Commit | Line | Data |
---|---|---|
ff3ead96 JS |
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 | ||
180bf812 JS |
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 | |
180bf812 | 36 | */ |
ff3ead96 JS |
37 | static struct alarm_base { |
38 | spinlock_t lock; | |
39 | struct timerqueue_head timerqueue; | |
ff3ead96 JS |
40 | ktime_t (*gettime)(void); |
41 | clockid_t base_clockid; | |
ff3ead96 JS |
42 | } alarm_bases[ALARM_NUMTYPE]; |
43 | ||
c008ba58 JS |
44 | /* freezer delta & lock used to handle clock_nanosleep triggered wakeups */ |
45 | static ktime_t freezer_delta; | |
46 | static DEFINE_SPINLOCK(freezer_delta_lock); | |
47 | ||
59a93c27 TP |
48 | static struct wakeup_source *ws; |
49 | ||
472647dc | 50 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 51 | /* rtc timer and device for setting alarm wakeups at suspend */ |
c5e14e76 | 52 | static struct rtc_timer rtctimer; |
ff3ead96 | 53 | static struct rtc_device *rtcdev; |
c008ba58 | 54 | static DEFINE_SPINLOCK(rtcdev_lock); |
ff3ead96 | 55 | |
c008ba58 JS |
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 | */ | |
57c498fa | 63 | struct rtc_device *alarmtimer_get_rtcdev(void) |
c008ba58 | 64 | { |
c008ba58 JS |
65 | unsigned long flags; |
66 | struct rtc_device *ret; | |
67 | ||
68 | spin_lock_irqsave(&rtcdev_lock, flags); | |
c008ba58 JS |
69 | ret = rtcdev; |
70 | spin_unlock_irqrestore(&rtcdev_lock, flags); | |
71 | ||
72 | return ret; | |
73 | } | |
71d5d2b7 | 74 | EXPORT_SYMBOL_GPL(alarmtimer_get_rtcdev); |
8bc0dafb JS |
75 | |
76 | static 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 | ||
c5e14e76 TG |
100 | static inline void alarmtimer_rtc_timer_init(void) |
101 | { | |
102 | rtc_timer_init(&rtctimer, NULL, NULL); | |
103 | } | |
104 | ||
8bc0dafb JS |
105 | static struct class_interface alarmtimer_rtc_interface = { |
106 | .add_dev = &alarmtimer_rtc_add_device, | |
107 | }; | |
108 | ||
4523f6ad | 109 | static int alarmtimer_rtc_interface_setup(void) |
8bc0dafb JS |
110 | { |
111 | alarmtimer_rtc_interface.class = rtc_class; | |
4523f6ad TG |
112 | return class_interface_register(&alarmtimer_rtc_interface); |
113 | } | |
114 | static void alarmtimer_rtc_interface_remove(void) | |
115 | { | |
116 | class_interface_unregister(&alarmtimer_rtc_interface); | |
8bc0dafb | 117 | } |
1c6b39ad | 118 | #else |
57c498fa | 119 | struct rtc_device *alarmtimer_get_rtcdev(void) |
4523f6ad TG |
120 | { |
121 | return NULL; | |
122 | } | |
123 | #define rtcdev (NULL) | |
124 | static inline int alarmtimer_rtc_interface_setup(void) { return 0; } | |
125 | static inline void alarmtimer_rtc_interface_remove(void) { } | |
c5e14e76 | 126 | static inline void alarmtimer_rtc_timer_init(void) { } |
c008ba58 | 127 | #endif |
ff3ead96 | 128 | |
180bf812 | 129 | /** |
ff3ead96 JS |
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 | * | |
dae373be | 134 | * Adds alarm to a alarm_base timerqueue |
ff3ead96 JS |
135 | * |
136 | * Must hold base->lock when calling. | |
137 | */ | |
138 | static void alarmtimer_enqueue(struct alarm_base *base, struct alarm *alarm) | |
139 | { | |
dae373be JS |
140 | if (alarm->state & ALARMTIMER_STATE_ENQUEUED) |
