Merge master.kernel.org:/pub/scm/linux/kernel/git/bunk/trivial
[linux-2.6] / 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  *    interrutps 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/config.h>
23 #include <linux/types.h>
24 #include <linux/kernel.h>
25 #include <linux/device.h>
26 #include <linux/dmapool.h>
27 #include <linux/bootmem.h>
28 #include <linux/vmalloc.h>
29 #include <linux/highmem.h>
30 #include <linux/jiffies.h>
31 #include <linux/interrupt.h>
32 #include <linux/rtc.h>
33 #include <linux/completion.h>
34 #include <linux/miscdevice.h>
35 #include <linux/delay.h>
36 #include <linux/sysdev.h>
37 #include <linux/poll.h>
38
39 #include <asm/byteorder.h>
40 #include <asm/io.h>
41 #include <asm/prom.h>
42 #include <asm/machdep.h>
43 #include <asm/pmac_feature.h>
44 #include <asm/smu.h>
45 #include <asm/sections.h>
46 #include <asm/abs_addr.h>
47 #include <asm/uaccess.h>
48 #include <asm/of_device.h>
49
50 #define VERSION "0.6"
51 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
52
53 #undef DEBUG_SMU
54
55 #ifdef DEBUG_SMU
56 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
57 #else
58 #define DPRINTK(fmt, args...) do { } while (0)
59 #endif
60
61 /*
62  * This is the command buffer passed to the SMU hardware
63  */
64 #define SMU_MAX_DATA    254
65
66 struct smu_cmd_buf {
67         u8 cmd;
68         u8 length;
69         u8 data[SMU_MAX_DATA];
70 };
71
72 struct smu_device {
73         spinlock_t              lock;
74         struct device_node      *of_node;
75         struct of_device        *of_dev;
76         int                     doorbell;       /* doorbell gpio */
77         u32 __iomem             *db_buf;        /* doorbell buffer */
78         int                     db_irq;
79         int                     msg;
80         int                     msg_irq;
81         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
82         u32                     cmd_buf_abs;    /* command buffer absolute */
83         struct list_head        cmd_list;
84         struct smu_cmd          *cmd_cur;       /* pending command */
85         struct list_head        cmd_i2c_list;
86         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
87         struct timer_list       i2c_timer;
88 };
89
90 /*
91  * I don't think there will ever be more than one SMU, so
92  * for now, just hard code that
93  */
94 static struct smu_device        *smu;
95
96
97 /*
98  * SMU driver low level stuff
99  */
100
101 static void smu_start_cmd(void)
102 {
103         unsigned long faddr, fend;
104         struct smu_cmd *cmd;
105
106         if (list_empty(&smu->cmd_list))
107                 return;
108
109         /* Fetch first command in queue */
110         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
111         smu->cmd_cur = cmd;
112         list_del(&cmd->link);
113
114         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
115                 cmd->data_len);
116         DPRINTK("SMU: data buffer: %02x %02x %02x %02x ...\n",
117                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
118                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3]);
119
120         /* Fill the SMU command buffer */
121         smu->cmd_buf->cmd = cmd->cmd;
122         smu->cmd_buf->length = cmd->data_len;
123         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
124
125         /* Flush command and data to RAM */
126         faddr = (unsigned long)smu->cmd_buf;
127         fend = faddr + smu->cmd_buf->length + 2;
128         flush_inval_dcache_range(faddr, fend);
129
130         /* This isn't exactly a DMA mapping here, I suspect
131          * the SMU is actually communicating with us via i2c to the
132          * northbridge or the CPU to access RAM.
