blob: 44e91e598f8d975ae7570b80366a67540611c8da [file] [log] [blame]
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>
David Brownell97144c62007-10-16 01:28:16 -070016#include <linux/log2.h>
John Stultz6610e082010-09-23 15:07:34 -070017#include <linux/workqueue.h>
18
John Stultzaa0be0f2011-01-20 15:26:12 -080019static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer);
20static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer);
21
John Stultz6610e082010-09-23 15:07:34 -070022static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
23{
24 int err;
25 if (!rtc->ops)
26 err = -ENODEV;
27 else if (!rtc->ops->read_time)
28 err = -EINVAL;
29 else {
30 memset(tm, 0, sizeof(struct rtc_time));
31 err = rtc->ops->read_time(rtc->dev.parent, tm);
32 }
33 return err;
34}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080035
David Brownellab6a2d72007-05-08 00:33:30 -070036int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080037{
38 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080039
40 err = mutex_lock_interruptible(&rtc->ops_lock);
41 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070042 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080043
John Stultz6610e082010-09-23 15:07:34 -070044 err = __rtc_read_time(rtc, tm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080045 mutex_unlock(&rtc->ops_lock);
46 return err;
47}
48EXPORT_SYMBOL_GPL(rtc_read_time);
49
David Brownellab6a2d72007-05-08 00:33:30 -070050int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080051{
52 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080053
54 err = rtc_valid_tm(tm);
55 if (err != 0)
56 return err;
57
58 err = mutex_lock_interruptible(&rtc->ops_lock);
59 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070060 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080061
62 if (!rtc->ops)
63 err = -ENODEV;
Alessandro Zummobbccf832009-01-06 14:42:21 -080064 else if (rtc->ops->set_time)
David Brownellcd966202007-05-08 00:33:40 -070065 err = rtc->ops->set_time(rtc->dev.parent, tm);
Alessandro Zummobbccf832009-01-06 14:42:21 -080066 else if (rtc->ops->set_mmss) {
67 unsigned long secs;
68 err = rtc_tm_to_time(tm, &secs);
69 if (err == 0)
70 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
71 } else
72 err = -EINVAL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080073
74 mutex_unlock(&rtc->ops_lock);
75 return err;
76}
77EXPORT_SYMBOL_GPL(rtc_set_time);
78
David Brownellab6a2d72007-05-08 00:33:30 -070079int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080080{
81 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080082
83 err = mutex_lock_interruptible(&rtc->ops_lock);
84 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070085 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080086
87 if (!rtc->ops)
88 err = -ENODEV;
89 else if (rtc->ops->set_mmss)
David Brownellcd966202007-05-08 00:33:40 -070090 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080091 else if (rtc->ops->read_time && rtc->ops->set_time) {
92 struct rtc_time new, old;
93
David Brownellcd966202007-05-08 00:33:40 -070094 err = rtc->ops->read_time(rtc->dev.parent, &old);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080095 if (err == 0) {
96 rtc_time_to_tm(secs, &new);
97
98 /*
99 * avoid writing when we're going to change the day of
100 * the month. We will retry in the next minute. This
101 * basically means that if the RTC must not drift
102 * by more than 1 minute in 11 minutes.
103 */
104 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
105 (new.tm_hour == 23 && new.tm_min == 59)))
David Brownellcd966202007-05-08 00:33:40 -0700106 err = rtc->ops->set_time(rtc->dev.parent,
David Brownellab6a2d72007-05-08 00:33:30 -0700107 &new);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800108 }
109 }
110 else
111 err = -EINVAL;
112
113 mutex_unlock(&rtc->ops_lock);
114
115 return err;
116}
117EXPORT_SYMBOL_GPL(rtc_set_mmss);
118
John Stultzf44f7f92011-02-21 22:58:51 -0800119static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
120{
121 int err;
122
123 err = mutex_lock_interruptible(&rtc->ops_lock);
124 if (err)
125 return err;
126
127 if (rtc->ops == NULL)
128 err = -ENODEV;
129 else if (!rtc->ops->read_alarm)
130 err = -EINVAL;
131 else {
132 memset(alarm, 0, sizeof(struct rtc_wkalrm));
133 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
134 }
135
136 mutex_unlock(&rtc->ops_lock);
137 return err;
138}
139
140int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
141{
142 int err;
143 struct rtc_time before, now;
144 int first_time = 1;
145 unsigned long t_now, t_alm;
146 enum { none, day, month, year } missing = none;
147 unsigned days;
148
149 /* The lower level RTC driver may return -1 in some fields,
150 * creating invalid alarm->time values, for reasons like:
151 *
152 * - The hardware may not be capable of filling them in;
153 * many alarms match only on time-of-day fields, not
154 * day/month/year calendar data.
