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John Stultzff3ead92011-01-11 09:42:13 -08001/*
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
John Stultz180bf812011-04-28 12:58:11 -070029/**
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
John Stultz180bf812011-04-28 12:58:11 -070036 */
John Stultzff3ead92011-01-11 09:42:13 -080037static struct alarm_base {
38 spinlock_t lock;
39 struct timerqueue_head timerqueue;
John Stultzff3ead92011-01-11 09:42:13 -080040 ktime_t (*gettime)(void);
41 clockid_t base_clockid;
John Stultzff3ead92011-01-11 09:42:13 -080042} alarm_bases[ALARM_NUMTYPE];
43
John Stultzc008ba52011-06-16 18:27:09 -070044/* freezer delta & lock used to handle clock_nanosleep triggered wakeups */
45static ktime_t freezer_delta;
46static DEFINE_SPINLOCK(freezer_delta_lock);
47
Todd Poynor59a93c22012-08-09 00:37:27 -070048static struct wakeup_source *ws;
49
John Stultz472647d2011-04-29 15:03:10 -070050#ifdef CONFIG_RTC_CLASS
John Stultz180bf812011-04-28 12:58:11 -070051/* rtc timer and device for setting alarm wakeups at suspend */
Thomas Gleixnerc5e14e72012-03-24 12:46:23 +010052static struct rtc_timer rtctimer;
John Stultzff3ead92011-01-11 09:42:13 -080053static struct rtc_device *rtcdev;
John Stultzc008ba52011-06-16 18:27:09 -070054static DEFINE_SPINLOCK(rtcdev_lock);
John Stultzff3ead92011-01-11 09:42:13 -080055
John Stultzc008ba52011-06-16 18:27:09 -070056/**
John Stultzc008ba52011-06-16 18:27:09 -070057 * 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 */
John Stultz57c498f2012-04-20 12:31:45 -070063struct rtc_device *alarmtimer_get_rtcdev(void)
John Stultzc008ba52011-06-16 18:27:09 -070064{
John Stultzc008ba52011-06-16 18:27:09 -070065 unsigned long flags;
66 struct rtc_device *ret;
67
68 spin_lock_irqsave(&rtcdev_lock, flags);
John Stultzc008ba52011-06-16 18:27:09 -070069 ret = rtcdev;
70 spin_unlock_irqrestore(&rtcdev_lock, flags);
71
72 return ret;
73}
John Stultz8bc0daf2011-07-14 18:35:13 -070074
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
Thomas Gleixnerc5e14e72012-03-24 12:46:23 +0100100static inline void alarmtimer_rtc_timer_init(void)
101{
102 rtc_timer_init(&rtctimer, NULL, NULL);
103}
104
John Stultz8bc0daf2011-07-14 18:35:13 -0700105static struct class_interface alarmtimer_rtc_interface = {
106 .add_dev = &alarmtimer_rtc_add_device,
107};
108
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200109static int alarmtimer_rtc_interface_setup(void)
John Stultz8bc0daf2011-07-14 18:35:13 -0700110{
111 alarmtimer_rtc_interface.class = rtc_class;
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200112 return class_interface_register(&alarmtimer_rtc_interface);
113}
114static void alarmtimer_rtc_interface_remove(void)
115{
116 class_interface_unregister(&alarmtimer_rtc_interface);
John Stultz8bc0daf2011-07-14 18:35:13 -0700117}
John Stultz1c6b39a2011-06-16 18:47:37 -0700118#else
John Stultz57c498f2012-04-20 12:31:45 -0700119struct rtc_device *alarmtimer_get_rtcdev(void)
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200120{
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) { }
Thomas Gleixnerc5e14e72012-03-24 12:46:23 +0100126static inline void alarmtimer_rtc_timer_init(void) { }
John Stultzc008ba52011-06-16 18:27:09 -0700127#endif
John Stultzff3ead92011-01-11 09:42:13 -0800128
John Stultz180bf812011-04-28 12:58:11 -0700129/**
John Stultzff3ead92011-01-11 09:42:13 -0800130 * 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 *
John Stultzdae373b2012-09-13 19:12:16 -0400134 * Adds alarm to a alarm_base timerqueue
John Stultzff3ead92011-01-11 09:42:13 -0800135 *
136 * Must hold base->lock when calling.
