Commit | Line | Data |
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cdf7545a | 1 | // SPDX-License-Identifier: GPL-2.0 |
0c86edc0 AZ |
2 | /* |
3 | * RTC subsystem, interface functions | |
4 | * | |
5 | * Copyright (C) 2005 Tower Technologies | |
6 | * Author: Alessandro Zummo <a.zummo@towertech.it> | |
7 | * | |
8 | * based on arch/arm/common/rtctime.c | |
cdf7545a | 9 | */ |
0c86edc0 AZ |
10 | |
11 | #include <linux/rtc.h> | |
d43c36dc | 12 | #include <linux/sched.h> |
2113852b | 13 | #include <linux/module.h> |
97144c67 | 14 | #include <linux/log2.h> |
6610e089 | 15 | #include <linux/workqueue.h> |
0c86edc0 | 16 | |
29a1f599 BW |
17 | #define CREATE_TRACE_POINTS |
18 | #include <trace/events/rtc.h> | |
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 | ||
98951564 BW |
23 | static void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm) |
24 | { | |
25 | time64_t secs; | |
26 | ||
27 | if (!rtc->offset_secs) | |
28 | return; | |
29 | ||
30 | secs = rtc_tm_to_time64(tm); | |
31 | ||
32 | /* | |
33 | * Since the reading time values from RTC device are always in the RTC | |
34 | * original valid range, but we need to skip the overlapped region | |
35 | * between expanded range and original range, which is no need to add | |
36 | * the offset. | |
37 | */ | |
38 | if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) || | |
39 | (rtc->start_secs < rtc->range_min && | |
40 | secs <= (rtc->start_secs + rtc->range_max - rtc->range_min))) | |
41 | return; | |
42 | ||
43 | rtc_time64_to_tm(secs + rtc->offset_secs, tm); | |
44 | } | |
45 | ||
46 | static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm) | |
47 | { | |
48 | time64_t secs; | |
49 | ||
50 | if (!rtc->offset_secs) | |
51 | return; | |
52 | ||
53 | secs = rtc_tm_to_time64(tm); | |
54 | ||
55 | /* | |
56 | * If the setting time values are in the valid range of RTC hardware | |
57 | * device, then no need to subtract the offset when setting time to RTC | |
58 | * device. Otherwise we need to subtract the offset to make the time | |
59 | * values are valid for RTC hardware device. | |
60 | */ | |
61 | if (secs >= rtc->range_min && secs <= rtc->range_max) | |
62 | return; | |
63 | ||
64 | rtc_time64_to_tm(secs - rtc->offset_secs, tm); | |
65 | } | |
66 | ||
4c4e5df1 BW |
67 | static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm) |
68 | { | |
69 | if (rtc->range_min != rtc->range_max) { | |
70 | time64_t time = rtc_tm_to_time64(tm); | |
98951564 BW |
71 | time64_t range_min = rtc->set_start_time ? rtc->start_secs : |
72 | rtc->range_min; | |
eaa6ef56 | 73 | timeu64_t range_max = rtc->set_start_time ? |
98951564 BW |
74 | (rtc->start_secs + rtc->range_max - rtc->range_min) : |
75 | rtc->range_max; | |
4c4e5df1 | 76 | |
98951564 | 77 | if (time < range_min || time > range_max) |
4c4e5df1 BW |
78 | return -ERANGE; |
79 | } | |
80 | ||
81 | return 0; | |
82 | } | |
83 | ||
6610e089 | 84 | static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 AZ |
85 | { |
86 | int err; | |
606cc43c AB |
87 | |
88 | if (!rtc->ops) { | |
0c86edc0 | 89 | err = -ENODEV; |
606cc43c | 90 | } else if (!rtc->ops->read_time) { |
0c86edc0 | 91 | err = -EINVAL; |
606cc43c | 92 | } else { |
0c86edc0 | 93 | memset(tm, 0, sizeof(struct rtc_time)); |
cd966209 | 94 | err = rtc->ops->read_time(rtc->dev.parent, tm); |
16682c86 | 95 | if (err < 0) { |
d0bddb51 AK |
96 | dev_dbg(&rtc->dev, "read_time: fail to read: %d\n", |
97 | err); | |
16682c86 HG |
98 | return err; |
99 | } | |
100 | ||
98951564 BW |
101 | rtc_add_offset(rtc, tm); |
102 | ||
16682c86 HG |
103 | err = rtc_valid_tm(tm); |
104 | if (err < 0) | |
d0bddb51 | 105 | dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n"); |
0c86edc0 | 106 | } |
6610e089 JS |
107 | return err; |
108 | } | |
109 | ||
110 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) | |
111 | { | |
112 | int err; | |
0c86edc0 | 113 | |
6610e089 JS |
114 | err = mutex_lock_interruptible(&rtc->ops_lock); |
115 | if (err) | |
116 | return err; | |
117 | ||
118 | err = __rtc_read_time(rtc, tm); | |
0c86edc0 | 119 | mutex_unlock(&rtc->ops_lock); |
29a1f599 BW |
120 | |
121 | trace_rtc_read_time(rtc_tm_to_time64(tm), err); | |
0c86edc0 AZ |
122 | return err; |
123 | } | |
124 | EXPORT_SYMBOL_GPL(rtc_read_time); | |
125 | ||
ab6a2d70 | 126 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) |
0c86edc0 | 127 | { |
7e7c005b | 128 | int err, uie; |
0c86edc0 AZ |
129 | |
130 | err = rtc_valid_tm(tm); | |
131 | if (err != 0) | |
132 | return err; | |
133 | ||
4c4e5df1 BW |
134 | err = rtc_valid_range(rtc, tm); |