155 *
156 * - Some hardware uses illegal values as "wildcard" match
157 * values, which non-Linux firmware (like a BIOS) may try
158 * to set up as e.g. "alarm 15 minutes after each hour".
159 * Linux uses only oneshot alarms.
160 *
161 * When we see that here, we deal with it by using values from
162 * a current RTC timestamp for any missing (-1) values. The
163 * RTC driver prevents "periodic alarm" modes.
164 *
165 * But this can be racey, because some fields of the RTC timestamp
166 * may have wrapped in the interval since we read the RTC alarm,
167 * which would lead to us inserting inconsistent values in place
168 * of the -1 fields.
169 *
170 * Reading the alarm and timestamp in the reverse sequence
171 * would have the same race condition, and not solve the issue.
172 *
173 * So, we must first read the RTC timestamp,
174 * then read the RTC alarm value,
175 * and then read a second RTC timestamp.
176 *
177 * If any fields of the second timestamp have changed
178 * when compared with the first timestamp, then we know
179 * our timestamp may be inconsistent with that used by
180 * the low-level rtc_read_alarm_internal() function.
181 *
182 * So, when the two timestamps disagree, we just loop and do
183 * the process again to get a fully consistent set of values.
184 *
185 * This could all instead be done in the lower level driver,
186 * but since more than one lower level RTC implementation needs it,
187 * then it's probably best best to do it here instead of there..
188 */
189
190 /* Get the "before" timestamp */
191 err = rtc_read_time(rtc, &before);
192 if (err < 0)
193 return err;
194 do {
195 if (!first_time)
196 memcpy(&before, &now, sizeof(struct rtc_time));
197 first_time = 0;
198
199 /* get the RTC alarm values, which may be incomplete */
200 err = rtc_read_alarm_internal(rtc, alarm);
201 if (err)
202 return err;
203
204 /* full-function RTCs won't have such missing fields */
205 if (rtc_valid_tm(&alarm->time) == 0)
206 return 0;
207
208 /* get the "after" timestamp, to detect wrapped fields */
209 err = rtc_read_time(rtc, &now);
210 if (err < 0)
211 return err;
212
213 /* note that tm_sec is a "don't care" value here: */
214 } while ( before.tm_min != now.tm_min
215 || before.tm_hour != now.tm_hour
216 || before.tm_mon != now.tm_mon
217 || before.tm_year != now.tm_year);
218
219 /* Fill in the missing alarm fields using the timestamp; we
220 * know there's at least one since alarm->time is invalid.
221 */
222 if (alarm->time.tm_sec == -1)
223 alarm->time.tm_sec = now.tm_sec;
224 if (alarm->time.tm_min == -1)
225 alarm->time.tm_min = now.tm_min;
226 if (alarm->time.tm_hour == -1)
227 alarm->time.tm_hour = now.tm_hour;
228
229 /* For simplicity, only support date rollover for now */
230 if (alarm->time.tm_mday == -1) {
231 alarm->time.tm_mday = now.tm_mday;
232 missing = day;
233 }
234 if (alarm->time.tm_mon == -1) {
235 alarm->time.tm_mon = now.tm_mon;
236 if (missing == none)
237 missing = month;
238 }
239 if (alarm->time.tm_year == -1) {
240 alarm->time.tm_year = now.tm_year;
241 if (missing == none)
242 missing = year;
243 }
244
245 /* with luck, no rollover is needed */
246 rtc_tm_to_time(&now, &t_now);
247 rtc_tm_to_time(&alarm->time, &t_alm);
248 if (t_now < t_alm)
249 goto done;
250
251 switch (missing) {
252
253 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
254 * that will trigger at 5am will do so at 5am Tuesday, which
255 * could also be in the next month or year. This is a common
256 * case, especially for PCs.
