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/mutex.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>
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.
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
45 LIST_HEAD(dpm_prepared_list);
46 LIST_HEAD(dpm_suspended_list);
47 LIST_HEAD(dpm_noirq_list);
49 static DEFINE_MUTEX(dpm_list_mtx);
50 static pm_message_t pm_transition;
52 static int async_error;
55 * device_pm_init - Initialize the PM-related part of a device object.
56 * @dev: Device object being initialized.
58 void device_pm_init(struct device *dev)
60 dev->power.in_suspend = false;
61 init_completion(&dev->power.completion);
62 complete_all(&dev->power.completion);
63 dev->power.wakeup = NULL;
64 spin_lock_init(&dev->power.lock);
66 INIT_LIST_HEAD(&dev->power.entry);
70 * device_pm_lock - Lock the list of active devices used by the PM core.
72 void device_pm_lock(void)
74 mutex_lock(&dpm_list_mtx);
78 * device_pm_unlock - Unlock the list of active devices used by the PM core.
80 void device_pm_unlock(void)
82 mutex_unlock(&dpm_list_mtx);
86 * device_pm_add - Add a device to the PM core's list of active devices.
87 * @dev: Device to add to the list.
89 void device_pm_add(struct device *dev)
91 pr_debug("PM: Adding info for %s:%s\n",
92 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
93 mutex_lock(&dpm_list_mtx);
94 if (dev->parent && dev->parent->power.in_suspend)
95 dev_warn(dev, "parent %s should not be sleeping\n",
96 dev_name(dev->parent));
97 list_add_tail(&dev->power.entry, &dpm_list);
98 mutex_unlock(&dpm_list_mtx);
102 * device_pm_remove - Remove a device from the PM core's list of active devices.
103 * @dev: Device to be removed from the list.
105 void device_pm_remove(struct device *dev)
107 pr_debug("PM: Removing info for %s:%s\n",
108 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
109 complete_all(&dev->power.completion);
110 mutex_lock(&dpm_list_mtx);
111 list_del_init(&dev->power.entry);
112 mutex_unlock(&dpm_list_mtx);
113 device_wakeup_disable(dev);
114 pm_runtime_remove(dev);
118 * device_pm_move_before - Move device in the PM core's list of active devices.
119 * @deva: Device to move in dpm_list.
120 * @devb: Device @deva should come before.
122 void device_pm_move_before(struct device *deva, struct device *devb)
124 pr_debug("PM: Moving %s:%s before %s:%s\n",
125 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
126 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
127 /* Delete deva from dpm_list and reinsert before devb. */
128 list_move_tail(&deva->power.entry, &devb->power.entry);
132 * device_pm_move_after - Move device in the PM core's list of active devices.
133 * @deva: Device to move in dpm_list.
134 * @devb: Device @deva should come after.
136 void device_pm_move_after(struct device *deva, struct device *devb)
138 pr_debug("PM: Moving %s:%s after %s:%s\n",
139 deva->bus ? deva->bus->name : "No Bus", dev_name(deva),
140 devb->bus ? devb->bus->name : "No Bus", dev_name(devb));
141 /* Delete deva from dpm_list and reinsert after devb. */
142 list_move(&deva->power.entry, &devb->power.entry);
146 * device_pm_move_last - Move device to end of the PM core's list of devices.
147 * @dev: Device to move in dpm_list.
149 void device_pm_move_last(struct device *dev)
151 pr_debug("PM: Moving %s:%s to end of list\n",
152 dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
153 list_move_tail(&dev->power.entry, &dpm_list);
156 static ktime_t initcall_debug_start(struct device *dev)
158 ktime_t calltime = ktime_set(0, 0);
160 if (initcall_debug) {
161 pr_info("calling %s+ @ %i\n",
162 dev_name(dev), task_pid_nr(current));
163 calltime = ktime_get();
169 static void initcall_debug_report(struct device *dev, ktime_t calltime,
172 ktime_t delta, rettime;
174 if (initcall_debug) {
175 rettime = ktime_get();
176 delta = ktime_sub(rettime, calltime);
177 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
178 error, (unsigned long long)ktime_to_ns(delta) >> 10);
183 * dpm_wait - Wait for a PM operation to complete.
184 * @dev: Device to wait for.
185 * @async: If unset, wait only if the device's power.async_suspend flag is set.
