb_to_ep(fotg210_to_hcd(fotg210), urb);
4591         if (unlikely(status))
4592                 goto done_not_linked;
4593         status = iso_stream_schedule(fotg210, urb, stream);
4594         if (likely(status == 0))
4595                 itd_link_urb(fotg210, urb, fotg210->periodic_size << 3, stream);
4596         else
4597                 usb_hcd_unlink_urb_from_ep(fotg210_to_hcd(fotg210), urb);
4598 done_not_linked:
4599         spin_unlock_irqrestore(&fotg210->lock, flags);
4600 done:
4601         return status;
4602 }
4603 
4604 static inline int scan_frame_queue(struct fotg210_hcd *fotg210, unsigned frame,
4605                 unsigned now_frame, bool live)
4606 {
4607         unsigned uf;
4608         bool modified;
4609         union fotg210_shadow q, *q_p;
4610         __hc32 type, *hw_p;
4611 
4612         /* scan each element in frame's queue for completions */
4613         q_p = &fotg210->pshadow[frame];
4614         hw_p = &fotg210->periodic[frame];
4615         q.ptr = q_p->ptr;
4616         type = Q_NEXT_TYPE(fotg210, *hw_p);
4617         modified = false;
4618 
4619         while (q.ptr) {
4620                 switch (hc32_to_cpu(fotg210, type)) {
4621                 case Q_TYPE_ITD:
4622                         /* If this ITD is still active, leave it for
4623                          * later processing ... check the next entry.
4624                          * No need to check for activity unless the
4625                          * frame is current.
4626                          */
4627                         if (frame == now_frame && live) {
4628                                 rmb();
4629                                 for (uf = 0; uf < 8; uf++) {
4630                                         if (q.itd->hw_transaction[uf] &
4631                                                         ITD_ACTIVE(fotg210))
4632                                                 break;
4633                                 }
4634                                 if (uf < 8) {
4635                                         q_p = &q.itd->itd_next;
4636                                         hw_p = &q.itd->hw_next;
4637                                         type = Q_NEXT_TYPE(fotg210,
4638                                                         q.itd->hw_next);
4639                                         q = *q_p;
4640                                         break;
4641                                 }
4642                         }
4643 
4644                         /* Take finished ITDs out of the schedule
4645                          * and process them:  recycle, maybe report
4646                          * URB completion.  HC won't cache the
4647                          * pointer for much longer, if at all.
4648                          */
4649                         *q_p = q.itd->itd_next;
4650                         *hw_p = q.itd->hw_next;
4651                         type = Q_NEXT_TYPE(fotg210, q.itd->hw_next);
4652                         wmb();
4653                         modified = itd_complete(fotg210, q.itd);
4654                         q = *q_p;
4655                         break;
4656                 default:
4657                         fotg210_dbg(fotg210, "corrupt type %d frame %d shadow %p\n",
4658                                         type, frame, q.ptr);
4659                         /* FALL THROUGH */
4660                 case Q_TYPE_QH:
4661                 case Q_TYPE_FSTN:
4662                         /* End of the iTDs and siTDs */
4663                         q.ptr = NULL;
4664                         break;
4665                 }
4666 
4667                 /* assume completion callbacks modify the queue */
4668                 if (unlikely(modified && fotg210->isoc_count > 0))
4669                         return -EINVAL;
4670         }
4671         return 0;
4672 }
4673 
4674 static void scan_isoc(struct fotg210_hcd *fotg210)
4675 {
4676         unsigned uf, now_frame, frame, ret;
4677         unsigned fmask = fotg210->periodic_size - 1;
4678         bool live;
4679 
4680         /*
4681          * When running, scan from last scan point up to "now"
4682          * else clean up by scanning everything that's left.
4683          * Touches as few pages as possible:  cache-friendly.
4684          */
4685         if (fotg210->rh_state >= FOTG210_RH_RUNNING) {
4686                 uf = fotg210_read_frame_index(fotg210);
4687                 now_frame = (uf >> 3) & fmask;
4688                 live = true;
4689         } else  {
4690                 now_frame = (fotg210->next_frame - 1) & fmask;
4691                 live = false;
4692         }
4693         fotg210->now_frame = now_frame;
4694 
4695         frame = fotg210->next_frame;
4696         for (;;) {
4697                 ret = 1;
4698                 while (ret != 0)
4699                         ret = scan_frame_queue(fotg210, frame,
4700                                         now_frame, live);
4701 
4702                 /* Stop when we have reached the current frame */
4703                 if (frame == now_frame)
4704                         break;
4705                 frame = (frame + 1) & fmask;
4706         }
4707         fotg210->next_frame = now_frame;
4708 }
4709 
4710 /* Display / Set uframe_periodic_max
4711  */
4712 static ssize_t show_uframe_periodic_max(struct device *dev,
4713                 struct device_attribute *attr, char *buf)
4714 {
4715         struct fotg210_hcd *fotg210;
4716         int n;
4717 
4718         fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
4719         n = scnprintf(buf, PAGE_SIZE, "%d\n", fotg210->uframe_periodic_max);
4720         return n;
4721 }
4722 
4723 
4724 static ssize_t store_uframe_periodic_max(struct device *dev,
4725                 struct device_attribute *attr, const char *buf, size_t count)
4726 {
4727         struct fotg210_hcd *fotg210;
4728         unsigned uframe_periodic_max;
4729         unsigned frame, uframe;
4730         unsigned short allocated_max;
4731         unsigned long flags;
4732         ssize_t ret;
4733 
4734         fotg210 = hcd_to_fotg210(bus_to_hcd(dev_get_drvdata(dev)));
4735         if (kstrtouint(buf, 0, &uframe_periodic_max) < 0)
4736                 return -EINVAL;
4737 
4738         if (uframe_periodic_max < 100 || uframe_periodic_max >= 125) {
4739                 fotg210_info(fotg210, "rejecting invalid request for uframe_periodic_max=%u\n",
4740                                 uframe_periodic_max);
4741                 return -EINVAL;
4742         }
4743 
4744         ret = -EINVAL;
4745 
4746         /*
4747          * lock, so that our checking does not race with possible periodic
4748          * bandwidth allocation through submitting new urbs.
