drm: proper fix for drm_context
[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 "0.7"
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 { udbg_printf(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 static DECLARE_MUTEX(smu_part_access);
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 %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                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
120                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
121
122         /* Fill the SMU command buffer */
123         smu->cmd_buf->cmd = cmd->cmd;
124         smu->cmd_buf->length = cmd->data_len;
125         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
126
127         /* Flush command and data to RAM */
128         faddr = (unsigned long)smu->cmd_buf;
129         fend = faddr + smu->cmd_buf->length + 2;
130         flush_inval_dcache_range(faddr, fend);
131
132         /* This isn't exactly a DMA mapping here, I suspect
133          * the SMU is actually communicating with us via i2c to the
134          * northbridge or the CPU to access RAM.
135          */
136         writel(smu->cmd_buf_abs, smu->db_buf);
137
138         /* Ring the SMU doorbell */
139         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
140 }
141
142
143 static irqreturn_t smu_db_intr(int irq, void *arg, struct pt_regs *regs)
144 {
145         unsigned long flags;
146         struct smu_cmd *cmd;
147         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
148         void *misc = NULL;
149         u8 gpio;
150         int rc = 0;
151
152         /* SMU completed the command, well, we hope, let's make sure
153          * of it
154          */
155         spin_lock_irqsave(&smu->lock, flags);
156
157         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
158         if ((gpio & 7) != 7) {
159                 spin_unlock_irqrestore(&smu->lock, flags);
160                 return IRQ_HANDLED;
161         }
162
163         cmd = smu->cmd_cur;
164         smu->cmd_cur = NULL;
165         if (cmd == NULL)
166                 goto bail;
167
168         if (rc == 0) {
169                 unsigned long faddr;
170                 int reply_len;
171                 u8 ack;
172
173                 /* CPU might have brought back the cache line, so we need
174                  * to flush again before peeking at the SMU response. We
175                  * flush the entire buffer for now as we haven't read the
176                  * reply lenght (it's only 2 cache lines anyway)
177                  */
178                 faddr = (unsigned long)smu->cmd_buf;
179                 flush_inval_dcache_range(faddr, faddr + 256);
180
181                 /* Now check ack */
182                 ack = (~cmd->cmd) & 0xff;
183                 if (ack != smu->cmd_buf->cmd) {
184                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
185                                 ack, smu->cmd_buf->cmd);
186                         rc = -EIO;
187                 }
188                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
189                 DPRINTK("SMU: reply len: %d\n", reply_len);
190                 if (reply_len > cmd->reply_len) {
191                         printk(KERN_WARNING "SMU: reply buffer too small,"
192                                "got %d bytes for a %d bytes buffer\n",
193                                reply_len, cmd->reply_len);
194                         reply_len = cmd->reply_len;
195                 }
196                 cmd->reply_len = reply_len;
197                 if (cmd->reply_buf && reply_len)
198                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
199         }
200
201         /* Now complete the command. Write status last in order as we lost
202          * ownership of the command structure as soon as it's no longer -1
203          */
204         done = cmd->done;
205         misc = cmd->misc;
206         mb();
207         cmd->status = rc;
208  bail:
209         /* Start next command if any */
210         smu_start_cmd();
211         spin_unlock_irqrestore(&smu->lock, flags);
212
213         /* Call command completion handler if any */
214         if (done)
215                 done(cmd, misc);
216
217         /* It's an edge interrupt, nothing to do */
218         return IRQ_HANDLED;
219 }
220
221
222 static irqreturn_t smu_msg_intr(int irq, void *arg, struct pt_regs *regs)
223 {
224         /* I don't quite know what to do with this one, we seem to never
225          * receive it, so I suspect we have to arm it someway in the SMU
226          * to start getting events that way.
227          */
228
229         printk(KERN_INFO "SMU: message interrupt !\n");
230
231         /* It's an edge interrupt, nothing to do */
232         return IRQ_HANDLED;
233 }
234
235
236 /*
237  * Queued command management.
238  *
239  */
240
241 int smu_queue_cmd(struct smu_cmd *cmd)
242 {
243         unsigned long flags;
244
245         if (smu == NULL)
246                 return -ENODEV;
247         if (cmd->data_len > SMU_MAX_DATA ||
248             cmd->reply_len > SMU_MAX_DATA)
249                 return -EINVAL;
250
251         cmd->status = 1;
252         spin_lock_irqsave(&smu->lock, flags);
253         list_add_tail(&cmd->link, &smu->cmd_list);
254         if (smu->cmd_cur == NULL)
255                 smu_start_cmd();
256         spin_unlock_irqrestore(&smu->lock, flags);
257
258         return 0;
259 }
260 EXPORT_SYMBOL(smu_queue_cmd);
261
262
263 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
264                      unsigned int data_len,
265                      void (*done)(struct smu_cmd *cmd, void *misc),
266                      void *misc, ...)
