2 * RTC subsystem, interface functions
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 * based on arch/arm/common/rtctime.c
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/rtc.h>
15 #include <linux/sched.h>
16 #include <linux/module.h>
17 #include <linux/log2.h>
18 #include <linux/workqueue.h>
20 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
21 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
23 static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
28 else if (!rtc->ops->read_time)
31 memset(tm, 0, sizeof(struct rtc_time));
32 err = rtc->ops->read_time(rtc->dev.parent, tm);
37 int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
41 err = mutex_lock_interruptible(&rtc->ops_lock);
45 err = __rtc_read_time(rtc, tm);
46 mutex_unlock(&rtc->ops_lock);
49 EXPORT_SYMBOL_GPL(rtc_read_time);
51 int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
55 err = rtc_valid_tm(tm);
59 err = mutex_lock_interruptible(&rtc->ops_lock);
65 else if (rtc->ops->set_time)
66 err = rtc->ops->set_time(rtc->dev.parent, tm);
67 else if (rtc->ops->set_mmss) {
69 err = rtc_tm_to_time(tm, &secs);
71 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
75 mutex_unlock(&rtc->ops_lock);
78 EXPORT_SYMBOL_GPL(rtc_set_time);
80 int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
84 err = mutex_lock_interruptible(&rtc->ops_lock);
90 else if (rtc->ops->set_mmss)
91 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
92 else if (rtc->ops->read_time && rtc->ops->set_time) {
93 struct rtc_time new, old;
95 err = rtc->ops->read_time(rtc->dev.parent, &old);
97 rtc_time_to_tm(secs, &new);
100 * avoid writing when we're going to change the day of
101 * the month. We will retry in the next minute. This
102 * basically means that if the RTC must not drift
103 * by more than 1 minute in 11 minutes.
105 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
106 (new.tm_hour == 23 && new.tm_min == 59)))
107 err = rtc->ops->set_time(rtc->dev.parent,
114 mutex_unlock(&rtc->ops_lock);
118 EXPORT_SYMBOL_GPL(rtc_set_mmss);
120 static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
124 err = mutex_lock_interruptible(&rtc->ops_lock);
128 if (rtc->ops == NULL)
130 else if (!rtc->ops->read_alarm)
133 memset(alarm, 0, sizeof(struct rtc_wkalrm));
134 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
137 mutex_unlock(&rtc->ops_lock);
141 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
144 struct rtc_time before, now;
146 unsigned long t_now, t_alm;
147 enum { none, day, month, year } missing = none;
150 /* The lower level RTC driver may return -1 in some fields,
151 * creating invalid alarm->time values, for reasons like:
153 * - The hardware may not be capable of filling them in;
154 * many alarms match only on time-of-day fields, not
155 * day/month/year calendar data.
157 * - Some hardware uses illegal values as "wildcard" match
158 * values, which non-Linux firmware (like a BIOS) may try
159 * to set up as e.g. "alarm 15 minutes after each hour".
160 * Linux uses only oneshot alarms.
162 * When we see that here, we deal with it by using values from
163 * a current RTC timestamp for any missing (-1) values. The
164 * RTC driver prevents "periodic alarm" modes.
166 * But this can be racey, because some fields of the RTC timestamp
167 * may have wrapped in the interval since we read the RTC alarm,
168 * which would lead to us inserting inconsistent values in place
171 * Reading the alarm and timestamp in the reverse sequence
172 * would have the same race condition, and not solve the issue.
174 * So, we must first read the RTC timestamp,
175 * then read the RTC alarm value,
176 * and then read a second RTC timestamp.
178 * If any fields of the second timestamp have changed
179 * when compared with the first timestamp, then we know
180 * our timestamp may be inconsistent with that used by
181 * the low-level rtc_read_alarm_internal() function.
183 * So, when the two timestamps disagree, we just loop and do
184 * the process again to get a fully consistent set of values.
