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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 <john.stultz@linaro.org>
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 * @timer: hrtimer used to schedule events while running
34 * @gettime: Function to read the time correlating to the base
35 * @base_clockid: clockid for the base
36 */
37static struct alarm_base {
38 spinlock_t lock;
39 struct timerqueue_head timerqueue;
40 ktime_t (*gettime)(void);
41 clockid_t base_clockid;
42} alarm_bases[ALARM_NUMTYPE];
43
44/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
45static ktime_t freezer_delta;
46static DEFINE_SPINLOCK(freezer_delta_lock);
47
48static struct wakeup_source *ws;
49
50#ifdef CONFIG_RTC_CLASS
51/* rtc timer and device for setting alarm wakeups at suspend */
52static struct rtc_timer rtctimer;
53static struct rtc_device *rtcdev;
54static DEFINE_SPINLOCK(rtcdev_lock);
55
56/**
57 * alarmtimer_get_rtcdev - Return selected rtcdevice
58 *
59 * This function returns the rtc device to use for wakealarms.
60 * If one has not already been chosen, it checks to see if a
61 * functional rtc device is available.
62 */
63struct rtc_device *alarmtimer_get_rtcdev(void)
64{
65 unsigned long flags;
66 struct rtc_device *ret;
67
68 spin_lock_irqsave(&rtcdev_lock, flags);
69 ret = rtcdev;
70 spin_unlock_irqrestore(&rtcdev_lock, flags);
71
72 return ret;
73}
74
75
76static int alarmtimer_rtc_add_device(struct device *dev,
77 struct class_interface *class_intf)
78{
79 unsigned long flags;
80 struct rtc_device *rtc = to_rtc_device(dev);
81
82 if (rtcdev)
83 return -EBUSY;
84
85 if (!rtc->ops->set_alarm)
86 return -1;
87 if (!device_may_wakeup(rtc->dev.parent))
88 return -1;
89
90 spin_lock_irqsave(&rtcdev_lock, flags);
91 if (!rtcdev) {
92 rtcdev = rtc;
93 /* hold a reference so it doesn't go away */
94 get_device(dev);
95 }
96 spin_unlock_irqrestore(&rtcdev_lock, flags);
97 return 0;
98}
99
100static inline void alarmtimer_rtc_timer_init(void)
101{
102 rtc_timer_init(&rtctimer, NULL, NULL);
103}
104
105static struct class_interface alarmtimer_rtc_interface = {
106 .add_dev = &alarmtimer_rtc_add_device,
107};
108
109static int alarmtimer_rtc_interface_setup(void)
110{
111 alarmtimer_rtc_interface.class = rtc_class;
112 return class_interface_register(&alarmtimer_rtc_interface);
113}
114static void alarmtimer_rtc_interface_remove(void)
115{
116 class_interface_unregister(&alarmtimer_rtc_interface);
117}
118#else
119struct rtc_device *alarmtimer_get_rtcdev(void)
120{
121 return NULL;
122}
123#define rtcdev (NULL)
124static inline int alarmtimer_rtc_interface_setup(void) { return 0; }
125static inline void alarmtimer_rtc_interface_remove(void) { }
126static inline void alarmtimer_rtc_timer_init(void) { }
127#endif
128
129/**
130 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
131 * @base: pointer to the base where the timer is being run
132 * @alarm: pointer to alarm being enqueued.
133 *
134 * Adds alarm to a alarm_base timerqueue
135 *
136 * Must hold base->lock when calling.
137 */
138static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
139{
140 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
141 timerqueue_del(&base->timerqueue, &alarm->node);
142
143 timerqueue_add(&base->timerqueue, &alarm->node);
144 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
145}
146
147/**
148 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
149 * @base: pointer to the base where the timer is running
150 * @alarm: pointer to alarm being removed
151 *
152 * Removes alarm to a alarm_base timerqueue
153 *
154 * Must hold base->lock when calling.
155 */
156static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
157{
158 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
159 return;
160
161 timerqueue_del(&base->timerqueue, &alarm->node);
162 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
163}
164
165
166/**
167 * alarmtimer_fired - Handles alarm hrtimer being fired.
168 * @timer: pointer to hrtimer being run
169 *
170 * When a alarm timer fires, this runs through the timerqueue to
171 * see which alarms expired, and runs those. If there are more alarm
172 * timers queued for the future, we set the hrtimer to fire when
173 * when the next future alarm timer expires.
174 */
175static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
176{
177 struct alarm *alarm = container_of(timer, struct alarm, timer);
178 struct alarm_base *base = &alarm_bases[alarm->type];
179 unsigned long flags;
180 int ret = HRTIMER_NORESTART;
181 int restart = ALARMTIMER_NORESTART;
182
183 spin_lock_irqsave(&base->lock, flags);
184 alarmtimer_dequeue(base, alarm);
185 spin_unlock_irqrestore(&base->lock, flags);
186
187 if (alarm->function)
188 restart = alarm->function(alarm, base->gettime());
189
190 spin_lock_irqsave(&base->lock, flags);
191 if (restart != ALARMTIMER_NORESTART) {
192 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
193 alarmtimer_enqueue(base, alarm);
194 ret = HRTIMER_RESTART;
195 }
196 spin_unlock_irqrestore(&base->lock, flags);
197
198 return ret;
199
200}
201
202ktime_t alarm_expires_remaining(const struct alarm *alarm)
203{
204 struct alarm_base *base = &alarm_bases[alarm->type];
205 return ktime_sub(alarm->node.expires, base->gettime());
206}
207EXPORT_SYMBOL_GPL(alarm_expires_remaining);
208
209#ifdef CONFIG_RTC_CLASS
210/**
211 * alarmtimer_suspend - Suspend time callback
212 * @dev: unused
213 * @state: unused
214 *
215 * When we are going into suspend, we look through the bases
216 * to see which is the soonest timer to expire. We then
217 * set an rtc timer to fire that far into the future, which
218 * will wake us from suspend.
