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 /* Can't proceed if alarm is still invalid after replacing
233 err
= rtc_valid_tm(&alarm
->time
);
237 /* with luck, no rollover is needed */
238 t_now
= rtc_tm_to_time64(&now
);
239 t_alm
= rtc_tm_to_time64(&alarm
->time
);
245 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
246 * that will trigger at 5am will do so at 5am Tuesday, which
247 * could also be in the next month or year. This is a common
248 * case, especially for PCs.
251 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "day");
252 t_alm
+= 24 * 60 * 60;
253 rtc_time64_to_tm(t_alm
, &alarm
->time
);
256 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
257 * be next month. An alarm matching on the 30th, 29th, or 28th
258 * may end up in the month after that! Many newer PCs support
259 * this type of alarm.
262 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "month");
264 if (alarm
->time
.tm_mon
< 11)
265 alarm
->time
.tm_mon
++;
267 alarm
->time
.tm_mon
= 0;
268 alarm
->time
.tm_year
++;
270 days
= rtc_month_days(alarm
->time
.tm_mon
,
271 alarm
->time
.tm_year
);
272 } while (days
< alarm
->time
.tm_mday
);
275 /* Year rollover ... easy except for leap years! */
277 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "year");
279 alarm
->time
.tm_year
++;
280 } while (!is_leap_year(alarm
->time
.tm_year
+ 1900)
281 && rtc_valid_tm(&alarm
->time
) != 0);
285 dev_warn(&rtc
->dev
, "alarm rollover not handled\n");
288 err
= rtc_valid_tm(&alarm
->time
);
292 dev_warn(&rtc
->dev
, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
293 alarm
->time
.tm_year
+ 1900, alarm
->time
.tm_mon
+ 1,
294 alarm
->time
.tm_mday
, alarm
->time
.tm_hour
, alarm
->time
.tm_min
,
301 int rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
305 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
308 if (rtc
->ops
== NULL
)
310 else if (!rtc
->ops
->read_alarm
)
313 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
314 alarm
->enabled
= rtc
->aie_timer
.enabled
;
315 alarm
->time
= rtc_ktime_to_tm(rtc
->aie_timer
.node
.expires
);
317 mutex_unlock(&rtc
->ops_lock
);
321 EXPORT_SYMBOL_GPL(rtc_read_alarm
);
323 static int __rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
326 time64_t now
, scheduled
;
329 err
= rtc_valid_tm(&alarm
->time
);
332 scheduled
= rtc_tm_to_time64(&alarm
->time
);
334 /* Make sure we're not setting alarms in the past */
335 err
= __rtc_read_time(rtc
, &tm
);
338 now
= rtc_tm_to_time64(&tm
);
339 if (scheduled
<= now
)
342 * XXX - We just checked to make sure the alarm time is not
343 * in the past, but there is still a race window where if
344 * the is alarm set for the next second and the second ticks
345 * over right here, before we set the alarm.
