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 (rtc_valid_tm(&alarm->time) != 0);
299 dev_warn(&rtc->dev, "alarm rollover not handled\n");
306 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
310 err = mutex_lock_interruptible(&rtc->ops_lock);
313 if (rtc->ops == NULL)
315 else if (!rtc->ops->read_alarm)
318 memset(alarm, 0, sizeof(struct rtc_wkalrm));
319 alarm->enabled = rtc->aie_timer.enabled;
320 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
322 mutex_unlock(&rtc->ops_lock);
326 EXPORT_SYMBOL_GPL(rtc_read_alarm);
328 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
334 err = rtc_valid_tm(&alarm->time);
337 rtc_tm_to_time(&alarm->time, &scheduled);
339 /* Make sure we're not setting alarms in the past */
340 err = __rtc_read_time(rtc, &tm);
341 rtc_tm_to_time(&tm, &now);
342 if (scheduled <= now)
345 * XXX - We just checked to make sure the alarm time is not
346 * in the past, but there is still a race window where if
347 * the is alarm set for the next second and the second ticks
348 * over right here, before we set the alarm.
353 else if (!rtc->ops->set_alarm)
356 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
361 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
365 err = rtc_valid_tm(&alarm->time);
369 err = mutex_lock_interruptible(&rtc->ops_lock);
372 if (rtc->aie_timer.enabled)
373 rtc_timer_remove(rtc, &rtc->aie_timer);
375 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
376 rtc->aie_timer.period = ktime_set(0, 0);
378 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
380 mutex_unlock(&rtc->ops_lock);
383 EXPORT_SYMBOL_GPL(rtc_set_alarm);
385 /* Called once per device from rtc_device_register */
386 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
391 err = rtc_valid_tm(&alarm->time);
395 err = rtc_read_time(rtc, &now);
399 err = mutex_lock_interruptible(&rtc->ops_lock);
403 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
404 rtc->aie_timer.period = ktime_set(0, 0);
406 /* Alarm has to be enabled & in the futrure for us to enqueue it */
407 if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 <
408 rtc->aie_timer.node.expires.tv64)) {
410 rtc->aie_timer.enabled = 1;
411 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
413 mutex_unlock(&rtc->ops_lock);
416 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
420 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
422 int err = mutex_lock_interruptible(&rtc->ops_lock);
426 if (rtc->aie_timer.enabled != enabled) {
428 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
430 rtc_timer_remove(rtc, &rtc->aie_timer);
437 else if (!rtc->ops->alarm_irq_enable)
440 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
442 mutex_unlock(&rtc->ops_lock);
445 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
447 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
449 int err = mutex_lock_interruptible(&rtc->ops_lock);
453 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
454 if (enabled == 0 && rtc->uie_irq_active) {
455 mutex_unlock(&rtc->ops_lock);
456 return rtc_dev_update_irq_enable_emul(rtc, 0);
459 /* make sure we're changing state */
460 if (rtc->uie_rtctimer.enabled == enabled)
463 if (rtc->uie_unsupported) {
472 __rtc_read_time(rtc, &tm);
473 onesec = ktime_set(1, 0);
474 now = rtc_tm_to_ktime(tm);
475 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
476 rtc->uie_rtctimer.period = ktime_set(1, 0);
477 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
479 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
482 mutex_unlock(&rtc->ops_lock);
483 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
485 * Enable emulation if the driver did not provide
486 * the update_irq_enable function pointer or if returned
487 * -EINVAL to signal that it has been configured without
488 * interrupts or that are not available at the moment.
491 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
496 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
500 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
501 * @rtc: pointer to the rtc device
503 * This function is called when an AIE, UIE or PIE mode interrupt
504 * has occurred (or been emulated).
506 * Triggers the registered irq_task function callback.
508 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
512 /* mark one irq of the appropriate mode */
513 spin_lock_irqsave(&rtc->irq_lock, flags);
514 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
515 spin_unlock_irqrestore(&rtc->irq_lock, flags);
517 /* call the task func */
518 spin_lock_irqsave(&rtc->irq_task_lock, flags);
520 rtc->irq_task->func(rtc->irq_task->private_data);
521 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
523 wake_up_interruptible(&rtc->irq_queue);
524 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
529 * rtc_aie_update_irq - AIE mode rtctimer hook
530 * @private: pointer to the rtc_device
532 * This functions is called when the aie_timer expires.