137 */
138static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm)
139{
John Stultzdae373b2012-09-13 19:12:16 -0400140 if (alarm->state & ALARMTIMER_STATE_ENQUEUED)
141 timerqueue_del(&base->timerqueue, &alarm->node);
142
John Stultzff3ead92011-01-11 09:42:13 -0800143 timerqueue_add(&base->timerqueue, &alarm->node);
John Stultza28cde82011-08-10 12:30:21 -0700144 alarm->state |= ALARMTIMER_STATE_ENQUEUED;
John Stultzff3ead92011-01-11 09:42:13 -0800145}
146
John Stultz180bf812011-04-28 12:58:11 -0700147/**
John Stultza65bcc12012-09-13 19:25:22 -0400148 * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue
John Stultzff3ead92011-01-11 09:42:13 -0800149 * @base: pointer to the base where the timer is running
150 * @alarm: pointer to alarm being removed
151 *
John Stultzdae373b2012-09-13 19:12:16 -0400152 * Removes alarm to a alarm_base timerqueue
John Stultzff3ead92011-01-11 09:42:13 -0800153 *
154 * Must hold base->lock when calling.
155 */
John Stultza65bcc12012-09-13 19:25:22 -0400156static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm)
John Stultzff3ead92011-01-11 09:42:13 -0800157{
John Stultza28cde82011-08-10 12:30:21 -0700158 if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED))
159 return;
160
John Stultzff3ead92011-01-11 09:42:13 -0800161 timerqueue_del(&base->timerqueue, &alarm->node);
John Stultza28cde82011-08-10 12:30:21 -0700162 alarm->state &= ~ALARMTIMER_STATE_ENQUEUED;
John Stultzff3ead92011-01-11 09:42:13 -0800163}
164
John Stultz7068b7a2011-04-28 13:29:18 -0700165
John Stultz180bf812011-04-28 12:58:11 -0700166/**
John Stultz7068b7a2011-04-28 13:29:18 -0700167 * alarmtimer_fired - Handles alarm hrtimer being fired.
168 * @timer: pointer to hrtimer being run
John Stultzff3ead92011-01-11 09:42:13 -0800169 *
John Stultz180bf812011-04-28 12:58:11 -0700170 * 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.
John Stultzff3ead92011-01-11 09:42:13 -0800174 */
John Stultz7068b7a2011-04-28 13:29:18 -0700175static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer)
John Stultzff3ead92011-01-11 09:42:13 -0800176{
John Stultzdae373b2012-09-13 19:12:16 -0400177 struct alarm *alarm = container_of(timer, struct alarm, timer);
178 struct alarm_base *base = &alarm_bases[alarm->type];
John Stultzff3ead92011-01-11 09:42:13 -0800179 unsigned long flags;
John Stultz7068b7a2011-04-28 13:29:18 -0700180 int ret = HRTIMER_NORESTART;
John Stultz54da23b2011-08-10 11:08:07 -0700181 int restart = ALARMTIMER_NORESTART;
John Stultzff3ead92011-01-11 09:42:13 -0800182
183 spin_lock_irqsave(&base->lock, flags);
John Stultza65bcc12012-09-13 19:25:22 -0400184 alarmtimer_dequeue(base, alarm);
John Stultzdae373b2012-09-13 19:12:16 -0400185 spin_unlock_irqrestore(&base->lock, flags);
John Stultzff3ead92011-01-11 09:42:13 -0800186
John Stultzdae373b2012-09-13 19:12:16 -0400187 if (alarm->function)
188 restart = alarm->function(alarm, base->gettime());
John Stultzff3ead92011-01-11 09:42:13 -0800189
John Stultzdae373b2012-09-13 19:12:16 -0400190 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);
John Stultz7068b7a2011-04-28 13:29:18 -0700194 ret = HRTIMER_RESTART;
John Stultzff3ead92011-01-11 09:42:13 -0800195 }
196 spin_unlock_irqrestore(&base->lock, flags);
John Stultzff3ead92011-01-11 09:42:13 -0800197
John Stultz7068b7a2011-04-28 13:29:18 -0700198 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800199
John Stultzff3ead92011-01-11 09:42:13 -0800200}
201
John Stultz472647d2011-04-29 15:03:10 -0700202#ifdef CONFIG_RTC_CLASS
John Stultz180bf812011-04-28 12:58:11 -0700203/**
John Stultzff3ead92011-01-11 09:42:13 -0800204 * alarmtimer_suspend - Suspend time callback
205 * @dev: unused
206 * @state: unused
207 *
208 * When we are going into suspend, we look through the bases
209 * to see which is the soonest timer to expire. We then
210 * set an rtc timer to fire that far into the future, which
211 * will wake us from suspend.
