2 * drivers/base/power/main.c - Where the driver meets power management.
4 * Copyright (c) 2003 Patrick Mochel
5 * Copyright (c) 2003 Open Source Development Lab
7 * This file is released under the GPLv2
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.
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.
20 #include <linux/device.h>
21 #include <linux/kallsyms.h>
22 #include <linux/export.h>
23 #include <linux/mutex.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 #include <linux/cpuidle.h>
35 typedef int (*pm_callback_t)(struct device *);
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.
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
48 static LIST_HEAD(dpm_prepared_list);
49 static LIST_HEAD(dpm_suspended_list);
50 static LIST_HEAD(dpm_late_early_list);
51 static LIST_HEAD(dpm_noirq_list);
53 struct suspend_stats suspend_stats;
54 static DEFINE_MUTEX(dpm_list_mtx);
55 static pm_message_t pm_transition;
57 static int async_error;
60 * device_pm_sleep_init - Initialize system suspend-related device fields.
61 * @dev: Device object being initialized.
63 void device_pm_sleep_init(struct device *dev)
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 INIT_LIST_HEAD(&dev->power.entry);
74 * device_pm_lock - Lock the list of active devices used by the PM core.
76 void device_pm_lock(void)
78 mutex_lock(&dpm_list_mtx);
82 * device_pm_unlock - Unlock the list of active devices used by the PM core.
84 void device_pm_unlock(void)
86 mutex_unlock(&dpm_list_mtx);
90 * device_pm_add - Add a device to the PM core's list of active devices.
91 * @dev: Device to add to the list.
93 void device_pm_add(struct device *dev)
95 pr_debug("PM: Adding info for %s:%s\n",
96 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
97 mutex_lock(&dpm_list_mtx);
98 if (dev->parent && dev->parent->power.is_prepared)
99 dev_warn(dev, "parent %s should not be sleeping\n",
100 dev_name(dev->parent));
101 list_add_tail(&dev->power.entry, &dpm_list);
102 mutex_unlock(&dpm_list_mtx);
106 * device_pm_remove - Remove a device from the PM core's list of active devices.
107 * @dev: Device to be removed from the list.
109 void device_pm_remove(struct device *dev)
111 pr_debug("PM: Removing info for %s:%s\n",
112 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
113 complete_all(&dev->power.completion);
114 mutex_lock(&dpm_list_mtx);
115 list_del_init(&dev->power.entry);
116 mutex_unlock(&dpm_list_mtx);
117 device_wakeup_disable(dev);
118 pm_runtime_remove(dev);
122 * device_pm_move_before - Move device in the PM core's list of active devices.
123 * @deva: Device to move in dpm_list.
124 * @devb: Device @deva should come before.
126 void device_pm_move_before(struct device *deva, struct device *devb)
128 pr_debug("PM: Moving %s:%s before %s:%s\n",
129 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
130 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
131 /* Delete deva from dpm_list and reinsert before devb. */
132 list_move_tail(&deva->power.entry, &devb->power.entry);
136 * device_pm_move_after - Move device in the PM core's list of active devices.
137 * @deva: Device to move in dpm_list.
138 * @devb: Device @deva should come after.
140 void device_pm_move_after(struct device *deva, struct device *devb)
142 pr_debug("PM: Moving %s:%s after %s:%s\n",
143 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
144 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
145 /* Delete deva from dpm_list and reinsert after devb. */
146 list_move(&deva->power.entry, &devb->power.entry);
150 * device_pm_move_last - Move device to end of the PM core's list of devices.
151 * @dev: Device to move in dpm_list.
