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Commit | Line | Data |
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0c86edc0 AZ |
1 | /* |
2 | * RTC subsystem, interface functions | |
3 | * | |
4 | * Copyright (C) 2005 Tower Technologies | |
5 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
6 | * | |
7 | * based on arch/arm/common/rtctime.c | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | */ | |
13 | ||
14 | #include <linux/rtc.h> | |
d43c36dc | 15 | #include <linux/sched.h> |
2113852b | 16 | #include <linux/module.h> |
97144c67 | 17 | #include <linux/log2.h> |
6610e089 | 18 | #include <linux/workqueue.h> |
0c86edc0 | 19 | |
aa0be0f4 JS |
20 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); |
21 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer); | |
22 | ||
6610e089 | 23 | static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
24 | { |
25 | int err; | |
0c86edc0 AZ |
26 | if (!rtc->ops) |
27 | err = -ENODEV; | |
28 | else if (!rtc->ops->read_time) | |
29 | err = -EINVAL; | |
30 | else { | |
31 | memset(tm, 0, sizeof(struct rtc_time)); | |
cd966209 | 32 | err = rtc->ops->read_time(rtc->dev.parent, tm); |
16682c86 | 33 | if (err < 0) { |
d0bddb51 AK |
34 | dev_dbg(&rtc->dev, "read_time: fail to read: %d\n", |
35 | err); | |
16682c86 HG |
36 | return err; |
37 | } | |
38 | ||
39 | err = rtc_valid_tm(tm); | |
40 | if (err < 0) | |
d0bddb51 | 41 | dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n"); |
0c86edc0 | 42 | } |
6610e089 JS |
43 | return err; |
44 | } | |
45 | ||
46 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
47 | { | |
48 | int err; | |
0c86edc0 | 49 | |
6610e089 JS |
50 | err = mutex_lock_interruptible(&rtc->ops_lock); |
51 | if (err) | |
52 | return err; | |
53 | ||
54 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 AZ |
55 | mutex_unlock(&rtc->ops_lock); |
56 | return err; | |
57 | } | |
58 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
59 | ||
ab6a2d70 | 60 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
61 | { |
62 | int err; | |
0c86edc0 AZ |
63 | |
64 | err = rtc_valid_tm(tm); | |
65 | if (err != 0) | |
66 | return err; | |
67 | ||
68 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
69 | if (err) | |
b68bb263 | 70 | return err; |
0c86edc0 AZ |
71 | |
72 | if (!rtc->ops) | |
73 | err = -ENODEV; | |
bbccf83f | 74 | else if (rtc->ops->set_time) |
cd966209 | 75 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
8e4ff1a8 XP |
76 | else if (rtc->ops->set_mmss64) { |
77 | time64_t secs64 = rtc_tm_to_time64(tm); | |
78 | ||
79 | err = rtc->ops->set_mmss64(rtc->dev.parent, secs64); | |
80 | } else if (rtc->ops->set_mmss) { | |
bc10aa93 XP |
81 | time64_t secs64 = rtc_tm_to_time64(tm); |
82 | err = rtc->ops->set_mmss(rtc->dev.parent, secs64); | |
bbccf83f AZ |
83 | } else |
84 | err = -EINVAL; | |
0c86edc0 | 85 | |
14d0e347 | 86 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 87 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
88 | /* A timer might have just expired */ |
89 | schedule_work(&rtc->irqwork); | |
0c86edc0 AZ |
90 | return err; |
91 | } | |
92 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
93 | ||
f44f7f96 JS |
94 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
95 | { | |
96 | int err; | |
97 | ||
98 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
99 | if (err) | |
100 | return err; | |
101 | ||
102 | if (rtc->ops == NULL) | |
103 | err = -ENODEV; | |
104 | else if (!rtc->ops->read_alarm) | |
105 | err = -EINVAL; | |
106 | else { | |
d68778b8 UKK |
107 | alarm->enabled = 0; |
108 | alarm->pending = 0; | |
109 | alarm->time.tm_sec = -1; | |
110 | alarm->time.tm_min = -1; | |
111 | alarm->time.tm_hour = -1; | |
112 | alarm->time.tm_mday = -1; | |
113 | alarm->time.tm_mon = -1; | |
114 | alarm->time.tm_year = -1; | |
115 | alarm->time.tm_wday = -1; | |
116 | alarm->time.tm_yday = -1; | |
117 | alarm->time.tm_isdst = -1; | |
f44f7f96 JS |
118 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); |
119 | } | |
120 | ||
121 | mutex_unlock(&rtc->ops_lock); | |
122 | return err; | |
123 | } | |
124 | ||
125 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
126 | { | |
127 | int err; | |
128 | struct rtc_time before, now; | |
129 | int first_time = 1; | |
bc10aa93 | 130 | time64_t t_now, t_alm; |
f44f7f96 JS |
131 | enum { none, day, month, year } missing = none; |
132 | unsigned days; | |
133 | ||
134 | /* The lower level RTC driver may return -1 in some fields, | |
135 | * creating invalid alarm->time values, for reasons like: | |
136 | * | |
