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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/poll.h>
36 #include <linux/mutex.h>
37 #include <linux/of_device.h>
38 #include <linux/of_platform.h>
39 #include <linux/slab.h>
40
41 #include <asm/byteorder.h>
42 #include <asm/io.h>
43 #include <asm/prom.h>
44 #include <asm/machdep.h>
45 #include <asm/pmac_feature.h>
46 #include <asm/smu.h>
47 #include <asm/sections.h>
48 #include <asm/uaccess.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 { printk(KERN_DEBUG fmt , ##args); } while (0)
57 #else
58 #define DPRINTK(fmt, args...) do { } while (0)
59 #endif
60
61 /*
62  * This is the command buffer passed to the SMU hardware
63  */
64 #define SMU_MAX_DATA    254
65
66 struct smu_cmd_buf {
67         u8 cmd;
68         u8 length;
69         u8 data[SMU_MAX_DATA];
70 };
71
72 struct smu_device {
73         spinlock_t              lock;
74         struct device_node      *of_node;
75         struct platform_device  *of_dev;
76         int                     doorbell;       /* doorbell gpio */
77         u32 __iomem             *db_buf;        /* doorbell buffer */
78         struct device_node      *db_node;
79         unsigned int            db_irq;
80         int                     msg;
81         struct device_node      *msg_node;
82         unsigned int            msg_irq;
83         struct smu_cmd_buf      *cmd_buf;       /* command buffer virtual */
84         u32                     cmd_buf_abs;    /* command buffer absolute */
85         struct list_head        cmd_list;
86         struct smu_cmd          *cmd_cur;       /* pending command */
87         int                     broken_nap;
88         struct list_head        cmd_i2c_list;
89         struct smu_i2c_cmd      *cmd_i2c_cur;   /* pending i2c command */
90         struct timer_list       i2c_timer;
91 };
92
93 /*
94  * I don't think there will ever be more than one SMU, so
95  * for now, just hard code that
96  */
97 static DEFINE_MUTEX(smu_mutex);
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         int ret = 0;
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                 ret = -EINVAL;
488                 goto fail_np;
489         }
490
491         smu = alloc_bootmem(sizeof(struct smu_device));
492
493         spin_lock_init(&smu->lock);
494         INIT_LIST_HEAD(&smu->cmd_list);
495         INIT_LIST_HEAD(&smu->cmd_i2c_list);
496         smu->of_node = np;
497         smu->db_irq = NO_IRQ;
498         smu->msg_irq = NO_IRQ;
499
500         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
501          * 32 bits value safely
502          */
503         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
504         smu->cmd_buf = __va(smu_cmdbuf_abs);
505
506         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
507         if (smu->db_node == NULL) {
508                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
509                 ret = -ENXIO;
510                 goto fail_bootmem;
511         }
512         data = of_get_property(smu->db_node, "reg", NULL);
513         if (data == NULL) {
514                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
515                 ret = -ENXIO;
516                 goto fail_db_node;
517         }
518
519         /* Current setup has one doorbell GPIO that does both doorbell
520          * and ack. GPIOs are at 0x50, best would be to find that out
521          * in the device-tree though.
522          */
523         smu->doorbell = *data;
524         if (smu->doorbell < 0x50)
525                 smu->doorbell += 0x50;
526
527         /* Now look for the smu-interrupt GPIO */
528         do {
529                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
530                 if (smu->msg_node == NULL)
531                         break;
532                 data = of_get_property(smu->msg_node, "reg", NULL);
533                 if (data == NULL) {
534                         of_node_put(smu->msg_node);
535                         smu->msg_node = NULL;
536                         break;
537                 }
538                 smu->msg = *data;
539                 if (smu->msg < 0x50)
540                         smu->msg += 0x50;
541         } while(0);
542
543         /* Doorbell buffer is currently hard-coded, I didn't find a proper
544          * device-tree entry giving the address. Best would probably to use
545          * an offset for K2 base though, but let's do it that way for now.
