1 // SPDX-License-Identifier: GPL-2.0
5  * This interface provides a timer which is similar to hrtimers,
6  * but triggers a RTC alarm if the box is suspend.
8  * This interface is influenced by the Android RTC Alarm timer
18 #include <linux/rtc.h>
24 #include <linux/posix-timers.h>
31 #include "posix-timers.h"
37  * struct alarm_base - Alarm timer bases
61 /* rtc timer and device for setting alarm wakeups at suspend */
67  * alarmtimer_get_rtcdev - Return selected rtcdevice
69  * This function returns the rtc device to use for wakealarms.
87 	struct rtc_device *rtc = to_rtc_device(dev);  in alarmtimer_rtc_add_device()  local
92 		return -EBUSY;  in alarmtimer_rtc_add_device()
94 	if (!test_bit(RTC_FEATURE_ALARM, rtc->features))  in alarmtimer_rtc_add_device()
95 		return -1;  in alarmtimer_rtc_add_device()
96 	if (!device_may_wakeup(rtc->dev.parent))  in alarmtimer_rtc_add_device()
97 		return -1;  in alarmtimer_rtc_add_device()
102 		device_init_wakeup(&pdev->dev, true);  in alarmtimer_rtc_add_device()
106 		if (!try_module_get(rtc->owner)) {  in alarmtimer_rtc_add_device()
107 			ret = -1;  in alarmtimer_rtc_add_device()
111 		rtcdev = rtc;  in alarmtimer_rtc_add_device()
116 		ret = -1;  in alarmtimer_rtc_add_device()
151  * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
152  * @base: pointer to the base where the timer is being run
157  * Must hold base->lock when calling.
161 	if (alarm->state & ALARMTIMER_STATE_ENQUEUED)  in alarmtimer_enqueue()
162 		timerqueue_del(&base->timerqueue, &alarm->node);  in alarmtimer_enqueue()
164 	timerqueue_add(&base->timerqueue, &alarm->node);  in alarmtimer_enqueue()
165 	alarm->state |= ALARMTIMER_STATE_ENQUEUED;  in alarmtimer_enqueue()
169  * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
170  * @base: pointer to the base where the timer is running
175  * Must hold base->lock when calling.
179 	if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))  in alarmtimer_dequeue()
182 	timerqueue_del(&base->timerqueue, &alarm->node);  in alarmtimer_dequeue()
183 	alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;  in alarmtimer_dequeue()
188  * alarmtimer_fired - Handles alarm hrtimer being fired.
189  * @timer: pointer to hrtimer being run
191  * When a alarm timer fires, this runs through the timerqueue to
194  * the next future alarm timer expires.
196 static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)  in alarmtimer_fired()  argument
198 	struct alarm *alarm = container_of(timer, struct alarm, timer);  in alarmtimer_fired()
199 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarmtimer_fired()
204 	spin_lock_irqsave(&base->lock, flags);  in alarmtimer_fired()
206 	spin_unlock_irqrestore(&base->lock, flags);  in alarmtimer_fired()
208 	if (alarm->function)  in alarmtimer_fired()
209 		restart = alarm->function(alarm, base->get_ktime());  in alarmtimer_fired()
211 	spin_lock_irqsave(&base->lock, flags);  in alarmtimer_fired()
213 		hrtimer_set_expires(&alarm->timer, alarm->node.expires);  in alarmtimer_fired()
217 	spin_unlock_irqrestore(&base->lock, flags);  in alarmtimer_fired()
219 	trace_alarmtimer_fired(alarm, base->get_ktime());  in alarmtimer_fired()
226 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_expires_remaining()
227 	return ktime_sub(alarm->node.expires, base->get_ktime());  in alarm_expires_remaining()
233  * alarmtimer_suspend - Suspend time callback
237  * to see which is the soonest timer to expire. We then
238  * set an rtc timer to fire that far into the future, which
245 	struct rtc_device *rtc;  in alarmtimer_suspend()  local
256 	rtc = alarmtimer_get_rtcdev();  in alarmtimer_suspend()
258 	if (!rtc)  in alarmtimer_suspend()
261 	/* Find the soonest timer to expire*/  in alarmtimer_suspend()
267 		spin_lock_irqsave(&base->lock, flags);  in alarmtimer_suspend()
268 		next = timerqueue_getnext(&base->timerqueue);  in alarmtimer_suspend()
269 		spin_unlock_irqrestore(&base->lock, flags);  in alarmtimer_suspend()
