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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 Stultzc008ba582011-06-16 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 Stultzc008ba582011-06-16 18:27:09 -070054static DEFINE_SPINLOCK(rtcdev_lock);
John Stultzff3ead92011-01-11 09:42:13 -080055
John Stultzc008ba582011-06-16 18:27:09 -070056/**
John Stultzc008ba582011-06-16 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 Stultzc008ba582011-06-16 18:27:09 -070064{
John Stultzc008ba582011-06-16 18:27:09 -070065 unsigned long flags;
66 struct rtc_device *ret;
67
68 spin_lock_irqsave(&rtcdev_lock, flags);
John Stultzc008ba582011-06-16 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 Stultzc008ba582011-06-16 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
Todd Poynor6cffe002013-05-15 14:38:11 -0700202ktime_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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200207EXPORT_SYMBOL_GPL(alarm_expires_remaining);
Todd Poynor6cffe002013-05-15 14:38:11 -0700208
John Stultz472647d2011-04-29 15:03:10 -0700209#ifdef CONFIG_RTC_CLASS
John Stultz180bf812011-04-28 12:58:11 -0700210/**
John Stultzff3ead92011-01-11 09:42:13 -0800211 * 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;
John Stultzc008ba582011-06-16 18:27:09 -0700225 struct rtc_device *rtc;
John Stultzff3ead92011-01-11 09:42:13 -0800226 int i;
Todd Poynor59a93c22012-08-09 00:37:27 -0700227 int ret;
John Stultzff3ead92011-01-11 09:42:13 -0800228
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
John Stultz8bc0daf2011-07-14 18:35:13 -0700234 rtc = alarmtimer_get_rtcdev();
John Stultzff3ead92011-01-11 09:42:13 -0800235 /* If we have no rtcdev, just return */
John Stultzc008ba582011-06-16 18:27:09 -0700236 if (!rtc)
John Stultzff3ead92011-01-11 09:42:13 -0800237 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
Todd Poynor59a93c22012-08-09 00:37:27 -0700257 if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) {
258 __pm_wakeup_event(ws, 2 * MSEC_PER_SEC);
259 return -EBUSY;
260 }
John Stultzff3ead92011-01-11 09:42:13 -0800261
262 /* Setup an rtc timer to fire that far in the future */
John Stultzc008ba582011-06-16 18:27:09 -0700263 rtc_timer_cancel(rtc, &rtctimer);
264 rtc_read_time(rtc, &tm);
John Stultzff3ead92011-01-11 09:42:13 -0800265 now = rtc_tm_to_ktime(tm);
266 now = ktime_add(now, min);
267
Todd Poynor59a93c22012-08-09 00:37:27 -0700268 /* 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;
John Stultzff3ead92011-01-11 09:42:13 -0800273}
John Stultz472647d2011-04-29 15:03:10 -0700274#else
275static int alarmtimer_suspend(struct device *dev)
276{
277 return 0;
278}
279#endif
John Stultzff3ead92011-01-11 09:42:13 -0800280
John Stultz9a7adcf2011-01-11 09:54:33 -0800281static 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
John Stultz180bf812011-04-28 12:58:11 -0700296/**
John Stultzff3ead92011-01-11 09:42:13 -0800297 * 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
John Stultzff3ead92011-01-11 09:42:13 -0800301 */
302void alarm_init(struct alarm *alarm, enum alarmtimer_type type,
John Stultz4b413082011-08-10 10:37:59 -0700303 enum alarmtimer_restart (*function)(struct alarm *, ktime_t))
John Stultzff3ead92011-01-11 09:42:13 -0800304{
305 timerqueue_init(&alarm->node);
John Stultzdae373b2012-09-13 19:12:16 -0400306 hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid,
307 HRTIMER_MODE_ABS);
308 alarm->timer.function = alarmtimer_fired;
John Stultzff3ead92011-01-11 09:42:13 -0800309 alarm->function = function;
310 alarm->type = type;
John Stultza28cde82011-08-10 12:30:21 -0700311 alarm->state = ALARMTIMER_STATE_INACTIVE;
John Stultzff3ead92011-01-11 09:42:13 -0800312}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200313EXPORT_SYMBOL_GPL(alarm_init);
John Stultzff3ead92011-01-11 09:42:13 -0800314
John Stultz180bf812011-04-28 12:58:11 -0700315/**
