1 // SPDX-License-Identifier: GPL-2.0
5 * This interface provides a timer which is similarto hrtimers,
6 * but triggers a RTC alarm if the box is suspend.
8 * This interface is influenced by the Android RTC Alarm timer
11 * Copyright (C) 2010 IBM Corperation
13 * Author: John Stultz <john.stultz@linaro.org>
15 #include <linux/time.h>
16 #include <linux/hrtimer.h>
17 #include <linux/timerqueue.h>
18 #include <linux/rtc.h>
19 #include <linux/sched/signal.h>
20 #include <linux/sched/debug.h>
21 #include <linux/alarmtimer.h>
22 #include <linux/mutex.h>
23 #include <linux/platform_device.h>
24 #include <linux/posix-timers.h>
25 #include <linux/workqueue.h>
26 #include <linux/freezer.h>
27 #include <linux/compat.h>
28 #include <linux/module.h>
30 #include "posix-timers.h"
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/alarmtimer.h>
36 * struct alarm_base - Alarm timer bases
37 * @lock: Lock for syncrhonized access to the base
38 * @timerqueue: Timerqueue head managing the list of events
39 * @gettime: Function to read the time correlating to the base
40 * @base_clockid: clockid for the base
42 static struct alarm_base {
44 struct timerqueue_head timerqueue;
45 ktime_t (*gettime)(void);
46 clockid_t base_clockid;
47 } alarm_bases[ALARM_NUMTYPE];
49 #if defined(CONFIG_POSIX_TIMERS) || defined(CONFIG_RTC_CLASS)
50 /* freezer information to handle clock_nanosleep triggered wakeups */
51 static enum alarmtimer_type freezer_alarmtype;
52 static ktime_t freezer_expires;
53 static ktime_t freezer_delta;
54 static DEFINE_SPINLOCK(freezer_delta_lock);
57 #ifdef CONFIG_RTC_CLASS
58 static struct wakeup_source *ws;
60 /* rtc timer and device for setting alarm wakeups at suspend */
61 static struct rtc_timer rtctimer;
62 static struct rtc_device *rtcdev;
63 static DEFINE_SPINLOCK(rtcdev_lock);
66 * alarmtimer_get_rtcdev - Return selected rtcdevice
68 * This function returns the rtc device to use for wakealarms.
69 * If one has not already been chosen, it checks to see if a
70 * functional rtc device is available.
72 struct rtc_device *alarmtimer_get_rtcdev(void)
75 struct rtc_device *ret;
77 spin_lock_irqsave(&rtcdev_lock, flags);
79 spin_unlock_irqrestore(&rtcdev_lock, flags);
83 EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
85 static int alarmtimer_rtc_add_device(struct device *dev,
86 struct class_interface *class_intf)
89 struct rtc_device *rtc = to_rtc_device(dev);
90 struct wakeup_source *__ws;
95 if (!rtc->ops->set_alarm)
97 if (!device_may_wakeup(rtc->dev.parent))
100 __ws = wakeup_source_register("alarmtimer");
102 spin_lock_irqsave(&rtcdev_lock, flags);
104 if (!try_module_get(rtc->owner)) {
105 spin_unlock_irqrestore(&rtcdev_lock, flags);
110 /* hold a reference so it doesn't go away */
115 spin_unlock_irqrestore(&rtcdev_lock, flags);
117 wakeup_source_unregister(__ws);
122 static inline void alarmtimer_rtc_timer_init(void)
124 rtc_timer_init(&rtctimer, NULL, NULL);
127 static struct class_interface alarmtimer_rtc_interface = {
128 .add_dev = &alarmtimer_rtc_add_device,
131 static int alarmtimer_rtc_interface_setup(void)
133 alarmtimer_rtc_interface.class = rtc_class;
134 return class_interface_register(&alarmtimer_rtc_interface);
136 static void alarmtimer_rtc_interface_remove(void)
138 class_interface_unregister(&alarmtimer_rtc_interface);
141 struct rtc_device *alarmtimer_get_rtcdev(void)
145 #define rtcdev (NULL)
146 static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
147 static inline void alarmtimer_rtc_interface_remove(void) { }
148 static inline void alarmtimer_rtc_timer_init(void) { }
152 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
153 * @base: pointer to the base where the timer is being run
154 * @alarm: pointer to alarm being enqueued.
156 * Adds alarm to a alarm_base timerqueue
158 * Must hold base->lock when calling.
