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Commit | Line | Data |
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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> |
2113852b | 16 | #include <linux/module.h> |
97144c67 | 17 | #include <linux/log2.h> |
6610e089 | 18 | #include <linux/workqueue.h> |
0c86edc0 | 19 | |
aa0be0f4 JS |
20 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); |
21 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer); | |
22 | ||
6610e089 | 23 | static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
24 | { |
25 | int err; | |
0c86edc0 AZ |
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); |
16682c86 | 33 | if (err < 0) { |
d0bddb51 AK |
34 | dev_dbg(&rtc->dev, "read_time: fail to read: %d\n", |
35 | err); | |
16682c86 HG |
36 | return err; |
37 | } | |
38 | ||
39 | err = rtc_valid_tm(tm); | |
40 | if (err < 0) | |
d0bddb51 | 41 | dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n"); |
0c86edc0 | 42 | } |
6610e089 JS |
43 | return err; |
44 | } | |
45 | ||
46 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
47 | { | |
48 | int err; | |
0c86edc0 | 49 | |
6610e089 JS |
50 | err = mutex_lock_interruptible(&rtc->ops_lock); |
51 | if (err) | |
52 | return err; | |
53 | ||
54 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 AZ |
55 | mutex_unlock(&rtc->ops_lock); |
56 | return err; | |
57 | } | |
58 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
59 | ||
ab6a2d70 | 60 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
61 | { |
62 | int err; | |
0c86edc0 AZ |
63 | |
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) | |
b68bb263 | 70 | return err; |
0c86edc0 AZ |
71 | |
72 | if (!rtc->ops) | |
73 | err = -ENODEV; | |
bbccf83f | 74 | else if (rtc->ops->set_time) |
cd966209 | 75 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
8e4ff1a8 XP |
76 | 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) { | |
bc10aa93 XP |
81 | time64_t secs64 = rtc_tm_to_time64(tm); |
82 | err = rtc->ops->set_mmss(rtc->dev.parent, secs64); | |
bbccf83f AZ |
83 | } else |
84 | err = -EINVAL; | |
0c86edc0 | 85 | |
14d0e347 | 86 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 87 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
88 | /* A timer might have just expired */ |
89 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
90 | return err; |
91 | } | |
92 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
93 | ||
f44f7f96 JS |
94 | static 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 { | |
d68778b8 UKK |
107 | alarm->enabled = 0; |
108 | alarm->pending = 0; | |
109 | alarm->time.tm_sec = -1; | |
110 | alarm->time.tm_min = -1; | |
111 | alarm->time.tm_hour = -1; | |
112 | alarm->time.tm_mday = -1; | |
113 | alarm->time.tm_mon = -1; | |
114 | alarm->time.tm_year = -1; | |
115 | alarm->time.tm_wday = -1; | |
116 | alarm->time.tm_yday = -1; | |
117 | alarm->time.tm_isdst = -1; | |
f44f7f96 JS |
118 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); |
119 | } | |
120 | ||
121 | mutex_unlock(&rtc->ops_lock); | |
122 | return err; | |
123 | } | |
124 | ||
125 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
126 | { | |
127 | int err; | |
128 | struct rtc_time before, now; | |
129 | int first_time = 1; | |
bc10aa93 | 130 | time64_t t_now, t_alm; |
f44f7f96 JS |
131 | enum { none, day, month, year } missing = none; |
132 | unsigned days; | |
133 | ||
134 | /* The lower level RTC driver may return -1 in some fields, | |
135 | * creating invalid alarm->time values, for reasons like: | |
136 | * | |
137 | * - The hardware may not be capable of filling them in; | |
138 | * many alarms match only on time-of-day fields, not | |
139 | * day/month/year calendar data. | |
140 | * | |
141 | * - Some hardware uses illegal values as "wildcard" match | |
142 | * values, which non-Linux firmware (like a BIOS) may try | |
143 | * to set up as e.g. "alarm 15 minutes after each hour". | |
144 | * Linux uses only oneshot alarms. | |
145 | * | |
146 | * When we see that here, we deal with it by using values from | |
147 | * a current RTC timestamp for any missing (-1) values. The | |
148 | * RTC driver prevents "periodic alarm" modes. | |
149 | * | |
150 | * But this can be racey, because some fields of the RTC timestamp | |
151 | * may have wrapped in the interval since we read the RTC alarm, | |
