[PATCH] ppc64: SMU driver update & i2c support
[linux-2.6.git] / 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                 return IRQ_HANDLED;
158
159         cmd = smu->cmd_cur;
160         smu->cmd_cur = NULL;
161         if (cmd == NULL)
162                 goto bail;
163
164         if (rc == 0) {
165                 unsigned long faddr;
166                 int reply_len;
167                 u8 ack;
168
169                 /* CPU might have brought back the cache line, so we need
170                  * to flush again before peeking at the SMU response. We
171                  * flush the entire buffer for now as we haven't read the
172                  * reply lenght (it's only 2 cache lines anyway)
173                  */
174                 faddr = (unsigned long)smu->cmd_buf;
175                 flush_inval_dcache_range(faddr, faddr + 256);
176
177                 /* Now check ack */
178                 ack = (~cmd->cmd) & 0xff;
179                 if (ack != smu->cmd_buf->cmd) {
180                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
181                                 ack, smu->cmd_buf->cmd);
182                         rc = -EIO;
183                 }
184                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
185                 DPRINTK("SMU: reply len: %d\n", reply_len);
186                 if (reply_len > cmd->reply_len) {
187                         printk(KERN_WARNING "SMU: reply buffer too small,"
188                                "got %d bytes for a %d bytes buffer\n",
189                                reply_len, cmd->reply_len);
190                         reply_len = cmd->reply_len;
191                 }
192                 cmd->reply_len = reply_len;
193                 if (cmd->reply_buf && reply_len)
194                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
195         }
196
197         /* Now complete the command. Write status last in order as we lost
198          * ownership of the command structure as soon as it's no longer -1
199          */
200         done = cmd->done;
201         misc = cmd->misc;
202         mb();
203         cmd->status = rc;
204  bail:
205         /* Start next command if any */
206         smu_start_cmd();
207         spin_unlock_irqrestore(&smu->lock, flags);
208
209         /* Call command completion handler if any */
210         if (done)
211                 done(cmd, misc);
212
213         /* It's an edge interrupt, nothing to do */
214         return IRQ_HANDLED;
215 }
216
217
218 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
219 {
220         /* I don't quite know what to do with this one, we seem to never
221          * receive it, so I suspect we have to arm it someway in the SMU
222          * to start getting events that way.
223          */
224
225         printk(KERN_INFO "SMU: message interrupt !\n");
226
227         /* It's an edge interrupt, nothing to do */
228         return IRQ_HANDLED;
229 }
230
231
232 /*
233  * Queued command management.
234  *
235  */
236
237 int smu_queue_cmd(struct smu_cmd *cmd)
238 {
239         unsigned long flags;
240
241         if (smu == NULL)
242                 return -ENODEV;
243         if (cmd->data_len > SMU_MAX_DATA ||
244             cmd->reply_len > SMU_MAX_DATA)
245                 return -EINVAL;
246
247         cmd->status = 1;
248         spin_lock_irqsave(&smu->lock, flags);
249         list_add_tail(&cmd->link, &smu->cmd_list);
250         if (smu->cmd_cur == NULL)
251                 smu_start_cmd();
252         spin_unlock_irqrestore(&smu->lock, flags);
253
254         return 0;
255 }
256 EXPORT_SYMBOL(smu_queue_cmd);
257
258
259 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
260                      unsigned int data_len,
261                      void (*done)(struct smu_cmd *cmd, void *misc),
262                      void *misc, ...)