160 static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
162 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
163 timerqueue_del(&base->timerqueue, &alarm->node);
165 timerqueue_add(&base->timerqueue, &alarm->node);
166 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
170 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
171 * @base: pointer to the base where the timer is running
172 * @alarm: pointer to alarm being removed
174 * Removes alarm to a alarm_base timerqueue
176 * Must hold base->lock when calling.
178 static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
180 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
183 timerqueue_del(&base->timerqueue, &alarm->node);
184 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
189 * alarmtimer_fired - Handles alarm hrtimer being fired.
190 * @timer: pointer to hrtimer being run
192 * When a alarm timer fires, this runs through the timerqueue to
193 * see which alarms expired, and runs those. If there are more alarm
194 * timers queued for the future, we set the hrtimer to fire when
195 * when the next future alarm timer expires.
197 static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
199 struct alarm *alarm = container_of(timer, struct alarm, timer);
200 struct alarm_base *base = &alarm_bases[alarm->type];
202 int ret = HRTIMER_NORESTART;
203 int restart = ALARMTIMER_NORESTART;
205 spin_lock_irqsave(&base->lock, flags);
206 alarmtimer_dequeue(base, alarm);
207 spin_unlock_irqrestore(&base->lock, flags);
210 restart = alarm->function(alarm, base->gettime());
212 spin_lock_irqsave(&base->lock, flags);
213 if (restart != ALARMTIMER_NORESTART) {
214 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
215 alarmtimer_enqueue(base, alarm);
216 ret = HRTIMER_RESTART;
218 spin_unlock_irqrestore(&base->lock, flags);
220 trace_alarmtimer_fired(alarm, base->gettime());
225 ktime_t alarm_expires_remaining(const struct alarm *alarm)
227 struct alarm_base *base = &alarm_bases[alarm->type];
228 return ktime_sub(alarm->node.expires, base->gettime());
230 EXPORT_SYMBOL_GPL(alarm_expires_remaining);
232 #ifdef CONFIG_RTC_CLASS
234 * alarmtimer_suspend - Suspend time callback
237 * When we are going into suspend, we look through the bases
238 * to see which is the soonest timer to expire. We then
239 * set an rtc timer to fire that far into the future, which
240 * will wake us from suspend.
242 static int alarmtimer_suspend(struct device *dev)
244 ktime_t min, now, expires;
246 struct rtc_device *rtc;
250 spin_lock_irqsave(&freezer_delta_lock, flags);
252 expires = freezer_expires;
253 type = freezer_alarmtype;
255 spin_unlock_irqrestore(&freezer_delta_lock, flags);
257 rtc = alarmtimer_get_rtcdev();
258 /* If we have no rtcdev, just return */
262 /* Find the soonest timer to expire*/
263 for (i = 0; i < ALARM_NUMTYPE; i++) {
264 struct alarm_base *base = &alarm_bases[i];
265 struct timerqueue_node *next;
268 spin_lock_irqsave(&base->lock, flags);
269 next = timerqueue_getnext(&base->timerqueue);
270 spin_unlock_irqrestore(&base->lock, flags);
273 delta = ktime_sub(next->expires, base->gettime());
274 if (!min || (delta < min)) {
275 expires = next->expires;
283 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
284 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
288 trace_alarmtimer_suspend(expires, type);
290 /* Setup an rtc timer to fire that far in the future */
291 rtc_timer_cancel(rtc, &rtctimer);
292 rtc_read_time(rtc, &tm);
293 now = rtc_tm_to_ktime(tm);
294 now = ktime_add(now, min);
296 /* Set alarm, if in the past reject suspend briefly to handle */
297 ret = rtc_timer_start(rtc, &rtctimer, now, 0);
299 __pm_wakeup_event(ws, MSEC_PER_SEC);
303 static int alarmtimer_resume(struct device *dev)
305 struct rtc_device *rtc;
307 rtc = alarmtimer_get_rtcdev();
309 rtc_timer_cancel(rtc, &rtctimer);
314 static int alarmtimer_suspend(struct device *dev)
319 static int alarmtimer_resume(struct device *dev)
326 __alarm_init(struct alarm *alarm, enum alarmtimer_type type,
327 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
329 timerqueue_init(&alarm->node);
330 alarm->timer.function = alarmtimer_fired;
331 alarm->function = function;
333 alarm->state = ALARMTIMER_STATE_INACTIVE;
337 * alarm_init - Initialize an alarm structure
