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> |
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 HG |
33 | if (err < 0) { |
34 | dev_err(&rtc->dev, "read_time: fail to read\n"); | |
35 | return err; | |
36 | } | |
37 | ||
38 | err = rtc_valid_tm(tm); | |
39 | if (err < 0) | |
40 | dev_err(&rtc->dev, "read_time: rtc_time isn't valid\n"); | |
0c86edc0 | 41 | } |
6610e089 JS |
42 | return err; |
43 | } | |
44 | ||
45 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
46 | { | |
47 | int err; | |
0c86edc0 | 48 | |
6610e089 JS |
49 | err = mutex_lock_interruptible(&rtc->ops_lock); |
50 | if (err) | |
51 | return err; | |
52 | ||
53 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 AZ |
54 | mutex_unlock(&rtc->ops_lock); |
55 | return err; | |
56 | } | |
57 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
58 | ||
ab6a2d70 | 59 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
60 | { |
61 | int err; | |
0c86edc0 AZ |
62 | |
63 | err = rtc_valid_tm(tm); | |
64 | if (err != 0) | |
65 | return err; | |
66 | ||
67 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
68 | if (err) | |
b68bb263 | 69 | return err; |
0c86edc0 AZ |
70 | |
71 | if (!rtc->ops) | |
72 | err = -ENODEV; | |
bbccf83f | 73 | else if (rtc->ops->set_time) |
cd966209 | 74 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
bbccf83f AZ |
75 | else if (rtc->ops->set_mmss) { |
76 | unsigned long secs; | |
77 | err = rtc_tm_to_time(tm, &secs); | |
78 | if (err == 0) | |
79 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); | |
80 | } else | |
81 | err = -EINVAL; | |
0c86edc0 | 82 | |
14d0e347 | 83 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 84 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
85 | /* A timer might have just expired */ |
86 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
87 | return err; |
88 | } | |
89 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
90 | ||
ab6a2d70 | 91 | int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) |
0c86edc0 AZ |
92 | { |
93 | int err; | |
0c86edc0 AZ |
94 | |
95 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
96 | if (err) | |
b68bb263 | 97 | return err; |
0c86edc0 AZ |
98 | |
99 | if (!rtc->ops) | |
100 | err = -ENODEV; | |
101 | else if (rtc->ops->set_mmss) | |
cd966209 | 102 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); |
0c86edc0 AZ |
103 | else if (rtc->ops->read_time && rtc->ops->set_time) { |
104 | struct rtc_time new, old; | |
105 | ||
cd966209 | 106 | err = rtc->ops->read_time(rtc->dev.parent, &old); |
0c86edc0 AZ |
107 | if (err == 0) { |
108 | rtc_time_to_tm(secs, &new); | |
109 | ||
110 | /* | |
111 | * avoid writing when we're going to change the day of | |
112 | * the month. We will retry in the next minute. This | |
113 | * basically means that if the RTC must not drift | |
114 | * by more than 1 minute in 11 minutes. | |
115 | */ | |
116 | if (!((old.tm_hour == 23 && old.tm_min == 59) || | |
117 | (new.tm_hour == 23 && new.tm_min == 59))) | |
cd966209 | 118 | err = rtc->ops->set_time(rtc->dev.parent, |
ab6a2d70 | 119 | &new); |
0c86edc0 | 120 | } |
3ff2e13c | 121 | } else { |
0c86edc0 | 122 | err = -EINVAL; |
3ff2e13c | 123 | } |
0c86edc0 | 124 | |
14d0e347 | 125 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 126 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
127 | /* A timer might have just expired */ |
128 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
129 | |
130 | return err; | |
131 | } | |
132 | EXPORT_SYMBOL_GPL(rtc_set_mmss); | |
133 | ||
f44f7f96 JS |
134 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
135 | { | |
136 | int err; | |
137 | ||
138 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
139 | if (err) | |
140 | return err; | |
141 | ||
142 | if (rtc->ops == NULL) | |
143 | err = -ENODEV; | |
144 | else if (!rtc->ops->read_alarm) | |
145 | err = -EINVAL; | |
146 | else { | |
147 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
148 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); | |
149 | } | |
150 | ||
151 | mutex_unlock(&rtc->ops_lock); | |
152 | return err; | |
153 | } | |
154 | ||
155 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
156 | { | |
157 | int err; | |
158 | struct rtc_time before, now; | |
159 | int first_time = 1; | |
160 | unsigned long t_now, t_alm; | |
161 | enum { none, day, month, year } missing = none; | |
162 | unsigned days; | |
163 | ||
164 | /* The lower level RTC driver may return -1 in some fields, | |
165 | * creating invalid alarm->time values, for reasons like: | |
166 | * | |
167 | * - The hardware may not be capable of filling them in; | |
168 | * many alarms match only on time-of-day fields, not | |
169 | * day/month/year calendar data. | |
170 | * | |
171 | * - Some hardware uses illegal values as "wildcard" match | |
172 | * values, which non-Linux firmware (like a BIOS) may try | |
173 | * to set up as e.g. "alarm 15 minutes after each hour". | |
174 | * Linux uses only oneshot alarms. | |
175 | * | |
176 | * When we see that here, we deal with it by using values from | |
177 | * a current RTC timestamp for any missing (-1) values. The | |
178 | * RTC driver prevents "periodic alarm" modes. | |
179 | * | |
180 | * But this can be racey, because some fields of the RTC timestamp | |
181 | * may have wrapped in the interval since we read the RTC alarm, | |
182 | * which would lead to us inserting inconsistent values in place | |
183 | * of the -1 fields. | |
184 | * | |
185 | * Reading the alarm and timestamp in the reverse sequence | |
186 | * would have the same race condition, and not solve the issue. | |
187 | * | |
188 | * So, we must first read the RTC timestamp, | |
189 | * then read the RTC alarm value, | |
190 | * and then read a second RTC timestamp. | |
191 | * | |
192 | * If any fields of the second timestamp have changed | |
193 | * when compared with the first timestamp, then we know | |
194 | * our timestamp may be inconsistent with that used by | |
195 | * the low-level rtc_read_alarm_internal() function. | |
196 | * | |
197 | * So, when the two timestamps disagree, we just loop and do | |
198 | * the process again to get a fully consistent set of values. | |
199 | * | |
200 | * This could all instead be done in the lower level driver, | |
201 | * but since more than one lower level RTC implementation needs it, | |
202 | * then it's probably best best to do it here instead of there.. | |
203 | */ | |
204 | ||
205 | /* Get the "before" timestamp */ | |
206 | err = rtc_read_time(rtc, &before); | |
207 | if (err < 0) | |
208 | return err; | |
209 | do { | |
210 | if (!first_time) | |
211 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
212 | first_time = 0; | |
213 | ||
214 | /* get the RTC alarm values, which may be incomplete */ | |
215 | err = rtc_read_alarm_internal(rtc, alarm); | |
216 | if (err) | |
217 | return err; | |
218 | ||
219 | /* full-function RTCs won't have such missing fields */ | |
220 | if (rtc_valid_tm(&alarm->time) == 0) | |
221 | return 0; | |
222 | ||
223 | /* get the "after" timestamp, to detect wrapped fields */ | |
224 | err = rtc_read_time(rtc, &now); | |
225 | if (err < 0) | |
226 | return err; | |
227 | ||
228 | /* note that tm_sec is a "don't care" value here: */ | |
229 | } while ( before.tm_min != now.tm_min | |
230 | || before.tm_hour != now.tm_hour | |
231 | || before.tm_mon != now.tm_mon | |
232 | || before.tm_year != now.tm_year); | |
233 | ||
234 | /* Fill in the missing alarm fields using the timestamp; we | |
235 | * know there's at least one since alarm->time is invalid. | |
236 | */ | |
237 | if (alarm->time.tm_sec == -1) | |
238 | alarm->time.tm_sec = now.tm_sec; | |
239 | if (alarm->time.tm_min == -1) | |
240 | alarm->time.tm_min = now.tm_min; | |
241 | if (alarm->time.tm_hour == -1) | |
242 | alarm->time.tm_hour = now.tm_hour; | |
243 | ||
244 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 245 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
246 | alarm->time.tm_mday = now.tm_mday; |
247 | missing = day; | |
248 | } | |
e74a8f2e | 249 | if ((unsigned)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
250 | alarm->time.tm_mon = now.tm_mon; |
251 | if (missing == none) | |
252 | missing = month; | |
253 | } | |
254 | if (alarm->time.tm_year == -1) { | |
255 | alarm->time.tm_year = now.tm_year; | |
256 | if (missing == none) | |
257 | missing = year; | |
258 | } | |
259 | ||
260 | /* with luck, no rollover is needed */ | |
261 | rtc_tm_to_time(&now, &t_now); | |
262 | rtc_tm_to_time(&alarm->time, &t_alm); | |
263 | if (t_now < t_alm) | |
264 | goto done; | |
265 | ||
266 | switch (missing) { | |
267 | ||
268 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that | |
269 | * that will trigger at 5am will do so at 5am Tuesday, which | |
270 | * could also be in the next month or year. This is a common | |
271 | * case, especially for PCs. | |
272 | */ | |
273 | case day: | |
274 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
275 | t_alm += 24 * 60 * 60; | |
276 | rtc_time_to_tm(t_alm, &alarm->time); | |
277 | break; | |
278 | ||
279 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
280 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
281 | * may end up in the month after that! Many newer PCs support | |
282 | * this type of alarm. | |
283 | */ | |
284 | case month: | |
285 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
286 | do { | |
287 | if (alarm->time.tm_mon < 11) | |
288 | alarm->time.tm_mon++; | |
289 | else { | |
290 | alarm->time.tm_mon = 0; | |
291 | alarm->time.tm_year++; | |
292 | } | |
293 | days = rtc_month_days(alarm->time.tm_mon, | |
294 | alarm->time.tm_year); | |
295 | } while (days < alarm->time.tm_mday); | |
296 | break; | |
297 | ||
298 | /* Year rollover ... easy except for leap years! */ | |
299 | case year: | |
300 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
301 | do { | |
302 | alarm->time.tm_year++; | |
ee1d9014 AN |
303 | } while (!is_leap_year(alarm->time.tm_year + 1900) |
304 | && rtc_valid_tm(&alarm->time) != 0); | |
f44f7f96 JS |
305 | break; |
306 | ||
307 | default: | |
308 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
309 | } | |
310 | ||
311 | done: | |
ee1d9014 AN |
312 | err = rtc_valid_tm(&alarm->time); |
313 | ||
314 | if (err) { | |
315 | dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n", | |
316 | alarm->time.tm_year + 1900, alarm->time.tm_mon + 1, | |
317 | alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min, | |
318 | alarm->time.tm_sec); | |
319 | } | |
320 | ||
321 | return err; | |
f44f7f96 JS |
322 | } |
323 | ||
6610e089 | 324 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
325 | { |
326 | int err; | |
0c86edc0 AZ |
327 | |
328 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
329 | if (err) | |
b68bb263 | 330 | return err; |
d5553a55 JS |
331 | if (rtc->ops == NULL) |
332 | err = -ENODEV; | |
333 | else if (!rtc->ops->read_alarm) | |
334 | err = -EINVAL; | |
335 | else { | |
336 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
337 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 338 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 339 | } |
0c86edc0 | 340 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 341 | |
d5553a55 | 342 | return err; |
0c86edc0 | 343 | } |
6610e089 | 344 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 345 | |
d576fe49 | 346 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 347 | { |
6610e089 JS |
348 | struct rtc_time tm; |
349 | long now, scheduled; | |
0e36a9a4 | 350 | int err; |
0e36a9a4 | 351 | |
6610e089 JS |
352 | err = rtc_valid_tm(&alarm->time); |
353 | if (err) | |
0e36a9a4 | 354 | return err; |
6610e089 | 355 | rtc_tm_to_time(&alarm->time, &scheduled); |
a01cc657 | 356 | |
6610e089 JS |
357 | /* Make sure we're not setting alarms in the past */ |
358 | err = __rtc_read_time(rtc, &tm); | |
ca6dc2da HG |
359 | if (err) |
360 | return err; | |
6610e089 JS |
361 | rtc_tm_to_time(&tm, &now); |
362 | if (scheduled <= now) | |
363 | return -ETIME; | |
364 | /* | |
365 | * XXX - We just checked to make sure the alarm time is not | |
366 | * in the past, but there is still a race window where if | |
367 | * the is alarm set for the next second and the second ticks | |
368 | * over right here, before we set the alarm. | |
a01cc657 | 369 | */ |
a01cc657 | 370 | |
157e8bf8 LT |
371 | if (!rtc->ops) |
372 | err = -ENODEV; | |
373 | else if (!rtc->ops->set_alarm) | |
374 | err = -EINVAL; | |
375 | else | |
376 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
377 | ||
378 | return err; | |
0e36a9a4 | 379 | } |
0c86edc0 | 380 | |
ab6a2d70 | 381 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
382 | { |
383 | int err; | |
0c86edc0 | 384 | |
f8245c26 DB |
385 | err = rtc_valid_tm(&alarm->time); |
386 | if (err != 0) | |
387 | return err; | |
388 | ||
0c86edc0 AZ |
389 | err = mutex_lock_interruptible(&rtc->ops_lock); |
390 | if (err) | |
b68bb263 | 391 | return err; |
3ff2e13c | 392 | if (rtc->aie_timer.enabled) |
96c8f06a | 393 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 394 | |
6610e089 JS |
395 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); |
396 | rtc->aie_timer.period = ktime_set(0, 0); | |
3ff2e13c | 397 | if (alarm->enabled) |
aa0be0f4 | 398 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 399 | |
0c86edc0 | 400 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 401 | return err; |
0c86edc0 AZ |
402 | } |
403 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
404 | ||
f6d5b331 JS |
405 | /* Called once per device from rtc_device_register */ |
406 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
407 | { | |
408 | int err; | |
bd729d72 | 409 | struct rtc_time now; |
f6d5b331 JS |
410 | |
411 | err = rtc_valid_tm(&alarm->time); | |
412 | if (err != 0) | |
413 | return err; | |
414 | ||
bd729d72 JS |
415 | err = rtc_read_time(rtc, &now); |
416 | if (err) | |
417 | return err; | |
418 | ||
f6d5b331 JS |
419 | err = mutex_lock_interruptible(&rtc->ops_lock); |
420 | if (err) | |
421 | return err; | |
422 | ||
423 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
424 | rtc->aie_timer.period = ktime_set(0, 0); | |
bd729d72 JS |
425 | |
426 | /* Alarm has to be enabled & in the futrure for us to enqueue it */ | |
427 | if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 < | |
428 | rtc->aie_timer.node.expires.tv64)) { | |
429 | ||
f6d5b331 JS |
430 | rtc->aie_timer.enabled = 1; |
431 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
432 | } | |
433 | mutex_unlock(&rtc->ops_lock); | |
434 | return err; | |
435 | } | |
436 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
437 | ||
438 | ||
439 | ||
099e6576 AZ |
440 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
441 | { | |
442 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
443 | if (err) | |
444 | return err; | |
445 | ||
6610e089 | 446 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
447 | if (enabled) |
448 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
449 | else | |
96c8f06a | 450 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
451 | } |
452 | ||
aa0be0f4 | 453 | if (err) |
516373b8 UKK |
454 | /* nothing */; |
455 | else if (!rtc->ops) | |
099e6576 AZ |
456 | err = -ENODEV; |
457 | else if (!rtc->ops->alarm_irq_enable) | |
458 | err = -EINVAL; | |
459 | else | |
460 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
461 | ||
462 | mutex_unlock(&rtc->ops_lock); | |
463 | return err; | |
464 | } | |
465 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
466 | ||
467 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
468 | { | |
469 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
470 | if (err) | |
471 | return err; | |
472 | ||
456d66ec JS |
473 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
474 | if (enabled == 0 && rtc->uie_irq_active) { | |
475 | mutex_unlock(&rtc->ops_lock); | |
476 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
477 | } | |
478 | #endif | |
6610e089 JS |
479 | /* make sure we're changing state */ |
480 | if (rtc->uie_rtctimer.enabled == enabled) | |
481 | goto out; | |
482 | ||
4a649903 JS |
483 | if (rtc->uie_unsupported) { |
484 | err = -EINVAL; | |
485 | goto out; | |
486 | } | |
487 | ||
6610e089 JS |
488 | if (enabled) { |
489 | struct rtc_time tm; | |
490 | ktime_t now, onesec; | |
491 | ||
492 | __rtc_read_time(rtc, &tm); | |
493 | onesec = ktime_set(1, 0); | |
494 | now = rtc_tm_to_ktime(tm); | |
495 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
496 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 JS |
497 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
498 | } else | |
96c8f06a | 499 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
099e6576 | 500 | |
6610e089 | 501 | out: |
099e6576 | 502 | mutex_unlock(&rtc->ops_lock); |
456d66ec JS |
503 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
504 | /* | |
505 | * Enable emulation if the driver did not provide | |
506 | * the update_irq_enable function pointer or if returned | |
507 | * -EINVAL to signal that it has been configured without | |
508 | * interrupts or that are not available at the moment. | |
509 | */ | |
510 | if (err == -EINVAL) | |
511 | err = rtc_dev_update_irq_enable_emul(rtc, enabled); | |
512 | #endif | |
099e6576 | 513 | return err; |
6610e089 | 514 | |
099e6576 AZ |
515 | } |
516 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
517 | ||
6610e089 | 518 | |
d728b1e6 | 519 | /** |
6610e089 JS |
520 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
521 | * @rtc: pointer to the rtc device | |
522 | * | |
523 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 524 | * has occurred (or been emulated). |
6610e089 JS |
525 | * |
526 | * Triggers the registered irq_task function callback. | |
d728b1e6 | 527 | */ |
456d66ec | 528 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 529 | { |
e6229bec AN |
530 | unsigned long flags; |
531 | ||
6610e089 | 532 | /* mark one irq of the appropriate mode */ |
e6229bec | 533 | spin_lock_irqsave(&rtc->irq_lock, flags); |
6610e089 | 534 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); |
e6229bec | 535 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 536 | |
6610e089 | 537 | /* call the task func */ |
e6229bec | 538 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
539 | if (rtc->irq_task) |
540 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 541 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
542 | |
543 | wake_up_interruptible(&rtc->irq_queue); | |
544 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
545 | } | |
6610e089 JS |
546 | |
547 | ||
548 | /** | |
549 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
550 | * @private: pointer to the rtc_device | |
551 | * | |
552 | * This functions is called when the aie_timer expires. | |
553 | */ | |
554 | void rtc_aie_update_irq(void *private) | |
555 | { | |
556 | struct rtc_device *rtc = (struct rtc_device *)private; | |
557 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); | |
558 | } | |
559 | ||
560 | ||
561 | /** | |
562 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
563 | * @private: pointer to the rtc_device | |
564 | * | |
565 | * This functions is called when the uie_timer expires. | |
566 | */ | |
567 | void rtc_uie_update_irq(void *private) | |
568 | { | |
569 | struct rtc_device *rtc = (struct rtc_device *)private; | |
570 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); | |
571 | } | |
572 | ||
573 | ||
574 | /** | |
575 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
576 | * @timer: pointer to the pie mode hrtimer | |
577 | * | |
578 | * This function is used to emulate PIE mode interrupts | |
579 | * using an hrtimer. This function is called when the periodic | |
580 | * hrtimer expires. | |
581 | */ | |
582 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
583 | { | |
584 | struct rtc_device *rtc; | |
585 | ktime_t period; | |
586 | int count; | |
587 | rtc = container_of(timer, struct rtc_device, pie_timer); | |
588 | ||
589 | period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); | |
590 | count = hrtimer_forward_now(timer, period); | |
591 | ||
592 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
593 | ||
594 | return HRTIMER_RESTART; | |
595 | } | |
596 | ||
597 | /** | |
598 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
599 | * @rtc: the rtc device | |
600 | * @num: how many irqs are being reported (usually one) | |
601 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
602 | * Context: any | |
603 | */ | |
604 | void rtc_update_irq(struct rtc_device *rtc, | |
605 | unsigned long num, unsigned long events) | |
606 | { | |
131c9cc8 AZ |
607 | if (unlikely(IS_ERR_OR_NULL(rtc))) |
608 | return; | |
609 | ||
7523ceed | 610 | pm_stay_awake(rtc->dev.parent); |
6610e089 JS |
611 | schedule_work(&rtc->irqwork); |
612 | } | |
0c86edc0 AZ |
613 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
614 | ||
9f3b795a | 615 | static int __rtc_match(struct device *dev, const void *data) |
71da8905 | 616 | { |
9f3b795a | 617 | const char *name = data; |
71da8905 | 618 | |
d4afc76c | 619 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
620 | return 1; |
621 | return 0; | |
622 | } | |
623 | ||
9f3b795a | 624 | struct rtc_device *rtc_class_open(const char *name) |
0c86edc0 | 625 | { |
cd966209 | 626 | struct device *dev; |
ab6a2d70 | 627 | struct rtc_device *rtc = NULL; |
0c86edc0 | 628 | |
695794ae | 629 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
630 | if (dev) |
631 | rtc = to_rtc_device(dev); | |
0c86edc0 | 632 | |
ab6a2d70 DB |
633 | if (rtc) { |
634 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 635 | put_device(dev); |
ab6a2d70 DB |
636 | rtc = NULL; |
637 | } | |
0c86edc0 | 638 | } |
0c86edc0 | 639 | |
ab6a2d70 | 640 | return rtc; |
0c86edc0 AZ |
641 | } |
642 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
643 | ||
ab6a2d70 | 644 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 645 | { |
ab6a2d70 | 646 | module_put(rtc->owner); |
cd966209 | 647 | put_device(&rtc->dev); |
0c86edc0 AZ |
648 | } |
649 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
650 | ||
ab6a2d70 | 651 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
652 | { |
653 | int retval = -EBUSY; | |
0c86edc0 AZ |
654 | |
655 | if (task == NULL || task->func == NULL) | |
656 | return -EINVAL; | |
657 | ||
d691eb90 | 658 | /* Cannot register while the char dev is in use */ |
372a302e | 659 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
660 | return -EBUSY; |
661 | ||
d728b1e6 | 662 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
663 | if (rtc->irq_task == NULL) { |
664 | rtc->irq_task = task; | |
665 | retval = 0; | |
666 | } | |
d728b1e6 | 667 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 668 | |
372a302e | 669 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 670 | |
0c86edc0 AZ |
671 | return retval; |
672 | } | |
673 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
674 | ||
ab6a2d70 | 675 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 676 | { |
d728b1e6 | 677 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
678 | if (rtc->irq_task == task) |
679 | rtc->irq_task = NULL; | |
d728b1e6 | 680 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
681 | } |
682 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
683 | ||
3c8bb90e TG |
684 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
685 | { | |
686 | /* | |
687 | * We always cancel the timer here first, because otherwise | |
688 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
689 | * when we manage to start the timer before the callback | |
690 | * returns HRTIMER_RESTART. | |
691 | * | |
692 | * We cannot use hrtimer_cancel() here as a running callback | |
693 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
694 | * would spin forever. | |
695 | */ | |
696 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
697 | return -1; | |
698 | ||
699 | if (enabled) { | |
700 | ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq); | |
701 | ||
702 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
703 | } | |
704 | return 0; | |
705 | } | |
706 | ||
97144c67 DB |
707 | /** |
708 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
709 | * @rtc: the rtc device | |
710 | * @task: currently registered with rtc_irq_register() | |
711 | * @enabled: true to enable periodic IRQs | |
712 | * Context: any | |
713 | * | |
714 | * Note that rtc_irq_set_freq() should previously have been used to | |
715 | * specify the desired frequency of periodic IRQ task->func() callbacks. | |
716 | */ | |
ab6a2d70 | 717 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
718 | { |
719 | int err = 0; | |
720 | unsigned long flags; | |
0c86edc0 | 721 | |
3c8bb90e | 722 | retry: |
0c86edc0 | 723 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
724 | if (rtc->irq_task != NULL && task == NULL) |
725 | err = -EBUSY; | |
0734e27f | 726 | else if (rtc->irq_task != task) |
d691eb90 | 727 | err = -EACCES; |
0734e27f | 728 | else { |
3c8bb90e TG |
729 | if (rtc_update_hrtimer(rtc, enabled) < 0) { |
730 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
731 | cpu_relax(); | |
732 | goto retry; | |
733 | } | |
734 | rtc->pie_enabled = enabled; | |
6610e089 | 735 | } |
6610e089 | 736 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
737 | return err; |
738 | } | |
739 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
740 | ||
97144c67 DB |
741 | /** |
742 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
743 | * @rtc: the rtc device | |
744 | * @task: currently registered with rtc_irq_register() | |
745 | * @freq: positive frequency with which task->func() will be called | |
746 | * Context: any | |
747 | * | |
748 | * Note that rtc_irq_set_state() is used to enable or disable the | |
749 | * periodic IRQs. | |
750 | */ | |
ab6a2d70 | 751 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 752 | { |
56f10c63 | 753 | int err = 0; |
0c86edc0 | 754 | unsigned long flags; |
0c86edc0 | 755 | |
6e7a333e | 756 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 757 | return -EINVAL; |
3c8bb90e | 758 | retry: |
0c86edc0 | 759 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
760 | if (rtc->irq_task != NULL && task == NULL) |
761 | err = -EBUSY; | |
0734e27f | 762 | else if (rtc->irq_task != task) |
d691eb90 | 763 | err = -EACCES; |
0734e27f | 764 | else { |
6610e089 | 765 | rtc->irq_freq = freq; |
3c8bb90e TG |
766 | if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { |
767 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
768 | cpu_relax(); | |
769 | goto retry; | |
6610e089 | 770 | } |
0c86edc0 | 771 | } |
6610e089 | 772 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
773 | return err; |
774 | } | |
2601a464 | 775 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |
6610e089 JS |
776 | |
777 | /** | |
96c8f06a | 778 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
6610e089 JS |
779 | * @rtc rtc device |
780 | * @timer timer being added. | |
781 | * | |
782 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
783 | * the next alarm event appropriately. | |
784 | * | |
aa0be0f4 JS |
785 | * Sets the enabled bit on the added timer. |
786 | * | |
6610e089 JS |
787 | * Must hold ops_lock for proper serialization of timerqueue |
788 | */ | |
aa0be0f4 | 789 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 790 | { |
aa0be0f4 | 791 | timer->enabled = 1; |
6610e089 JS |
792 | timerqueue_add(&rtc->timerqueue, &timer->node); |
793 | if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { | |
794 | struct rtc_wkalrm alarm; | |
795 | int err; | |
796 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
797 | alarm.enabled = 1; | |
798 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
799 | if (err == -ETIME) { |
800 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 801 | schedule_work(&rtc->irqwork); |
14d0e347 | 802 | } else if (err) { |
aa0be0f4 JS |
803 | timerqueue_del(&rtc->timerqueue, &timer->node); |
804 | timer->enabled = 0; | |
805 | return err; | |
806 | } | |
6610e089 | 807 | } |
aa0be0f4 | 808 | return 0; |
6610e089 JS |
809 | } |
810 | ||
41c7f742 RV |
811 | static void rtc_alarm_disable(struct rtc_device *rtc) |
812 | { | |
813 | if (!rtc->ops || !rtc->ops->alarm_irq_enable) | |
814 | return; | |
815 | ||
816 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
817 | } | |
818 | ||
6610e089 | 819 | /** |
96c8f06a | 820 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
821 | * @rtc rtc device |
822 | * @timer timer being removed. | |
823 | * | |
824 | * Removes a timer onto the rtc devices timerqueue and sets | |
825 | * the next alarm event appropriately. | |
826 | * | |
aa0be0f4 JS |
827 | * Clears the enabled bit on the removed timer. |
828 | * | |
6610e089 JS |
829 | * Must hold ops_lock for proper serialization of timerqueue |
830 | */ | |
aa0be0f4 | 831 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
832 | { |
833 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
834 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 835 | timer->enabled = 0; |
6610e089 JS |
836 | if (next == &timer->node) { |
837 | struct rtc_wkalrm alarm; | |
838 | int err; | |
839 | next = timerqueue_getnext(&rtc->timerqueue); | |
41c7f742 RV |
840 | if (!next) { |
841 | rtc_alarm_disable(rtc); | |
6610e089 | 842 | return; |
41c7f742 | 843 | } |
6610e089 JS |
844 | alarm.time = rtc_ktime_to_tm(next->expires); |
845 | alarm.enabled = 1; | |
846 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
847 | if (err == -ETIME) { |
848 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 849 | schedule_work(&rtc->irqwork); |
14d0e347 | 850 | } |
6610e089 JS |
851 | } |
852 | } | |
853 | ||
854 | /** | |
96c8f06a | 855 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
856 | * @rtc rtc device |
857 | * @timer timer being removed. | |
858 | * | |
859 | * Expires rtc timers. Reprograms next alarm event if needed. | |
860 | * Called via worktask. | |
861 | * | |
862 | * Serializes access to timerqueue via ops_lock mutex | |
863 | */ | |
96c8f06a | 864 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
865 | { |
866 | struct rtc_timer *timer; | |
867 | struct timerqueue_node *next; | |
868 | ktime_t now; | |
869 | struct rtc_time tm; | |
870 | ||
871 | struct rtc_device *rtc = | |
872 | container_of(work, struct rtc_device, irqwork); | |
873 | ||
874 | mutex_lock(&rtc->ops_lock); | |
875 | again: | |
876 | __rtc_read_time(rtc, &tm); | |
877 | now = rtc_tm_to_ktime(tm); | |
878 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
879 | if (next->expires.tv64 > now.tv64) | |
880 | break; | |
881 | ||
882 | /* expire timer */ | |
883 | timer = container_of(next, struct rtc_timer, node); | |
884 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
885 | timer->enabled = 0; | |
886 | if (timer->task.func) | |
887 | timer->task.func(timer->task.private_data); | |
888 | ||
889 | /* Re-add/fwd periodic timers */ | |
890 | if (ktime_to_ns(timer->period)) { | |
891 | timer->node.expires = ktime_add(timer->node.expires, | |
892 | timer->period); | |
893 | timer->enabled = 1; | |
894 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
895 | } | |
896 | } | |
897 | ||
898 | /* Set next alarm */ | |
899 | if (next) { | |
900 | struct rtc_wkalrm alarm; | |
901 | int err; | |
6528b889 XP |
902 | int retry = 3; |
903 | ||
6610e089 JS |
904 | alarm.time = rtc_ktime_to_tm(next->expires); |
905 | alarm.enabled = 1; | |
6528b889 | 906 | reprogram: |
6610e089 JS |
907 | err = __rtc_set_alarm(rtc, &alarm); |
908 | if (err == -ETIME) | |
909 | goto again; | |
6528b889 XP |
910 | else if (err) { |
911 | if (retry-- > 0) | |
912 | goto reprogram; | |
913 | ||
914 | timer = container_of(next, struct rtc_timer, node); | |
915 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
916 | timer->enabled = 0; | |
917 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); | |
918 | goto again; | |
919 | } | |
41c7f742 RV |
920 | } else |
921 | rtc_alarm_disable(rtc); | |
6610e089 | 922 | |
14d0e347 | 923 | pm_relax(rtc->dev.parent); |
6610e089 JS |
924 | mutex_unlock(&rtc->ops_lock); |
925 | } | |
926 | ||
927 | ||
96c8f06a | 928 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
929 | * @timer: timer to be intiialized |
930 | * @f: function pointer to be called when timer fires | |
931 | * @data: private data passed to function pointer | |
932 | * | |
933 | * Kernel interface to initializing an rtc_timer. | |
934 | */ | |
3ff2e13c | 935 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) |
6610e089 JS |
936 | { |
937 | timerqueue_init(&timer->node); | |
938 | timer->enabled = 0; | |
939 | timer->task.func = f; | |
940 | timer->task.private_data = data; | |
941 | } | |
942 | ||
96c8f06a | 943 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
944 | * @ rtc: rtc device to be used |
945 | * @ timer: timer being set | |
946 | * @ expires: time at which to expire the timer | |
947 | * @ period: period that the timer will recur | |
948 | * | |
949 | * Kernel interface to set an rtc_timer | |
950 | */ | |
3ff2e13c | 951 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
6610e089 JS |
952 | ktime_t expires, ktime_t period) |
953 | { | |
954 | int ret = 0; | |
955 | mutex_lock(&rtc->ops_lock); | |
956 | if (timer->enabled) | |
96c8f06a | 957 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
958 | |
959 | timer->node.expires = expires; | |
960 | timer->period = period; | |
961 | ||
aa0be0f4 | 962 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
963 | |
964 | mutex_unlock(&rtc->ops_lock); | |
965 | return ret; | |
966 | } | |
967 | ||
96c8f06a | 968 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
969 | * @ rtc: rtc device to be used |
970 | * @ timer: timer being set | |
971 | * | |
972 | * Kernel interface to cancel an rtc_timer | |
973 | */ | |
3ff2e13c | 974 | int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
975 | { |
976 | int ret = 0; | |
977 | mutex_lock(&rtc->ops_lock); | |
978 | if (timer->enabled) | |
96c8f06a | 979 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
980 | mutex_unlock(&rtc->ops_lock); |
981 | return ret; | |
982 | } | |
983 | ||
984 |