Merge branch 'for-2.6.25' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus...
[sfrench/cifs-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/types.h>
23 #include <linux/kernel.h>
24 #include <linux/device.h>
25 #include <linux/dmapool.h>
26 #include <linux/bootmem.h>
27 #include <linux/vmalloc.h>
28 #include <linux/highmem.h>
29 #include <linux/jiffies.h>
30 #include <linux/interrupt.h>
31 #include <linux/rtc.h>
32 #include <linux/completion.h>
33 #include <linux/miscdevice.h>
34 #include <linux/delay.h>
35 #include <linux/sysdev.h>
36 #include <linux/poll.h>
37 #include <linux/mutex.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 #include <asm/of_platform.h>
50
51 #define VERSION "0.7"
52 #define AUTHOR  "(c) 2005 Benjamin Herrenschmidt, IBM Corp."
53
54 #undef DEBUG_SMU
55
56 #ifdef DEBUG_SMU
57 #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0)
58 #else
59 #define DPRINTK(fmt, args...) do { } while (0)
60 #endif
61
62 /*
63  * This is the command buffer passed to the SMU hardware
64  */
65 #define SMU_MAX_DATA    254
66
67 struct smu_cmd_buf {
68         u8 cmd;
69         u8 length;
70         u8 data[SMU_MAX_DATA];
71 };
72
73 struct smu_device {
74         spinlock_t              lock;
75         struct device_node      *of_node;
76         struct of_device        *of_dev;
77         int                     doorbell;       /* doorbell gpio */
78         u32 __iomem             *db_buf;        /* doorbell buffer */
79         struct device_node      *db_node;
80         unsigned int            db_irq;
81         int                     msg;
82         struct device_node      *msg_node;
83         unsigned int            msg_irq;
84         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
85         u32                     cmd_buf_abs;    /* command buffer absolute */
86         struct list_head        cmd_list;
87         struct smu_cmd          *cmd_cur;       /* pending command */
88         int                     broken_nap;
89         struct list_head        cmd_i2c_list;
90         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
91         struct timer_list       i2c_timer;
92 };
93
94 /*
95  * I don't think there will ever be more than one SMU, so
96  * for now, just hard code that
97  */
98 static struct smu_device        *smu;
99 static DEFINE_MUTEX(smu_part_access);
100 static int smu_irq_inited;
101
102 static void smu_i2c_retry(unsigned long data);
103
104 /*
105  * SMU driver low level stuff
106  */
107
108 static void smu_start_cmd(void)
109 {
110         unsigned long faddr, fend;
111         struct smu_cmd *cmd;
112
113         if (list_empty(&smu->cmd_list))
114                 return;
115
116         /* Fetch first command in queue */
117         cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
118         smu->cmd_cur = cmd;
119         list_del(&cmd->link);
120
121         DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
122                 cmd->data_len);
123         DPRINTK("SMU: data buffer: %02x %02x %02x %02x %02x %02x %02x %02x\n",
124                 ((u8 *)cmd->data_buf)[0], ((u8 *)cmd->data_buf)[1],
125                 ((u8 *)cmd->data_buf)[2], ((u8 *)cmd->data_buf)[3],
126                 ((u8 *)cmd->data_buf)[4], ((u8 *)cmd->data_buf)[5],
127                 ((u8 *)cmd->data_buf)[6], ((u8 *)cmd->data_buf)[7]);
128
129         /* Fill the SMU command buffer */
130         smu->cmd_buf->cmd = cmd->cmd;
131         smu->cmd_buf->length = cmd->data_len;
132         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
133
134         /* Flush command and data to RAM */
135         faddr = (unsigned long)smu->cmd_buf;
136         fend = faddr + smu->cmd_buf->length + 2;
137         flush_inval_dcache_range(faddr, fend);
138
139
140         /* We also disable NAP mode for the duration of the command
141          * on U3 based machines.
142          * This is slightly racy as it can be written back to 1 by a sysctl
143          * but that never happens in practice. There seem to be an issue with
144          * U3 based machines such as the iMac G5 where napping for the
145          * whole duration of the command prevents the SMU from fetching it
146          * from memory. This might be related to the strange i2c based
147          * mechanism the SMU uses to access memory.
148          */
149         if (smu->broken_nap)
150                 powersave_nap = 0;
151
152         /* This isn't exactly a DMA mapping here, I suspect
153          * the SMU is actually communicating with us via i2c to the
154          * northbridge or the CPU to access RAM.
