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Linux/drivers/macintosh/smu.c

  1 /*
  2  * PowerMac G5 SMU driver
  3  *
  4  * Copyright 2004 J. Mayer <l_indien@magic.fr>
  5  * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
  6  *
  7  * Released under the term of the GNU GPL v2.
  8  */
  9 
 10 /*
 11  * TODO:
 12  *  - maybe add timeout to commands ?
 13  *  - blocking version of time functions
 14  *  - polling version of i2c commands (including timer that works with
 15  *    interrupts off)
 16  *  - maybe avoid some data copies with i2c by directly using the smu cmd
 17  *    buffer and a lower level internal interface
 18  *  - understand SMU -> CPU events and implement reception of them via
 19  *    the userland interface
 20  */
 21 
 22 #include <linux/types.h>
 23 #include <linux/kernel.h>
 24 #include <linux/device.h>
 25 #include <linux/dmapool.h>
 26 #include <linux/bootmem.h>
 27 #include <linux/vmalloc.h>
 28 #include <linux/highmem.h>
 29 #include <linux/jiffies.h>
 30 #include <linux/interrupt.h>
 31 #include <linux/rtc.h>
 32 #include <linux/completion.h>
 33 #include <linux/miscdevice.h>
 34 #include <linux/delay.h>
 35 #include <linux/poll.h>
 36 #include <linux/mutex.h>
 37 #include <linux/of_device.h>
 38 #include <linux/of_irq.h>
 39 #include <linux/of_platform.h>
 40 #include <linux/slab.h>
 41 #include <linux/memblock.h>
 42 
 43 #include <asm/byteorder.h>
 44 #include <asm/io.h>
 45 #include <asm/prom.h>
 46 #include <asm/machdep.h>
 47 #include <asm/pmac_feature.h>
 48 #include <asm/smu.h>
 49 #include <asm/sections.h>
 50 #include <asm/uaccess.h>
 51 
 52 #define VERSION "0.7"
 53 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
 54 
 55 #undef DEBUG_SMU
 56 
 57 #ifdef DEBUG_SMU
 58 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
 59 #else
 60 #define DPRINTK(fmt, args...) do { } while (0)
 61 #endif
 62 
 63 /*
 64  * This is the command buffer passed to the SMU hardware
 65  */
 66 #define SMU_MAX_DATA    254
 67 
 68 struct smu_cmd_buf {
 69         u8 cmd;
 70         u8 length;
 71         u8 data[SMU_MAX_DATA];
 72 };
 73 
 74 struct smu_device {
 75         spinlock_t              lock;
 76         struct device_node      *of_node;
 77         struct platform_device  *of_dev;
 78         int                     doorbell;       /* doorbell gpio */
 79         u32 __iomem             *db_buf;        /* doorbell buffer */
 80         struct device_node      *db_node;
 81         unsigned int            db_irq;
 82         int                     msg;
 83         struct device_node      *msg_node;
 84         unsigned int            msg_irq;
 85         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
 86         u32                     cmd_buf_abs;    /* command buffer absolute */
 87         struct list_head        cmd_list;
 88         struct smu_cmd          *cmd_cur;       /* pending command */
 89         int                     broken_nap;
 90         struct list_head        cmd_i2c_list;
 91         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
 92         struct timer_list       i2c_timer;
 93 };
 94 
 95 /*
 96  * I don't think there will ever be more than one SMU, so
 97  * for now, just hard code that
 98  */
 99 static DEFINE_MUTEX(smu_mutex);
100 static struct smu_device        *smu;
101 static DEFINE_MUTEX(smu_part_access);
102 static int smu_irq_inited;
103 static unsigned long smu_cmdbuf_abs;
104 
105 static void smu_i2c_retry(unsigned long data);
106 
107 /*
108  * SMU driver low level stuff
109  */
110 
111 static void smu_start_cmd(void)
112 {
113         unsigned long faddr, fend;
114         struct smu_cmd *cmd;
115 
116         if (list_empty(&smu->cmd_list))
117                 return;
118 
119         /* Fetch first command in queue */
120         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
121         smu->cmd_cur = cmd;
122         list_del(&cmd->link);
123 
124         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
125                 cmd->data_len);
126         DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
127 
128         /* Fill the SMU command buffer */
129         smu->cmd_buf->cmd = cmd->cmd;
130         smu->cmd_buf->length = cmd->data_len;
131         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
132 
133         /* Flush command and data to RAM */
134         faddr = (unsigned long)smu->cmd_buf;
135         fend = faddr + smu->cmd_buf->length + 2;
136         flush_inval_dcache_range(faddr, fend);
137 
138 
139         /* We also disable NAP mode for the duration of the command
140          * on U3 based machines.
141          * This is slightly racy as it can be written back to 1 by a sysctl
142          * but that never happens in practice. There seem to be an issue with
143          * U3 based machines such as the iMac G5 where napping for the
144          * whole duration of the command prevents the SMU from fetching it
145          * from memory. This might be related to the strange i2c based
146          * mechanism the SMU uses to access memory.
147          */
148         if (smu->broken_nap)
149                 powersave_nap = 0;
150 
151         /* This isn't exactly a DMA mapping here, I suspect
152          * the SMU is actually communicating with us via i2c to the
153          * northbridge or the CPU to access RAM.