133          */
134         writel(smu->cmd_buf_abs, smu->db_buf);
135
136         /* Ring the SMU doorbell */
137         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
138 }
139
140
141 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
142 {
143         unsigned long flags;
144         struct smu_cmd *cmd;
145         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
146         void *misc = NULL;
147         u8 gpio;
148         int rc = 0;
149
150         /* SMU completed the command, well, we hope, let's make sure
151          * of it
152          */
153         spin_lock_irqsave(&smu->lock, flags);
154
155         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
156         if ((gpio & 7) != 7) {
157                 spin_unlock_irqrestore(&smu->lock, flags);
158                 return IRQ_HANDLED;
159         }
160
161         cmd = smu->cmd_cur;
162         smu->cmd_cur = NULL;
163         if (cmd == NULL)
164                 goto bail;
165
166         if (rc == 0) {
167                 unsigned long faddr;
168                 int reply_len;
169                 u8 ack;
170
171                 /* CPU might have brought back the cache line, so we need
172                  * to flush again before peeking at the SMU response. We
173                  * flush the entire buffer for now as we haven't read the
174                  * reply lenght (it's only 2 cache lines anyway)
175                  */
176                 faddr = (unsigned long)smu->cmd_buf;
177                 flush_inval_dcache_range(faddr, faddr + 256);
178
179                 /* Now check ack */
180                 ack = (~cmd->cmd) & 0xff;
181                 if (ack != smu->cmd_buf->cmd) {
182                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
183                                 ack, smu->cmd_buf->cmd);
184                         rc = -EIO;
185                 }
186                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
187                 DPRINTK("SMU: reply len: %d\n", reply_len);
188                 if (reply_len > cmd->reply_len) {
189                         printk(KERN_WARNING "SMU: reply buffer too small,"
190                                "got %d bytes for a %d bytes buffer\n",
191                                reply_len, cmd->reply_len);
192                         reply_len = cmd->reply_len;
193                 }
194                 cmd->reply_len = reply_len;
195                 if (cmd->reply_buf && reply_len)
196                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
197         }
198
199         /* Now complete the command. Write status last in order as we lost
200          * ownership of the command structure as soon as it's no longer -1
201          */
202         done = cmd->done;
203         misc = cmd->misc;
204         mb();
205         cmd->status = rc;
206  bail:
207         /* Start next command if any */
208         smu_start_cmd();
209         spin_unlock_irqrestore(&smu->lock, flags);
210
211         /* Call command completion handler if any */
212         if (done)
213                 done(cmd, misc);
214
215         /* It's an edge interrupt, nothing to do */
216         return IRQ_HANDLED;
217 }
218
219
220 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
221 {
222         /* I don't quite know what to do with this one, we seem to never
223          * receive it, so I suspect we have to arm it someway in the SMU
224          * to start getting events that way.
225          */
226
227         printk(KERN_INFO "SMU: message interrupt !\n");
228
229         /* It's an edge interrupt, nothing to do */
230         return IRQ_HANDLED;
231 }
232
233
234 /*
235  * Queued command management.
236  *
237  */
238
239 int smu_queue_cmd(struct smu_cmd *cmd)
240 {
241         unsigned long flags;
242
243         if (smu == NULL)
244                 return -ENODEV;
245         if (cmd->data_len > SMU_MAX_DATA ||
246             cmd->reply_len > SMU_MAX_DATA)
247                 return -EINVAL;
248
249         cmd->status = 1;
250         spin_lock_irqsave(&smu->lock, flags);
251         list_add_tail(&cmd->link, &smu->cmd_list);
252         if (smu->cmd_cur == NULL)
253                 smu_start_cmd();
254         spin_unlock_irqrestore(&smu->lock, flags);
255
256         return 0;
257 }
258 EXPORT_SYMBOL(smu_queue_cmd);
259
260
261 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
262                      unsigned int data_len,
263                      void (*done)(struct smu_cmd *cmd, void *misc),
264                      void *misc, ...)
