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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);
Hyogi Gim16682c862014-12-10 15:52:27 -080033 if (err < 0) {
Aaro Koskinend0bddb52015-04-16 12:45:51 -070034 dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
35 err);
Hyogi Gim16682c862014-12-10 15:52:27 -080036 return err;
37 }
38
39 err = rtc_valid_tm(tm);
40 if (err < 0)
Aaro Koskinend0bddb52015-04-16 12:45:51 -070041 dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
John Stultz6610e082010-09-23 15:07:34 -070042 }
43 return err;
44}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080045
David Brownellab6a2d72007-05-08 00:33:30 -070046int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080047{
48 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080049
50 err = mutex_lock_interruptible(&rtc->ops_lock);
51 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070052 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080053
John Stultz6610e082010-09-23 15:07:34 -070054 err = __rtc_read_time(rtc, tm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080055 mutex_unlock(&rtc->ops_lock);
56 return err;
57}
58EXPORT_SYMBOL_GPL(rtc_read_time);
59
David Brownellab6a2d72007-05-08 00:33:30 -070060int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080061{
62 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080063
64 err = rtc_valid_tm(tm);
65 if (err != 0)
66 return err;
67
68 err = mutex_lock_interruptible(&rtc->ops_lock);
69 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070070 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080071
72 if (!rtc->ops)
73 err = -ENODEV;
Alessandro Zummobbccf832009-01-06 14:42:21 -080074 else if (rtc->ops->set_time)
David Brownellcd966202007-05-08 00:33:40 -070075 err = rtc->ops->set_time(rtc->dev.parent, tm);
Xunlei Pang8e4ff1a2015-04-01 20:34:27 -070076 else if (rtc->ops->set_mmss64) {
77 time64_t secs64 = rtc_tm_to_time64(tm);
78
79 err = rtc->ops->set_mmss64(rtc->dev.parent, secs64);
80 } else if (rtc->ops->set_mmss) {
Xunlei Pangbc10aa92015-01-22 02:31:51 +000081 time64_t secs64 = rtc_tm_to_time64(tm);
82 err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
Alessandro Zummobbccf832009-01-06 14:42:21 -080083 } else
84 err = -EINVAL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080085
Zoran Markovic14d0e342013-06-26 16:09:13 -070086 pm_stay_awake(rtc->dev.parent);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080087 mutex_unlock(&rtc->ops_lock);
NeilBrown5f9679d2011-12-09 09:39:15 +110088 /* A timer might have just expired */
89 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080090 return err;
91}
92EXPORT_SYMBOL_GPL(rtc_set_time);
93
John Stultzf44f7f92011-02-21 22:58:51 -080094static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
95{
96 int err;
97
98 err = mutex_lock_interruptible(&rtc->ops_lock);
99 if (err)
100 return err;
101
102 if (rtc->ops == NULL)
103 err = -ENODEV;
104 else if (!rtc->ops->read_alarm)
105 err = -EINVAL;
106 else {
107 memset(alarm, 0, sizeof(struct rtc_wkalrm));
108 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
109 }
110
111 mutex_unlock(&rtc->ops_lock);
112 return err;
113}
114
115int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
116{
117 int err;
118 struct rtc_time before, now;
119 int first_time = 1;
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000120 time64_t t_now, t_alm;
John Stultzf44f7f92011-02-21 22:58:51 -0800121 enum { none, day, month, year } missing = none;
122 unsigned days;
123
124 /* The lower level RTC driver may return -1 in some fields,
125 * creating invalid alarm->time values, for reasons like:
126 *
127 * - The hardware may not be capable of filling them in;
128 * many alarms match only on time-of-day fields, not
129 * day/month/year calendar data.
130 *
131 * - Some hardware uses illegal values as "wildcard" match
132 * values, which non-Linux firmware (like a BIOS) may try
133 * to set up as e.g. "alarm 15 minutes after each hour".
134 * Linux uses only oneshot alarms.
135 *
136 * When we see that here, we deal with it by using values from
137 * a current RTC timestamp for any missing (-1) values. The
138 * RTC driver prevents "periodic alarm" modes.
139 *
140 * But this can be racey, because some fields of the RTC timestamp
141 * may have wrapped in the interval since we read the RTC alarm,
142 * which would lead to us inserting inconsistent values in place
143 * of the -1 fields.
144 *
145 * Reading the alarm and timestamp in the reverse sequence
146 * would have the same race condition, and not solve the issue.
147 *
148 * So, we must first read the RTC timestamp,
149 * then read the RTC alarm value,
150 * and then read a second RTC timestamp.
151 *
152 * If any fields of the second timestamp have changed
153 * when compared with the first timestamp, then we know
154 * our timestamp may be inconsistent with that used by
155 * the low-level rtc_read_alarm_internal() function.