154          */
155         writel(smu->cmd_buf_abs, smu->db_buf);
156 
157         /* Ring the SMU doorbell */
158         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
159 }
160 
161 
162 static irqreturn_t smu_db_intr(int irq, void *arg)
163 {
164         unsigned long flags;
165         struct smu_cmd *cmd;
166         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
167         void *misc = NULL;
168         u8 gpio;
169         int rc = 0;
170 
171         /* SMU completed the command, well, we hope, let's make sure
172          * of it
173          */
174         spin_lock_irqsave(&smu->lock, flags);
175 
176         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
177         if ((gpio & 7) != 7) {
178                 spin_unlock_irqrestore(&smu->lock, flags);
179                 return IRQ_HANDLED;
180         }
181 
182         cmd = smu->cmd_cur;
183         smu->cmd_cur = NULL;
184         if (cmd == NULL)
185                 goto bail;
186 
187         if (rc == 0) {
188                 unsigned long faddr;
189                 int reply_len;
190                 u8 ack;
191 
192                 /* CPU might have brought back the cache line, so we need
193                  * to flush again before peeking at the SMU response. We
194                  * flush the entire buffer for now as we haven't read the
195                  * reply length (it's only 2 cache lines anyway)
196                  */
197                 faddr = (unsigned long)smu->cmd_buf;
198                 flush_inval_dcache_range(faddr, faddr + 256);
199 
200                 /* Now check ack */
201                 ack = (~cmd->cmd) & 0xff;
202                 if (ack != smu->cmd_buf->cmd) {
203                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
204                                 ack, smu->cmd_buf->cmd);
205                         rc = -EIO;
206                 }
207                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
208                 DPRINTK("SMU: reply len: %d\n", reply_len);
209                 if (reply_len > cmd->reply_len) {
210                         printk(KERN_WARNING "SMU: reply buffer too small,"
211                                "got %d bytes for a %d bytes buffer\n",
212                                reply_len, cmd->reply_len);
213                         reply_len = cmd->reply_len;
214                 }
215                 cmd->reply_len = reply_len;
216                 if (cmd->reply_buf && reply_len)
217                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
218         }
219 
220         /* Now complete the command. Write status last in order as we lost
221          * ownership of the command structure as soon as it's no longer -1
222          */
223         done = cmd->done;
224         misc = cmd->misc;
225         mb();
226         cmd->status = rc;
227 
228         /* Re-enable NAP mode */
229         if (smu->broken_nap)
230                 powersave_nap = 1;
231  bail:
232         /* Start next command if any */
233         smu_start_cmd();
234         spin_unlock_irqrestore(&smu->lock, flags);
235 
236         /* Call command completion handler if any */
237         if (done)
238                 done(cmd, misc);
239 
240         /* It's an edge interrupt, nothing to do */
241         return IRQ_HANDLED;
242 }
243 
244 
245 static irqreturn_t smu_msg_intr(int irq, void *arg)
246 {
247         /* I don't quite know what to do with this one, we seem to never
248          * receive it, so I suspect we have to arm it someway in the SMU
249          * to start getting events that way.
250          */
251 
252         printk(KERN_INFO "SMU: message interrupt !\n");
253 
254         /* It's an edge interrupt, nothing to do */
255         return IRQ_HANDLED;
256 }
257 
258 
259 /*
260  * Queued command management.
261  *
262  */
263 
264 int smu_queue_cmd(struct smu_cmd *cmd)
265 {
266         unsigned long flags;
267 
268         if (smu == NULL)
269                 return -ENODEV;
270         if (cmd->data_len > SMU_MAX_DATA ||
271             cmd->reply_len > SMU_MAX_DATA)
272                 return -EINVAL;
273 
274         cmd->status = 1;
275         spin_lock_irqsave(&smu->lock, flags);
276         list_add_tail(&cmd->link, &smu->cmd_list);
277         if (smu->cmd_cur == NULL)
278                 smu_start_cmd();
279         spin_unlock_irqrestore(&smu->lock, flags);
280 
281         /* Workaround for early calls when irq isn't available */
282         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
283                 smu_spinwait_cmd(cmd);
284 
285         return 0;
286 }
287 EXPORT_SYMBOL(smu_queue_cmd);
288 
289 
290 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
291                      unsigned int data_len,
292                      void (*done)(struct smu_cmd *cmd, void *misc),
293                      void *misc, ...)