267 {
268         struct smu_cmd *cmd = &scmd->cmd;
269         va_list list;
270         int i;
271
272         if (data_len > sizeof(scmd->buffer))
273                 return -EINVAL;
274
275         memset(scmd, 0, sizeof(*scmd));
276         cmd->cmd = command;
277         cmd->data_len = data_len;
278         cmd->data_buf = scmd->buffer;
279         cmd->reply_len = sizeof(scmd->buffer);
280         cmd->reply_buf = scmd->buffer;
281         cmd->done = done;
282         cmd->misc = misc;
283
284         va_start(list, misc);
285         for (i = 0; i < data_len; ++i)
286                 scmd->buffer[i] = (u8)va_arg(list, int);
287         va_end(list);
288
289         return smu_queue_cmd(cmd);
290 }
291 EXPORT_SYMBOL(smu_queue_simple);
292
293
294 void smu_poll(void)
295 {
296         u8 gpio;
297
298         if (smu == NULL)
299                 return;
300
301         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
302         if ((gpio & 7) == 7)
303                 smu_db_intr(smu->db_irq, smu, NULL);
304 }
305 EXPORT_SYMBOL(smu_poll);
306
307
308 void smu_done_complete(struct smu_cmd *cmd, void *misc)
309 {
310         struct completion *comp = misc;
311
312         complete(comp);
313 }
314 EXPORT_SYMBOL(smu_done_complete);
315
316
317 void smu_spinwait_cmd(struct smu_cmd *cmd)
318 {
319         while(cmd->status == 1)
320                 smu_poll();
321 }
322 EXPORT_SYMBOL(smu_spinwait_cmd);
323
324
325 /* RTC low level commands */
326 static inline int bcd2hex (int n)
327 {
328         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
329 }
330
331
332 static inline int hex2bcd (int n)
333 {
334         return ((n / 10) << 4) + (n % 10);
335 }
336
337
338 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
339                                         struct rtc_time *time)
340 {
341         cmd_buf->cmd = 0x8e;
342         cmd_buf->length = 8;
343         cmd_buf->data[0] = 0x80;
344         cmd_buf->data[1] = hex2bcd(time->tm_sec);
345         cmd_buf->data[2] = hex2bcd(time->tm_min);
346         cmd_buf->data[3] = hex2bcd(time->tm_hour);
347         cmd_buf->data[4] = time->tm_wday;
348         cmd_buf->data[5] = hex2bcd(time->tm_mday);
349         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
350         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
351 }
352
353
354 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
355 {
356         struct smu_simple_cmd cmd;
357         int rc;
358
359         if (smu == NULL)
360                 return -ENODEV;
361
362         memset(time, 0, sizeof(struct rtc_time));
363         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
364                               SMU_CMD_RTC_GET_DATETIME);
365         if (rc)
366                 return rc;
367         smu_spinwait_simple(&cmd);
368
369         time->tm_sec = bcd2hex(cmd.buffer[0]);
370         time->tm_min = bcd2hex(cmd.buffer[1]);
371         time->tm_hour = bcd2hex(cmd.buffer[2]);
372         time->tm_wday = bcd2hex(cmd.buffer[3]);
373         time->tm_mday = bcd2hex(cmd.buffer[4]);
374         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
375         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
376
377         return 0;
378 }
379
380
381 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
382 {
383         struct smu_simple_cmd cmd;
384         int rc;
385
386         if (smu == NULL)
387                 return -ENODEV;
388
389         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
390                               SMU_CMD_RTC_SET_DATETIME,
391                               hex2bcd(time->tm_sec),
392                               hex2bcd(time->tm_min),
393                               hex2bcd(time->tm_hour),
394                               time->tm_wday,
395                               hex2bcd(time->tm_mday),
396                               hex2bcd(time->tm_mon) + 1,
397                               hex2bcd(time->tm_year - 100));
398         if (rc)
399                 return rc;