265 {
266         struct smu_cmd *cmd = &scmd->cmd;
267         va_list list;
268         int i;
269
270         if (data_len > sizeof(scmd->buffer))
271                 return -EINVAL;
272
273         memset(scmd, 0, sizeof(*scmd));
274         cmd->cmd = command;
275         cmd->data_len = data_len;
276         cmd->data_buf = scmd->buffer;
277         cmd->reply_len = sizeof(scmd->buffer);
278         cmd->reply_buf = scmd->buffer;
279         cmd->done = done;
280         cmd->misc = misc;
281
282         va_start(list, misc);
283         for (i = 0; i < data_len; ++i)
284                 scmd->buffer[i] = (u8)va_arg(list, int);
285         va_end(list);
286
287         return smu_queue_cmd(cmd);
288 }
289 EXPORT_SYMBOL(smu_queue_simple);
290
291
292 void smu_poll(void)
293 {
294         u8 gpio;
295
296         if (smu == NULL)
297                 return;
298
299         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
300         if ((gpio & 7) == 7)
301                 smu_db_intr(smu->db_irq, smu, NULL);
302 }
303 EXPORT_SYMBOL(smu_poll);
304
305
306 void smu_done_complete(struct smu_cmd *cmd, void *misc)
307 {
308         struct completion *comp = misc;
309
310         complete(comp);
311 }
312 EXPORT_SYMBOL(smu_done_complete);
313
314
315 void smu_spinwait_cmd(struct smu_cmd *cmd)
316 {
317         while(cmd->status == 1)
318                 smu_poll();
319 }
320 EXPORT_SYMBOL(smu_spinwait_cmd);
321
322
323 /* RTC low level commands */
324 static inline int bcd2hex (int n)
325 {
326         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
327 }
328
329
330 static inline int hex2bcd (int n)
331 {
332         return ((n / 10) << 4) + (n % 10);
333 }
334
335
336 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
337                                         struct rtc_time *time)
338 {
339         cmd_buf->cmd = 0x8e;
340         cmd_buf->length = 8;
341         cmd_buf->data[0] = 0x80;
342         cmd_buf->data[1] = hex2bcd(time->tm_sec);
343         cmd_buf->data[2] = hex2bcd(time->tm_min);
344         cmd_buf->data[3] = hex2bcd(time->tm_hour);
345         cmd_buf->data[4] = time->tm_wday;
346         cmd_buf->data[5] = hex2bcd(time->tm_mday);
347         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
348         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
349 }
350
351
352 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
353 {
354         struct smu_simple_cmd cmd;
355         int rc;
356
357         if (smu == NULL)
358                 return -ENODEV;
359
360         memset(time, 0, sizeof(struct rtc_time));
361         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
362                               SMU_CMD_RTC_GET_DATETIME);
363         if (rc)
364                 return rc;
365         smu_spinwait_simple(&cmd);
366
367         time->tm_sec = bcd2hex(cmd.buffer[0]);
368         time->tm_min = bcd2hex(cmd.buffer[1]);
369         time->tm_hour = bcd2hex(cmd.buffer[2]);
370         time->tm_wday = bcd2hex(cmd.buffer[3]);
371         time->tm_mday = bcd2hex(cmd.buffer[4]);
372         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
373         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
374
375         return 0;
376 }
377
378
379 int smu_set_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         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
388                               SMU_CMD_RTC_SET_DATETIME,
389                               hex2bcd(time->tm_sec),
390                               hex2bcd(time->tm_min),
391                               hex2bcd(time->tm_hour),
392                               time->tm_wday,
393                               hex2bcd(time->tm_mday),
394                               hex2bcd(time->tm_mon) + 1,
395                               hex2bcd(time->tm_year - 100));
396         if (rc)
397                 return rc;
398         smu_spinwait_simple(&cmd);
399
400         return 0;
401 }
402
403
404 void smu_shutdown(void)
405 {
406         struct smu_simple_cmd cmd;
407
408         if (smu == NULL)
409                 return;
410
411         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
412                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
413                 return;
414         smu_spinwait_simple(&cmd);
415         for (;;)
416                 ;
417 }
418
419
420 void smu_restart(void)
421 {
422         struct smu_simple_cmd cmd;
423
424         if (smu == NULL)
425                 return;
426
427         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
428                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
429                 return;
430         smu_spinwait_simple(&cmd);
431         for (;;)
432                 ;
433 }
434
435
436 int smu_present(void)
437 {
438         return smu != NULL;
439 }
440 EXPORT_SYMBOL(smu_present);
441
442
443 int smu_init (void)
444 {
445         struct device_node *np;
446         u32 *data;
447
448         np = of_find_node_by_type(NULL, "smu");
449         if (np == NULL)
450                 return -ENODEV;
451
452         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
453
454         if (smu_cmdbuf_abs == 0) {
455                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
456                 return -EINVAL;
457         }
458
459         smu = alloc_bootmem(sizeof(struct smu_device));
460         if (smu == NULL)
461                 return -ENOMEM;
462         memset(smu, 0, sizeof(*smu));
463
464         spin_lock_init(&smu->lock);
465         INIT_LIST_HEAD(&smu->cmd_list);
466         INIT_LIST_HEAD(&smu->cmd_i2c_list);
