4 * This interface provides a timer which is similarto hrtimers,
5 * but triggers a RTC alarm if the box is suspend.
7 * This interface is influenced by the Android RTC Alarm timer
10 * Copyright (C) 2010 IBM Corperation
12 * Author: John Stultz <john.stultz@linaro.org>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
18 #include <linux/time.h>
19 #include <linux/hrtimer.h>
20 #include <linux/timerqueue.h>
21 #include <linux/rtc.h>
22 #include <linux/sched/signal.h>
23 #include <linux/sched/debug.h>
24 #include <linux/alarmtimer.h>
25 #include <linux/mutex.h>
26 #include <linux/platform_device.h>
27 #include <linux/posix-timers.h>
28 #include <linux/workqueue.h>
29 #include <linux/freezer.h>
30 #include <linux/compat.h>
31 #include <linux/module.h>
33 #include "posix-timers.h"
35 #define CREATE_TRACE_POINTS
36 #include <trace/events/alarmtimer.h>
39 * struct alarm_base - Alarm timer bases
40 * @lock: Lock for syncrhonized access to the base
41 * @timerqueue: Timerqueue head managing the list of events
42 * @gettime: Function to read the time correlating to the base
43 * @base_clockid: clockid for the base
45 static struct alarm_base {
47 struct timerqueue_head timerqueue;
48 ktime_t (*gettime)(void);
49 clockid_t base_clockid;
50 } alarm_bases[ALARM_NUMTYPE];
52 #if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS)
53 /* freezer information to handle clock_nanosleep triggered wakeups */
54 static enum alarmtimer_type freezer_alarmtype;
55 static ktime_t freezer_expires;
56 static ktime_t freezer_delta;
57 static DEFINE_SPINLOCK(freezer_delta_lock);
60 #ifdef CONFIG_RTC_CLASS
61 static struct wakeup_source *ws;
63 /* rtc timer and device for setting alarm wakeups at suspend */
64 static struct rtc_timer rtctimer;
65 static struct rtc_device *rtcdev;
66 static DEFINE_SPINLOCK(rtcdev_lock);
69 * alarmtimer_get_rtcdev - Return selected rtcdevice
71 * This function returns the rtc device to use for wakealarms.
72 * If one has not already been chosen, it checks to see if a
73 * functional rtc device is available.
75 struct rtc_device *alarmtimer_get_rtcdev(void)
78 struct rtc_device *ret;
80 spin_lock_irqsave(&rtcdev_lock, flags);
82 spin_unlock_irqrestore(&rtcdev_lock, flags);
86 EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
88 static int alarmtimer_rtc_add_device(struct device *dev,
89 struct class_interface *class_intf)
92 struct rtc_device *rtc = to_rtc_device(dev);
93 struct wakeup_source *__ws;
99 if (!rtc->ops->set_alarm)
101 if (!device_may_wakeup(rtc->dev.parent))
104 __ws = wakeup_source_register("alarmtimer");
106 spin_lock_irqsave(&rtcdev_lock, flags);
108 if (!try_module_get(rtc->owner)) {
114 /* hold a reference so it doesn't go away */
120 spin_unlock_irqrestore(&rtcdev_lock, flags);
122 wakeup_source_unregister(__ws);
127 static inline void alarmtimer_rtc_timer_init(void)
129 rtc_timer_init(&rtctimer, NULL, NULL);
132 static struct class_interface alarmtimer_rtc_interface = {
133 .add_dev = &alarmtimer_rtc_add_device,
136 static int alarmtimer_rtc_interface_setup(void)
138 alarmtimer_rtc_interface.class = rtc_class;
139 return class_interface_register(&alarmtimer_rtc_interface);
141 static void alarmtimer_rtc_interface_remove(void)
143 class_interface_unregister(&alarmtimer_rtc_interface);
146 struct rtc_device *alarmtimer_get_rtcdev(void)
150 #define rtcdev (NULL)
151 static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
152 static inline void alarmtimer_rtc_interface_remove(void) { }
153 static inline void alarmtimer_rtc_timer_init(void) { }
157 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
158 * @base: pointer to the base where the timer is being run
159 * @alarm: pointer to alarm being enqueued.
161 * Adds alarm to a alarm_base timerqueue
163 * Must hold base->lock when calling.
165 static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
167 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
168 timerqueue_del(&base->timerqueue, &alarm->node);
170 timerqueue_add(&base->timerqueue, &alarm->node);
171 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
175 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
176 * @base: pointer to the base where the timer is running
177 * @alarm: pointer to alarm being removed
179 * Removes alarm to a alarm_base timerqueue
181 * Must hold base->lock when calling.
