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1 // SPDX-License-Identifier: GPL-2.0
3 * RTC subsystem, interface functions
5 * Copyright (C) 2005 Tower Technologies
6 * Author: Alessandro Zummo <a.zummo@towertech.it>
8 * based on arch/arm/common/rtctime.c
11 #include <linux/rtc.h>
12 #include <linux/sched.h>
13 #include <linux/module.h>
14 #include <linux/log2.h>
15 #include <linux/workqueue.h>
17 #define CREATE_TRACE_POINTS
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
)
27 if (!rtc
->offset_secs
)
30 secs
= rtc_tm_to_time64(tm
);
33 * Since the reading time values from RTC device are always in the RTC
34 * original valid range, but we need to skip the overlapped region
35 * between expanded range and original range, which is no need to add
38 if ((rtc
->start_secs
> rtc
->range_min
&& secs
>= rtc
->start_secs
) ||
39 (rtc
->start_secs
< rtc
->range_min
&&
40 secs
<= (rtc
->start_secs
+ rtc
->range_max
- rtc
->range_min
)))
43 rtc_time64_to_tm(secs
+ rtc
->offset_secs
, tm
);
46 static void rtc_subtract_offset(struct rtc_device
*rtc
, struct rtc_time
*tm
)
50 if (!rtc
->offset_secs
)
53 secs
= rtc_tm_to_time64(tm
);
56 * If the setting time values are in the valid range of RTC hardware
57 * device, then no need to subtract the offset when setting time to RTC
58 * device. Otherwise we need to subtract the offset to make the time
59 * values are valid for RTC hardware device.
61 if (secs
>= rtc
->range_min
&& secs
<= rtc
->range_max
)
64 rtc_time64_to_tm(secs
- rtc
->offset_secs
, tm
);
67 static int rtc_valid_range(struct rtc_device
*rtc
, struct rtc_time
*tm
)
69 if (rtc
->range_min
!= rtc
->range_max
) {
70 time64_t time
= rtc_tm_to_time64(tm
);
71 time64_t range_min
= rtc
->set_start_time
? rtc
->start_secs
:
73 time64_t range_max
= rtc
->set_start_time
?
74 (rtc
->start_secs
+ rtc
->range_max
- rtc
->range_min
) :
77 if (time
< range_min
|| time
> range_max
)
84 static int __rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
90 } else if (!rtc
->ops
->read_time
) {
93 memset(tm
, 0, sizeof(struct rtc_time
));
94 err
= rtc
->ops
->read_time(rtc
->dev
.parent
, tm
);
96 dev_dbg(&rtc
->dev
, "read_time: fail to read: %d\n",
101 rtc_add_offset(rtc
, tm
);
103 err
= rtc_valid_tm(tm
);
105 dev_dbg(&rtc
->dev
, "read_time: rtc_time isn't valid\n");
110 int rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
114 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
118 err
= __rtc_read_time(rtc
, tm
);
119 mutex_unlock(&rtc
->ops_lock
);
121 trace_rtc_read_time(rtc_tm_to_time64(tm
), err
);
124 EXPORT_SYMBOL_GPL(rtc_read_time
);
126 int rtc_set_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
130 err
= rtc_valid_tm(tm
);
134 err
= rtc_valid_range(rtc
, tm
);
138 rtc_subtract_offset(rtc
, tm
);
140 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
146 else if (rtc
->ops
->set_time
)
147 err
= rtc
->ops
->set_time(rtc
->dev
.parent
, tm
);
151 pm_stay_awake(rtc
->dev
.parent
);
152 mutex_unlock(&rtc
->ops_lock
);
153 /* A timer might have just expired */
154 schedule_work(&rtc
->irqwork
);
156 trace_rtc_set_time(rtc_tm_to_time64(tm
), err
);
159 EXPORT_SYMBOL_GPL(rtc_set_time
);
161 static int rtc_read_alarm_internal(struct rtc_device
*rtc
,
162 struct rtc_wkalrm
*alarm
)
166 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
172 } else if (!rtc
->ops
->read_alarm
) {
177 alarm
->time
.tm_sec
= -1;
178 alarm
->time
.tm_min
= -1;
179 alarm
->time
.tm_hour
= -1;
180 alarm
->time
.tm_mday
= -1;
181 alarm
->time
.tm_mon
= -1;
182 alarm
->time
.tm_year
= -1;
183 alarm
->time
.tm_wday
= -1;
184 alarm
->time
.tm_yday
= -1;
185 alarm
->time
.tm_isdst
= -1;
186 err
= rtc
->ops
->read_alarm(rtc
->dev
.parent
, alarm
);
189 mutex_unlock(&rtc
->ops_lock
);
191 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
195 int __rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
198 struct rtc_time before
, now
;
200 time64_t t_now
, t_alm
;
201 enum { none
, day
, month
, year
} missing
= none
;
204 /* The lower level RTC driver may return -1 in some fields,
205 * creating invalid alarm->time values, for reasons like:
207 * - The hardware may not be capable of filling them in;
208 * many alarms match only on time-of-day fields, not
209 * day/month/year calendar data.