Todd Poynor6cffe002013-05-15 14:38:11 -0700316 * alarm_start - Sets an absolute alarm to fire
John Stultzff3ead92011-01-11 09:42:13 -0800317 * @alarm: ptr to alarm to set
318 * @start: time to run the alarm
John Stultzff3ead92011-01-11 09:42:13 -0800319 */
John Stultzdae373b2012-09-13 19:12:16 -0400320int alarm_start(struct alarm *alarm, ktime_t start)
John Stultzff3ead92011-01-11 09:42:13 -0800321{
322 struct alarm_base *base = &alarm_bases[alarm->type];
323 unsigned long flags;
John Stultzdae373b2012-09-13 19:12:16 -0400324 int ret;
John Stultzff3ead92011-01-11 09:42:13 -0800325
326 spin_lock_irqsave(&base->lock, flags);
John Stultzff3ead92011-01-11 09:42:13 -0800327 alarm->node.expires = start;
John Stultzff3ead92011-01-11 09:42:13 -0800328 alarmtimer_enqueue(base, alarm);
John Stultzdae373b2012-09-13 19:12:16 -0400329 ret = hrtimer_start(&alarm->timer, alarm->node.expires,
330 HRTIMER_MODE_ABS);
John Stultzff3ead92011-01-11 09:42:13 -0800331 spin_unlock_irqrestore(&base->lock, flags);
John Stultzdae373b2012-09-13 19:12:16 -0400332 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800333}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200334EXPORT_SYMBOL_GPL(alarm_start);
John Stultzff3ead92011-01-11 09:42:13 -0800335
John Stultz180bf812011-04-28 12:58:11 -0700336/**
Todd Poynor6cffe002013-05-15 14:38:11 -0700337 * 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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200348EXPORT_SYMBOL_GPL(alarm_start_relative);
Todd Poynor6cffe002013-05-15 14:38:11 -0700349
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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200361EXPORT_SYMBOL_GPL(alarm_restart);
Todd Poynor6cffe002013-05-15 14:38:11 -0700362
363/**
John Stultz9082c462011-08-10 12:41:36 -0700364 * alarm_try_to_cancel - Tries to cancel an alarm timer
John Stultzff3ead92011-01-11 09:42:13 -0800365 * @alarm: ptr to alarm to be canceled
John Stultz9082c462011-08-10 12:41:36 -0700366 *
367 * Returns 1 if the timer was canceled, 0 if it was not running,
368 * and -1 if the callback was running
John Stultzff3ead92011-01-11 09:42:13 -0800369 */
John Stultz9082c462011-08-10 12:41:36 -0700370int alarm_try_to_cancel(struct alarm *alarm)
John Stultzff3ead92011-01-11 09:42:13 -0800371{
372 struct alarm_base *base = &alarm_bases[alarm->type];
373 unsigned long flags;
John Stultzdae373b2012-09-13 19:12:16 -0400374 int ret;
375
John Stultzff3ead92011-01-11 09:42:13 -0800376 spin_lock_irqsave(&base->lock, flags);
John Stultzdae373b2012-09-13 19:12:16 -0400377 ret = hrtimer_try_to_cancel(&alarm->timer);
378 if (ret >= 0)
John Stultza65bcc12012-09-13 19:25:22 -0400379 alarmtimer_dequeue(base, alarm);
John Stultzff3ead92011-01-11 09:42:13 -0800380 spin_unlock_irqrestore(&base->lock, flags);
John Stultz9082c462011-08-10 12:41:36 -0700381 return ret;
John Stultzff3ead92011-01-11 09:42:13 -0800382}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200383EXPORT_SYMBOL_GPL(alarm_try_to_cancel);
John Stultzff3ead92011-01-11 09:42:13 -0800384
385
John Stultz9082c462011-08-10 12:41:36 -0700386/**
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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200401EXPORT_SYMBOL_GPL(alarm_cancel);
John Stultz9082c462011-08-10 12:41:36 -0700402
John Stultzdce75a82011-08-10 11:31:03 -0700403
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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200434EXPORT_SYMBOL_GPL(alarm_forward);
John Stultzdce75a82011-08-10 11:31:03 -0700435
Todd Poynor6cffe002013-05-15 14:38:11 -0700436u64 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}
Marcus Gelderie11682a42013-06-04 09:32:09 +0200442EXPORT_SYMBOL_GPL(alarm_forward_now);
John Stultzdce75a82011-08-10 11:31:03 -0700443
444
John Stultz180bf812011-04-28 12:58:11 -0700445/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800446 * clock2alarm - helper that converts from clockid to alarmtypes
447 * @clockid: clockid.