4749          */
4750         spin_lock_irqsave(&fotg210->lock, flags);
4751 
4752         /*
4753          * for request to decrease max periodic bandwidth, we have to check
4754          * every microframe in the schedule to see whether the decrease is
4755          * possible.
4756          */
4757         if (uframe_periodic_max < fotg210->uframe_periodic_max) {
4758                 allocated_max = 0;
4759 
4760                 for (frame = 0; frame < fotg210->periodic_size; ++frame)
4761                         for (uframe = 0; uframe < 7; ++uframe)
4762                                 allocated_max = max(allocated_max,
4763                                                 periodic_usecs(fotg210, frame,
4764                                                 uframe));
4765 
4766                 if (allocated_max > uframe_periodic_max) {
4767                         fotg210_info(fotg210,
4768                                         "cannot decrease uframe_periodic_max because periodic bandwidth is already allocated (%u > %u)\n",
4769                                         allocated_max, uframe_periodic_max);
4770                         goto out_unlock;
4771                 }
4772         }
4773 
4774         /* increasing is always ok */
4775 
4776         fotg210_info(fotg210,
4777                         "setting max periodic bandwidth to %u%% (== %u usec/uframe)\n",
4778                         100 * uframe_periodic_max/125, uframe_periodic_max);
4779 
4780         if (uframe_periodic_max != 100)
4781                 fotg210_warn(fotg210, "max periodic bandwidth set is non-standard\n");
4782 
4783         fotg210->uframe_periodic_max = uframe_periodic_max;
4784         ret = count;
4785 
4786 out_unlock:
4787         spin_unlock_irqrestore(&fotg210->lock, flags);
4788         return ret;
4789 }
4790 
4791 static DEVICE_ATTR(uframe_periodic_max, 0644, show_uframe_periodic_max,
4792                    store_uframe_periodic_max);
4793 
4794 static inline int create_sysfs_files(struct fotg210_hcd *fotg210)
4795 {
4796         struct device *controller = fotg210_to_hcd(fotg210)->self.controller;
4797 
4798         return device_create_file(controller, &dev_attr_uframe_periodic_max);
4799 }
4800 
4801 static inline void remove_sysfs_files(struct fotg210_hcd *fotg210)
4802 {
4803         struct device *controller = fotg210_to_hcd(fotg210)->self.controller;
4804 
4805         device_remove_file(controller, &dev_attr_uframe_periodic_max);
4806 }
4807 /* On some systems, leaving remote wakeup enabled prevents system shutdown.
4808  * The firmware seems to think that powering off is a wakeup event!
4809  * This routine turns off remote wakeup and everything else, on all ports.
4810  */
4811 static void fotg210_turn_off_all_ports(struct fotg210_hcd *fotg210)
4812 {
4813         u32 __iomem *status_reg = &fotg210->regs->port_status;
4814 
4815         fotg210_writel(fotg210, PORT_RWC_BITS, status_reg);
4816 }
4817 
4818 /* Halt HC, turn off all ports, and let the BIOS use the companion controllers.
4819  * Must be called with interrupts enabled and the lock not held.
4820  */
4821 static void fotg210_silence_controller(struct fotg210_hcd *fotg210)
4822 {
4823         fotg210_halt(fotg210);
4824 
4825         spin_lock_irq(&fotg210->lock);
4826         fotg210->rh_state = FOTG210_RH_HALTED;
4827         fotg210_turn_off_all_ports(fotg210);
4828         spin_unlock_irq(&fotg210->lock);
4829 }
4830 
4831 /* fotg210_shutdown kick in for silicon on any bus (not just pci, etc).
4832  * This forcibly disables dma and IRQs, helping kexec and other cases
4833  * where the next system software may expect clean state.
4834  */
4835 static void fotg210_shutdown(struct usb_hcd *hcd)
4836 {
4837         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
4838 
4839         spin_lock_irq(&fotg210->lock);
4840         fotg210->shutdown = true;
4841         fotg210->rh_state = FOTG210_RH_STOPPING;
4842         fotg210->enabled_hrtimer_events = 0;
4843         spin_unlock_irq(&fotg210->lock);
4844 
4845         fotg210_silence_controller(fotg210);
4846 
4847         hrtimer_cancel(&fotg210->hrtimer);
4848 }
4849 
4850 /* fotg210_work is called from some interrupts, timers, and so on.
4851  * it calls driver completion functions, after dropping fotg210->lock.
4852  */
4853 static void fotg210_work(struct fotg210_hcd *fotg210)
4854 {
4855         /* another CPU may drop fotg210->lock during a schedule scan while
4856          * it reports urb completions.  this flag guards against bogus
4857          * attempts at re-entrant schedule scanning.
4858          */
4859         if (fotg210->scanning) {
4860                 fotg210->need_rescan = true;
4861                 return;
4862         }
4863         fotg210->scanning = true;
4864 
4865 rescan:
4866         fotg210->need_rescan = false;
4867         if (fotg210->async_count)
4868                 scan_async(fotg210);
4869         if (fotg210->intr_count > 0)
4870                 scan_intr(fotg210);
4871         if (fotg210->isoc_count > 0)
4872                 scan_isoc(fotg210);
4873         if (fotg210->need_rescan)
4874                 goto rescan;
4875         fotg210->scanning = false;
4876 
4877         /* the IO watchdog guards against hardware or driver bugs that
4878          * misplace IRQs, and should let us run completely without IRQs.
