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 pm_stay_awake(rtc->dev.parent);
76 mutex_unlock(&rtc->ops_lock);
77 /* A timer might have just expired */
78 schedule_work(&rtc->irqwork);
81 EXPORT_SYMBOL_GPL(rtc_set_time);
83 int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
87 err = mutex_lock_interruptible(&rtc->ops_lock);
93 else if (rtc->ops->set_mmss)
94 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
95 else if (rtc->ops->read_time && rtc->ops->set_time) {
96 struct rtc_time new, old;
98 err = rtc->ops->read_time(rtc->dev.parent, &old);
100 rtc_time_to_tm(secs, &new);
103 * avoid writing when we're going to change the day of
104 * the month. We will retry in the next minute. This
105 * basically means that if the RTC must not drift
106 * by more than 1 minute in 11 minutes.
108 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
109 (new.tm_hour == 23 && new.tm_min == 59)))
110 err = rtc->ops->set_time(rtc->dev.parent,
117 pm_stay_awake(rtc->dev.parent);
118 mutex_unlock(&rtc->ops_lock);
119 /* A timer might have just expired */
120 schedule_work(&rtc->irqwork);
124 EXPORT_SYMBOL_GPL(rtc_set_mmss);
126 static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
130 err = mutex_lock_interruptible(&rtc->ops_lock);
134 if (rtc->ops == NULL)
136 else if (!rtc->ops->read_alarm)
139 memset(alarm, 0, sizeof(struct rtc_wkalrm));
140 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
143 mutex_unlock(&rtc->ops_lock);
147 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
150 struct rtc_time before, now;
152 unsigned long t_now, t_alm;
153 enum { none, day, month, year } missing = none;
156 /* The lower level RTC driver may return -1 in some fields,
157 * creating invalid alarm->time values, for reasons like:
159 * - The hardware may not be capable of filling them in;
160 * many alarms match only on time-of-day fields, not
161 * day/month/year calendar data.
163 * - Some hardware uses illegal values as "wildcard" match
164 * values, which non-Linux firmware (like a BIOS) may try
165 * to set up as e.g. "alarm 15 minutes after each hour".
166 * Linux uses only oneshot alarms.
168 * When we see that here, we deal with it by using values from
169 * a current RTC timestamp for any missing (-1) values. The
170 * RTC driver prevents "periodic alarm" modes.
172 * But this can be racey, because some fields of the RTC timestamp
173 * may have wrapped in the interval since we read the RTC alarm,
174 * which would lead to us inserting inconsistent values in place
177 * Reading the alarm and timestamp in the reverse sequence
178 * would have the same race condition, and not solve the issue.
180 * So, we must first read the RTC timestamp,
181 * then read the RTC alarm value,
182 * and then read a second RTC timestamp.
184 * If any fields of the second timestamp have changed
185 * when compared with the first timestamp, then we know
186 * our timestamp may be inconsistent with that used by
187 * the low-level rtc_read_alarm_internal() function.
189 * So, when the two timestamps disagree, we just loop and do
190 * the process again to get a fully consistent set of values.
192 * This could all instead be done in the lower level driver,
193 * but since more than one lower level RTC implementation needs it,
194 * then it's probably best best to do it here instead of there..
197 /* Get the "before" timestamp */
198 err = rtc_read_time(rtc, &before);
203 memcpy(&before, &now, sizeof(struct rtc_time));
206 /* get the RTC alarm values, which may be incomplete */
207 err = rtc_read_alarm_internal(rtc, alarm);
211 /* full-function RTCs won't have such missing fields */
212 if (rtc_valid_tm(&alarm->time) == 0)
215 /* get the "after" timestamp, to detect wrapped fields */
216 err = rtc_read_time(rtc, &now);
220 /* note that tm_sec is a "don't care" value here: */
221 } while ( before.tm_min != now.tm_min
222 || before.tm_hour != now.tm_hour
223 || before.tm_mon != now.tm_mon
224 || before.tm_year != now.tm_year);
226 /* Fill in the missing alarm fields using the timestamp; we
227 * know there's at least one since alarm->time is invalid.
229 if (alarm->time.tm_sec == -1)
230 alarm->time.tm_sec = now.tm_sec;
231 if (alarm->time.tm_min == -1)
232 alarm->time.tm_min = now.tm_min;
233 if (alarm->time.tm_hour == -1)
234 alarm->time.tm_hour = now.tm_hour;
236 /* For simplicity, only support date rollover for now */
237 if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
238 alarm->time.tm_mday = now.tm_mday;
241 if ((unsigned)alarm->time.tm_mon >= 12) {
242 alarm->time.tm_mon = now.tm_mon;
246 if (alarm->time.tm_year == -1) {
247 alarm->time.tm_year = now.tm_year;
252 /* with luck, no rollover is needed */
253 rtc_tm_to_time(&now, &t_now);
254 rtc_tm_to_time(&alarm->time, &t_alm);
260 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
261 * that will trigger at 5am will do so at 5am Tuesday, which
262 * could also be in the next month or year. This is a common
263 * case, especially for PCs.