263 {
264         struct smu_cmd *cmd = &scmd->cmd;
265         va_list list;
266         int i;
267
268         if (data_len > sizeof(scmd->buffer))
269                 return -EINVAL;
270
271         memset(scmd, 0, sizeof(*scmd));
272         cmd->cmd = command;
273         cmd->data_len = data_len;
274         cmd->data_buf = scmd->buffer;
275         cmd->reply_len = sizeof(scmd->buffer);
276         cmd->reply_buf = scmd->buffer;
277         cmd->done = done;
278         cmd->misc = misc;
279
280         va_start(list, misc);
281         for (i = 0; i < data_len; ++i)
282                 scmd->buffer[i] = (u8)va_arg(list, int);
283         va_end(list);
284
285         return smu_queue_cmd(cmd);
286 }
287 EXPORT_SYMBOL(smu_queue_simple);
288
289
290 void smu_poll(void)
291 {
292         u8 gpio;
293
294         if (smu == NULL)
295                 return;
296
297         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
298         if ((gpio & 7) == 7)
299                 smu_db_intr(smu->db_irq, smu, NULL);
300 }
301 EXPORT_SYMBOL(smu_poll);
302
303
304 void smu_done_complete(struct smu_cmd *cmd, void *misc)
305 {
306         struct completion *comp = misc;
307
308         complete(comp);
309 }
310 EXPORT_SYMBOL(smu_done_complete);
311
312
313 void smu_spinwait_cmd(struct smu_cmd *cmd)
314 {
315         while(cmd->status == 1)
316                 smu_poll();
317 }
318 EXPORT_SYMBOL(smu_spinwait_cmd);
319
320
321 /* RTC low level commands */
322 static inline int bcd2hex (int n)
323 {
324         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
325 }
326
327
328 static inline int hex2bcd (int n)
329 {
330         return ((n / 10) << 4) + (n % 10);
331 }
332
333
334 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
335                                         struct rtc_time *time)
336 {
337         cmd_buf->cmd = 0x8e;
338         cmd_buf->length = 8;
339         cmd_buf->data[0] = 0x80;
340         cmd_buf->data[1] = hex2bcd(time->tm_sec);
341         cmd_buf->data[2] = hex2bcd(time->tm_min);
342         cmd_buf->data[3] = hex2bcd(time->tm_hour);
343         cmd_buf->data[4] = time->tm_wday;
344         cmd_buf->data[5] = hex2bcd(time->tm_mday);
345         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
346         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
347 }
348
349
350 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
351 {
352         struct smu_simple_cmd cmd;
353         int rc;
354
355         if (smu == NULL)
356                 return -ENODEV;
357
358         memset(time, 0, sizeof(struct rtc_time));
359         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
360                               SMU_CMD_RTC_GET_DATETIME);
361         if (rc)
362                 return rc;
363         smu_spinwait_simple(&cmd);
364
365         time->tm_sec = bcd2hex(cmd.buffer[0]);
366         time->tm_min = bcd2hex(cmd.buffer[1]);
367         time->tm_hour = bcd2hex(cmd.buffer[2]);
368         time->tm_wday = bcd2hex(cmd.buffer[3]);
369         time->tm_mday = bcd2hex(cmd.buffer[4]);
370         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
371         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
372
373         return 0;
374 }
375
376
377 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
378 {
379         struct smu_simple_cmd cmd;
380         int rc;
381
382         if (smu == NULL)
383                 return -ENODEV;
384
385         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
386                               SMU_CMD_RTC_SET_DATETIME,
387                               hex2bcd(time->tm_sec),
388                               hex2bcd(time->tm_min),
389                               hex2bcd(time->tm_hour),
390                               time->tm_wday,
391                               hex2bcd(time->tm_mday),
392                               hex2bcd(time->tm_mon) + 1,
393                               hex2bcd(time->tm_year - 100));
394         if (rc)
395                 return rc;
396         smu_spinwait_simple(&cmd);
397
398         return 0;
399 }
400
401
402 void smu_shutdown(void)
403 {
404         struct smu_simple_cmd cmd;
405
406         if (smu == NULL)
407                 return;
408
409         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
410                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
411                 return;
412         smu_spinwait_simple(&cmd);
413         for (;;)
414                 ;
415 }
416
417
418 void smu_restart(void)
419 {
420         struct smu_simple_cmd cmd;
421
422         if (smu == NULL)
423                 return;
424
425         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
426                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
427                 return;
428         smu_spinwait_simple(&cmd);
429         for (;;)
430                 ;
431 }
432
433
434 int smu_present(void)
435 {
436         return smu != NULL;
437 }
438 EXPORT_SYMBOL(smu_present);
439
440
441 int smu_init (void)
442 {
443         struct device_node *np;
444         u32 *data;
445
446         np = of_find_node_by_type(NULL, "smu");
447         if (np == NULL)
448                 return -ENODEV;
449
450         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
451
452         if (smu_cmdbuf_abs == 0) {
453                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
454                 return -EINVAL;
455         }
456
457         smu = alloc_bootmem(sizeof(struct smu_device));
458         if (smu == NULL)
459                 return -ENOMEM;
460         memset(smu, 0, sizeof(*smu));
461
462         spin_lock_init(&smu->lock);
463         INIT_LIST_HEAD(&smu->cmd_list);
