]>
git.proxmox.com Git - mirror_ubuntu-hirsute-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 #define CREATE_TRACE_POINTS
21 #include <trace/events/rtc.h>
23 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
);
24 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
);
26 static void rtc_add_offset(struct rtc_device
*rtc
, struct rtc_time
*tm
)
30 if (!rtc
->offset_secs
)
33 secs
= rtc_tm_to_time64(tm
);
36 * Since the reading time values from RTC device are always in the RTC
37 * original valid range, but we need to skip the overlapped region
38 * between expanded range and original range, which is no need to add
41 if ((rtc
->start_secs
> rtc
->range_min
&& secs
>= rtc
->start_secs
) ||
42 (rtc
->start_secs
< rtc
->range_min
&&
43 secs
<= (rtc
->start_secs
+ rtc
->range_max
- rtc
->range_min
)))
46 rtc_time64_to_tm(secs
+ rtc
->offset_secs
, tm
);
49 static void rtc_subtract_offset(struct rtc_device
*rtc
, struct rtc_time
*tm
)
53 if (!rtc
->offset_secs
)
56 secs
= rtc_tm_to_time64(tm
);
59 * If the setting time values are in the valid range of RTC hardware
60 * device, then no need to subtract the offset when setting time to RTC
61 * device. Otherwise we need to subtract the offset to make the time
62 * values are valid for RTC hardware device.
64 if (secs
>= rtc
->range_min
&& secs
<= rtc
->range_max
)
67 rtc_time64_to_tm(secs
- rtc
->offset_secs
, tm
);
70 static int rtc_valid_range(struct rtc_device
*rtc
, struct rtc_time
*tm
)
72 if (rtc
->range_min
!= rtc
->range_max
) {
73 time64_t time
= rtc_tm_to_time64(tm
);
74 time64_t range_min
= rtc
->set_start_time
? rtc
->start_secs
:
76 time64_t range_max
= rtc
->set_start_time
?
77 (rtc
->start_secs
+ rtc
->range_max
- rtc
->range_min
) :
80 if (time
< range_min
|| time
> range_max
)
87 static int __rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
92 else if (!rtc
->ops
->read_time
)
95 memset(tm
, 0, sizeof(struct rtc_time
));
96 err
= rtc
->ops
->read_time(rtc
->dev
.parent
, tm
);
98 dev_dbg(&rtc
->dev
, "read_time: fail to read: %d\n",
103 rtc_add_offset(rtc
, tm
);
105 err
= rtc_valid_tm(tm
);
107 dev_dbg(&rtc
->dev
, "read_time: rtc_time isn't valid\n");
112 int rtc_read_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
116 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
120 err
= __rtc_read_time(rtc
, tm
);
121 mutex_unlock(&rtc
->ops_lock
);
123 trace_rtc_read_time(rtc_tm_to_time64(tm
), err
);
126 EXPORT_SYMBOL_GPL(rtc_read_time
);
128 int rtc_set_time(struct rtc_device
*rtc
, struct rtc_time
*tm
)
132 err
= rtc_valid_tm(tm
);
136 err
= rtc_valid_range(rtc
, tm
);
140 rtc_subtract_offset(rtc
, tm
);
142 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
148 else if (rtc
->ops
->set_time
)
149 err
= rtc
->ops
->set_time(rtc
->dev
.parent
, tm
);
150 else if (rtc
->ops
->set_mmss64
) {
151 time64_t secs64
= rtc_tm_to_time64(tm
);
153 err
= rtc
->ops
->set_mmss64(rtc
->dev
.parent
, secs64
);
154 } else if (rtc
->ops
->set_mmss
) {
155 time64_t secs64
= rtc_tm_to_time64(tm
);
156 err
= rtc
->ops
->set_mmss(rtc
->dev
.parent
, secs64
);
160 pm_stay_awake(rtc
->dev
.parent
);
161 mutex_unlock(&rtc
->ops_lock
);
162 /* A timer might have just expired */
163 schedule_work(&rtc
->irqwork
);
165 trace_rtc_set_time(rtc_tm_to_time64(tm
), err
);
168 EXPORT_SYMBOL_GPL(rtc_set_time
);
