Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
[firefly-linux-kernel-4.4.55.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/poll.h>
36 #include <linux/mutex.h>
37 #include <linux/of_device.h>
38 #include <linux/of_irq.h>
39 #include <linux/of_platform.h>
40 #include <linux/slab.h>
41
42 #include <asm/byteorder.h>
43 #include <asm/io.h>
44 #include <asm/prom.h>
45 #include <asm/machdep.h>
46 #include <asm/pmac_feature.h>
47 #include <asm/smu.h>
48 #include <asm/sections.h>
49 #include <asm/uaccess.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 platform_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 DEFINE_MUTEX(smu_mutex);
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: %8ph\n", cmd->data_buf);
125
126         /* Fill the SMU command buffer */
127         smu->cmd_buf->cmd = cmd->cmd;
128         smu->cmd_buf->length = cmd->data_len;
129         memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
130
131         /* Flush command and data to RAM */
132         faddr = (unsigned long)smu->cmd_buf;
133         fend = faddr + smu->cmd_buf->length + 2;
134         flush_inval_dcache_range(faddr, fend);
135
136
137         /* We also disable NAP mode for the duration of the command
138          * on U3 based machines.
139          * This is slightly racy as it can be written back to 1 by a sysctl
140          * but that never happens in practice. There seem to be an issue with
141          * U3 based machines such as the iMac G5 where napping for the
142          * whole duration of the command prevents the SMU from fetching it
143          * from memory. This might be related to the strange i2c based
144          * mechanism the SMU uses to access memory.
145          */
146         if (smu->broken_nap)
147                 powersave_nap = 0;
148
149         /* This isn't exactly a DMA mapping here, I suspect
150          * the SMU is actually communicating with us via i2c to the
151          * northbridge or the CPU to access RAM.
152          */
153         writel(smu->cmd_buf_abs, smu->db_buf);
154
155         /* Ring the SMU doorbell */
156         pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
157 }
158
159
160 static irqreturn_t smu_db_intr(int irq, void *arg)
161 {
162         unsigned long flags;
163         struct smu_cmd *cmd;
164         void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
165         void *misc = NULL;
166         u8 gpio;
167         int rc = 0;
168
169         /* SMU completed the command, well, we hope, let's make sure
170          * of it
171          */
172         spin_lock_irqsave(&smu->lock, flags);
173
174         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
175         if ((gpio & 7) != 7) {
176                 spin_unlock_irqrestore(&smu->lock, flags);
177                 return IRQ_HANDLED;
178         }
179
180         cmd = smu->cmd_cur;
181         smu->cmd_cur = NULL;
182         if (cmd == NULL)
183                 goto bail;
184
185         if (rc == 0) {
186                 unsigned long faddr;
187                 int reply_len;
188                 u8 ack;
189
190                 /* CPU might have brought back the cache line, so we need
191                  * to flush again before peeking at the SMU response. We
192                  * flush the entire buffer for now as we haven't read the
193                  * reply length (it's only 2 cache lines anyway)
194                  */
195                 faddr = (unsigned long)smu->cmd_buf;
196                 flush_inval_dcache_range(faddr, faddr + 256);
197
198                 /* Now check ack */
199                 ack = (~cmd->cmd) & 0xff;
200                 if (ack != smu->cmd_buf->cmd) {
201                         DPRINTK("SMU: incorrect ack, want %x got %x\n",
202                                 ack, smu->cmd_buf->cmd);
203                         rc = -EIO;
204                 }
205                 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
206                 DPRINTK("SMU: reply len: %d\n", reply_len);
207                 if (reply_len > cmd->reply_len) {
208                         printk(KERN_WARNING "SMU: reply buffer too small,"
209                                "got %d bytes for a %d bytes buffer\n",
210                                reply_len, cmd->reply_len);
211                         reply_len = cmd->reply_len;
212                 }
213                 cmd->reply_len = reply_len;
214                 if (cmd->reply_buf && reply_len)
215                         memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
216         }
217
218         /* Now complete the command. Write status last in order as we lost
219          * ownership of the command structure as soon as it's no longer -1
220          */
221         done = cmd->done;
222         misc = cmd->misc;
223         mb();
224         cmd->status = rc;
225
226         /* Re-enable NAP mode */
227         if (smu->broken_nap)
228                 powersave_nap = 1;
229  bail:
230         /* Start next command if any */
231         smu_start_cmd();
232         spin_unlock_irqrestore(&smu->lock, flags);
233
234         /* Call command completion handler if any */
235         if (done)
236                 done(cmd, misc);
237
238         /* It's an edge interrupt, nothing to do */
239         return IRQ_HANDLED;
240 }
241
242
243 static irqreturn_t smu_msg_intr(int irq, void *arg)
244 {
245         /* I don't quite know what to do with this one, we seem to never
246          * receive it, so I suspect we have to arm it someway in the SMU
247          * to start getting events that way.
