]>
git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/rtc/interface.c
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
);
37 int rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
41 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
45 err
= __rtc_read_time(rtc
, tm
);
46 mutex_unlock(&rtc
->ops_lock
);
49 EXPORT_SYMBOL_GPL(rtc_read_time
);
51 int rtc_set_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
55 err
= rtc_valid_tm(tm
);
59 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
65 else if (rtc
->ops
->set_time
)
66 err
= rtc
->ops
->set_time(rtc
->dev
.parent
, tm
);
67 else if (rtc
->ops
->set_mmss
) {
69 err
= rtc_tm_to_time(tm
, &secs
);
71 err
= rtc
->ops
->set_mmss(rtc
->dev
.parent
, secs
);
75 mutex_unlock(&rtc
->ops_lock
);
76 /* A timer might have just expired */
77 schedule_work(&rtc
->irqwork
);
80 EXPORT_SYMBOL_GPL(rtc_set_time
);
82 int rtc_set_mmss(struct rtc_device
*rtc
, unsigned long secs
)
86 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
92 else if (rtc
->ops
->set_mmss
)
93 err
= rtc
->ops
->set_mmss(rtc
->dev
.parent
, secs
);
94 else if (rtc
->ops
->read_time
&& rtc
->ops
->set_time
) {
95 struct rtc_time
new, old
;
97 err
= rtc
->ops
->read_time(rtc
->dev
.parent
, &old
);
99 rtc_time_to_tm(secs
, &new);
102 * avoid writing when we're going to change the day of
103 * the month. We will retry in the next minute. This
104 * basically means that if the RTC must not drift
105 * by more than 1 minute in 11 minutes.
107 if (!((old
.tm_hour
== 23 && old
.tm_min
== 59) ||
108 (new.tm_hour
== 23 && new.tm_min
== 59)))
109 err
= rtc
->ops
->set_time(rtc
->dev
.parent
,
116 mutex_unlock(&rtc
->ops_lock
);
117 /* A timer might have just expired */
118 schedule_work(&rtc
->irqwork
);
122 EXPORT_SYMBOL_GPL(rtc_set_mmss
);
124 static int rtc_read_alarm_internal(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
128 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
132 if (rtc
->ops
== NULL
)
134 else if (!rtc
->ops
->read_alarm
)
137 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
138 err
= rtc
->ops
->read_alarm(rtc
->dev
.parent
, alarm
);
141 mutex_unlock(&rtc
->ops_lock
);
145 int __rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
148 struct rtc_time before
, now
;
150 unsigned long t_now
, t_alm
;
151 enum { none
, day
, month
, year
} missing
= none
;
154 /* The lower level RTC driver may return -1 in some fields,
155 * creating invalid alarm->time values, for reasons like:
157 * - The hardware may not be capable of filling them in;
158 * many alarms match only on time-of-day fields, not
159 * day/month/year calendar data.
161 * - Some hardware uses illegal values as "wildcard" match
162 * values, which non-Linux firmware (like a BIOS) may try
163 * to set up as e.g. "alarm 15 minutes after each hour".
164 * Linux uses only oneshot alarms.
166 * When we see that here, we deal with it by using values from
167 * a current RTC timestamp for any missing (-1) values. The
168 * RTC driver prevents "periodic alarm" modes.
170 * But this can be racey, because some fields of the RTC timestamp
171 * may have wrapped in the interval since we read the RTC alarm,
172 * which would lead to us inserting inconsistent values in place
175 * Reading the alarm and timestamp in the reverse sequence
176 * would have the same race condition, and not solve the issue.
178 * So, we must first read the RTC timestamp,
179 * then read the RTC alarm value,
180 * and then read a second RTC timestamp.
182 * If any fields of the second timestamp have changed
183 * when compared with the first timestamp, then we know
184 * our timestamp may be inconsistent with that used by
185 * the low-level rtc_read_alarm_internal() function.
187 * So, when the two timestamps disagree, we just loop and do
188 * the process again to get a fully consistent set of values.
190 * This could all instead be done in the lower level driver,
191 * but since more than one lower level RTC implementation needs it,
192 * then it's probably best best to do it here instead of there..
195 /* Get the "before" timestamp */
196 err
= rtc_read_time(rtc
, &before
);
201 memcpy(&before
, &now
, sizeof(struct rtc_time
));
204 /* get the RTC alarm values, which may be incomplete */
205 err
= rtc_read_alarm_internal(rtc
, alarm
);
209 /* full-function RTCs won't have such missing fields */
210 if (rtc_valid_tm(&alarm
->time
) == 0)
213 /* get the "after" timestamp, to detect wrapped fields */
214 err
= rtc_read_time(rtc
, &now
);
218 /* note that tm_sec is a "don't care" value here: */
219 } while ( before
.tm_min
!= now
.tm_min
220 || before
.tm_hour
!= now
.tm_hour
221 || before
.tm_mon
!= now
.tm_mon
222 || before
.tm_year
!= now
.tm_year
);
224 /* Fill in the missing alarm fields using the timestamp; we
225 * know there's at least one since alarm->time is invalid.