141 | timerqueue_del(&base->timerqueue, &alarm->node); | |
142 | ||
ff3ead96 | 143 | timerqueue_add(&base->timerqueue, &alarm->node); |
a28cde81 | 144 | alarm->state |= ALARMTIMER_STATE_ENQUEUED; |
ff3ead96 JS |
145 | } |
146 | ||
180bf812 | 147 | /** |
a65bcc12 | 148 | * alarmtimer_dequeue - Removes an alarm timer from an alarm_base timerqueue |
ff3ead96 JS |
149 | * @base: pointer to the base where the timer is running |
150 | * @alarm: pointer to alarm being removed | |
151 | * | |
dae373be | 152 | * Removes alarm to a alarm_base timerqueue |
ff3ead96 JS |
153 | * |
154 | * Must hold base->lock when calling. | |
155 | */ | |
a65bcc12 | 156 | static void alarmtimer_dequeue(struct alarm_base *base, struct alarm *alarm) |
ff3ead96 | 157 | { |
a28cde81 JS |
158 | if (!(alarm->state & ALARMTIMER_STATE_ENQUEUED)) |
159 | return; | |
160 | ||
ff3ead96 | 161 | timerqueue_del(&base->timerqueue, &alarm->node); |
a28cde81 | 162 | alarm->state &= ~ALARMTIMER_STATE_ENQUEUED; |
ff3ead96 JS |
163 | } |
164 | ||
7068b7a1 | 165 | |
180bf812 | 166 | /** |
7068b7a1 JS |
167 | * alarmtimer_fired - Handles alarm hrtimer being fired. |
168 | * @timer: pointer to hrtimer being run | |
ff3ead96 | 169 | * |
180bf812 JS |
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. | |
ff3ead96 | 174 | */ |
7068b7a1 | 175 | static enum hrtimer_restart alarmtimer_fired(struct hrtimer *timer) |
ff3ead96 | 176 | { |
dae373be JS |
177 | struct alarm *alarm = container_of(timer, struct alarm, timer); |
178 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
ff3ead96 | 179 | unsigned long flags; |
7068b7a1 | 180 | int ret = HRTIMER_NORESTART; |
54da23b7 | 181 | int restart = ALARMTIMER_NORESTART; |
ff3ead96 JS |
182 | |
183 | spin_lock_irqsave(&base->lock, flags); | |
a65bcc12 | 184 | alarmtimer_dequeue(base, alarm); |
dae373be | 185 | spin_unlock_irqrestore(&base->lock, flags); |
54da23b7 | 186 | |
dae373be JS |
187 | if (alarm->function) |
188 | restart = alarm->function(alarm, base->gettime()); | |
ff3ead96 | 189 | |
dae373be JS |
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); | |
7068b7a1 | 194 | ret = HRTIMER_RESTART; |
ff3ead96 JS |
195 | } |
196 | spin_unlock_irqrestore(&base->lock, flags); | |
ff3ead96 | 197 | |
7068b7a1 | 198 | return ret; |
ff3ead96 | 199 | |
ff3ead96 JS |
200 | } |
201 | ||
6cffe00f TP |
202 | ktime_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 | } | |
11682a41 | 207 | EXPORT_SYMBOL_GPL(alarm_expires_remaining); |
6cffe00f | 208 | |
472647dc | 209 | #ifdef CONFIG_RTC_CLASS |
180bf812 | 210 | /** |
ff3ead96 JS |
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 | */ | |
220 | static int alarmtimer_suspend(struct device *dev) | |
221 | { | |
222 | struct rtc_time tm; | |
223 | ktime_t min, now; | |
224 | unsigned long flags; | |
c008ba58 | 225 | struct rtc_device *rtc; |
ff3ead96 | 226 | int i; |
59a93c27 | 227 | int ret; |
ff3ead96 JS |
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 | ||
8bc0dafb | 234 | rtc = alarmtimer_get_rtcdev(); |
ff3ead96 | 235 | /* If we have no rtcdev, just return */ |
c008ba58 | 236 | if (!rtc) |
ff3ead96 JS |