400         smu_spinwait_simple(&cmd);
401
402         return 0;
403 }
404
405
406 void smu_shutdown(void)
407 {
408         struct smu_simple_cmd cmd;
409
410         if (smu == NULL)
411                 return;
412
413         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
414                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
415                 return;
416         smu_spinwait_simple(&cmd);
417         for (;;)
418                 ;
419 }
420
421
422 void smu_restart(void)
423 {
424         struct smu_simple_cmd cmd;
425
426         if (smu == NULL)
427                 return;
428
429         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
430                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
431                 return;
432         smu_spinwait_simple(&cmd);
433         for (;;)
434                 ;
435 }
436
437
438 int smu_present(void)
439 {
440         return smu != NULL;
441 }
442 EXPORT_SYMBOL(smu_present);
443
444
445 int __init smu_init (void)
446 {
447         struct device_node *np;
448         u32 *data;
449
450         np = of_find_node_by_type(NULL, "smu");
451         if (np == NULL)
452                 return -ENODEV;
453
454         printk(KERN_INFO "SMU driver %s %s\n", VERSION, AUTHOR);
455
456         if (smu_cmdbuf_abs == 0) {
457                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
458                 return -EINVAL;
459         }
460
461         smu = alloc_bootmem(sizeof(struct smu_device));
462         if (smu == NULL)
463                 return -ENOMEM;
464         memset(smu, 0, sizeof(*smu));
465
466         spin_lock_init(&smu->lock);
467         INIT_LIST_HEAD(&smu->cmd_list);
468         INIT_LIST_HEAD(&smu->cmd_i2c_list);
469         smu->of_node = np;
470         smu->db_irq = NO_IRQ;
471         smu->msg_irq = NO_IRQ;
472         init_timer(&smu->i2c_timer);
473
474         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
475          * 32 bits value safely
476          */
477         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
478         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
479
480         np = of_find_node_by_name(NULL, "smu-doorbell");
481         if (np == NULL) {
482                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
483                 goto fail;
484         }
485         data = (u32 *)get_property(np, "reg", NULL);
486         if (data == NULL) {
487                 of_node_put(np);
488                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
489                 goto fail;
490         }
491
492         /* Current setup has one doorbell GPIO that does both doorbell
493          * and ack. GPIOs are at 0x50, best would be to find that out
494          * in the device-tree though.
495          */
496         smu->doorbell = *data;
497         if (smu->doorbell < 0x50)
498                 smu->doorbell += 0x50;
499         if (np->n_intrs > 0)
500                 smu->db_irq = np->intrs[0].line;
501
502         of_node_put(np);
503
504         /* Now look for the smu-interrupt GPIO */
505         do {
506                 np = of_find_node_by_name(NULL, "smu-interrupt");
507                 if (np == NULL)
508                         break;
509                 data = (u32 *)get_property(np, "reg", NULL);
510                 if (data == NULL) {
511                         of_node_put(np);
512                         break;
513                 }
514                 smu->msg = *data;
515                 if (smu->msg < 0x50)
516                         smu->msg += 0x50;
517                 if (np->n_intrs > 0)
518                         smu->msg_irq = np->intrs[0].line;
519                 of_node_put(np);
520         } while(0);
521
522         /* Doorbell buffer is currently hard-coded, I didn't find a proper
523          * device-tree entry giving the address. Best would probably to use
524          * an offset for K2 base though, but let's do it that way for now.
