1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * PowerMac G5 SMU driver
4 *
5 * Copyright 2004 J. Mayer <l_indien@magic.fr>
6 * Copyright 2005 Benjamin Herrenschmidt, IBM Corp.
7 */
8
9 /*
10 * TODO:
11 * - maybe add timeout to commands ?
12 * - blocking version of time functions
13 * - polling version of i2c commands (including timer that works with
14 * interrupts off)
15 * - maybe avoid some data copies with i2c by directly using the smu cmd
16 * buffer and a lower level internal interface
17 * - understand SMU -> CPU events and implement reception of them via
18 * the userland interface
19 */
20
21 #include <linux/types.h>
22 #include <linux/kernel.h>
23 #include <linux/device.h>
24 #include <linux/dmapool.h>
25 #include <linux/memblock.h>
26 #include <linux/vmalloc.h>
27 #include <linux/highmem.h>
28 #include <linux/jiffies.h>
29 #include <linux/interrupt.h>
30 #include <linux/rtc.h>
31 #include <linux/completion.h>
32 #include <linux/miscdevice.h>
33 #include <linux/delay.h>
34 #include <linux/poll.h>
35 #include <linux/mutex.h>
36 #include <linux/of_device.h>
37 #include <linux/of_irq.h>
38 #include <linux/of_platform.h>
39 #include <linux/slab.h>
40 #include <linux/sched/signal.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 <linux/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 static unsigned long smu_cmdbuf_abs;
103
104 static void smu_i2c_retry(struct timer_list *t);
105
106 /*
107 * SMU driver low level stuff
108 */
109
smu_start_cmd(void)110 static void smu_start_cmd(void)
111 {
112 unsigned long faddr, fend;
113 struct smu_cmd *cmd;
114
115 if (list_empty(&smu->cmd_list))
116 return;
117
118 /* Fetch first command in queue */
119 cmd = list_entry(smu->cmd_list.next, struct smu_cmd, link);
120 smu->cmd_cur = cmd;
121 list_del(&cmd->link);
122
123 DPRINTK("SMU: starting cmd %x, %d bytes data\n", cmd->cmd,
124 cmd->data_len);
125 DPRINTK("SMU: data buffer: %8ph\n", cmd->data_buf);
126
127 /* Fill the SMU command buffer */
128 smu->cmd_buf->cmd = cmd->cmd;
129 smu->cmd_buf->length = cmd->data_len;
130 memcpy(smu->cmd_buf->data, cmd->data_buf, cmd->data_len);
131
132 /* Flush command and data to RAM */
133 faddr = (unsigned long)smu->cmd_buf;
134 fend = faddr + smu->cmd_buf->length + 2;
135 flush_dcache_range(faddr, fend);
136
137
138 /* We also disable NAP mode for the duration of the command
139 * on U3 based machines.
140 * This is slightly racy as it can be written back to 1 by a sysctl
141 * but that never happens in practice. There seem to be an issue with
142 * U3 based machines such as the iMac G5 where napping for the
143 * whole duration of the command prevents the SMU from fetching it
144 * from memory. This might be related to the strange i2c based
145 * mechanism the SMU uses to access memory.
146 */
147 if (smu->broken_nap)
148 powersave_nap = 0;
149
150 /* This isn't exactly a DMA mapping here, I suspect
151 * the SMU is actually communicating with us via i2c to the
152 * northbridge or the CPU to access RAM.
153 */
154 writel(smu->cmd_buf_abs, smu->db_buf);
155
156 /* Ring the SMU doorbell */
157 pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, smu->doorbell, 4);
158 }
159
160
smu_db_intr(int irq,void * arg)161 static irqreturn_t smu_db_intr(int irq, void *arg)
162 {
163 unsigned long flags;
164 struct smu_cmd *cmd;
165 void (*done)(struct smu_cmd *cmd, void *misc) = NULL;
166 void *misc = NULL;
167 u8 gpio;
168 int rc = 0;
169
170 /* SMU completed the command, well, we hope, let's make sure
171 * of it
172 */
173 spin_lock_irqsave(&smu->lock, flags);
174
175 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
176 if ((gpio & 7) != 7) {
177 spin_unlock_irqrestore(&smu->lock, flags);
178 return IRQ_HANDLED;
179 }
180
181 cmd = smu->cmd_cur;
182 smu->cmd_cur = NULL;
183 if (cmd == NULL)
184 goto bail;
185
186 if (rc == 0) {
187 unsigned long faddr;
188 int reply_len;
189 u8 ack;
190
191 /* CPU might have brought back the cache line, so we need
192 * to flush again before peeking at the SMU response. We
193 * flush the entire buffer for now as we haven't read the
194 * reply length (it's only 2 cache lines anyway)
195 */
196 faddr = (unsigned long)smu->cmd_buf;
197 flush_dcache_range(faddr, faddr + 256);
198
199 /* Now check ack */
200 ack = (~cmd->cmd) & 0xff;
201 if (ack != smu->cmd_buf->cmd) {
202 DPRINTK("SMU: incorrect ack, want %x got %x\n",
203 ack, smu->cmd_buf->cmd);
204 rc = -EIO;
205 }
206 reply_len = rc == 0 ? smu->cmd_buf->length : 0;
207 DPRINTK("SMU: reply len: %d\n", reply_len);
208 if (reply_len > cmd->reply_len) {
209 printk(KERN_WARNING "SMU: reply buffer too small,"
210 "got %d bytes for a %d bytes buffer\n",
211 reply_len, cmd->reply_len);
212 reply_len = cmd->reply_len;
213 }
214 cmd->reply_len = reply_len;
215 if (cmd->reply_buf && reply_len)
216 memcpy(cmd->reply_buf, smu->cmd_buf->data, reply_len);
217 }
218
219 /* Now complete the command. Write status last in order as we lost
220 * ownership of the command structure as soon as it's no longer -1
221 */
222 done = cmd->done;
223 misc = cmd->misc;
224 mb();
225 cmd->status = rc;
226
227 /* Re-enable NAP mode */
228 if (smu->broken_nap)
229 powersave_nap = 1;
230 bail:
231 /* Start next command if any */
232 smu_start_cmd();
233 spin_unlock_irqrestore(&smu->lock, flags);
234
235 /* Call command completion handler if any */
236 if (done)
237 done(cmd, misc);
238
239 /* It's an edge interrupt, nothing to do */
240 return IRQ_HANDLED;
241 }
242
243
smu_msg_intr(int irq,void * arg)244 static irqreturn_t smu_msg_intr(int irq, void *arg)
245 {
246 /* I don't quite know what to do with this one, we seem to never
247 * receive it, so I suspect we have to arm it someway in the SMU
248 * to start getting events that way.