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 | ||
59a93c27 TP |
257 | if (ktime_to_ns(min) < 2 * NSEC_PER_SEC) { |
258 | __pm_wakeup_event(ws, 2 * MSEC_PER_SEC); | |
259 | return -EBUSY; | |
260 | } | |
ff3ead96 JS |
261 | |
262 | /* Setup an rtc timer to fire that far in the future */ | |
c008ba58 JS |
263 | rtc_timer_cancel(rtc, &rtctimer); |
264 | rtc_read_time(rtc, &tm); | |
ff3ead96 JS |
265 | now = rtc_tm_to_ktime(tm); |
266 | now = ktime_add(now, min); | |
267 | ||
59a93c27 TP |
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; | |
ff3ead96 | 273 | } |
472647dc JS |
274 | #else |
275 | static int alarmtimer_suspend(struct device *dev) | |
276 | { | |
277 | return 0; | |
278 | } | |
279 | #endif | |
ff3ead96 | 280 | |
9a7adcf5 JS |
281 | static 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 | ||
180bf812 | 296 | /** |
ff3ead96 JS |
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 | |
ff3ead96 JS |
301 | */ |
302 | void alarm_init(struct alarm *alarm, enum alarmtimer_type type, | |
4b41308d | 303 | enum alarmtimer_restart (*function)(struct alarm *, ktime_t)) |
ff3ead96 JS |
304 | { |
305 | timerqueue_init(&alarm->node); | |
dae373be JS |
306 | hrtimer_init(&alarm->timer, alarm_bases[type].base_clockid, |
307 | HRTIMER_MODE_ABS); | |
308 | alarm->timer.function = alarmtimer_fired; | |
ff3ead96 JS |
309 | alarm->function = function; |
310 | alarm->type = type; | |
a28cde81 | 311 | alarm->state = ALARMTIMER_STATE_INACTIVE; |
ff3ead96 | 312 | } |
11682a41 | 313 | EXPORT_SYMBOL_GPL(alarm_init); |
ff3ead96 | 314 | |
180bf812 | 315 | /** |
6cffe00f | 316 | * alarm_start - Sets an absolute alarm to fire |
ff3ead96 JS |
317 | * @alarm: ptr to alarm to set |
318 | * @start: time to run the alarm | |
ff3ead96 | 319 | */ |
dae373be | 320 | int alarm_start(struct alarm *alarm, ktime_t start) |
ff3ead96 JS |
321 | { |
322 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
323 | unsigned long flags; | |
dae373be | 324 | int ret; |
ff3ead96 JS |
325 | |
326 | spin_lock_irqsave(&base->lock, flags); | |
ff3ead96 | 327 | alarm->node.expires = start; |
ff3ead96 | 328 | alarmtimer_enqueue(base, alarm); |
dae373be JS |
329 | ret = hrtimer_start(&alarm->timer, alarm->node.expires, |
330 | HRTIMER_MODE_ABS); | |
ff3ead96 | 331 | spin_unlock_irqrestore(&base->lock, flags); |
dae373be | 332 | return ret; |
ff3ead96 | 333 | } |
11682a41 | 334 | EXPORT_SYMBOL_GPL(alarm_start); |
ff3ead96 | 335 | |
6cffe00f TP |
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 | */ | |
341 | int 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 | } | |
11682a41 | 348 | EXPORT_SYMBOL_GPL(alarm_start_relative); |
6cffe00f TP |
349 | |
350 | void 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 | } | |
11682a41 | 361 | EXPORT_SYMBOL_GPL(alarm_restart); |
6cffe00f | 362 | |
180bf812 | 363 | /** |
9082c465 | 364 | * alarm_try_to_cancel - Tries to cancel an alarm timer |
ff3ead96 | 365 | * @alarm: ptr to alarm to be canceled |
9082c465 JS |
366 | * |
367 | * Returns 1 if the timer was canceled, 0 if it was not running, | |
368 | * and -1 if the callback was running | |
ff3ead96 | 369 | */ |
9082c465 | 370 | int alarm_try_to_cancel(struct alarm *alarm) |
