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1/*
2 * drivers/base/power/main.c - Where the driver meets power management.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 *
10 * The driver model core calls device_pm_add() when a device is registered.
11 * This will initialize the embedded device_pm_info object in the device
12 * and add it to the list of power-controlled devices. sysfs entries for
13 * controlling device power management will also be added.
14 *
15 * A separate list is used for keeping track of power info, because the power
16 * domain dependencies may differ from the ancestral dependencies that the
17 * subsystem list maintains.
18 */
19
20#include <linux/device.h>
21#include <linux/kallsyms.h>
22#include <linux/mutex.h>
23#include <linux/pm.h>
24#include <linux/pm_runtime.h>
25#include <linux/resume-trace.h>
26#include <linux/interrupt.h>
27#include <linux/sched.h>
28#include <linux/async.h>
29#include <linux/suspend.h>
30
31#include "../base.h"
32#include "power.h"
33
34/*
35 * The entries in the dpm_list list are in a depth first order, simply
36 * because children are guaranteed to be discovered after parents, and
37 * are inserted at the back of the list on discovery.
38 *
39 * Since device_pm_add() may be called with a device lock held,
40 * we must never try to acquire a device lock while holding
41 * dpm_list_mutex.
42 */
43
44LIST_HEAD(dpm_list);
45LIST_HEAD(dpm_prepared_list);
46LIST_HEAD(dpm_suspended_list);
47LIST_HEAD(dpm_noirq_list);
48
49static DEFINE_MUTEX(dpm_list_mtx);
50static pm_message_t pm_transition;
51
52static int async_error;
53
54/**
55 * device_pm_init - Initialize the PM-related part of a device object.
56 * @dev: Device object being initialized.
57 */
58void device_pm_init(struct device *dev)
59{
60 dev->power.is_prepared = false;
61 dev->power.is_suspended = false;
62 init_completion(&dev->power.completion);
63 complete_all(&dev->power.completion);
64 dev->power.wakeup = NULL;
65 spin_lock_init(&dev->power.lock);
66 pm_runtime_init(dev);
67 INIT_LIST_HEAD(&dev->power.entry);
68}
69
70/**
71 * device_pm_lock - Lock the list of active devices used by the PM core.
72 */
73void device_pm_lock(void)
74{
75 mutex_lock(&dpm_list_mtx);
76}
77
78/**
79 * device_pm_unlock - Unlock the list of active devices used by the PM core.
80 */
81void device_pm_unlock(void)
82{
83 mutex_unlock(&dpm_list_mtx);
84}
85
86/**
87 * device_pm_add - Add a device to the PM core's list of active devices.
88 * @dev: Device to add to the list.
89 */
90void device_pm_add(struct device *dev)
91{
92 pr_debug("PM: Adding info for %s:%s\n",
93 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
94 mutex_lock(&dpm_list_mtx);
95 if (dev->parent && dev->parent->power.is_prepared)
96 dev_warn(dev, "parent %s should not be sleeping\n",
97 dev_name(dev->parent));
98 list_add_tail(&dev->power.entry, &dpm_list);
99 mutex_unlock(&dpm_list_mtx);
100}
101
102/**
103 * device_pm_remove - Remove a device from the PM core's list of active devices.
104 * @dev: Device to be removed from the list.
105 */
106void device_pm_remove(struct device *dev)
107{
108 pr_debug("PM: Removing info for %s:%s\n",
109 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
110 complete_all(&dev->power.completion);
111 mutex_lock(&dpm_list_mtx);
112 list_del_init(&dev->power.entry);
113 mutex_unlock(&dpm_list_mtx);
114 device_wakeup_disable(dev);
115 pm_runtime_remove(dev);
116}
117
118/**
119 * device_pm_move_before - Move device in the PM core's list of active devices.
120 * @deva: Device to move in dpm_list.
121 * @devb: Device @deva should come before.
122 */
123void device_pm_move_before(struct device *deva, struct device *devb)
124{
125 pr_debug("PM: Moving %s:%s before %s:%s\n",
126 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
127 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
128 /* Delete deva from dpm_list and reinsert before devb. */
129 list_move_tail(&deva->power.entry, &devb->power.entry);
130}
131
132/**
133 * device_pm_move_after - Move device in the PM core's list of active devices.
134 * @deva: Device to move in dpm_list.
135 * @devb: Device @deva should come after.
136 */
137void device_pm_move_after(struct device *deva, struct device *devb)
138{
139 pr_debug("PM: Moving %s:%s after %s:%s\n",
140 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
141 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
142 /* Delete deva from dpm_list and reinsert after devb. */
143 list_move(&deva->power.entry, &devb->power.entry);
144}
145
146/**
147 * device_pm_move_last - Move device to end of the PM core's list of devices.
148 * @dev: Device to move in dpm_list.
149 */
150void device_pm_move_last(struct device *dev)
151{
152 pr_debug("PM: Moving %s:%s to end of list\n",
153 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
154 list_move_tail(&dev->power.entry, &dpm_list);
155}
156
157static ktime_t initcall_debug_start(struct device *dev)
158{
159 ktime_t calltime = ktime_set(0, 0);
160
161 if (initcall_debug) {
162 pr_info("calling %s+ @ %i\n",
163 dev_name(dev), task_pid_nr(current));
164 calltime = ktime_get();
165 }
166
167 return calltime;
168}
169
170static void initcall_debug_report(struct device *dev, ktime_t calltime,
171 int error)
172{
173 ktime_t delta, rettime;
174
175 if (initcall_debug) {
176 rettime = ktime_get();
177 delta = ktime_sub(rettime, calltime);
178 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
179 error, (unsigned long long)ktime_to_ns(delta) >> 10);
180 }
181}
182
183/**
184 * dpm_wait - Wait for a PM operation to complete.
185 * @dev: Device to wait for.
186 * @async: If unset, wait only if the device's power.async_suspend flag is set.
187 */
188static void dpm_wait(struct device *dev, bool async)
189{
190 if (!dev)
191 return;
192
193 if (async || (pm_async_enabled && dev->power.async_suspend))
194 wait_for_completion(&dev->power.completion);
195}
196
197static int dpm_wait_fn(struct device *dev, void *async_ptr)
198{
199 dpm_wait(dev, *((bool *)async_ptr));
200 return 0;
201}
202
203static void dpm_wait_for_children(struct device *dev, bool async)
204{
205 device_for_each_child(dev, &async, dpm_wait_fn);
206}
207
208/**
209 * pm_op - Execute the PM operation appropriate for given PM event.
210 * @dev: Device to handle.
211 * @ops: PM operations to choose from.
212 * @state: PM transition of the system being carried out.
213 */
214static int pm_op(struct device *dev,
215 const struct dev_pm_ops *ops,
216 pm_message_t state)
217{
218 int error = 0;
219 ktime_t calltime;
220
221 calltime = initcall_debug_start(dev);
222
223 switch (state.event) {
224#ifdef CONFIG_SUSPEND
225 case PM_EVENT_SUSPEND:
226 if (ops->suspend) {
227 error = ops->suspend(dev);
228 suspend_report_result(ops->suspend, error);
229 }
230 break;
231 case PM_EVENT_RESUME:
232 if (ops->resume) {
233 error = ops->resume(dev);
234 suspend_report_result(ops->resume, error);
235 }
236 break;
237#endif /* CONFIG_SUSPEND */
238#ifdef CONFIG_HIBERNATE_CALLBACKS
239 case PM_EVENT_FREEZE:
240 case PM_EVENT_QUIESCE:
241 if (ops->freeze) {
242 error = ops->freeze(dev);
243 suspend_report_result(ops->freeze, error);
244 }
245 break;
246 case PM_EVENT_HIBERNATE:
247 if (ops->poweroff) {
248 error = ops->poweroff(dev);
249 suspend_report_result(ops->poweroff, error);
250 }
251 break;
252 case PM_EVENT_THAW:
253 case PM_EVENT_RECOVER:
254 if (ops->thaw) {
255 error = ops->thaw(dev);
256 suspend_report_result(ops->thaw, error);
257 }
258 break;
259 case PM_EVENT_RESTORE:
260 if (ops->restore) {
261 error = ops->restore(dev);
262 suspend_report_result(ops->restore, error);
263 }
264 break;
265#endif /* CONFIG_HIBERNATE_CALLBACKS */
266 default:
267 error = -EINVAL;
268 }
269
270 initcall_debug_report(dev, calltime, error);
271
272 return error;
273}
274
275/**
276 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
277 * @dev: Device to handle.
278 * @ops: PM operations to choose from.
279 * @state: PM transition of the system being carried out.
280 *
281 * The driver of @dev will not receive interrupts while this function is being
282 * executed.