155          */
156         writel(smu->cmd_buf_abs, smu->db_buf);
157
158         /* Ring the SMU doorbell */
159         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
160 }
161
162
163 static irqreturn_t smu_db_intr(int irq, void *arg)
164 {
165         unsigned long flags;
166         struct smu_cmd *cmd;
167         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
168         void *misc = NULL;
169         u8 gpio;
170         int rc = 0;
171
172         /* SMU completed the command, well, we hope, let's make sure
173          * of it
174          */
175         spin_lock_irqsave(&smu->lock, flags);
176
177         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
178         if ((gpio & 7) != 7) {
179                 spin_unlock_irqrestore(&smu->lock, flags);
180                 return IRQ_HANDLED;
181         }
182
183         cmd = smu->cmd_cur;
184         smu->cmd_cur = NULL;
185         if (cmd == NULL)
186                 goto bail;
187
188         if (rc == 0) {
189                 unsigned long faddr;
190                 int reply_len;
191                 u8 ack;
192
193                 /* CPU might have brought back the cache line, so we need
194                  * to flush again before peeking at the SMU response. We
195                  * flush the entire buffer for now as we haven't read the
196                  * reply length (it's only 2 cache lines anyway)
197                  */
198                 faddr = (unsigned long)smu->cmd_buf;
199                 flush_inval_dcache_range(faddr, faddr + 256);
200
201                 /* Now check ack */
202                 ack = (~cmd->cmd) & 0xff;
203                 if (ack != smu->cmd_buf->cmd) {
204                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
205                                 ack, smu->cmd_buf->cmd);
206                         rc = -EIO;
207                 }
208                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
209                 DPRINTK("SMU: reply len: %d\n", reply_len);
210                 if (reply_len > cmd->reply_len) {
211                         printk(KERN_WARNING "SMU: reply buffer too small,"
212                                "got %d bytes for a %d bytes buffer\n",
213                                reply_len, cmd->reply_len);
214                         reply_len = cmd->reply_len;
215                 }
216                 cmd->reply_len = reply_len;
217                 if (cmd->reply_buf && reply_len)
218                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
219         }
220
221         /* Now complete the command. Write status last in order as we lost
222          * ownership of the command structure as soon as it's no longer -1
223          */
224         done = cmd->done;
225         misc = cmd->misc;
226         mb();
227         cmd->status = rc;
228
229         /* Re-enable NAP mode */
230         if (smu->broken_nap)
231                 powersave_nap = 1;
232  bail:
233         /* Start next command if any */
234         smu_start_cmd();
235         spin_unlock_irqrestore(&smu->lock, flags);
236
237         /* Call command completion handler if any */
238         if (done)
239                 done(cmd, misc);
240
241         /* It's an edge interrupt, nothing to do */
242         return IRQ_HANDLED;
243 }
244
245
246 static irqreturn_t smu_msg_intr(int irq, void *arg)
247 {
248         /* I don't quite know what to do with this one, we seem to never
249          * receive it, so I suspect we have to arm it someway in the SMU
250          * to start getting events that way.
251          */
252
253         printk(KERN_INFO "SMU: message interrupt !\n");
254
255         /* It's an edge interrupt, nothing to do */
256         return IRQ_HANDLED;
257 }
258
259
260 /*
261  * Queued command management.
262  *
263  */
264
265 int smu_queue_cmd(struct smu_cmd *cmd)
266 {
267         unsigned long flags;
268
269         if (smu == NULL)
270                 return -ENODEV;
271         if (cmd->data_len > SMU_MAX_DATA ||
272             cmd->reply_len > SMU_MAX_DATA)
273                 return -EINVAL;
274
275         cmd->status = 1;
276         spin_lock_irqsave(&smu->lock, flags);
277         list_add_tail(&cmd->link, &smu->cmd_list);
278         if (smu->cmd_cur == NULL)
279                 smu_start_cmd();
280         spin_unlock_irqrestore(&smu->lock, flags);
281
282         /* Workaround for early calls when irq isn't available */
283         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
284                 smu_spinwait_cmd(cmd);
285
286         return 0;
287 }
288 EXPORT_SYMBOL(smu_queue_cmd);
289
290
291 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
292                      unsigned int data_len,
293                      void (*done)(struct smu_cmd *cmd, void *misc),
294                      void *misc, ...)
