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Alessandro Zummo0c86edc2006-03-27 01:16:37 -08001/*
2 * RTC subsystem, interface functions
3 *
4 * Copyright (C) 2005 Tower Technologies
5 * Author: Alessandro Zummo <a.zummo@towertech.it>
6 *
7 * based on arch/arm/common/rtctime.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12*/
13
14#include <linux/rtc.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040015#include <linux/sched.h>
Paul Gortmaker21138522011-05-27 09:57:25 -040016#include <linux/module.h>
David Brownell97144c62007-10-16 01:28:16 -070017#include <linux/log2.h>
John Stultz6610e082010-09-23 15:07:34 -070018#include <linux/workqueue.h>
19
John Stultzaa0be0f2011-01-20 15:26:12 -080020static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
21static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
22
John Stultz6610e082010-09-23 15:07:34 -070023static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
24{
25 int err;
26 if (!rtc->ops)
27 err = -ENODEV;
28 else if (!rtc->ops->read_time)
29 err = -EINVAL;
30 else {
31 memset(tm, 0, sizeof(struct rtc_time));
32 err = rtc->ops->read_time(rtc->dev.parent, tm);
33 }
34 return err;
35}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080036
David Brownellab6a2d72007-05-08 00:33:30 -070037int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080038{
39 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080040
41 err = mutex_lock_interruptible(&rtc->ops_lock);
42 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070043 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080044
John Stultz6610e082010-09-23 15:07:34 -070045 err = __rtc_read_time(rtc, tm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080046 mutex_unlock(&rtc->ops_lock);
47 return err;
48}
49EXPORT_SYMBOL_GPL(rtc_read_time);
50
David Brownellab6a2d72007-05-08 00:33:30 -070051int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080052{
53 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080054
55 err = rtc_valid_tm(tm);
56 if (err != 0)
57 return err;
58
59 err = mutex_lock_interruptible(&rtc->ops_lock);
60 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070061 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080062
63 if (!rtc->ops)
64 err = -ENODEV;
Alessandro Zummobbccf832009-01-06 14:42:21 -080065 else if (rtc->ops->set_time)
David Brownellcd966202007-05-08 00:33:40 -070066 err = rtc->ops->set_time(rtc->dev.parent, tm);
Alessandro Zummobbccf832009-01-06 14:42:21 -080067 else if (rtc->ops->set_mmss) {
68 unsigned long secs;
69 err = rtc_tm_to_time(tm, &secs);
70 if (err == 0)
71 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
72 } else
73 err = -EINVAL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080074
Zoran Markovic14d0e342013-06-26 16:09:13 -070075 pm_stay_awake(rtc->dev.parent);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080076 mutex_unlock(&rtc->ops_lock);
NeilBrown5f9679d2011-12-09 09:39:15 +110077 /* A timer might have just expired */
78 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080079 return err;
80}
81EXPORT_SYMBOL_GPL(rtc_set_time);
82
David Brownellab6a2d72007-05-08 00:33:30 -070083int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080084{
85 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080086
87 err = mutex_lock_interruptible(&rtc->ops_lock);
88 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070089 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080090
91 if (!rtc->ops)
92 err = -ENODEV;
93 else if (rtc->ops->set_mmss)
David Brownellcd966202007-05-08 00:33:40 -070094 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080095 else if (rtc->ops->read_time && rtc->ops->set_time) {
96 struct rtc_time new, old;
97
David Brownellcd966202007-05-08 00:33:40 -070098 err = rtc->ops->read_time(rtc->dev.parent, &old);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080099 if (err == 0) {
100 rtc_time_to_tm(secs, &new);
101
102 /*
103 * avoid writing when we're going to change the day of
104 * the month. We will retry in the next minute. This
105 * basically means that if the RTC must not drift
106 * by more than 1 minute in 11 minutes.