187 static void dpm_wait(struct device *dev, bool async)
192 if (async || (pm_async_enabled && dev->power.async_suspend))
193 wait_for_completion(&dev->power.completion);
196 static int dpm_wait_fn(struct device *dev, void *async_ptr)
198 dpm_wait(dev, *((bool *)async_ptr));
202 static void dpm_wait_for_children(struct device *dev, bool async)
204 device_for_each_child(dev, &async, dpm_wait_fn);
208 * pm_op - Execute the PM operation appropriate for given PM event.
209 * @dev: Device to handle.
210 * @ops: PM operations to choose from.
211 * @state: PM transition of the system being carried out.
213 static int pm_op(struct device *dev,
214 const struct dev_pm_ops *ops,
220 calltime = initcall_debug_start(dev);
222 switch (state.event) {
223 #ifdef CONFIG_SUSPEND
224 case PM_EVENT_SUSPEND:
226 error = ops->suspend(dev);
227 suspend_report_result(ops->suspend, error);
230 case PM_EVENT_RESUME:
232 error = ops->resume(dev);
233 suspend_report_result(ops->resume, error);
236 #endif /* CONFIG_SUSPEND */
237 #ifdef CONFIG_HIBERNATE_CALLBACKS
238 case PM_EVENT_FREEZE:
239 case PM_EVENT_QUIESCE:
241 error = ops->freeze(dev);
242 suspend_report_result(ops->freeze, error);
245 case PM_EVENT_HIBERNATE:
247 error = ops->poweroff(dev);
248 suspend_report_result(ops->poweroff, error);
252 case PM_EVENT_RECOVER:
254 error = ops->thaw(dev);
255 suspend_report_result(ops->thaw, error);
258 case PM_EVENT_RESTORE:
260 error = ops->restore(dev);
261 suspend_report_result(ops->restore, error);
264 #endif /* CONFIG_HIBERNATE_CALLBACKS */
269 initcall_debug_report(dev, calltime, error);
275 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
276 * @dev: Device to handle.
277 * @ops: PM operations to choose from.
278 * @state: PM transition of the system being carried out.
280 * The driver of @dev will not receive interrupts while this function is being
283 static int pm_noirq_op(struct device *dev,
284 const struct dev_pm_ops *ops,
288 ktime_t calltime = ktime_set(0, 0), delta, rettime;
290 if (initcall_debug) {
291 pr_info("calling %s+ @ %i, parent: %s\n",
292 dev_name(dev), task_pid_nr(current),
293 dev->parent ? dev_name(dev->parent) : "none");
294 calltime = ktime_get();
297 switch (state.event) {
298 #ifdef CONFIG_SUSPEND
299 case PM_EVENT_SUSPEND:
300 if (ops->suspend_noirq) {
301 error = ops->suspend_noirq(dev);
302 suspend_report_result(ops->suspend_noirq, error);
305 case PM_EVENT_RESUME:
306 if (ops->resume_noirq) {
307 error = ops->resume_noirq(dev);
308 suspend_report_result(ops->resume_noirq, error);
311 #endif /* CONFIG_SUSPEND */
312 #ifdef CONFIG_HIBERNATE_CALLBACKS
313 case PM_EVENT_FREEZE:
314 case PM_EVENT_QUIESCE:
315 if (ops->freeze_noirq) {
316 error = ops->freeze_noirq(dev);
317 suspend_report_result(ops->freeze_noirq, error);
320 case PM_EVENT_HIBERNATE:
321 if (ops->poweroff_noirq) {
322 error = ops->poweroff_noirq(dev);
323 suspend_report_result(ops->poweroff_noirq, error);
327 case PM_EVENT_RECOVER:
328 if (ops->thaw_noirq) {
329 error = ops->thaw_noirq(dev);
330 suspend_report_result(ops->thaw_noirq, error);
333 case PM_EVENT_RESTORE:
334 if (ops->restore_noirq) {
335 error = ops->restore_noirq(dev);
336 suspend_report_result(ops->restore_noirq, error);
339 #endif /* CONFIG_HIBERNATE_CALLBACKS */
344 if (initcall_debug) {
345 rettime = ktime_get();
346 delta = ktime_sub(rettime, calltime);
347 printk("initcall %s_i+ returned %d after %Ld usecs\n",
348 dev_name(dev), error,
349 (unsigned long long)ktime_to_ns(delta) >> 10);
355 static char *pm_verb(int event)
358 case PM_EVENT_SUSPEND:
360 case PM_EVENT_RESUME:
362 case PM_EVENT_FREEZE:
364 case PM_EVENT_QUIESCE:
366 case PM_EVENT_HIBERNATE:
370 case PM_EVENT_RESTORE:
372 case PM_EVENT_RECOVER:
375 return "(unknown PM event)";
379 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
381 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
382 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
383 ", may wakeup" : "");
386 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
389 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
390 dev_name(dev), pm_verb(state.event), info, error);
393 static void dpm_show_time(ktime_t starttime, pm_message_t state, char *info)
399 calltime = ktime_get();
400 usecs64 = ktime_to_ns(ktime_sub(calltime, starttime));
401 do_div(usecs64, NSEC_PER_USEC);
405 pr_info("PM: %s%s%s of devices complete after %ld.%03ld msecs\n",
406 info ?: "", info ? " " : "", pm_verb(state.event),
407 usecs / USEC_PER_MSEC, usecs % USEC_PER_MSEC);
410 /*------------------------- Resume routines -------------------------*/
413 * device_resume_noirq - Execute an "early resume" callback for given device.