ff3ead96 JS |
371 | { |
372 | struct alarm_base *base = &alarm_bases[alarm->type]; | |
373 | unsigned long flags; | |
dae373be | 374 | int ret; |
9082c465 | 375 | |
dae373be JS |
376 | spin_lock_irqsave(&base->lock, flags); |
377 | ret = hrtimer_try_to_cancel(&alarm->timer); | |
378 | if (ret >= 0) | |
a65bcc12 | 379 | alarmtimer_dequeue(base, alarm); |
ff3ead96 | 380 | spin_unlock_irqrestore(&base->lock, flags); |
9082c465 | 381 | return ret; |
ff3ead96 | 382 | } |
11682a41 | 383 | EXPORT_SYMBOL_GPL(alarm_try_to_cancel); |
ff3ead96 JS |
384 | |
385 | ||
9082c465 JS |
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 | */ | |
392 | int 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 | } | |
11682a41 | 401 | EXPORT_SYMBOL_GPL(alarm_cancel); |
9082c465 | 402 | |
dce75a8c JS |
403 | |
404 | u64 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 | } | |
11682a41 | 434 | EXPORT_SYMBOL_GPL(alarm_forward); |
dce75a8c | 435 | |
6cffe00f TP |
436 | u64 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 | } | |
11682a41 | 442 | EXPORT_SYMBOL_GPL(alarm_forward_now); |
dce75a8c JS |
443 | |
444 | ||
180bf812 | 445 | /** |
9a7adcf5 JS |
446 | * clock2alarm - helper that converts from clockid to alarmtypes |
447 | * @clockid: clockid. | |
9a7adcf5 JS |
448 | */ |
449 | static 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 | ||
180bf812 | 458 | /** |
9a7adcf5 JS |
459 | * alarm_handle_timer - Callback for posix timers |
460 | * @alarm: alarm that fired | |
461 | * | |
462 | * Posix timer callback for expired alarm timers. | |
463 | */ | |
4b41308d JS |
464 | static enum alarmtimer_restart alarm_handle_timer(struct alarm *alarm, |
465 | ktime_t now) | |
9a7adcf5 | 466 | { |
474e941b | 467 | unsigned long flags; |
9a7adcf5 | 468 | struct k_itimer *ptr = container_of(alarm, struct k_itimer, |
9e264762 | 469 | it.alarm.alarmtimer); |
474e941b RL |
470 | enum alarmtimer_restart result = ALARMTIMER_NORESTART; |
471 | ||
472 | spin_lock_irqsave(&ptr->it_lock, flags); | |
265b81d2 RL |
473 | if ((ptr->it_sigev_notify & ~SIGEV_THREAD_ID) != SIGEV_NONE) { |
474 | if (posix_timer_event(ptr, 0) != 0) | |
475 | ptr->it_overrun++; | |
476 | } | |
4b41308d | 477 | |
54da23b7 | 478 | /* Re-add periodic timers */ |
9e264762 JS |
479 | if (ptr->it.alarm.interval.tv64) { |
480 | ptr->it_overrun += alarm_forward(alarm, now, | |
481 | ptr->it.alarm.interval); | |
474e941b | 482 | result = ALARMTIMER_RESTART; |
54da23b7 | 483 | } |
474e941b RL |
484 | spin_unlock_irqrestore(&ptr->it_lock, flags); |
485 | ||
486 | return result; | |
9a7adcf5 JS |
487 | } |
488 | ||
180bf812 | 489 | /** |
9a7adcf5 JS |
490 | * alarm_clock_getres - posix getres interface |
491 | * @which_clock: clockid | |
492 | * @tp: timespec to fill | |
493 | * | |
494 | * Returns the granularity of underlying alarm base clock | |
495 | */ | |
496 | static int alarm_clock_getres(const clockid_t which_clock, struct timespec *tp) | |
497 | { | |
498 | clockid_t baseid = alarm_bases[clock2alarm(which_clock)].base_clockid; | |
499 | ||
1c6b39ad | 500 | if (!alarmtimer_get_rtcdev()) |
98d6f4dd | 501 | return -EINVAL; |