212 */
213static int alarmtimer_suspend(struct device *dev)
214{
215 struct rtc_time tm;
216 ktime_t min, now;
217 unsigned long flags;
John Stultzc008ba52011-06-16 18:27:09 -0700218 struct rtc_device *rtc;
John Stultzff3ead92011-01-11 09:42:13 -0800219 int i;
Todd Poynor59a93c22012-08-09 00:37:27 -0700220 int ret;
John Stultzff3ead92011-01-11 09:42:13 -0800221
222 spin_lock_irqsave(&freezer_delta_lock, flags);
223 min = freezer_delta;
224 freezer_delta = ktime_set(0, 0);
225 spin_unlock_irqrestore(&freezer_delta_lock, flags);
226
John Stultz8bc0daf2011-07-14 18:35:13 -0700227 rtc = alarmtimer_get_rtcdev();
John Stultzff3ead92011-01-11 09:42:13 -0800228 /* If we have no rtcdev, just return */
John Stultzc008ba52011-06-16 18:27:09 -0700229 if (!rtc)
John Stultzff3ead92011-01-11 09:42:13 -0800230 return 0;
231
232 /* Find the soonest timer to expire*/
233 for (i = 0; i < ALARM_NUMTYPE; i++) {
234 struct alarm_base *base = &alarm_bases[i];
235 struct timerqueue_node *next;
236 ktime_t delta;
237
238 spin_lock_irqsave(&base->lock, flags);
239 next = timerqueue_getnext(&base->timerqueue);
240 spin_unlock_irqrestore(&base->lock, flags);
241 if (!next)
242 continue;
243 delta = ktime_sub(next->expires, base->gettime());
244 if (!min.tv64 || (delta.tv64 < min.tv64))
245 min = delta;
246 }
247 if (min.tv64 == 0)
248 return 0;
249
Todd Poynor59a93c22012-08-09 00:37:27 -0700250 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
251 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
252 return -EBUSY;
253 }
John Stultzff3ead92011-01-11 09:42:13 -0800254
255 /* Setup an rtc timer to fire that far in the future */
John Stultzc008ba52011-06-16 18:27:09 -0700256 rtc_timer_cancel(rtc, &rtctimer);
257 rtc_read_time(rtc, &tm);
John Stultzff3ead92011-01-11 09:42:13 -0800258 now = rtc_tm_to_ktime(tm);
259 now = ktime_add(now, min);
260
Todd Poynor59a93c22012-08-09 00:37:27 -0700261 /* Set alarm, if in the past reject suspend briefly to handle */
262 ret = rtc_timer_start(rtc, &rtctimer, now, ktime_set(0, 0));
263 if (ret < 0)
264 __pm_wakeup_event(ws, MSEC_PER_SEC);
265 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800266}
John Stultz472647d2011-04-29 15:03:10 -0700267#else
268static int alarmtimer_suspend(struct device *dev)
269{
270 return 0;
271}
272#endif
John Stultzff3ead92011-01-11 09:42:13 -0800273
John Stultz9a7adcf2011-01-11 09:54:33 -0800274static void alarmtimer_freezerset(ktime_t absexp, enum alarmtimer_type type)
275{
276 ktime_t delta;
277 unsigned long flags;
278 struct alarm_base *base = &alarm_bases[type];
279
280 delta = ktime_sub(absexp, base->gettime());
281
282 spin_lock_irqsave(&freezer_delta_lock, flags);
283 if (!freezer_delta.tv64 || (delta.tv64 < freezer_delta.tv64))
284 freezer_delta = delta;
285 spin_unlock_irqrestore(&freezer_delta_lock, flags);
286}
287
288
John Stultz180bf812011-04-28 12:58:11 -0700289/**
John Stultzff3ead92011-01-11 09:42:13 -0800290 * alarm_init - Initialize an alarm structure
291 * @alarm: ptr to alarm to be initialized
292 * @type: the type of the alarm
293 * @function: callback that is run when the alarm fires
John Stultzff3ead92011-01-11 09:42:13 -0800294 */
295void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
John Stultz4b413082011-08-10 10:37:59 -0700296 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
John Stultzff3ead92011-01-11 09:42:13 -0800297{
298 timerqueue_init(&alarm->node);