152 | * which would lead to us inserting inconsistent values in place | |
153 | * of the -1 fields. | |
154 | * | |
155 | * Reading the alarm and timestamp in the reverse sequence | |
156 | * would have the same race condition, and not solve the issue. | |
157 | * | |
158 | * So, we must first read the RTC timestamp, | |
159 | * then read the RTC alarm value, | |
160 | * and then read a second RTC timestamp. | |
161 | * | |
162 | * If any fields of the second timestamp have changed | |
163 | * when compared with the first timestamp, then we know | |
164 | * our timestamp may be inconsistent with that used by | |
165 | * the low-level rtc_read_alarm_internal() function. | |
166 | * | |
167 | * So, when the two timestamps disagree, we just loop and do | |
168 | * the process again to get a fully consistent set of values. | |
169 | * | |
170 | * This could all instead be done in the lower level driver, | |
171 | * but since more than one lower level RTC implementation needs it, | |
172 | * then it's probably best best to do it here instead of there.. | |
173 | */ | |
174 | ||
175 | /* Get the "before" timestamp */ | |
176 | err = rtc_read_time(rtc, &before); | |
177 | if (err < 0) | |
178 | return err; | |
179 | do { | |
180 | if (!first_time) | |
181 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
182 | first_time = 0; | |
183 | ||
184 | /* get the RTC alarm values, which may be incomplete */ | |
185 | err = rtc_read_alarm_internal(rtc, alarm); | |
186 | if (err) | |
187 | return err; | |
188 | ||
189 | /* full-function RTCs won't have such missing fields */ | |
190 | if (rtc_valid_tm(&alarm->time) == 0) | |
191 | return 0; | |
192 | ||
193 | /* get the "after" timestamp, to detect wrapped fields */ | |
194 | err = rtc_read_time(rtc, &now); | |
195 | if (err < 0) | |
196 | return err; | |
197 | ||
198 | /* note that tm_sec is a "don't care" value here: */ | |
199 | } while ( before.tm_min != now.tm_min | |
200 | || before.tm_hour != now.tm_hour | |
201 | || before.tm_mon != now.tm_mon | |
202 | || before.tm_year != now.tm_year); | |
203 | ||
204 | /* Fill in the missing alarm fields using the timestamp; we | |
205 | * know there's at least one since alarm->time is invalid. | |
206 | */ | |
207 | if (alarm->time.tm_sec == -1) | |
208 | alarm->time.tm_sec = now.tm_sec; | |
209 | if (alarm->time.tm_min == -1) | |
210 | alarm->time.tm_min = now.tm_min; | |
211 | if (alarm->time.tm_hour == -1) | |
212 | alarm->time.tm_hour = now.tm_hour; | |
213 | ||
214 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 215 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
216 | alarm->time.tm_mday = now.tm_mday; |
217 | missing = day; | |
218 | } | |
e74a8f2e | 219 | if ((unsigned)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
220 | alarm->time.tm_mon = now.tm_mon; |
221 | if (missing == none) | |
222 | missing = month; | |
223 | } | |
224 | if (alarm->time.tm_year == -1) { | |
225 | alarm->time.tm_year = now.tm_year; | |
226 | if (missing == none) | |
227 | missing = year; | |
228 | } | |
229 | ||
da96aea0 VJ |
230 | /* Can't proceed if alarm is still invalid after replacing |
231 | * missing fields. | |
232 | */ | |
233 | err = rtc_valid_tm(&alarm->time); | |
234 | if (err) | |
235 | goto done; | |
236 | ||
f44f7f96 | 237 | /* with luck, no rollover is needed */ |
bc10aa93 XP |
238 | t_now = rtc_tm_to_time64(&now); |
239 | t_alm = rtc_tm_to_time64(&alarm->time); | |
f44f7f96 JS |
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; | |
bc10aa93 | 253 | rtc_time64_to_tm(t_alm, &alarm->time); |
f44f7f96 JS |
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++; | |
ee1d9014 AN |
280 | } while (!is_leap_year(alarm->time.tm_year + 1900) |
281 | && rtc_valid_tm(&alarm->time) != 0); | |
f44f7f96 JS |
282 | break; |
283 | ||
284 | default: | |
285 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
286 | } | |
287 | ||
ee1d9014 AN |
288 | err = rtc_valid_tm(&alarm->time); |
289 | ||
da96aea0 | 290 | done: |
ee1d9014 AN |
291 | if (err) { |
292 | dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n", | |
293 | alarm->time.tm_year + 1900, alarm->time.tm_mon + 1, | |
294 | alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min, | |
295 | alarm->time.tm_sec); | |
296 | } | |
297 | ||
298 | return err; | |
f44f7f96 JS |
299 | } |
300 | ||
6610e089 | 301 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
302 | { |