137 | * - The hardware may not be capable of filling them in; | |
138 | * many alarms match only on time-of-day fields, not | |
139 | * day/month/year calendar data. | |
140 | * | |
141 | * - Some hardware uses illegal values as "wildcard" match | |
142 | * values, which non-Linux firmware (like a BIOS) may try | |
143 | * to set up as e.g. "alarm 15 minutes after each hour". | |
144 | * Linux uses only oneshot alarms. | |
145 | * | |
146 | * When we see that here, we deal with it by using values from | |
147 | * a current RTC timestamp for any missing (-1) values. The | |
148 | * RTC driver prevents "periodic alarm" modes. | |
149 | * | |
150 | * But this can be racey, because some fields of the RTC timestamp | |
151 | * may have wrapped in the interval since we read the RTC alarm, | |
152 | * which would lead to us inserting inconsistent values in place | |
153 | * of the -1 fields. | |
154 | * | |
155 | * Reading the alarm and timestamp in the reverse sequence | |
156 | * would have the same race condition, and not solve the issue. | |
157 | * | |
158 | * So, we must first read the RTC timestamp, | |
159 | * then read the RTC alarm value, | |
160 | * and then read a second RTC timestamp. | |
161 | * | |
162 | * If any fields of the second timestamp have changed | |
163 | * when compared with the first timestamp, then we know | |
164 | * our timestamp may be inconsistent with that used by | |
165 | * the low-level rtc_read_alarm_internal() function. | |
166 | * | |
167 | * So, when the two timestamps disagree, we just loop and do | |
168 | * the process again to get a fully consistent set of values. | |
169 | * | |
170 | * This could all instead be done in the lower level driver, | |
171 | * but since more than one lower level RTC implementation needs it, | |
172 | * then it's probably best best to do it here instead of there.. | |
173 | */ | |
174 | ||
175 | /* Get the "before" timestamp */ | |
176 | err = rtc_read_time(rtc, &before); | |
177 | if (err < 0) | |
178 | return err; | |
179 | do { | |
180 | if (!first_time) | |
181 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
182 | first_time = 0; | |
183 | ||
184 | /* get the RTC alarm values, which may be incomplete */ | |
185 | err = rtc_read_alarm_internal(rtc, alarm); | |
186 | if (err) | |
187 | return err; | |
188 | ||
189 | /* full-function RTCs won't have such missing fields */ | |
190 | if (rtc_valid_tm(&alarm->time) == 0) | |
191 | return 0; | |
192 | ||
193 | /* get the "after" timestamp, to detect wrapped fields */ | |
194 | err = rtc_read_time(rtc, &now); | |
195 | if (err < 0) | |
196 | return err; | |
197 | ||
198 | /* note that tm_sec is a "don't care" value here: */ | |
199 | } while ( before.tm_min != now.tm_min | |
200 | || before.tm_hour != now.tm_hour | |
201 | || before.tm_mon != now.tm_mon | |
202 | || before.tm_year != now.tm_year); | |
203 | ||
204 | /* Fill in the missing alarm fields using the timestamp; we | |
205 | * know there's at least one since alarm->time is invalid. | |
206 | */ | |
207 | if (alarm->time.tm_sec == -1) | |
208 | alarm->time.tm_sec = now.tm_sec; | |
209 | if (alarm->time.tm_min == -1) | |
210 | alarm->time.tm_min = now.tm_min; | |
211 | if (alarm->time.tm_hour == -1) | |
212 | alarm->time.tm_hour = now.tm_hour; | |
213 | ||
214 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 215 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
216 | alarm->time.tm_mday = now.tm_mday; |
217 | missing = day; | |
218 | } | |
e74a8f2e | 219 | if ((unsigned)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
220 | alarm->time.tm_mon = now.tm_mon; |
221 | if (missing == none) | |
222 | missing = month; | |
223 | } | |
224 | if (alarm->time.tm_year == -1) { | |
225 | alarm->time.tm_year = now.tm_year; | |
226 | if (missing == none) | |
227 | missing = year; | |
228 | } | |
229 | ||
230 | /* with luck, no rollover is needed */ | |
bc10aa93 XP |
231 | t_now = rtc_tm_to_time64(&now); |
232 | t_alm = rtc_tm_to_time64(&alarm->time); | |
f44f7f96 JS |
233 | if (t_now < t_alm) |
234 | goto done; | |
235 | ||
236 | switch (missing) { | |
237 | ||
238 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that | |
239 | * that will trigger at 5am will do so at 5am Tuesday, which | |
240 | * could also be in the next month or year. This is a common | |
241 | * case, especially for PCs. | |
242 | */ | |
243 | case day: | |
244 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
245 | t_alm += 24 * 60 * 60; | |
bc10aa93 | 246 | rtc_time64_to_tm(t_alm, &alarm->time); |
f44f7f96 JS |
247 | break; |
248 | ||
