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 intialize 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>
33 * The entries in the dpm_list list are in a depth first order, simply
34 * because children are guaranteed to be discovered after parents, and
35 * are inserted at the back of the list on discovery.
37 * Since device_pm_add() may be called with a device semaphore held,
38 * we must never try to acquire a device semaphore while holding
44 static DEFINE_MUTEX(dpm_list_mtx);
47 * Set once the preparation of devices for a PM transition has started, reset
48 * before starting to resume devices. Protected by dpm_list_mtx.
50 static bool transition_started;
53 * device_pm_init - Initialize the PM-related part of a device object.
54 * @dev: Device object being initialized.
56 void device_pm_init(struct device *dev)
58 dev->power.status = DPM_ON;
63 * device_pm_lock - Lock the list of active devices used by the PM core.
65 void device_pm_lock(void)
67 mutex_lock(&dpm_list_mtx);
71 * device_pm_unlock - Unlock the list of active devices used by the PM core.
73 void device_pm_unlock(void)
75 mutex_unlock(&dpm_list_mtx);
79 * device_pm_add - Add a device to the PM core's list of active devices.
80 * @dev: Device to add to the list.
82 void device_pm_add(struct device *dev)
84 pr_debug("PM: Adding info for %s:%s\n",
85 dev->bus ? dev->bus->name : "No Bus",
86 kobject_name(&dev->kobj));
87 mutex_lock(&dpm_list_mtx);
89 if (dev->parent->power.status >= DPM_SUSPENDING)
90 dev_warn(dev, "parent %s should not be sleeping\n",
91 dev_name(dev->parent));
92 } else if (transition_started) {
94 * We refuse to register parentless devices while a PM
95 * transition is in progress in order to avoid leaving them
96 * unhandled down the road
98 dev_WARN(dev, "Parentless device registered during a PM transaction\n");
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",
113 kobject_name(&dev->kobj));
114 mutex_lock(&dpm_list_mtx);
115 list_del_init(&dev->power.entry);
116 mutex_unlock(&dpm_list_mtx);
117 pm_runtime_remove(dev);
121 * device_pm_move_before - Move device in the PM core's list of active devices.
122 * @deva: Device to move in dpm_list.
123 * @devb: Device @deva should come before.
125 void device_pm_move_before(struct device *deva, struct device *devb)
127 pr_debug("PM: Moving %s:%s before %s:%s\n",
128 deva->bus ? deva->bus->name : "No Bus",
129 kobject_name(&deva->kobj),
130 devb->bus ? devb->bus->name : "No Bus",
131 kobject_name(&devb->kobj));
132 /* Delete deva from dpm_list and reinsert before devb. */
133 list_move_tail(&deva->power.entry, &devb->power.entry);
137 * device_pm_move_after - Move device in the PM core's list of active devices.
138 * @deva: Device to move in dpm_list.
139 * @devb: Device @deva should come after.
141 void device_pm_move_after(struct device *deva, struct device *devb)
143 pr_debug("PM: Moving %s:%s after %s:%s\n",
144 deva->bus ? deva->bus->name : "No Bus",
145 kobject_name(&deva->kobj),
146 devb->bus ? devb->bus->name : "No Bus",
147 kobject_name(&devb->kobj));
148 /* Delete deva from dpm_list and reinsert after devb. */
149 list_move(&deva->power.entry, &devb->power.entry);
153 * device_pm_move_last - Move device to end of the PM core's list of devices.
154 * @dev: Device to move in dpm_list.
156 void device_pm_move_last(struct device *dev)
158 pr_debug("PM: Moving %s:%s to end of list\n",
159 dev->bus ? dev->bus->name : "No Bus",
160 kobject_name(&dev->kobj));
161 list_move_tail(&dev->power.entry, &dpm_list);
165 * pm_op - Execute the PM operation appropriate for given PM event.
166 * @dev: Device to handle.
167 * @ops: PM operations to choose from.
168 * @state: PM transition of the system being carried out.