266 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
267 t_alm += 24 * 60 * 60;
268 rtc_time_to_tm(t_alm, &alarm->time);
271 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
272 * be next month. An alarm matching on the 30th, 29th, or 28th
273 * may end up in the month after that! Many newer PCs support
274 * this type of alarm.
277 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
279 if (alarm->time.tm_mon < 11)
280 alarm->time.tm_mon++;
282 alarm->time.tm_mon = 0;
283 alarm->time.tm_year++;
285 days = rtc_month_days(alarm->time.tm_mon,
286 alarm->time.tm_year);
287 } while (days < alarm->time.tm_mday);
290 /* Year rollover ... easy except for leap years! */
292 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
294 alarm->time.tm_year++;
295 } while (!is_leap_year(alarm->time.tm_year + 1900)
296 && rtc_valid_tm(&alarm->time) != 0);
300 dev_warn(&rtc->dev, "alarm rollover not handled\n");
304 err = rtc_valid_tm(&alarm->time);
307 dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
308 alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
309 alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
316 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
320 err = mutex_lock_interruptible(&rtc->ops_lock);
323 if (rtc->ops == NULL)
325 else if (!rtc->ops->read_alarm)
328 memset(alarm, 0, sizeof(struct rtc_wkalrm));
329 alarm->enabled = rtc->aie_timer.enabled;
330 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
332 mutex_unlock(&rtc->ops_lock);
336 EXPORT_SYMBOL_GPL(rtc_read_alarm);
338 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
344 err = rtc_valid_tm(&alarm->time);
347 rtc_tm_to_time(&alarm->time, &scheduled);
349 /* Make sure we're not setting alarms in the past */
350 err = __rtc_read_time(rtc, &tm);
351 rtc_tm_to_time(&tm, &now);
352 if (scheduled <= now)
355 * XXX - We just checked to make sure the alarm time is not
356 * in the past, but there is still a race window where if
357 * the is alarm set for the next second and the second ticks
358 * over right here, before we set the alarm.
363 else if (!rtc->ops->set_alarm)
366 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
371 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
375 err = rtc_valid_tm(&alarm->time);
379 err = mutex_lock_interruptible(&rtc->ops_lock);
382 if (rtc->aie_timer.enabled)
383 rtc_timer_remove(rtc, &rtc->aie_timer);
385 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
386 rtc->aie_timer.period = ktime_set(0, 0);
388 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
390 mutex_unlock(&rtc->ops_lock);
393 EXPORT_SYMBOL_GPL(rtc_set_alarm);
395 /* Called once per device from rtc_device_register */
396 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
401 err = rtc_valid_tm(&alarm->time);
405 err = rtc_read_time(rtc, &now);
409 err = mutex_lock_interruptible(&rtc->ops_lock);
413 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
414 rtc->aie_timer.period = ktime_set(0, 0);
416 /* Alarm has to be enabled & in the futrure for us to enqueue it */
417 if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 <
418 rtc->aie_timer.node.expires.tv64)) {
420 rtc->aie_timer.enabled = 1;
421 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
423 mutex_unlock(&rtc->ops_lock);
426 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
430 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
432 int err = mutex_lock_interruptible(&rtc->ops_lock);
436 if (rtc->aie_timer.enabled != enabled) {
438 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
440 rtc_timer_remove(rtc, &rtc->aie_timer);
447 else if (!rtc->ops->alarm_irq_enable)
450 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
452 mutex_unlock(&rtc->ops_lock);
455 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
457 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
459 int err = mutex_lock_interruptible(&rtc->ops_lock);
463 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
464 if (enabled == 0 && rtc->uie_irq_active) {
465 mutex_unlock(&rtc->ops_lock);
466 return rtc_dev_update_irq_enable_emul(rtc, 0);
469 /* make sure we're changing state */
470 if (rtc->uie_rtctimer.enabled == enabled)
473 if (rtc->uie_unsupported) {
482 __rtc_read_time(rtc, &tm);
483 onesec = ktime_set(1, 0);
484 now = rtc_tm_to_ktime(tm);
485 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
486 rtc->uie_rtctimer.period = ktime_set(1, 0);
487 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
489 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
492 mutex_unlock(&rtc->ops_lock);
493 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
495 * Enable emulation if the driver did not provide
496 * the update_irq_enable function pointer or if returned
497 * -EINVAL to signal that it has been configured without
498 * interrupts or that are not available at the moment.