249 */
250
251 printk(KERN_INFO "SMU: message interrupt !\n");
252
253 /* It's an edge interrupt, nothing to do */
254 return IRQ_HANDLED;
255 }
256
257
258 /*
259 * Queued command management.
260 *
261 */
262
smu_queue_cmd(struct smu_cmd * cmd)263 int smu_queue_cmd(struct smu_cmd *cmd)
264 {
265 unsigned long flags;
266
267 if (smu == NULL)
268 return -ENODEV;
269 if (cmd->data_len > SMU_MAX_DATA ||
270 cmd->reply_len > SMU_MAX_DATA)
271 return -EINVAL;
272
273 cmd->status = 1;
274 spin_lock_irqsave(&smu->lock, flags);
275 list_add_tail(&cmd->link, &smu->cmd_list);
276 if (smu->cmd_cur == NULL)
277 smu_start_cmd();
278 spin_unlock_irqrestore(&smu->lock, flags);
279
280 /* Workaround for early calls when irq isn't available */
281 if (!smu_irq_inited || !smu->db_irq)
282 smu_spinwait_cmd(cmd);
283
284 return 0;
285 }
286 EXPORT_SYMBOL(smu_queue_cmd);
287
288
smu_queue_simple(struct smu_simple_cmd * scmd,u8 command,unsigned int data_len,void (* done)(struct smu_cmd * cmd,void * misc),void * misc,...)289 int smu_queue_simple(struct smu_simple_cmd *scmd, u8 command,
290 unsigned int data_len,
291 void (*done)(struct smu_cmd *cmd, void *misc),
292 void *misc, ...)
293 {
294 struct smu_cmd *cmd = &scmd->cmd;
295 va_list list;
296 int i;
297
298 if (data_len > sizeof(scmd->buffer))
299 return -EINVAL;
300
301 memset(scmd, 0, sizeof(*scmd));
302 cmd->cmd = command;
303 cmd->data_len = data_len;
304 cmd->data_buf = scmd->buffer;
305 cmd->reply_len = sizeof(scmd->buffer);
306 cmd->reply_buf = scmd->buffer;
307 cmd->done = done;
308 cmd->misc = misc;
309
310 va_start(list, misc);
311 for (i = 0; i < data_len; ++i)
312 scmd->buffer[i] = (u8)va_arg(list, int);
313 va_end(list);
314
315 return smu_queue_cmd(cmd);
316 }
317 EXPORT_SYMBOL(smu_queue_simple);
318
319
smu_poll(void)320 void smu_poll(void)
321 {
322 u8 gpio;
323
324 if (smu == NULL)
325 return;
326
327 gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, smu->doorbell);
328 if ((gpio & 7) == 7)
329 smu_db_intr(smu->db_irq, smu);
330 }
331 EXPORT_SYMBOL(smu_poll);
332
333
smu_done_complete(struct smu_cmd * cmd,void * misc)334 void smu_done_complete(struct smu_cmd *cmd, void *misc)
335 {
336 struct completion *comp = misc;
337
338 complete(comp);
339 }
340 EXPORT_SYMBOL(smu_done_complete);
341
342
smu_spinwait_cmd(struct smu_cmd * cmd)343 void smu_spinwait_cmd(struct smu_cmd *cmd)
344 {
345 while(cmd->status == 1)
346 smu_poll();
347 }
348 EXPORT_SYMBOL(smu_spinwait_cmd);
349
350
351 /* RTC low level commands */
bcd2hex(int n)352 static inline int bcd2hex (int n)
353 {
354 return (((n & 0xf0) >> 4) * 10) + (n & 0xf);
355 }
356
357
hex2bcd(int n)358 static inline int hex2bcd (int n)
359 {
360 return ((n / 10) << 4) + (n % 10);
361 }
362
363
smu_fill_set_rtc_cmd(struct smu_cmd_buf * cmd_buf,struct rtc_time * time)364 static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf,
365 struct rtc_time *time)
366 {
367 cmd_buf->cmd = 0x8e;
368 cmd_buf->length = 8;
369 cmd_buf->data[0] = 0x80;
370 cmd_buf->data[1] = hex2bcd(time->tm_sec);
371 cmd_buf->data[2] = hex2bcd(time->tm_min);
372 cmd_buf->data[3] = hex2bcd(time->tm_hour);
373 cmd_buf->data[4] = time->tm_wday;
374 cmd_buf->data[5] = hex2bcd(time->tm_mday);
375 cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1;
376 cmd_buf->data[7] = hex2bcd(time->tm_year - 100);
377 }
378
379
smu_get_rtc_time(struct rtc_time * time,int spinwait)380 int smu_get_rtc_time(struct rtc_time *time, int spinwait)
381 {
382 struct smu_simple_cmd cmd;
383 int rc;
384
385 if (smu == NULL)
386 return -ENODEV;
387
388 memset(time, 0, sizeof(struct rtc_time));
389 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 1, NULL, NULL,
390 SMU_CMD_RTC_GET_DATETIME);
391 if (rc)
392 return rc;
393 smu_spinwait_simple(&cmd);
394
395 time->tm_sec = bcd2hex(cmd.buffer[0]);
396 time->tm_min = bcd2hex(cmd.buffer[1]);
397 time->tm_hour = bcd2hex(cmd.buffer[2]);
398 time->tm_wday = bcd2hex(cmd.buffer[3]);