170 static int rtc_read_alarm_internal(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
174 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
178 if (rtc
->ops
== NULL
)
180 else if (!rtc
->ops
->read_alarm
)
185 alarm
->time
.tm_sec
= -1;
186 alarm
->time
.tm_min
= -1;
187 alarm
->time
.tm_hour
= -1;
188 alarm
->time
.tm_mday
= -1;
189 alarm
->time
.tm_mon
= -1;
190 alarm
->time
.tm_year
= -1;
191 alarm
->time
.tm_wday
= -1;
192 alarm
->time
.tm_yday
= -1;
193 alarm
->time
.tm_isdst
= -1;
194 err
= rtc
->ops
->read_alarm(rtc
->dev
.parent
, alarm
);
197 mutex_unlock(&rtc
->ops_lock
);
199 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
203 int __rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
206 struct rtc_time before
, now
;
208 time64_t t_now
, t_alm
;
209 enum { none
, day
, month
, year
} missing
= none
;
212 /* The lower level RTC driver may return -1 in some fields,
213 * creating invalid alarm->time values, for reasons like:
215 * - The hardware may not be capable of filling them in;
216 * many alarms match only on time-of-day fields, not
217 * day/month/year calendar data.
219 * - Some hardware uses illegal values as "wildcard" match
220 * values, which non-Linux firmware (like a BIOS) may try
221 * to set up as e.g. "alarm 15 minutes after each hour".
222 * Linux uses only oneshot alarms.
224 * When we see that here, we deal with it by using values from
225 * a current RTC timestamp for any missing (-1) values. The
226 * RTC driver prevents "periodic alarm" modes.
228 * But this can be racey, because some fields of the RTC timestamp
229 * may have wrapped in the interval since we read the RTC alarm,
230 * which would lead to us inserting inconsistent values in place
233 * Reading the alarm and timestamp in the reverse sequence
234 * would have the same race condition, and not solve the issue.
236 * So, we must first read the RTC timestamp,
237 * then read the RTC alarm value,
238 * and then read a second RTC timestamp.
240 * If any fields of the second timestamp have changed
241 * when compared with the first timestamp, then we know
242 * our timestamp may be inconsistent with that used by
243 * the low-level rtc_read_alarm_internal() function.
245 * So, when the two timestamps disagree, we just loop and do
246 * the process again to get a fully consistent set of values.
248 * This could all instead be done in the lower level driver,
249 * but since more than one lower level RTC implementation needs it,
250 * then it's probably best best to do it here instead of there..
253 /* Get the "before" timestamp */
254 err
= rtc_read_time(rtc
, &before
);
259 memcpy(&before
, &now
, sizeof(struct rtc_time
));
262 /* get the RTC alarm values, which may be incomplete */
263 err
= rtc_read_alarm_internal(rtc
, alarm
);
267 /* full-function RTCs won't have such missing fields */
268 if (rtc_valid_tm(&alarm
->time
) == 0)
271 /* get the "after" timestamp, to detect wrapped fields */
272 err
= rtc_read_time(rtc
, &now
);
276 /* note that tm_sec is a "don't care" value here: */
277 } while ( before
.tm_min
!= now
.tm_min
278 || before
.tm_hour
!= now
.tm_hour
279 || before
.tm_mon
!= now
.tm_mon
280 || before
.tm_year
!= now
.tm_year
);
282 /* Fill in the missing alarm fields using the timestamp; we
283 * know there's at least one since alarm->time is invalid.
