3  * RTC subsystem, interface functions
11 #include <linux/rtc.h>
18 #include <trace/events/rtc.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 void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm)  in rtc_add_offset()  argument
27 	if (!rtc->offset_secs)  in rtc_add_offset()
33 	 * Since the reading time values from RTC device are always in the RTC  in rtc_add_offset()
38 	if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) ||  in rtc_add_offset()
39 	    (rtc->start_secs < rtc->range_min &&  in rtc_add_offset()
40 	     secs <= (rtc->start_secs + rtc->range_max - rtc->range_min)))  in rtc_add_offset()
43 	rtc_time64_to_tm(secs + rtc->offset_secs, tm);  in rtc_add_offset()
46 static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm)  in rtc_subtract_offset()  argument
50 	if (!rtc->offset_secs)  in rtc_subtract_offset()
56 	 * If the setting time values are in the valid range of RTC hardware  in rtc_subtract_offset()
57 	 * device, then no need to subtract the offset when setting time to RTC  in rtc_subtract_offset()
59 	 * values are valid for RTC hardware device.  in rtc_subtract_offset()
61 	if (secs >= rtc->range_min && secs <= rtc->range_max)  in rtc_subtract_offset()
64 	rtc_time64_to_tm(secs - rtc->offset_secs, tm);  in rtc_subtract_offset()
67 static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm)  in rtc_valid_range()  argument
69 	if (rtc->range_min != rtc->range_max) {  in rtc_valid_range()
71 		time64_t range_min = rtc->set_start_time ? rtc->start_secs :  in rtc_valid_range()
72 			rtc->range_min;  in rtc_valid_range()
73 		timeu64_t range_max = rtc->set_start_time ?  in rtc_valid_range()
74 			(rtc->start_secs + rtc->range_max - rtc->range_min) :  in rtc_valid_range()
75 			rtc->range_max;  in rtc_valid_range()
84 static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)  in __rtc_read_time()  argument
88 	if (!rtc->ops) {  in __rtc_read_time()
90 	} else if (!rtc->ops->read_time) {  in __rtc_read_time()
94 		err = rtc->ops->read_time(rtc->dev.parent, tm);  in __rtc_read_time()
96 			dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",  in __rtc_read_time()
101 		rtc_add_offset(rtc, tm);  in __rtc_read_time()
105 			dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");  in __rtc_read_time()
110 int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)  in rtc_read_time()  argument
114 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_read_time()
118 	err = __rtc_read_time(rtc, tm);  in rtc_read_time()
119 	mutex_unlock(&rtc->ops_lock);  in rtc_read_time()
126 int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)  in rtc_set_time()  argument
134 	err = rtc_valid_range(rtc, tm);  in rtc_set_time()
138 	rtc_subtract_offset(rtc, tm);  in rtc_set_time()
141 	uie = rtc->uie_rtctimer.enabled || rtc->uie_irq_active;  in rtc_set_time()
143 	uie = rtc->uie_rtctimer.enabled;  in rtc_set_time()
146 		err = rtc_update_irq_enable(rtc, 0);  in rtc_set_time()
151 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_set_time()
155 	if (!rtc->ops)  in rtc_set_time()
157 	else if (rtc->ops->set_time)  in rtc_set_time()
158 		err = rtc->ops->set_time(rtc->dev.parent, tm);  in rtc_set_time()
162 	pm_stay_awake(rtc->dev.parent);  in rtc_set_time()
163 	mutex_unlock(&rtc->ops_lock);  in rtc_set_time()
165 	schedule_work(&rtc->irqwork);  in rtc_set_time()
168 		err = rtc_update_irq_enable(rtc, 1);  in rtc_set_time()
178 static int rtc_read_alarm_internal(struct rtc_device *rtc,  in rtc_read_alarm_internal()  argument
183 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_read_alarm_internal()
187 	if (!rtc->ops) {  in rtc_read_alarm_internal()
189 	} else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->read_alarm) {  in rtc_read_alarm_internal()