4879          * such lossage has been observed on both VT6202 and VT8235.
4880          */
4881         turn_on_io_watchdog(fotg210);
4882 }
4883 
4884 /* Called when the fotg210_hcd module is removed.
4885  */
4886 static void fotg210_stop(struct usb_hcd *hcd)
4887 {
4888         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
4889 
4890         fotg210_dbg(fotg210, "stop\n");
4891 
4892         /* no more interrupts ... */
4893 
4894         spin_lock_irq(&fotg210->lock);
4895         fotg210->enabled_hrtimer_events = 0;
4896         spin_unlock_irq(&fotg210->lock);
4897 
4898         fotg210_quiesce(fotg210);
4899         fotg210_silence_controller(fotg210);
4900         fotg210_reset(fotg210);
4901 
4902         hrtimer_cancel(&fotg210->hrtimer);
4903         remove_sysfs_files(fotg210);
4904         remove_debug_files(fotg210);
4905 
4906         /* root hub is shut down separately (first, when possible) */
4907         spin_lock_irq(&fotg210->lock);
4908         end_free_itds(fotg210);
4909         spin_unlock_irq(&fotg210->lock);
4910         fotg210_mem_cleanup(fotg210);
4911 
4912 #ifdef FOTG210_STATS
4913         fotg210_dbg(fotg210, "irq normal %ld err %ld iaa %ld (lost %ld)\n",
4914                         fotg210->stats.normal, fotg210->stats.error,
4915                         fotg210->stats.iaa, fotg210->stats.lost_iaa);
4916         fotg210_dbg(fotg210, "complete %ld unlink %ld\n",
4917                         fotg210->stats.complete, fotg210->stats.unlink);
4918 #endif
4919 
4920         dbg_status(fotg210, "fotg210_stop completed",
4921                         fotg210_readl(fotg210, &fotg210->regs->status));
4922 }
4923 
4924 /* one-time init, only for memory state */
4925 static int hcd_fotg210_init(struct usb_hcd *hcd)
4926 {
4927         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
4928         u32 temp;
4929         int retval;
4930         u32 hcc_params;
4931         struct fotg210_qh_hw *hw;
4932 
4933         spin_lock_init(&fotg210->lock);
4934 
4935         /*
4936          * keep io watchdog by default, those good HCDs could turn off it later
4937          */
4938         fotg210->need_io_watchdog = 1;
4939 
4940         hrtimer_init(&fotg210->hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
4941         fotg210->hrtimer.function = fotg210_hrtimer_func;
4942         fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;
4943 
4944         hcc_params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
4945 
4946         /*
4947          * by default set standard 80% (== 100 usec/uframe) max periodic
4948          * bandwidth as required by USB 2.0
4949          */
4950         fotg210->uframe_periodic_max = 100;
4951 
4952         /*
4953          * hw default: 1K periodic list heads, one per frame.
4954          * periodic_size can shrink by USBCMD update if hcc_params allows.
4955          */
4956         fotg210->periodic_size = DEFAULT_I_TDPS;
4957         INIT_LIST_HEAD(&fotg210->intr_qh_list);
4958         INIT_LIST_HEAD(&fotg210->cached_itd_list);
4959 
4960         if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
4961                 /* periodic schedule size can be smaller than default */
4962                 switch (FOTG210_TUNE_FLS) {
4963                 case 0:
4964                         fotg210->periodic_size = 1024;
4965                         break;
4966                 case 1:
4967                         fotg210->periodic_size = 512;
4968                         break;
4969                 case 2:
4970                         fotg210->periodic_size = 256;
4971                         break;
4972                 default:
4973                         BUG();
4974                 }
4975         }
4976         retval = fotg210_mem_init(fotg210, GFP_KERNEL);
4977         if (retval < 0)
4978                 return retval;
4979 
4980         /* controllers may cache some of the periodic schedule ... */
4981         fotg210->i_thresh = 2;
4982 
4983         /*
4984          * dedicate a qh for the async ring head, since we couldn't unlink
4985          * a 'real' qh without stopping the async schedule [4.8].  use it
4986          * as the 'reclamation list head' too.
4987          * its dummy is used in hw_alt_next of many tds, to prevent the qh
4988          * from automatically advancing to the next td after short reads.
4989          */
4990         fotg210->async->qh_next.qh = NULL;
4991         hw = fotg210->async->hw;
4992         hw->hw_next = QH_NEXT(fotg210, fotg210->async->qh_dma);
4993         hw->hw_info1 = cpu_to_hc32(fotg210, QH_HEAD);
4994         hw->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
4995         hw->hw_qtd_next = FOTG210_LIST_END(fotg210);
4996         fotg210->async->qh_state = QH_STATE_LINKED;
4997         hw->hw_alt_next = QTD_NEXT(fotg210, fotg210->async->dummy->qtd_dma);
4998 
4999         /* clear interrupt enables, set irq latency */
5000         if (log2_irq_thresh < 0 || log2_irq_thresh > 6)
5001                 log2_irq_thresh = 0;
5002         temp = 1 << (16 + log2_irq_thresh);
5003         if (HCC_CANPARK(hcc_params)) {
5004                 /* HW default park == 3, on hardware that supports it (like
5005                  * NVidia and ALI silicon), maximizes throughput on the async
5006                  * schedule by avoiding QH fetches between transfers.
5007                  *
5008                  * With fast usb storage devices and NForce2, "park" seems to
5009                  * make problems:  throughput reduction (!), data errors...