414 * @dev: Device to handle.
415 * @state: PM transition of the system being carried out.
417 * The driver of @dev will not receive interrupts while this function is being
420 static int device_resume_noirq(struct device *dev, pm_message_t state)
427 if (dev->pwr_domain) {
428 pm_dev_dbg(dev, state, "EARLY power domain ");
429 pm_noirq_op(dev, &dev->pwr_domain->ops, state);
432 if (dev->type && dev->type->pm) {
433 pm_dev_dbg(dev, state, "EARLY type ");
434 error = pm_noirq_op(dev, dev->type->pm, state);
435 } else if (dev->class && dev->class->pm) {
436 pm_dev_dbg(dev, state, "EARLY class ");
437 error = pm_noirq_op(dev, dev->class->pm, state);
438 } else if (dev->bus && dev->bus->pm) {
439 pm_dev_dbg(dev, state, "EARLY ");
440 error = pm_noirq_op(dev, dev->bus->pm, state);
448 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
449 * @state: PM transition of the system being carried out.
451 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
452 * enable device drivers to receive interrupts.
454 void dpm_resume_noirq(pm_message_t state)
456 ktime_t starttime = ktime_get();
458 mutex_lock(&dpm_list_mtx);
459 while (!list_empty(&dpm_noirq_list)) {
460 struct device *dev = to_device(dpm_noirq_list.next);
464 list_move_tail(&dev->power.entry, &dpm_suspended_list);
465 mutex_unlock(&dpm_list_mtx);
467 error = device_resume_noirq(dev, state);
469 pm_dev_err(dev, state, " early", error);
471 mutex_lock(&dpm_list_mtx);
474 mutex_unlock(&dpm_list_mtx);
475 dpm_show_time(starttime, state, "early");
476 resume_device_irqs();
478 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
481 * legacy_resume - Execute a legacy (bus or class) resume callback for device.
482 * @dev: Device to resume.
483 * @cb: Resume callback to execute.
485 static int legacy_resume(struct device *dev, int (*cb)(struct device *dev))
490 calltime = initcall_debug_start(dev);
493 suspend_report_result(cb, error);
495 initcall_debug_report(dev, calltime, error);
501 * device_resume - Execute "resume" callbacks for given device.
502 * @dev: Device to handle.
503 * @state: PM transition of the system being carried out.
504 * @async: If true, the device is being resumed asynchronously.
506 static int device_resume(struct device *dev, pm_message_t state, bool async)
513 dpm_wait(dev->parent, async);
516 dev->power.in_suspend = false;
518 if (dev->pwr_domain) {
519 pm_dev_dbg(dev, state, "power domain ");
520 pm_op(dev, &dev->pwr_domain->ops, state);
523 if (dev->type && dev->type->pm) {
524 pm_dev_dbg(dev, state, "type ");
525 error = pm_op(dev, dev->type->pm, state);
530 if (dev->class->pm) {
531 pm_dev_dbg(dev, state, "class ");
532 error = pm_op(dev, dev->class->pm, state);
534 } else if (dev->class->resume) {
535 pm_dev_dbg(dev, state, "legacy class ");
536 error = legacy_resume(dev, dev->class->resume);
543 pm_dev_dbg(dev, state, "");
544 error = pm_op(dev, dev->bus->pm, state);
545 } else if (dev->bus->resume) {
546 pm_dev_dbg(dev, state, "legacy ");
547 error = legacy_resume(dev, dev->bus->resume);
553 complete_all(&dev->power.completion);
559 static void async_resume(void *data, async_cookie_t cookie)
561 struct device *dev = (struct device *)data;
564 error = device_resume(dev, pm_transition, true);
566 pm_dev_err(dev, pm_transition, " async", error);
570 static bool is_async(struct device *dev)
572 return dev->power.async_suspend && pm_async_enabled
573 && !pm_trace_is_enabled();
577 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
578 * @state: PM transition of the system being carried out.
