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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> |
97144c67 | 16 | #include <linux/log2.h> |
6610e089 | 17 | #include <linux/workqueue.h> |
0c86edc0 | 18 | |
aa0be0f4 JS |
19 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); |
20 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer); | |
21 | ||
6610e089 | 22 | static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
23 | { |
24 | int err; | |
0c86edc0 AZ |
25 | if (!rtc->ops) |
26 | err = -ENODEV; | |
27 | else if (!rtc->ops->read_time) | |
28 | err = -EINVAL; | |
29 | else { | |
30 | memset(tm, 0, sizeof(struct rtc_time)); | |
cd966209 | 31 | err = rtc->ops->read_time(rtc->dev.parent, tm); |
0c86edc0 | 32 | } |
6610e089 JS |
33 | return err; |
34 | } | |
35 | ||
36 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
37 | { | |
38 | int err; | |
0c86edc0 | 39 | |
6610e089 JS |
40 | err = mutex_lock_interruptible(&rtc->ops_lock); |
41 | if (err) | |
42 | return err; | |
43 | ||
44 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 AZ |
45 | mutex_unlock(&rtc->ops_lock); |
46 | return err; | |
47 | } | |
48 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
49 | ||
ab6a2d70 | 50 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
51 | { |
52 | int err; | |
0c86edc0 AZ |
53 | |
54 | err = rtc_valid_tm(tm); | |
55 | if (err != 0) | |
56 | return err; | |
57 | ||
58 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
59 | if (err) | |
b68bb263 | 60 | return err; |
0c86edc0 AZ |
61 | |
62 | if (!rtc->ops) | |
63 | err = -ENODEV; | |
bbccf83f | 64 | else if (rtc->ops->set_time) |
cd966209 | 65 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
bbccf83f AZ |
66 | else if (rtc->ops->set_mmss) { |
67 | unsigned long secs; | |
68 | err = rtc_tm_to_time(tm, &secs); | |
69 | if (err == 0) | |
70 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); | |
71 | } else | |
72 | err = -EINVAL; | |
0c86edc0 AZ |
73 | |
74 | mutex_unlock(&rtc->ops_lock); | |
75 | return err; | |
76 | } | |
77 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
78 | ||
ab6a2d70 | 79 | int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) |
0c86edc0 AZ |
80 | { |
81 | int err; | |
0c86edc0 AZ |
82 | |
83 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
84 | if (err) | |
b68bb263 | 85 | return err; |
0c86edc0 AZ |
86 | |
87 | if (!rtc->ops) | |
88 | err = -ENODEV; | |
89 | else if (rtc->ops->set_mmss) | |
cd966209 | 90 | err = rtc->ops->set_mmss(rtc->dev.parent, secs); |
0c86edc0 AZ |
91 | else if (rtc->ops->read_time && rtc->ops->set_time) { |
92 | struct rtc_time new, old; | |
93 | ||
cd966209 | 94 | err = rtc->ops->read_time(rtc->dev.parent, &old); |
0c86edc0 AZ |
95 | if (err == 0) { |
96 | rtc_time_to_tm(secs, &new); | |
97 | ||
98 | /* | |
99 | * avoid writing when we're going to change the day of | |
100 | * the month. We will retry in the next minute. This | |
101 | * basically means that if the RTC must not drift | |
102 | * by more than 1 minute in 11 minutes. | |
103 | */ | |
104 | if (!((old.tm_hour == 23 && old.tm_min == 59) || | |
105 | (new.tm_hour == 23 && new.tm_min == 59))) | |
cd966209 | 106 | err = rtc->ops->set_time(rtc->dev.parent, |
ab6a2d70 | 107 | &new); |
0c86edc0 AZ |
108 | } |
109 | } | |
110 | else | |
111 | err = -EINVAL; | |
112 | ||
113 | mutex_unlock(&rtc->ops_lock); | |
114 | ||
115 | return err; | |
116 | } | |
117 | EXPORT_SYMBOL_GPL(rtc_set_mmss); | |
118 | ||
f44f7f96 JS |
119 | static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
120 | { | |
121 | int err; | |
122 | ||
123 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
124 | if (err) | |
125 | return err; | |
126 | ||
127 | if (rtc->ops == NULL) | |
128 | err = -ENODEV; | |
129 | else if (!rtc->ops->read_alarm) | |
130 | err = -EINVAL; | |
131 | else { | |
132 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
133 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); | |
134 | } | |
135 | ||
136 | mutex_unlock(&rtc->ops_lock); | |