248          */
249
250         printk(KERN_INFO "SMU: message interrupt !\n");
251
252         /* It's an edge interrupt, nothing to do */
253         return IRQ_HANDLED;
254 }
255
256
257 /*
258  * Queued command management.
259  *
260  */
261
262 int smu_queue_cmd(struct smu_cmd *cmd)
263 {
264         unsigned long flags;
265
266         if (smu == NULL)
267                 return -ENODEV;
268         if (cmd->data_len > SMU_MAX_DATA ||
269             cmd->reply_len > SMU_MAX_DATA)
270                 return -EINVAL;
271
272         cmd->status = 1;
273         spin_lock_irqsave(&smu->lock, flags);
274         list_add_tail(&cmd->link, &smu->cmd_list);
275         if (smu->cmd_cur == NULL)
276                 smu_start_cmd();
277         spin_unlock_irqrestore(&smu->lock, flags);
278
279         /* Workaround for early calls when irq isn't available */
280         if (!smu_irq_inited || smu->db_irq == NO_IRQ)
281                 smu_spinwait_cmd(cmd);
282
283         return 0;
284 }
285 EXPORT_SYMBOL(smu_queue_cmd);
286
287
288 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
289                      unsigned int data_len,
290                      void (*done)(struct smu_cmd *cmd, void *misc),
291                      void *misc, ...)
292 {
293         struct smu_cmd *cmd = &scmd->cmd;
294         va_list list;
295         int i;
296
297         if (data_len > sizeof(scmd->buffer))
298                 return -EINVAL;
299
300         memset(scmd, 0, sizeof(*scmd));
301         cmd->cmd = command;
302         cmd->data_len = data_len;
303         cmd->data_buf = scmd->buffer;
304         cmd->reply_len = sizeof(scmd->buffer);
305         cmd->reply_buf = scmd->buffer;
306         cmd->done = done;
307         cmd->misc = misc;
308
309         va_start(list, misc);
310         for (i = 0; i < data_len; ++i)
311                 scmd->buffer[i] = (u8)va_arg(list, int);
312         va_end(list);
313
314         return smu_queue_cmd(cmd);
315 }
316 EXPORT_SYMBOL(smu_queue_simple);
317
318
319 void smu_poll(void)
320 {
321         u8 gpio;
322
323         if (smu == NULL)
324                 return;
325
326         gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
327         if ((gpio & 7) == 7)
328                 smu_db_intr(smu->db_irq, smu);
329 }
330 EXPORT_SYMBOL(smu_poll);
331
332
333 void smu_done_complete(struct smu_cmd *cmd, void *misc)
334 {
335         struct completion *comp = misc;
336
337         complete(comp);
338 }
339 EXPORT_SYMBOL(smu_done_complete);
340
341
342 void smu_spinwait_cmd(struct smu_cmd *cmd)
343 {
344         while(cmd->status == 1)
345                 smu_poll();
346 }
347 EXPORT_SYMBOL(smu_spinwait_cmd);
348
349
350 /* RTC low level commands */
351 static inline int bcd2hex (int n)
352 {
353         return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
354 }
355
356
357 static inline int hex2bcd (int n)
358 {
359         return ((n / 10) << 4) + (n % 10);
360 }
361
362
363 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
364                                         struct rtc_time *time)
365 {
366         cmd_buf->cmd = 0x8e;
367         cmd_buf->length = 8;
368         cmd_buf->data[0] = 0x80;
369         cmd_buf->data[1] = hex2bcd(time->tm_sec);
370         cmd_buf->data[2] = hex2bcd(time->tm_min);
371         cmd_buf->data[3] = hex2bcd(time->tm_hour);
372         cmd_buf->data[4] = time->tm_wday;
373         cmd_buf->data[5] = hex2bcd(time->tm_mday);
374         cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
375         cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
376 }
377
378
379 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
380 {
381         struct smu_simple_cmd cmd;
382         int rc;
383
384         if (smu == NULL)
385                 return -ENODEV;
386
387         memset(time, 0, sizeof(struct rtc_time));
388         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
389                               SMU_CMD_RTC_GET_DATETIME);
390         if (rc)
391                 return rc;
392         smu_spinwait_simple(&cmd);
393
394         time->tm_sec = bcd2hex(cmd.buffer[0]);
395         time->tm_min = bcd2hex(cmd.buffer[1]);
396         time->tm_hour = bcd2hex(cmd.buffer[2]);
397         time->tm_wday = bcd2hex(cmd.buffer[3]);
398         time->tm_mday = bcd2hex(cmd.buffer[4]);
399         time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
400         time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
401
402         return 0;
403 }
404
405
406 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