283 */
284static int pm_noirq_op(struct device *dev,
285 const struct dev_pm_ops *ops,
286 pm_message_t state)
287{
288 int error = 0;
289 ktime_t calltime = ktime_set(0, 0), delta, rettime;
290
291 if (initcall_debug) {
292 pr_info("calling %s+ @ %i, parent: %s\n",
293 dev_name(dev), task_pid_nr(current),
294 dev->parent ? dev_name(dev->parent) : "none");
295 calltime = ktime_get();
296 }
297
298 switch (state.event) {
299#ifdef CONFIG_SUSPEND
300 case PM_EVENT_SUSPEND:
301 if (ops->suspend_noirq) {
302 error = ops->suspend_noirq(dev);
303 suspend_report_result(ops->suspend_noirq, error);
304 }
305 break;
306 case PM_EVENT_RESUME:
307 if (ops->resume_noirq) {
308 error = ops->resume_noirq(dev);
309 suspend_report_result(ops->resume_noirq, error);
310 }
311 break;
312#endif /* CONFIG_SUSPEND */
313#ifdef CONFIG_HIBERNATE_CALLBACKS
314 case PM_EVENT_FREEZE:
315 case PM_EVENT_QUIESCE:
316 if (ops->freeze_noirq) {
317 error = ops->freeze_noirq(dev);
318 suspend_report_result(ops->freeze_noirq, error);
319 }
320 break;
321 case PM_EVENT_HIBERNATE:
322 if (ops->poweroff_noirq) {
323 error = ops->poweroff_noirq(dev);
324 suspend_report_result(ops->poweroff_noirq, error);
325 }
326 break;
327 case PM_EVENT_THAW:
328 case PM_EVENT_RECOVER:
329 if (ops->thaw_noirq) {
330 error = ops->thaw_noirq(dev);
331 suspend_report_result(ops->thaw_noirq, error);
332 }
333 break;
334 case PM_EVENT_RESTORE:
335 if (ops->restore_noirq) {
336 error = ops->restore_noirq(dev);
337 suspend_report_result(ops->restore_noirq, error);
338 }
339 break;
340#endif /* CONFIG_HIBERNATE_CALLBACKS */
341 default:
342 error = -EINVAL;
343 }
344
345 if (initcall_debug) {
346 rettime = ktime_get();
347 delta = ktime_sub(rettime, calltime);
348 printk("initcall %s_i+ returned %d after %Ld usecs\n",
349 dev_name(dev), error,
350 (unsigned long long)ktime_to_ns(delta) >> 10);
351 }
352
353 return error;
354}
355
356static char *pm_verb(int event)
357{
358 switch (event) {
359 case PM_EVENT_SUSPEND:
360 return "suspend";
361 case PM_EVENT_RESUME:
362 return "resume";
363 case PM_EVENT_FREEZE:
364 return "freeze";
365 case PM_EVENT_QUIESCE:
366 return "quiesce";
367 case PM_EVENT_HIBERNATE:
368 return "hibernate";
369 case PM_EVENT_THAW:
370 return "thaw";
371 case PM_EVENT_RESTORE:
372 return "restore";
373 case PM_EVENT_RECOVER:
374 return "recover";
375 default:
376 return "(unknown PM event)";
377 }
378}
379
380static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
381{
382 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
383 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
384 ", may wakeup" : "");
385}
386
387static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
388 int error)
389{
390 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
391 dev_name(dev), pm_verb(state.event), info, error);
392}
393
394static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
395{
396 ktime_t calltime;
397 u64 usecs64;
398 int usecs;
399
400 calltime = ktime_get();
401 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
402 do_div(usecs64, NSEC_PER_USEC);
403 usecs = usecs64;
404 if (usecs == 0)
405 usecs = 1;
406 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
407 info ?: "", info ? " " : "", pm_verb(state.event),
408 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
409}
410
411/*------------------------- Resume routines -------------------------*/
412
413/**
414 * device_resume_noirq - Execute an "early resume" callback for given device.
415 * @dev: Device to handle.
416 * @state: PM transition of the system being carried out.
417 *
418 * The driver of @dev will not receive interrupts while this function is being
419 * executed.
420 */
421static int device_resume_noirq(struct device *dev, pm_message_t state)
422{
423 int error = 0;
424
425 TRACE_DEVICE(dev);
426 TRACE_RESUME(0);
427
428 if (dev->pm_domain) {
429 pm_dev_dbg(dev, state, "EARLY power domain ");
430 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
431 } else if (dev->type && dev->type->pm) {
432 pm_dev_dbg(dev, state, "EARLY type ");
433 error = pm_noirq_op(dev, dev->type->pm, state);
434 } else if (dev->class && dev->class->pm) {
435 pm_dev_dbg(dev, state, "EARLY class ");
436 error = pm_noirq_op(dev, dev->class->pm, state);
437 } else if (dev->bus && dev->bus->pm) {
438 pm_dev_dbg(dev, state, "EARLY ");
439 error = pm_noirq_op(dev, dev->bus->pm, state);
440 }
441
442 TRACE_RESUME(error);
443 return error;
444}
445
446/**
447 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
448 * @state: PM transition of the system being carried out.
449 *
450 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
451 * enable device drivers to receive interrupts.
452 */
453void dpm_resume_noirq(pm_message_t state)
454{
455 ktime_t starttime = ktime_get();
456
457 mutex_lock(&dpm_list_mtx);
458 while (!list_empty(&dpm_noirq_list)) {
459 struct device *dev = to_device(dpm_noirq_list.next);
460 int error;
461
462 get_device(dev);
463 list_move_tail(&dev->power.entry, &dpm_suspended_list);
464 mutex_unlock(&dpm_list_mtx);
465
466 error = device_resume_noirq(dev, state);
467 if (error)
468 pm_dev_err(dev, state, " early", error);
469
470 mutex_lock(&dpm_list_mtx);
471 put_device(dev);
472 }
473 mutex_unlock(&dpm_list_mtx);
474 dpm_show_time(starttime, state, "early");
475 resume_device_irqs();
476}
477EXPORT_SYMBOL_GPL(dpm_resume_noirq);
478
479/**
480 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
481 * @dev: Device to resume.
482 * @cb: Resume callback to execute.
483 */
484static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
485{
486 int error;
487 ktime_t calltime;
488
489 calltime = initcall_debug_start(dev);
490
491 error = cb(dev);
492 suspend_report_result(cb, error);
493
494 initcall_debug_report(dev, calltime, error);
495
496 return error;
497}
498
499/**
500 * device_resume - Execute "resume" callbacks for given device.
501 * @dev: Device to handle.
502 * @state: PM transition of the system being carried out.
503 * @async: If true, the device is being resumed asynchronously.
504 */
505static int device_resume(struct device *dev, pm_message_t state, bool async)
506{
507 int error = 0;
508 bool put = false;
509
510 TRACE_DEVICE(dev);
511 TRACE_RESUME(0);
512
513 dpm_wait(dev->parent, async);
514 device_lock(dev);
515
516 /*
517 * This is a fib. But we'll allow new children to be added below
518 * a resumed device, even if the device hasn't been completed yet.
519 */
520 dev->power.is_prepared = false;
521
522 if (!dev->power.is_suspended)
523 goto Unlock;
524
525 pm_runtime_enable(dev);
526 put = true;
527
528 if (dev->pm_domain) {
529 pm_dev_dbg(dev, state, "power domain ");
530 error = pm_op(dev, &dev->pm_domain->ops, state);
531 goto End;
532 }
533
534 if (dev->type && dev->type->pm) {
535 pm_dev_dbg(dev, state, "type ");
536 error = pm_op(dev, dev->type->pm, state);
537 goto End;
538 }
539
540 if (dev->class) {
541 if (dev->class->pm) {
542 pm_dev_dbg(dev, state, "class ");
543 error = pm_op(dev, dev->class->pm, state);
544 goto End;
545 } else if (dev->class->resume) {
546 pm_dev_dbg(dev, state, "legacy class ");
547 error = legacy_resume(dev, dev->class->resume);
548 goto End;
549 }
550 }
551
552 if (dev->bus) {
553 if (dev->bus->pm) {
554 pm_dev_dbg(dev, state, "");
555 error = pm_op(dev, dev->bus->pm, state);
556 } else if (dev->bus->resume) {
557 pm_dev_dbg(dev, state, "legacy ");
558 error = legacy_resume(dev, dev->bus->resume);
559 }
560 }
561
562 End:
563 dev->power.is_suspended = false;
564
565 Unlock:
566 device_unlock(dev);
567 complete_all(&dev->power.completion);
568
569 TRACE_RESUME(error);
570
571 if (put)
572 pm_runtime_put_sync(dev);
573
574 return error;
575}
576
577static void async_resume(void *data, async_cookie_t cookie)
578{
579 struct device *dev = (struct device *)data;
580 int error;
581
582 error = device_resume(dev, pm_transition, true);
583 if (error)
584 pm_dev_err(dev, pm_transition, " async", error);
585 put_device(dev);
586}
587
588static bool is_async(struct device *dev)
589{
590 return dev->power.async_suspend && pm_async_enabled
591 && !pm_trace_is_enabled();
592}
593
594/**
595 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
596 * @state: PM transition of the system being carried out.
597 *
598 * Execute the appropriate "resume" callback for all devices whose status
599 * indicates that they are suspended.