580 * Execute the appropriate "resume" callback for all devices whose status
581 * indicates that they are suspended.
583 static void dpm_resume(pm_message_t state)
586 ktime_t starttime = ktime_get();
588 mutex_lock(&dpm_list_mtx);
589 pm_transition = state;
592 list_for_each_entry(dev, &dpm_suspended_list, power.entry) {
593 INIT_COMPLETION(dev->power.completion);
596 async_schedule(async_resume, dev);
600 while (!list_empty(&dpm_suspended_list)) {
601 dev = to_device(dpm_suspended_list.next);
603 if (!is_async(dev)) {
606 mutex_unlock(&dpm_list_mtx);
608 error = device_resume(dev, state, false);
610 pm_dev_err(dev, state, "", error);
612 mutex_lock(&dpm_list_mtx);
614 if (!list_empty(&dev->power.entry))
615 list_move_tail(&dev->power.entry, &dpm_prepared_list);
618 mutex_unlock(&dpm_list_mtx);
619 async_synchronize_full();
620 dpm_show_time(starttime, state, NULL);
624 * device_complete - Complete a PM transition for given device.
625 * @dev: Device to handle.
626 * @state: PM transition of the system being carried out.
628 static void device_complete(struct device *dev, pm_message_t state)
632 if (dev->pwr_domain && dev->pwr_domain->ops.complete) {
633 pm_dev_dbg(dev, state, "completing power domain ");
634 dev->pwr_domain->ops.complete(dev);
637 if (dev->type && dev->type->pm) {
638 pm_dev_dbg(dev, state, "completing type ");
639 if (dev->type->pm->complete)
640 dev->type->pm->complete(dev);
641 } else if (dev->class && dev->class->pm) {
642 pm_dev_dbg(dev, state, "completing class ");
643 if (dev->class->pm->complete)
644 dev->class->pm->complete(dev);
645 } else if (dev->bus && dev->bus->pm) {
646 pm_dev_dbg(dev, state, "completing ");
647 if (dev->bus->pm->complete)
648 dev->bus->pm->complete(dev);
655 * dpm_complete - Complete a PM transition for all non-sysdev devices.
656 * @state: PM transition of the system being carried out.
658 * Execute the ->complete() callbacks for all devices whose PM status is not
659 * DPM_ON (this allows new devices to be registered).
661 static void dpm_complete(pm_message_t state)
663 struct list_head list;
665 INIT_LIST_HEAD(&list);
666 mutex_lock(&dpm_list_mtx);
667 while (!list_empty(&dpm_prepared_list)) {
668 struct device *dev = to_device(dpm_prepared_list.prev);
671 dev->power.in_suspend = false;
672 list_move(&dev->power.entry, &list);
673 mutex_unlock(&dpm_list_mtx);
675 device_complete(dev, state);
677 mutex_lock(&dpm_list_mtx);
680 list_splice(&list, &dpm_list);
681 mutex_unlock(&dpm_list_mtx);
685 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
686 * @state: PM transition of the system being carried out.
688 * Execute "resume" callbacks for all devices and complete the PM transition of
691 void dpm_resume_end(pm_message_t state)
697 EXPORT_SYMBOL_GPL(dpm_resume_end);
700 /*------------------------- Suspend routines -------------------------*/
703 * resume_event - Return a "resume" message for given "suspend" sleep state.
704 * @sleep_state: PM message representing a sleep state.
706 * Return a PM message representing the resume event corresponding to given
709 static pm_message_t resume_event(pm_message_t sleep_state)
711 switch (sleep_state.event) {
712 case PM_EVENT_SUSPEND:
714 case PM_EVENT_FREEZE:
715 case PM_EVENT_QUIESCE:
717 case PM_EVENT_HIBERNATE:
724 * device_suspend_noirq - Execute a "late suspend" callback for given device.