399 time->tm_mday = bcd2hex(cmd.buffer[4]);
400 time->tm_mon = bcd2hex(cmd.buffer[5]) - 1;
401 time->tm_year = bcd2hex(cmd.buffer[6]) + 100;
402
403 return 0;
404 }
405
406
smu_set_rtc_time(struct rtc_time * time,int spinwait)407 int smu_set_rtc_time(struct rtc_time *time, int spinwait)
408 {
409 struct smu_simple_cmd cmd;
410 int rc;
411
412 if (smu == NULL)
413 return -ENODEV;
414
415 rc = smu_queue_simple(&cmd, SMU_CMD_RTC_COMMAND, 8, NULL, NULL,
416 SMU_CMD_RTC_SET_DATETIME,
417 hex2bcd(time->tm_sec),
418 hex2bcd(time->tm_min),
419 hex2bcd(time->tm_hour),
420 time->tm_wday,
421 hex2bcd(time->tm_mday),
422 hex2bcd(time->tm_mon) + 1,
423 hex2bcd(time->tm_year - 100));
424 if (rc)
425 return rc;
426 smu_spinwait_simple(&cmd);
427
428 return 0;
429 }
430
431
smu_shutdown(void)432 void smu_shutdown(void)
433 {
434 struct smu_simple_cmd cmd;
435
436 if (smu == NULL)
437 return;
438
439 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 9, NULL, NULL,
440 'S', 'H', 'U', 'T', 'D', 'O', 'W', 'N', 0))
441 return;
442 smu_spinwait_simple(&cmd);
443 for (;;)
444 ;
445 }
446
447
smu_restart(void)448 void smu_restart(void)
449 {
450 struct smu_simple_cmd cmd;
451
452 if (smu == NULL)
453 return;
454
455 if (smu_queue_simple(&cmd, SMU_CMD_POWER_COMMAND, 8, NULL, NULL,
456 'R', 'E', 'S', 'T', 'A', 'R', 'T', 0))
457 return;
458 smu_spinwait_simple(&cmd);
459 for (;;)
460 ;
461 }
462
463
smu_present(void)464 int smu_present(void)
465 {
466 return smu != NULL;
467 }
468 EXPORT_SYMBOL(smu_present);
469
470
smu_init(void)471 int __init smu_init (void)
472 {
473 struct device_node *np;
474 const u32 *data;
475 int ret = 0;
476
477 np = of_find_node_by_type(NULL, "smu");
478 if (np == NULL)
479 return -ENODEV;
480
481 printk(KERN_INFO "SMU: Driver %s %s\n", VERSION, AUTHOR);
482
483 /*
484 * SMU based G5s need some memory below 2Gb. Thankfully this is
485 * called at a time where memblock is still available.
486 */
487 smu_cmdbuf_abs = memblock_phys_alloc_range(4096, 4096, 0, 0x80000000UL);
488 if (smu_cmdbuf_abs == 0) {
489 printk(KERN_ERR "SMU: Command buffer allocation failed !\n");
490 ret = -EINVAL;
491 goto fail_np;
492 }
493
494 smu = memblock_alloc(sizeof(struct smu_device), SMP_CACHE_BYTES);
495 if (!smu)
496 panic("%s: Failed to allocate %zu bytes\n", __func__,
497 sizeof(struct smu_device));
498
499 spin_lock_init(&smu->lock);
500 INIT_LIST_HEAD(&smu->cmd_list);
501 INIT_LIST_HEAD(&smu->cmd_i2c_list);
502 smu->of_node = np;
503 smu->db_irq = 0;
504 smu->msg_irq = 0;
505
506 /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a
507 * 32 bits value safely
508 */
509 smu->cmd_buf_abs = (u32)smu_cmdbuf_abs;
510 smu->cmd_buf = __va(smu_cmdbuf_abs);
511
512 smu->db_node = of_find_node_by_name(NULL, "smu-doorbell");
513 if (smu->db_node == NULL) {
514 printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n");
515 ret = -ENXIO;
516 goto fail_bootmem;
517 }
518 data = of_get_property(smu->db_node, "reg", NULL);
519 if (data == NULL) {
520 printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n");
521 ret = -ENXIO;
522 goto fail_db_node;
523 }
524
525 /* Current setup has one doorbell GPIO that does both doorbell
526 * and ack. GPIOs are at 0x50, best would be to find that out
527 * in the device-tree though.
528 */
529 smu->doorbell = *data;
530 if (smu->doorbell < 0x50)
531 smu->doorbell += 0x50;
532
533 /* Now look for the smu-interrupt GPIO */
534 do {
535 smu->msg_node = of_find_node_by_name(NULL, "smu-interrupt");
536 if (smu->msg_node == NULL)
537 break;
538 data = of_get_property(smu->msg_node, "reg", NULL);
539 if (data == NULL) {
540 of_node_put(smu->msg_node);
541 smu->msg_node = NULL;
542 break;
543 }
544 smu->msg = *data;
545 if (smu->msg < 0x50)
546 smu->msg += 0x50;
547 } while(0);
548
549 /* Doorbell buffer is currently hard-coded, I didn't find a proper
550 * device-tree entry giving the address. Best would probably to use
551 * an offset for K2 base though, but let's do it that way for now.