525          */
526         smu->db_buf = ioremap(0x8000860c, 0x1000);
527         if (smu->db_buf == NULL) {
528                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
529                 goto fail;
530         }
531
532         sys_ctrler = SYS_CTRLER_SMU;
533         return 0;
534
535  fail:
536         smu = NULL;
537         return -ENXIO;
538
539 }
540
541
542 static int smu_late_init(void)
543 {
544         if (!smu)
545                 return 0;
546
547         /*
548          * Try to request the interrupts
549          */
550
551         if (smu->db_irq != NO_IRQ) {
552                 if (request_irq(smu->db_irq, smu_db_intr,
553                                 SA_SHIRQ, "SMU doorbell", smu) < 0) {
554                         printk(KERN_WARNING "SMU: can't "
555                                "request interrupt %d\n",
556                                smu->db_irq);
557                         smu->db_irq = NO_IRQ;
558                 }
559         }
560
561         if (smu->msg_irq != NO_IRQ) {
562                 if (request_irq(smu->msg_irq, smu_msg_intr,
563                                 SA_SHIRQ, "SMU message", smu) < 0) {
564                         printk(KERN_WARNING "SMU: can't "
565                                "request interrupt %d\n",
566                                smu->msg_irq);
567                         smu->msg_irq = NO_IRQ;
568                 }
569         }
570
571         return 0;
572 }
573 arch_initcall(smu_late_init);
574
575 /*
576  * sysfs visibility
577  */
578
579 static void smu_expose_childs(void *unused)
580 {
581         struct device_node *np;
582
583         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;) {
584                 if (device_is_compatible(np, "smu-i2c")) {
585                         char name[32];
586                         u32 *reg = (u32 *)get_property(np, "reg", NULL);
587
588                         if (reg == NULL)
589                                 continue;
590                         sprintf(name, "smu-i2c-%02x", *reg);
591                         of_platform_device_create(np, name, &smu->of_dev->dev);
592                 }
593                 if (device_is_compatible(np, "smu-sensors"))
594                         of_platform_device_create(np, "smu-sensors", &smu->of_dev->dev);
595         }
596
597 }
598
599 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs, NULL);
600
601 static int smu_platform_probe(struct of_device* dev,
602                               const struct of_device_id *match)
603 {
604         if (!smu)
605                 return -ENODEV;
606         smu->of_dev = dev;
607
608         /*
609          * Ok, we are matched, now expose all i2c busses. We have to defer
610          * that unfortunately or it would deadlock inside the device model
611          */
612         schedule_work(&smu_expose_childs_work);
613
614         return 0;
615 }
616
617 static struct of_device_id smu_platform_match[] =
618 {
619         {
620                 .type           = "smu",
621         },
622         {},
623 };
624
625 static struct of_platform_driver smu_of_platform_driver =
626 {
627         .name           = "smu",
628         .match_table    = smu_platform_match,
629         .probe          = smu_platform_probe,
630 };
631
632 static int __init smu_init_sysfs(void)
633 {
634         int rc;
635
636         /*
637          * Due to sysfs bogosity, a sysdev is not a real device, so
638          * we should in fact create both if we want sysdev semantics
639          * for power management.
640          * For now, we don't power manage machines with an SMU chip,
641          * I'm a bit too far from figuring out how that works with those
642          * new chipsets, but that will come back and bite us
643          */
644         rc = of_register_driver(&smu_of_platform_driver);
645         return 0;
646 }
647
648 device_initcall(smu_init_sysfs);
649
650 struct of_device *smu_get_ofdev(void)
651 {
652         if (!smu)
653                 return NULL;
654         return smu->of_dev;
655 }
656
657 EXPORT_SYMBOL_GPL(smu_get_ofdev);
658
659 /*
660  * i2c interface
661  */
662
663 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
664 {
665         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
666         void *misc = cmd->misc;
667         unsigned long flags;
668
669         /* Check for read case */
670         if (!fail && cmd->read) {
671                 if (cmd->pdata[0] < 1)
672                         fail = 1;
673                 else
674                         memcpy(cmd->info.data, &cmd->pdata[1],
675                                cmd->info.datalen);
676         }
677
678         DPRINTK("SMU: completing, success: %d\n", !fail);
679
680         /* Update status and mark no pending i2c command with lock
681          * held so nobody comes in while we dequeue an eventual
682          * pending next i2c command
683          */
684         spin_lock_irqsave(&smu->lock, flags);
685         smu->cmd_i2c_cur = NULL;
686         wmb();
687         cmd->status = fail ? -EIO : 0;
688
689         /* Is there another i2c command waiting ? */
690         if (!list_empty(&smu->cmd_i2c_list)) {