294 {
295         struct smu_cmd *cmd = &scmd->cmd;
296         va_list list;
297         int i;
298 
299         if (data_len > sizeof(scmd->buffer))
300                 return -EINVAL;
301 
302         memset(scmd, 0, sizeof(*scmd));
303         cmd->cmd = command;
304         cmd->data_len = data_len;
305         cmd->data_buf = scmd->buffer;
306         cmd->reply_len = sizeof(scmd->buffer);
307         cmd->reply_buf = scmd->buffer;
308         cmd->done = done;
309         cmd->misc = misc;
310 
311         va_start(list, misc);
312         for (i = 0; i < data_len; ++i)
313                 scmd->buffer[i] = (u8)va_arg(list, int);
314         va_end(list);
315 
316         return smu_queue_cmd(cmd);
317 }
318 EXPORT_SYMBOL(smu_queue_simple);
319 
320 
321 void smu_poll(void)
322 {
323         u8 gpio;
324 
325         if (smu == NULL)
326                 return;
327 
328         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
329         if ((gpio & 7) == 7)
330                 smu_db_intr(smu->db_irq, smu);
331 }
332 EXPORT_SYMBOL(smu_poll);
333 
334 
335 void smu_done_complete(struct smu_cmd *cmd, void *misc)
336 {
337         struct completion *comp = misc;
338 
339         complete(comp);
340 }
341 EXPORT_SYMBOL(smu_done_complete);
342 
343 
344 void smu_spinwait_cmd(struct smu_cmd *cmd)
345 {
346         while(cmd->status == 1)
347                 smu_poll();
348 }
349 EXPORT_SYMBOL(smu_spinwait_cmd);
350 
351 
352 /* RTC low level commands */
353 static inline int bcd2hex (int n)
354 {
355         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
356 }
357 
358 
359 static inline int hex2bcd (int n)
360 {
361         return ((n / 10) << 4) + (n % 10);
362 }
363 
364 
365 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
366                                         struct rtc_time *time)
367 {
368         cmd_buf->cmd = 0x8e;
369         cmd_buf->length = 8;
370         cmd_buf->data[0] = 0x80;
371         cmd_buf->data[1] = hex2bcd(time->tm_sec);
372         cmd_buf->data[2] = hex2bcd(time->tm_min);
373         cmd_buf->data[3] = hex2bcd(time->tm_hour);
374         cmd_buf->data[4] = time->tm_wday;
375         cmd_buf->data[5] = hex2bcd(time->tm_mday);
376         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
377         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
378 }
379 
380 
381 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
382 {
383         struct smu_simple_cmd cmd;
384         int rc;
385 
386         if (smu == NULL)
387                 return -ENODEV;
388 
389         memset(time, 0, sizeof(struct rtc_time));
390         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
391                               SMU_CMD_RTC_GET_DATETIME);
392         if (rc)
393                 return rc;
394         smu_spinwait_simple(&cmd);
395 
396         time->tm_sec = bcd2hex(cmd.buffer[0]);
397         time->tm_min = bcd2hex(cmd.buffer[1]);
398         time->tm_hour = bcd2hex(cmd.buffer[2]);
399         time->tm_wday = bcd2hex(cmd.buffer[3]);
400         time->tm_mday = bcd2hex(cmd.buffer[4]);
401         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
402         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
403 
404         return 0;
405 }
406 
407 
408 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
409 {
410         struct smu_simple_cmd cmd;
411         int rc;
412 
413         if (smu == NULL)
414                 return -ENODEV;
415 
416         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
417                               SMU_CMD_RTC_SET_DATETIME,
418                               hex2bcd(time->tm_sec),
419                               hex2bcd(time->tm_min),
420                               hex2bcd(time->tm_hour),
421                               time->tm_wday,
422                               hex2bcd(time->tm_mday),
423                               hex2bcd(time->tm_mon) + 1,
424                               hex2bcd(time->tm_year - 100));
425         if (rc)
426                 return rc;
427         smu_spinwait_simple(&cmd);
428 
429         return 0;
430 }
431 
432 
433 void smu_shutdown(void)
434 {
435         struct smu_simple_cmd cmd;
436 
437         if (smu == NULL)
438                 return;
439 
440         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
441                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
442                 return;
443         smu_spinwait_simple(&cmd);
444         for (;;)
445                 ;
446 }
447 
448 
449 void smu_restart(void)
450 {
451         struct smu_simple_cmd cmd;
452 
453         if (smu == NULL)
454                 return;
455 
456         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
457                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
458                 return;
459         smu_spinwait_simple(&cmd);
460         for (;;)
461                 ;
462 }
463 
464 
465 int smu_present(void)
466 {
467         return smu != NULL;
468 }
469 EXPORT_SYMBOL(smu_present);
470 
471 
472 int __init smu_init (void)
473 {
474         struct device_node *np;
475         const u32 *data;
476         int ret = 0;
477 
478         np = of_find_node_by_type(NULL, "smu");
479         if (np == NULL)
480                 return -ENODEV;
481 
482         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
483 
484         /*
485          * SMU based G5s need some memory below 2Gb. Thankfully this is
486          * called at a time where memblock is still available.
487          */
488         smu_cmdbuf_abs = memblock_alloc_base(4096, 4096, 0x80000000UL);
489         if (smu_cmdbuf_abs == 0) {
490                 printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
491                 ret = -EINVAL;
492                 goto fail_np;
493         }
494 
495         smu = alloc_bootmem(sizeof(struct smu_device));
496 
497         spin_lock_init(&smu->lock);
498         INIT_LIST_HEAD(&smu->cmd_list);
499         INIT_LIST_HEAD(&smu->cmd_i2c_list);
500         smu->of_node = np;
501         smu->db_irq = NO_IRQ;
502         smu->msg_irq = NO_IRQ;
503 
504         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
505          * 32 bits value safely
506          */
507         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
508         smu->cmd_buf = __va(smu_cmdbuf_abs);
509 
510         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
511         if (smu->db_node == NULL) {
512                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
513                 ret = -ENXIO;
514                 goto fail_bootmem;
515         }
516         data = of_get_property(smu->db_node, "reg", NULL);
517         if (data == NULL) {
518                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
519                 ret = -ENXIO;
520                 goto fail_db_node;
521         }
522 
523         /* Current setup has one doorbell GPIO that does both doorbell
524          * and ack. GPIOs are at 0x50, best would be to find that out
525          * in the device-tree though.
