2 * RTC subsystem, interface functions
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
7 * based on arch/arm/common/rtctime.c
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/rtc.h>
15 #include <linux/sched.h>
16 #include <linux/module.h>
17 #include <linux/log2.h>
18 #include <linux/workqueue.h>
20 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
);
21 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
);
23 static int __rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
28 else if (!rtc
->ops
->read_time
)
31 memset(tm
, 0, sizeof(struct rtc_time
));
32 err
= rtc
->ops
->read_time(rtc
->dev
.parent
, tm
);
34 dev_dbg(&rtc
->dev
, "read_time: fail to read: %d\n",
39 err
= rtc_valid_tm(tm
);
41 dev_dbg(&rtc
->dev
, "read_time: rtc_time isn't valid\n");
46 int rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
50 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
54 err
= __rtc_read_time(rtc
, tm
);
55 mutex_unlock(&rtc
->ops_lock
);
58 EXPORT_SYMBOL_GPL(rtc_read_time
);
60 int rtc_set_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
64 err
= rtc_valid_tm(tm
);
68 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
74 else if (rtc
->ops
->set_time
)
75 err
= rtc
->ops
->set_time(rtc
->dev
.parent
, tm
);
76 else if (rtc
->ops
->set_mmss64
) {
77 time64_t secs64
= rtc_tm_to_time64(tm
);
79 err
= rtc
->ops
->set_mmss64(rtc
->dev
.parent
, secs64
);
80 } else if (rtc
->ops
->set_mmss
) {
81 time64_t secs64
= rtc_tm_to_time64(tm
);
82 err
= rtc
->ops
->set_mmss(rtc
->dev
.parent
, secs64
);
86 pm_stay_awake(rtc
->dev
.parent
);
87 mutex_unlock(&rtc
->ops_lock
);
88 /* A timer might have just expired */
89 schedule_work(&rtc
->irqwork
);
92 EXPORT_SYMBOL_GPL(rtc_set_time
);
94 static int rtc_read_alarm_internal(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
98 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
102 if (rtc
->ops
== NULL
)
104 else if (!rtc
->ops
->read_alarm
)
109 alarm
->time
.tm_sec
= -1;
110 alarm
->time
.tm_min
= -1;
111 alarm
->time
.tm_hour
= -1;
112 alarm
->time
.tm_mday
= -1;
113 alarm
->time
.tm_mon
= -1;
114 alarm
->time
.tm_year
= -1;
115 alarm
->time
.tm_wday
= -1;
116 alarm
->time
.tm_yday
= -1;
117 alarm
->time
.tm_isdst
= -1;
118 err
= rtc
->ops
->read_alarm(rtc
->dev
.parent
, alarm
);
121 mutex_unlock(&rtc
->ops_lock
);
125 int __rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
128 struct rtc_time before
, now
;
130 time64_t t_now
, t_alm
;
131 enum { none
, day
, month
, year
} missing
= none
;
134 /* The lower level RTC driver may return -1 in some fields,
135 * creating invalid alarm->time values, for reasons like:
137 * - The hardware may not be capable of filling them in;
138 * many alarms match only on time-of-day fields, not
139 * day/month/year calendar data.
141 * - Some hardware uses illegal values as "wildcard" match
142 * values, which non-Linux firmware (like a BIOS) may try
143 * to set up as e.g. "alarm 15 minutes after each hour".
144 * Linux uses only oneshot alarms.
146 * When we see that here, we deal with it by using values from
147 * a current RTC timestamp for any missing (-1) values. The
148 * RTC driver prevents "periodic alarm" modes.
150 * But this can be racey, because some fields of the RTC timestamp
151 * may have wrapped in the interval since we read the RTC alarm,
152 * which would lead to us inserting inconsistent values in place
155 * Reading the alarm and timestamp in the reverse sequence
156 * would have the same race condition, and not solve the issue.
158 * So, we must first read the RTC timestamp,
159 * then read the RTC alarm value,
160 * and then read a second RTC timestamp.
162 * If any fields of the second timestamp have changed
163 * when compared with the first timestamp, then we know
164 * our timestamp may be inconsistent with that used by
165 * the low-level rtc_read_alarm_internal() function.
167 * So, when the two timestamps disagree, we just loop and do
168 * the process again to get a fully consistent set of values.