203 		err = rtc->ops->read_alarm(rtc->dev.parent, alarm);  in rtc_read_alarm_internal()
206 	mutex_unlock(&rtc->ops_lock);  in rtc_read_alarm_internal()
212 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)  in __rtc_read_alarm()  argument
221 	/* The lower level RTC driver may return -1 in some fields,  in __rtc_read_alarm()
234 	 * a current RTC timestamp for any missing (-1) values.  The  in __rtc_read_alarm()
235 	 * RTC driver prevents "periodic alarm" modes.  in __rtc_read_alarm()
237 	 * But this can be racey, because some fields of the RTC timestamp  in __rtc_read_alarm()
238 	 * may have wrapped in the interval since we read the RTC alarm,  in __rtc_read_alarm()
245 	 * So, we must first read the RTC timestamp,  in __rtc_read_alarm()
246 	 * then read the RTC alarm value,  in __rtc_read_alarm()
247 	 * and then read a second RTC timestamp.  in __rtc_read_alarm()
258 	 * but since more than one lower level RTC implementation needs it,  in __rtc_read_alarm()
263 	err = rtc_read_time(rtc, &before);  in __rtc_read_alarm()
271 		/* get the RTC alarm values, which may be incomplete */  in __rtc_read_alarm()
272 		err = rtc_read_alarm_internal(rtc, alarm);  in __rtc_read_alarm()
282 		err = rtc_read_time(rtc, &now);  in __rtc_read_alarm()
338 		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");  in __rtc_read_alarm()
349 		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");  in __rtc_read_alarm()
364 		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");  in __rtc_read_alarm()
372 		dev_warn(&rtc->dev, "alarm rollover not handled\n");  in __rtc_read_alarm()
379 		dev_warn(&rtc->dev, "invalid alarm value: %ptR\n",  in __rtc_read_alarm()
382 		rtc_add_offset(rtc, &alarm->time);  in __rtc_read_alarm()
387 int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)  in rtc_read_alarm()  argument
391 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_read_alarm()
394 	if (!rtc->ops) {  in rtc_read_alarm()
396 	} else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) {  in rtc_read_alarm()
400 		alarm->enabled = rtc->aie_timer.enabled;  in rtc_read_alarm()
401 		alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);  in rtc_read_alarm()
403 	mutex_unlock(&rtc->ops_lock);  in rtc_read_alarm()
410 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)  in __rtc_set_alarm()  argument
423 	err = __rtc_read_time(rtc, &tm);  in __rtc_set_alarm()
437 	rtc_subtract_offset(rtc, &alarm->time);  in __rtc_set_alarm()
439 	if (!rtc->ops)  in __rtc_set_alarm()
441 	else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))  in __rtc_set_alarm()
444 		err = rtc->ops->set_alarm(rtc->dev.parent, alarm);  in __rtc_set_alarm()
450 int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)  in rtc_set_alarm()  argument
455 	if (!rtc->ops)  in rtc_set_alarm()
457 	else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))  in rtc_set_alarm()
464 	err = rtc_valid_range(rtc, &alarm->time);  in rtc_set_alarm()
468 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_set_alarm()
471 	if (rtc->aie_timer.enabled)  in rtc_set_alarm()
472 		rtc_timer_remove(rtc, &rtc->aie_timer);  in rtc_set_alarm()
479 	if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features))  in rtc_set_alarm()
482 	rtc->aie_timer.node.expires = alarm_time;  in rtc_set_alarm()
483 	rtc->aie_timer.period = 0;  in rtc_set_alarm()
485 		err = rtc_timer_enqueue(rtc, &rtc->aie_timer);  in rtc_set_alarm()
487 	mutex_unlock(&rtc->ops_lock);  in rtc_set_alarm()
494 int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)  in rtc_initialize_alarm()  argument
503 	err = rtc_read_time(rtc, &now);  in rtc_initialize_alarm()
507 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_initialize_alarm()