135 | if (err) | |
136 | return err; | |
71db049e | 137 | |
98951564 BW |
138 | rtc_subtract_offset(rtc, tm); |
139 | ||
7e7c005b AB |
140 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
141 | uie = rtc->uie_rtctimer.enabled || rtc->uie_irq_active; | |
142 | #else | |
143 | uie = rtc->uie_rtctimer.enabled; | |
144 | #endif | |
145 | if (uie) { | |
146 | err = rtc_update_irq_enable(rtc, 0); | |
147 | if (err) | |
148 | return err; | |
149 | } | |
150 | ||
0c86edc0 AZ |
151 | err = mutex_lock_interruptible(&rtc->ops_lock); |
152 | if (err) | |
b68bb263 | 153 | return err; |
0c86edc0 AZ |
154 | |
155 | if (!rtc->ops) | |
156 | err = -ENODEV; | |
bbccf83f | 157 | else if (rtc->ops->set_time) |
cd966209 | 158 | err = rtc->ops->set_time(rtc->dev.parent, tm); |
606cc43c | 159 | else |
bbccf83f | 160 | err = -EINVAL; |
0c86edc0 | 161 | |
14d0e347 | 162 | pm_stay_awake(rtc->dev.parent); |
0c86edc0 | 163 | mutex_unlock(&rtc->ops_lock); |
5f9679d2 N |
164 | /* A timer might have just expired */ |
165 | schedule_work(&rtc->irqwork); | |
29a1f599 | 166 | |
7e7c005b AB |
167 | if (uie) { |
168 | err = rtc_update_irq_enable(rtc, 1); | |
169 | if (err) | |
170 | return err; | |
171 | } | |
172 | ||
29a1f599 | 173 | trace_rtc_set_time(rtc_tm_to_time64(tm), err); |
0c86edc0 AZ |
174 | return err; |
175 | } | |
176 | EXPORT_SYMBOL_GPL(rtc_set_time); | |
177 | ||
606cc43c AB |
178 | static int rtc_read_alarm_internal(struct rtc_device *rtc, |
179 | struct rtc_wkalrm *alarm) | |
f44f7f96 JS |
180 | { |
181 | int err; | |
182 | ||
183 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
184 | if (err) | |
185 | return err; | |
186 | ||
606cc43c | 187 | if (!rtc->ops) { |
f44f7f96 | 188 | err = -ENODEV; |
7ae41220 | 189 | } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->read_alarm) { |
f44f7f96 | 190 | err = -EINVAL; |
606cc43c | 191 | } else { |
d68778b8 UKK |
192 | alarm->enabled = 0; |
193 | alarm->pending = 0; | |
194 | alarm->time.tm_sec = -1; | |
195 | alarm->time.tm_min = -1; | |
196 | alarm->time.tm_hour = -1; | |
197 | alarm->time.tm_mday = -1; | |
198 | alarm->time.tm_mon = -1; | |
199 | alarm->time.tm_year = -1; | |
200 | alarm->time.tm_wday = -1; | |
201 | alarm->time.tm_yday = -1; | |
202 | alarm->time.tm_isdst = -1; | |
f44f7f96 JS |
203 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm); |
204 | } | |
205 | ||
206 | mutex_unlock(&rtc->ops_lock); | |
29a1f599 BW |
207 | |
208 | trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err); | |
f44f7f96 JS |
209 | return err; |
210 | } | |
211 | ||
212 | int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
213 | { | |
214 | int err; | |
215 | struct rtc_time before, now; | |
216 | int first_time = 1; | |
bc10aa93 | 217 | time64_t t_now, t_alm; |
f44f7f96 | 218 | enum { none, day, month, year } missing = none; |
606cc43c | 219 | unsigned int days; |
f44f7f96 JS |
220 | |
221 | /* The lower level RTC driver may return -1 in some fields, | |
222 | * creating invalid alarm->time values, for reasons like: | |
223 | * | |
224 | * - The hardware may not be capable of filling them in; | |
225 | * many alarms match only on time-of-day fields, not | |
226 | * day/month/year calendar data. | |
227 | * | |
228 | * - Some hardware uses illegal values as "wildcard" match | |
229 | * values, which non-Linux firmware (like a BIOS) may try | |
230 | * to set up as e.g. "alarm 15 minutes after each hour". | |
231 | * Linux uses only oneshot alarms. | |
232 | * | |
233 | * When we see that here, we deal with it by using values from | |
234 | * a current RTC timestamp for any missing (-1) values. The | |
235 | * RTC driver prevents "periodic alarm" modes. | |
236 | * | |
237 | * But this can be racey, because some fields of the RTC timestamp | |
238 | * may have wrapped in the interval since we read the RTC alarm, | |
239 | * which would lead to us inserting inconsistent values in place | |
240 | * of the -1 fields. | |
241 | * | |
242 | * Reading the alarm and timestamp in the reverse sequence | |
243 | * would have the same race condition, and not solve the issue. | |
244 | * | |
245 | * So, we must first read the RTC timestamp, | |
246 | * then read the RTC alarm value, | |
247 | * and then read a second RTC timestamp. | |
248 | * | |
249 | * If any fields of the second timestamp have changed | |
250 | * when compared with the first timestamp, then we know | |
251 | * our timestamp may be inconsistent with that used by | |
252 | * the low-level rtc_read_alarm_internal() function. | |
253 | * | |