156 *
157 * So, when the two timestamps disagree, we just loop and do
158 * the process again to get a fully consistent set of values.
159 *
160 * This could all instead be done in the lower level driver,
161 * but since more than one lower level RTC implementation needs it,
162 * then it's probably best best to do it here instead of there..
163 */
164
165 /* Get the "before" timestamp */
166 err = rtc_read_time(rtc, &before);
167 if (err < 0)
168 return err;
169 do {
170 if (!first_time)
171 memcpy(&before, &now, sizeof(struct rtc_time));
172 first_time = 0;
173
174 /* get the RTC alarm values, which may be incomplete */
175 err = rtc_read_alarm_internal(rtc, alarm);
176 if (err)
177 return err;
178
179 /* full-function RTCs won't have such missing fields */
180 if (rtc_valid_tm(&alarm->time) == 0)
181 return 0;
182
183 /* get the "after" timestamp, to detect wrapped fields */
184 err = rtc_read_time(rtc, &now);
185 if (err < 0)
186 return err;
187
188 /* note that tm_sec is a "don't care" value here: */
189 } while ( before.tm_min != now.tm_min
190 || before.tm_hour != now.tm_hour
191 || before.tm_mon != now.tm_mon
192 || before.tm_year != now.tm_year);
193
194 /* Fill in the missing alarm fields using the timestamp; we
195 * know there's at least one since alarm->time is invalid.
196 */
197 if (alarm->time.tm_sec == -1)
198 alarm->time.tm_sec = now.tm_sec;
199 if (alarm->time.tm_min == -1)
200 alarm->time.tm_min = now.tm_min;
201 if (alarm->time.tm_hour == -1)
202 alarm->time.tm_hour = now.tm_hour;
203
204 /* For simplicity, only support date rollover for now */
Ben Hutchingse74a8f22012-01-10 15:11:02 -0800205 if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
John Stultzf44f7f92011-02-21 22:58:51 -0800206 alarm->time.tm_mday = now.tm_mday;
207 missing = day;
208 }
Ben Hutchingse74a8f22012-01-10 15:11:02 -0800209 if ((unsigned)alarm->time.tm_mon >= 12) {
John Stultzf44f7f92011-02-21 22:58:51 -0800210 alarm->time.tm_mon = now.tm_mon;
211 if (missing == none)
212 missing = month;
213 }
214 if (alarm->time.tm_year == -1) {
215 alarm->time.tm_year = now.tm_year;
216 if (missing == none)
217 missing = year;
218 }
219
220 /* with luck, no rollover is needed */
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000221 t_now = rtc_tm_to_time64(&now);
222 t_alm = rtc_tm_to_time64(&alarm->time);
John Stultzf44f7f92011-02-21 22:58:51 -0800223 if (t_now < t_alm)
224 goto done;
225
226 switch (missing) {
227
228 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
229 * that will trigger at 5am will do so at 5am Tuesday, which
230 * could also be in the next month or year. This is a common
231 * case, especially for PCs.
232 */
233 case day:
234 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
235 t_alm += 24 * 60 * 60;
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000236 rtc_time64_to_tm(t_alm, &alarm->time);
John Stultzf44f7f92011-02-21 22:58:51 -0800237 break;
238
239 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
240 * be next month. An alarm matching on the 30th, 29th, or 28th
241 * may end up in the month after that! Many newer PCs support
242 * this type of alarm.