511 	rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);  in rtc_initialize_alarm()
512 	rtc->aie_timer.period = 0;  in rtc_initialize_alarm()
516 			 rtc->aie_timer.node.expires)) {  in rtc_initialize_alarm()
517 		rtc->aie_timer.enabled = 1;  in rtc_initialize_alarm()
518 		timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);  in rtc_initialize_alarm()
519 		trace_rtc_timer_enqueue(&rtc->aie_timer);  in rtc_initialize_alarm()
521 	mutex_unlock(&rtc->ops_lock);  in rtc_initialize_alarm()
526 int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)  in rtc_alarm_irq_enable()  argument
530 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_alarm_irq_enable()
534 	if (rtc->aie_timer.enabled != enabled) {  in rtc_alarm_irq_enable()
536 			err = rtc_timer_enqueue(rtc, &rtc->aie_timer);  in rtc_alarm_irq_enable()
538 			rtc_timer_remove(rtc, &rtc->aie_timer);  in rtc_alarm_irq_enable()
543 	else if (!rtc->ops)  in rtc_alarm_irq_enable()
545 	else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)  in rtc_alarm_irq_enable()
548 		err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);  in rtc_alarm_irq_enable()
550 	mutex_unlock(&rtc->ops_lock);  in rtc_alarm_irq_enable()
557 int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)  in rtc_update_irq_enable()  argument
561 	err = mutex_lock_interruptible(&rtc->ops_lock);  in rtc_update_irq_enable()
566 	if (enabled == 0 && rtc->uie_irq_active) {  in rtc_update_irq_enable()
567 		mutex_unlock(&rtc->ops_lock);  in rtc_update_irq_enable()
568 		return rtc_dev_update_irq_enable_emul(rtc, 0);  in rtc_update_irq_enable()
572 	if (rtc->uie_rtctimer.enabled == enabled)  in rtc_update_irq_enable()
575 	if (!test_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features) ||  in rtc_update_irq_enable()
576 	    !test_bit(RTC_FEATURE_ALARM, rtc->features)) {  in rtc_update_irq_enable()
577 		mutex_unlock(&rtc->ops_lock);  in rtc_update_irq_enable()
579 		return rtc_dev_update_irq_enable_emul(rtc, enabled);  in rtc_update_irq_enable()
589 		err = __rtc_read_time(rtc, &tm);  in rtc_update_irq_enable()
594 		rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);  in rtc_update_irq_enable()
595 		rtc->uie_rtctimer.period = ktime_set(1, 0);  in rtc_update_irq_enable()
596 		err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);  in rtc_update_irq_enable()
598 		rtc_timer_remove(rtc, &rtc->uie_rtctimer);  in rtc_update_irq_enable()
602 	mutex_unlock(&rtc->ops_lock);  in rtc_update_irq_enable()
610  * @rtc: pointer to the rtc device
618 void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)  in rtc_handle_legacy_irq()  argument
623 	spin_lock_irqsave(&rtc->irq_lock, flags);  in rtc_handle_legacy_irq()
624 	rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF | mode);  in rtc_handle_legacy_irq()
625 	spin_unlock_irqrestore(&rtc->irq_lock, flags);  in rtc_handle_legacy_irq()
627 	wake_up_interruptible(&rtc->irq_queue);  in rtc_handle_legacy_irq()
628 	kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);  in rtc_handle_legacy_irq()
633  * @rtc: pointer to the rtc_device
637 void rtc_aie_update_irq(struct rtc_device *rtc)  in rtc_aie_update_irq()  argument
639 	rtc_handle_legacy_irq(rtc, 1, RTC_AF);  in rtc_aie_update_irq()
644  * @rtc: pointer to the rtc_device
648 void rtc_uie_update_irq(struct rtc_device *rtc)  in rtc_uie_update_irq()  argument
650 	rtc_handle_legacy_irq(rtc, 1,  RTC_UF);  in rtc_uie_update_irq()
663 	struct rtc_device *rtc;  in rtc_pie_update_irq()  local
667 	rtc = container_of(timer, struct rtc_device, pie_timer);  in rtc_pie_update_irq()
669 	period = NSEC_PER_SEC / rtc->irq_freq;  in rtc_pie_update_irq()
672 	rtc_handle_legacy_irq(rtc, count, RTC_PF);  in rtc_pie_update_irq()
678  * rtc_update_irq - Triggered when a RTC interrupt occurs.