170 * This could all instead be done in the lower level driver,
171 * but since more than one lower level RTC implementation needs it,
172 * then it's probably best best to do it here instead of there..
175 /* Get the "before" timestamp */
176 err
= rtc_read_time(rtc
, &before
);
181 memcpy(&before
, &now
, sizeof(struct rtc_time
));
184 /* get the RTC alarm values, which may be incomplete */
185 err
= rtc_read_alarm_internal(rtc
, alarm
);
189 /* full-function RTCs won't have such missing fields */
190 if (rtc_valid_tm(&alarm
->time
) == 0)
193 /* get the "after" timestamp, to detect wrapped fields */
194 err
= rtc_read_time(rtc
, &now
);
198 /* note that tm_sec is a "don't care" value here: */
199 } while ( before
.tm_min
!= now
.tm_min
200 || before
.tm_hour
!= now
.tm_hour
201 || before
.tm_mon
!= now
.tm_mon
202 || before
.tm_year
!= now
.tm_year
);
204 /* Fill in the missing alarm fields using the timestamp; we
205 * know there's at least one since alarm->time is invalid.
207 if (alarm
->time
.tm_sec
== -1)
208 alarm
->time
.tm_sec
= now
.tm_sec
;
209 if (alarm
->time
.tm_min
== -1)
210 alarm
->time
.tm_min
= now
.tm_min
;
211 if (alarm
->time
.tm_hour
== -1)
212 alarm
->time
.tm_hour
= now
.tm_hour
;
214 /* For simplicity, only support date rollover for now */
215 if (alarm
->time
.tm_mday
< 1 || alarm
->time
.tm_mday
> 31) {
216 alarm
->time
.tm_mday
= now
.tm_mday
;
219 if ((unsigned)alarm
->time
.tm_mon
>= 12) {
220 alarm
->time
.tm_mon
= now
.tm_mon
;
224 if (alarm
->time
.tm_year
== -1) {
225 alarm
->time
.tm_year
= now
.tm_year
;
230 /* with luck, no rollover is needed */
231 t_now
= rtc_tm_to_time64(&now
);
232 t_alm
= rtc_tm_to_time64(&alarm
->time
);
238 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
239 * that will trigger at 5am will do so at 5am Tuesday, which
240 * could also be in the next month or year. This is a common
241 * case, especially for PCs.
244 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "day");
245 t_alm
+= 24 * 60 * 60;
246 rtc_time64_to_tm(t_alm
, &alarm
->time
);
249 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
250 * be next month. An alarm matching on the 30th, 29th, or 28th
251 * may end up in the month after that! Many newer PCs support
252 * this type of alarm.
255 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "month");
257 if (alarm
->time
.tm_mon
< 11)
258 alarm
->time
.tm_mon
++;
260 alarm
->time
.tm_mon
= 0;
261 alarm
->time
.tm_year
++;
263 days
= rtc_month_days(alarm
->time
.tm_mon
,
264 alarm
->time
.tm_year
);
265 } while (days
< alarm
->time
.tm_mday
);
268 /* Year rollover ... easy except for leap years! */
270 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "year");
272 alarm
->time
.tm_year
++;
273 } while (!is_leap_year(alarm
->time
.tm_year
+ 1900)
274 && rtc_valid_tm(&alarm
->time
) != 0);
278 dev_warn(&rtc
->dev
, "alarm rollover not handled\n");
282 err
= rtc_valid_tm(&alarm
->time
);
285 dev_warn(&rtc
->dev
, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
286 alarm
->time
.tm_year
+ 1900, alarm
->time
.tm_mon
+ 1,
287 alarm
->time
.tm_mday
, alarm
->time
.tm_hour
, alarm
->time
.tm_min
,
294 int rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
298 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
301 if (rtc
->ops
== NULL
)
303 else if (!rtc
->ops
->read_alarm
)
306 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
307 alarm
->enabled
= rtc
->aie_timer
.enabled
;
308 alarm
->time
= rtc_ktime_to_tm(rtc
->aie_timer
.node
.expires
);
310 mutex_unlock(&rtc
->ops_lock
);
314 EXPORT_SYMBOL_GPL(rtc_read_alarm
);
316 static int __rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
319 time64_t now
, scheduled
;
322 err
= rtc_valid_tm(&alarm
->time
);
325 scheduled
= rtc_tm_to_time64(&alarm
->time
);
327 /* Make sure we're not setting alarms in the past */
328 err
= __rtc_read_time(rtc
, &tm
);
331 now
= rtc_tm_to_time64(&tm
);
332 if (scheduled
<= now
)
335 * XXX - We just checked to make sure the alarm time is not
336 * in the past, but there is still a race window where if
337 * the is alarm set for the next second and the second ticks
338 * over right here, before we set the alarm.