170 static int pm_op(struct device *dev,
171 const struct dev_pm_ops *ops,
175 ktime_t calltime, delta, rettime;
177 if (initcall_debug) {
178 pr_info("calling %s+ @ %i\n",
179 dev_name(dev), task_pid_nr(current));
180 calltime = ktime_get();
183 switch (state.event) {
184 #ifdef CONFIG_SUSPEND
185 case PM_EVENT_SUSPEND:
187 error = ops->suspend(dev);
188 suspend_report_result(ops->suspend, error);
191 case PM_EVENT_RESUME:
193 error = ops->resume(dev);
194 suspend_report_result(ops->resume, error);
197 #endif /* CONFIG_SUSPEND */
198 #ifdef CONFIG_HIBERNATION
199 case PM_EVENT_FREEZE:
200 case PM_EVENT_QUIESCE:
202 error = ops->freeze(dev);
203 suspend_report_result(ops->freeze, error);
206 case PM_EVENT_HIBERNATE:
208 error = ops->poweroff(dev);
209 suspend_report_result(ops->poweroff, error);
213 case PM_EVENT_RECOVER:
215 error = ops->thaw(dev);
216 suspend_report_result(ops->thaw, error);
219 case PM_EVENT_RESTORE:
221 error = ops->restore(dev);
222 suspend_report_result(ops->restore, error);
225 #endif /* CONFIG_HIBERNATION */
230 if (initcall_debug) {
231 rettime = ktime_get();
232 delta = ktime_sub(rettime, calltime);
233 pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev),
234 error, (unsigned long long)ktime_to_ns(delta) >> 10);
241 * pm_noirq_op - Execute the PM operation appropriate for given PM event.
242 * @dev: Device to handle.
243 * @ops: PM operations to choose from.
244 * @state: PM transition of the system being carried out.
246 * The driver of @dev will not receive interrupts while this function is being
249 static int pm_noirq_op(struct device *dev,
250 const struct dev_pm_ops *ops,
254 ktime_t calltime, delta, rettime;
256 if (initcall_debug) {
257 pr_info("calling %s_i+ @ %i\n",
258 dev_name(dev), task_pid_nr(current));
259 calltime = ktime_get();
262 switch (state.event) {
263 #ifdef CONFIG_SUSPEND
264 case PM_EVENT_SUSPEND:
265 if (ops->suspend_noirq) {
266 error = ops->suspend_noirq(dev);
267 suspend_report_result(ops->suspend_noirq, error);
270 case PM_EVENT_RESUME:
271 if (ops->resume_noirq) {
272 error = ops->resume_noirq(dev);
273 suspend_report_result(ops->resume_noirq, error);
276 #endif /* CONFIG_SUSPEND */
277 #ifdef CONFIG_HIBERNATION
278 case PM_EVENT_FREEZE:
279 case PM_EVENT_QUIESCE:
280 if (ops->freeze_noirq) {
281 error = ops->freeze_noirq(dev);
282 suspend_report_result(ops->freeze_noirq, error);
285 case PM_EVENT_HIBERNATE:
286 if (ops->poweroff_noirq) {
287 error = ops->poweroff_noirq(dev);
288 suspend_report_result(ops->poweroff_noirq, error);
292 case PM_EVENT_RECOVER:
293 if (ops->thaw_noirq) {
294 error = ops->thaw_noirq(dev);
295 suspend_report_result(ops->thaw_noirq, error);
298 case PM_EVENT_RESTORE:
299 if (ops->restore_noirq) {
300 error = ops->restore_noirq(dev);
301 suspend_report_result(ops->restore_noirq, error);
304 #endif /* CONFIG_HIBERNATION */
309 if (initcall_debug) {
310 rettime = ktime_get();
311 delta = ktime_sub(rettime, calltime);
312 printk("initcall %s_i+ returned %d after %Ld usecs\n", dev_name(dev),
313 error, (unsigned long long)ktime_to_ns(delta) >> 10);
319 static char *pm_verb(int event)
322 case PM_EVENT_SUSPEND:
324 case PM_EVENT_RESUME:
326 case PM_EVENT_FREEZE:
328 case PM_EVENT_QUIESCE:
330 case PM_EVENT_HIBERNATE:
334 case PM_EVENT_RESTORE:
336 case PM_EVENT_RECOVER:
339 return "(unknown PM event)";
343 static void pm_dev_dbg(struct device *dev, pm_message_t state, char *info)
345 dev_dbg(dev, "%s%s%s\n", info, pm_verb(state.event),
346 ((state.event & PM_EVENT_SLEEP) && device_may_wakeup(dev)) ?