153 void device_pm_move_last(struct device *dev)
155 pr_debug("PM: Moving %s:%s to end of list\n",
156 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
157 list_move_tail(&dev->power.entry, &dpm_list);
160 static ktime_t initcall_debug_start(struct device *dev)
162 ktime_t calltime = ktime_set(0, 0);
164 if (pm_print_times_enabled) {
165 pr_info("calling %s+ @ %i, parent: %s\n",
166 dev_name(dev), task_pid_nr(current),
167 dev->parent ? dev_name(dev->parent) : "none");
168 calltime = ktime_get();
174 static void initcall_debug_report(struct device *dev, ktime_t calltime,
177 ktime_t delta, rettime;
179 if (pm_print_times_enabled) {
180 rettime = ktime_get();
181 delta = ktime_sub(rettime, calltime);
182 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
183 error, (unsigned long long)ktime_to_ns(delta) >> 10);
188 * dpm_wait - Wait for a PM operation to complete.
189 * @dev: Device to wait for.
190 * @async: If unset, wait only if the device's power.async_suspend flag is set.
192 static void dpm_wait(struct device *dev, bool async)
197 if (async || (pm_async_enabled && dev->power.async_suspend))
198 wait_for_completion(&dev->power.completion);
201 static int dpm_wait_fn(struct device *dev, void *async_ptr)
203 dpm_wait(dev, *((bool *)async_ptr));
207 static void dpm_wait_for_children(struct device *dev, bool async)
209 device_for_each_child(dev, &async, dpm_wait_fn);
213 * pm_op - Return the PM operation appropriate for given PM event.
214 * @ops: PM operations to choose from.
215 * @state: PM transition of the system being carried out.
217 static pm_callback_t pm_op(const struct dev_pm_ops *ops, pm_message_t state)
219 switch (state.event) {
220 #ifdef CONFIG_SUSPEND
221 case PM_EVENT_SUSPEND:
223 case PM_EVENT_RESUME:
225 #endif /* CONFIG_SUSPEND */
226 #ifdef CONFIG_HIBERNATE_CALLBACKS
227 case PM_EVENT_FREEZE:
228 case PM_EVENT_QUIESCE:
230 case PM_EVENT_HIBERNATE:
231 return ops->poweroff;
233 case PM_EVENT_RECOVER:
236 case PM_EVENT_RESTORE:
238 #endif /* CONFIG_HIBERNATE_CALLBACKS */
245 * pm_late_early_op - Return the PM operation appropriate for given PM event.
246 * @ops: PM operations to choose from.
247 * @state: PM transition of the system being carried out.
249 * Runtime PM is disabled for @dev while this function is being executed.
251 static pm_callback_t pm_late_early_op(const struct dev_pm_ops *ops,
254 switch (state.event) {
255 #ifdef CONFIG_SUSPEND
256 case PM_EVENT_SUSPEND:
257 return ops->suspend_late;
258 case PM_EVENT_RESUME:
259 return ops->resume_early;
260 #endif /* CONFIG_SUSPEND */
261 #ifdef CONFIG_HIBERNATE_CALLBACKS
262 case PM_EVENT_FREEZE:
263 case PM_EVENT_QUIESCE:
264 return ops->freeze_late;
265 case PM_EVENT_HIBERNATE:
266 return ops->poweroff_late;
268 case PM_EVENT_RECOVER:
269 return ops->thaw_early;
270 case PM_EVENT_RESTORE:
271 return ops->restore_early;
272 #endif /* CONFIG_HIBERNATE_CALLBACKS */
279 * pm_noirq_op - Return the PM operation appropriate for given PM event.
280 * @ops: PM operations to choose from.
281 * @state: PM transition of the system being carried out.