600 */
601void dpm_resume(pm_message_t state)
602{
603 struct device *dev;
604 ktime_t starttime = ktime_get();
605
606 might_sleep();
607
608 mutex_lock(&dpm_list_mtx);
609 pm_transition = state;
610 async_error = 0;
611
612 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
613 INIT_COMPLETION(dev->power.completion);
614 if (is_async(dev)) {
615 get_device(dev);
616 async_schedule(async_resume, dev);
617 }
618 }
619
620 while (!list_empty(&dpm_suspended_list)) {
621 dev = to_device(dpm_suspended_list.next);
622 get_device(dev);
623 if (!is_async(dev)) {
624 int error;
625
626 mutex_unlock(&dpm_list_mtx);
627
628 error = device_resume(dev, state, false);
629 if (error)
630 pm_dev_err(dev, state, "", error);
631
632 mutex_lock(&dpm_list_mtx);
633 }
634 if (!list_empty(&dev->power.entry))
635 list_move_tail(&dev->power.entry, &dpm_prepared_list);
636 put_device(dev);
637 }
638 mutex_unlock(&dpm_list_mtx);
639 async_synchronize_full();
640 dpm_show_time(starttime, state, NULL);
641}
642
643/**
644 * device_complete - Complete a PM transition for given device.
645 * @dev: Device to handle.
646 * @state: PM transition of the system being carried out.
647 */
648static void device_complete(struct device *dev, pm_message_t state)
649{
650 device_lock(dev);
651
652 if (dev->pm_domain) {
653 pm_dev_dbg(dev, state, "completing power domain ");
654 if (dev->pm_domain->ops.complete)
655 dev->pm_domain->ops.complete(dev);
656 } else if (dev->type && dev->type->pm) {
657 pm_dev_dbg(dev, state, "completing type ");
658 if (dev->type->pm->complete)
659 dev->type->pm->complete(dev);
660 } else if (dev->class && dev->class->pm) {
661 pm_dev_dbg(dev, state, "completing class ");
662 if (dev->class->pm->complete)
663 dev->class->pm->complete(dev);
664 } else if (dev->bus && dev->bus->pm) {
665 pm_dev_dbg(dev, state, "completing ");
666 if (dev->bus->pm->complete)
667 dev->bus->pm->complete(dev);
668 }
669
670 device_unlock(dev);
671}
672
673/**
674 * dpm_complete - Complete a PM transition for all non-sysdev devices.
675 * @state: PM transition of the system being carried out.
676 *
677 * Execute the ->complete() callbacks for all devices whose PM status is not
678 * DPM_ON (this allows new devices to be registered).
679 */
680void dpm_complete(pm_message_t state)
681{
682 struct list_head list;
683
684 might_sleep();
685
686 INIT_LIST_HEAD(&list);
687 mutex_lock(&dpm_list_mtx);
688 while (!list_empty(&dpm_prepared_list)) {
689 struct device *dev = to_device(dpm_prepared_list.prev);
690
691 get_device(dev);
692 dev->power.is_prepared = false;
693 list_move(&dev->power.entry, &list);
694 mutex_unlock(&dpm_list_mtx);
695
696 device_complete(dev, state);
697
698 mutex_lock(&dpm_list_mtx);
699 put_device(dev);
700 }
701 list_splice(&list, &dpm_list);
702 mutex_unlock(&dpm_list_mtx);
703}
704
705/**
706 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
707 * @state: PM transition of the system being carried out.
708 *
709 * Execute "resume" callbacks for all devices and complete the PM transition of
710 * the system.
711 */
712void dpm_resume_end(pm_message_t state)
713{
714 dpm_resume(state);
715 dpm_complete(state);
716}
717EXPORT_SYMBOL_GPL(dpm_resume_end);
718
719
720/*------------------------- Suspend routines -------------------------*/
721
722/**
723 * resume_event - Return a "resume" message for given "suspend" sleep state.
724 * @sleep_state: PM message representing a sleep state.
725 *
726 * Return a PM message representing the resume event corresponding to given
727 * sleep state.
728 */
729static pm_message_t resume_event(pm_message_t sleep_state)
730{
731 switch (sleep_state.event) {
732 case PM_EVENT_SUSPEND:
733 return PMSG_RESUME;
734 case PM_EVENT_FREEZE:
735 case PM_EVENT_QUIESCE:
736 return PMSG_RECOVER;
737 case PM_EVENT_HIBERNATE:
738 return PMSG_RESTORE;
739 }
740 return PMSG_ON;
741}
742
743/**
744 * device_suspend_noirq - Execute a "late suspend" callback for given device.
745 * @dev: Device to handle.
746 * @state: PM transition of the system being carried out.
747 *
748 * The driver of @dev will not receive interrupts while this function is being
749 * executed.
750 */
751static int device_suspend_noirq(struct device *dev, pm_message_t state)
752{
753 int error;
754
755 if (dev->pm_domain) {
756 pm_dev_dbg(dev, state, "LATE power domain ");
757 error = pm_noirq_op(dev, &dev->pm_domain->ops, state);
758 if (error)
759 return error;
760 } else if (dev->type && dev->type->pm) {
761 pm_dev_dbg(dev, state, "LATE type ");
762 error = pm_noirq_op(dev, dev->type->pm, state);
763 if (error)
764 return error;
765 } else if (dev->class && dev->class->pm) {
766 pm_dev_dbg(dev, state, "LATE class ");
767 error = pm_noirq_op(dev, dev->class->pm, state);
768 if (error)
769 return error;
770 } else if (dev->bus && dev->bus->pm) {
771 pm_dev_dbg(dev, state, "LATE ");
772 error = pm_noirq_op(dev, dev->bus->pm, state);
773 if (error)
774 return error;
775 }
776
777 return 0;
778}
779
780/**
781 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
782 * @state: PM transition of the system being carried out.
783 *
784 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
785 * handlers for all non-sysdev devices.
786 */
787int dpm_suspend_noirq(pm_message_t state)
788{
789 ktime_t starttime = ktime_get();
790 int error = 0;
791
792 suspend_device_irqs();
793 mutex_lock(&dpm_list_mtx);
794 while (!list_empty(&dpm_suspended_list)) {
795 struct device *dev = to_device(dpm_suspended_list.prev);
796
797 get_device(dev);
798 mutex_unlock(&dpm_list_mtx);
799
800 error = device_suspend_noirq(dev, state);
801
802 mutex_lock(&dpm_list_mtx);
803 if (error) {
804 pm_dev_err(dev, state, " late", error);
805 put_device(dev);
806 break;
807 }
808 if (!list_empty(&dev->power.entry))
809 list_move(&dev->power.entry, &dpm_noirq_list);
810 put_device(dev);
811 }
812 mutex_unlock(&dpm_list_mtx);
813 if (error)
814 dpm_resume_noirq(resume_event(state));
815 else
816 dpm_show_time(starttime, state, "late");
817 return error;
818}
819EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
820
821/**
822 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
823 * @dev: Device to suspend.
824 * @state: PM transition of the system being carried out.
825 * @cb: Suspend callback to execute.
826 */
827static int legacy_suspend(struct device *dev, pm_message_t state,
828 int (*cb)(struct device *dev, pm_message_t state))
829{
830 int error;
831 ktime_t calltime;
832
833 calltime = initcall_debug_start(dev);
834
835 error = cb(dev, state);
836 suspend_report_result(cb, error);
837
838 initcall_debug_report(dev, calltime, error);
839
840 return error;
841}
842
843/**
844 * device_suspend - Execute "suspend" callbacks for given device.
845 * @dev: Device to handle.
846 * @state: PM transition of the system being carried out.
847 * @async: If true, the device is being suspended asynchronously.
848 */
849static int __device_suspend(struct device *dev, pm_message_t state, bool async)
850{
851 int error = 0;
852
853 dpm_wait_for_children(dev, async);
854
855 if (async_error)
856 return 0;
857
858 pm_runtime_get_noresume(dev);
859 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
860 pm_wakeup_event(dev, 0);
861
862 if (pm_wakeup_pending()) {
863 pm_runtime_put_sync(dev);
864 async_error = -EBUSY;
865 return 0;
866 }
867
868 device_lock(dev);
869
870 if (dev->pm_domain) {
871 pm_dev_dbg(dev, state, "power domain ");
872 error = pm_op(dev, &dev->pm_domain->ops, state);
873 goto End;
874 }
875
876 if (dev->type && dev->type->pm) {
877 pm_dev_dbg(dev, state, "type ");
878 error = pm_op(dev, dev->type->pm, state);
879 goto End;
880 }
881
882 if (dev->class) {
883 if (dev->class->pm) {
884 pm_dev_dbg(dev, state, "class ");
885 error = pm_op(dev, dev->class->pm, state);
886 goto End;
887 } else if (dev->class->suspend) {
888 pm_dev_dbg(dev, state, "legacy class ");
889 error = legacy_suspend(dev, state, dev->class->suspend);
890 goto End;
891 }
892 }
893
894 if (dev->bus) {
895 if (dev->bus->pm) {
896 pm_dev_dbg(dev, state, "");
897 error = pm_op(dev, dev->bus->pm, state);
898 } else if (dev->bus->suspend) {
899 pm_dev_dbg(dev, state, "legacy ");
900 error = legacy_suspend(dev, state, dev->bus->suspend);
901 }
902 }
903
904 End:
905 dev->power.is_suspended = !error;
906
907 device_unlock(dev);
908 complete_all(&dev->power.completion);
909
910 if (error) {
911 pm_runtime_put_sync(dev);
912 async_error = error;
913 } else if (dev->power.is_suspended) {
914 __pm_runtime_disable(dev, false);
915 }
916
917 return error;
918}
919
920static void async_suspend(void *data, async_cookie_t cookie)
921{
922 struct device *dev = (struct device *)data;
923 int error;
924
925 error = __device_suspend(dev, pm_transition, true);
926 if (error)
927 pm_dev_err(dev, pm_transition, " async", error);
928
929 put_device(dev);
930}
931
932static int device_suspend(struct device *dev)
933{
934 INIT_COMPLETION(dev->power.completion);
935
936 if (pm_async_enabled && dev->power.async_suspend) {
937 get_device(dev);
938 async_schedule(async_suspend, dev);
939 return 0;
940 }
941
942 return __device_suspend(dev, pm_transition, false);
943}
944
945/**
946 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
947 * @state: PM transition of the system being carried out.