254 | * So, when the two timestamps disagree, we just loop and do | |
255 | * the process again to get a fully consistent set of values. | |
256 | * | |
257 | * This could all instead be done in the lower level driver, | |
258 | * but since more than one lower level RTC implementation needs it, | |
b9354487 | 259 | * then it's probably best to do it here instead of there.. |
f44f7f96 JS |
260 | */ |
261 | ||
262 | /* Get the "before" timestamp */ | |
263 | err = rtc_read_time(rtc, &before); | |
264 | if (err < 0) | |
265 | return err; | |
266 | do { | |
267 | if (!first_time) | |
268 | memcpy(&before, &now, sizeof(struct rtc_time)); | |
269 | first_time = 0; | |
270 | ||
271 | /* get the RTC alarm values, which may be incomplete */ | |
272 | err = rtc_read_alarm_internal(rtc, alarm); | |
273 | if (err) | |
274 | return err; | |
275 | ||
276 | /* full-function RTCs won't have such missing fields */ | |
fd6792bb AB |
277 | if (rtc_valid_tm(&alarm->time) == 0) { |
278 | rtc_add_offset(rtc, &alarm->time); | |
f44f7f96 | 279 | return 0; |
fd6792bb | 280 | } |
f44f7f96 JS |
281 | |
282 | /* get the "after" timestamp, to detect wrapped fields */ | |
283 | err = rtc_read_time(rtc, &now); | |
284 | if (err < 0) | |
285 | return err; | |
286 | ||
287 | /* note that tm_sec is a "don't care" value here: */ | |
606cc43c AB |
288 | } while (before.tm_min != now.tm_min || |
289 | before.tm_hour != now.tm_hour || | |
290 | before.tm_mon != now.tm_mon || | |
291 | before.tm_year != now.tm_year); | |
f44f7f96 JS |
292 | |
293 | /* Fill in the missing alarm fields using the timestamp; we | |
294 | * know there's at least one since alarm->time is invalid. | |
295 | */ | |
296 | if (alarm->time.tm_sec == -1) | |
297 | alarm->time.tm_sec = now.tm_sec; | |
298 | if (alarm->time.tm_min == -1) | |
299 | alarm->time.tm_min = now.tm_min; | |
300 | if (alarm->time.tm_hour == -1) | |
301 | alarm->time.tm_hour = now.tm_hour; | |
302 | ||
303 | /* For simplicity, only support date rollover for now */ | |
e74a8f2e | 304 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { |
f44f7f96 JS |
305 | alarm->time.tm_mday = now.tm_mday; |
306 | missing = day; | |
307 | } | |
606cc43c | 308 | if ((unsigned int)alarm->time.tm_mon >= 12) { |
f44f7f96 JS |
309 | alarm->time.tm_mon = now.tm_mon; |
310 | if (missing == none) | |
311 | missing = month; | |
312 | } | |
313 | if (alarm->time.tm_year == -1) { | |
314 | alarm->time.tm_year = now.tm_year; | |
315 | if (missing == none) | |
316 | missing = year; | |
317 | } | |
318 | ||
da96aea0 VJ |
319 | /* Can't proceed if alarm is still invalid after replacing |
320 | * missing fields. | |
321 | */ | |
322 | err = rtc_valid_tm(&alarm->time); | |
323 | if (err) | |
324 | goto done; | |
325 | ||
f44f7f96 | 326 | /* with luck, no rollover is needed */ |
bc10aa93 XP |
327 | t_now = rtc_tm_to_time64(&now); |
328 | t_alm = rtc_tm_to_time64(&alarm->time); | |
f44f7f96 JS |
329 | if (t_now < t_alm) |
330 | goto done; | |
331 | ||
332 | switch (missing) { | |
f44f7f96 JS |
333 | /* 24 hour rollover ... if it's now 10am Monday, an alarm that |
334 | * that will trigger at 5am will do so at 5am Tuesday, which | |
335 | * could also be in the next month or year. This is a common | |
336 | * case, especially for PCs. | |
337 | */ | |
338 | case day: | |
339 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); | |
340 | t_alm += 24 * 60 * 60; | |
bc10aa93 | 341 | rtc_time64_to_tm(t_alm, &alarm->time); |
f44f7f96 JS |
342 | break; |
343 | ||
344 | /* Month rollover ... if it's the 31th, an alarm on the 3rd will | |
345 | * be next month. An alarm matching on the 30th, 29th, or 28th | |
346 | * may end up in the month after that! Many newer PCs support | |
347 | * this type of alarm. | |
348 | */ | |
349 | case month: | |
350 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); | |
351 | do { | |
606cc43c | 352 | if (alarm->time.tm_mon < 11) { |
f44f7f96 | 353 | alarm->time.tm_mon++; |
606cc43c | 354 | } else { |
f44f7f96 JS |
355 | alarm->time.tm_mon = 0; |
356 | alarm->time.tm_year++; | |
357 | } | |
358 | days = rtc_month_days(alarm->time.tm_mon, | |
606cc43c | 359 | alarm->time.tm_year); |
f44f7f96 JS |
360 | } while (days < alarm->time.tm_mday); |
361 | break; | |
362 | ||
363 | /* Year rollover ... easy except for leap years! */ | |
364 | case year: | |
365 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); | |
366 | do { | |
367 | alarm->time.tm_year++; | |
606cc43c AB |
368 | } while (!is_leap_year(alarm->time.tm_year + 1900) && |
369 | rtc_valid_tm(&alarm->time) != 0); | |
f44f7f96 JS |
370 | break; |
371 | ||