338 * @alarm: ptr to alarm to be initialized
339 * @type: the type of the alarm
340 * @function: callback that is run when the alarm fires
342 void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
343 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
345 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
347 __alarm_init(alarm, type, function);
349 EXPORT_SYMBOL_GPL(alarm_init);
352 * alarm_start - Sets an absolute alarm to fire
353 * @alarm: ptr to alarm to set
354 * @start: time to run the alarm
356 void alarm_start(struct alarm *alarm, ktime_t start)
358 struct alarm_base *base = &alarm_bases[alarm->type];
361 spin_lock_irqsave(&base->lock, flags);
362 alarm->node.expires = start;
363 alarmtimer_enqueue(base, alarm);
364 hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
365 spin_unlock_irqrestore(&base->lock, flags);
367 trace_alarmtimer_start(alarm, base->gettime());
369 EXPORT_SYMBOL_GPL(alarm_start);
372 * alarm_start_relative - Sets a relative alarm to fire
373 * @alarm: ptr to alarm to set
374 * @start: time relative to now to run the alarm
376 void alarm_start_relative(struct alarm *alarm, ktime_t start)
378 struct alarm_base *base = &alarm_bases[alarm->type];
380 start = ktime_add_safe(start, base->gettime());
381 alarm_start(alarm, start);
383 EXPORT_SYMBOL_GPL(alarm_start_relative);
385 void alarm_restart(struct alarm *alarm)
387 struct alarm_base *base = &alarm_bases[alarm->type];
390 spin_lock_irqsave(&base->lock, flags);
391 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
392 hrtimer_restart(&alarm->timer);
393 alarmtimer_enqueue(base, alarm);
394 spin_unlock_irqrestore(&base->lock, flags);
396 EXPORT_SYMBOL_GPL(alarm_restart);
399 * alarm_try_to_cancel - Tries to cancel an alarm timer
400 * @alarm: ptr to alarm to be canceled
402 * Returns 1 if the timer was canceled, 0 if it was not running,
403 * and -1 if the callback was running
405 int alarm_try_to_cancel(struct alarm *alarm)
407 struct alarm_base *base = &alarm_bases[alarm->type];
411 spin_lock_irqsave(&base->lock, flags);
412 ret = hrtimer_try_to_cancel(&alarm->timer);
414 alarmtimer_dequeue(base, alarm);
415 spin_unlock_irqrestore(&base->lock, flags);
417 trace_alarmtimer_cancel(alarm, base->gettime());
420 EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
424 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
425 * @alarm: ptr to alarm to be canceled
427 * Returns 1 if the timer was canceled, 0 if it was not active.
429 int alarm_cancel(struct alarm *alarm)
432 int ret = alarm_try_to_cancel(alarm);
438 EXPORT_SYMBOL_GPL(alarm_cancel);
441 u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
446 delta = ktime_sub(now, alarm->node.expires);
451 if (unlikely(delta >= interval)) {
452 s64 incr = ktime_to_ns(interval);
454 overrun = ktime_divns(delta, incr);
456 alarm->node.expires = ktime_add_ns(alarm->node.expires,
459 if (alarm->node.expires > now)
462 * This (and the ktime_add() below) is the
463 * correction for exact:
468 alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);
471 EXPORT_SYMBOL_GPL(alarm_forward);
473 u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
475 struct alarm_base *base = &alarm_bases[alarm->type];
477 return alarm_forward(alarm, base->gettime(), interval);
479 EXPORT_SYMBOL_GPL(alarm_forward_now);
481 #ifdef CONFIG_POSIX_TIMERS
483 static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
485 struct alarm_base *base;
491 base = &alarm_bases[ALARM_REALTIME];
492 type = ALARM_REALTIME_FREEZER;
495 base = &alarm_bases[ALARM_BOOTTIME];
496 type = ALARM_BOOTTIME_FREEZER;
499 WARN_ONCE(1, "Invalid alarm type: %d\n", type);
503 delta = ktime_sub(absexp, base->gettime());
505 spin_lock_irqsave(&freezer_delta_lock, flags);
506 if (!freezer_delta || (delta < freezer_delta)) {
507 freezer_delta = delta;
508 freezer_expires = absexp;
509 freezer_alarmtype = type;
511 spin_unlock_irqrestore(&freezer_delta_lock, flags);
515 * clock2alarm - helper that converts from clockid to alarmtypes
518 static enum alarmtimer_type clock2alarm(clockid_t clockid)
520 if (clockid == CLOCK_REALTIME_ALARM)
521 return ALARM_REALTIME;
522 if (clockid == CLOCK_BOOTTIME_ALARM)
523 return ALARM_BOOTTIME;
528 * alarm_handle_timer - Callback for posix timers
529 * @alarm: alarm that fired
531 * Posix timer callback for expired alarm timers.
