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 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
143 uie = rtc->uie_rtctimer.enabled || rtc->uie_irq_active;
145 uie = rtc->uie_rtctimer.enabled;
148 err = rtc_update_irq_enable(rtc, 0);
153 err = mutex_lock_interruptible(&rtc->ops_lock);
159 else if (rtc->ops->set_time)
160 err = rtc->ops->set_time(rtc->dev.parent, tm);
161 else if (rtc->ops->set_mmss64) {
162 time64_t secs64 = rtc_tm_to_time64(tm);
164 err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
165 } else if (rtc->ops->set_mmss) {
166 time64_t secs64 = rtc_tm_to_time64(tm);
167 err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
171 pm_stay_awake(rtc->dev.parent);
172 mutex_unlock(&rtc->ops_lock);
173 /* A timer might have just expired */
174 schedule_work(&rtc->irqwork);
177 err = rtc_update_irq_enable(rtc, 1);
182 trace_rtc_set_time(rtc_tm_to_time64(tm), err);
185 EXPORT_SYMBOL_GPL(rtc_set_time);
187 static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
191 err = mutex_lock_interruptible(&rtc->ops_lock);
195 if (rtc->ops == NULL)
197 else if (!rtc->ops->read_alarm)
202 alarm->time.tm_sec = -1;
203 alarm->time.tm_min = -1;
204 alarm->time.tm_hour = -1;
205 alarm->time.tm_mday = -1;
206 alarm->time.tm_mon = -1;
207 alarm->time.tm_year = -1;
208 alarm->time.tm_wday = -1;
209 alarm->time.tm_yday = -1;
210 alarm->time.tm_isdst = -1;
211 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
214 mutex_unlock(&rtc->ops_lock);
216 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
220 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
223 struct rtc_time before, now;
225 time64_t t_now, t_alm;
226 enum { none, day, month, year } missing = none;
229 /* The lower level RTC driver may return -1 in some fields,
230 * creating invalid alarm->time values, for reasons like:
232 * - The hardware may not be capable of filling them in;
233 * many alarms match only on time-of-day fields, not
234 * day/month/year calendar data.
236 * - Some hardware uses illegal values as "wildcard" match
237 * values, which non-Linux firmware (like a BIOS) may try
238 * to set up as e.g. "alarm 15 minutes after each hour".
239 * Linux uses only oneshot alarms.
241 * When we see that here, we deal with it by using values from
242 * a current RTC timestamp for any missing (-1) values. The
243 * RTC driver prevents "periodic alarm" modes.
245 * But this can be racey, because some fields of the RTC timestamp
246 * may have wrapped in the interval since we read the RTC alarm,
247 * which would lead to us inserting inconsistent values in place
250 * Reading the alarm and timestamp in the reverse sequence
251 * would have the same race condition, and not solve the issue.
253 * So, we must first read the RTC timestamp,
254 * then read the RTC alarm value,
255 * and then read a second RTC timestamp.
257 * If any fields of the second timestamp have changed
258 * when compared with the first timestamp, then we know
259 * our timestamp may be inconsistent with that used by
260 * the low-level rtc_read_alarm_internal() function.
262 * So, when the two timestamps disagree, we just loop and do
263 * the process again to get a fully consistent set of values.
265 * This could all instead be done in the lower level driver,
266 * but since more than one lower level RTC implementation needs it,
267 * then it's probably best best to do it here instead of there..
270 /* Get the "before" timestamp */
271 err = rtc_read_time(rtc, &before);
276 memcpy(&before, &now, sizeof(struct rtc_time));
279 /* get the RTC alarm values, which may be incomplete */
280 err = rtc_read_alarm_internal(rtc, alarm);
284 /* full-function RTCs won't have such missing fields */
285 if (rtc_valid_tm(&alarm->time) == 0) {
286 rtc_add_offset(rtc, &alarm->time);
290 /* get the "after" timestamp, to detect wrapped fields */
291 err = rtc_read_time(rtc, &now);
295 /* note that tm_sec is a "don't care" value here: */
296 } while ( before.tm_min != now.tm_min
297 || before.tm_hour != now.tm_hour
298 || before.tm_mon != now.tm_mon
299 || before.tm_year != now.tm_year);
301 /* Fill in the missing alarm fields using the timestamp; we
302 * know there's at least one since alarm->time is invalid.