372 | default: | |
373 | dev_warn(&rtc->dev, "alarm rollover not handled\n"); | |
374 | } | |
375 | ||
ee1d9014 AN |
376 | err = rtc_valid_tm(&alarm->time); |
377 | ||
da96aea0 | 378 | done: |
348c11a7 | 379 | if (err && alarm->enabled) |
606cc43c AB |
380 | dev_warn(&rtc->dev, "invalid alarm value: %ptR\n", |
381 | &alarm->time); | |
ee1d9014 AN |
382 | |
383 | return err; | |
f44f7f96 JS |
384 | } |
385 | ||
6610e089 | 386 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 AZ |
387 | { |
388 | int err; | |
0c86edc0 AZ |
389 | |
390 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
391 | if (err) | |
b68bb263 | 392 | return err; |
606cc43c | 393 | if (!rtc->ops) { |
d5553a55 | 394 | err = -ENODEV; |
a783c962 | 395 | } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) { |
d5553a55 | 396 | err = -EINVAL; |
606cc43c | 397 | } else { |
d5553a55 JS |
398 | memset(alarm, 0, sizeof(struct rtc_wkalrm)); |
399 | alarm->enabled = rtc->aie_timer.enabled; | |
6610e089 | 400 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); |
d5553a55 | 401 | } |
0c86edc0 | 402 | mutex_unlock(&rtc->ops_lock); |
6610e089 | 403 | |
29a1f599 | 404 | trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err); |
d5553a55 | 405 | return err; |
0c86edc0 | 406 | } |
6610e089 | 407 | EXPORT_SYMBOL_GPL(rtc_read_alarm); |
0e36a9a4 | 408 | |
d576fe49 | 409 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0e36a9a4 | 410 | { |
6610e089 | 411 | struct rtc_time tm; |
bc10aa93 | 412 | time64_t now, scheduled; |
0e36a9a4 | 413 | int err; |
0e36a9a4 | 414 | |
6610e089 JS |
415 | err = rtc_valid_tm(&alarm->time); |
416 | if (err) | |
0e36a9a4 | 417 | return err; |
98951564 | 418 | |
bc10aa93 | 419 | scheduled = rtc_tm_to_time64(&alarm->time); |
a01cc657 | 420 | |
6610e089 JS |
421 | /* Make sure we're not setting alarms in the past */ |
422 | err = __rtc_read_time(rtc, &tm); | |
ca6dc2da HG |
423 | if (err) |
424 | return err; | |
bc10aa93 | 425 | now = rtc_tm_to_time64(&tm); |
d87f741d | 426 | |
6610e089 JS |
427 | if (scheduled <= now) |
428 | return -ETIME; | |
429 | /* | |
430 | * XXX - We just checked to make sure the alarm time is not | |
431 | * in the past, but there is still a race window where if | |
432 | * the is alarm set for the next second and the second ticks | |
433 | * over right here, before we set the alarm. | |
a01cc657 | 434 | */ |
a01cc657 | 435 | |
fd6792bb AB |
436 | rtc_subtract_offset(rtc, &alarm->time); |
437 | ||
157e8bf8 LT |
438 | if (!rtc->ops) |
439 | err = -ENODEV; | |
7ae41220 | 440 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) |
157e8bf8 LT |
441 | err = -EINVAL; |
442 | else | |
443 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm); | |
444 | ||
29a1f599 | 445 | trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err); |
157e8bf8 | 446 | return err; |
0e36a9a4 | 447 | } |
0c86edc0 | 448 | |
ab6a2d70 | 449 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) |
0c86edc0 | 450 | { |
d87f741d | 451 | ktime_t alarm_time; |
0c86edc0 | 452 | int err; |
0c86edc0 | 453 | |
abfdff44 AB |
454 | if (!rtc->ops) |
455 | return -ENODEV; | |
7ae41220 | 456 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) |
abfdff44 AB |
457 | return -EINVAL; |
458 | ||
f8245c26 DB |
459 | err = rtc_valid_tm(&alarm->time); |
460 | if (err != 0) | |
461 | return err; | |
462 | ||
4c4e5df1 BW |
463 | err = rtc_valid_range(rtc, &alarm->time); |
464 | if (err) | |
465 | return err; | |
71db049e | 466 | |
0c86edc0 AZ |
467 | err = mutex_lock_interruptible(&rtc->ops_lock); |
468 | if (err) | |
b68bb263 | 469 | return err; |
3ff2e13c | 470 | if (rtc->aie_timer.enabled) |
96c8f06a | 471 | rtc_timer_remove(rtc, &rtc->aie_timer); |
3ff2e13c | 472 | |
d87f741d AB |
473 | alarm_time = rtc_tm_to_ktime(alarm->time); |
474 | /* | |
475 | * Round down so we never miss a deadline, checking for past deadline is | |
476 | * done in __rtc_set_alarm | |
477 | */ | |
478 | if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features)) | |
479 | alarm_time = ktime_sub_ns(alarm_time, (u64)alarm->time.tm_sec * NSEC_PER_SEC); | |
480 | ||
481 | rtc->aie_timer.node.expires = alarm_time; | |
8b0e1953 | 482 | rtc->aie_timer.period = 0; |
3ff2e13c | 483 | if (alarm->enabled) |
aa0be0f4 | 484 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); |
3ff2e13c | 485 | |
0c86edc0 | 486 | mutex_unlock(&rtc->ops_lock); |
98951564 | 487 | |
aa0be0f4 | 488 | return err; |
0c86edc0 AZ |
489 | } |
490 | EXPORT_SYMBOL_GPL(rtc_set_alarm); | |
491 | ||
f6d5b331 JS |
492 | /* Called once per device from rtc_device_register */ |