249 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
250 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
251 | * may end up in the month after that! Many newer PCs support | |
252 | * this type of alarm. | |
253 | */ | |
254 | case month: | |
255 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
256 | do { | |
257 | if (alarm->time.tm_mon < 11) | |
258 | alarm->time.tm_mon++; | |
259 | else { | |
260 | alarm->time.tm_mon = 0; | |
261 | alarm->time.tm_year++; | |
262 | } | |
263 | days = rtc_month_days(alarm->time.tm_mon, | |
264 | alarm->time.tm_year); | |
265 | } while (days < alarm->time.tm_mday); | |
266 | break; | |
267 | ||
268 | /* Year rollover ... easy except for leap years! */ | |
269 | case year: | |
270 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
271 | do { | |
272 | alarm->time.tm_year++; | |
ee1d9014 AN |
273 | } while (!is_leap_year(alarm->time.tm_year + 1900) |
274 | && rtc_valid_tm(&alarm->time) != 0); | |
f44f7f96 JS |
275 | break; |
276 | ||
277 | default: | |
278 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
279 | } | |
280 | ||
281 | done: | |
ee1d9014 AN |
282 | err = rtc_valid_tm(&alarm->time); |
283 | ||
284 | if (err) { | |
285 | dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n", | |
286 | alarm->time.tm_year + 1900, alarm->time.tm_mon + 1, | |
287 | alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min, | |
288 | alarm->time.tm_sec); | |
289 | } | |
290 | ||
291 | return err; | |
f44f7f96 JS |
292 | } |
293 | ||
6610e089 | 294 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
295 | { |
296 | int err; | |
0c86edc0 AZ |
297 | |
298 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
299 | if (err) | |
b68bb263 | 300 | return err; |
d5553a55 JS |
301 | if (rtc->ops == NULL) |
302 | err = -ENODEV; | |
303 | else if (!rtc->ops->read_alarm) | |
304 | err = -EINVAL; | |
305 | else { | |
306 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
307 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 308 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 309 | } |
0c86edc0 | 310 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 311 | |
d5553a55 | 312 | return err; |
0c86edc0 | 313 | } |
6610e089 | 314 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 315 | |
d576fe49 | 316 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 317 | { |
6610e089 | 318 | struct rtc_time tm; |
bc10aa93 | 319 | time64_t now, scheduled; |
0e36a9a4 | 320 | int err; |
0e36a9a4 | 321 | |
6610e089 JS |
322 | err = rtc_valid_tm(&alarm->time); |
323 | if (err) | |
0e36a9a4 | 324 | return err; |
bc10aa93 | 325 | scheduled = rtc_tm_to_time64(&alarm->time); |
a01cc657 | 326 | |
6610e089 JS |
327 | /* Make sure we're not setting alarms in the past */ |
328 | err = __rtc_read_time(rtc, &tm); | |
ca6dc2da HG |
329 | if (err) |
330 | return err; | |
bc10aa93 | 331 | now = rtc_tm_to_time64(&tm); |
6610e089 JS |
332 | if (scheduled <= now) |
333 | return -ETIME; | |
334 | /* | |
335 | * XXX - We just checked to make sure the alarm time is not | |
336 | * in the past, but there is still a race window where if | |
337 | * the is alarm set for the next second and the second ticks | |
338 | * over right here, before we set the alarm. | |
a01cc657 | 339 | */ |
a01cc657 | 340 | |
157e8bf8 LT |
341 | if (!rtc->ops) |
342 | err = -ENODEV; | |
343 | else if (!rtc->ops->set_alarm) | |
344 | err = -EINVAL; | |
345 | else | |
346 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
347 | ||
348 | return err; | |
0e36a9a4 | 349 | } |
0c86edc0 | 350 | |
ab6a2d70 | 351 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
352 | { |
353 | int err; | |
0c86edc0 | 354 | |
f8245c26 DB |
355 | err = rtc_valid_tm(&alarm->time); |
356 | if (err != 0) | |
357 | return err; | |
358 | ||
0c86edc0 AZ |
359 | err = mutex_lock_interruptible(&rtc->ops_lock); |
360 | if (err) | |
b68bb263 | 361 | return err; |
3ff2e13c | 362 | if (rtc->aie_timer.enabled) |
96c8f06a | 363 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 364 | |
6610e089 | 365 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); |
8b0e1953 | 366 | rtc->aie_timer.period = 0; |
3ff2e13c | 367 | if (alarm->enabled) |
aa0be0f4 | 368 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 369 | |
0c86edc0 | 370 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 371 | return err; |
0c86edc0 AZ |
372 | } |
373 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
374 | ||
f6d5b331 JS |
375 | /* Called once per device from rtc_device_register */ |
376 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
377 | { | |