243 */
244 case month:
245 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
246 do {
247 if (alarm->time.tm_mon < 11)
248 alarm->time.tm_mon++;
249 else {
250 alarm->time.tm_mon = 0;
251 alarm->time.tm_year++;
252 }
253 days = rtc_month_days(alarm->time.tm_mon,
254 alarm->time.tm_year);
255 } while (days < alarm->time.tm_mday);
256 break;
257
258 /* Year rollover ... easy except for leap years! */
259 case year:
260 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
261 do {
262 alarm->time.tm_year++;
Ales Novakee1d9012014-06-06 14:35:39 -0700263 } while (!is_leap_year(alarm->time.tm_year + 1900)
264 && rtc_valid_tm(&alarm->time) != 0);
John Stultzf44f7f92011-02-21 22:58:51 -0800265 break;
266
267 default:
268 dev_warn(&rtc->dev, "alarm rollover not handled\n");
269 }
270
271done:
Ales Novakee1d9012014-06-06 14:35:39 -0700272 err = rtc_valid_tm(&alarm->time);
273
274 if (err) {
275 dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n",
276 alarm->time.tm_year + 1900, alarm->time.tm_mon + 1,
277 alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min,
278 alarm->time.tm_sec);
279 }
280
281 return err;
John Stultzf44f7f92011-02-21 22:58:51 -0800282}
283
John Stultz6610e082010-09-23 15:07:34 -0700284int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800285{
286 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800287
288 err = mutex_lock_interruptible(&rtc->ops_lock);
289 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700290 return err;
John Stultzd5553a52011-01-20 15:26:13 -0800291 if (rtc->ops == NULL)
292 err = -ENODEV;
293 else if (!rtc->ops->read_alarm)
294 err = -EINVAL;
295 else {
296 memset(alarm, 0, sizeof(struct rtc_wkalrm));
297 alarm->enabled = rtc->aie_timer.enabled;
John Stultz6610e082010-09-23 15:07:34 -0700298 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
John Stultzd5553a52011-01-20 15:26:13 -0800299 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800300 mutex_unlock(&rtc->ops_lock);
Mark Lord0e36a9a2007-10-16 01:28:21 -0700301
John Stultzd5553a52011-01-20 15:26:13 -0800302 return err;
Mark Lord0e36a9a2007-10-16 01:28:21 -0700303}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800304EXPORT_SYMBOL_GPL(rtc_read_alarm);
305
Mark Brownd576fe42011-06-01 11:13:16 +0100306static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
John Stultz6610e082010-09-23 15:07:34 -0700307{
308 struct rtc_time tm;
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000309 time64_t now, scheduled;
John Stultz6610e082010-09-23 15:07:34 -0700310 int err;
311
312 err = rtc_valid_tm(&alarm->time);
313 if (err)
314 return err;
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000315 scheduled = rtc_tm_to_time64(&alarm->time);
John Stultz6610e082010-09-23 15:07:34 -0700316
317 /* Make sure we're not setting alarms in the past */
318 err = __rtc_read_time(rtc, &tm);
Hyogi Gimca6dc2d2014-08-08 14:20:11 -0700319 if (err)
320 return err;
Xunlei Pangbc10aa92015-01-22 02:31:51 +0000321 now = rtc_tm_to_time64(&tm);
John Stultz6610e082010-09-23 15:07:34 -0700322 if (scheduled <= now)
323 return -ETIME;
324 /*
325 * XXX - We just checked to make sure the alarm time is not
326 * in the past, but there is still a race window where if
327 * the is alarm set for the next second and the second ticks
328 * over right here, before we set the alarm.
329 */
330
Linus Torvalds157e8bf2012-01-03 17:32:13 -0800331 if (!rtc->ops)
332 err = -ENODEV;
333 else if (!rtc->ops->set_alarm)
334 err = -EINVAL;
335 else
336 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
337
338 return err;
John Stultz6610e082010-09-23 15:07:34 -0700339}
340
David Brownellab6a2d72007-05-08 00:33:30 -0700341int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800342{
343 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800344
David Brownellf8245c22007-05-08 00:34:07 -0700345 err = rtc_valid_tm(&alarm->time);
346 if (err != 0)
347 return err;
348
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800349 err = mutex_lock_interruptible(&rtc->ops_lock);
350 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700351 return err;
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700352 if (rtc->aie_timer.enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100353 rtc_timer_remove(rtc, &rtc->aie_timer);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700354
John Stultz6610e082010-09-23 15:07:34 -0700355 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
356 rtc->aie_timer.period = ktime_set(0, 0);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700357 if (alarm->enabled)
John Stultzaa0be0f2011-01-20 15:26:12 -0800358 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700359
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800360 mutex_unlock(&rtc->ops_lock);
John Stultzaa0be0f2011-01-20 15:26:12 -0800361 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800362}
363EXPORT_SYMBOL_GPL(rtc_set_alarm);
364
John Stultzf6d5b332011-03-29 18:00:27 -0700365/* Called once per device from rtc_device_register */
366int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
367{
368 int err;
John Stultzbd729d72012-01-05 15:21:19 -0800369 struct rtc_time now;
John Stultzf6d5b332011-03-29 18:00:27 -0700370
371 err = rtc_valid_tm(&alarm->time);
372 if (err != 0)
373 return err;
374