464         INIT_LIST_HEAD(&smu->cmd_i2c_list);
465         smu->of_node = np;
466         smu->db_irq = NO_IRQ;
467         smu->msg_irq = NO_IRQ;
468         init_timer(&smu->i2c_timer);
469
470         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
471          * 32 bits value safely
472          */
473         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
474         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
475
476         np = of_find_node_by_name(NULL, "smu-doorbell");
477         if (np == NULL) {
478                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
479                 goto fail;
480         }
481         data = (u32 *)get_property(np, "reg", NULL);
482         if (data == NULL) {
483                 of_node_put(np);
484                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
485                 goto fail;
486         }
487
488         /* Current setup has one doorbell GPIO that does both doorbell
489          * and ack. GPIOs are at 0x50, best would be to find that out
490          * in the device-tree though.
491          */
492         smu->doorbell = *data;
493         if (smu->doorbell < 0x50)
494                 smu->doorbell += 0x50;
495         if (np->n_intrs > 0)
496                 smu->db_irq = np->intrs[0].line;
497
498         of_node_put(np);
499
500         /* Now look for the smu-interrupt GPIO */
501         do {
502                 np = of_find_node_by_name(NULL, "smu-interrupt");
503                 if (np == NULL)
504                         break;
505                 data = (u32 *)get_property(np, "reg", NULL);
506                 if (data == NULL) {
507                         of_node_put(np);
508                         break;
509                 }
510                 smu->msg = *data;
511                 if (smu->msg < 0x50)
512                         smu->msg += 0x50;
513                 if (np->n_intrs > 0)
514                         smu->msg_irq = np->intrs[0].line;
515                 of_node_put(np);
516         } while(0);
517
518         /* Doorbell buffer is currently hard-coded, I didn't find a proper
519          * device-tree entry giving the address. Best would probably to use
520          * an offset for K2 base though, but let's do it that way for now.
521          */
522         smu->db_buf = ioremap(0x8000860c, 0x1000);
523         if (smu->db_buf == NULL) {
524                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
525                 goto fail;
526         }
527
528         sys_ctrler = SYS_CTRLER_SMU;
529         return 0;
530
531  fail:
532         smu = NULL;
533         return -ENXIO;
534
535 }
536
537
538 static int smu_late_init(void)
539 {
540         if (!smu)
541                 return 0;
542
543         /*
544          * Try to request the interrupts
545          */
546
547         if (smu->db_irq != NO_IRQ) {
548                 if (request_irq(smu->db_irq, smu_db_intr,
549                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
550                         printk(KERN_WARNING "SMU: can't "
551                                "request interrupt %d\n",
552                                smu->db_irq);
553                         smu->db_irq = NO_IRQ;
554                 }
555         }
556
557         if (smu->msg_irq != NO_IRQ) {
558                 if (request_irq(smu->msg_irq, smu_msg_intr,
559                                 SA_SHIRQ, "SMU message", smu) < 0) {
560                         printk(KERN_WARNING "SMU: can't "
561                                "request interrupt %d\n",
562                                smu->msg_irq);
563                         smu->msg_irq = NO_IRQ;
564                 }
565         }
566
567         return 0;
568 }
569 arch_initcall(smu_late_init);
570
571 /*
572  * sysfs visibility
573  */
574
575 static void smu_expose_childs(void *unused)
576 {
577         struct device_node *np;
578
579         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
580                 if (device_is_compatible(np, "smu-i2c")) {
581                         char name[32];
582                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
583
584                         if (reg == NULL)
585                                 continue;
586                         sprintf(name, "smu-i2c-%02x", *reg);
587                         of_platform_device_create(np, name, &smu->of_dev->dev);
588                 }
589         }
590
591 }
592
593 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
594
595 static int smu_platform_probe(struct of_device* dev,
596                               const struct of_device_id *match)
597 {
598         if (!smu)
599                 return -ENODEV;
600         smu->of_dev = dev;
601
602         /*
603          * Ok, we are matched, now expose all i2c busses. We have to defer
604          * that unfortunately or it would deadlock inside the device model
605          */
606         schedule_work(&smu_expose_childs_work);
607
608         return 0;
609 }
610
611 static struct of_device_id smu_platform_match[] =
612 {
613         {
614                 .type           = "smu",
615         },
616         {},
617 };
618
619 static struct of_platform_driver smu_of_platform_driver =
620 {
621         .name           = "smu",
622         .match_table    = smu_platform_match,
623         .probe          = smu_platform_probe,
624 };
625
626 static int __init smu_init_sysfs(void)
627 {
628         int rc;
629
630         /*
631          * Due to sysfs bogosity, a sysdev is not a real device, so
632          * we should in fact create both if we want sysdev semantics
633          * for power management.
