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}
 74EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev);
 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
275static int alarmtimer_resume(struct device *dev)
276{
277	struct rtc_device *rtc;
278
279	rtc = alarmtimer_get_rtcdev();
280	if (rtc)
281		rtc_timer_cancel(rtc, &rtctimer);
282	return 0;
283}
284
285#else
286static int alarmtimer_suspend(struct device *dev)
287{
288	return 0;
289}
290
291static int alarmtimer_resume(struct device *dev)
292{
293	return 0;
294}
295#endif
296
297static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
298{
299	ktime_t delta;
300	unsigned long flags;
301	struct alarm_base *base = &alarm_bases[type];
302
303	delta = ktime_sub(absexp, base->gettime());
304
305	spin_lock_irqsave(&freezer_delta_lock, flags);
306	if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
307		freezer_delta = delta;
308	spin_unlock_irqrestore(&freezer_delta_lock, flags);
309}
310
311
312/**
313 * alarm_init - Initialize an alarm structure
314 * @alarm: ptr to alarm to be initialized
315 * @type: the type of the alarm
316 * @function: callback that is run when the alarm fires
317 */
318void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
319		enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
320{
321	timerqueue_init(&alarm->node);
322	hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
323			HRTIMER_MODE_ABS);
324	alarm->timer.function = alarmtimer_fired;
325	alarm->function = function;
326	alarm->type = type;
327	alarm->state = ALARMTIMER_STATE_INACTIVE;
328}
329EXPORT_SYMBOL_GPL(alarm_init);
330
331/**
332 * alarm_start - Sets an absolute alarm to fire
333 * @alarm: ptr to alarm to set
334 * @start: time to run the alarm
335 */
336void alarm_start(struct alarm *alarm, ktime_t start)
337{
338	struct alarm_base *base = &alarm_bases[alarm->type];
339	unsigned long flags;
340
341	spin_lock_irqsave(&base->lock, flags);
 
 
342	alarm->node.expires = start;
343	alarmtimer_enqueue(base, alarm);
344	hrtimer_start(&alarm->timer, alarm->node.expires, HRTIMER_MODE_ABS);
345	spin_unlock_irqrestore(&base->lock, flags);
346}
347EXPORT_SYMBOL_GPL(alarm_start);
348
349/**
350 * alarm_start_relative - Sets a relative alarm to fire
351 * @alarm: ptr to alarm to set
352 * @start: time relative to now to run the alarm
353 */
354void alarm_start_relative(struct alarm *alarm, ktime_t start)
355{
356	struct alarm_base *base = &alarm_bases[alarm->type];
357
358	start = ktime_add(start, base->gettime());
359	alarm_start(alarm, start);
360}
361EXPORT_SYMBOL_GPL(alarm_start_relative);
362
363void alarm_restart(struct alarm *alarm)
364{
365	struct alarm_base *base = &alarm_bases[alarm->type];
366	unsigned long flags;
367
368	spin_lock_irqsave(&base->lock, flags);
369	hrtimer_set_expires(&alarm->timer, alarm->node.expires);
370	hrtimer_restart(&alarm->timer);
371	alarmtimer_enqueue(base, alarm);
372	spin_unlock_irqrestore(&base->lock, flags);
373}
374EXPORT_SYMBOL_GPL(alarm_restart);
375
376/**
377 * alarm_try_to_cancel - Tries to cancel an alarm timer
378 * @alarm: ptr to alarm to be canceled
379 *
380 * Returns 1 if the timer was canceled, 0 if it was not running,
381 * and -1 if the callback was running
382 */
383int alarm_try_to_cancel(struct alarm *alarm)
384{
385	struct alarm_base *base = &alarm_bases[alarm->type];
386	unsigned long flags;
387	int ret;
388
389	spin_lock_irqsave(&base->lock, flags);
390	ret = hrtimer_try_to_cancel(&alarm->timer);
391	if (ret >= 0)
392		alarmtimer_dequeue(base, alarm);
 
 
 
 
 
 
 