552 */
553 smu->db_buf = ioremap(0x8000860c, 0x1000);
554 if (smu->db_buf == NULL) {
555 printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n");
556 ret = -ENXIO;
557 goto fail_msg_node;
558 }
559
560 /* U3 has an issue with NAP mode when issuing SMU commands */
561 smu->broken_nap = pmac_get_uninorth_variant() < 4;
562 if (smu->broken_nap)
563 printk(KERN_INFO "SMU: using NAP mode workaround\n");
564
565 sys_ctrler = SYS_CTRLER_SMU;
566 return 0;
567
568 fail_msg_node:
569 of_node_put(smu->msg_node);
570 fail_db_node:
571 of_node_put(smu->db_node);
572 fail_bootmem:
573 memblock_free(__pa(smu), sizeof(struct smu_device));
574 smu = NULL;
575 fail_np:
576 of_node_put(np);
577 return ret;
578 }
579
580
smu_late_init(void)581 static int smu_late_init(void)
582 {
583 if (!smu)
584 return 0;
585
586 timer_setup(&smu->i2c_timer, smu_i2c_retry, 0);
587
588 if (smu->db_node) {
589 smu->db_irq = irq_of_parse_and_map(smu->db_node, 0);
590 if (!smu->db_irq)
591 printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
592 smu->db_node);
593 }
594 if (smu->msg_node) {
595 smu->msg_irq = irq_of_parse_and_map(smu->msg_node, 0);
596 if (!smu->msg_irq)
597 printk(KERN_ERR "smu: failed to map irq for node %pOF\n",
598 smu->msg_node);
599 }
600
601 /*
602 * Try to request the interrupts
603 */
604
605 if (smu->db_irq) {
606 if (request_irq(smu->db_irq, smu_db_intr,
607 IRQF_SHARED, "SMU doorbell", smu) < 0) {
608 printk(KERN_WARNING "SMU: can't "
609 "request interrupt %d\n",
610 smu->db_irq);
611 smu->db_irq = 0;
612 }
613 }
614
615 if (smu->msg_irq) {
616 if (request_irq(smu->msg_irq, smu_msg_intr,
617 IRQF_SHARED, "SMU message", smu) < 0) {
618 printk(KERN_WARNING "SMU: can't "
619 "request interrupt %d\n",
620 smu->msg_irq);
621 smu->msg_irq = 0;
622 }
623 }
624
625 smu_irq_inited = 1;
626 return 0;
627 }
628 /* This has to be before arch_initcall as the low i2c stuff relies on the
629 * above having been done before we reach arch_initcalls
630 */
631 core_initcall(smu_late_init);
632
633 /*
634 * sysfs visibility
635 */
636
smu_expose_childs(struct work_struct * unused)637 static void smu_expose_childs(struct work_struct *unused)
638 {
639 struct device_node *np;
640
641 for (np = NULL; (np = of_get_next_child(smu->of_node, np)) != NULL;)
642 if (of_device_is_compatible(np, "smu-sensors"))
643 of_platform_device_create(np, "smu-sensors",
644 &smu->of_dev->dev);
645 }
646
647 static DECLARE_WORK(smu_expose_childs_work, smu_expose_childs);
648
smu_platform_probe(struct platform_device * dev)649 static int smu_platform_probe(struct platform_device* dev)
650 {
651 if (!smu)
652 return -ENODEV;
653 smu->of_dev = dev;
654
655 /*
656 * Ok, we are matched, now expose all i2c busses. We have to defer
657 * that unfortunately or it would deadlock inside the device model
658 */
659 schedule_work(&smu_expose_childs_work);
660
661 return 0;
662 }
663
664 static const struct of_device_id smu_platform_match[] =
665 {
666 {
667 .type = "smu",
668 },
669 {},
670 };
671
672 static struct platform_driver smu_of_platform_driver =
673 {
674 .driver = {
675 .name = "smu",
676 .of_match_table = smu_platform_match,
677 },
678 .probe = smu_platform_probe,
679 };
680
smu_init_sysfs(void)681 static int __init smu_init_sysfs(void)
682 {
683 /*
684 * For now, we don't power manage machines with an SMU chip,
685 * I'm a bit too far from figuring out how that works with those
686 * new chipsets, but that will come back and bite us
687 */
688 platform_driver_register(&smu_of_platform_driver);
689 return 0;
690 }
691
692 device_initcall(smu_init_sysfs);
693
smu_get_ofdev(void)694 struct platform_device *smu_get_ofdev(void)
695 {
696 if (!smu)
697 return NULL;
698 return smu->of_dev;
699 }
700
701 EXPORT_SYMBOL_GPL(smu_get_ofdev);
702
703 /*
704 * i2c interface
705 */
706
smu_i2c_complete_command(struct smu_i2c_cmd * cmd,int fail)707 static void smu_i2c_complete_command(struct smu_i2c_cmd *cmd, int fail)
708 {
709 void (*done)(struct smu_i2c_cmd *cmd, void *misc) = cmd->done;
710 void *misc = cmd->misc;
711 unsigned long flags;
712
713 /* Check for read case */
714 if (!fail && cmd->read) {
715 if (cmd->pdata[0] < 1)
716 fail = 1;
717 else
718 memcpy(cmd->info.data, &cmd->pdata[1],
719 cmd->info.datalen);
720 }
721
722 DPRINTK("SMU: completing, success: %d\n", !fail);