304 if (alarm->time.tm_sec == -1)
305 alarm->time.tm_sec = now.tm_sec;
306 if (alarm->time.tm_min == -1)
307 alarm->time.tm_min = now.tm_min;
308 if (alarm->time.tm_hour == -1)
309 alarm->time.tm_hour = now.tm_hour;
311 /* For simplicity, only support date rollover for now */
312 if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
313 alarm->time.tm_mday = now.tm_mday;
316 if ((unsigned)alarm->time.tm_mon >= 12) {
317 alarm->time.tm_mon = now.tm_mon;
321 if (alarm->time.tm_year == -1) {
322 alarm->time.tm_year = now.tm_year;
327 /* Can't proceed if alarm is still invalid after replacing
330 err = rtc_valid_tm(&alarm->time);
334 /* with luck, no rollover is needed */
335 t_now = rtc_tm_to_time64(&now);
336 t_alm = rtc_tm_to_time64(&alarm->time);
342 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
343 * that will trigger at 5am will do so at 5am Tuesday, which
344 * could also be in the next month or year. This is a common
345 * case, especially for PCs.
348 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
349 t_alm += 24 * 60 * 60;
350 rtc_time64_to_tm(t_alm, &alarm->time);
353 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
354 * be next month. An alarm matching on the 30th, 29th, or 28th
355 * may end up in the month after that! Many newer PCs support
356 * this type of alarm.
359 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
361 if (alarm->time.tm_mon < 11)
362 alarm->time.tm_mon++;
364 alarm->time.tm_mon = 0;
365 alarm->time.tm_year++;
367 days = rtc_month_days(alarm->time.tm_mon,
368 alarm->time.tm_year);
369 } while (days < alarm->time.tm_mday);
372 /* Year rollover ... easy except for leap years! */
374 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
376 alarm->time.tm_year++;
377 } while (!is_leap_year(alarm->time.tm_year + 1900)
378 && rtc_valid_tm(&alarm->time) != 0);
382 dev_warn(&rtc->dev, "alarm rollover not handled\n");
385 err = rtc_valid_tm(&alarm->time);
389 dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
390 alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
391 alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
398 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
402 err = mutex_lock_interruptible(&rtc->ops_lock);
405 if (rtc->ops == NULL)
407 else if (!rtc->ops->read_alarm)
410 memset(alarm, 0, sizeof(struct rtc_wkalrm));
411 alarm->enabled = rtc->aie_timer.enabled;
412 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
414 mutex_unlock(&rtc->ops_lock);
416 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
419 EXPORT_SYMBOL_GPL(rtc_read_alarm);
421 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
424 time64_t now, scheduled;
427 err = rtc_valid_tm(&alarm->time);
431 scheduled = rtc_tm_to_time64(&alarm->time);
433 /* Make sure we're not setting alarms in the past */
434 err = __rtc_read_time(rtc, &tm);
437 now = rtc_tm_to_time64(&tm);
438 if (scheduled <= now)
441 * XXX - We just checked to make sure the alarm time is not
442 * in the past, but there is still a race window where if
443 * the is alarm set for the next second and the second ticks
444 * over right here, before we set the alarm.