350 else if (!rtc
->ops
->set_alarm
)
353 err
= rtc
->ops
->set_alarm(rtc
->dev
.parent
, alarm
);
358 int rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
362 err
= rtc_valid_tm(&alarm
->time
);
366 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
369 if (rtc
->aie_timer
.enabled
)
370 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
372 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
373 rtc
->aie_timer
.period
= 0;
375 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
377 mutex_unlock(&rtc
->ops_lock
);
380 EXPORT_SYMBOL_GPL(rtc_set_alarm
);
382 /* Called once per device from rtc_device_register */
383 int rtc_initialize_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
388 err
= rtc_valid_tm(&alarm
->time
);
392 err
= rtc_read_time(rtc
, &now
);
396 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
400 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
401 rtc
->aie_timer
.period
= 0;
403 /* Alarm has to be enabled & in the future for us to enqueue it */
404 if (alarm
->enabled
&& (rtc_tm_to_ktime(now
) <
405 rtc
->aie_timer
.node
.expires
)) {
407 rtc
->aie_timer
.enabled
= 1;
408 timerqueue_add(&rtc
->timerqueue
, &rtc
->aie_timer
.node
);
410 mutex_unlock(&rtc
->ops_lock
);
413 EXPORT_SYMBOL_GPL(rtc_initialize_alarm
);
415 int rtc_alarm_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
417 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
421 if (rtc
->aie_timer
.enabled
!= enabled
) {
423 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
425 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
432 else if (!rtc
->ops
->alarm_irq_enable
)
435 err
= rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, enabled
);
437 mutex_unlock(&rtc
->ops_lock
);
440 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable
);
442 int rtc_update_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
444 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
448 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
449 if (enabled
== 0 && rtc
->uie_irq_active
) {
450 mutex_unlock(&rtc
->ops_lock
);
451 return rtc_dev_update_irq_enable_emul(rtc
, 0);
454 /* make sure we're changing state */
455 if (rtc
->uie_rtctimer
.enabled
== enabled
)
458 if (rtc
->uie_unsupported
) {
467 __rtc_read_time(rtc
, &tm
);
468 onesec
= ktime_set(1, 0);
469 now
= rtc_tm_to_ktime(tm
);
470 rtc
->uie_rtctimer
.node
.expires
= ktime_add(now
, onesec
);
471 rtc
->uie_rtctimer
.period
= ktime_set(1, 0);
472 err
= rtc_timer_enqueue(rtc
, &rtc
->uie_rtctimer
);
474 rtc_timer_remove(rtc
, &rtc
->uie_rtctimer
);
477 mutex_unlock(&rtc
->ops_lock
);
478 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
480 * Enable emulation if the driver did not provide
481 * the update_irq_enable function pointer or if returned
482 * -EINVAL to signal that it has been configured without
483 * interrupts or that are not available at the moment.
486 err
= rtc_dev_update_irq_enable_emul(rtc
, enabled
);
491 EXPORT_SYMBOL_GPL(rtc_update_irq_enable
);
495 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
496 * @rtc: pointer to the rtc device
498 * This function is called when an AIE, UIE or PIE mode interrupt
499 * has occurred (or been emulated).
501 * Triggers the registered irq_task function callback.
503 void rtc_handle_legacy_irq(struct rtc_device
*rtc
, int num
, int mode
)
507 /* mark one irq of the appropriate mode */
508 spin_lock_irqsave(&rtc
->irq_lock
, flags
);
509 rtc
->irq_data
= (rtc
->irq_data
+ (num
<< 8)) | (RTC_IRQF
|mode
);
510 spin_unlock_irqrestore(&rtc
->irq_lock
, flags
);
512 /* call the task func */
513 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
515 rtc
->irq_task
->func(rtc
->irq_task
->private_data
);
516 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
518 wake_up_interruptible(&rtc
->irq_queue
);
519 kill_fasync(&rtc
->async_queue
, SIGIO
, POLL_IN
);
524 * rtc_aie_update_irq - AIE mode rtctimer hook
525 * @private: pointer to the rtc_device
527 * This functions is called when the aie_timer expires.
529 void rtc_aie_update_irq(void *private)
531 struct rtc_device
*rtc
= (struct rtc_device
*)private;
532 rtc_handle_legacy_irq(rtc
, 1, RTC_AF
);
537 * rtc_uie_update_irq - UIE mode rtctimer hook
538 * @private: pointer to the rtc_device
540 * This functions is called when the uie_timer expires.