295 {
296         struct smu_cmd *cmd = &scmd->cmd;
297         va_list list;
298         int i;
299
300         if (data_len > sizeof(scmd->buffer))
301                 return -EINVAL;
302
303         memset(scmd, 0, sizeof(*scmd));
304         cmd->cmd = command;
305         cmd->data_len = data_len;
306         cmd->data_buf = scmd->buffer;
307         cmd->reply_len = sizeof(scmd->buffer);
308         cmd->reply_buf = scmd->buffer;
309         cmd->done = done;
310         cmd->misc = misc;
311
312         va_start(list, misc);
313         for (i = 0; i < data_len; ++i)
314                 scmd->buffer[i] = (u8)va_arg(list, int);
315         va_end(list);
316
317         return smu_queue_cmd(cmd);
318 }
319 EXPORT_SYMBOL(smu_queue_simple);
320
321
322 void smu_poll(void)
323 {
324         u8 gpio;
325
326         if (smu == NULL)
327                 return;
328
329         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
330         if ((gpio & 7) == 7)
331                 smu_db_intr(smu->db_irq, smu);
332 }
333 EXPORT_SYMBOL(smu_poll);
334
335
336 void smu_done_complete(struct smu_cmd *cmd, void *misc)
337 {
338         struct completion *comp = misc;
339
340         complete(comp);
341 }
342 EXPORT_SYMBOL(smu_done_complete);
343
344
345 void smu_spinwait_cmd(struct smu_cmd *cmd)
346 {
347         while(cmd->status == 1)
348                 smu_poll();
349 }
350 EXPORT_SYMBOL(smu_spinwait_cmd);
351
352
353 /* RTC low level commands */
354 static inline int bcd2hex (int n)
355 {
356         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
357 }
358
359
360 static inline int hex2bcd (int n)
361 {
362         return ((n / 10) << 4) + (n % 10);
363 }
364
365
366 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
367                                         struct rtc_time *time)
368 {
369         cmd_buf->cmd = 0x8e;
370         cmd_buf->length = 8;
371         cmd_buf->data[0] = 0x80;
372         cmd_buf->data[1] = hex2bcd(time->tm_sec);
373         cmd_buf->data[2] = hex2bcd(time->tm_min);
374         cmd_buf->data[3] = hex2bcd(time->tm_hour);
375         cmd_buf->data[4] = time->tm_wday;
376         cmd_buf->data[5] = hex2bcd(time->tm_mday);
377         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
378         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
379 }
380
381
382 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
383 {
384         struct smu_simple_cmd cmd;
385         int rc;
386
387         if (smu == NULL)
388                 return -ENODEV;
389
390         memset(time, 0, sizeof(struct rtc_time));
391         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
392                               SMU_CMD_RTC_GET_DATETIME);
393         if (rc)
394                 return rc;
395         smu_spinwait_simple(&cmd);
396
397         time->tm_sec = bcd2hex(cmd.buffer[0]);
398         time->tm_min = bcd2hex(cmd.buffer[1]);
399         time->tm_hour = bcd2hex(cmd.buffer[2]);
400         time->tm_wday = bcd2hex(cmd.buffer[3]);
401         time->tm_mday = bcd2hex(cmd.buffer[4]);
402         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
403         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
404
405         return 0;
406 }
407
408
409 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
410 {
411         struct smu_simple_cmd cmd;
412         int rc;
413
414         if (smu == NULL)
415                 return -ENODEV;
416
417         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
418                               SMU_CMD_RTC_SET_DATETIME,
419                               hex2bcd(time->tm_sec),
420                               hex2bcd(time->tm_min),
421                               hex2bcd(time->tm_hour),
422                               time->tm_wday,
423                               hex2bcd(time->tm_mday),
424                               hex2bcd(time->tm_mon) + 1,
425                               hex2bcd(time->tm_year - 100));
426         if (rc)
427                 return rc;
428         smu_spinwait_simple(&cmd);
429
430         return 0;
431 }
432
433
434 void smu_shutdown(void)
435 {
436         struct smu_simple_cmd cmd;
437
438         if (smu == NULL)
439                 return;
440
441         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
442                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
443                 return;
444         smu_spinwait_simple(&cmd);
445         for (;;)
446                 ;
447 }
448
449
450 void smu_restart(void)
451 {
452         struct smu_simple_cmd cmd;
453
454         if (smu == NULL)
455                 return;
456
457         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
458                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
459                 return;
460         smu_spinwait_simple(&cmd);
461         for (;;)
462                 ;
463 }
464
465
466 int smu_present(void)
467 {
468         return smu != NULL;
469 }
470 EXPORT_SYMBOL(smu_present);
471
472
473 int __init smu_init (void)
474 {
475         struct device_node *np;
476         const u32 *data;
477
478         np = of_find_node_by_type(NULL, "smu");
479         if (np == NULL)
480                 return -ENODEV;
481
482         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
483
484         if (smu_cmdbuf_abs == 0) {
485                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
486                 return -EINVAL;
487         }
488
489         smu = alloc_bootmem(sizeof(struct smu_device));
490         if (smu == NULL)
491                 return -ENOMEM;
492         memset(smu, 0, sizeof(*smu));
493
494         spin_lock_init(&smu->lock);
495         INIT_LIST_HEAD(&smu->cmd_list);
496         INIT_LIST_HEAD(&smu->cmd_i2c_list);
497         smu->of_node = np;
498         smu->db_irq = NO_IRQ;
499         smu->msg_irq = NO_IRQ;
500
501         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
502          * 32 bits value safely
503          */
504         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
505         smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs);
506
507         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
508         if (smu->db_node == NULL) {
509                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
510                 goto fail;
511         }
512         data = of_get_property(smu->db_node, "reg", NULL);
513         if (data == NULL) {
514                 of_node_put(smu->db_node);
515                 smu->db_node = NULL;
516                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
517                 goto fail;
518         }
519
520         /* Current setup has one doorbell GPIO that does both doorbell
521          * and ack. GPIOs are at 0x50, best would be to find that out
522          * in the device-tree though.