725 * @dev: Device to handle.
726 * @state: PM transition of the system being carried out.
728 * The driver of @dev will not receive interrupts while this function is being
731 static int device_suspend_noirq(struct device *dev, pm_message_t state)
735 if (dev->type && dev->type->pm) {
736 pm_dev_dbg(dev, state, "LATE type ");
737 error = pm_noirq_op(dev, dev->type->pm, state);
740 } else if (dev->class && dev->class->pm) {
741 pm_dev_dbg(dev, state, "LATE class ");
742 error = pm_noirq_op(dev, dev->class->pm, state);
745 } else if (dev->bus && dev->bus->pm) {
746 pm_dev_dbg(dev, state, "LATE ");
747 error = pm_noirq_op(dev, dev->bus->pm, state);
752 if (dev->pwr_domain) {
753 pm_dev_dbg(dev, state, "LATE power domain ");
754 pm_noirq_op(dev, &dev->pwr_domain->ops, state);
761 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
762 * @state: PM transition of the system being carried out.
764 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
765 * handlers for all non-sysdev devices.
767 int dpm_suspend_noirq(pm_message_t state)
769 ktime_t starttime = ktime_get();
772 suspend_device_irqs();
773 mutex_lock(&dpm_list_mtx);
774 while (!list_empty(&dpm_suspended_list)) {
775 struct device *dev = to_device(dpm_suspended_list.prev);
778 mutex_unlock(&dpm_list_mtx);
780 error = device_suspend_noirq(dev, state);
782 mutex_lock(&dpm_list_mtx);
784 pm_dev_err(dev, state, " late", error);
788 if (!list_empty(&dev->power.entry))
789 list_move(&dev->power.entry, &dpm_noirq_list);
792 mutex_unlock(&dpm_list_mtx);
794 dpm_resume_noirq(resume_event(state));
796 dpm_show_time(starttime, state, "late");
799 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
802 * legacy_suspend - Execute a legacy (bus or class) suspend callback for device.
803 * @dev: Device to suspend.
804 * @state: PM transition of the system being carried out.
805 * @cb: Suspend callback to execute.
807 static int legacy_suspend(struct device *dev, pm_message_t state,
808 int (*cb)(struct device *dev, pm_message_t state))
813 calltime = initcall_debug_start(dev);
815 error = cb(dev, state);
816 suspend_report_result(cb, error);
818 initcall_debug_report(dev, calltime, error);
824 * device_suspend - Execute "suspend" callbacks for given device.
825 * @dev: Device to handle.
826 * @state: PM transition of the system being carried out.
827 * @async: If true, the device is being suspended asynchronously.
829 static int __device_suspend(struct device *dev, pm_message_t state, bool async)
833 dpm_wait_for_children(dev, async);
839 if (pm_wakeup_pending()) {
840 async_error = -EBUSY;
844 if (dev->type && dev->type->pm) {
845 pm_dev_dbg(dev, state, "type ");
846 error = pm_op(dev, dev->type->pm, state);
851 if (dev->class->pm) {
852 pm_dev_dbg(dev, state, "class ");
853 error = pm_op(dev, dev->class->pm, state);
855 } else if (dev->class->suspend) {
856 pm_dev_dbg(dev, state, "legacy class ");
857 error = legacy_suspend(dev, state, dev->class->suspend);
864 pm_dev_dbg(dev, state, "");
865 error = pm_op(dev, dev->bus->pm, state);
866 } else if (dev->bus->suspend) {
867 pm_dev_dbg(dev, state, "legacy ");
868 error = legacy_suspend(dev, state, dev->bus->suspend);
873 if (!error && dev->pwr_domain) {
874 pm_dev_dbg(dev, state, "power domain ");
875 pm_op(dev, &dev->pwr_domain->ops, state);
880 complete_all(&dev->power.completion);
888 static void async_suspend(void *data, async_cookie_t cookie)
890 struct device *dev = (struct device *)data;
893 error = __device_suspend(dev, pm_transition, true);
895 pm_dev_err(dev, pm_transition, " async", error);
900 static int device_suspend(struct device *dev)
902 INIT_COMPLETION(dev->power.completion);
904 if (pm_async_enabled && dev->power.async_suspend) {
906 async_schedule(async_suspend, dev);
910 return __device_suspend(dev, pm_transition, false);
914 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
915 * @state: PM transition of the system being carried out.