393	spin_unlock_irqrestore(&base->lock, flags);
394	return ret;
395}
396EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
397
398
399/**
400 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
401 * @alarm: ptr to alarm to be canceled
402 *
403 * Returns 1 if the timer was canceled, 0 if it was not active.
404 */
405int alarm_cancel(struct alarm *alarm)
406{
407	for (;;) {
408		int ret = alarm_try_to_cancel(alarm);
409		if (ret >= 0)
410			return ret;
411		cpu_relax();
412	}
413}
414EXPORT_SYMBOL_GPL(alarm_cancel);
415
416
417u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
418{
419	u64 overrun = 1;
420	ktime_t delta;
421
422	delta = ktime_sub(now, alarm->node.expires);
423
424	if (delta.tv64 < 0)
425		return 0;
426
427	if (unlikely(delta.tv64 >= interval.tv64)) {
428		s64 incr = ktime_to_ns(interval);
429
430		overrun = ktime_divns(delta, incr);
431
432		alarm->node.expires = ktime_add_ns(alarm->node.expires,
433							incr*overrun);
434
435		if (alarm->node.expires.tv64 > now.tv64)
436			return overrun;
437		/*
438		 * This (and the ktime_add() below) is the
439		 * correction for exact:
440		 */
441		overrun++;
442	}
443
444	alarm->node.expires = ktime_add(alarm->node.expires, interval);
445	return overrun;
446}
447EXPORT_SYMBOL_GPL(alarm_forward);
448
449u64 alarm_forward_now(struct alarm *alarm, ktime_t interval)
450{
451	struct alarm_base *base = &alarm_bases[alarm->type];
452
453	return alarm_forward(alarm, base->gettime(), interval);
454}
455EXPORT_SYMBOL_GPL(alarm_forward_now);
456
457
458/**
459 * clock2alarm - helper that converts from clockid to alarmtypes
460 * @clockid: clockid.
461 */
462static enum alarmtimer_type clock2alarm(clockid_t clockid)
463{
464	if (clockid == CLOCK_REALTIME_ALARM)
465		return ALARM_REALTIME;
466	if (clockid == CLOCK_BOOTTIME_ALARM)
467		return ALARM_BOOTTIME;
468	return -1;
469}
470
471/**
472 * alarm_handle_timer - Callback for posix timers
473 * @alarm: alarm that fired
474 *
475 * Posix timer callback for expired alarm timers.
476 */
477static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
478							ktime_t now)
479{
480	unsigned long flags;
481	struct k_itimer *ptr = container_of(alarm, struct k_itimer,
482						it.alarm.alarmtimer);
483	enum alarmtimer_restart result = ALARMTIMER_NORESTART;
484
485	spin_lock_irqsave(&ptr->it_lock, flags);
486	if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) {
487		if (posix_timer_event(ptr, 0) != 0)
488			ptr->it_overrun++;
489	}
490
491	/* Re-add periodic timers */
492	if (ptr->it.alarm.interval.tv64) {
493		ptr->it_overrun += alarm_forward(alarm, now,
494						ptr->it.alarm.interval);
495		result = ALARMTIMER_RESTART;
496	}
497	spin_unlock_irqrestore(&ptr->it_lock, flags);
498
499	return result;
500}
501
502/**
503 * alarm_clock_getres - posix getres interface
504 * @which_clock: clockid
505 * @tp: timespec to fill
506 *
507 * Returns the granularity of underlying alarm base clock
508 */
509static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
510{
 
 
511	if (!alarmtimer_get_rtcdev())
512		return -EINVAL;
513
514	tp->tv_sec = 0;
515	tp->tv_nsec = hrtimer_resolution;
516	return 0;
517}
518
519/**
520 * alarm_clock_get - posix clock_get interface
521 * @which_clock: clockid
522 * @tp: timespec to fill.
523 *
524 * Provides the underlying alarm base time.
525 */
526static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
527{
528	struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
529
530	if (!alarmtimer_get_rtcdev())
531		return -EINVAL;
532
533	*tp = ktime_to_timespec(base->gettime());
534	return 0;
535}
536
537/**
538 * alarm_timer_create - posix timer_create interface
539 * @new_timer: k_itimer pointer to manage
540 *
541 * Initializes the k_itimer structure.
542 */
543static int alarm_timer_create(struct k_itimer *new_timer)
544{
545	enum  alarmtimer_type type;
546	struct alarm_base *base;
547
548	if (!alarmtimer_get_rtcdev())
549		return -ENOTSUPP;
550
551	if (!capable(CAP_WAKE_ALARM))
552		return -EPERM;
553
554	type = clock2alarm(new_timer->it_clock);
555	base = &alarm_bases[type];
556	alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
557	return 0;
558}
559
560/**
561 * alarm_timer_get - posix timer_get interface
562 * @new_timer: k_itimer pointer
563 * @cur_setting: itimerspec data to fill
564 *
565 * Copies out the current itimerspec data
566 */
567static void alarm_timer_get(struct k_itimer *timr,
568				struct itimerspec *cur_setting)
569{
570	ktime_t relative_expiry_time =
571		alarm_expires_remaining(&(timr->it.alarm.alarmtimer));
572
573	if (ktime_to_ns(relative_expiry_time) > 0) {
574		cur_setting->it_value = ktime_to_timespec(relative_expiry_time);
575	} else {
576		cur_setting->it_value.tv_sec = 0;
577		cur_setting->it_value.tv_nsec = 0;
578	}
579
580	cur_setting->it_interval = ktime_to_timespec(timr->it.alarm.interval);
 