107 */
108 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
109 (new.tm_hour == 23 && new.tm_min == 59)))
David Brownellcd966202007-05-08 00:33:40 -0700110 err = rtc->ops->set_time(rtc->dev.parent,
David Brownellab6a2d72007-05-08 00:33:30 -0700111 &new);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800112 }
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700113 } else {
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800114 err = -EINVAL;
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700115 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800116
Zoran Markovic14d0e342013-06-26 16:09:13 -0700117 pm_stay_awake(rtc->dev.parent);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800118 mutex_unlock(&rtc->ops_lock);
NeilBrown5f9679d2011-12-09 09:39:15 +1100119 /* A timer might have just expired */
120 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800121
122 return err;
123}
124EXPORT_SYMBOL_GPL(rtc_set_mmss);
125
John Stultzf44f7f92011-02-21 22:58:51 -0800126static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
127{
128 int err;
129
130 err = mutex_lock_interruptible(&rtc->ops_lock);
131 if (err)
132 return err;
133
134 if (rtc->ops == NULL)
135 err = -ENODEV;
136 else if (!rtc->ops->read_alarm)
137 err = -EINVAL;
138 else {
139 memset(alarm, 0, sizeof(struct rtc_wkalrm));
140 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
141 }
142
143 mutex_unlock(&rtc->ops_lock);
144 return err;
145}
146
147int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
148{
149 int err;
150 struct rtc_time before, now;
151 int first_time = 1;
152 unsigned long t_now, t_alm;
153 enum { none, day, month, year } missing = none;
154 unsigned days;
155
156 /* The lower level RTC driver may return -1 in some fields,
157 * creating invalid alarm->time values, for reasons like:
158 *
159 * - The hardware may not be capable of filling them in;
160 * many alarms match only on time-of-day fields, not
161 * day/month/year calendar data.
162 *
163 * - Some hardware uses illegal values as "wildcard" match
164 * values, which non-Linux firmware (like a BIOS) may try
165 * to set up as e.g. "alarm 15 minutes after each hour".
166 * Linux uses only oneshot alarms.
167 *
168 * When we see that here, we deal with it by using values from
169 * a current RTC timestamp for any missing (-1) values. The
170 * RTC driver prevents "periodic alarm" modes.
171 *
172 * But this can be racey, because some fields of the RTC timestamp
173 * may have wrapped in the interval since we read the RTC alarm,
174 * which would lead to us inserting inconsistent values in place
175 * of the -1 fields.
176 *
177 * Reading the alarm and timestamp in the reverse sequence
178 * would have the same race condition, and not solve the issue.
179 *
180 * So, we must first read the RTC timestamp,
181 * then read the RTC alarm value,
182 * and then read a second RTC timestamp.
183 *
184 * If any fields of the second timestamp have changed
185 * when compared with the first timestamp, then we know
186 * our timestamp may be inconsistent with that used by
187 * the low-level rtc_read_alarm_internal() function.
188 *
189 * So, when the two timestamps disagree, we just loop and do
190 * the process again to get a fully consistent set of values.
191 *
192 * This could all instead be done in the lower level driver,
193 * but since more than one lower level RTC implementation needs it,
194 * then it's probably best best to do it here instead of there..
195 */
196
197 /* Get the "before" timestamp */
198 err = rtc_read_time(rtc, &before);
199 if (err < 0)
200 return err;
201 do {
202 if (!first_time)
203 memcpy(&before, &now, sizeof(struct rtc_time));
204 first_time = 0;
205
206 /* get the RTC alarm values, which may be incomplete */
207 err = rtc_read_alarm_internal(rtc, alarm);
208 if (err)
209 return err;
210
211 /* full-function RTCs won't have such missing fields */
212 if (rtc_valid_tm(&alarm->time) == 0)
213 return 0;
214
215 /* get the "after" timestamp, to detect wrapped fields */
216 err = rtc_read_time(rtc, &now);
217 if (err < 0)
218 return err;
219
220 /* note that tm_sec is a "don't care" value here: */
221 } while ( before.tm_min != now.tm_min
222 || before.tm_hour != now.tm_hour
223 || before.tm_mon != now.tm_mon
224 || before.tm_year != now.tm_year);
225
226 /* Fill in the missing alarm fields using the timestamp; we
227 * know there's at least one since alarm->time is invalid.