227 if (alarm
->time
.tm_sec
== -1)
228 alarm
->time
.tm_sec
= now
.tm_sec
;
229 if (alarm
->time
.tm_min
== -1)
230 alarm
->time
.tm_min
= now
.tm_min
;
231 if (alarm
->time
.tm_hour
== -1)
232 alarm
->time
.tm_hour
= now
.tm_hour
;
234 /* For simplicity, only support date rollover for now */
235 if (alarm
->time
.tm_mday
< 1 || alarm
->time
.tm_mday
> 31) {
236 alarm
->time
.tm_mday
= now
.tm_mday
;
239 if ((unsigned)alarm
->time
.tm_mon
>= 12) {
240 alarm
->time
.tm_mon
= now
.tm_mon
;
244 if (alarm
->time
.tm_year
== -1) {
245 alarm
->time
.tm_year
= now
.tm_year
;
250 /* with luck, no rollover is needed */
251 rtc_tm_to_time(&now
, &t_now
);
252 rtc_tm_to_time(&alarm
->time
, &t_alm
);
258 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
259 * that will trigger at 5am will do so at 5am Tuesday, which
260 * could also be in the next month or year. This is a common
261 * case, especially for PCs.
264 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "day");
265 t_alm
+= 24 * 60 * 60;
266 rtc_time_to_tm(t_alm
, &alarm
->time
);
269 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
270 * be next month. An alarm matching on the 30th, 29th, or 28th
271 * may end up in the month after that! Many newer PCs support
272 * this type of alarm.
275 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "month");
277 if (alarm
->time
.tm_mon
< 11)
278 alarm
->time
.tm_mon
++;
280 alarm
->time
.tm_mon
= 0;
281 alarm
->time
.tm_year
++;
283 days
= rtc_month_days(alarm
->time
.tm_mon
,
284 alarm
->time
.tm_year
);
285 } while (days
< alarm
->time
.tm_mday
);
288 /* Year rollover ... easy except for leap years! */
290 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "year");
292 alarm
->time
.tm_year
++;
293 } while (rtc_valid_tm(&alarm
->time
) != 0);
297 dev_warn(&rtc
->dev
, "alarm rollover not handled\n");
304 int rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
308 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
311 if (rtc
->ops
== NULL
)
313 else if (!rtc
->ops
->read_alarm
)
316 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
317 alarm
->enabled
= rtc
->aie_timer
.enabled
;
318 alarm
->time
= rtc_ktime_to_tm(rtc
->aie_timer
.node
.expires
);
320 mutex_unlock(&rtc
->ops_lock
);
324 EXPORT_SYMBOL_GPL(rtc_read_alarm
);
326 static int __rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
332 err
= rtc_valid_tm(&alarm
->time
);
335 rtc_tm_to_time(&alarm
->time
, &scheduled
);
337 /* Make sure we're not setting alarms in the past */
338 err
= __rtc_read_time(rtc
, &tm
);
339 rtc_tm_to_time(&tm
, &now
);
340 if (scheduled
<= now
)
343 * XXX - We just checked to make sure the alarm time is not
344 * in the past, but there is still a race window where if
345 * the is alarm set for the next second and the second ticks
346 * over right here, before we set the alarm.