723
724 /* Update status and mark no pending i2c command with lock
725 * held so nobody comes in while we dequeue an eventual
726 * pending next i2c command
727 */
728 spin_lock_irqsave(&smu->lock, flags);
729 smu->cmd_i2c_cur = NULL;
730 wmb();
731 cmd->status = fail ? -EIO : 0;
732
733 /* Is there another i2c command waiting ? */
734 if (!list_empty(&smu->cmd_i2c_list)) {
735 struct smu_i2c_cmd *newcmd;
736
737 /* Fetch it, new current, remove from list */
738 newcmd = list_entry(smu->cmd_i2c_list.next,
739 struct smu_i2c_cmd, link);
740 smu->cmd_i2c_cur = newcmd;
741 list_del(&cmd->link);
742
743 /* Queue with low level smu */
744 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
745 if (smu->cmd_cur == NULL)
746 smu_start_cmd();
747 }
748 spin_unlock_irqrestore(&smu->lock, flags);
749
750 /* Call command completion handler if any */
751 if (done)
752 done(cmd, misc);
753
754 }
755
756
smu_i2c_retry(struct timer_list * unused)757 static void smu_i2c_retry(struct timer_list *unused)
758 {
759 struct smu_i2c_cmd *cmd = smu->cmd_i2c_cur;
760
761 DPRINTK("SMU: i2c failure, requeuing...\n");
762
763 /* requeue command simply by resetting reply_len */
764 cmd->pdata[0] = 0xff;
765 cmd->scmd.reply_len = sizeof(cmd->pdata);
766 smu_queue_cmd(&cmd->scmd);
767 }
768
769
smu_i2c_low_completion(struct smu_cmd * scmd,void * misc)770 static void smu_i2c_low_completion(struct smu_cmd *scmd, void *misc)
771 {
772 struct smu_i2c_cmd *cmd = misc;
773 int fail = 0;
774
775 DPRINTK("SMU: i2c compl. stage=%d status=%x pdata[0]=%x rlen: %x\n",
776 cmd->stage, scmd->status, cmd->pdata[0], scmd->reply_len);
777
778 /* Check for possible status */
779 if (scmd->status < 0)
780 fail = 1;
781 else if (cmd->read) {
782 if (cmd->stage == 0)
783 fail = cmd->pdata[0] != 0;
784 else
785 fail = cmd->pdata[0] >= 0x80;
786 } else {
787 fail = cmd->pdata[0] != 0;
788 }
789
790 /* Handle failures by requeuing command, after 5ms interval
791 */
792 if (fail && --cmd->retries > 0) {
793 DPRINTK("SMU: i2c failure, starting timer...\n");
794 BUG_ON(cmd != smu->cmd_i2c_cur);
795 if (!smu_irq_inited) {
796 mdelay(5);
797 smu_i2c_retry(NULL);
798 return;
799 }
800 mod_timer(&smu->i2c_timer, jiffies + msecs_to_jiffies(5));
801 return;
802 }
803
804 /* If failure or stage 1, command is complete */
805 if (fail || cmd->stage != 0) {
806 smu_i2c_complete_command(cmd, fail);
807 return;
808 }
809
810 DPRINTK("SMU: going to stage 1\n");
811
812 /* Ok, initial command complete, now poll status */
813 scmd->reply_buf = cmd->pdata;
814 scmd->reply_len = sizeof(cmd->pdata);
815 scmd->data_buf = cmd->pdata;
816 scmd->data_len = 1;
817 cmd->pdata[0] = 0;
818 cmd->stage = 1;
819 cmd->retries = 20;
820 smu_queue_cmd(scmd);
821 }
822
823
smu_queue_i2c(struct smu_i2c_cmd * cmd)824 int smu_queue_i2c(struct smu_i2c_cmd *cmd)
825 {
826 unsigned long flags;
827
828 if (smu == NULL)
829 return -ENODEV;
830
831 /* Fill most fields of scmd */
832 cmd->scmd.cmd = SMU_CMD_I2C_COMMAND;
833 cmd->scmd.done = smu_i2c_low_completion;
834 cmd->scmd.misc = cmd;
835 cmd->scmd.reply_buf = cmd->pdata;
836 cmd->scmd.reply_len = sizeof(cmd->pdata);
837 cmd->scmd.data_buf = (u8 *)(char *)&cmd->info;
838 cmd->scmd.status = 1;
839 cmd->stage = 0;
840 cmd->pdata[0] = 0xff;
841 cmd->retries = 20;
842 cmd->status = 1;
843
844 /* Check transfer type, sanitize some "info" fields
845 * based on transfer type and do more checking
846 */
847 cmd->info.caddr = cmd->info.devaddr;
848 cmd->read = cmd->info.devaddr & 0x01;
849 switch(cmd->info.type) {
850 case SMU_I2C_TRANSFER_SIMPLE:
851 memset(&cmd->info.sublen, 0, 4);
852 break;
853 case SMU_I2C_TRANSFER_COMBINED:
854 cmd->info.devaddr &= 0xfe;
855 /* fall through */
856 case SMU_I2C_TRANSFER_STDSUB:
857 if (cmd->info.sublen > 3)
858 return -EINVAL;
859 break;
860 default:
861 return -EINVAL;
862 }
863
864 /* Finish setting up command based on transfer direction
865 */
866 if (cmd->read) {
867 if (cmd->info.datalen > SMU_I2C_READ_MAX)
868 return -EINVAL;
869 memset(cmd->info.data, 0xff, cmd->info.datalen);
870 cmd->scmd.data_len = 9;
871 } else {
872 if (cmd->info.datalen > SMU_I2C_WRITE_MAX)
873 return -EINVAL;
874 cmd->scmd.data_len = 9 + cmd->info.datalen;
875 }
876
877 DPRINTK("SMU: i2c enqueuing command\n");
878 DPRINTK("SMU: %s, len=%d bus=%x addr=%x sub0=%x type=%x\n",