467         smu->of_node = np;
468         smu->db_irq = NO_IRQ;
469         smu->msg_irq = NO_IRQ;
470         init_timer(&smu->i2c_timer);
471
472         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
473          * 32 bits value safely
474          */
475         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
476         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
477
478         np = of_find_node_by_name(NULL, "smu-doorbell");
479         if (np == NULL) {
480                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
481                 goto fail;
482         }
483         data = (u32 *)get_property(np, "reg", NULL);
484         if (data == NULL) {
485                 of_node_put(np);
486                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
487                 goto fail;
488         }
489
490         /* Current setup has one doorbell GPIO that does both doorbell
491          * and ack. GPIOs are at 0x50, best would be to find that out
492          * in the device-tree though.
493          */
494         smu->doorbell = *data;
495         if (smu->doorbell < 0x50)
496                 smu->doorbell += 0x50;
497         if (np->n_intrs > 0)
498                 smu->db_irq = np->intrs[0].line;
499
500         of_node_put(np);
501
502         /* Now look for the smu-interrupt GPIO */
503         do {
504                 np = of_find_node_by_name(NULL, "smu-interrupt");
505                 if (np == NULL)
506                         break;
507                 data = (u32 *)get_property(np, "reg", NULL);
508                 if (data == NULL) {
509                         of_node_put(np);
510                         break;
511                 }
512                 smu->msg = *data;
513                 if (smu->msg < 0x50)
514                         smu->msg += 0x50;
515                 if (np->n_intrs > 0)
516                         smu->msg_irq = np->intrs[0].line;
517                 of_node_put(np);
518         } while(0);
519
520         /* Doorbell buffer is currently hard-coded, I didn't find a proper
521          * device-tree entry giving the address. Best would probably to use
522          * an offset for K2 base though, but let's do it that way for now.
523          */
524         smu->db_buf = ioremap(0x8000860c, 0x1000);
525         if (smu->db_buf == NULL) {
526                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
527                 goto fail;
528         }
529
530         sys_ctrler = SYS_CTRLER_SMU;
531         return 0;
532
533  fail:
534         smu = NULL;
535         return -ENXIO;
536
537 }
538
539
540 static int smu_late_init(void)
541 {
542         if (!smu)
543                 return 0;
544
545         /*
546          * Try to request the interrupts
547          */
548
549         if (smu->db_irq != NO_IRQ) {
550                 if (request_irq(smu->db_irq, smu_db_intr,
551                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
552                         printk(KERN_WARNING "SMU: can't "
553                                "request interrupt %d\n",
554                                smu->db_irq);
555                         smu->db_irq = NO_IRQ;
556                 }
557         }
558
559         if (smu->msg_irq != NO_IRQ) {
560                 if (request_irq(smu->msg_irq, smu_msg_intr,
561                                 SA_SHIRQ, "SMU message", smu) < 0) {
562                         printk(KERN_WARNING "SMU: can't "
563                                "request interrupt %d\n",
564                                smu->msg_irq);
565                         smu->msg_irq = NO_IRQ;
566                 }
567         }
568
569         return 0;
570 }
571 arch_initcall(smu_late_init);
572
573 /*
574  * sysfs visibility
575  */
576
577 static void smu_expose_childs(void *unused)
578 {
579         struct device_node *np;
580
581         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
582                 if (device_is_compatible(np, "smu-i2c")) {
583                         char name[32];
584                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
585
586                         if (reg == NULL)
587                                 continue;
588                         sprintf(name, "smu-i2c-%02x", *reg);
589                         of_platform_device_create(np, name, &smu->of_dev->dev);
590                 }
591         }
592
593 }
594
595 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
596
597 static int smu_platform_probe(struct of_device* dev,
598                               const struct of_device_id *match)
599 {
600         if (!smu)
601                 return -ENODEV;
602         smu->of_dev = dev;
603
604         /*
605          * Ok, we are matched, now expose all i2c busses. We have to defer
606          * that unfortunately or it would deadlock inside the device model
607          */
608         schedule_work(&smu_expose_childs_work);
609
610         return 0;
611 }
612
613 static struct of_device_id smu_platform_match[] =
614 {
615         {
616                 .type           = "smu",
617         },
618         {},
619 };
620
621 static struct of_platform_driver smu_of_platform_driver =
622 {
623         .name           = "smu",
624         .match_table    = smu_platform_match,
625         .probe          = smu_platform_probe,
626 };
627
628 static int __init smu_init_sysfs(void)
629 {
630         int rc;
631
632         /*
633          * Due to sysfs bogosity, a sysdev is not a real device, so
634          * we should in fact create both if we want sysdev semantics
635          * for power management.