183 static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
185 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
188 timerqueue_del(&base->timerqueue, &alarm->node);
189 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
194 * alarmtimer_fired - Handles alarm hrtimer being fired.
195 * @timer: pointer to hrtimer being run
197 * When a alarm timer fires, this runs through the timerqueue to
198 * see which alarms expired, and runs those. If there are more alarm
199 * timers queued for the future, we set the hrtimer to fire when
200 * when the next future alarm timer expires.
202 static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
204 struct alarm *alarm = container_of(timer, struct alarm, timer);
205 struct alarm_base *base = &alarm_bases[alarm->type];
207 int ret = HRTIMER_NORESTART;
208 int restart = ALARMTIMER_NORESTART;
210 spin_lock_irqsave(&base->lock, flags);
211 alarmtimer_dequeue(base, alarm);
212 spin_unlock_irqrestore(&base->lock, flags);
215 restart = alarm->function(alarm, base->gettime());
217 spin_lock_irqsave(&base->lock, flags);
218 if (restart != ALARMTIMER_NORESTART) {
219 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
220 alarmtimer_enqueue(base, alarm);
221 ret = HRTIMER_RESTART;
223 spin_unlock_irqrestore(&base->lock, flags);
225 trace_alarmtimer_fired(alarm, base->gettime());
230 ktime_t alarm_expires_remaining(const struct alarm *alarm)
232 struct alarm_base *base = &alarm_bases[alarm->type];
233 return ktime_sub(alarm->node.expires, base->gettime());
235 EXPORT_SYMBOL_GPL(alarm_expires_remaining);
237 #ifdef CONFIG_RTC_CLASS
239 * alarmtimer_suspend - Suspend time callback
243 * When we are going into suspend, we look through the bases
244 * to see which is the soonest timer to expire. We then
245 * set an rtc timer to fire that far into the future, which
246 * will wake us from suspend.
248 static int alarmtimer_suspend(struct device *dev)
250 ktime_t min, now, expires;
252 struct rtc_device *rtc;
256 spin_lock_irqsave(&freezer_delta_lock, flags);
258 expires = freezer_expires;
259 type = freezer_alarmtype;
261 spin_unlock_irqrestore(&freezer_delta_lock, flags);
263 rtc = alarmtimer_get_rtcdev();
264 /* If we have no rtcdev, just return */
268 /* Find the soonest timer to expire*/
269 for (i = 0; i < ALARM_NUMTYPE; i++) {
270 struct alarm_base *base = &alarm_bases[i];
271 struct timerqueue_node *next;
274 spin_lock_irqsave(&base->lock, flags);
275 next = timerqueue_getnext(&base->timerqueue);
276 spin_unlock_irqrestore(&base->lock, flags);
279 delta = ktime_sub(next->expires, base->gettime());
280 if (!min || (delta < min)) {
281 expires = next->expires;
289 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
290 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
294 trace_alarmtimer_suspend(expires, type);
296 /* Setup an rtc timer to fire that far in the future */
297 rtc_timer_cancel(rtc, &rtctimer);
298 rtc_read_time(rtc, &tm);
299 now = rtc_tm_to_ktime(tm);
300 now = ktime_add(now, min);
302 /* Set alarm, if in the past reject suspend briefly to handle */
303 ret = rtc_timer_start(rtc, &rtctimer, now, 0);
305 __pm_wakeup_event(ws, MSEC_PER_SEC);
309 static int alarmtimer_resume(struct device *dev)
311 struct rtc_device *rtc;
313 rtc = alarmtimer_get_rtcdev();
315 rtc_timer_cancel(rtc, &rtctimer);
320 static int alarmtimer_suspend(struct device *dev)
325 static int alarmtimer_resume(struct device *dev)
332 __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
333 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
335 timerqueue_init(&alarm->node);
336 alarm->timer.function = alarmtimer_fired;
337 alarm->function = function;
339 alarm->state = ALARMTIMER_STATE_INACTIVE;
343 * alarm_init - Initialize an alarm structure
344 * @alarm: ptr to alarm to be initialized
345 * @type: the type of the alarm
346 * @function: callback that is run when the alarm fires
348 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
349 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
351 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
353 __alarm_init(alarm, type, function);
355 EXPORT_SYMBOL_GPL(alarm_init);
358 * alarm_start - Sets an absolute alarm to fire
359 * @alarm: ptr to alarm to set
360 * @start: time to run the alarm
362 void alarm_start(struct alarm *alarm, ktime_t start)
364 struct alarm_base *base = &alarm_bases[alarm->type];
367 spin_lock_irqsave(&base->lock, flags);