378 | int err; | |
bd729d72 | 379 | struct rtc_time now; |
f6d5b331 JS |
380 | |
381 | err = rtc_valid_tm(&alarm->time); | |
382 | if (err != 0) | |
383 | return err; | |
384 | ||
bd729d72 JS |
385 | err = rtc_read_time(rtc, &now); |
386 | if (err) | |
387 | return err; | |
388 | ||
f6d5b331 JS |
389 | err = mutex_lock_interruptible(&rtc->ops_lock); |
390 | if (err) | |
391 | return err; | |
392 | ||
393 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
8b0e1953 | 394 | rtc->aie_timer.period = 0; |
bd729d72 | 395 | |
6785b3b6 | 396 | /* Alarm has to be enabled & in the future for us to enqueue it */ |
2456e855 TG |
397 | if (alarm->enabled && (rtc_tm_to_ktime(now) < |
398 | rtc->aie_timer.node.expires)) { | |
bd729d72 | 399 | |
f6d5b331 JS |
400 | rtc->aie_timer.enabled = 1; |
401 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
402 | } | |
403 | mutex_unlock(&rtc->ops_lock); | |
404 | return err; | |
405 | } | |
406 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
407 | ||
099e6576 AZ |
408 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
409 | { | |
410 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
411 | if (err) | |
412 | return err; | |
413 | ||
6610e089 | 414 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
415 | if (enabled) |
416 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
417 | else | |
96c8f06a | 418 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
419 | } |
420 | ||
aa0be0f4 | 421 | if (err) |
516373b8 UKK |
422 | /* nothing */; |
423 | else if (!rtc->ops) | |
099e6576 AZ |
424 | err = -ENODEV; |
425 | else if (!rtc->ops->alarm_irq_enable) | |
426 | err = -EINVAL; | |
427 | else | |
428 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
429 | ||
430 | mutex_unlock(&rtc->ops_lock); | |
431 | return err; | |
432 | } | |
433 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
434 | ||
435 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
436 | { | |
437 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
438 | if (err) | |
439 | return err; | |
440 | ||
456d66ec JS |
441 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
442 | if (enabled == 0 && rtc->uie_irq_active) { | |
443 | mutex_unlock(&rtc->ops_lock); | |
444 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
445 | } | |
446 | #endif | |
6610e089 JS |
447 | /* make sure we're changing state */ |
448 | if (rtc->uie_rtctimer.enabled == enabled) | |
449 | goto out; | |
450 | ||
4a649903 JS |
451 | if (rtc->uie_unsupported) { |
452 | err = -EINVAL; | |
453 | goto out; | |
454 | } | |
455 | ||
6610e089 JS |
456 | if (enabled) { |
457 | struct rtc_time tm; | |
458 | ktime_t now, onesec; | |
459 | ||
460 | __rtc_read_time(rtc, &tm); | |
461 | onesec = ktime_set(1, 0); | |
462 | now = rtc_tm_to_ktime(tm); | |
463 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
464 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 JS |
465 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
466 | } else | |
96c8f06a | 467 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
099e6576 | 468 | |
6610e089 | 469 | out: |
099e6576 | 470 | mutex_unlock(&rtc->ops_lock); |
456d66ec JS |
471 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
472 | /* | |
473 | * Enable emulation if the driver did not provide | |
474 | * the update_irq_enable function pointer or if returned | |
475 | * -EINVAL to signal that it has been configured without | |
476 | * interrupts or that are not available at the moment. | |
477 | */ | |
478 | if (err == -EINVAL) | |
479 | err = rtc_dev_update_irq_enable_emul(rtc, enabled); | |
480 | #endif | |
099e6576 | 481 | return err; |
6610e089 | 482 | |
099e6576 AZ |
483 | } |
484 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
485 | ||
6610e089 | 486 | |
d728b1e6 | 487 | /** |
6610e089 JS |
488 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
489 | * @rtc: pointer to the rtc device | |
490 | * | |
491 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 492 | * has occurred (or been emulated). |
6610e089 JS |
493 | * |
494 | * Triggers the registered irq_task function callback. | |
d728b1e6 | 495 | */ |
456d66ec | 496 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 497 | { |
e6229bec AN |
498 | unsigned long flags; |
499 | ||
6610e089 | 500 | /* mark one irq of the appropriate mode */ |
e6229bec | 501 | spin_lock_irqsave(&rtc->irq_lock, flags); |
6610e089 | 502 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); |
e6229bec | 503 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 504 | |
6610e089 | 505 | /* call the task func */ |