303 | int err; | |
0c86edc0 AZ |
304 | |
305 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
306 | if (err) | |
b68bb263 | 307 | return err; |
d5553a55 JS |
308 | if (rtc->ops == NULL) |
309 | err = -ENODEV; | |
310 | else if (!rtc->ops->read_alarm) | |
311 | err = -EINVAL; | |
312 | else { | |
313 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
314 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 315 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 316 | } |
0c86edc0 | 317 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 318 | |
d5553a55 | 319 | return err; |
0c86edc0 | 320 | } |
6610e089 | 321 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 322 | |
d576fe49 | 323 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 324 | { |
6610e089 | 325 | struct rtc_time tm; |
bc10aa93 | 326 | time64_t now, scheduled; |
0e36a9a4 | 327 | int err; |
0e36a9a4 | 328 | |
6610e089 JS |
329 | err = rtc_valid_tm(&alarm->time); |
330 | if (err) | |
0e36a9a4 | 331 | return err; |
bc10aa93 | 332 | scheduled = rtc_tm_to_time64(&alarm->time); |
a01cc657 | 333 | |
6610e089 JS |
334 | /* Make sure we're not setting alarms in the past */ |
335 | err = __rtc_read_time(rtc, &tm); | |
ca6dc2da HG |
336 | if (err) |
337 | return err; | |
bc10aa93 | 338 | now = rtc_tm_to_time64(&tm); |
6610e089 JS |
339 | if (scheduled <= now) |
340 | return -ETIME; | |
341 | /* | |
342 | * XXX - We just checked to make sure the alarm time is not | |
343 | * in the past, but there is still a race window where if | |
344 | * the is alarm set for the next second and the second ticks | |
345 | * over right here, before we set the alarm. | |
a01cc657 | 346 | */ |
a01cc657 | 347 | |
157e8bf8 LT |
348 | if (!rtc->ops) |
349 | err = -ENODEV; | |
350 | else if (!rtc->ops->set_alarm) | |
351 | err = -EINVAL; | |
352 | else | |
353 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
354 | ||
355 | return err; | |
0e36a9a4 | 356 | } |
0c86edc0 | 357 | |
ab6a2d70 | 358 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
359 | { |
360 | int err; | |
0c86edc0 | 361 | |
03b2c662 AB |
362 | if (!rtc->ops) |
363 | return -ENODEV; | |
364 | else if (!rtc->ops->set_alarm) | |
365 | return -EINVAL; | |
366 | ||
f8245c26 DB |
367 | err = rtc_valid_tm(&alarm->time); |
368 | if (err != 0) | |
369 | return err; | |
370 | ||
0c86edc0 AZ |
371 | err = mutex_lock_interruptible(&rtc->ops_lock); |
372 | if (err) | |
b68bb263 | 373 | return err; |
3ff2e13c | 374 | if (rtc->aie_timer.enabled) |
96c8f06a | 375 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 376 | |
6610e089 | 377 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); |
8b0e1953 | 378 | rtc->aie_timer.period = 0; |
3ff2e13c | 379 | if (alarm->enabled) |
aa0be0f4 | 380 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 381 | |
0c86edc0 | 382 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 383 | return err; |
0c86edc0 AZ |
384 | } |
385 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
386 | ||
f6d5b331 JS |
387 | /* Called once per device from rtc_device_register */ |
388 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
389 | { | |
390 | int err; | |
bd729d72 | 391 | struct rtc_time now; |
f6d5b331 JS |
392 | |
393 | err = rtc_valid_tm(&alarm->time); | |
394 | if (err != 0) | |
395 | return err; | |
396 | ||
bd729d72 JS |
397 | err = rtc_read_time(rtc, &now); |
398 | if (err) | |
399 | return err; | |
400 | ||
f6d5b331 JS |
401 | err = mutex_lock_interruptible(&rtc->ops_lock); |
402 | if (err) | |
403 | return err; | |
404 | ||
405 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
8b0e1953 | 406 | rtc->aie_timer.period = 0; |
bd729d72 | 407 | |
6785b3b6 | 408 | /* Alarm has to be enabled & in the future for us to enqueue it */ |
2456e855 TG |
409 | if (alarm->enabled && (rtc_tm_to_ktime(now) < |
410 | rtc->aie_timer.node.expires)) { | |
bd729d72 | 411 | |
f6d5b331 JS |
412 | rtc->aie_timer.enabled = 1; |
413 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
414 | } | |
415 | mutex_unlock(&rtc->ops_lock); | |
416 | return err; | |
417 | } | |
418 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
419 | ||
099e6576 AZ |
420 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
421 | { | |
422 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
423 | if (err) | |
424 | return err; | |
425 | ||
6610e089 | 426 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