272 		delta = ktime_sub(next->expires, base->get_ktime());  in alarmtimer_suspend()
274 			expires = next->expires;  in alarmtimer_suspend()
284 		return -EBUSY;  in alarmtimer_suspend()
289 	/* Setup an rtc timer to fire that far in the future */  in alarmtimer_suspend()
290 	rtc_timer_cancel(rtc, &rtctimer);  in alarmtimer_suspend()
291 	rtc_read_time(rtc, &tm);  in alarmtimer_suspend()
295 	 * If the RTC alarm timer only supports a limited time offset, set the  in alarmtimer_suspend()
299 	 * the alarmtimer exceeds the time that the rtc device can be programmed  in alarmtimer_suspend()
302 	min = rtc_bound_alarmtime(rtc, min);  in alarmtimer_suspend()
307 	ret = rtc_timer_start(rtc, &rtctimer, now, 0);  in alarmtimer_suspend()
315 	struct rtc_device *rtc;  in alarmtimer_resume()  local
317 	rtc = alarmtimer_get_rtcdev();  in alarmtimer_resume()
318 	if (rtc)  in alarmtimer_resume()
319 		rtc_timer_cancel(rtc, &rtctimer);  in alarmtimer_resume()
339 	timerqueue_init(&alarm->node);  in __alarm_init()
340 	alarm->timer.function = alarmtimer_fired;  in __alarm_init()
341 	alarm->function = function;  in __alarm_init()
342 	alarm->type = type;  in __alarm_init()
343 	alarm->state = ALARMTIMER_STATE_INACTIVE;  in __alarm_init()
347  * alarm_init - Initialize an alarm structure
355 	hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,  in alarm_init()
362  * alarm_start - Sets an absolute alarm to fire
368 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_start()
371 	spin_lock_irqsave(&base->lock, flags);  in alarm_start()
372 	alarm->node.expires = start;  in alarm_start()
374 	hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);  in alarm_start()
375 	spin_unlock_irqrestore(&base->lock, flags);  in alarm_start()
377 	trace_alarmtimer_start(alarm, base->get_ktime());  in alarm_start()
382  * alarm_start_relative - Sets a relative alarm to fire
388 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_start_relative()
390 	start = ktime_add_safe(start, base->get_ktime());  in alarm_start_relative()
397 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_restart()
400 	spin_lock_irqsave(&base->lock, flags);  in alarm_restart()
401 	hrtimer_set_expires(&alarm->timer, alarm->node.expires);  in alarm_restart()
402 	hrtimer_restart(&alarm->timer);  in alarm_restart()
404 	spin_unlock_irqrestore(&base->lock, flags);  in alarm_restart()
409  * alarm_try_to_cancel - Tries to cancel an alarm timer
412  * Returns 1 if the timer was canceled, 0 if it was not running,
413  * and -1 if the callback was running
417 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_try_to_cancel()
421 	spin_lock_irqsave(&base->lock, flags);  in alarm_try_to_cancel()
422 	ret = hrtimer_try_to_cancel(&alarm->timer);  in alarm_try_to_cancel()
425 	spin_unlock_irqrestore(&base->lock, flags);  in alarm_try_to_cancel()
427 	trace_alarmtimer_cancel(alarm, base->get_ktime());  in alarm_try_to_cancel()
434  * alarm_cancel - Spins trying to cancel an alarm timer until it is done
437  * Returns 1 if the timer was canceled, 0 if it was not active.
445 		hrtimer_cancel_wait_running(&alarm->timer);  in alarm_cancel()
456 	delta = ktime_sub(now, alarm->node.expires);  in alarm_forward()
466 		alarm->node.expires = ktime_add_ns(alarm->node.expires,  in alarm_forward()
469 		if (alarm->node.expires > now)  in alarm_forward()
478 	alarm->node.expires = ktime_add_safe(alarm->node.expires, interval);  in alarm_forward()
485 	struct alarm_base *base = &alarm_bases[alarm->type];  in __alarm_forward_now()
486 	ktime_t now = base->get_ktime();  in __alarm_forward_now()
537 	delta = ktime_sub(absexp, base->get_ktime());  in alarmtimer_freezerset()
549  * clock2alarm - helper that converts from clockid to alarmtypes
558 	return -1;  in clock2alarm()
562  * alarm_handle_timer - Callback for posix timers
564  * @now: time at the timer expiration
566  * Posix timer callback for expired alarm timers.