285 if (alarm
->time
.tm_sec
== -1)
286 alarm
->time
.tm_sec
= now
.tm_sec
;
287 if (alarm
->time
.tm_min
== -1)
288 alarm
->time
.tm_min
= now
.tm_min
;
289 if (alarm
->time
.tm_hour
== -1)
290 alarm
->time
.tm_hour
= now
.tm_hour
;
292 /* For simplicity, only support date rollover for now */
293 if (alarm
->time
.tm_mday
< 1 || alarm
->time
.tm_mday
> 31) {
294 alarm
->time
.tm_mday
= now
.tm_mday
;
297 if ((unsigned)alarm
->time
.tm_mon
>= 12) {
298 alarm
->time
.tm_mon
= now
.tm_mon
;
302 if (alarm
->time
.tm_year
== -1) {
303 alarm
->time
.tm_year
= now
.tm_year
;
308 /* Can't proceed if alarm is still invalid after replacing
311 err
= rtc_valid_tm(&alarm
->time
);
315 /* with luck, no rollover is needed */
316 t_now
= rtc_tm_to_time64(&now
);
317 t_alm
= rtc_tm_to_time64(&alarm
->time
);
323 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
324 * that will trigger at 5am will do so at 5am Tuesday, which
325 * could also be in the next month or year. This is a common
326 * case, especially for PCs.
329 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "day");
330 t_alm
+= 24 * 60 * 60;
331 rtc_time64_to_tm(t_alm
, &alarm
->time
);
334 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
335 * be next month. An alarm matching on the 30th, 29th, or 28th
336 * may end up in the month after that! Many newer PCs support
337 * this type of alarm.
340 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "month");
342 if (alarm
->time
.tm_mon
< 11)
343 alarm
->time
.tm_mon
++;
345 alarm
->time
.tm_mon
= 0;
346 alarm
->time
.tm_year
++;
348 days
= rtc_month_days(alarm
->time
.tm_mon
,
349 alarm
->time
.tm_year
);
350 } while (days
< alarm
->time
.tm_mday
);
353 /* Year rollover ... easy except for leap years! */
355 dev_dbg(&rtc
->dev
, "alarm rollover: %s\n", "year");
357 alarm
->time
.tm_year
++;
358 } while (!is_leap_year(alarm
->time
.tm_year
+ 1900)
359 && rtc_valid_tm(&alarm
->time
) != 0);
363 dev_warn(&rtc
->dev
, "alarm rollover not handled\n");
366 err
= rtc_valid_tm(&alarm
->time
);
370 dev_warn(&rtc
->dev
, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
371 alarm
->time
.tm_year
+ 1900, alarm
->time
.tm_mon
+ 1,
372 alarm
->time
.tm_mday
, alarm
->time
.tm_hour
, alarm
->time
.tm_min
,
379 int rtc_read_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
383 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
386 if (rtc
->ops
== NULL
)
388 else if (!rtc
->ops
->read_alarm
)
391 memset(alarm
, 0, sizeof(struct rtc_wkalrm
));
392 alarm
->enabled
= rtc
->aie_timer
.enabled
;
393 alarm
->time
= rtc_ktime_to_tm(rtc
->aie_timer
.node
.expires
);
395 mutex_unlock(&rtc
->ops_lock
);
397 trace_rtc_read_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
400 EXPORT_SYMBOL_GPL(rtc_read_alarm
);
402 static int __rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
405 time64_t now
, scheduled
;
408 err
= rtc_valid_tm(&alarm
->time
);
412 rtc_subtract_offset(rtc
, &alarm
->time
);
413 scheduled
= rtc_tm_to_time64(&alarm
->time
);
415 /* Make sure we're not setting alarms in the past */
416 err
= __rtc_read_time(rtc
, &tm
);
419 now
= rtc_tm_to_time64(&tm
);
420 if (scheduled
<= now
)
423 * XXX - We just checked to make sure the alarm time is not
424 * in the past, but there is still a race window where if
425 * the is alarm set for the next second and the second ticks
426 * over right here, before we set the alarm.