351 else if (!rtc
->ops
->set_alarm
)
354 err
= rtc
->ops
->set_alarm(rtc
->dev
.parent
, alarm
);
359 int rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
363 err
= rtc_valid_tm(&alarm
->time
);
367 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
370 if (rtc
->aie_timer
.enabled
) {
371 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
373 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
374 rtc
->aie_timer
.period
= ktime_set(0, 0);
375 if (alarm
->enabled
) {
376 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
378 mutex_unlock(&rtc
->ops_lock
);
381 EXPORT_SYMBOL_GPL(rtc_set_alarm
);
383 /* Called once per device from rtc_device_register */
384 int rtc_initialize_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
389 err
= rtc_valid_tm(&alarm
->time
);
393 err
= rtc_read_time(rtc
, &now
);
397 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
401 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
402 rtc
->aie_timer
.period
= ktime_set(0, 0);
404 /* Alarm has to be enabled & in the futrure for us to enqueue it */
405 if (alarm
->enabled
&& (rtc_tm_to_ktime(now
).tv64
<
406 rtc
->aie_timer
.node
.expires
.tv64
)) {
408 rtc
->aie_timer
.enabled
= 1;
409 timerqueue_add(&rtc
->timerqueue
, &rtc
->aie_timer
.node
);
411 mutex_unlock(&rtc
->ops_lock
);
414 EXPORT_SYMBOL_GPL(rtc_initialize_alarm
);
418 int rtc_alarm_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
420 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
424 if (rtc
->aie_timer
.enabled
!= enabled
) {
426 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
428 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
435 else if (!rtc
->ops
->alarm_irq_enable
)
438 err
= rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, enabled
);
440 mutex_unlock(&rtc
->ops_lock
);
443 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable
);
445 int rtc_update_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
447 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
451 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
452 if (enabled
== 0 && rtc
->uie_irq_active
) {
453 mutex_unlock(&rtc
->ops_lock
);
454 return rtc_dev_update_irq_enable_emul(rtc
, 0);
457 /* make sure we're changing state */
458 if (rtc
->uie_rtctimer
.enabled
== enabled
)
461 if (rtc
->uie_unsupported
) {
470 __rtc_read_time(rtc
, &tm
);
471 onesec
= ktime_set(1, 0);
472 now
= rtc_tm_to_ktime(tm
);
473 rtc
->uie_rtctimer
.node
.expires
= ktime_add(now
, onesec
);
474 rtc
->uie_rtctimer
.period
= ktime_set(1, 0);
475 err
= rtc_timer_enqueue(rtc
, &rtc
->uie_rtctimer
);
477 rtc_timer_remove(rtc
, &rtc
->uie_rtctimer
);
480 mutex_unlock(&rtc
->ops_lock
);
481 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
483 * Enable emulation if the driver did not provide
484 * the update_irq_enable function pointer or if returned
485 * -EINVAL to signal that it has been configured without
486 * interrupts or that are not available at the moment.
489 err
= rtc_dev_update_irq_enable_emul(rtc
, enabled
);
494 EXPORT_SYMBOL_GPL(rtc_update_irq_enable
);
498 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
499 * @rtc: pointer to the rtc device
501 * This function is called when an AIE, UIE or PIE mode interrupt
502 * has occurred (or been emulated).
504 * Triggers the registered irq_task function callback.
506 void rtc_handle_legacy_irq(struct rtc_device
*rtc
, int num
, int mode
)
510 /* mark one irq of the appropriate mode */
511 spin_lock_irqsave(&rtc
->irq_lock
, flags
);
512 rtc
->irq_data
= (rtc
->irq_data
+ (num
<< 8)) | (RTC_IRQF
|mode
);
513 spin_unlock_irqrestore(&rtc
->irq_lock
, flags
);
515 /* call the task func */
516 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
518 rtc
->irq_task
->func(rtc
->irq_task
->private_data
);
519 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
521 wake_up_interruptible(&rtc
->irq_queue
);
522 kill_fasync(&rtc
->async_queue
, SIGIO
, POLL_IN
);
527 * rtc_aie_update_irq - AIE mode rtctimer hook
528 * @private: pointer to the rtc_device
530 * This functions is called when the aie_timer expires.
532 void rtc_aie_update_irq(void *private)
534 struct rtc_device
*rtc
= (struct rtc_device
*)private;
535 rtc_handle_legacy_irq(rtc
, 1, RTC_AF
);
540 * rtc_uie_update_irq - UIE mode rtctimer hook
541 * @private: pointer to the rtc_device
543 * This functions is called when the uie_timer expires.
545 void rtc_uie_update_irq(void *private)
547 struct rtc_device
*rtc
= (struct rtc_device
*)private;
548 rtc_handle_legacy_irq(rtc
, 1, RTC_UF
);
553 * rtc_pie_update_irq - PIE mode hrtimer hook
554 * @timer: pointer to the pie mode hrtimer
556 * This function is used to emulate PIE mode interrupts
557 * using an hrtimer. This function is called when the periodic
560 enum hrtimer_restart
rtc_pie_update_irq(struct hrtimer
*timer
)
562 struct rtc_device
*rtc
;
565 rtc
= container_of(timer
, struct rtc_device
, pie_timer
);
567 period
= ktime_set(0, NSEC_PER_SEC
/rtc
->irq_freq
);
568 count
= hrtimer_forward_now(timer
, period
);
570 rtc_handle_legacy_irq(rtc
, count
, RTC_PF
);
572 return HRTIMER_RESTART
;
576 * rtc_update_irq - Triggered when a RTC interrupt occurs.
