projects/linux·blob v4.9 · refs

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1/*
2 * Alarmtimer interface
3 *
4 * This interface provides a timer which is similarto hrtimers,
5 * but triggers a RTC alarm if the box is suspend.
6 *
7 * This interface is influenced by the Android RTC Alarm timer
8 * interface.
9 *
10 * Copyright (C) 2010 IBM Corperation
11 *
12 * Author: John Stultz <[email protected]>
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
17 */
18#include <linux/time.h>
19#include <linux/hrtimer.h>
20#include <linux/timerqueue.h>
21#include <linux/rtc.h>
22#include <linux/alarmtimer.h>
23#include <linux/mutex.h>
24#include <linux/platform_device.h>
25#include <linux/posix-timers.h>
26#include <linux/workqueue.h>
27#include <linux/freezer.h>
28
29/**
30 * struct alarm_base - Alarm timer bases
31 * @lock: Lock for syncrhonized access to the base
32 * @timerqueue: Timerqueue head managing the list of events
33 * @gettime: Function to read the time correlating to the base
34 * @base_clockid: clockid for the base
35 */
36static struct alarm_base {
37 spinlock_t lock;
38 struct timerqueue_head timerqueue;
39 ktime_t (*gettime)(void);
40 clockid_t base_clockid;
41} alarm_bases[ALARM_NUMTYPE];
42
43/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
44static ktime_t freezer_delta;
45static DEFINE_SPINLOCK(freezer_delta_lock);
46
47static struct wakeup_source *ws;
48
49#ifdef CONFIG_RTC_CLASS
50/* rtc timer and device for setting alarm wakeups at suspend */
51static struct rtc_timer rtctimer;
52static struct rtc_device *rtcdev;
53static DEFINE_SPINLOCK(rtcdev_lock);
54
55/**
56 * alarmtimer_get_rtcdev - Return selected rtcdevice
57 *
58 * This function returns the rtc device to use for wakealarms.
59 * If one has not already been chosen, it checks to see if a
60 * functional rtc device is available.
61 */
62struct rtc_device *alarmtimer_get_rtcdev(void)
63{
64 unsigned long flags;
65 struct rtc_device *ret;
66
67 spin_lock_irqsave(&rtcdev_lock, flags);
68 ret = rtcdev;
69 spin_unlock_irqrestore(&rtcdev_lock, flags);
70
71 return ret;
72}
73EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
74
75static int alarmtimer_rtc_add_device(struct device *dev,
76 struct class_interface *class_intf)
77{
78 unsigned long flags;
79 struct rtc_device *rtc = to_rtc_device(dev);
80
81 if (rtcdev)
82 return -EBUSY;
83
84 if (!rtc->ops->set_alarm)
85 return -1;
86 if (!device_may_wakeup(rtc->dev.parent))
87 return -1;
88
89 spin_lock_irqsave(&rtcdev_lock, flags);
90 if (!rtcdev) {
91 rtcdev = rtc;
92 /* hold a reference so it doesn't go away */
93 get_device(dev);
94 }
95 spin_unlock_irqrestore(&rtcdev_lock, flags);
96 return 0;
97}
98
99static inline void alarmtimer_rtc_timer_init(void)
100{
101 rtc_timer_init(&rtctimer, NULL, NULL);
102}
103
104static struct class_interface alarmtimer_rtc_interface = {
105 .add_dev = &alarmtimer_rtc_add_device,
106};
107
108static int alarmtimer_rtc_interface_setup(void)
109{
110 alarmtimer_rtc_interface.class = rtc_class;
111 return class_interface_register(&alarmtimer_rtc_interface);
112}
113static void alarmtimer_rtc_interface_remove(void)
114{
115 class_interface_unregister(&alarmtimer_rtc_interface);
116}
117#else
118struct rtc_device *alarmtimer_get_rtcdev(void)
119{
120 return NULL;
121}
122#define rtcdev (NULL)
123static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
124static inline void alarmtimer_rtc_interface_remove(void) { }
125static inline void alarmtimer_rtc_timer_init(void) { }
126#endif
127
128/**
129 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
130 * @base: pointer to the base where the timer is being run
131 * @alarm: pointer to alarm being enqueued.
132 *
133 * Adds alarm to a alarm_base timerqueue
134 *
135 * Must hold base->lock when calling.