679  * @rtc: the rtc device
684 void rtc_update_irq(struct rtc_device *rtc,  in rtc_update_irq()  argument
687 	if (IS_ERR_OR_NULL(rtc))  in rtc_update_irq()
690 	pm_stay_awake(rtc->dev.parent);  in rtc_update_irq()
691 	schedule_work(&rtc->irqwork);  in rtc_update_irq()
698 	struct rtc_device *rtc = NULL;  in rtc_class_open()  local
702 		rtc = to_rtc_device(dev);  in rtc_class_open()
704 	if (rtc) {  in rtc_class_open()
705 		if (!try_module_get(rtc->owner)) {  in rtc_class_open()
707 			rtc = NULL;  in rtc_class_open()
711 	return rtc;  in rtc_class_open()
715 void rtc_class_close(struct rtc_device *rtc)  in rtc_class_close()  argument
717 	module_put(rtc->owner);  in rtc_class_close()
718 	put_device(&rtc->dev);  in rtc_class_close()
722 static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)  in rtc_update_hrtimer()  argument
731 	 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()  in rtc_update_hrtimer()
734 	if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)  in rtc_update_hrtimer()
738 		ktime_t period = NSEC_PER_SEC / rtc->irq_freq;  in rtc_update_hrtimer()
740 		hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);  in rtc_update_hrtimer()
747  * @rtc: the rtc device
754 int rtc_irq_set_state(struct rtc_device *rtc, int enabled)  in rtc_irq_set_state()  argument
758 	while (rtc_update_hrtimer(rtc, enabled) < 0)  in rtc_irq_set_state()
761 	rtc->pie_enabled = enabled;  in rtc_irq_set_state()
769  * @rtc: the rtc device
776 int rtc_irq_set_freq(struct rtc_device *rtc, int freq)  in rtc_irq_set_freq()  argument
783 	rtc->irq_freq = freq;  in rtc_irq_set_freq()
784 	while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0)  in rtc_irq_set_freq()
793  * @rtc: rtc device
796  * Enqueues a timer onto the rtc devices timerqueue and sets
803 static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)  in rtc_timer_enqueue()  argument
805 	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);  in rtc_timer_enqueue()
810 	err = __rtc_read_time(rtc, &tm);  in rtc_timer_enqueue()
824 	timerqueue_add(&rtc->timerqueue, &timer->node);  in rtc_timer_enqueue()
831 		err = __rtc_set_alarm(rtc, &alarm);  in rtc_timer_enqueue()
833 			pm_stay_awake(rtc->dev.parent);  in rtc_timer_enqueue()
834 			schedule_work(&rtc->irqwork);  in rtc_timer_enqueue()
836 			timerqueue_del(&rtc->timerqueue, &timer->node);  in rtc_timer_enqueue()
845 static void rtc_alarm_disable(struct rtc_device *rtc)  in rtc_alarm_disable()  argument
847 	if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)  in rtc_alarm_disable()
850 	rtc->ops->alarm_irq_enable(rtc->dev.parent, false);  in rtc_alarm_disable()
856  * @rtc: rtc device
859  * Removes a timer onto the rtc devices timerqueue and sets
866 static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)  in rtc_timer_remove()  argument
868 	struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);  in rtc_timer_remove()
870 	timerqueue_del(&rtc->timerqueue, &timer->node);  in rtc_timer_remove()
877 		next = timerqueue_getnext(&rtc->timerqueue);  in rtc_timer_remove()
879 			rtc_alarm_disable(rtc);  in rtc_timer_remove()
884 		err = __rtc_set_alarm(rtc, &alarm);  in rtc_timer_remove()
886 			pm_stay_awake(rtc->dev.parent);  in rtc_timer_remove()
887 			schedule_work(&rtc->irqwork);  in rtc_timer_remove()
893  * rtc_timer_do_work - Expires rtc timers
896  * Expires rtc timers. Reprograms next alarm event if needed.