523          */
524         smu->doorbell = *data;
525         if (smu->doorbell < 0x50)
526                 smu->doorbell += 0x50;
527
528         /* Now look for the smu-interrupt GPIO */
529         do {
530                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
531                 if (smu->msg_node == NULL)
532                         break;
533                 data = of_get_property(smu->msg_node, "reg", NULL);
534                 if (data == NULL) {
535                         of_node_put(smu->msg_node);
536                         smu->msg_node = NULL;
537                         break;
538                 }
539                 smu->msg = *data;
540                 if (smu->msg < 0x50)
541                         smu->msg += 0x50;
542         } while(0);
543
544         /* Doorbell buffer is currently hard-coded, I didn't find a proper
545          * device-tree entry giving the address. Best would probably to use
546          * an offset for K2 base though, but let's do it that way for now.
547          */
548         smu->db_buf = ioremap(0x8000860c, 0x1000);
549         if (smu->db_buf == NULL) {
550                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
551                 goto fail;
552         }
553
554         /* U3 has an issue with NAP mode when issuing SMU commands */
555         smu->broken_nap = pmac_get_uninorth_variant() < 4;
556         if (smu->broken_nap)
557                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
558
559         sys_ctrler = SYS_CTRLER_SMU;
560         return 0;
561
562  fail:
563         smu = NULL;
564         return -ENXIO;
565
566 }
567
568
569 static int smu_late_init(void)
570 {
571         if (!smu)
572                 return 0;
573
574         init_timer(&smu->i2c_timer);
575         smu->i2c_timer.function = smu_i2c_retry;
576         smu->i2c_timer.data = (unsigned long)smu;
577
578         if (smu->db_node) {
579                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
580                 if (smu->db_irq == NO_IRQ)
581                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
582                                smu->db_node->full_name);
583         }
584         if (smu->msg_node) {
585                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
586                 if (smu->msg_irq == NO_IRQ)
587                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
588                                smu->msg_node->full_name);
589         }
590
591         /*
592          * Try to request the interrupts
593          */
594
595         if (smu->db_irq != NO_IRQ) {
596                 if (request_irq(smu->db_irq, smu_db_intr,
597                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
598                         printk(KERN_WARNING "SMU: can't "
599                                "request interrupt %d\n",
600                                smu->db_irq);
601                         smu->db_irq = NO_IRQ;
602                 }
603         }
604
605         if (smu->msg_irq != NO_IRQ) {
606                 if (request_irq(smu->msg_irq, smu_msg_intr,
607                                 IRQF_SHARED, "SMU message", smu) < 0) {
608                         printk(KERN_WARNING "SMU: can't "
609                                "request interrupt %d\n",
610                                smu->msg_irq);
611                         smu->msg_irq = NO_IRQ;
612                 }
613         }
614
615         smu_irq_inited = 1;
616         return 0;
617 }
618 /* This has to be before arch_initcall as the low i2c stuff relies on the
619  * above having been done before we reach arch_initcalls
620  */
621 core_initcall(smu_late_init);
622
623 /*
624  * sysfs visibility
625  */
626
627 static void smu_expose_childs(struct work_struct *unused)
628 {
629         struct device_node *np;
630
631         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
632                 if (of_device_is_compatible(np, "smu-sensors"))
633                         of_platform_device_create(np, "smu-sensors",
634                                                   &smu->of_dev->dev);
635 }
636
637 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
638
639 static int smu_platform_probe(struct of_device* dev,
640                               const struct of_device_id *match)
641 {
642         if (!smu)
643                 return -ENODEV;
644         smu->of_dev = dev;
645
646         /*
647          * Ok, we are matched, now expose all i2c busses. We have to defer
648          * that unfortunately or it would deadlock inside the device model
649          */
650         schedule_work(&smu_expose_childs_work);
651
652         return 0;
653 }
654
655 static struct of_device_id smu_platform_match[] =
656 {
657         {
658                 .type           = "smu",
659         },
660         {},
661 };
662
663 static struct of_platform_driver smu_of_platform_driver =
664 {
665         .name           = "smu",
666         .match_table    = smu_platform_match,
667         .probe          = smu_platform_probe,
668 };
669
670 static int __init smu_init_sysfs(void)
671 {
672         /*
673          * Due to sysfs bogosity, a sysdev is not a real device, so
674          * we should in fact create both if we want sysdev semantics
675          * for power management.
