blob: a0c816238aa9bd0966c78a67262141fa25c2ab02 [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>
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080017
David Brownellab6a2d72007-05-08 00:33:30 -070018int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080019{
20 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080021
22 err = mutex_lock_interruptible(&rtc->ops_lock);
23 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070024 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080025
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));
David Brownellcd966202007-05-08 00:33:40 -070032 err = rtc->ops->read_time(rtc->dev.parent, tm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080033 }
34
35 mutex_unlock(&rtc->ops_lock);
36 return err;
37}
38EXPORT_SYMBOL_GPL(rtc_read_time);
39
David Brownellab6a2d72007-05-08 00:33:30 -070040int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080041{
42 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080043
44 err = rtc_valid_tm(tm);
45 if (err != 0)
46 return err;
47
48 err = mutex_lock_interruptible(&rtc->ops_lock);
49 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070050 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080051
52 if (!rtc->ops)
53 err = -ENODEV;
Alessandro Zummobbccf832009-01-06 14:42:21 -080054 else if (rtc->ops->set_time)
David Brownellcd966202007-05-08 00:33:40 -070055 err = rtc->ops->set_time(rtc->dev.parent, tm);
Alessandro Zummobbccf832009-01-06 14:42:21 -080056 else if (rtc->ops->set_mmss) {
57 unsigned long secs;
58 err = rtc_tm_to_time(tm, &secs);
59 if (err == 0)
60 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
61 } else
62 err = -EINVAL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080063
64 mutex_unlock(&rtc->ops_lock);
65 return err;
66}
67EXPORT_SYMBOL_GPL(rtc_set_time);
68
David Brownellab6a2d72007-05-08 00:33:30 -070069int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080070{
71 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080072
73 err = mutex_lock_interruptible(&rtc->ops_lock);
74 if (err)
David Brownellb68bb262008-07-29 22:33:30 -070075 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080076
77 if (!rtc->ops)
78 err = -ENODEV;
79 else if (rtc->ops->set_mmss)
David Brownellcd966202007-05-08 00:33:40 -070080 err = rtc->ops->set_mmss(rtc->dev.parent, secs);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080081 else if (rtc->ops->read_time && rtc->ops->set_time) {
82 struct rtc_time new, old;
83
David Brownellcd966202007-05-08 00:33:40 -070084 err = rtc->ops->read_time(rtc->dev.parent, &old);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080085 if (err == 0) {
86 rtc_time_to_tm(secs, &new);
87
88 /*
89 * avoid writing when we're going to change the day of
90 * the month. We will retry in the next minute. This
91 * basically means that if the RTC must not drift
92 * by more than 1 minute in 11 minutes.
93 */
94 if (!((old.tm_hour == 23 && old.tm_min == 59) ||
95 (new.tm_hour == 23 && new.tm_min == 59)))
David Brownellcd966202007-05-08 00:33:40 -070096 err = rtc->ops->set_time(rtc->dev.parent,
David Brownellab6a2d72007-05-08 00:33:30 -070097 &new);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -080098 }
99 }
100 else
101 err = -EINVAL;
102
103 mutex_unlock(&rtc->ops_lock);
104
105 return err;
106}
107EXPORT_SYMBOL_GPL(rtc_set_mmss);
108
Mark Lord0e36a9a2007-10-16 01:28:21 -0700109static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800110{
111 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800112
113 err = mutex_lock_interruptible(&rtc->ops_lock);
114 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700115 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800116
117 if (rtc->ops == NULL)
118 err = -ENODEV;
119 else if (!rtc->ops->read_alarm)
120 err = -EINVAL;
121 else {
122 memset(alarm, 0, sizeof(struct rtc_wkalrm));
David Brownellcd966202007-05-08 00:33:40 -0700123 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800124 }
125
126 mutex_unlock(&rtc->ops_lock);
127 return err;
128}
Mark Lord0e36a9a2007-10-16 01:28:21 -0700129
130int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
131{
132 int err;
133 struct rtc_time before, now;
134 int first_time = 1;
David Brownella01cc652008-07-04 09:59:26 -0700135 unsigned long t_now, t_alm;
136 enum { none, day, month, year } missing = none;
137 unsigned days;
Mark Lord0e36a9a2007-10-16 01:28:21 -0700138
David Brownella01cc652008-07-04 09:59:26 -0700139 /* The lower level RTC driver may return -1 in some fields,
140 * creating invalid alarm->time values, for reasons like:
141 *
142 * - The hardware may not be capable of filling them in;
143 * many alarms match only on time-of-day fields, not
144 * day/month/year calendar data.