228 */
229 if (alarm->time.tm_sec == -1)
230 alarm->time.tm_sec = now.tm_sec;
231 if (alarm->time.tm_min == -1)
232 alarm->time.tm_min = now.tm_min;
233 if (alarm->time.tm_hour == -1)
234 alarm->time.tm_hour = now.tm_hour;
235
236 /* For simplicity, only support date rollover for now */
Ben Hutchingse74a8f22012-01-10 15:11:02 -0800237 if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
John Stultzf44f7f92011-02-21 22:58:51 -0800238 alarm->time.tm_mday = now.tm_mday;
239 missing = day;
240 }
Ben Hutchingse74a8f22012-01-10 15:11:02 -0800241 if ((unsigned)alarm->time.tm_mon >= 12) {
John Stultzf44f7f92011-02-21 22:58:51 -0800242 alarm->time.tm_mon = now.tm_mon;
243 if (missing == none)
244 missing = month;
245 }
246 if (alarm->time.tm_year == -1) {
247 alarm->time.tm_year = now.tm_year;
248 if (missing == none)
249 missing = year;
250 }
251
252 /* with luck, no rollover is needed */
253 rtc_tm_to_time(&now, &t_now);
254 rtc_tm_to_time(&alarm->time, &t_alm);
255 if (t_now < t_alm)
256 goto done;
257
258 switch (missing) {
259
260 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
261 * that will trigger at 5am will do so at 5am Tuesday, which
262 * could also be in the next month or year. This is a common
263 * case, especially for PCs.
264 */
265 case day:
266 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
267 t_alm += 24 * 60 * 60;
268 rtc_time_to_tm(t_alm, &alarm->time);
269 break;
270
271 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
272 * be next month. An alarm matching on the 30th, 29th, or 28th
273 * may end up in the month after that! Many newer PCs support
274 * this type of alarm.
275 */
276 case month:
277 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
278 do {
279 if (alarm->time.tm_mon < 11)
280 alarm->time.tm_mon++;
281 else {
282 alarm->time.tm_mon = 0;
283 alarm->time.tm_year++;
284 }
285 days = rtc_month_days(alarm->time.tm_mon,
286 alarm->time.tm_year);
287 } while (days < alarm->time.tm_mday);
288 break;
289
290 /* Year rollover ... easy except for leap years! */
291 case year:
292 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
293 do {
294 alarm->time.tm_year++;
295 } while (rtc_valid_tm(&alarm->time) != 0);
296 break;
297
298 default:
299 dev_warn(&rtc->dev, "alarm rollover not handled\n");
300 }
301
302done:
303 return 0;
304}
305
John Stultz6610e082010-09-23 15:07:34 -0700306int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800307{
308 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800309
310 err = mutex_lock_interruptible(&rtc->ops_lock);
311 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700312 return err;
John Stultzd5553a52011-01-20 15:26:13 -0800313 if (rtc->ops == NULL)
314 err = -ENODEV;
315 else if (!rtc->ops->read_alarm)
316 err = -EINVAL;
317 else {
318 memset(alarm, 0, sizeof(struct rtc_wkalrm));
319 alarm->enabled = rtc->aie_timer.enabled;
John Stultz6610e082010-09-23 15:07:34 -0700320 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
John Stultzd5553a52011-01-20 15:26:13 -0800321 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800322 mutex_unlock(&rtc->ops_lock);
Mark Lord0e36a9a2007-10-16 01:28:21 -0700323
John Stultzd5553a52011-01-20 15:26:13 -0800324 return err;
Mark Lord0e36a9a2007-10-16 01:28:21 -0700325}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800326EXPORT_SYMBOL_GPL(rtc_read_alarm);
327
Mark Brownd576fe42011-06-01 11:13:16 +0100328static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
John Stultz6610e082010-09-23 15:07:34 -0700329{
330 struct rtc_time tm;
331 long now, scheduled;
332 int err;
333
334 err = rtc_valid_tm(&alarm->time);
335 if (err)
336 return err;
337 rtc_tm_to_time(&alarm->time, &scheduled);
338
339 /* Make sure we're not setting alarms in the past */
340 err = __rtc_read_time(rtc, &tm);
341 rtc_tm_to_time(&tm, &now);
342 if (scheduled <= now)
343 return -ETIME;
344 /*
345 * XXX - We just checked to make sure the alarm time is not
346 * in the past, but there is still a race window where if
347 * the is alarm set for the next second and the second ticks
348 * over right here, before we set the alarm.