347 ", may wakeup" : "");
350 static void pm_dev_err(struct device *dev, pm_message_t state, char *info,
353 printk(KERN_ERR "PM: Device %s failed to %s%s: error %d\n",
354 kobject_name(&dev->kobj), pm_verb(state.event), info, error);
357 /*------------------------- Resume routines -------------------------*/
360 * device_resume_noirq - Execute an "early resume" callback for given device.
361 * @dev: Device to handle.
362 * @state: PM transition of the system being carried out.
364 * The driver of @dev will not receive interrupts while this function is being
367 static int device_resume_noirq(struct device *dev, pm_message_t state)
374 if (dev->bus && dev->bus->pm) {
375 pm_dev_dbg(dev, state, "EARLY ");
376 error = pm_noirq_op(dev, dev->bus->pm, state);
384 * dpm_resume_noirq - Execute "early resume" callbacks for non-sysdev devices.
385 * @state: PM transition of the system being carried out.
387 * Call the "noirq" resume handlers for all devices marked as DPM_OFF_IRQ and
388 * enable device drivers to receive interrupts.
390 void dpm_resume_noirq(pm_message_t state)
394 mutex_lock(&dpm_list_mtx);
395 transition_started = false;
396 list_for_each_entry(dev, &dpm_list, power.entry)
397 if (dev->power.status > DPM_OFF) {
400 dev->power.status = DPM_OFF;
401 error = device_resume_noirq(dev, state);
403 pm_dev_err(dev, state, " early", error);
405 mutex_unlock(&dpm_list_mtx);
406 resume_device_irqs();
408 EXPORT_SYMBOL_GPL(dpm_resume_noirq);
411 * device_resume - Execute "resume" callbacks for given device.
412 * @dev: Device to handle.
413 * @state: PM transition of the system being carried out.
415 static int device_resume(struct device *dev, pm_message_t state)
426 pm_dev_dbg(dev, state, "");
427 error = pm_op(dev, dev->bus->pm, state);
428 } else if (dev->bus->resume) {
429 pm_dev_dbg(dev, state, "legacy ");
430 error = dev->bus->resume(dev);
438 pm_dev_dbg(dev, state, "type ");
439 error = pm_op(dev, dev->type->pm, state);
446 if (dev->class->pm) {
447 pm_dev_dbg(dev, state, "class ");
448 error = pm_op(dev, dev->class->pm, state);
449 } else if (dev->class->resume) {
450 pm_dev_dbg(dev, state, "legacy class ");
451 error = dev->class->resume(dev);
462 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.
463 * @state: PM transition of the system being carried out.
465 * Execute the appropriate "resume" callback for all devices whose status
466 * indicates that they are suspended.
468 static void dpm_resume(pm_message_t state)
470 struct list_head list;
472 INIT_LIST_HEAD(&list);
473 mutex_lock(&dpm_list_mtx);
474 while (!list_empty(&dpm_list)) {
475 struct device *dev = to_device(dpm_list.next);
478 if (dev->power.status >= DPM_OFF) {
481 dev->power.status = DPM_RESUMING;
482 mutex_unlock(&dpm_list_mtx);
484 error = device_resume(dev, state);
486 mutex_lock(&dpm_list_mtx);
488 pm_dev_err(dev, state, "", error);
489 } else if (dev->power.status == DPM_SUSPENDING) {
490 /* Allow new children of the device to be registered */
491 dev->power.status = DPM_RESUMING;
493 if (!list_empty(&dev->power.entry))
494 list_move_tail(&dev->power.entry, &list);
497 list_splice(&list, &dpm_list);
498 mutex_unlock(&dpm_list_mtx);
502 * device_complete - Complete a PM transition for given device.
503 * @dev: Device to handle.
504 * @state: PM transition of the system being carried out.
506 static void device_complete(struct device *dev, pm_message_t state)
510 if (dev->class && dev->class->pm && dev->class->pm->complete) {
511 pm_dev_dbg(dev, state, "completing class ");
512 dev->class->pm->complete(dev);
515 if (dev->type && dev->type->pm && dev->type->pm->complete) {
516 pm_dev_dbg(dev, state, "completing type ");
517 dev->type->pm->complete(dev);
520 if (dev->bus && dev->bus->pm && dev->bus->pm->complete) {
521 pm_dev_dbg(dev, state, "completing ");
522 dev->bus->pm->complete(dev);
529 * dpm_complete - Complete a PM transition for all non-sysdev devices.
