2 * drivers/base/power/wakeup.c - System wakeup events framework
4 * Copyright (c) 2010 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 * This file is released under the GPLv2.
9 #include <linux/device.h>
10 #include <linux/slab.h>
11 #include <linux/sched.h>
12 #include <linux/capability.h>
13 #include <linux/export.h>
14 #include <linux/suspend.h>
15 #include <linux/seq_file.h>
16 #include <linux/debugfs.h>
17 #include <trace/events/power.h>
22 * If set, the suspend/hibernate code will abort transitions to a sleep state
23 * if wakeup events are registered during or immediately before the transition.
25 bool events_check_enabled __read_mostly
;
28 * Combined counters of registered wakeup events and wakeup events in progress.
29 * They need to be modified together atomically, so it's better to use one
30 * atomic variable to hold them both.
32 static atomic_t combined_event_count
= ATOMIC_INIT(0);
34 #define IN_PROGRESS_BITS (sizeof(int) * 4)
35 #define MAX_IN_PROGRESS ((1 << IN_PROGRESS_BITS) - 1)
37 static void split_counters(unsigned int *cnt
, unsigned int *inpr
)
39 unsigned int comb
= atomic_read(&combined_event_count
);
41 *cnt
= (comb
>> IN_PROGRESS_BITS
);
42 *inpr
= comb
& MAX_IN_PROGRESS
;
45 /* A preserved old value of the events counter. */
46 static unsigned int saved_count
;
48 static DEFINE_SPINLOCK(events_lock
);
50 static void pm_wakeup_timer_fn(unsigned long data
);
52 static LIST_HEAD(wakeup_sources
);
54 static DECLARE_WAIT_QUEUE_HEAD(wakeup_count_wait_queue
);
57 * wakeup_source_prepare - Prepare a new wakeup source for initialization.
58 * @ws: Wakeup source to prepare.
59 * @name: Pointer to the name of the new wakeup source.
61 * Callers must ensure that the @name string won't be freed when @ws is still in
64 void wakeup_source_prepare(struct wakeup_source
*ws
, const char *name
)
67 memset(ws
, 0, sizeof(*ws
));
71 EXPORT_SYMBOL_GPL(wakeup_source_prepare
);
74 * wakeup_source_create - Create a struct wakeup_source object.
75 * @name: Name of the new wakeup source.
77 struct wakeup_source
*wakeup_source_create(const char *name
)
79 struct wakeup_source
*ws
;
81 ws
= kmalloc(sizeof(*ws
), GFP_KERNEL
);
85 wakeup_source_prepare(ws
, name
? kstrdup(name
, GFP_KERNEL
) : NULL
);
88 EXPORT_SYMBOL_GPL(wakeup_source_create
);
91 * wakeup_source_drop - Prepare a struct wakeup_source object for destruction.
92 * @ws: Wakeup source to prepare for destruction.
94 * Callers must ensure that __pm_stay_awake() or __pm_wakeup_event() will never
95 * be run in parallel with this function for the same wakeup source object.
97 void wakeup_source_drop(struct wakeup_source
*ws
)
102 del_timer_sync(&ws
->timer
);
105 EXPORT_SYMBOL_GPL(wakeup_source_drop
);
108 * wakeup_source_destroy - Destroy a struct wakeup_source object.
109 * @ws: Wakeup source to destroy.
111 * Use only for wakeup source objects created with wakeup_source_create().
113 void wakeup_source_destroy(struct wakeup_source
*ws
)
118 wakeup_source_drop(ws
);
122 EXPORT_SYMBOL_GPL(wakeup_source_destroy
);
125 * wakeup_source_add - Add given object to the list of wakeup sources.
126 * @ws: Wakeup source object to add to the list.
128 void wakeup_source_add(struct wakeup_source
*ws
)
133 spin_lock_init(&ws
->lock
);
134 setup_timer(&ws
->timer
, pm_wakeup_timer_fn
, (unsigned long)ws
);
137 spin_lock_irq(&events_lock
);
138 list_add_rcu(&ws
->entry
, &wakeup_sources
);
139 spin_unlock_irq(&events_lock
);
141 EXPORT_SYMBOL_GPL(wakeup_source_add
);
144 * wakeup_source_remove - Remove given object from the wakeup sources list.
145 * @ws: Wakeup source object to remove from the list.