John Stultzdae373b2012-09-13 19:12:16 -0400299 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
300 HRTIMER_MODE_ABS);
301 alarm->timer.function = alarmtimer_fired;
John Stultzff3ead92011-01-11 09:42:13 -0800302 alarm->function = function;
303 alarm->type = type;
John Stultza28cde82011-08-10 12:30:21 -0700304 alarm->state = ALARMTIMER_STATE_INACTIVE;
John Stultzff3ead92011-01-11 09:42:13 -0800305}
306
John Stultz180bf812011-04-28 12:58:11 -0700307/**
John Stultzff3ead92011-01-11 09:42:13 -0800308 * alarm_start - Sets an alarm to fire
309 * @alarm: ptr to alarm to set
310 * @start: time to run the alarm
John Stultzff3ead92011-01-11 09:42:13 -0800311 */
John Stultzdae373b2012-09-13 19:12:16 -0400312int alarm_start(struct alarm *alarm, ktime_t start)
John Stultzff3ead92011-01-11 09:42:13 -0800313{
314 struct alarm_base *base = &alarm_bases[alarm->type];
315 unsigned long flags;
John Stultzdae373b2012-09-13 19:12:16 -0400316 int ret;
John Stultzff3ead92011-01-11 09:42:13 -0800317
318 spin_lock_irqsave(&base->lock, flags);
John Stultzff3ead92011-01-11 09:42:13 -0800319 alarm->node.expires = start;
John Stultzff3ead92011-01-11 09:42:13 -0800320 alarmtimer_enqueue(base, alarm);
John Stultzdae373b2012-09-13 19:12:16 -0400321 ret = hrtimer_start(&alarm->timer, alarm->node.expires,
322 HRTIMER_MODE_ABS);
John Stultzff3ead92011-01-11 09:42:13 -0800323 spin_unlock_irqrestore(&base->lock, flags);
John Stultzdae373b2012-09-13 19:12:16 -0400324 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800325}
326
Todd Poynor0ccfc3c2013-05-08 15:49:18 -0700327void alarm_restart(struct alarm *alarm)
328{
329 struct alarm_base *base = &alarm_bases[alarm->type];
330 unsigned long flags;
331
332 spin_lock_irqsave(&base->lock, flags);
333 hrtimer_set_expires(&alarm->timer, alarm->node.expires);
334 hrtimer_restart(&alarm->timer);
335 alarmtimer_enqueue(base, alarm);
336 spin_unlock_irqrestore(&base->lock, flags);
337}
338
John Stultz180bf812011-04-28 12:58:11 -0700339/**
John Stultz9082c462011-08-10 12:41:36 -0700340 * alarm_try_to_cancel - Tries to cancel an alarm timer
John Stultzff3ead92011-01-11 09:42:13 -0800341 * @alarm: ptr to alarm to be canceled
John Stultz9082c462011-08-10 12:41:36 -0700342 *
343 * Returns 1 if the timer was canceled, 0 if it was not running,
344 * and -1 if the callback was running
John Stultzff3ead92011-01-11 09:42:13 -0800345 */
John Stultz9082c462011-08-10 12:41:36 -0700346int alarm_try_to_cancel(struct alarm *alarm)
John Stultzff3ead92011-01-11 09:42:13 -0800347{
348 struct alarm_base *base = &alarm_bases[alarm->type];
349 unsigned long flags;
John Stultzdae373b2012-09-13 19:12:16 -0400350 int ret;
351
John Stultzff3ead92011-01-11 09:42:13 -0800352 spin_lock_irqsave(&base->lock, flags);
John Stultzdae373b2012-09-13 19:12:16 -0400353 ret = hrtimer_try_to_cancel(&alarm->timer);
354 if (ret >= 0)
John Stultza65bcc12012-09-13 19:25:22 -0400355 alarmtimer_dequeue(base, alarm);
John Stultzff3ead92011-01-11 09:42:13 -0800356 spin_unlock_irqrestore(&base->lock, flags);
John Stultz9082c462011-08-10 12:41:36 -0700357 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800358}
359
360
John Stultz9082c462011-08-10 12:41:36 -0700361/**
362 * alarm_cancel - Spins trying to cancel an alarm timer until it is done
363 * @alarm: ptr to alarm to be canceled
364 *
365 * Returns 1 if the timer was canceled, 0 if it was not active.