948 */
949int dpm_suspend(pm_message_t state)
950{
951 ktime_t starttime = ktime_get();
952 int error = 0;
953
954 might_sleep();
955
956 mutex_lock(&dpm_list_mtx);
957 pm_transition = state;
958 async_error = 0;
959 while (!list_empty(&dpm_prepared_list)) {
960 struct device *dev = to_device(dpm_prepared_list.prev);
961
962 get_device(dev);
963 mutex_unlock(&dpm_list_mtx);
964
965 error = device_suspend(dev);
966
967 mutex_lock(&dpm_list_mtx);
968 if (error) {
969 pm_dev_err(dev, state, "", error);
970 put_device(dev);
971 break;
972 }
973 if (!list_empty(&dev->power.entry))
974 list_move(&dev->power.entry, &dpm_suspended_list);
975 put_device(dev);
976 if (async_error)
977 break;
978 }
979 mutex_unlock(&dpm_list_mtx);
980 async_synchronize_full();
981 if (!error)
982 error = async_error;
983 if (!error)
984 dpm_show_time(starttime, state, NULL);
985 return error;
986}
987
988/**
989 * device_prepare - Prepare a device for system power transition.
990 * @dev: Device to handle.
991 * @state: PM transition of the system being carried out.
992 *
993 * Execute the ->prepare() callback(s) for given device. No new children of the
994 * device may be registered after this function has returned.
995 */
996static int device_prepare(struct device *dev, pm_message_t state)
997{
998 int error = 0;
999
1000 device_lock(dev);
1001
1002 if (dev->pm_domain) {
1003 pm_dev_dbg(dev, state, "preparing power domain ");
1004 if (dev->pm_domain->ops.prepare)
1005 error = dev->pm_domain->ops.prepare(dev);
1006 suspend_report_result(dev->pm_domain->ops.prepare, error);
1007 if (error)
1008 goto End;
1009 } else if (dev->type && dev->type->pm) {
1010 pm_dev_dbg(dev, state, "preparing type ");
1011 if (dev->type->pm->prepare)
1012 error = dev->type->pm->prepare(dev);
1013 suspend_report_result(dev->type->pm->prepare, error);
1014 if (error)
1015 goto End;
1016 } else if (dev->class && dev->class->pm) {
1017 pm_dev_dbg(dev, state, "preparing class ");
1018 if (dev->class->pm->prepare)
1019 error = dev->class->pm->prepare(dev);
1020 suspend_report_result(dev->class->pm->prepare, error);
1021 if (error)
1022 goto End;
1023 } else if (dev->bus && dev->bus->pm) {
1024 pm_dev_dbg(dev, state, "preparing ");
1025 if (dev->bus->pm->prepare)
1026 error = dev->bus->pm->prepare(dev);
1027 suspend_report_result(dev->bus->pm->prepare, error);
1028 }
1029
1030 End:
1031 device_unlock(dev);
1032
1033 return error;
1034}
1035
1036/**
1037 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1038 * @state: PM transition of the system being carried out.
1039 *
1040 * Execute the ->prepare() callback(s) for all devices.
1041 */
1042int dpm_prepare(pm_message_t state)
1043{
1044 int error = 0;
1045
1046 might_sleep();
1047
1048 mutex_lock(&dpm_list_mtx);
1049 while (!list_empty(&dpm_list)) {
1050 struct device *dev = to_device(dpm_list.next);
1051
1052 get_device(dev);
1053 mutex_unlock(&dpm_list_mtx);
1054
1055 error = device_prepare(dev, state);
1056
1057 mutex_lock(&dpm_list_mtx);
1058 if (error) {
1059 if (error == -EAGAIN) {
1060 put_device(dev);
1061 error = 0;
1062 continue;
1063 }
1064 printk(KERN_INFO "PM: Device %s not prepared "
1065 "for power transition: code %d\n",
1066 dev_name(dev), error);
1067 put_device(dev);
1068 break;
1069 }
1070 dev->power.is_prepared = true;
1071 if (!list_empty(&dev->power.entry))
1072 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1073 put_device(dev);
1074 }
1075 mutex_unlock(&dpm_list_mtx);
1076 return error;
1077}
1078
1079/**
1080 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1081 * @state: PM transition of the system being carried out.
1082 *
1083 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1084 * callbacks for them.
1085 */
1086int dpm_suspend_start(pm_message_t state)
1087{
1088 int error;
1089
1090 error = dpm_prepare(state);
1091 if (!error)
1092 error = dpm_suspend(state);
1093 return error;
1094}
1095EXPORT_SYMBOL_GPL(dpm_suspend_start);
1096
1097void __suspend_report_result(const char *function, void *fn, int ret)
1098{
1099 if (ret)
1100 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1101}
1102EXPORT_SYMBOL_GPL(__suspend_report_result);
1103
1104/**
1105 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1106 * @dev: Device to wait for.
1107 * @subordinate: Device that needs to wait for @dev.
1108 */
1109int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1110{
1111 dpm_wait(dev, subordinate->power.async_suspend);
1112 return async_error;
1113}
1114EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1/*
2 * drivers/base/power/main.c - Where the driver meets power management.
3 *
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
6 *
7 * This file is released under the GPLv2
8 *
9 *
10 * The driver model core calls device_pm_add() when a device is registered.
11 * This will initialize the embedded device_pm_info object in the device
12 * and add it to the list of power-controlled devices. sysfs entries for
13 * controlling device power management will also be added.
14 *
15 * A separate list is used for keeping track of power info, because the power
16 * domain dependencies may differ from the ancestral dependencies that the
17 * subsystem list maintains.
18 */
19
20#include <linux/device.h>
21#include <linux/kallsyms.h>
22#include <linux/export.h>
23#include <linux/mutex.h>
24#include <linux/pm.h>
25#include <linux/pm_runtime.h>
26#include <linux/resume-trace.h>
27#include <linux/interrupt.h>
28#include <linux/sched.h>
29#include <linux/async.h>
30#include <linux/suspend.h>
31
32#include "../base.h"
33#include "power.h"
34
35typedef int (*pm_callback_t)(struct device *);
36
37/*
38 * The entries in the dpm_list list are in a depth first order, simply
39 * because children are guaranteed to be discovered after parents, and
40 * are inserted at the back of the list on discovery.
41 *
42 * Since device_pm_add() may be called with a device lock held,
43 * we must never try to acquire a device lock while holding
44 * dpm_list_mutex.
45 */
46
47LIST_HEAD(dpm_list);
48LIST_HEAD(dpm_prepared_list);
49LIST_HEAD(dpm_suspended_list);
50LIST_HEAD(dpm_late_early_list);
51LIST_HEAD(dpm_noirq_list);
52
53struct suspend_stats suspend_stats;
54static DEFINE_MUTEX(dpm_list_mtx);
55static pm_message_t pm_transition;
56
57static int async_error;
58
59/**
60 * device_pm_init - Initialize the PM-related part of a device object.
61 * @dev: Device object being initialized.
62 */
63void device_pm_init(struct device *dev)
64{
65 dev->power.is_prepared = false;
66 dev->power.is_suspended = false;
67 init_completion(&dev->power.completion);
68 complete_all(&dev->power.completion);
69 dev->power.wakeup = NULL;
70 spin_lock_init(&dev->power.lock);
71 pm_runtime_init(dev);
72 INIT_LIST_HEAD(&dev->power.entry);
73 dev->power.power_state = PMSG_INVALID;
74}
75
76/**
77 * device_pm_lock - Lock the list of active devices used by the PM core.
78 */
79void device_pm_lock(void)
80{
81 mutex_lock(&dpm_list_mtx);
82}
83
84/**
85 * device_pm_unlock - Unlock the list of active devices used by the PM core.
86 */
87void device_pm_unlock(void)
88{
89 mutex_unlock(&dpm_list_mtx);
90}
91
92/**
93 * device_pm_add - Add a device to the PM core's list of active devices.
94 * @dev: Device to add to the list.
95 */
96void device_pm_add(struct device *dev)
97{
98 pr_debug("PM: Adding info for %s:%s\n",
99 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
100 mutex_lock(&dpm_list_mtx);
101 if (dev->parent && dev->parent->power.is_prepared)
102 dev_warn(dev, "parent %s should not be sleeping\n",
103 dev_name(dev->parent));
104 list_add_tail(&dev->power.entry, &dpm_list);
105 dev_pm_qos_constraints_init(dev);
106 mutex_unlock(&dpm_list_mtx);
107}
108
109/**
110 * device_pm_remove - Remove a device from the PM core's list of active devices.