186 * This could all instead be done in the lower level driver,
187 * but since more than one lower level RTC implementation needs it,
188 * then it's probably best best to do it here instead of there..
191 /* Get the "before" timestamp */
192 err = rtc_read_time(rtc, &before);
197 memcpy(&before, &now, sizeof(struct rtc_time));
200 /* get the RTC alarm values, which may be incomplete */
201 err = rtc_read_alarm_internal(rtc, alarm);
205 /* full-function RTCs won't have such missing fields */
206 if (rtc_valid_tm(&alarm->time) == 0)
209 /* get the "after" timestamp, to detect wrapped fields */
210 err = rtc_read_time(rtc, &now);
214 /* note that tm_sec is a "don't care" value here: */
215 } while ( before.tm_min != now.tm_min
216 || before.tm_hour != now.tm_hour
217 || before.tm_mon != now.tm_mon
218 || before.tm_year != now.tm_year);
220 /* Fill in the missing alarm fields using the timestamp; we
221 * know there's at least one since alarm->time is invalid.
223 if (alarm->time.tm_sec == -1)
224 alarm->time.tm_sec = now.tm_sec;
225 if (alarm->time.tm_min == -1)
226 alarm->time.tm_min = now.tm_min;
227 if (alarm->time.tm_hour == -1)
228 alarm->time.tm_hour = now.tm_hour;
230 /* For simplicity, only support date rollover for now */
231 if (alarm->time.tm_mday == -1) {
232 alarm->time.tm_mday = now.tm_mday;
235 if (alarm->time.tm_mon == -1) {
236 alarm->time.tm_mon = now.tm_mon;
240 if (alarm->time.tm_year == -1) {
241 alarm->time.tm_year = now.tm_year;
246 /* with luck, no rollover is needed */
247 rtc_tm_to_time(&now, &t_now);
248 rtc_tm_to_time(&alarm->time, &t_alm);
254 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
255 * that will trigger at 5am will do so at 5am Tuesday, which
256 * could also be in the next month or year. This is a common
257 * case, especially for PCs.
260 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
261 t_alm += 24 * 60 * 60;
262 rtc_time_to_tm(t_alm, &alarm->time);
265 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
266 * be next month. An alarm matching on the 30th, 29th, or 28th
267 * may end up in the month after that! Many newer PCs support
268 * this type of alarm.
271 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
273 if (alarm->time.tm_mon < 11)
274 alarm->time.tm_mon++;
276 alarm->time.tm_mon = 0;
277 alarm->time.tm_year++;
279 days = rtc_month_days(alarm->time.tm_mon,
280 alarm->time.tm_year);
281 } while (days < alarm->time.tm_mday);
284 /* Year rollover ... easy except for leap years! */
286 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
288 alarm->time.tm_year++;
289 } while (rtc_valid_tm(&alarm->time) != 0);
293 dev_warn(&rtc->dev, "alarm rollover not handled\n");
300 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
304 err = mutex_lock_interruptible(&rtc->ops_lock);
307 if (rtc->ops == NULL)
309 else if (!rtc->ops->read_alarm)
312 memset(alarm, 0, sizeof(struct rtc_wkalrm));
313 alarm->enabled = rtc->aie_timer.enabled;
314 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
316 mutex_unlock(&rtc->ops_lock);
320 EXPORT_SYMBOL_GPL(rtc_read_alarm);
322 static int ___rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
328 else if (!rtc->ops->set_alarm)
331 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
336 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
342 err = rtc_valid_tm(&alarm->time);
345 rtc_tm_to_time(&alarm->time, &scheduled);
347 /* Make sure we're not setting alarms in the past */
348 err = __rtc_read_time(rtc, &tm);
349 rtc_tm_to_time(&tm, &now);
350 if (scheduled <= now)
353 * XXX - We just checked to make sure the alarm time is not
354 * in the past, but there is still a race window where if
355 * the is alarm set for the next second and the second ticks
356 * over right here, before we set the alarm.