147 void wakeup_source_remove(struct wakeup_source
*ws
)
152 spin_lock_irq(&events_lock
);
153 list_del_rcu(&ws
->entry
);
154 spin_unlock_irq(&events_lock
);
157 EXPORT_SYMBOL_GPL(wakeup_source_remove
);
160 * wakeup_source_register - Create wakeup source and add it to the list.
161 * @name: Name of the wakeup source to register.
163 struct wakeup_source
*wakeup_source_register(const char *name
)
165 struct wakeup_source
*ws
;
167 ws
= wakeup_source_create(name
);
169 wakeup_source_add(ws
);
173 EXPORT_SYMBOL_GPL(wakeup_source_register
);
176 * wakeup_source_unregister - Remove wakeup source from the list and remove it.
177 * @ws: Wakeup source object to unregister.
179 void wakeup_source_unregister(struct wakeup_source
*ws
)
182 wakeup_source_remove(ws
);
183 wakeup_source_destroy(ws
);
186 EXPORT_SYMBOL_GPL(wakeup_source_unregister
);
189 * device_wakeup_attach - Attach a wakeup source object to a device object.
190 * @dev: Device to handle.
191 * @ws: Wakeup source object to attach to @dev.
193 * This causes @dev to be treated as a wakeup device.
195 static int device_wakeup_attach(struct device
*dev
, struct wakeup_source
*ws
)
197 spin_lock_irq(&dev
->power
.lock
);
198 if (dev
->power
.wakeup
) {
199 spin_unlock_irq(&dev
->power
.lock
);
202 dev
->power
.wakeup
= ws
;
203 spin_unlock_irq(&dev
->power
.lock
);
208 * device_wakeup_enable - Enable given device to be a wakeup source.
209 * @dev: Device to handle.
211 * Create a wakeup source object, register it and attach it to @dev.
213 int device_wakeup_enable(struct device
*dev
)
215 struct wakeup_source
*ws
;
218 if (!dev
|| !dev
->power
.can_wakeup
)
221 ws
= wakeup_source_register(dev_name(dev
));
225 ret
= device_wakeup_attach(dev
, ws
);
227 wakeup_source_unregister(ws
);
231 EXPORT_SYMBOL_GPL(device_wakeup_enable
);
234 * device_wakeup_detach - Detach a device's wakeup source object from it.
235 * @dev: Device to detach the wakeup source object from.
237 * After it returns, @dev will not be treated as a wakeup device any more.
239 static struct wakeup_source
*device_wakeup_detach(struct device
*dev
)
241 struct wakeup_source
*ws
;
243 spin_lock_irq(&dev
->power
.lock
);
244 ws
= dev
->power
.wakeup
;
245 dev
->power
.wakeup
= NULL
;
246 spin_unlock_irq(&dev
->power
.lock
);
251 * device_wakeup_disable - Do not regard a device as a wakeup source any more.
252 * @dev: Device to handle.
254 * Detach the @dev's wakeup source object from it, unregister this wakeup source
255 * object and destroy it.
257 int device_wakeup_disable(struct device
*dev
)
259 struct wakeup_source
*ws
;
261 if (!dev
|| !dev
->power
.can_wakeup
)
264 ws
= device_wakeup_detach(dev
);
266 wakeup_source_unregister(ws
);
270 EXPORT_SYMBOL_GPL(device_wakeup_disable
);
273 * device_set_wakeup_capable - Set/reset device wakeup capability flag.
274 * @dev: Device to handle.
275 * @capable: Whether or not @dev is capable of waking up the system from sleep.
277 * If @capable is set, set the @dev's power.can_wakeup flag and add its
278 * wakeup-related attributes to sysfs. Otherwise, unset the @dev's
279 * power.can_wakeup flag and remove its wakeup-related attributes from sysfs.
281 * This function may sleep and it can't be called from any context where
282 * sleeping is not allowed.
284 void device_set_wakeup_capable(struct device
*dev
, bool capable
)
286 if (!!dev
->power
.can_wakeup
== !!capable
)
289 if (device_is_registered(dev
) && !list_empty(&dev
->power
.entry
)) {
291 if (wakeup_sysfs_add(dev
))
294 wakeup_sysfs_remove(dev
);
297 dev
->power
.can_wakeup
= capable
;
299 EXPORT_SYMBOL_GPL(device_set_wakeup_capable
);
302 * device_init_wakeup - Device wakeup initialization.