111 * @dev: Device to be removed from the list.
112 */
113void device_pm_remove(struct device *dev)
114{
115 pr_debug("PM: Removing info for %s:%s\n",
116 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
117 complete_all(&dev->power.completion);
118 mutex_lock(&dpm_list_mtx);
119 dev_pm_qos_constraints_destroy(dev);
120 list_del_init(&dev->power.entry);
121 mutex_unlock(&dpm_list_mtx);
122 device_wakeup_disable(dev);
123 pm_runtime_remove(dev);
124}
125
126/**
127 * device_pm_move_before - Move device in the PM core's list of active devices.
128 * @deva: Device to move in dpm_list.
129 * @devb: Device @deva should come before.
130 */
131void device_pm_move_before(struct device *deva, struct device *devb)
132{
133 pr_debug("PM: Moving %s:%s before %s:%s\n",
134 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
135 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
136 /* Delete deva from dpm_list and reinsert before devb. */
137 list_move_tail(&deva->power.entry, &devb->power.entry);
138}
139
140/**
141 * device_pm_move_after - Move device in the PM core's list of active devices.
142 * @deva: Device to move in dpm_list.
143 * @devb: Device @deva should come after.
144 */
145void device_pm_move_after(struct device *deva, struct device *devb)
146{
147 pr_debug("PM: Moving %s:%s after %s:%s\n",
148 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
149 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
150 /* Delete deva from dpm_list and reinsert after devb. */
151 list_move(&deva->power.entry, &devb->power.entry);
152}
153
154/**
155 * device_pm_move_last - Move device to end of the PM core's list of devices.
156 * @dev: Device to move in dpm_list.
157 */
158void device_pm_move_last(struct device *dev)
159{
160 pr_debug("PM: Moving %s:%s to end of list\n",
161 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
162 list_move_tail(&dev->power.entry, &dpm_list);
163}
164
165static ktime_t initcall_debug_start(struct device *dev)
166{
167 ktime_t calltime = ktime_set(0, 0);
168
169 if (initcall_debug) {
170 pr_info("calling %s+ @ %i, parent: %s\n",
171 dev_name(dev), task_pid_nr(current),
172 dev->parent ? dev_name(dev->parent) : "none");
173 calltime = ktime_get();
174 }
175
176 return calltime;
177}
178
179static void initcall_debug_report(struct device *dev, ktime_t calltime,
180 int error)
181{
182 ktime_t delta, rettime;
183
184 if (initcall_debug) {
185 rettime = ktime_get();
186 delta = ktime_sub(rettime, calltime);
187 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
188 error, (unsigned long long)ktime_to_ns(delta) >> 10);
189 }
190}
191
192/**
193 * dpm_wait - Wait for a PM operation to complete.
194 * @dev: Device to wait for.
195 * @async: If unset, wait only if the device's power.async_suspend flag is set.
196 */
197static void dpm_wait(struct device *dev, bool async)
198{
199 if (!dev)
200 return;
201
202 if (async || (pm_async_enabled && dev->power.async_suspend))
203 wait_for_completion(&dev->power.completion);
204}
205
206static int dpm_wait_fn(struct device *dev, void *async_ptr)
207{
208 dpm_wait(dev, *((bool *)async_ptr));
209 return 0;
210}
211
212static void dpm_wait_for_children(struct device *dev, bool async)
213{
214 device_for_each_child(dev, &async, dpm_wait_fn);
215}
216
217/**
218 * pm_op - Return the PM operation appropriate for given PM event.
219 * @ops: PM operations to choose from.
220 * @state: PM transition of the system being carried out.
221 */
222static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
223{
224 switch (state.event) {
225#ifdef CONFIG_SUSPEND
226 case PM_EVENT_SUSPEND:
227 return ops->suspend;
228 case PM_EVENT_RESUME:
229 return ops->resume;
230#endif /* CONFIG_SUSPEND */
231#ifdef CONFIG_HIBERNATE_CALLBACKS
232 case PM_EVENT_FREEZE:
233 case PM_EVENT_QUIESCE:
234 return ops->freeze;
235 case PM_EVENT_HIBERNATE:
236 return ops->poweroff;
237 case PM_EVENT_THAW:
238 case PM_EVENT_RECOVER:
239 return ops->thaw;
240 break;
241 case PM_EVENT_RESTORE:
242 return ops->restore;
243#endif /* CONFIG_HIBERNATE_CALLBACKS */
244 }
245
246 return NULL;
247}
248
249/**
250 * pm_late_early_op - Return the PM operation appropriate for given PM event.
251 * @ops: PM operations to choose from.
252 * @state: PM transition of the system being carried out.
253 *
254 * Runtime PM is disabled for @dev while this function is being executed.
255 */
256static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
257 pm_message_t state)
258{
259 switch (state.event) {
260#ifdef CONFIG_SUSPEND
261 case PM_EVENT_SUSPEND:
262 return ops->suspend_late;
263 case PM_EVENT_RESUME:
264 return ops->resume_early;
265#endif /* CONFIG_SUSPEND */
266#ifdef CONFIG_HIBERNATE_CALLBACKS
267 case PM_EVENT_FREEZE:
268 case PM_EVENT_QUIESCE:
269 return ops->freeze_late;
270 case PM_EVENT_HIBERNATE:
271 return ops->poweroff_late;
272 case PM_EVENT_THAW:
273 case PM_EVENT_RECOVER:
274 return ops->thaw_early;
275 case PM_EVENT_RESTORE:
276 return ops->restore_early;
277#endif /* CONFIG_HIBERNATE_CALLBACKS */
278 }
279
280 return NULL;
281}
282
283/**
284 * pm_noirq_op - Return the PM operation appropriate for given PM event.
285 * @ops: PM operations to choose from.
286 * @state: PM transition of the system being carried out.
287 *
288 * The driver of @dev will not receive interrupts while this function is being
289 * executed.
290 */
291static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
292{
293 switch (state.event) {
294#ifdef CONFIG_SUSPEND
295 case PM_EVENT_SUSPEND:
296 return ops->suspend_noirq;
297 case PM_EVENT_RESUME:
298 return ops->resume_noirq;
299#endif /* CONFIG_SUSPEND */
300#ifdef CONFIG_HIBERNATE_CALLBACKS
301 case PM_EVENT_FREEZE:
302 case PM_EVENT_QUIESCE:
303 return ops->freeze_noirq;
304 case PM_EVENT_HIBERNATE:
305 return ops->poweroff_noirq;
306 case PM_EVENT_THAW:
307 case PM_EVENT_RECOVER:
308 return ops->thaw_noirq;
309 case PM_EVENT_RESTORE:
310 return ops->restore_noirq;
311#endif /* CONFIG_HIBERNATE_CALLBACKS */
312 }
313
314 return NULL;
315}
316
317static char *pm_verb(int event)
318{
319 switch (event) {
320 case PM_EVENT_SUSPEND:
321 return "suspend";
322 case PM_EVENT_RESUME:
323 return "resume";
324 case PM_EVENT_FREEZE:
325 return "freeze";
326 case PM_EVENT_QUIESCE:
327 return "quiesce";
328 case PM_EVENT_HIBERNATE:
329 return "hibernate";
330 case PM_EVENT_THAW:
331 return "thaw";
332 case PM_EVENT_RESTORE:
333 return "restore";
334 case PM_EVENT_RECOVER:
335 return "recover";
336 default:
337 return "(unknown PM event)";
338 }
339}
340
341static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
342{
343 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
344 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
345 ", may wakeup" : "");
346}
347
348static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
349 int error)
350{
351 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
352 dev_name(dev), pm_verb(state.event), info, error);
353}
354
355static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
356{
357 ktime_t calltime;
358 u64 usecs64;
359 int usecs;
360
361 calltime = ktime_get();
362 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
363 do_div(usecs64, NSEC_PER_USEC);
364 usecs = usecs64;
365 if (usecs == 0)
366 usecs = 1;
367 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
368 info ?: "", info ? " " : "", pm_verb(state.event),
369 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
370}
371
372static int dpm_run_callback(pm_callback_t cb, struct device *dev,
373 pm_message_t state, char *info)
374{
375 ktime_t calltime;
376 int error;
377
378 if (!cb)
379 return 0;
380
381 calltime = initcall_debug_start(dev);
382
383 pm_dev_dbg(dev, state, info);
384 error = cb(dev);
385 suspend_report_result(cb, error);
386
387 initcall_debug_report(dev, calltime, error);
388
389 return error;
390}
391
392/*------------------------- Resume routines -------------------------*/
393
394/**
395 * device_resume_noirq - Execute an "early resume" callback for given device.
396 * @dev: Device to handle.
397 * @state: PM transition of the system being carried out.
398 *
399 * The driver of @dev will not receive interrupts while this function is being
400 * executed.