1c6b39ad | 502 | |
9a7adcf5 JS |
503 | return hrtimer_get_res(baseid, tp); |
504 | } | |
505 | ||
506 | /** | |
507 | * alarm_clock_get - posix clock_get interface | |
508 | * @which_clock: clockid | |
509 | * @tp: timespec to fill. | |
510 | * | |
511 | * Provides the underlying alarm base time. | |
512 | */ | |
513 | static int alarm_clock_get(clockid_t which_clock, struct timespec *tp) | |
514 | { | |
515 | struct alarm_base *base = &alarm_bases[clock2alarm(which_clock)]; | |
516 | ||
1c6b39ad | 517 | if (!alarmtimer_get_rtcdev()) |
98d6f4dd | 518 | return -EINVAL; |
1c6b39ad | 519 | |
9a7adcf5 JS |
520 | *tp = ktime_to_timespec(base->gettime()); |
521 | return 0; | |
522 | } | |
523 | ||
524 | /** | |
525 | * alarm_timer_create - posix timer_create interface | |
526 | * @new_timer: k_itimer pointer to manage | |
527 | * | |
528 | * Initializes the k_itimer structure. | |
529 | */ | |
530 | static int alarm_timer_create(struct k_itimer *new_timer) | |
531 | { | |
532 | enum alarmtimer_type type; | |
533 | struct alarm_base *base; | |
534 | ||
1c6b39ad JS |
535 | if (!alarmtimer_get_rtcdev()) |
536 | return -ENOTSUPP; | |
537 | ||
9a7adcf5 JS |
538 | if (!capable(CAP_WAKE_ALARM)) |
539 | return -EPERM; | |
540 | ||
541 | type = clock2alarm(new_timer->it_clock); | |
542 | base = &alarm_bases[type]; | |
9e264762 | 543 | alarm_init(&new_timer->it.alarm.alarmtimer, type, alarm_handle_timer); |
9a7adcf5 JS |
544 | return 0; |
545 | } | |
546 | ||
547 | /** | |
548 | * alarm_timer_get - posix timer_get interface | |
549 | * @new_timer: k_itimer pointer | |
550 | * @cur_setting: itimerspec data to fill | |
551 | * | |
e86fea76 | 552 | * Copies out the current itimerspec data |
9a7adcf5 JS |
553 | */ |
554 | static void alarm_timer_get(struct k_itimer *timr, | |
555 | struct itimerspec *cur_setting) | |
556 | { | |
e86fea76 RL |
557 | ktime_t relative_expiry_time = |
558 | alarm_expires_remaining(&(timr->it.alarm.alarmtimer)); | |
559 | ||
560 | if (ktime_to_ns(relative_expiry_time) > 0) { | |
561 | cur_setting->it_value = ktime_to_timespec(relative_expiry_time); | |
562 | } else { | |
563 | cur_setting->it_value.tv_sec = 0; | |
564 | cur_setting->it_value.tv_nsec = 0; | |
565 | } | |
ea7802f6 | 566 | |
e86fea76 | 567 | cur_setting->it_interval = ktime_to_timespec(timr->it.alarm.interval); |
9a7adcf5 JS |
568 | } |
569 | ||
570 | /** | |
571 | * alarm_timer_del - posix timer_del interface | |
572 | * @timr: k_itimer pointer to be deleted | |
573 | * | |
574 | * Cancels any programmed alarms for the given timer. | |
575 | */ | |
576 | static int alarm_timer_del(struct k_itimer *timr) | |
577 | { | |
1c6b39ad JS |
578 | if (!rtcdev) |
579 | return -ENOTSUPP; | |
580 | ||
9082c465 JS |
581 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
582 | return TIMER_RETRY; | |
583 | ||
9a7adcf5 JS |
584 | return 0; |
585 | } | |
586 | ||
587 | /** | |
588 | * alarm_timer_set - posix timer_set interface | |
589 | * @timr: k_itimer pointer to be deleted | |
590 | * @flags: timer flags | |
591 | * @new_setting: itimerspec to be used | |
592 | * @old_setting: itimerspec being replaced | |
593 | * | |
