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)
446 else if (!rtc->ops->set_alarm)
449 err = rtc_valid_tm(&alarm->time);
453 err = rtc_valid_range(rtc, &alarm->time);
457 err = mutex_lock_interruptible(&rtc->ops_lock);
460 if (rtc->aie_timer.enabled)
461 rtc_timer_remove(rtc, &rtc->aie_timer);
463 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
464 rtc->aie_timer.period = 0;
466 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
468 mutex_unlock(&rtc->ops_lock);
470 rtc_add_offset(rtc, &alarm->time);
473 EXPORT_SYMBOL_GPL(rtc_set_alarm);
475 /* Called once per device from rtc_device_register */
476 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
481 err = rtc_valid_tm(&alarm->time);
485 err = rtc_read_time(rtc, &now);
489 err = mutex_lock_interruptible(&rtc->ops_lock);
493 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
494 rtc->aie_timer.period = 0;
496 /* Alarm has to be enabled & in the future for us to enqueue it */
497 if (alarm->enabled && (rtc_tm_to_ktime(now) <
498 rtc->aie_timer.node.expires)) {
500 rtc->aie_timer.enabled = 1;
501 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
502 trace_rtc_timer_enqueue(&rtc->aie_timer);
504 mutex_unlock(&rtc->ops_lock);
507 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
509 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
511 int err = mutex_lock_interruptible(&rtc->ops_lock);
515 if (rtc->aie_timer.enabled != enabled) {
517 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
519 rtc_timer_remove(rtc, &rtc->aie_timer);
526 else if (!rtc->ops->alarm_irq_enable)
529 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
531 mutex_unlock(&rtc->ops_lock);
533 trace_rtc_alarm_irq_enable(enabled, err);
536 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
538 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
540 int err = mutex_lock_interruptible(&rtc->ops_lock);
544 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
545 if (enabled == 0 && rtc->uie_irq_active) {
546 mutex_unlock(&rtc->ops_lock);
547 return rtc_dev_update_irq_enable_emul(rtc, 0);
550 /* make sure we're changing state */
551 if (rtc->uie_rtctimer.enabled == enabled)
554 if (rtc->uie_unsupported) {
563 __rtc_read_time(rtc, &tm);
564 onesec = ktime_set(1, 0);
565 now = rtc_tm_to_ktime(tm);
566 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
567 rtc->uie_rtctimer.period = ktime_set(1, 0);
568 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
570 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
573 mutex_unlock(&rtc->ops_lock);
574 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
576 * Enable emulation if the driver did not provide
577 * the update_irq_enable function pointer or if returned
578 * -EINVAL to signal that it has been configured without
579 * interrupts or that are not available at the moment.
582 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
587 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
591 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
592 * @rtc: pointer to the rtc device
594 * This function is called when an AIE, UIE or PIE mode interrupt
595 * has occurred (or been emulated).
597 * Triggers the registered irq_task function callback.
599 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
603 /* mark one irq of the appropriate mode */
604 spin_lock_irqsave(&rtc->irq_lock, flags);
605 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
606 spin_unlock_irqrestore(&rtc->irq_lock, flags);
608 /* call the task func */
609 spin_lock_irqsave(&rtc->irq_task_lock, flags);
611 rtc->irq_task->func(rtc->irq_task->private_data);
612 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
614 wake_up_interruptible(&rtc->irq_queue);
615 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
620 * rtc_aie_update_irq - AIE mode rtctimer hook
621 * @private: pointer to the rtc_device
623 * This functions is called when the aie_timer expires.
625 void rtc_aie_update_irq(void *private)
627 struct rtc_device *rtc = (struct rtc_device *)private;
628 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
633 * rtc_uie_update_irq - UIE mode rtctimer hook
634 * @private: pointer to the rtc_device
636 * This functions is called when the uie_timer expires.
638 void rtc_uie_update_irq(void *private)
640 struct rtc_device *rtc = (struct rtc_device *)private;
641 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
646 * rtc_pie_update_irq - PIE mode hrtimer hook
647 * @timer: pointer to the pie mode hrtimer
649 * This function is used to emulate PIE mode interrupts
650 * using an hrtimer. This function is called when the periodic
653 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
655 struct rtc_device *rtc;
658 rtc = container_of(timer, struct rtc_device, pie_timer);
660 period = NSEC_PER_SEC / rtc->irq_freq;
661 count = hrtimer_forward_now(timer, period);
663 rtc_handle_legacy_irq(rtc, count, RTC_PF);
665 return HRTIMER_RESTART;
669 * rtc_update_irq - Triggered when a RTC interrupt occurs.