401 */
402static int device_resume_noirq(struct device *dev, pm_message_t state)
403{
404 pm_callback_t callback = NULL;
405 char *info = NULL;
406 int error = 0;
407
408 TRACE_DEVICE(dev);
409 TRACE_RESUME(0);
410
411 if (dev->pm_domain) {
412 info = "noirq power domain ";
413 callback = pm_noirq_op(&dev->pm_domain->ops, state);
414 } else if (dev->type && dev->type->pm) {
415 info = "noirq type ";
416 callback = pm_noirq_op(dev->type->pm, state);
417 } else if (dev->class && dev->class->pm) {
418 info = "noirq class ";
419 callback = pm_noirq_op(dev->class->pm, state);
420 } else if (dev->bus && dev->bus->pm) {
421 info = "noirq bus ";
422 callback = pm_noirq_op(dev->bus->pm, state);
423 }
424
425 if (!callback && dev->driver && dev->driver->pm) {
426 info = "noirq driver ";
427 callback = pm_noirq_op(dev->driver->pm, state);
428 }
429
430 error = dpm_run_callback(callback, dev, state, info);
431
432 TRACE_RESUME(error);
433 return error;
434}
435
436/**
437 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
438 * @state: PM transition of the system being carried out.
439 *
440 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
441 * enable device drivers to receive interrupts.
442 */
443static void dpm_resume_noirq(pm_message_t state)
444{
445 ktime_t starttime = ktime_get();
446
447 mutex_lock(&dpm_list_mtx);
448 while (!list_empty(&dpm_noirq_list)) {
449 struct device *dev = to_device(dpm_noirq_list.next);
450 int error;
451
452 get_device(dev);
453 list_move_tail(&dev->power.entry, &dpm_late_early_list);
454 mutex_unlock(&dpm_list_mtx);
455
456 error = device_resume_noirq(dev, state);
457 if (error) {
458 suspend_stats.failed_resume_noirq++;
459 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
460 dpm_save_failed_dev(dev_name(dev));
461 pm_dev_err(dev, state, " noirq", error);
462 }
463
464 mutex_lock(&dpm_list_mtx);
465 put_device(dev);
466 }
467 mutex_unlock(&dpm_list_mtx);
468 dpm_show_time(starttime, state, "noirq");
469 resume_device_irqs();
470}
471
472/**
473 * device_resume_early - Execute an "early resume" callback for given device.
474 * @dev: Device to handle.
475 * @state: PM transition of the system being carried out.
476 *
477 * Runtime PM is disabled for @dev while this function is being executed.
478 */
479static int device_resume_early(struct device *dev, pm_message_t state)
480{
481 pm_callback_t callback = NULL;
482 char *info = NULL;
483 int error = 0;
484
485 TRACE_DEVICE(dev);
486 TRACE_RESUME(0);
487
488 if (dev->pm_domain) {
489 info = "early power domain ";
490 callback = pm_late_early_op(&dev->pm_domain->ops, state);
491 } else if (dev->type && dev->type->pm) {
492 info = "early type ";
493 callback = pm_late_early_op(dev->type->pm, state);
494 } else if (dev->class && dev->class->pm) {
495 info = "early class ";
496 callback = pm_late_early_op(dev->class->pm, state);
497 } else if (dev->bus && dev->bus->pm) {
498 info = "early bus ";
499 callback = pm_late_early_op(dev->bus->pm, state);
500 }
501
502 if (!callback && dev->driver && dev->driver->pm) {
503 info = "early driver ";
504 callback = pm_late_early_op(dev->driver->pm, state);
505 }
506
507 error = dpm_run_callback(callback, dev, state, info);
508
509 TRACE_RESUME(error);
510 return error;
511}
512
513/**
514 * dpm_resume_early - Execute "early resume" callbacks for all devices.
515 * @state: PM transition of the system being carried out.
516 */
517static void dpm_resume_early(pm_message_t state)
518{
519 ktime_t starttime = ktime_get();
520
521 mutex_lock(&dpm_list_mtx);
522 while (!list_empty(&dpm_late_early_list)) {
523 struct device *dev = to_device(dpm_late_early_list.next);
524 int error;
525
526 get_device(dev);
527 list_move_tail(&dev->power.entry, &dpm_suspended_list);
528 mutex_unlock(&dpm_list_mtx);
529
530 error = device_resume_early(dev, state);
531 if (error) {
532 suspend_stats.failed_resume_early++;
533 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
534 dpm_save_failed_dev(dev_name(dev));
535 pm_dev_err(dev, state, " early", error);
536 }
537
538 mutex_lock(&dpm_list_mtx);
539 put_device(dev);
540 }
541 mutex_unlock(&dpm_list_mtx);
542 dpm_show_time(starttime, state, "early");
543}
544
545/**
546 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
547 * @state: PM transition of the system being carried out.
548 */
549void dpm_resume_start(pm_message_t state)
550{
551 dpm_resume_noirq(state);
552 dpm_resume_early(state);
553}
554EXPORT_SYMBOL_GPL(dpm_resume_start);
555
556/**
557 * device_resume - Execute "resume" callbacks for given device.
558 * @dev: Device to handle.
559 * @state: PM transition of the system being carried out.
560 * @async: If true, the device is being resumed asynchronously.
561 */
562static int device_resume(struct device *dev, pm_message_t state, bool async)
563{
564 pm_callback_t callback = NULL;
565 char *info = NULL;
566 int error = 0;
567 bool put = false;
568
569 TRACE_DEVICE(dev);
570 TRACE_RESUME(0);
571
572 dpm_wait(dev->parent, async);
573 device_lock(dev);
574
575 /*
576 * This is a fib. But we'll allow new children to be added below
577 * a resumed device, even if the device hasn't been completed yet.
578 */
579 dev->power.is_prepared = false;
580
581 if (!dev->power.is_suspended)
582 goto Unlock;
583
584 pm_runtime_enable(dev);
585 put = true;
586
587 if (dev->pm_domain) {
588 info = "power domain ";
589 callback = pm_op(&dev->pm_domain->ops, state);
590 goto Driver;
591 }
592
593 if (dev->type && dev->type->pm) {
594 info = "type ";
595 callback = pm_op(dev->type->pm, state);
596 goto Driver;
597 }
598
599 if (dev->class) {
600 if (dev->class->pm) {
601 info = "class ";
602 callback = pm_op(dev->class->pm, state);
603 goto Driver;
604 } else if (dev->class->resume) {
605 info = "legacy class ";
606 callback = dev->class->resume;
607 goto End;
608 }
609 }
610
611 if (dev->bus) {
612 if (dev->bus->pm) {
613 info = "bus ";
614 callback = pm_op(dev->bus->pm, state);
615 } else if (dev->bus->resume) {
616 info = "legacy bus ";
617 callback = dev->bus->resume;
618 goto End;
619 }
620 }
621
622 Driver:
623 if (!callback && dev->driver && dev->driver->pm) {
624 info = "driver ";
625 callback = pm_op(dev->driver->pm, state);
626 }
627
628 End:
629 error = dpm_run_callback(callback, dev, state, info);
630 dev->power.is_suspended = false;
631
632 Unlock:
633 device_unlock(dev);
634 complete_all(&dev->power.completion);
635
636 TRACE_RESUME(error);
637
638 if (put)
639 pm_runtime_put_sync(dev);
640
641 return error;
642}
643
644static void async_resume(void *data, async_cookie_t cookie)
645{
646 struct device *dev = (struct device *)data;
647 int error;
648
649 error = device_resume(dev, pm_transition, true);
650 if (error)
651 pm_dev_err(dev, pm_transition, " async", error);
652 put_device(dev);
653}
654
655static bool is_async(struct device *dev)
656{
657 return dev->power.async_suspend && pm_async_enabled
658 && !pm_trace_is_enabled();
659}
660
661/**
662 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
663 * @state: PM transition of the system being carried out.
664 *
665 * Execute the appropriate "resume" callback for all devices whose status
666 * indicates that they are suspended.
667 */
668void dpm_resume(pm_message_t state)
669{
670 struct device *dev;
671 ktime_t starttime = ktime_get();
672
673 might_sleep();
674
675 mutex_lock(&dpm_list_mtx);
676 pm_transition = state;
677 async_error = 0;
678
679 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
680 INIT_COMPLETION(dev->power.completion);
681 if (is_async(dev)) {
682 get_device(dev);
683 async_schedule(async_resume, dev);
684 }
685 }
686
687 while (!list_empty(&dpm_suspended_list)) {
688 dev = to_device(dpm_suspended_list.next);
689 get_device(dev);
690 if (!is_async(dev)) {
691 int error;
692
693 mutex_unlock(&dpm_list_mtx);
694
695 error = device_resume(dev, state, false);
696 if (error) {
697 suspend_stats.failed_resume++;
698 dpm_save_failed_step(SUSPEND_RESUME);
699 dpm_save_failed_dev(dev_name(dev));
700 pm_dev_err(dev, state, "", error);
701 }
702
703 mutex_lock(&dpm_list_mtx);
704 }
705 if (!list_empty(&dev->power.entry))
706 list_move_tail(&dev->power.entry, &dpm_prepared_list);
707 put_device(dev);
708 }
709 mutex_unlock(&dpm_list_mtx);
710 async_synchronize_full();
711 dpm_show_time(starttime, state, NULL);
712}
713
714/**
715 * device_complete - Complete a PM transition for given device.