219 */
220static int alarmtimer_suspend(struct device *dev)
221{
222 struct rtc_time tm;
223 ktime_t min, now;
224 unsigned long flags;
225 struct rtc_device *rtc;
226 int i;
227 int ret;
228
229 spin_lock_irqsave(&freezer_delta_lock, flags);
230 min = freezer_delta;
231 freezer_delta = ktime_set(0, 0);
232 spin_unlock_irqrestore(&freezer_delta_lock, flags);
233
234 rtc = alarmtimer_get_rtcdev();
235 /* If we have no rtcdev, just return */
236 if (!rtc)
237 return 0;
238
239 /* Find the soonest timer to expire*/
240 for (i = 0; i < ALARM_NUMTYPE; i++) {
241 struct alarm_base *base = &alarm_bases[i];
242 struct timerqueue_node *next;
243 ktime_t delta;
244
245 spin_lock_irqsave(&base->lock, flags);
246 next = timerqueue_getnext(&base->timerqueue);
247 spin_unlock_irqrestore(&base->lock, flags);
248 if (!next)
249 continue;
250 delta = ktime_sub(next->expires, base->gettime());
251 if (!min.tv64 || (delta.tv64 < min.tv64))
252 min = delta;
253 }
254 if (min.tv64 == 0)
255 return 0;
256
257 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
258 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
259 return -EBUSY;
260 }
261
262 /* Setup an rtc timer to fire that far in the future */
263 rtc_timer_cancel(rtc, &rtctimer);
264 rtc_read_time(rtc, &tm);
265 now = rtc_tm_to_ktime(tm);
266 now = ktime_add(now, min);
267
268 /* Set alarm, if in the past reject suspend briefly to handle */
269 ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
270 if (ret < 0)
271 __pm_wakeup_event(ws, MSEC_PER_SEC);
272 return ret;
273}
274#else
275static int alarmtimer_suspend(struct device *dev)
276{
277 return 0;
278}
279#endif
280
281static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
282{
283 ktime_t delta;
284 unsigned long flags;
285 struct alarm_base *base = &alarm_bases[type];
286
287 delta = ktime_sub(absexp, base->gettime());
288
289 spin_lock_irqsave(&freezer_delta_lock, flags);
290 if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
291 freezer_delta = delta;
292 spin_unlock_irqrestore(&freezer_delta_lock, flags);
293}
294
295
296/**
297 * alarm_init - Initialize an alarm structure
298 * @alarm: ptr to alarm to be initialized
299 * @type: the type of the alarm
300 * @function: callback that is run when the alarm fires
301 */
302void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
303 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
304{
305 timerqueue_init(&alarm->node);
306 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
307 HRTIMER_MODE_ABS);
308 alarm->timer.function = alarmtimer_fired;
309 alarm->function = function;
310 alarm->type = type;
311 alarm->state = ALARMTIMER_STATE_INACTIVE;
312}
313EXPORT_SYMBOL_GPL(alarm_init);
314
315/**
316 * alarm_start - Sets an absolute alarm to fire
317 * @alarm: ptr to alarm to set
318 * @start: time to run the alarm
319 */
320int alarm_start(struct alarm *alarm, ktime_t start)
321{
322 struct alarm_base *base = &alarm_bases[alarm->type];
323 unsigned long flags;
324 int ret;
325
326 spin_lock_irqsave(&base->lock, flags);
327 alarm->node.expires = start;
328 alarmtimer_enqueue(base, alarm);
329 ret = hrtimer_start(&alarm->timer, alarm->node.expires,
330 HRTIMER_MODE_ABS);
331 spin_unlock_irqrestore(&base->lock, flags);
332 return ret;
333}
334EXPORT_SYMBOL_GPL(alarm_start);
335
336/**
337 * alarm_start_relative - Sets a relative alarm to fire
338 * @alarm: ptr to alarm to set
339 * @start: time relative to now to run the alarm
340 */
341int alarm_start_relative(struct alarm *alarm, ktime_t start)
342{
343 struct alarm_base *base = &alarm_bases[alarm->type];
344
345 start = ktime_add(start, base->gettime());
346 return alarm_start(alarm, start);
347}
348EXPORT_SYMBOL_GPL(alarm_start_relative);
349
350void alarm_restart(struct alarm *alarm)
351{
352 struct alarm_base *base = &alarm_bases[alarm->type];
353 unsigned long flags;
354
355 spin_lock_irqsave(&base->lock, flags);
356 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
357 hrtimer_restart(&alarm->timer);
358 alarmtimer_enqueue(base, alarm);
359 spin_unlock_irqrestore(&base->lock, flags);
360}
361EXPORT_SYMBOL_GPL(alarm_restart);
362
363/**
364 * alarm_try_to_cancel - Tries to cancel an alarm timer
365 * @alarm: ptr to alarm to be canceled
366 *
367 * Returns 1 if the timer was canceled, 0 if it was not running,
368 * and -1 if the callback was running
369 */
370int alarm_try_to_cancel(struct alarm *alarm)
371{
372 struct alarm_base *base = &alarm_bases[alarm->type];
373 unsigned long flags;
374 int ret;
375
376 spin_lock_irqsave(&base->lock, flags);
377 ret = hrtimer_try_to_cancel(&alarm->timer);
378 if (ret >= 0)
379 alarmtimer_dequeue(base, alarm);
380 spin_unlock_irqrestore(&base->lock, flags);
381 return ret;
382}
383EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
384
385
386/**
387 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
388 * @alarm: ptr to alarm to be canceled
389 *
390 * Returns 1 if the timer was canceled, 0 if it was not active.
391 */
392int alarm_cancel(struct alarm *alarm)
393{
394 for (;;) {
395 int ret = alarm_try_to_cancel(alarm);
396 if (ret >= 0)
397 return ret;
398 cpu_relax();
399 }
400}
401EXPORT_SYMBOL_GPL(alarm_cancel);
402
403
404u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
405{
406 u64 overrun = 1;
407 ktime_t delta;
408
409 delta = ktime_sub(now, alarm->node.expires);
410
411 if (delta.tv64 < 0)
412 return 0;
413
414 if (unlikely(delta.tv64 >= interval.tv64)) {
415 s64 incr = ktime_to_ns(interval);
416
417 overrun = ktime_divns(delta, incr);
418
419 alarm->node.expires = ktime_add_ns(alarm->node.expires,
420 incr*overrun);
421
422 if (alarm->node.expires.tv64 > now.tv64)
423 return overrun;
424 /*
425 * This (and the ktime_add() below) is the
426 * correction for exact:
427 */
428 overrun++;
429 }
430
431 alarm->node.expires = ktime_add(alarm->node.expires, interval);
432 return overrun;
433}
434EXPORT_SYMBOL_GPL(alarm_forward);
435
436u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
437{
438 struct alarm_base *base = &alarm_bases[alarm->type];
439
440 return alarm_forward(alarm, base->gettime(), interval);
441}
442EXPORT_SYMBOL_GPL(alarm_forward_now);
443
444
445/**
446 * clock2alarm - helper that converts from clockid to alarmtypes
447 * @clockid: clockid.
448 */
449static enum alarmtimer_type clock2alarm(clockid_t clockid)
450{
451 if (clockid == CLOCK_REALTIME_ALARM)
452 return ALARM_REALTIME;
453 if (clockid == CLOCK_BOOTTIME_ALARM)
454 return ALARM_BOOTTIME;
455 return -1;
456}
457
458/**
459 * alarm_handle_timer - Callback for posix timers
460 * @alarm: alarm that fired
461 *
462 * Posix timer callback for expired alarm timers.
463 */
464static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
465 ktime_t now)
466{
467 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
468 it.alarm.alarmtimer);
469 if (posix_timer_event(ptr, 0) != 0)
470 ptr->it_overrun++;
471
472 /* Re-add periodic timers */
473 if (ptr->it.alarm.interval.tv64) {
474 ptr->it_overrun += alarm_forward(alarm, now,
475 ptr->it.alarm.interval);
476 return ALARMTIMER_RESTART;
477 }
478 return ALARMTIMER_NORESTART;
479}
480
481/**
482 * alarm_clock_getres - posix getres interface
483 * @which_clock: clockid
484 * @tp: timespec to fill
485 *
486 * Returns the granularity of underlying alarm base clock
487 */
488static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
489{
490 clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
491
492 if (!alarmtimer_get_rtcdev())
493 return -EINVAL;
494
495 return hrtimer_get_res(baseid, tp);
496}
497
498/**
499 * alarm_clock_get - posix clock_get interface
500 * @which_clock: clockid
501 * @tp: timespec to fill.
502 *
503 * Provides the underlying alarm base time.
504 */
505static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
506{
507 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
508
509 if (!alarmtimer_get_rtcdev())
510 return -EINVAL;
511
512 *tp = ktime_to_timespec(base->gettime());
513 return 0;
514}
515
516/**
517 * alarm_timer_create - posix timer_create interface
518 * @new_timer: k_itimer pointer to manage
519 *
520 * Initializes the k_itimer structure.
521 */
522static int alarm_timer_create(struct k_itimer *new_timer)
523{
524 enum alarmtimer_type type;
525 struct alarm_base *base;
526
527 if (!alarmtimer_get_rtcdev())
528 return -ENOTSUPP;
529
530 if (!capable(CAP_WAKE_ALARM))
531 return -EPERM;
532
533 type = clock2alarm(new_timer->it_clock);
534 base = &alarm_bases[type];
535 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
536 return 0;
537}
538
539/**
540 * alarm_timer_get - posix timer_get interface
541 * @new_timer: k_itimer pointer
542 * @cur_setting: itimerspec data to fill
543 *
544 * Copies the itimerspec data out from the k_itimer
545 */
546static void alarm_timer_get(struct k_itimer *timr,
547 struct itimerspec *cur_setting)
548{
549 memset(cur_setting, 0, sizeof(struct itimerspec));
550
551 cur_setting->it_interval =
552 ktime_to_timespec(timr->it.alarm.interval);
553 cur_setting->it_value =
554 ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires);
555 return;
556}
557
558/**
559 * alarm_timer_del - posix timer_del interface
560 * @timr: k_itimer pointer to be deleted
561 *
562 * Cancels any programmed alarms for the given timer.
563 */
564static int alarm_timer_del(struct k_itimer *timr)
565{
566 if (!rtcdev)
567 return -ENOTSUPP;
568
569 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
570 return TIMER_RETRY;
571
572 return 0;
573}
574
575/**
576 * alarm_timer_set - posix timer_set interface
577 * @timr: k_itimer pointer to be deleted
578 * @flags: timer flags
579 * @new_setting: itimerspec to be used
580 * @old_setting: itimerspec being replaced
581 *
582 * Sets the timer to new_setting, and starts the timer.