546          */
547         smu->db_buf = ioremap(0x8000860c, 0x1000);
548         if (smu->db_buf == NULL) {
549                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
550                 ret = -ENXIO;
551                 goto fail_msg_node;
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_msg_node:
563         if (smu->msg_node)
564                 of_node_put(smu->msg_node);
565 fail_db_node:
566         of_node_put(smu->db_node);
567 fail_bootmem:
568         free_bootmem((unsigned long)smu, sizeof(struct smu_device));
569         smu = NULL;
570 fail_np:
571         of_node_put(np);
572         return ret;
573 }
574
575
576 static int smu_late_init(void)
577 {
578         if (!smu)
579                 return 0;
580
581         init_timer(&smu->i2c_timer);
582         smu->i2c_timer.function = smu_i2c_retry;
583         smu->i2c_timer.data = (unsigned long)smu;
584
585         if (smu->db_node) {
586                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
587                 if (smu->db_irq == NO_IRQ)
588                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
589                                smu->db_node->full_name);
590         }
591         if (smu->msg_node) {
592                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
593                 if (smu->msg_irq == NO_IRQ)
594                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
595                                smu->msg_node->full_name);
596         }
597
598         /*
599          * Try to request the interrupts
600          */
601
602         if (smu->db_irq != NO_IRQ) {
603                 if (request_irq(smu->db_irq, smu_db_intr,
604                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
605                         printk(KERN_WARNING "SMU: can't "
606                                "request interrupt %d\n",
607                                smu->db_irq);
608                         smu->db_irq = NO_IRQ;
609                 }
610         }
611
612         if (smu->msg_irq != NO_IRQ) {
613                 if (request_irq(smu->msg_irq, smu_msg_intr,
614                                 IRQF_SHARED, "SMU message", smu) < 0) {
615                         printk(KERN_WARNING "SMU: can't "
616                                "request interrupt %d\n",
617                                smu->msg_irq);
618                         smu->msg_irq = NO_IRQ;
619                 }
620         }
621
622         smu_irq_inited = 1;
623         return 0;
624 }
625 /* This has to be before arch_initcall as the low i2c stuff relies on the
626  * above having been done before we reach arch_initcalls
627  */
628 core_initcall(smu_late_init);
629
630 /*
631  * sysfs visibility
632  */
633
634 static void smu_expose_childs(struct work_struct *unused)
635 {
636         struct device_node *np;
637
638         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
639                 if (of_device_is_compatible(np, "smu-sensors"))
640                         of_platform_device_create(np, "smu-sensors",
641                                                   &smu->of_dev->dev);
642 }
643
644 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
645
646 static int smu_platform_probe(struct platform_device* dev)
647 {
648         if (!smu)
649                 return -ENODEV;
650         smu->of_dev = dev;
651
652         /*
653          * Ok, we are matched, now expose all i2c busses. We have to defer
654          * that unfortunately or it would deadlock inside the device model
655          */
656         schedule_work(&smu_expose_childs_work);
657
658         return 0;
659 }
660
661 static const struct of_device_id smu_platform_match[] =
662 {
663         {
664                 .type           = "smu",
665         },
666         {},
667 };
668
669 static struct platform_driver smu_of_platform_driver =
670 {
671         .driver = {
672                 .name = "smu",
673                 .owner = THIS_MODULE,
674                 .of_match_table = smu_platform_match,
675         },
676         .probe          = smu_platform_probe,
677 };
678
679 static int __init smu_init_sysfs(void)
680 {
681         /*
682          * For now, we don't power manage machines with an SMU chip,
683          * I'm a bit too far from figuring out how that works with those
684          * new chipsets, but that will come back and bite us
685          */
686         platform_driver_register(&smu_of_platform_driver);
687         return 0;
688 }
689
690 device_initcall(smu_init_sysfs);