691                 struct smu_i2c_cmd *newcmd;
692
693                 /* Fetch it, new current, remove from list */
694                 newcmd = list_entry(smu->cmd_i2c_list.next,
695                                     struct smu_i2c_cmd, link);
696                 smu->cmd_i2c_cur = newcmd;
697                 list_del(&cmd->link);
698
699                 /* Queue with low level smu */
700                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
701                 if (smu->cmd_cur == NULL)
702                         smu_start_cmd();
703         }
704         spin_unlock_irqrestore(&smu->lock, flags);
705
706         /* Call command completion handler if any */
707         if (done)
708                 done(cmd, misc);
709
710 }
711
712
713 static void smu_i2c_retry(unsigned long data)
714 {
715         struct smu_i2c_cmd      *cmd = (struct smu_i2c_cmd *)data;
716
717         DPRINTK("SMU: i2c failure, requeuing...\n");
718
719         /* requeue command simply by resetting reply_len */
720         cmd->pdata[0] = 0xff;
721         cmd->scmd.reply_len = 0x10;
722         smu_queue_cmd(&cmd->scmd);
723 }
724
725
726 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
727 {
728         struct smu_i2c_cmd      *cmd = misc;
729         int                     fail = 0;
730
731         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
732                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
733
734         /* Check for possible status */
735         if (scmd->status < 0)
736                 fail = 1;
737         else if (cmd->read) {
738                 if (cmd->stage == 0)
739                         fail = cmd->pdata[0] != 0;
740                 else
741                         fail = cmd->pdata[0] >= 0x80;
742         } else {
743                 fail = cmd->pdata[0] != 0;
744         }
745
746         /* Handle failures by requeuing command, after 5ms interval
747          */
748         if (fail && --cmd->retries > 0) {
749                 DPRINTK("SMU: i2c failure, starting timer...\n");
750                 smu->i2c_timer.function = smu_i2c_retry;
751                 smu->i2c_timer.data = (unsigned long)cmd;
752                 smu->i2c_timer.expires = jiffies + msecs_to_jiffies(5);
753                 add_timer(&smu->i2c_timer);
754                 return;
755         }
756
757         /* If failure or stage 1, command is complete */
758         if (fail || cmd->stage != 0) {
759                 smu_i2c_complete_command(cmd, fail);
760                 return;
761         }
762
763         DPRINTK("SMU: going to stage 1\n");
764
765         /* Ok, initial command complete, now poll status */
766         scmd->reply_buf = cmd->pdata;
767         scmd->reply_len = 0x10;
768         scmd->data_buf = cmd->pdata;
769         scmd->data_len = 1;
770         cmd->pdata[0] = 0;
771         cmd->stage = 1;
772         cmd->retries = 20;
773         smu_queue_cmd(scmd);
774 }
775
776
777 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
778 {
779         unsigned long flags;
780
781         if (smu == NULL)
782                 return -ENODEV;
783
784         /* Fill most fields of scmd */
785         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
786         cmd->scmd.done = smu_i2c_low_completion;
787         cmd->scmd.misc = cmd;
788         cmd->scmd.reply_buf = cmd->pdata;
789         cmd->scmd.reply_len = 0x10;
790         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
791         cmd->scmd.status = 1;
792         cmd->stage = 0;
793         cmd->pdata[0] = 0xff;
794         cmd->retries = 20;
795         cmd->status = 1;
796
797         /* Check transfer type, sanitize some "info" fields
798          * based on transfer type and do more checking
799          */
800         cmd->info.caddr = cmd->info.devaddr;
801         cmd->read = cmd->info.devaddr & 0x01;
802         switch(cmd->info.type) {
803         case SMU_I2C_TRANSFER_SIMPLE:
804                 memset(&cmd->info.sublen, 0, 4);
805                 break;
806         case SMU_I2C_TRANSFER_COMBINED:
807                 cmd->info.devaddr &= 0xfe;
808         case SMU_I2C_TRANSFER_STDSUB:
809                 if (cmd->info.sublen > 3)
810                         return -EINVAL;
811                 break;
812         default:
813                 return -EINVAL;
814         }
815
816         /* Finish setting up command based on transfer direction
817          */
818         if (cmd->read) {
819                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
820                         return -EINVAL;
821                 memset(cmd->info.data, 0xff, cmd->info.datalen);
822                 cmd->scmd.data_len = 9;
823         } else {
824                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
825                         return -EINVAL;
826                 cmd->scmd.data_len = 9 + cmd->info.datalen;
827         }
828
829         DPRINTK("SMU: i2c enqueuing command\n");
830         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
831                 cmd->read ? "read" : "write", cmd->info.datalen,
832                 cmd->info.bus, cmd->info.caddr,
833                 cmd->info.subaddr[0], cmd->info.type);