283 * The driver of @dev will not receive interrupts while this function is being
286 static pm_callback_t pm_noirq_op(const struct dev_pm_ops *ops, pm_message_t state)
288 switch (state.event) {
289 #ifdef CONFIG_SUSPEND
290 case PM_EVENT_SUSPEND:
291 return ops->suspend_noirq;
292 case PM_EVENT_RESUME:
293 return ops->resume_noirq;
294 #endif /* CONFIG_SUSPEND */
295 #ifdef CONFIG_HIBERNATE_CALLBACKS
296 case PM_EVENT_FREEZE:
297 case PM_EVENT_QUIESCE:
298 return ops->freeze_noirq;
299 case PM_EVENT_HIBERNATE:
300 return ops->poweroff_noirq;
302 case PM_EVENT_RECOVER:
303 return ops->thaw_noirq;
304 case PM_EVENT_RESTORE:
305 return ops->restore_noirq;
306 #endif /* CONFIG_HIBERNATE_CALLBACKS */
312 static char *pm_verb(int event)
315 case PM_EVENT_SUSPEND:
317 case PM_EVENT_RESUME:
319 case PM_EVENT_FREEZE:
321 case PM_EVENT_QUIESCE:
323 case PM_EVENT_HIBERNATE:
327 case PM_EVENT_RESTORE:
329 case PM_EVENT_RECOVER:
332 return "(unknown PM event)";
336 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
338 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
339 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
340 ", may wakeup" : "");
343 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
346 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
347 dev_name(dev), pm_verb(state.event), info, error);
350 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
356 calltime = ktime_get();
357 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
358 do_div(usecs64, NSEC_PER_USEC);
362 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
363 info ?: "", info ? " " : "", pm_verb(state.event),
364 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
367 static int dpm_run_callback(pm_callback_t cb, struct device *dev,
368 pm_message_t state, char *info)
376 calltime = initcall_debug_start(dev);
378 pm_dev_dbg(dev, state, info);
380 suspend_report_result(cb, error);
382 initcall_debug_report(dev, calltime, error);
387 /*------------------------- Resume routines -------------------------*/
390 * device_resume_noirq - Execute an "early resume" callback for given device.
391 * @dev: Device to handle.
392 * @state: PM transition of the system being carried out.
394 * The driver of @dev will not receive interrupts while this function is being
397 static int device_resume_noirq(struct device *dev, pm_message_t state)
399 pm_callback_t callback = NULL;
406 if (dev->power.syscore)
409 if (dev->pm_domain) {
410 info = "noirq power domain ";
411 callback = pm_noirq_op(&dev->pm_domain->ops, state);
412 } else if (dev->type && dev->type->pm) {
413 info = "noirq type ";
414 callback = pm_noirq_op(dev->type->pm, state);
415 } else if (dev->class && dev->class->pm) {
416 info = "noirq class ";
417 callback = pm_noirq_op(dev->class->pm, state);
418 } else if (dev->bus && dev->bus->pm) {
420 callback = pm_noirq_op(dev->bus->pm, state);
423 if (!callback && dev->driver && dev->driver->pm) {
424 info = "noirq driver ";
425 callback = pm_noirq_op(dev->driver->pm, state);
428 error = dpm_run_callback(callback, dev, state, info);
436 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.
437 * @state: PM transition of the system being carried out.
439 * Call the "noirq" resume handlers for all devices in dpm_noirq_list and
440 * enable device drivers to receive interrupts.
442 static void dpm_resume_noirq(pm_message_t state)
444 ktime_t starttime = ktime_get();
446 mutex_lock(&dpm_list_mtx);
447 while (!list_empty(&dpm_noirq_list)) {
448 struct device *dev = to_device(dpm_noirq_list.next);
452 list_move_tail(&dev->power.entry, &dpm_late_early_list);
453 mutex_unlock(&dpm_list_mtx);
455 error = device_resume_noirq(dev, state);
457 suspend_stats.failed_resume_noirq++;
458 dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);
459 dpm_save_failed_dev(dev_name(dev));
460 pm_dev_err(dev, state, " noirq", error);
463 mutex_lock(&dpm_list_mtx);
466 mutex_unlock(&dpm_list_mtx);
467 dpm_show_time(starttime, state, "noirq");
468 resume_device_irqs();
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.
477 * Runtime PM is disabled for @dev while this function is being executed.