636          * For now, we don't power manage machines with an SMU chip,
637          * I'm a bit too far from figuring out how that works with those
638          * new chipsets, but that will come back and bite us
639          */
640         rc = of_register_driver(&smu_of_platform_driver);
641         return 0;
642 }
643
644 device_initcall(smu_init_sysfs);
645
646 struct of_device *smu_get_ofdev(void)
647 {
648         if (!smu)
649                 return NULL;
650         return smu->of_dev;
651 }
652
653 EXPORT_SYMBOL_GPL(smu_get_ofdev);
654
655 /*
656  * i2c interface
657  */
658
659 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
660 {
661         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
662         void *misc = cmd->misc;
663         unsigned long flags;
664
665         /* Check for read case */
666         if (!fail && cmd->read) {
667                 if (cmd->pdata[0] < 1)
668                         fail = 1;
669                 else
670                         memcpy(cmd->info.data, &cmd->pdata[1],
671                                cmd->info.datalen);
672         }
673
674         DPRINTK("SMU: completing, success: %d\n", !fail);
675
676         /* Update status and mark no pending i2c command with lock
677          * held so nobody comes in while we dequeue an eventual
678          * pending next i2c command
679          */
680         spin_lock_irqsave(&smu->lock, flags);
681         smu->cmd_i2c_cur = NULL;
682         wmb();
683         cmd->status = fail ? -EIO : 0;
684
685         /* Is there another i2c command waiting ? */
686         if (!list_empty(&smu->cmd_i2c_list)) {
687                 struct smu_i2c_cmd *newcmd;
688
689                 /* Fetch it, new current, remove from list */
690                 newcmd = list_entry(smu->cmd_i2c_list.next,
691                                     struct smu_i2c_cmd, link);
692                 smu->cmd_i2c_cur = newcmd;
693                 list_del(&cmd->link);
694
695                 /* Queue with low level smu */
696                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
697                 if (smu->cmd_cur == NULL)
698                         smu_start_cmd();
699         }
700         spin_unlock_irqrestore(&smu->lock, flags);
701
702         /* Call command completion handler if any */
703         if (done)
704                 done(cmd, misc);
705
706 }
707
708
709 static void smu_i2c_retry(unsigned long data)
710 {
711         struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
712
713         DPRINTK("SMU: i2c failure, requeuing...\n");
714
715         /* requeue command simply by resetting reply_len */
716         cmd->pdata[0] = 0xff;
717         cmd->scmd.reply_len = 0x10;
718         smu_queue_cmd(&cmd->scmd);
719 }
720
721
722 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
723 {
724         struct smu_i2c_cmd      *cmd = misc;
725         int                     fail = 0;
726
727         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
728                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
729
730         /* Check for possible status */
731         if (scmd->status < 0)
732                 fail = 1;
733         else if (cmd->read) {
734                 if (cmd->stage == 0)
735                         fail = cmd->pdata[0] != 0;
736                 else
737                         fail = cmd->pdata[0] >= 0x80;
738         } else {
739                 fail = cmd->pdata[0] != 0;
740         }
741
742         /* Handle failures by requeuing command, after 5ms interval
743          */
744         if (fail && --cmd->retries > 0) {
745                 DPRINTK("SMU: i2c failure, starting timer...\n");
746                 smu->i2c_timer.function = smu_i2c_retry;
747                 smu->i2c_timer.data = (unsigned long)cmd;
748                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
749                 add_timer(&smu->i2c_timer);
750                 return;
751         }
752
753         /* If failure or stage 1, command is complete */
754         if (fail || cmd->stage != 0) {
755                 smu_i2c_complete_command(cmd, fail);