211 * - Some hardware uses illegal values as "wildcard" match
212 * values, which non-Linux firmware (like a BIOS) may try
213 * to set up as e.g. "alarm 15 minutes after each hour".
214 * Linux uses only oneshot alarms.
216 * When we see that here, we deal with it by using values from
217 * a current RTC timestamp for any missing (-1) values. The
218 * RTC driver prevents "periodic alarm" modes.
220 * But this can be racey, because some fields of the RTC timestamp
221 * may have wrapped in the interval since we read the RTC alarm,
222 * which would lead to us inserting inconsistent values in place
225 * Reading the alarm and timestamp in the reverse sequence
226 * would have the same race condition, and not solve the issue.
228 * So, we must first read the RTC timestamp,
229 * then read the RTC alarm value,
230 * and then read a second RTC timestamp.
232 * If any fields of the second timestamp have changed
233 * when compared with the first timestamp, then we know
234 * our timestamp may be inconsistent with that used by
235 * the low-level rtc_read_alarm_internal() function.
237 * So, when the two timestamps disagree, we just loop and do
238 * the process again to get a fully consistent set of values.
240 * This could all instead be done in the lower level driver,
241 * but since more than one lower level RTC implementation needs it,
242 * then it's probably best best to do it here instead of there..
245 /* Get the "before" timestamp */
246 err
= rtc_read_time(rtc
, &before
);
251 memcpy(&before
, &now
, sizeof(struct rtc_time
));
254 /* get the RTC alarm values, which may be incomplete */
255 err
= rtc_read_alarm_internal(rtc
, alarm
);
259 /* full-function RTCs won't have such missing fields */
260 if (rtc_valid_tm(&alarm
->time
) == 0) {
261 rtc_add_offset(rtc
, &alarm
->time
);
265 /* get the "after" timestamp, to detect wrapped fields */
266 err
= rtc_read_time(rtc
, &now
);
270 /* note that tm_sec is a "don't care" value here: */
271 } while (before
.tm_min
!= now
.tm_min
||
272 before
.tm_hour
!= now
.tm_hour
||
273 before
.tm_mon
!= now
.tm_mon
||
274 before
.tm_year
!= now
.tm_year
);
276 /* Fill in the missing alarm fields using the timestamp; we
277 * know there's at least one since alarm->time is invalid.
279 if (alarm
->time
.tm_sec
== -1)
280 alarm
->time
.tm_sec
= now
.tm_sec
;
281 if (alarm
->time
.tm_min
== -1)
282 alarm
->time
.tm_min
= now
.tm_min
;
283 if (alarm
->time
.tm_hour
== -1)
284 alarm
->time
.tm_hour
= now
.tm_hour
;
286 /* For simplicity, only support date rollover for now */
287 if (alarm
->time
.tm_mday
< 1 || alarm
->time
.tm_mday
> 31) {
288 alarm
->time
.tm_mday
= now
.tm_mday
;
291 if ((unsigned int)alarm
->time
.tm_mon
>= 12) {
292 alarm
->time
.tm_mon
= now
.tm_mon
;
296 if (alarm
->time
.tm_year
== -1) {
297 alarm
->time
.tm_year
= now
.tm_year
;
302 /* Can't proceed if alarm is still invalid after replacing
305 err
= rtc_valid_tm(&alarm
->time
);
309 /* with luck, no rollover is needed */
310 t_now
= rtc_tm_to_time64(&now
);
311 t_alm
= rtc_tm_to_time64(&alarm
->time
);
316 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
317 * that will trigger at 5am will do so at 5am Tuesday, which
318 * could also be in the next month or year. This is a common
319 * case, especially for PCs.
322 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "day");
323 t_alm
+= 24 * 60 * 60;
324 rtc_time64_to_tm(t_alm
, &alarm
->time
);
327 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
328 * be next month. An alarm matching on the 30th, 29th, or 28th
329 * may end up in the month after that! Many newer PCs support
330 * this type of alarm.
333 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "month");
335 if (alarm
->time
.tm_mon
< 11) {
336 alarm
->time
.tm_mon
++;
338 alarm
->time
.tm_mon
= 0;
339 alarm
->time
.tm_year
++;
341 days
= rtc_month_days(alarm
->time
.tm_mon
,
342 alarm
->time
.tm_year
);
343 } while (days
< alarm
->time
.tm_mday
);
346 /* Year rollover ... easy except for leap years! */
348 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "year");
350 alarm
->time
.tm_year
++;
351 } while (!is_leap_year(alarm
->time
.tm_year
+ 1900) &&
352 rtc_valid_tm(&alarm
->time
) != 0);
356 dev_warn(&rtc
->dev
, "alarm rollover not handled\n");
359 err
= rtc_valid_tm(&alarm
->time
);
363 dev_warn(&rtc
->dev
, "invalid alarm value: %ptR\n",
369 int rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
373 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
378 } else if (!rtc
->ops
->read_alarm
) {
381 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
382 alarm
->enabled
= rtc
->aie_timer
.enabled
;
383 alarm
->time
= rtc_ktime_to_tm(rtc
->aie_timer
.node
.expires
);
385 mutex_unlock(&rtc
->ops_lock
);
387 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
390 EXPORT_SYMBOL_GPL(rtc_read_alarm
);
392 static int __rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
395 time64_t now
, scheduled
;
398 err
= rtc_valid_tm(&alarm
->time
);
402 scheduled
= rtc_tm_to_time64(&alarm
->time
);
404 /* Make sure we're not setting alarms in the past */
405 err
= __rtc_read_time(rtc
, &tm
);
408 now
= rtc_tm_to_time64(&tm
);
409 if (scheduled
<= now
)
412 * XXX - We just checked to make sure the alarm time is not
413 * in the past, but there is still a race window where if
414 * the is alarm set for the next second and the second ticks
415 * over right here, before we set the alarm.
418 rtc_subtract_offset(rtc
, &alarm
->time
);
422 else if (!rtc
->ops
->set_alarm
)
425 err
= rtc
->ops
->set_alarm(rtc
->dev
.parent
, alarm
);
427 trace_rtc_set_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
431 int rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
437 else if (!rtc
->ops
->set_alarm
)
440 err
= rtc_valid_tm(&alarm
->time
);
444 err
= rtc_valid_range(rtc
, &alarm
->time
);
448 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
451 if (rtc
->aie_timer
.enabled
)
452 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
454 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
455 rtc
->aie_timer
.period
= 0;
457 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
459 mutex_unlock(&rtc
->ops_lock
);
463 EXPORT_SYMBOL_GPL(rtc_set_alarm
);
465 /* Called once per device from rtc_device_register */
466 int rtc_initialize_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
471 err
= rtc_valid_tm(&alarm
->time
);
475 err
= rtc_read_time(rtc
, &now
);
479 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
483 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
484 rtc
->aie_timer
.period
= 0;
486 /* Alarm has to be enabled & in the future for us to enqueue it */
487 if (alarm
->enabled
&& (rtc_tm_to_ktime(now
) <
488 rtc
->aie_timer
.node
.expires
)) {
489 rtc
->aie_timer
.enabled
= 1;
490 timerqueue_add(&rtc
->timerqueue
, &rtc
->aie_timer
.node
);
491 trace_rtc_timer_enqueue(&rtc
->aie_timer
);
493 mutex_unlock(&rtc
->ops_lock
);
496 EXPORT_SYMBOL_GPL(rtc_initialize_alarm
);
498 int rtc_alarm_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
502 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
506 if (rtc
->aie_timer
.enabled
!= enabled
) {
508 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
510 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
517 else if (!rtc
->ops
->alarm_irq_enable
)
520 err
= rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, enabled
);
522 mutex_unlock(&rtc
->ops_lock
);
524 trace_rtc_alarm_irq_enable(enabled
, err
);
527 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable
);
529 int rtc_update_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
533 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
537 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
538 if (enabled
== 0 && rtc
->uie_irq_active
) {
539 mutex_unlock(&rtc
->ops_lock
);
540 return rtc_dev_update_irq_enable_emul(rtc
, 0);
543 /* make sure we're changing state */
544 if (rtc
->uie_rtctimer
.enabled
== enabled
)
547 if (rtc
->uie_unsupported
) {
556 __rtc_read_time(rtc
, &tm
);
557 onesec
= ktime_set(1, 0);
558 now
= rtc_tm_to_ktime(tm
);
559 rtc
->uie_rtctimer
.node
.expires
= ktime_add(now
, onesec
);
560 rtc
->uie_rtctimer
.period
= ktime_set(1, 0);
561 err
= rtc_timer_enqueue(rtc
, &rtc
->uie_rtctimer
);
563 rtc_timer_remove(rtc
, &rtc
->uie_rtctimer
);
567 mutex_unlock(&rtc
->ops_lock
);
568 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
570 * Enable emulation if the driver returned -EINVAL to signal that it has
571 * been configured without interrupts or they are not available at the
575 err
= rtc_dev_update_irq_enable_emul(rtc
, enabled
);
579 EXPORT_SYMBOL_GPL(rtc_update_irq_enable
);
582 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
583 * @rtc: pointer to the rtc device
585 * This function is called when an AIE, UIE or PIE mode interrupt
586 * has occurred (or been emulated).
589 void rtc_handle_legacy_irq(struct rtc_device
*rtc
, int num
, int mode
)
593 /* mark one irq of the appropriate mode */
594 spin_lock_irqsave(&rtc
->irq_lock
, flags
);
595 rtc
->irq_data
= (rtc
->irq_data
+ (num
<< 8)) | (RTC_IRQF
| mode
);
596 spin_unlock_irqrestore(&rtc
->irq_lock
, flags
);
598 wake_up_interruptible(&rtc
->irq_queue
);
599 kill_fasync(&rtc
->async_queue
, SIGIO
, POLL_IN
);
603 * rtc_aie_update_irq - AIE mode rtctimer hook
604 * @rtc: pointer to the rtc_device
606 * This functions is called when the aie_timer expires.
608 void rtc_aie_update_irq(struct rtc_device
*rtc
)
610 rtc_handle_legacy_irq(rtc
, 1, RTC_AF
);
614 * rtc_uie_update_irq - UIE mode rtctimer hook
615 * @rtc: pointer to the rtc_device
617 * This functions is called when the uie_timer expires.
619 void rtc_uie_update_irq(struct rtc_device
*rtc
)
621 rtc_handle_legacy_irq(rtc
, 1, RTC_UF
);
625 * rtc_pie_update_irq - PIE mode hrtimer hook
626 * @timer: pointer to the pie mode hrtimer
628 * This function is used to emulate PIE mode interrupts
629 * using an hrtimer. This function is called when the periodic
632 enum hrtimer_restart
rtc_pie_update_irq(struct hrtimer
*timer
)
634 struct rtc_device
*rtc
;
638 rtc
= container_of(timer
, struct rtc_device
, pie_timer
);
640 period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
641 count
= hrtimer_forward_now(timer
, period
);
643 rtc_handle_legacy_irq(rtc
, count
, RTC_PF
);
645 return HRTIMER_RESTART
;
649 * rtc_update_irq - Triggered when a RTC interrupt occurs.
650 * @rtc: the rtc device
651 * @num: how many irqs are being reported (usually one)
652 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
655 void rtc_update_irq(struct rtc_device
*rtc
,
656 unsigned long num
, unsigned long events
)
658 if (IS_ERR_OR_NULL(rtc
))
661 pm_stay_awake(rtc
->dev
.parent
);
662 schedule_work(&rtc
->irqwork
);
664 EXPORT_SYMBOL_GPL(rtc_update_irq
);
666 static int __rtc_match(struct device
*dev
, const void *data
)
668 const char *name
= data
;
670 if (strcmp(dev_name(dev
), name
) == 0)
675 struct rtc_device
*rtc_class_open(const char *name
)
678 struct rtc_device
*rtc
= NULL
;
680 dev
= class_find_device(rtc_class
, NULL
, name
, __rtc_match
);
682 rtc
= to_rtc_device(dev
);
685 if (!try_module_get(rtc
->owner
)) {
693 EXPORT_SYMBOL_GPL(rtc_class_open
);
695 void rtc_class_close(struct rtc_device
*rtc
)
697 module_put(rtc
->owner
);
698 put_device(&rtc
->dev
);
700 EXPORT_SYMBOL_GPL(rtc_class_close
);
702 static int rtc_update_hrtimer(struct rtc_device
*rtc
, int enabled
)
705 * We always cancel the timer here first, because otherwise
706 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
707 * when we manage to start the timer before the callback
708 * returns HRTIMER_RESTART.
710 * We cannot use hrtimer_cancel() here as a running callback
711 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
712 * would spin forever.
714 if (hrtimer_try_to_cancel(&rtc
->pie_timer
) < 0)
718 ktime_t period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
720 hrtimer_start(&rtc
->pie_timer
, period
, HRTIMER_MODE_REL
);
726 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
727 * @rtc: the rtc device
728 * @enabled: true to enable periodic IRQs
731 * Note that rtc_irq_set_freq() should previously have been used to
732 * specify the desired frequency of periodic IRQ.
734 int rtc_irq_set_state(struct rtc_device
*rtc
, int enabled
)
738 while (rtc_update_hrtimer(rtc
, enabled
) < 0)
741 rtc
->pie_enabled
= enabled
;
743 trace_rtc_irq_set_state(enabled
, err
);
748 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
749 * @rtc: the rtc device
750 * @freq: positive frequency
753 * Note that rtc_irq_set_state() is used to enable or disable the
756 int rtc_irq_set_freq(struct rtc_device
*rtc
, int freq
)
760 if (freq
<= 0 || freq
> RTC_MAX_FREQ
)
763 rtc
->irq_freq
= freq
;
764 while (rtc
->pie_enabled
&& rtc_update_hrtimer(rtc
, 1) < 0)
767 trace_rtc_irq_set_freq(freq
, err
);
772 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
774 * @timer timer being added.
776 * Enqueues a timer onto the rtc devices timerqueue and sets
777 * the next alarm event appropriately.
779 * Sets the enabled bit on the added timer.
781 * Must hold ops_lock for proper serialization of timerqueue
783 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
785 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
790 __rtc_read_time(rtc
, &tm
);
791 now
= rtc_tm_to_ktime(tm
);
793 /* Skip over expired timers */
795 if (next
->expires
>= now
)
797 next
= timerqueue_iterate_next(next
);
800 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
801 trace_rtc_timer_enqueue(timer
);
802 if (!next
|| ktime_before(timer
->node
.expires
, next
->expires
)) {
803 struct rtc_wkalrm alarm
;
806 alarm
.time
= rtc_ktime_to_tm(timer
->node
.expires
);
808 err
= __rtc_set_alarm(rtc
, &alarm
);
810 pm_stay_awake(rtc
->dev
.parent
);
811 schedule_work(&rtc
->irqwork
);
813 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
814 trace_rtc_timer_dequeue(timer
);
822 static void rtc_alarm_disable(struct rtc_device
*rtc
)
824 if (!rtc
->ops
|| !rtc
->ops
->alarm_irq_enable
)
827 rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, false);
828 trace_rtc_alarm_irq_enable(0, 0);
832 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
834 * @timer timer being removed.
836 * Removes a timer onto the rtc devices timerqueue and sets
837 * the next alarm event appropriately.
839 * Clears the enabled bit on the removed timer.
841 * Must hold ops_lock for proper serialization of timerqueue
843 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
845 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
847 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
848 trace_rtc_timer_dequeue(timer
);
850 if (next
== &timer
->node
) {
851 struct rtc_wkalrm alarm
;
854 next
= timerqueue_getnext(&rtc
->timerqueue
);
856 rtc_alarm_disable(rtc
);
859 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
861 err
= __rtc_set_alarm(rtc
, &alarm
);
863 pm_stay_awake(rtc
->dev
.parent
);
864 schedule_work(&rtc
->irqwork
);
870 * rtc_timer_do_work - Expires rtc timers
872 * @timer timer being removed.
874 * Expires rtc timers. Reprograms next alarm event if needed.
875 * Called via worktask.