303 * @dev: Device to handle.
304 * @enable: Whether or not to enable @dev as a wakeup device.
306 * By default, most devices should leave wakeup disabled. The exceptions are
307 * devices that everyone expects to be wakeup sources: keyboards, power buttons,
308 * possibly network interfaces, etc. Also, devices that don't generate their
309 * own wakeup requests but merely forward requests from one bus to another
310 * (like PCI bridges) should have wakeup enabled by default.
312 int device_init_wakeup(struct device
*dev
, bool enable
)
317 device_set_wakeup_capable(dev
, true);
318 ret
= device_wakeup_enable(dev
);
320 device_set_wakeup_capable(dev
, false);
325 EXPORT_SYMBOL_GPL(device_init_wakeup
);
328 * device_set_wakeup_enable - Enable or disable a device to wake up the system.
329 * @dev: Device to handle.
331 int device_set_wakeup_enable(struct device
*dev
, bool enable
)
333 if (!dev
|| !dev
->power
.can_wakeup
)
336 return enable
? device_wakeup_enable(dev
) : device_wakeup_disable(dev
);
338 EXPORT_SYMBOL_GPL(device_set_wakeup_enable
);
341 * The functions below use the observation that each wakeup event starts a
342 * period in which the system should not be suspended. The moment this period
343 * will end depends on how the wakeup event is going to be processed after being
344 * detected and all of the possible cases can be divided into two distinct
347 * First, a wakeup event may be detected by the same functional unit that will
348 * carry out the entire processing of it and possibly will pass it to user space
349 * for further processing. In that case the functional unit that has detected
350 * the event may later "close" the "no suspend" period associated with it
351 * directly as soon as it has been dealt with. The pair of pm_stay_awake() and
352 * pm_relax(), balanced with each other, is supposed to be used in such
355 * Second, a wakeup event may be detected by one functional unit and processed
356 * by another one. In that case the unit that has detected it cannot really
357 * "close" the "no suspend" period associated with it, unless it knows in
358 * advance what's going to happen to the event during processing. This
359 * knowledge, however, may not be available to it, so it can simply specify time
360 * to wait before the system can be suspended and pass it as the second
361 * argument of pm_wakeup_event().
363 * It is valid to call pm_relax() after pm_wakeup_event(), in which case the
364 * "no suspend" period will be ended either by the pm_relax(), or by the timer
365 * function executed when the timer expires, whichever comes first.
369 * wakup_source_activate - Mark given wakeup source as active.
370 * @ws: Wakeup source to handle.
372 * Update the @ws' statistics and, if @ws has just been activated, notify the PM
373 * core of the event by incrementing the counter of of wakeup events being
376 static void wakeup_source_activate(struct wakeup_source
*ws
)
382 ws
->last_time
= ktime_get();
383 if (ws
->autosleep_enabled
)
384 ws
->start_prevent_time
= ws
->last_time
;
386 /* Increment the counter of events in progress. */
387 cec
= atomic_inc_return(&combined_event_count
);
389 trace_wakeup_source_activate(ws
->name
, cec
);
393 * wakeup_source_report_event - Report wakeup event using the given source.
394 * @ws: Wakeup source to report the event for.
396 static void wakeup_source_report_event(struct wakeup_source
*ws
)
399 /* This is racy, but the counter is approximate anyway. */
400 if (events_check_enabled
)
404 wakeup_source_activate(ws
);
408 * __pm_stay_awake - Notify the PM core of a wakeup event.
409 * @ws: Wakeup source object associated with the source of the event.
411 * It is safe to call this function from interrupt context.
413 void __pm_stay_awake(struct wakeup_source
*ws
)
420 spin_lock_irqsave(&ws
->lock
, flags
);
422 wakeup_source_report_event(ws
);
423 del_timer(&ws
->timer
);
424 ws
->timer_expires
= 0;
426 spin_unlock_irqrestore(&ws
->lock
, flags
);
428 EXPORT_SYMBOL_GPL(__pm_stay_awake
);
431 * pm_stay_awake - Notify the PM core that a wakeup event is being processed.
432 * @dev: Device the wakeup event is related to.
434 * Notify the PM core of a wakeup event (signaled by @dev) by calling
435 * __pm_stay_awake for the @dev's wakeup source object.