427 | if (enabled) |
428 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
429 | else | |
96c8f06a | 430 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
431 | } |
432 | ||
aa0be0f4 | 433 | if (err) |
516373b8 UKK |
434 | /* nothing */; |
435 | else if (!rtc->ops) | |
099e6576 AZ |
436 | err = -ENODEV; |
437 | else if (!rtc->ops->alarm_irq_enable) | |
438 | err = -EINVAL; | |
439 | else | |
440 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
441 | ||
442 | mutex_unlock(&rtc->ops_lock); | |
443 | return err; | |
444 | } | |
445 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
446 | ||
447 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
448 | { | |
449 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
450 | if (err) | |
451 | return err; | |
452 | ||
456d66ec JS |
453 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
454 | if (enabled == 0 && rtc->uie_irq_active) { | |
455 | mutex_unlock(&rtc->ops_lock); | |
456 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
457 | } | |
458 | #endif | |
6610e089 JS |
459 | /* make sure we're changing state */ |
460 | if (rtc->uie_rtctimer.enabled == enabled) | |
461 | goto out; | |
462 | ||
4a649903 JS |
463 | if (rtc->uie_unsupported) { |
464 | err = -EINVAL; | |
465 | goto out; | |
466 | } | |
467 | ||
6610e089 JS |
468 | if (enabled) { |
469 | struct rtc_time tm; | |
470 | ktime_t now, onesec; | |
471 | ||
472 | __rtc_read_time(rtc, &tm); | |
473 | onesec = ktime_set(1, 0); | |
474 | now = rtc_tm_to_ktime(tm); | |
475 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
476 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 JS |
477 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
478 | } else | |
96c8f06a | 479 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
099e6576 | 480 | |
6610e089 | 481 | out: |
099e6576 | 482 | mutex_unlock(&rtc->ops_lock); |
456d66ec JS |
483 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
484 | /* | |
485 | * Enable emulation if the driver did not provide | |
486 | * the update_irq_enable function pointer or if returned | |
487 | * -EINVAL to signal that it has been configured without | |
488 | * interrupts or that are not available at the moment. | |
489 | */ | |
490 | if (err == -EINVAL) | |
491 | err = rtc_dev_update_irq_enable_emul(rtc, enabled); | |
492 | #endif | |
099e6576 | 493 | return err; |
6610e089 | 494 | |
099e6576 AZ |
495 | } |
496 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
497 | ||
6610e089 | 498 | |
d728b1e6 | 499 | /** |
6610e089 JS |
500 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
501 | * @rtc: pointer to the rtc device | |
502 | * | |
503 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 504 | * has occurred (or been emulated). |
6610e089 JS |
505 | * |
506 | * Triggers the registered irq_task function callback. | |
d728b1e6 | 507 | */ |
456d66ec | 508 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 509 | { |
e6229bec AN |
510 | unsigned long flags; |
511 | ||
6610e089 | 512 | /* mark one irq of the appropriate mode */ |
e6229bec | 513 | spin_lock_irqsave(&rtc->irq_lock, flags); |
6610e089 | 514 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); |
e6229bec | 515 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 516 | |
6610e089 | 517 | /* call the task func */ |
e6229bec | 518 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
519 | if (rtc->irq_task) |
520 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 521 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
522 | |
523 | wake_up_interruptible(&rtc->irq_queue); | |
524 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
525 | } | |
6610e089 JS |
526 | |
527 | ||
528 | /** | |
529 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
530 | * @private: pointer to the rtc_device | |
531 | * | |
532 | * This functions is called when the aie_timer expires. | |
533 | */ | |
534 | void rtc_aie_update_irq(void *private) | |
535 | { | |
536 | struct rtc_device *rtc = (struct rtc_device *)private; | |
537 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); | |
538 | } | |
539 | ||
540 | ||
541 | /** | |
542 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
543 | * @private: pointer to the rtc_device | |
544 | * | |
545 | * This functions is called when the uie_timer expires. | |
546 | */ | |
547 | void rtc_uie_update_irq(void *private) | |