542 void rtc_uie_update_irq(void *private)
544 struct rtc_device
*rtc
= (struct rtc_device
*)private;
545 rtc_handle_legacy_irq(rtc
, 1, RTC_UF
);
550 * rtc_pie_update_irq - PIE mode hrtimer hook
551 * @timer: pointer to the pie mode hrtimer
553 * This function is used to emulate PIE mode interrupts
554 * using an hrtimer. This function is called when the periodic
557 enum hrtimer_restart
rtc_pie_update_irq(struct hrtimer
*timer
)
559 struct rtc_device
*rtc
;
562 rtc
= container_of(timer
, struct rtc_device
, pie_timer
);
564 period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
565 count
= hrtimer_forward_now(timer
, period
);
567 rtc_handle_legacy_irq(rtc
, count
, RTC_PF
);
569 return HRTIMER_RESTART
;
573 * rtc_update_irq - Triggered when a RTC interrupt occurs.
574 * @rtc: the rtc device
575 * @num: how many irqs are being reported (usually one)
576 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
579 void rtc_update_irq(struct rtc_device
*rtc
,
580 unsigned long num
, unsigned long events
)
582 if (IS_ERR_OR_NULL(rtc
))
585 pm_stay_awake(rtc
->dev
.parent
);
586 schedule_work(&rtc
->irqwork
);
588 EXPORT_SYMBOL_GPL(rtc_update_irq
);
590 static int __rtc_match(struct device
*dev
, const void *data
)
592 const char *name
= data
;
594 if (strcmp(dev_name(dev
), name
) == 0)
599 struct rtc_device
*rtc_class_open(const char *name
)
602 struct rtc_device
*rtc
= NULL
;
604 dev
= class_find_device(rtc_class
, NULL
, name
, __rtc_match
);
606 rtc
= to_rtc_device(dev
);
609 if (!try_module_get(rtc
->owner
)) {
617 EXPORT_SYMBOL_GPL(rtc_class_open
);
619 void rtc_class_close(struct rtc_device
*rtc
)
621 module_put(rtc
->owner
);
622 put_device(&rtc
->dev
);
624 EXPORT_SYMBOL_GPL(rtc_class_close
);
626 int rtc_irq_register(struct rtc_device
*rtc
, struct rtc_task
*task
)
630 if (task
== NULL
|| task
->func
== NULL
)
633 /* Cannot register while the char dev is in use */
634 if (test_and_set_bit_lock(RTC_DEV_BUSY
, &rtc
->flags
))
637 spin_lock_irq(&rtc
->irq_task_lock
);
638 if (rtc
->irq_task
== NULL
) {
639 rtc
->irq_task
= task
;
642 spin_unlock_irq(&rtc
->irq_task_lock
);
644 clear_bit_unlock(RTC_DEV_BUSY
, &rtc
->flags
);
648 EXPORT_SYMBOL_GPL(rtc_irq_register
);
650 void rtc_irq_unregister(struct rtc_device
*rtc
, struct rtc_task
*task
)
652 spin_lock_irq(&rtc
->irq_task_lock
);
653 if (rtc
->irq_task
== task
)
654 rtc
->irq_task
= NULL
;
655 spin_unlock_irq(&rtc
->irq_task_lock
);
657 EXPORT_SYMBOL_GPL(rtc_irq_unregister
);
659 static int rtc_update_hrtimer(struct rtc_device
*rtc
, int enabled
)
662 * We always cancel the timer here first, because otherwise
663 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
664 * when we manage to start the timer before the callback
665 * returns HRTIMER_RESTART.
667 * We cannot use hrtimer_cancel() here as a running callback
668 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
669 * would spin forever.
671 if (hrtimer_try_to_cancel(&rtc
->pie_timer
) < 0)
675 ktime_t period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
677 hrtimer_start(&rtc
->pie_timer
, period
, HRTIMER_MODE_REL
);
683 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
684 * @rtc: the rtc device
685 * @task: currently registered with rtc_irq_register()
686 * @enabled: true to enable periodic IRQs
689 * Note that rtc_irq_set_freq() should previously have been used to
690 * specify the desired frequency of periodic IRQ task->func() callbacks.