e6229bec | 506 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
507 | if (rtc->irq_task) |
508 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 509 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
510 | |
511 | wake_up_interruptible(&rtc->irq_queue); | |
512 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
513 | } | |
6610e089 JS |
514 | |
515 | ||
516 | /** | |
517 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
518 | * @private: pointer to the rtc_device | |
519 | * | |
520 | * This functions is called when the aie_timer expires. | |
521 | */ | |
522 | void rtc_aie_update_irq(void *private) | |
523 | { | |
524 | struct rtc_device *rtc = (struct rtc_device *)private; | |
525 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); | |
526 | } | |
527 | ||
528 | ||
529 | /** | |
530 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
531 | * @private: pointer to the rtc_device | |
532 | * | |
533 | * This functions is called when the uie_timer expires. | |
534 | */ | |
535 | void rtc_uie_update_irq(void *private) | |
536 | { | |
537 | struct rtc_device *rtc = (struct rtc_device *)private; | |
538 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); | |
539 | } | |
540 | ||
541 | ||
542 | /** | |
543 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
544 | * @timer: pointer to the pie mode hrtimer | |
545 | * | |
546 | * This function is used to emulate PIE mode interrupts | |
547 | * using an hrtimer. This function is called when the periodic | |
548 | * hrtimer expires. | |
549 | */ | |
550 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
551 | { | |
552 | struct rtc_device *rtc; | |
553 | ktime_t period; | |
554 | int count; | |
555 | rtc = container_of(timer, struct rtc_device, pie_timer); | |
556 | ||
8b0e1953 | 557 | period = NSEC_PER_SEC / rtc->irq_freq; |
6610e089 JS |
558 | count = hrtimer_forward_now(timer, period); |
559 | ||
560 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
561 | ||
562 | return HRTIMER_RESTART; | |
563 | } | |
564 | ||
565 | /** | |
566 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
567 | * @rtc: the rtc device | |
568 | * @num: how many irqs are being reported (usually one) | |
569 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
570 | * Context: any | |
571 | */ | |
572 | void rtc_update_irq(struct rtc_device *rtc, | |
573 | unsigned long num, unsigned long events) | |
574 | { | |
e7cba884 | 575 | if (IS_ERR_OR_NULL(rtc)) |
131c9cc8 AZ |
576 | return; |
577 | ||
7523ceed | 578 | pm_stay_awake(rtc->dev.parent); |
6610e089 JS |
579 | schedule_work(&rtc->irqwork); |
580 | } | |
0c86edc0 AZ |
581 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
582 | ||
9f3b795a | 583 | static int __rtc_match(struct device *dev, const void *data) |
71da8905 | 584 | { |
9f3b795a | 585 | const char *name = data; |
71da8905 | 586 | |
d4afc76c | 587 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
588 | return 1; |
589 | return 0; | |
590 | } | |
591 | ||
9f3b795a | 592 | struct rtc_device *rtc_class_open(const char *name) |
0c86edc0 | 593 | { |
cd966209 | 594 | struct device *dev; |
ab6a2d70 | 595 | struct rtc_device *rtc = NULL; |
0c86edc0 | 596 | |
695794ae | 597 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
598 | if (dev) |
599 | rtc = to_rtc_device(dev); | |
0c86edc0 | 600 | |
ab6a2d70 DB |
601 | if (rtc) { |
602 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 603 | put_device(dev); |
ab6a2d70 DB |
604 | rtc = NULL; |
605 | } | |
0c86edc0 | 606 | } |
0c86edc0 | 607 | |
ab6a2d70 | 608 | return rtc; |
0c86edc0 AZ |
609 | } |
610 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
611 | ||
ab6a2d70 | 612 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 613 | { |
ab6a2d70 | 614 | module_put(rtc->owner); |
cd966209 | 615 | put_device(&rtc->dev); |
0c86edc0 AZ |
616 | } |
617 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
618 | ||
ab6a2d70 | 619 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
620 | { |
621 | int retval = -EBUSY; | |
0c86edc0 AZ |
622 | |
623 | if (task == NULL || task->func == NULL) | |
624 | return -EINVAL; | |
625 | ||
d691eb90 | 626 | /* Cannot register while the char dev is in use */ |
372a302e | 627 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
628 | return -EBUSY; |
629 | ||
d728b1e6 | 630 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
631 | if (rtc->irq_task == NULL) { |
632 | rtc->irq_task = task; | |
633 | retval = 0; | |
634 | } | |
d728b1e6 | 635 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 636 | |
372a302e | 637 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 638 | |