568  * Return: whether the timer is to be restarted
579 	spin_lock_irqsave(&ptr->it_lock, flags);  in alarm_handle_timer()
581 	ptr->it_active = 0;  in alarm_handle_timer()
582 	if (ptr->it_interval)  in alarm_handle_timer()
583 		si_private = ++ptr->it_requeue_pending;  in alarm_handle_timer()
585 	if (posix_timer_event(ptr, si_private) && ptr->it_interval) {  in alarm_handle_timer()
587 		 * Handle ignored signals and rearm the timer. This will go  in alarm_handle_timer()
591 		ptr->it_overrun += __alarm_forward_now(alarm, ptr->it_interval, true);  in alarm_handle_timer()
592 		++ptr->it_requeue_pending;  in alarm_handle_timer()
593 		ptr->it_active = 1;  in alarm_handle_timer()
596 	spin_unlock_irqrestore(&ptr->it_lock, flags);  in alarm_handle_timer()
602  * alarm_timer_rearm - Posix timer callback for rearming timer
607 	struct alarm *alarm = &timr->it.alarm.alarmtimer;  in alarm_timer_rearm()
609 	timr->it_overrun += alarm_forward_now(alarm, timr->it_interval);  in alarm_timer_rearm()
610 	alarm_start(alarm, alarm->node.expires);  in alarm_timer_rearm()
614  * alarm_timer_forward - Posix timer callback for forwarding timer
616  * @now:	Current time to forward the timer against
620 	struct alarm *alarm = &timr->it.alarm.alarmtimer;  in alarm_timer_forward()
622 	return alarm_forward(alarm, timr->it_interval, now);  in alarm_timer_forward()
626  * alarm_timer_remaining - Posix timer callback to retrieve remaining time
632 	struct alarm *alarm = &timr->it.alarm.alarmtimer;  in alarm_timer_remaining()
634 	return ktime_sub(alarm->node.expires, now);  in alarm_timer_remaining()
638  * alarm_timer_try_to_cancel - Posix timer callback to cancel a timer
643 	return alarm_try_to_cancel(&timr->it.alarm.alarmtimer);  in alarm_timer_try_to_cancel()
647  * alarm_timer_wait_running - Posix timer callback to wait for a timer
650  * Called from the core code when timer cancel detected that the callback
656 	hrtimer_cancel_wait_running(&timr->it.alarm.alarmtimer.timer);  in alarm_timer_wait_running()
660  * alarm_timer_arm - Posix timer callback to arm a timer
664  * @sigev_none:	Posix timer does not deliver signals
669 	struct alarm *alarm = &timr->it.alarm.alarmtimer;  in alarm_timer_arm()
670 	struct alarm_base *base = &alarm_bases[alarm->type];  in alarm_timer_arm()
673 		expires = ktime_add_safe(expires, base->get_ktime());  in alarm_timer_arm()
675 		alarm->node.expires = expires;  in alarm_timer_arm()
677 		alarm_start(&timr->it.alarm.alarmtimer, expires);  in alarm_timer_arm()
681  * alarm_clock_getres - posix getres interface
690 		return -EINVAL;  in alarm_clock_getres()
692 	tp->tv_sec = 0;  in alarm_clock_getres()
693 	tp->tv_nsec = hrtimer_resolution;  in alarm_clock_getres()
698  * alarm_clock_get_timespec - posix clock_get_timespec interface
709 		return -EINVAL;  in alarm_clock_get_timespec()
711 	base->get_timespec(tp);  in alarm_clock_get_timespec()
717  * alarm_clock_get_ktime - posix clock_get_ktime interface
727 		return -EINVAL;  in alarm_clock_get_ktime()
729 	return base->get_ktime();  in alarm_clock_get_ktime()
733  * alarm_timer_create - posix timer_create interface
743 		return -EOPNOTSUPP;  in alarm_timer_create()
746 		return -EPERM;  in alarm_timer_create()
748 	type = clock2alarm(new_timer->it_clock);  in alarm_timer_create()
749 	alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);  in alarm_timer_create()
754  * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
756  * @now: time at the timer expiration
765 	struct task_struct *task = alarm->data;  in alarmtimer_nsleep_wakeup()
767 	alarm->data = NULL;  in alarmtimer_nsleep_wakeup()
774  * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
779  * Sets the alarm timer and sleeps until it is fired or interrupted.
785 	alarm->data = (void *)current;  in alarmtimer_do_nsleep()
789 		if (likely(alarm->data))  in alarmtimer_do_nsleep()
793 	} while (alarm->data && !signal_pending(current));  in alarmtimer_do_nsleep()
797 	destroy_hrtimer_on_stack(&alarm->timer);  in alarmtimer_do_nsleep()
799 	if (!alarm->data)  in alarmtimer_do_nsleep()
804 	restart = &current->restart_block;  in alarmtimer_do_nsleep()
805 	if (restart->nanosleep.type != TT_NONE) {  in alarmtimer_do_nsleep()
817 	return -ERESTART_RESTARTBLOCK;  in alarmtimer_do_nsleep()
824 	hrtimer_init_on_stack(&alarm->timer, alarm_bases[type].base_clockid,  in alarm_init_on_stack()
830  * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
837 	enum  alarmtimer_type type = restart->nanosleep.clockid;  in alarm_timer_nsleep_restart()
838 	ktime_t exp = restart->nanosleep.expires;  in alarm_timer_nsleep_restart()
847  * alarm_timer_nsleep - alarmtimer nanosleep
858 	struct restart_block *restart = &current->restart_block;  in alarm_timer_nsleep()
864 		return -EOPNOTSUPP;  in alarm_timer_nsleep()
867 		return -EINVAL;  in alarm_timer_nsleep()
870 		return -EPERM;  in alarm_timer_nsleep()
885 	if (ret != -ERESTART_RESTARTBLOCK)  in alarm_timer_nsleep()
890 		return -ERESTARTNOHAND;  in alarm_timer_nsleep()
892 	restart->nanosleep.clockid = type;  in alarm_timer_nsleep()
893 	restart->nanosleep.expires = exp;  in alarm_timer_nsleep()
937  * alarmtimer_init - Initialize alarm timer code