530 * @state: PM transition of the system being carried out.
532 * Execute the ->complete() callbacks for all devices whose PM status is not
533 * DPM_ON (this allows new devices to be registered).
535 static void dpm_complete(pm_message_t state)
537 struct list_head list;
539 INIT_LIST_HEAD(&list);
540 mutex_lock(&dpm_list_mtx);
541 transition_started = false;
542 while (!list_empty(&dpm_list)) {
543 struct device *dev = to_device(dpm_list.prev);
546 if (dev->power.status > DPM_ON) {
547 dev->power.status = DPM_ON;
548 mutex_unlock(&dpm_list_mtx);
550 device_complete(dev, state);
551 pm_runtime_put_noidle(dev);
553 mutex_lock(&dpm_list_mtx);
555 if (!list_empty(&dev->power.entry))
556 list_move(&dev->power.entry, &list);
559 list_splice(&list, &dpm_list);
560 mutex_unlock(&dpm_list_mtx);
564 * dpm_resume_end - Execute "resume" callbacks and complete system transition.
565 * @state: PM transition of the system being carried out.
567 * Execute "resume" callbacks for all devices and complete the PM transition of
570 void dpm_resume_end(pm_message_t state)
576 EXPORT_SYMBOL_GPL(dpm_resume_end);
579 /*------------------------- Suspend routines -------------------------*/
582 * resume_event - Return a "resume" message for given "suspend" sleep state.
583 * @sleep_state: PM message representing a sleep state.
585 * Return a PM message representing the resume event corresponding to given
588 static pm_message_t resume_event(pm_message_t sleep_state)
590 switch (sleep_state.event) {
591 case PM_EVENT_SUSPEND:
593 case PM_EVENT_FREEZE:
594 case PM_EVENT_QUIESCE:
596 case PM_EVENT_HIBERNATE:
603 * device_suspend_noirq - Execute a "late suspend" callback for given device.
604 * @dev: Device to handle.
605 * @state: PM transition of the system being carried out.
607 * The driver of @dev will not receive interrupts while this function is being
610 static int device_suspend_noirq(struct device *dev, pm_message_t state)
614 if (dev->bus && dev->bus->pm) {
615 pm_dev_dbg(dev, state, "LATE ");
616 error = pm_noirq_op(dev, dev->bus->pm, state);
622 * dpm_suspend_noirq - Execute "late suspend" callbacks for non-sysdev devices.
623 * @state: PM transition of the system being carried out.
625 * Prevent device drivers from receiving interrupts and call the "noirq" suspend
626 * handlers for all non-sysdev devices.
628 int dpm_suspend_noirq(pm_message_t state)
633 suspend_device_irqs();
634 mutex_lock(&dpm_list_mtx);
635 list_for_each_entry_reverse(dev, &dpm_list, power.entry) {
636 error = device_suspend_noirq(dev, state);
638 pm_dev_err(dev, state, " late", error);
641 dev->power.status = DPM_OFF_IRQ;
643 mutex_unlock(&dpm_list_mtx);
645 dpm_resume_noirq(resume_event(state));
648 EXPORT_SYMBOL_GPL(dpm_suspend_noirq);
651 * device_suspend - Execute "suspend" callbacks for given device.
652 * @dev: Device to handle.
653 * @state: PM transition of the system being carried out.
655 static int device_suspend(struct device *dev, pm_message_t state)
662 if (dev->class->pm) {
663 pm_dev_dbg(dev, state, "class ");
664 error = pm_op(dev, dev->class->pm, state);
665 } else if (dev->class->suspend) {
666 pm_dev_dbg(dev, state, "legacy class ");
667 error = dev->class->suspend(dev, state);
668 suspend_report_result(dev->class->suspend, error);
676 pm_dev_dbg(dev, state, "type ");
677 error = pm_op(dev, dev->type->pm, state);
685 pm_dev_dbg(dev, state, "");
686 error = pm_op(dev, dev->bus->pm, state);
687 } else if (dev->bus->suspend) {
688 pm_dev_dbg(dev, state, "legacy ");
689 error = dev->bus->suspend(dev, state);
690 suspend_report_result(dev->bus->suspend, error);
700 * dpm_suspend - Execute "suspend" callbacks for all non-sysdev devices.