368 alarm->node.expires = start;
369 alarmtimer_enqueue(base, alarm);
370 hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
371 spin_unlock_irqrestore(&base->lock, flags);
373 trace_alarmtimer_start(alarm, base->gettime());
375 EXPORT_SYMBOL_GPL(alarm_start);
378 * alarm_start_relative - Sets a relative alarm to fire
379 * @alarm: ptr to alarm to set
380 * @start: time relative to now to run the alarm
382 void alarm_start_relative(struct alarm *alarm, ktime_t start)
384 struct alarm_base *base = &alarm_bases[alarm->type];
386 start = ktime_add_safe(start, base->gettime());
387 alarm_start(alarm, start);
389 EXPORT_SYMBOL_GPL(alarm_start_relative);
391 void alarm_restart(struct alarm *alarm)
393 struct alarm_base *base = &alarm_bases[alarm->type];
396 spin_lock_irqsave(&base->lock, flags);
397 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
398 hrtimer_restart(&alarm->timer);
399 alarmtimer_enqueue(base, alarm);
400 spin_unlock_irqrestore(&base->lock, flags);
402 EXPORT_SYMBOL_GPL(alarm_restart);
405 * alarm_try_to_cancel - Tries to cancel an alarm timer
406 * @alarm: ptr to alarm to be canceled
408 * Returns 1 if the timer was canceled, 0 if it was not running,
409 * and -1 if the callback was running
411 int alarm_try_to_cancel(struct alarm *alarm)
413 struct alarm_base *base = &alarm_bases[alarm->type];
417 spin_lock_irqsave(&base->lock, flags);
418 ret = hrtimer_try_to_cancel(&alarm->timer);
420 alarmtimer_dequeue(base, alarm);
421 spin_unlock_irqrestore(&base->lock, flags);
423 trace_alarmtimer_cancel(alarm, base->gettime());
426 EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
430 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
431 * @alarm: ptr to alarm to be canceled
433 * Returns 1 if the timer was canceled, 0 if it was not active.
435 int alarm_cancel(struct alarm *alarm)
438 int ret = alarm_try_to_cancel(alarm);
444 EXPORT_SYMBOL_GPL(alarm_cancel);
447 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
452 delta = ktime_sub(now, alarm->node.expires);
457 if (unlikely(delta >= interval)) {
458 s64 incr = ktime_to_ns(interval);
460 overrun = ktime_divns(delta, incr);
462 alarm->node.expires = ktime_add_ns(alarm->node.expires,
465 if (alarm->node.expires > now)
468 * This (and the ktime_add() below) is the
469 * correction for exact:
474 alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
477 EXPORT_SYMBOL_GPL(alarm_forward);
479 static u64 __alarm_forward_now(struct alarm *alarm, ktime_t interval, bool throttle)
481 struct alarm_base *base = &alarm_bases[alarm->type];
482 ktime_t now = base->gettime();
484 if (IS_ENABLED(CONFIG_HIGH_RES_TIMERS) && throttle) {
486 * Same issue as with posix_timer_fn(). Timers which are
487 * periodic but the signal is ignored can starve the system
488 * with a very small interval. The real fix which was
489 * promised in the context of posix_timer_fn() never
490 * materialized, but someone should really work on it.
492 * To prevent DOS fake @now to be 1 jiffie out which keeps
493 * the overrun accounting correct but creates an
494 * inconsistency vs. timer_gettime(2).
496 ktime_t kj = NSEC_PER_SEC / HZ;
499 now = ktime_add(now, kj);
502 return alarm_forward(alarm, now, interval);
505 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
507 return __alarm_forward_now(alarm, interval, false);
509 EXPORT_SYMBOL_GPL(alarm_forward_now);
511 #ifdef CONFIG_POSIX_TIMERS
513 static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
515 struct alarm_base *base;
521 base = &alarm_bases[ALARM_REALTIME];
522 type = ALARM_REALTIME_FREEZER;
525 base = &alarm_bases[ALARM_BOOTTIME];
526 type = ALARM_BOOTTIME_FREEZER;
529 WARN_ONCE(1, "Invalid alarm type: %d\n", type);
533 delta = ktime_sub(absexp, base->gettime());
535 spin_lock_irqsave(&freezer_delta_lock, flags);
536 if (!freezer_delta || (delta < freezer_delta)) {
537 freezer_delta = delta;
538 freezer_expires = absexp;
539 freezer_alarmtype = type;
541 spin_unlock_irqrestore(&freezer_delta_lock, flags);
545 * clock2alarm - helper that converts from clockid to alarmtypes
548 static enum alarmtimer_type clock2alarm(clockid_t clockid)
550 if (clockid == CLOCK_REALTIME_ALARM)
551 return ALARM_REALTIME;
552 if (clockid == CLOCK_BOOTTIME_ALARM)
553 return ALARM_BOOTTIME;
558 * alarm_handle_timer - Callback for posix timers
559 * @alarm: alarm that fired
561 * Posix timer callback for expired alarm timers.