501 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
506 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
510 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
511 * @rtc: pointer to the rtc device
513 * This function is called when an AIE, UIE or PIE mode interrupt
514 * has occurred (or been emulated).
516 * Triggers the registered irq_task function callback.
518 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
522 /* mark one irq of the appropriate mode */
523 spin_lock_irqsave(&rtc->irq_lock, flags);
524 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
525 spin_unlock_irqrestore(&rtc->irq_lock, flags);
527 /* call the task func */
528 spin_lock_irqsave(&rtc->irq_task_lock, flags);
530 rtc->irq_task->func(rtc->irq_task->private_data);
531 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
533 wake_up_interruptible(&rtc->irq_queue);
534 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
539 * rtc_aie_update_irq - AIE mode rtctimer hook
540 * @private: pointer to the rtc_device
542 * This functions is called when the aie_timer expires.
544 void rtc_aie_update_irq(void *private)
546 struct rtc_device *rtc = (struct rtc_device *)private;
547 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
552 * rtc_uie_update_irq - UIE mode rtctimer hook
553 * @private: pointer to the rtc_device
555 * This functions is called when the uie_timer expires.
557 void rtc_uie_update_irq(void *private)
559 struct rtc_device *rtc = (struct rtc_device *)private;
560 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
565 * rtc_pie_update_irq - PIE mode hrtimer hook
566 * @timer: pointer to the pie mode hrtimer
568 * This function is used to emulate PIE mode interrupts
569 * using an hrtimer. This function is called when the periodic
572 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
574 struct rtc_device *rtc;
577 rtc = container_of(timer, struct rtc_device, pie_timer);
579 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
580 count = hrtimer_forward_now(timer, period);
582 rtc_handle_legacy_irq(rtc, count, RTC_PF);
584 return HRTIMER_RESTART;
588 * rtc_update_irq - Triggered when a RTC interrupt occurs.
589 * @rtc: the rtc device
590 * @num: how many irqs are being reported (usually one)
591 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
594 void rtc_update_irq(struct rtc_device *rtc,
595 unsigned long num, unsigned long events)
597 if (unlikely(IS_ERR_OR_NULL(rtc)))
600 pm_stay_awake(rtc->dev.parent);
601 schedule_work(&rtc->irqwork);
603 EXPORT_SYMBOL_GPL(rtc_update_irq);
605 static int __rtc_match(struct device *dev, const void *data)
607 const char *name = data;
609 if (strcmp(dev_name(dev), name) == 0)
614 struct rtc_device *rtc_class_open(const char *name)
617 struct rtc_device *rtc = NULL;
619 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
621 rtc = to_rtc_device(dev);
624 if (!try_module_get(rtc->owner)) {
632 EXPORT_SYMBOL_GPL(rtc_class_open);
634 void rtc_class_close(struct rtc_device *rtc)
636 module_put(rtc->owner);
637 put_device(&rtc->dev);
639 EXPORT_SYMBOL_GPL(rtc_class_close);
641 int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
645 if (task == NULL || task->func == NULL)
648 /* Cannot register while the char dev is in use */
649 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
652 spin_lock_irq(&rtc->irq_task_lock);
653 if (rtc->irq_task == NULL) {
654 rtc->irq_task = task;
657 spin_unlock_irq(&rtc->irq_task_lock);
659 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
663 EXPORT_SYMBOL_GPL(rtc_irq_register);
665 void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
667 spin_lock_irq(&rtc->irq_task_lock);
668 if (rtc->irq_task == task)
669 rtc->irq_task = NULL;
670 spin_unlock_irq(&rtc->irq_task_lock);
672 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
674 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
677 * We always cancel the timer here first, because otherwise
678 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
679 * when we manage to start the timer before the callback
680 * returns HRTIMER_RESTART.
682 * We cannot use hrtimer_cancel() here as a running callback
683 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
684 * would spin forever.
686 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
690 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
692 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
698 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
699 * @rtc: the rtc device
700 * @task: currently registered with rtc_irq_register()
701 * @enabled: true to enable periodic IRQs
704 * Note that rtc_irq_set_freq() should previously have been used to
705 * specify the desired frequency of periodic IRQ task->func() callbacks.
707 int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
713 spin_lock_irqsave(&rtc->irq_task_lock, flags);
714 if (rtc->irq_task != NULL && task == NULL)
716 else if (rtc->irq_task != task)
719 if (rtc_update_hrtimer(rtc, enabled) < 0) {
720 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
724 rtc->pie_enabled = enabled;
726 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
729 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
732 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
733 * @rtc: the rtc device
734 * @task: currently registered with rtc_irq_register()
735 * @freq: positive frequency with which task->func() will be called
738 * Note that rtc_irq_set_state() is used to enable or disable the
741 int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
746 if (freq <= 0 || freq > RTC_MAX_FREQ)
749 spin_lock_irqsave(&rtc->irq_task_lock, flags);
750 if (rtc->irq_task != NULL && task == NULL)
752 else if (rtc->irq_task != task)
755 rtc->irq_freq = freq;
756 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
757 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
762 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
765 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
768 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
770 * @timer timer being added.