407 {
408         struct smu_simple_cmd cmd;
409         int rc;
410
411         if (smu == NULL)
412                 return -ENODEV;
413
414         rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
415                               SMU_CMD_RTC_SET_DATETIME,
416                               hex2bcd(time->tm_sec),
417                               hex2bcd(time->tm_min),
418                               hex2bcd(time->tm_hour),
419                               time->tm_wday,
420                               hex2bcd(time->tm_mday),
421                               hex2bcd(time->tm_mon) + 1,
422                               hex2bcd(time->tm_year - 100));
423         if (rc)
424                 return rc;
425         smu_spinwait_simple(&cmd);
426
427         return 0;
428 }
429
430
431 void smu_shutdown(void)
432 {
433         struct smu_simple_cmd cmd;
434
435         if (smu == NULL)
436                 return;
437
438         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
439                              'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
440                 return;
441         smu_spinwait_simple(&cmd);
442         for (;;)
443                 ;
444 }
445
446
447 void smu_restart(void)
448 {
449         struct smu_simple_cmd cmd;
450
451         if (smu == NULL)
452                 return;
453
454         if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
455                              'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
456                 return;
457         smu_spinwait_simple(&cmd);
458         for (;;)
459                 ;
460 }
461
462
463 int smu_present(void)
464 {
465         return smu != NULL;
466 }
467 EXPORT_SYMBOL(smu_present);
468
469
470 int __init smu_init (void)
471 {
472         struct device_node *np;
473         const u32 *data;
474         int ret = 0;
475
476         np = of_find_node_by_type(NULL, "smu");
477         if (np == NULL)
478                 return -ENODEV;
479
480         printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
481
482         if (smu_cmdbuf_abs == 0) {
483                 printk(KERN_ERR "SMU: Command buffer not allocated !\n");
484                 ret = -EINVAL;
485                 goto fail_np;
486         }
487
488         smu = alloc_bootmem(sizeof(struct smu_device));
489
490         spin_lock_init(&smu->lock);
491         INIT_LIST_HEAD(&smu->cmd_list);
492         INIT_LIST_HEAD(&smu->cmd_i2c_list);
493         smu->of_node = np;
494         smu->db_irq = NO_IRQ;
495         smu->msg_irq = NO_IRQ;
496
497         /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
498          * 32 bits value safely
499          */
500         smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
501         smu->cmd_buf = __va(smu_cmdbuf_abs);
502
503         smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
504         if (smu->db_node == NULL) {
505                 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
506                 ret = -ENXIO;
507                 goto fail_bootmem;
508         }
509         data = of_get_property(smu->db_node, "reg", NULL);
510         if (data == NULL) {
511                 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
512                 ret = -ENXIO;
513                 goto fail_db_node;
514         }
515
516         /* Current setup has one doorbell GPIO that does both doorbell
517          * and ack. GPIOs are at 0x50, best would be to find that out
518          * in the device-tree though.
519          */
520         smu->doorbell = *data;
521         if (smu->doorbell < 0x50)
522                 smu->doorbell += 0x50;
523
524         /* Now look for the smu-interrupt GPIO */
525         do {
526                 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
527                 if (smu->msg_node == NULL)
528                         break;
529                 data = of_get_property(smu->msg_node, "reg", NULL);
530                 if (data == NULL) {
531                         of_node_put(smu->msg_node);
532                         smu->msg_node = NULL;
533                         break;
534                 }
535                 smu->msg = *data;
536                 if (smu->msg < 0x50)
537                         smu->msg += 0x50;
538         } while(0);
539
540         /* Doorbell buffer is currently hard-coded, I didn't find a proper
541          * device-tree entry giving the address. Best would probably to use
542          * an offset for K2 base though, but let's do it that way for now.