583 */
584static int alarm_timer_set(struct k_itimer *timr, int flags,
585 struct itimerspec *new_setting,
586 struct itimerspec *old_setting)
587{
588 if (!rtcdev)
589 return -ENOTSUPP;
590
591 if (old_setting)
592 alarm_timer_get(timr, old_setting);
593
594 /* If the timer was already set, cancel it */
595 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
596 return TIMER_RETRY;
597
598 /* start the timer */
599 timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval);
600 alarm_start(&timr->it.alarm.alarmtimer,
601 timespec_to_ktime(new_setting->it_value));
602 return 0;
603}
604
605/**
606 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
607 * @alarm: ptr to alarm that fired
608 *
609 * Wakes up the task that set the alarmtimer
610 */
611static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
612 ktime_t now)
613{
614 struct task_struct *task = (struct task_struct *)alarm->data;
615
616 alarm->data = NULL;
617 if (task)
618 wake_up_process(task);
619 return ALARMTIMER_NORESTART;
620}
621
622/**
623 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
624 * @alarm: ptr to alarmtimer
625 * @absexp: absolute expiration time
626 *
627 * Sets the alarm timer and sleeps until it is fired or interrupted.
628 */
629static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp)
630{
631 alarm->data = (void *)current;
632 do {
633 set_current_state(TASK_INTERRUPTIBLE);
634 alarm_start(alarm, absexp);
635 if (likely(alarm->data))
636 schedule();
637
638 alarm_cancel(alarm);
639 } while (alarm->data && !signal_pending(current));
640
641 __set_current_state(TASK_RUNNING);
642
643 return (alarm->data == NULL);
644}
645
646
647/**
648 * update_rmtp - Update remaining timespec value
649 * @exp: expiration time
650 * @type: timer type
651 * @rmtp: user pointer to remaining timepsec value
652 *
653 * Helper function that fills in rmtp value with time between
654 * now and the exp value
655 */
656static int update_rmtp(ktime_t exp, enum alarmtimer_type type,
657 struct timespec __user *rmtp)
658{
659 struct timespec rmt;
660 ktime_t rem;
661
662 rem = ktime_sub(exp, alarm_bases[type].gettime());
663
664 if (rem.tv64 <= 0)
665 return 0;
666 rmt = ktime_to_timespec(rem);
667
668 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
669 return -EFAULT;
670
671 return 1;
672
673}
674
675/**
676 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
677 * @restart: ptr to restart block
678 *
679 * Handles restarted clock_nanosleep calls
680 */
681static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
682{
683 enum alarmtimer_type type = restart->nanosleep.clockid;
684 ktime_t exp;
685 struct timespec __user *rmtp;
686 struct alarm alarm;
687 int ret = 0;
688
689 exp.tv64 = restart->nanosleep.expires;
690 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
691
692 if (alarmtimer_do_nsleep(&alarm, exp))
693 goto out;
694
695 if (freezing(current))
696 alarmtimer_freezerset(exp, type);
697
698 rmtp = restart->nanosleep.rmtp;
699 if (rmtp) {
700 ret = update_rmtp(exp, type, rmtp);
701 if (ret <= 0)
702 goto out;
703 }
704
705
706 /* The other values in restart are already filled in */
707 ret = -ERESTART_RESTARTBLOCK;
708out:
709 return ret;
710}
711
712/**
713 * alarm_timer_nsleep - alarmtimer nanosleep
714 * @which_clock: clockid
715 * @flags: determins abstime or relative
716 * @tsreq: requested sleep time (abs or rel)
717 * @rmtp: remaining sleep time saved
718 *
719 * Handles clock_nanosleep calls against _ALARM clockids
720 */
721static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
722 struct timespec *tsreq, struct timespec __user *rmtp)
723{
724 enum alarmtimer_type type = clock2alarm(which_clock);
725 struct alarm alarm;
726 ktime_t exp;
727 int ret = 0;
728 struct restart_block *restart;
729
730 if (!alarmtimer_get_rtcdev())
731 return -ENOTSUPP;
732
733 if (!capable(CAP_WAKE_ALARM))
734 return -EPERM;
735
736 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
737
738 exp = timespec_to_ktime(*tsreq);
739 /* Convert (if necessary) to absolute time */
740 if (flags != TIMER_ABSTIME) {
741 ktime_t now = alarm_bases[type].gettime();
742 exp = ktime_add(now, exp);
743 }
744
745 if (alarmtimer_do_nsleep(&alarm, exp))
746 goto out;
747
748 if (freezing(current))
749 alarmtimer_freezerset(exp, type);
750
751 /* abs timers don't set remaining time or restart */
752 if (flags == TIMER_ABSTIME) {
753 ret = -ERESTARTNOHAND;
754 goto out;
755 }
756
757 if (rmtp) {
758 ret = update_rmtp(exp, type, rmtp);
759 if (ret <= 0)
760 goto out;
761 }
762
763 restart = ¤t_thread_info()->restart_block;
764 restart->fn = alarm_timer_nsleep_restart;
765 restart->nanosleep.clockid = type;
766 restart->nanosleep.expires = exp.tv64;
767 restart->nanosleep.rmtp = rmtp;
768 ret = -ERESTART_RESTARTBLOCK;
769
770out:
771 return ret;
772}
773
774
775/* Suspend hook structures */
776static const struct dev_pm_ops alarmtimer_pm_ops = {
777 .suspend = alarmtimer_suspend,
778};
779
780static struct platform_driver alarmtimer_driver = {
781 .driver = {
782 .name = "alarmtimer",
783 .pm = &alarmtimer_pm_ops,
784 }
785};
786
787/**
788 * alarmtimer_init - Initialize alarm timer code
789 *
790 * This function initializes the alarm bases and registers
791 * the posix clock ids.