548 | { | |
549 | struct rtc_device *rtc = (struct rtc_device *)private; | |
550 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); | |
551 | } | |
552 | ||
553 | ||
554 | /** | |
555 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
556 | * @timer: pointer to the pie mode hrtimer | |
557 | * | |
558 | * This function is used to emulate PIE mode interrupts | |
559 | * using an hrtimer. This function is called when the periodic | |
560 | * hrtimer expires. | |
561 | */ | |
562 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
563 | { | |
564 | struct rtc_device *rtc; | |
565 | ktime_t period; | |
566 | int count; | |
567 | rtc = container_of(timer, struct rtc_device, pie_timer); | |
568 | ||
8b0e1953 | 569 | period = NSEC_PER_SEC / rtc->irq_freq; |
6610e089 JS |
570 | count = hrtimer_forward_now(timer, period); |
571 | ||
572 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
573 | ||
574 | return HRTIMER_RESTART; | |
575 | } | |
576 | ||
577 | /** | |
578 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
579 | * @rtc: the rtc device | |
580 | * @num: how many irqs are being reported (usually one) | |
581 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
582 | * Context: any | |
583 | */ | |
584 | void rtc_update_irq(struct rtc_device *rtc, | |
585 | unsigned long num, unsigned long events) | |
586 | { | |
e7cba884 | 587 | if (IS_ERR_OR_NULL(rtc)) |
131c9cc8 AZ |
588 | return; |
589 | ||
7523ceed | 590 | pm_stay_awake(rtc->dev.parent); |
6610e089 JS |
591 | schedule_work(&rtc->irqwork); |
592 | } | |
0c86edc0 AZ |
593 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
594 | ||
9f3b795a | 595 | static int __rtc_match(struct device *dev, const void *data) |
71da8905 | 596 | { |
9f3b795a | 597 | const char *name = data; |
71da8905 | 598 | |
d4afc76c | 599 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
600 | return 1; |
601 | return 0; | |
602 | } | |
603 | ||
9f3b795a | 604 | struct rtc_device *rtc_class_open(const char *name) |
0c86edc0 | 605 | { |
cd966209 | 606 | struct device *dev; |
ab6a2d70 | 607 | struct rtc_device *rtc = NULL; |
0c86edc0 | 608 | |
695794ae | 609 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
610 | if (dev) |
611 | rtc = to_rtc_device(dev); | |
0c86edc0 | 612 | |
ab6a2d70 DB |
613 | if (rtc) { |
614 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 615 | put_device(dev); |
ab6a2d70 DB |
616 | rtc = NULL; |
617 | } | |
0c86edc0 | 618 | } |
0c86edc0 | 619 | |
ab6a2d70 | 620 | return rtc; |
0c86edc0 AZ |
621 | } |
622 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
623 | ||
ab6a2d70 | 624 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 625 | { |
ab6a2d70 | 626 | module_put(rtc->owner); |
cd966209 | 627 | put_device(&rtc->dev); |
0c86edc0 AZ |
628 | } |
629 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
630 | ||
ab6a2d70 | 631 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
632 | { |
633 | int retval = -EBUSY; | |
0c86edc0 AZ |
634 | |
635 | if (task == NULL || task->func == NULL) | |
636 | return -EINVAL; | |
637 | ||
d691eb90 | 638 | /* Cannot register while the char dev is in use */ |
372a302e | 639 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
640 | return -EBUSY; |
641 | ||
d728b1e6 | 642 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
643 | if (rtc->irq_task == NULL) { |
644 | rtc->irq_task = task; | |
645 | retval = 0; | |
646 | } | |
d728b1e6 | 647 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 648 | |
372a302e | 649 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 650 | |
0c86edc0 AZ |
651 | return retval; |
652 | } | |
653 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
654 | ||
ab6a2d70 | 655 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 656 | { |
d728b1e6 | 657 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
658 | if (rtc->irq_task == task) |
659 | rtc->irq_task = NULL; | |
d728b1e6 | 660 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
661 | } |
662 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
663 | ||
3c8bb90e TG |
664 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
665 | { | |
666 | /* | |
667 | * We always cancel the timer here first, because otherwise | |
668 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
669 | * when we manage to start the timer before the callback | |
670 | * returns HRTIMER_RESTART. | |
671 | * | |