136 */
137static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
138{
139 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
140 timerqueue_del(&base->timerqueue, &alarm->node);
141
142 timerqueue_add(&base->timerqueue, &alarm->node);
143 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
144}
145
146/**
147 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
148 * @base: pointer to the base where the timer is running
149 * @alarm: pointer to alarm being removed
150 *
151 * Removes alarm to a alarm_base timerqueue
152 *
153 * Must hold base->lock when calling.
154 */
155static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
156{
157 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
158 return;
159
160 timerqueue_del(&base->timerqueue, &alarm->node);
161 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
162}
163
164
165/**
166 * alarmtimer_fired - Handles alarm hrtimer being fired.
167 * @timer: pointer to hrtimer being run
168 *
169 * When a alarm timer fires, this runs through the timerqueue to
170 * see which alarms expired, and runs those. If there are more alarm
171 * timers queued for the future, we set the hrtimer to fire when
172 * when the next future alarm timer expires.
173 */
174static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
175{
176 struct alarm *alarm = container_of(timer, struct alarm, timer);
177 struct alarm_base *base = &alarm_bases[alarm->type];
178 unsigned long flags;
179 int ret = HRTIMER_NORESTART;
180 int restart = ALARMTIMER_NORESTART;
181
182 spin_lock_irqsave(&base->lock, flags);
183 alarmtimer_dequeue(base, alarm);
184 spin_unlock_irqrestore(&base->lock, flags);
185
186 if (alarm->function)
187 restart = alarm->function(alarm, base->gettime());
188
189 spin_lock_irqsave(&base->lock, flags);
190 if (restart != ALARMTIMER_NORESTART) {
191 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
192 alarmtimer_enqueue(base, alarm);
193 ret = HRTIMER_RESTART;
194 }
195 spin_unlock_irqrestore(&base->lock, flags);
196
197 return ret;
198
199}
200
201ktime_t alarm_expires_remaining(const struct alarm *alarm)
202{
203 struct alarm_base *base = &alarm_bases[alarm->type];
204 return ktime_sub(alarm->node.expires, base->gettime());
205}
206EXPORT_SYMBOL_GPL(alarm_expires_remaining);
207
208#ifdef CONFIG_RTC_CLASS
209/**
210 * alarmtimer_suspend - Suspend time callback
211 * @dev: unused
212 * @state: unused
213 *
214 * When we are going into suspend, we look through the bases
215 * to see which is the soonest timer to expire. We then
216 * set an rtc timer to fire that far into the future, which
217 * will wake us from suspend.
218 */
219static int alarmtimer_suspend(struct device *dev)
220{
221 struct rtc_time tm;
222 ktime_t min, now;
223 unsigned long flags;
224 struct rtc_device *rtc;
225 int i;
226 int ret;
227
228 spin_lock_irqsave(&freezer_delta_lock, flags);
229 min = freezer_delta;
230 freezer_delta = ktime_set(0, 0);
231 spin_unlock_irqrestore(&freezer_delta_lock, flags);
232
233 rtc = alarmtimer_get_rtcdev();
234 /* If we have no rtcdev, just return */
235 if (!rtc)
236 return 0;
237
238 /* Find the soonest timer to expire*/
239 for (i = 0; i < ALARM_NUMTYPE; i++) {
240 struct alarm_base *base = &alarm_bases[i];
241 struct timerqueue_node *next;
242 ktime_t delta;
243
244 spin_lock_irqsave(&base->lock, flags);
245 next = timerqueue_getnext(&base->timerqueue);
246 spin_unlock_irqrestore(&base->lock, flags);
247 if (!next)
248 continue;
249 delta = ktime_sub(next->expires, base->gettime());
250 if (!min.tv64 || (delta.tv64 < min.tv64))
251 min = delta;
252 }
253 if (min.tv64 == 0)
254 return 0;
255
256 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
257 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
258 return -EBUSY;
259 }
260
261 /* Setup an rtc timer to fire that far in the future */
262 rtc_timer_cancel(rtc, &rtctimer);
263 rtc_read_time(rtc, &tm);
