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 #define CREATE_TRACE_POINTS
21 #include <trace/events/rtc.h>
23 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
24 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
26 static void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm)
30 if (!rtc->offset_secs)
33 secs = rtc_tm_to_time64(tm);
36 * Since the reading time values from RTC device are always in the RTC
37 * original valid range, but we need to skip the overlapped region
38 * between expanded range and original range, which is no need to add
41 if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) ||
42 (rtc->start_secs < rtc->range_min &&
43 secs <= (rtc->start_secs + rtc->range_max - rtc->range_min)))
46 rtc_time64_to_tm(secs + rtc->offset_secs, tm);
49 static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm)
53 if (!rtc->offset_secs)
56 secs = rtc_tm_to_time64(tm);
59 * If the setting time values are in the valid range of RTC hardware
60 * device, then no need to subtract the offset when setting time to RTC
61 * device. Otherwise we need to subtract the offset to make the time
62 * values are valid for RTC hardware device.
64 if (secs >= rtc->range_min && secs <= rtc->range_max)
67 rtc_time64_to_tm(secs - rtc->offset_secs, tm);
70 static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm)
72 if (rtc->range_min != rtc->range_max) {
73 time64_t time = rtc_tm_to_time64(tm);
74 time64_t range_min = rtc->set_start_time ? rtc->start_secs :
76 time64_t range_max = rtc->set_start_time ?
77 (rtc->start_secs + rtc->range_max - rtc->range_min) :
80 if (time < range_min || time > range_max)
87 static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
92 else if (!rtc->ops->read_time)
95 memset(tm, 0, sizeof(struct rtc_time));
96 err = rtc->ops->read_time(rtc->dev.parent, tm);
98 dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
103 rtc_add_offset(rtc, tm);
105 err = rtc_valid_tm(tm);
107 dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
112 int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
116 err = mutex_lock_interruptible(&rtc->ops_lock);
120 err = __rtc_read_time(rtc, tm);
121 mutex_unlock(&rtc->ops_lock);
123 trace_rtc_read_time(rtc_tm_to_time64(tm), err);
126 EXPORT_SYMBOL_GPL(rtc_read_time);
128 int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
132 err = rtc_valid_tm(tm);
136 err = rtc_valid_range(rtc, tm);
140 rtc_subtract_offset(rtc, tm);
142 err = mutex_lock_interruptible(&rtc->ops_lock);
148 else if (rtc->ops->set_time)
149 err = rtc->ops->set_time(rtc->dev.parent, tm);
150 else if (rtc->ops->set_mmss64) {
151 time64_t secs64 = rtc_tm_to_time64(tm);
153 err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
154 } else if (rtc->ops->set_mmss) {
155 time64_t secs64 = rtc_tm_to_time64(tm);
156 err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
160 pm_stay_awake(rtc->dev.parent);
161 mutex_unlock(&rtc->ops_lock);
162 /* A timer might have just expired */
163 schedule_work(&rtc->irqwork);
165 trace_rtc_set_time(rtc_tm_to_time64(tm), err);
168 EXPORT_SYMBOL_GPL(rtc_set_time);
170 static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
174 err = mutex_lock_interruptible(&rtc->ops_lock);
178 if (rtc->ops == NULL)
180 else if (!rtc->ops->read_alarm)
185 alarm->time.tm_sec = -1;
186 alarm->time.tm_min = -1;
187 alarm->time.tm_hour = -1;
188 alarm->time.tm_mday = -1;
189 alarm->time.tm_mon = -1;
190 alarm->time.tm_year = -1;
191 alarm->time.tm_wday = -1;
192 alarm->time.tm_yday = -1;
193 alarm->time.tm_isdst = -1;
194 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
197 mutex_unlock(&rtc->ops_lock);
199 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
203 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
206 struct rtc_time before, now;
208 time64_t t_now, t_alm;
209 enum { none, day, month, year } missing = none;
212 /* The lower level RTC driver may return -1 in some fields,
213 * creating invalid alarm->time values, for reasons like:
215 * - The hardware may not be capable of filling them in;
216 * many alarms match only on time-of-day fields, not
217 * day/month/year calendar data.