634          * For now, we don't power manage machines with an SMU chip,
635          * I'm a bit too far from figuring out how that works with those
636          * new chipsets, but that will come back and bite us
637          */
638         rc = of_register_driver(&smu_of_platform_driver);
639         return 0;
640 }
641
642 device_initcall(smu_init_sysfs);
643
644 struct of_device *smu_get_ofdev(void)
645 {
646         if (!smu)
647                 return NULL;
648         return smu->of_dev;
649 }
650
651 EXPORT_SYMBOL_GPL(smu_get_ofdev);
652
653 /*
654  * i2c interface
655  */
656
657 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
658 {
659         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
660         void *misc = cmd->misc;
661         unsigned long flags;
662
663         /* Check for read case */
664         if (!fail && cmd->read) {
665                 if (cmd->pdata[0] < 1)
666                         fail = 1;
667                 else
668                         memcpy(cmd->info.data, &cmd->pdata[1],
669                                cmd->info.datalen);
670         }
671
672         DPRINTK("SMU: completing, success: %d\n", !fail);
673
674         /* Update status and mark no pending i2c command with lock
675          * held so nobody comes in while we dequeue an eventual
676          * pending next i2c command
677          */
678         spin_lock_irqsave(&smu->lock, flags);
679         smu->cmd_i2c_cur = NULL;
680         wmb();
681         cmd->status = fail ? -EIO : 0;
682
683         /* Is there another i2c command waiting ? */
684         if (!list_empty(&smu->cmd_i2c_list)) {
685                 struct smu_i2c_cmd *newcmd;
686
687                 /* Fetch it, new current, remove from list */
688                 newcmd = list_entry(smu->cmd_i2c_list.next,
689                                     struct smu_i2c_cmd, link);
690                 smu->cmd_i2c_cur = newcmd;
691                 list_del(&cmd->link);
692
693                 /* Queue with low level smu */
694                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
695                 if (smu->cmd_cur == NULL)
696                         smu_start_cmd();
697         }
698         spin_unlock_irqrestore(&smu->lock, flags);
699
700         /* Call command completion handler if any */
701         if (done)
702                 done(cmd, misc);
703
704 }
705
706
707 static void smu_i2c_retry(unsigned long data)
708 {
709         struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
710
711         DPRINTK("SMU: i2c failure, requeuing...\n");
712
713         /* requeue command simply by resetting reply_len */
714         cmd->pdata[0] = 0xff;
715         cmd->scmd.reply_len = 0x10;
716         smu_queue_cmd(&cmd->scmd);
717 }
718
719
720 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
721 {
722         struct smu_i2c_cmd      *cmd = misc;
723         int                     fail = 0;
724
725         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
726                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
727
728         /* Check for possible status */
729         if (scmd->status < 0)
730                 fail = 1;
731         else if (cmd->read) {
732                 if (cmd->stage == 0)
733                         fail = cmd->pdata[0] != 0;
734                 else
735                         fail = cmd->pdata[0] >= 0x80;
736         } else {
737                 fail = cmd->pdata[0] != 0;
738         }
739
740         /* Handle failures by requeuing command, after 5ms interval
741          */
742         if (fail && --cmd->retries > 0) {
743                 DPRINTK("SMU: i2c failure, starting timer...\n");
744                 smu->i2c_timer.function = smu_i2c_retry;
745                 smu->i2c_timer.data = (unsigned long)cmd;
746                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
747                 add_timer(&smu->i2c_timer);
748                 return;
749         }
750
751         /* If failure or stage 1, command is complete */
752         if (fail || cmd->stage != 0) {
753                 smu_i2c_complete_command(cmd, fail);