908 	struct rtc_device *rtc =  in rtc_timer_do_work()  local
911 	mutex_lock(&rtc->ops_lock);  in rtc_timer_do_work()
913 	__rtc_read_time(rtc, &tm);  in rtc_timer_do_work()
915 	while ((next = timerqueue_getnext(&rtc->timerqueue))) {  in rtc_timer_do_work()
921 		timerqueue_del(&rtc->timerqueue, &timer->node);  in rtc_timer_do_work()
925 			timer->func(timer->rtc);  in rtc_timer_do_work()
933 			timerqueue_add(&rtc->timerqueue, &timer->node);  in rtc_timer_do_work()
947 		err = __rtc_set_alarm(rtc, &alarm);  in rtc_timer_do_work()
955 			timerqueue_del(&rtc->timerqueue, &timer->node);  in rtc_timer_do_work()
958 			dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);  in rtc_timer_do_work()
962 		rtc_alarm_disable(rtc);  in rtc_timer_do_work()
965 	pm_relax(rtc->dev.parent);  in rtc_timer_do_work()
966 	mutex_unlock(&rtc->ops_lock);  in rtc_timer_do_work()
972  * @rtc: pointer to the rtc_device
977 		    struct rtc_device *rtc)  in rtc_timer_init()  argument
982 	timer->rtc = rtc;  in rtc_timer_init()
986  * @ rtc: rtc device to be used
993 int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,  in rtc_timer_start()  argument
998 	mutex_lock(&rtc->ops_lock);  in rtc_timer_start()
1000 		rtc_timer_remove(rtc, timer);  in rtc_timer_start()
1005 	ret = rtc_timer_enqueue(rtc, timer);  in rtc_timer_start()
1007 	mutex_unlock(&rtc->ops_lock);  in rtc_timer_start()
1012  * @ rtc: rtc device to be used
1017 void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)  in rtc_timer_cancel()  argument
1019 	mutex_lock(&rtc->ops_lock);  in rtc_timer_cancel()
1021 		rtc_timer_remove(rtc, timer);  in rtc_timer_cancel()
1022 	mutex_unlock(&rtc->ops_lock);  in rtc_timer_cancel()
1026  * rtc_read_offset - Read the amount of rtc offset in parts per billion
1027  * @rtc: rtc device to be used
1032  * Kernel interface to read rtc clock offset
1034  * If read_offset() is not implemented for the rtc, return -EINVAL
1036 int rtc_read_offset(struct rtc_device *rtc, long *offset)  in rtc_read_offset()  argument
1040 	if (!rtc->ops)  in rtc_read_offset()
1043 	if (!rtc->ops->read_offset)  in rtc_read_offset()
1046 	mutex_lock(&rtc->ops_lock);  in rtc_read_offset()
1047 	ret = rtc->ops->read_offset(rtc->dev.parent, offset);  in rtc_read_offset()
1048 	mutex_unlock(&rtc->ops_lock);  in rtc_read_offset()
1056  * @rtc: rtc device to be used
1059  * Some rtc's allow an adjustment to the average duration of a second
1065  * where t0 is the measured length of 1 RTC second with offset = 0
1067  * Kernel interface to adjust an rtc clock offset.
1069  * If the rtc offset is not setable (or not implemented), return -EINVAL
1071 int rtc_set_offset(struct rtc_device *rtc, long offset)  in rtc_set_offset()  argument
1075 	if (!rtc->ops)  in rtc_set_offset()
1078 	if (!rtc->ops->set_offset)  in rtc_set_offset()
1081 	mutex_lock(&rtc->ops_lock);  in rtc_set_offset()
1082 	ret = rtc->ops->set_offset(rtc->dev.parent, offset);  in rtc_set_offset()
1083 	mutex_unlock(&rtc->ops_lock);  in rtc_set_offset()