431 else if (!rtc
->ops
->set_alarm
)
434 err
= rtc
->ops
->set_alarm(rtc
->dev
.parent
, alarm
);
436 trace_rtc_set_alarm(rtc_tm_to_time64(&alarm
->time
), err
);
440 int rtc_set_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
444 err
= rtc_valid_tm(&alarm
->time
);
448 err
= rtc_valid_range(rtc
, &alarm
->time
);
452 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
455 if (rtc
->aie_timer
.enabled
)
456 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
458 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
459 rtc
->aie_timer
.period
= 0;
461 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
463 mutex_unlock(&rtc
->ops_lock
);
465 rtc_add_offset(rtc
, &alarm
->time
);
468 EXPORT_SYMBOL_GPL(rtc_set_alarm
);
470 /* Called once per device from rtc_device_register */
471 int rtc_initialize_alarm(struct rtc_device
*rtc
, struct rtc_wkalrm
*alarm
)
476 err
= rtc_valid_tm(&alarm
->time
);
480 err
= rtc_read_time(rtc
, &now
);
484 err
= mutex_lock_interruptible(&rtc
->ops_lock
);
488 rtc
->aie_timer
.node
.expires
= rtc_tm_to_ktime(alarm
->time
);
489 rtc
->aie_timer
.period
= 0;
491 /* Alarm has to be enabled & in the future for us to enqueue it */
492 if (alarm
->enabled
&& (rtc_tm_to_ktime(now
) <
493 rtc
->aie_timer
.node
.expires
)) {
495 rtc
->aie_timer
.enabled
= 1;
496 timerqueue_add(&rtc
->timerqueue
, &rtc
->aie_timer
.node
);
497 trace_rtc_timer_enqueue(&rtc
->aie_timer
);
499 mutex_unlock(&rtc
->ops_lock
);
502 EXPORT_SYMBOL_GPL(rtc_initialize_alarm
);
504 int rtc_alarm_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
506 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
510 if (rtc
->aie_timer
.enabled
!= enabled
) {
512 err
= rtc_timer_enqueue(rtc
, &rtc
->aie_timer
);
514 rtc_timer_remove(rtc
, &rtc
->aie_timer
);
521 else if (!rtc
->ops
->alarm_irq_enable
)
524 err
= rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, enabled
);
526 mutex_unlock(&rtc
->ops_lock
);
528 trace_rtc_alarm_irq_enable(enabled
, err
);
531 EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable
);
533 int rtc_update_irq_enable(struct rtc_device
*rtc
, unsigned int enabled
)
535 int err
= mutex_lock_interruptible(&rtc
->ops_lock
);
539 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
540 if (enabled
== 0 && rtc
->uie_irq_active
) {
541 mutex_unlock(&rtc
->ops_lock
);
542 return rtc_dev_update_irq_enable_emul(rtc
, 0);
545 /* make sure we're changing state */
546 if (rtc
->uie_rtctimer
.enabled
== enabled
)
549 if (rtc
->uie_unsupported
) {
558 __rtc_read_time(rtc
, &tm
);
559 onesec
= ktime_set(1, 0);
560 now
= rtc_tm_to_ktime(tm
);
561 rtc
->uie_rtctimer
.node
.expires
= ktime_add(now
, onesec
);
562 rtc
->uie_rtctimer
.period
= ktime_set(1, 0);
563 err
= rtc_timer_enqueue(rtc
, &rtc
->uie_rtctimer
);
565 rtc_timer_remove(rtc
, &rtc
->uie_rtctimer
);
568 mutex_unlock(&rtc
->ops_lock
);
569 #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
571 * Enable emulation if the driver did not provide
572 * the update_irq_enable function pointer or if returned
573 * -EINVAL to signal that it has been configured without
574 * interrupts or that are not available at the moment.
