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