670 * @rtc: the rtc device
671 * @num: how many irqs are being reported (usually one)
672 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
675 void rtc_update_irq(struct rtc_device *rtc,
676 unsigned long num, unsigned long events)
678 if (IS_ERR_OR_NULL(rtc))
681 pm_stay_awake(rtc->dev.parent);
682 schedule_work(&rtc->irqwork);
684 EXPORT_SYMBOL_GPL(rtc_update_irq);
686 static int __rtc_match(struct device *dev, const void *data)
688 const char *name = data;
690 if (strcmp(dev_name(dev), name) == 0)
695 struct rtc_device *rtc_class_open(const char *name)
698 struct rtc_device *rtc = NULL;
700 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
702 rtc = to_rtc_device(dev);
705 if (!try_module_get(rtc->owner)) {
713 EXPORT_SYMBOL_GPL(rtc_class_open);
715 void rtc_class_close(struct rtc_device *rtc)
717 module_put(rtc->owner);
718 put_device(&rtc->dev);
720 EXPORT_SYMBOL_GPL(rtc_class_close);
722 int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
726 if (task == NULL || task->func == NULL)
729 /* Cannot register while the char dev is in use */
730 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
733 spin_lock_irq(&rtc->irq_task_lock);
734 if (rtc->irq_task == NULL) {
735 rtc->irq_task = task;
738 spin_unlock_irq(&rtc->irq_task_lock);
740 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
744 EXPORT_SYMBOL_GPL(rtc_irq_register);
746 void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
748 spin_lock_irq(&rtc->irq_task_lock);
749 if (rtc->irq_task == task)
750 rtc->irq_task = NULL;
751 spin_unlock_irq(&rtc->irq_task_lock);
753 EXPORT_SYMBOL_GPL(rtc_irq_unregister);
755 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
758 * We always cancel the timer here first, because otherwise
759 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
760 * when we manage to start the timer before the callback
761 * returns HRTIMER_RESTART.
763 * We cannot use hrtimer_cancel() here as a running callback
764 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
765 * would spin forever.
767 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
771 ktime_t period = NSEC_PER_SEC / rtc->irq_freq;
773 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
779 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
780 * @rtc: the rtc device
781 * @task: currently registered with rtc_irq_register()
782 * @enabled: true to enable periodic IRQs
785 * Note that rtc_irq_set_freq() should previously have been used to
786 * specify the desired frequency of periodic IRQ task->func() callbacks.
788 int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
794 spin_lock_irqsave(&rtc->irq_task_lock, flags);
795 if (rtc->irq_task != NULL && task == NULL)
797 else if (rtc->irq_task != task)
800 if (rtc_update_hrtimer(rtc, enabled) < 0) {
801 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
805 rtc->pie_enabled = enabled;
807 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
809 trace_rtc_irq_set_state(enabled, err);
812 EXPORT_SYMBOL_GPL(rtc_irq_set_state);
815 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
816 * @rtc: the rtc device
817 * @task: currently registered with rtc_irq_register()
818 * @freq: positive frequency with which task->func() will be called
821 * Note that rtc_irq_set_state() is used to enable or disable the
824 int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
829 if (freq <= 0 || freq > RTC_MAX_FREQ)
832 spin_lock_irqsave(&rtc->irq_task_lock, flags);
833 if (rtc->irq_task != NULL && task == NULL)
835 else if (rtc->irq_task != task)
838 rtc->irq_freq = freq;
839 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
840 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
845 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
847 trace_rtc_irq_set_freq(freq, err);
850 EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
853 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
855 * @timer timer being added.
857 * Enqueues a timer onto the rtc devices timerqueue and sets
858 * the next alarm event appropriately.
860 * Sets the enabled bit on the added timer.
862 * Must hold ops_lock for proper serialization of timerqueue
864 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
866 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
871 __rtc_read_time(rtc, &tm);
872 now = rtc_tm_to_ktime(tm);
874 /* Skip over expired timers */
876 if (next->expires >= now)
878 next = timerqueue_iterate_next(next);
881 timerqueue_add(&rtc->timerqueue, &timer->node);
882 trace_rtc_timer_enqueue(timer);
883 if (!next || ktime_before(timer->node.expires, next->expires)) {
884 struct rtc_wkalrm alarm;
886 alarm.time = rtc_ktime_to_tm(timer->node.expires);
888 err = __rtc_set_alarm(rtc, &alarm);
890 pm_stay_awake(rtc->dev.parent);
891 schedule_work(&rtc->irqwork);
893 timerqueue_del(&rtc->timerqueue, &timer->node);
894 trace_rtc_timer_dequeue(timer);
902 static void rtc_alarm_disable(struct rtc_device *rtc)
904 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
907 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
908 trace_rtc_alarm_irq_enable(0, 0);
912 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
914 * @timer timer being removed.
916 * Removes a timer onto the rtc devices timerqueue and sets
917 * the next alarm event appropriately.
919 * Clears the enabled bit on the removed timer.
921 * Must hold ops_lock for proper serialization of timerqueue
923 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
925 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
926 timerqueue_del(&rtc->timerqueue, &timer->node);
927 trace_rtc_timer_dequeue(timer);
929 if (next == &timer->node) {
930 struct rtc_wkalrm alarm;
932 next = timerqueue_getnext(&rtc->timerqueue);
934 rtc_alarm_disable(rtc);
937 alarm.time = rtc_ktime_to_tm(next->expires);
939 err = __rtc_set_alarm(rtc, &alarm);
941 pm_stay_awake(rtc->dev.parent);
942 schedule_work(&rtc->irqwork);
948 * rtc_timer_do_work - Expires rtc timers
950 * @timer timer being removed.