577 err
= rtc_dev_update_irq_enable_emul(rtc
, enabled
);
582 EXPORT_SYMBOL_GPL(rtc_update_irq_enable
);
586 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
587 * @rtc: pointer to the rtc device
589 * This function is called when an AIE, UIE or PIE mode interrupt
590 * has occurred (or been emulated).
592 * Triggers the registered irq_task function callback.
594 void rtc_handle_legacy_irq(struct rtc_device
*rtc
, int num
, int mode
)
598 /* mark one irq of the appropriate mode */
599 spin_lock_irqsave(&rtc
->irq_lock
, flags
);
600 rtc
->irq_data
= (rtc
->irq_data
+ (num
<< 8)) | (RTC_IRQF
|mode
);
601 spin_unlock_irqrestore(&rtc
->irq_lock
, flags
);
603 /* call the task func */
604 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
606 rtc
->irq_task
->func(rtc
->irq_task
->private_data
);
607 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
609 wake_up_interruptible(&rtc
->irq_queue
);
610 kill_fasync(&rtc
->async_queue
, SIGIO
, POLL_IN
);
615 * rtc_aie_update_irq - AIE mode rtctimer hook
616 * @private: pointer to the rtc_device
618 * This functions is called when the aie_timer expires.
620 void rtc_aie_update_irq(void *private)
622 struct rtc_device
*rtc
= (struct rtc_device
*)private;
623 rtc_handle_legacy_irq(rtc
, 1, RTC_AF
);
628 * rtc_uie_update_irq - UIE mode rtctimer hook
629 * @private: pointer to the rtc_device
631 * This functions is called when the uie_timer expires.
633 void rtc_uie_update_irq(void *private)
635 struct rtc_device
*rtc
= (struct rtc_device
*)private;
636 rtc_handle_legacy_irq(rtc
, 1, RTC_UF
);
641 * rtc_pie_update_irq - PIE mode hrtimer hook
642 * @timer: pointer to the pie mode hrtimer
644 * This function is used to emulate PIE mode interrupts
645 * using an hrtimer. This function is called when the periodic
648 enum hrtimer_restart
rtc_pie_update_irq(struct hrtimer
*timer
)
650 struct rtc_device
*rtc
;
653 rtc
= container_of(timer
, struct rtc_device
, pie_timer
);
655 period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
656 count
= hrtimer_forward_now(timer
, period
);
658 rtc_handle_legacy_irq(rtc
, count
, RTC_PF
);
660 return HRTIMER_RESTART
;
664 * rtc_update_irq - Triggered when a RTC interrupt occurs.
665 * @rtc: the rtc device
666 * @num: how many irqs are being reported (usually one)
667 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
670 void rtc_update_irq(struct rtc_device
*rtc
,
671 unsigned long num
, unsigned long events
)
673 if (IS_ERR_OR_NULL(rtc
))
676 pm_stay_awake(rtc
->dev
.parent
);
677 schedule_work(&rtc
->irqwork
);
679 EXPORT_SYMBOL_GPL(rtc_update_irq
);
681 static int __rtc_match(struct device
*dev
, const void *data
)
683 const char *name
= data
;
685 if (strcmp(dev_name(dev
), name
) == 0)
690 struct rtc_device
*rtc_class_open(const char *name
)
693 struct rtc_device
*rtc
= NULL
;
695 dev
= class_find_device(rtc_class
, NULL
, name
, __rtc_match
);
697 rtc
= to_rtc_device(dev
);
700 if (!try_module_get(rtc
->owner
)) {
708 EXPORT_SYMBOL_GPL(rtc_class_open
);
710 void rtc_class_close(struct rtc_device
*rtc
)
712 module_put(rtc
->owner
);
713 put_device(&rtc
->dev
);
715 EXPORT_SYMBOL_GPL(rtc_class_close
);
717 int rtc_irq_register(struct rtc_device
*rtc
, struct rtc_task
*task
)