264 now = rtc_tm_to_ktime(tm);
265 now = ktime_add(now, min);
266
267 /* Set alarm, if in the past reject suspend briefly to handle */
268 ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
269 if (ret < 0)
270 __pm_wakeup_event(ws, MSEC_PER_SEC);
271 return ret;
272}
273
274static int alarmtimer_resume(struct device *dev)
275{
276 struct rtc_device *rtc;
277
278 rtc = alarmtimer_get_rtcdev();
279 if (rtc)
280 rtc_timer_cancel(rtc, &rtctimer);
281 return 0;
282}
283
284#else
285static int alarmtimer_suspend(struct device *dev)
286{
287 return 0;
288}
289
290static int alarmtimer_resume(struct device *dev)
291{
292 return 0;
293}
294#endif
295
296static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
297{
298 ktime_t delta;
299 unsigned long flags;
300 struct alarm_base *base = &alarm_bases[type];
301
302 delta = ktime_sub(absexp, base->gettime());
303
304 spin_lock_irqsave(&freezer_delta_lock, flags);
305 if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
306 freezer_delta = delta;
307 spin_unlock_irqrestore(&freezer_delta_lock, flags);
308}
309
310
311/**
312 * alarm_init - Initialize an alarm structure
313 * @alarm: ptr to alarm to be initialized
314 * @type: the type of the alarm
315 * @function: callback that is run when the alarm fires
316 */
317void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
318 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
319{
320 timerqueue_init(&alarm->node);
321 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
322 HRTIMER_MODE_ABS);
323 alarm->timer.function = alarmtimer_fired;
324 alarm->function = function;
325 alarm->type = type;
326 alarm->state = ALARMTIMER_STATE_INACTIVE;
327}
328EXPORT_SYMBOL_GPL(alarm_init);
329
330/**
331 * alarm_start - Sets an absolute alarm to fire
332 * @alarm: ptr to alarm to set
333 * @start: time to run the alarm
334 */
335void alarm_start(struct alarm *alarm, ktime_t start)
336{
337 struct alarm_base *base = &alarm_bases[alarm->type];
338 unsigned long flags;
339
340 spin_lock_irqsave(&base->lock, flags);
341 alarm->node.expires = start;
342 alarmtimer_enqueue(base, alarm);
343 hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
344 spin_unlock_irqrestore(&base->lock, flags);
345}
346EXPORT_SYMBOL_GPL(alarm_start);
347
348/**
349 * alarm_start_relative - Sets a relative alarm to fire
350 * @alarm: ptr to alarm to set
351 * @start: time relative to now to run the alarm
352 */
353void alarm_start_relative(struct alarm *alarm, ktime_t start)
354{
355 struct alarm_base *base = &alarm_bases[alarm->type];
356
357 start = ktime_add(start, base->gettime());
358 alarm_start(alarm, start);
359}
360EXPORT_SYMBOL_GPL(alarm_start_relative);
361
362void alarm_restart(struct alarm *alarm)
363{
364 struct alarm_base *base = &alarm_bases[alarm->type];
365 unsigned long flags;
366
367 spin_lock_irqsave(&base->lock, flags);
368 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
369 hrtimer_restart(&alarm->timer);
370 alarmtimer_enqueue(base, alarm);
371 spin_unlock_irqrestore(&base->lock, flags);
372}
373EXPORT_SYMBOL_GPL(alarm_restart);
374
375/**
376 * alarm_try_to_cancel - Tries to cancel an alarm timer
377 * @alarm: ptr to alarm to be canceled
378 *
379 * Returns 1 if the timer was canceled, 0 if it was not running,
380 * and -1 if the callback was running
381 */
382int alarm_try_to_cancel(struct alarm *alarm)
383{
384 struct alarm_base *base = &alarm_bases[alarm->type];
385 unsigned long flags;
386 int ret;
387
388 spin_lock_irqsave(&base->lock, flags);
389 ret = hrtimer_try_to_cancel(&alarm->timer);
390 if (ret >= 0)
391 alarmtimer_dequeue(base, alarm);
392 spin_unlock_irqrestore(&base->lock, flags);
393 return ret;
394}
395EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
396
397
398/**
399 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
400 * @alarm: ptr to alarm to be canceled
401 *
402 * Returns 1 if the timer was canceled, 0 if it was not active.