834
835
836         /* Enqueue command in i2c list, and if empty, enqueue also in
837          * main command list
838          */
839         spin_lock_irqsave(&smu->lock, flags);
840         if (smu->cmd_i2c_cur == NULL) {
841                 smu->cmd_i2c_cur = cmd;
842                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
843                 if (smu->cmd_cur == NULL)
844                         smu_start_cmd();
845         } else
846                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
847         spin_unlock_irqrestore(&smu->lock, flags);
848
849         return 0;
850 }
851
852 /*
853  * Handling of "partitions"
854  */
855
856 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
857 {
858         DECLARE_COMPLETION(comp);
859         unsigned int chunk;
860         struct smu_cmd cmd;
861         int rc;
862         u8 params[8];
863
864         /* We currently use a chunk size of 0xe. We could check the
865          * SMU firmware version and use bigger sizes though
866          */
867         chunk = 0xe;
868
869         while (len) {
870                 unsigned int clen = min(len, chunk);
871
872                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
873                 cmd.data_len = 7;
874                 cmd.data_buf = params;
875                 cmd.reply_len = chunk;
876                 cmd.reply_buf = dest;
877                 cmd.done = smu_done_complete;
878                 cmd.misc = &comp;
879                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
880                 params[1] = 0x4;
881                 *((u32 *)&params[2]) = addr;
882                 params[6] = clen;
883
884                 rc = smu_queue_cmd(&cmd);
885                 if (rc)
886                         return rc;
887                 wait_for_completion(&comp);
888                 if (cmd.status != 0)
889                         return rc;
890                 if (cmd.reply_len != clen) {
891                         printk(KERN_DEBUG "SMU: short read in "
892                                "smu_read_datablock, got: %d, want: %d\n",
893                                cmd.reply_len, clen);
894                         return -EIO;
895                 }
896                 len -= clen;
897                 addr += clen;
898                 dest += clen;
899         }
900         return 0;
901 }
902
903 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
904 {
905         DECLARE_COMPLETION(comp);
906         struct smu_simple_cmd cmd;
907         unsigned int addr, len, tlen;
908         struct smu_sdbp_header *hdr;
909         struct property *prop;
910
911         /* First query the partition info */
912         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
913                          smu_done_complete, &comp,
914                          SMU_CMD_PARTITION_LATEST, id);
915         wait_for_completion(&comp);
916
917         /* Partition doesn't exist (or other error) */
918         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
919                 return NULL;
920
921         /* Fetch address and length from reply */
922         addr = *((u16 *)cmd.buffer);
923         len = cmd.buffer[3] << 2;
924         /* Calucluate total length to allocate, including the 17 bytes
925          * for "sdb-partition-XX" that we append at the end of the buffer
926          */
927         tlen = sizeof(struct property) + len + 18;
928
929         prop = kcalloc(tlen, 1, GFP_KERNEL);
930         if (prop == NULL)
931                 return NULL;
932         hdr = (struct smu_sdbp_header *)(prop + 1);
933         prop->name = ((char *)prop) + tlen - 18;
934         sprintf(prop->name, "sdb-partition-%02x", id);
935         prop->length = len;
936         prop->value = (unsigned char *)hdr;
937         prop->next = NULL;
938
939         /* Read the datablock */
940         if (smu_read_datablock((u8 *)hdr, addr, len)) {
941                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
942                        "partition %02x !\n", id);
943                 goto failure;
944         }
945
946         /* Got it, check a few things and create the property */
947         if (hdr->id != id) {
948                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
949                        "%02x !\n", id, hdr->id);
950                 goto failure;
951         }
952         if (prom_add_property(smu->of_node, prop)) {
953                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
954                        "property !\n", id);
955                 goto failure;
956         }
957
958         return hdr;
959  failure:
960         kfree(prop);
961         return NULL;
962 }
963
964 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
965  * when interruptible is 1
966  */
967 struct smu_sdbp_header *__smu_get_sdb_partition(int id, unsigned int *size,
968                                                 int interruptible)
969 {
970         char pname[32];
971         struct smu_sdbp_header *part;
972
973         if (!smu)
974                 return NULL;
975
976         sprintf(pname, "sdb-partition-%02x", id);
977
978         if (interruptible) {
979                 int rc;