594 | * Sets the timer to new_setting, and starts the timer. | |
595 | */ | |
596 | static int alarm_timer_set(struct k_itimer *timr, int flags, | |
597 | struct itimerspec *new_setting, | |
598 | struct itimerspec *old_setting) | |
599 | { | |
16927776 JS |
600 | ktime_t exp; |
601 | ||
1c6b39ad JS |
602 | if (!rtcdev) |
603 | return -ENOTSUPP; | |
604 | ||
16927776 JS |
605 | if (flags & ~TIMER_ABSTIME) |
606 | return -EINVAL; | |
607 | ||
971c90bf JS |
608 | if (old_setting) |
609 | alarm_timer_get(timr, old_setting); | |
9a7adcf5 JS |
610 | |
611 | /* If the timer was already set, cancel it */ | |
9082c465 JS |
612 | if (alarm_try_to_cancel(&timr->it.alarm.alarmtimer) < 0) |
613 | return TIMER_RETRY; | |
9a7adcf5 JS |
614 | |
615 | /* start the timer */ | |
9e264762 | 616 | timr->it.alarm.interval = timespec_to_ktime(new_setting->it_interval); |
16927776 JS |
617 | exp = timespec_to_ktime(new_setting->it_value); |
618 | /* Convert (if necessary) to absolute time */ | |
619 | if (flags != TIMER_ABSTIME) { | |
620 | ktime_t now; | |
621 | ||
622 | now = alarm_bases[timr->it.alarm.alarmtimer.type].gettime(); | |
623 | exp = ktime_add(now, exp); | |
624 | } | |
625 | ||
626 | alarm_start(&timr->it.alarm.alarmtimer, exp); | |
9a7adcf5 JS |
627 | return 0; |
628 | } | |
629 | ||
630 | /** | |
631 | * alarmtimer_nsleep_wakeup - Wakeup function for alarm_timer_nsleep | |
632 | * @alarm: ptr to alarm that fired | |
633 | * | |
634 | * Wakes up the task that set the alarmtimer | |
635 | */ | |
4b41308d JS |
636 | static enum alarmtimer_restart alarmtimer_nsleep_wakeup(struct alarm *alarm, |
637 | ktime_t now) | |
9a7adcf5 JS |
638 | { |
639 | struct task_struct *task = (struct task_struct *)alarm->data; | |
640 | ||
641 | alarm->data = NULL; | |
642 | if (task) | |
643 | wake_up_process(task); | |
4b41308d | 644 | return ALARMTIMER_NORESTART; |
9a7adcf5 JS |
645 | } |
646 | ||
647 | /** | |
648 | * alarmtimer_do_nsleep - Internal alarmtimer nsleep implementation | |
649 | * @alarm: ptr to alarmtimer | |
650 | * @absexp: absolute expiration time | |
651 | * | |
652 | * Sets the alarm timer and sleeps until it is fired or interrupted. | |
653 | */ | |
654 | static int alarmtimer_do_nsleep(struct alarm *alarm, ktime_t absexp) | |
655 | { | |
656 | alarm->data = (void *)current; | |
657 | do { | |
658 | set_current_state(TASK_INTERRUPTIBLE); | |
9e264762 | 659 | alarm_start(alarm, absexp); |
9a7adcf5 JS |
660 | if (likely(alarm->data)) |
661 | schedule(); | |
662 | ||
663 | alarm_cancel(alarm); | |
664 | } while (alarm->data && !signal_pending(current)); | |
665 | ||
666 | __set_current_state(TASK_RUNNING); | |
667 | ||
668 | return (alarm->data == NULL); | |
669 | } | |
670 | ||
671 | ||
672 | /** | |
673 | * update_rmtp - Update remaining timespec value | |
674 | * @exp: expiration time | |
675 | * @type: timer type | |
676 | * @rmtp: user pointer to remaining timepsec value | |
677 | * | |
678 | * Helper function that fills in rmtp value with time between | |
679 | * now and the exp value | |
680 | */ | |
681 | static int update_rmtp(ktime_t exp, enum alarmtimer_type type, | |
682 | struct timespec __user *rmtp) | |