754                 return;
755         }
756
757         DPRINTK("SMU: going to stage 1\n");
758
759         /* Ok, initial command complete, now poll status */
760         scmd->reply_buf = cmd->pdata;
761         scmd->reply_len = 0x10;
762         scmd->data_buf = cmd->pdata;
763         scmd->data_len = 1;
764         cmd->pdata[0] = 0;
765         cmd->stage = 1;
766         cmd->retries = 20;
767         smu_queue_cmd(scmd);
768 }
769
770
771 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
772 {
773         unsigned long flags;
774
775         if (smu == NULL)
776                 return -ENODEV;
777
778         /* Fill most fields of scmd */
779         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
780         cmd->scmd.done = smu_i2c_low_completion;
781         cmd->scmd.misc = cmd;
782         cmd->scmd.reply_buf = cmd->pdata;
783         cmd->scmd.reply_len = 0x10;
784         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
785         cmd->scmd.status = 1;
786         cmd->stage = 0;
787         cmd->pdata[0] = 0xff;
788         cmd->retries = 20;
789         cmd->status = 1;
790
791         /* Check transfer type, sanitize some "info" fields
792          * based on transfer type and do more checking
793          */
794         cmd->info.caddr = cmd->info.devaddr;
795         cmd->read = cmd->info.devaddr & 0x01;
796         switch(cmd->info.type) {
797         case SMU_I2C_TRANSFER_SIMPLE:
798                 memset(&cmd->info.sublen, 0, 4);
799                 break;
800         case SMU_I2C_TRANSFER_COMBINED:
801                 cmd->info.devaddr &= 0xfe;
802         case SMU_I2C_TRANSFER_STDSUB:
803                 if (cmd->info.sublen > 3)
804                         return -EINVAL;
805                 break;
806         default:
807                 return -EINVAL;
808         }
809
810         /* Finish setting up command based on transfer direction
811          */
812         if (cmd->read) {
813                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
814                         return -EINVAL;
815                 memset(cmd->info.data, 0xff, cmd->info.datalen);
816                 cmd->scmd.data_len = 9;
817         } else {
818                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
819                         return -EINVAL;
820                 cmd->scmd.data_len = 9 + cmd->info.datalen;
821         }
822
823         DPRINTK("SMU: i2c enqueuing command\n");
824         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
825                 cmd->read ? "read" : "write", cmd->info.datalen,
826                 cmd->info.bus, cmd->info.caddr,
827                 cmd->info.subaddr[0], cmd->info.type);
828
829
830         /* Enqueue command in i2c list, and if empty, enqueue also in
831          * main command list
832          */
833         spin_lock_irqsave(&smu->lock, flags);
834         if (smu->cmd_i2c_cur == NULL) {
835                 smu->cmd_i2c_cur = cmd;
836                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
837                 if (smu->cmd_cur == NULL)
838                         smu_start_cmd();
839         } else
840                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
841         spin_unlock_irqrestore(&smu->lock, flags);
842
843         return 0;
844 }
845
846
847
848 /*
849  * Userland driver interface
850  */
851
852
853 static LIST_HEAD(smu_clist);
854 static DEFINE_SPINLOCK(smu_clist_lock);
855
856 enum smu_file_mode {
857         smu_file_commands,
858         smu_file_events,
859         smu_file_closing
860 };
861
862 struct smu_private
863 {
864         struct list_head        list;
865         enum smu_file_mode      mode;
866         int                     busy;
867         struct smu_cmd          cmd;
868         spinlock_t              lock;
869         wait_queue_head_t       wait;
870         u8                      buffer[SMU_MAX_DATA];
871 };
872
873
874 static int smu_open(struct inode *inode, struct file *file)
875 {
876         struct smu_private *pp;
877         unsigned long flags;
878
879         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