5010                  */
5011                 if (park) {
5012                         park = min_t(unsigned, park, 3);
5013                         temp |= CMD_PARK;
5014                         temp |= park << 8;
5015                 }
5016                 fotg210_dbg(fotg210, "park %d\n", park);
5017         }
5018         if (HCC_PGM_FRAMELISTLEN(hcc_params)) {
5019                 /* periodic schedule size can be smaller than default */
5020                 temp &= ~(3 << 2);
5021                 temp |= (FOTG210_TUNE_FLS << 2);
5022         }
5023         fotg210->command = temp;
5024 
5025         /* Accept arbitrarily long scatter-gather lists */
5026         if (!(hcd->driver->flags & HCD_LOCAL_MEM))
5027                 hcd->self.sg_tablesize = ~0;
5028         return 0;
5029 }
5030 
5031 /* start HC running; it's halted, hcd_fotg210_init() has been run (once) */
5032 static int fotg210_run(struct usb_hcd *hcd)
5033 {
5034         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5035         u32 temp;
5036         u32 hcc_params;
5037 
5038         hcd->uses_new_polling = 1;
5039 
5040         /* EHCI spec section 4.1 */
5041 
5042         fotg210_writel(fotg210, fotg210->periodic_dma,
5043                         &fotg210->regs->frame_list);
5044         fotg210_writel(fotg210, (u32)fotg210->async->qh_dma,
5045                         &fotg210->regs->async_next);
5046 
5047         /*
5048          * hcc_params controls whether fotg210->regs->segment must (!!!)
5049          * be used; it constrains QH/ITD/SITD and QTD locations.
5050          * pci_pool consistent memory always uses segment zero.
5051          * streaming mappings for I/O buffers, like pci_map_single(),
5052          * can return segments above 4GB, if the device allows.
5053          *
5054          * NOTE:  the dma mask is visible through dev->dma_mask, so
5055          * drivers can pass this info along ... like NETIF_F_HIGHDMA,
5056          * Scsi_Host.highmem_io, and so forth.  It's readonly to all
5057          * host side drivers though.
5058          */
5059         hcc_params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
5060 
5061         /*
5062          * Philips, Intel, and maybe others need CMD_RUN before the
5063          * root hub will detect new devices (why?); NEC doesn't
5064          */
5065         fotg210->command &= ~(CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
5066         fotg210->command |= CMD_RUN;
5067         fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
5068         dbg_cmd(fotg210, "init", fotg210->command);
5069 
5070         /*
5071          * Start, enabling full USB 2.0 functionality ... usb 1.1 devices
5072          * are explicitly handed to companion controller(s), so no TT is
5073          * involved with the root hub.  (Except where one is integrated,
5074          * and there's no companion controller unless maybe for USB OTG.)
5075          *
5076          * Turning on the CF flag will transfer ownership of all ports
5077          * from the companions to the EHCI controller.  If any of the
5078          * companions are in the middle of a port reset at the time, it
5079          * could cause trouble.  Write-locking ehci_cf_port_reset_rwsem
5080          * guarantees that no resets are in progress.  After we set CF,
5081          * a short delay lets the hardware catch up; new resets shouldn't
5082          * be started before the port switching actions could complete.
5083          */
5084         down_write(&ehci_cf_port_reset_rwsem);
5085         fotg210->rh_state = FOTG210_RH_RUNNING;
5086         /* unblock posted writes */
5087         fotg210_readl(fotg210, &fotg210->regs->command);
5088         usleep_range(5000, 10000);
5089         up_write(&ehci_cf_port_reset_rwsem);
5090         fotg210->last_periodic_enable = ktime_get_real();
5091 
5092         temp = HC_VERSION(fotg210,
5093                         fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
5094         fotg210_info(fotg210,
5095                         "USB %x.%x started, EHCI %x.%02x\n",
5096                         ((fotg210->sbrn & 0xf0) >> 4), (fotg210->sbrn & 0x0f),
5097                         temp >> 8, temp & 0xff);
5098 
5099         fotg210_writel(fotg210, INTR_MASK,
5100                         &fotg210->regs->intr_enable); /* Turn On Interrupts */
5101 
5102         /* GRR this is run-once init(), being done every time the HC starts.
5103          * So long as they're part of class devices, we can't do it init()
5104          * since the class device isn't created that early.
5105          */
5106         create_debug_files(fotg210);
5107         create_sysfs_files(fotg210);
5108 
5109         return 0;
5110 }
5111 
5112 static int fotg210_setup(struct usb_hcd *hcd)
5113 {
5114         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5115         int retval;
5116 
5117         fotg210->regs = (void __iomem *)fotg210->caps +
5118                         HC_LENGTH(fotg210,
5119                         fotg210_readl(fotg210, &fotg210->caps->hc_capbase));
5120         dbg_hcs_params(fotg210, "reset");
5121         dbg_hcc_params(fotg210, "reset");
5122 
5123         /* cache this readonly data; minimize chip reads */
5124         fotg210->hcs_params = fotg210_readl(fotg210,
5125                         &fotg210->caps->hcs_params);
5126 
5127         fotg210->sbrn = HCD_USB2;
5128 
5129         /* data structure init */
5130         retval = hcd_fotg210_init(hcd);
5131         if (retval)
5132                 return retval;
5133 
5134         retval = fotg210_halt(fotg210);
5135         if (retval)
5136                 return retval;
5137 
5138         fotg210_reset(fotg210);
5139 
5140         return 0;
5141 }
5142 
5143 static irqreturn_t fotg210_irq(struct usb_hcd *hcd)
5144 {
5145         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5146         u32 status, masked_status, pcd_status = 0, cmd;
5147         int bh;
5148 
5149         spin_lock(&fotg210->lock);
5150 
5151         status = fotg210_readl(fotg210, &fotg210->regs->status);
5152 
5153         /* e.g. cardbus physical eject */
5154         if (status == ~(u32) 0) {
5155                 fotg210_dbg(fotg210, "device removed\n");
5156                 goto dead;
5157         }
5158 
5159         /*
5160          * We don't use STS_FLR, but some controllers don't like it to
5161          * remain on, so mask it out along with the other status bits.