0c86edc0 AZ |
639 | return retval; |
640 | } | |
641 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
642 | ||
ab6a2d70 | 643 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 644 | { |
d728b1e6 | 645 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
646 | if (rtc->irq_task == task) |
647 | rtc->irq_task = NULL; | |
d728b1e6 | 648 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
649 | } |
650 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
651 | ||
3c8bb90e TG |
652 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
653 | { | |
654 | /* | |
655 | * We always cancel the timer here first, because otherwise | |
656 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
657 | * when we manage to start the timer before the callback | |
658 | * returns HRTIMER_RESTART. | |
659 | * | |
660 | * We cannot use hrtimer_cancel() here as a running callback | |
661 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
662 | * would spin forever. | |
663 | */ | |
664 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
665 | return -1; | |
666 | ||
667 | if (enabled) { | |
8b0e1953 | 668 | ktime_t period = NSEC_PER_SEC / rtc->irq_freq; |
3c8bb90e TG |
669 | |
670 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
671 | } | |
672 | return 0; | |
673 | } | |
674 | ||
97144c67 DB |
675 | /** |
676 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
677 | * @rtc: the rtc device | |
678 | * @task: currently registered with rtc_irq_register() | |
679 | * @enabled: true to enable periodic IRQs | |
680 | * Context: any | |
681 | * | |
682 | * Note that rtc_irq_set_freq() should previously have been used to | |
683 | * specify the desired frequency of periodic IRQ task->func() callbacks. | |
684 | */ | |
ab6a2d70 | 685 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
686 | { |
687 | int err = 0; | |
688 | unsigned long flags; | |
0c86edc0 | 689 | |
3c8bb90e | 690 | retry: |
0c86edc0 | 691 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
692 | if (rtc->irq_task != NULL && task == NULL) |
693 | err = -EBUSY; | |
0734e27f | 694 | else if (rtc->irq_task != task) |
d691eb90 | 695 | err = -EACCES; |
0734e27f | 696 | else { |
3c8bb90e TG |
697 | if (rtc_update_hrtimer(rtc, enabled) < 0) { |
698 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
699 | cpu_relax(); | |
700 | goto retry; | |
701 | } | |
702 | rtc->pie_enabled = enabled; | |
6610e089 | 703 | } |
6610e089 | 704 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
705 | return err; |
706 | } | |
707 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
708 | ||
97144c67 DB |
709 | /** |
710 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
711 | * @rtc: the rtc device | |
712 | * @task: currently registered with rtc_irq_register() | |
713 | * @freq: positive frequency with which task->func() will be called | |
714 | * Context: any | |
715 | * | |
716 | * Note that rtc_irq_set_state() is used to enable or disable the | |
717 | * periodic IRQs. | |
718 | */ | |
ab6a2d70 | 719 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 720 | { |
56f10c63 | 721 | int err = 0; |
0c86edc0 | 722 | unsigned long flags; |
0c86edc0 | 723 | |
6e7a333e | 724 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 725 | return -EINVAL; |
3c8bb90e | 726 | retry: |
0c86edc0 | 727 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
728 | if (rtc->irq_task != NULL && task == NULL) |
729 | err = -EBUSY; | |
0734e27f | 730 | else if (rtc->irq_task != task) |
d691eb90 | 731 | err = -EACCES; |
0734e27f | 732 | else { |
6610e089 | 733 | rtc->irq_freq = freq; |
3c8bb90e TG |
734 | if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { |
735 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
736 | cpu_relax(); | |
737 | goto retry; | |
6610e089 | 738 | } |
0c86edc0 | 739 | } |
6610e089 | 740 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
741 | return err; |
742 | } | |
2601a464 | 743 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |
6610e089 JS |
744 | |
745 | /** | |
96c8f06a | 746 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
6610e089 JS |
747 | * @rtc rtc device |
748 | * @timer timer being added. | |
749 | * | |
750 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
751 | * the next alarm event appropriately. | |
752 | * | |
aa0be0f4 JS |
753 | * Sets the enabled bit on the added timer. |
754 | * | |
6610e089 JS |
755 | * Must hold ops_lock for proper serialization of timerqueue |
756 | */ | |
aa0be0f4 | 757 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 758 | { |