257 */
258 case day:
259 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
260 t_alm += 24 * 60 * 60;
261 rtc_time_to_tm(t_alm, &alarm->time);
262 break;
263
264 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
265 * be next month. An alarm matching on the 30th, 29th, or 28th
266 * may end up in the month after that! Many newer PCs support
267 * this type of alarm.
268 */
269 case month:
270 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
271 do {
272 if (alarm->time.tm_mon < 11)
273 alarm->time.tm_mon++;
274 else {
275 alarm->time.tm_mon = 0;
276 alarm->time.tm_year++;
277 }
278 days = rtc_month_days(alarm->time.tm_mon,
279 alarm->time.tm_year);
280 } while (days < alarm->time.tm_mday);
281 break;
282
283 /* Year rollover ... easy except for leap years! */
284 case year:
285 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
286 do {
287 alarm->time.tm_year++;
288 } while (rtc_valid_tm(&alarm->time) != 0);
289 break;
290
291 default:
292 dev_warn(&rtc->dev, "alarm rollover not handled\n");
293 }
294
295done:
296 return 0;
297}
298
John Stultz6610e082010-09-23 15:07:34 -0700299int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800300{
301 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800302
303 err = mutex_lock_interruptible(&rtc->ops_lock);
304 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700305 return err;
John Stultzd5553a52011-01-20 15:26:13 -0800306 if (rtc->ops == NULL)
307 err = -ENODEV;
308 else if (!rtc->ops->read_alarm)
309 err = -EINVAL;
310 else {
311 memset(alarm, 0, sizeof(struct rtc_wkalrm));
312 alarm->enabled = rtc->aie_timer.enabled;
John Stultz6610e082010-09-23 15:07:34 -0700313 alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
John Stultzd5553a52011-01-20 15:26:13 -0800314 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800315 mutex_unlock(&rtc->ops_lock);
Mark Lord0e36a9a2007-10-16 01:28:21 -0700316
John Stultzd5553a52011-01-20 15:26:13 -0800317 return err;
Mark Lord0e36a9a2007-10-16 01:28:21 -0700318}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800319EXPORT_SYMBOL_GPL(rtc_read_alarm);
320
Mark Brownd576fe42011-06-01 11:13:16 +0100321static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
John Stultz6610e082010-09-23 15:07:34 -0700322{
323 struct rtc_time tm;
324 long now, scheduled;
325 int err;
326
327 err = rtc_valid_tm(&alarm->time);
328 if (err)
329 return err;
330 rtc_tm_to_time(&alarm->time, &scheduled);
331
332 /* Make sure we're not setting alarms in the past */
333 err = __rtc_read_time(rtc, &tm);
334 rtc_tm_to_time(&tm, &now);
335 if (scheduled <= now)
336 return -ETIME;
337 /*
338 * XXX - We just checked to make sure the alarm time is not
339 * in the past, but there is still a race window where if
340 * the is alarm set for the next second and the second ticks
341 * over right here, before we set the alarm.