543          */
544         smu->db_buf = ioremap(0x8000860c, 0x1000);
545         if (smu->db_buf == NULL) {
546                 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
547                 ret = -ENXIO;
548                 goto fail_msg_node;
549         }
550
551         /* U3 has an issue with NAP mode when issuing SMU commands */
552         smu->broken_nap = pmac_get_uninorth_variant() < 4;
553         if (smu->broken_nap)
554                 printk(KERN_INFO "SMU: using NAP mode workaround\n");
555
556         sys_ctrler = SYS_CTRLER_SMU;
557         return 0;
558
559 fail_msg_node:
560         of_node_put(smu->msg_node);
561 fail_db_node:
562         of_node_put(smu->db_node);
563 fail_bootmem:
564         free_bootmem(__pa(smu), sizeof(struct smu_device));
565         smu = NULL;
566 fail_np:
567         of_node_put(np);
568         return ret;
569 }
570
571
572 static int smu_late_init(void)
573 {
574         if (!smu)
575                 return 0;
576
577         init_timer(&smu->i2c_timer);
578         smu->i2c_timer.function = smu_i2c_retry;
579         smu->i2c_timer.data = (unsigned long)smu;
580
581         if (smu->db_node) {
582                 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
583                 if (smu->db_irq == NO_IRQ)
584                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
585                                smu->db_node->full_name);
586         }
587         if (smu->msg_node) {
588                 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
589                 if (smu->msg_irq == NO_IRQ)
590                         printk(KERN_ERR "smu: failed to map irq for node %s\n",
591                                smu->msg_node->full_name);
592         }
593
594         /*
595          * Try to request the interrupts
596          */
597
598         if (smu->db_irq != NO_IRQ) {
599                 if (request_irq(smu->db_irq, smu_db_intr,
600                                 IRQF_SHARED, "SMU doorbell", smu) < 0) {
601                         printk(KERN_WARNING "SMU: can't "
602                                "request interrupt %d\n",
603                                smu->db_irq);
604                         smu->db_irq = NO_IRQ;
605                 }
606         }
607
608         if (smu->msg_irq != NO_IRQ) {
609                 if (request_irq(smu->msg_irq, smu_msg_intr,
610                                 IRQF_SHARED, "SMU message", smu) < 0) {
611                         printk(KERN_WARNING "SMU: can't "
612                                "request interrupt %d\n",
613                                smu->msg_irq);
614                         smu->msg_irq = NO_IRQ;
615                 }
616         }
617
618         smu_irq_inited = 1;
619         return 0;
620 }
621 /* This has to be before arch_initcall as the low i2c stuff relies on the
622  * above having been done before we reach arch_initcalls
623  */
624 core_initcall(smu_late_init);
625
626 /*
627  * sysfs visibility
628  */
629
630 static void smu_expose_childs(struct work_struct *unused)
631 {
632         struct device_node *np;
633
634         for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
635                 if (of_device_is_compatible(np, "smu-sensors"))
636                         of_platform_device_create(np, "smu-sensors",
637                                                   &smu->of_dev->dev);
638 }
639
640 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
641
642 static int smu_platform_probe(struct platform_device* dev)
643 {
644         if (!smu)
645                 return -ENODEV;
646         smu->of_dev = dev;
647
648         /*
649          * Ok, we are matched, now expose all i2c busses. We have to defer
650          * that unfortunately or it would deadlock inside the device model
651          */
652         schedule_work(&smu_expose_childs_work);
653
654         return 0;
655 }
656
657 static const struct of_device_id smu_platform_match[] =
658 {
659         {
660                 .type           = "smu",
661         },
662         {},
663 };
664
665 static struct platform_driver smu_of_platform_driver =
666 {
667         .driver = {
668                 .name = "smu",
669                 .of_match_table = smu_platform_match,
670         },
671         .probe          = smu_platform_probe,
672 };
673
674 static int __init smu_init_sysfs(void)
675 {
676         /*
677          * For now, we don't power manage machines with an SMU chip,
678          * I'm a bit too far from figuring out how that works with those
679          * new chipsets, but that will come back and bite us
680          */
681         platform_driver_register(&smu_of_platform_driver);
682         return 0;
683 }
684
685 device_initcall(smu_init_sysfs);
686
687 struct platform_device *smu_get_ofdev(void)
688 {
689         if (!smu)
690                 return NULL;
691         return smu->of_dev;
692 }
693
694 EXPORT_SYMBOL_GPL(smu_get_ofdev);
695
696 /*
697  * i2c interface
698  */
699