577 * @rtc: the rtc device
578 * @num: how many irqs are being reported (usually one)
579 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
582 void rtc_update_irq(struct rtc_device
*rtc
,
583 unsigned long num
, unsigned long events
)
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
, void *data
)
592 char *name
= (char *)data
;
594 if (strcmp(dev_name(dev
), name
) == 0)
599 struct rtc_device
*rtc_class_open(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
= ktime_set(0, 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 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 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
)
767 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
768 if (&timer
->node
== timerqueue_getnext(&rtc
->timerqueue
)) {
769 struct rtc_wkalrm alarm
;
771 alarm
.time
= rtc_ktime_to_tm(timer
->node
.expires
);
773 err
= __rtc_set_alarm(rtc
, &alarm
);
775 schedule_work(&rtc
->irqwork
);
777 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
785 static void rtc_alarm_disable(struct rtc_device
*rtc
)
787 if (!rtc
->ops
|| !rtc
->ops
->alarm_irq_enable
)
790 rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, false);
794 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
796 * @timer timer being removed.
798 * Removes a timer onto the rtc devices timerqueue and sets
799 * the next alarm event appropriately.
801 * Clears the enabled bit on the removed timer.
803 * Must hold ops_lock for proper serialization of timerqueue
805 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
807 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
808 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
810 if (next
== &timer
->node
) {
811 struct rtc_wkalrm alarm
;
813 next
= timerqueue_getnext(&rtc
->timerqueue
);
815 rtc_alarm_disable(rtc
);
818 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
820 err
= __rtc_set_alarm(rtc
, &alarm
);
822 schedule_work(&rtc
->irqwork
);
827 * rtc_timer_do_work - Expires rtc timers
829 * @timer timer being removed.
831 * Expires rtc timers. Reprograms next alarm event if needed.
832 * Called via worktask.
834 * Serializes access to timerqueue via ops_lock mutex
836 void rtc_timer_do_work(struct work_struct
*work
)
838 struct rtc_timer
*timer
;
839 struct timerqueue_node
*next
;
843 struct rtc_device
*rtc
=
844 container_of(work
, struct rtc_device
, irqwork
);
846 mutex_lock(&rtc
->ops_lock
);
848 pm_relax(rtc
->dev
.parent
);
849 __rtc_read_time(rtc
, &tm
);
850 now
= rtc_tm_to_ktime(tm
);
851 while ((next
= timerqueue_getnext(&rtc
->timerqueue
))) {
852 if (next
->expires
.tv64
> now
.tv64
)
856 timer
= container_of(next
, struct rtc_timer
, node
);
857 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
859 if (timer
->task
.func
)
860 timer
->task
.func(timer
->task
.private_data
);
862 /* Re-add/fwd periodic timers */
863 if (ktime_to_ns(timer
->period
)) {
864 timer
->node
.expires
= ktime_add(timer
->node
.expires
,
867 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
873 struct rtc_wkalrm alarm
;
875 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
877 err
= __rtc_set_alarm(rtc
, &alarm
);
881 rtc_alarm_disable(rtc
);
883 mutex_unlock(&rtc
->ops_lock
);
887 /* rtc_timer_init - Initializes an rtc_timer
888 * @timer: timer to be intiialized
889 * @f: function pointer to be called when timer fires
890 * @data: private data passed to function pointer
892 * Kernel interface to initializing an rtc_timer.
894 void rtc_timer_init(struct rtc_timer
*timer
, void (*f
)(void* p
), void* data
)
896 timerqueue_init(&timer
->node
);
898 timer
->task
.func
= f
;
899 timer
->task
.private_data
= data
;
902 /* rtc_timer_start - Sets an rtc_timer to fire in the future
903 * @ rtc: rtc device to be used
904 * @ timer: timer being set
905 * @ expires: time at which to expire the timer
906 * @ period: period that the timer will recur
908 * Kernel interface to set an rtc_timer
910 int rtc_timer_start(struct rtc_device
*rtc
, struct rtc_timer
* timer
,
911 ktime_t expires
, ktime_t period
)
914 mutex_lock(&rtc
->ops_lock
);
916 rtc_timer_remove(rtc
, timer
);
918 timer
->node
.expires
= expires
;
919 timer
->period
= period
;
921 ret
= rtc_timer_enqueue(rtc
, timer
);
923 mutex_unlock(&rtc
->ops_lock
);
927 /* rtc_timer_cancel - Stops an rtc_timer
928 * @ rtc: rtc device to be used
929 * @ timer: timer being set
931 * Kernel interface to cancel an rtc_timer
933 int rtc_timer_cancel(struct rtc_device
*rtc
, struct rtc_timer
* timer
)
936 mutex_lock(&rtc
->ops_lock
);
938 rtc_timer_remove(rtc
, timer
);
939 mutex_unlock(&rtc
->ops_lock
);