493 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) | |
494 | { | |
495 | int err; | |
bd729d72 | 496 | struct rtc_time now; |
f6d5b331 JS |
497 | |
498 | err = rtc_valid_tm(&alarm->time); | |
499 | if (err != 0) | |
500 | return err; | |
501 | ||
bd729d72 JS |
502 | err = rtc_read_time(rtc, &now); |
503 | if (err) | |
504 | return err; | |
505 | ||
f6d5b331 JS |
506 | err = mutex_lock_interruptible(&rtc->ops_lock); |
507 | if (err) | |
508 | return err; | |
509 | ||
510 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); | |
8b0e1953 | 511 | rtc->aie_timer.period = 0; |
bd729d72 | 512 | |
6785b3b6 | 513 | /* Alarm has to be enabled & in the future for us to enqueue it */ |
2456e855 TG |
514 | if (alarm->enabled && (rtc_tm_to_ktime(now) < |
515 | rtc->aie_timer.node.expires)) { | |
f6d5b331 JS |
516 | rtc->aie_timer.enabled = 1; |
517 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); | |
29a1f599 | 518 | trace_rtc_timer_enqueue(&rtc->aie_timer); |
f6d5b331 JS |
519 | } |
520 | mutex_unlock(&rtc->ops_lock); | |
521 | return err; | |
522 | } | |
523 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm); | |
524 | ||
099e6576 AZ |
525 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) |
526 | { | |
606cc43c AB |
527 | int err; |
528 | ||
529 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
099e6576 AZ |
530 | if (err) |
531 | return err; | |
532 | ||
6610e089 | 533 | if (rtc->aie_timer.enabled != enabled) { |
aa0be0f4 JS |
534 | if (enabled) |
535 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer); | |
536 | else | |
96c8f06a | 537 | rtc_timer_remove(rtc, &rtc->aie_timer); |
6610e089 JS |
538 | } |
539 | ||
aa0be0f4 | 540 | if (err) |
516373b8 UKK |
541 | /* nothing */; |
542 | else if (!rtc->ops) | |
099e6576 | 543 | err = -ENODEV; |
7ae41220 | 544 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable) |
099e6576 AZ |
545 | err = -EINVAL; |
546 | else | |
547 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); | |
548 | ||
549 | mutex_unlock(&rtc->ops_lock); | |
29a1f599 BW |
550 | |
551 | trace_rtc_alarm_irq_enable(enabled, err); | |
099e6576 AZ |
552 | return err; |
553 | } | |
554 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); | |
555 | ||
556 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) | |
557 | { | |
c55c3a51 | 558 | int err; |
606cc43c AB |
559 | |
560 | err = mutex_lock_interruptible(&rtc->ops_lock); | |
099e6576 AZ |
561 | if (err) |
562 | return err; | |
563 | ||
456d66ec JS |
564 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL |
565 | if (enabled == 0 && rtc->uie_irq_active) { | |
566 | mutex_unlock(&rtc->ops_lock); | |
567 | return rtc_dev_update_irq_enable_emul(rtc, 0); | |
568 | } | |
569 | #endif | |
6610e089 JS |
570 | /* make sure we're changing state */ |
571 | if (rtc->uie_rtctimer.enabled == enabled) | |
572 | goto out; | |
573 | ||
adb17a05 AB |
574 | if (!test_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features) || |
575 | !test_bit(RTC_FEATURE_ALARM, rtc->features)) { | |
c55c3a51 AB |
576 | mutex_unlock(&rtc->ops_lock); |
577 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL | |
578 | return rtc_dev_update_irq_enable_emul(rtc, enabled); | |
579 | #else | |
580 | return -EINVAL; | |
581 | #endif | |
4a649903 JS |
582 | } |
583 | ||
6610e089 JS |
584 | if (enabled) { |
585 | struct rtc_time tm; | |
586 | ktime_t now, onesec; | |
587 | ||
c55c3a51 AB |
588 | err = __rtc_read_time(rtc, &tm); |
589 | if (err) | |
3e74ddaa | 590 | goto out; |
6610e089 JS |
591 | onesec = ktime_set(1, 0); |
592 | now = rtc_tm_to_ktime(tm); | |
593 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); | |
594 | rtc->uie_rtctimer.period = ktime_set(1, 0); | |
aa0be0f4 | 595 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); |
606cc43c | 596 | } else { |
96c8f06a | 597 | rtc_timer_remove(rtc, &rtc->uie_rtctimer); |
606cc43c | 598 | } |
099e6576 | 599 | |
6610e089 | 600 | out: |
099e6576 | 601 | mutex_unlock(&rtc->ops_lock); |
3e74ddaa | 602 | |
099e6576 AZ |
603 | return err; |
604 | } | |
605 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable); | |
606 | ||
d728b1e6 | 607 | /** |
6610e089 JS |
608 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook |
609 | * @rtc: pointer to the rtc device | |
55dcf7a2 AB |
610 | * @num: number of occurence of the event |
611 | * @mode: type of the event, RTC_AF, RTC_UF of RTC_PF | |
6610e089 JS |
612 | * |
613 | * This function is called when an AIE, UIE or PIE mode interrupt | |
25985edc | 614 | * has occurred (or been emulated). |