366 */
367int alarm_cancel(struct alarm *alarm)
368{
369 for (;;) {
370 int ret = alarm_try_to_cancel(alarm);
371 if (ret >= 0)
372 return ret;
373 cpu_relax();
374 }
375}
376
John Stultzdce75a82011-08-10 11:31:03 -0700377
378u64 alarm_forward(struct alarm *alarm, ktime_t now, ktime_t interval)
379{
380 u64 overrun = 1;
381 ktime_t delta;
382
383 delta = ktime_sub(now, alarm->node.expires);
384
385 if (delta.tv64 < 0)
386 return 0;
387
388 if (unlikely(delta.tv64 >= interval.tv64)) {
389 s64 incr = ktime_to_ns(interval);
390
391 overrun = ktime_divns(delta, incr);
392
393 alarm->node.expires = ktime_add_ns(alarm->node.expires,
394 incr*overrun);
395
396 if (alarm->node.expires.tv64 > now.tv64)
397 return overrun;
398 /*
399 * This (and the ktime_add() below) is the
400 * correction for exact:
401 */
402 overrun++;
403 }
404
405 alarm->node.expires = ktime_add(alarm->node.expires, interval);
406 return overrun;
407}
408
409
410
411
John Stultz180bf812011-04-28 12:58:11 -0700412/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800413 * clock2alarm - helper that converts from clockid to alarmtypes
414 * @clockid: clockid.
John Stultz9a7adcf2011-01-11 09:54:33 -0800415 */
416static enum alarmtimer_type clock2alarm(clockid_t clockid)
417{
418 if (clockid == CLOCK_REALTIME_ALARM)
419 return ALARM_REALTIME;
420 if (clockid == CLOCK_BOOTTIME_ALARM)
421 return ALARM_BOOTTIME;
422 return -1;
423}
424
John Stultz180bf812011-04-28 12:58:11 -0700425/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800426 * alarm_handle_timer - Callback for posix timers
427 * @alarm: alarm that fired
428 *
429 * Posix timer callback for expired alarm timers.
430 */
John Stultz4b413082011-08-10 10:37:59 -0700431static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
432 ktime_t now)
John Stultz9a7adcf2011-01-11 09:54:33 -0800433{
434 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
John Stultz9e264762011-08-10 12:09:24 -0700435 it.alarm.alarmtimer);
John Stultz9a7adcf2011-01-11 09:54:33 -0800436 if (posix_timer_event(ptr, 0) != 0)
437 ptr->it_overrun++;
John Stultz4b413082011-08-10 10:37:59 -0700438
John Stultz54da23b2011-08-10 11:08:07 -0700439 /* Re-add periodic timers */
John Stultz9e264762011-08-10 12:09:24 -0700440 if (ptr->it.alarm.interval.tv64) {
441 ptr->it_overrun += alarm_forward(alarm, now,
442 ptr->it.alarm.interval);
John Stultz54da23b2011-08-10 11:08:07 -0700443 return ALARMTIMER_RESTART;
444 }
John Stultz4b413082011-08-10 10:37:59 -0700445 return ALARMTIMER_NORESTART;
John Stultz9a7adcf2011-01-11 09:54:33 -0800446}
447
John Stultz180bf812011-04-28 12:58:11 -0700448/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800449 * alarm_clock_getres - posix getres interface
450 * @which_clock: clockid
451 * @tp: timespec to fill
452 *
453 * Returns the granularity of underlying alarm base clock
454 */
455static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp)
456{
457 clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid;
458
John Stultz1c6b39a2011-06-16 18:47:37 -0700459 if (!alarmtimer_get_rtcdev())
460 return -ENOTSUPP;
461
John Stultz9a7adcf2011-01-11 09:54:33 -0800462 return hrtimer_get_res(baseid, tp);
463}
464
465/**
466 * alarm_clock_get - posix clock_get interface
467 * @which_clock: clockid
468 * @tp: timespec to fill.
469 *
470 * Provides the underlying alarm base time.