672 | * We cannot use hrtimer_cancel() here as a running callback | |
673 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
674 | * would spin forever. | |
675 | */ | |
676 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
677 | return -1; | |
678 | ||
679 | if (enabled) { | |
8b0e1953 | 680 | ktime_t period = NSEC_PER_SEC / rtc->irq_freq; |
3c8bb90e TG |
681 | |
682 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
683 | } | |
684 | return 0; | |
685 | } | |
686 | ||
97144c67 DB |
687 | /** |
688 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
689 | * @rtc: the rtc device | |
690 | * @task: currently registered with rtc_irq_register() | |
691 | * @enabled: true to enable periodic IRQs | |
692 | * Context: any | |
693 | * | |
694 | * Note that rtc_irq_set_freq() should previously have been used to | |
695 | * specify the desired frequency of periodic IRQ task->func() callbacks. | |
696 | */ | |
ab6a2d70 | 697 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
698 | { |
699 | int err = 0; | |
700 | unsigned long flags; | |
0c86edc0 | 701 | |
3c8bb90e | 702 | retry: |
0c86edc0 | 703 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
704 | if (rtc->irq_task != NULL && task == NULL) |
705 | err = -EBUSY; | |
0734e27f | 706 | else if (rtc->irq_task != task) |
d691eb90 | 707 | err = -EACCES; |
0734e27f | 708 | else { |
3c8bb90e TG |
709 | if (rtc_update_hrtimer(rtc, enabled) < 0) { |
710 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
711 | cpu_relax(); | |
712 | goto retry; | |
713 | } | |
714 | rtc->pie_enabled = enabled; | |
6610e089 | 715 | } |
6610e089 | 716 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
717 | return err; |
718 | } | |
719 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
720 | ||
97144c67 DB |
721 | /** |
722 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
723 | * @rtc: the rtc device | |
724 | * @task: currently registered with rtc_irq_register() | |
725 | * @freq: positive frequency with which task->func() will be called | |
726 | * Context: any | |
727 | * | |
728 | * Note that rtc_irq_set_state() is used to enable or disable the | |
729 | * periodic IRQs. | |
730 | */ | |
ab6a2d70 | 731 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 732 | { |
56f10c63 | 733 | int err = 0; |
0c86edc0 | 734 | unsigned long flags; |
0c86edc0 | 735 | |
6e7a333e | 736 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 737 | return -EINVAL; |
3c8bb90e | 738 | retry: |
0c86edc0 | 739 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
740 | if (rtc->irq_task != NULL && task == NULL) |
741 | err = -EBUSY; | |
0734e27f | 742 | else if (rtc->irq_task != task) |
d691eb90 | 743 | err = -EACCES; |
0734e27f | 744 | else { |
6610e089 | 745 | rtc->irq_freq = freq; |
3c8bb90e TG |
746 | if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { |
747 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
748 | cpu_relax(); | |
749 | goto retry; | |
6610e089 | 750 | } |
0c86edc0 | 751 | } |
6610e089 | 752 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
753 | return err; |
754 | } | |
2601a464 | 755 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |
6610e089 JS |
756 | |
757 | /** | |
96c8f06a | 758 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
6610e089 JS |
759 | * @rtc rtc device |
760 | * @timer timer being added. | |
761 | * | |
762 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
763 | * the next alarm event appropriately. | |
764 | * | |
aa0be0f4 JS |
765 | * Sets the enabled bit on the added timer. |
766 | * | |
6610e089 JS |
767 | * Must hold ops_lock for proper serialization of timerqueue |
768 | */ | |
aa0be0f4 | 769 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 770 | { |
2b2f5ff0 CIK |
771 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); |
772 | struct rtc_time tm; | |
773 | ktime_t now; | |
774 | ||
aa0be0f4 | 775 | timer->enabled = 1; |
2b2f5ff0 CIK |
776 | __rtc_read_time(rtc, &tm); |
777 | now = rtc_tm_to_ktime(tm); | |
778 | ||
779 | /* Skip over expired timers */ | |
780 | while (next) { | |
2456e855 | 781 | if (next->expires >= now) |
2b2f5ff0 CIK |
782 | break; |
783 | next = timerqueue_iterate_next(next); | |
784 | } | |
785 | ||
6610e089 | 786 | timerqueue_add(&rtc->timerqueue, &timer->node); |
74717b28 | 787 | if (!next || ktime_before(timer->node.expires, next->expires)) { |
6610e089 JS |
788 | struct rtc_wkalrm alarm; |