343 else if (!rtc
->ops
->set_alarm
)
346 err
= rtc
->ops
->set_alarm(rtc
->dev
.parent
, alarm
);
351 int rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
355 err
= rtc_valid_tm(&alarm
->time
);
359 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
362 if (rtc
->aie_timer
.enabled
)
363 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
365 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
366 rtc
->aie_timer
.period
= ktime_set(0, 0);
368 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
370 mutex_unlock(&rtc
->ops_lock
);
373 EXPORT_SYMBOL_GPL(rtc_set_alarm
);
375 /* Called once per device from rtc_device_register */
376 int rtc_initialize_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
381 err
= rtc_valid_tm(&alarm
->time
);
385 err
= rtc_read_time(rtc
, &now
);
389 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
393 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
394 rtc
->aie_timer
.period
= ktime_set(0, 0);
396 /* Alarm has to be enabled & in the future for us to enqueue it */
397 if (alarm
->enabled
&& (rtc_tm_to_ktime(now
).tv64
<
398 rtc
->aie_timer
.node
.expires
.tv64
)) {
400 rtc
->aie_timer
.enabled
= 1;
401 timerqueue_add(&rtc
->timerqueue
, &rtc
->aie_timer
.node
);
403 mutex_unlock(&rtc
->ops_lock
);
406 EXPORT_SYMBOL_GPL(rtc_initialize_alarm
);
408 int rtc_alarm_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
410 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
414 if (rtc
->aie_timer
.enabled
!= enabled
) {
416 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
418 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
425 else if (!rtc
->ops
->alarm_irq_enable
)
428 err
= rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, enabled
);
430 mutex_unlock(&rtc
->ops_lock
);
433 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable
);
435 int rtc_update_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
437 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
441 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
442 if (enabled
== 0 && rtc
->uie_irq_active
) {
443 mutex_unlock(&rtc
->ops_lock
);
444 return rtc_dev_update_irq_enable_emul(rtc
, 0);
447 /* make sure we're changing state */
448 if (rtc
->uie_rtctimer
.enabled
== enabled
)
451 if (rtc
->uie_unsupported
) {
460 __rtc_read_time(rtc
, &tm
);
461 onesec
= ktime_set(1, 0);
462 now
= rtc_tm_to_ktime(tm
);
463 rtc
->uie_rtctimer
.node
.expires
= ktime_add(now
, onesec
);
464 rtc
->uie_rtctimer
.period
= ktime_set(1, 0);
465 err
= rtc_timer_enqueue(rtc
, &rtc
->uie_rtctimer
);
467 rtc_timer_remove(rtc
, &rtc
->uie_rtctimer
);
470 mutex_unlock(&rtc
->ops_lock
);
471 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
473 * Enable emulation if the driver did not provide
474 * the update_irq_enable function pointer or if returned
475 * -EINVAL to signal that it has been configured without
476 * interrupts or that are not available at the moment.
479 err
= rtc_dev_update_irq_enable_emul(rtc
, enabled
);
484 EXPORT_SYMBOL_GPL(rtc_update_irq_enable
);
488 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
489 * @rtc: pointer to the rtc device
491 * This function is called when an AIE, UIE or PIE mode interrupt
492 * has occurred (or been emulated).
494 * Triggers the registered irq_task function callback.
496 void rtc_handle_legacy_irq(struct rtc_device
*rtc
, int num
, int mode
)
500 /* mark one irq of the appropriate mode */
501 spin_lock_irqsave(&rtc
->irq_lock
, flags
);
502 rtc
->irq_data
= (rtc
->irq_data
+ (num
<< 8)) | (RTC_IRQF
|mode
);
503 spin_unlock_irqrestore(&rtc
->irq_lock
, flags
);
505 /* call the task func */
506 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
508 rtc
->irq_task
->func(rtc
->irq_task
->private_data
);
509 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
511 wake_up_interruptible(&rtc
->irq_queue
);
512 kill_fasync(&rtc
->async_queue
, SIGIO
, POLL_IN
);
517 * rtc_aie_update_irq - AIE mode rtctimer hook
518 * @private: pointer to the rtc_device
520 * This functions is called when the aie_timer expires.