952 * Expires rtc timers. Reprograms next alarm event if needed.
953 * Called via worktask.
955 * Serializes access to timerqueue via ops_lock mutex
957 void rtc_timer_do_work(struct work_struct *work)
959 struct rtc_timer *timer;
960 struct timerqueue_node *next;
964 struct rtc_device *rtc =
965 container_of(work, struct rtc_device, irqwork);
967 mutex_lock(&rtc->ops_lock);
969 __rtc_read_time(rtc, &tm);
970 now = rtc_tm_to_ktime(tm);
971 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
972 if (next->expires > now)
976 timer = container_of(next, struct rtc_timer, node);
977 timerqueue_del(&rtc->timerqueue, &timer->node);
978 trace_rtc_timer_dequeue(timer);
980 if (timer->task.func)
981 timer->task.func(timer->task.private_data);
983 trace_rtc_timer_fired(timer);
984 /* Re-add/fwd periodic timers */
985 if (ktime_to_ns(timer->period)) {
986 timer->node.expires = ktime_add(timer->node.expires,
989 timerqueue_add(&rtc->timerqueue, &timer->node);
990 trace_rtc_timer_enqueue(timer);
996 struct rtc_wkalrm alarm;
1000 alarm.time = rtc_ktime_to_tm(next->expires);
1003 err = __rtc_set_alarm(rtc, &alarm);
1010 timer = container_of(next, struct rtc_timer, node);
1011 timerqueue_del(&rtc->timerqueue, &timer->node);
1012 trace_rtc_timer_dequeue(timer);
1014 dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
1018 rtc_alarm_disable(rtc);
1020 pm_relax(rtc->dev.parent);
1021 mutex_unlock(&rtc->ops_lock);
1025 /* rtc_timer_init - Initializes an rtc_timer
1026 * @timer: timer to be intiialized
1027 * @f: function pointer to be called when timer fires
1028 * @data: private data passed to function pointer
1030 * Kernel interface to initializing an rtc_timer.
1032 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
1034 timerqueue_init(&timer->node);
1036 timer->task.func = f;
1037 timer->task.private_data = data;
1040 /* rtc_timer_start - Sets an rtc_timer to fire in the future
1041 * @ rtc: rtc device to be used
1042 * @ timer: timer being set
1043 * @ expires: time at which to expire the timer
1044 * @ period: period that the timer will recur
1046 * Kernel interface to set an rtc_timer
1048 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
1049 ktime_t expires, ktime_t period)
1052 mutex_lock(&rtc->ops_lock);
1054 rtc_timer_remove(rtc, timer);
1056 timer->node.expires = expires;
1057 timer->period = period;
1059 ret = rtc_timer_enqueue(rtc, timer);
1061 mutex_unlock(&rtc->ops_lock);
1065 /* rtc_timer_cancel - Stops an rtc_timer
1066 * @ rtc: rtc device to be used
1067 * @ timer: timer being set
1069 * Kernel interface to cancel an rtc_timer
1071 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
1073 mutex_lock(&rtc->ops_lock);
1075 rtc_timer_remove(rtc, timer);
1076 mutex_unlock(&rtc->ops_lock);
1080 * rtc_read_offset - Read the amount of rtc offset in parts per billion
1081 * @ rtc: rtc device to be used
1082 * @ offset: the offset in parts per billion
1084 * see below for details.
1086 * Kernel interface to read rtc clock offset
1087 * Returns 0 on success, or a negative number on error.
1088 * If read_offset() is not implemented for the rtc, return -EINVAL
1090 int rtc_read_offset(struct rtc_device *rtc, long *offset)
1097 if (!rtc->ops->read_offset)
1100 mutex_lock(&rtc->ops_lock);
1101 ret = rtc->ops->read_offset(rtc->dev.parent, offset);
1102 mutex_unlock(&rtc->ops_lock);
1104 trace_rtc_read_offset(*offset, ret);
1109 * rtc_set_offset - Adjusts the duration of the average second
1110 * @ rtc: rtc device to be used
1111 * @ offset: the offset in parts per billion
1113 * Some rtc's allow an adjustment to the average duration of a second
1114 * to compensate for differences in the actual clock rate due to temperature,
1115 * the crystal, capacitor, etc.
1117 * The adjustment applied is as follows:
1118 * t = t0 * (1 + offset * 1e-9)
1119 * where t0 is the measured length of 1 RTC second with offset = 0
1121 * Kernel interface to adjust an rtc clock offset.
1122 * Return 0 on success, or a negative number on error.
1123 * If the rtc offset is not setable (or not implemented), return -EINVAL
1125 int rtc_set_offset(struct rtc_device *rtc, long offset)
1132 if (!rtc->ops->set_offset)
1135 mutex_lock(&rtc->ops_lock);
1136 ret = rtc->ops->set_offset(rtc->dev.parent, offset);
1137 mutex_unlock(&rtc->ops_lock);
1139 trace_rtc_set_offset(offset, ret);