756                 return;
757         }
758
759         DPRINTK("SMU: going to stage 1\n");
760
761         /* Ok, initial command complete, now poll status */
762         scmd->reply_buf = cmd->pdata;
763         scmd->reply_len = 0x10;
764         scmd->data_buf = cmd->pdata;
765         scmd->data_len = 1;
766         cmd->pdata[0] = 0;
767         cmd->stage = 1;
768         cmd->retries = 20;
769         smu_queue_cmd(scmd);
770 }
771
772
773 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
774 {
775         unsigned long flags;
776
777         if (smu == NULL)
778                 return -ENODEV;
779
780         /* Fill most fields of scmd */
781         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
782         cmd->scmd.done = smu_i2c_low_completion;
783         cmd->scmd.misc = cmd;
784         cmd->scmd.reply_buf = cmd->pdata;
785         cmd->scmd.reply_len = 0x10;
786         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
787         cmd->scmd.status = 1;
788         cmd->stage = 0;
789         cmd->pdata[0] = 0xff;
790         cmd->retries = 20;
791         cmd->status = 1;
792
793         /* Check transfer type, sanitize some "info" fields
794          * based on transfer type and do more checking
795          */
796         cmd->info.caddr = cmd->info.devaddr;
797         cmd->read = cmd->info.devaddr & 0x01;
798         switch(cmd->info.type) {
799         case SMU_I2C_TRANSFER_SIMPLE:
800                 memset(&cmd->info.sublen, 0, 4);
801                 break;
802         case SMU_I2C_TRANSFER_COMBINED:
803                 cmd->info.devaddr &= 0xfe;
804         case SMU_I2C_TRANSFER_STDSUB:
805                 if (cmd->info.sublen > 3)
806                         return -EINVAL;
807                 break;
808         default:
809                 return -EINVAL;
810         }
811
812         /* Finish setting up command based on transfer direction
813          */
814         if (cmd->read) {
815                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
816                         return -EINVAL;
817                 memset(cmd->info.data, 0xff, cmd->info.datalen);
818                 cmd->scmd.data_len = 9;
819         } else {
820                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
821                         return -EINVAL;
822                 cmd->scmd.data_len = 9 + cmd->info.datalen;
823         }
824
825         DPRINTK("SMU: i2c enqueuing command\n");
826         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
827                 cmd->read ? "read" : "write", cmd->info.datalen,
828                 cmd->info.bus, cmd->info.caddr,
829                 cmd->info.subaddr[0], cmd->info.type);
830
831
832         /* Enqueue command in i2c list, and if empty, enqueue also in
833          * main command list
834          */
835         spin_lock_irqsave(&smu->lock, flags);
836         if (smu->cmd_i2c_cur == NULL) {
837                 smu->cmd_i2c_cur = cmd;
838                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
839                 if (smu->cmd_cur == NULL)
840                         smu_start_cmd();
841         } else
842                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
843         spin_unlock_irqrestore(&smu->lock, flags);
844
845         return 0;
846 }
847
848
849
850 /*
851  * Userland driver interface
852  */
853
854
855 static LIST_HEAD(smu_clist);
856 static DEFINE_SPINLOCK(smu_clist_lock);
857
858 enum smu_file_mode {
859         smu_file_commands,
860         smu_file_events,
861         smu_file_closing
862 };
863
864 struct smu_private
865 {
866         struct list_head        list;
867         enum smu_file_mode      mode;
868         int                     busy;
869         struct smu_cmd          cmd;
870         spinlock_t              lock;
871         wait_queue_head_t       wait;
872         u8                      buffer[SMU_MAX_DATA];
873 };
874
875
876 static int smu_open(struct inode *inode, struct file *file)
877 {
878         struct smu_private *pp;
879         unsigned long flags;
880
881         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