437 * Call this function after detecting of a wakeup event if pm_relax() is going
438 * to be called directly after processing the event (and possibly passing it to
439 * user space for further processing).
441 void pm_stay_awake(struct device
*dev
)
448 spin_lock_irqsave(&dev
->power
.lock
, flags
);
449 __pm_stay_awake(dev
->power
.wakeup
);
450 spin_unlock_irqrestore(&dev
->power
.lock
, flags
);
452 EXPORT_SYMBOL_GPL(pm_stay_awake
);
454 #ifdef CONFIG_PM_AUTOSLEEP
455 static void update_prevent_sleep_time(struct wakeup_source
*ws
, ktime_t now
)
457 ktime_t delta
= ktime_sub(now
, ws
->start_prevent_time
);
458 ws
->prevent_sleep_time
= ktime_add(ws
->prevent_sleep_time
, delta
);
461 static inline void update_prevent_sleep_time(struct wakeup_source
*ws
,
466 * wakup_source_deactivate - Mark given wakeup source as inactive.
467 * @ws: Wakeup source to handle.
469 * Update the @ws' statistics and notify the PM core that the wakeup source has
470 * become inactive by decrementing the counter of wakeup events being processed
471 * and incrementing the counter of registered wakeup events.
473 static void wakeup_source_deactivate(struct wakeup_source
*ws
)
475 unsigned int cnt
, inpr
, cec
;
481 * __pm_relax() may be called directly or from a timer function.
482 * If it is called directly right after the timer function has been
483 * started, but before the timer function calls __pm_relax(), it is
484 * possible that __pm_stay_awake() will be called in the meantime and
485 * will set ws->active. Then, ws->active may be cleared immediately
486 * by the __pm_relax() called from the timer function, but in such a
487 * case ws->relax_count will be different from ws->active_count.
489 if (ws
->relax_count
!= ws
->active_count
) {
497 duration
= ktime_sub(now
, ws
->last_time
);
498 ws
->total_time
= ktime_add(ws
->total_time
, duration
);
499 if (ktime_to_ns(duration
) > ktime_to_ns(ws
->max_time
))
500 ws
->max_time
= duration
;
503 del_timer(&ws
->timer
);
504 ws
->timer_expires
= 0;
506 if (ws
->autosleep_enabled
)
507 update_prevent_sleep_time(ws
, now
);
510 * Increment the counter of registered wakeup events and decrement the
511 * couter of wakeup events in progress simultaneously.
513 cec
= atomic_add_return(MAX_IN_PROGRESS
, &combined_event_count
);
514 trace_wakeup_source_deactivate(ws
->name
, cec
);
516 split_counters(&cnt
, &inpr
);
517 if (!inpr
&& waitqueue_active(&wakeup_count_wait_queue
))
518 wake_up(&wakeup_count_wait_queue
);
522 * __pm_relax - Notify the PM core that processing of a wakeup event has ended.
523 * @ws: Wakeup source object associated with the source of the event.
525 * Call this function for wakeup events whose processing started with calling
528 * It is safe to call it from interrupt context.
530 void __pm_relax(struct wakeup_source
*ws
)
537 spin_lock_irqsave(&ws
->lock
, flags
);
539 wakeup_source_deactivate(ws
);
540 spin_unlock_irqrestore(&ws
->lock
, flags
);
542 EXPORT_SYMBOL_GPL(__pm_relax
);
545 * pm_relax - Notify the PM core that processing of a wakeup event has ended.
546 * @dev: Device that signaled the event.
548 * Execute __pm_relax() for the @dev's wakeup source object.
550 void pm_relax(struct device
*dev
)
557 spin_lock_irqsave(&dev
->power
.lock
, flags
);
558 __pm_relax(dev
->power
.wakeup
);
559 spin_unlock_irqrestore(&dev
->power
.lock
, flags
);
561 EXPORT_SYMBOL_GPL(pm_relax
);
564 * pm_wakeup_timer_fn - Delayed finalization of a wakeup event.
565 * @data: Address of the wakeup source object associated with the event source.
567 * Call wakeup_source_deactivate() for the wakeup source whose address is stored
568 * in @data if it is currently active and its timer has not been canceled and
569 * the expiration time of the timer is not in future.