522 void rtc_aie_update_irq(void *private)
524 struct rtc_device
*rtc
= (struct rtc_device
*)private;
525 rtc_handle_legacy_irq(rtc
, 1, RTC_AF
);
530 * rtc_uie_update_irq - UIE mode rtctimer hook
531 * @private: pointer to the rtc_device
533 * This functions is called when the uie_timer expires.
535 void rtc_uie_update_irq(void *private)
537 struct rtc_device
*rtc
= (struct rtc_device
*)private;
538 rtc_handle_legacy_irq(rtc
, 1, RTC_UF
);
543 * rtc_pie_update_irq - PIE mode hrtimer hook
544 * @timer: pointer to the pie mode hrtimer
546 * This function is used to emulate PIE mode interrupts
547 * using an hrtimer. This function is called when the periodic
550 enum hrtimer_restart
rtc_pie_update_irq(struct hrtimer
*timer
)
552 struct rtc_device
*rtc
;
555 rtc
= container_of(timer
, struct rtc_device
, pie_timer
);
557 period
= ktime_set(0, NSEC_PER_SEC
/rtc
->irq_freq
);
558 count
= hrtimer_forward_now(timer
, period
);
560 rtc_handle_legacy_irq(rtc
, count
, RTC_PF
);
562 return HRTIMER_RESTART
;
566 * rtc_update_irq - Triggered when a RTC interrupt occurs.
567 * @rtc: the rtc device
568 * @num: how many irqs are being reported (usually one)
569 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
572 void rtc_update_irq(struct rtc_device
*rtc
,
573 unsigned long num
, unsigned long events
)
575 if (IS_ERR_OR_NULL(rtc
))
578 pm_stay_awake(rtc
->dev
.parent
);
579 schedule_work(&rtc
->irqwork
);
581 EXPORT_SYMBOL_GPL(rtc_update_irq
);
583 static int __rtc_match(struct device
*dev
, const void *data
)
585 const char *name
= data
;
587 if (strcmp(dev_name(dev
), name
) == 0)
592 struct rtc_device
*rtc_class_open(const char *name
)
595 struct rtc_device
*rtc
= NULL
;
597 dev
= class_find_device(rtc_class
, NULL
, name
, __rtc_match
);
599 rtc
= to_rtc_device(dev
);
602 if (!try_module_get(rtc
->owner
)) {
610 EXPORT_SYMBOL_GPL(rtc_class_open
);
612 void rtc_class_close(struct rtc_device
*rtc
)
614 module_put(rtc
->owner
);
615 put_device(&rtc
->dev
);
617 EXPORT_SYMBOL_GPL(rtc_class_close
);
619 int rtc_irq_register(struct rtc_device
*rtc
, struct rtc_task
*task
)
623 if (task
== NULL
|| task
->func
== NULL
)
626 /* Cannot register while the char dev is in use */
627 if (test_and_set_bit_lock(RTC_DEV_BUSY
, &rtc
->flags
))
630 spin_lock_irq(&rtc
->irq_task_lock
);
631 if (rtc
->irq_task
== NULL
) {
632 rtc
->irq_task
= task
;
635 spin_unlock_irq(&rtc
->irq_task_lock
);
637 clear_bit_unlock(RTC_DEV_BUSY
, &rtc
->flags
);
641 EXPORT_SYMBOL_GPL(rtc_irq_register
);
643 void rtc_irq_unregister(struct rtc_device
*rtc
, struct rtc_task
*task
)
645 spin_lock_irq(&rtc
->irq_task_lock
);
646 if (rtc
->irq_task
== task
)
647 rtc
->irq_task
= NULL
;
648 spin_unlock_irq(&rtc
->irq_task_lock
);
650 EXPORT_SYMBOL_GPL(rtc_irq_unregister
);
652 static int rtc_update_hrtimer(struct rtc_device
*rtc
, int enabled
)
655 * We always cancel the timer here first, because otherwise
656 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
657 * when we manage to start the timer before the callback
658 * returns HRTIMER_RESTART.