882         if (pp == 0)
883                 return -ENOMEM;
884         memset(pp, 0, sizeof(struct smu_private));
885         spin_lock_init(&pp->lock);
886         pp->mode = smu_file_commands;
887         init_waitqueue_head(&pp->wait);
888
889         spin_lock_irqsave(&smu_clist_lock, flags);
890         list_add(&pp->list, &smu_clist);
891         spin_unlock_irqrestore(&smu_clist_lock, flags);
892         file->private_data = pp;
893
894         return 0;
895 }
896
897
898 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
899 {
900         struct smu_private *pp = misc;
901
902         wake_up_all(&pp->wait);
903 }
904
905
906 static ssize_t smu_write(struct file *file, const char __user *buf,
907                          size_t count, loff_t *ppos)
908 {
909         struct smu_private *pp = file->private_data;
910         unsigned long flags;
911         struct smu_user_cmd_hdr hdr;
912         int rc = 0;
913
914         if (pp->busy)
915                 return -EBUSY;
916         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
917                 return -EFAULT;
918         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
919                 pp->mode = smu_file_events;
920                 return 0;
921         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
922                 return -EINVAL;
923         else if (pp->mode != smu_file_commands)
924                 return -EBADFD;
925         else if (hdr.data_len > SMU_MAX_DATA)
926                 return -EINVAL;
927
928         spin_lock_irqsave(&pp->lock, flags);
929         if (pp->busy) {
930                 spin_unlock_irqrestore(&pp->lock, flags);
931                 return -EBUSY;
932         }
933         pp->busy = 1;
934         pp->cmd.status = 1;
935         spin_unlock_irqrestore(&pp->lock, flags);
936
937         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
938                 pp->busy = 0;
939                 return -EFAULT;
940         }
941
942         pp->cmd.cmd = hdr.cmd;
943         pp->cmd.data_len = hdr.data_len;
944         pp->cmd.reply_len = SMU_MAX_DATA;
945         pp->cmd.data_buf = pp->buffer;
946         pp->cmd.reply_buf = pp->buffer;
947         pp->cmd.done = smu_user_cmd_done;
948         pp->cmd.misc = pp;
949         rc = smu_queue_cmd(&pp->cmd);
950         if (rc < 0)
951                 return rc;
952         return count;
953 }
954
955
956 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
957                                 char __user *buf, size_t count)
958 {
959         DECLARE_WAITQUEUE(wait, current);
960         struct smu_user_reply_hdr hdr;
961         unsigned long flags;
962         int size, rc = 0;
963
964         if (!pp->busy)
965                 return 0;
966         if (count < sizeof(struct smu_user_reply_hdr))
967                 return -EOVERFLOW;
968         spin_lock_irqsave(&pp->lock, flags);
969         if (pp->cmd.status == 1) {
970                 if (file->f_flags & O_NONBLOCK)
971                         return -EAGAIN;
972                 add_wait_queue(&pp->wait, &wait);
973                 for (;;) {
974                         set_current_state(TASK_INTERRUPTIBLE);
975                         rc = 0;
976                         if (pp->cmd.status != 1)
977                                 break;
978                         rc = -ERESTARTSYS;
979                         if (signal_pending(current))
980                                 break;
981                         spin_unlock_irqrestore(&pp->lock, flags);
982                         schedule();
983                         spin_lock_irqsave(&pp->lock, flags);
984                 }
985                 set_current_state(TASK_RUNNING);
986                 remove_wait_queue(&pp->wait, &wait);
987         }
988         spin_unlock_irqrestore(&pp->lock, flags);
989         if (rc)
990                 return rc;
991         if (pp->cmd.status != 0)
992                 pp->cmd.reply_len = 0;
993         size = sizeof(hdr) + pp->cmd.reply_len;
994         if (count < size)
995                 size = count;
996         rc = size;