359 return ___rtc_set_alarm(rtc, alarm);
362 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
366 err = rtc_valid_tm(&alarm->time);
370 err = mutex_lock_interruptible(&rtc->ops_lock);
373 if (rtc->aie_timer.enabled) {
374 rtc_timer_remove(rtc, &rtc->aie_timer);
376 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
377 rtc->aie_timer.period = ktime_set(0, 0);
378 if (alarm->enabled) {
379 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
381 mutex_unlock(&rtc->ops_lock);
384 EXPORT_SYMBOL_GPL(rtc_set_alarm);
386 /* Called once per device from rtc_device_register */
387 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
391 err = rtc_valid_tm(&alarm->time);
395 err = mutex_lock_interruptible(&rtc->ops_lock);
399 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
400 rtc->aie_timer.period = ktime_set(0, 0);
401 if (alarm->enabled) {
402 rtc->aie_timer.enabled = 1;
403 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
405 mutex_unlock(&rtc->ops_lock);
408 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
412 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
414 int err = mutex_lock_interruptible(&rtc->ops_lock);
418 if (rtc->aie_timer.enabled != enabled) {
420 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
422 rtc_timer_remove(rtc, &rtc->aie_timer);
429 else if (!rtc->ops->alarm_irq_enable)
432 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
434 mutex_unlock(&rtc->ops_lock);
437 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
439 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
441 int err = mutex_lock_interruptible(&rtc->ops_lock);
445 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
446 if (enabled == 0 && rtc->uie_irq_active) {
447 mutex_unlock(&rtc->ops_lock);
448 return rtc_dev_update_irq_enable_emul(rtc, 0);
451 /* make sure we're changing state */
452 if (rtc->uie_rtctimer.enabled == enabled)
459 __rtc_read_time(rtc, &tm);
460 onesec = ktime_set(1, 0);
461 now = rtc_tm_to_ktime(tm);
462 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
463 rtc->uie_rtctimer.period = ktime_set(1, 0);
464 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
466 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
469 mutex_unlock(&rtc->ops_lock);
470 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
472 * Enable emulation if the driver did not provide
473 * the update_irq_enable function pointer or if returned
474 * -EINVAL to signal that it has been configured without
475 * interrupts or that are not available at the moment.
478 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
483 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
487 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
488 * @rtc: pointer to the rtc device
490 * This function is called when an AIE, UIE or PIE mode interrupt
491 * has occurred (or been emulated).
493 * Triggers the registered irq_task function callback.
495 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
499 /* mark one irq of the appropriate mode */
500 spin_lock_irqsave(&rtc->irq_lock, flags);
501 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
502 spin_unlock_irqrestore(&rtc->irq_lock, flags);
504 /* call the task func */
505 spin_lock_irqsave(&rtc->irq_task_lock, flags);
507 rtc->irq_task->func(rtc->irq_task->private_data);
508 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
510 wake_up_interruptible(&rtc->irq_queue);
511 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
516 * rtc_aie_update_irq - AIE mode rtctimer hook
517 * @private: pointer to the rtc_device
519 * This functions is called when the aie_timer expires.
521 void rtc_aie_update_irq(void *private)
523 struct rtc_device *rtc = (struct rtc_device *)private;
524 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
529 * rtc_uie_update_irq - UIE mode rtctimer hook
530 * @private: pointer to the rtc_device
532 * This functions is called when the uie_timer expires.
534 void rtc_uie_update_irq(void *private)
536 struct rtc_device *rtc = (struct rtc_device *)private;
537 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
542 * rtc_pie_update_irq - PIE mode hrtimer hook
543 * @timer: pointer to the pie mode hrtimer
545 * This function is used to emulate PIE mode interrupts
546 * using an hrtimer. This function is called when the periodic
549 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
551 struct rtc_device *rtc;
554 rtc = container_of(timer, struct rtc_device, pie_timer);
556 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
557 count = hrtimer_forward_now(timer, period);
559 rtc_handle_legacy_irq(rtc, count, RTC_PF);
561 return HRTIMER_RESTART;
565 * rtc_update_irq - Triggered when a RTC interrupt occurs.