700 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
701 {
702         void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
703         void *misc = cmd->misc;
704         unsigned long flags;
705
706         /* Check for read case */
707         if (!fail && cmd->read) {
708                 if (cmd->pdata[0] < 1)
709                         fail = 1;
710                 else
711                         memcpy(cmd->info.data, &cmd->pdata[1],
712                                cmd->info.datalen);
713         }
714
715         DPRINTK("SMU: completing, success: %d\n", !fail);
716
717         /* Update status and mark no pending i2c command with lock
718          * held so nobody comes in while we dequeue an eventual
719          * pending next i2c command
720          */
721         spin_lock_irqsave(&smu->lock, flags);
722         smu->cmd_i2c_cur = NULL;
723         wmb();
724         cmd->status = fail ? -EIO : 0;
725
726         /* Is there another i2c command waiting ? */
727         if (!list_empty(&smu->cmd_i2c_list)) {
728                 struct smu_i2c_cmd *newcmd;
729
730                 /* Fetch it, new current, remove from list */
731                 newcmd = list_entry(smu->cmd_i2c_list.next,
732                                     struct smu_i2c_cmd, link);
733                 smu->cmd_i2c_cur = newcmd;
734                 list_del(&cmd->link);
735
736                 /* Queue with low level smu */
737                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
738                 if (smu->cmd_cur == NULL)
739                         smu_start_cmd();
740         }
741         spin_unlock_irqrestore(&smu->lock, flags);
742
743         /* Call command completion handler if any */
744         if (done)
745                 done(cmd, misc);
746
747 }
748
749
750 static void smu_i2c_retry(unsigned long data)
751 {
752         struct smu_i2c_cmd      *cmd = smu->cmd_i2c_cur;
753
754         DPRINTK("SMU: i2c failure, requeuing...\n");
755
756         /* requeue command simply by resetting reply_len */
757         cmd->pdata[0] = 0xff;
758         cmd->scmd.reply_len = sizeof(cmd->pdata);
759         smu_queue_cmd(&cmd->scmd);
760 }
761
762
763 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
764 {
765         struct smu_i2c_cmd      *cmd = misc;
766         int                     fail = 0;
767
768         DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
769                 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
770
771         /* Check for possible status */
772         if (scmd->status < 0)
773                 fail = 1;
774         else if (cmd->read) {
775                 if (cmd->stage == 0)
776                         fail = cmd->pdata[0] != 0;
777                 else
778                         fail = cmd->pdata[0] >= 0x80;
779         } else {
780                 fail = cmd->pdata[0] != 0;
781         }
782
783         /* Handle failures by requeuing command, after 5ms interval
784          */
785         if (fail && --cmd->retries > 0) {
786                 DPRINTK("SMU: i2c failure, starting timer...\n");
787                 BUG_ON(cmd != smu->cmd_i2c_cur);
788                 if (!smu_irq_inited) {
789                         mdelay(5);
790                         smu_i2c_retry(0);
791                         return;
792                 }
793                 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
794                 return;
795         }
796
797         /* If failure or stage 1, command is complete */
798         if (fail || cmd->stage != 0) {
799                 smu_i2c_complete_command(cmd, fail);
800                 return;
801         }
802
803         DPRINTK("SMU: going to stage 1\n");
804
805         /* Ok, initial command complete, now poll status */
806         scmd->reply_buf = cmd->pdata;
807         scmd->reply_len = sizeof(cmd->pdata);
808         scmd->data_buf = cmd->pdata;
809         scmd->data_len = 1;
810         cmd->pdata[0] = 0;
811         cmd->stage = 1;
812         cmd->retries = 20;
813         smu_queue_cmd(scmd);
814 }
815
816
817 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
818 {
819         unsigned long flags;
820
821         if (smu == NULL)
822                 return -ENODEV;
823
824         /* Fill most fields of scmd */
825         cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
826         cmd->scmd.done = smu_i2c_low_completion;
827         cmd->scmd.misc = cmd;
828         cmd->scmd.reply_buf = cmd->pdata;
829         cmd->scmd.reply_len = sizeof(cmd->pdata);
830         cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
831         cmd->scmd.status = 1;
832         cmd->stage = 0;
833         cmd->pdata[0] = 0xff;
834         cmd->retries = 20;
835         cmd->status = 1;
836
837         /* Check transfer type, sanitize some "info" fields
838          * based on transfer type and do more checking
839          */
840         cmd->info.caddr = cmd->info.devaddr;
841         cmd->read = cmd->info.devaddr & 0x01;