980                 rc = down_interruptible(&smu_part_access);
981                 if (rc)
982                         return ERR_PTR(rc);
983         } else
984                 down(&smu_part_access);
985
986         part = (struct smu_sdbp_header *)get_property(smu->of_node,
987                                                       pname, size);
988         if (part == NULL) {
989                 part = smu_create_sdb_partition(id);
990                 if (part != NULL && size)
991                         *size = part->len << 2;
992         }
993         up(&smu_part_access);
994         return part;
995 }
996
997 struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
998 {
999         return __smu_get_sdb_partition(id, size, 0);
1000 }
1001 EXPORT_SYMBOL(smu_get_sdb_partition);
1002
1003
1004 /*
1005  * Userland driver interface
1006  */
1007
1008
1009 static LIST_HEAD(smu_clist);
1010 static DEFINE_SPINLOCK(smu_clist_lock);
1011
1012 enum smu_file_mode {
1013         smu_file_commands,
1014         smu_file_events,
1015         smu_file_closing
1016 };
1017
1018 struct smu_private
1019 {
1020         struct list_head        list;
1021         enum smu_file_mode      mode;
1022         int                     busy;
1023         struct smu_cmd          cmd;
1024         spinlock_t              lock;
1025         wait_queue_head_t       wait;
1026         u8                      buffer[SMU_MAX_DATA];
1027 };
1028
1029
1030 static int smu_open(struct inode *inode, struct file *file)
1031 {
1032         struct smu_private *pp;
1033         unsigned long flags;
1034
1035         pp = kmalloc(sizeof(struct smu_private), GFP_KERNEL);
1036         if (pp == 0)
1037                 return -ENOMEM;
1038         memset(pp, 0, sizeof(struct smu_private));
1039         spin_lock_init(&pp->lock);
1040         pp->mode = smu_file_commands;
1041         init_waitqueue_head(&pp->wait);
1042
1043         spin_lock_irqsave(&smu_clist_lock, flags);
1044         list_add(&pp->list, &smu_clist);
1045         spin_unlock_irqrestore(&smu_clist_lock, flags);
1046         file->private_data = pp;
1047
1048         return 0;
1049 }
1050
1051
1052 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1053 {
1054         struct smu_private *pp = misc;
1055
1056         wake_up_all(&pp->wait);
1057 }
1058
1059
1060 static ssize_t smu_write(struct file *file, const char __user *buf,
1061                          size_t count, loff_t *ppos)
1062 {
1063         struct smu_private *pp = file->private_data;
1064         unsigned long flags;
1065         struct smu_user_cmd_hdr hdr;
1066         int rc = 0;
1067
1068         if (pp->busy)
1069                 return -EBUSY;
1070         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1071                 return -EFAULT;
1072         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1073                 pp->mode = smu_file_events;
1074                 return 0;
1075         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1076                 struct smu_sdbp_header *part;
1077                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1078                 if (part == NULL)
1079                         return -EINVAL;
1080                 else if (IS_ERR(part))
1081                         return PTR_ERR(part);
1082                 return 0;
1083         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1084                 return -EINVAL;
1085         else if (pp->mode != smu_file_commands)
1086                 return -EBADFD;
1087         else if (hdr.data_len > SMU_MAX_DATA)
1088                 return -EINVAL;
1089
1090         spin_lock_irqsave(&pp->lock, flags);
1091         if (pp->busy) {
1092                 spin_unlock_irqrestore(&pp->lock, flags);
1093                 return -EBUSY;
1094         }
1095         pp->busy = 1;
1096         pp->cmd.status = 1;
1097         spin_unlock_irqrestore(&pp->lock, flags);
1098
1099         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1100                 pp->busy = 0;
1101                 return -EFAULT;
1102         }
1103
1104         pp->cmd.cmd = hdr.cmd;
1105         pp->cmd.data_len = hdr.data_len;
1106         pp->cmd.reply_len = SMU_MAX_DATA;
1107         pp->cmd.data_buf = pp->buffer;
1108         pp->cmd.reply_buf = pp->buffer;
1109         pp->cmd.done = smu_user_cmd_done;
1110         pp->cmd.misc = pp;
1111         rc = smu_queue_cmd(&pp->cmd);
1112         if (rc < 0)
1113                 return rc;
1114         return count;
1115 }
1116
1117
1118 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1119                                 char __user *buf, size_t count)
1120 {
1121         DECLARE_WAITQUEUE(wait, current);
1122         struct smu_user_reply_hdr hdr;
1123         unsigned long flags;
1124         int size, rc = 0;
1125
1126         if (!pp->busy)
1127                 return 0;
1128         if (count < sizeof(struct smu_user_reply_hdr))
1129                 return -EOVERFLOW;
1130         spin_lock_irqsave(&pp->lock, flags);
1131         if (pp->cmd.status == 1) {
1132                 if (file->f_flags & O_NONBLOCK)
1133                         return -EAGAIN;
1134                 add_wait_queue(&pp->wait, &wait);
