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