479 static int device_resume_early(struct device *dev, pm_message_t state)
481 pm_callback_t callback = NULL;
488 if (dev->power.syscore)
491 if (dev->pm_domain) {
492 info = "early power domain ";
493 callback = pm_late_early_op(&dev->pm_domain->ops, state);
494 } else if (dev->type && dev->type->pm) {
495 info = "early type ";
496 callback = pm_late_early_op(dev->type->pm, state);
497 } else if (dev->class && dev->class->pm) {
498 info = "early class ";
499 callback = pm_late_early_op(dev->class->pm, state);
500 } else if (dev->bus && dev->bus->pm) {
502 callback = pm_late_early_op(dev->bus->pm, state);
505 if (!callback && dev->driver && dev->driver->pm) {
506 info = "early driver ";
507 callback = pm_late_early_op(dev->driver->pm, state);
510 error = dpm_run_callback(callback, dev, state, info);
515 pm_runtime_enable(dev);
520 * dpm_resume_early - Execute "early resume" callbacks for all devices.
521 * @state: PM transition of the system being carried out.
523 static void dpm_resume_early(pm_message_t state)
525 ktime_t starttime = ktime_get();
527 mutex_lock(&dpm_list_mtx);
528 while (!list_empty(&dpm_late_early_list)) {
529 struct device *dev = to_device(dpm_late_early_list.next);
533 list_move_tail(&dev->power.entry, &dpm_suspended_list);
534 mutex_unlock(&dpm_list_mtx);
536 error = device_resume_early(dev, state);
538 suspend_stats.failed_resume_early++;
539 dpm_save_failed_step(SUSPEND_RESUME_EARLY);
540 dpm_save_failed_dev(dev_name(dev));
541 pm_dev_err(dev, state, " early", error);
544 mutex_lock(&dpm_list_mtx);
547 mutex_unlock(&dpm_list_mtx);
548 dpm_show_time(starttime, state, "early");
552 * dpm_resume_start - Execute "noirq" and "early" device callbacks.
553 * @state: PM transition of the system being carried out.
555 void dpm_resume_start(pm_message_t state)
557 dpm_resume_noirq(state);
558 dpm_resume_early(state);
560 EXPORT_SYMBOL_GPL(dpm_resume_start);
563 * device_resume - Execute "resume" callbacks for given device.
564 * @dev: Device to handle.
565 * @state: PM transition of the system being carried out.
566 * @async: If true, the device is being resumed asynchronously.
568 static int device_resume(struct device *dev, pm_message_t state, bool async)
570 pm_callback_t callback = NULL;
577 if (dev->power.syscore)
580 dpm_wait(dev->parent, async);
584 * This is a fib. But we'll allow new children to be added below
585 * a resumed device, even if the device hasn't been completed yet.
587 dev->power.is_prepared = false;
589 if (!dev->power.is_suspended)
592 if (dev->pm_domain) {
593 info = "power domain ";
594 callback = pm_op(&dev->pm_domain->ops, state);
598 if (dev->type && dev->type->pm) {
600 callback = pm_op(dev->type->pm, state);
605 if (dev->class->pm) {
607 callback = pm_op(dev->class->pm, state);
609 } else if (dev->class->resume) {
610 info = "legacy class ";
611 callback = dev->class->resume;
619 callback = pm_op(dev->bus->pm, state);
620 } else if (dev->bus->resume) {
621 info = "legacy bus ";
622 callback = dev->bus->resume;
628 if (!callback && dev->driver && dev->driver->pm) {
630 callback = pm_op(dev->driver->pm, state);
634 error = dpm_run_callback(callback, dev, state, info);
635 dev->power.is_suspended = false;
641 complete_all(&dev->power.completion);
648 static void async_resume(void *data, async_cookie_t cookie)
650 struct device *dev = (struct device *)data;
653 error = device_resume(dev, pm_transition, true);
655 pm_dev_err(dev, pm_transition, " async", error);
659 static bool is_async(struct device *dev)
661 return dev->power.async_suspend && pm_async_enabled
662 && !pm_trace_is_enabled();
666 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
667 * @state: PM transition of the system being carried out.
669 * Execute the appropriate "resume" callback for all devices whose status
670 * indicates that they are suspended.