534 void rtc_aie_update_irq(void *private)
536 struct rtc_device *rtc = (struct rtc_device *)private;
537 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
542 * rtc_uie_update_irq - UIE mode rtctimer hook
543 * @private: pointer to the rtc_device
545 * This functions is called when the uie_timer expires.
547 void rtc_uie_update_irq(void *private)
549 struct rtc_device *rtc = (struct rtc_device *)private;
550 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
555 * rtc_pie_update_irq - PIE mode hrtimer hook
556 * @timer: pointer to the pie mode hrtimer
558 * This function is used to emulate PIE mode interrupts
559 * using an hrtimer. This function is called when the periodic
562 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
564 struct rtc_device *rtc;
567 rtc = container_of(timer, struct rtc_device, pie_timer);
569 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
570 count = hrtimer_forward_now(timer, period);
572 rtc_handle_legacy_irq(rtc, count, RTC_PF);
574 return HRTIMER_RESTART;
578 * rtc_update_irq - Triggered when a RTC interrupt occurs.
579 * @rtc: the rtc device
580 * @num: how many irqs are being reported (usually one)
581 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
584 void rtc_update_irq(struct rtc_device *rtc,
585 unsigned long num, unsigned long events)
587 if (unlikely(IS_ERR_OR_NULL(rtc)))
590 pm_stay_awake(rtc->dev.parent);
591 schedule_work(&rtc->irqwork);
593 EXPORT_SYMBOL_GPL(rtc_update_irq);
595 static int __rtc_match(struct device *dev, const void *data)
597 const char *name = data;
599 if (strcmp(dev_name(dev), name) == 0)
604 struct rtc_device *rtc_class_open(const char *name)
607 struct rtc_device *rtc = NULL;
609 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
611 rtc = to_rtc_device(dev);
614 if (!try_module_get(rtc->owner)) {
622 EXPORT_SYMBOL_GPL(rtc_class_open);
624 void rtc_class_close(struct rtc_device *rtc)
626 module_put(rtc->owner);
627 put_device(&rtc->dev);
629 EXPORT_SYMBOL_GPL(rtc_class_close);
631 int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
635 if (task == NULL || task->func == NULL)
638 /* Cannot register while the char dev is in use */
639 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
642 spin_lock_irq(&rtc->irq_task_lock);
643 if (rtc->irq_task == NULL) {
644 rtc->irq_task = task;
647 spin_unlock_irq(&rtc->irq_task_lock);
649 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
653 EXPORT_SYMBOL_GPL(rtc_irq_register);
655 void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
657 spin_lock_irq(&rtc->irq_task_lock);
658 if (rtc->irq_task == task)
659 rtc->irq_task = NULL;
660 spin_unlock_irq(&rtc->irq_task_lock);
662 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
664 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
667 * We always cancel the timer here first, because otherwise
668 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
669 * when we manage to start the timer before the callback
670 * returns HRTIMER_RESTART.
672 * We cannot use hrtimer_cancel() here as a running callback
673 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
674 * would spin forever.
676 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
680 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
682 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
688 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
689 * @rtc: the rtc device
690 * @task: currently registered with rtc_irq_register()
691 * @enabled: true to enable periodic IRQs
694 * Note that rtc_irq_set_freq() should previously have been used to
695 * specify the desired frequency of periodic IRQ task->func() callbacks.
697 int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
703 spin_lock_irqsave(&rtc->irq_task_lock, flags);
704 if (rtc->irq_task != NULL && task == NULL)
706 else if (rtc->irq_task != task)
709 if (rtc_update_hrtimer(rtc, enabled) < 0) {
710 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
714 rtc->pie_enabled = enabled;
716 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
719 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
722 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
723 * @rtc: the rtc device
724 * @task: currently registered with rtc_irq_register()
725 * @freq: positive frequency with which task->func() will be called
728 * Note that rtc_irq_set_state() is used to enable or disable the
731 int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
736 if (freq <= 0 || freq > RTC_MAX_FREQ)
739 spin_lock_irqsave(&rtc->irq_task_lock, flags);
740 if (rtc->irq_task != NULL && task == NULL)
742 else if (rtc->irq_task != task)
745 rtc->irq_freq = freq;
746 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
747 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
752 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
755 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
758 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
760 * @timer timer being added.