137 | return err; | |
138 | } | |
139 | ||
140 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
141 | { | |
142 | int err; | |
143 | struct rtc_time before, now; | |
144 | int first_time = 1; | |
145 | unsigned long t_now, t_alm; | |
146 | enum { none, day, month, year } missing = none; | |
147 | unsigned days; | |
148 | ||
149 | /* The lower level RTC driver may return -1 in some fields, | |
150 | * creating invalid alarm->time values, for reasons like: | |
151 | * | |
152 | * - The hardware may not be capable of filling them in; | |
153 | * many alarms match only on time-of-day fields, not | |
154 | * day/month/year calendar data. | |
155 | * | |
156 | * - Some hardware uses illegal values as "wildcard" match | |
157 | * values, which non-Linux firmware (like a BIOS) may try | |
158 | * to set up as e.g. "alarm 15 minutes after each hour". | |
159 | * Linux uses only oneshot alarms. | |
160 | * | |
161 | * When we see that here, we deal with it by using values from | |
162 | * a current RTC timestamp for any missing (-1) values. The | |
163 | * RTC driver prevents "periodic alarm" modes. | |
164 | * | |
165 | * But this can be racey, because some fields of the RTC timestamp | |
166 | * may have wrapped in the interval since we read the RTC alarm, | |
167 | * which would lead to us inserting inconsistent values in place | |
168 | * of the -1 fields. | |
169 | * | |
170 | * Reading the alarm and timestamp in the reverse sequence | |
171 | * would have the same race condition, and not solve the issue. | |
172 | * | |
173 | * So, we must first read the RTC timestamp, | |
174 | * then read the RTC alarm value, | |
175 | * and then read a second RTC timestamp. | |
176 | * | |
177 | * If any fields of the second timestamp have changed | |
178 | * when compared with the first timestamp, then we know | |
179 | * our timestamp may be inconsistent with that used by | |
180 | * the low-level rtc_read_alarm_internal() function. | |
181 | * | |
182 | * So, when the two timestamps disagree, we just loop and do | |
183 | * the process again to get a fully consistent set of values. | |
184 | * | |
185 | * This could all instead be done in the lower level driver, | |
186 | * but since more than one lower level RTC implementation needs it, | |
187 | * then it's probably best best to do it here instead of there.. | |
188 | */ | |
189 | ||
190 | /* Get the "before" timestamp */ | |
191 | err = rtc_read_time(rtc, &before); | |
192 | if (err < 0) | |
193 | return err; | |
194 | do { | |
195 | if (!first_time) | |
196 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
197 | first_time = 0; | |
198 | ||
199 | /* get the RTC alarm values, which may be incomplete */ | |
200 | err = rtc_read_alarm_internal(rtc, alarm); | |
201 | if (err) | |
202 | return err; | |
203 | ||
204 | /* full-function RTCs won't have such missing fields */ | |
205 | if (rtc_valid_tm(&alarm->time) == 0) | |
206 | return 0; | |
207 | ||
208 | /* get the "after" timestamp, to detect wrapped fields */ | |
209 | err = rtc_read_time(rtc, &now); | |
210 | if (err < 0) | |
211 | return err; | |
212 | ||
213 | /* note that tm_sec is a "don't care" value here: */ | |
214 | } while ( before.tm_min != now.tm_min | |
215 | || before.tm_hour != now.tm_hour | |
216 | || before.tm_mon != now.tm_mon | |
217 | || before.tm_year != now.tm_year); | |
218 | ||
219 | /* Fill in the missing alarm fields using the timestamp; we | |
220 | * know there's at least one since alarm->time is invalid. | |
221 | */ | |
222 | if (alarm->time.tm_sec == -1) | |
223 | alarm->time.tm_sec = now.tm_sec; | |
224 | if (alarm->time.tm_min == -1) | |
225 | alarm->time.tm_min = now.tm_min; | |
226 | if (alarm->time.tm_hour == -1) | |
227 | alarm->time.tm_hour = now.tm_hour; | |
228 | ||
229 | /* For simplicity, only support date rollover for now */ | |
230 | if (alarm->time.tm_mday == -1) { | |
231 | alarm->time.tm_mday = now.tm_mday; | |
232 | missing = day; | |
233 | } | |