403 */
404int alarm_cancel(struct alarm *alarm)
405{
406 for (;;) {
407 int ret = alarm_try_to_cancel(alarm);
408 if (ret >= 0)
409 return ret;
410 cpu_relax();
411 }
412}
413EXPORT_SYMBOL_GPL(alarm_cancel);
414
415
416u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
417{
418 u64 overrun = 1;
419 ktime_t delta;
420
421 delta = ktime_sub(now, alarm->node.expires);
422
423 if (delta.tv64 < 0)
424 return 0;
425
426 if (unlikely(delta.tv64 >= interval.tv64)) {
427 s64 incr = ktime_to_ns(interval);
428
429 overrun = ktime_divns(delta, incr);
430
431 alarm->node.expires = ktime_add_ns(alarm->node.expires,
432 incr*overrun);
433
434 if (alarm->node.expires.tv64 > now.tv64)
435 return overrun;
436 /*
437 * This (and the ktime_add() below) is the
438 * correction for exact:
439 */
440 overrun++;
441 }
442
443 alarm->node.expires = ktime_add(alarm->node.expires, interval);
444 return overrun;
445}
446EXPORT_SYMBOL_GPL(alarm_forward);
447
448u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
449{
450 struct alarm_base *base = &alarm_bases[alarm->type];
451
452 return alarm_forward(alarm, base->gettime(), interval);
453}
454EXPORT_SYMBOL_GPL(alarm_forward_now);
455
456
457/**
458 * clock2alarm - helper that converts from clockid to alarmtypes
459 * @clockid: clockid.
460 */
461static enum alarmtimer_type clock2alarm(clockid_t clockid)
462{
463 if (clockid == CLOCK_REALTIME_ALARM)
464 return ALARM_REALTIME;
465 if (clockid == CLOCK_BOOTTIME_ALARM)
466 return ALARM_BOOTTIME;
467 return -1;
468}
469
470/**
471 * alarm_handle_timer - Callback for posix timers
472 * @alarm: alarm that fired
473 *
474 * Posix timer callback for expired alarm timers.
475 */
476static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
477 ktime_t now)
478{
479 unsigned long flags;
480 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
481 it.alarm.alarmtimer);
482 enum alarmtimer_restart result = ALARMTIMER_NORESTART;
483
484 spin_lock_irqsave(&ptr->it_lock, flags);
485 if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
486 if (posix_timer_event(ptr, 0) != 0)
487 ptr->it_overrun++;
488 }
489
490 /* Re-add periodic timers */
491 if (ptr->it.alarm.interval.tv64) {
492 ptr->it_overrun += alarm_forward(alarm, now,
493 ptr->it.alarm.interval);
494 result = ALARMTIMER_RESTART;
495 }
496 spin_unlock_irqrestore(&ptr->it_lock, flags);
497
498 return result;
499}
500
501/**
502 * alarm_clock_getres - posix getres interface
503 * @which_clock: clockid
504 * @tp: timespec to fill
505 *
506 * Returns the granularity of underlying alarm base clock
507 */
508static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
509{
510 if (!alarmtimer_get_rtcdev())
511 return -EINVAL;
512
513 tp->tv_sec = 0;
514 tp->tv_nsec = hrtimer_resolution;
515 return 0;
516}
517
518/**
519 * alarm_clock_get - posix clock_get interface
520 * @which_clock: clockid
521 * @tp: timespec to fill.
522 *
523 * Provides the underlying alarm base time.
524 */
525static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
526{
527 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
528
529 if (!alarmtimer_get_rtcdev())
530 return -EINVAL;
531
532 *tp = ktime_to_timespec(base->gettime());
533 return 0;
534}
535
536/**
537 * alarm_timer_create - posix timer_create interface
538 * @new_timer: k_itimer pointer to manage
539 *
540 * Initializes the k_itimer structure.
541 */
542static int alarm_timer_create(struct k_itimer *new_timer)
543{
544 enum alarmtimer_type type;
545
546 if (!alarmtimer_get_rtcdev())
547 return -ENOTSUPP;
548
549 if (!capable(CAP_WAKE_ALARM))
550 return -EPERM;
551
552 type = clock2alarm(new_timer->it_clock);
553 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
554 return 0;
555}
556
557/**
558 * alarm_timer_get - posix timer_get interface
559 * @new_timer: k_itimer pointer
560 * @cur_setting: itimerspec data to fill
561 *
562 * Copies out the current itimerspec data
563 */
564static void alarm_timer_get(struct k_itimer *timr,
565 struct itimerspec *cur_setting)
566{
567 ktime_t relative_expiry_time =
568 alarm_expires_remaining(&(timr->it.alarm.alarmtimer));
569
570 if (ktime_to_ns(relative_expiry_time) > 0) {
571 cur_setting->it_value = ktime_to_timespec(relative_expiry_time);
572 } else {
573 cur_setting->it_value.tv_sec = 0;
574 cur_setting->it_value.tv_nsec = 0;
575 }
576
577 cur_setting->it_interval = ktime_to_timespec(timr->it.alarm.interval);
578}
579
580/**
581 * alarm_timer_del - posix timer_del interface
582 * @timr: k_itimer pointer to be deleted
583 *
584 * Cancels any programmed alarms for the given timer.