219 * - Some hardware uses illegal values as "wildcard" match
220 * values, which non-Linux firmware (like a BIOS) may try
221 * to set up as e.g. "alarm 15 minutes after each hour".
222 * Linux uses only oneshot alarms.
224 * When we see that here, we deal with it by using values from
225 * a current RTC timestamp for any missing (-1) values. The
226 * RTC driver prevents "periodic alarm" modes.
228 * But this can be racey, because some fields of the RTC timestamp
229 * may have wrapped in the interval since we read the RTC alarm,
230 * which would lead to us inserting inconsistent values in place
233 * Reading the alarm and timestamp in the reverse sequence
234 * would have the same race condition, and not solve the issue.
236 * So, we must first read the RTC timestamp,
237 * then read the RTC alarm value,
238 * and then read a second RTC timestamp.
240 * If any fields of the second timestamp have changed
241 * when compared with the first timestamp, then we know
242 * our timestamp may be inconsistent with that used by
243 * the low-level rtc_read_alarm_internal() function.
245 * So, when the two timestamps disagree, we just loop and do
246 * the process again to get a fully consistent set of values.
248 * This could all instead be done in the lower level driver,
249 * but since more than one lower level RTC implementation needs it,
250 * then it's probably best best to do it here instead of there..
253 /* Get the "before" timestamp */
254 err = rtc_read_time(rtc, &before);
259 memcpy(&before, &now, sizeof(struct rtc_time));
262 /* get the RTC alarm values, which may be incomplete */
263 err = rtc_read_alarm_internal(rtc, alarm);
267 /* full-function RTCs won't have such missing fields */
268 if (rtc_valid_tm(&alarm->time) == 0)
271 /* get the "after" timestamp, to detect wrapped fields */
272 err = rtc_read_time(rtc, &now);
276 /* note that tm_sec is a "don't care" value here: */
277 } while ( before.tm_min != now.tm_min
278 || before.tm_hour != now.tm_hour
279 || before.tm_mon != now.tm_mon
280 || before.tm_year != now.tm_year);
282 /* Fill in the missing alarm fields using the timestamp; we
283 * know there's at least one since alarm->time is invalid.
285 if (alarm->time.tm_sec == -1)
286 alarm->time.tm_sec = now.tm_sec;
287 if (alarm->time.tm_min == -1)
288 alarm->time.tm_min = now.tm_min;
289 if (alarm->time.tm_hour == -1)
290 alarm->time.tm_hour = now.tm_hour;
292 /* For simplicity, only support date rollover for now */
293 if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
294 alarm->time.tm_mday = now.tm_mday;
297 if ((unsigned)alarm->time.tm_mon >= 12) {
298 alarm->time.tm_mon = now.tm_mon;
302 if (alarm->time.tm_year == -1) {
303 alarm->time.tm_year = now.tm_year;
308 /* Can't proceed if alarm is still invalid after replacing
311 err = rtc_valid_tm(&alarm->time);
315 /* with luck, no rollover is needed */
316 t_now = rtc_tm_to_time64(&now);
317 t_alm = rtc_tm_to_time64(&alarm->time);
323 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
324 * that will trigger at 5am will do so at 5am Tuesday, which
325 * could also be in the next month or year. This is a common
326 * case, especially for PCs.
329 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
330 t_alm += 24 * 60 * 60;
331 rtc_time64_to_tm(t_alm, &alarm->time);
334 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
335 * be next month. An alarm matching on the 30th, 29th, or 28th
336 * may end up in the month after that! Many newer PCs support
337 * this type of alarm.