5162          */
5163         masked_status = status & (INTR_MASK | STS_FLR);
5164 
5165         /* Shared IRQ? */
5166         if (!masked_status ||
5167                         unlikely(fotg210->rh_state == FOTG210_RH_HALTED)) {
5168                 spin_unlock(&fotg210->lock);
5169                 return IRQ_NONE;
5170         }
5171 
5172         /* clear (just) interrupts */
5173         fotg210_writel(fotg210, masked_status, &fotg210->regs->status);
5174         cmd = fotg210_readl(fotg210, &fotg210->regs->command);
5175         bh = 0;
5176 
5177         /* unrequested/ignored: Frame List Rollover */
5178         dbg_status(fotg210, "irq", status);
5179 
5180         /* INT, ERR, and IAA interrupt rates can be throttled */
5181 
5182         /* normal [4.15.1.2] or error [4.15.1.1] completion */
5183         if (likely((status & (STS_INT|STS_ERR)) != 0)) {
5184                 if (likely((status & STS_ERR) == 0))
5185                         COUNT(fotg210->stats.normal);
5186                 else
5187                         COUNT(fotg210->stats.error);
5188                 bh = 1;
5189         }
5190 
5191         /* complete the unlinking of some qh [4.15.2.3] */
5192         if (status & STS_IAA) {
5193 
5194                 /* Turn off the IAA watchdog */
5195                 fotg210->enabled_hrtimer_events &=
5196                         ~BIT(FOTG210_HRTIMER_IAA_WATCHDOG);
5197 
5198                 /*
5199                  * Mild optimization: Allow another IAAD to reset the
5200                  * hrtimer, if one occurs before the next expiration.
5201                  * In theory we could always cancel the hrtimer, but
5202                  * tests show that about half the time it will be reset
5203                  * for some other event anyway.
5204                  */
5205                 if (fotg210->next_hrtimer_event == FOTG210_HRTIMER_IAA_WATCHDOG)
5206                         ++fotg210->next_hrtimer_event;
5207 
5208                 /* guard against (alleged) silicon errata */
5209                 if (cmd & CMD_IAAD)
5210                         fotg210_dbg(fotg210, "IAA with IAAD still set?\n");
5211                 if (fotg210->async_iaa) {
5212                         COUNT(fotg210->stats.iaa);
5213                         end_unlink_async(fotg210);
5214                 } else
5215                         fotg210_dbg(fotg210, "IAA with nothing unlinked?\n");
5216         }
5217 
5218         /* remote wakeup [4.3.1] */
5219         if (status & STS_PCD) {
5220                 int pstatus;
5221                 u32 __iomem *status_reg = &fotg210->regs->port_status;
5222 
5223                 /* kick root hub later */
5224                 pcd_status = status;
5225 
5226                 /* resume root hub? */
5227                 if (fotg210->rh_state == FOTG210_RH_SUSPENDED)
5228                         usb_hcd_resume_root_hub(hcd);
5229 
5230                 pstatus = fotg210_readl(fotg210, status_reg);
5231 
5232                 if (test_bit(0, &fotg210->suspended_ports) &&
5233                                 ((pstatus & PORT_RESUME) ||
5234                                 !(pstatus & PORT_SUSPEND)) &&
5235                                 (pstatus & PORT_PE) &&
5236                                 fotg210->reset_done[0] == 0) {
5237 
5238                         /* start 20 msec resume signaling from this port,
5239                          * and make hub_wq collect PORT_STAT_C_SUSPEND to
5240                          * stop that signaling.  Use 5 ms extra for safety,
5241                          * like usb_port_resume() does.
5242                          */
5243                         fotg210->reset_done[0] = jiffies + msecs_to_jiffies(25);
5244                         set_bit(0, &fotg210->resuming_ports);
5245                         fotg210_dbg(fotg210, "port 1 remote wakeup\n");
5246                         mod_timer(&hcd->rh_timer, fotg210->reset_done[0]);
5247                 }
5248         }
5249 
5250         /* PCI errors [4.15.2.4] */
5251         if (unlikely((status & STS_FATAL) != 0)) {
5252                 fotg210_err(fotg210, "fatal error\n");
5253                 dbg_cmd(fotg210, "fatal", cmd);
5254                 dbg_status(fotg210, "fatal", status);
5255 dead:
5256                 usb_hc_died(hcd);
5257 
5258                 /* Don't let the controller do anything more */
5259                 fotg210->shutdown = true;
5260                 fotg210->rh_state = FOTG210_RH_STOPPING;
5261                 fotg210->command &= ~(CMD_RUN | CMD_ASE | CMD_PSE);
5262                 fotg210_writel(fotg210, fotg210->command,
5263                                 &fotg210->regs->command);
5264                 fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
5265                 fotg210_handle_controller_death(fotg210);
5266 
5267                 /* Handle completions when the controller stops */
5268                 bh = 0;
5269         }
5270 
5271         if (bh)
5272                 fotg210_work(fotg210);
5273         spin_unlock(&fotg210->lock);
5274         if (pcd_status)
5275                 usb_hcd_poll_rh_status(hcd);
5276         return IRQ_HANDLED;
5277 }
5278 
5279 /* non-error returns are a promise to giveback() the urb later
5280  * we drop ownership so next owner (or urb unlink) can get it
5281  *
5282  * urb + dev is in hcd.self.controller.urb_list
5283  * we're queueing TDs onto software and hardware lists
5284  *
5285  * hcd-specific init for hcpriv hasn't been done yet
5286  *
5287  * NOTE:  control, bulk, and interrupt share the same code to append TDs
5288  * to a (possibly active) QH, and the same QH scanning code.