660 * We cannot use hrtimer_cancel() here as a running callback
661 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
662 * would spin forever.
664 if (hrtimer_try_to_cancel(&rtc
->pie_timer
) < 0)
668 ktime_t period
= ktime_set(0, NSEC_PER_SEC
/ rtc
->irq_freq
);
670 hrtimer_start(&rtc
->pie_timer
, period
, HRTIMER_MODE_REL
);
676 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
677 * @rtc: the rtc device
678 * @task: currently registered with rtc_irq_register()
679 * @enabled: true to enable periodic IRQs
682 * Note that rtc_irq_set_freq() should previously have been used to
683 * specify the desired frequency of periodic IRQ task->func() callbacks.
685 int rtc_irq_set_state(struct rtc_device
*rtc
, struct rtc_task
*task
, int enabled
)
691 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
692 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
694 else if (rtc
->irq_task
!= task
)
697 if (rtc_update_hrtimer(rtc
, enabled
) < 0) {
698 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
702 rtc
->pie_enabled
= enabled
;
704 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
707 EXPORT_SYMBOL_GPL(rtc_irq_set_state
);
710 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
711 * @rtc: the rtc device
712 * @task: currently registered with rtc_irq_register()
713 * @freq: positive frequency with which task->func() will be called
716 * Note that rtc_irq_set_state() is used to enable or disable the
719 int rtc_irq_set_freq(struct rtc_device
*rtc
, struct rtc_task
*task
, int freq
)
724 if (freq
<= 0 || freq
> RTC_MAX_FREQ
)
727 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
728 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
730 else if (rtc
->irq_task
!= task
)
733 rtc
->irq_freq
= freq
;
734 if (rtc
->pie_enabled
&& rtc_update_hrtimer(rtc
, 1) < 0) {
735 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
740 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
743 EXPORT_SYMBOL_GPL(rtc_irq_set_freq
);
746 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
748 * @timer timer being added.
750 * Enqueues a timer onto the rtc devices timerqueue and sets
751 * the next alarm event appropriately.
753 * Sets the enabled bit on the added timer.
755 * Must hold ops_lock for proper serialization of timerqueue
757 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
759 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
764 __rtc_read_time(rtc
, &tm
);
765 now
= rtc_tm_to_ktime(tm
);
767 /* Skip over expired timers */
769 if (next
->expires
.tv64
>= now
.tv64
)
771 next
= timerqueue_iterate_next(next
);
774 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
776 struct rtc_wkalrm alarm
;
778 alarm
.time
= rtc_ktime_to_tm(timer
->node
.expires
);
780 err
= __rtc_set_alarm(rtc
, &alarm
);
782 pm_stay_awake(rtc
->dev
.parent
);
783 schedule_work(&rtc
->irqwork
);
785 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
793 static void rtc_alarm_disable(struct rtc_device
*rtc
)
795 if (!rtc
->ops
|| !rtc
->ops
->alarm_irq_enable
)
798 rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, false);
802 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
804 * @timer timer being removed.
806 * Removes a timer onto the rtc devices timerqueue and sets
807 * the next alarm event appropriately.
809 * Clears the enabled bit on the removed timer.
811 * Must hold ops_lock for proper serialization of timerqueue
813 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
815 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
816 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
818 if (next
== &timer
->node
) {
819 struct rtc_wkalrm alarm
;
821 next
= timerqueue_getnext(&rtc
->timerqueue
);
823 rtc_alarm_disable(rtc
);
826 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
828 err
= __rtc_set_alarm(rtc
, &alarm
);
830 pm_stay_awake(rtc
->dev
.parent
);
831 schedule_work(&rtc
->irqwork
);
837 * rtc_timer_do_work - Expires rtc timers
839 * @timer timer being removed.
841 * Expires rtc timers. Reprograms next alarm event if needed.
842 * Called via worktask.