571 static void pm_wakeup_timer_fn(unsigned long data
)
573 struct wakeup_source
*ws
= (struct wakeup_source
*)data
;
576 spin_lock_irqsave(&ws
->lock
, flags
);
578 if (ws
->active
&& ws
->timer_expires
579 && time_after_eq(jiffies
, ws
->timer_expires
)) {
580 wakeup_source_deactivate(ws
);
584 spin_unlock_irqrestore(&ws
->lock
, flags
);
588 * __pm_wakeup_event - Notify the PM core of a wakeup event.
589 * @ws: Wakeup source object associated with the event source.
590 * @msec: Anticipated event processing time (in milliseconds).
592 * Notify the PM core of a wakeup event whose source is @ws that will take
593 * approximately @msec milliseconds to be processed by the kernel. If @ws is
594 * not active, activate it. If @msec is nonzero, set up the @ws' timer to
595 * execute pm_wakeup_timer_fn() in future.
597 * It is safe to call this function from interrupt context.
599 void __pm_wakeup_event(struct wakeup_source
*ws
, unsigned int msec
)
602 unsigned long expires
;
607 spin_lock_irqsave(&ws
->lock
, flags
);
609 wakeup_source_report_event(ws
);
612 wakeup_source_deactivate(ws
);
616 expires
= jiffies
+ msecs_to_jiffies(msec
);
620 if (!ws
->timer_expires
|| time_after(expires
, ws
->timer_expires
)) {
621 mod_timer(&ws
->timer
, expires
);
622 ws
->timer_expires
= expires
;
626 spin_unlock_irqrestore(&ws
->lock
, flags
);
628 EXPORT_SYMBOL_GPL(__pm_wakeup_event
);
632 * pm_wakeup_event - Notify the PM core of a wakeup event.
633 * @dev: Device the wakeup event is related to.
634 * @msec: Anticipated event processing time (in milliseconds).
636 * Call __pm_wakeup_event() for the @dev's wakeup source object.
638 void pm_wakeup_event(struct device
*dev
, unsigned int msec
)
645 spin_lock_irqsave(&dev
->power
.lock
, flags
);
646 __pm_wakeup_event(dev
->power
.wakeup
, msec
);
647 spin_unlock_irqrestore(&dev
->power
.lock
, flags
);
649 EXPORT_SYMBOL_GPL(pm_wakeup_event
);
652 * pm_wakeup_pending - Check if power transition in progress should be aborted.
654 * Compare the current number of registered wakeup events with its preserved
655 * value from the past and return true if new wakeup events have been registered
656 * since the old value was stored. Also return true if the current number of
657 * wakeup events being processed is different from zero.
659 bool pm_wakeup_pending(void)
664 spin_lock_irqsave(&events_lock
, flags
);
665 if (events_check_enabled
) {
666 unsigned int cnt
, inpr
;
668 split_counters(&cnt
, &inpr
);
669 ret
= (cnt
!= saved_count
|| inpr
> 0);
670 events_check_enabled
= !ret
;
672 spin_unlock_irqrestore(&events_lock
, flags
);
677 * pm_get_wakeup_count - Read the number of registered wakeup events.
678 * @count: Address to store the value at.
679 * @block: Whether or not to block.
681 * Store the number of registered wakeup events at the address in @count. If
682 * @block is set, block until the current number of wakeup events being
685 * Return 'false' if the current number of wakeup events being processed is
686 * nonzero. Otherwise return 'true'.
688 bool pm_get_wakeup_count(unsigned int *count
, bool block
)
690 unsigned int cnt
, inpr
;
696 prepare_to_wait(&wakeup_count_wait_queue
, &wait
,
698 split_counters(&cnt
, &inpr
);
699 if (inpr
== 0 || signal_pending(current
))
704 finish_wait(&wakeup_count_wait_queue
, &wait
);
707 split_counters(&cnt
, &inpr
);
713 * pm_save_wakeup_count - Save the current number of registered wakeup events.
714 * @count: Value to compare with the current number of registered wakeup events.
716 * If @count is equal to the current number of registered wakeup events and the
717 * current number of wakeup events being processed is zero, store @count as the
718 * old number of registered wakeup events for pm_check_wakeup_events(), enable
719 * wakeup events detection and return 'true'. Otherwise disable wakeup events
720 * detection and return 'false'.