340 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
342 if (alarm->time.tm_mon < 11)
343 alarm->time.tm_mon++;
345 alarm->time.tm_mon = 0;
346 alarm->time.tm_year++;
348 days = rtc_month_days(alarm->time.tm_mon,
349 alarm->time.tm_year);
350 } while (days < alarm->time.tm_mday);
353 /* Year rollover ... easy except for leap years! */
355 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
357 alarm->time.tm_year++;
358 } while (!is_leap_year(alarm->time.tm_year + 1900)
359 && rtc_valid_tm(&alarm->time) != 0);
363 dev_warn(&rtc->dev, "alarm rollover not handled\n");
366 err = rtc_valid_tm(&alarm->time);
370 dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
371 alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
372 alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
379 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
383 err = mutex_lock_interruptible(&rtc->ops_lock);
386 if (rtc->ops == NULL)
388 else if (!rtc->ops->read_alarm)
391 memset(alarm, 0, sizeof(struct rtc_wkalrm));
392 alarm->enabled = rtc->aie_timer.enabled;
393 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
395 mutex_unlock(&rtc->ops_lock);
397 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
400 EXPORT_SYMBOL_GPL(rtc_read_alarm);
402 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
405 time64_t now, scheduled;
408 err = rtc_valid_tm(&alarm->time);
412 rtc_subtract_offset(rtc, &alarm->time);
413 scheduled = rtc_tm_to_time64(&alarm->time);
415 /* Make sure we're not setting alarms in the past */
416 err = __rtc_read_time(rtc, &tm);
419 now = rtc_tm_to_time64(&tm);
420 if (scheduled <= now)
423 * XXX - We just checked to make sure the alarm time is not
424 * in the past, but there is still a race window where if
425 * the is alarm set for the next second and the second ticks
426 * over right here, before we set the alarm.
431 else if (!rtc->ops->set_alarm)
434 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
436 trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err);
440 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
444 err = rtc_valid_tm(&alarm->time);
448 err = rtc_valid_range(rtc, &alarm->time);
452 err = mutex_lock_interruptible(&rtc->ops_lock);
455 if (rtc->aie_timer.enabled)
456 rtc_timer_remove(rtc, &rtc->aie_timer);
458 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
459 rtc->aie_timer.period = 0;
461 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
463 mutex_unlock(&rtc->ops_lock);
465 rtc_add_offset(rtc, &alarm->time);
468 EXPORT_SYMBOL_GPL(rtc_set_alarm);
470 /* Called once per device from rtc_device_register */
471 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
476 err = rtc_valid_tm(&alarm->time);
480 err = rtc_read_time(rtc, &now);
484 err = mutex_lock_interruptible(&rtc->ops_lock);
488 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
489 rtc->aie_timer.period = 0;
491 /* Alarm has to be enabled & in the future for us to enqueue it */
492 if (alarm->enabled && (rtc_tm_to_ktime(now) <
493 rtc->aie_timer.node.expires)) {
495 rtc->aie_timer.enabled = 1;
496 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
497 trace_rtc_timer_enqueue(&rtc->aie_timer);
499 mutex_unlock(&rtc->ops_lock);
502 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
504 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
506 int err = mutex_lock_interruptible(&rtc->ops_lock);
510 if (rtc->aie_timer.enabled != enabled) {
512 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
514 rtc_timer_remove(rtc, &rtc->aie_timer);
521 else if (!rtc->ops->alarm_irq_enable)
524 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
526 mutex_unlock(&rtc->ops_lock);
528 trace_rtc_alarm_irq_enable(enabled, err);
531 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
533 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
535 int err = mutex_lock_interruptible(&rtc->ops_lock);
539 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
540 if (enabled == 0 && rtc->uie_irq_active) {
541 mutex_unlock(&rtc->ops_lock);
542 return rtc_dev_update_irq_enable_emul(rtc, 0);
545 /* make sure we're changing state */
546 if (rtc->uie_rtctimer.enabled == enabled)
549 if (rtc->uie_unsupported) {
558 __rtc_read_time(rtc, &tm);
559 onesec = ktime_set(1, 0);
560 now = rtc_tm_to_ktime(tm);
561 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
562 rtc->uie_rtctimer.period = ktime_set(1, 0);
563 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
565 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
568 mutex_unlock(&rtc->ops_lock);
569 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
571 * Enable emulation if the driver did not provide
572 * the update_irq_enable function pointer or if returned
573 * -EINVAL to signal that it has been configured without
574 * interrupts or that are not available at the moment.
577 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
582 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
586 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
587 * @rtc: pointer to the rtc device
589 * This function is called when an AIE, UIE or PIE mode interrupt
590 * has occurred (or been emulated).