762 * Enqueues a timer onto the rtc devices timerqueue and sets
763 * the next alarm event appropriately.
765 * Sets the enabled bit on the added timer.
767 * Must hold ops_lock for proper serialization of timerqueue
769 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
772 timerqueue_add(&rtc->timerqueue, &timer->node);
773 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
774 struct rtc_wkalrm alarm;
776 alarm.time = rtc_ktime_to_tm(timer->node.expires);
778 err = __rtc_set_alarm(rtc, &alarm);
780 pm_stay_awake(rtc->dev.parent);
781 schedule_work(&rtc->irqwork);
783 timerqueue_del(&rtc->timerqueue, &timer->node);
791 static void rtc_alarm_disable(struct rtc_device *rtc)
793 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
796 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
800 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
802 * @timer timer being removed.
804 * Removes a timer onto the rtc devices timerqueue and sets
805 * the next alarm event appropriately.
807 * Clears the enabled bit on the removed timer.
809 * Must hold ops_lock for proper serialization of timerqueue
811 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
813 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
814 timerqueue_del(&rtc->timerqueue, &timer->node);
816 if (next == &timer->node) {
817 struct rtc_wkalrm alarm;
819 next = timerqueue_getnext(&rtc->timerqueue);
821 rtc_alarm_disable(rtc);
824 alarm.time = rtc_ktime_to_tm(next->expires);
826 err = __rtc_set_alarm(rtc, &alarm);
828 pm_stay_awake(rtc->dev.parent);
829 schedule_work(&rtc->irqwork);
835 * rtc_timer_do_work - Expires rtc timers
837 * @timer timer being removed.
839 * Expires rtc timers. Reprograms next alarm event if needed.
840 * Called via worktask.
842 * Serializes access to timerqueue via ops_lock mutex
844 void rtc_timer_do_work(struct work_struct *work)
846 struct rtc_timer *timer;
847 struct timerqueue_node *next;
851 struct rtc_device *rtc =
852 container_of(work, struct rtc_device, irqwork);
854 mutex_lock(&rtc->ops_lock);
856 __rtc_read_time(rtc, &tm);
857 now = rtc_tm_to_ktime(tm);
858 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
859 if (next->expires.tv64 > now.tv64)
863 timer = container_of(next, struct rtc_timer, node);
864 timerqueue_del(&rtc->timerqueue, &timer->node);
866 if (timer->task.func)
867 timer->task.func(timer->task.private_data);
869 /* Re-add/fwd periodic timers */
870 if (ktime_to_ns(timer->period)) {
871 timer->node.expires = ktime_add(timer->node.expires,
874 timerqueue_add(&rtc->timerqueue, &timer->node);
880 struct rtc_wkalrm alarm;
882 alarm.time = rtc_ktime_to_tm(next->expires);
884 err = __rtc_set_alarm(rtc, &alarm);
888 rtc_alarm_disable(rtc);
890 pm_relax(rtc->dev.parent);
891 mutex_unlock(&rtc->ops_lock);
895 /* rtc_timer_init - Initializes an rtc_timer
896 * @timer: timer to be intiialized
897 * @f: function pointer to be called when timer fires
898 * @data: private data passed to function pointer
900 * Kernel interface to initializing an rtc_timer.
902 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
904 timerqueue_init(&timer->node);
906 timer->task.func = f;
907 timer->task.private_data = data;
910 /* rtc_timer_start - Sets an rtc_timer to fire in the future
911 * @ rtc: rtc device to be used
912 * @ timer: timer being set
913 * @ expires: time at which to expire the timer
914 * @ period: period that the timer will recur
916 * Kernel interface to set an rtc_timer
918 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
919 ktime_t expires, ktime_t period)
922 mutex_lock(&rtc->ops_lock);
924 rtc_timer_remove(rtc, timer);
926 timer->node.expires = expires;
927 timer->period = period;
929 ret = rtc_timer_enqueue(rtc, timer);
931 mutex_unlock(&rtc->ops_lock);
935 /* rtc_timer_cancel - Stops an rtc_timer
936 * @ rtc: rtc device to be used
937 * @ timer: timer being set
939 * Kernel interface to cancel an rtc_timer
941 int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
944 mutex_lock(&rtc->ops_lock);
946 rtc_timer_remove(rtc, timer);
947 mutex_unlock(&rtc->ops_lock);