691
692 struct platform_device *smu_get_ofdev(void)
693 {
694         if (!smu)
695                 return NULL;
696         return smu->of_dev;
697 }
698
699 EXPORT_SYMBOL_GPL(smu_get_ofdev);
700
701 /*
702  * i2c interface
703  */
704
705 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
706 {
707         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
708         void *misc = cmd->misc;
709         unsigned long flags;
710
711         /* Check for read case */
712         if (!fail && cmd->read) {
713                 if (cmd->pdata[0] < 1)
714                         fail = 1;
715                 else
716                         memcpy(cmd->info.data, &cmd->pdata[1],
717                                cmd->info.datalen);
718         }
719
720         DPRINTK("SMU: completing, success: %d\n", !fail);
721
722         /* Update status and mark no pending i2c command with lock
723          * held so nobody comes in while we dequeue an eventual
724          * pending next i2c command
725          */
726         spin_lock_irqsave(&smu->lock, flags);
727         smu->cmd_i2c_cur = NULL;
728         wmb();
729         cmd->status = fail ? -EIO : 0;
730
731         /* Is there another i2c command waiting ? */
732         if (!list_empty(&smu->cmd_i2c_list)) {
733                 struct smu_i2c_cmd *newcmd;
734
735                 /* Fetch it, new current, remove from list */
736                 newcmd = list_entry(smu->cmd_i2c_list.next,
737                                     struct smu_i2c_cmd, link);
738                 smu->cmd_i2c_cur = newcmd;
739                 list_del(&cmd->link);
740
741                 /* Queue with low level smu */
742                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
743                 if (smu->cmd_cur == NULL)
744                         smu_start_cmd();
745         }
746         spin_unlock_irqrestore(&smu->lock, flags);
747
748         /* Call command completion handler if any */
749         if (done)
750                 done(cmd, misc);
751
752 }
753
754
755 static void smu_i2c_retry(unsigned long data)
756 {
757         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
758
759         DPRINTK("SMU: i2c failure, requeuing...\n");
760
761         /* requeue command simply by resetting reply_len */
762         cmd->pdata[0] = 0xff;
763         cmd->scmd.reply_len = sizeof(cmd->pdata);
764         smu_queue_cmd(&cmd->scmd);
765 }
766
767
768 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
769 {
770         struct smu_i2c_cmd      *cmd = misc;
771         int                     fail = 0;
772
773         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
774                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
775
776         /* Check for possible status */
777         if (scmd->status < 0)
778                 fail = 1;
779         else if (cmd->read) {
780                 if (cmd->stage == 0)
781                         fail = cmd->pdata[0] != 0;
782                 else
783                         fail = cmd->pdata[0] >= 0x80;
784         } else {
785                 fail = cmd->pdata[0] != 0;
786         }
787
788         /* Handle failures by requeuing command, after 5ms interval
789          */
790         if (fail && --cmd->retries > 0) {
791                 DPRINTK("SMU: i2c failure, starting timer...\n");
792                 BUG_ON(cmd != smu->cmd_i2c_cur);
793                 if (!smu_irq_inited) {
794                         mdelay(5);
795                         smu_i2c_retry(0);
796                         return;
797                 }
798                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
799                 return;
800         }
801
802         /* If failure or stage 1, command is complete */
803         if (fail || cmd->stage != 0) {
804                 smu_i2c_complete_command(cmd, fail);
805                 return;
806         }
807
808         DPRINTK("SMU: going to stage 1\n");
809
810         /* Ok, initial command complete, now poll status */
811         scmd->reply_buf = cmd->pdata;
812         scmd->reply_len = sizeof(cmd->pdata);
813         scmd->data_buf = cmd->pdata;
814         scmd->data_len = 1;
815         cmd->pdata[0] = 0;
816         cmd->stage = 1;
817         cmd->retries = 20;
818         smu_queue_cmd(scmd);
819 }
820
821
822 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
823 {
824         unsigned long flags;
825
826         if (smu == NULL)
827                 return -ENODEV;
828