877 * Serializes access to timerqueue via ops_lock mutex
879 void rtc_timer_do_work(struct work_struct
*work
)
881 struct rtc_timer
*timer
;
882 struct timerqueue_node
*next
;
886 struct rtc_device
*rtc
=
887 container_of(work
, struct rtc_device
, irqwork
);
889 mutex_lock(&rtc
->ops_lock
);
891 __rtc_read_time(rtc
, &tm
);
892 now
= rtc_tm_to_ktime(tm
);
893 while ((next
= timerqueue_getnext(&rtc
->timerqueue
))) {
894 if (next
->expires
> now
)
898 timer
= container_of(next
, struct rtc_timer
, node
);
899 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
900 trace_rtc_timer_dequeue(timer
);
903 timer
->func(timer
->rtc
);
905 trace_rtc_timer_fired(timer
);
906 /* Re-add/fwd periodic timers */
907 if (ktime_to_ns(timer
->period
)) {
908 timer
->node
.expires
= ktime_add(timer
->node
.expires
,
911 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
912 trace_rtc_timer_enqueue(timer
);
918 struct rtc_wkalrm alarm
;
922 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
925 err
= __rtc_set_alarm(rtc
, &alarm
);
932 timer
= container_of(next
, struct rtc_timer
, node
);
933 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
934 trace_rtc_timer_dequeue(timer
);
936 dev_err(&rtc
->dev
, "__rtc_set_alarm: err=%d\n", err
);
940 rtc_alarm_disable(rtc
);
943 pm_relax(rtc
->dev
.parent
);
944 mutex_unlock(&rtc
->ops_lock
);
947 /* rtc_timer_init - Initializes an rtc_timer
948 * @timer: timer to be intiialized
949 * @f: function pointer to be called when timer fires
950 * @rtc: pointer to the rtc_device
952 * Kernel interface to initializing an rtc_timer.
954 void rtc_timer_init(struct rtc_timer
*timer
, void (*f
)(struct rtc_device
*r
),
955 struct rtc_device
*rtc
)
957 timerqueue_init(&timer
->node
);
963 /* rtc_timer_start - Sets an rtc_timer to fire in the future
964 * @ rtc: rtc device to be used
965 * @ timer: timer being set
966 * @ expires: time at which to expire the timer
967 * @ period: period that the timer will recur
969 * Kernel interface to set an rtc_timer
971 int rtc_timer_start(struct rtc_device
*rtc
, struct rtc_timer
*timer
,
972 ktime_t expires
, ktime_t period
)
976 mutex_lock(&rtc
->ops_lock
);
978 rtc_timer_remove(rtc
, timer
);
980 timer
->node
.expires
= expires
;
981 timer
->period
= period
;
983 ret
= rtc_timer_enqueue(rtc
, timer
);
985 mutex_unlock(&rtc
->ops_lock
);
989 /* rtc_timer_cancel - Stops an rtc_timer
990 * @ rtc: rtc device to be used
991 * @ timer: timer being set
993 * Kernel interface to cancel an rtc_timer
995 void rtc_timer_cancel(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
997 mutex_lock(&rtc
->ops_lock
);
999 rtc_timer_remove(rtc
, timer
);
1000 mutex_unlock(&rtc
->ops_lock
);
1004 * rtc_read_offset - Read the amount of rtc offset in parts per billion
1005 * @ rtc: rtc device to be used
1006 * @ offset: the offset in parts per billion
1008 * see below for details.
1010 * Kernel interface to read rtc clock offset
1011 * Returns 0 on success, or a negative number on error.
1012 * If read_offset() is not implemented for the rtc, return -EINVAL
1014 int rtc_read_offset(struct rtc_device
*rtc
, long *offset
)
1021 if (!rtc
->ops
->read_offset
)
1024 mutex_lock(&rtc
->ops_lock
);
1025 ret
= rtc
->ops
->read_offset(rtc
->dev
.parent
, offset
);
1026 mutex_unlock(&rtc
->ops_lock
);
1028 trace_rtc_read_offset(*offset
, ret
);
1033 * rtc_set_offset - Adjusts the duration of the average second
1034 * @ rtc: rtc device to be used
1035 * @ offset: the offset in parts per billion
1037 * Some rtc's allow an adjustment to the average duration of a second
1038 * to compensate for differences in the actual clock rate due to temperature,
1039 * the crystal, capacitor, etc.
1041 * The adjustment applied is as follows:
1042 * t = t0 * (1 + offset * 1e-9)
1043 * where t0 is the measured length of 1 RTC second with offset = 0
1045 * Kernel interface to adjust an rtc clock offset.
1046 * Return 0 on success, or a negative number on error.
1047 * If the rtc offset is not setable (or not implemented), return -EINVAL
1049 int rtc_set_offset(struct rtc_device
*rtc
, long offset
)
1056 if (!rtc
->ops
->set_offset
)
1059 mutex_lock(&rtc
->ops_lock
);
1060 ret
= rtc
->ops
->set_offset(rtc
->dev
.parent
, offset
);
1061 mutex_unlock(&rtc
->ops_lock
);
1063 trace_rtc_set_offset(offset
, ret
);