John Stultz9a7adcf2011-01-11 09:54:33 -0800448 */
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
John Stultz180bf812011-04-28 12:58:11 -0700458/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800459 * alarm_handle_timer - Callback for posix timers
460 * @alarm: alarm that fired
461 *
462 * Posix timer callback for expired alarm timers.
463 */
John Stultz4b413082011-08-10 10:37:59 -0700464static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm,
465 ktime_t now)
John Stultz9a7adcf2011-01-11 09:54:33 -0800466{
467 struct k_itimer *ptr = container_of(alarm, struct k_itimer,
John Stultz9e264762011-08-10 12:09:24 -0700468 it.alarm.alarmtimer);
John Stultz9a7adcf2011-01-11 09:54:33 -0800469 if (posix_timer_event(ptr, 0) != 0)
470 ptr->it_overrun++;
John Stultz4b413082011-08-10 10:37:59 -0700471
John Stultz54da23b2011-08-10 11:08:07 -0700472 /* Re-add periodic timers */
John Stultz9e264762011-08-10 12:09:24 -0700473 if (ptr->it.alarm.interval.tv64) {
474 ptr->it_overrun += alarm_forward(alarm, now,
475 ptr->it.alarm.interval);
John Stultz54da23b2011-08-10 11:08:07 -0700476 return ALARMTIMER_RESTART;
477 }
John Stultz4b413082011-08-10 10:37:59 -0700478 return ALARMTIMER_NORESTART;
John Stultz9a7adcf2011-01-11 09:54:33 -0800479}
480
John Stultz180bf812011-04-28 12:58:11 -0700481/**
John Stultz9a7adcf2011-01-11 09:54:33 -0800482 * 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
John Stultz1c6b39a2011-06-16 18:47:37 -0700492 if (!alarmtimer_get_rtcdev())
493 return -ENOTSUPP;
494
John Stultz9a7adcf2011-01-11 09:54:33 -0800495 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
John Stultz1c6b39a2011-06-16 18:47:37 -0700509 if (!alarmtimer_get_rtcdev())
510 return -ENOTSUPP;
511
John Stultz9a7adcf2011-01-11 09:54:33 -0800512 *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
John Stultz1c6b39a2011-06-16 18:47:37 -0700527 if (!alarmtimer_get_rtcdev())
528 return -ENOTSUPP;
529
John Stultz9a7adcf2011-01-11 09:54:33 -0800530 if (!capable(CAP_WAKE_ALARM))
531 return -EPERM;
532
533 type = clock2alarm(new_timer->it_clock);
534 base = &alarm_bases[type];
John Stultz9e264762011-08-10 12:09:24 -0700535 alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer);
John Stultz9a7adcf2011-01-11 09:54:33 -0800536 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{
John Stultzea7802f2011-08-04 07:51:56 -0700549 memset(cur_setting, 0, sizeof(struct itimerspec));
550
John Stultz9a7adcf2011-01-11 09:54:33 -0800551 cur_setting->it_interval =
John Stultz9e264762011-08-10 12:09:24 -0700552 ktime_to_timespec(timr->it.alarm.interval);
John Stultz9a7adcf2011-01-11 09:54:33 -0800553 cur_setting->it_value =
John Stultz9e264762011-08-10 12:09:24 -0700554 ktime_to_timespec(timr->it.alarm.alarmtimer.node.expires);
John Stultz9a7adcf2011-01-11 09:54:33 -0800555 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{
John Stultz1c6b39a2011-06-16 18:47:37 -0700566 if (!rtcdev)
567 return -ENOTSUPP;
568
John Stultz9082c462011-08-10 12:41:36 -0700569 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
570 return TIMER_RETRY;
571
John Stultz9a7adcf2011-01-11 09:54:33 -0800572 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{
John Stultz1c6b39a2011-06-16 18:47:37 -0700588 if (!rtcdev)
589 return -ENOTSUPP;
590
John Stultz971c90b2011-08-04 07:25:35 -0700591 if (old_setting)
592 alarm_timer_get(timr, old_setting);
John Stultz9a7adcf2011-01-11 09:54:33 -0800593
594 /* If the timer was already set, cancel it */