533 static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
536 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
537 it.alarm.alarmtimer);
538 enum alarmtimer_restart result = ALARMTIMER_NORESTART;
542 spin_lock_irqsave(&ptr->it_lock, flags);
545 if (ptr->it_interval)
546 si_private = ++ptr->it_requeue_pending;
548 if (posix_timer_event(ptr, si_private) && ptr->it_interval) {
550 * Handle ignored signals and rearm the timer. This will go
551 * away once we handle ignored signals proper.
553 ptr->it_overrun += alarm_forward_now(alarm, ptr->it_interval);
554 ++ptr->it_requeue_pending;
556 result = ALARMTIMER_RESTART;
558 spin_unlock_irqrestore(&ptr->it_lock, flags);
564 * alarm_timer_rearm - Posix timer callback for rearming timer
565 * @timr: Pointer to the posixtimer data struct
567 static void alarm_timer_rearm(struct k_itimer *timr)
569 struct alarm *alarm = &timr->it.alarm.alarmtimer;
571 timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);
572 alarm_start(alarm, alarm->node.expires);
576 * alarm_timer_forward - Posix timer callback for forwarding timer
577 * @timr: Pointer to the posixtimer data struct
578 * @now: Current time to forward the timer against
580 static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now)
582 struct alarm *alarm = &timr->it.alarm.alarmtimer;
584 return alarm_forward(alarm, timr->it_interval, now);
588 * alarm_timer_remaining - Posix timer callback to retrieve remaining time
589 * @timr: Pointer to the posixtimer data struct
590 * @now: Current time to calculate against
592 static ktime_t alarm_timer_remaining(struct k_itimer *timr, ktime_t now)
594 struct alarm *alarm = &timr->it.alarm.alarmtimer;
596 return ktime_sub(alarm->node.expires, now);
600 * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer
601 * @timr: Pointer to the posixtimer data struct
603 static int alarm_timer_try_to_cancel(struct k_itimer *timr)
605 return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);
609 * alarm_timer_arm - Posix timer callback to arm a timer
610 * @timr: Pointer to the posixtimer data struct
611 * @expires: The new expiry time
612 * @absolute: Expiry value is absolute time
613 * @sigev_none: Posix timer does not deliver signals
615 static void alarm_timer_arm(struct k_itimer *timr, ktime_t expires,
616 bool absolute, bool sigev_none)
618 struct alarm *alarm = &timr->it.alarm.alarmtimer;
619 struct alarm_base *base = &alarm_bases[alarm->type];
622 expires = ktime_add_safe(expires, base->gettime());
624 alarm->node.expires = expires;
626 alarm_start(&timr->it.alarm.alarmtimer, expires);
630 * alarm_clock_getres - posix getres interface
631 * @which_clock: clockid
632 * @tp: timespec to fill
634 * Returns the granularity of underlying alarm base clock
636 static int alarm_clock_getres(const clockid_t which_clock, struct timespec64 *tp)
638 if (!alarmtimer_get_rtcdev())
642 tp->tv_nsec = hrtimer_resolution;
647 * alarm_clock_get - posix clock_get interface
648 * @which_clock: clockid
649 * @tp: timespec to fill.
651 * Provides the underlying alarm base time.
653 static int alarm_clock_get(clockid_t which_clock, struct timespec64 *tp)
655 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
657 if (!alarmtimer_get_rtcdev())
660 *tp = ktime_to_timespec64(base->gettime());
665 * alarm_timer_create - posix timer_create interface
666 * @new_timer: k_itimer pointer to manage
668 * Initializes the k_itimer structure.
670 static int alarm_timer_create(struct k_itimer *new_timer)
672 enum alarmtimer_type type;
674 if (!alarmtimer_get_rtcdev())
677 if (!capable(CAP_WAKE_ALARM))
680 type = clock2alarm(new_timer->it_clock);
681 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
686 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
687 * @alarm: ptr to alarm that fired
689 * Wakes up the task that set the alarmtimer
691 static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
694 struct task_struct *task = (struct task_struct *)alarm->data;
698 wake_up_process(task);
699 return ALARMTIMER_NORESTART;
703 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
704 * @alarm: ptr to alarmtimer
705 * @absexp: absolute expiration time
707 * Sets the alarm timer and sleeps until it is fired or interrupted.