792 */
793static int __init alarmtimer_init(void)
794{
795 struct platform_device *pdev;
796 int error = 0;
797 int i;
798 struct k_clock alarm_clock = {
799 .clock_getres = alarm_clock_getres,
800 .clock_get = alarm_clock_get,
801 .timer_create = alarm_timer_create,
802 .timer_set = alarm_timer_set,
803 .timer_del = alarm_timer_del,
804 .timer_get = alarm_timer_get,
805 .nsleep = alarm_timer_nsleep,
806 };
807
808 alarmtimer_rtc_timer_init();
809
810 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
811 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
812
813 /* Initialize alarm bases */
814 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
815 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
816 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
817 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
818 for (i = 0; i < ALARM_NUMTYPE; i++) {
819 timerqueue_init_head(&alarm_bases[i].timerqueue);
820 spin_lock_init(&alarm_bases[i].lock);
821 }
822
823 error = alarmtimer_rtc_interface_setup();
824 if (error)
825 return error;
826
827 error = platform_driver_register(&alarmtimer_driver);
828 if (error)
829 goto out_if;
830
831 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
832 if (IS_ERR(pdev)) {
833 error = PTR_ERR(pdev);
834 goto out_drv;
835 }
836 ws = wakeup_source_register("alarmtimer");
837 return 0;
838
839out_drv:
840 platform_driver_unregister(&alarmtimer_driver);
841out_if:
842 alarmtimer_rtc_interface_remove();
843 return error;
844}
845device_initcall(alarmtimer_init);
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 <john.stultz@linaro.org>
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 * @timer: hrtimer used to schedule events while running
34 * @gettime: Function to read the time correlating to the base
35 * @base_clockid: clockid for the base
36 */
37static struct alarm_base {
38 spinlock_t lock;
39 struct timerqueue_head timerqueue;
40 struct hrtimer timer;
41 ktime_t (*gettime)(void);
42 clockid_t base_clockid;
43} alarm_bases[ALARM_NUMTYPE];
44
45/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
46static ktime_t freezer_delta;
47static DEFINE_SPINLOCK(freezer_delta_lock);
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 * has_wakealarm - check rtc device has wakealarm ability
57 * @dev: current device
58 * @name_ptr: name to be returned
59 *
60 * This helper function checks to see if the rtc device can wake
61 * from suspend.
62 */
63static int has_wakealarm(struct device *dev, void *name_ptr)
64{
65 struct rtc_device *candidate = to_rtc_device(dev);
66
67 if (!candidate->ops->set_alarm)
68 return 0;
69 if (!device_may_wakeup(candidate->dev.parent))
70 return 0;
71
72 *(const char **)name_ptr = dev_name(dev);
73 return 1;
74}
75
76/**
77 * alarmtimer_get_rtcdev - Return selected rtcdevice
78 *
79 * This function returns the rtc device to use for wakealarms.
80 * If one has not already been chosen, it checks to see if a
81 * functional rtc device is available.
82 */
83static struct rtc_device *alarmtimer_get_rtcdev(void)
84{
85 struct device *dev;
86 char *str;
87 unsigned long flags;
88 struct rtc_device *ret;
89
90 spin_lock_irqsave(&rtcdev_lock, flags);
91 if (!rtcdev) {
92 /* Find an rtc device and init the rtc_timer */
93 dev = class_find_device(rtc_class, NULL, &str, has_wakealarm);
94 /* If we have a device then str is valid. See has_wakealarm() */
95 if (dev) {
96 rtcdev = rtc_class_open(str);
97 /*
98 * Drop the reference we got in class_find_device,
99 * rtc_open takes its own.
100 */
101 put_device(dev);
102 rtc_timer_init(&rtctimer, NULL, NULL);
103 }
104 }
105 ret = rtcdev;
106 spin_unlock_irqrestore(&rtcdev_lock, flags);
107
108 return ret;
109}
110#else
111#define alarmtimer_get_rtcdev() (0)
112#define rtcdev (0)
113#endif
114
115
116/**
117 * alarmtimer_enqueue - Adds an alarm timer to an alarm_base timerqueue
118 * @base: pointer to the base where the timer is being run
119 * @alarm: pointer to alarm being enqueued.
120 *
121 * Adds alarm to a alarm_base timerqueue and if necessary sets
122 * an hrtimer to run.
123 *
124 * Must hold base->lock when calling.
125 */
126static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
127{
128 timerqueue_add(&base->timerqueue, &alarm->node);
129 if (&alarm->node == timerqueue_getnext(&base->timerqueue)) {
130 hrtimer_try_to_cancel(&base->timer);
131 hrtimer_start(&base->timer, alarm->node.expires,
132 HRTIMER_MODE_ABS);
133 }
134}
135
136/**
137 * alarmtimer_remove - Removes an alarm timer from an alarm_base timerqueue
138 * @base: pointer to the base where the timer is running
139 * @alarm: pointer to alarm being removed
140 *
141 * Removes alarm to a alarm_base timerqueue and if necessary sets
142 * a new timer to run.
143 *
144 * Must hold base->lock when calling.
145 */
146static void alarmtimer_remove(struct alarm_base *base, struct alarm *alarm)
147{
148 struct timerqueue_node *next = timerqueue_getnext(&base->timerqueue);
149
150 timerqueue_del(&base->timerqueue, &alarm->node);
151 if (next == &alarm->node) {
152 hrtimer_try_to_cancel(&base->timer);
153 next = timerqueue_getnext(&base->timerqueue);
154 if (!next)
155 return;
156 hrtimer_start(&base->timer, next->expires, HRTIMER_MODE_ABS);
157 }
158}
159
160
161/**
162 * alarmtimer_fired - Handles alarm hrtimer being fired.