234 | if (alarm->time.tm_mon == -1) { | |
235 | alarm->time.tm_mon = now.tm_mon; | |
236 | if (missing == none) | |
237 | missing = month; | |
238 | } | |
239 | if (alarm->time.tm_year == -1) { | |
240 | alarm->time.tm_year = now.tm_year; | |
241 | if (missing == none) | |
242 | missing = year; | |
243 | } | |
244 | ||
245 | /* with luck, no rollover is needed */ | |
246 | rtc_tm_to_time(&now, &t_now); | |
247 | rtc_tm_to_time(&alarm->time, &t_alm); | |
248 | if (t_now < t_alm) | |
249 | goto done; | |
250 | ||
251 | switch (missing) { | |
252 | ||
253 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that | |
254 | * that will trigger at 5am will do so at 5am Tuesday, which | |
255 | * could also be in the next month or year. This is a common | |
256 | * case, especially for PCs. | |
257 | */ | |
258 | case day: | |
259 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
260 | t_alm += 24 * 60 * 60; | |
261 | rtc_time_to_tm(t_alm, &alarm->time); | |
262 | break; | |
263 | ||
264 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
265 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
266 | * may end up in the month after that! Many newer PCs support | |
267 | * this type of alarm. | |
268 | */ | |
269 | case month: | |
270 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
271 | do { | |
272 | if (alarm->time.tm_mon < 11) | |
273 | alarm->time.tm_mon++; | |
274 | else { | |
275 | alarm->time.tm_mon = 0; | |
276 | alarm->time.tm_year++; | |
277 | } | |
278 | days = rtc_month_days(alarm->time.tm_mon, | |
279 | alarm->time.tm_year); | |
280 | } while (days < alarm->time.tm_mday); | |
281 | break; | |
282 | ||
283 | /* Year rollover ... easy except for leap years! */ | |
284 | case year: | |
285 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
286 | do { | |
287 | alarm->time.tm_year++; | |
288 | } while (rtc_valid_tm(&alarm->time) != 0); | |
289 | break; | |
290 | ||
291 | default: | |
292 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
293 | } | |
294 | ||
295 | done: | |
296 | return 0; | |
297 | } | |
298 | ||
6610e089 | 299 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
300 | { |
301 | int err; | |
0c86edc0 AZ |
302 | |
303 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
304 | if (err) | |
b68bb263 | 305 | return err; |
d5553a55 JS |
306 | if (rtc->ops == NULL) |
307 | err = -ENODEV; | |
308 | else if (!rtc->ops->read_alarm) | |
309 | err = -EINVAL; | |
310 | else { | |
311 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); | |
312 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 313 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 314 | } |
0c86edc0 | 315 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 316 | |
d5553a55 | 317 | return err; |
0c86edc0 | 318 | } |
6610e089 | 319 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 320 | |
d576fe49 | 321 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 322 | { |
6610e089 JS |
323 | struct rtc_time tm; |
324 | long now, scheduled; | |
0e36a9a4 | 325 | int err; |
0e36a9a4 | 326 | |
6610e089 JS |
327 | err = rtc_valid_tm(&alarm->time); |
328 | if (err) | |
0e36a9a4 | 329 | return err; |
6610e089 | 330 | rtc_tm_to_time(&alarm->time, &scheduled); |
a01cc657 | 331 | |
6610e089 JS |
332 | /* Make sure we're not setting alarms in the past */ |
333 | err = __rtc_read_time(rtc, &tm); | |
334 | rtc_tm_to_time(&tm, &now); | |
335 | if (scheduled <= now) | |
336 | return -ETIME; | |
337 | /* | |
338 | * XXX - We just checked to make sure the alarm time is not | |
339 | * in the past, but there is still a race window where if | |
340 | * the is alarm set for the next second and the second ticks | |
341 | * over right here, before we set the alarm. | |
a01cc657 | 342 | */ |
a01cc657 | 343 | |
6610e089 JS |
344 | if (!rtc->ops) |
345 | err = -ENODEV; | |
346 | else if (!rtc->ops->set_alarm) | |
347 | err = -EINVAL; | |
348 | else | |
349 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
350 | ||
351 | return err; | |
0e36a9a4 | 352 | } |