842         switch(cmd->info.type) {
843         case SMU_I2C_TRANSFER_SIMPLE:
844                 memset(&cmd->info.sublen, 0, 4);
845                 break;
846         case SMU_I2C_TRANSFER_COMBINED:
847                 cmd->info.devaddr &= 0xfe;
848         case SMU_I2C_TRANSFER_STDSUB:
849                 if (cmd->info.sublen > 3)
850                         return -EINVAL;
851                 break;
852         default:
853                 return -EINVAL;
854         }
855
856         /* Finish setting up command based on transfer direction
857          */
858         if (cmd->read) {
859                 if (cmd->info.datalen > SMU_I2C_READ_MAX)
860                         return -EINVAL;
861                 memset(cmd->info.data, 0xff, cmd->info.datalen);
862                 cmd->scmd.data_len = 9;
863         } else {
864                 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
865                         return -EINVAL;
866                 cmd->scmd.data_len = 9 + cmd->info.datalen;
867         }
868
869         DPRINTK("SMU: i2c enqueuing command\n");
870         DPRINTK("SMU:   %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
871                 cmd->read ? "read" : "write", cmd->info.datalen,
872                 cmd->info.bus, cmd->info.caddr,
873                 cmd->info.subaddr[0], cmd->info.type);
874
875
876         /* Enqueue command in i2c list, and if empty, enqueue also in
877          * main command list
878          */
879         spin_lock_irqsave(&smu->lock, flags);
880         if (smu->cmd_i2c_cur == NULL) {
881                 smu->cmd_i2c_cur = cmd;
882                 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
883                 if (smu->cmd_cur == NULL)
884                         smu_start_cmd();
885         } else
886                 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
887         spin_unlock_irqrestore(&smu->lock, flags);
888
889         return 0;
890 }
891
892 /*
893  * Handling of "partitions"
894  */
895
896 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
897 {
898         DECLARE_COMPLETION_ONSTACK(comp);
899         unsigned int chunk;
900         struct smu_cmd cmd;
901         int rc;
902         u8 params[8];
903
904         /* We currently use a chunk size of 0xe. We could check the
905          * SMU firmware version and use bigger sizes though
906          */
907         chunk = 0xe;
908
909         while (len) {
910                 unsigned int clen = min(len, chunk);
911
912                 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
913                 cmd.data_len = 7;
914                 cmd.data_buf = params;
915                 cmd.reply_len = chunk;
916                 cmd.reply_buf = dest;
917                 cmd.done = smu_done_complete;
918                 cmd.misc = &comp;
919                 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
920                 params[1] = 0x4;
921                 *((u32 *)&params[2]) = addr;
922                 params[6] = clen;
923
924                 rc = smu_queue_cmd(&cmd);
925                 if (rc)
926                         return rc;
927                 wait_for_completion(&comp);
928                 if (cmd.status != 0)
929                         return rc;
930                 if (cmd.reply_len != clen) {
931                         printk(KERN_DEBUG "SMU: short read in "
932                                "smu_read_datablock, got: %d, want: %d\n",
933                                cmd.reply_len, clen);
934                         return -EIO;
935                 }
936                 len -= clen;
937                 addr += clen;
938                 dest += clen;
939         }
940         return 0;
941 }
942
943 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
944 {
945         DECLARE_COMPLETION_ONSTACK(comp);
946         struct smu_simple_cmd cmd;
947         unsigned int addr, len, tlen;
948         struct smu_sdbp_header *hdr;
949         struct property *prop;
950
951         /* First query the partition info */
952         DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
953         smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
954                          smu_done_complete, &comp,
955                          SMU_CMD_PARTITION_LATEST, id);
956         wait_for_completion(&comp);
957         DPRINTK("SMU: done, status: %d, reply_len: %d\n",
958                 cmd.cmd.status, cmd.cmd.reply_len);
959
960         /* Partition doesn't exist (or other error) */
961         if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
962                 return NULL;
963
964         /* Fetch address and length from reply */
965         addr = *((u16 *)cmd.buffer);
966         len = cmd.buffer[3] << 2;
967         /* Calucluate total length to allocate, including the 17 bytes
968          * for "sdb-partition-XX" that we append at the end of the buffer
969          */
970         tlen = sizeof(struct property) + len + 18;
971