683 | { | |
684 | struct timespec rmt; | |
685 | ktime_t rem; | |
686 | ||
687 | rem = ktime_sub(exp, alarm_bases[type].gettime()); | |
688 | ||
689 | if (rem.tv64 <= 0) | |
690 | return 0; | |
691 | rmt = ktime_to_timespec(rem); | |
692 | ||
693 | if (copy_to_user(rmtp, &rmt, sizeof(*rmtp))) | |
694 | return -EFAULT; | |
695 | ||
696 | return 1; | |
697 | ||
698 | } | |
699 | ||
700 | /** | |
701 | * alarm_timer_nsleep_restart - restartblock alarmtimer nsleep | |
702 | * @restart: ptr to restart block | |
703 | * | |
704 | * Handles restarted clock_nanosleep calls | |
705 | */ | |
706 | static long __sched alarm_timer_nsleep_restart(struct restart_block *restart) | |
707 | { | |
ab8177bc | 708 | enum alarmtimer_type type = restart->nanosleep.clockid; |
9a7adcf5 JS |
709 | ktime_t exp; |
710 | struct timespec __user *rmtp; | |
711 | struct alarm alarm; | |
712 | int ret = 0; | |
713 | ||
714 | exp.tv64 = restart->nanosleep.expires; | |
715 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
716 | ||
717 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
718 | goto out; | |
719 | ||
720 | if (freezing(current)) | |
721 | alarmtimer_freezerset(exp, type); | |
722 | ||
723 | rmtp = restart->nanosleep.rmtp; | |
724 | if (rmtp) { | |
725 | ret = update_rmtp(exp, type, rmtp); | |
726 | if (ret <= 0) | |
727 | goto out; | |
728 | } | |
729 | ||
730 | ||
731 | /* The other values in restart are already filled in */ | |
732 | ret = -ERESTART_RESTARTBLOCK; | |
733 | out: | |
734 | return ret; | |
735 | } | |
736 | ||
737 | /** | |
738 | * alarm_timer_nsleep - alarmtimer nanosleep | |
739 | * @which_clock: clockid | |
740 | * @flags: determins abstime or relative | |
741 | * @tsreq: requested sleep time (abs or rel) | |
742 | * @rmtp: remaining sleep time saved | |
743 | * | |
744 | * Handles clock_nanosleep calls against _ALARM clockids | |
745 | */ | |
746 | static int alarm_timer_nsleep(const clockid_t which_clock, int flags, | |
747 | struct timespec *tsreq, struct timespec __user *rmtp) | |
748 | { | |
749 | enum alarmtimer_type type = clock2alarm(which_clock); | |
750 | struct alarm alarm; | |
751 | ktime_t exp; | |
752 | int ret = 0; | |
753 | struct restart_block *restart; | |
754 | ||
1c6b39ad JS |
755 | if (!alarmtimer_get_rtcdev()) |
756 | return -ENOTSUPP; | |
757 | ||
16927776 JS |
758 | if (flags & ~TIMER_ABSTIME) |
759 | return -EINVAL; | |
760 | ||
9a7adcf5 JS |
761 | if (!capable(CAP_WAKE_ALARM)) |
762 | return -EPERM; | |
763 | ||
764 | alarm_init(&alarm, type, alarmtimer_nsleep_wakeup); | |
765 | ||
766 | exp = timespec_to_ktime(*tsreq); | |
767 | /* Convert (if necessary) to absolute time */ | |
768 | if (flags != TIMER_ABSTIME) { | |
769 | ktime_t now = alarm_bases[type].gettime(); | |
770 | exp = ktime_add(now, exp); | |
771 | } | |
772 | ||
773 | if (alarmtimer_do_nsleep(&alarm, exp)) | |
774 | goto out; | |
775 | ||
776 | if (freezing(current)) | |
777 | alarmtimer_freezerset(exp, type); | |
778 | ||
779 | /* abs timers don't set remaining time or restart */ | |
780 | if (flags == TIMER_ABSTIME) { | |
781 | ret = -ERESTARTNOHAND; | |
782 | goto out; | |
783 | } | |
784 | ||