342 */
343
344 if (!rtc->ops)
345 err = -ENODEV;
346 else if (!rtc->ops->set_alarm)
347 err = -EINVAL;
348 else
349 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
350
351 return err;
352}
353
David Brownellab6a2d72007-05-08 00:33:30 -0700354int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800355{
356 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800357
David Brownellf8245c22007-05-08 00:34:07 -0700358 err = rtc_valid_tm(&alarm->time);
359 if (err != 0)
360 return err;
361
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800362 err = mutex_lock_interruptible(&rtc->ops_lock);
363 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700364 return err;
John Stultz6610e082010-09-23 15:07:34 -0700365 if (rtc->aie_timer.enabled) {
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100366 rtc_timer_remove(rtc, &rtc->aie_timer);
John Stultz6610e082010-09-23 15:07:34 -0700367 }
368 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
369 rtc->aie_timer.period = ktime_set(0, 0);
370 if (alarm->enabled) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800371 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
John Stultz6610e082010-09-23 15:07:34 -0700372 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800373 mutex_unlock(&rtc->ops_lock);
John Stultzaa0be0f2011-01-20 15:26:12 -0800374 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800375}
376EXPORT_SYMBOL_GPL(rtc_set_alarm);
377
John Stultzf6d5b332011-03-29 18:00:27 -0700378/* Called once per device from rtc_device_register */
379int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
380{
381 int err;
382
383 err = rtc_valid_tm(&alarm->time);
384 if (err != 0)
385 return err;
386
387 err = mutex_lock_interruptible(&rtc->ops_lock);
388 if (err)
389 return err;
390
391 rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
392 rtc->aie_timer.period = ktime_set(0, 0);
393 if (alarm->enabled) {
394 rtc->aie_timer.enabled = 1;
395 timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
396 }
397 mutex_unlock(&rtc->ops_lock);
398 return err;
399}
400EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
401
402
403
Alessandro Zummo099e6572009-01-04 12:00:54 -0800404int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
405{
406 int err = mutex_lock_interruptible(&rtc->ops_lock);
407 if (err)
408 return err;
409
John Stultz6610e082010-09-23 15:07:34 -0700410 if (rtc->aie_timer.enabled != enabled) {
John Stultzaa0be0f2011-01-20 15:26:12 -0800411 if (enabled)
412 err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
413 else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100414 rtc_timer_remove(rtc, &rtc->aie_timer);
John Stultz6610e082010-09-23 15:07:34 -0700415 }
416
John Stultzaa0be0f2011-01-20 15:26:12 -0800417 if (err)
Uwe Kleine-König516373b2011-02-14 11:33:17 +0100418 /* nothing */;
419 else if (!rtc->ops)
Alessandro Zummo099e6572009-01-04 12:00:54 -0800420 err = -ENODEV;
421 else if (!rtc->ops->alarm_irq_enable)
422 err = -EINVAL;
423 else
424 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
425
426 mutex_unlock(&rtc->ops_lock);
427 return err;
428}
429EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
430
431int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
432{
433 int err = mutex_lock_interruptible(&rtc->ops_lock);
434 if (err)
435 return err;
436
John Stultz456d66e2011-02-11 18:15:23 -0800437#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
438 if (enabled == 0 && rtc->uie_irq_active) {
439 mutex_unlock(&rtc->ops_lock);
440 return rtc_dev_update_irq_enable_emul(rtc, 0);
441 }
442#endif
John Stultz6610e082010-09-23 15:07:34 -0700443 /* make sure we're changing state */
444 if (rtc->uie_rtctimer.enabled == enabled)
445 goto out;
446
447 if (enabled) {
448 struct rtc_time tm;
449 ktime_t now, onesec;
450
451 __rtc_read_time(rtc, &tm);
452 onesec = ktime_set(1, 0);
453 now = rtc_tm_to_ktime(tm);
454 rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
455 rtc->uie_rtctimer.period = ktime_set(1, 0);
John Stultzaa0be0f2011-01-20 15:26:12 -0800456 err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
457 } else
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100458 rtc_timer_remove(rtc, &rtc->uie_rtctimer);
Alessandro Zummo099e6572009-01-04 12:00:54 -0800459
John Stultz6610e082010-09-23 15:07:34 -0700460out:
Alessandro Zummo099e6572009-01-04 12:00:54 -0800461 mutex_unlock(&rtc->ops_lock);
John Stultz456d66e2011-02-11 18:15:23 -0800462#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
463 /*
464 * Enable emulation if the driver did not provide
465 * the update_irq_enable function pointer or if returned
466 * -EINVAL to signal that it has been configured without
467 * interrupts or that are not available at the moment.
468 */
469 if (err == -EINVAL)
470 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
471#endif
Alessandro Zummo099e6572009-01-04 12:00:54 -0800472 return err;
John Stultz6610e082010-09-23 15:07:34 -0700473
Alessandro Zummo099e6572009-01-04 12:00:54 -0800474}
475EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
476
John Stultz6610e082010-09-23 15:07:34 -0700477
David Brownelld728b1e2006-11-25 11:09:28 -0800478/**
John Stultz6610e082010-09-23 15:07:34 -0700479 * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
480 * @rtc: pointer to the rtc device
481 *
482 * This function is called when an AIE, UIE or PIE mode interrupt
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300483 * has occurred (or been emulated).