163 * @timer: pointer to hrtimer being run
164 *
165 * When a alarm timer fires, this runs through the timerqueue to
166 * see which alarms expired, and runs those. If there are more alarm
167 * timers queued for the future, we set the hrtimer to fire when
168 * when the next future alarm timer expires.
169 */
170static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
171{
172 struct alarm_base *base = container_of(timer, struct alarm_base, timer);
173 struct timerqueue_node *next;
174 unsigned long flags;
175 ktime_t now;
176 int ret = HRTIMER_NORESTART;
177
178 spin_lock_irqsave(&base->lock, flags);
179 now = base->gettime();
180 while ((next = timerqueue_getnext(&base->timerqueue))) {
181 struct alarm *alarm;
182 ktime_t expired = next->expires;
183
184 if (expired.tv64 >= now.tv64)
185 break;
186
187 alarm = container_of(next, struct alarm, node);
188
189 timerqueue_del(&base->timerqueue, &alarm->node);
190 alarm->enabled = 0;
191 /* Re-add periodic timers */
192 if (alarm->period.tv64) {
193 alarm->node.expires = ktime_add(expired, alarm->period);
194 timerqueue_add(&base->timerqueue, &alarm->node);
195 alarm->enabled = 1;
196 }
197 spin_unlock_irqrestore(&base->lock, flags);
198 if (alarm->function)
199 alarm->function(alarm);
200 spin_lock_irqsave(&base->lock, flags);
201 }
202
203 if (next) {
204 hrtimer_set_expires(&base->timer, next->expires);
205 ret = HRTIMER_RESTART;
206 }
207 spin_unlock_irqrestore(&base->lock, flags);
208
209 return ret;
210
211}
212
213#ifdef CONFIG_RTC_CLASS
214/**
215 * alarmtimer_suspend - Suspend time callback
216 * @dev: unused
217 * @state: unused
218 *
219 * When we are going into suspend, we look through the bases
220 * to see which is the soonest timer to expire. We then
221 * set an rtc timer to fire that far into the future, which
222 * will wake us from suspend.
223 */
224static int alarmtimer_suspend(struct device *dev)
225{
226 struct rtc_time tm;
227 ktime_t min, now;
228 unsigned long flags;
229 struct rtc_device *rtc;
230 int i;
231
232 spin_lock_irqsave(&freezer_delta_lock, flags);
233 min = freezer_delta;
234 freezer_delta = ktime_set(0, 0);
235 spin_unlock_irqrestore(&freezer_delta_lock, flags);
236
237 rtc = rtcdev;
238 /* If we have no rtcdev, just return */
239 if (!rtc)
240 return 0;
241
242 /* Find the soonest timer to expire*/
243 for (i = 0; i < ALARM_NUMTYPE; i++) {
244 struct alarm_base *base = &alarm_bases[i];
245 struct timerqueue_node *next;
246 ktime_t delta;
247
248 spin_lock_irqsave(&base->lock, flags);
249 next = timerqueue_getnext(&base->timerqueue);
250 spin_unlock_irqrestore(&base->lock, flags);
251 if (!next)
252 continue;
253 delta = ktime_sub(next->expires, base->gettime());
254 if (!min.tv64 || (delta.tv64 < min.tv64))
255 min = delta;
256 }
257 if (min.tv64 == 0)
258 return 0;
259
260 /* XXX - Should we enforce a minimum sleep time? */
261 WARN_ON(min.tv64 < NSEC_PER_SEC);
262
263 /* Setup an rtc timer to fire that far in the future */
264 rtc_timer_cancel(rtc, &rtctimer);
265 rtc_read_time(rtc, &tm);
266 now = rtc_tm_to_ktime(tm);
267 now = ktime_add(now, min);
268
269 rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
270
271 return 0;
272}
273#else
274static int alarmtimer_suspend(struct device *dev)
275{
276 return 0;
277}
278#endif
279
280static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
281{
282 ktime_t delta;
283 unsigned long flags;
284 struct alarm_base *base = &alarm_bases[type];
285
286 delta = ktime_sub(absexp, base->gettime());
287
288 spin_lock_irqsave(&freezer_delta_lock, flags);
289 if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
290 freezer_delta = delta;
291 spin_unlock_irqrestore(&freezer_delta_lock, flags);
292}
293
294
295/**
296 * alarm_init - Initialize an alarm structure
297 * @alarm: ptr to alarm to be initialized
298 * @type: the type of the alarm
299 * @function: callback that is run when the alarm fires
300 */
301void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
302 void (*function)(struct alarm *))
303{
304 timerqueue_init(&alarm->node);
305 alarm->period = ktime_set(0, 0);
306 alarm->function = function;
307 alarm->type = type;
308 alarm->enabled = 0;
309}
310
311/**
312 * alarm_start - Sets an alarm to fire
313 * @alarm: ptr to alarm to set
314 * @start: time to run the alarm
315 * @period: period at which the alarm will recur
316 */
317void alarm_start(struct alarm *alarm, ktime_t start, ktime_t period)
318{
319 struct alarm_base *base = &alarm_bases[alarm->type];
320 unsigned long flags;
321
322 spin_lock_irqsave(&base->lock, flags);
323 if (alarm->enabled)
324 alarmtimer_remove(base, alarm);
325 alarm->node.expires = start;
326 alarm->period = period;
327 alarmtimer_enqueue(base, alarm);
328 alarm->enabled = 1;
329 spin_unlock_irqrestore(&base->lock, flags);
330}
331
332/**
333 * alarm_cancel - Tries to cancel an alarm timer
334 * @alarm: ptr to alarm to be canceled
335 */
336void alarm_cancel(struct alarm *alarm)
337{
338 struct alarm_base *base = &alarm_bases[alarm->type];
339 unsigned long flags;
340
341 spin_lock_irqsave(&base->lock, flags);
342 if (alarm->enabled)
343 alarmtimer_remove(base, alarm);
344 alarm->enabled = 0;
345 spin_unlock_irqrestore(&base->lock, flags);
346}
347
348
349/**
350 * clock2alarm - helper that converts from clockid to alarmtypes
351 * @clockid: clockid.