John Stultzbd729d72012-01-05 15:21:19 -0800375 err = rtc_read_time(rtc, &now);
376 if (err)
377 return err;
378
John Stultzf6d5b332011-03-29 18:00:27 -0700379 err = mutex_lock_interruptible(&rtc->ops_lock);
380 if (err)
381 return err;
382
383 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
384 rtc->aie_timer.period = ktime_set(0, 0);
John Stultzbd729d72012-01-05 15:21:19 -0800385
386 /* Alarm has to be enabled & in the futrure for us to enqueue it */
387 if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 <
388 rtc->aie_timer.node.expires.tv64)) {
389
John Stultzf6d5b332011-03-29 18:00:27 -0700390 rtc->aie_timer.enabled = 1;
391 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
392 }
393 mutex_unlock(&rtc->ops_lock);
394 return err;
395}
396EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
397
398
399
Alessandro Zummo099e6572009-01-04 12:00:54 -0800400int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
401{
402 int err = mutex_lock_interruptible(&rtc->ops_lock);
403 if (err)
404 return err;
405
John Stultz6610e082010-09-23 15:07:34 -0700406 if (rtc->aie_timer.enabled != enabled) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800407 if (enabled)
408 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
409 else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100410 rtc_timer_remove(rtc, &rtc->aie_timer);
John Stultz6610e082010-09-23 15:07:34 -0700411 }
412
John Stultzaa0be0f2011-01-20 15:26:12 -0800413 if (err)
Uwe Kleine-König516373b2011-02-14 11:33:17 +0100414 /* nothing */;
415 else if (!rtc->ops)
Alessandro Zummo099e6572009-01-04 12:00:54 -0800416 err = -ENODEV;
417 else if (!rtc->ops->alarm_irq_enable)
418 err = -EINVAL;
419 else
420 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
421
422 mutex_unlock(&rtc->ops_lock);
423 return err;
424}
425EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
426
427int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
428{
429 int err = mutex_lock_interruptible(&rtc->ops_lock);
430 if (err)
431 return err;
432
John Stultz456d66e2011-02-11 18:15:23 -0800433#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
434 if (enabled == 0 && rtc->uie_irq_active) {
435 mutex_unlock(&rtc->ops_lock);
436 return rtc_dev_update_irq_enable_emul(rtc, 0);
437 }
438#endif
John Stultz6610e082010-09-23 15:07:34 -0700439 /* make sure we're changing state */
440 if (rtc->uie_rtctimer.enabled == enabled)
441 goto out;
442
John Stultz4a649902012-03-06 17:16:09 -0800443 if (rtc->uie_unsupported) {
444 err = -EINVAL;
445 goto out;
446 }
447
John Stultz6610e082010-09-23 15:07:34 -0700448 if (enabled) {
449 struct rtc_time tm;
450 ktime_t now, onesec;
451
452 __rtc_read_time(rtc, &tm);
453 onesec = ktime_set(1, 0);
454 now = rtc_tm_to_ktime(tm);
455 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
456 rtc->uie_rtctimer.period = ktime_set(1, 0);
John Stultzaa0be0f2011-01-20 15:26:12 -0800457 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
458 } else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100459 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
Alessandro Zummo099e6572009-01-04 12:00:54 -0800460
John Stultz6610e082010-09-23 15:07:34 -0700461out:
Alessandro Zummo099e6572009-01-04 12:00:54 -0800462 mutex_unlock(&rtc->ops_lock);
John Stultz456d66e2011-02-11 18:15:23 -0800463#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
464 /*
465 * Enable emulation if the driver did not provide
466 * the update_irq_enable function pointer or if returned
467 * -EINVAL to signal that it has been configured without
468 * interrupts or that are not available at the moment.
469 */
470 if (err == -EINVAL)
471 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
472#endif
Alessandro Zummo099e6572009-01-04 12:00:54 -0800473 return err;
John Stultz6610e082010-09-23 15:07:34 -0700474
Alessandro Zummo099e6572009-01-04 12:00:54 -0800475}
476EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
477
John Stultz6610e082010-09-23 15:07:34 -0700478
David Brownelld728b1e2006-11-25 11:09:28 -0800479/**
John Stultz6610e082010-09-23 15:07:34 -0700480 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
481 * @rtc: pointer to the rtc device
482 *
483 * This function is called when an AIE, UIE or PIE mode interrupt
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300484 * has occurred (or been emulated).
John Stultz6610e082010-09-23 15:07:34 -0700485 *
486 * Triggers the registered irq_task function callback.
487 */
John Stultz456d66e2011-02-11 18:15:23 -0800488void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
John Stultz6610e082010-09-23 15:07:34 -0700489{
490 unsigned long flags;
491
492 /* mark one irq of the appropriate mode */
493 spin_lock_irqsave(&rtc->irq_lock, flags);
494 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
495 spin_unlock_irqrestore(&rtc->irq_lock, flags);
496
497 /* call the task func */
498 spin_lock_irqsave(&rtc->irq_task_lock, flags);
499 if (rtc->irq_task)
500 rtc->irq_task->func(rtc->irq_task->private_data);
501 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
502
503 wake_up_interruptible(&rtc->irq_queue);
504 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
505}
506
507
508/**
509 * rtc_aie_update_irq - AIE mode rtctimer hook
510 * @private: pointer to the rtc_device
511 *
512 * This functions is called when the aie_timer expires.