829         /* Fill most fields of scmd */
830         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
831         cmd->scmd.done = smu_i2c_low_completion;
832         cmd->scmd.misc = cmd;
833         cmd->scmd.reply_buf = cmd->pdata;
834         cmd->scmd.reply_len = sizeof(cmd->pdata);
835         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
836         cmd->scmd.status = 1;
837         cmd->stage = 0;
838         cmd->pdata[0] = 0xff;
839         cmd->retries = 20;
840         cmd->status = 1;
841
842         /* Check transfer type, sanitize some "info" fields
843          * based on transfer type and do more checking
844          */
845         cmd->info.caddr = cmd->info.devaddr;
846         cmd->read = cmd->info.devaddr & 0x01;
847         switch(cmd->info.type) {
848         case SMU_I2C_TRANSFER_SIMPLE:
849                 memset(&cmd->info.sublen, 0, 4);
850                 break;
851         case SMU_I2C_TRANSFER_COMBINED:
852                 cmd->info.devaddr &= 0xfe;
853         case SMU_I2C_TRANSFER_STDSUB:
854                 if (cmd->info.sublen > 3)
855                         return -EINVAL;
856                 break;
857         default:
858                 return -EINVAL;
859         }
860
861         /* Finish setting up command based on transfer direction
862          */
863         if (cmd->read) {
864                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
865                         return -EINVAL;
866                 memset(cmd->info.data, 0xff, cmd->info.datalen);
867                 cmd->scmd.data_len = 9;
868         } else {
869                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
870                         return -EINVAL;
871                 cmd->scmd.data_len = 9 + cmd->info.datalen;
872         }
873
874         DPRINTK("SMU: i2c enqueuing command\n");
875         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
876                 cmd->read ? "read" : "write", cmd->info.datalen,
877                 cmd->info.bus, cmd->info.caddr,
878                 cmd->info.subaddr[0], cmd->info.type);
879
880
881         /* Enqueue command in i2c list, and if empty, enqueue also in
882          * main command list
883          */
884         spin_lock_irqsave(&smu->lock, flags);
885         if (smu->cmd_i2c_cur == NULL) {
886                 smu->cmd_i2c_cur = cmd;
887                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
888                 if (smu->cmd_cur == NULL)
889                         smu_start_cmd();
890         } else
891                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
892         spin_unlock_irqrestore(&smu->lock, flags);
893
894         return 0;
895 }
896
897 /*
898  * Handling of "partitions"
899  */
900
901 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
902 {
903         DECLARE_COMPLETION_ONSTACK(comp);
904         unsigned int chunk;
905         struct smu_cmd cmd;
906         int rc;
907         u8 params[8];
908
909         /* We currently use a chunk size of 0xe. We could check the
910          * SMU firmware version and use bigger sizes though
911          */
912         chunk = 0xe;
913
914         while (len) {
915                 unsigned int clen = min(len, chunk);
916
917                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
918                 cmd.data_len = 7;
919                 cmd.data_buf = params;
920                 cmd.reply_len = chunk;
921                 cmd.reply_buf = dest;
922                 cmd.done = smu_done_complete;
923                 cmd.misc = &comp;
924                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
925                 params[1] = 0x4;
926                 *((u32 *)&params[2]) = addr;
927                 params[6] = clen;
928
929                 rc = smu_queue_cmd(&cmd);
930                 if (rc)
931                         return rc;
932                 wait_for_completion(&comp);
933                 if (cmd.status != 0)
934                         return rc;
935                 if (cmd.reply_len != clen) {
936                         printk(KERN_DEBUG "SMU: short read in "
937                                "smu_read_datablock, got: %d, want: %d\n",
938                                cmd.reply_len, clen);
939                         return -EIO;
940                 }
941                 len -= clen;
942                 addr += clen;
943                 dest += clen;
944         }
945         return 0;
946 }
947
948 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