772 * Enqueues a timer onto the rtc devices timerqueue and sets
773 * the next alarm event appropriately.
775 * Sets the enabled bit on the added timer.
777 * Must hold ops_lock for proper serialization of timerqueue
779 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
782 timerqueue_add(&rtc->timerqueue, &timer->node);
783 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
784 struct rtc_wkalrm alarm;
786 alarm.time = rtc_ktime_to_tm(timer->node.expires);
788 err = __rtc_set_alarm(rtc, &alarm);
790 pm_stay_awake(rtc->dev.parent);
791 schedule_work(&rtc->irqwork);
793 timerqueue_del(&rtc->timerqueue, &timer->node);
801 static void rtc_alarm_disable(struct rtc_device *rtc)
803 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
806 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
810 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
812 * @timer timer being removed.
814 * Removes a timer onto the rtc devices timerqueue and sets
815 * the next alarm event appropriately.
817 * Clears the enabled bit on the removed timer.
819 * Must hold ops_lock for proper serialization of timerqueue
821 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
823 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
824 timerqueue_del(&rtc->timerqueue, &timer->node);
826 if (next == &timer->node) {
827 struct rtc_wkalrm alarm;
829 next = timerqueue_getnext(&rtc->timerqueue);
831 rtc_alarm_disable(rtc);
834 alarm.time = rtc_ktime_to_tm(next->expires);
836 err = __rtc_set_alarm(rtc, &alarm);
838 pm_stay_awake(rtc->dev.parent);
839 schedule_work(&rtc->irqwork);
845 * rtc_timer_do_work - Expires rtc timers
847 * @timer timer being removed.
849 * Expires rtc timers. Reprograms next alarm event if needed.
850 * Called via worktask.
852 * Serializes access to timerqueue via ops_lock mutex
854 void rtc_timer_do_work(struct work_struct *work)
856 struct rtc_timer *timer;
857 struct timerqueue_node *next;
861 struct rtc_device *rtc =
862 container_of(work, struct rtc_device, irqwork);
864 mutex_lock(&rtc->ops_lock);
866 __rtc_read_time(rtc, &tm);
867 now = rtc_tm_to_ktime(tm);
868 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
869 if (next->expires.tv64 > now.tv64)
873 timer = container_of(next, struct rtc_timer, node);
874 timerqueue_del(&rtc->timerqueue, &timer->node);
876 if (timer->task.func)
877 timer->task.func(timer->task.private_data);
879 /* Re-add/fwd periodic timers */
880 if (ktime_to_ns(timer->period)) {
881 timer->node.expires = ktime_add(timer->node.expires,
884 timerqueue_add(&rtc->timerqueue, &timer->node);
890 struct rtc_wkalrm alarm;
892 alarm.time = rtc_ktime_to_tm(next->expires);
894 err = __rtc_set_alarm(rtc, &alarm);
898 rtc_alarm_disable(rtc);
900 pm_relax(rtc->dev.parent);
901 mutex_unlock(&rtc->ops_lock);
905 /* rtc_timer_init - Initializes an rtc_timer
906 * @timer: timer to be intiialized
907 * @f: function pointer to be called when timer fires
908 * @data: private data passed to function pointer
910 * Kernel interface to initializing an rtc_timer.
912 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
914 timerqueue_init(&timer->node);
916 timer->task.func = f;
917 timer->task.private_data = data;
920 /* rtc_timer_start - Sets an rtc_timer to fire in the future
921 * @ rtc: rtc device to be used
922 * @ timer: timer being set
923 * @ expires: time at which to expire the timer
924 * @ period: period that the timer will recur
926 * Kernel interface to set an rtc_timer
928 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
929 ktime_t expires, ktime_t period)
932 mutex_lock(&rtc->ops_lock);
934 rtc_timer_remove(rtc, timer);
936 timer->node.expires = expires;
937 timer->period = period;
939 ret = rtc_timer_enqueue(rtc, timer);
941 mutex_unlock(&rtc->ops_lock);
945 /* rtc_timer_cancel - Stops an rtc_timer
946 * @ rtc: rtc device to be used
947 * @ timer: timer being set
949 * Kernel interface to cancel an rtc_timer
951 int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
954 mutex_lock(&rtc->ops_lock);
956 rtc_timer_remove(rtc, timer);
957 mutex_unlock(&rtc->ops_lock);