352 */
353static enum alarmtimer_type clock2alarm(clockid_t clockid)
354{
355 if (clockid == CLOCK_REALTIME_ALARM)
356 return ALARM_REALTIME;
357 if (clockid == CLOCK_BOOTTIME_ALARM)
358 return ALARM_BOOTTIME;
359 return -1;
360}
361
362/**
363 * alarm_handle_timer - Callback for posix timers
364 * @alarm: alarm that fired
365 *
366 * Posix timer callback for expired alarm timers.
367 */
368static void alarm_handle_timer(struct alarm *alarm)
369{
370 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
371 it.alarmtimer);
372 if (posix_timer_event(ptr, 0) != 0)
373 ptr->it_overrun++;
374}
375
376/**
377 * alarm_clock_getres - posix getres interface
378 * @which_clock: clockid
379 * @tp: timespec to fill
380 *
381 * Returns the granularity of underlying alarm base clock
382 */
383static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
384{
385 clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
386
387 if (!alarmtimer_get_rtcdev())
388 return -ENOTSUPP;
389
390 return hrtimer_get_res(baseid, tp);
391}
392
393/**
394 * alarm_clock_get - posix clock_get interface
395 * @which_clock: clockid
396 * @tp: timespec to fill.
397 *
398 * Provides the underlying alarm base time.
399 */
400static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
401{
402 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
403
404 if (!alarmtimer_get_rtcdev())
405 return -ENOTSUPP;
406
407 *tp = ktime_to_timespec(base->gettime());
408 return 0;
409}
410
411/**
412 * alarm_timer_create - posix timer_create interface
413 * @new_timer: k_itimer pointer to manage
414 *
415 * Initializes the k_itimer structure.
416 */
417static int alarm_timer_create(struct k_itimer *new_timer)
418{
419 enum alarmtimer_type type;
420 struct alarm_base *base;
421
422 if (!alarmtimer_get_rtcdev())
423 return -ENOTSUPP;
424
425 if (!capable(CAP_WAKE_ALARM))
426 return -EPERM;
427
428 type = clock2alarm(new_timer->it_clock);
429 base = &alarm_bases[type];
430 alarm_init(&new_timer->it.alarmtimer, type, alarm_handle_timer);
431 return 0;
432}
433
434/**
435 * alarm_timer_get - posix timer_get interface
436 * @new_timer: k_itimer pointer
437 * @cur_setting: itimerspec data to fill
438 *
439 * Copies the itimerspec data out from the k_itimer
440 */
441static void alarm_timer_get(struct k_itimer *timr,
442 struct itimerspec *cur_setting)
443{
444 memset(cur_setting, 0, sizeof(struct itimerspec));
445
446 cur_setting->it_interval =
447 ktime_to_timespec(timr->it.alarmtimer.period);
448 cur_setting->it_value =
449 ktime_to_timespec(timr->it.alarmtimer.node.expires);
450 return;
451}
452
453/**
454 * alarm_timer_del - posix timer_del interface
455 * @timr: k_itimer pointer to be deleted
456 *
457 * Cancels any programmed alarms for the given timer.
458 */
459static int alarm_timer_del(struct k_itimer *timr)
460{
461 if (!rtcdev)
462 return -ENOTSUPP;
463
464 alarm_cancel(&timr->it.alarmtimer);
465 return 0;
466}
467
468/**
469 * alarm_timer_set - posix timer_set interface
470 * @timr: k_itimer pointer to be deleted
471 * @flags: timer flags
472 * @new_setting: itimerspec to be used
473 * @old_setting: itimerspec being replaced
474 *
475 * Sets the timer to new_setting, and starts the timer.
476 */
477static int alarm_timer_set(struct k_itimer *timr, int flags,
478 struct itimerspec *new_setting,
479 struct itimerspec *old_setting)
480{
481 if (!rtcdev)
482 return -ENOTSUPP;
483
484 /*
485 * XXX HACK! Currently we can DOS a system if the interval
486 * period on alarmtimers is too small. Cap the interval here
487 * to 100us and solve this properly in a future patch! -jstultz
488 */
489 if ((new_setting->it_interval.tv_sec == 0) &&
490 (new_setting->it_interval.tv_nsec < 100000))
491 new_setting->it_interval.tv_nsec = 100000;
492
493 if (old_setting)
494 alarm_timer_get(timr, old_setting);
495
496 /* If the timer was already set, cancel it */
497 alarm_cancel(&timr->it.alarmtimer);
498
499 /* start the timer */
500 alarm_start(&timr->it.alarmtimer,
501 timespec_to_ktime(new_setting->it_value),
502 timespec_to_ktime(new_setting->it_interval));
503 return 0;
504}
505
506/**
507 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
508 * @alarm: ptr to alarm that fired
509 *
510 * Wakes up the task that set the alarmtimer
511 */
512static void alarmtimer_nsleep_wakeup(struct alarm *alarm)
513{
514 struct task_struct *task = (struct task_struct *)alarm->data;
515
516 alarm->data = NULL;
517 if (task)
518 wake_up_process(task);
519}
520
521/**
522 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
523 * @alarm: ptr to alarmtimer
524 * @absexp: absolute expiration time
525 *
526 * Sets the alarm timer and sleeps until it is fired or interrupted.