716 * @dev: Device to handle.
717 * @state: PM transition of the system being carried out.
718 */
719static void device_complete(struct device *dev, pm_message_t state)
720{
721 void (*callback)(struct device *) = NULL;
722 char *info = NULL;
723
724 device_lock(dev);
725
726 if (dev->pm_domain) {
727 info = "completing power domain ";
728 callback = dev->pm_domain->ops.complete;
729 } else if (dev->type && dev->type->pm) {
730 info = "completing type ";
731 callback = dev->type->pm->complete;
732 } else if (dev->class && dev->class->pm) {
733 info = "completing class ";
734 callback = dev->class->pm->complete;
735 } else if (dev->bus && dev->bus->pm) {
736 info = "completing bus ";
737 callback = dev->bus->pm->complete;
738 }
739
740 if (!callback && dev->driver && dev->driver->pm) {
741 info = "completing driver ";
742 callback = dev->driver->pm->complete;
743 }
744
745 if (callback) {
746 pm_dev_dbg(dev, state, info);
747 callback(dev);
748 }
749
750 device_unlock(dev);
751}
752
753/**
754 * dpm_complete - Complete a PM transition for all non-sysdev devices.
755 * @state: PM transition of the system being carried out.
756 *
757 * Execute the ->complete() callbacks for all devices whose PM status is not
758 * DPM_ON (this allows new devices to be registered).
759 */
760void dpm_complete(pm_message_t state)
761{
762 struct list_head list;
763
764 might_sleep();
765
766 INIT_LIST_HEAD(&list);
767 mutex_lock(&dpm_list_mtx);
768 while (!list_empty(&dpm_prepared_list)) {
769 struct device *dev = to_device(dpm_prepared_list.prev);
770
771 get_device(dev);
772 dev->power.is_prepared = false;
773 list_move(&dev->power.entry, &list);
774 mutex_unlock(&dpm_list_mtx);
775
776 device_complete(dev, state);
777
778 mutex_lock(&dpm_list_mtx);
779 put_device(dev);
780 }
781 list_splice(&list, &dpm_list);
782 mutex_unlock(&dpm_list_mtx);
783}
784
785/**
786 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
787 * @state: PM transition of the system being carried out.
788 *
789 * Execute "resume" callbacks for all devices and complete the PM transition of
790 * the system.
791 */
792void dpm_resume_end(pm_message_t state)
793{
794 dpm_resume(state);
795 dpm_complete(state);
796}
797EXPORT_SYMBOL_GPL(dpm_resume_end);
798
799
800/*------------------------- Suspend routines -------------------------*/
801
802/**
803 * resume_event - Return a "resume" message for given "suspend" sleep state.
804 * @sleep_state: PM message representing a sleep state.
805 *
806 * Return a PM message representing the resume event corresponding to given
807 * sleep state.
808 */
809static pm_message_t resume_event(pm_message_t sleep_state)
810{
811 switch (sleep_state.event) {
812 case PM_EVENT_SUSPEND:
813 return PMSG_RESUME;
814 case PM_EVENT_FREEZE:
815 case PM_EVENT_QUIESCE:
816 return PMSG_RECOVER;
817 case PM_EVENT_HIBERNATE:
818 return PMSG_RESTORE;
819 }
820 return PMSG_ON;
821}
822
823/**
824 * device_suspend_noirq - Execute a "late suspend" callback for given device.
825 * @dev: Device to handle.
826 * @state: PM transition of the system being carried out.
827 *
828 * The driver of @dev will not receive interrupts while this function is being
829 * executed.
830 */
831static int device_suspend_noirq(struct device *dev, pm_message_t state)
832{
833 pm_callback_t callback = NULL;
834 char *info = NULL;
835
836 if (dev->pm_domain) {
837 info = "noirq power domain ";
838 callback = pm_noirq_op(&dev->pm_domain->ops, state);
839 } else if (dev->type && dev->type->pm) {
840 info = "noirq type ";
841 callback = pm_noirq_op(dev->type->pm, state);
842 } else if (dev->class && dev->class->pm) {
843 info = "noirq class ";
844 callback = pm_noirq_op(dev->class->pm, state);
845 } else if (dev->bus && dev->bus->pm) {
846 info = "noirq bus ";
847 callback = pm_noirq_op(dev->bus->pm, state);
848 }
849
850 if (!callback && dev->driver && dev->driver->pm) {
851 info = "noirq driver ";
852 callback = pm_noirq_op(dev->driver->pm, state);
853 }
854
855 return dpm_run_callback(callback, dev, state, info);
856}
857
858/**
859 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
860 * @state: PM transition of the system being carried out.
861 *
862 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
863 * handlers for all non-sysdev devices.
864 */
865static int dpm_suspend_noirq(pm_message_t state)
866{
867 ktime_t starttime = ktime_get();
868 int error = 0;
869
870 suspend_device_irqs();
871 mutex_lock(&dpm_list_mtx);
872 while (!list_empty(&dpm_late_early_list)) {
873 struct device *dev = to_device(dpm_late_early_list.prev);
874
875 get_device(dev);
876 mutex_unlock(&dpm_list_mtx);
877
878 error = device_suspend_noirq(dev, state);
879
880 mutex_lock(&dpm_list_mtx);
881 if (error) {
882 pm_dev_err(dev, state, " noirq", error);
883 suspend_stats.failed_suspend_noirq++;
884 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
885 dpm_save_failed_dev(dev_name(dev));
886 put_device(dev);
887 break;
888 }
889 if (!list_empty(&dev->power.entry))
890 list_move(&dev->power.entry, &dpm_noirq_list);
891 put_device(dev);
892
893 if (pm_wakeup_pending()) {
894 error = -EBUSY;
895 break;
896 }
897 }
898 mutex_unlock(&dpm_list_mtx);
899 if (error)
900 dpm_resume_noirq(resume_event(state));
901 else
902 dpm_show_time(starttime, state, "noirq");
903 return error;
904}
905
906/**
907 * device_suspend_late - Execute a "late suspend" callback for given device.
908 * @dev: Device to handle.
909 * @state: PM transition of the system being carried out.
910 *
911 * Runtime PM is disabled for @dev while this function is being executed.
912 */
913static int device_suspend_late(struct device *dev, pm_message_t state)
914{
915 pm_callback_t callback = NULL;
916 char *info = NULL;
917
918 if (dev->pm_domain) {
919 info = "late power domain ";
920 callback = pm_late_early_op(&dev->pm_domain->ops, state);
921 } else if (dev->type && dev->type->pm) {
922 info = "late type ";
923 callback = pm_late_early_op(dev->type->pm, state);
924 } else if (dev->class && dev->class->pm) {
925 info = "late class ";
926 callback = pm_late_early_op(dev->class->pm, state);
927 } else if (dev->bus && dev->bus->pm) {
928 info = "late bus ";
929 callback = pm_late_early_op(dev->bus->pm, state);
930 }
931
932 if (!callback && dev->driver && dev->driver->pm) {
933 info = "late driver ";
934 callback = pm_late_early_op(dev->driver->pm, state);
935 }
936
937 return dpm_run_callback(callback, dev, state, info);
938}
939
940/**
941 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
942 * @state: PM transition of the system being carried out.
943 */
944static int dpm_suspend_late(pm_message_t state)
945{
946 ktime_t starttime = ktime_get();
947 int error = 0;
948
949 mutex_lock(&dpm_list_mtx);
950 while (!list_empty(&dpm_suspended_list)) {
951 struct device *dev = to_device(dpm_suspended_list.prev);
952
953 get_device(dev);
954 mutex_unlock(&dpm_list_mtx);
955
956 error = device_suspend_late(dev, state);
957
958 mutex_lock(&dpm_list_mtx);
959 if (error) {
960 pm_dev_err(dev, state, " late", error);
961 suspend_stats.failed_suspend_late++;
962 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
963 dpm_save_failed_dev(dev_name(dev));
964 put_device(dev);
965 break;
966 }
967 if (!list_empty(&dev->power.entry))
968 list_move(&dev->power.entry, &dpm_late_early_list);
969 put_device(dev);
970
971 if (pm_wakeup_pending()) {
972 error = -EBUSY;
973 break;
974 }
975 }
976 mutex_unlock(&dpm_list_mtx);
977 if (error)
978 dpm_resume_early(resume_event(state));
979 else
980 dpm_show_time(starttime, state, "late");
981
982 return error;
983}
984
985/**
986 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
987 * @state: PM transition of the system being carried out.
988 */
989int dpm_suspend_end(pm_message_t state)
990{
991 int error = dpm_suspend_late(state);
992 if (error)
993 return error;
994
995 error = dpm_suspend_noirq(state);
996 if (error) {
997 dpm_resume_early(state);
998 return error;
999 }
1000
1001 return 0;
1002}
1003EXPORT_SYMBOL_GPL(dpm_suspend_end);
1004
1005/**
1006 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1007 * @dev: Device to suspend.
1008 * @state: PM transition of the system being carried out.
1009 * @cb: Suspend callback to execute.