0c86edc0 | 353 | |
ab6a2d70 | 354 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
355 | { |
356 | int err; | |
0c86edc0 | 357 | |
f8245c26 DB |
358 | err = rtc_valid_tm(&alarm->time); |
359 | if (err != 0) | |
360 | return err; | |
361 | ||
0c86edc0 AZ |
362 | err = mutex_lock_interruptible(&rtc->ops_lock); |
363 | if (err) | |
b68bb263 | 364 | return err; |
6610e089 | 365 | if (rtc->aie_timer.enabled) { |
96c8f06a | 366 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
367 | } |
368 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
369 | rtc->aie_timer.period = ktime_set(0, 0); | |
370 | if (alarm->enabled) { | |
aa0be0f4 | 371 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
6610e089 | 372 | } |
0c86edc0 | 373 | mutex_unlock(&rtc->ops_lock); |
aa0be0f4 | 374 | return err; |
0c86edc0 AZ |
375 | } |
376 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
377 | ||
f6d5b331 JS |
378 | /* Called once per device from rtc_device_register */ |
379 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
380 | { | |
381 | int err; | |
382 | ||
383 | err = rtc_valid_tm(&alarm->time); | |
384 | if (err != 0) | |
385 | return err; | |
386 | ||
387 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
388 | if (err) | |
389 | return err; | |
390 | ||
391 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
392 | rtc->aie_timer.period = ktime_set(0, 0); | |
393 | if (alarm->enabled) { | |
394 | rtc->aie_timer.enabled = 1; | |
395 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
396 | } | |
397 | mutex_unlock(&rtc->ops_lock); | |
398 | return err; | |
399 | } | |
400 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
401 | ||
402 | ||
403 | ||
099e6576 AZ |
404 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
405 | { | |
406 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
407 | if (err) | |
408 | return err; | |
409 | ||
6610e089 | 410 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
411 | if (enabled) |
412 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
413 | else | |
96c8f06a | 414 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
415 | } |
416 | ||
aa0be0f4 | 417 | if (err) |
516373b8 UKK |
418 | /* nothing */; |
419 | else if (!rtc->ops) | |
099e6576 AZ |
420 | err = -ENODEV; |
421 | else if (!rtc->ops->alarm_irq_enable) | |
422 | err = -EINVAL; | |
423 | else | |
424 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
425 | ||
426 | mutex_unlock(&rtc->ops_lock); | |
427 | return err; | |
428 | } | |
429 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
430 | ||
431 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
432 | { | |
433 | int err = mutex_lock_interruptible(&rtc->ops_lock); | |
434 | if (err) | |
435 | return err; | |
436 | ||
456d66ec JS |
437 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
438 | if (enabled == 0 && rtc->uie_irq_active) { | |
439 | mutex_unlock(&rtc->ops_lock); | |
440 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
441 | } | |
442 | #endif | |
6610e089 JS |
443 | /* make sure we're changing state */ |
444 | if (rtc->uie_rtctimer.enabled == enabled) | |
445 | goto out; | |
446 | ||
447 | if (enabled) { | |
448 | struct rtc_time tm; | |
449 | ktime_t now, onesec; | |
450 | ||
451 | __rtc_read_time(rtc, &tm); | |
452 | onesec = ktime_set(1, 0); | |
453 | now = rtc_tm_to_ktime(tm); | |
454 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
455 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 JS |
456 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
457 | } else | |
96c8f06a | 458 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
099e6576 | 459 | |
6610e089 | 460 | out: |
099e6576 | 461 | mutex_unlock(&rtc->ops_lock); |
456d66ec JS |
462 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
463 | /* | |
464 | * Enable emulation if the driver did not provide | |
465 | * the update_irq_enable function pointer or if returned | |
466 | * -EINVAL to signal that it has been configured without | |
467 | * interrupts or that are not available at the moment. | |