John Stultz9082c462011-08-10 12:41:36 -0700595 if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0)
596 return TIMER_RETRY;
John Stultz9a7adcf2011-01-11 09:54:33 -0800597
598 /* start the timer */
John Stultz9e264762011-08-10 12:09:24 -0700599 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));
John Stultz9a7adcf2011-01-11 09:54:33 -0800602 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 */
John Stultz4b413082011-08-10 10:37:59 -0700611static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm,
612 ktime_t now)
John Stultz9a7adcf2011-01-11 09:54:33 -0800613{
614 struct task_struct *task = (struct task_struct *)alarm->data;
615
616 alarm->data = NULL;
617 if (task)
618 wake_up_process(task);
John Stultz4b413082011-08-10 10:37:59 -0700619 return ALARMTIMER_NORESTART;
John Stultz9a7adcf2011-01-11 09:54:33 -0800620}
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);
John Stultz9e264762011-08-10 12:09:24 -0700634 alarm_start(alarm, absexp);
John Stultz9a7adcf2011-01-11 09:54:33 -0800635 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{
Thomas Gleixnerab8177b2011-05-20 13:05:15 +0200683 enum alarmtimer_type type = restart->nanosleep.clockid;
John Stultz9a7adcf2011-01-11 09:54:33 -0800684 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
John Stultz1c6b39a2011-06-16 18:47:37 -0700730 if (!alarmtimer_get_rtcdev())
731 return -ENOTSUPP;
732
John Stultz9a7adcf2011-01-11 09:54:33 -0800733 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 = &current_thread_info()->restart_block;
764 restart->fn = alarm_timer_nsleep_restart;
Thomas Gleixnerab8177b2011-05-20 13:05:15 +0200765 restart->nanosleep.clockid = type;
John Stultz9a7adcf2011-01-11 09:54:33 -0800766 restart->nanosleep.expires = exp.tv64;
767 restart->nanosleep.rmtp = rmtp;
768 ret = -ERESTART_RESTARTBLOCK;
769
770out:
771 return ret;
772}
John Stultzff3ead92011-01-11 09:42:13 -0800773
John Stultzff3ead92011-01-11 09:42:13 -0800774
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{
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200795 struct platform_device *pdev;
John Stultzff3ead92011-01-11 09:42:13 -0800796 int error = 0;
797 int i;
John Stultz9a7adcf2011-01-11 09:54:33 -0800798 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
Thomas Gleixnerc5e14e72012-03-24 12:46:23 +0100808 alarmtimer_rtc_timer_init();
John Stultzad30dfa2012-03-23 15:52:25 -0700809
John Stultz9a7adcf2011-01-11 09:54:33 -0800810 posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock);
811 posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock);
John Stultzff3ead92011-01-11 09:42:13 -0800812
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);
John Stultzff3ead92011-01-11 09:42:13 -0800821 }
John Stultz8bc0daf2011-07-14 18:35:13 -0700822
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200823 error = alarmtimer_rtc_interface_setup();
824 if (error)
825 return error;
John Stultzff3ead92011-01-11 09:42:13 -0800826
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200827 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 }
Todd Poynor59a93c22012-08-09 00:37:27 -0700836 ws = wakeup_source_register("alarmtimer");
Thomas Gleixner4523f6a2011-09-14 10:54:29 +0200837 return 0;
838
839out_drv:
840 platform_driver_unregister(&alarmtimer_driver);
841out_if:
842 alarmtimer_rtc_interface_remove();
John Stultzff3ead92011-01-11 09:42:13 -0800843 return error;
844}
845device_initcall(alarmtimer_init);