585 */
586static int alarm_timer_del(struct k_itimer *timr)
587{
588 if (!rtcdev)
589 return -ENOTSUPP;
590
591 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
592 return TIMER_RETRY;
593
594 return 0;
595}
596
597/**
598 * alarm_timer_set - posix timer_set interface
599 * @timr: k_itimer pointer to be deleted
600 * @flags: timer flags
601 * @new_setting: itimerspec to be used
602 * @old_setting: itimerspec being replaced
603 *
604 * Sets the timer to new_setting, and starts the timer.
605 */
606static int alarm_timer_set(struct k_itimer *timr, int flags,
607 struct itimerspec *new_setting,
608 struct itimerspec *old_setting)
609{
610 ktime_t exp;
611
612 if (!rtcdev)
613 return -ENOTSUPP;
614
615 if (flags & ~TIMER_ABSTIME)
616 return -EINVAL;
617
618 if (old_setting)
619 alarm_timer_get(timr, old_setting);
620
621 /* If the timer was already set, cancel it */
622 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
623 return TIMER_RETRY;
624
625 /* start the timer */
626 timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval);
627 exp = timespec_to_ktime(new_setting->it_value);
628 /* Convert (if necessary) to absolute time */
629 if (flags != TIMER_ABSTIME) {
630 ktime_t now;
631
632 now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
633 exp = ktime_add(now, exp);
634 }
635
636 alarm_start(&timr->it.alarm.alarmtimer, exp);
637 return 0;
638}
639
640/**
641 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
642 * @alarm: ptr to alarm that fired
643 *
644 * Wakes up the task that set the alarmtimer
645 */
646static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
647 ktime_t now)
648{
649 struct task_struct *task = (struct task_struct *)alarm->data;
650
651 alarm->data = NULL;
652 if (task)
653 wake_up_process(task);
654 return ALARMTIMER_NORESTART;
655}
656
657/**
658 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
659 * @alarm: ptr to alarmtimer
660 * @absexp: absolute expiration time
661 *
662 * Sets the alarm timer and sleeps until it is fired or interrupted.
663 */
664static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp)
665{
666 alarm->data = (void *)current;
667 do {
668 set_current_state(TASK_INTERRUPTIBLE);
669 alarm_start(alarm, absexp);
670 if (likely(alarm->data))
671 schedule();
672
673 alarm_cancel(alarm);
674 } while (alarm->data && !signal_pending(current));
675
676 __set_current_state(TASK_RUNNING);
677
678 return (alarm->data == NULL);
679}
680
681
682/**
683 * update_rmtp - Update remaining timespec value
684 * @exp: expiration time
685 * @type: timer type
686 * @rmtp: user pointer to remaining timepsec value
687 *
688 * Helper function that fills in rmtp value with time between
689 * now and the exp value
690 */
691static int update_rmtp(ktime_t exp, enum alarmtimer_type type,
692 struct timespec __user *rmtp)
693{
694 struct timespec rmt;
695 ktime_t rem;
696
697 rem = ktime_sub(exp, alarm_bases[type].gettime());
698
699 if (rem.tv64 <= 0)
700 return 0;
701 rmt = ktime_to_timespec(rem);
702
703 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
704 return -EFAULT;
705
706 return 1;
707
708}
709
710/**
711 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
712 * @restart: ptr to restart block
713 *
714 * Handles restarted clock_nanosleep calls
715 */
716static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
717{
718 enum alarmtimer_type type = restart->nanosleep.clockid;
719 ktime_t exp;
720 struct timespec __user *rmtp;
721 struct alarm alarm;
722 int ret = 0;
723
724 exp.tv64 = restart->nanosleep.expires;
725 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
726
727 if (alarmtimer_do_nsleep(&alarm, exp))
728 goto out;
729
730 if (freezing(current))
731 alarmtimer_freezerset(exp, type);
732
733 rmtp = restart->nanosleep.rmtp;
734 if (rmtp) {
735 ret = update_rmtp(exp, type, rmtp);