513 */
514void rtc_aie_update_irq(void *private)
515{
516 struct rtc_device *rtc = (struct rtc_device *)private;
517 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
518}
519
520
521/**
522 * rtc_uie_update_irq - UIE mode rtctimer hook
523 * @private: pointer to the rtc_device
524 *
525 * This functions is called when the uie_timer expires.
526 */
527void rtc_uie_update_irq(void *private)
528{
529 struct rtc_device *rtc = (struct rtc_device *)private;
530 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
531}
532
533
534/**
535 * rtc_pie_update_irq - PIE mode hrtimer hook
536 * @timer: pointer to the pie mode hrtimer
537 *
538 * This function is used to emulate PIE mode interrupts
539 * using an hrtimer. This function is called when the periodic
540 * hrtimer expires.
541 */
542enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
543{
544 struct rtc_device *rtc;
545 ktime_t period;
546 int count;
547 rtc = container_of(timer, struct rtc_device, pie_timer);
548
549 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
550 count = hrtimer_forward_now(timer, period);
551
552 rtc_handle_legacy_irq(rtc, count, RTC_PF);
553
554 return HRTIMER_RESTART;
555}
556
557/**
558 * rtc_update_irq - Triggered when a RTC interrupt occurs.
David Brownellab6a2d72007-05-08 00:33:30 -0700559 * @rtc: the rtc device
David Brownelld728b1e2006-11-25 11:09:28 -0800560 * @num: how many irqs are being reported (usually one)
561 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700562 * Context: any
David Brownelld728b1e2006-11-25 11:09:28 -0800563 */
David Brownellab6a2d72007-05-08 00:33:30 -0700564void rtc_update_irq(struct rtc_device *rtc,
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800565 unsigned long num, unsigned long events)
566{
viresh kumare7cba882015-07-31 16:23:43 +0530567 if (IS_ERR_OR_NULL(rtc))
Alessandro Zummo131c9cc2014-04-03 14:50:09 -0700568 return;
569
NeilBrown7523cee2012-08-05 22:56:20 +0200570 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700571 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800572}
573EXPORT_SYMBOL_GPL(rtc_update_irq);
574
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100575static int __rtc_match(struct device *dev, const void *data)
Dave Young71da8902008-01-22 14:00:34 +0800576{
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100577 const char *name = data;
Dave Young71da8902008-01-22 14:00:34 +0800578
Kay Sieversd4afc762009-01-06 14:42:11 -0800579 if (strcmp(dev_name(dev), name) == 0)
Dave Young71da8902008-01-22 14:00:34 +0800580 return 1;
581 return 0;
582}
583
Michał Mirosław9f3b7952013-02-01 20:40:17 +0100584struct rtc_device *rtc_class_open(const char *name)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800585{
David Brownellcd966202007-05-08 00:33:40 -0700586 struct device *dev;
David Brownellab6a2d72007-05-08 00:33:30 -0700587 struct rtc_device *rtc = NULL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800588
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400589 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
Dave Young71da8902008-01-22 14:00:34 +0800590 if (dev)
591 rtc = to_rtc_device(dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800592
David Brownellab6a2d72007-05-08 00:33:30 -0700593 if (rtc) {
594 if (!try_module_get(rtc->owner)) {
David Brownellcd966202007-05-08 00:33:40 -0700595 put_device(dev);
David Brownellab6a2d72007-05-08 00:33:30 -0700596 rtc = NULL;
597 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800598 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800599
David Brownellab6a2d72007-05-08 00:33:30 -0700600 return rtc;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800601}
602EXPORT_SYMBOL_GPL(rtc_class_open);
603
David Brownellab6a2d72007-05-08 00:33:30 -0700604void rtc_class_close(struct rtc_device *rtc)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800605{
David Brownellab6a2d72007-05-08 00:33:30 -0700606 module_put(rtc->owner);
David Brownellcd966202007-05-08 00:33:40 -0700607 put_device(&rtc->dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800608}
609EXPORT_SYMBOL_GPL(rtc_class_close);
610
David Brownellab6a2d72007-05-08 00:33:30 -0700611int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800612{
613 int retval = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800614
615 if (task == NULL || task->func == NULL)
616 return -EINVAL;
617
Alessandro Zummod691eb92007-10-16 01:28:15 -0700618 /* Cannot register while the char dev is in use */
Jiri Kosina372a3022007-12-04 23:45:05 -0800619 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
Alessandro Zummod691eb92007-10-16 01:28:15 -0700620 return -EBUSY;
621
David Brownelld728b1e2006-11-25 11:09:28 -0800622 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800623 if (rtc->irq_task == NULL) {
624 rtc->irq_task = task;
625 retval = 0;
626 }
David Brownelld728b1e2006-11-25 11:09:28 -0800627 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800628
Jiri Kosina372a3022007-12-04 23:45:05 -0800629 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700630
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800631 return retval;
632}
633EXPORT_SYMBOL_GPL(rtc_irq_register);
634
David Brownellab6a2d72007-05-08 00:33:30 -0700635void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800636{
David Brownelld728b1e2006-11-25 11:09:28 -0800637 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800638 if (rtc->irq_task == task)
639 rtc->irq_task = NULL;
David Brownelld728b1e2006-11-25 11:09:28 -0800640 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800641}
642EXPORT_SYMBOL_GPL(rtc_irq_unregister);
643
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000644static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
645{
646 /*
647 * We always cancel the timer here first, because otherwise
648 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
649 * when we manage to start the timer before the callback
650 * returns HRTIMER_RESTART.