592 * Triggers the registered irq_task function callback.
594 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
598 /* mark one irq of the appropriate mode */
599 spin_lock_irqsave(&rtc->irq_lock, flags);
600 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
601 spin_unlock_irqrestore(&rtc->irq_lock, flags);
603 /* call the task func */
604 spin_lock_irqsave(&rtc->irq_task_lock, flags);
606 rtc->irq_task->func(rtc->irq_task->private_data);
607 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
609 wake_up_interruptible(&rtc->irq_queue);
610 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
615 * rtc_aie_update_irq - AIE mode rtctimer hook
616 * @private: pointer to the rtc_device
618 * This functions is called when the aie_timer expires.
620 void rtc_aie_update_irq(void *private)
622 struct rtc_device *rtc = (struct rtc_device *)private;
623 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
628 * rtc_uie_update_irq - UIE mode rtctimer hook
629 * @private: pointer to the rtc_device
631 * This functions is called when the uie_timer expires.
633 void rtc_uie_update_irq(void *private)
635 struct rtc_device *rtc = (struct rtc_device *)private;
636 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
641 * rtc_pie_update_irq - PIE mode hrtimer hook
642 * @timer: pointer to the pie mode hrtimer
644 * This function is used to emulate PIE mode interrupts
645 * using an hrtimer. This function is called when the periodic
648 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
650 struct rtc_device *rtc;
653 rtc = container_of(timer, struct rtc_device, pie_timer);
655 period = NSEC_PER_SEC / rtc->irq_freq;
656 count = hrtimer_forward_now(timer, period);
658 rtc_handle_legacy_irq(rtc, count, RTC_PF);
660 return HRTIMER_RESTART;
664 * rtc_update_irq - Triggered when a RTC interrupt occurs.
665 * @rtc: the rtc device
666 * @num: how many irqs are being reported (usually one)
667 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
670 void rtc_update_irq(struct rtc_device *rtc,
671 unsigned long num, unsigned long events)
673 if (IS_ERR_OR_NULL(rtc))
676 pm_stay_awake(rtc->dev.parent);
677 schedule_work(&rtc->irqwork);
679 EXPORT_SYMBOL_GPL(rtc_update_irq);
681 static int __rtc_match(struct device *dev, const void *data)
683 const char *name = data;
685 if (strcmp(dev_name(dev), name) == 0)
690 struct rtc_device *rtc_class_open(const char *name)
693 struct rtc_device *rtc = NULL;
695 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
697 rtc = to_rtc_device(dev);
700 if (!try_module_get(rtc->owner)) {
708 EXPORT_SYMBOL_GPL(rtc_class_open);
710 void rtc_class_close(struct rtc_device *rtc)
712 module_put(rtc->owner);
713 put_device(&rtc->dev);
715 EXPORT_SYMBOL_GPL(rtc_class_close);
717 int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
721 if (task == NULL || task->func == NULL)
724 /* Cannot register while the char dev is in use */
725 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
728 spin_lock_irq(&rtc->irq_task_lock);
729 if (rtc->irq_task == NULL) {
730 rtc->irq_task = task;
733 spin_unlock_irq(&rtc->irq_task_lock);
735 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
739 EXPORT_SYMBOL_GPL(rtc_irq_register);
741 void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
743 spin_lock_irq(&rtc->irq_task_lock);
744 if (rtc->irq_task == task)
745 rtc->irq_task = NULL;
746 spin_unlock_irq(&rtc->irq_task_lock);
748 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
750 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
753 * We always cancel the timer here first, because otherwise
754 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
755 * when we manage to start the timer before the callback
756 * returns HRTIMER_RESTART.
758 * We cannot use hrtimer_cancel() here as a running callback
759 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
760 * would spin forever.
762 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
766 ktime_t period = NSEC_PER_SEC / rtc->irq_freq;
768 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
774 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
775 * @rtc: the rtc device
776 * @task: currently registered with rtc_irq_register()
777 * @enabled: true to enable periodic IRQs
780 * Note that rtc_irq_set_freq() should previously have been used to
781 * specify the desired frequency of periodic IRQ task->func() callbacks.