676          * For now, we don't power manage machines with an SMU chip,
677          * I'm a bit too far from figuring out how that works with those
678          * new chipsets, but that will come back and bite us
679          */
680         of_register_platform_driver(&smu_of_platform_driver);
681         return 0;
682 }
683
684 device_initcall(smu_init_sysfs);
685
686 struct of_device *smu_get_ofdev(void)
687 {
688         if (!smu)
689                 return NULL;
690         return smu->of_dev;
691 }
692
693 EXPORT_SYMBOL_GPL(smu_get_ofdev);
694
695 /*
696  * i2c interface
697  */
698
699 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
700 {
701         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
702         void *misc = cmd->misc;
703         unsigned long flags;
704
705         /* Check for read case */
706         if (!fail && cmd->read) {
707                 if (cmd->pdata[0] < 1)
708                         fail = 1;
709                 else
710                         memcpy(cmd->info.data, &cmd->pdata[1],
711                                cmd->info.datalen);
712         }
713
714         DPRINTK("SMU: completing, success: %d\n", !fail);
715
716         /* Update status and mark no pending i2c command with lock
717          * held so nobody comes in while we dequeue an eventual
718          * pending next i2c command
719          */
720         spin_lock_irqsave(&smu->lock, flags);
721         smu->cmd_i2c_cur = NULL;
722         wmb();
723         cmd->status = fail ? -EIO : 0;
724
725         /* Is there another i2c command waiting ? */
726         if (!list_empty(&smu->cmd_i2c_list)) {
727                 struct smu_i2c_cmd *newcmd;
728
729                 /* Fetch it, new current, remove from list */
730                 newcmd = list_entry(smu->cmd_i2c_list.next,
731                                     struct smu_i2c_cmd, link);
732                 smu->cmd_i2c_cur = newcmd;
733                 list_del(&cmd->link);
734
735                 /* Queue with low level smu */
736                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
737                 if (smu->cmd_cur == NULL)
738                         smu_start_cmd();
739         }
740         spin_unlock_irqrestore(&smu->lock, flags);
741
742         /* Call command completion handler if any */
743         if (done)
744                 done(cmd, misc);
745
746 }
747
748
749 static void smu_i2c_retry(unsigned long data)
750 {
751         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
752
753         DPRINTK("SMU: i2c failure, requeuing...\n");
754
755         /* requeue command simply by resetting reply_len */
756         cmd->pdata[0] = 0xff;
757         cmd->scmd.reply_len = sizeof(cmd->pdata);
758         smu_queue_cmd(&cmd->scmd);
759 }
760
761
762 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
763 {
764         struct smu_i2c_cmd      *cmd = misc;
765         int                     fail = 0;
766
767         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
768                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
769
770         /* Check for possible status */
771         if (scmd->status < 0)
772                 fail = 1;
773         else if (cmd->read) {
774                 if (cmd->stage == 0)
775                         fail = cmd->pdata[0] != 0;
776                 else
777                         fail = cmd->pdata[0] >= 0x80;
778         } else {
779                 fail = cmd->pdata[0] != 0;
780         }
781
782         /* Handle failures by requeuing command, after 5ms interval
783          */
784         if (fail && --cmd->retries > 0) {
785                 DPRINTK("SMU: i2c failure, starting timer...\n");
786                 BUG_ON(cmd != smu->cmd_i2c_cur);
787                 if (!smu_irq_inited) {
788                         mdelay(5);
789                         smu_i2c_retry(0);
790                         return;
791                 }
792                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
793                 return;
794         }
795
796         /* If failure or stage 1, command is complete */
797         if (fail || cmd->stage != 0) {
798                 smu_i2c_complete_command(cmd, fail);
799                 return;
800         }
801
802         DPRINTK("SMU: going to stage 1\n");
803
804         /* Ok, initial command complete, now poll status */
805         scmd->reply_buf = cmd->pdata;
806         scmd->reply_len = sizeof(cmd->pdata);
807         scmd->data_buf = cmd->pdata;
808         scmd->data_len = 1;
809         cmd->pdata[0] = 0;
810         cmd->stage = 1;
811         cmd->retries = 20;
812         smu_queue_cmd(scmd);
813 }
814
815
816 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
817 {
818         unsigned long flags;
819
820         if (smu == NULL)
821                 return -ENODEV;
822
823         /* Fill most fields of scmd */
824         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
825         cmd->scmd.done = smu_i2c_low_completion;
826         cmd->scmd.misc = cmd;
827         cmd->scmd.reply_buf = cmd->pdata;
828         cmd->scmd.reply_len = sizeof(cmd->pdata);
829         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
830         cmd->scmd.status = 1;
831         cmd->stage = 0;
832         cmd->pdata[0] = 0xff;
833         cmd->retries = 20;
834         cmd->status = 1;
835
836         /* Check transfer type, sanitize some "info" fields
837          * based on transfer type and do more checking
838          */
839         cmd->info.caddr = cmd->info.devaddr;
840         cmd->read = cmd->info.devaddr & 0x01;
841         switch(cmd->info.type) {
842         case SMU_I2C_TRANSFER_SIMPLE:
843                 memset(&cmd->info.sublen, 0, 4);
844                 break;
845         case SMU_I2C_TRANSFER_COMBINED:
846                 cmd->info.devaddr &= 0xfe;
847         case SMU_I2C_TRANSFER_STDSUB:
848                 if (cmd->info.sublen > 3)
849                         return -EINVAL;
850                 break;
851         default:
852                 return -EINVAL;
853         }
854
855         /* Finish setting up command based on transfer direction
856          */
857         if (cmd->read) {
858                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
859                         return -EINVAL;
860                 memset(cmd->info.data, 0xff, cmd->info.datalen);
861                 cmd->scmd.data_len = 9;
862         } else {
863                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
864                         return -EINVAL;
865                 cmd->scmd.data_len = 9 + cmd->info.datalen;
866         }
867
868         DPRINTK("SMU: i2c enqueuing command\n");
869         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
870                 cmd->read ? "read" : "write", cmd->info.datalen,
871                 cmd->info.bus, cmd->info.caddr,
872                 cmd->info.subaddr[0], cmd->info.type);
873
874
875         /* Enqueue command in i2c list, and if empty, enqueue also in
876          * main command list
877          */
878         spin_lock_irqsave(&smu->lock, flags);
879         if (smu->cmd_i2c_cur == NULL) {
880                 smu->cmd_i2c_cur = cmd;
881                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
882                 if (smu->cmd_cur == NULL)
883                         smu_start_cmd();
884         } else
885                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
886         spin_unlock_irqrestore(&smu->lock, flags);
887
888         return 0;
889 }
890
891 /*
892  * Handling of "partitions"
893  */
894
895 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
896 {
897         DECLARE_COMPLETION_ONSTACK(comp);
898         unsigned int chunk;
899         struct smu_cmd cmd;
900         int rc;
901         u8 params[8];
902
903         /* We currently use a chunk size of 0xe. We could check the
904          * SMU firmware version and use bigger sizes though
905          */
906         chunk = 0xe;
907
908         while (len) {
909                 unsigned int clen = min(len, chunk);
910
911                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
912                 cmd.data_len = 7;
913                 cmd.data_buf = params;
914                 cmd.reply_len = chunk;
915                 cmd.reply_buf = dest;
916                 cmd.done = smu_done_complete;
917                 cmd.misc = &comp;
918                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
919                 params[1] = 0x4;
920                 *((u32 *)&params[2]) = addr;
921                 params[6] = clen;
922
923                 rc = smu_queue_cmd(&cmd);
924                 if (rc)
925                         return rc;
926                 wait_for_completion(&comp);
927                 if (cmd.status != 0)
928                         return rc;
929                 if (cmd.reply_len != clen) {
930                         printk(KERN_DEBUG "SMU: short read in "
931                                "smu_read_datablock, got: %d, want: %d\n",
932                                cmd.reply_len, clen);
933                         return -EIO;
934                 }
935                 len -= clen;
936                 addr += clen;
937                 dest += clen;
938         }
939         return 0;
940 }
941
942 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
943 {
944         DECLARE_COMPLETION_ONSTACK(comp);
945         struct smu_simple_cmd cmd;
946         unsigned int addr, len, tlen;
947         struct smu_sdbp_header *hdr;
948         struct property *prop;
949
950         /* First query the partition info */
951         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
952         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
953                          smu_done_complete, &comp,
954                          SMU_CMD_PARTITION_LATEST, id);
955         wait_for_completion(&comp);
956         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
957                 cmd.cmd.status, cmd.cmd.reply_len);
958
959         /* Partition doesn't exist (or other error) */
960         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
961                 return NULL;
962
963         /* Fetch address and length from reply */
964         addr = *((u16 *)cmd.buffer);
965         len = cmd.buffer[3] << 2;
966         /* Calucluate total length to allocate, including the 17 bytes
967          * for "sdb-partition-XX" that we append at the end of the buffer
968          */
969         tlen = sizeof(struct property) + len + 18;
970
971         prop = kzalloc(tlen, GFP_KERNEL);
972         if (prop == NULL)
973                 return NULL;
974         hdr = (struct smu_sdbp_header *)(prop + 1);
975         prop->name = ((char *)prop) + tlen - 18;
976         sprintf(prop->name, "sdb-partition-%02x", id);
977         prop->length = len;
978         prop->value = hdr;
979         prop->next = NULL;
980
981         /* Read the datablock */
982         if (smu_read_datablock((u8 *)hdr, addr, len)) {
983                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
984                        "partition %02x !\n", id);
985                 goto failure;
986         }
987
988         /* Got it, check a few things and create the property */
989         if (hdr->id != id) {
990                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
