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 | 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 | ||
ab6a2d70 | 94 | int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) |
0c86edc0 AZ |
95 | { |
96 | int err; | |
0c86edc0 AZ |
97 | |
98 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
99 | if (err) | |
b68bb263 | 100 | return err; |
0c86edc0 AZ |
101 | |
102 | if (!rtc->ops) | |
103 | err = -ENODEV; | |
8e4ff1a8 XP |
104 | else if (rtc->ops->set_mmss64) |
105 | err = rtc->ops->set_mmss64(rtc->dev.parent, secs); | |
0c86edc0 | 106 | else if (rtc->ops->set_mmss) |
cd966209 | 107 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); |
0c86edc0 AZ |
108 | else if (rtc->ops->read_time && rtc->ops->set_time) { |
109 | struct rtc_time new, old; | |
110 | ||
cd966209 | 111 | err = rtc->ops->read_time(rtc->dev.parent, &old); |
0c86edc0 | 112 | if (err == 0) { |
bc10aa93 | 113 | rtc_time64_to_tm(secs, &new); |
0c86edc0 AZ |
114 | |
115 | /* | |
116 | * avoid writing when we're going to change the day of | |
117 | * the month. We will retry in the next minute. This | |
118 | * basically means that if the RTC must not drift | |
119 | * by more than 1 minute in 11 minutes. | |
120 | */ | |
121 | if (!((old.tm_hour == 23 && old.tm_min == 59) || | |
122 | (new.tm_hour == 23 && new.tm_min == 59))) | |
cd966209 | 123 | err = rtc->ops->set_time(rtc->dev.parent, |
ab6a2d70 | 124 | &new); |
0c86edc0 | 125 | } |
3ff2e13c | 126 | } else { |
0c86edc0 | 127 | err = -EINVAL; |
3ff2e13c | 128 | } |
0c86edc0 | 129 | |
14d0e347 | 130 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 131 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
132 | /* A timer might have just expired */ |
133 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
134 | |
135 | return err; | |
136 | } | |
137 | EXPORT_SYMBOL_GPL(rtc_set_mmss); | |
138 | ||
f44f7f96 JS |
139 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
140 | { | |
141 | int err; | |
142 | ||
143 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
144 | if (err) | |
145 | return err; | |
146 | ||
147 | if (rtc->ops == NULL) | |
148 | err = -ENODEV; | |
149 | else if (!rtc->ops->read_alarm) | |
150 | err = -EINVAL; | |
151 | else { | |
152 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
153 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); | |
154 | } | |
155 | ||
156 | mutex_unlock(&rtc->ops_lock); | |
157 | return err; | |
158 | } | |
159 | ||
160 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
161 | { | |
162 | int err; | |
163 | struct rtc_time before, now; | |
164 | int first_time = 1; | |
bc10aa93 | 165 | time64_t t_now, t_alm; |
f44f7f96 JS |
166 | enum { none, day, month, year } missing = none; |
167 | unsigned days; | |
168 | ||
169 | /* The lower level RTC driver may return -1 in some fields, | |
170 | * creating invalid alarm->time values, for reasons like: | |
171 | * | |
172 | * - The hardware may not be capable of filling them in; | |
173 | * many alarms match only on time-of-day fields, not | |
174 | * day/month/year calendar data. | |
175 | * | |
176 | * - Some hardware uses illegal values as "wildcard" match | |
177 | * values, which non-Linux firmware (like a BIOS) may try | |
178 | * to set up as e.g. "alarm 15 minutes after each hour". | |
179 | * Linux uses only oneshot alarms. | |
180 | * | |
181 | * When we see that here, we deal with it by using values from | |
182 | * a current RTC timestamp for any missing (-1) values. The | |
183 | * RTC driver prevents "periodic alarm" modes. | |
184 | * | |
185 | * But this can be racey, because some fields of the RTC timestamp | |
186 | * may have wrapped in the interval since we read the RTC alarm, | |
187 | * which would lead to us inserting inconsistent values in place | |
188 | * of the -1 fields. | |
189 | * | |
190 | * Reading the alarm and timestamp in the reverse sequence | |
191 | * would have the same race condition, and not solve the issue. | |
192 | * | |
193 | * So, we must first read the RTC timestamp, | |
194 | * then read the RTC alarm value, | |
195 | * and then read a second RTC timestamp. | |
196 | * | |
197 | * If any fields of the second timestamp have changed | |
198 | * when compared with the first timestamp, then we know | |
199 | * our timestamp may be inconsistent with that used by | |
200 | * the low-level rtc_read_alarm_internal() function. | |
201 | * | |
202 | * So, when the two timestamps disagree, we just loop and do | |
203 | * the process again to get a fully consistent set of values. | |
204 | * | |
205 | * This could all instead be done in the lower level driver, | |
206 | * but since more than one lower level RTC implementation needs it, | |
207 | * then it's probably best best to do it here instead of there.. | |
208 | */ | |
209 | ||
210 | /* Get the "before" timestamp */ | |
211 | err = rtc_read_time(rtc, &before); | |
212 | if (err < 0) | |
213 | return err; | |
214 | do { | |
215 | if (!first_time) | |
216 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
217 | first_time = 0; | |
218 | ||
219 | /* get the RTC alarm values, which may be incomplete */ | |
220 | err = rtc_read_alarm_internal(rtc, alarm); | |
221 | if (err) | |
222 | return err; | |
223 | ||
224 | /* full-function RTCs won't have such missing fields */ | |
225 | if (rtc_valid_tm(&alarm->time) == 0) | |
226 | return 0; | |
227 | ||
228 | /* get the "after" timestamp, to detect wrapped fields */ | |
229 | err = rtc_read_time(rtc, &now); | |
230 | if (err < 0) | |
231 | return err; | |
232 | ||
233 | /* note that tm_sec is a "don't care" value here: */ | |
234 | } while ( before.tm_min != now.tm_min | |
235 | || before.tm_hour != now.tm_hour | |
236 | || before.tm_mon != now.tm_mon | |
237 | || before.tm_year != now.tm_year); | |
238 | ||
239 | /* Fill in the missing alarm fields using the timestamp; we | |
240 | * know there's at least one since alarm->time is invalid. | |
241 | */ | |
242 | if (alarm->time.tm_sec == -1) | |
243 | alarm->time.tm_sec = now.tm_sec; | |
244 | if (alarm->time.tm_min == -1) | |
245 | alarm->time.tm_min = now.tm_min; | |
246 | if (alarm->time.tm_hour == -1) | |
247 | alarm->time.tm_hour = now.tm_hour; | |
248 | ||
249 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 250 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
251 | alarm->time.tm_mday = now.tm_mday; |
252 | missing = day; | |
253 | } | |
e74a8f2e | 254 | if ((unsigned)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
255 | alarm->time.tm_mon = now.tm_mon; |
256 | if (missing == none) | |
257 | missing = month; | |
258 | } | |
259 | if (alarm->time.tm_year == -1) { | |
260 | alarm->time.tm_year = now.tm_year; | |
261 | if (missing == none) | |
262 | missing = year; | |
263 | } | |
264 | ||
265 | /* with luck, no rollover is needed */ | |
bc10aa93 XP |
266 | t_now = rtc_tm_to_time64(&now); |
267 | t_alm = rtc_tm_to_time64(&alarm->time); | |
f44f7f96 JS |
268 | if (t_now < t_alm) |
269 | goto done; | |
270 | ||
271 | switch (missing) { | |
272 | ||
273 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that | |
274 | * that will trigger at 5am will do so at 5am Tuesday, which | |
275 | * could also be in the next month or year. This is a common | |
276 | * case, especially for PCs. | |
277 | */ | |
278 | case day: | |
279 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
280 | t_alm += 24 * 60 * 60; | |
bc10aa93 | 281 | rtc_time64_to_tm(t_alm, &alarm->time); |
f44f7f96 JS |
282 | break; |
283 | ||
284 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
285 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
286 | * may end up in the month after that! Many newer PCs support | |
287 | * this type of alarm. | |
288 | */ | |
289 | case month: | |
290 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
291 | do { | |
292 | if (alarm->time.tm_mon < 11) | |
293 | alarm->time.tm_mon++; | |
294 | else { | |
295 | alarm->time.tm_mon = 0; | |
296 | alarm->time.tm_year++; | |
297 | } | |
298 | days = rtc_month_days(alarm->time.tm_mon, | |
299 | alarm->time.tm_year); | |
300 | } while (days < alarm->time.tm_mday); | |
301 | break; | |
302 | ||
303 | /* Year rollover ... easy except for leap years! */ | |
304 | case year: | |
305 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
306 | do { | |
307 | alarm->time.tm_year++; | |
ee1d9014 AN |
308 | } while (!is_leap_year(alarm->time.tm_year + 1900) |
309 | && rtc_valid_tm(&alarm->time) != 0); | |
f44f7f96 JS |
310 | break; |
311 | ||
312 | default: | |
313 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
314 | } | |
315 | ||
316 | done: | |
ee1d9014 AN |
317 | err = rtc_valid_tm(&alarm->time); |
318 | ||
319 | if (err) { | |
320 | dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n", | |
321 | alarm->time.tm_year + 1900, alarm->time.tm_mon + 1, | |
322 | alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min, | |
323 | alarm->time.tm_sec); | |
324 | } | |
325 | ||
326 | return err; | |
f44f7f96 JS |
327 | } |
328 | ||
6610e089 | 329 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
330 | { |
331 | int err; | |
0c86edc0 AZ |
332 | |
333 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
334 | if (err) | |
b68bb263 | 335 | return err; |
d5553a55 JS |
336 | if (rtc->ops == NULL) |
337 | err = -ENODEV; | |
338 | else if (!rtc->ops->read_alarm) | |
339 | err = -EINVAL; | |
340 | else { | |
341 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
342 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 343 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 344 | } |
0c86edc0 | 345 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 346 | |
d5553a55 | 347 | return err; |
0c86edc0 | 348 | } |
6610e089 | 349 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 350 | |
d576fe49 | 351 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 352 | { |
6610e089 | 353 | struct rtc_time tm; |
bc10aa93 | 354 | time64_t now, scheduled; |
0e36a9a4 | 355 | int err; |
0e36a9a4 | 356 | |
6610e089 JS |
357 | err = rtc_valid_tm(&alarm->time); |
358 | if (err) | |
0e36a9a4 | 359 | return err; |
bc10aa93 | 360 | scheduled = rtc_tm_to_time64(&alarm->time); |
a01cc657 | 361 | |
6610e089 JS |
362 | /* Make sure we're not setting alarms in the past */ |
363 | err = __rtc_read_time(rtc, &tm); | |
ca6dc2da HG |
364 | if (err) |
365 | return err; | |
bc10aa93 | 366 | now = rtc_tm_to_time64(&tm); |
6610e089 JS |
367 | if (scheduled <= now) |
368 | return -ETIME; | |
369 | /* | |
370 | * XXX - We just checked to make sure the alarm time is not | |
371 | * in the past, but there is still a race window where if | |
372 | * the is alarm set for the next second and the second ticks | |
373 | * over right here, before we set the alarm. | |
a01cc657 | 374 | */ |
a01cc657 | 375 | |
157e8bf8 LT |
376 | if (!rtc->ops) |
377 | err = -ENODEV; | |
378 | else if (!rtc->ops->set_alarm) | |
379 | err = -EINVAL; | |
380 | else | |
381 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
382 | ||
383 | return err; | |
0e36a9a4 | 384 | } |
0c86edc0 | 385 | |
ab6a2d70 | 386 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
387 | { |
388 | int err; | |
0c86edc0 | 389 | |
f8245c26 DB |
390 | err = rtc_valid_tm(&alarm->time); |
391 | if (err != 0) | |
392 | return err; | |
393 | ||
0c86edc0 AZ |
394 | err = mutex_lock_interruptible(&rtc->ops_lock); |
395 | if (err) | |
b68bb263 | 396 | return err; |
3ff2e13c | 397 | if (rtc->aie_timer.enabled) |
96c8f06a | 398 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 399 | |
6610e089 JS |
400 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); |
401 | rtc->aie_timer.period = ktime_set(0, 0); | |
3ff2e13c | 402 | if (alarm->enabled) |
aa0be0f4 | 403 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 404 | |
0c86edc0 | 405 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 406 | return err; |
0c86edc0 AZ |
407 | } |
408 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
409 | ||
f6d5b331 JS |
410 | /* Called once per device from rtc_device_register */ |
411 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
412 | { | |
413 | int err; | |
bd729d72 | 414 | struct rtc_time now; |
f6d5b331 JS |
415 | |
416 | err = rtc_valid_tm(&alarm->time); | |
417 | if (err != 0) | |
418 | return err; | |
419 | ||
bd729d72 JS |
420 | err = rtc_read_time(rtc, &now); |
421 | if (err) | |
422 | return err; | |
423 | ||
f6d5b331 JS |
424 | err = mutex_lock_interruptible(&rtc->ops_lock); |
425 | if (err) | |
426 | return err; | |
427 | ||
428 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
429 | rtc->aie_timer.period = ktime_set(0, 0); | |
bd729d72 JS |
430 | |
431 | /* Alarm has to be enabled & in the futrure for us to enqueue it */ | |
432 | if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 < | |
433 | rtc->aie_timer.node.expires.tv64)) { | |
434 | ||
f6d5b331 JS |
435 | rtc->aie_timer.enabled = 1; |
436 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
437 | } | |
438 | mutex_unlock(&rtc->ops_lock); | |
439 | return err; | |
440 | } | |
441 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
442 | ||
443 | ||
444 | ||
099e6576 AZ |
445 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
446 | { | |
447 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
448 | if (err) | |
449 | return err; | |
450 | ||
6610e089 | 451 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
452 | if (enabled) |
453 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
454 | else | |
96c8f06a | 455 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
456 | } |
457 | ||
aa0be0f4 | 458 | if (err) |
516373b8 UKK |
459 | /* nothing */; |
460 | else if (!rtc->ops) | |
099e6576 AZ |
461 | err = -ENODEV; |
462 | else if (!rtc->ops->alarm_irq_enable) | |
463 | err = -EINVAL; | |
464 | else | |
465 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
466 | ||
467 | mutex_unlock(&rtc->ops_lock); | |
468 | return err; | |
469 | } | |
470 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
471 | ||
472 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
473 | { | |
474 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
475 | if (err) | |
476 | return err; | |
477 | ||
456d66ec JS |
478 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
479 | if (enabled == 0 && rtc->uie_irq_active) { | |
480 | mutex_unlock(&rtc->ops_lock); | |
481 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
482 | } | |
483 | #endif | |
6610e089 JS |
484 | /* make sure we're changing state */ |
485 | if (rtc->uie_rtctimer.enabled == enabled) | |
486 | goto out; | |
487 | ||
4a649903 JS |
488 | if (rtc->uie_unsupported) { |
489 | err = -EINVAL; | |
490 | goto out; | |
491 | } | |
492 | ||
6610e089 JS |
493 | if (enabled) { |
494 | struct rtc_time tm; | |
495 | ktime_t now, onesec; | |
496 | ||
497 | __rtc_read_time(rtc, &tm); | |
498 | onesec = ktime_set(1, 0); | |
499 | now = rtc_tm_to_ktime(tm); | |
500 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
501 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 JS |
502 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
503 | } else | |
96c8f06a | 504 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
099e6576 | 505 | |
6610e089 | 506 | out: |
099e6576 | 507 | mutex_unlock(&rtc->ops_lock); |
456d66ec JS |
508 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
509 | /* | |
510 | * Enable emulation if the driver did not provide | |
511 | * the update_irq_enable function pointer or if returned | |
512 | * -EINVAL to signal that it has been configured without | |
513 | * interrupts or that are not available at the moment. | |
514 | */ | |
515 | if (err == -EINVAL) | |
516 | err = rtc_dev_update_irq_enable_emul(rtc, enabled); | |
517 | #endif | |
099e6576 | 518 | return err; |
6610e089 | 519 | |
099e6576 AZ |
520 | } |
521 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
522 | ||
6610e089 | 523 | |
d728b1e6 | 524 | /** |
6610e089 JS |
525 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
526 | * @rtc: pointer to the rtc device | |
527 | * | |
528 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 529 | * has occurred (or been emulated). |
6610e089 JS |
530 | * |
531 | * Triggers the registered irq_task function callback. | |
d728b1e6 | 532 | */ |
456d66ec | 533 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 534 | { |
e6229bec AN |
535 | unsigned long flags; |
536 | ||
6610e089 | 537 | /* mark one irq of the appropriate mode */ |
e6229bec | 538 | spin_lock_irqsave(&rtc->irq_lock, flags); |
6610e089 | 539 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); |
e6229bec | 540 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 541 | |
6610e089 | 542 | /* call the task func */ |
e6229bec | 543 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
544 | if (rtc->irq_task) |
545 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 546 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
547 | |
548 | wake_up_interruptible(&rtc->irq_queue); | |
549 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
550 | } | |
6610e089 JS |
551 | |
552 | ||
553 | /** | |
554 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
555 | * @private: pointer to the rtc_device | |
556 | * | |
557 | * This functions is called when the aie_timer expires. | |
558 | */ | |
559 | void rtc_aie_update_irq(void *private) | |
560 | { | |
561 | struct rtc_device *rtc = (struct rtc_device *)private; | |
562 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); | |
563 | } | |
564 | ||
565 | ||
566 | /** | |
567 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
568 | * @private: pointer to the rtc_device | |
569 | * | |
570 | * This functions is called when the uie_timer expires. | |
571 | */ | |
572 | void rtc_uie_update_irq(void *private) | |
573 | { | |
574 | struct rtc_device *rtc = (struct rtc_device *)private; | |
575 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); | |
576 | } | |
577 | ||
578 | ||
579 | /** | |
580 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
581 | * @timer: pointer to the pie mode hrtimer | |
582 | * | |
583 | * This function is used to emulate PIE mode interrupts | |
584 | * using an hrtimer. This function is called when the periodic | |
585 | * hrtimer expires. | |
586 | */ | |
587 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
588 | { | |
589 | struct rtc_device *rtc; | |
590 | ktime_t period; | |
591 | int count; | |
592 | rtc = container_of(timer, struct rtc_device, pie_timer); | |
593 | ||
594 | period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); | |
595 | count = hrtimer_forward_now(timer, period); | |
596 | ||
597 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
598 | ||
599 | return HRTIMER_RESTART; | |
600 | } | |
601 | ||
602 | /** | |
603 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
604 | * @rtc: the rtc device | |
605 | * @num: how many irqs are being reported (usually one) | |
606 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
607 | * Context: any | |
608 | */ | |
609 | void rtc_update_irq(struct rtc_device *rtc, | |
610 | unsigned long num, unsigned long events) | |
611 | { | |
131c9cc8 AZ |
612 | if (unlikely(IS_ERR_OR_NULL(rtc))) |
613 | return; | |
614 | ||
7523ceed | 615 | pm_stay_awake(rtc->dev.parent); |
6610e089 JS |
616 | schedule_work(&rtc->irqwork); |
617 | } | |
0c86edc0 AZ |
618 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
619 | ||
9f3b795a | 620 | static int __rtc_match(struct device *dev, const void *data) |
71da8905 | 621 | { |
9f3b795a | 622 | const char *name = data; |
71da8905 | 623 | |
d4afc76c | 624 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
625 | return 1; |
626 | return 0; | |
627 | } | |
628 | ||
9f3b795a | 629 | struct rtc_device *rtc_class_open(const char *name) |
0c86edc0 | 630 | { |
cd966209 | 631 | struct device *dev; |
ab6a2d70 | 632 | struct rtc_device *rtc = NULL; |
0c86edc0 | 633 | |
695794ae | 634 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
635 | if (dev) |
636 | rtc = to_rtc_device(dev); | |
0c86edc0 | 637 | |
ab6a2d70 DB |
638 | if (rtc) { |
639 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 640 | put_device(dev); |
ab6a2d70 DB |
641 | rtc = NULL; |
642 | } | |
0c86edc0 | 643 | } |
0c86edc0 | 644 | |
ab6a2d70 | 645 | return rtc; |
0c86edc0 AZ |
646 | } |
647 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
648 | ||
ab6a2d70 | 649 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 650 | { |
ab6a2d70 | 651 | module_put(rtc->owner); |
cd966209 | 652 | put_device(&rtc->dev); |
0c86edc0 AZ |
653 | } |
654 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
655 | ||
ab6a2d70 | 656 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
657 | { |
658 | int retval = -EBUSY; | |
0c86edc0 AZ |
659 | |
660 | if (task == NULL || task->func == NULL) | |
661 | return -EINVAL; | |
662 | ||
d691eb90 | 663 | /* Cannot register while the char dev is in use */ |
372a302e | 664 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
665 | return -EBUSY; |
666 | ||
d728b1e6 | 667 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
668 | if (rtc->irq_task == NULL) { |
669 | rtc->irq_task = task; | |
670 | retval = 0; | |
671 | } | |
d728b1e6 | 672 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 673 | |
372a302e | 674 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 675 | |
0c86edc0 AZ |
676 | return retval; |
677 | } | |
678 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
679 | ||
ab6a2d70 | 680 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 681 | { |
d728b1e6 | 682 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
683 | if (rtc->irq_task == task) |
684 | rtc->irq_task = NULL; | |
d728b1e6 | 685 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
686 | } |
687 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
688 | ||
3c8bb90e TG |
689 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
690 | { | |
691 | /* | |
692 | * We always cancel the timer here first, because otherwise | |
693 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
694 | * when we manage to start the timer before the callback | |
695 | * returns HRTIMER_RESTART. | |
696 | * | |
697 | * We cannot use hrtimer_cancel() here as a running callback | |
698 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
699 | * would spin forever. | |
700 | */ | |
701 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
702 | return -1; | |
703 | ||
704 | if (enabled) { | |
705 | ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq); | |
706 | ||
707 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
708 | } | |
709 | return 0; | |
710 | } | |
711 | ||
97144c67 DB |
712 | /** |
713 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
714 | * @rtc: the rtc device | |
715 | * @task: currently registered with rtc_irq_register() | |
716 | * @enabled: true to enable periodic IRQs | |
717 | * Context: any | |
718 | * | |
719 | * Note that rtc_irq_set_freq() should previously have been used to | |
720 | * specify the desired frequency of periodic IRQ task->func() callbacks. | |
721 | */ | |
ab6a2d70 | 722 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
723 | { |
724 | int err = 0; | |
725 | unsigned long flags; | |
0c86edc0 | 726 | |
3c8bb90e | 727 | retry: |
0c86edc0 | 728 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
729 | if (rtc->irq_task != NULL && task == NULL) |
730 | err = -EBUSY; | |
0734e27f | 731 | else if (rtc->irq_task != task) |
d691eb90 | 732 | err = -EACCES; |
0734e27f | 733 | else { |
3c8bb90e TG |
734 | if (rtc_update_hrtimer(rtc, enabled) < 0) { |
735 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
736 | cpu_relax(); | |
737 | goto retry; | |
738 | } | |
739 | rtc->pie_enabled = enabled; | |
6610e089 | 740 | } |
6610e089 | 741 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
742 | return err; |
743 | } | |
744 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
745 | ||
97144c67 DB |
746 | /** |
747 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
748 | * @rtc: the rtc device | |
749 | * @task: currently registered with rtc_irq_register() | |
750 | * @freq: positive frequency with which task->func() will be called | |
751 | * Context: any | |
752 | * | |
753 | * Note that rtc_irq_set_state() is used to enable or disable the | |
754 | * periodic IRQs. | |
755 | */ | |
ab6a2d70 | 756 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 757 | { |
56f10c63 | 758 | int err = 0; |
0c86edc0 | 759 | unsigned long flags; |
0c86edc0 | 760 | |
6e7a333e | 761 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 762 | return -EINVAL; |
3c8bb90e | 763 | retry: |
0c86edc0 | 764 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
765 | if (rtc->irq_task != NULL && task == NULL) |
766 | err = -EBUSY; | |
0734e27f | 767 | else if (rtc->irq_task != task) |
d691eb90 | 768 | err = -EACCES; |
0734e27f | 769 | else { |
6610e089 | 770 | rtc->irq_freq = freq; |
3c8bb90e TG |
771 | if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { |
772 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
773 | cpu_relax(); | |
774 | goto retry; | |
6610e089 | 775 | } |
0c86edc0 | 776 | } |
6610e089 | 777 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
778 | return err; |
779 | } | |
2601a464 | 780 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |
6610e089 JS |
781 | |
782 | /** | |
96c8f06a | 783 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
6610e089 JS |
784 | * @rtc rtc device |
785 | * @timer timer being added. | |
786 | * | |
787 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
788 | * the next alarm event appropriately. | |
789 | * | |
aa0be0f4 JS |
790 | * Sets the enabled bit on the added timer. |
791 | * | |
6610e089 JS |
792 | * Must hold ops_lock for proper serialization of timerqueue |
793 | */ | |
aa0be0f4 | 794 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 795 | { |
aa0be0f4 | 796 | timer->enabled = 1; |
6610e089 JS |
797 | timerqueue_add(&rtc->timerqueue, &timer->node); |
798 | if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { | |
799 | struct rtc_wkalrm alarm; | |
800 | int err; | |
801 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
802 | alarm.enabled = 1; | |
803 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
804 | if (err == -ETIME) { |
805 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 806 | schedule_work(&rtc->irqwork); |
14d0e347 | 807 | } else if (err) { |
aa0be0f4 JS |
808 | timerqueue_del(&rtc->timerqueue, &timer->node); |
809 | timer->enabled = 0; | |
810 | return err; | |
811 | } | |
6610e089 | 812 | } |
aa0be0f4 | 813 | return 0; |
6610e089 JS |
814 | } |
815 | ||
41c7f742 RV |
816 | static void rtc_alarm_disable(struct rtc_device *rtc) |
817 | { | |
818 | if (!rtc->ops || !rtc->ops->alarm_irq_enable) | |
819 | return; | |
820 | ||
821 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
822 | } | |
823 | ||
6610e089 | 824 | /** |
96c8f06a | 825 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
826 | * @rtc rtc device |
827 | * @timer timer being removed. | |
828 | * | |
829 | * Removes a timer onto the rtc devices timerqueue and sets | |
830 | * the next alarm event appropriately. | |
831 | * | |
aa0be0f4 JS |
832 | * Clears the enabled bit on the removed timer. |
833 | * | |
6610e089 JS |
834 | * Must hold ops_lock for proper serialization of timerqueue |
835 | */ | |
aa0be0f4 | 836 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
837 | { |
838 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
839 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 840 | timer->enabled = 0; |
6610e089 JS |
841 | if (next == &timer->node) { |
842 | struct rtc_wkalrm alarm; | |
843 | int err; | |
844 | next = timerqueue_getnext(&rtc->timerqueue); | |
41c7f742 RV |
845 | if (!next) { |
846 | rtc_alarm_disable(rtc); | |
6610e089 | 847 | return; |
41c7f742 | 848 | } |
6610e089 JS |
849 | alarm.time = rtc_ktime_to_tm(next->expires); |
850 | alarm.enabled = 1; | |
851 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
852 | if (err == -ETIME) { |
853 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 854 | schedule_work(&rtc->irqwork); |
14d0e347 | 855 | } |
6610e089 JS |
856 | } |
857 | } | |
858 | ||
859 | /** | |
96c8f06a | 860 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
861 | * @rtc rtc device |
862 | * @timer timer being removed. | |
863 | * | |
864 | * Expires rtc timers. Reprograms next alarm event if needed. | |
865 | * Called via worktask. | |
866 | * | |
867 | * Serializes access to timerqueue via ops_lock mutex | |
868 | */ | |
96c8f06a | 869 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
870 | { |
871 | struct rtc_timer *timer; | |
872 | struct timerqueue_node *next; | |
873 | ktime_t now; | |
874 | struct rtc_time tm; | |
875 | ||
876 | struct rtc_device *rtc = | |
877 | container_of(work, struct rtc_device, irqwork); | |
878 | ||
879 | mutex_lock(&rtc->ops_lock); | |
880 | again: | |
881 | __rtc_read_time(rtc, &tm); | |
882 | now = rtc_tm_to_ktime(tm); | |
883 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
884 | if (next->expires.tv64 > now.tv64) | |
885 | break; | |
886 | ||
887 | /* expire timer */ | |
888 | timer = container_of(next, struct rtc_timer, node); | |
889 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
890 | timer->enabled = 0; | |
891 | if (timer->task.func) | |
892 | timer->task.func(timer->task.private_data); | |
893 | ||
894 | /* Re-add/fwd periodic timers */ | |
895 | if (ktime_to_ns(timer->period)) { | |
896 | timer->node.expires = ktime_add(timer->node.expires, | |
897 | timer->period); | |
898 | timer->enabled = 1; | |
899 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
900 | } | |
901 | } | |
902 | ||
903 | /* Set next alarm */ | |
904 | if (next) { | |
905 | struct rtc_wkalrm alarm; | |
906 | int err; | |
6528b889 XP |
907 | int retry = 3; |
908 | ||
6610e089 JS |
909 | alarm.time = rtc_ktime_to_tm(next->expires); |
910 | alarm.enabled = 1; | |
6528b889 | 911 | reprogram: |
6610e089 JS |
912 | err = __rtc_set_alarm(rtc, &alarm); |
913 | if (err == -ETIME) | |
914 | goto again; | |
6528b889 XP |
915 | else if (err) { |
916 | if (retry-- > 0) | |
917 | goto reprogram; | |
918 | ||
919 | timer = container_of(next, struct rtc_timer, node); | |
920 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
921 | timer->enabled = 0; | |
922 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); | |
923 | goto again; | |
924 | } | |
41c7f742 RV |
925 | } else |
926 | rtc_alarm_disable(rtc); | |
6610e089 | 927 | |
14d0e347 | 928 | pm_relax(rtc->dev.parent); |
6610e089 JS |
929 | mutex_unlock(&rtc->ops_lock); |
930 | } | |
931 | ||
932 | ||
96c8f06a | 933 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
934 | * @timer: timer to be intiialized |
935 | * @f: function pointer to be called when timer fires | |
936 | * @data: private data passed to function pointer | |
937 | * | |
938 | * Kernel interface to initializing an rtc_timer. | |
939 | */ | |
3ff2e13c | 940 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) |
6610e089 JS |
941 | { |
942 | timerqueue_init(&timer->node); | |
943 | timer->enabled = 0; | |
944 | timer->task.func = f; | |
945 | timer->task.private_data = data; | |
946 | } | |
947 | ||
96c8f06a | 948 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
949 | * @ rtc: rtc device to be used |
950 | * @ timer: timer being set | |
951 | * @ expires: time at which to expire the timer | |
952 | * @ period: period that the timer will recur | |
953 | * | |
954 | * Kernel interface to set an rtc_timer | |
955 | */ | |
3ff2e13c | 956 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
6610e089 JS |
957 | ktime_t expires, ktime_t period) |
958 | { | |
959 | int ret = 0; | |
960 | mutex_lock(&rtc->ops_lock); | |
961 | if (timer->enabled) | |
96c8f06a | 962 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
963 | |
964 | timer->node.expires = expires; | |
965 | timer->period = period; | |
966 | ||
aa0be0f4 | 967 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
968 | |
969 | mutex_unlock(&rtc->ops_lock); | |
970 | return ret; | |
971 | } | |
972 | ||
96c8f06a | 973 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
974 | * @ rtc: rtc device to be used |
975 | * @ timer: timer being set | |
976 | * | |
977 | * Kernel interface to cancel an rtc_timer | |
978 | */ | |
3ff2e13c | 979 | int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
980 | { |
981 | int ret = 0; | |
982 | mutex_lock(&rtc->ops_lock); | |
983 | if (timer->enabled) | |
96c8f06a | 984 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
985 | mutex_unlock(&rtc->ops_lock); |
986 | return ret; | |
987 | } | |
988 | ||
989 |