722 bool pm_save_wakeup_count(unsigned int count
)
724 unsigned int cnt
, inpr
;
726 events_check_enabled
= false;
727 spin_lock_irq(&events_lock
);
728 split_counters(&cnt
, &inpr
);
729 if (cnt
== count
&& inpr
== 0) {
731 events_check_enabled
= true;
733 spin_unlock_irq(&events_lock
);
734 return events_check_enabled
;
737 #ifdef CONFIG_PM_AUTOSLEEP
739 * pm_wakep_autosleep_enabled - Modify autosleep_enabled for all wakeup sources.
740 * @enabled: Whether to set or to clear the autosleep_enabled flags.
742 void pm_wakep_autosleep_enabled(bool set
)
744 struct wakeup_source
*ws
;
745 ktime_t now
= ktime_get();
748 list_for_each_entry_rcu(ws
, &wakeup_sources
, entry
) {
749 spin_lock_irq(&ws
->lock
);
750 if (ws
->autosleep_enabled
!= set
) {
751 ws
->autosleep_enabled
= set
;
754 ws
->start_prevent_time
= now
;
756 update_prevent_sleep_time(ws
, now
);
759 spin_unlock_irq(&ws
->lock
);
763 #endif /* CONFIG_PM_AUTOSLEEP */
765 static struct dentry
*wakeup_sources_stats_dentry
;
768 * print_wakeup_source_stats - Print wakeup source statistics information.
769 * @m: seq_file to print the statistics into.
770 * @ws: Wakeup source object to print the statistics for.
772 static int print_wakeup_source_stats(struct seq_file
*m
,
773 struct wakeup_source
*ws
)
778 unsigned long active_count
;
780 ktime_t prevent_sleep_time
;
783 spin_lock_irqsave(&ws
->lock
, flags
);
785 total_time
= ws
->total_time
;
786 max_time
= ws
->max_time
;
787 prevent_sleep_time
= ws
->prevent_sleep_time
;
788 active_count
= ws
->active_count
;
790 ktime_t now
= ktime_get();
792 active_time
= ktime_sub(now
, ws
->last_time
);
793 total_time
= ktime_add(total_time
, active_time
);
794 if (active_time
.tv64
> max_time
.tv64
)
795 max_time
= active_time
;
797 if (ws
->autosleep_enabled
)
798 prevent_sleep_time
= ktime_add(prevent_sleep_time
,
799 ktime_sub(now
, ws
->start_prevent_time
));
801 active_time
= ktime_set(0, 0);
804 ret
= seq_printf(m
, "%-12s\t%lu\t\t%lu\t\t%lu\t\t%lu\t\t"
805 "%lld\t\t%lld\t\t%lld\t\t%lld\t\t%lld\n",
806 ws
->name
, active_count
, ws
->event_count
,
807 ws
->wakeup_count
, ws
->expire_count
,
808 ktime_to_ms(active_time
), ktime_to_ms(total_time
),
809 ktime_to_ms(max_time
), ktime_to_ms(ws
->last_time
),
810 ktime_to_ms(prevent_sleep_time
));
812 spin_unlock_irqrestore(&ws
->lock
, flags
);
818 * wakeup_sources_stats_show - Print wakeup sources statistics information.
819 * @m: seq_file to print the statistics into.
821 static int wakeup_sources_stats_show(struct seq_file
*m
, void *unused
)
823 struct wakeup_source
*ws
;
825 seq_puts(m
, "name\t\tactive_count\tevent_count\twakeup_count\t"
826 "expire_count\tactive_since\ttotal_time\tmax_time\t"
827 "last_change\tprevent_suspend_time\n");
830 list_for_each_entry_rcu(ws
, &wakeup_sources
, entry
)
831 print_wakeup_source_stats(m
, ws
);
837 static int wakeup_sources_stats_open(struct inode
*inode
, struct file
*file
)
839 return single_open(file
, wakeup_sources_stats_show
, NULL
);
842 static const struct file_operations wakeup_sources_stats_fops
= {
843 .owner
= THIS_MODULE
,
844 .open
= wakeup_sources_stats_open
,
847 .release
= single_release
,
850 static int __init
wakeup_sources_debugfs_init(void)
852 wakeup_sources_stats_dentry
= debugfs_create_file("wakeup_sources",
853 S_IRUGO
, NULL
, NULL
, &wakeup_sources_stats_fops
);
857 postcore_initcall(wakeup_sources_debugfs_init
);