991                        "%02x !\n", id, hdr->id);
992                 goto failure;
993         }
994         if (prom_add_property(smu->of_node, prop)) {
995                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
996                        "property !\n", id);
997                 goto failure;
998         }
999
1000         return hdr;
1001  failure:
1002         kfree(prop);
1003         return NULL;
1004 }
1005
1006 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1007  * when interruptible is 1
1008  */
1009 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1010                 unsigned int *size, int interruptible)
1011 {
1012         char pname[32];
1013         const struct smu_sdbp_header *part;
1014
1015         if (!smu)
1016                 return NULL;
1017
1018         sprintf(pname, "sdb-partition-%02x", id);
1019
1020         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1021
1022         if (interruptible) {
1023                 int rc;
1024                 rc = mutex_lock_interruptible(&smu_part_access);
1025                 if (rc)
1026                         return ERR_PTR(rc);
1027         } else
1028                 mutex_lock(&smu_part_access);
1029
1030         part = of_get_property(smu->of_node, pname, size);
1031         if (part == NULL) {
1032                 DPRINTK("trying to extract from SMU ...\n");
1033                 part = smu_create_sdb_partition(id);
1034                 if (part != NULL && size)
1035                         *size = part->len << 2;
1036         }
1037         mutex_unlock(&smu_part_access);
1038         return part;
1039 }
1040
1041 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1042 {
1043         return __smu_get_sdb_partition(id, size, 0);
1044 }
1045 EXPORT_SYMBOL(smu_get_sdb_partition);
1046
1047
1048 /*
1049  * Userland driver interface
1050  */
1051
1052
1053 static LIST_HEAD(smu_clist);
1054 static DEFINE_SPINLOCK(smu_clist_lock);
1055
1056 enum smu_file_mode {
1057         smu_file_commands,
1058         smu_file_events,
1059         smu_file_closing
1060 };
1061
1062 struct smu_private
1063 {
1064         struct list_head        list;
1065         enum smu_file_mode      mode;
1066         int                     busy;
1067         struct smu_cmd          cmd;
1068         spinlock_t              lock;
1069         wait_queue_head_t       wait;
1070         u8                      buffer[SMU_MAX_DATA];
1071 };
1072
1073
1074 static int smu_open(struct inode *inode, struct file *file)
1075 {
1076         struct smu_private *pp;
1077         unsigned long flags;
1078
1079         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1080         if (pp == 0)
1081                 return -ENOMEM;
1082         spin_lock_init(&pp->lock);
1083         pp->mode = smu_file_commands;
1084         init_waitqueue_head(&pp->wait);
1085
1086         spin_lock_irqsave(&smu_clist_lock, flags);
1087         list_add(&pp->list, &smu_clist);
1088         spin_unlock_irqrestore(&smu_clist_lock, flags);
1089         file->private_data = pp;
1090
1091         return 0;
1092 }
1093
1094
1095 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1096 {
1097         struct smu_private *pp = misc;
1098
1099         wake_up_all(&pp->wait);
1100 }
1101
1102
1103 static ssize_t smu_write(struct file *file, const char __user *buf,
1104                          size_t count, loff_t *ppos)
1105 {
1106         struct smu_private *pp = file->private_data;
1107         unsigned long flags;
1108         struct smu_user_cmd_hdr hdr;
1109         int rc = 0;
1110
1111         if (pp->busy)
1112                 return -EBUSY;
1113         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1114                 return -EFAULT;
1115         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1116                 pp->mode = smu_file_events;
1117                 return 0;
1118         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1119                 const struct smu_sdbp_header *part;
1120                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1121                 if (part == NULL)
1122                         return -EINVAL;
1123                 else if (IS_ERR(part))
1124                         return PTR_ERR(part);
1125                 return 0;
1126         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1127                 return -EINVAL;
1128         else if (pp->mode != smu_file_commands)
1129                 return -EBADFD;
1130         else if (hdr.data_len > SMU_MAX_DATA)
1131                 return -EINVAL;
1132
1133         spin_lock_irqsave(&pp->lock, flags);
1134         if (pp->busy) {
1135                 spin_unlock_irqrestore(&pp->lock, flags);
1136                 return -EBUSY;
1137         }
1138         pp->busy = 1;
1139         pp->cmd.status = 1;
1140         spin_unlock_irqrestore(&pp->lock, flags);
1141
1142         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1143                 pp->busy = 0;
1144                 return -EFAULT;
1145         }
1146
1147         pp->cmd.cmd = hdr.cmd;
1148         pp->cmd.data_len = hdr.data_len;
1149         pp->cmd.reply_len = SMU_MAX_DATA;
1150         pp->cmd.data_buf = pp->buffer;
1151         pp->cmd.reply_buf = pp->buffer;
1152         pp->cmd.done = smu_user_cmd_done;
1153         pp->cmd.misc = pp;
1154         rc = smu_queue_cmd(&pp->cmd);
1155         if (rc < 0)
1156                 return rc;
1157         return count;
1158 }
1159
1160
1161 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1162                                 char __user *buf, size_t count)
1163 {
1164         DECLARE_WAITQUEUE(wait, current);