563 static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
566 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
567 it.alarm.alarmtimer);
568 enum alarmtimer_restart result = ALARMTIMER_NORESTART;
572 spin_lock_irqsave(&ptr->it_lock, flags);
575 if (ptr->it_interval)
576 si_private = ++ptr->it_requeue_pending;
578 if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
580 * Handle ignored signals and rearm the timer. This will go
581 * away once we handle ignored signals proper. Ensure that
582 * small intervals cannot starve the system.
584 ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);
585 ++ptr->it_requeue_pending;
587 result = ALARMTIMER_RESTART;
589 spin_unlock_irqrestore(&ptr->it_lock, flags);
595 * alarm_timer_rearm - Posix timer callback for rearming timer
596 * @timr: Pointer to the posixtimer data struct
598 static void alarm_timer_rearm(struct k_itimer *timr)
600 struct alarm *alarm = &timr->it.alarm.alarmtimer;
602 timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);
603 alarm_start(alarm, alarm->node.expires);
607 * alarm_timer_forward - Posix timer callback for forwarding timer
608 * @timr: Pointer to the posixtimer data struct
609 * @now: Current time to forward the timer against
611 static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now)
613 struct alarm *alarm = &timr->it.alarm.alarmtimer;
615 return alarm_forward(alarm, timr->it_interval, now);
619 * alarm_timer_remaining - Posix timer callback to retrieve remaining time
620 * @timr: Pointer to the posixtimer data struct
621 * @now: Current time to calculate against
623 static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now)
625 struct alarm *alarm = &timr->it.alarm.alarmtimer;
627 return ktime_sub(alarm->node.expires, now);
631 * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer
632 * @timr: Pointer to the posixtimer data struct
634 static int alarm_timer_try_to_cancel(struct k_itimer *timr)
636 return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
640 * alarm_timer_arm - Posix timer callback to arm a timer
641 * @timr: Pointer to the posixtimer data struct
642 * @expires: The new expiry time
643 * @absolute: Expiry value is absolute time
644 * @sigev_none: Posix timer does not deliver signals
646 static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires,
647 bool absolute, bool sigev_none)
649 struct alarm *alarm = &timr->it.alarm.alarmtimer;
650 struct alarm_base *base = &alarm_bases[alarm->type];
653 expires = ktime_add_safe(expires, base->gettime());
655 alarm->node.expires = expires;
657 alarm_start(&timr->it.alarm.alarmtimer, expires);
661 * alarm_clock_getres - posix getres interface
662 * @which_clock: clockid
663 * @tp: timespec to fill
665 * Returns the granularity of underlying alarm base clock
667 static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
669 if (!alarmtimer_get_rtcdev())
673 tp->tv_nsec = hrtimer_resolution;
678 * alarm_clock_get - posix clock_get interface
679 * @which_clock: clockid
680 * @tp: timespec to fill.
682 * Provides the underlying alarm base time.
684 static int alarm_clock_get(clockid_t which_clock, struct timespec64 *tp)
686 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
688 if (!alarmtimer_get_rtcdev())
691 *tp = ktime_to_timespec64(base->gettime());
696 * alarm_timer_create - posix timer_create interface
697 * @new_timer: k_itimer pointer to manage
699 * Initializes the k_itimer structure.
701 static int alarm_timer_create(struct k_itimer *new_timer)
703 enum alarmtimer_type type;
705 if (!alarmtimer_get_rtcdev())
708 if (!capable(CAP_WAKE_ALARM))
711 type = clock2alarm(new_timer->it_clock);
712 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
717 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
718 * @alarm: ptr to alarm that fired
720 * Wakes up the task that set the alarmtimer
722 static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
725 struct task_struct *task = (struct task_struct *)alarm->data;
729 wake_up_process(task);
730 return ALARMTIMER_NORESTART;
734 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
735 * @alarm: ptr to alarmtimer
736 * @absexp: absolute expiration time
738 * Sets the alarm timer and sleeps until it is fired or interrupted.