 
 
 
581}
582
583/**
584 * alarm_timer_del - posix timer_del interface
585 * @timr: k_itimer pointer to be deleted
586 *
587 * Cancels any programmed alarms for the given timer.
588 */
589static int alarm_timer_del(struct k_itimer *timr)
590{
591	if (!rtcdev)
592		return -ENOTSUPP;
593
594	if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
595		return TIMER_RETRY;
596
597	return 0;
598}
599
600/**
601 * alarm_timer_set - posix timer_set interface
602 * @timr: k_itimer pointer to be deleted
603 * @flags: timer flags
604 * @new_setting: itimerspec to be used
605 * @old_setting: itimerspec being replaced
606 *
607 * Sets the timer to new_setting, and starts the timer.
608 */
609static int alarm_timer_set(struct k_itimer *timr, int flags,
610				struct itimerspec *new_setting,
611				struct itimerspec *old_setting)
612{
613	ktime_t exp;
614
615	if (!rtcdev)
616		return -ENOTSUPP;
617
618	if (flags & ~TIMER_ABSTIME)
619		return -EINVAL;
620
621	if (old_setting)
622		alarm_timer_get(timr, old_setting);
623
624	/* If the timer was already set, cancel it */
625	if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
626		return TIMER_RETRY;
627
628	/* start the timer */
629	timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval);
630	exp = timespec_to_ktime(new_setting->it_value);
631	/* Convert (if necessary) to absolute time */
632	if (flags != TIMER_ABSTIME) {
633		ktime_t now;
634
635		now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime();
636		exp = ktime_add(now, exp);
637	}
638
639	alarm_start(&timr->it.alarm.alarmtimer, exp);
640	return 0;
641}
642
643/**
644 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
645 * @alarm: ptr to alarm that fired
646 *
647 * Wakes up the task that set the alarmtimer
648 */
649static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
650								ktime_t now)
651{
652	struct task_struct *task = (struct task_struct *)alarm->data;
653
654	alarm->data = NULL;
655	if (task)
656		wake_up_process(task);
657	return ALARMTIMER_NORESTART;
658}
659
660/**
661 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
662 * @alarm: ptr to alarmtimer
663 * @absexp: absolute expiration time
664 *
665 * Sets the alarm timer and sleeps until it is fired or interrupted.
666 */
667static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp)
668{
669	alarm->data = (void *)current;
670	do {
671		set_current_state(TASK_INTERRUPTIBLE);
672		alarm_start(alarm, absexp);
673		if (likely(alarm->data))
674			schedule();
675
676		alarm_cancel(alarm);
677	} while (alarm->data && !signal_pending(current));
678
679	__set_current_state(TASK_RUNNING);
680
681	return (alarm->data == NULL);
682}
683
684
685/**
686 * update_rmtp - Update remaining timespec value
687 * @exp: expiration time
688 * @type: timer type
689 * @rmtp: user pointer to remaining timepsec value
690 *
691 * Helper function that fills in rmtp value with time between
692 * now and the exp value
693 */
694static int update_rmtp(ktime_t exp, enum  alarmtimer_type type,
695			struct timespec __user *rmtp)
696{
697	struct timespec rmt;
698	ktime_t rem;
699
700	rem = ktime_sub(exp, alarm_bases[type].gettime());
701
702	if (rem.tv64 <= 0)
703		return 0;
704	rmt = ktime_to_timespec(rem);
705
706	if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
707		return -EFAULT;
708
709	return 1;
710
711}
712
713/**
714 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
715 * @restart: ptr to restart block
716 *
717 * Handles restarted clock_nanosleep calls
718 */
719static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
720{
721	enum  alarmtimer_type type = restart->nanosleep.clockid;
722	ktime_t exp;
723	struct timespec __user  *rmtp;
724	struct alarm alarm;
725	int ret = 0;
726
727	exp.tv64 = restart->nanosleep.expires;
728	alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
729
730	if (alarmtimer_do_nsleep(&alarm, exp))
731		goto out;
732
733	if (freezing(current))
734		alarmtimer_freezerset(exp, type);
735