526          */
527         smu->doorbell = *data;
528         if (smu->doorbell < 0x50)
529                 smu->doorbell += 0x50;
530 
531         /* Now look for the smu-interrupt GPIO */
532         do {
533                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
534                 if (smu->msg_node == NULL)
535                         break;
536                 data = of_get_property(smu->msg_node, "reg", NULL);
537                 if (data == NULL) {
538                         of_node_put(smu->msg_node);
539                         smu->msg_node = NULL;
540                         break;
541                 }
542                 smu->msg = *data;
543                 if (smu->msg < 0x50)
544                         smu->msg += 0x50;
545         } while(0);
546 
547         /* Doorbell buffer is currently hard-coded, I didn't find a proper
548          * device-tree entry giving the address. Best would probably to use
549          * an offset for K2 base though, but let's do it that way for now.
550          */
551         smu->db_buf = ioremap(0x8000860c, 0x1000);
552         if (smu->db_buf == NULL) {
553                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
554                 ret = -ENXIO;
555                 goto fail_msg_node;
556         }
557 
558         /* U3 has an issue with NAP mode when issuing SMU commands */
559         smu->broken_nap = pmac_get_uninorth_variant() < 4;
560         if (smu->broken_nap)
561                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
562 
563         sys_ctrler = SYS_CTRLER_SMU;
564         return 0;
565 
566 fail_msg_node:
567         of_node_put(smu->msg_node);
568 fail_db_node:
569         of_node_put(smu->db_node);
570 fail_bootmem:
571         free_bootmem(__pa(smu), sizeof(struct smu_device));
572         smu = NULL;
573 fail_np:
574         of_node_put(np);
575         return ret;
576 }
577 
578 
579 static int smu_late_init(void)
580 {
581         if (!smu)
582                 return 0;
583 
584         init_timer(&smu->i2c_timer);
585         smu->i2c_timer.function = smu_i2c_retry;
586         smu->i2c_timer.data = (unsigned long)smu;
587 
588         if (smu->db_node) {
589                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
590                 if (smu->db_irq == NO_IRQ)
591                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
592                                smu->db_node->full_name);
593         }
594         if (smu->msg_node) {
595                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
596                 if (smu->msg_irq == NO_IRQ)
597                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
598                                smu->msg_node->full_name);
599         }
600 
601         /*
602          * Try to request the interrupts
603          */
604 
605         if (smu->db_irq != NO_IRQ) {
606                 if (request_irq(smu->db_irq, smu_db_intr,
607                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
608                         printk(KERN_WARNING "SMU: can't "
609                                "request interrupt %d\n",
610                                smu->db_irq);
611                         smu->db_irq = NO_IRQ;
612                 }
613         }
614 
615         if (smu->msg_irq != NO_IRQ) {
616                 if (request_irq(smu->msg_irq, smu_msg_intr,
617                                 IRQF_SHARED, "SMU message", smu) < 0) {
618                         printk(KERN_WARNING "SMU: can't "
619                                "request interrupt %d\n",
620                                smu->msg_irq);
621                         smu->msg_irq = NO_IRQ;
622                 }
623         }
624 
625         smu_irq_inited = 1;
626         return 0;
627 }
628 /* This has to be before arch_initcall as the low i2c stuff relies on the
629  * above having been done before we reach arch_initcalls
630  */
631 core_initcall(smu_late_init);
632 
633 /*
634  * sysfs visibility
635  */
636 
637 static void smu_expose_childs(struct work_struct *unused)
638 {
639         struct device_node *np;
640 
641         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
642                 if (of_device_is_compatible(np, "smu-sensors"))
643                         of_platform_device_create(np, "smu-sensors",
644                                                   &smu->of_dev->dev);
645 }
646 
647 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
648 
649 static int smu_platform_probe(struct platform_device* dev)
650 {
651         if (!smu)
652                 return -ENODEV;
653         smu->of_dev = dev;
654 
655         /*
656          * Ok, we are matched, now expose all i2c busses. We have to defer
657          * that unfortunately or it would deadlock inside the device model
658          */
659         schedule_work(&smu_expose_childs_work);
660 
661         return 0;
662 }
663 
664 static const struct of_device_id smu_platform_match[] =
665 {
666         {
667                 .type           = "smu",
668         },
669         {},
670 };
671 
672 static struct platform_driver smu_of_platform_driver =
673 {
674         .driver = {
675                 .name = "smu",
676                 .of_match_table = smu_platform_match,
677         },
678         .probe          = smu_platform_probe,
679 };
680 
681 static int __init smu_init_sysfs(void)
682 {
683         /*
684          * For now, we don't power manage machines with an SMU chip,
685          * I'm a bit too far from figuring out how that works with those
686          * new chipsets, but that will come back and bite us
687          */
688         platform_driver_register(&smu_of_platform_driver);