879 cmd->read ? "read" : "write", cmd->info.datalen,
880 cmd->info.bus, cmd->info.caddr,
881 cmd->info.subaddr[0], cmd->info.type);
882
883
884 /* Enqueue command in i2c list, and if empty, enqueue also in
885 * main command list
886 */
887 spin_lock_irqsave(&smu->lock, flags);
888 if (smu->cmd_i2c_cur == NULL) {
889 smu->cmd_i2c_cur = cmd;
890 list_add_tail(&cmd->scmd.link, &smu->cmd_list);
891 if (smu->cmd_cur == NULL)
892 smu_start_cmd();
893 } else
894 list_add_tail(&cmd->link, &smu->cmd_i2c_list);
895 spin_unlock_irqrestore(&smu->lock, flags);
896
897 return 0;
898 }
899
900 /*
901 * Handling of "partitions"
902 */
903
smu_read_datablock(u8 * dest,unsigned int addr,unsigned int len)904 static int smu_read_datablock(u8 *dest, unsigned int addr, unsigned int len)
905 {
906 DECLARE_COMPLETION_ONSTACK(comp);
907 unsigned int chunk;
908 struct smu_cmd cmd;
909 int rc;
910 u8 params[8];
911
912 /* We currently use a chunk size of 0xe. We could check the
913 * SMU firmware version and use bigger sizes though
914 */
915 chunk = 0xe;
916
917 while (len) {
918 unsigned int clen = min(len, chunk);
919
920 cmd.cmd = SMU_CMD_MISC_ee_COMMAND;
921 cmd.data_len = 7;
922 cmd.data_buf = params;
923 cmd.reply_len = chunk;
924 cmd.reply_buf = dest;
925 cmd.done = smu_done_complete;
926 cmd.misc = ∁
927 params[0] = SMU_CMD_MISC_ee_GET_DATABLOCK_REC;
928 params[1] = 0x4;
929 *((u32 *)¶ms[2]) = addr;
930 params[6] = clen;
931
932 rc = smu_queue_cmd(&cmd);
933 if (rc)
934 return rc;
935 wait_for_completion(&comp);
936 if (cmd.status != 0)
937 return rc;
938 if (cmd.reply_len != clen) {
939 printk(KERN_DEBUG "SMU: short read in "
940 "smu_read_datablock, got: %d, want: %d\n",
941 cmd.reply_len, clen);
942 return -EIO;
943 }
944 len -= clen;
945 addr += clen;
946 dest += clen;
947 }
948 return 0;
949 }
950
smu_create_sdb_partition(int id)951 static struct smu_sdbp_header *smu_create_sdb_partition(int id)
952 {
953 DECLARE_COMPLETION_ONSTACK(comp);
954 struct smu_simple_cmd cmd;
955 unsigned int addr, len, tlen;
956 struct smu_sdbp_header *hdr;
957 struct property *prop;
958
959 /* First query the partition info */
960 DPRINTK("SMU: Query partition infos ... (irq=%d)\n", smu->db_irq);
961 smu_queue_simple(&cmd, SMU_CMD_PARTITION_COMMAND, 2,
962 smu_done_complete, &comp,
963 SMU_CMD_PARTITION_LATEST, id);
964 wait_for_completion(&comp);
965 DPRINTK("SMU: done, status: %d, reply_len: %d\n",
966 cmd.cmd.status, cmd.cmd.reply_len);
967
968 /* Partition doesn't exist (or other error) */
969 if (cmd.cmd.status != 0 || cmd.cmd.reply_len != 6)
970 return NULL;
971
972 /* Fetch address and length from reply */
973 addr = *((u16 *)cmd.buffer);
974 len = cmd.buffer[3] << 2;
975 /* Calucluate total length to allocate, including the 17 bytes
976 * for "sdb-partition-XX" that we append at the end of the buffer
977 */
978 tlen = sizeof(struct property) + len + 18;
979
980 prop = kzalloc(tlen, GFP_KERNEL);
981 if (prop == NULL)
982 return NULL;
983 hdr = (struct smu_sdbp_header *)(prop + 1);
984 prop->name = ((char *)prop) + tlen - 18;
985 sprintf(prop->name, "sdb-partition-%02x", id);
986 prop->length = len;
987 prop->value = hdr;
988 prop->next = NULL;
989
990 /* Read the datablock */
991 if (smu_read_datablock((u8 *)hdr, addr, len)) {
992 printk(KERN_DEBUG "SMU: datablock read failed while reading "
993 "partition %02x !\n", id);
994 goto failure;
995 }
996
997 /* Got it, check a few things and create the property */
998 if (hdr->id != id) {
999 printk(KERN_DEBUG "SMU: Reading partition %02x and got "
1000 "%02x !\n", id, hdr->id);
1001 goto failure;
1002 }
1003 if (of_add_property(smu->of_node, prop)) {
1004 printk(KERN_DEBUG "SMU: Failed creating sdb-partition-%02x "
1005 "property !\n", id);
1006 goto failure;
1007 }
1008
1009 return hdr;
1010 failure:
1011 kfree(prop);
1012 return NULL;
1013 }
1014
1015 /* Note: Only allowed to return error code in pointers (using ERR_PTR)
1016 * when interruptible is 1
1017 */
__smu_get_sdb_partition(int id,unsigned int * size,int interruptible)1018 const struct smu_sdbp_header *__smu_get_sdb_partition(int id,
1019 unsigned int *size, int interruptible)
1020 {
1021 char pname[32];
1022 const struct smu_sdbp_header *part;
1023
1024 if (!smu)
1025 return NULL;
1026
1027 sprintf(pname, "sdb-partition-%02x", id);
1028