349 */
350
Linus Torvalds157e8bf2012-01-03 17:32:13 -0800351 if (!rtc->ops)
352 err = -ENODEV;
353 else if (!rtc->ops->set_alarm)
354 err = -EINVAL;
355 else
356 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
357
358 return err;
John Stultz6610e082010-09-23 15:07:34 -0700359}
360
David Brownellab6a2d72007-05-08 00:33:30 -0700361int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800362{
363 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800364
David Brownellf8245c22007-05-08 00:34:07 -0700365 err = rtc_valid_tm(&alarm->time);
366 if (err != 0)
367 return err;
368
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800369 err = mutex_lock_interruptible(&rtc->ops_lock);
370 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700371 return err;
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700372 if (rtc->aie_timer.enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100373 rtc_timer_remove(rtc, &rtc->aie_timer);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700374
John Stultz6610e082010-09-23 15:07:34 -0700375 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
376 rtc->aie_timer.period = ktime_set(0, 0);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700377 if (alarm->enabled)
John Stultzaa0be0f2011-01-20 15:26:12 -0800378 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700379
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800380 mutex_unlock(&rtc->ops_lock);
John Stultzaa0be0f2011-01-20 15:26:12 -0800381 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800382}
383EXPORT_SYMBOL_GPL(rtc_set_alarm);
384
John Stultzf6d5b332011-03-29 18:00:27 -0700385/* Called once per device from rtc_device_register */
386int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
387{
388 int err;
John Stultzbd729d72012-01-05 15:21:19 -0800389 struct rtc_time now;
John Stultzf6d5b332011-03-29 18:00:27 -0700390
391 err = rtc_valid_tm(&alarm->time);
392 if (err != 0)
393 return err;
394
John Stultzbd729d72012-01-05 15:21:19 -0800395 err = rtc_read_time(rtc, &now);
396 if (err)
397 return err;
398
John Stultzf6d5b332011-03-29 18:00:27 -0700399 err = mutex_lock_interruptible(&rtc->ops_lock);
400 if (err)
401 return err;
402
403 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
404 rtc->aie_timer.period = ktime_set(0, 0);
John Stultzbd729d72012-01-05 15:21:19 -0800405
406 /* Alarm has to be enabled & in the futrure for us to enqueue it */
407 if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 <
408 rtc->aie_timer.node.expires.tv64)) {
409
John Stultzf6d5b332011-03-29 18:00:27 -0700410 rtc->aie_timer.enabled = 1;
411 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
412 }
413 mutex_unlock(&rtc->ops_lock);
414 return err;
415}
416EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
417
418
419
Alessandro Zummo099e6572009-01-04 12:00:54 -0800420int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
421{
422 int err = mutex_lock_interruptible(&rtc->ops_lock);
423 if (err)
424 return err;
425
John Stultz6610e082010-09-23 15:07:34 -0700426 if (rtc->aie_timer.enabled != enabled) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800427 if (enabled)
428 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
429 else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100430 rtc_timer_remove(rtc, &rtc->aie_timer);
John Stultz6610e082010-09-23 15:07:34 -0700431 }
432
John Stultzaa0be0f2011-01-20 15:26:12 -0800433 if (err)
Uwe Kleine-König516373b2011-02-14 11:33:17 +0100434 /* nothing */;
435 else if (!rtc->ops)
Alessandro Zummo099e6572009-01-04 12:00:54 -0800436 err = -ENODEV;
437 else if (!rtc->ops->alarm_irq_enable)
438 err = -EINVAL;
439 else
440 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
441
442 mutex_unlock(&rtc->ops_lock);
443 return err;
444}
445EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
446
447int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
448{
449 int err = mutex_lock_interruptible(&rtc->ops_lock);
450 if (err)
451 return err;
452
John Stultz456d66e2011-02-11 18:15:23 -0800453#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
454 if (enabled == 0 && rtc->uie_irq_active) {
455 mutex_unlock(&rtc->ops_lock);
456 return rtc_dev_update_irq_enable_emul(rtc, 0);
457 }
458#endif
John Stultz6610e082010-09-23 15:07:34 -0700459 /* make sure we're changing state */
460 if (rtc->uie_rtctimer.enabled == enabled)
461 goto out;
462
John Stultz4a649902012-03-06 17:16:09 -0800463 if (rtc->uie_unsupported) {
464 err = -EINVAL;
465 goto out;
466 }
467
John Stultz6610e082010-09-23 15:07:34 -0700468 if (enabled) {
469 struct rtc_time tm;
470 ktime_t now, onesec;
471
472 __rtc_read_time(rtc, &tm);
473 onesec = ktime_set(1, 0);
474 now = rtc_tm_to_ktime(tm);
475 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
476 rtc->uie_rtctimer.period = ktime_set(1, 0);
John Stultzaa0be0f2011-01-20 15:26:12 -0800477 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
478 } else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100479 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
Alessandro Zummo099e6572009-01-04 12:00:54 -0800480
John Stultz6610e082010-09-23 15:07:34 -0700481out:
Alessandro Zummo099e6572009-01-04 12:00:54 -0800482 mutex_unlock(&rtc->ops_lock);
John Stultz456d66e2011-02-11 18:15:23 -0800483#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
484 /*
485 * Enable emulation if the driver did not provide
486 * the update_irq_enable function pointer or if returned
487 * -EINVAL to signal that it has been configured without
488 * interrupts or that are not available at the moment.