6610e089 | 615 | * |
d728b1e6 | 616 | */ |
456d66ec | 617 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) |
0c86edc0 | 618 | { |
e6229bec AN |
619 | unsigned long flags; |
620 | ||
6610e089 | 621 | /* mark one irq of the appropriate mode */ |
e6229bec | 622 | spin_lock_irqsave(&rtc->irq_lock, flags); |
606cc43c | 623 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF | mode); |
e6229bec | 624 | spin_unlock_irqrestore(&rtc->irq_lock, flags); |
0c86edc0 | 625 | |
0c86edc0 AZ |
626 | wake_up_interruptible(&rtc->irq_queue); |
627 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); | |
628 | } | |
6610e089 | 629 | |
6610e089 JS |
630 | /** |
631 | * rtc_aie_update_irq - AIE mode rtctimer hook | |
9a032011 | 632 | * @rtc: pointer to the rtc_device |
6610e089 JS |
633 | * |
634 | * This functions is called when the aie_timer expires. | |
635 | */ | |
9a032011 | 636 | void rtc_aie_update_irq(struct rtc_device *rtc) |
6610e089 | 637 | { |
6610e089 JS |
638 | rtc_handle_legacy_irq(rtc, 1, RTC_AF); |
639 | } | |
640 | ||
6610e089 JS |
641 | /** |
642 | * rtc_uie_update_irq - UIE mode rtctimer hook | |
9a032011 | 643 | * @rtc: pointer to the rtc_device |
6610e089 JS |
644 | * |
645 | * This functions is called when the uie_timer expires. | |
646 | */ | |
9a032011 | 647 | void rtc_uie_update_irq(struct rtc_device *rtc) |
6610e089 | 648 | { |
6610e089 JS |
649 | rtc_handle_legacy_irq(rtc, 1, RTC_UF); |
650 | } | |
651 | ||
6610e089 JS |
652 | /** |
653 | * rtc_pie_update_irq - PIE mode hrtimer hook | |
654 | * @timer: pointer to the pie mode hrtimer | |
655 | * | |
656 | * This function is used to emulate PIE mode interrupts | |
657 | * using an hrtimer. This function is called when the periodic | |
658 | * hrtimer expires. | |
659 | */ | |
660 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) | |
661 | { | |
662 | struct rtc_device *rtc; | |
663 | ktime_t period; | |
3126790d | 664 | u64 count; |
606cc43c | 665 | |
6610e089 JS |
666 | rtc = container_of(timer, struct rtc_device, pie_timer); |
667 | ||
8b0e1953 | 668 | period = NSEC_PER_SEC / rtc->irq_freq; |
6610e089 JS |
669 | count = hrtimer_forward_now(timer, period); |
670 | ||
671 | rtc_handle_legacy_irq(rtc, count, RTC_PF); | |
672 | ||
673 | return HRTIMER_RESTART; | |
674 | } | |
675 | ||
676 | /** | |
677 | * rtc_update_irq - Triggered when a RTC interrupt occurs. | |
678 | * @rtc: the rtc device | |
679 | * @num: how many irqs are being reported (usually one) | |
680 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF | |
681 | * Context: any | |
682 | */ | |
683 | void rtc_update_irq(struct rtc_device *rtc, | |
606cc43c | 684 | unsigned long num, unsigned long events) |
6610e089 | 685 | { |
e7cba884 | 686 | if (IS_ERR_OR_NULL(rtc)) |
131c9cc8 AZ |
687 | return; |
688 | ||
7523ceed | 689 | pm_stay_awake(rtc->dev.parent); |
6610e089 JS |
690 | schedule_work(&rtc->irqwork); |
691 | } | |
0c86edc0 AZ |
692 | EXPORT_SYMBOL_GPL(rtc_update_irq); |
693 | ||
9f3b795a | 694 | struct rtc_device *rtc_class_open(const char *name) |
0c86edc0 | 695 | { |
cd966209 | 696 | struct device *dev; |
ab6a2d70 | 697 | struct rtc_device *rtc = NULL; |
0c86edc0 | 698 | |
6cda08a2 | 699 | dev = class_find_device_by_name(rtc_class, name); |
71da8905 DY |
700 | if (dev) |
701 | rtc = to_rtc_device(dev); | |
0c86edc0 | 702 | |
ab6a2d70 DB |
703 | if (rtc) { |
704 | if (!try_module_get(rtc->owner)) { | |
cd966209 | 705 | put_device(dev); |
ab6a2d70 DB |
706 | rtc = NULL; |
707 | } | |
0c86edc0 | 708 | } |
0c86edc0 | 709 | |
ab6a2d70 | 710 | return rtc; |
0c86edc0 AZ |
711 | } |
712 | EXPORT_SYMBOL_GPL(rtc_class_open); | |
713 | ||
ab6a2d70 | 714 | void rtc_class_close(struct rtc_device *rtc) |
0c86edc0 | 715 | { |
ab6a2d70 | 716 | module_put(rtc->owner); |
cd966209 | 717 | put_device(&rtc->dev); |
0c86edc0 AZ |
718 | } |
719 | EXPORT_SYMBOL_GPL(rtc_class_close); | |
720 | ||
3c8bb90e TG |
721 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) |
722 | { | |
723 | /* | |
724 | * We always cancel the timer here first, because otherwise | |
725 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); | |
726 | * when we manage to start the timer before the callback | |
727 | * returns HRTIMER_RESTART. | |
728 | * | |
729 | * We cannot use hrtimer_cancel() here as a running callback | |
730 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel() | |
731 | * would spin forever. | |
732 | */ | |
733 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) | |
734 | return -1; | |
735 | ||
736 | if (enabled) { | |
8b0e1953 | 737 | ktime_t period = NSEC_PER_SEC / rtc->irq_freq; |