471 */
472static int alarm_clock_get(clockid_t which_clock, struct timespec *tp)
473{
474 struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)];
475
John Stultz1c6b39a2011-06-16 18:47:37 -0700476 if (!alarmtimer_get_rtcdev())
477 return -ENOTSUPP;
478
John Stultz9a7adcf2011-01-11 09:54:33 -0800479 *tp = ktime_to_timespec(base->gettime());
480 return 0;
481}
482
483/**
484 * alarm_timer_create - posix timer_create interface
485 * @new_timer: k_itimer pointer to manage
486 *
487 * Initializes the k_itimer structure.
488 */
489static int alarm_timer_create(struct k_itimer *new_timer)
490{
491 enum alarmtimer_type type;
492 struct alarm_base *base;
493
John Stultz1c6b39a2011-06-16 18:47:37 -0700494 if (!alarmtimer_get_rtcdev())
495 return -ENOTSUPP;
496
John Stultz9a7adcf2011-01-11 09:54:33 -0800497 if (!capable(CAP_WAKE_ALARM))
498 return -EPERM;
499
500 type = clock2alarm(new_timer->it_clock);
501 base = &alarm_bases[type];
John Stultz9e264762011-08-10 12:09:24 -0700502 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
John Stultz9a7adcf2011-01-11 09:54:33 -0800503 return 0;
504}
505
506/**
507 * alarm_timer_get - posix timer_get interface
508 * @new_timer: k_itimer pointer
509 * @cur_setting: itimerspec data to fill
510 *
511 * Copies the itimerspec data out from the k_itimer
512 */
513static void alarm_timer_get(struct k_itimer *timr,
514 struct itimerspec *cur_setting)
515{
John Stultzea7802f2011-08-04 07:51:56 -0700516 memset(cur_setting, 0, sizeof(struct itimerspec));
517
John Stultz9a7adcf2011-01-11 09:54:33 -0800518 cur_setting->it_interval =
John Stultz9e264762011-08-10 12:09:24 -0700519 ktime_to_timespec(timr->it.alarm.interval);
John Stultz9a7adcf2011-01-11 09:54:33 -0800520 cur_setting->it_value =
John Stultz9e264762011-08-10 12:09:24 -0700521 ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires);
John Stultz9a7adcf2011-01-11 09:54:33 -0800522 return;
523}
524
525/**
526 * alarm_timer_del - posix timer_del interface
527 * @timr: k_itimer pointer to be deleted
528 *
529 * Cancels any programmed alarms for the given timer.
530 */
531static int alarm_timer_del(struct k_itimer *timr)
532{
John Stultz1c6b39a2011-06-16 18:47:37 -0700533 if (!rtcdev)
534 return -ENOTSUPP;
535
John Stultz9082c462011-08-10 12:41:36 -0700536 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
537 return TIMER_RETRY;
538
John Stultz9a7adcf2011-01-11 09:54:33 -0800539 return 0;
540}
541
542/**
543 * alarm_timer_set - posix timer_set interface
544 * @timr: k_itimer pointer to be deleted
545 * @flags: timer flags
546 * @new_setting: itimerspec to be used
547 * @old_setting: itimerspec being replaced
548 *
549 * Sets the timer to new_setting, and starts the timer.
550 */
551static int alarm_timer_set(struct k_itimer *timr, int flags,
552 struct itimerspec *new_setting,
553 struct itimerspec *old_setting)
554{
John Stultz1c6b39a2011-06-16 18:47:37 -0700555 if (!rtcdev)
556 return -ENOTSUPP;
557
John Stultz971c90b2011-08-04 07:25:35 -0700558 if (old_setting)
559 alarm_timer_get(timr, old_setting);
John Stultz9a7adcf2011-01-11 09:54:33 -0800560
561 /* If the timer was already set, cancel it */
John Stultz9082c462011-08-10 12:41:36 -0700562 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
563 return TIMER_RETRY;
John Stultz9a7adcf2011-01-11 09:54:33 -0800564
565 /* start the timer */
John Stultz9e264762011-08-10 12:09:24 -0700566 timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval);
567 alarm_start(&timr->it.alarm.alarmtimer,
568 timespec_to_ktime(new_setting->it_value));
John Stultz9a7adcf2011-01-11 09:54:33 -0800569 return 0;
570}
571
572/**
573 * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep
574 * @alarm: ptr to alarm that fired
575 *
576 * Wakes up the task that set the alarmtimer
577 */
John Stultz4b413082011-08-10 10:37:59 -0700578static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
579 ktime_t now)
John Stultz9a7adcf2011-01-11 09:54:33 -0800580{
581 struct task_struct *task = (struct task_struct *)alarm->data;
582
583 alarm->data = NULL;
584 if (task)
585 wake_up_process(task);
John Stultz4b413082011-08-10 10:37:59 -0700586 return ALARMTIMER_NORESTART;
John Stultz9a7adcf2011-01-11 09:54:33 -0800587}
588
589/**
590 * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation
591 * @alarm: ptr to alarmtimer
592 * @absexp: absolute expiration time
593 *
594 * Sets the alarm timer and sleeps until it is fired or interrupted.