489 */
490 if (err == -EINVAL)
491 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
492#endif
Alessandro Zummo099e6572009-01-04 12:00:54 -0800493 return err;
John Stultz6610e082010-09-23 15:07:34 -0700494
Alessandro Zummo099e6572009-01-04 12:00:54 -0800495}
496EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
497
John Stultz6610e082010-09-23 15:07:34 -0700498
David Brownelld728b1e2006-11-25 11:09:28 -0800499/**
John Stultz6610e082010-09-23 15:07:34 -0700500 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
501 * @rtc: pointer to the rtc device
502 *
503 * This function is called when an AIE, UIE or PIE mode interrupt
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300504 * has occurred (or been emulated).
John Stultz6610e082010-09-23 15:07:34 -0700505 *
506 * Triggers the registered irq_task function callback.
507 */
John Stultz456d66e2011-02-11 18:15:23 -0800508void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
John Stultz6610e082010-09-23 15:07:34 -0700509{
510 unsigned long flags;
511
512 /* mark one irq of the appropriate mode */
513 spin_lock_irqsave(&rtc->irq_lock, flags);
514 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
515 spin_unlock_irqrestore(&rtc->irq_lock, flags);
516
517 /* call the task func */
518 spin_lock_irqsave(&rtc->irq_task_lock, flags);
519 if (rtc->irq_task)
520 rtc->irq_task->func(rtc->irq_task->private_data);
521 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
522
523 wake_up_interruptible(&rtc->irq_queue);
524 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
525}
526
527
528/**
529 * rtc_aie_update_irq - AIE mode rtctimer hook
530 * @private: pointer to the rtc_device
531 *
532 * This functions is called when the aie_timer expires.
533 */
534void rtc_aie_update_irq(void *private)
535{
536 struct rtc_device *rtc = (struct rtc_device *)private;
537 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
538}
539
540
541/**
542 * rtc_uie_update_irq - UIE mode rtctimer hook
543 * @private: pointer to the rtc_device
544 *
545 * This functions is called when the uie_timer expires.
546 */
547void rtc_uie_update_irq(void *private)
548{
549 struct rtc_device *rtc = (struct rtc_device *)private;
550 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
551}
552
553
554/**
555 * rtc_pie_update_irq - PIE mode hrtimer hook
556 * @timer: pointer to the pie mode hrtimer
557 *
558 * This function is used to emulate PIE mode interrupts
559 * using an hrtimer. This function is called when the periodic
560 * hrtimer expires.
561 */
562enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
563{
564 struct rtc_device *rtc;
565 ktime_t period;
566 int count;
567 rtc = container_of(timer, struct rtc_device, pie_timer);
568
569 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
570 count = hrtimer_forward_now(timer, period);
571
572 rtc_handle_legacy_irq(rtc, count, RTC_PF);
573
574 return HRTIMER_RESTART;
575}
576
577/**
578 * rtc_update_irq - Triggered when a RTC interrupt occurs.
