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