701 * @state: PM transition of the system being carried out.
703 static int dpm_suspend(pm_message_t state)
705 struct list_head list;
708 INIT_LIST_HEAD(&list);
709 mutex_lock(&dpm_list_mtx);
710 while (!list_empty(&dpm_list)) {
711 struct device *dev = to_device(dpm_list.prev);
714 mutex_unlock(&dpm_list_mtx);
716 error = device_suspend(dev, state);
718 mutex_lock(&dpm_list_mtx);
720 pm_dev_err(dev, state, "", error);
724 dev->power.status = DPM_OFF;
725 if (!list_empty(&dev->power.entry))
726 list_move(&dev->power.entry, &list);
729 list_splice(&list, dpm_list.prev);
730 mutex_unlock(&dpm_list_mtx);
735 * device_prepare - Prepare a device for system power transition.
736 * @dev: Device to handle.
737 * @state: PM transition of the system being carried out.
739 * Execute the ->prepare() callback(s) for given device. No new children of the
740 * device may be registered after this function has returned.
742 static int device_prepare(struct device *dev, pm_message_t state)
748 if (dev->bus && dev->bus->pm && dev->bus->pm->prepare) {
749 pm_dev_dbg(dev, state, "preparing ");
750 error = dev->bus->pm->prepare(dev);
751 suspend_report_result(dev->bus->pm->prepare, error);
756 if (dev->type && dev->type->pm && dev->type->pm->prepare) {
757 pm_dev_dbg(dev, state, "preparing type ");
758 error = dev->type->pm->prepare(dev);
759 suspend_report_result(dev->type->pm->prepare, error);
764 if (dev->class && dev->class->pm && dev->class->pm->prepare) {
765 pm_dev_dbg(dev, state, "preparing class ");
766 error = dev->class->pm->prepare(dev);
767 suspend_report_result(dev->class->pm->prepare, error);
776 * dpm_prepare - Prepare all non-sysdev devices for a system PM transition.
777 * @state: PM transition of the system being carried out.
779 * Execute the ->prepare() callback(s) for all devices.
781 static int dpm_prepare(pm_message_t state)
783 struct list_head list;
786 INIT_LIST_HEAD(&list);
787 mutex_lock(&dpm_list_mtx);
788 transition_started = true;
789 while (!list_empty(&dpm_list)) {
790 struct device *dev = to_device(dpm_list.next);
793 dev->power.status = DPM_PREPARING;
794 mutex_unlock(&dpm_list_mtx);
796 pm_runtime_get_noresume(dev);
797 if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) {
798 /* Wake-up requested during system sleep transition. */
799 pm_runtime_put_noidle(dev);
802 error = device_prepare(dev, state);
805 mutex_lock(&dpm_list_mtx);
807 dev->power.status = DPM_ON;
808 if (error == -EAGAIN) {
813 printk(KERN_ERR "PM: Failed to prepare device %s "
814 "for power transition: error %d\n",
815 kobject_name(&dev->kobj), error);
819 dev->power.status = DPM_SUSPENDING;
820 if (!list_empty(&dev->power.entry))
821 list_move_tail(&dev->power.entry, &list);
824 list_splice(&list, &dpm_list);
825 mutex_unlock(&dpm_list_mtx);
830 * dpm_suspend_start - Prepare devices for PM transition and suspend them.
831 * @state: PM transition of the system being carried out.
833 * Prepare all non-sysdev devices for system PM transition and execute "suspend"
834 * callbacks for them.
836 int dpm_suspend_start(pm_message_t state)
841 error = dpm_prepare(state);
843 error = dpm_suspend(state);
846 EXPORT_SYMBOL_GPL(dpm_suspend_start);
848 void __suspend_report_result(const char *function, void *fn, int ret)
851 printk(KERN_ERR "%s(): %pF returns %d\n", function, fn, ret);
853 EXPORT_SYMBOL_GPL(__suspend_report_result);