709 static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp,
710 enum alarmtimer_type type)
712 struct restart_block *restart;
713 alarm->data = (void *)current;
715 set_current_state(TASK_INTERRUPTIBLE);
716 alarm_start(alarm, absexp);
717 if (likely(alarm->data))
721 } while (alarm->data && !signal_pending(current));
723 __set_current_state(TASK_RUNNING);
725 destroy_hrtimer_on_stack(&alarm->timer);
730 if (freezing(current))
731 alarmtimer_freezerset(absexp, type);
732 restart = ¤t->restart_block;
733 if (restart->nanosleep.type != TT_NONE) {
734 struct timespec64 rmt;
737 rem = ktime_sub(absexp, alarm_bases[type].gettime());
741 rmt = ktime_to_timespec64(rem);
743 return nanosleep_copyout(restart, &rmt);
745 return -ERESTART_RESTARTBLOCK;
749 alarm_init_on_stack(struct alarm *alarm, enum alarmtimer_type type,
750 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
752 hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,
754 __alarm_init(alarm, type, function);
758 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
759 * @restart: ptr to restart block
761 * Handles restarted clock_nanosleep calls
763 static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
765 enum alarmtimer_type type = restart->nanosleep.clockid;
766 ktime_t exp = restart->nanosleep.expires;
769 alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
771 return alarmtimer_do_nsleep(&alarm, exp, type);
775 * alarm_timer_nsleep - alarmtimer nanosleep
776 * @which_clock: clockid
777 * @flags: determins abstime or relative
778 * @tsreq: requested sleep time (abs or rel)
779 * @rmtp: remaining sleep time saved
781 * Handles clock_nanosleep calls against _ALARM clockids
783 static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
784 const struct timespec64 *tsreq)
786 enum alarmtimer_type type = clock2alarm(which_clock);
787 struct restart_block *restart = ¤t->restart_block;
792 if (!alarmtimer_get_rtcdev())
795 if (flags & ~TIMER_ABSTIME)
798 if (!capable(CAP_WAKE_ALARM))
801 alarm_init_on_stack(&alarm, type, alarmtimer_nsleep_wakeup);
803 exp = timespec64_to_ktime(*tsreq);
804 /* Convert (if necessary) to absolute time */
805 if (flags != TIMER_ABSTIME) {
806 ktime_t now = alarm_bases[type].gettime();
808 exp = ktime_add_safe(now, exp);
811 ret = alarmtimer_do_nsleep(&alarm, exp, type);
812 if (ret != -ERESTART_RESTARTBLOCK)
815 /* abs timers don't set remaining time or restart */
816 if (flags == TIMER_ABSTIME)
817 return -ERESTARTNOHAND;
819 restart->fn = alarm_timer_nsleep_restart;
820 restart->nanosleep.clockid = type;
821 restart->nanosleep.expires = exp;
825 const struct k_clock alarm_clock = {
826 .clock_getres = alarm_clock_getres,
827 .clock_get = alarm_clock_get,
828 .timer_create = alarm_timer_create,
829 .timer_set = common_timer_set,
830 .timer_del = common_timer_del,
831 .timer_get = common_timer_get,
832 .timer_arm = alarm_timer_arm,
833 .timer_rearm = alarm_timer_rearm,
834 .timer_forward = alarm_timer_forward,
835 .timer_remaining = alarm_timer_remaining,
836 .timer_try_to_cancel = alarm_timer_try_to_cancel,
837 .nsleep = alarm_timer_nsleep,
839 #endif /* CONFIG_POSIX_TIMERS */
842 /* Suspend hook structures */
843 static const struct dev_pm_ops alarmtimer_pm_ops = {
844 .suspend = alarmtimer_suspend,
845 .resume = alarmtimer_resume,
848 static struct platform_driver alarmtimer_driver = {
850 .name = "alarmtimer",
851 .pm = &alarmtimer_pm_ops,
856 * alarmtimer_init - Initialize alarm timer code
858 * This function initializes the alarm bases and registers
859 * the posix clock ids.
861 static int __init alarmtimer_init(void)
863 struct platform_device *pdev;
867 alarmtimer_rtc_timer_init();
869 /* Initialize alarm bases */
870 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
871 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
872 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
873 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
874 for (i = 0; i < ALARM_NUMTYPE; i++) {
875 timerqueue_init_head(&alarm_bases[i].timerqueue);
876 spin_lock_init(&alarm_bases[i].lock);
879 error = alarmtimer_rtc_interface_setup();
883 error = platform_driver_register(&alarmtimer_driver);
887 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
889 error = PTR_ERR(pdev);
895 platform_driver_unregister(&alarmtimer_driver);
897 alarmtimer_rtc_interface_remove();
900 device_initcall(alarmtimer_init);