949 {
950         DECLARE_COMPLETION_ONSTACK(comp);
951         struct smu_simple_cmd cmd;
952         unsigned int addr, len, tlen;
953         struct smu_sdbp_header *hdr;
954         struct property *prop;
955
956         /* First query the partition info */
957         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
958         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
959                          smu_done_complete, &comp,
960                          SMU_CMD_PARTITION_LATEST, id);
961         wait_for_completion(&comp);
962         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
963                 cmd.cmd.status, cmd.cmd.reply_len);
964
965         /* Partition doesn't exist (or other error) */
966         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
967                 return NULL;
968
969         /* Fetch address and length from reply */
970         addr = *((u16 *)cmd.buffer);
971         len = cmd.buffer[3] << 2;
972         /* Calucluate total length to allocate, including the 17 bytes
973          * for "sdb-partition-XX" that we append at the end of the buffer
974          */
975         tlen = sizeof(struct property) + len + 18;
976
977         prop = kzalloc(tlen, GFP_KERNEL);
978         if (prop == NULL)
979                 return NULL;
980         hdr = (struct smu_sdbp_header *)(prop + 1);
981         prop->name = ((char *)prop) + tlen - 18;
982         sprintf(prop->name, "sdb-partition-%02x", id);
983         prop->length = len;
984         prop->value = hdr;
985         prop->next = NULL;
986
987         /* Read the datablock */
988         if (smu_read_datablock((u8 *)hdr, addr, len)) {
989                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
990                        "partition %02x !\n", id);
991                 goto failure;
992         }
993
994         /* Got it, check a few things and create the property */
995         if (hdr->id != id) {
996                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
997                        "%02x !\n", id, hdr->id);
998                 goto failure;
999         }
1000         if (prom_add_property(smu->of_node, prop)) {
1001                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1002                        "property !\n", id);
1003                 goto failure;
1004         }
1005
1006         return hdr;
1007  failure:
1008         kfree(prop);
1009         return NULL;
1010 }
1011
1012 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1013  * when interruptible is 1
1014  */
1015 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1016                 unsigned int *size, int interruptible)
1017 {
1018         char pname[32];
1019         const struct smu_sdbp_header *part;
1020
1021         if (!smu)
1022                 return NULL;
1023
1024         sprintf(pname, "sdb-partition-%02x", id);
1025
1026         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1027
1028         if (interruptible) {
1029                 int rc;
1030                 rc = mutex_lock_interruptible(&smu_part_access);
1031                 if (rc)
1032                         return ERR_PTR(rc);
1033         } else
1034                 mutex_lock(&smu_part_access);
1035
1036         part = of_get_property(smu->of_node, pname, size);
1037         if (part == NULL) {
1038                 DPRINTK("trying to extract from SMU ...\n");
1039                 part = smu_create_sdb_partition(id);
1040                 if (part != NULL && size)
1041                         *size = part->len << 2;
1042         }
1043         mutex_unlock(&smu_part_access);
1044         return part;
1045 }
1046
1047 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1048 {
1049         return __smu_get_sdb_partition(id, size, 0);
1050 }
1051 EXPORT_SYMBOL(smu_get_sdb_partition);
1052
1053
1054 /*
1055  * Userland driver interface
1056  */
1057
1058
1059 static LIST_HEAD(smu_clist);
1060 static DEFINE_SPINLOCK(smu_clist_lock);
1061
1062 enum smu_file_mode {
1063         smu_file_commands,
1064         smu_file_events,
1065         smu_file_closing
1066 };
1067
1068 struct smu_private
1069 {
1070         struct list_head        list;
1071         enum smu_file_mode      mode;
1072         int                     busy;
1073         struct smu_cmd          cmd;
1074         spinlock_t              lock;
1075         wait_queue_head_t       wait;
1076         u8                      buffer[SMU_MAX_DATA];
1077 };
1078
1079
1080 static int smu_open(struct inode *inode, struct file *file)