5289  */
5290 static int fotg210_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
5291                 gfp_t mem_flags)
5292 {
5293         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5294         struct list_head qtd_list;
5295 
5296         INIT_LIST_HEAD(&qtd_list);
5297 
5298         switch (usb_pipetype(urb->pipe)) {
5299         case PIPE_CONTROL:
5300                 /* qh_completions() code doesn't handle all the fault cases
5301                  * in multi-TD control transfers.  Even 1KB is rare anyway.
5302                  */
5303                 if (urb->transfer_buffer_length > (16 * 1024))
5304                         return -EMSGSIZE;
5305                 /* FALLTHROUGH */
5306         /* case PIPE_BULK: */
5307         default:
5308                 if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
5309                         return -ENOMEM;
5310                 return submit_async(fotg210, urb, &qtd_list, mem_flags);
5311 
5312         case PIPE_INTERRUPT:
5313                 if (!qh_urb_transaction(fotg210, urb, &qtd_list, mem_flags))
5314                         return -ENOMEM;
5315                 return intr_submit(fotg210, urb, &qtd_list, mem_flags);
5316 
5317         case PIPE_ISOCHRONOUS:
5318                 return itd_submit(fotg210, urb, mem_flags);
5319         }
5320 }
5321 
5322 /* remove from hardware lists
5323  * completions normally happen asynchronously
5324  */
5325 
5326 static int fotg210_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
5327 {
5328         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5329         struct fotg210_qh *qh;
5330         unsigned long flags;
5331         int rc;
5332 
5333         spin_lock_irqsave(&fotg210->lock, flags);
5334         rc = usb_hcd_check_unlink_urb(hcd, urb, status);
5335         if (rc)
5336                 goto done;
5337 
5338         switch (usb_pipetype(urb->pipe)) {
5339         /* case PIPE_CONTROL: */
5340         /* case PIPE_BULK:*/
5341         default:
5342                 qh = (struct fotg210_qh *) urb->hcpriv;
5343                 if (!qh)
5344                         break;
5345                 switch (qh->qh_state) {
5346                 case QH_STATE_LINKED:
5347                 case QH_STATE_COMPLETING:
5348                         start_unlink_async(fotg210, qh);
5349                         break;
5350                 case QH_STATE_UNLINK:
5351                 case QH_STATE_UNLINK_WAIT:
5352                         /* already started */
5353                         break;
5354                 case QH_STATE_IDLE:
5355                         /* QH might be waiting for a Clear-TT-Buffer */
5356                         qh_completions(fotg210, qh);
5357                         break;
5358                 }
5359                 break;
5360 
5361         case PIPE_INTERRUPT:
5362                 qh = (struct fotg210_qh *) urb->hcpriv;
5363                 if (!qh)
5364                         break;
5365                 switch (qh->qh_state) {
5366                 case QH_STATE_LINKED:
5367                 case QH_STATE_COMPLETING:
5368                         start_unlink_intr(fotg210, qh);
5369                         break;
5370                 case QH_STATE_IDLE:
5371                         qh_completions(fotg210, qh);
5372                         break;
5373                 default:
5374                         fotg210_dbg(fotg210, "bogus qh %p state %d\n",
5375                                         qh, qh->qh_state);
5376                         goto done;
5377                 }
5378                 break;
5379 
5380         case PIPE_ISOCHRONOUS:
5381                 /* itd... */
5382 
5383                 /* wait till next completion, do it then. */
5384                 /* completion irqs can wait up to 1024 msec, */
5385                 break;
5386         }
5387 done:
5388         spin_unlock_irqrestore(&fotg210->lock, flags);
5389         return rc;
5390 }
5391 
5392 /* bulk qh holds the data toggle */
5393 
5394 static void fotg210_endpoint_disable(struct usb_hcd *hcd,
5395                 struct usb_host_endpoint *ep)
5396 {
5397         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5398         unsigned long flags;
5399         struct fotg210_qh *qh, *tmp;
5400 
5401         /* ASSERT:  any requests/urbs are being unlinked */
5402         /* ASSERT:  nobody can be submitting urbs for this any more */
5403 
5404 rescan:
5405         spin_lock_irqsave(&fotg210->lock, flags);
5406         qh = ep->hcpriv;
5407         if (!qh)
5408                 goto done;
5409 
5410         /* endpoints can be iso streams.  for now, we don't
5411          * accelerate iso completions ... so spin a while.
5412          */
5413         if (qh->hw == NULL) {
5414                 struct fotg210_iso_stream *stream = ep->hcpriv;
5415 
5416                 if (!list_empty(&stream->td_list))
5417                         goto idle_timeout;
5418 
5419                 /* BUG_ON(!list_empty(&stream->free_list)); */
5420                 kfree(stream);
5421                 goto done;
5422         }
5423 
5424         if (fotg210->rh_state < FOTG210_RH_RUNNING)
5425                 qh->qh_state = QH_STATE_IDLE;
5426         switch (qh->qh_state) {
5427         case QH_STATE_LINKED:
5428         case QH_STATE_COMPLETING:
5429                 for (tmp = fotg210->async->qh_next.qh;
5430                                 tmp && tmp != qh;
5431                                 tmp = tmp->qh_next.qh)
5432                         continue;
5433                 /* periodic qh self-unlinks on empty, and a COMPLETING qh
5434                  * may already be unlinked.