468 | */ | |
469 | if (err == -EINVAL) | |
470 | err = rtc_dev_update_irq_enable_emul(rtc, enabled); | |
471 | #endif | |
099e6576 | 472 | return err; |
6610e089 | 473 | |
099e6576 AZ |
474 | } |
475 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
476 | ||
6610e089 | 477 | |
d728b1e6 | 478 | /** |
6610e089 JS |
479 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
480 | * @rtc: pointer to the rtc device | |
481 | * | |
482 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 483 | * has occurred (or been emulated). |
6610e089 JS |
484 | * |
485 | * Triggers the registered irq_task function callback. | |
d728b1e6 | 486 | */ |
456d66ec | 487 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 488 | { |
e6229bec AN |
489 | unsigned long flags; |
490 | ||
6610e089 | 491 | /* mark one irq of the appropriate mode */ |
e6229bec | 492 | spin_lock_irqsave(&rtc->irq_lock, flags); |
6610e089 | 493 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); |
e6229bec | 494 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 495 | |
6610e089 | 496 | /* call the task func */ |
e6229bec | 497 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
498 | if (rtc->irq_task) |
499 | rtc->irq_task->func(rtc->irq_task->private_data); | |
e6229bec | 500 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
501 | |
502 | wake_up_interruptible(&rtc->irq_queue); | |
503 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
504 | } | |
6610e089 JS |
505 | |
506 | ||
507 | /** | |
508 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
509 | * @private: pointer to the rtc_device | |
510 | * | |
511 | * This functions is called when the aie_timer expires. | |
512 | */ | |
513 | void rtc_aie_update_irq(void *private) | |
514 | { | |
515 | struct rtc_device *rtc = (struct rtc_device *)private; | |
516 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); | |
517 | } | |
518 | ||
519 | ||
520 | /** | |
521 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
522 | * @private: pointer to the rtc_device | |
523 | * | |
524 | * This functions is called when the uie_timer expires. | |
525 | */ | |
526 | void rtc_uie_update_irq(void *private) | |
527 | { | |
528 | struct rtc_device *rtc = (struct rtc_device *)private; | |
529 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); | |
530 | } | |
531 | ||
532 | ||
533 | /** | |
534 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
535 | * @timer: pointer to the pie mode hrtimer | |
536 | * | |
537 | * This function is used to emulate PIE mode interrupts | |
538 | * using an hrtimer. This function is called when the periodic | |
539 | * hrtimer expires. | |
540 | */ | |
541 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
542 | { | |
543 | struct rtc_device *rtc; | |
544 | ktime_t period; | |
545 | int count; | |
546 | rtc = container_of(timer, struct rtc_device, pie_timer); | |
547 | ||
548 | period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); | |
549 | count = hrtimer_forward_now(timer, period); | |
550 | ||
551 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
552 | ||
553 | return HRTIMER_RESTART; | |
554 | } | |
555 | ||
556 | /** | |
557 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
558 | * @rtc: the rtc device | |
559 | * @num: how many irqs are being reported (usually one) | |
560 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
561 | * Context: any | |
562 | */ | |
563 | void rtc_update_irq(struct rtc_device *rtc, | |
564 | unsigned long num, unsigned long events) | |
565 | { | |
566 | schedule_work(&rtc->irqwork); | |
567 | } | |
0c86edc0 AZ |
568 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
569 | ||
71da8905 DY |
570 | static int __rtc_match(struct device *dev, void *data) |
571 | { | |
572 | char *name = (char *)data; | |
573 | ||
d4afc76c | 574 | if (strcmp(dev_name(dev), name) == 0) |
71da8905 DY |
575 | return 1; |
576 | return 0; | |
577 | } | |
578 | ||
ab6a2d70 | 579 | struct rtc_device *rtc_class_open(char *name) |