672 void dpm_resume(pm_message_t state)
675 ktime_t starttime = ktime_get();
679 mutex_lock(&dpm_list_mtx);
680 pm_transition = state;
683 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
684 INIT_COMPLETION(dev->power.completion);
687 async_schedule(async_resume, dev);
691 while (!list_empty(&dpm_suspended_list)) {
692 dev = to_device(dpm_suspended_list.next);
694 if (!is_async(dev)) {
697 mutex_unlock(&dpm_list_mtx);
699 error = device_resume(dev, state, false);
701 suspend_stats.failed_resume++;
702 dpm_save_failed_step(SUSPEND_RESUME);
703 dpm_save_failed_dev(dev_name(dev));
704 pm_dev_err(dev, state, "", error);
707 mutex_lock(&dpm_list_mtx);
709 if (!list_empty(&dev->power.entry))
710 list_move_tail(&dev->power.entry, &dpm_prepared_list);
713 mutex_unlock(&dpm_list_mtx);
714 async_synchronize_full();
715 dpm_show_time(starttime, state, NULL);
719 * device_complete - Complete a PM transition for given device.
720 * @dev: Device to handle.
721 * @state: PM transition of the system being carried out.
723 static void device_complete(struct device *dev, pm_message_t state)
725 void (*callback)(struct device *) = NULL;
728 if (dev->power.syscore)
733 if (dev->pm_domain) {
734 info = "completing power domain ";
735 callback = dev->pm_domain->ops.complete;
736 } else if (dev->type && dev->type->pm) {
737 info = "completing type ";
738 callback = dev->type->pm->complete;
739 } else if (dev->class && dev->class->pm) {
740 info = "completing class ";
741 callback = dev->class->pm->complete;
742 } else if (dev->bus && dev->bus->pm) {
743 info = "completing bus ";
744 callback = dev->bus->pm->complete;
747 if (!callback && dev->driver && dev->driver->pm) {
748 info = "completing driver ";
749 callback = dev->driver->pm->complete;
753 pm_dev_dbg(dev, state, info);
759 pm_runtime_put_sync(dev);
763 * dpm_complete - Complete a PM transition for all non-sysdev devices.
764 * @state: PM transition of the system being carried out.
766 * Execute the ->complete() callbacks for all devices whose PM status is not
767 * DPM_ON (this allows new devices to be registered).
769 void dpm_complete(pm_message_t state)
771 struct list_head list;
775 INIT_LIST_HEAD(&list);
776 mutex_lock(&dpm_list_mtx);
777 while (!list_empty(&dpm_prepared_list)) {
778 struct device *dev = to_device(dpm_prepared_list.prev);
781 dev->power.is_prepared = false;
782 list_move(&dev->power.entry, &list);
783 mutex_unlock(&dpm_list_mtx);
785 device_complete(dev, state);
787 mutex_lock(&dpm_list_mtx);
790 list_splice(&list, &dpm_list);
791 mutex_unlock(&dpm_list_mtx);
795 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
796 * @state: PM transition of the system being carried out.
798 * Execute "resume" callbacks for all devices and complete the PM transition of
801 void dpm_resume_end(pm_message_t state)
806 EXPORT_SYMBOL_GPL(dpm_resume_end);
809 /*------------------------- Suspend routines -------------------------*/
812 * resume_event - Return a "resume" message for given "suspend" sleep state.
813 * @sleep_state: PM message representing a sleep state.
815 * Return a PM message representing the resume event corresponding to given
818 static pm_message_t resume_event(pm_message_t sleep_state)
820 switch (sleep_state.event) {
821 case PM_EVENT_SUSPEND:
823 case PM_EVENT_FREEZE:
824 case PM_EVENT_QUIESCE:
826 case PM_EVENT_HIBERNATE:
833 * device_suspend_noirq - Execute a "late suspend" callback for given device.
834 * @dev: Device to handle.
835 * @state: PM transition of the system being carried out.