740 static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
741 enum alarmtimer_type type)
743 struct restart_block *restart;
744 alarm->data = (void *)current;
746 set_current_state(TASK_INTERRUPTIBLE);
747 alarm_start(alarm, absexp);
748 if (likely(alarm->data))
752 } while (alarm->data && !signal_pending(current));
754 __set_current_state(TASK_RUNNING);
756 destroy_hrtimer_on_stack(&alarm->timer);
761 if (freezing(current))
762 alarmtimer_freezerset(absexp, type);
763 restart = ¤t->restart_block;
764 if (restart->nanosleep.type != TT_NONE) {
765 struct timespec64 rmt;
768 rem = ktime_sub(absexp, alarm_bases[type].gettime());
772 rmt = ktime_to_timespec64(rem);
774 return nanosleep_copyout(restart, &rmt);
776 return -ERESTART_RESTARTBLOCK;
780 alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type,
781 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
783 hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,
785 __alarm_init(alarm, type, function);
789 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
790 * @restart: ptr to restart block
792 * Handles restarted clock_nanosleep calls
794 static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
796 enum alarmtimer_type type = restart->nanosleep.clockid;
797 ktime_t exp = restart->nanosleep.expires;
800 alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
802 return alarmtimer_do_nsleep(&alarm, exp, type);
806 * alarm_timer_nsleep - alarmtimer nanosleep
807 * @which_clock: clockid
808 * @flags: determins abstime or relative
809 * @tsreq: requested sleep time (abs or rel)
810 * @rmtp: remaining sleep time saved
812 * Handles clock_nanosleep calls against _ALARM clockids
814 static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
815 const struct timespec64 *tsreq)
817 enum alarmtimer_type type = clock2alarm(which_clock);
818 struct restart_block *restart = ¤t->restart_block;
823 if (!alarmtimer_get_rtcdev())
826 if (flags & ~TIMER_ABSTIME)
829 if (!capable(CAP_WAKE_ALARM))
832 alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
834 exp = timespec64_to_ktime(*tsreq);
835 /* Convert (if necessary) to absolute time */
836 if (flags != TIMER_ABSTIME) {
837 ktime_t now = alarm_bases[type].gettime();
839 exp = ktime_add_safe(now, exp);
842 ret = alarmtimer_do_nsleep(&alarm, exp, type);
843 if (ret != -ERESTART_RESTARTBLOCK)
846 /* abs timers don't set remaining time or restart */
847 if (flags == TIMER_ABSTIME)
848 return -ERESTARTNOHAND;
850 restart->nanosleep.clockid = type;
851 restart->nanosleep.expires = exp;
852 set_restart_fn(restart, alarm_timer_nsleep_restart);
856 const struct k_clock alarm_clock = {
857 .clock_getres = alarm_clock_getres,
858 .clock_get = alarm_clock_get,
859 .timer_create = alarm_timer_create,
860 .timer_set = common_timer_set,
861 .timer_del = common_timer_del,
862 .timer_get = common_timer_get,
863 .timer_arm = alarm_timer_arm,
864 .timer_rearm = alarm_timer_rearm,
865 .timer_forward = alarm_timer_forward,
866 .timer_remaining = alarm_timer_remaining,
867 .timer_try_to_cancel = alarm_timer_try_to_cancel,
868 .nsleep = alarm_timer_nsleep,
870 #endif /* CONFIG_POSIX_TIMERS */
873 /* Suspend hook structures */
874 static const struct dev_pm_ops alarmtimer_pm_ops = {
875 .suspend = alarmtimer_suspend,
876 .resume = alarmtimer_resume,
879 static struct platform_driver alarmtimer_driver = {
881 .name = "alarmtimer",
882 .pm = &alarmtimer_pm_ops,
887 * alarmtimer_init - Initialize alarm timer code
889 * This function initializes the alarm bases and registers
890 * the posix clock ids.
892 static int __init alarmtimer_init(void)
894 struct platform_device *pdev;
898 alarmtimer_rtc_timer_init();
900 /* Initialize alarm bases */
901 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
902 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
903 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
904 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
905 for (i = 0; i < ALARM_NUMTYPE; i++) {
906 timerqueue_init_head(&alarm_bases[i].timerqueue);
907 spin_lock_init(&alarm_bases[i].lock);
910 error = alarmtimer_rtc_interface_setup();
914 error = platform_driver_register(&alarmtimer_driver);
918 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
920 error = PTR_ERR(pdev);
926 platform_driver_unregister(&alarmtimer_driver);
928 alarmtimer_rtc_interface_remove();
931 device_initcall(alarmtimer_init);