527 */
528static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp)
529{
530 alarm->data = (void *)current;
531 do {
532 set_current_state(TASK_INTERRUPTIBLE);
533 alarm_start(alarm, absexp, ktime_set(0, 0));
534 if (likely(alarm->data))
535 schedule();
536
537 alarm_cancel(alarm);
538 } while (alarm->data && !signal_pending(current));
539
540 __set_current_state(TASK_RUNNING);
541
542 return (alarm->data == NULL);
543}
544
545
546/**
547 * update_rmtp - Update remaining timespec value
548 * @exp: expiration time
549 * @type: timer type
550 * @rmtp: user pointer to remaining timepsec value
551 *
552 * Helper function that fills in rmtp value with time between
553 * now and the exp value
554 */
555static int update_rmtp(ktime_t exp, enum alarmtimer_type type,
556 struct timespec __user *rmtp)
557{
558 struct timespec rmt;
559 ktime_t rem;
560
561 rem = ktime_sub(exp, alarm_bases[type].gettime());
562
563 if (rem.tv64 <= 0)
564 return 0;
565 rmt = ktime_to_timespec(rem);
566
567 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
568 return -EFAULT;
569
570 return 1;
571
572}
573
574/**
575 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
576 * @restart: ptr to restart block
577 *
578 * Handles restarted clock_nanosleep calls
579 */
580static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
581{
582 enum alarmtimer_type type = restart->nanosleep.clockid;
583 ktime_t exp;
584 struct timespec __user *rmtp;
585 struct alarm alarm;
586 int ret = 0;
587
588 exp.tv64 = restart->nanosleep.expires;
589 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
590
591 if (alarmtimer_do_nsleep(&alarm, exp))
592 goto out;
593
594 if (freezing(current))
595 alarmtimer_freezerset(exp, type);
596
597 rmtp = restart->nanosleep.rmtp;
598 if (rmtp) {
599 ret = update_rmtp(exp, type, rmtp);
600 if (ret <= 0)
601 goto out;
602 }
603
604
605 /* The other values in restart are already filled in */
606 ret = -ERESTART_RESTARTBLOCK;
607out:
608 return ret;
609}
610
611/**
612 * alarm_timer_nsleep - alarmtimer nanosleep
613 * @which_clock: clockid
614 * @flags: determins abstime or relative
615 * @tsreq: requested sleep time (abs or rel)
616 * @rmtp: remaining sleep time saved
617 *
618 * Handles clock_nanosleep calls against _ALARM clockids
619 */
620static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
621 struct timespec *tsreq, struct timespec __user *rmtp)
622{
623 enum alarmtimer_type type = clock2alarm(which_clock);
624 struct alarm alarm;
625 ktime_t exp;
626 int ret = 0;
627 struct restart_block *restart;
628
629 if (!alarmtimer_get_rtcdev())
630 return -ENOTSUPP;
631
632 if (!capable(CAP_WAKE_ALARM))
633 return -EPERM;
634
635 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
636
637 exp = timespec_to_ktime(*tsreq);
638 /* Convert (if necessary) to absolute time */
639 if (flags != TIMER_ABSTIME) {
640 ktime_t now = alarm_bases[type].gettime();
641 exp = ktime_add(now, exp);
642 }
643
644 if (alarmtimer_do_nsleep(&alarm, exp))
645 goto out;
646
647 if (freezing(current))
648 alarmtimer_freezerset(exp, type);
649
650 /* abs timers don't set remaining time or restart */
651 if (flags == TIMER_ABSTIME) {
652 ret = -ERESTARTNOHAND;
653 goto out;
654 }
655
656 if (rmtp) {
657 ret = update_rmtp(exp, type, rmtp);
658 if (ret <= 0)
659 goto out;
660 }
661
662 restart = ¤t_thread_info()->restart_block;
663 restart->fn = alarm_timer_nsleep_restart;
664 restart->nanosleep.clockid = type;
665 restart->nanosleep.expires = exp.tv64;
666 restart->nanosleep.rmtp = rmtp;
667 ret = -ERESTART_RESTARTBLOCK;
668
669out:
670 return ret;
671}
672
673
674/* Suspend hook structures */
675static const struct dev_pm_ops alarmtimer_pm_ops = {
676 .suspend = alarmtimer_suspend,
677};
678
679static struct platform_driver alarmtimer_driver = {
680 .driver = {
681 .name = "alarmtimer",
682 .pm = &alarmtimer_pm_ops,
683 }
684};
685
686/**
687 * alarmtimer_init - Initialize alarm timer code
688 *
689 * This function initializes the alarm bases and registers
690 * the posix clock ids.
691 */
692static int __init alarmtimer_init(void)
693{
694 int error = 0;
695 int i;
696 struct k_clock alarm_clock = {
697 .clock_getres = alarm_clock_getres,
698 .clock_get = alarm_clock_get,
699 .timer_create = alarm_timer_create,
700 .timer_set = alarm_timer_set,
701 .timer_del = alarm_timer_del,
702 .timer_get = alarm_timer_get,
703 .nsleep = alarm_timer_nsleep,
704 };
705
706 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
707 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
708
709 /* Initialize alarm bases */
710 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
711 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
712 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
713 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
714 for (i = 0; i < ALARM_NUMTYPE; i++) {
715 timerqueue_init_head(&alarm_bases[i].timerqueue);
716 spin_lock_init(&alarm_bases[i].lock);
717 hrtimer_init(&alarm_bases[i].timer,
718 alarm_bases[i].base_clockid,
719 HRTIMER_MODE_ABS);
720 alarm_bases[i].timer.function = alarmtimer_fired;
721 }
722 error = platform_driver_register(&alarmtimer_driver);
723 platform_device_register_simple("alarmtimer", -1, NULL, 0);
724
725 return error;
726}
727device_initcall(alarmtimer_init);
728