837 * The driver of @dev will not receive interrupts while this function is being
840 static int device_suspend_noirq(struct device *dev, pm_message_t state)
842 pm_callback_t callback = NULL;
845 if (dev->power.syscore)
848 if (dev->pm_domain) {
849 info = "noirq power domain ";
850 callback = pm_noirq_op(&dev->pm_domain->ops, state);
851 } else if (dev->type && dev->type->pm) {
852 info = "noirq type ";
853 callback = pm_noirq_op(dev->type->pm, state);
854 } else if (dev->class && dev->class->pm) {
855 info = "noirq class ";
856 callback = pm_noirq_op(dev->class->pm, state);
857 } else if (dev->bus && dev->bus->pm) {
859 callback = pm_noirq_op(dev->bus->pm, state);
862 if (!callback && dev->driver && dev->driver->pm) {
863 info = "noirq driver ";
864 callback = pm_noirq_op(dev->driver->pm, state);
867 return dpm_run_callback(callback, dev, state, info);
871 * dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
872 * @state: PM transition of the system being carried out.
874 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
875 * handlers for all non-sysdev devices.
877 static int dpm_suspend_noirq(pm_message_t state)
879 ktime_t starttime = ktime_get();
883 suspend_device_irqs();
884 mutex_lock(&dpm_list_mtx);
885 while (!list_empty(&dpm_late_early_list)) {
886 struct device *dev = to_device(dpm_late_early_list.prev);
889 mutex_unlock(&dpm_list_mtx);
891 error = device_suspend_noirq(dev, state);
893 mutex_lock(&dpm_list_mtx);
895 pm_dev_err(dev, state, " noirq", error);
896 suspend_stats.failed_suspend_noirq++;
897 dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
898 dpm_save_failed_dev(dev_name(dev));
902 if (!list_empty(&dev->power.entry))
903 list_move(&dev->power.entry, &dpm_noirq_list);
906 if (pm_wakeup_pending()) {
911 mutex_unlock(&dpm_list_mtx);
913 dpm_resume_noirq(resume_event(state));
915 dpm_show_time(starttime, state, "noirq");
920 * device_suspend_late - Execute a "late suspend" callback for given device.
921 * @dev: Device to handle.
922 * @state: PM transition of the system being carried out.
924 * Runtime PM is disabled for @dev while this function is being executed.
926 static int device_suspend_late(struct device *dev, pm_message_t state)
928 pm_callback_t callback = NULL;
931 __pm_runtime_disable(dev, false);
933 if (dev->power.syscore)
936 if (dev->pm_domain) {
937 info = "late power domain ";
938 callback = pm_late_early_op(&dev->pm_domain->ops, state);
939 } else if (dev->type && dev->type->pm) {
941 callback = pm_late_early_op(dev->type->pm, state);
942 } else if (dev->class && dev->class->pm) {
943 info = "late class ";
944 callback = pm_late_early_op(dev->class->pm, state);
945 } else if (dev->bus && dev->bus->pm) {
947 callback = pm_late_early_op(dev->bus->pm, state);
950 if (!callback && dev->driver && dev->driver->pm) {
951 info = "late driver ";
952 callback = pm_late_early_op(dev->driver->pm, state);
955 return dpm_run_callback(callback, dev, state, info);
959 * dpm_suspend_late - Execute "late suspend" callbacks for all devices.
960 * @state: PM transition of the system being carried out.
962 static int dpm_suspend_late(pm_message_t state)
964 ktime_t starttime = ktime_get();
967 mutex_lock(&dpm_list_mtx);
968 while (!list_empty(&dpm_suspended_list)) {
969 struct device *dev = to_device(dpm_suspended_list.prev);
972 mutex_unlock(&dpm_list_mtx);
974 error = device_suspend_late(dev, state);
976 mutex_lock(&dpm_list_mtx);
978 pm_dev_err(dev, state, " late", error);
979 suspend_stats.failed_suspend_late++;
980 dpm_save_failed_step(SUSPEND_SUSPEND_LATE);
981 dpm_save_failed_dev(dev_name(dev));
985 if (!list_empty(&dev->power.entry))
986 list_move(&dev->power.entry, &dpm_late_early_list);
989 if (pm_wakeup_pending()) {
994 mutex_unlock(&dpm_list_mtx);
996 dpm_resume_early(resume_event(state));
998 dpm_show_time(starttime, state, "late");
1004 * dpm_suspend_end - Execute "late" and "noirq" device suspend callbacks.