0c86edc0 | 580 | { |
cd966209 | 581 | struct device *dev; |
ab6a2d70 | 582 | struct rtc_device *rtc = NULL; |
0c86edc0 | 583 | |
695794ae | 584 | dev = class_find_device(rtc_class, NULL, name, __rtc_match); |
71da8905 DY |
585 | if (dev) |
586 | rtc = to_rtc_device(dev); | |
0c86edc0 | 587 | |
ab6a2d70 DB |
588 | if (rtc) { |
589 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 590 | put_device(dev); |
ab6a2d70 DB |
591 | rtc = NULL; |
592 | } | |
0c86edc0 | 593 | } |
0c86edc0 | 594 | |
ab6a2d70 | 595 | return rtc; |
0c86edc0 AZ |
596 | } |
597 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
598 | ||
ab6a2d70 | 599 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 600 | { |
ab6a2d70 | 601 | module_put(rtc->owner); |
cd966209 | 602 | put_device(&rtc->dev); |
0c86edc0 AZ |
603 | } |
604 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
605 | ||
ab6a2d70 | 606 | int rtc_irq_register(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 AZ |
607 | { |
608 | int retval = -EBUSY; | |
0c86edc0 AZ |
609 | |
610 | if (task == NULL || task->func == NULL) | |
611 | return -EINVAL; | |
612 | ||
d691eb90 | 613 | /* Cannot register while the char dev is in use */ |
372a302e | 614 | if (test_and_set_bit_lock(RTC_DEV_BUSY, &rtc->flags)) |
d691eb90 AZ |
615 | return -EBUSY; |
616 | ||
d728b1e6 | 617 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
618 | if (rtc->irq_task == NULL) { |
619 | rtc->irq_task = task; | |
620 | retval = 0; | |
621 | } | |
d728b1e6 | 622 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 | 623 | |
372a302e | 624 | clear_bit_unlock(RTC_DEV_BUSY, &rtc->flags); |
d691eb90 | 625 | |
0c86edc0 AZ |
626 | return retval; |
627 | } | |
628 | EXPORT_SYMBOL_GPL(rtc_irq_register); | |
629 | ||
ab6a2d70 | 630 | void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) |
0c86edc0 | 631 | { |
d728b1e6 | 632 | spin_lock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
633 | if (rtc->irq_task == task) |
634 | rtc->irq_task = NULL; | |
d728b1e6 | 635 | spin_unlock_irq(&rtc->irq_task_lock); |
0c86edc0 AZ |
636 | } |
637 | EXPORT_SYMBOL_GPL(rtc_irq_unregister); | |
638 | ||
3c8bb90e TG |
639 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
640 | { | |
641 | /* | |
642 | * We always cancel the timer here first, because otherwise | |
643 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
644 | * when we manage to start the timer before the callback | |
645 | * returns HRTIMER_RESTART. | |
646 | * | |
647 | * We cannot use hrtimer_cancel() here as a running callback | |
648 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
649 | * would spin forever. | |
650 | */ | |
651 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
652 | return -1; | |
653 | ||
654 | if (enabled) { | |
655 | ktime_t period = ktime_set(0, NSEC_PER_SEC / rtc->irq_freq); | |
656 | ||
657 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
658 | } | |
659 | return 0; | |
660 | } | |
661 | ||
97144c67 DB |
662 | /** |
663 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
664 | * @rtc: the rtc device | |
665 | * @task: currently registered with rtc_irq_register() | |
666 | * @enabled: true to enable periodic IRQs | |
667 | * Context: any | |
668 | * | |
669 | * Note that rtc_irq_set_freq() should previously have been used to | |
670 | * specify the desired frequency of periodic IRQ task->func() callbacks. | |
671 | */ | |
ab6a2d70 | 672 | int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) |
0c86edc0 AZ |
673 | { |
674 | int err = 0; | |
675 | unsigned long flags; | |
0c86edc0 | 676 | |
3c8bb90e | 677 | retry: |
0c86edc0 | 678 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
679 | if (rtc->irq_task != NULL && task == NULL) |
680 | err = -EBUSY; | |
0c86edc0 | 681 | if (rtc->irq_task != task) |
d691eb90 | 682 | err = -EACCES; |
3c8bb90e TG |
683 | if (!err) { |
684 | if (rtc_update_hrtimer(rtc, enabled) < 0) { | |
685 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
686 | cpu_relax(); | |
687 | goto retry; | |