5435                  */
5436                 if (tmp)
5437                         start_unlink_async(fotg210, qh);
5438                 /* FALL THROUGH */
5439         case QH_STATE_UNLINK:           /* wait for hw to finish? */
5440         case QH_STATE_UNLINK_WAIT:
5441 idle_timeout:
5442                 spin_unlock_irqrestore(&fotg210->lock, flags);
5443                 schedule_timeout_uninterruptible(1);
5444                 goto rescan;
5445         case QH_STATE_IDLE:             /* fully unlinked */
5446                 if (qh->clearing_tt)
5447                         goto idle_timeout;
5448                 if (list_empty(&qh->qtd_list)) {
5449                         qh_destroy(fotg210, qh);
5450                         break;
5451                 }
5452                 /* else FALL THROUGH */
5453         default:
5454                 /* caller was supposed to have unlinked any requests;
5455                  * that's not our job.  just leak this memory.
5456                  */
5457                 fotg210_err(fotg210, "qh %p (#%02x) state %d%s\n",
5458                                 qh, ep->desc.bEndpointAddress, qh->qh_state,
5459                                 list_empty(&qh->qtd_list) ? "" : "(has tds)");
5460                 break;
5461         }
5462 done:
5463         ep->hcpriv = NULL;
5464         spin_unlock_irqrestore(&fotg210->lock, flags);
5465 }
5466 
5467 static void fotg210_endpoint_reset(struct usb_hcd *hcd,
5468                 struct usb_host_endpoint *ep)
5469 {
5470         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5471         struct fotg210_qh *qh;
5472         int eptype = usb_endpoint_type(&ep->desc);
5473         int epnum = usb_endpoint_num(&ep->desc);
5474         int is_out = usb_endpoint_dir_out(&ep->desc);
5475         unsigned long flags;
5476 
5477         if (eptype != USB_ENDPOINT_XFER_BULK && eptype != USB_ENDPOINT_XFER_INT)
5478                 return;
5479 
5480         spin_lock_irqsave(&fotg210->lock, flags);
5481         qh = ep->hcpriv;
5482 
5483         /* For Bulk and Interrupt endpoints we maintain the toggle state
5484          * in the hardware; the toggle bits in udev aren't used at all.
5485          * When an endpoint is reset by usb_clear_halt() we must reset
5486          * the toggle bit in the QH.
5487          */
5488         if (qh) {
5489                 usb_settoggle(qh->dev, epnum, is_out, 0);
5490                 if (!list_empty(&qh->qtd_list)) {
5491                         WARN_ONCE(1, "clear_halt for a busy endpoint\n");
5492                 } else if (qh->qh_state == QH_STATE_LINKED ||
5493                                 qh->qh_state == QH_STATE_COMPLETING) {
5494 
5495                         /* The toggle value in the QH can't be updated
5496                          * while the QH is active.  Unlink it now;
5497                          * re-linking will call qh_refresh().
5498                          */
5499                         if (eptype == USB_ENDPOINT_XFER_BULK)
5500                                 start_unlink_async(fotg210, qh);
5501                         else
5502                                 start_unlink_intr(fotg210, qh);
5503                 }
5504         }
5505         spin_unlock_irqrestore(&fotg210->lock, flags);
5506 }
5507 
5508 static int fotg210_get_frame(struct usb_hcd *hcd)
5509 {
5510         struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
5511 
5512         return (fotg210_read_frame_index(fotg210) >> 3) %
5513                 fotg210->periodic_size;
5514 }
5515 
5516 /* The EHCI in ChipIdea HDRC cannot be a separate module or device,
5517  * because its registers (and irq) are shared between host/gadget/otg
5518  * functions  and in order to facilitate role switching we cannot
5519  * give the fotg210 driver exclusive access to those.
5520  */
5521 MODULE_DESCRIPTION(DRIVER_DESC);
5522 MODULE_AUTHOR(DRIVER_AUTHOR);
5523 MODULE_LICENSE("GPL");
5524 
5525 static const struct hc_driver fotg210_fotg210_hc_driver = {
5526         .description            = hcd_name,
5527         .product_desc           = "Faraday USB2.0 Host Controller",
5528         .hcd_priv_size          = sizeof(struct fotg210_hcd),
5529 
5530         /*
5531          * generic hardware linkage
5532          */
5533         .irq                    = fotg210_irq,
5534         .flags                  = HCD_MEMORY | HCD_USB2,
5535 
5536         /*
5537          * basic lifecycle operations
5538          */
5539         .reset                  = hcd_fotg210_init,
5540         .start                  = fotg210_run,
5541         .stop                   = fotg210_stop,
5542         .shutdown               = fotg210_shutdown,
5543 
5544         /*
5545          * managing i/o requests and associated device resources
5546          */
5547         .urb_enqueue            = fotg210_urb_enqueue,
5548         .urb_dequeue            = fotg210_urb_dequeue,
5549         .endpoint_disable       = fotg210_endpoint_disable,
5550         .endpoint_reset         = fotg210_endpoint_reset,
5551 
5552         /*
5553          * scheduling support
5554          */
5555         .get_frame_number       = fotg210_get_frame,
5556 
5557         /*
5558          * root hub support
5559          */
5560         .hub_status_data        = fotg210_hub_status_data,
5561         .hub_control            = fotg210_hub_control,
5562         .bus_suspend            = fotg210_bus_suspend,
5563         .bus_resume             = fotg210_bus_resume,
5564 
5565         .relinquish_port        = fotg210_relinquish_port,
5566         .port_handed_over       = fotg210_port_handed_over,
5567 
5568         .clear_tt_buffer_complete = fotg210_clear_tt_buffer_complete,
5569 };
5570 
5571 static void fotg210_init(struct fotg210_hcd *fotg210)
5572 {
5573         u32 value;
5574 
5575         iowrite32(GMIR_MDEV_INT | GMIR_MOTG_INT | GMIR_INT_POLARITY,
5576                         &fotg210->regs->gmir);
5577 
5578         value = ioread32(&fotg210->regs->otgcsr);
5579         value &= ~OTGCSR_A_BUS_DROP;
5580         value |= OTGCSR_A_BUS_REQ;
5581         iowrite32(value, &fotg210->regs->otgcsr);
5582 }
5583 
5584 /**
5585  * fotg210_hcd_probe - initialize faraday FOTG210 HCDs
5586  *
5587  * Allocates basic resources for this USB host controller, and
5588  * then invokes the start() method for the HCD associated with it
5589  * through the hotplug entry's driver_data.