1005 * @state: PM transition of the system being carried out.
1007 int dpm_suspend_end(pm_message_t state)
1009 int error = dpm_suspend_late(state);
1013 error = dpm_suspend_noirq(state);
1015 dpm_resume_early(resume_event(state));
1021 EXPORT_SYMBOL_GPL(dpm_suspend_end);
1024 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
1025 * @dev: Device to suspend.
1026 * @state: PM transition of the system being carried out.
1027 * @cb: Suspend callback to execute.
1029 static int legacy_suspend(struct device *dev, pm_message_t state,
1030 int (*cb)(struct device *dev, pm_message_t state))
1035 calltime = initcall_debug_start(dev);
1037 error = cb(dev, state);
1038 suspend_report_result(cb, error);
1040 initcall_debug_report(dev, calltime, error);
1046 * device_suspend - Execute "suspend" callbacks for given device.
1047 * @dev: Device to handle.
1048 * @state: PM transition of the system being carried out.
1049 * @async: If true, the device is being suspended asynchronously.
1051 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
1053 pm_callback_t callback = NULL;
1057 dpm_wait_for_children(dev, async);
1063 * If a device configured to wake up the system from sleep states
1064 * has been suspended at run time and there's a resume request pending
1065 * for it, this is equivalent to the device signaling wakeup, so the
1066 * system suspend operation should be aborted.
1068 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1069 pm_wakeup_event(dev, 0);
1071 if (pm_wakeup_pending()) {
1072 async_error = -EBUSY;
1076 if (dev->power.syscore)
1081 if (dev->pm_domain) {
1082 info = "power domain ";
1083 callback = pm_op(&dev->pm_domain->ops, state);
1087 if (dev->type && dev->type->pm) {
1089 callback = pm_op(dev->type->pm, state);
1094 if (dev->class->pm) {
1096 callback = pm_op(dev->class->pm, state);
1098 } else if (dev->class->suspend) {
1099 pm_dev_dbg(dev, state, "legacy class ");
1100 error = legacy_suspend(dev, state, dev->class->suspend);
1108 callback = pm_op(dev->bus->pm, state);
1109 } else if (dev->bus->suspend) {
1110 pm_dev_dbg(dev, state, "legacy bus ");
1111 error = legacy_suspend(dev, state, dev->bus->suspend);
1117 if (!callback && dev->driver && dev->driver->pm) {
1119 callback = pm_op(dev->driver->pm, state);
1122 error = dpm_run_callback(callback, dev, state, info);
1126 dev->power.is_suspended = true;
1127 if (dev->power.wakeup_path
1128 && dev->parent && !dev->parent->power.ignore_children)
1129 dev->parent->power.wakeup_path = true;
1135 complete_all(&dev->power.completion);
1137 async_error = error;
1142 static void async_suspend(void *data, async_cookie_t cookie)
1144 struct device *dev = (struct device *)data;
1147 error = __device_suspend(dev, pm_transition, true);
1149 dpm_save_failed_dev(dev_name(dev));
1150 pm_dev_err(dev, pm_transition, " async", error);
1156 static int device_suspend(struct device *dev)
1158 INIT_COMPLETION(dev->power.completion);
1160 if (pm_async_enabled && dev->power.async_suspend) {
1162 async_schedule(async_suspend, dev);
1166 return __device_suspend(dev, pm_transition, false);
1170 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
1171 * @state: PM transition of the system being carried out.
1173 int dpm_suspend(pm_message_t state)
1175 ktime_t starttime = ktime_get();
1180 mutex_lock(&dpm_list_mtx);
1181 pm_transition = state;
1183 while (!list_empty(&dpm_prepared_list)) {
1184 struct device *dev = to_device(dpm_prepared_list.prev);
1187 mutex_unlock(&dpm_list_mtx);
1189 error = device_suspend(dev);
1191 mutex_lock(&dpm_list_mtx);
1193 pm_dev_err(dev, state, "", error);
1194 dpm_save_failed_dev(dev_name(dev));
1198 if (!list_empty(&dev->power.entry))
1199 list_move(&dev->power.entry, &dpm_suspended_list);
1204 mutex_unlock(&dpm_list_mtx);
1205 async_synchronize_full();
1207 error = async_error;
1209 suspend_stats.failed_suspend++;
1210 dpm_save_failed_step(SUSPEND_SUSPEND);
1212 dpm_show_time(starttime, state, NULL);
1217 * device_prepare - Prepare a device for system power transition.