145 *
146 * - Some hardware uses illegal values as "wildcard" match
147 * values, which non-Linux firmware (like a BIOS) may try
148 * to set up as e.g. "alarm 15 minutes after each hour".
149 * Linux uses only oneshot alarms.
150 *
151 * When we see that here, we deal with it by using values from
152 * a current RTC timestamp for any missing (-1) values. The
153 * RTC driver prevents "periodic alarm" modes.
Mark Lord0e36a9a2007-10-16 01:28:21 -0700154 *
155 * But this can be racey, because some fields of the RTC timestamp
156 * may have wrapped in the interval since we read the RTC alarm,
157 * which would lead to us inserting inconsistent values in place
158 * of the -1 fields.
159 *
160 * Reading the alarm and timestamp in the reverse sequence
161 * would have the same race condition, and not solve the issue.
162 *
163 * So, we must first read the RTC timestamp,
164 * then read the RTC alarm value,
165 * and then read a second RTC timestamp.
166 *
167 * If any fields of the second timestamp have changed
168 * when compared with the first timestamp, then we know
169 * our timestamp may be inconsistent with that used by
170 * the low-level rtc_read_alarm_internal() function.
171 *
172 * So, when the two timestamps disagree, we just loop and do
173 * the process again to get a fully consistent set of values.
174 *
175 * This could all instead be done in the lower level driver,
176 * but since more than one lower level RTC implementation needs it,
177 * then it's probably best best to do it here instead of there..
178 */
179
180 /* Get the "before" timestamp */
181 err = rtc_read_time(rtc, &before);
182 if (err < 0)
183 return err;
184 do {
185 if (!first_time)
186 memcpy(&before, &now, sizeof(struct rtc_time));
187 first_time = 0;
188
189 /* get the RTC alarm values, which may be incomplete */
190 err = rtc_read_alarm_internal(rtc, alarm);
191 if (err)
192 return err;
193 if (!alarm->enabled)
194 return 0;
195
David Brownella01cc652008-07-04 09:59:26 -0700196 /* full-function RTCs won't have such missing fields */
197 if (rtc_valid_tm(&alarm->time) == 0)
198 return 0;
199
Mark Lord0e36a9a2007-10-16 01:28:21 -0700200 /* get the "after" timestamp, to detect wrapped fields */
201 err = rtc_read_time(rtc, &now);
202 if (err < 0)
203 return err;
204
205 /* note that tm_sec is a "don't care" value here: */
206 } while ( before.tm_min != now.tm_min
207 || before.tm_hour != now.tm_hour
208 || before.tm_mon != now.tm_mon
David Brownella01cc652008-07-04 09:59:26 -0700209 || before.tm_year != now.tm_year);
Mark Lord0e36a9a2007-10-16 01:28:21 -0700210
David Brownella01cc652008-07-04 09:59:26 -0700211 /* Fill in the missing alarm fields using the timestamp; we
212 * know there's at least one since alarm->time is invalid.
213 */
Mark Lord0e36a9a2007-10-16 01:28:21 -0700214 if (alarm->time.tm_sec == -1)
215 alarm->time.tm_sec = now.tm_sec;
216 if (alarm->time.tm_min == -1)
217 alarm->time.tm_min = now.tm_min;
218 if (alarm->time.tm_hour == -1)
219 alarm->time.tm_hour = now.tm_hour;
David Brownella01cc652008-07-04 09:59:26 -0700220
221 /* For simplicity, only support date rollover for now */
222 if (alarm->time.tm_mday == -1) {
Mark Lord0e36a9a2007-10-16 01:28:21 -0700223 alarm->time.tm_mday = now.tm_mday;
David Brownella01cc652008-07-04 09:59:26 -0700224 missing = day;
225 }
226 if (alarm->time.tm_mon == -1) {
Mark Lord0e36a9a2007-10-16 01:28:21 -0700227 alarm->time.tm_mon = now.tm_mon;
David Brownella01cc652008-07-04 09:59:26 -0700228 if (missing == none)
229 missing = month;
230 }
231 if (alarm->time.tm_year == -1) {
Mark Lord0e36a9a2007-10-16 01:28:21 -0700232 alarm->time.tm_year = now.tm_year;
David Brownella01cc652008-07-04 09:59:26 -0700233 if (missing == none)
234 missing = year;
235 }
236
237 /* with luck, no rollover is needed */
238 rtc_tm_to_time(&now, &t_now);
239 rtc_tm_to_time(&alarm->time, &t_alm);
240 if (t_now < t_alm)
241 goto done;
242
243 switch (missing) {
244
245 /* 24 hour rollover ... if it's now 10am Monday, an alarm that
246 * that will trigger at 5am will do so at 5am Tuesday, which
247 * could also be in the next month or year. This is a common
248 * case, especially for PCs.
249 */
250 case day:
251 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
252 t_alm += 24 * 60 * 60;
253 rtc_time_to_tm(t_alm, &alarm->time);
254 break;
255
256 /* Month rollover ... if it's the 31th, an alarm on the 3rd will
257 * be next month. An alarm matching on the 30th, 29th, or 28th
258 * may end up in the month after that! Many newer PCs support
259 * this type of alarm.
260 */
261 case month:
262 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
263 do {
264 if (alarm->time.tm_mon < 11)
265 alarm->time.tm_mon++;
266 else {
267 alarm->time.tm_mon = 0;
268 alarm->time.tm_year++;
269 }
270 days = rtc_month_days(alarm->time.tm_mon,
271 alarm->time.tm_year);
272 } while (days < alarm->time.tm_mday);
273 break;
274
275 /* Year rollover ... easy except for leap years! */
276 case year:
277 dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
278 do {
279 alarm->time.tm_year++;
Mark Brown9e3a4af2008-11-06 12:53:18 -0800280 } while (rtc_valid_tm(&alarm->time) != 0);
David Brownella01cc652008-07-04 09:59:26 -0700281 break;
282
283 default:
284 dev_warn(&rtc->dev, "alarm rollover not handled\n");
285 }
286
287done:
Mark Lord0e36a9a2007-10-16 01:28:21 -0700288 return 0;
289}
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800290EXPORT_SYMBOL_GPL(rtc_read_alarm);
291
David Brownellab6a2d72007-05-08 00:33:30 -0700292int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800293{
294 int err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800295
David Brownellf8245c22007-05-08 00:34:07 -0700296 err = rtc_valid_tm(&alarm->time);
297 if (err != 0)
298 return err;
299
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800300 err = mutex_lock_interruptible(&rtc->ops_lock);
301 if (err)
David Brownellb68bb262008-07-29 22:33:30 -0700302 return err;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800303
304 if (!rtc->ops)
305 err = -ENODEV;
306 else if (!rtc->ops->set_alarm)
307 err = -EINVAL;
308 else
David Brownellcd966202007-05-08 00:33:40 -0700309 err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800310
311 mutex_unlock(&rtc->ops_lock);
312 return err;
313}
314EXPORT_SYMBOL_GPL(rtc_set_alarm);
315
Alessandro Zummo099e6572009-01-04 12:00:54 -0800316int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
317{
318 int err = mutex_lock_interruptible(&rtc->ops_lock);
319 if (err)
320 return err;
321
322 if (!rtc->ops)
323 err = -ENODEV;
324 else if (!rtc->ops->alarm_irq_enable)
325 err = -EINVAL;
326 else
327 err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
328
329 mutex_unlock(&rtc->ops_lock);
330 return err;
331}
332EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
333
334int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
335{
336 int err = mutex_lock_interruptible(&rtc->ops_lock);
337 if (err)
338 return err;
339
340#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
341 if (enabled == 0 && rtc->uie_irq_active) {
342 mutex_unlock(&rtc->ops_lock);
343 return rtc_dev_update_irq_enable_emul(rtc, enabled);
344 }
345#endif
346
347 if (!rtc->ops)
348 err = -ENODEV;
349 else if (!rtc->ops->update_irq_enable)
350 err = -EINVAL;
351 else
352 err = rtc->ops->update_irq_enable(rtc->dev.parent, enabled);
353
354 mutex_unlock(&rtc->ops_lock);
355
356#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
357 /*
358 * Enable emulation if the driver did not provide
359 * the update_irq_enable function pointer or if returned
360 * -EINVAL to signal that it has been configured without
361 * interrupts or that are not available at the moment.
362 */
363 if (err == -EINVAL)
364 err = rtc_dev_update_irq_enable_emul(rtc, enabled);
365#endif
366 return err;
367}
368EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
369
David Brownelld728b1e2006-11-25 11:09:28 -0800370/**
371 * rtc_update_irq - report RTC periodic, alarm, and/or update irqs
David Brownellab6a2d72007-05-08 00:33:30 -0700372 * @rtc: the rtc device
David Brownelld728b1e2006-11-25 11:09:28 -0800373 * @num: how many irqs are being reported (usually one)
374 * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700375 * Context: any
David Brownelld728b1e2006-11-25 11:09:28 -0800376 */
David Brownellab6a2d72007-05-08 00:33:30 -0700377void rtc_update_irq(struct rtc_device *rtc,
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800378 unsigned long num, unsigned long events)
379{
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700380 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800381
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700382 spin_lock_irqsave(&rtc->irq_lock, flags);
383 rtc->irq_data = (rtc->irq_data + (num << 8)) | events;
384 spin_unlock_irqrestore(&rtc->irq_lock, flags);
385
386 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800387 if (rtc->irq_task)
388 rtc->irq_task->func(rtc->irq_task->private_data);
Atsushi Nemotoe6229bec2009-06-18 16:49:09 -0700389 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800390
391 wake_up_interruptible(&rtc->irq_queue);
392 kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
393}
394EXPORT_SYMBOL_GPL(rtc_update_irq);
395
Dave Young71da8902008-01-22 14:00:34 +0800396static int __rtc_match(struct device *dev, void *data)
397{
398 char *name = (char *)data;
399
Kay Sieversd4afc762009-01-06 14:42:11 -0800400 if (strcmp(dev_name(dev), name) == 0)
Dave Young71da8902008-01-22 14:00:34 +0800401 return 1;
402 return 0;
403}
404
David Brownellab6a2d72007-05-08 00:33:30 -0700405struct rtc_device *rtc_class_open(char *name)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800406{
David Brownellcd966202007-05-08 00:33:40 -0700407 struct device *dev;
David Brownellab6a2d72007-05-08 00:33:30 -0700408 struct rtc_device *rtc = NULL;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800409
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400410 dev = class_find_device(rtc_class, NULL, name, __rtc_match);
Dave Young71da8902008-01-22 14:00:34 +0800411 if (dev)
412 rtc = to_rtc_device(dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800413
David Brownellab6a2d72007-05-08 00:33:30 -0700414 if (rtc) {
415 if (!try_module_get(rtc->owner)) {
David Brownellcd966202007-05-08 00:33:40 -0700416 put_device(dev);
David Brownellab6a2d72007-05-08 00:33:30 -0700417 rtc = NULL;
418 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800419 }
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800420
David Brownellab6a2d72007-05-08 00:33:30 -0700421 return rtc;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800422}
423EXPORT_SYMBOL_GPL(rtc_class_open);
424
David Brownellab6a2d72007-05-08 00:33:30 -0700425void rtc_class_close(struct rtc_device *rtc)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800426{
David Brownellab6a2d72007-05-08 00:33:30 -0700427 module_put(rtc->owner);
David Brownellcd966202007-05-08 00:33:40 -0700428 put_device(&rtc->dev);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800429}
430EXPORT_SYMBOL_GPL(rtc_class_close);
431
David Brownellab6a2d72007-05-08 00:33:30 -0700432int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800433{
434 int retval = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800435
436 if (task == NULL || task->func == NULL)
437 return -EINVAL;
438
Alessandro Zummod691eb92007-10-16 01:28:15 -0700439 /* Cannot register while the char dev is in use */
Jiri Kosina372a3022007-12-04 23:45:05 -0800440 if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags))
Alessandro Zummod691eb92007-10-16 01:28:15 -0700441 return -EBUSY;
442
David Brownelld728b1e2006-11-25 11:09:28 -0800443 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800444 if (rtc->irq_task == NULL) {
