Commit | Line | Data |
---|---|---|
0c86edc0 AZ |
1 | /* |
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> | |
d43c36dc | 15 | #include <linux/sched.h> |
97144c67 | 16 | #include <linux/log2.h> |
0c86edc0 | 17 | |
ab6a2d70 | 18 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
19 | { |
20 | int err; | |
0c86edc0 AZ |
21 | |
22 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
23 | if (err) | |
b68bb263 | 24 | return err; |
0c86edc0 AZ |
25 | |
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)); | |
cd966209 | 32 | err = rtc->ops->read_time(rtc->dev.parent, tm); |
0c86edc0 AZ |
33 | } |
34 | ||
35 | mutex_unlock(&rtc->ops_lock); | |
36 | return err; | |
37 | } | |
38 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
39 | ||
ab6a2d70 | 40 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
41 | { |
42 | int err; | |
0c86edc0 AZ |
43 | |
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) | |
b68bb263 | 50 | return err; |
0c86edc0 AZ |
51 | |
52 | if (!rtc->ops) | |
53 | err = -ENODEV; | |
bbccf83f | 54 | else if (rtc->ops->set_time) |
cd966209 | 55 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
bbccf83f AZ |
56 | 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; | |
0c86edc0 AZ |
63 | |
64 | mutex_unlock(&rtc->ops_lock); | |
65 | return err; | |
66 | } | |
67 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
68 | ||
ab6a2d70 | 69 | int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) |
0c86edc0 AZ |
70 | { |
71 | int err; | |
0c86edc0 AZ |
72 | |
73 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
74 | if (err) | |
b68bb263 | 75 | return err; |
0c86edc0 AZ |
76 | |
77 | if (!rtc->ops) | |
78 | err = -ENODEV; | |
79 | else if (rtc->ops->set_mmss) | |
cd966209 | 80 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); |
0c86edc0 AZ |
81 | else if (rtc->ops->read_time && rtc->ops->set_time) { |
82 | struct rtc_time new, old; | |
83 | ||
cd966209 | 84 | err = rtc->ops->read_time(rtc->dev.parent, &old); |
0c86edc0 AZ |
85 | 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))) | |
cd966209 | 96 | err = rtc->ops->set_time(rtc->dev.parent, |
ab6a2d70 | 97 | &new); |
0c86edc0 AZ |
98 | } |
99 | } | |
100 | else | |
101 | err = -EINVAL; | |
102 | ||
103 | mutex_unlock(&rtc->ops_lock); | |
104 | ||
105 | return err; | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(rtc_set_mmss); | |
108 | ||
0e36a9a4 | 109 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
110 | { |
111 | int err; | |
0c86edc0 AZ |
112 | |
113 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
114 | if (err) | |
b68bb263 | 115 | return err; |
0c86edc0 AZ |
116 | |
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)); | |
cd966209 | 123 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); |
0c86edc0 AZ |
124 | } |
125 | ||
126 | mutex_unlock(&rtc->ops_lock); | |
127 | return err; | |
128 | } | |
0e36a9a4 ML |
129 | |
130 | int 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; | |
a01cc657 DB |
135 | unsigned long t_now, t_alm; |
136 | enum { none, day, month, year } missing = none; | |
137 | unsigned days; | |
0e36a9a4 | 138 | |
a01cc657 DB |
139 | /* 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. | |
0e36a9a4 ML |
154 | * |
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 | ||
a01cc657 DB |
196 | /* full-function RTCs won't have such missing fields */ |
197 | if (rtc_valid_tm(&alarm->time) == 0) | |
198 | return 0; | |
199 | ||
0e36a9a4 ML |
200 | /* 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 | |
a01cc657 | 209 | || before.tm_year != now.tm_year); |
0e36a9a4 | 210 | |
a01cc657 DB |
211 | /* Fill in the missing alarm fields using the timestamp; we |
212 | * know there's at least one since alarm->time is invalid. | |
213 | */ | |
0e36a9a4 ML |
214 | 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; | |
a01cc657 DB |
220 | |
221 | /* For simplicity, only support date rollover for now */ | |
222 | if (alarm->time.tm_mday == -1) { | |
0e36a9a4 | 223 | alarm->time.tm_mday = now.tm_mday; |
a01cc657 DB |
224 | missing = day; |
225 | } | |
226 | if (alarm->time.tm_mon == -1) { | |
0e36a9a4 | 227 | alarm->time.tm_mon = now.tm_mon; |
a01cc657 DB |
228 | if (missing == none) |
229 | missing = month; | |
230 | } | |
231 | if (alarm->time.tm_year == -1) { | |
0e36a9a4 | 232 | alarm->time.tm_year = now.tm_year; |
a01cc657 DB |
233 | 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++; | |
9e3a4afd | 280 | } while (rtc_valid_tm(&alarm->time) != 0); |
a01cc657 DB |
281 | break; |
282 | ||
283 | default: | |
284 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
285 | } | |
286 | ||
287 | done: | |
0e36a9a4 ML |
288 | return 0; |
289 | } | |
0c86edc0 AZ |
290 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
291 | ||
ab6a2d70 | 292 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
293 | { |
294 | int err; | |
0c86edc0 | 295 | |
f8245c26 DB |
296 | err = rtc_valid_tm(&alarm->time); |
297 | if (err != 0) | |
298 | return err; | |
299 | ||
0c86edc0 AZ |
300 | err = mutex_lock_interruptible(&rtc->ops_lock); |
301 | if (err) | |
b68bb263 | 302 | return err; |
0c86edc0 AZ |
303 | |
304 | if (!rtc->ops) | |
305 | err = -ENODEV; | |
306 | else if (!rtc->ops->set_alarm) | |
307 | err = -EINVAL; | |
308 | else | |
cd966209 | 309 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); |
0c86edc0 AZ |
310 | |
311 | mutex_unlock(&rtc->ops_lock); | |
312 | return err; | |
313 | } | |
314 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
315 | ||
099e6576 AZ |