John Stultz6610e082010-09-23 15:07:34 -0700484 *
485 * Triggers the registered irq_task function callback.
486 */
John Stultz456d66e2011-02-11 18:15:23 -0800487void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
John Stultz6610e082010-09-23 15:07:34 -0700488{
489 unsigned long flags;
490
491 /* mark one irq of the appropriate mode */
492 spin_lock_irqsave(&rtc->irq_lock, flags);
493 rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode);
494 spin_unlock_irqrestore(&rtc->irq_lock, flags);
495
496 /* call the task func */
497 spin_lock_irqsave(&rtc->irq_task_lock, flags);
498 if (rtc->irq_task)
499 rtc->irq_task->func(rtc->irq_task->private_data);
500 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
501
502 wake_up_interruptible(&rtc->irq_queue);
503 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
504}
505
506
507/**
508 * rtc_aie_update_irq - AIE mode rtctimer hook
509 * @private: pointer to the rtc_device
510 *
511 * This functions is called when the aie_timer expires.
512 */
513void rtc_aie_update_irq(void *private)
514{
515 struct rtc_device *rtc = (struct rtc_device *)private;
516 rtc_handle_legacy_irq(rtc, 1, RTC_AF);
517}
518
519
520/**
521 * rtc_uie_update_irq - UIE mode rtctimer hook
522 * @private: pointer to the rtc_device
523 *
524 * This functions is called when the uie_timer expires.
525 */
526void rtc_uie_update_irq(void *private)
527{
528 struct rtc_device *rtc = (struct rtc_device *)private;
529 rtc_handle_legacy_irq(rtc, 1, RTC_UF);
530}
531
532
533/**
534 * rtc_pie_update_irq - PIE mode hrtimer hook
535 * @timer: pointer to the pie mode hrtimer
536 *
537 * This function is used to emulate PIE mode interrupts
538 * using an hrtimer. This function is called when the periodic
539 * hrtimer expires.
540 */
541enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
542{
543 struct rtc_device *rtc;
544 ktime_t period;
545 int count;
546 rtc = container_of(timer, struct rtc_device, pie_timer);
547
548 period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq);
549 count = hrtimer_forward_now(timer, period);
550
551 rtc_handle_legacy_irq(rtc, count, RTC_PF);
552
553 return HRTIMER_RESTART;
554}
555
556/**
557 * rtc_update_irq - Triggered when a RTC interrupt occurs.
David Brownellab6a2d72007-05-08 00:33:30 -0700558 * @rtc: the rtc device
David Brownelld728b1e2006-11-25 11:09:28 -0800559 * @num: how many irqs are being reported (usually one)
560 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700561 * Context: any
David Brownelld728b1e2006-11-25 11:09:28 -0800562 */
David Brownellab6a2d72007-05-08 00:33:30 -0700563void rtc_update_irq(struct rtc_device *rtc,
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800564 unsigned long num, unsigned long events)
565{
John Stultz6610e082010-09-23 15:07:34 -0700566 schedule_work(&rtc->irqwork);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800567}
568EXPORT_SYMBOL_GPL(rtc_update_irq);
569
Dave Young71da8902008-01-22 14:00:34 +0800570static int __rtc_match(struct device *dev, void *data)
571{
572 char *name = (char *)data;
573
Kay Sieversd4afc762009-01-06 14:42:11 -0800574 if (strcmp(dev_name(dev), name) == 0)
Dave Young71da8902008-01-22 14:00:34 +0800575 return 1;
576 return 0;
577}
578
David Brownellab6a2d72007-05-08 00:33:30 -0700579struct rtc_device *rtc_class_open(char *name)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800580{
David Brownellcd966202007-05-08 00:33:40 -0700581 struct device *dev;
David Brownellab6a2d72007-05-08 00:33:30 -0700582 struct rtc_device *rtc = NULL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800583
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400584 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
Dave Young71da8902008-01-22 14:00:34 +0800585 if (dev)
586 rtc = to_rtc_device(dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800587
David Brownellab6a2d72007-05-08 00:33:30 -0700588 if (rtc) {
589 if (!try_module_get(rtc->owner)) {
David Brownellcd966202007-05-08 00:33:40 -0700590 put_device(dev);
David Brownellab6a2d72007-05-08 00:33:30 -0700591 rtc = NULL;
592 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800593 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800594
David Brownellab6a2d72007-05-08 00:33:30 -0700595 return rtc;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800596}
597EXPORT_SYMBOL_GPL(rtc_class_open);
598