445 rtc->irq_task = task;
446 retval = 0;
447 }
David Brownelld728b1e2006-11-25 11:09:28 -0800448 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800449
Jiri Kosina372a3022007-12-04 23:45:05 -0800450 clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700451
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800452 return retval;
453}
454EXPORT_SYMBOL_GPL(rtc_irq_register);
455
David Brownellab6a2d72007-05-08 00:33:30 -0700456void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800457{
David Brownelld728b1e2006-11-25 11:09:28 -0800458 spin_lock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800459 if (rtc->irq_task == task)
460 rtc->irq_task = NULL;
David Brownelld728b1e2006-11-25 11:09:28 -0800461 spin_unlock_irq(&rtc->irq_task_lock);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800462}
463EXPORT_SYMBOL_GPL(rtc_irq_unregister);
464
David Brownell97144c62007-10-16 01:28:16 -0700465/**
466 * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
467 * @rtc: the rtc device
468 * @task: currently registered with rtc_irq_register()
469 * @enabled: true to enable periodic IRQs
470 * Context: any
471 *
472 * Note that rtc_irq_set_freq() should previously have been used to
473 * specify the desired frequency of periodic IRQ task->func() callbacks.
474 */
David Brownellab6a2d72007-05-08 00:33:30 -0700475int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800476{
477 int err = 0;
478 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800479
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700480 if (rtc->ops->irq_set_state == NULL)
481 return -ENXIO;
482
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800483 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700484 if (rtc->irq_task != NULL && task == NULL)
485 err = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800486 if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700487 err = -EACCES;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800488 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
489
490 if (err == 0)
David Brownellcd966202007-05-08 00:33:40 -0700491 err = rtc->ops->irq_set_state(rtc->dev.parent, enabled);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800492
493 return err;
494}
495EXPORT_SYMBOL_GPL(rtc_irq_set_state);
496
David Brownell97144c62007-10-16 01:28:16 -0700497/**
498 * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
499 * @rtc: the rtc device
500 * @task: currently registered with rtc_irq_register()
501 * @freq: positive frequency with which task->func() will be called
502 * Context: any
503 *
504 * Note that rtc_irq_set_state() is used to enable or disable the
505 * periodic IRQs.
506 */
David Brownellab6a2d72007-05-08 00:33:30 -0700507int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq)
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800508{
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700509 int err = 0;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800510 unsigned long flags;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800511
Alessandro Zummo56f10c62006-06-25 05:48:20 -0700512 if (rtc->ops->irq_set_freq == NULL)
513 return -ENXIO;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800514
515 spin_lock_irqsave(&rtc->irq_task_lock, flags);
Alessandro Zummod691eb92007-10-16 01:28:15 -0700516 if (rtc->irq_task != NULL && task == NULL)
517 err = -EBUSY;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800518 if (rtc->irq_task != task)
Alessandro Zummod691eb92007-10-16 01:28:15 -0700519 err = -EACCES;
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800520 spin_unlock_irqrestore(&rtc->irq_task_lock, flags);
521
522 if (err == 0) {
David Brownellcd966202007-05-08 00:33:40 -0700523 err = rtc->ops->irq_set_freq(rtc->dev.parent, freq);
Alessandro Zummo0c86edc2006-03-27 01:16:37 -0800524 if (err == 0)
525 rtc->irq_freq = freq;
526 }
527 return err;
528}
David Brownell2601a462006-11-25 11:09:27 -0800529EXPORT_SYMBOL_GPL(rtc_irq_set_freq);