David Brownellab6a2d72007-05-08 00:33:30 -0700579 * @rtc: the rtc device
David Brownelld728b1e2006-11-25 11:09:28 -0800580 * @num: how many irqs are being reported (usually one)
581 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700582 * Context: any
David Brownelld728b1e2006-11-25 11:09:28 -0800583 */
David Brownellab6a2d72007-05-08 00:33:30 -0700584void rtc_update_irq(struct rtc_device *rtc,
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800585 unsigned long num, unsigned long events)
586{
Alessandro Zummo131c9cc2014-04-03 14:50:09 -0700587 if (unlikely(IS_ERR_OR_NULL(rtc)))
588 return;
589
NeilBrown7523cee2012-08-05 22:56:20 +0200590 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700591 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800592}
593EXPORT_SYMBOL_GPL(rtc_update_irq);
594
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100595static int __rtc_match(struct device *dev, const void *data)
Dave Young71da8902008-01-22 14:00:34 +0800596{
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100597 const char *name = data;
Dave Young71da8902008-01-22 14:00:34 +0800598
Kay Sieversd4afc762009-01-06 14:42:11 -0800599 if (strcmp(dev_name(dev), name) == 0)
Dave Young71da8902008-01-22 14:00:34 +0800600 return 1;
601 return 0;
602}
603
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100604struct rtc_device *rtc_class_open(const char *name)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800605{
David Brownellcd966202007-05-08 00:33:40 -0700606 struct device *dev;
David Brownellab6a2d72007-05-08 00:33:30 -0700607 struct rtc_device *rtc = NULL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800608
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400609 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
Dave Young71da8902008-01-22 14:00:34 +0800610 if (dev)
611 rtc = to_rtc_device(dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800612
David Brownellab6a2d72007-05-08 00:33:30 -0700613 if (rtc) {
614 if (!try_module_get(rtc->owner)) {
David Brownellcd966202007-05-08 00:33:40 -0700615 put_device(dev);
David Brownellab6a2d72007-05-08 00:33:30 -0700616 rtc = NULL;
617 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800618 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800619
David Brownellab6a2d72007-05-08 00:33:30 -0700620 return rtc;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800621}
622EXPORT_SYMBOL_GPL(rtc_class_open);
623
David Brownellab6a2d72007-05-08 00:33:30 -0700624void rtc_class_close(struct rtc_device *rtc)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800625{
David Brownellab6a2d72007-05-08 00:33:30 -0700626 module_put(rtc->owner);
David Brownellcd966202007-05-08 00:33:40 -0700627 put_device(&rtc->dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800628}
629EXPORT_SYMBOL_GPL(rtc_class_close);
630
David Brownellab6a2d72007-05-08 00:33:30 -0700631int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800632{
633 int retval = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800634
635 if (task == NULL || task->func == NULL)
636 return -EINVAL;
637
Alessandro Zummod691eb92007-10-16 01:28:15 -0700638 /* Cannot register while the char dev is in use */
Jiri Kosina372a3022007-12-04 23:45:05 -0800639 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
Alessandro Zummod691eb92007-10-16 01:28:15 -0700640 return -EBUSY;
641
David Brownelld728b1e2006-11-25 11:09:28 -0800642 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800643 if (rtc->irq_task == NULL) {
644 rtc->irq_task = task;
645 retval = 0;
646 }
David Brownelld728b1e2006-11-25 11:09:28 -0800647 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800648
Jiri Kosina372a3022007-12-04 23:45:05 -0800649 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700650
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800651 return retval;
652}
653EXPORT_SYMBOL_GPL(rtc_irq_register);
654
David Brownellab6a2d72007-05-08 00:33:30 -0700655void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800656{
David Brownelld728b1e2006-11-25 11:09:28 -0800657 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800658 if (rtc->irq_task == task)
659 rtc->irq_task = NULL;
David Brownelld728b1e2006-11-25 11:09:28 -0800660 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800661}
662EXPORT_SYMBOL_GPL(rtc_irq_unregister);
663
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000664static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
665{
666 /*
667 * We always cancel the timer here first, because otherwise
668 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
669 * when we manage to start the timer before the callback
670 * returns HRTIMER_RESTART.
671 *
672 * We cannot use hrtimer_cancel() here as a running callback
673 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
674 * would spin forever.
675 */
676 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
677 return -1;
678
679 if (enabled) {
680 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
681
682 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
683 }
684 return 0;
685}
686
David Brownell97144c62007-10-16 01:28:16 -0700687/**
688 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
689 * @rtc: the rtc device
690 * @task: currently registered with rtc_irq_register()
691 * @enabled: true to enable periodic IRQs
692 * Context: any
693 *
694 * Note that rtc_irq_set_freq() should previously have been used to
695 * specify the desired frequency of periodic IRQ task->func() callbacks.
696 */
David Brownellab6a2d72007-05-08 00:33:30 -0700697int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800698{
699 int err = 0;
700 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800701
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000702retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800703 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700704 if (rtc->irq_task != NULL && task == NULL)
705 err = -EBUSY;
Chris Brand0734e272013-07-03 15:07:57 -0700706 else if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700707 err = -EACCES;
Chris Brand0734e272013-07-03 15:07:57 -0700708 else {
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000709 if (rtc_update_hrtimer(rtc, enabled) < 0) {
710 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
711 cpu_relax();
712 goto retry;
713 }
714 rtc->pie_enabled = enabled;
John Stultz6610e082010-09-23 15:07:34 -0700715 }
John Stultz6610e082010-09-23 15:07:34 -0700716 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800717 return err;
718}
719EXPORT_SYMBOL_GPL(rtc_irq_set_state);
720
David Brownell97144c62007-10-16 01:28:16 -0700721/**
722 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
723 * @rtc: the rtc device
724 * @task: currently registered with rtc_irq_register()
725 * @freq: positive frequency with which task->func() will be called
726 * Context: any
727 *
728 * Note that rtc_irq_set_state() is used to enable or disable the
729 * periodic IRQs.