David Brownellab6a2d72007-05-08 00:33:30 -0700599void rtc_class_close(struct rtc_device *rtc)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800600{
David Brownellab6a2d72007-05-08 00:33:30 -0700601 module_put(rtc->owner);
David Brownellcd966202007-05-08 00:33:40 -0700602 put_device(&rtc->dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800603}
604EXPORT_SYMBOL_GPL(rtc_class_close);
605
David Brownellab6a2d72007-05-08 00:33:30 -0700606int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800607{
608 int retval = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800609
610 if (task == NULL || task->func == NULL)
611 return -EINVAL;
612
Alessandro Zummod691eb92007-10-16 01:28:15 -0700613 /* Cannot register while the char dev is in use */
Jiri Kosina372a3022007-12-04 23:45:05 -0800614 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
Alessandro Zummod691eb92007-10-16 01:28:15 -0700615 return -EBUSY;
616
David Brownelld728b1e2006-11-25 11:09:28 -0800617 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800618 if (rtc->irq_task == NULL) {
619 rtc->irq_task = task;
620 retval = 0;
621 }
David Brownelld728b1e2006-11-25 11:09:28 -0800622 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800623
Jiri Kosina372a3022007-12-04 23:45:05 -0800624 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700625
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800626 return retval;
627}
628EXPORT_SYMBOL_GPL(rtc_irq_register);
629
David Brownellab6a2d72007-05-08 00:33:30 -0700630void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800631{
David Brownelld728b1e2006-11-25 11:09:28 -0800632 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800633 if (rtc->irq_task == task)
634 rtc->irq_task = NULL;
David Brownelld728b1e2006-11-25 11:09:28 -0800635 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800636}
637EXPORT_SYMBOL_GPL(rtc_irq_unregister);
638
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000639static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
640{
641 /*
642 * We always cancel the timer here first, because otherwise
643 * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
644 * when we manage to start the timer before the callback
645 * returns HRTIMER_RESTART.
646 *
647 * We cannot use hrtimer_cancel() here as a running callback
648 * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
649 * would spin forever.
650 */
651 if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
652 return -1;
653
654 if (enabled) {
655 ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq);
656
657 hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
658 }
659 return 0;
660}
661
David Brownell97144c62007-10-16 01:28:16 -0700662/**
663 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
664 * @rtc: the rtc device
665 * @task: currently registered with rtc_irq_register()
666 * @enabled: true to enable periodic IRQs
667 * Context: any
668 *
669 * Note that rtc_irq_set_freq() should previously have been used to
670 * specify the desired frequency of periodic IRQ task->func() callbacks.
671 */
David Brownellab6a2d72007-05-08 00:33:30 -0700672int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800673{
674 int err = 0;
675 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800676
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000677retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800678 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700679 if (rtc->irq_task != NULL && task == NULL)
680 err = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800681 if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700682 err = -EACCES;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000683 if (!err) {
684 if (rtc_update_hrtimer(rtc, enabled) < 0) {
685 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
686 cpu_relax();
687 goto retry;
688 }
689 rtc->pie_enabled = enabled;
John Stultz6610e082010-09-23 15:07:34 -0700690 }
John Stultz6610e082010-09-23 15:07:34 -0700691 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800692 return err;
693}
694EXPORT_SYMBOL_GPL(rtc_irq_set_state);
695
David Brownell97144c62007-10-16 01:28:16 -0700696/**
697 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
698 * @rtc: the rtc device
699 * @task: currently registered with rtc_irq_register()
700 * @freq: positive frequency with which task->func() will be called
701 * Context: any
702 *
703 * Note that rtc_irq_set_state() is used to enable or disable the
704 * periodic IRQs.