997         hdr.status = pp->cmd.status;
998         hdr.reply_len = pp->cmd.reply_len;
999         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1000                 return -EFAULT;
1001         size -= sizeof(hdr);
1002         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1003                 return -EFAULT;
1004         pp->busy = 0;
1005
1006         return rc;
1007 }
1008
1009
1010 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1011                                char __user *buf, size_t count)
1012 {
1013         /* Not implemented */
1014         msleep_interruptible(1000);
1015         return 0;
1016 }
1017
1018
1019 static ssize_t smu_read(struct file *file, char __user *buf,
1020                         size_t count, loff_t *ppos)
1021 {
1022         struct smu_private *pp = file->private_data;
1023
1024         if (pp->mode == smu_file_commands)
1025                 return smu_read_command(file, pp, buf, count);
1026         if (pp->mode == smu_file_events)
1027                 return smu_read_events(file, pp, buf, count);
1028
1029         return -EBADFD;
1030 }
1031
1032 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1033 {
1034         struct smu_private *pp = file->private_data;
1035         unsigned int mask = 0;
1036         unsigned long flags;
1037
1038         if (pp == 0)
1039                 return 0;
1040
1041         if (pp->mode == smu_file_commands) {
1042                 poll_wait(file, &pp->wait, wait);
1043
1044                 spin_lock_irqsave(&pp->lock, flags);
1045                 if (pp->busy && pp->cmd.status != 1)
1046                         mask |= POLLIN;
1047                 spin_unlock_irqrestore(&pp->lock, flags);
1048         } if (pp->mode == smu_file_events) {
1049                 /* Not yet implemented */
1050         }
1051         return mask;
1052 }
1053
1054 static int smu_release(struct inode *inode, struct file *file)
1055 {
1056         struct smu_private *pp = file->private_data;
1057         unsigned long flags;
1058         unsigned int busy;
1059
1060         if (pp == 0)
1061                 return 0;
1062
1063         file->private_data = NULL;
1064
1065         /* Mark file as closing to avoid races with new request */
1066         spin_lock_irqsave(&pp->lock, flags);
1067         pp->mode = smu_file_closing;
1068         busy = pp->busy;
1069
1070         /* Wait for any pending request to complete */
1071         if (busy && pp->cmd.status == 1) {
1072                 DECLARE_WAITQUEUE(wait, current);
1073
1074                 add_wait_queue(&pp->wait, &wait);
1075                 for (;;) {
1076                         set_current_state(TASK_UNINTERRUPTIBLE);
1077                         if (pp->cmd.status != 1)
1078                                 break;
1079                         spin_lock_irqsave(&pp->lock, flags);
1080                         schedule();
1081                         spin_unlock_irqrestore(&pp->lock, flags);
1082                 }
1083                 set_current_state(TASK_RUNNING);
1084                 remove_wait_queue(&pp->wait, &wait);
1085         }
1086         spin_unlock_irqrestore(&pp->lock, flags);
1087
1088         spin_lock_irqsave(&smu_clist_lock, flags);
1089         list_del(&pp->list);
1090         spin_unlock_irqrestore(&smu_clist_lock, flags);
1091         kfree(pp);
1092
1093         return 0;
1094 }
1095
1096
1097 static struct file_operations smu_device_fops = {
1098         .llseek         = no_llseek,
1099         .read           = smu_read,
1100         .write          = smu_write,
1101         .poll           = smu_fpoll,
1102         .open           = smu_open,
1103         .release        = smu_release,
1104 };
1105
1106 static struct miscdevice pmu_device = {
1107         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1108 };
1109
1110 static int smu_device_init(void)
1111 {
1112         if (!smu)
1113                 return -ENODEV;
1114         if (misc_register(&pmu_device) < 0)
1115                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1116         return 0;
1117 }
1118 device_initcall(smu_device_init);