730 */
David Brownellab6a2d72007-05-08 00:33:30 -0700731int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800732{
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700733 int err = 0;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800734 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800735
Thomas Gleixner6e7a3332011-07-22 09:12:51 +0000736 if (freq <= 0 || freq > RTC_MAX_FREQ)
Marcelo Roberto Jimenez83a06bf2011-02-02 16:04:02 -0200737 return -EINVAL;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000738retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800739 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700740 if (rtc->irq_task != NULL && task == NULL)
741 err = -EBUSY;
Chris Brand0734e272013-07-03 15:07:57 -0700742 else if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700743 err = -EACCES;
Chris Brand0734e272013-07-03 15:07:57 -0700744 else {
John Stultz6610e082010-09-23 15:07:34 -0700745 rtc->irq_freq = freq;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000746 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
747 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
748 cpu_relax();
749 goto retry;
John Stultz6610e082010-09-23 15:07:34 -0700750 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800751 }
John Stultz6610e082010-09-23 15:07:34 -0700752 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800753 return err;
754}
David Brownell2601a462006-11-25 11:09:27 -0800755EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
John Stultz6610e082010-09-23 15:07:34 -0700756
757/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100758 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700759 * @rtc rtc device
760 * @timer timer being added.
761 *
762 * Enqueues a timer onto the rtc devices timerqueue and sets
763 * the next alarm event appropriately.
764 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800765 * Sets the enabled bit on the added timer.
766 *
John Stultz6610e082010-09-23 15:07:34 -0700767 * Must hold ops_lock for proper serialization of timerqueue
768 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800769static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700770{
John Stultzaa0be0f2011-01-20 15:26:12 -0800771 timer->enabled = 1;
John Stultz6610e082010-09-23 15:07:34 -0700772 timerqueue_add(&rtc->timerqueue, &timer->node);
773 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
774 struct rtc_wkalrm alarm;
775 int err;
776 alarm.time = rtc_ktime_to_tm(timer->node.expires);
777 alarm.enabled = 1;
778 err = __rtc_set_alarm(rtc, &alarm);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700779 if (err == -ETIME) {
780 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700781 schedule_work(&rtc->irqwork);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700782 } else if (err) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800783 timerqueue_del(&rtc->timerqueue, &timer->node);
784 timer->enabled = 0;
785 return err;
786 }
John Stultz6610e082010-09-23 15:07:34 -0700787 }
John Stultzaa0be0f2011-01-20 15:26:12 -0800788 return 0;
John Stultz6610e082010-09-23 15:07:34 -0700789}
790
Rabin Vincent41c7f742011-11-22 11:03:14 +0100791static void rtc_alarm_disable(struct rtc_device *rtc)
792{
793 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
794 return;
795
796 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
797}
798
John Stultz6610e082010-09-23 15:07:34 -0700799/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100800 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700801 * @rtc rtc device
802 * @timer timer being removed.
803 *
804 * Removes a timer onto the rtc devices timerqueue and sets
805 * the next alarm event appropriately.
806 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800807 * Clears the enabled bit on the removed timer.
808 *
John Stultz6610e082010-09-23 15:07:34 -0700809 * Must hold ops_lock for proper serialization of timerqueue
810 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800811static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700812{
813 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
814 timerqueue_del(&rtc->timerqueue, &timer->node);
John Stultzaa0be0f2011-01-20 15:26:12 -0800815 timer->enabled = 0;
John Stultz6610e082010-09-23 15:07:34 -0700816 if (next == &timer->node) {
817 struct rtc_wkalrm alarm;
818 int err;
819 next = timerqueue_getnext(&rtc->timerqueue);
Rabin Vincent41c7f742011-11-22 11:03:14 +0100820 if (!next) {
821 rtc_alarm_disable(rtc);
John Stultz6610e082010-09-23 15:07:34 -0700822 return;
Rabin Vincent41c7f742011-11-22 11:03:14 +0100823 }
John Stultz6610e082010-09-23 15:07:34 -0700824 alarm.time = rtc_ktime_to_tm(next->expires);
825 alarm.enabled = 1;
826 err = __rtc_set_alarm(rtc, &alarm);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700827 if (err == -ETIME) {
828 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700829 schedule_work(&rtc->irqwork);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700830 }
John Stultz6610e082010-09-23 15:07:34 -0700831 }
832}
833
834/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100835 * rtc_timer_do_work - Expires rtc timers
John Stultz6610e082010-09-23 15:07:34 -0700836 * @rtc rtc device
837 * @timer timer being removed.