2b2f5ff0 CIK |
759 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); |
760 | struct rtc_time tm; | |
761 | ktime_t now; | |
762 | ||
aa0be0f4 | 763 | timer->enabled = 1; |
2b2f5ff0 CIK |
764 | __rtc_read_time(rtc, &tm); |
765 | now = rtc_tm_to_ktime(tm); | |
766 | ||
767 | /* Skip over expired timers */ | |
768 | while (next) { | |
2456e855 | 769 | if (next->expires >= now) |
2b2f5ff0 CIK |
770 | break; |
771 | next = timerqueue_iterate_next(next); | |
772 | } | |
773 | ||
6610e089 | 774 | timerqueue_add(&rtc->timerqueue, &timer->node); |
2b2f5ff0 | 775 | if (!next) { |
6610e089 JS |
776 | struct rtc_wkalrm alarm; |
777 | int err; | |
778 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
779 | alarm.enabled = 1; | |
780 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
781 | if (err == -ETIME) { |
782 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 783 | schedule_work(&rtc->irqwork); |
14d0e347 | 784 | } else if (err) { |
aa0be0f4 JS |
785 | timerqueue_del(&rtc->timerqueue, &timer->node); |
786 | timer->enabled = 0; | |
787 | return err; | |
788 | } | |
6610e089 | 789 | } |
aa0be0f4 | 790 | return 0; |
6610e089 JS |
791 | } |
792 | ||
41c7f742 RV |
793 | static void rtc_alarm_disable(struct rtc_device *rtc) |
794 | { | |
795 | if (!rtc->ops || !rtc->ops->alarm_irq_enable) | |
796 | return; | |
797 | ||
798 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
799 | } | |
800 | ||
6610e089 | 801 | /** |
96c8f06a | 802 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
803 | * @rtc rtc device |
804 | * @timer timer being removed. | |
805 | * | |
806 | * Removes a timer onto the rtc devices timerqueue and sets | |
807 | * the next alarm event appropriately. | |
808 | * | |
aa0be0f4 JS |
809 | * Clears the enabled bit on the removed timer. |
810 | * | |
6610e089 JS |
811 | * Must hold ops_lock for proper serialization of timerqueue |
812 | */ | |
aa0be0f4 | 813 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
814 | { |
815 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
816 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 817 | timer->enabled = 0; |
6610e089 JS |
818 | if (next == &timer->node) { |
819 | struct rtc_wkalrm alarm; | |
820 | int err; | |
821 | next = timerqueue_getnext(&rtc->timerqueue); | |
41c7f742 RV |
822 | if (!next) { |
823 | rtc_alarm_disable(rtc); | |
6610e089 | 824 | return; |
41c7f742 | 825 | } |
6610e089 JS |
826 | alarm.time = rtc_ktime_to_tm(next->expires); |
827 | alarm.enabled = 1; | |
828 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
829 | if (err == -ETIME) { |
830 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 831 | schedule_work(&rtc->irqwork); |
14d0e347 | 832 | } |
6610e089 JS |
833 | } |
834 | } | |
835 | ||
836 | /** | |
96c8f06a | 837 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
838 | * @rtc rtc device |
839 | * @timer timer being removed. | |
840 | * | |
841 | * Expires rtc timers. Reprograms next alarm event if needed. | |
842 | * Called via worktask. | |
843 | * | |
844 | * Serializes access to timerqueue via ops_lock mutex | |
845 | */ | |
96c8f06a | 846 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
847 | { |
848 | struct rtc_timer *timer; | |
849 | struct timerqueue_node *next; | |
850 | ktime_t now; | |
851 | struct rtc_time tm; | |
852 | ||
853 | struct rtc_device *rtc = | |
854 | container_of(work, struct rtc_device, irqwork); | |
855 | ||
856 | mutex_lock(&rtc->ops_lock); | |
857 | again: | |
858 | __rtc_read_time(rtc, &tm); | |
859 | now = rtc_tm_to_ktime(tm); | |
860 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
2456e855 | 861 | if (next->expires > now) |
6610e089 JS |
862 | break; |
863 | ||
864 | /* expire timer */ | |
865 | timer = container_of(next, struct rtc_timer, node); | |
866 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
867 | timer->enabled = 0; | |
868 | if (timer->task.func) | |
869 | timer->task.func(timer->task.private_data); | |
870 | ||
871 | /* Re-add/fwd periodic timers */ | |
872 | if (ktime_to_ns(timer->period)) { | |
873 | timer->node.expires = ktime_add(timer->node.expires, | |
874 | timer->period); | |
875 | timer->enabled = 1; | |
876 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
877 | } | |
878 | } | |
879 | ||
880 | /* Set next alarm */ | |
881 | if (next) { | |
882 | struct rtc_wkalrm alarm; | |
883 | int err; | |
6528b889 XP |
884 | int retry = 3; |
885 | ||
6610e089 JS |
886 | alarm.time = rtc_ktime_to_tm(next->expires); |
887 | alarm.enabled = 1; | |
6528b889 | 888 | reprogram: |
6610e089 JS |
889 | err = __rtc_set_alarm(rtc, &alarm); |