1218 * @dev: Device to handle.
1219 * @state: PM transition of the system being carried out.
1221 * Execute the ->prepare() callback(s) for given device. No new children of the
1222 * device may be registered after this function has returned.
1224 static int device_prepare(struct device *dev, pm_message_t state)
1226 int (*callback)(struct device *) = NULL;
1230 if (dev->power.syscore)
1234 * If a device's parent goes into runtime suspend at the wrong time,
1235 * it won't be possible to resume the device. To prevent this we
1236 * block runtime suspend here, during the prepare phase, and allow
1237 * it again during the complete phase.
1239 pm_runtime_get_noresume(dev);
1243 dev->power.wakeup_path = device_may_wakeup(dev);
1245 if (dev->pm_domain) {
1246 info = "preparing power domain ";
1247 callback = dev->pm_domain->ops.prepare;
1248 } else if (dev->type && dev->type->pm) {
1249 info = "preparing type ";
1250 callback = dev->type->pm->prepare;
1251 } else if (dev->class && dev->class->pm) {
1252 info = "preparing class ";
1253 callback = dev->class->pm->prepare;
1254 } else if (dev->bus && dev->bus->pm) {
1255 info = "preparing bus ";
1256 callback = dev->bus->pm->prepare;
1259 if (!callback && dev->driver && dev->driver->pm) {
1260 info = "preparing driver ";
1261 callback = dev->driver->pm->prepare;
1265 error = callback(dev);
1266 suspend_report_result(callback, error);
1275 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1276 * @state: PM transition of the system being carried out.
1278 * Execute the ->prepare() callback(s) for all devices.
1280 int dpm_prepare(pm_message_t state)
1286 mutex_lock(&dpm_list_mtx);
1287 while (!list_empty(&dpm_list)) {
1288 struct device *dev = to_device(dpm_list.next);
1291 mutex_unlock(&dpm_list_mtx);
1293 error = device_prepare(dev, state);
1295 mutex_lock(&dpm_list_mtx);
1297 if (error == -EAGAIN) {
1302 printk(KERN_INFO "PM: Device %s not prepared "
1303 "for power transition: code %d\n",
1304 dev_name(dev), error);
1308 dev->power.is_prepared = true;
1309 if (!list_empty(&dev->power.entry))
1310 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1313 mutex_unlock(&dpm_list_mtx);
1318 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1319 * @state: PM transition of the system being carried out.
1321 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1322 * callbacks for them.
1324 int dpm_suspend_start(pm_message_t state)
1328 error = dpm_prepare(state);
1330 suspend_stats.failed_prepare++;
1331 dpm_save_failed_step(SUSPEND_PREPARE);
1333 error = dpm_suspend(state);
1336 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1338 void __suspend_report_result(const char *function, void *fn, int ret)
1341 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1343 EXPORT_SYMBOL_GPL(__suspend_report_result);
1346 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1347 * @dev: Device to wait for.
1348 * @subordinate: Device that needs to wait for @dev.
1350 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1352 dpm_wait(dev, subordinate->power.async_suspend);
1355 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);
1358 * dpm_for_each_dev - device iterator.
1359 * @data: data for the callback.
1360 * @fn: function to be called for each device.
1362 * Iterate over devices in dpm_list, and call @fn for each device,
1365 void dpm_for_each_dev(void *data, void (*fn)(struct device *, void *))
1373 list_for_each_entry(dev, &dpm_list, power.entry)
1377 EXPORT_SYMBOL_GPL(dpm_for_each_dev);