736	rmtp = restart->nanosleep.rmtp;
737	if (rmtp) {
738		ret = update_rmtp(exp, type, rmtp);
739		if (ret <= 0)
740			goto out;
741	}
742
743
744	/* The other values in restart are already filled in */
745	ret = -ERESTART_RESTARTBLOCK;
746out:
747	return ret;
748}
749
750/**
751 * alarm_timer_nsleep - alarmtimer nanosleep
752 * @which_clock: clockid
753 * @flags: determins abstime or relative
754 * @tsreq: requested sleep time (abs or rel)
755 * @rmtp: remaining sleep time saved
756 *
757 * Handles clock_nanosleep calls against _ALARM clockids
758 */
759static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
760		     struct timespec *tsreq, struct timespec __user *rmtp)
761{
762	enum  alarmtimer_type type = clock2alarm(which_clock);
763	struct alarm alarm;
764	ktime_t exp;
765	int ret = 0;
766	struct restart_block *restart;
767
768	if (!alarmtimer_get_rtcdev())
769		return -ENOTSUPP;
770
771	if (flags & ~TIMER_ABSTIME)
772		return -EINVAL;
773
774	if (!capable(CAP_WAKE_ALARM))
775		return -EPERM;
776
777	alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
778
779	exp = timespec_to_ktime(*tsreq);
780	/* Convert (if necessary) to absolute time */
781	if (flags != TIMER_ABSTIME) {
782		ktime_t now = alarm_bases[type].gettime();
783		exp = ktime_add(now, exp);
784	}
785
786	if (alarmtimer_do_nsleep(&alarm, exp))
787		goto out;
788
789	if (freezing(current))
790		alarmtimer_freezerset(exp, type);
791
792	/* abs timers don't set remaining time or restart */
793	if (flags == TIMER_ABSTIME) {
794		ret = -ERESTARTNOHAND;
795		goto out;
796	}
797
798	if (rmtp) {
799		ret = update_rmtp(exp, type, rmtp);
800		if (ret <= 0)
801			goto out;
802	}
803
804	restart = &current->restart_block;
805	restart->fn = alarm_timer_nsleep_restart;
806	restart->nanosleep.clockid = type;
807	restart->nanosleep.expires = exp.tv64;
808	restart->nanosleep.rmtp = rmtp;
809	ret = -ERESTART_RESTARTBLOCK;
810
811out:
812	return ret;
813}
814
815
816/* Suspend hook structures */
817static const struct dev_pm_ops alarmtimer_pm_ops = {
818	.suspend = alarmtimer_suspend,
819	.resume = alarmtimer_resume,
820};
821
822static struct platform_driver alarmtimer_driver = {
823	.driver = {
824		.name = "alarmtimer",
825		.pm = &alarmtimer_pm_ops,
826	}
827};
828
829/**
830 * alarmtimer_init - Initialize alarm timer code
831 *
832 * This function initializes the alarm bases and registers
833 * the posix clock ids.
834 */
835static int __init alarmtimer_init(void)
836{
837	struct platform_device *pdev;
838	int error = 0;
839	int i;
840	struct k_clock alarm_clock = {
841		.clock_getres	= alarm_clock_getres,
842		.clock_get	= alarm_clock_get,
843		.timer_create	= alarm_timer_create,
844		.timer_set	= alarm_timer_set,
845		.timer_del	= alarm_timer_del,
846		.timer_get	= alarm_timer_get,
847		.nsleep		= alarm_timer_nsleep,
848	};
849
850	alarmtimer_rtc_timer_init();
851
852	posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
853	posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
854
855	/* Initialize alarm bases */
856	alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
857	alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
858	alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
859	alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
860	for (i = 0; i < ALARM_NUMTYPE; i++) {
861		timerqueue_init_head(&alarm_bases[i].timerqueue);
862		spin_lock_init(&alarm_bases[i].lock);
 
 
 
 
863	}
864
865	error = alarmtimer_rtc_interface_setup();
866	if (error)
867		return error;
868
869	error = platform_driver_register(&alarmtimer_driver);
870	if (error)
871		goto out_if;
872
873	pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
874	if (IS_ERR(pdev)) {
875		error = PTR_ERR(pdev);
876		goto out_drv;
877	}
878	ws = wakeup_source_register("alarmtimer");
879	return 0;
880
881out_drv:
882	platform_driver_unregister(&alarmtimer_driver);
883out_if:
884	alarmtimer_rtc_interface_remove();
885	return error;
886}
887device_initcall(alarmtimer_init);