1165         struct smu_user_reply_hdr hdr;
1166         unsigned long flags;
1167         int size, rc = 0;
1168
1169         if (!pp->busy)
1170                 return 0;
1171         if (count < sizeof(struct smu_user_reply_hdr))
1172                 return -EOVERFLOW;
1173         spin_lock_irqsave(&pp->lock, flags);
1174         if (pp->cmd.status == 1) {
1175                 if (file->f_flags & O_NONBLOCK)
1176                         return -EAGAIN;
1177                 add_wait_queue(&pp->wait, &wait);
1178                 for (;;) {
1179                         set_current_state(TASK_INTERRUPTIBLE);
1180                         rc = 0;
1181                         if (pp->cmd.status != 1)
1182                                 break;
1183                         rc = -ERESTARTSYS;
1184                         if (signal_pending(current))
1185                                 break;
1186                         spin_unlock_irqrestore(&pp->lock, flags);
1187                         schedule();
1188                         spin_lock_irqsave(&pp->lock, flags);
1189                 }
1190                 set_current_state(TASK_RUNNING);
1191                 remove_wait_queue(&pp->wait, &wait);
1192         }
1193         spin_unlock_irqrestore(&pp->lock, flags);
1194         if (rc)
1195                 return rc;
1196         if (pp->cmd.status != 0)
1197                 pp->cmd.reply_len = 0;
1198         size = sizeof(hdr) + pp->cmd.reply_len;
1199         if (count < size)
1200                 size = count;
1201         rc = size;
1202         hdr.status = pp->cmd.status;
1203         hdr.reply_len = pp->cmd.reply_len;
1204         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1205                 return -EFAULT;
1206         size -= sizeof(hdr);
1207         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1208                 return -EFAULT;
1209         pp->busy = 0;
1210
1211         return rc;
1212 }
1213
1214
1215 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1216                                char __user *buf, size_t count)
1217 {
1218         /* Not implemented */
1219         msleep_interruptible(1000);
1220         return 0;
1221 }
1222
1223
1224 static ssize_t smu_read(struct file *file, char __user *buf,
1225                         size_t count, loff_t *ppos)
1226 {
1227         struct smu_private *pp = file->private_data;
1228
1229         if (pp->mode == smu_file_commands)
1230                 return smu_read_command(file, pp, buf, count);
1231         if (pp->mode == smu_file_events)
1232                 return smu_read_events(file, pp, buf, count);
1233
1234         return -EBADFD;
1235 }
1236
1237 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1238 {
1239         struct smu_private *pp = file->private_data;
1240         unsigned int mask = 0;
1241         unsigned long flags;
1242
1243         if (pp == 0)
1244                 return 0;
1245
1246         if (pp->mode == smu_file_commands) {
1247                 poll_wait(file, &pp->wait, wait);
1248
1249                 spin_lock_irqsave(&pp->lock, flags);
1250                 if (pp->busy && pp->cmd.status != 1)
1251                         mask |= POLLIN;
1252                 spin_unlock_irqrestore(&pp->lock, flags);
1253         } if (pp->mode == smu_file_events) {
1254                 /* Not yet implemented */
1255         }
1256         return mask;
1257 }
1258
1259 static int smu_release(struct inode *inode, struct file *file)
1260 {
1261         struct smu_private *pp = file->private_data;
1262         unsigned long flags;
1263         unsigned int busy;
1264
1265         if (pp == 0)
1266                 return 0;
1267
1268         file->private_data = NULL;
1269
1270         /* Mark file as closing to avoid races with new request */
1271         spin_lock_irqsave(&pp->lock, flags);
1272         pp->mode = smu_file_closing;
1273         busy = pp->busy;
1274
1275         /* Wait for any pending request to complete */
1276         if (busy && pp->cmd.status == 1) {
1277                 DECLARE_WAITQUEUE(wait, current);
1278
1279                 add_wait_queue(&pp->wait, &wait);
1280                 for (;;) {
1281                         set_current_state(TASK_UNINTERRUPTIBLE);
1282                         if (pp->cmd.status != 1)
1283                                 break;
1284                         spin_unlock_irqrestore(&pp->lock, flags);
1285                         schedule();
1286                         spin_lock_irqsave(&pp->lock, flags);
1287                 }
1288                 set_current_state(TASK_RUNNING);
1289                 remove_wait_queue(&pp->wait, &wait);
1290         }
1291         spin_unlock_irqrestore(&pp->lock, flags);
1292
1293         spin_lock_irqsave(&smu_clist_lock, flags);
1294         list_del(&pp->list);
1295         spin_unlock_irqrestore(&smu_clist_lock, flags);
1296         kfree(pp);
1297
1298         return 0;
1299 }
1300
1301
1302 static const struct file_operations smu_device_fops = {
1303         .llseek         = no_llseek,
1304         .read           = smu_read,
1305         .write          = smu_write,
1306         .poll           = smu_fpoll,
1307         .open           = smu_open,
1308         .release        = smu_release,
1309 };
1310
1311 static struct miscdevice pmu_device = {
1312         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1313 };
1314
1315 static int smu_device_init(void)
1316 {
1317         if (!smu)
1318                 return -ENODEV;
1319         if (misc_register(&pmu_device) < 0)
1320                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1321         return 0;
1322 }
1323 device_initcall(smu_device_init);