1029 DPRINTK("smu_get_sdb_partition(%02x)\n", id);
1030
1031 if (interruptible) {
1032 int rc;
1033 rc = mutex_lock_interruptible(&smu_part_access);
1034 if (rc)
1035 return ERR_PTR(rc);
1036 } else
1037 mutex_lock(&smu_part_access);
1038
1039 part = of_get_property(smu->of_node, pname, size);
1040 if (part == NULL) {
1041 DPRINTK("trying to extract from SMU ...\n");
1042 part = smu_create_sdb_partition(id);
1043 if (part != NULL && size)
1044 *size = part->len << 2;
1045 }
1046 mutex_unlock(&smu_part_access);
1047 return part;
1048 }
1049
smu_get_sdb_partition(int id,unsigned int * size)1050 const struct smu_sdbp_header *smu_get_sdb_partition(int id, unsigned int *size)
1051 {
1052 return __smu_get_sdb_partition(id, size, 0);
1053 }
1054 EXPORT_SYMBOL(smu_get_sdb_partition);
1055
1056
1057 /*
1058 * Userland driver interface
1059 */
1060
1061
1062 static LIST_HEAD(smu_clist);
1063 static DEFINE_SPINLOCK(smu_clist_lock);
1064
1065 enum smu_file_mode {
1066 smu_file_commands,
1067 smu_file_events,
1068 smu_file_closing
1069 };
1070
1071 struct smu_private
1072 {
1073 struct list_head list;
1074 enum smu_file_mode mode;
1075 int busy;
1076 struct smu_cmd cmd;
1077 spinlock_t lock;
1078 wait_queue_head_t wait;
1079 u8 buffer[SMU_MAX_DATA];
1080 };
1081
1082
smu_open(struct inode * inode,struct file * file)1083 static int smu_open(struct inode *inode, struct file *file)
1084 {
1085 struct smu_private *pp;
1086 unsigned long flags;
1087
1088 pp = kzalloc(sizeof(struct smu_private), GFP_KERNEL);
1089 if (pp == 0)
1090 return -ENOMEM;
1091 spin_lock_init(&pp->lock);
1092 pp->mode = smu_file_commands;
1093 init_waitqueue_head(&pp->wait);
1094
1095 mutex_lock(&smu_mutex);
1096 spin_lock_irqsave(&smu_clist_lock, flags);
1097 list_add(&pp->list, &smu_clist);
1098 spin_unlock_irqrestore(&smu_clist_lock, flags);
1099 file->private_data = pp;
1100 mutex_unlock(&smu_mutex);
1101
1102 return 0;
1103 }
1104
1105
smu_user_cmd_done(struct smu_cmd * cmd,void * misc)1106 static void smu_user_cmd_done(struct smu_cmd *cmd, void *misc)
1107 {
1108 struct smu_private *pp = misc;
1109
1110 wake_up_all(&pp->wait);
1111 }
1112
1113
smu_write(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1114 static ssize_t smu_write(struct file *file, const char __user *buf,
1115 size_t count, loff_t *ppos)
1116 {
1117 struct smu_private *pp = file->private_data;
1118 unsigned long flags;
1119 struct smu_user_cmd_hdr hdr;
1120 int rc = 0;
1121
1122 if (pp->busy)
1123 return -EBUSY;
1124 else if (copy_from_user(&hdr, buf, sizeof(hdr)))
1125 return -EFAULT;
1126 else if (hdr.cmdtype == SMU_CMDTYPE_WANTS_EVENTS) {
1127 pp->mode = smu_file_events;
1128 return 0;
1129 } else if (hdr.cmdtype == SMU_CMDTYPE_GET_PARTITION) {
1130 const struct smu_sdbp_header *part;
1131 part = __smu_get_sdb_partition(hdr.cmd, NULL, 1);
1132 if (part == NULL)
1133 return -EINVAL;
1134 else if (IS_ERR(part))
1135 return PTR_ERR(part);
1136 return 0;
1137 } else if (hdr.cmdtype != SMU_CMDTYPE_SMU)
1138 return -EINVAL;
1139 else if (pp->mode != smu_file_commands)
1140 return -EBADFD;
1141 else if (hdr.data_len > SMU_MAX_DATA)
1142 return -EINVAL;
1143
1144 spin_lock_irqsave(&pp->lock, flags);
1145 if (pp->busy) {
1146 spin_unlock_irqrestore(&pp->lock, flags);
1147 return -EBUSY;
1148 }
1149 pp->busy = 1;
1150 pp->cmd.status = 1;
1151 spin_unlock_irqrestore(&pp->lock, flags);
1152
1153 if (copy_from_user(pp->buffer, buf + sizeof(hdr), hdr.data_len)) {
1154 pp->busy = 0;
1155 return -EFAULT;
1156 }
1157
1158 pp->cmd.cmd = hdr.cmd;
1159 pp->cmd.data_len = hdr.data_len;
1160 pp->cmd.reply_len = SMU_MAX_DATA;
1161 pp->cmd.data_buf = pp->buffer;
1162 pp->cmd.reply_buf = pp->buffer;
1163 pp->cmd.done = smu_user_cmd_done;
1164 pp->cmd.misc = pp;
1165 rc = smu_queue_cmd(&pp->cmd);
1166 if (rc < 0)
1167 return rc;
1168 return count;
1169 }
1170
1171
smu_read_command(struct file * file,struct smu_private * pp,char __user * buf,size_t count)1172 static ssize_t smu_read_command(struct file *file, struct smu_private *pp,
1173 char __user *buf, size_t count)
1174 {
1175 DECLARE_WAITQUEUE(wait, current);
1176 struct smu_user_reply_hdr hdr;
1177 unsigned long flags;
1178 int size, rc = 0;
1179
1180 if (!pp->busy)
1181 return 0;
1182 if (count < sizeof(struct smu_user_reply_hdr))
1183 return -EOVERFLOW;