838 *
839 * Expires rtc timers. Reprograms next alarm event if needed.
840 * Called via worktask.
841 *
842 * Serializes access to timerqueue via ops_lock mutex
843 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100844void rtc_timer_do_work(struct work_struct *work)
John Stultz6610e082010-09-23 15:07:34 -0700845{
846 struct rtc_timer *timer;
847 struct timerqueue_node *next;
848 ktime_t now;
849 struct rtc_time tm;
850
851 struct rtc_device *rtc =
852 container_of(work, struct rtc_device, irqwork);
853
854 mutex_lock(&rtc->ops_lock);
855again:
856 __rtc_read_time(rtc, &tm);
857 now = rtc_tm_to_ktime(tm);
858 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
859 if (next->expires.tv64 > now.tv64)
860 break;
861
862 /* expire timer */
863 timer = container_of(next, struct rtc_timer, node);
864 timerqueue_del(&rtc->timerqueue, &timer->node);
865 timer->enabled = 0;
866 if (timer->task.func)
867 timer->task.func(timer->task.private_data);
868
869 /* Re-add/fwd periodic timers */
870 if (ktime_to_ns(timer->period)) {
871 timer->node.expires = ktime_add(timer->node.expires,
872 timer->period);
873 timer->enabled = 1;
874 timerqueue_add(&rtc->timerqueue, &timer->node);
875 }
876 }
877
878 /* Set next alarm */
879 if (next) {
880 struct rtc_wkalrm alarm;
881 int err;
882 alarm.time = rtc_ktime_to_tm(next->expires);
883 alarm.enabled = 1;
884 err = __rtc_set_alarm(rtc, &alarm);
885 if (err == -ETIME)
886 goto again;
Rabin Vincent41c7f742011-11-22 11:03:14 +0100887 } else
888 rtc_alarm_disable(rtc);
John Stultz6610e082010-09-23 15:07:34 -0700889
Zoran Markovic14d0e342013-06-26 16:09:13 -0700890 pm_relax(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700891 mutex_unlock(&rtc->ops_lock);
892}
893
894
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100895/* rtc_timer_init - Initializes an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700896 * @timer: timer to be intiialized
897 * @f: function pointer to be called when timer fires
898 * @data: private data passed to function pointer
899 *
900 * Kernel interface to initializing an rtc_timer.
901 */
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700902void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
John Stultz6610e082010-09-23 15:07:34 -0700903{
904 timerqueue_init(&timer->node);
905 timer->enabled = 0;
906 timer->task.func = f;
907 timer->task.private_data = data;
908}
909
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100910/* rtc_timer_start - Sets an rtc_timer to fire in the future
John Stultz6610e082010-09-23 15:07:34 -0700911 * @ rtc: rtc device to be used
912 * @ timer: timer being set
913 * @ expires: time at which to expire the timer
914 * @ period: period that the timer will recur
915 *
916 * Kernel interface to set an rtc_timer
917 */
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700918int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
John Stultz6610e082010-09-23 15:07:34 -0700919 ktime_t expires, ktime_t period)
920{
921 int ret = 0;
922 mutex_lock(&rtc->ops_lock);
923 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100924 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700925
926 timer->node.expires = expires;
927 timer->period = period;
928
John Stultzaa0be0f2011-01-20 15:26:12 -0800929 ret = rtc_timer_enqueue(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700930
931 mutex_unlock(&rtc->ops_lock);
932 return ret;
933}
934
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100935/* rtc_timer_cancel - Stops an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700936 * @ rtc: rtc device to be used
937 * @ timer: timer being set
938 *
939 * Kernel interface to cancel an rtc_timer
940 */
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700941int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700942{
943 int ret = 0;
944 mutex_lock(&rtc->ops_lock);
945 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100946 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700947 mutex_unlock(&rtc->ops_lock);
948 return ret;
949}
950
951