447 rtc_subtract_offset(rtc, &alarm->time);
451 else if (!rtc->ops->set_alarm)
454 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
456 trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err);
460 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
466 else if (!rtc->ops->set_alarm)
469 err = rtc_valid_tm(&alarm->time);
473 err = rtc_valid_range(rtc, &alarm->time);
477 err = mutex_lock_interruptible(&rtc->ops_lock);
480 if (rtc->aie_timer.enabled)
481 rtc_timer_remove(rtc, &rtc->aie_timer);
483 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
484 rtc->aie_timer.period = 0;
486 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
488 mutex_unlock(&rtc->ops_lock);
492 EXPORT_SYMBOL_GPL(rtc_set_alarm);
494 /* Called once per device from rtc_device_register */
495 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
500 err = rtc_valid_tm(&alarm->time);
504 err = rtc_read_time(rtc, &now);
508 err = mutex_lock_interruptible(&rtc->ops_lock);
512 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
513 rtc->aie_timer.period = 0;
515 /* Alarm has to be enabled & in the future for us to enqueue it */
516 if (alarm->enabled && (rtc_tm_to_ktime(now) <
517 rtc->aie_timer.node.expires)) {
519 rtc->aie_timer.enabled = 1;
520 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
521 trace_rtc_timer_enqueue(&rtc->aie_timer);
523 mutex_unlock(&rtc->ops_lock);
526 EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
528 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
530 int err = mutex_lock_interruptible(&rtc->ops_lock);
534 if (rtc->aie_timer.enabled != enabled) {
536 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
538 rtc_timer_remove(rtc, &rtc->aie_timer);
545 else if (!rtc->ops->alarm_irq_enable)
548 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
550 mutex_unlock(&rtc->ops_lock);
552 trace_rtc_alarm_irq_enable(enabled, err);
555 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
557 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
559 int err = mutex_lock_interruptible(&rtc->ops_lock);
563 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
564 if (enabled == 0 && rtc->uie_irq_active) {
565 mutex_unlock(&rtc->ops_lock);
566 return rtc_dev_update_irq_enable_emul(rtc, 0);
569 /* make sure we're changing state */
570 if (rtc->uie_rtctimer.enabled == enabled)
573 if (rtc->uie_unsupported) {
582 __rtc_read_time(rtc, &tm);
583 onesec = ktime_set(1, 0);
584 now = rtc_tm_to_ktime(tm);
585 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
586 rtc->uie_rtctimer.period = ktime_set(1, 0);
587 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
589 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
592 mutex_unlock(&rtc->ops_lock);
593 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
595 * Enable emulation if the driver did not provide
596 * the update_irq_enable function pointer or if returned
597 * -EINVAL to signal that it has been configured without
598 * interrupts or that are not available at the moment.
601 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
606 EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
610 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
611 * @rtc: pointer to the rtc device
613 * This function is called when an AIE, UIE or PIE mode interrupt
614 * has occurred (or been emulated).
616 * Triggers the registered irq_task function callback.
618 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
622 /* mark one irq of the appropriate mode */
623 spin_lock_irqsave(&rtc->irq_lock, flags);
624 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
625 spin_unlock_irqrestore(&rtc->irq_lock, flags);
627 wake_up_interruptible(&rtc->irq_queue);
628 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
633 * rtc_aie_update_irq - AIE mode rtctimer hook
634 * @private: pointer to the rtc_device
636 * This functions is called when the aie_timer expires.
638 void rtc_aie_update_irq(void *private)
640 struct rtc_device *rtc = (struct rtc_device *)private;
641 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
646 * rtc_uie_update_irq - UIE mode rtctimer hook
647 * @private: pointer to the rtc_device
649 * This functions is called when the uie_timer expires.
651 void rtc_uie_update_irq(void *private)
653 struct rtc_device *rtc = (struct rtc_device *)private;
654 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
659 * rtc_pie_update_irq - PIE mode hrtimer hook
660 * @timer: pointer to the pie mode hrtimer
662 * This function is used to emulate PIE mode interrupts
663 * using an hrtimer. This function is called when the periodic
666 enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
668 struct rtc_device *rtc;
671 rtc = container_of(timer, struct rtc_device, pie_timer);
673 period = NSEC_PER_SEC / rtc->irq_freq;
674 count = hrtimer_forward_now(timer, period);
676 rtc_handle_legacy_irq(rtc, count, RTC_PF);
678 return HRTIMER_RESTART;
682 * rtc_update_irq - Triggered when a RTC interrupt occurs.
683 * @rtc: the rtc device
684 * @num: how many irqs are being reported (usually one)
685 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
688 void rtc_update_irq(struct rtc_device *rtc,
689 unsigned long num, unsigned long events)
691 if (IS_ERR_OR_NULL(rtc))
694 pm_stay_awake(rtc->dev.parent);
695 schedule_work(&rtc->irqwork);
697 EXPORT_SYMBOL_GPL(rtc_update_irq);
699 static int __rtc_match(struct device *dev, const void *data)
701 const char *name = data;
703 if (strcmp(dev_name(dev), name) == 0)
708 struct rtc_device *rtc_class_open(const char *name)
711 struct rtc_device *rtc = NULL;
713 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
715 rtc = to_rtc_device(dev);
718 if (!try_module_get(rtc->owner)) {
726 EXPORT_SYMBOL_GPL(rtc_class_open);
728 void rtc_class_close(struct rtc_device *rtc)
730 module_put(rtc->owner);
731 put_device(&rtc->dev);
733 EXPORT_SYMBOL_GPL(rtc_class_close);
735 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
738 * We always cancel the timer here first, because otherwise
739 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
740 * when we manage to start the timer before the callback
741 * returns HRTIMER_RESTART.