1135                 for (;;) {
1136                         set_current_state(TASK_INTERRUPTIBLE);
1137                         rc = 0;
1138                         if (pp->cmd.status != 1)
1139                                 break;
1140                         rc = -ERESTARTSYS;
1141                         if (signal_pending(current))
1142                                 break;
1143                         spin_unlock_irqrestore(&pp->lock, flags);
1144                         schedule();
1145                         spin_lock_irqsave(&pp->lock, flags);
1146                 }
1147                 set_current_state(TASK_RUNNING);
1148                 remove_wait_queue(&pp->wait, &wait);
1149         }
1150         spin_unlock_irqrestore(&pp->lock, flags);
1151         if (rc)
1152                 return rc;
1153         if (pp->cmd.status != 0)
1154                 pp->cmd.reply_len = 0;
1155         size = sizeof(hdr) + pp->cmd.reply_len;
1156         if (count < size)
1157                 size = count;
1158         rc = size;
1159         hdr.status = pp->cmd.status;
1160         hdr.reply_len = pp->cmd.reply_len;
1161         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1162                 return -EFAULT;
1163         size -= sizeof(hdr);
1164         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1165                 return -EFAULT;
1166         pp->busy = 0;
1167
1168         return rc;
1169 }
1170
1171
1172 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1173                                char __user *buf, size_t count)
1174 {
1175         /* Not implemented */
1176         msleep_interruptible(1000);
1177         return 0;
1178 }
1179
1180
1181 static ssize_t smu_read(struct file *file, char __user *buf,
1182                         size_t count, loff_t *ppos)
1183 {
1184         struct smu_private *pp = file->private_data;
1185
1186         if (pp->mode == smu_file_commands)
1187                 return smu_read_command(file, pp, buf, count);
1188         if (pp->mode == smu_file_events)
1189                 return smu_read_events(file, pp, buf, count);
1190
1191         return -EBADFD;
1192 }
1193
1194 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1195 {
1196         struct smu_private *pp = file->private_data;
1197         unsigned int mask = 0;
1198         unsigned long flags;
1199
1200         if (pp == 0)
1201                 return 0;
1202
1203         if (pp->mode == smu_file_commands) {
1204                 poll_wait(file, &pp->wait, wait);
1205
1206                 spin_lock_irqsave(&pp->lock, flags);
1207                 if (pp->busy && pp->cmd.status != 1)
1208                         mask |= POLLIN;
1209                 spin_unlock_irqrestore(&pp->lock, flags);
1210         } if (pp->mode == smu_file_events) {
1211                 /* Not yet implemented */
1212         }
1213         return mask;
1214 }
1215
1216 static int smu_release(struct inode *inode, struct file *file)
1217 {
1218         struct smu_private *pp = file->private_data;
1219         unsigned long flags;
1220         unsigned int busy;
1221
1222         if (pp == 0)
1223                 return 0;
1224
1225         file->private_data = NULL;
1226
1227         /* Mark file as closing to avoid races with new request */
1228         spin_lock_irqsave(&pp->lock, flags);
1229         pp->mode = smu_file_closing;
1230         busy = pp->busy;
1231
1232         /* Wait for any pending request to complete */
1233         if (busy && pp->cmd.status == 1) {
1234                 DECLARE_WAITQUEUE(wait, current);
1235
1236                 add_wait_queue(&pp->wait, &wait);
1237                 for (;;) {
1238                         set_current_state(TASK_UNINTERRUPTIBLE);
1239                         if (pp->cmd.status != 1)
1240                                 break;
1241                         spin_lock_irqsave(&pp->lock, flags);
1242                         schedule();
1243                         spin_unlock_irqrestore(&pp->lock, flags);
1244                 }
1245                 set_current_state(TASK_RUNNING);
1246                 remove_wait_queue(&pp->wait, &wait);
1247         }
1248         spin_unlock_irqrestore(&pp->lock, flags);
1249
1250         spin_lock_irqsave(&smu_clist_lock, flags);
1251         list_del(&pp->list);
1252         spin_unlock_irqrestore(&smu_clist_lock, flags);
1253         kfree(pp);
1254
1255         return 0;
1256 }
1257
1258
1259 static struct file_operations smu_device_fops = {
1260         .llseek         = no_llseek,
1261         .read           = smu_read,
1262         .write          = smu_write,
1263         .poll           = smu_fpoll,
1264         .open           = smu_open,
1265         .release        = smu_release,
1266 };
1267
1268 static struct miscdevice pmu_device = {
1269         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1270 };
1271
1272 static int smu_device_init(void)
1273 {
1274         if (!smu)
1275                 return -ENODEV;
1276         if (misc_register(&pmu_device) < 0)
1277                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1278         return 0;
1279 }
1280 device_initcall(smu_device_init);