5590  */
5591 static int fotg210_hcd_probe(struct platform_device *pdev)
5592 {
5593         struct device *dev = &pdev->dev;
5594         struct usb_hcd *hcd;
5595         struct resource *res;
5596         int irq;
5597         int retval = -ENODEV;
5598         struct fotg210_hcd *fotg210;
5599 
5600         if (usb_disabled())
5601                 return -ENODEV;
5602 
5603         pdev->dev.power.power_state = PMSG_ON;
5604 
5605         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
5606         if (!res) {
5607                 dev_err(dev, "Found HC with no IRQ. Check %s setup!\n",
5608                                 dev_name(dev));
5609                 return -ENODEV;
5610         }
5611 
5612         irq = res->start;
5613 
5614         hcd = usb_create_hcd(&fotg210_fotg210_hc_driver, dev,
5615                         dev_name(dev));
5616         if (!hcd) {
5617                 dev_err(dev, "failed to create hcd with err %d\n", retval);
5618                 retval = -ENOMEM;
5619                 goto fail_create_hcd;
5620         }
5621 
5622         hcd->has_tt = 1;
5623 
5624         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
5625         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
5626         if (IS_ERR(hcd->regs)) {
5627                 retval = PTR_ERR(hcd->regs);
5628                 goto failed;
5629         }
5630 
5631         hcd->rsrc_start = res->start;
5632         hcd->rsrc_len = resource_size(res);
5633 
5634         fotg210 = hcd_to_fotg210(hcd);
5635 
5636         fotg210->caps = hcd->regs;
5637 
5638         retval = fotg210_setup(hcd);
5639         if (retval)
5640                 goto failed;
5641 
5642         fotg210_init(fotg210);
5643 
5644         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
5645         if (retval) {
5646                 dev_err(dev, "failed to add hcd with err %d\n", retval);
5647                 goto failed;
5648         }
5649         device_wakeup_enable(hcd->self.controller);
5650 
5651         return retval;
5652 
5653 failed:
5654         usb_put_hcd(hcd);
5655 fail_create_hcd:
5656         dev_err(dev, "init %s fail, %d\n", dev_name(dev), retval);
5657         return retval;
5658 }
5659 
5660 /**
5661  * fotg210_hcd_remove - shutdown processing for EHCI HCDs
5662  * @dev: USB Host Controller being removed
5663  *
5664  */
5665 static int fotg210_hcd_remove(struct platform_device *pdev)
5666 {
5667         struct device *dev = &pdev->dev;
5668         struct usb_hcd *hcd = dev_get_drvdata(dev);
5669 
5670         if (!hcd)
5671                 return 0;
5672 
5673         usb_remove_hcd(hcd);
5674         usb_put_hcd(hcd);
5675 
5676         return 0;
5677 }
5678 
5679 static struct platform_driver fotg210_hcd_driver = {
5680         .driver = {
5681                 .name   = "fotg210-hcd",
5682         },
5683         .probe  = fotg210_hcd_probe,
5684         .remove = fotg210_hcd_remove,
5685 };
5686 
5687 static int __init fotg210_hcd_init(void)
5688 {
5689         int retval = 0;
5690 
5691         if (usb_disabled())
5692                 return -ENODEV;
5693 
5694         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
5695         set_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
5696         if (test_bit(USB_UHCI_LOADED, &usb_hcds_loaded) ||
5697                         test_bit(USB_OHCI_LOADED, &usb_hcds_loaded))
5698                 pr_warn("Warning! fotg210_hcd should always be loaded before uhci_hcd and ohci_hcd, not after\n");
5699 
5700         pr_debug("%s: block sizes: qh %Zd qtd %Zd itd %Zd\n",
5701                         hcd_name, sizeof(struct fotg210_qh),
5702                         sizeof(struct fotg210_qtd),
5703                         sizeof(struct fotg210_itd));
5704 
5705         fotg210_debug_root = debugfs_create_dir("fotg210", usb_debug_root);
5706         if (!fotg210_debug_root) {
5707                 retval = -ENOENT;
5708                 goto err_debug;
5709         }
5710 
5711         retval = platform_driver_register(&fotg210_hcd_driver);
5712         if (retval < 0)
5713                 goto clean;
5714         return retval;
5715 
5716 clean:
5717         debugfs_remove(fotg210_debug_root);
5718         fotg210_debug_root = NULL;
5719 err_debug:
5720         clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
5721         return retval;
5722 }
5723 module_init(fotg210_hcd_init);
5724 
5725 static void __exit fotg210_hcd_cleanup(void)
5726 {
5727         platform_driver_unregister(&fotg210_hcd_driver);
5728         debugfs_remove(fotg210_debug_root);
5729         clear_bit(USB_EHCI_LOADED, &usb_hcds_loaded);
5730 }
5731 module_exit(fotg210_hcd_cleanup);
5732 

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