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

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