785 | if (rmtp) { | |
786 | ret = update_rmtp(exp, type, rmtp); | |
787 | if (ret <= 0) | |
788 | goto out; | |
789 | } | |
790 | ||
f56141e3 | 791 | restart = ¤t->restart_block; |
9a7adcf5 | 792 | restart->fn = alarm_timer_nsleep_restart; |
ab8177bc | 793 | restart->nanosleep.clockid = type; |
9a7adcf5 JS |
794 | restart->nanosleep.expires = exp.tv64; |
795 | restart->nanosleep.rmtp = rmtp; | |
796 | ret = -ERESTART_RESTARTBLOCK; | |
797 | ||
798 | out: | |
799 | return ret; | |
800 | } | |
ff3ead96 | 801 | |
ff3ead96 JS |
802 | |
803 | /* Suspend hook structures */ | |
804 | static const struct dev_pm_ops alarmtimer_pm_ops = { | |
805 | .suspend = alarmtimer_suspend, | |
806 | }; | |
807 | ||
808 | static struct platform_driver alarmtimer_driver = { | |
809 | .driver = { | |
810 | .name = "alarmtimer", | |
811 | .pm = &alarmtimer_pm_ops, | |
812 | } | |
813 | }; | |
814 | ||
815 | /** | |
816 | * alarmtimer_init - Initialize alarm timer code | |
817 | * | |
818 | * This function initializes the alarm bases and registers | |
819 | * the posix clock ids. | |
820 | */ | |
821 | static int __init alarmtimer_init(void) | |
822 | { | |
4523f6ad | 823 | struct platform_device *pdev; |
ff3ead96 JS |
824 | int error = 0; |
825 | int i; | |
9a7adcf5 JS |
826 | struct k_clock alarm_clock = { |
827 | .clock_getres = alarm_clock_getres, | |
828 | .clock_get = alarm_clock_get, | |
829 | .timer_create = alarm_timer_create, | |
830 | .timer_set = alarm_timer_set, | |
831 | .timer_del = alarm_timer_del, | |
832 | .timer_get = alarm_timer_get, | |
833 | .nsleep = alarm_timer_nsleep, | |
834 | }; | |
835 | ||
c5e14e76 | 836 | alarmtimer_rtc_timer_init(); |
ad30dfa9 | 837 | |
9a7adcf5 JS |
838 | posix_timers_register_clock(CLOCK_REALTIME_ALARM, &alarm_clock); |
839 | posix_timers_register_clock(CLOCK_BOOTTIME_ALARM, &alarm_clock); | |
ff3ead96 JS |
840 | |
841 | /* Initialize alarm bases */ | |
842 | alarm_bases[ALARM_REALTIME].base_clockid = CLOCK_REALTIME; | |
843 | alarm_bases[ALARM_REALTIME].gettime = &ktime_get_real; | |
844 | alarm_bases[ALARM_BOOTTIME].base_clockid = CLOCK_BOOTTIME; | |
845 | alarm_bases[ALARM_BOOTTIME].gettime = &ktime_get_boottime; | |
846 | for (i = 0; i < ALARM_NUMTYPE; i++) { | |
847 | timerqueue_init_head(&alarm_bases[i].timerqueue); | |
848 | spin_lock_init(&alarm_bases[i].lock); | |
ff3ead96 | 849 | } |
8bc0dafb | 850 | |
4523f6ad TG |
851 | error = alarmtimer_rtc_interface_setup(); |
852 | if (error) | |
853 | return error; | |
854 | ||
ff3ead96 | 855 | error = platform_driver_register(&alarmtimer_driver); |
4523f6ad TG |
856 | if (error) |
857 | goto out_if; | |
ff3ead96 | 858 | |
4523f6ad TG |
859 | pdev = platform_device_register_simple("alarmtimer", -1, NULL, 0); |
860 | if (IS_ERR(pdev)) { | |
861 | error = PTR_ERR(pdev); | |
862 | goto out_drv; | |
863 | } | |
59a93c27 | 864 | ws = wakeup_source_register("alarmtimer"); |
4523f6ad TG |
865 | return 0; |
866 | ||
867 | out_drv: | |
868 | platform_driver_unregister(&alarmtimer_driver); | |
869 | out_if: | |
870 | alarmtimer_rtc_interface_remove(); | |
ff3ead96 JS |
871 | return error; |
872 | } | |
873 | device_initcall(alarmtimer_init); |