721 if (task
== NULL
|| task
->func
== NULL
)
724 /* Cannot register while the char dev is in use */
725 if (test_and_set_bit_lock(RTC_DEV_BUSY
, &rtc
->flags
))
728 spin_lock_irq(&rtc
->irq_task_lock
);
729 if (rtc
->irq_task
== NULL
) {
730 rtc
->irq_task
= task
;
733 spin_unlock_irq(&rtc
->irq_task_lock
);
735 clear_bit_unlock(RTC_DEV_BUSY
, &rtc
->flags
);
739 EXPORT_SYMBOL_GPL(rtc_irq_register
);
741 void rtc_irq_unregister(struct rtc_device
*rtc
, struct rtc_task
*task
)
743 spin_lock_irq(&rtc
->irq_task_lock
);
744 if (rtc
->irq_task
== task
)
745 rtc
->irq_task
= NULL
;
746 spin_unlock_irq(&rtc
->irq_task_lock
);
748 EXPORT_SYMBOL_GPL(rtc_irq_unregister
);
750 static int rtc_update_hrtimer(struct rtc_device
*rtc
, int enabled
)
753 * We always cancel the timer here first, because otherwise
754 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
755 * when we manage to start the timer before the callback
756 * returns HRTIMER_RESTART.
758 * We cannot use hrtimer_cancel() here as a running callback
759 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
760 * would spin forever.
762 if (hrtimer_try_to_cancel(&rtc
->pie_timer
) < 0)
766 ktime_t period
= NSEC_PER_SEC
/ rtc
->irq_freq
;
768 hrtimer_start(&rtc
->pie_timer
, period
, HRTIMER_MODE_REL
);
774 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
775 * @rtc: the rtc device
776 * @task: currently registered with rtc_irq_register()
777 * @enabled: true to enable periodic IRQs
780 * Note that rtc_irq_set_freq() should previously have been used to
781 * specify the desired frequency of periodic IRQ task->func() callbacks.
783 int rtc_irq_set_state(struct rtc_device
*rtc
, struct rtc_task
*task
, int enabled
)
789 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
790 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
792 else if (rtc
->irq_task
!= task
)
795 if (rtc_update_hrtimer(rtc
, enabled
) < 0) {
796 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
800 rtc
->pie_enabled
= enabled
;
802 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
804 trace_rtc_irq_set_state(enabled
, err
);
807 EXPORT_SYMBOL_GPL(rtc_irq_set_state
);
810 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
811 * @rtc: the rtc device
812 * @task: currently registered with rtc_irq_register()
813 * @freq: positive frequency with which task->func() will be called
816 * Note that rtc_irq_set_state() is used to enable or disable the
819 int rtc_irq_set_freq(struct rtc_device
*rtc
, struct rtc_task
*task
, int freq
)
824 if (freq
<= 0 || freq
> RTC_MAX_FREQ
)
827 spin_lock_irqsave(&rtc
->irq_task_lock
, flags
);
828 if (rtc
->irq_task
!= NULL
&& task
== NULL
)
830 else if (rtc
->irq_task
!= task
)
833 rtc
->irq_freq
= freq
;
834 if (rtc
->pie_enabled
&& rtc_update_hrtimer(rtc
, 1) < 0) {
835 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
840 spin_unlock_irqrestore(&rtc
->irq_task_lock
, flags
);
842 trace_rtc_irq_set_freq(freq
, err
);
845 EXPORT_SYMBOL_GPL(rtc_irq_set_freq
);
848 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
850 * @timer timer being added.
852 * Enqueues a timer onto the rtc devices timerqueue and sets
853 * the next alarm event appropriately.
855 * Sets the enabled bit on the added timer.