692 int rtc_irq_set_state(struct rtc_device
*rtc
, struct rtc_task
*task
, int enabled
)
698 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
699 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
701 else if (rtc
->irq_task
!= task
)
704 if (rtc_update_hrtimer(rtc
, enabled
) < 0) {
705 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
709 rtc
->pie_enabled
= enabled
;
711 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
714 EXPORT_SYMBOL_GPL(rtc_irq_set_state
);
717 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
718 * @rtc: the rtc device
719 * @task: currently registered with rtc_irq_register()
720 * @freq: positive frequency with which task->func() will be called
723 * Note that rtc_irq_set_state() is used to enable or disable the
726 int rtc_irq_set_freq(struct rtc_device
*rtc
, struct rtc_task
*task
, int freq
)
731 if (freq
<= 0 || freq
> RTC_MAX_FREQ
)
734 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
735 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
737 else if (rtc
->irq_task
!= task
)
740 rtc
->irq_freq
= freq
;
741 if (rtc
->pie_enabled
&& rtc_update_hrtimer(rtc
, 1) < 0) {
742 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
747 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
750 EXPORT_SYMBOL_GPL(rtc_irq_set_freq
);
753 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
755 * @timer timer being added.
757 * Enqueues a timer onto the rtc devices timerqueue and sets
758 * the next alarm event appropriately.
760 * Sets the enabled bit on the added timer.
762 * Must hold ops_lock for proper serialization of timerqueue
764 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
766 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
771 __rtc_read_time(rtc
, &tm
);
772 now
= rtc_tm_to_ktime(tm
);
774 /* Skip over expired timers */
776 if (next
->expires
>= now
)
778 next
= timerqueue_iterate_next(next
);
781 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
783 struct rtc_wkalrm alarm
;
785 alarm
.time
= rtc_ktime_to_tm(timer
->node
.expires
);
787 err
= __rtc_set_alarm(rtc
, &alarm
);
789 pm_stay_awake(rtc
->dev
.parent
);
790 schedule_work(&rtc
->irqwork
);
792 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
800 static void rtc_alarm_disable(struct rtc_device
*rtc
)
802 if (!rtc
->ops
|| !rtc
->ops
->alarm_irq_enable
)
805 rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, false);
809 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
811 * @timer timer being removed.
813 * Removes a timer onto the rtc devices timerqueue and sets
814 * the next alarm event appropriately.
816 * Clears the enabled bit on the removed timer.
818 * Must hold ops_lock for proper serialization of timerqueue
820 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
822 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
823 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
825 if (next
== &timer
->node
) {
826 struct rtc_wkalrm alarm
;
828 next
= timerqueue_getnext(&rtc
->timerqueue
);
830 rtc_alarm_disable(rtc
);
833 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
835 err
= __rtc_set_alarm(rtc
, &alarm
);
837 pm_stay_awake(rtc
->dev
.parent
);
838 schedule_work(&rtc
->irqwork
);
844 * rtc_timer_do_work - Expires rtc timers
846 * @timer timer being removed.
848 * Expires rtc timers. Reprograms next alarm event if needed.
849 * Called via worktask.