789 | int err; | |
790 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
791 | alarm.enabled = 1; | |
792 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
793 | if (err == -ETIME) { |
794 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 795 | schedule_work(&rtc->irqwork); |
14d0e347 | 796 | } else if (err) { |
aa0be0f4 JS |
797 | timerqueue_del(&rtc->timerqueue, &timer->node); |
798 | timer->enabled = 0; | |
799 | return err; | |
800 | } | |
6610e089 | 801 | } |
aa0be0f4 | 802 | return 0; |
6610e089 JS |
803 | } |
804 | ||
41c7f742 RV |
805 | static void rtc_alarm_disable(struct rtc_device *rtc) |
806 | { | |
807 | if (!rtc->ops || !rtc->ops->alarm_irq_enable) | |
808 | return; | |
809 | ||
810 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
811 | } | |
812 | ||
6610e089 | 813 | /** |
96c8f06a | 814 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
815 | * @rtc rtc device |
816 | * @timer timer being removed. | |
817 | * | |
818 | * Removes a timer onto the rtc devices timerqueue and sets | |
819 | * the next alarm event appropriately. | |
820 | * | |
aa0be0f4 JS |
821 | * Clears the enabled bit on the removed timer. |
822 | * | |
6610e089 JS |
823 | * Must hold ops_lock for proper serialization of timerqueue |
824 | */ | |
aa0be0f4 | 825 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
826 | { |
827 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
828 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 829 | timer->enabled = 0; |
6610e089 JS |
830 | if (next == &timer->node) { |
831 | struct rtc_wkalrm alarm; | |
832 | int err; | |
833 | next = timerqueue_getnext(&rtc->timerqueue); | |
41c7f742 RV |
834 | if (!next) { |
835 | rtc_alarm_disable(rtc); | |
6610e089 | 836 | return; |
41c7f742 | 837 | } |
6610e089 JS |
838 | alarm.time = rtc_ktime_to_tm(next->expires); |
839 | alarm.enabled = 1; | |
840 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
841 | if (err == -ETIME) { |
842 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 843 | schedule_work(&rtc->irqwork); |
14d0e347 | 844 | } |
6610e089 JS |
845 | } |
846 | } | |
847 | ||
848 | /** | |
96c8f06a | 849 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
850 | * @rtc rtc device |
851 | * @timer timer being removed. | |
852 | * | |
853 | * Expires rtc timers. Reprograms next alarm event if needed. | |
854 | * Called via worktask. | |
855 | * | |
856 | * Serializes access to timerqueue via ops_lock mutex | |
857 | */ | |
96c8f06a | 858 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
859 | { |
860 | struct rtc_timer *timer; | |
861 | struct timerqueue_node *next; | |
862 | ktime_t now; | |
863 | struct rtc_time tm; | |
864 | ||
865 | struct rtc_device *rtc = | |
866 | container_of(work, struct rtc_device, irqwork); | |
867 | ||
868 | mutex_lock(&rtc->ops_lock); | |
869 | again: | |
870 | __rtc_read_time(rtc, &tm); | |
871 | now = rtc_tm_to_ktime(tm); | |
872 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
2456e855 | 873 | if (next->expires > now) |
6610e089 JS |
874 | break; |
875 | ||
876 | /* expire timer */ | |
877 | timer = container_of(next, struct rtc_timer, node); | |
878 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
879 | timer->enabled = 0; | |
880 | if (timer->task.func) | |
881 | timer->task.func(timer->task.private_data); | |
882 | ||
883 | /* Re-add/fwd periodic timers */ | |
884 | if (ktime_to_ns(timer->period)) { | |
885 | timer->node.expires = ktime_add(timer->node.expires, | |
886 | timer->period); | |
887 | timer->enabled = 1; | |
888 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
889 | } | |
890 | } | |
891 | ||
892 | /* Set next alarm */ | |
893 | if (next) { | |
894 | struct rtc_wkalrm alarm; | |
895 | int err; | |
6528b889 XP |
896 | int retry = 3; |
897 | ||
6610e089 JS |
898 | alarm.time = rtc_ktime_to_tm(next->expires); |
899 | alarm.enabled = 1; | |
6528b889 | 900 | reprogram: |
6610e089 JS |
901 | err = __rtc_set_alarm(rtc, &alarm); |
902 | if (err == -ETIME) | |
903 | goto again; | |
6528b889 XP |
904 | else if (err) { |
905 | if (retry-- > 0) | |
906 | goto reprogram; | |
907 | ||
908 | timer = container_of(next, struct rtc_timer, node); | |
909 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
910 | timer->enabled = 0; | |
911 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); | |
912 | goto again; | |
913 | } | |