651 *
652 * We cannot use hrtimer_cancel() here as a running callback
653 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
654 * would spin forever.
655 */
656 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
657 return -1;
658
659 if (enabled) {
660 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
661
662 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
663 }
664 return 0;
665}
666
David Brownell97144c62007-10-16 01:28:16 -0700667/**
668 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
669 * @rtc: the rtc device
670 * @task: currently registered with rtc_irq_register()
671 * @enabled: true to enable periodic IRQs
672 * Context: any
673 *
674 * Note that rtc_irq_set_freq() should previously have been used to
675 * specify the desired frequency of periodic IRQ task->func() callbacks.
676 */
David Brownellab6a2d72007-05-08 00:33:30 -0700677int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800678{
679 int err = 0;
680 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800681
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000682retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800683 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700684 if (rtc->irq_task != NULL && task == NULL)
685 err = -EBUSY;
Chris Brand0734e272013-07-03 15:07:57 -0700686 else if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700687 err = -EACCES;
Chris Brand0734e272013-07-03 15:07:57 -0700688 else {
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000689 if (rtc_update_hrtimer(rtc, enabled) < 0) {
690 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
691 cpu_relax();
692 goto retry;
693 }
694 rtc->pie_enabled = enabled;
John Stultz6610e082010-09-23 15:07:34 -0700695 }
John Stultz6610e082010-09-23 15:07:34 -0700696 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800697 return err;
698}
699EXPORT_SYMBOL_GPL(rtc_irq_set_state);
700
David Brownell97144c62007-10-16 01:28:16 -0700701/**
702 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
703 * @rtc: the rtc device
704 * @task: currently registered with rtc_irq_register()
705 * @freq: positive frequency with which task->func() will be called
706 * Context: any
707 *
708 * Note that rtc_irq_set_state() is used to enable or disable the
709 * periodic IRQs.
710 */
David Brownellab6a2d72007-05-08 00:33:30 -0700711int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800712{
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700713 int err = 0;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800714 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800715
Thomas Gleixner6e7a3332011-07-22 09:12:51 +0000716 if (freq <= 0 || freq > RTC_MAX_FREQ)
Marcelo Roberto Jimenez83a06bf2011-02-02 16:04:02 -0200717 return -EINVAL;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000718retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800719 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700720 if (rtc->irq_task != NULL && task == NULL)
721 err = -EBUSY;
Chris Brand0734e272013-07-03 15:07:57 -0700722 else if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700723 err = -EACCES;
Chris Brand0734e272013-07-03 15:07:57 -0700724 else {
John Stultz6610e082010-09-23 15:07:34 -0700725 rtc->irq_freq = freq;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000726 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
727 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
728 cpu_relax();
729 goto retry;
John Stultz6610e082010-09-23 15:07:34 -0700730 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800731 }
John Stultz6610e082010-09-23 15:07:34 -0700732 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800733 return err;
734}
David Brownell2601a462006-11-25 11:09:27 -0800735EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
John Stultz6610e082010-09-23 15:07:34 -0700736
737/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100738 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700739 * @rtc rtc device
740 * @timer timer being added.
741 *
742 * Enqueues a timer onto the rtc devices timerqueue and sets
743 * the next alarm event appropriately.
744 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800745 * Sets the enabled bit on the added timer.