688 | } | |
689 | rtc->pie_enabled = enabled; | |
6610e089 | 690 | } |
6610e089 | 691 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
692 | return err; |
693 | } | |
694 | EXPORT_SYMBOL_GPL(rtc_irq_set_state); | |
695 | ||
97144c67 DB |
696 | /** |
697 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
698 | * @rtc: the rtc device | |
699 | * @task: currently registered with rtc_irq_register() | |
700 | * @freq: positive frequency with which task->func() will be called | |
701 | * Context: any | |
702 | * | |
703 | * Note that rtc_irq_set_state() is used to enable or disable the | |
704 | * periodic IRQs. | |
705 | */ | |
ab6a2d70 | 706 | int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) |
0c86edc0 | 707 | { |
56f10c63 | 708 | int err = 0; |
0c86edc0 | 709 | unsigned long flags; |
0c86edc0 | 710 | |
6e7a333e | 711 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 712 | return -EINVAL; |
3c8bb90e | 713 | retry: |
0c86edc0 | 714 | spin_lock_irqsave(&rtc->irq_task_lock, flags); |
d691eb90 AZ |
715 | if (rtc->irq_task != NULL && task == NULL) |
716 | err = -EBUSY; | |
0c86edc0 | 717 | if (rtc->irq_task != task) |
d691eb90 | 718 | err = -EACCES; |
3c8bb90e | 719 | if (!err) { |
6610e089 | 720 | rtc->irq_freq = freq; |
3c8bb90e TG |
721 | if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { |
722 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); | |
723 | cpu_relax(); | |
724 | goto retry; | |
6610e089 | 725 | } |
0c86edc0 | 726 | } |
6610e089 | 727 | spin_unlock_irqrestore(&rtc->irq_task_lock, flags); |
0c86edc0 AZ |
728 | return err; |
729 | } | |
2601a464 | 730 | EXPORT_SYMBOL_GPL(rtc_irq_set_freq); |
6610e089 JS |
731 | |
732 | /** | |
96c8f06a | 733 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
6610e089 JS |
734 | * @rtc rtc device |
735 | * @timer timer being added. | |
736 | * | |
737 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
738 | * the next alarm event appropriately. | |
739 | * | |
aa0be0f4 JS |
740 | * Sets the enabled bit on the added timer. |
741 | * | |
6610e089 JS |
742 | * Must hold ops_lock for proper serialization of timerqueue |
743 | */ | |
aa0be0f4 | 744 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 745 | { |
aa0be0f4 | 746 | timer->enabled = 1; |
6610e089 JS |
747 | timerqueue_add(&rtc->timerqueue, &timer->node); |
748 | if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { | |
749 | struct rtc_wkalrm alarm; | |
750 | int err; | |
751 | alarm.time = rtc_ktime_to_tm(timer->node.expires); | |
752 | alarm.enabled = 1; | |
753 | err = __rtc_set_alarm(rtc, &alarm); | |
754 | if (err == -ETIME) | |
755 | schedule_work(&rtc->irqwork); | |
aa0be0f4 JS |
756 | else if (err) { |
757 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
758 | timer->enabled = 0; | |
759 | return err; | |
760 | } | |
6610e089 | 761 | } |
aa0be0f4 | 762 | return 0; |
6610e089 JS |
763 | } |
764 | ||
765 | /** | |
96c8f06a | 766 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
6610e089 JS |
767 | * @rtc rtc device |
768 | * @timer timer being removed. | |
769 | * | |
770 | * Removes a timer onto the rtc devices timerqueue and sets | |
771 | * the next alarm event appropriately. | |
772 | * | |
aa0be0f4 JS |
773 | * Clears the enabled bit on the removed timer. |
774 | * | |
6610e089 JS |
775 | * Must hold ops_lock for proper serialization of timerqueue |
776 | */ | |
aa0be0f4 | 777 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
778 | { |
779 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
780 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
aa0be0f4 | 781 | timer->enabled = 0; |
6610e089 JS |
782 | if (next == &timer->node) { |
783 | struct rtc_wkalrm alarm; | |
784 | int err; | |
785 | next = timerqueue_getnext(&rtc->timerqueue); | |
786 | if (!next) | |
787 | return; | |
788 | alarm.time = rtc_ktime_to_tm(next->expires); | |
789 | alarm.enabled = 1; | |
790 | err = __rtc_set_alarm(rtc, &alarm); | |
791 | if (err == -ETIME) | |
792 | schedule_work(&rtc->irqwork); | |