736 if (ret <= 0)
737 goto out;
738 }
739
740
741 /* The other values in restart are already filled in */
742 ret = -ERESTART_RESTARTBLOCK;
743out:
744 return ret;
745}
746
747/**
748 * alarm_timer_nsleep - alarmtimer nanosleep
749 * @which_clock: clockid
750 * @flags: determins abstime or relative
751 * @tsreq: requested sleep time (abs or rel)
752 * @rmtp: remaining sleep time saved
753 *
754 * Handles clock_nanosleep calls against _ALARM clockids
755 */
756static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
757 struct timespec *tsreq, struct timespec __user *rmtp)
758{
759 enum alarmtimer_type type = clock2alarm(which_clock);
760 struct alarm alarm;
761 ktime_t exp;
762 int ret = 0;
763 struct restart_block *restart;
764
765 if (!alarmtimer_get_rtcdev())
766 return -ENOTSUPP;
767
768 if (flags & ~TIMER_ABSTIME)
769 return -EINVAL;
770
771 if (!capable(CAP_WAKE_ALARM))
772 return -EPERM;
773
774 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
775
776 exp = timespec_to_ktime(*tsreq);
777 /* Convert (if necessary) to absolute time */
778 if (flags != TIMER_ABSTIME) {
779 ktime_t now = alarm_bases[type].gettime();
780 exp = ktime_add(now, exp);
781 }
782
783 if (alarmtimer_do_nsleep(&alarm, exp))
784 goto out;
785
786 if (freezing(current))
787 alarmtimer_freezerset(exp, type);
788
789 /* abs timers don't set remaining time or restart */
790 if (flags == TIMER_ABSTIME) {
791 ret = -ERESTARTNOHAND;
792 goto out;
793 }
794
795 if (rmtp) {
796 ret = update_rmtp(exp, type, rmtp);
797 if (ret <= 0)
798 goto out;
799 }
800
801 restart = &current->restart_block;
802 restart->fn = alarm_timer_nsleep_restart;
803 restart->nanosleep.clockid = type;
804 restart->nanosleep.expires = exp.tv64;
805 restart->nanosleep.rmtp = rmtp;
806 ret = -ERESTART_RESTARTBLOCK;
807
808out:
809 return ret;
810}
811
812
813/* Suspend hook structures */
814static const struct dev_pm_ops alarmtimer_pm_ops = {
815 .suspend = alarmtimer_suspend,
816 .resume = alarmtimer_resume,
817};
818
819static struct platform_driver alarmtimer_driver = {
820 .driver = {
821 .name = "alarmtimer",
822 .pm = &alarmtimer_pm_ops,
823 }
824};
825
826/**
827 * alarmtimer_init - Initialize alarm timer code
828 *
829 * This function initializes the alarm bases and registers
830 * the posix clock ids.
831 */
832static int __init alarmtimer_init(void)
833{
834 struct platform_device *pdev;
835 int error = 0;
836 int i;
837 struct k_clock alarm_clock = {
838 .clock_getres = alarm_clock_getres,
839 .clock_get = alarm_clock_get,
840 .timer_create = alarm_timer_create,
841 .timer_set = alarm_timer_set,
842 .timer_del = alarm_timer_del,
843 .timer_get = alarm_timer_get,
844 .nsleep = alarm_timer_nsleep,
845 };
846
847 alarmtimer_rtc_timer_init();
848
849 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
850 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
851
852 /* Initialize alarm bases */
853 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
854 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
855 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
856 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
857 for (i = 0; i < ALARM_NUMTYPE; i++) {
858 timerqueue_init_head(&alarm_bases[i].timerqueue);
859 spin_lock_init(&alarm_bases[i].lock);
860 }
861
862 error = alarmtimer_rtc_interface_setup();
863 if (error)
864 return error;
865
866 error = platform_driver_register(&alarmtimer_driver);
867 if (error)
868 goto out_if;
869
870 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
871 if (IS_ERR(pdev)) {
872 error = PTR_ERR(pdev);
873 goto out_drv;
874 }
875 ws = wakeup_source_register("alarmtimer");
876 return 0;
877
878out_drv:
879 platform_driver_unregister(&alarmtimer_driver);
880out_if:
881 alarmtimer_rtc_interface_remove();
882 return error;
883}
884device_initcall(alarmtimer_init);