746 *
John Stultz6610e082010-09-23 15:07:34 -0700747 * Must hold ops_lock for proper serialization of timerqueue
748 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800749static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700750{
John Stultzaa0be0f2011-01-20 15:26:12 -0800751 timer->enabled = 1;
John Stultz6610e082010-09-23 15:07:34 -0700752 timerqueue_add(&rtc->timerqueue, &timer->node);
753 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
754 struct rtc_wkalrm alarm;
755 int err;
756 alarm.time = rtc_ktime_to_tm(timer->node.expires);
757 alarm.enabled = 1;
758 err = __rtc_set_alarm(rtc, &alarm);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700759 if (err == -ETIME) {
760 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700761 schedule_work(&rtc->irqwork);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700762 } else if (err) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800763 timerqueue_del(&rtc->timerqueue, &timer->node);
764 timer->enabled = 0;
765 return err;
766 }
John Stultz6610e082010-09-23 15:07:34 -0700767 }
John Stultzaa0be0f2011-01-20 15:26:12 -0800768 return 0;
John Stultz6610e082010-09-23 15:07:34 -0700769}
770
Rabin Vincent41c7f742011-11-22 11:03:14 +0100771static void rtc_alarm_disable(struct rtc_device *rtc)
772{
773 if (!rtc->ops || !rtc->ops->alarm_irq_enable)
774 return;
775
776 rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
777}
778
John Stultz6610e082010-09-23 15:07:34 -0700779/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100780 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700781 * @rtc rtc device
782 * @timer timer being removed.
783 *
784 * Removes a timer onto the rtc devices timerqueue and sets
785 * the next alarm event appropriately.
786 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800787 * Clears the enabled bit on the removed timer.
788 *
John Stultz6610e082010-09-23 15:07:34 -0700789 * Must hold ops_lock for proper serialization of timerqueue
790 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800791static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700792{
793 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
794 timerqueue_del(&rtc->timerqueue, &timer->node);
John Stultzaa0be0f2011-01-20 15:26:12 -0800795 timer->enabled = 0;
John Stultz6610e082010-09-23 15:07:34 -0700796 if (next == &timer->node) {
797 struct rtc_wkalrm alarm;
798 int err;
799 next = timerqueue_getnext(&rtc->timerqueue);
Rabin Vincent41c7f742011-11-22 11:03:14 +0100800 if (!next) {
801 rtc_alarm_disable(rtc);
John Stultz6610e082010-09-23 15:07:34 -0700802 return;
Rabin Vincent41c7f742011-11-22 11:03:14 +0100803 }
John Stultz6610e082010-09-23 15:07:34 -0700804 alarm.time = rtc_ktime_to_tm(next->expires);
805 alarm.enabled = 1;
806 err = __rtc_set_alarm(rtc, &alarm);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700807 if (err == -ETIME) {
808 pm_stay_awake(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700809 schedule_work(&rtc->irqwork);
Zoran Markovic14d0e342013-06-26 16:09:13 -0700810 }
John Stultz6610e082010-09-23 15:07:34 -0700811 }
812}
813
814/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100815 * rtc_timer_do_work - Expires rtc timers
John Stultz6610e082010-09-23 15:07:34 -0700816 * @rtc rtc device
817 * @timer timer being removed.
818 *
819 * Expires rtc timers. Reprograms next alarm event if needed.
820 * Called via worktask.
821 *
822 * Serializes access to timerqueue via ops_lock mutex
823 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100824void rtc_timer_do_work(struct work_struct *work)
John Stultz6610e082010-09-23 15:07:34 -0700825{
826 struct rtc_timer *timer;
827 struct timerqueue_node *next;
828 ktime_t now;
829 struct rtc_time tm;
830
831 struct rtc_device *rtc =
832 container_of(work, struct rtc_device, irqwork);
833
834 mutex_lock(&rtc->ops_lock);
835again:
836 __rtc_read_time(rtc, &tm);
837 now = rtc_tm_to_ktime(tm);
838 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
839 if (next->expires.tv64 > now.tv64)
840 break;
841
842 /* expire timer */
843 timer = container_of(next, struct rtc_timer, node);
844 timerqueue_del(&rtc->timerqueue, &timer->node);
845 timer->enabled = 0;
846 if (timer->task.func)
847 timer->task.func(timer->task.private_data);
848
849 /* Re-add/fwd periodic timers */
850 if (ktime_to_ns(timer->period)) {
851 timer->node.expires = ktime_add(timer->node.expires,
852 timer->period);
853 timer->enabled = 1;
854 timerqueue_add(&rtc->timerqueue, &timer->node);
855 }
856 }
857
858 /* Set next alarm */
859 if (next) {
860 struct rtc_wkalrm alarm;
861 int err;
Xunlei Pang6528b882014-12-10 15:54:26 -0800862 int retry = 3;
863
John Stultz6610e082010-09-23 15:07:34 -0700864 alarm.time = rtc_ktime_to_tm(next->expires);
865 alarm.enabled = 1;
Xunlei Pang6528b882014-12-10 15:54:26 -0800866reprogram:
John Stultz6610e082010-09-23 15:07:34 -0700867 err = __rtc_set_alarm(rtc, &alarm);
868 if (err == -ETIME)
869 goto again;
Xunlei Pang6528b882014-12-10 15:54:26 -0800870 else if (err) {
871 if (retry-- > 0)
872 goto reprogram;
873
874 timer = container_of(next, struct rtc_timer, node);
875 timerqueue_del(&rtc->timerqueue, &timer->node);
876 timer->enabled = 0;
877 dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
878 goto again;
879 }
Rabin Vincent41c7f742011-11-22 11:03:14 +0100880 } else
881 rtc_alarm_disable(rtc);
John Stultz6610e082010-09-23 15:07:34 -0700882
Zoran Markovic14d0e342013-06-26 16:09:13 -0700883 pm_relax(rtc->dev.parent);
John Stultz6610e082010-09-23 15:07:34 -0700884 mutex_unlock(&rtc->ops_lock);
885}
886
887
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100888/* rtc_timer_init - Initializes an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700889 * @timer: timer to be intiialized
890 * @f: function pointer to be called when timer fires
891 * @data: private data passed to function pointer
892 *
893 * Kernel interface to initializing an rtc_timer.