705 */
David Brownellab6a2d72007-05-08 00:33:30 -0700706int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800707{
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700708 int err = 0;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800709 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800710
Thomas Gleixner6e7a3332011-07-22 09:12:51 +0000711 if (freq <= 0 || freq > RTC_MAX_FREQ)
Marcelo Roberto Jimenez83a06bf2011-02-02 16:04:02 -0200712 return -EINVAL;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000713retry:
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800714 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700715 if (rtc->irq_task != NULL && task == NULL)
716 err = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800717 if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700718 err = -EACCES;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000719 if (!err) {
John Stultz6610e082010-09-23 15:07:34 -0700720 rtc->irq_freq = freq;
Thomas Gleixner3c8bb902011-07-22 09:12:51 +0000721 if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) {
722 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
723 cpu_relax();
724 goto retry;
John Stultz6610e082010-09-23 15:07:34 -0700725 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800726 }
John Stultz6610e082010-09-23 15:07:34 -0700727 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800728 return err;
729}
David Brownell2601a462006-11-25 11:09:27 -0800730EXPORT_SYMBOL_GPL(rtc_irq_set_freq);
John Stultz6610e082010-09-23 15:07:34 -0700731
732/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100733 * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700734 * @rtc rtc device
735 * @timer timer being added.
736 *
737 * Enqueues a timer onto the rtc devices timerqueue and sets
738 * the next alarm event appropriately.
739 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800740 * Sets the enabled bit on the added timer.
741 *
John Stultz6610e082010-09-23 15:07:34 -0700742 * Must hold ops_lock for proper serialization of timerqueue
743 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800744static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700745{
John Stultzaa0be0f2011-01-20 15:26:12 -0800746 timer->enabled = 1;
John Stultz6610e082010-09-23 15:07:34 -0700747 timerqueue_add(&rtc->timerqueue, &timer->node);
748 if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) {
749 struct rtc_wkalrm alarm;
750 int err;
751 alarm.time = rtc_ktime_to_tm(timer->node.expires);
752 alarm.enabled = 1;
753 err = __rtc_set_alarm(rtc, &alarm);
754 if (err == -ETIME)
755 schedule_work(&rtc->irqwork);
John Stultzaa0be0f2011-01-20 15:26:12 -0800756 else if (err) {
757 timerqueue_del(&rtc->timerqueue, &timer->node);
758 timer->enabled = 0;
759 return err;
760 }
John Stultz6610e082010-09-23 15:07:34 -0700761 }
John Stultzaa0be0f2011-01-20 15:26:12 -0800762 return 0;
John Stultz6610e082010-09-23 15:07:34 -0700763}
764
765/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100766 * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
John Stultz6610e082010-09-23 15:07:34 -0700767 * @rtc rtc device
768 * @timer timer being removed.
769 *
770 * Removes a timer onto the rtc devices timerqueue and sets
771 * the next alarm event appropriately.
772 *
John Stultzaa0be0f2011-01-20 15:26:12 -0800773 * Clears the enabled bit on the removed timer.
774 *
John Stultz6610e082010-09-23 15:07:34 -0700775 * Must hold ops_lock for proper serialization of timerqueue
776 */
John Stultzaa0be0f2011-01-20 15:26:12 -0800777static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
John Stultz6610e082010-09-23 15:07:34 -0700778{
779 struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
780 timerqueue_del(&rtc->timerqueue, &timer->node);
John Stultzaa0be0f2011-01-20 15:26:12 -0800781 timer->enabled = 0;
John Stultz6610e082010-09-23 15:07:34 -0700782 if (next == &timer->node) {
783 struct rtc_wkalrm alarm;
784 int err;
785 next = timerqueue_getnext(&rtc->timerqueue);
786 if (!next)
787 return;
788 alarm.time = rtc_ktime_to_tm(next->expires);
789 alarm.enabled = 1;
790 err = __rtc_set_alarm(rtc, &alarm);
791 if (err == -ETIME)
792 schedule_work(&rtc->irqwork);
793 }
794}
795
796/**
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100797 * rtc_timer_do_work - Expires rtc timers
John Stultz6610e082010-09-23 15:07:34 -0700798 * @rtc rtc device
799 * @timer timer being removed.