743 * We cannot use hrtimer_cancel() here as a running callback
744 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
745 * would spin forever.
747 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
751 ktime_t period = NSEC_PER_SEC / rtc->irq_freq;
753 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
759 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
760 * @rtc: the rtc device
761 * @task: currently registered with rtc_irq_register()
762 * @enabled: true to enable periodic IRQs
765 * Note that rtc_irq_set_freq() should previously have been used to
766 * specify the desired frequency of periodic IRQ.
768 int rtc_irq_set_state(struct rtc_device *rtc, int enabled)
772 while (rtc_update_hrtimer(rtc, enabled) < 0)
775 rtc->pie_enabled = enabled;
777 trace_rtc_irq_set_state(enabled, err);
782 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
783 * @rtc: the rtc device
784 * @task: currently registered with rtc_irq_register()
785 * @freq: positive frequency
788 * Note that rtc_irq_set_state() is used to enable or disable the
791 int rtc_irq_set_freq(struct rtc_device *rtc, int freq)
795 if (freq <= 0 || freq > RTC_MAX_FREQ)
798 rtc->irq_freq = freq;
799 while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0)
802 trace_rtc_irq_set_freq(freq, err);
807 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
809 * @timer timer being added.
811 * Enqueues a timer onto the rtc devices timerqueue and sets
812 * the next alarm event appropriately.
814 * Sets the enabled bit on the added timer.
816 * Must hold ops_lock for proper serialization of timerqueue
818 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
820 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
825 __rtc_read_time(rtc, &tm);
826 now = rtc_tm_to_ktime(tm);
828 /* Skip over expired timers */
830 if (next->expires >= now)
832 next = timerqueue_iterate_next(next);
835 timerqueue_add(&rtc->timerqueue, &timer->node);
836 trace_rtc_timer_enqueue(timer);
837 if (!next || ktime_before(timer->node.expires, next->expires)) {
838 struct rtc_wkalrm alarm;
840 alarm.time = rtc_ktime_to_tm(timer->node.expires);
842 err = __rtc_set_alarm(rtc, &alarm);
844 pm_stay_awake(rtc->dev.parent);
845 schedule_work(&rtc->irqwork);
847 timerqueue_del(&rtc->timerqueue, &timer->node);
848 trace_rtc_timer_dequeue(timer);
856 static void rtc_alarm_disable(struct rtc_device *rtc)
858 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
861 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
862 trace_rtc_alarm_irq_enable(0, 0);
866 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
868 * @timer timer being removed.
870 * Removes a timer onto the rtc devices timerqueue and sets
871 * the next alarm event appropriately.
873 * Clears the enabled bit on the removed timer.
875 * Must hold ops_lock for proper serialization of timerqueue
877 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
879 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
880 timerqueue_del(&rtc->timerqueue, &timer->node);
881 trace_rtc_timer_dequeue(timer);
883 if (next == &timer->node) {
884 struct rtc_wkalrm alarm;
886 next = timerqueue_getnext(&rtc->timerqueue);
888 rtc_alarm_disable(rtc);
891 alarm.time = rtc_ktime_to_tm(next->expires);
893 err = __rtc_set_alarm(rtc, &alarm);
895 pm_stay_awake(rtc->dev.parent);
896 schedule_work(&rtc->irqwork);
902 * rtc_timer_do_work - Expires rtc timers
904 * @timer timer being removed.
906 * Expires rtc timers. Reprograms next alarm event if needed.
907 * Called via worktask.