890 | if (err == -ETIME) | |
891 | goto again; | |
6528b889 XP |
892 | else if (err) { |
893 | if (retry-- > 0) | |
894 | goto reprogram; | |
895 | ||
896 | timer = container_of(next, struct rtc_timer, node); | |
897 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
898 | timer->enabled = 0; | |
899 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); | |
900 | goto again; | |
901 | } | |
41c7f742 RV |
902 | } else |
903 | rtc_alarm_disable(rtc); | |
6610e089 | 904 | |
14d0e347 | 905 | pm_relax(rtc->dev.parent); |
6610e089 JS |
906 | mutex_unlock(&rtc->ops_lock); |
907 | } | |
908 | ||
909 | ||
96c8f06a | 910 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
911 | * @timer: timer to be intiialized |
912 | * @f: function pointer to be called when timer fires | |
913 | * @data: private data passed to function pointer | |
914 | * | |
915 | * Kernel interface to initializing an rtc_timer. | |
916 | */ | |
3ff2e13c | 917 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) |
6610e089 JS |
918 | { |
919 | timerqueue_init(&timer->node); | |
920 | timer->enabled = 0; | |
921 | timer->task.func = f; | |
922 | timer->task.private_data = data; | |
923 | } | |
924 | ||
96c8f06a | 925 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
926 | * @ rtc: rtc device to be used |
927 | * @ timer: timer being set | |
928 | * @ expires: time at which to expire the timer | |
929 | * @ period: period that the timer will recur | |
930 | * | |
931 | * Kernel interface to set an rtc_timer | |
932 | */ | |
3ff2e13c | 933 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
6610e089 JS |
934 | ktime_t expires, ktime_t period) |
935 | { | |
936 | int ret = 0; | |
937 | mutex_lock(&rtc->ops_lock); | |
938 | if (timer->enabled) | |
96c8f06a | 939 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
940 | |
941 | timer->node.expires = expires; | |
942 | timer->period = period; | |
943 | ||
aa0be0f4 | 944 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
945 | |
946 | mutex_unlock(&rtc->ops_lock); | |
947 | return ret; | |
948 | } | |
949 | ||
96c8f06a | 950 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
951 | * @ rtc: rtc device to be used |
952 | * @ timer: timer being set | |
953 | * | |
954 | * Kernel interface to cancel an rtc_timer | |
955 | */ | |
73744a64 | 956 | void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 957 | { |
6610e089 JS |
958 | mutex_lock(&rtc->ops_lock); |
959 | if (timer->enabled) | |
96c8f06a | 960 | rtc_timer_remove(rtc, timer); |
6610e089 | 961 | mutex_unlock(&rtc->ops_lock); |
6610e089 JS |
962 | } |
963 | ||
b3967067 JC |
964 | /** |
965 | * rtc_read_offset - Read the amount of rtc offset in parts per billion | |
966 | * @ rtc: rtc device to be used | |
967 | * @ offset: the offset in parts per billion | |
968 | * | |
969 | * see below for details. | |
970 | * | |
971 | * Kernel interface to read rtc clock offset | |
972 | * Returns 0 on success, or a negative number on error. | |
973 | * If read_offset() is not implemented for the rtc, return -EINVAL | |
974 | */ | |
975 | int rtc_read_offset(struct rtc_device *rtc, long *offset) | |
976 | { | |
977 | int ret; | |
978 | ||
979 | if (!rtc->ops) | |
980 | return -ENODEV; | |
981 | ||
982 | if (!rtc->ops->read_offset) | |
983 | return -EINVAL; | |
984 | ||
985 | mutex_lock(&rtc->ops_lock); | |
986 | ret = rtc->ops->read_offset(rtc->dev.parent, offset); | |
987 | mutex_unlock(&rtc->ops_lock); | |
988 | return ret; | |
989 | } | |
6610e089 | 990 | |
b3967067 JC |
991 | /** |
992 | * rtc_set_offset - Adjusts the duration of the average second | |
993 | * @ rtc: rtc device to be used | |
994 | * @ offset: the offset in parts per billion | |
995 | * | |
996 | * Some rtc's allow an adjustment to the average duration of a second | |
997 | * to compensate for differences in the actual clock rate due to temperature, | |
998 | * the crystal, capacitor, etc. | |
999 | * | |
1000 | * Kernel interface to adjust an rtc clock offset. | |
1001 | * Return 0 on success, or a negative number on error. | |
1002 | * If the rtc offset is not setable (or not implemented), return -EINVAL | |
1003 | */ | |
1004 | int rtc_set_offset(struct rtc_device *rtc, long offset) | |
1005 | { | |
1006 | int ret; | |
1007 | ||
1008 | if (!rtc->ops) | |
1009 | return -ENODEV; | |
1010 | ||
1011 | if (!rtc->ops->set_offset) | |
1012 | return -EINVAL; | |
1013 | ||
1014 | mutex_lock(&rtc->ops_lock); | |
1015 | ret = rtc->ops->set_offset(rtc->dev.parent, offset); | |
1016 | mutex_unlock(&rtc->ops_lock); | |
1017 | return ret; | |
1018 | } |