783 int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
789 spin_lock_irqsave(&rtc->irq_task_lock, flags);
790 if (rtc->irq_task != NULL && task == NULL)
792 else if (rtc->irq_task != task)
795 if (rtc_update_hrtimer(rtc, enabled) < 0) {
796 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
800 rtc->pie_enabled = enabled;
802 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
804 trace_rtc_irq_set_state(enabled, err);
807 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
810 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
811 * @rtc: the rtc device
812 * @task: currently registered with rtc_irq_register()
813 * @freq: positive frequency with which task->func() will be called
816 * Note that rtc_irq_set_state() is used to enable or disable the
819 int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
824 if (freq <= 0 || freq > RTC_MAX_FREQ)
827 spin_lock_irqsave(&rtc->irq_task_lock, flags);
828 if (rtc->irq_task != NULL && task == NULL)
830 else if (rtc->irq_task != task)
833 rtc->irq_freq = freq;
834 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
835 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
840 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
842 trace_rtc_irq_set_freq(freq, err);
845 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
848 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
850 * @timer timer being added.
852 * Enqueues a timer onto the rtc devices timerqueue and sets
853 * the next alarm event appropriately.
855 * Sets the enabled bit on the added timer.
857 * Must hold ops_lock for proper serialization of timerqueue
859 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
861 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
866 __rtc_read_time(rtc, &tm);
867 now = rtc_tm_to_ktime(tm);
869 /* Skip over expired timers */
871 if (next->expires >= now)
873 next = timerqueue_iterate_next(next);
876 timerqueue_add(&rtc->timerqueue, &timer->node);
877 trace_rtc_timer_enqueue(timer);
878 if (!next || ktime_before(timer->node.expires, next->expires)) {
879 struct rtc_wkalrm alarm;
881 alarm.time = rtc_ktime_to_tm(timer->node.expires);
883 err = __rtc_set_alarm(rtc, &alarm);
885 pm_stay_awake(rtc->dev.parent);
886 schedule_work(&rtc->irqwork);
888 timerqueue_del(&rtc->timerqueue, &timer->node);
889 trace_rtc_timer_dequeue(timer);
897 static void rtc_alarm_disable(struct rtc_device *rtc)
899 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
902 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
903 trace_rtc_alarm_irq_enable(0, 0);
907 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
909 * @timer timer being removed.
911 * Removes a timer onto the rtc devices timerqueue and sets
912 * the next alarm event appropriately.
914 * Clears the enabled bit on the removed timer.
916 * Must hold ops_lock for proper serialization of timerqueue
918 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
920 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
921 timerqueue_del(&rtc->timerqueue, &timer->node);
922 trace_rtc_timer_dequeue(timer);
924 if (next == &timer->node) {
925 struct rtc_wkalrm alarm;
927 next = timerqueue_getnext(&rtc->timerqueue);
929 rtc_alarm_disable(rtc);
932 alarm.time = rtc_ktime_to_tm(next->expires);
934 err = __rtc_set_alarm(rtc, &alarm);
936 pm_stay_awake(rtc->dev.parent);
937 schedule_work(&rtc->irqwork);
943 * rtc_timer_do_work - Expires rtc timers
945 * @timer timer being removed.
947 * Expires rtc timers. Reprograms next alarm event if needed.
948 * Called via worktask.