800 *
801 * Expires rtc timers. Reprograms next alarm event if needed.
802 * Called via worktask.
803 *
804 * Serializes access to timerqueue via ops_lock mutex
805 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100806void rtc_timer_do_work(struct work_struct *work)
John Stultz6610e082010-09-23 15:07:34 -0700807{
808 struct rtc_timer *timer;
809 struct timerqueue_node *next;
810 ktime_t now;
811 struct rtc_time tm;
812
813 struct rtc_device *rtc =
814 container_of(work, struct rtc_device, irqwork);
815
816 mutex_lock(&rtc->ops_lock);
817again:
818 __rtc_read_time(rtc, &tm);
819 now = rtc_tm_to_ktime(tm);
820 while ((next = timerqueue_getnext(&rtc->timerqueue))) {
821 if (next->expires.tv64 > now.tv64)
822 break;
823
824 /* expire timer */
825 timer = container_of(next, struct rtc_timer, node);
826 timerqueue_del(&rtc->timerqueue, &timer->node);
827 timer->enabled = 0;
828 if (timer->task.func)
829 timer->task.func(timer->task.private_data);
830
831 /* Re-add/fwd periodic timers */
832 if (ktime_to_ns(timer->period)) {
833 timer->node.expires = ktime_add(timer->node.expires,
834 timer->period);
835 timer->enabled = 1;
836 timerqueue_add(&rtc->timerqueue, &timer->node);
837 }
838 }
839
840 /* Set next alarm */
841 if (next) {
842 struct rtc_wkalrm alarm;
843 int err;
844 alarm.time = rtc_ktime_to_tm(next->expires);
845 alarm.enabled = 1;
846 err = __rtc_set_alarm(rtc, &alarm);
847 if (err == -ETIME)
848 goto again;
849 }
850
851 mutex_unlock(&rtc->ops_lock);
852}
853
854
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100855/* rtc_timer_init - Initializes an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700856 * @timer: timer to be intiialized
857 * @f: function pointer to be called when timer fires
858 * @data: private data passed to function pointer
859 *
860 * Kernel interface to initializing an rtc_timer.
861 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100862void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data)
John Stultz6610e082010-09-23 15:07:34 -0700863{
864 timerqueue_init(&timer->node);
865 timer->enabled = 0;
866 timer->task.func = f;
867 timer->task.private_data = data;
868}
869
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100870/* rtc_timer_start - Sets an rtc_timer to fire in the future
John Stultz6610e082010-09-23 15:07:34 -0700871 * @ rtc: rtc device to be used
872 * @ timer: timer being set
873 * @ expires: time at which to expire the timer
874 * @ period: period that the timer will recur
875 *
876 * Kernel interface to set an rtc_timer
877 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100878int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer,
John Stultz6610e082010-09-23 15:07:34 -0700879 ktime_t expires, ktime_t period)
880{
881 int ret = 0;
882 mutex_lock(&rtc->ops_lock);
883 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100884 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700885
886 timer->node.expires = expires;
887 timer->period = period;
888
John Stultzaa0be0f2011-01-20 15:26:12 -0800889 ret = rtc_timer_enqueue(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700890
891 mutex_unlock(&rtc->ops_lock);
892 return ret;
893}
894
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100895/* rtc_timer_cancel - Stops an rtc_timer
John Stultz6610e082010-09-23 15:07:34 -0700896 * @ rtc: rtc device to be used
897 * @ timer: timer being set
898 *
899 * Kernel interface to cancel an rtc_timer
900 */
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100901int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer)
John Stultz6610e082010-09-23 15:07:34 -0700902{
903 int ret = 0;
904 mutex_lock(&rtc->ops_lock);
905 if (timer->enabled)
Thomas Gleixner96c8f062010-12-13 22:45:48 +0100906 rtc_timer_remove(rtc, timer);
John Stultz6610e082010-09-23 15:07:34 -0700907 mutex_unlock(&rtc->ops_lock);
908 return ret;
909}
910
911