1081 {
1082         struct smu_private *pp;
1083         unsigned long flags;
1084
1085         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1086         if (pp == 0)
1087                 return -ENOMEM;
1088         spin_lock_init(&pp->lock);
1089         pp->mode = smu_file_commands;
1090         init_waitqueue_head(&pp->wait);
1091
1092         mutex_lock(&smu_mutex);
1093         spin_lock_irqsave(&smu_clist_lock, flags);
1094         list_add(&pp->list, &smu_clist);
1095         spin_unlock_irqrestore(&smu_clist_lock, flags);
1096         file->private_data = pp;
1097         mutex_unlock(&smu_mutex);
1098
1099         return 0;
1100 }
1101
1102
1103 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1104 {
1105         struct smu_private *pp = misc;
1106
1107         wake_up_all(&pp->wait);
1108 }
1109
1110
1111 static ssize_t smu_write(struct file *file, const char __user *buf,
1112                          size_t count, loff_t *ppos)
1113 {
1114         struct smu_private *pp = file->private_data;
1115         unsigned long flags;
1116         struct smu_user_cmd_hdr hdr;
1117         int rc = 0;
1118
1119         if (pp->busy)
1120                 return -EBUSY;
1121         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1122                 return -EFAULT;
1123         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1124                 pp->mode = smu_file_events;
1125                 return 0;
1126         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1127                 const struct smu_sdbp_header *part;
1128                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1129                 if (part == NULL)
1130                         return -EINVAL;
1131                 else if (IS_ERR(part))
1132                         return PTR_ERR(part);
1133                 return 0;
1134         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1135                 return -EINVAL;
1136         else if (pp->mode != smu_file_commands)
1137                 return -EBADFD;
1138         else if (hdr.data_len > SMU_MAX_DATA)
1139                 return -EINVAL;
1140
1141         spin_lock_irqsave(&pp->lock, flags);
1142         if (pp->busy) {
1143                 spin_unlock_irqrestore(&pp->lock, flags);
1144                 return -EBUSY;
1145         }
1146         pp->busy = 1;
1147         pp->cmd.status = 1;
1148         spin_unlock_irqrestore(&pp->lock, flags);
1149
1150         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1151                 pp->busy = 0;
1152                 return -EFAULT;
1153         }
1154
1155         pp->cmd.cmd = hdr.cmd;
1156         pp->cmd.data_len = hdr.data_len;
1157         pp->cmd.reply_len = SMU_MAX_DATA;
1158         pp->cmd.data_buf = pp->buffer;
1159         pp->cmd.reply_buf = pp->buffer;
1160         pp->cmd.done = smu_user_cmd_done;
1161         pp->cmd.misc = pp;
1162         rc = smu_queue_cmd(&pp->cmd);
1163         if (rc < 0)
1164                 return rc;
1165         return count;
1166 }
1167
1168
1169 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1170                                 char __user *buf, size_t count)
1171 {
1172         DECLARE_WAITQUEUE(wait, current);
1173         struct smu_user_reply_hdr hdr;
1174         unsigned long flags;
1175         int size, rc = 0;
1176
1177         if (!pp->busy)
1178                 return 0;
1179         if (count < sizeof(struct smu_user_reply_hdr))
1180                 return -EOVERFLOW;
1181         spin_lock_irqsave(&pp->lock, flags);
1182         if (pp->cmd.status == 1) {
1183                 if (file->f_flags & O_NONBLOCK) {
1184                         spin_unlock_irqrestore(&pp->lock, flags);
1185                         return -EAGAIN;
1186                 }
1187                 add_wait_queue(&pp->wait, &wait);
1188                 for (;;) {
1189                         set_current_state(TASK_INTERRUPTIBLE);
1190                         rc = 0;
1191                         if (pp->cmd.status != 1)
1192                                 break;
1193                         rc = -ERESTARTSYS;
1194                         if (signal_pending(current))
1195                                 break;
1196                         spin_unlock_irqrestore(&pp->lock, flags);
1197                         schedule();
1198                         spin_lock_irqsave(&pp->lock, flags);
1199                 }
1200                 set_current_state(TASK_RUNNING);