793 | } | |
794 | } | |
795 | ||
796 | /** | |
96c8f06a | 797 | * rtc_timer_do_work - Expires rtc timers |
6610e089 JS |
798 | * @rtc rtc device |
799 | * @timer timer being removed. | |
800 | * | |
801 | * Expires rtc timers. Reprograms next alarm event if needed. | |
802 | * Called via worktask. | |
803 | * | |
804 | * Serializes access to timerqueue via ops_lock mutex | |
805 | */ | |
96c8f06a | 806 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
807 | { |
808 | struct rtc_timer *timer; | |
809 | struct timerqueue_node *next; | |
810 | ktime_t now; | |
811 | struct rtc_time tm; | |
812 | ||
813 | struct rtc_device *rtc = | |
814 | container_of(work, struct rtc_device, irqwork); | |
815 | ||
816 | mutex_lock(&rtc->ops_lock); | |
817 | again: | |
818 | __rtc_read_time(rtc, &tm); | |
819 | now = rtc_tm_to_ktime(tm); | |
820 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
821 | if (next->expires.tv64 > now.tv64) | |
822 | break; | |
823 | ||
824 | /* expire timer */ | |
825 | timer = container_of(next, struct rtc_timer, node); | |
826 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
827 | timer->enabled = 0; | |
828 | if (timer->task.func) | |
829 | timer->task.func(timer->task.private_data); | |
830 | ||
831 | /* Re-add/fwd periodic timers */ | |
832 | if (ktime_to_ns(timer->period)) { | |
833 | timer->node.expires = ktime_add(timer->node.expires, | |
834 | timer->period); | |
835 | timer->enabled = 1; | |
836 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
837 | } | |
838 | } | |
839 | ||
840 | /* Set next alarm */ | |
841 | if (next) { | |
842 | struct rtc_wkalrm alarm; | |
843 | int err; | |
844 | alarm.time = rtc_ktime_to_tm(next->expires); | |
845 | alarm.enabled = 1; | |
846 | err = __rtc_set_alarm(rtc, &alarm); | |
847 | if (err == -ETIME) | |
848 | goto again; | |
849 | } | |
850 | ||
851 | mutex_unlock(&rtc->ops_lock); | |
852 | } | |
853 | ||
854 | ||
96c8f06a | 855 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
856 | * @timer: timer to be intiialized |
857 | * @f: function pointer to be called when timer fires | |
858 | * @data: private data passed to function pointer | |
859 | * | |
860 | * Kernel interface to initializing an rtc_timer. | |
861 | */ | |
96c8f06a | 862 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(void* p), void* data) |
6610e089 JS |
863 | { |
864 | timerqueue_init(&timer->node); | |
865 | timer->enabled = 0; | |
866 | timer->task.func = f; | |
867 | timer->task.private_data = data; | |
868 | } | |
869 | ||
96c8f06a | 870 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
871 | * @ rtc: rtc device to be used |
872 | * @ timer: timer being set | |
873 | * @ expires: time at which to expire the timer | |
874 | * @ period: period that the timer will recur | |
875 | * | |
876 | * Kernel interface to set an rtc_timer | |
877 | */ | |
96c8f06a | 878 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer* timer, |
6610e089 JS |
879 | ktime_t expires, ktime_t period) |
880 | { | |
881 | int ret = 0; | |
882 | mutex_lock(&rtc->ops_lock); | |
883 | if (timer->enabled) | |
96c8f06a | 884 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
885 | |
886 | timer->node.expires = expires; | |
887 | timer->period = period; | |
888 | ||
aa0be0f4 | 889 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
890 | |
891 | mutex_unlock(&rtc->ops_lock); | |
892 | return ret; | |
893 | } | |
894 | ||
96c8f06a | 895 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
896 | * @ rtc: rtc device to be used |
897 | * @ timer: timer being set | |
898 | * | |
899 | * Kernel interface to cancel an rtc_timer | |
900 | */ | |
96c8f06a | 901 | int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer* timer) |
6610e089 JS |
902 | { |
903 | int ret = 0; | |
904 | mutex_lock(&rtc->ops_lock); | |
905 | if (timer->enabled) | |
96c8f06a | 906 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
907 | mutex_unlock(&rtc->ops_lock); |
908 | return ret; | |
909 | } | |
910 | ||
911 |