857 * Must hold ops_lock for proper serialization of timerqueue
859 static int rtc_timer_enqueue(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
861 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
866 __rtc_read_time(rtc
, &tm
);
867 now
= rtc_tm_to_ktime(tm
);
869 /* Skip over expired timers */
871 if (next
->expires
>= now
)
873 next
= timerqueue_iterate_next(next
);
876 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
877 trace_rtc_timer_enqueue(timer
);
878 if (!next
|| ktime_before(timer
->node
.expires
, next
->expires
)) {
879 struct rtc_wkalrm alarm
;
881 alarm
.time
= rtc_ktime_to_tm(timer
->node
.expires
);
883 err
= __rtc_set_alarm(rtc
, &alarm
);
885 pm_stay_awake(rtc
->dev
.parent
);
886 schedule_work(&rtc
->irqwork
);
888 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
889 trace_rtc_timer_dequeue(timer
);
897 static void rtc_alarm_disable(struct rtc_device
*rtc
)
899 if (!rtc
->ops
|| !rtc
->ops
->alarm_irq_enable
)
902 rtc
->ops
->alarm_irq_enable(rtc
->dev
.parent
, false);
903 trace_rtc_alarm_irq_enable(0, 0);
907 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
909 * @timer timer being removed.
911 * Removes a timer onto the rtc devices timerqueue and sets
912 * the next alarm event appropriately.
914 * Clears the enabled bit on the removed timer.
916 * Must hold ops_lock for proper serialization of timerqueue
918 static void rtc_timer_remove(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
920 struct timerqueue_node
*next
= timerqueue_getnext(&rtc
->timerqueue
);
921 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
922 trace_rtc_timer_dequeue(timer
);
924 if (next
== &timer
->node
) {
925 struct rtc_wkalrm alarm
;
927 next
= timerqueue_getnext(&rtc
->timerqueue
);
929 rtc_alarm_disable(rtc
);
932 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
934 err
= __rtc_set_alarm(rtc
, &alarm
);
936 pm_stay_awake(rtc
->dev
.parent
);
937 schedule_work(&rtc
->irqwork
);
943 * rtc_timer_do_work - Expires rtc timers
945 * @timer timer being removed.
947 * Expires rtc timers. Reprograms next alarm event if needed.
948 * Called via worktask.
950 * Serializes access to timerqueue via ops_lock mutex
952 void rtc_timer_do_work(struct work_struct
*work
)
954 struct rtc_timer
*timer
;
955 struct timerqueue_node
*next
;
959 struct rtc_device
*rtc
=
960 container_of(work
, struct rtc_device
, irqwork
);
962 mutex_lock(&rtc
->ops_lock
);
964 __rtc_read_time(rtc
, &tm
);
965 now
= rtc_tm_to_ktime(tm
);
966 while ((next
= timerqueue_getnext(&rtc
->timerqueue
))) {
967 if (next
->expires
> now
)
971 timer
= container_of(next
, struct rtc_timer
, node
);
972 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
973 trace_rtc_timer_dequeue(timer
);
975 if (timer
->task
.func
)
976 timer
->task
.func(timer
->task
.private_data
);
978 trace_rtc_timer_fired(timer
);
979 /* Re-add/fwd periodic timers */
980 if (ktime_to_ns(timer
->period
)) {
981 timer
->node
.expires
= ktime_add(timer
->node
.expires
,
984 timerqueue_add(&rtc
->timerqueue
, &timer
->node
);
985 trace_rtc_timer_enqueue(timer
);
991 struct rtc_wkalrm alarm
;
995 alarm
.time
= rtc_ktime_to_tm(next
->expires
);
998 err
= __rtc_set_alarm(rtc
, &alarm
);
1005 timer
= container_of(next
, struct rtc_timer
, node
);
1006 timerqueue_del(&rtc
->timerqueue
, &timer
->node
);
1007 trace_rtc_timer_dequeue(timer
);
1009 dev_err(&rtc
->dev
, "__rtc_set_alarm: err=%d\n", err
);
1013 rtc_alarm_disable(rtc
);
1015 pm_relax(rtc
->dev
.parent
);
1016 mutex_unlock(&rtc
->ops_lock
);
1020 /* rtc_timer_init - Initializes an rtc_timer
1021 * @timer: timer to be intiialized
1022 * @f: function pointer to be called when timer fires
1023 * @data: private data passed to function pointer
1025 * Kernel interface to initializing an rtc_timer.