880         if (pp == 0)
881                 return -ENOMEM;
882         memset(pp, 0, sizeof(struct smu_private));
883         spin_lock_init(&pp->lock);
884         pp->mode = smu_file_commands;
885         init_waitqueue_head(&pp->wait);
886
887         spin_lock_irqsave(&smu_clist_lock, flags);
888         list_add(&pp->list, &smu_clist);
889         spin_unlock_irqrestore(&smu_clist_lock, flags);
890         file->private_data = pp;
891
892         return 0;
893 }
894
895
896 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
897 {
898         struct smu_private *pp = misc;
899
900         wake_up_all(&pp->wait);
901 }
902
903
904 static ssize_t smu_write(struct file *file, const char __user *buf,
905                          size_t count, loff_t *ppos)
906 {
907         struct smu_private *pp = file->private_data;
908         unsigned long flags;
909         struct smu_user_cmd_hdr hdr;
910         int rc = 0;
911
912         if (pp->busy)
913                 return -EBUSY;
914         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
915                 return -EFAULT;
916         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
917                 pp->mode = smu_file_events;
918                 return 0;
919         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
920                 return -EINVAL;
921         else if (pp->mode != smu_file_commands)
922                 return -EBADFD;
923         else if (hdr.data_len > SMU_MAX_DATA)
924                 return -EINVAL;
925
926         spin_lock_irqsave(&pp->lock, flags);
927         if (pp->busy) {
928                 spin_unlock_irqrestore(&pp->lock, flags);
929                 return -EBUSY;
930         }
931         pp->busy = 1;
932         pp->cmd.status = 1;
933         spin_unlock_irqrestore(&pp->lock, flags);
934
935         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
936                 pp->busy = 0;
937                 return -EFAULT;
938         }
939
940         pp->cmd.cmd = hdr.cmd;
941         pp->cmd.data_len = hdr.data_len;
942         pp->cmd.reply_len = SMU_MAX_DATA;
943         pp->cmd.data_buf = pp->buffer;
944         pp->cmd.reply_buf = pp->buffer;
945         pp->cmd.done = smu_user_cmd_done;
946         pp->cmd.misc = pp;
947         rc = smu_queue_cmd(&pp->cmd);
948         if (rc < 0)
949                 return rc;
950         return count;
951 }
952
953
954 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
955                                 char __user *buf, size_t count)
956 {
957         DECLARE_WAITQUEUE(wait, current);
958         struct smu_user_reply_hdr hdr;
959         unsigned long flags;
960         int size, rc = 0;
961
962         if (!pp->busy)
963                 return 0;
964         if (count < sizeof(struct smu_user_reply_hdr))
965                 return -EOVERFLOW;
966         spin_lock_irqsave(&pp->lock, flags);
967         if (pp->cmd.status == 1) {
968                 if (file->f_flags & O_NONBLOCK)
969                         return -EAGAIN;
970                 add_wait_queue(&pp->wait, &wait);
971                 for (;;) {
972                         set_current_state(TASK_INTERRUPTIBLE);
973                         rc = 0;
974                         if (pp->cmd.status != 1)
975                                 break;
976                         rc = -ERESTARTSYS;
977                         if (signal_pending(current))
978                                 break;
979                         spin_unlock_irqrestore(&pp->lock, flags);
980                         schedule();
981                         spin_lock_irqsave(&pp->lock, flags);
982                 }
983                 set_current_state(TASK_RUNNING);
984                 remove_wait_queue(&pp->wait, &wait);
985         }
986         spin_unlock_irqrestore(&pp->lock, flags);
987         if (rc)
988                 return rc;
989         if (pp->cmd.status != 0)
990                 pp->cmd.reply_len = 0;
991         size = sizeof(hdr) + pp->cmd.reply_len;
992         if (count < size)
993                 size = count;
994         rc = size;