595 */
596static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp)
597{
598 alarm->data = (void *)current;
599 do {
600 set_current_state(TASK_INTERRUPTIBLE);
John Stultz9e264762011-08-10 12:09:24 -0700601 alarm_start(alarm, absexp);
John Stultz9a7adcf2011-01-11 09:54:33 -0800602 if (likely(alarm->data))
603 schedule();
604
605 alarm_cancel(alarm);
606 } while (alarm->data && !signal_pending(current));
607
608 __set_current_state(TASK_RUNNING);
609
610 return (alarm->data == NULL);
611}
612
613
614/**
615 * update_rmtp - Update remaining timespec value
616 * @exp: expiration time
617 * @type: timer type
618 * @rmtp: user pointer to remaining timepsec value
619 *
620 * Helper function that fills in rmtp value with time between
621 * now and the exp value
622 */
623static int update_rmtp(ktime_t exp, enum alarmtimer_type type,
624 struct timespec __user *rmtp)
625{
626 struct timespec rmt;
627 ktime_t rem;
628
629 rem = ktime_sub(exp, alarm_bases[type].gettime());
630
631 if (rem.tv64 <= 0)
632 return 0;
633 rmt = ktime_to_timespec(rem);
634
635 if (copy_to_user(rmtp, &rmt, sizeof(*rmtp)))
636 return -EFAULT;
637
638 return 1;
639
640}
641
642/**
643 * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep
644 * @restart: ptr to restart block
645 *
646 * Handles restarted clock_nanosleep calls
647 */
648static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
649{
Thomas Gleixnerab8177b2011-05-20 13:05:15 +0200650 enum alarmtimer_type type = restart->nanosleep.clockid;
John Stultz9a7adcf2011-01-11 09:54:33 -0800651 ktime_t exp;
652 struct timespec __user *rmtp;
653 struct alarm alarm;
654 int ret = 0;
655
656 exp.tv64 = restart->nanosleep.expires;
657 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
658
659 if (alarmtimer_do_nsleep(&alarm, exp))
660 goto out;
661
662 if (freezing(current))
663 alarmtimer_freezerset(exp, type);
664
665 rmtp = restart->nanosleep.rmtp;
666 if (rmtp) {
667 ret = update_rmtp(exp, type, rmtp);
668 if (ret <= 0)
669 goto out;
670 }
671
672
673 /* The other values in restart are already filled in */
674 ret = -ERESTART_RESTARTBLOCK;
675out:
676 return ret;
677}
678
679/**
680 * alarm_timer_nsleep - alarmtimer nanosleep
681 * @which_clock: clockid
682 * @flags: determins abstime or relative
683 * @tsreq: requested sleep time (abs or rel)
684 * @rmtp: remaining sleep time saved
685 *
686 * Handles clock_nanosleep calls against _ALARM clockids
687 */
688static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
689 struct timespec *tsreq, struct timespec __user *rmtp)
690{
691 enum alarmtimer_type type = clock2alarm(which_clock);
692 struct alarm alarm;
693 ktime_t exp;
694 int ret = 0;
695 struct restart_block *restart;
696
John Stultz1c6b39a2011-06-16 18:47:37 -0700697 if (!alarmtimer_get_rtcdev())
698 return -ENOTSUPP;
699
John Stultz9a7adcf2011-01-11 09:54:33 -0800700 if (!capable(CAP_WAKE_ALARM))
701 return -EPERM;
702
703 alarm_init(&alarm, type, alarmtimer_nsleep_wakeup);
704
705 exp = timespec_to_ktime(*tsreq);
706 /* Convert (if necessary) to absolute time */
707 if (flags != TIMER_ABSTIME) {
708 ktime_t now = alarm_bases[type].gettime();
709 exp = ktime_add(now, exp);
710 }
711
712 if (alarmtimer_do_nsleep(&alarm, exp))
713 goto out;
714
715 if (freezing(current))
716 alarmtimer_freezerset(exp, type);
717
718 /* abs timers don't set remaining time or restart */
719 if (flags == TIMER_ABSTIME) {
720 ret = -ERESTARTNOHAND;
721 goto out;
722 }
723
724 if (rmtp) {
725 ret = update_rmtp(exp, type, rmtp);
726 if (ret <= 0)
727 goto out;
728 }
729
730 restart = &current_thread_info()->restart_block;
731 restart->fn = alarm_timer_nsleep_restart;
Thomas Gleixnerab8177b2011-05-20 13:05:15 +0200732 restart->nanosleep.clockid = type;
John Stultz9a7adcf2011-01-11 09:54:33 -0800733 restart->nanosleep.expires = exp.tv64;
734 restart->nanosleep.rmtp = rmtp;
735 ret = -ERESTART_RESTARTBLOCK;
736
737out:
738 return ret;
739}
John Stultzff3ead92011-01-11 09:42:13 -0800740
John Stultzff3ead92011-01-11 09:42:13 -0800741
742/* Suspend hook structures */
743static const struct dev_pm_ops alarmtimer_pm_ops = {
744 .suspend = alarmtimer_suspend,
745};
746
747static struct platform_driver alarmtimer_driver = {
748 .driver = {
749 .name = "alarmtimer",
750 .pm = &alarmtimer_pm_ops,
751 }
752};
753
754/**
755 * alarmtimer_init - Initialize alarm timer code
756 *
757 * This function initializes the alarm bases and registers
758 * the posix clock ids.
759 */
760static int __init alarmtimer_init(void)
761{
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200762 struct platform_device *pdev;
John Stultzff3ead92011-01-11 09:42:13 -0800763 int error = 0;
764 int i;
John Stultz9a7adcf2011-01-11 09:54:33 -0800765 struct k_clock alarm_clock = {
766 .clock_getres = alarm_clock_getres,
767 .clock_get = alarm_clock_get,
768 .timer_create = alarm_timer_create,
769 .timer_set = alarm_timer_set,
770 .timer_del = alarm_timer_del,
771 .timer_get = alarm_timer_get,
772 .nsleep = alarm_timer_nsleep,
773 };
774
Thomas Gleixnerc5e14e72012-03-24 12:46:23 +0100775 alarmtimer_rtc_timer_init();
John Stultzad30dfa2012-03-23 15:52:25 -0700776
John Stultz9a7adcf2011-01-11 09:54:33 -0800777 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
778 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
John Stultzff3ead92011-01-11 09:42:13 -0800779
780 /* Initialize alarm bases */
781 alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME;
782 alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real;
783 alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME;
784 alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime;
785 for (i = 0; i < ALARM_NUMTYPE; i++) {
786 timerqueue_init_head(&alarm_bases[i].timerqueue);
787 spin_lock_init(&alarm_bases[i].lock);
John Stultzff3ead92011-01-11 09:42:13 -0800788 }
John Stultz8bc0daf2011-07-14 18:35:13 -0700789
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200790 error = alarmtimer_rtc_interface_setup();
791 if (error)
792 return error;
John Stultzff3ead92011-01-11 09:42:13 -0800793
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200794 error = platform_driver_register(&alarmtimer_driver);
795 if (error)
796 goto out_if;
797
798 pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0);
799 if (IS_ERR(pdev)) {
800 error = PTR_ERR(pdev);
801 goto out_drv;
802 }
Todd Poynor59a93c22012-08-09 00:37:27 -0700803 ws = wakeup_source_register("alarmtimer");
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200804 return 0;
805
806out_drv:
807 platform_driver_unregister(&alarmtimer_driver);
808out_if:
809 alarmtimer_rtc_interface_remove();
John Stultzff3ead92011-01-11 09:42:13 -0800810 return error;
811}
812device_initcall(alarmtimer_init);