689         return 0;
690 }
691 
692 device_initcall(smu_init_sysfs);
693 
694 struct platform_device *smu_get_ofdev(void)
695 {
696         if (!smu)
697                 return NULL;
698         return smu->of_dev;
699 }
700 
701 EXPORT_SYMBOL_GPL(smu_get_ofdev);
702 
703 /*
704  * i2c interface
705  */
706 
707 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
708 {
709         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
710         void *misc = cmd->misc;
711         unsigned long flags;
712 
713         /* Check for read case */
714         if (!fail && cmd->read) {
715                 if (cmd->pdata[0] < 1)
716                         fail = 1;
717                 else
718                         memcpy(cmd->info.data, &cmd->pdata[1],
719                                cmd->info.datalen);
720         }
721 
722         DPRINTK("SMU: completing, success: %d\n", !fail);
723 
724         /* Update status and mark no pending i2c command with lock
725          * held so nobody comes in while we dequeue an eventual
726          * pending next i2c command
727          */
728         spin_lock_irqsave(&smu->lock, flags);
729         smu->cmd_i2c_cur = NULL;
730         wmb();
731         cmd->status = fail ? -EIO : 0;
732 
733         /* Is there another i2c command waiting ? */
734         if (!list_empty(&smu->cmd_i2c_list)) {
735                 struct smu_i2c_cmd *newcmd;
736 
737                 /* Fetch it, new current, remove from list */
738                 newcmd = list_entry(smu->cmd_i2c_list.next,
739                                     struct smu_i2c_cmd, link);
740                 smu->cmd_i2c_cur = newcmd;
741                 list_del(&cmd->link);
742 
743                 /* Queue with low level smu */
744                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
745                 if (smu->cmd_cur == NULL)
746                         smu_start_cmd();
747         }
748         spin_unlock_irqrestore(&smu->lock, flags);
749 
750         /* Call command completion handler if any */
751         if (done)
752                 done(cmd, misc);
753 
754 }
755 
756 
757 static void smu_i2c_retry(unsigned long data)
758 {
759         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
760 
761         DPRINTK("SMU: i2c failure, requeuing...\n");
762 
763         /* requeue command simply by resetting reply_len */
764         cmd->pdata[0] = 0xff;
765         cmd->scmd.reply_len = sizeof(cmd->pdata);
766         smu_queue_cmd(&cmd->scmd);
767 }
768 
769 
770 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
771 {
772         struct smu_i2c_cmd      *cmd = misc;
773         int                     fail = 0;
774 
775         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
776                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
777 
778         /* Check for possible status */
779         if (scmd->status < 0)
780                 fail = 1;
781         else if (cmd->read) {
782                 if (cmd->stage == 0)
783                         fail = cmd->pdata[0] != 0;
784                 else
785                         fail = cmd->pdata[0] >= 0x80;
786         } else {
787                 fail = cmd->pdata[0] != 0;
788         }
789 
790         /* Handle failures by requeuing command, after 5ms interval
791          */
792         if (fail && --cmd->retries > 0) {
793                 DPRINTK("SMU: i2c failure, starting timer...\n");
794                 BUG_ON(cmd != smu->cmd_i2c_cur);
795                 if (!smu_irq_inited) {
796                         mdelay(5);
797                         smu_i2c_retry(0);
798                         return;
799                 }
800                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
801                 return;
802         }
803 
804         /* If failure or stage 1, command is complete */
805         if (fail || cmd->stage != 0) {
806                 smu_i2c_complete_command(cmd, fail);
807                 return;
808         }
809 
810         DPRINTK("SMU: going to stage 1\n");
811 
812         /* Ok, initial command complete, now poll status */
813         scmd->reply_buf = cmd->pdata;
814         scmd->reply_len = sizeof(cmd->pdata);
815         scmd->data_buf = cmd->pdata;
816         scmd->data_len = 1;
817         cmd->pdata[0] = 0;
818         cmd->stage = 1;
819         cmd->retries = 20;
820         smu_queue_cmd(scmd);
821 }
822 
823 
824 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
825 {
826         unsigned long flags;
827 
828         if (smu == NULL)
829                 return -ENODEV;
830 
831         /* Fill most fields of scmd */
832         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
833         cmd->scmd.done = smu_i2c_low_completion;
834         cmd->scmd.misc = cmd;
835         cmd->scmd.reply_buf = cmd->pdata;
836         cmd->scmd.reply_len = sizeof(cmd->pdata);
837         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
838         cmd->scmd.status = 1;
839         cmd->stage = 0;
840         cmd->pdata[0] = 0xff;
841         cmd->retries = 20;
842         cmd->status = 1;
843 
844         /* Check transfer type, sanitize some "info" fields
845          * based on transfer type and do more checking
846          */
847         cmd->info.caddr = cmd->info.devaddr;
848         cmd->read = cmd->info.devaddr & 0x01;
849         switch(cmd->info.type) {
850         case SMU_I2C_TRANSFER_SIMPLE:
851                 memset(&cmd->info.sublen, 0, 4);
852                 break;
853         case SMU_I2C_TRANSFER_COMBINED:
854                 cmd->info.devaddr &= 0xfe;
855         case SMU_I2C_TRANSFER_STDSUB:
856                 if (cmd->info.sublen > 3)