844 * Serializes access to timerqueue via ops_lock mutex
846 void rtc_timer_do_work(struct work_struct
*work
)
848 struct rtc_timer
*timer
;
849 struct timerqueue_node
*next
;
853 struct rtc_device
*rtc
=
854 container_of(work
, struct rtc_device
, irqwork
);
856 mutex_lock(&rtc
->ops_lock
);
858 __rtc_read_time(rtc
, &tm
);
859 now
= rtc_tm_to_ktime(tm
);
860 while ((next
= timerqueue_getnext(&rtc
->timerqueue
))) {
861 if (next
->expires
.tv64
> now
.tv64
)
865 timer
= container_of(next
, struct rtc_timer
, node
);
866 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
868 if (timer
->task
.func
)
869 timer
->task
.func(timer
->task
.private_data
);
871 /* Re-add/fwd periodic timers */
872 if (ktime_to_ns(timer
->period
)) {
873 timer
->node
.expires
= ktime_add(timer
->node
.expires
,
876 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
882 struct rtc_wkalrm alarm
;
886 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
889 err
= __rtc_set_alarm(rtc
, &alarm
);
896 timer
= container_of(next
, struct rtc_timer
, node
);
897 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
899 dev_err(&rtc
->dev
, "__rtc_set_alarm: err=%d\n", err
);
903 rtc_alarm_disable(rtc
);
905 pm_relax(rtc
->dev
.parent
);
906 mutex_unlock(&rtc
->ops_lock
);
910 /* rtc_timer_init - Initializes an rtc_timer
911 * @timer: timer to be intiialized
912 * @f: function pointer to be called when timer fires
913 * @data: private data passed to function pointer
915 * Kernel interface to initializing an rtc_timer.
917 void rtc_timer_init(struct rtc_timer
*timer
, void (*f
)(void *p
), void *data
)
919 timerqueue_init(&timer
->node
);
921 timer
->task
.func
= f
;
922 timer
->task
.private_data
= data
;
925 /* rtc_timer_start - Sets an rtc_timer to fire in the future
926 * @ rtc: rtc device to be used
927 * @ timer: timer being set
928 * @ expires: time at which to expire the timer
929 * @ period: period that the timer will recur
931 * Kernel interface to set an rtc_timer
933 int rtc_timer_start(struct rtc_device
*rtc
, struct rtc_timer
*timer
,
934 ktime_t expires
, ktime_t period
)
937 mutex_lock(&rtc
->ops_lock
);
939 rtc_timer_remove(rtc
, timer
);
941 timer
->node
.expires
= expires
;
942 timer
->period
= period
;
944 ret
= rtc_timer_enqueue(rtc
, timer
);
946 mutex_unlock(&rtc
->ops_lock
);
950 /* rtc_timer_cancel - Stops an rtc_timer
951 * @ rtc: rtc device to be used
952 * @ timer: timer being set
954 * Kernel interface to cancel an rtc_timer
956 void rtc_timer_cancel(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
958 mutex_lock(&rtc
->ops_lock
);
960 rtc_timer_remove(rtc
, timer
);
961 mutex_unlock(&rtc
->ops_lock
);
965 * rtc_read_offset - Read the amount of rtc offset in parts per billion
966 * @ rtc: rtc device to be used
967 * @ offset: the offset in parts per billion
969 * see below for details.
971 * Kernel interface to read rtc clock offset
972 * Returns 0 on success, or a negative number on error.
973 * If read_offset() is not implemented for the rtc, return -EINVAL
975 int rtc_read_offset(struct rtc_device
*rtc
, long *offset
)
982 if (!rtc
->ops
->read_offset
)
985 mutex_lock(&rtc
->ops_lock
);
986 ret
= rtc
->ops
->read_offset(rtc
->dev
.parent
, offset
);
987 mutex_unlock(&rtc
->ops_lock
);
992 * rtc_set_offset - Adjusts the duration of the average second
993 * @ rtc: rtc device to be used
994 * @ offset: the offset in parts per billion
996 * Some rtc's allow an adjustment to the average duration of a second
997 * to compensate for differences in the actual clock rate due to temperature,
998 * the crystal, capacitor, etc.
1000 * Kernel interface to adjust an rtc clock offset.
1001 * Return 0 on success, or a negative number on error.
1002 * If the rtc offset is not setable (or not implemented), return -EINVAL
1004 int rtc_set_offset(struct rtc_device
*rtc
, long offset
)
1011 if (!rtc
->ops
->set_offset
)
1014 mutex_lock(&rtc
->ops_lock
);
1015 ret
= rtc
->ops
->set_offset(rtc
->dev
.parent
, offset
);
1016 mutex_unlock(&rtc
->ops_lock
);