3c8bb90e TG |
738 | |
739 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); | |
740 | } | |
741 | return 0; | |
742 | } | |
743 | ||
97144c67 DB |
744 | /** |
745 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs | |
746 | * @rtc: the rtc device | |
97144c67 DB |
747 | * @enabled: true to enable periodic IRQs |
748 | * Context: any | |
749 | * | |
750 | * Note that rtc_irq_set_freq() should previously have been used to | |
acecb3ad | 751 | * specify the desired frequency of periodic IRQ. |
97144c67 | 752 | */ |
8719d3c9 | 753 | int rtc_irq_set_state(struct rtc_device *rtc, int enabled) |
0c86edc0 AZ |
754 | { |
755 | int err = 0; | |
0c86edc0 | 756 | |
acecb3ad AB |
757 | while (rtc_update_hrtimer(rtc, enabled) < 0) |
758 | cpu_relax(); | |
759 | ||
760 | rtc->pie_enabled = enabled; | |
29a1f599 BW |
761 | |
762 | trace_rtc_irq_set_state(enabled, err); | |
0c86edc0 AZ |
763 | return err; |
764 | } | |
0c86edc0 | 765 | |
97144c67 DB |
766 | /** |
767 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ | |
768 | * @rtc: the rtc device | |
acecb3ad | 769 | * @freq: positive frequency |
97144c67 DB |
770 | * Context: any |
771 | * | |
772 | * Note that rtc_irq_set_state() is used to enable or disable the | |
773 | * periodic IRQs. | |
774 | */ | |
8719d3c9 | 775 | int rtc_irq_set_freq(struct rtc_device *rtc, int freq) |
0c86edc0 | 776 | { |
56f10c63 | 777 | int err = 0; |
0c86edc0 | 778 | |
6e7a333e | 779 | if (freq <= 0 || freq > RTC_MAX_FREQ) |
83a06bf5 | 780 | return -EINVAL; |
acecb3ad AB |
781 | |
782 | rtc->irq_freq = freq; | |
783 | while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) | |
784 | cpu_relax(); | |
29a1f599 BW |
785 | |
786 | trace_rtc_irq_set_freq(freq, err); | |
0c86edc0 AZ |
787 | return err; |
788 | } | |
6610e089 JS |
789 | |
790 | /** | |
96c8f06a | 791 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue |
55dcf7a2 AB |
792 | * @rtc: rtc device |
793 | * @timer: timer being added. | |
6610e089 JS |
794 | * |
795 | * Enqueues a timer onto the rtc devices timerqueue and sets | |
796 | * the next alarm event appropriately. | |
797 | * | |
aa0be0f4 JS |
798 | * Sets the enabled bit on the added timer. |
799 | * | |
6610e089 JS |
800 | * Must hold ops_lock for proper serialization of timerqueue |
801 | */ | |
aa0be0f4 | 802 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 803 | { |
2b2f5ff0 CIK |
804 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); |
805 | struct rtc_time tm; | |
806 | ktime_t now; | |
915593a7 TR |
807 | int err; |
808 | ||
809 | err = __rtc_read_time(rtc, &tm); | |
810 | if (err) | |
811 | return err; | |
2b2f5ff0 | 812 | |
aa0be0f4 | 813 | timer->enabled = 1; |
2b2f5ff0 CIK |
814 | now = rtc_tm_to_ktime(tm); |
815 | ||
816 | /* Skip over expired timers */ | |
817 | while (next) { | |
2456e855 | 818 | if (next->expires >= now) |
2b2f5ff0 CIK |
819 | break; |
820 | next = timerqueue_iterate_next(next); | |
821 | } | |
822 | ||
6610e089 | 823 | timerqueue_add(&rtc->timerqueue, &timer->node); |
29a1f599 | 824 | trace_rtc_timer_enqueue(timer); |
74717b28 | 825 | if (!next || ktime_before(timer->node.expires, next->expires)) { |
6610e089 | 826 | struct rtc_wkalrm alarm; |
606cc43c | 827 | |
6610e089 JS |
828 | alarm.time = rtc_ktime_to_tm(timer->node.expires); |
829 | alarm.enabled = 1; | |
830 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
831 | if (err == -ETIME) { |
832 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 833 | schedule_work(&rtc->irqwork); |
14d0e347 | 834 | } else if (err) { |
aa0be0f4 | 835 | timerqueue_del(&rtc->timerqueue, &timer->node); |
29a1f599 | 836 | trace_rtc_timer_dequeue(timer); |
aa0be0f4 JS |
837 | timer->enabled = 0; |
838 | return err; | |
839 | } | |
6610e089 | 840 | } |
aa0be0f4 | 841 | return 0; |
6610e089 JS |
842 | } |
843 | ||
41c7f742 RV |
844 | static void rtc_alarm_disable(struct rtc_device *rtc) |
845 | { | |
7ae41220 | 846 | if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable) |
41c7f742 RV |
847 | return; |
848 | ||
849 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false); | |
29a1f599 | 850 | trace_rtc_alarm_irq_enable(0, 0); |
41c7f742 RV |
851 | } |
852 | ||
6610e089 | 853 | /** |
96c8f06a | 854 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue |
55dcf7a2 AB |
855 | * @rtc: rtc device |
856 | * @timer: timer being removed. | |
6610e089 JS |
857 | * |
858 | * Removes a timer onto the rtc devices timerqueue and sets | |
859 | * the next alarm event appropriately. | |
860 | * | |
aa0be0f4 JS |