1010 */
1011static int legacy_suspend(struct device *dev, pm_message_t state,
1012 int (*cb)(struct device *dev, pm_message_t state))
1013{
1014 int error;
1015 ktime_t calltime;
1016
1017 calltime = initcall_debug_start(dev);
1018
1019 error = cb(dev, state);
1020 suspend_report_result(cb, error);
1021
1022 initcall_debug_report(dev, calltime, error);
1023
1024 return error;
1025}
1026
1027/**
1028 * device_suspend - Execute "suspend" callbacks for given device.
1029 * @dev: Device to handle.
1030 * @state: PM transition of the system being carried out.
1031 * @async: If true, the device is being suspended asynchronously.
1032 */
1033static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1034{
1035 pm_callback_t callback = NULL;
1036 char *info = NULL;
1037 int error = 0;
1038
1039 dpm_wait_for_children(dev, async);
1040
1041 if (async_error)
1042 goto Complete;
1043
1044 pm_runtime_get_noresume(dev);
1045 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1046 pm_wakeup_event(dev, 0);
1047
1048 if (pm_wakeup_pending()) {
1049 pm_runtime_put_sync(dev);
1050 async_error = -EBUSY;
1051 goto Complete;
1052 }
1053
1054 device_lock(dev);
1055
1056 if (dev->pm_domain) {
1057 info = "power domain ";
1058 callback = pm_op(&dev->pm_domain->ops, state);
1059 goto Run;
1060 }
1061
1062 if (dev->type && dev->type->pm) {
1063 info = "type ";
1064 callback = pm_op(dev->type->pm, state);
1065 goto Run;
1066 }
1067
1068 if (dev->class) {
1069 if (dev->class->pm) {
1070 info = "class ";
1071 callback = pm_op(dev->class->pm, state);
1072 goto Run;
1073 } else if (dev->class->suspend) {
1074 pm_dev_dbg(dev, state, "legacy class ");
1075 error = legacy_suspend(dev, state, dev->class->suspend);
1076 goto End;
1077 }
1078 }
1079
1080 if (dev->bus) {
1081 if (dev->bus->pm) {
1082 info = "bus ";
1083 callback = pm_op(dev->bus->pm, state);
1084 } else if (dev->bus->suspend) {
1085 pm_dev_dbg(dev, state, "legacy bus ");
1086 error = legacy_suspend(dev, state, dev->bus->suspend);
1087 goto End;
1088 }
1089 }
1090
1091 Run:
1092 if (!callback && dev->driver && dev->driver->pm) {
1093 info = "driver ";
1094 callback = pm_op(dev->driver->pm, state);
1095 }
1096
1097 error = dpm_run_callback(callback, dev, state, info);
1098
1099 End:
1100 if (!error) {
1101 dev->power.is_suspended = true;
1102 if (dev->power.wakeup_path
1103 && dev->parent && !dev->parent->power.ignore_children)
1104 dev->parent->power.wakeup_path = true;
1105 }
1106
1107 device_unlock(dev);
1108
1109 Complete:
1110 complete_all(&dev->power.completion);
1111
1112 if (error) {
1113 pm_runtime_put_sync(dev);
1114 async_error = error;
1115 } else if (dev->power.is_suspended) {
1116 __pm_runtime_disable(dev, false);
1117 }
1118
1119 return error;
1120}
1121
1122static void async_suspend(void *data, async_cookie_t cookie)
1123{
1124 struct device *dev = (struct device *)data;
1125 int error;
1126
1127 error = __device_suspend(dev, pm_transition, true);
1128 if (error) {
1129 dpm_save_failed_dev(dev_name(dev));
1130 pm_dev_err(dev, pm_transition, " async", error);
1131 }
1132
1133 put_device(dev);
1134}
1135
1136static int device_suspend(struct device *dev)
1137{
1138 INIT_COMPLETION(dev->power.completion);
1139
1140 if (pm_async_enabled && dev->power.async_suspend) {
1141 get_device(dev);
1142 async_schedule(async_suspend, dev);
1143 return 0;
1144 }
1145
1146 return __device_suspend(dev, pm_transition, false);
1147}
1148
1149/**
1150 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1151 * @state: PM transition of the system being carried out.
1152 */
1153int dpm_suspend(pm_message_t state)
1154{
1155 ktime_t starttime = ktime_get();
1156 int error = 0;
1157
1158 might_sleep();
1159
1160 mutex_lock(&dpm_list_mtx);
1161 pm_transition = state;
1162 async_error = 0;
1163 while (!list_empty(&dpm_prepared_list)) {
1164 struct device *dev = to_device(dpm_prepared_list.prev);
1165
1166 get_device(dev);
1167 mutex_unlock(&dpm_list_mtx);
1168
1169 error = device_suspend(dev);
1170
1171 mutex_lock(&dpm_list_mtx);
1172 if (error) {
1173 pm_dev_err(dev, state, "", error);
1174 dpm_save_failed_dev(dev_name(dev));
1175 put_device(dev);
1176 break;
1177 }
1178 if (!list_empty(&dev->power.entry))
1179 list_move(&dev->power.entry, &dpm_suspended_list);
1180 put_device(dev);
1181 if (async_error)
1182 break;
1183 }
1184 mutex_unlock(&dpm_list_mtx);
1185 async_synchronize_full();
1186 if (!error)
1187 error = async_error;
1188 if (error) {
1189 suspend_stats.failed_suspend++;
1190 dpm_save_failed_step(SUSPEND_SUSPEND);
1191 } else
1192 dpm_show_time(starttime, state, NULL);
1193 return error;
1194}
1195
1196/**
1197 * device_prepare - Prepare a device for system power transition.
1198 * @dev: Device to handle.
1199 * @state: PM transition of the system being carried out.
1200 *
1201 * Execute the ->prepare() callback(s) for given device. No new children of the
1202 * device may be registered after this function has returned.
1203 */
1204static int device_prepare(struct device *dev, pm_message_t state)
1205{
1206 int (*callback)(struct device *) = NULL;
1207 char *info = NULL;
1208 int error = 0;
1209
1210 device_lock(dev);
1211
1212 dev->power.wakeup_path = device_may_wakeup(dev);
1213
1214 if (dev->pm_domain) {
1215 info = "preparing power domain ";
1216 callback = dev->pm_domain->ops.prepare;
1217 } else if (dev->type && dev->type->pm) {
1218 info = "preparing type ";
1219 callback = dev->type->pm->prepare;
1220 } else if (dev->class && dev->class->pm) {
1221 info = "preparing class ";
1222 callback = dev->class->pm->prepare;
1223 } else if (dev->bus && dev->bus->pm) {
1224 info = "preparing bus ";
1225 callback = dev->bus->pm->prepare;
1226 }
1227
1228 if (!callback && dev->driver && dev->driver->pm) {
1229 info = "preparing driver ";
1230 callback = dev->driver->pm->prepare;
1231 }
1232
1233 if (callback) {
1234 error = callback(dev);
1235 suspend_report_result(callback, error);
1236 }
1237
1238 device_unlock(dev);
1239
1240 return error;
1241}
1242
1243/**
1244 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1245 * @state: PM transition of the system being carried out.
1246 *
1247 * Execute the ->prepare() callback(s) for all devices.
1248 */
1249int dpm_prepare(pm_message_t state)
1250{
1251 int error = 0;
1252
1253 might_sleep();
1254
1255 mutex_lock(&dpm_list_mtx);
1256 while (!list_empty(&dpm_list)) {
1257 struct device *dev = to_device(dpm_list.next);
1258
1259 get_device(dev);
1260 mutex_unlock(&dpm_list_mtx);
1261
1262 error = device_prepare(dev, state);
1263
1264 mutex_lock(&dpm_list_mtx);
1265 if (error) {
1266 if (error == -EAGAIN) {
1267 put_device(dev);
1268 error = 0;
1269 continue;
1270 }
1271 printk(KERN_INFO "PM: Device %s not prepared "
1272 "for power transition: code %d\n",
1273 dev_name(dev), error);
1274 put_device(dev);
1275 break;
1276 }
1277 dev->power.is_prepared = true;
1278 if (!list_empty(&dev->power.entry))
1279 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1280 put_device(dev);
1281 }
1282 mutex_unlock(&dpm_list_mtx);
1283 return error;
1284}
1285
1286/**
1287 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1288 * @state: PM transition of the system being carried out.
1289 *
1290 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1291 * callbacks for them.
1292 */
1293int dpm_suspend_start(pm_message_t state)
1294{
1295 int error;
1296
1297 error = dpm_prepare(state);
1298 if (error) {
1299 suspend_stats.failed_prepare++;
1300 dpm_save_failed_step(SUSPEND_PREPARE);
1301 } else
1302 error = dpm_suspend(state);
1303 return error;
1304}
1305EXPORT_SYMBOL_GPL(dpm_suspend_start);
1306
1307void __suspend_report_result(const char *function, void *fn, int ret)
1308{
1309 if (ret)
1310 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1311}
1312EXPORT_SYMBOL_GPL(__suspend_report_result);
1313
1314/**
1315 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1316 * @dev: Device to wait for.
1317 * @subordinate: Device that needs to wait for @dev.
1318 */
1319int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1320{
1321 dpm_wait(dev, subordinate->power.async_suspend);
1322 return async_error;
1323}
1324EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);