909 * Serializes access to timerqueue via ops_lock mutex
911 void rtc_timer_do_work(struct work_struct *work)
913 struct rtc_timer *timer;
914 struct timerqueue_node *next;
918 struct rtc_device *rtc =
919 container_of(work, struct rtc_device, irqwork);
921 mutex_lock(&rtc->ops_lock);
923 __rtc_read_time(rtc, &tm);
924 now = rtc_tm_to_ktime(tm);
925 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
926 if (next->expires > now)
930 timer = container_of(next, struct rtc_timer, node);
931 timerqueue_del(&rtc->timerqueue, &timer->node);
932 trace_rtc_timer_dequeue(timer);
935 timer->func(timer->private_data);
937 trace_rtc_timer_fired(timer);
938 /* Re-add/fwd periodic timers */
939 if (ktime_to_ns(timer->period)) {
940 timer->node.expires = ktime_add(timer->node.expires,
943 timerqueue_add(&rtc->timerqueue, &timer->node);
944 trace_rtc_timer_enqueue(timer);
950 struct rtc_wkalrm alarm;
954 alarm.time = rtc_ktime_to_tm(next->expires);
957 err = __rtc_set_alarm(rtc, &alarm);
964 timer = container_of(next, struct rtc_timer, node);
965 timerqueue_del(&rtc->timerqueue, &timer->node);
966 trace_rtc_timer_dequeue(timer);
968 dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
972 rtc_alarm_disable(rtc);
974 pm_relax(rtc->dev.parent);
975 mutex_unlock(&rtc->ops_lock);
979 /* rtc_timer_init - Initializes an rtc_timer
980 * @timer: timer to be intiialized
981 * @f: function pointer to be called when timer fires
982 * @data: private data passed to function pointer
984 * Kernel interface to initializing an rtc_timer.
986 void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
988 timerqueue_init(&timer->node);
991 timer->private_data = data;
994 /* rtc_timer_start - Sets an rtc_timer to fire in the future
995 * @ rtc: rtc device to be used
996 * @ timer: timer being set
997 * @ expires: time at which to expire the timer
998 * @ period: period that the timer will recur
1000 * Kernel interface to set an rtc_timer
1002 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
1003 ktime_t expires, ktime_t period)
1006 mutex_lock(&rtc->ops_lock);
1008 rtc_timer_remove(rtc, timer);
1010 timer->node.expires = expires;
1011 timer->period = period;
1013 ret = rtc_timer_enqueue(rtc, timer);
1015 mutex_unlock(&rtc->ops_lock);
1019 /* rtc_timer_cancel - Stops an rtc_timer
1020 * @ rtc: rtc device to be used
1021 * @ timer: timer being set
1023 * Kernel interface to cancel an rtc_timer
1025 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
1027 mutex_lock(&rtc->ops_lock);
1029 rtc_timer_remove(rtc, timer);
1030 mutex_unlock(&rtc->ops_lock);
1034 * rtc_read_offset - Read the amount of rtc offset in parts per billion
1035 * @ rtc: rtc device to be used
1036 * @ offset: the offset in parts per billion
1038 * see below for details.
1040 * Kernel interface to read rtc clock offset
1041 * Returns 0 on success, or a negative number on error.
1042 * If read_offset() is not implemented for the rtc, return -EINVAL
1044 int rtc_read_offset(struct rtc_device *rtc, long *offset)
1051 if (!rtc->ops->read_offset)
1054 mutex_lock(&rtc->ops_lock);
1055 ret = rtc->ops->read_offset(rtc->dev.parent, offset);
1056 mutex_unlock(&rtc->ops_lock);
1058 trace_rtc_read_offset(*offset, ret);
1063 * rtc_set_offset - Adjusts the duration of the average second
1064 * @ rtc: rtc device to be used
1065 * @ offset: the offset in parts per billion
1067 * Some rtc's allow an adjustment to the average duration of a second
1068 * to compensate for differences in the actual clock rate due to temperature,
1069 * the crystal, capacitor, etc.
1071 * The adjustment applied is as follows:
1072 * t = t0 * (1 + offset * 1e-9)
1073 * where t0 is the measured length of 1 RTC second with offset = 0
1075 * Kernel interface to adjust an rtc clock offset.
1076 * Return 0 on success, or a negative number on error.
1077 * If the rtc offset is not setable (or not implemented), return -EINVAL
1079 int rtc_set_offset(struct rtc_device *rtc, long offset)
1086 if (!rtc->ops->set_offset)
1089 mutex_lock(&rtc->ops_lock);
1090 ret = rtc->ops->set_offset(rtc->dev.parent, offset);
1091 mutex_unlock(&rtc->ops_lock);
1093 trace_rtc_set_offset(offset, ret);