995         hdr.status = pp->cmd.status;
996         hdr.reply_len = pp->cmd.reply_len;
997         if (copy_to_user(buf, &hdr, sizeof(hdr)))
998                 return -EFAULT;
999         size -= sizeof(hdr);
1000         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1001                 return -EFAULT;
1002         pp->busy = 0;
1003
1004         return rc;
1005 }
1006
1007
1008 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1009                                char __user *buf, size_t count)
1010 {
1011         /* Not implemented */
1012         msleep_interruptible(1000);
1013         return 0;
1014 }
1015
1016
1017 static ssize_t smu_read(struct file *file, char __user *buf,
1018                         size_t count, loff_t *ppos)
1019 {
1020         struct smu_private *pp = file->private_data;
1021
1022         if (pp->mode == smu_file_commands)
1023                 return smu_read_command(file, pp, buf, count);
1024         if (pp->mode == smu_file_events)
1025                 return smu_read_events(file, pp, buf, count);
1026
1027         return -EBADFD;
1028 }
1029
1030 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1031 {
1032         struct smu_private *pp = file->private_data;
1033         unsigned int mask = 0;
1034         unsigned long flags;
1035
1036         if (pp == 0)
1037                 return 0;
1038
1039         if (pp->mode == smu_file_commands) {
1040                 poll_wait(file, &pp->wait, wait);
1041
1042                 spin_lock_irqsave(&pp->lock, flags);
1043                 if (pp->busy && pp->cmd.status != 1)
1044                         mask |= POLLIN;
1045                 spin_unlock_irqrestore(&pp->lock, flags);
1046         } if (pp->mode == smu_file_events) {
1047                 /* Not yet implemented */
1048         }
1049         return mask;
1050 }
1051
1052 static int smu_release(struct inode *inode, struct file *file)
1053 {
1054         struct smu_private *pp = file->private_data;
1055         unsigned long flags;
1056         unsigned int busy;
1057
1058         if (pp == 0)
1059                 return 0;
1060
1061         file->private_data = NULL;
1062
1063         /* Mark file as closing to avoid races with new request */
1064         spin_lock_irqsave(&pp->lock, flags);
1065         pp->mode = smu_file_closing;
1066         busy = pp->busy;
1067
1068         /* Wait for any pending request to complete */
1069         if (busy && pp->cmd.status == 1) {
1070                 DECLARE_WAITQUEUE(wait, current);
1071
1072                 add_wait_queue(&pp->wait, &wait);
1073                 for (;;) {
1074                         set_current_state(TASK_UNINTERRUPTIBLE);
1075                         if (pp->cmd.status != 1)
1076                                 break;
1077                         spin_lock_irqsave(&pp->lock, flags);
1078                         schedule();
1079                         spin_unlock_irqrestore(&pp->lock, flags);
1080                 }
1081                 set_current_state(TASK_RUNNING);
1082                 remove_wait_queue(&pp->wait, &wait);
1083         }
1084         spin_unlock_irqrestore(&pp->lock, flags);
1085
1086         spin_lock_irqsave(&smu_clist_lock, flags);
1087         list_del(&pp->list);
1088         spin_unlock_irqrestore(&smu_clist_lock, flags);
1089         kfree(pp);
1090
1091         return 0;
1092 }
1093
1094
1095 static struct file_operations smu_device_fops __pmacdata = {
1096         .llseek         = no_llseek,
1097         .read           = smu_read,
1098         .write          = smu_write,
1099         .poll           = smu_fpoll,
1100         .open           = smu_open,
1101         .release        = smu_release,
1102 };
1103
1104 static struct miscdevice pmu_device __pmacdata = {
1105         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1106 };
1107
1108 static int smu_device_init(void)
1109 {
1110         if (!smu)
1111                 return -ENODEV;
1112         if (misc_register(&pmu_device) < 0)
1113                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1114         return 0;
1115 }
1116 device_initcall(smu_device_init);