950 * Serializes access to timerqueue via ops_lock mutex
952 void rtc_timer_do_work(struct work_struct *work)
954 struct rtc_timer *timer;
955 struct timerqueue_node *next;
959 struct rtc_device *rtc =
960 container_of(work, struct rtc_device, irqwork);
962 mutex_lock(&rtc->ops_lock);
964 __rtc_read_time(rtc, &tm);
965 now = rtc_tm_to_ktime(tm);
966 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
967 if (next->expires > now)
971 timer = container_of(next, struct rtc_timer, node);
972 timerqueue_del(&rtc->timerqueue, &timer->node);
973 trace_rtc_timer_dequeue(timer);
975 if (timer->task.func)
976 timer->task.func(timer->task.private_data);
978 trace_rtc_timer_fired(timer);
979 /* Re-add/fwd periodic timers */
980 if (ktime_to_ns(timer->period)) {
981 timer->node.expires = ktime_add(timer->node.expires,
984 timerqueue_add(&rtc->timerqueue, &timer->node);
985 trace_rtc_timer_enqueue(timer);
991 struct rtc_wkalrm alarm;
995 alarm.time = rtc_ktime_to_tm(next->expires);
998 err = __rtc_set_alarm(rtc, &alarm);
1005 timer = container_of(next, struct rtc_timer, node);
1006 timerqueue_del(&rtc->timerqueue, &timer->node);
1007 trace_rtc_timer_dequeue(timer);
1009 dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
1013 rtc_alarm_disable(rtc);
1015 pm_relax(rtc->dev.parent);
1016 mutex_unlock(&rtc->ops_lock);
1020 /* rtc_timer_init - Initializes an rtc_timer
1021 * @timer: timer to be intiialized
1022 * @f: function pointer to be called when timer fires
1023 * @data: private data passed to function pointer
1025 * Kernel interface to initializing an rtc_timer.
1027 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
1029 timerqueue_init(&timer->node);
1031 timer->task.func = f;
1032 timer->task.private_data = data;
1035 /* rtc_timer_start - Sets an rtc_timer to fire in the future
1036 * @ rtc: rtc device to be used
1037 * @ timer: timer being set
1038 * @ expires: time at which to expire the timer
1039 * @ period: period that the timer will recur
1041 * Kernel interface to set an rtc_timer
1043 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
1044 ktime_t expires, ktime_t period)
1047 mutex_lock(&rtc->ops_lock);
1049 rtc_timer_remove(rtc, timer);
1051 timer->node.expires = expires;
1052 timer->period = period;
1054 ret = rtc_timer_enqueue(rtc, timer);
1056 mutex_unlock(&rtc->ops_lock);
1060 /* rtc_timer_cancel - Stops an rtc_timer
1061 * @ rtc: rtc device to be used
1062 * @ timer: timer being set
1064 * Kernel interface to cancel an rtc_timer
1066 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
1068 mutex_lock(&rtc->ops_lock);
1070 rtc_timer_remove(rtc, timer);
1071 mutex_unlock(&rtc->ops_lock);
1075 * rtc_read_offset - Read the amount of rtc offset in parts per billion
1076 * @ rtc: rtc device to be used
1077 * @ offset: the offset in parts per billion
1079 * see below for details.
1081 * Kernel interface to read rtc clock offset
1082 * Returns 0 on success, or a negative number on error.
1083 * If read_offset() is not implemented for the rtc, return -EINVAL
1085 int rtc_read_offset(struct rtc_device *rtc, long *offset)
1092 if (!rtc->ops->read_offset)
1095 mutex_lock(&rtc->ops_lock);
1096 ret = rtc->ops->read_offset(rtc->dev.parent, offset);
1097 mutex_unlock(&rtc->ops_lock);
1099 trace_rtc_read_offset(*offset, ret);
1104 * rtc_set_offset - Adjusts the duration of the average second
1105 * @ rtc: rtc device to be used
1106 * @ offset: the offset in parts per billion
1108 * Some rtc's allow an adjustment to the average duration of a second
1109 * to compensate for differences in the actual clock rate due to temperature,
1110 * the crystal, capacitor, etc.
1112 * The adjustment applied is as follows:
1113 * t = t0 * (1 + offset * 1e-9)
1114 * where t0 is the measured length of 1 RTC second with offset = 0
1116 * Kernel interface to adjust an rtc clock offset.
1117 * Return 0 on success, or a negative number on error.
1118 * If the rtc offset is not setable (or not implemented), return -EINVAL
1120 int rtc_set_offset(struct rtc_device *rtc, long offset)
1127 if (!rtc->ops->set_offset)
1130 mutex_lock(&rtc->ops_lock);
1131 ret = rtc->ops->set_offset(rtc->dev.parent, offset);
1132 mutex_unlock(&rtc->ops_lock);
1134 trace_rtc_set_offset(offset, ret);