316 | int 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 | } | |
332 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
333 | ||
334 | int 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 | } | |
368 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
369 | ||
d728b1e6 DB |
370 | /** |
371 | * rtc_update_irq - report RTC periodic, alarm, and/or update irqs | |
ab6a2d70 | 372 | * @rtc: the rtc device |
d728b1e6 DB |
373 | * @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 | |
e6229bec | 375 | * Context: any |
d728b1e6 | 376 | */ |
ab6a2d70 | 377 | void rtc_update_irq(struct rtc_device *rtc, |
0c86edc0 AZ |
378 | unsigned long num, unsigned long events) |
379 | { | |
e6229bec AN |
380 | unsigned long flags; |
381 | ||
382 | spin_lock_irqsave(&rtc->irq_lock, flags); | |
0c86edc0 | 383 | rtc->irq_data = (rtc->irq_data + (num << 8)) | events; |
e6229bec | 384 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 385 | |
e6229bec | 386 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
387 | if (rtc->irq_task) |
388 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 389 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
390 | |
391 | wake_up_interruptible(&rtc->irq_queue); | |
392 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
393 | } | |
394 | EXPORT_SYMBOL_GPL(rtc_update_irq); | |
395 | ||
71da8905 DY |
396 | static int __rtc_match(struct device *dev, void *data) |
397 | { | |
398 | char *name = (char *)data; | |
399 | ||
d4afc76c | 400 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
401 | return 1; |
402 | return 0; | |
403 | } | |
404 | ||
ab6a2d70 | 405 | struct rtc_device *rtc_class_open(char *name) |
0c86edc0 | 406 | { |
cd966209 | 407 | struct device *dev; |
ab6a2d70 | 408 | struct rtc_device *rtc = NULL; |
0c86edc0 | 409 | |
695794ae | 410 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
411 | if (dev) |
412 | rtc = to_rtc_device(dev); | |
0c86edc0 | 413 | |
ab6a2d70 DB |
414 | if (rtc) { |
415 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 416 | put_device(dev); |
ab6a2d70 DB |
417 | rtc = NULL; |
418 | } | |
0c86edc0 | 419 | } |
0c86edc0 | 420 | |
ab6a2d70 | 421 | return rtc; |
0c86edc0 AZ |
422 | } |
423 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
424 | ||
ab6a2d70 | 425 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 426 | { |
ab6a2d70 | 427 | module_put(rtc->owner); |
cd966209 | 428 | put_device(&rtc->dev); |
0c86edc0 AZ |
429 | } |
430 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
431 | ||
ab6a2d70 | 432 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
433 | { |
434 | int retval = -EBUSY; | |
0c86edc0 AZ |
435 | |
436 | if (task == NULL || task->func == NULL) | |
437 | return -EINVAL; | |
438 | ||
d691eb90 | 439 | /* Cannot register while the char dev is in use */ |
372a302e | 440 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
441 | return -EBUSY; |
442 | ||
d728b1e6 | 443 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
444 | if (rtc->irq_task == NULL) { |
445 | rtc->irq_task = task; | |
446 | retval = 0; | |
447 | } | |
d728b1e6 | 448 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 449 | |
372a302e | 450 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 451 | |
0c86edc0 AZ |
452 | return retval; |
453 | } | |
454 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
455 | ||
ab6a2d70 | 456 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 457 | { |
d728b1e6 | 458 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
459 | if (rtc->irq_task == task) |
460 | rtc->irq_task = NULL; | |
d728b1e6 | 461 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
462 | } |
463 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
464 | ||
97144c67 DB |
465 | /** |
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 | */ | |
ab6a2d70 | 475 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
476 | { |
477 | int err = 0; | |
478 | unsigned long flags; | |
0c86edc0 | 479 | |
56f10c63 AZ |
480 | if (rtc->ops->irq_set_state == NULL) |
481 | return -ENXIO; | |
482 | ||
0c86edc0 | 483 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
484 | if (rtc->irq_task != NULL && task == NULL) |
485 | err = -EBUSY; | |
0c86edc0 | 486 | if (rtc->irq_task != task) |
d691eb90 | 487 | err = -EACCES; |
0c86edc0 AZ |
488 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
489 | ||
490 | if (err == 0) | |
cd966209 | 491 | err = rtc->ops->irq_set_state(rtc->dev.parent, enabled); |
0c86edc0 AZ |
492 | |
493 | return err; | |
494 | } | |
495 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
496 | ||
97144c67 DB |
497 | /** |
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 | */ | |
ab6a2d70 | 507 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 508 | { |
56f10c63 | 509 | int err = 0; |
0c86edc0 | 510 | unsigned long flags; |
0c86edc0 | 511 | |
56f10c63 AZ |
512 | if (rtc->ops->irq_set_freq == NULL) |
513 | return -ENXIO; | |
0c86edc0 AZ |
514 | |
515 | spin_lock_irqsave(&rtc->irq_task_lock, flags); | |
d691eb90 AZ |
516 | if (rtc->irq_task != NULL && task == NULL) |
517 | err = -EBUSY; | |
0c86edc0 | 518 | if (rtc->irq_task != task) |
d691eb90 | 519 | err = -EACCES; |
0c86edc0 AZ |
520 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
521 | ||
522 | if (err == 0) { | |
cd966209 | 523 | err = rtc->ops->irq_set_freq(rtc->dev.parent, freq); |
0c86edc0 AZ |
524 | if (err == 0) |
525 | rtc->irq_freq = freq; | |
526 | } | |
527 | return err; | |
528 | } | |
2601a464 | 529 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |