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); |
0c86edc0 | 33 | } |
6610e089 JS |
34 | return err; |
35 | } | |
36 | ||
37 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
38 | { | |
39 | int err; | |
0c86edc0 | 40 | |
6610e089 JS |
41 | err = mutex_lock_interruptible(&rtc->ops_lock); |
42 | if (err) | |
43 | return err; | |
44 | ||
45 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 AZ |
46 | mutex_unlock(&rtc->ops_lock); |
47 | return err; | |
48 | } | |
49 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
50 | ||
ab6a2d70 | 51 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
52 | { |
53 | int err; | |
0c86edc0 AZ |
54 | |
55 | err = rtc_valid_tm(tm); | |
56 | if (err != 0) | |
57 | return err; | |
58 | ||
59 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
60 | if (err) | |
b68bb263 | 61 | return err; |
0c86edc0 AZ |
62 | |
63 | if (!rtc->ops) | |
64 | err = -ENODEV; | |
bbccf83f | 65 | else if (rtc->ops->set_time) |
cd966209 | 66 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
bbccf83f AZ |
67 | else if (rtc->ops->set_mmss) { |
68 | unsigned long secs; | |
69 | err = rtc_tm_to_time(tm, &secs); | |
70 | if (err == 0) | |
71 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); | |
72 | } else | |
73 | err = -EINVAL; | |
0c86edc0 | 74 | |
14d0e347 | 75 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 76 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
77 | /* A timer might have just expired */ |
78 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
79 | return err; |
80 | } | |
81 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
82 | ||
ab6a2d70 | 83 | int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) |
0c86edc0 AZ |
84 | { |
85 | int err; | |
0c86edc0 AZ |
86 | |
87 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
88 | if (err) | |
b68bb263 | 89 | return err; |
0c86edc0 AZ |
90 | |
91 | if (!rtc->ops) | |
92 | err = -ENODEV; | |
93 | else if (rtc->ops->set_mmss) | |
cd966209 | 94 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); |
0c86edc0 AZ |
95 | else if (rtc->ops->read_time && rtc->ops->set_time) { |
96 | struct rtc_time new, old; | |
97 | ||
cd966209 | 98 | err = rtc->ops->read_time(rtc->dev.parent, &old); |
0c86edc0 AZ |
99 | if (err == 0) { |
100 | rtc_time_to_tm(secs, &new); | |
101 | ||
102 | /* | |
103 | * avoid writing when we're going to change the day of | |
104 | * the month. We will retry in the next minute. This | |
105 | * basically means that if the RTC must not drift | |
106 | * by more than 1 minute in 11 minutes. | |
107 | */ | |
108 | if (!((old.tm_hour == 23 && old.tm_min == 59) || | |
109 | (new.tm_hour == 23 && new.tm_min == 59))) | |
cd966209 | 110 | err = rtc->ops->set_time(rtc->dev.parent, |
ab6a2d70 | 111 | &new); |
0c86edc0 | 112 | } |
3ff2e13c | 113 | } else { |
0c86edc0 | 114 | err = -EINVAL; |
3ff2e13c | 115 | } |
0c86edc0 | 116 | |
14d0e347 | 117 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 118 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
119 | /* A timer might have just expired */ |
120 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
121 | |
122 | return err; | |
123 | } | |
124 | EXPORT_SYMBOL_GPL(rtc_set_mmss); | |
125 | ||
f44f7f96 JS |
126 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
127 | { | |
128 | int err; | |
129 | ||
130 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
131 | if (err) | |
132 | return err; | |
133 | ||
134 | if (rtc->ops == NULL) | |
135 | err = -ENODEV; | |
136 | else if (!rtc->ops->read_alarm) | |
137 | err = -EINVAL; | |
138 | else { | |
139 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
140 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); | |
141 | } | |
142 | ||
143 | mutex_unlock(&rtc->ops_lock); | |
144 | return err; | |
145 | } | |
146 | ||
147 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
148 | { | |
149 | int err; | |
150 | struct rtc_time before, now; | |
151 | int first_time = 1; | |
152 | unsigned long t_now, t_alm; | |
153 | enum { none, day, month, year } missing = none; | |
154 | unsigned days; | |
155 | ||
156 | /* The lower level RTC driver may return -1 in some fields, | |
157 | * creating invalid alarm->time values, for reasons like: | |
158 | * | |
159 | * - The hardware may not be capable of filling them in; | |
160 | * many alarms match only on time-of-day fields, not | |
161 | * day/month/year calendar data. | |
162 | * | |
163 | * - Some hardware uses illegal values as "wildcard" match | |
164 | * values, which non-Linux firmware (like a BIOS) may try | |
165 | * to set up as e.g. "alarm 15 minutes after each hour". | |
166 | * Linux uses only oneshot alarms. | |
167 | * | |
168 | * When we see that here, we deal with it by using values from | |
169 | * a current RTC timestamp for any missing (-1) values. The | |
170 | * RTC driver prevents "periodic alarm" modes. | |
171 | * | |
172 | * But this can be racey, because some fields of the RTC timestamp | |
173 | * may have wrapped in the interval since we read the RTC alarm, | |
174 | * which would lead to us inserting inconsistent values in place | |
175 | * of the -1 fields. | |
176 | * | |
177 | * Reading the alarm and timestamp in the reverse sequence | |
178 | * would have the same race condition, and not solve the issue. | |
179 | * | |
180 | * So, we must first read the RTC timestamp, | |
181 | * then read the RTC alarm value, | |
182 | * and then read a second RTC timestamp. | |
183 | * | |
184 | * If any fields of the second timestamp have changed | |
185 | * when compared with the first timestamp, then we know | |
186 | * our timestamp may be inconsistent with that used by | |
187 | * the low-level rtc_read_alarm_internal() function. | |
188 | * | |
189 | * So, when the two timestamps disagree, we just loop and do | |
190 | * the process again to get a fully consistent set of values. | |
191 | * | |
192 | * This could all instead be done in the lower level driver, | |
193 | * but since more than one lower level RTC implementation needs it, | |
194 | * then it's probably best best to do it here instead of there.. | |
195 | */ | |
196 | ||
197 | /* Get the "before" timestamp */ | |
198 | err = rtc_read_time(rtc, &before); | |
199 | if (err < 0) | |
200 | return err; | |
201 | do { | |
202 | if (!first_time) | |
203 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
204 | first_time = 0; | |
205 | ||
206 | /* get the RTC alarm values, which may be incomplete */ | |
207 | err = rtc_read_alarm_internal(rtc, alarm); | |
208 | if (err) | |
209 | return err; | |
210 | ||
211 | /* full-function RTCs won't have such missing fields */ | |
212 | if (rtc_valid_tm(&alarm->time) == 0) | |
213 | return 0; | |
214 | ||
215 | /* get the "after" timestamp, to detect wrapped fields */ | |
216 | err = rtc_read_time(rtc, &now); | |
217 | if (err < 0) | |
218 | return err; | |
219 | ||
220 | /* note that tm_sec is a "don't care" value here: */ | |
221 | } while ( before.tm_min != now.tm_min | |
222 | || before.tm_hour != now.tm_hour | |
223 | || before.tm_mon != now.tm_mon | |
224 | || before.tm_year != now.tm_year); | |
225 | ||
226 | /* Fill in the missing alarm fields using the timestamp; we | |
227 | * know there's at least one since alarm->time is invalid. | |
228 | */ | |
229 | if (alarm->time.tm_sec == -1) | |
230 | alarm->time.tm_sec = now.tm_sec; | |
231 | if (alarm->time.tm_min == -1) | |
232 | alarm->time.tm_min = now.tm_min; | |
233 | if (alarm->time.tm_hour == -1) | |
234 | alarm->time.tm_hour = now.tm_hour; | |
235 | ||
236 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 237 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
238 | alarm->time.tm_mday = now.tm_mday; |
239 | missing = day; | |
240 | } | |
e74a8f2e | 241 | if ((unsigned)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
242 | alarm->time.tm_mon = now.tm_mon; |
243 | if (missing == none) | |
244 | missing = month; | |
245 | } | |
246 | if (alarm->time.tm_year == -1) { | |
247 | alarm->time.tm_year = now.tm_year; | |
248 | if (missing == none) | |
249 | missing = year; | |
250 | } | |
251 | ||
252 | /* with luck, no rollover is needed */ | |
253 | rtc_tm_to_time(&now, &t_now); | |
254 | rtc_tm_to_time(&alarm->time, &t_alm); | |
255 | if (t_now < t_alm) | |
256 | goto done; | |
257 | ||
258 | switch (missing) { | |
259 | ||
260 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that | |
261 | * that will trigger at 5am will do so at 5am Tuesday, which | |
262 | * could also be in the next month or year. This is a common | |
263 | * case, especially for PCs. | |
264 | */ | |
265 | case day: | |
266 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
267 | t_alm += 24 * 60 * 60; | |
268 | rtc_time_to_tm(t_alm, &alarm->time); | |
269 | break; | |
270 | ||
271 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
272 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
273 | * may end up in the month after that! Many newer PCs support | |
274 | * this type of alarm. | |
275 | */ | |
276 | case month: | |
277 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
278 | do { | |
279 | if (alarm->time.tm_mon < 11) | |
280 | alarm->time.tm_mon++; | |
281 | else { | |
282 | alarm->time.tm_mon = 0; | |
283 | alarm->time.tm_year++; | |
284 | } | |
285 | days = rtc_month_days(alarm->time.tm_mon, | |
286 | alarm->time.tm_year); | |
287 | } while (days < alarm->time.tm_mday); | |
288 | break; | |
289 | ||
290 | /* Year rollover ... easy except for leap years! */ | |
291 | case year: | |
292 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
293 | do { | |
294 | alarm->time.tm_year++; | |
295 | } while (rtc_valid_tm(&alarm->time) != 0); | |
296 | break; | |
297 | ||
298 | default: | |
299 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
300 | } | |
301 | ||
302 | done: | |
303 | return 0; | |
304 | } | |
305 | ||
6610e089 | 306 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
307 | { |
308 | int err; | |
0c86edc0 AZ |
309 | |
310 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
311 | if (err) | |
b68bb263 | 312 | return err; |
d5553a55 JS |
313 | if (rtc->ops == NULL) |
314 | err = -ENODEV; | |
315 | else if (!rtc->ops->read_alarm) | |
316 | err = -EINVAL; | |
317 | else { | |
318 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
319 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 320 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 321 | } |
0c86edc0 | 322 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 323 | |
d5553a55 | 324 | return err; |
0c86edc0 | 325 | } |
6610e089 | 326 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 327 | |
d576fe49 | 328 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 329 | { |
6610e089 JS |
330 | struct rtc_time tm; |
331 | long now, scheduled; | |
0e36a9a4 | 332 | int err; |
0e36a9a4 | 333 | |
6610e089 JS |
334 | err = rtc_valid_tm(&alarm->time); |
335 | if (err) | |
0e36a9a4 | 336 | return err; |
6610e089 | 337 | rtc_tm_to_time(&alarm->time, &scheduled); |
a01cc657 | 338 | |
6610e089 JS |
339 | /* Make sure we're not setting alarms in the past */ |
340 | err = __rtc_read_time(rtc, &tm); | |
341 | rtc_tm_to_time(&tm, &now); | |
342 | if (scheduled <= now) | |
343 | return -ETIME; | |
344 | /* | |
345 | * XXX - We just checked to make sure the alarm time is not | |
346 | * in the past, but there is still a race window where if | |
347 | * the is alarm set for the next second and the second ticks | |
348 | * over right here, before we set the alarm. | |
a01cc657 | 349 | */ |
a01cc657 | 350 | |
157e8bf8 LT |
351 | if (!rtc->ops) |
352 | err = -ENODEV; | |
353 | else if (!rtc->ops->set_alarm) | |
354 | err = -EINVAL; | |
355 | else | |
356 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
357 | ||
358 | return err; | |
0e36a9a4 | 359 | } |
0c86edc0 | 360 | |
ab6a2d70 | 361 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
362 | { |
363 | int err; | |
0c86edc0 | 364 | |
f8245c26 DB |
365 | err = rtc_valid_tm(&alarm->time); |
366 | if (err != 0) | |
367 | return err; | |
368 | ||
0c86edc0 AZ |
369 | err = mutex_lock_interruptible(&rtc->ops_lock); |
370 | if (err) | |
b68bb263 | 371 | return err; |
3ff2e13c | 372 | if (rtc->aie_timer.enabled) |
96c8f06a | 373 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 374 | |
6610e089 JS |
375 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); |
376 | rtc->aie_timer.period = ktime_set(0, 0); | |
3ff2e13c | 377 | if (alarm->enabled) |
aa0be0f4 | 378 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 379 | |
0c86edc0 | 380 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 381 | return err; |
0c86edc0 AZ |
382 | } |
383 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
384 | ||
f6d5b331 JS |
385 | /* Called once per device from rtc_device_register */ |
386 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
387 | { | |
388 | int err; | |
bd729d72 | 389 | struct rtc_time now; |
f6d5b331 JS |
390 | |
391 | err = rtc_valid_tm(&alarm->time); | |
392 | if (err != 0) | |
393 | return err; | |
394 | ||
bd729d72 JS |
395 | err = rtc_read_time(rtc, &now); |
396 | if (err) | |
397 | return err; | |
398 | ||
f6d5b331 JS |
399 | err = mutex_lock_interruptible(&rtc->ops_lock); |
400 | if (err) | |
401 | return err; | |
402 | ||
403 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
404 | rtc->aie_timer.period = ktime_set(0, 0); | |
bd729d72 JS |
405 | |
406 | /* Alarm has to be enabled & in the futrure for us to enqueue it */ | |
407 | if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 < | |
408 | rtc->aie_timer.node.expires.tv64)) { | |
409 | ||
f6d5b331 JS |
410 | rtc->aie_timer.enabled = 1; |
411 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
412 | } | |
413 | mutex_unlock(&rtc->ops_lock); | |
414 | return err; | |
415 | } | |
416 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
417 | ||
418 | ||
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 | ||
569 | period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); | |
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 | { | |
131c9cc8 AZ |
587 | if (unlikely(IS_ERR_OR_NULL(rtc))) |
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) { | |
680 | ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq); | |
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 | { |
aa0be0f4 | 771 | timer->enabled = 1; |
6610e089 JS |
772 | timerqueue_add(&rtc->timerqueue, &timer->node); |
773 | if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { | |
774 | struct rtc_wkalrm alarm; | |
775 | int err; | |
776 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
777 | alarm.enabled = 1; | |
778 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
779 | if (err == -ETIME) { |
780 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 781 | schedule_work(&rtc->irqwork); |
14d0e347 | 782 | } else if (err) { |
aa0be0f4 JS |
783 | timerqueue_del(&rtc->timerqueue, &timer->node); |
784 | timer->enabled = 0; | |
785 | return err; | |
786 | } | |
6610e089 | 787 | } |
aa0be0f4 | 788 | return 0; |
6610e089 JS |
789 | } |
790 | ||
41c7f742 RV |
791 | static void rtc_alarm_disable(struct rtc_device *rtc) |
792 | { | |
793 | if (!rtc->ops || !rtc->ops->alarm_irq_enable) | |
794 | return; | |
795 | ||
796 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
797 | } | |
798 | ||
6610e089 | 799 | /** |
96c8f06a | 800 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
801 | * @rtc rtc device |
802 | * @timer timer being removed. | |
803 | * | |
804 | * Removes a timer onto the rtc devices timerqueue and sets | |
805 | * the next alarm event appropriately. | |
806 | * | |
aa0be0f4 JS |
807 | * Clears the enabled bit on the removed timer. |
808 | * | |
6610e089 JS |
809 | * Must hold ops_lock for proper serialization of timerqueue |
810 | */ | |
aa0be0f4 | 811 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
812 | { |
813 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
814 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 815 | timer->enabled = 0; |
6610e089 JS |
816 | if (next == &timer->node) { |
817 | struct rtc_wkalrm alarm; | |
818 | int err; | |
819 | next = timerqueue_getnext(&rtc->timerqueue); | |
41c7f742 RV |
820 | if (!next) { |
821 | rtc_alarm_disable(rtc); | |
6610e089 | 822 | return; |
41c7f742 | 823 | } |
6610e089 JS |
824 | alarm.time = rtc_ktime_to_tm(next->expires); |
825 | alarm.enabled = 1; | |
826 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
827 | if (err == -ETIME) { |
828 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 829 | schedule_work(&rtc->irqwork); |
14d0e347 | 830 | } |
6610e089 JS |
831 | } |
832 | } | |
833 | ||
834 | /** | |
96c8f06a | 835 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
836 | * @rtc rtc device |
837 | * @timer timer being removed. | |
838 | * | |
839 | * Expires rtc timers. Reprograms next alarm event if needed. | |
840 | * Called via worktask. | |
841 | * | |
842 | * Serializes access to timerqueue via ops_lock mutex | |
843 | */ | |
96c8f06a | 844 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
845 | { |
846 | struct rtc_timer *timer; | |
847 | struct timerqueue_node *next; | |
848 | ktime_t now; | |
849 | struct rtc_time tm; | |
850 | ||
851 | struct rtc_device *rtc = | |
852 | container_of(work, struct rtc_device, irqwork); | |
853 | ||
854 | mutex_lock(&rtc->ops_lock); | |
855 | again: | |
856 | __rtc_read_time(rtc, &tm); | |
857 | now = rtc_tm_to_ktime(tm); | |
858 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
859 | if (next->expires.tv64 > now.tv64) | |
860 | break; | |
861 | ||
862 | /* expire timer */ | |
863 | timer = container_of(next, struct rtc_timer, node); | |
864 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
865 | timer->enabled = 0; | |
866 | if (timer->task.func) | |
867 | timer->task.func(timer->task.private_data); | |
868 | ||
869 | /* Re-add/fwd periodic timers */ | |
870 | if (ktime_to_ns(timer->period)) { | |
871 | timer->node.expires = ktime_add(timer->node.expires, | |
872 | timer->period); | |
873 | timer->enabled = 1; | |
874 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
875 | } | |
876 | } | |
877 | ||
878 | /* Set next alarm */ | |
879 | if (next) { | |
880 | struct rtc_wkalrm alarm; | |
881 | int err; | |
882 | alarm.time = rtc_ktime_to_tm(next->expires); | |
883 | alarm.enabled = 1; | |
884 | err = __rtc_set_alarm(rtc, &alarm); | |
885 | if (err == -ETIME) | |
886 | goto again; | |
41c7f742 RV |
887 | } else |
888 | rtc_alarm_disable(rtc); | |
6610e089 | 889 | |
14d0e347 | 890 | pm_relax(rtc->dev.parent); |
6610e089 JS |
891 | mutex_unlock(&rtc->ops_lock); |
892 | } | |
893 | ||
894 | ||
96c8f06a | 895 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
896 | * @timer: timer to be intiialized |
897 | * @f: function pointer to be called when timer fires | |
898 | * @data: private data passed to function pointer | |
899 | * | |
900 | * Kernel interface to initializing an rtc_timer. | |
901 | */ | |
3ff2e13c | 902 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) |
6610e089 JS |
903 | { |
904 | timerqueue_init(&timer->node); | |
905 | timer->enabled = 0; | |
906 | timer->task.func = f; | |
907 | timer->task.private_data = data; | |
908 | } | |
909 | ||
96c8f06a | 910 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
911 | * @ rtc: rtc device to be used |
912 | * @ timer: timer being set | |
913 | * @ expires: time at which to expire the timer | |
914 | * @ period: period that the timer will recur | |
915 | * | |
916 | * Kernel interface to set an rtc_timer | |
917 | */ | |
3ff2e13c | 918 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
6610e089 JS |
919 | ktime_t expires, ktime_t period) |
920 | { | |
921 | int ret = 0; | |
922 | mutex_lock(&rtc->ops_lock); | |
923 | if (timer->enabled) | |
96c8f06a | 924 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
925 | |
926 | timer->node.expires = expires; | |
927 | timer->period = period; | |
928 | ||
aa0be0f4 | 929 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
930 | |
931 | mutex_unlock(&rtc->ops_lock); | |
932 | return ret; | |
933 | } | |
934 | ||
96c8f06a | 935 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
936 | * @ rtc: rtc device to be used |
937 | * @ timer: timer being set | |
938 | * | |
939 | * Kernel interface to cancel an rtc_timer | |
940 | */ | |
3ff2e13c | 941 | int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
942 | { |
943 | int ret = 0; | |
944 | mutex_lock(&rtc->ops_lock); | |
945 | if (timer->enabled) | |
96c8f06a | 946 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
947 | mutex_unlock(&rtc->ops_lock); |
948 | return ret; | |
949 | } | |
950 | ||
951 |