566 * @rtc: the rtc device
567 * @num: how many irqs are being reported (usually one)
568 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
571 void rtc_update_irq(struct rtc_device *rtc,
572 unsigned long num, unsigned long events)
574 schedule_work(&rtc->irqwork);
576 EXPORT_SYMBOL_GPL(rtc_update_irq);
578 static int __rtc_match(struct device *dev, void *data)
580 char *name = (char *)data;
582 if (strcmp(dev_name(dev), name) == 0)
587 struct rtc_device *rtc_class_open(char *name)
590 struct rtc_device *rtc = NULL;
592 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
594 rtc = to_rtc_device(dev);
597 if (!try_module_get(rtc->owner)) {
605 EXPORT_SYMBOL_GPL(rtc_class_open);
607 void rtc_class_close(struct rtc_device *rtc)
609 module_put(rtc->owner);
610 put_device(&rtc->dev);
612 EXPORT_SYMBOL_GPL(rtc_class_close);
614 int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
618 if (task == NULL || task->func == NULL)
621 /* Cannot register while the char dev is in use */
622 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
625 spin_lock_irq(&rtc->irq_task_lock);
626 if (rtc->irq_task == NULL) {
627 rtc->irq_task = task;
630 spin_unlock_irq(&rtc->irq_task_lock);
632 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
636 EXPORT_SYMBOL_GPL(rtc_irq_register);
638 void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
640 spin_lock_irq(&rtc->irq_task_lock);
641 if (rtc->irq_task == task)
642 rtc->irq_task = NULL;
643 spin_unlock_irq(&rtc->irq_task_lock);
645 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
647 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
650 * We always cancel the timer here first, because otherwise
651 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
652 * when we manage to start the timer before the callback
653 * returns HRTIMER_RESTART.
655 * We cannot use hrtimer_cancel() here as a running callback
656 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
657 * would spin forever.
659 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
663 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
665 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
671 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
672 * @rtc: the rtc device
673 * @task: currently registered with rtc_irq_register()
674 * @enabled: true to enable periodic IRQs
677 * Note that rtc_irq_set_freq() should previously have been used to
678 * specify the desired frequency of periodic IRQ task->func() callbacks.
680 int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
686 spin_lock_irqsave(&rtc->irq_task_lock, flags);
687 if (rtc->irq_task != NULL && task == NULL)
689 if (rtc->irq_task != task)
692 if (rtc_update_hrtimer(rtc, enabled) < 0) {
693 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
697 rtc->pie_enabled = enabled;
699 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
702 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
705 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
706 * @rtc: the rtc device
707 * @task: currently registered with rtc_irq_register()
708 * @freq: positive frequency with which task->func() will be called
711 * Note that rtc_irq_set_state() is used to enable or disable the
714 int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
719 if (freq <= 0 || freq > RTC_MAX_FREQ)
722 spin_lock_irqsave(&rtc->irq_task_lock, flags);
723 if (rtc->irq_task != NULL && task == NULL)
725 if (rtc->irq_task != task)
728 rtc->irq_freq = freq;
729 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
730 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
735 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
738 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
741 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
743 * @timer timer being added.
745 * Enqueues a timer onto the rtc devices timerqueue and sets
746 * the next alarm event appropriately.
748 * Sets the enabled bit on the added timer.
750 * Must hold ops_lock for proper serialization of timerqueue
752 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
755 timerqueue_add(&rtc->timerqueue, &timer->node);
756 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
757 struct rtc_wkalrm alarm;
759 alarm.time = rtc_ktime_to_tm(timer->node.expires);
761 err = __rtc_set_alarm(rtc, &alarm);
763 schedule_work(&rtc->irqwork);
765 timerqueue_del(&rtc->timerqueue, &timer->node);
773 static void rtc_alarm_disable(struct rtc_device *rtc)
775 struct rtc_wkalrm alarm;
778 __rtc_read_time(rtc, &tm);
780 alarm.time = rtc_ktime_to_tm(ktime_add(rtc_tm_to_ktime(tm),
784 ___rtc_set_alarm(rtc, &alarm);
788 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
790 * @timer timer being removed.
792 * Removes a timer onto the rtc devices timerqueue and sets
793 * the next alarm event appropriately.
795 * Clears the enabled bit on the removed timer.
797 * Must hold ops_lock for proper serialization of timerqueue
799 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
801 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
802 timerqueue_del(&rtc->timerqueue, &timer->node);
804 if (next == &timer->node) {
805 struct rtc_wkalrm alarm;
807 next = timerqueue_getnext(&rtc->timerqueue);
809 rtc_alarm_disable(rtc);
812 alarm.time = rtc_ktime_to_tm(next->expires);
814 err = __rtc_set_alarm(rtc, &alarm);
816 schedule_work(&rtc->irqwork);
821 * rtc_timer_do_work - Expires rtc timers
823 * @timer timer being removed.
825 * Expires rtc timers. Reprograms next alarm event if needed.
826 * Called via worktask.
828 * Serializes access to timerqueue via ops_lock mutex
830 void rtc_timer_do_work(struct work_struct *work)
832 struct rtc_timer *timer;
833 struct timerqueue_node *next;
837 struct rtc_device *rtc =
838 container_of(work, struct rtc_device, irqwork);
840 mutex_lock(&rtc->ops_lock);
842 __rtc_read_time(rtc, &tm);
843 now = rtc_tm_to_ktime(tm);
844 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
845 if (next->expires.tv64 > now.tv64)
849 timer = container_of(next, struct rtc_timer, node);
850 timerqueue_del(&rtc->timerqueue, &timer->node);
852 if (timer->task.func)
853 timer->task.func(timer->task.private_data);
855 /* Re-add/fwd periodic timers */
856 if (ktime_to_ns(timer->period)) {
857 timer->node.expires = ktime_add(timer->node.expires,
860 timerqueue_add(&rtc->timerqueue, &timer->node);
866 struct rtc_wkalrm alarm;
868 alarm.time = rtc_ktime_to_tm(next->expires);
870 err = __rtc_set_alarm(rtc, &alarm);
874 rtc_alarm_disable(rtc);
876 mutex_unlock(&rtc->ops_lock);
880 /* rtc_timer_init - Initializes an rtc_timer
881 * @timer: timer to be intiialized
882 * @f: function pointer to be called when timer fires
883 * @data: private data passed to function pointer
885 * Kernel interface to initializing an rtc_timer.
887 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data)
889 timerqueue_init(&timer->node);
891 timer->task.func = f;
892 timer->task.private_data = data;
895 /* rtc_timer_start - Sets an rtc_timer to fire in the future
896 * @ rtc: rtc device to be used
897 * @ timer: timer being set
898 * @ expires: time at which to expire the timer
899 * @ period: period that the timer will recur
901 * Kernel interface to set an rtc_timer
903 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer,
904 ktime_t expires, ktime_t period)
907 mutex_lock(&rtc->ops_lock);
909 rtc_timer_remove(rtc, timer);
911 timer->node.expires = expires;
912 timer->period = period;
914 ret = rtc_timer_enqueue(rtc, timer);
916 mutex_unlock(&rtc->ops_lock);
920 /* rtc_timer_cancel - Stops an rtc_timer
921 * @ rtc: rtc device to be used
922 * @ timer: timer being set
924 * Kernel interface to cancel an rtc_timer
926 int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer)
929 mutex_lock(&rtc->ops_lock);
931 rtc_timer_remove(rtc, timer);
932 mutex_unlock(&rtc->ops_lock);