41c7f742 RV |
914 | } else |
915 | rtc_alarm_disable(rtc); | |
6610e089 | 916 | |
14d0e347 | 917 | pm_relax(rtc->dev.parent); |
6610e089 JS |
918 | mutex_unlock(&rtc->ops_lock); |
919 | } | |
920 | ||
921 | ||
96c8f06a | 922 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
923 | * @timer: timer to be intiialized |
924 | * @f: function pointer to be called when timer fires | |
925 | * @data: private data passed to function pointer | |
926 | * | |
927 | * Kernel interface to initializing an rtc_timer. | |
928 | */ | |
3ff2e13c | 929 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) |
6610e089 JS |
930 | { |
931 | timerqueue_init(&timer->node); | |
932 | timer->enabled = 0; | |
933 | timer->task.func = f; | |
934 | timer->task.private_data = data; | |
935 | } | |
936 | ||
96c8f06a | 937 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
938 | * @ rtc: rtc device to be used |
939 | * @ timer: timer being set | |
940 | * @ expires: time at which to expire the timer | |
941 | * @ period: period that the timer will recur | |
942 | * | |
943 | * Kernel interface to set an rtc_timer | |
944 | */ | |
3ff2e13c | 945 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
6610e089 JS |
946 | ktime_t expires, ktime_t period) |
947 | { | |
948 | int ret = 0; | |
949 | mutex_lock(&rtc->ops_lock); | |
950 | if (timer->enabled) | |
96c8f06a | 951 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
952 | |
953 | timer->node.expires = expires; | |
954 | timer->period = period; | |
955 | ||
aa0be0f4 | 956 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
957 | |
958 | mutex_unlock(&rtc->ops_lock); | |
959 | return ret; | |
960 | } | |
961 | ||
96c8f06a | 962 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
963 | * @ rtc: rtc device to be used |
964 | * @ timer: timer being set | |
965 | * | |
966 | * Kernel interface to cancel an rtc_timer | |
967 | */ | |
73744a64 | 968 | void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 969 | { |
6610e089 JS |
970 | mutex_lock(&rtc->ops_lock); |
971 | if (timer->enabled) | |
96c8f06a | 972 | rtc_timer_remove(rtc, timer); |
6610e089 | 973 | mutex_unlock(&rtc->ops_lock); |
6610e089 JS |
974 | } |
975 | ||
b3967067 JC |
976 | /** |
977 | * rtc_read_offset - Read the amount of rtc offset in parts per billion | |
978 | * @ rtc: rtc device to be used | |
979 | * @ offset: the offset in parts per billion | |
980 | * | |
981 | * see below for details. | |
982 | * | |
983 | * Kernel interface to read rtc clock offset | |
984 | * Returns 0 on success, or a negative number on error. | |
985 | * If read_offset() is not implemented for the rtc, return -EINVAL | |
986 | */ | |
987 | int rtc_read_offset(struct rtc_device *rtc, long *offset) | |
988 | { | |
989 | int ret; | |
990 | ||
991 | if (!rtc->ops) | |
992 | return -ENODEV; | |
993 | ||
994 | if (!rtc->ops->read_offset) | |
995 | return -EINVAL; | |
996 | ||
997 | mutex_lock(&rtc->ops_lock); | |
998 | ret = rtc->ops->read_offset(rtc->dev.parent, offset); | |
999 | mutex_unlock(&rtc->ops_lock); | |
1000 | return ret; | |
1001 | } | |
6610e089 | 1002 | |
b3967067 JC |
1003 | /** |
1004 | * rtc_set_offset - Adjusts the duration of the average second | |
1005 | * @ rtc: rtc device to be used | |
1006 | * @ offset: the offset in parts per billion | |
1007 | * | |
1008 | * Some rtc's allow an adjustment to the average duration of a second | |
1009 | * to compensate for differences in the actual clock rate due to temperature, | |
1010 | * the crystal, capacitor, etc. | |
1011 | * | |
8a25c8f6 RK |
1012 | * The adjustment applied is as follows: |
1013 | * t = t0 * (1 + offset * 1e-9) | |
1014 | * where t0 is the measured length of 1 RTC second with offset = 0 | |
1015 | * | |
b3967067 JC |
1016 | * Kernel interface to adjust an rtc clock offset. |
1017 | * Return 0 on success, or a negative number on error. | |
1018 | * If the rtc offset is not setable (or not implemented), return -EINVAL | |
1019 | */ | |
1020 | int rtc_set_offset(struct rtc_device *rtc, long offset) | |
1021 | { | |
1022 | int ret; | |
1023 | ||
1024 | if (!rtc->ops) | |
1025 | return -ENODEV; | |
1026 | ||
1027 | if (!rtc->ops->set_offset) | |
1028 | return -EINVAL; | |
1029 | ||
1030 | mutex_lock(&rtc->ops_lock); | |
1031 | ret = rtc->ops->set_offset(rtc->dev.parent, offset); | |
1032 | mutex_unlock(&rtc->ops_lock); | |
1033 | return ret; | |
1034 | } |