857                         return -EINVAL;
858                 break;
859         default:
860                 return -EINVAL;
861         }
862 
863         /* Finish setting up command based on transfer direction
864          */
865         if (cmd->read) {
866                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
867                         return -EINVAL;
868                 memset(cmd->info.data, 0xff, cmd->info.datalen);
869                 cmd->scmd.data_len = 9;
870         } else {
871                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
872                         return -EINVAL;
873                 cmd->scmd.data_len = 9 + cmd->info.datalen;
874         }
875 
876         DPRINTK("SMU: i2c enqueuing command\n");
877         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
878                 cmd->read ? "read" : "write", cmd->info.datalen,
879                 cmd->info.bus, cmd->info.caddr,
880                 cmd->info.subaddr[0], cmd->info.type);
881 
882 
883         /* Enqueue command in i2c list, and if empty, enqueue also in
884          * main command list
885          */
886         spin_lock_irqsave(&smu->lock, flags);
887         if (smu->cmd_i2c_cur == NULL) {
888                 smu->cmd_i2c_cur = cmd;
889                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
890                 if (smu->cmd_cur == NULL)
891                         smu_start_cmd();
892         } else
893                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
894         spin_unlock_irqrestore(&smu->lock, flags);
895 
896         return 0;
897 }
898 
899 /*
900  * Handling of "partitions"
901  */
902 
903 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
904 {
905         DECLARE_COMPLETION_ONSTACK(comp);
906         unsigned int chunk;
907         struct smu_cmd cmd;
908         int rc;
909         u8 params[8];
910 
911         /* We currently use a chunk size of 0xe. We could check the
912          * SMU firmware version and use bigger sizes though
913          */
914         chunk = 0xe;
915 
916         while (len) {
917                 unsigned int clen = min(len, chunk);
918 
919                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
920                 cmd.data_len = 7;
921                 cmd.data_buf = params;
922                 cmd.reply_len = chunk;
923                 cmd.reply_buf = dest;
924                 cmd.done = smu_done_complete;
925                 cmd.misc = &comp;
926                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
927                 params[1] = 0x4;
928                 *((u32 *)&params[2]) = addr;
929                 params[6] = clen;
930 
931                 rc = smu_queue_cmd(&cmd);
932                 if (rc)
933                         return rc;
934                 wait_for_completion(&comp);
935                 if (cmd.status != 0)
936                         return rc;
937                 if (cmd.reply_len != clen) {
938                         printk(KERN_DEBUG "SMU: short read in "
939                                "smu_read_datablock, got: %d, want: %d\n",
940                                cmd.reply_len, clen);
941                         return -EIO;
942                 }
943                 len -= clen;
944                 addr += clen;
945                 dest += clen;
946         }
947         return 0;
948 }
949 
950 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
951 {
952         DECLARE_COMPLETION_ONSTACK(comp);
953         struct smu_simple_cmd cmd;
954         unsigned int addr, len, tlen;
955         struct smu_sdbp_header *hdr;
956         struct property *prop;
957 
958         /* First query the partition info */
959         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
960         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
961                          smu_done_complete, &comp,
962                          SMU_CMD_PARTITION_LATEST, id);
963         wait_for_completion(&comp);
964         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
965                 cmd.cmd.status, cmd.cmd.reply_len);
966 
967         /* Partition doesn't exist (or other error) */
968         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
969                 return NULL;
970 
971         /* Fetch address and length from reply */
972         addr = *((u16 *)cmd.buffer);
973         len = cmd.buffer[3] << 2;
974         /* Calucluate total length to allocate, including the 17 bytes
975          * for "sdb-partition-XX" that we append at the end of the buffer
976          */
977         tlen = sizeof(struct property) + len + 18;
978 
979         prop = kzalloc(tlen, GFP_KERNEL);
980         if (prop == NULL)
981                 return NULL;
982         hdr = (struct smu_sdbp_header *)(prop + 1);
983         prop->name = ((char *)prop) + tlen - 18;
984         sprintf(prop->name, "sdb-partition-%02x", id);
985         prop->length = len;
986         prop->value = hdr;
987         prop->next = NULL;
988 
989         /* Read the datablock */
990         if (smu_read_datablock((u8 *)hdr, addr, len)) {
991                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
992                        "partition %02x !\n", id);
993                 goto failure;
994         }
995 
996         /* Got it, check a few things and create the property */
997         if (hdr->id != id) {
998                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
999                        "%02x !\n", id, hdr->id);
1000                 goto failure;
1001         }
1002         if (of_add_property(smu->of_node, prop)) {
1003                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1004                        "property !\n", id);
1005                 goto failure;
1006         }
1007 
1008         return hdr;
1009  failure:
1010         kfree(prop);
1011         return NULL;
1012 }
1013 
1014 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1015  * when interruptible is 1
1016  */
1017 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1018                 unsigned int *size, int interruptible)
1019 {
1020         char pname[32];
1021         const struct smu_sdbp_header *part;
1022 
1023         if (!smu)
1024                 return NULL;
1025 
1026         sprintf(pname, "sdb-partition-%02x", id);
1027 
1028         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1029 
1030         if (interruptible) {
1031                 int rc;
1032                 rc = mutex_lock_interruptible(&smu_part_access);
1033                 if (rc)
1034                         return ERR_PTR(rc);
1035         } else
1036                 mutex_lock(&smu_part_access);
1037 
1038         part = of_get_property(smu->of_node, pname, size);
1039         if (part == NULL) {
1040                 DPRINTK("trying to extract from SMU ...\n");
1041                 part = smu_create_sdb_partition(id);
1042                 if (part != NULL && size)
1043                         *size = part->len << 2;
1044         }
1045         mutex_unlock(&smu_part_access);
1046         return part;
1047 }
1048 
1049 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1050 {
1051         return __smu_get_sdb_partition(id, size, 0);
1052 }
1053 EXPORT_SYMBOL(smu_get_sdb_partition);
1054 
1055 
1056 /*
1057  * Userland driver interface
1058  */
1059 
1060 
1061 static LIST_HEAD(smu_clist);
1062 static DEFINE_SPINLOCK(smu_clist_lock);
1063 
1064 enum smu_file_mode {
1065         smu_file_commands,
1066         smu_file_events,
1067         smu_file_closing
1068 };
1069 
1070 struct smu_private
1071 {
1072         struct list_head        list;
1073         enum smu_file_mode      mode;
1074         int                     busy;
1075         struct smu_cmd          cmd;
1076         spinlock_t              lock;
1077         wait_queue_head_t       wait;
1078         u8                      buffer[SMU_MAX_DATA];
1079 };
1080 
1081 
1082 static int smu_open(struct inode *inode, struct file *file)
1083 {
1084         struct smu_private *pp;
1085         unsigned long flags;
1086 
1087         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1088         if (pp == 0)
1089                 return -ENOMEM;
1090         spin_lock_init(&pp->lock);
1091         pp->mode = smu_file_commands;
1092         init_waitqueue_head(&pp->wait);
1093 
1094         mutex_lock(&smu_mutex);
1095         spin_lock_irqsave(&smu_clist_lock, flags);
1096         list_add(&pp->list, &smu_clist);
1097         spin_unlock_irqrestore(&smu_clist_lock, flags);
1098         file->private_data = pp;
1099         mutex_unlock(&smu_mutex);
1100 
1101         return 0;
1102 }
1103 
1104 
1105 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1106 {
1107         struct smu_private *pp = misc;
1108 
1109         wake_up_all(&pp->wait);
1110 }
1111 
1112 
1113 static ssize_t smu_write(struct file *file, const char __user *buf,
1114                          size_t count, loff_t *ppos)
1115 {
1116         struct smu_private *pp = file->private_data;
1117         unsigned long flags;
1118         struct smu_user_cmd_hdr hdr;
1119         int rc = 0;
1120 
1121         if (pp->busy)
1122                 return -EBUSY;
1123         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1124                 return -EFAULT;
1125         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1126                 pp->mode = smu_file_events;
1127                 return 0;
1128         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1129                 const struct smu_sdbp_header *part;
1130                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1131                 if (part == NULL)
1132                         return -EINVAL;
1133                 else if (IS_ERR(part))
1134                         return PTR_ERR(part);
1135                 return 0;
1136         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1137                 return -EINVAL;
1138         else if (pp->mode != smu_file_commands)
1139                 return -EBADFD;
1140         else if (hdr.data_len > SMU_MAX_DATA)
1141                 return -EINVAL;
1142 
1143         spin_lock_irqsave(&pp->lock, flags);
1144         if (pp->busy) {
1145                 spin_unlock_irqrestore(&pp->lock, flags);
1146                 return -EBUSY;
1147         }
1148         pp->busy = 1;
1149         pp->cmd.status = 1;
1150         spin_unlock_irqrestore(&pp->lock, flags);
1151 
1152         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1153                 pp->busy = 0;
1154                 return -EFAULT;
1155         }
1156 
1157         pp->cmd.cmd = hdr.cmd;
1158         pp->cmd.data_len = hdr.data_len;
1159         pp->cmd.reply_len = SMU_MAX_DATA;
1160         pp->cmd.data_buf = pp->buffer;
1161         pp->cmd.reply_buf = pp->buffer;
1162         pp->cmd.done = smu_user_cmd_done;
1163         pp->cmd.misc = pp;
1164         rc = smu_queue_cmd(&pp->cmd);
1165         if (rc < 0)
1166                 return rc;
1167         return count;
1168 }
1169 
1170 
1171 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1172                                 char __user *buf, size_t count)
1173 {
1174         DECLARE_WAITQUEUE(wait, current);
1175         struct smu_user_reply_hdr hdr;
1176         unsigned long flags;
1177         int size, rc = 0;
1178 
1179         if (!pp->busy)
1180                 return 0;
1181         if (count < sizeof(struct smu_user_reply_hdr))
1182                 return -EOVERFLOW;
1183         spin_lock_irqsave(&pp->lock, flags);
1184         if (pp->cmd.status == 1) {
1185                 if (file->f_flags & O_NONBLOCK) {
1186                         spin_unlock_irqrestore(&pp->lock, flags);
1187                         return -EAGAIN;
1188                 }
1189                 add_wait_queue(&pp->wait, &wait);
1190                 for (;;) {
1191                         set_current_state(TASK_INTERRUPTIBLE);
1192                         rc = 0;
1193                         if (pp->cmd.status != 1)
1194                                 break;
1195                         rc = -ERESTARTSYS;
1196                         if (signal_pending(current))
1197                                 break;
1198                         spin_unlock_irqrestore(&pp->lock, flags);
1199                         schedule();
1200                         spin_lock_irqsave(&pp->lock, flags);
1201                 }
1202                 set_current_state(TASK_RUNNING);
1203                 remove_wait_queue(&pp->wait, &wait);
1204         }
1205         spin_unlock_irqrestore(&pp->lock, flags);
1206         if (rc)
1207                 return rc;
1208         if (pp->cmd.status != 0)
1209                 pp->cmd.reply_len = 0;
1210         size = sizeof(hdr) + pp->cmd.reply_len;
1211         if (count < size)
1212                 size = count;
1213         rc = size;
1214         hdr.status = pp->cmd.status;
1215         hdr.reply_len = pp->cmd.reply_len;
1216         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1217                 return -EFAULT;
1218         size -= sizeof(hdr);
1219         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1220                 return -EFAULT;
1221         pp->busy = 0;
1222 
1223         return rc;
1224 }
1225 
1226 
1227 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1228                                char __user *buf, size_t count)
1229 {
1230         /* Not implemented */
1231         msleep_interruptible(1000);
1232         return 0;
1233 }
1234 
1235 
1236 static ssize_t smu_read(struct file *file, char __user *buf,
1237                         size_t count, loff_t *ppos)
1238 {
1239         struct smu_private *pp = file->private_data;
1240 
1241         if (pp->mode == smu_file_commands)
1242                 return smu_read_command(file, pp, buf, count);
1243         if (pp->mode == smu_file_events)
1244                 return smu_read_events(file, pp, buf, count);
1245 
1246         return -EBADFD;
1247 }
1248 
1249 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1250 {
1251         struct smu_private *pp = file->private_data;
1252         unsigned int mask = 0;
1253         unsigned long flags;
1254 
1255         if (pp == 0)
1256                 return 0;
1257 
1258         if (pp->mode == smu_file_commands) {
1259                 poll_wait(file, &pp->wait, wait);
1260 
1261                 spin_lock_irqsave(&pp->lock, flags);
1262                 if (pp->busy && pp->cmd.status != 1)
1263                         mask |= POLLIN;
1264                 spin_unlock_irqrestore(&pp->lock, flags);
1265         }
1266         if (pp->mode == smu_file_events) {
1267                 /* Not yet implemented */
1268         }
1269         return mask;
1270 }
1271 
1272 static int smu_release(struct inode *inode, struct file *file)
1273 {
1274         struct smu_private *pp = file->private_data;
1275         unsigned long flags;
1276         unsigned int busy;
1277 
1278         if (pp == 0)
1279                 return 0;
1280 
1281         file->private_data = NULL;
1282 
1283         /* Mark file as closing to avoid races with new request */
1284         spin_lock_irqsave(&pp->lock, flags);
1285         pp->mode = smu_file_closing;
1286         busy = pp->busy;
1287 
1288         /* Wait for any pending request to complete */
1289         if (busy && pp->cmd.status == 1) {
1290                 DECLARE_WAITQUEUE(wait, current);
1291 
1292                 add_wait_queue(&pp->wait, &wait);
1293                 for (;;) {
1294                         set_current_state(TASK_UNINTERRUPTIBLE);
1295                         if (pp->cmd.status != 1)
1296                                 break;
1297                         spin_unlock_irqrestore(&pp->lock, flags);
1298                         schedule();
1299                         spin_lock_irqsave(&pp->lock, flags);
1300                 }
1301                 set_current_state(TASK_RUNNING);
1302                 remove_wait_queue(&pp->wait, &wait);
1303         }
1304         spin_unlock_irqrestore(&pp->lock, flags);
1305 
1306         spin_lock_irqsave(&smu_clist_lock, flags);
1307         list_del(&pp->list);
1308         spin_unlock_irqrestore(&smu_clist_lock, flags);
1309         kfree(pp);
1310 
1311         return 0;
1312 }
1313 
1314 
1315 static const struct file_operations smu_device_fops = {
1316         .llseek         = no_llseek,
1317         .read           = smu_read,
1318         .write          = smu_write,
1319         .poll           = smu_fpoll,
1320         .open           = smu_open,
1321         .release        = smu_release,
1322 };
1323 
1324 static struct miscdevice pmu_device = {
1325         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1326 };
1327 
1328 static int smu_device_init(void)
1329 {
1330         if (!smu)
1331                 return -ENODEV;
1332         if (misc_register(&pmu_device) < 0)
1333                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1334         return 0;
1335 }
1336 device_initcall(smu_device_init);
1337 

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