1027 void rtc_timer_init(struct rtc_timer
*timer
, void (*f
)(void *p
), void *data
)
1029 timerqueue_init(&timer
->node
);
1031 timer
->task
.func
= f
;
1032 timer
->task
.private_data
= data
;
1035 /* rtc_timer_start - Sets an rtc_timer to fire in the future
1036 * @ rtc: rtc device to be used
1037 * @ timer: timer being set
1038 * @ expires: time at which to expire the timer
1039 * @ period: period that the timer will recur
1041 * Kernel interface to set an rtc_timer
1043 int rtc_timer_start(struct rtc_device
*rtc
, struct rtc_timer
*timer
,
1044 ktime_t expires
, ktime_t period
)
1047 mutex_lock(&rtc
->ops_lock
);
1049 rtc_timer_remove(rtc
, timer
);
1051 timer
->node
.expires
= expires
;
1052 timer
->period
= period
;
1054 ret
= rtc_timer_enqueue(rtc
, timer
);
1056 mutex_unlock(&rtc
->ops_lock
);
1060 /* rtc_timer_cancel - Stops an rtc_timer
1061 * @ rtc: rtc device to be used
1062 * @ timer: timer being set
1064 * Kernel interface to cancel an rtc_timer
1066 void rtc_timer_cancel(struct rtc_device
*rtc
, struct rtc_timer
*timer
)
1068 mutex_lock(&rtc
->ops_lock
);
1070 rtc_timer_remove(rtc
, timer
);
1071 mutex_unlock(&rtc
->ops_lock
);
1075 * rtc_read_offset - Read the amount of rtc offset in parts per billion
1076 * @ rtc: rtc device to be used
1077 * @ offset: the offset in parts per billion
1079 * see below for details.
1081 * Kernel interface to read rtc clock offset
1082 * Returns 0 on success, or a negative number on error.
1083 * If read_offset() is not implemented for the rtc, return -EINVAL
1085 int rtc_read_offset(struct rtc_device
*rtc
, long *offset
)
1092 if (!rtc
->ops
->read_offset
)
1095 mutex_lock(&rtc
->ops_lock
);
1096 ret
= rtc
->ops
->read_offset(rtc
->dev
.parent
, offset
);
1097 mutex_unlock(&rtc
->ops_lock
);
1099 trace_rtc_read_offset(*offset
, ret
);
1104 * rtc_set_offset - Adjusts the duration of the average second
1105 * @ rtc: rtc device to be used
1106 * @ offset: the offset in parts per billion
1108 * Some rtc's allow an adjustment to the average duration of a second
1109 * to compensate for differences in the actual clock rate due to temperature,
1110 * the crystal, capacitor, etc.
1112 * The adjustment applied is as follows:
1113 * t = t0 * (1 + offset * 1e-9)
1114 * where t0 is the measured length of 1 RTC second with offset = 0
1116 * Kernel interface to adjust an rtc clock offset.
1117 * Return 0 on success, or a negative number on error.
1118 * If the rtc offset is not setable (or not implemented), return -EINVAL
1120 int rtc_set_offset(struct rtc_device
*rtc
, long offset
)
1127 if (!rtc
->ops
->set_offset
)
1130 mutex_lock(&rtc
->ops_lock
);
1131 ret
= rtc
->ops
->set_offset(rtc
->dev
.parent
, offset
);
1132 mutex_unlock(&rtc
->ops_lock
);
1134 trace_rtc_set_offset(offset
, ret
);