972         prop = kzalloc(tlen, GFP_KERNEL);
973         if (prop == NULL)
974                 return NULL;
975         hdr = (struct smu_sdbp_header *)(prop + 1);
976         prop->name = ((char *)prop) + tlen - 18;
977         sprintf(prop->name, "sdb-partition-%02x", id);
978         prop->length = len;
979         prop->value = hdr;
980         prop->next = NULL;
981
982         /* Read the datablock */
983         if (smu_read_datablock((u8 *)hdr, addr, len)) {
984                 printk(KERN_DEBUG "SMU: datablock read failed while reading "
985                        "partition %02x !\n", id);
986                 goto failure;
987         }
988
989         /* Got it, check a few things and create the property */
990         if (hdr->id != id) {
991                 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
992                        "%02x !\n", id, hdr->id);
993                 goto failure;
994         }
995         if (of_add_property(smu->of_node, prop)) {
996                 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
997                        "property !\n", id);
998                 goto failure;
999         }
1000
1001         return hdr;
1002  failure:
1003         kfree(prop);
1004         return NULL;
1005 }
1006
1007 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1008  * when interruptible is 1
1009  */
1010 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1011                 unsigned int *size, int interruptible)
1012 {
1013         char pname[32];
1014         const struct smu_sdbp_header *part;
1015
1016         if (!smu)
1017                 return NULL;
1018
1019         sprintf(pname, "sdb-partition-%02x", id);
1020
1021         DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1022
1023         if (interruptible) {
1024                 int rc;
1025                 rc = mutex_lock_interruptible(&smu_part_access);
1026                 if (rc)
1027                         return ERR_PTR(rc);
1028         } else
1029                 mutex_lock(&smu_part_access);
1030
1031         part = of_get_property(smu->of_node, pname, size);
1032         if (part == NULL) {
1033                 DPRINTK("trying to extract from SMU ...\n");
1034                 part = smu_create_sdb_partition(id);
1035                 if (part != NULL && size)
1036                         *size = part->len << 2;
1037         }
1038         mutex_unlock(&smu_part_access);
1039         return part;
1040 }
1041
1042 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1043 {
1044         return __smu_get_sdb_partition(id, size, 0);
1045 }
1046 EXPORT_SYMBOL(smu_get_sdb_partition);
1047
1048
1049 /*
1050  * Userland driver interface
1051  */
1052
1053
1054 static LIST_HEAD(smu_clist);
1055 static DEFINE_SPINLOCK(smu_clist_lock);
1056
1057 enum smu_file_mode {
1058         smu_file_commands,
1059         smu_file_events,
1060         smu_file_closing
1061 };
1062
1063 struct smu_private
1064 {
1065         struct list_head        list;
1066         enum smu_file_mode      mode;
1067         int                     busy;
1068         struct smu_cmd          cmd;
1069         spinlock_t              lock;
1070         wait_queue_head_t       wait;
1071         u8                      buffer[SMU_MAX_DATA];
1072 };
1073
1074
1075 static int smu_open(struct inode *inode, struct file *file)
1076 {
1077         struct smu_private *pp;
1078         unsigned long flags;
1079
1080         pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1081         if (pp == 0)
1082                 return -ENOMEM;
1083         spin_lock_init(&pp->lock);
1084         pp->mode = smu_file_commands;
1085         init_waitqueue_head(&pp->wait);
1086
1087         mutex_lock(&smu_mutex);
1088         spin_lock_irqsave(&smu_clist_lock, flags);
1089         list_add(&pp->list, &smu_clist);
1090         spin_unlock_irqrestore(&smu_clist_lock, flags);
1091         file->private_data = pp;
1092         mutex_unlock(&smu_mutex);
1093
1094         return 0;
1095 }
1096
1097
1098 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1099 {
1100         struct smu_private *pp = misc;
1101
1102         wake_up_all(&pp->wait);
1103 }
1104
1105
1106 static ssize_t smu_write(struct file *file, const char __user *buf,
1107                          size_t count, loff_t *ppos)
1108 {
1109         struct smu_private *pp = file->private_data;
1110         unsigned long flags;
1111         struct smu_user_cmd_hdr hdr;
1112         int rc = 0;
1113
1114         if (pp->busy)
1115                 return -EBUSY;
1116         else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1117                 return -EFAULT;
1118         else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1119                 pp->mode = smu_file_events;
1120                 return 0;
1121         } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1122                 const struct smu_sdbp_header *part;
1123                 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1124                 if (part == NULL)