1184 spin_lock_irqsave(&pp->lock, flags);
1185 if (pp->cmd.status == 1) {
1186 if (file->f_flags & O_NONBLOCK) {
1187 spin_unlock_irqrestore(&pp->lock, flags);
1188 return -EAGAIN;
1189 }
1190 add_wait_queue(&pp->wait, &wait);
1191 for (;;) {
1192 set_current_state(TASK_INTERRUPTIBLE);
1193 rc = 0;
1194 if (pp->cmd.status != 1)
1195 break;
1196 rc = -ERESTARTSYS;
1197 if (signal_pending(current))
1198 break;
1199 spin_unlock_irqrestore(&pp->lock, flags);
1200 schedule();
1201 spin_lock_irqsave(&pp->lock, flags);
1202 }
1203 set_current_state(TASK_RUNNING);
1204 remove_wait_queue(&pp->wait, &wait);
1205 }
1206 spin_unlock_irqrestore(&pp->lock, flags);
1207 if (rc)
1208 return rc;
1209 if (pp->cmd.status != 0)
1210 pp->cmd.reply_len = 0;
1211 size = sizeof(hdr) + pp->cmd.reply_len;
1212 if (count < size)
1213 size = count;
1214 rc = size;
1215 hdr.status = pp->cmd.status;
1216 hdr.reply_len = pp->cmd.reply_len;
1217 if (copy_to_user(buf, &hdr, sizeof(hdr)))
1218 return -EFAULT;
1219 size -= sizeof(hdr);
1220 if (size && copy_to_user(buf + sizeof(hdr), pp->buffer, size))
1221 return -EFAULT;
1222 pp->busy = 0;
1223
1224 return rc;
1225 }
1226
1227
smu_read_events(struct file * file,struct smu_private * pp,char __user * buf,size_t count)1228 static ssize_t smu_read_events(struct file *file, struct smu_private *pp,
1229 char __user *buf, size_t count)
1230 {
1231 /* Not implemented */
1232 msleep_interruptible(1000);
1233 return 0;
1234 }
1235
1236
smu_read(struct file * file,char __user * buf,size_t count,loff_t * ppos)1237 static ssize_t smu_read(struct file *file, char __user *buf,
1238 size_t count, loff_t *ppos)
1239 {
1240 struct smu_private *pp = file->private_data;
1241
1242 if (pp->mode == smu_file_commands)
1243 return smu_read_command(file, pp, buf, count);
1244 if (pp->mode == smu_file_events)
1245 return smu_read_events(file, pp, buf, count);
1246
1247 return -EBADFD;
1248 }
1249
smu_fpoll(struct file * file,poll_table * wait)1250 static __poll_t smu_fpoll(struct file *file, poll_table *wait)
1251 {
1252 struct smu_private *pp = file->private_data;
1253 __poll_t mask = 0;
1254 unsigned long flags;
1255
1256 if (pp == 0)
1257 return 0;
1258
1259 if (pp->mode == smu_file_commands) {
1260 poll_wait(file, &pp->wait, wait);
1261
1262 spin_lock_irqsave(&pp->lock, flags);
1263 if (pp->busy && pp->cmd.status != 1)
1264 mask |= EPOLLIN;
1265 spin_unlock_irqrestore(&pp->lock, flags);
1266 }
1267 if (pp->mode == smu_file_events) {
1268 /* Not yet implemented */
1269 }
1270 return mask;
1271 }
1272
smu_release(struct inode * inode,struct file * file)1273 static int smu_release(struct inode *inode, struct file *file)
1274 {
1275 struct smu_private *pp = file->private_data;
1276 unsigned long flags;
1277 unsigned int busy;
1278
1279 if (pp == 0)
1280 return 0;
1281
1282 file->private_data = NULL;
1283
1284 /* Mark file as closing to avoid races with new request */
1285 spin_lock_irqsave(&pp->lock, flags);
1286 pp->mode = smu_file_closing;
1287 busy = pp->busy;
1288
1289 /* Wait for any pending request to complete */
1290 if (busy && pp->cmd.status == 1) {
1291 DECLARE_WAITQUEUE(wait, current);
1292
1293 add_wait_queue(&pp->wait, &wait);
1294 for (;;) {
1295 set_current_state(TASK_UNINTERRUPTIBLE);
1296 if (pp->cmd.status != 1)
1297 break;
1298 spin_unlock_irqrestore(&pp->lock, flags);
1299 schedule();
1300 spin_lock_irqsave(&pp->lock, flags);
1301 }
1302 set_current_state(TASK_RUNNING);
1303 remove_wait_queue(&pp->wait, &wait);
1304 }
1305 spin_unlock_irqrestore(&pp->lock, flags);
1306
1307 spin_lock_irqsave(&smu_clist_lock, flags);
1308 list_del(&pp->list);
1309 spin_unlock_irqrestore(&smu_clist_lock, flags);
1310 kfree(pp);
1311
1312 return 0;
1313 }
1314
1315
1316 static const struct file_operations smu_device_fops = {
1317 .llseek = no_llseek,
1318 .read = smu_read,
1319 .write = smu_write,
1320 .poll = smu_fpoll,
1321 .open = smu_open,
1322 .release = smu_release,
1323 };
1324
1325 static struct miscdevice pmu_device = {
1326 MISC_DYNAMIC_MINOR, "smu", &smu_device_fops
1327 };
1328
smu_device_init(void)1329 static int smu_device_init(void)
1330 {
1331 if (!smu)
1332 return -ENODEV;
1333 if (misc_register(&pmu_device) < 0)
1334 printk(KERN_ERR "via-pmu: cannot register misc device.\n");
1335 return 0;
1336 }
1337 device_initcall(smu_device_init);
1338