851 * Serializes access to timerqueue via ops_lock mutex
853 void rtc_timer_do_work(struct work_struct
*work
)
855 struct rtc_timer
*timer
;
856 struct timerqueue_node
*next
;
860 struct rtc_device
*rtc
=
861 container_of(work
, struct rtc_device
, irqwork
);
863 mutex_lock(&rtc
->ops_lock
);
865 __rtc_read_time(rtc
, &tm
);
866 now
= rtc_tm_to_ktime(tm
);
867 while ((next
= timerqueue_getnext(&rtc
->timerqueue
))) {
868 if (next
->expires
> now
)
872 timer
= container_of(next
, struct rtc_timer
, node
);
873 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
875 if (timer
->task
.func
)
876 timer
->task
.func(timer
->task
.private_data
);
878 /* Re-add/fwd periodic timers */
879 if (ktime_to_ns(timer
->period
)) {
880 timer
->node
.expires
= ktime_add(timer
->node
.expires
,
883 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
889 struct rtc_wkalrm alarm
;
893 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
896 err
= __rtc_set_alarm(rtc
, &alarm
);
903 timer
= container_of(next
, struct rtc_timer
, node
);
904 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
906 dev_err(&rtc
->dev
, "__rtc_set_alarm: err=%d\n", err
);
910 rtc_alarm_disable(rtc
);
912 pm_relax(rtc
->dev
.parent
);
913 mutex_unlock(&rtc
->ops_lock
);
917 /* rtc_timer_init - Initializes an rtc_timer
918 * @timer: timer to be intiialized
919 * @f: function pointer to be called when timer fires
920 * @data: private data passed to function pointer
922 * Kernel interface to initializing an rtc_timer.
924 void rtc_timer_init(struct rtc_timer
*timer
, void (*f
)(void *p
), void *data
)
926 timerqueue_init(&timer
->node
);
928 timer
->task
.func
= f
;
929 timer
->task
.private_data
= data
;
932 /* rtc_timer_start - Sets an rtc_timer to fire in the future
933 * @ rtc: rtc device to be used
934 * @ timer: timer being set
935 * @ expires: time at which to expire the timer
936 * @ period: period that the timer will recur
938 * Kernel interface to set an rtc_timer
940 int rtc_timer_start(struct rtc_device
*rtc
, struct rtc_timer
*timer
,
941 ktime_t expires
, ktime_t period
)
944 mutex_lock(&rtc
->ops_lock
);
946 rtc_timer_remove(rtc
, timer
);
948 timer
->node
.expires
= expires
;
949 timer
->period
= period
;
951 ret
= rtc_timer_enqueue(rtc
, timer
);
953 mutex_unlock(&rtc
->ops_lock
);
957 /* rtc_timer_cancel - Stops an rtc_timer
958 * @ rtc: rtc device to be used
959 * @ timer: timer being set
961 * Kernel interface to cancel an rtc_timer
963 void rtc_timer_cancel(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
965 mutex_lock(&rtc
->ops_lock
);
967 rtc_timer_remove(rtc
, timer
);
968 mutex_unlock(&rtc
->ops_lock
);
972 * rtc_read_offset - Read the amount of rtc offset in parts per billion
973 * @ rtc: rtc device to be used
974 * @ offset: the offset in parts per billion
976 * see below for details.
978 * Kernel interface to read rtc clock offset
979 * Returns 0 on success, or a negative number on error.
980 * If read_offset() is not implemented for the rtc, return -EINVAL
982 int rtc_read_offset(struct rtc_device
*rtc
, long *offset
)
989 if (!rtc
->ops
->read_offset
)
992 mutex_lock(&rtc
->ops_lock
);
993 ret
= rtc
->ops
->read_offset(rtc
->dev
.parent
, offset
);
994 mutex_unlock(&rtc
->ops_lock
);
999 * rtc_set_offset - Adjusts the duration of the average second
1000 * @ rtc: rtc device to be used
1001 * @ offset: the offset in parts per billion
1003 * Some rtc's allow an adjustment to the average duration of a second
1004 * to compensate for differences in the actual clock rate due to temperature,
1005 * the crystal, capacitor, etc.
1007 * Kernel interface to adjust an rtc clock offset.
1008 * Return 0 on success, or a negative number on error.
1009 * If the rtc offset is not setable (or not implemented), return -EINVAL
1011 int rtc_set_offset(struct rtc_device
*rtc
, long offset
)
1018 if (!rtc
->ops
->set_offset
)
1021 mutex_lock(&rtc
->ops_lock
);
1022 ret
= rtc
->ops
->set_offset(rtc
->dev
.parent
, offset
);
1023 mutex_unlock(&rtc
->ops_lock
);