1125                         return -EINVAL;
1126                 else if (IS_ERR(part))
1127                         return PTR_ERR(part);
1128                 return 0;
1129         } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1130                 return -EINVAL;
1131         else if (pp->mode != smu_file_commands)
1132                 return -EBADFD;
1133         else if (hdr.data_len > SMU_MAX_DATA)
1134                 return -EINVAL;
1135
1136         spin_lock_irqsave(&pp->lock, flags);
1137         if (pp->busy) {
1138                 spin_unlock_irqrestore(&pp->lock, flags);
1139                 return -EBUSY;
1140         }
1141         pp->busy = 1;
1142         pp->cmd.status = 1;
1143         spin_unlock_irqrestore(&pp->lock, flags);
1144
1145         if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1146                 pp->busy = 0;
1147                 return -EFAULT;
1148         }
1149
1150         pp->cmd.cmd = hdr.cmd;
1151         pp->cmd.data_len = hdr.data_len;
1152         pp->cmd.reply_len = SMU_MAX_DATA;
1153         pp->cmd.data_buf = pp->buffer;
1154         pp->cmd.reply_buf = pp->buffer;
1155         pp->cmd.done = smu_user_cmd_done;
1156         pp->cmd.misc = pp;
1157         rc = smu_queue_cmd(&pp->cmd);
1158         if (rc < 0)
1159                 return rc;
1160         return count;
1161 }
1162
1163
1164 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1165                                 char __user *buf, size_t count)
1166 {
1167         DECLARE_WAITQUEUE(wait, current);
1168         struct smu_user_reply_hdr hdr;
1169         unsigned long flags;
1170         int size, rc = 0;
1171
1172         if (!pp->busy)
1173                 return 0;
1174         if (count < sizeof(struct smu_user_reply_hdr))
1175                 return -EOVERFLOW;
1176         spin_lock_irqsave(&pp->lock, flags);
1177         if (pp->cmd.status == 1) {
1178                 if (file->f_flags & O_NONBLOCK) {
1179                         spin_unlock_irqrestore(&pp->lock, flags);
1180                         return -EAGAIN;
1181                 }
1182                 add_wait_queue(&pp->wait, &wait);
1183                 for (;;) {
1184                         set_current_state(TASK_INTERRUPTIBLE);
1185                         rc = 0;
1186                         if (pp->cmd.status != 1)
1187                                 break;
1188                         rc = -ERESTARTSYS;
1189                         if (signal_pending(current))
1190                                 break;
1191                         spin_unlock_irqrestore(&pp->lock, flags);
1192                         schedule();
1193                         spin_lock_irqsave(&pp->lock, flags);
1194                 }
1195                 set_current_state(TASK_RUNNING);
1196                 remove_wait_queue(&pp->wait, &wait);
1197         }
1198         spin_unlock_irqrestore(&pp->lock, flags);
1199         if (rc)
1200                 return rc;
1201         if (pp->cmd.status != 0)
1202                 pp->cmd.reply_len = 0;
1203         size = sizeof(hdr) + pp->cmd.reply_len;
1204         if (count < size)
1205                 size = count;
1206         rc = size;
1207         hdr.status = pp->cmd.status;
1208         hdr.reply_len = pp->cmd.reply_len;
1209         if (copy_to_user(buf, &hdr, sizeof(hdr)))
1210                 return -EFAULT;
1211         size -= sizeof(hdr);
1212         if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1213                 return -EFAULT;
1214         pp->busy = 0;
1215
1216         return rc;
1217 }
1218
1219
1220 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1221                                char __user *buf, size_t count)
1222 {
1223         /* Not implemented */
1224         msleep_interruptible(1000);
1225         return 0;
1226 }
1227
1228
1229 static ssize_t smu_read(struct file *file, char __user *buf,
1230                         size_t count, loff_t *ppos)
1231 {
1232         struct smu_private *pp = file->private_data;
1233
1234         if (pp->mode == smu_file_commands)
1235                 return smu_read_command(file, pp, buf, count);
1236         if (pp->mode == smu_file_events)
1237                 return smu_read_events(file, pp, buf, count);
1238
1239         return -EBADFD;
1240 }
1241
1242 static unsigned int smu_fpoll(struct file *file, poll_table *wait)
1243 {
1244         struct smu_private *pp = file->private_data;
1245         unsigned int mask = 0;
1246         unsigned long flags;
1247
1248         if (pp == 0)
1249                 return 0;
1250
1251         if (pp->mode == smu_file_commands) {
1252                 poll_wait(file, &pp->wait, wait);
1253
1254                 spin_lock_irqsave(&pp->lock, flags);
1255                 if (pp->busy && pp->cmd.status != 1)
1256                         mask |= POLLIN;
1257                 spin_unlock_irqrestore(&pp->lock, flags);
1258         }
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);