894 */
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700895void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data)
John Stultz6610e082010-09-23 15:07:34 -0700896{
897 timerqueue_init(&timer->node);
898 timer->enabled = 0;
899 timer->task.func = f;
900 timer->task.private_data = data;
901}
902
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100903/* rtc_timer_start - Sets an rtc_timer to fire in the future
John Stultz6610e082010-09-23 15:07:34 -0700904 * @ rtc: rtc device to be used
905 * @ timer: timer being set
906 * @ expires: time at which to expire the timer
907 * @ period: period that the timer will recur
908 *
909 * Kernel interface to set an rtc_timer
910 */
Sachin Kamat3ff2e132013-07-03 15:05:42 -0700911int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
John Stultz6610e082010-09-23 15:07:34 -0700912 ktime_t expires, ktime_t period)
913{
914 int ret = 0;
915 mutex_lock(&rtc->ops_lock);
916 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100917 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700918
919 timer->node.expires = expires;
920 timer->period = period;
921
John Stultzaa0be0f2011-01-20 15:26:12 -0800922 ret = rtc_timer_enqueue(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700923
924 mutex_unlock(&rtc->ops_lock);
925 return ret;
926}
927
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100928/* rtc_timer_cancel - Stops an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700929 * @ rtc: rtc device to be used
930 * @ timer: timer being set
931 *
932 * Kernel interface to cancel an rtc_timer
933 */
Krzysztof Kozlowski73744a62015-05-03 18:57:11 +0900934void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700935{
John Stultz6610e082010-09-23 15:07:34 -0700936 mutex_lock(&rtc->ops_lock);
937 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100938 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700939 mutex_unlock(&rtc->ops_lock);
John Stultz6610e082010-09-23 15:07:34 -0700940}
941
Joshua Claytonb3967062016-02-05 12:41:11 -0800942/**
943 * rtc_read_offset - Read the amount of rtc offset in parts per billion
944 * @ rtc: rtc device to be used
945 * @ offset: the offset in parts per billion
946 *
947 * see below for details.
948 *
949 * Kernel interface to read rtc clock offset
950 * Returns 0 on success, or a negative number on error.
951 * If read_offset() is not implemented for the rtc, return -EINVAL
952 */
953int rtc_read_offset(struct rtc_device *rtc, long *offset)
954{
955 int ret;
John Stultz6610e082010-09-23 15:07:34 -0700956
Joshua Claytonb3967062016-02-05 12:41:11 -0800957 if (!rtc->ops)
958 return -ENODEV;
959
960 if (!rtc->ops->read_offset)
961 return -EINVAL;
962
963 mutex_lock(&rtc->ops_lock);
964 ret = rtc->ops->read_offset(rtc->dev.parent, offset);
965 mutex_unlock(&rtc->ops_lock);
966 return ret;
967}
968
969/**
970 * rtc_set_offset - Adjusts the duration of the average second
971 * @ rtc: rtc device to be used
972 * @ offset: the offset in parts per billion
973 *
974 * Some rtc's allow an adjustment to the average duration of a second
975 * to compensate for differences in the actual clock rate due to temperature,
976 * the crystal, capacitor, etc.
977 *
978 * Kernel interface to adjust an rtc clock offset.
979 * Return 0 on success, or a negative number on error.
980 * If the rtc offset is not setable (or not implemented), return -EINVAL
981 */
982int rtc_set_offset(struct rtc_device *rtc, long offset)
983{
984 int ret;
985
986 if (!rtc->ops)
987 return -ENODEV;
988
989 if (!rtc->ops->set_offset)
990 return -EINVAL;
991
992 mutex_lock(&rtc->ops_lock);
993 ret = rtc->ops->set_offset(rtc->dev.parent, offset);
994 mutex_unlock(&rtc->ops_lock);
995 return ret;
996}