917 static int dpm_suspend(pm_message_t state)
919 ktime_t starttime = ktime_get();
922 mutex_lock(&dpm_list_mtx);
923 pm_transition = state;
925 while (!list_empty(&dpm_prepared_list)) {
926 struct device *dev = to_device(dpm_prepared_list.prev);
929 mutex_unlock(&dpm_list_mtx);
931 error = device_suspend(dev);
933 mutex_lock(&dpm_list_mtx);
935 pm_dev_err(dev, state, "", error);
939 if (!list_empty(&dev->power.entry))
940 list_move(&dev->power.entry, &dpm_suspended_list);
945 mutex_unlock(&dpm_list_mtx);
946 async_synchronize_full();
950 dpm_show_time(starttime, state, NULL);
955 * device_prepare - Prepare a device for system power transition.
956 * @dev: Device to handle.
957 * @state: PM transition of the system being carried out.
959 * Execute the ->prepare() callback(s) for given device. No new children of the
960 * device may be registered after this function has returned.
962 static int device_prepare(struct device *dev, pm_message_t state)
968 if (dev->type && dev->type->pm) {
969 pm_dev_dbg(dev, state, "preparing type ");
970 if (dev->type->pm->prepare)
971 error = dev->type->pm->prepare(dev);
972 suspend_report_result(dev->type->pm->prepare, error);
975 } else if (dev->class && dev->class->pm) {
976 pm_dev_dbg(dev, state, "preparing class ");
977 if (dev->class->pm->prepare)
978 error = dev->class->pm->prepare(dev);
979 suspend_report_result(dev->class->pm->prepare, error);
982 } else if (dev->bus && dev->bus->pm) {
983 pm_dev_dbg(dev, state, "preparing ");
984 if (dev->bus->pm->prepare)
985 error = dev->bus->pm->prepare(dev);
986 suspend_report_result(dev->bus->pm->prepare, error);
991 if (dev->pwr_domain && dev->pwr_domain->ops.prepare) {
992 pm_dev_dbg(dev, state, "preparing power domain ");
993 dev->pwr_domain->ops.prepare(dev);
1003 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
1004 * @state: PM transition of the system being carried out.
1006 * Execute the ->prepare() callback(s) for all devices.
1008 static int dpm_prepare(pm_message_t state)
1012 mutex_lock(&dpm_list_mtx);
1013 while (!list_empty(&dpm_list)) {
1014 struct device *dev = to_device(dpm_list.next);
1017 mutex_unlock(&dpm_list_mtx);
1019 pm_runtime_get_noresume(dev);
1020 if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
1021 pm_wakeup_event(dev, 0);
1023 pm_runtime_put_sync(dev);
1024 error = pm_wakeup_pending() ?
1025 -EBUSY : device_prepare(dev, state);
1027 mutex_lock(&dpm_list_mtx);
1029 if (error == -EAGAIN) {
1034 printk(KERN_INFO "PM: Device %s not prepared "
1035 "for power transition: code %d\n",
1036 dev_name(dev), error);
1040 dev->power.in_suspend = true;
1041 if (!list_empty(&dev->power.entry))
1042 list_move_tail(&dev->power.entry, &dpm_prepared_list);
1045 mutex_unlock(&dpm_list_mtx);
1050 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
1051 * @state: PM transition of the system being carried out.
1053 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
1054 * callbacks for them.
1056 int dpm_suspend_start(pm_message_t state)
1061 error = dpm_prepare(state);
1063 error = dpm_suspend(state);
1066 EXPORT_SYMBOL_GPL(dpm_suspend_start);
1068 void __suspend_report_result(const char *function, void *fn, int ret)
1071 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
1073 EXPORT_SYMBOL_GPL(__suspend_report_result);
1076 * device_pm_wait_for_dev - Wait for suspend/resume of a device to complete.
1077 * @dev: Device to wait for.
1078 * @subordinate: Device that needs to wait for @dev.
1080 int device_pm_wait_for_dev(struct device *subordinate, struct device *dev)
1082 dpm_wait(dev, subordinate->power.async_suspend);
1085 EXPORT_SYMBOL_GPL(device_pm_wait_for_dev);