1201                 remove_wait_queue(&pp->wait, &wait);
1202         }
1203         spin_unlock_irqrestore(&pp->lock, flags);
1204         if (rc)
1205                 return rc;
1206         if (pp->cmd.status != 0)
1207                 pp->cmd.reply_len = 0;
1208         size = sizeof(hdr) + pp->cmd.reply_len;
1209         if (count < size)
1210                 size = count;
1211         rc = size;
1212         hdr.status = pp->cmd.status;
1213         hdr.reply_len = pp->cmd.reply_len;
1214         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1215                 return -EFAULT;
1216         size -= sizeof(hdr);
1217         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1218                 return -EFAULT;
1219         pp->busy = 0;
1220
1221         return rc;
1222 }
1223
1224
1225 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1226                                char __user *buf, size_t count)
1227 {
1228         /* Not implemented */
1229         msleep_interruptible(1000);
1230         return 0;
1231 }
1232
1233
1234 static ssize_t smu_read(struct file *file, char __user *buf,
1235                         size_t count, loff_t *ppos)
1236 {
1237         struct smu_private *pp = file->private_data;
1238
1239         if (pp->mode == smu_file_commands)
1240                 return smu_read_command(file, pp, buf, count);
1241         if (pp->mode == smu_file_events)
1242                 return smu_read_events(file, pp, buf, count);
1243
1244         return -EBADFD;
1245 }
1246
1247 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1248 {
1249         struct smu_private *pp = file->private_data;
1250         unsigned int mask = 0;
1251         unsigned long flags;
1252
1253         if (pp == 0)
1254                 return 0;
1255
1256         if (pp->mode == smu_file_commands) {
1257                 poll_wait(file, &pp->wait, wait);
1258
1259                 spin_lock_irqsave(&pp->lock, flags);
1260                 if (pp->busy && pp->cmd.status != 1)
1261                         mask |= POLLIN;
1262                 spin_unlock_irqrestore(&pp->lock, flags);
1263         } if (pp->mode == smu_file_events) {
1264                 /* Not yet implemented */
1265         }
1266         return mask;
1267 }
1268
1269 static int smu_release(struct inode *inode, struct file *file)
1270 {
1271         struct smu_private *pp = file->private_data;
1272         unsigned long flags;
1273         unsigned int busy;
1274
1275         if (pp == 0)
1276                 return 0;
1277
1278         file->private_data = NULL;
1279
1280         /* Mark file as closing to avoid races with new request */
1281         spin_lock_irqsave(&pp->lock, flags);
1282         pp->mode = smu_file_closing;
1283         busy = pp->busy;
1284
1285         /* Wait for any pending request to complete */
1286         if (busy && pp->cmd.status == 1) {
1287                 DECLARE_WAITQUEUE(wait, current);
1288
1289                 add_wait_queue(&pp->wait, &wait);
1290                 for (;;) {
1291                         set_current_state(TASK_UNINTERRUPTIBLE);
1292                         if (pp->cmd.status != 1)
1293                                 break;
1294                         spin_unlock_irqrestore(&pp->lock, flags);
1295                         schedule();
1296                         spin_lock_irqsave(&pp->lock, flags);
1297                 }
1298                 set_current_state(TASK_RUNNING);
1299                 remove_wait_queue(&pp->wait, &wait);
1300         }
1301         spin_unlock_irqrestore(&pp->lock, flags);
1302
1303         spin_lock_irqsave(&smu_clist_lock, flags);
1304         list_del(&pp->list);
1305         spin_unlock_irqrestore(&smu_clist_lock, flags);
1306         kfree(pp);
1307
1308         return 0;
1309 }
1310
1311
1312 static const struct file_operations smu_device_fops = {
1313         .llseek         = no_llseek,
1314         .read           = smu_read,
1315         .write          = smu_write,
1316         .poll           = smu_fpoll,
1317         .open           = smu_open,
1318         .release        = smu_release,
1319 };
1320
1321 static struct miscdevice pmu_device = {
1322         MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1323 };
1324
1325 static int smu_device_init(void)
1326 {
1327         if (!smu)
1328                 return -ENODEV;
1329         if (misc_register(&pmu_device) < 0)
1330                 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1331         return 0;
1332 }
1333 device_initcall(smu_device_init);