861 | * Clears the enabled bit on the removed timer. |
862 | * | |
6610e089 JS |
863 | * Must hold ops_lock for proper serialization of timerqueue |
864 | */ | |
aa0be0f4 | 865 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 JS |
866 | { |
867 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); | |
606cc43c | 868 | |
6610e089 | 869 | timerqueue_del(&rtc->timerqueue, &timer->node); |
29a1f599 | 870 | trace_rtc_timer_dequeue(timer); |
aa0be0f4 | 871 | timer->enabled = 0; |
6610e089 JS |
872 | if (next == &timer->node) { |
873 | struct rtc_wkalrm alarm; | |
874 | int err; | |
606cc43c | 875 | |
6610e089 | 876 | next = timerqueue_getnext(&rtc->timerqueue); |
41c7f742 RV |
877 | if (!next) { |
878 | rtc_alarm_disable(rtc); | |
6610e089 | 879 | return; |
41c7f742 | 880 | } |
6610e089 JS |
881 | alarm.time = rtc_ktime_to_tm(next->expires); |
882 | alarm.enabled = 1; | |
883 | err = __rtc_set_alarm(rtc, &alarm); | |
14d0e347 ZM |
884 | if (err == -ETIME) { |
885 | pm_stay_awake(rtc->dev.parent); | |
6610e089 | 886 | schedule_work(&rtc->irqwork); |
14d0e347 | 887 | } |
6610e089 JS |
888 | } |
889 | } | |
890 | ||
891 | /** | |
96c8f06a | 892 | * rtc_timer_do_work - Expires rtc timers |
55dcf7a2 | 893 | * @work: work item |
6610e089 JS |
894 | * |
895 | * Expires rtc timers. Reprograms next alarm event if needed. | |
896 | * Called via worktask. | |
897 | * | |
898 | * Serializes access to timerqueue via ops_lock mutex | |
899 | */ | |
96c8f06a | 900 | void rtc_timer_do_work(struct work_struct *work) |
6610e089 JS |
901 | { |
902 | struct rtc_timer *timer; | |
903 | struct timerqueue_node *next; | |
904 | ktime_t now; | |
905 | struct rtc_time tm; | |
906 | ||
907 | struct rtc_device *rtc = | |
908 | container_of(work, struct rtc_device, irqwork); | |
909 | ||
910 | mutex_lock(&rtc->ops_lock); | |
911 | again: | |
912 | __rtc_read_time(rtc, &tm); | |
913 | now = rtc_tm_to_ktime(tm); | |
914 | while ((next = timerqueue_getnext(&rtc->timerqueue))) { | |
2456e855 | 915 | if (next->expires > now) |
6610e089 JS |
916 | break; |
917 | ||
918 | /* expire timer */ | |
919 | timer = container_of(next, struct rtc_timer, node); | |
920 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
29a1f599 | 921 | trace_rtc_timer_dequeue(timer); |
6610e089 | 922 | timer->enabled = 0; |
5a5ba10f | 923 | if (timer->func) |
9a032011 | 924 | timer->func(timer->rtc); |
6610e089 | 925 | |
29a1f599 | 926 | trace_rtc_timer_fired(timer); |
6610e089 JS |
927 | /* Re-add/fwd periodic timers */ |
928 | if (ktime_to_ns(timer->period)) { | |
929 | timer->node.expires = ktime_add(timer->node.expires, | |
930 | timer->period); | |
931 | timer->enabled = 1; | |
932 | timerqueue_add(&rtc->timerqueue, &timer->node); | |
29a1f599 | 933 | trace_rtc_timer_enqueue(timer); |
6610e089 JS |
934 | } |
935 | } | |
936 | ||
937 | /* Set next alarm */ | |
938 | if (next) { | |
939 | struct rtc_wkalrm alarm; | |
940 | int err; | |
6528b889 XP |
941 | int retry = 3; |
942 | ||
6610e089 JS |
943 | alarm.time = rtc_ktime_to_tm(next->expires); |
944 | alarm.enabled = 1; | |
6528b889 | 945 | reprogram: |
6610e089 | 946 | err = __rtc_set_alarm(rtc, &alarm); |
606cc43c | 947 | if (err == -ETIME) { |
6610e089 | 948 | goto again; |
606cc43c | 949 | } else if (err) { |
6528b889 XP |
950 | if (retry-- > 0) |
951 | goto reprogram; | |
952 | ||
953 | timer = container_of(next, struct rtc_timer, node); | |
954 | timerqueue_del(&rtc->timerqueue, &timer->node); | |
29a1f599 | 955 | trace_rtc_timer_dequeue(timer); |
6528b889 XP |
956 | timer->enabled = 0; |
957 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); | |
958 | goto again; | |
959 | } | |
606cc43c | 960 | } else { |
41c7f742 | 961 | rtc_alarm_disable(rtc); |
606cc43c | 962 | } |
6610e089 | 963 | |
14d0e347 | 964 | pm_relax(rtc->dev.parent); |
6610e089 JS |
965 | mutex_unlock(&rtc->ops_lock); |
966 | } | |
967 | ||
96c8f06a | 968 | /* rtc_timer_init - Initializes an rtc_timer |
6610e089 JS |
969 | * @timer: timer to be intiialized |
970 | * @f: function pointer to be called when timer fires | |
9a032011 | 971 | * @rtc: pointer to the rtc_device |
6610e089 JS |
972 | * |
973 | * Kernel interface to initializing an rtc_timer. | |
974 | */ | |
9a032011 AB |
975 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r), |
976 | struct rtc_device *rtc) | |
6610e089 JS |
977 | { |
978 | timerqueue_init(&timer->node); | |
979 | timer->enabled = 0; | |
5a5ba10f | 980 | timer->func = f; |
9a032011 | 981 | timer->rtc = rtc; |
6610e089 JS |
982 | } |
983 | ||
96c8f06a | 984 | /* rtc_timer_start - Sets an rtc_timer to fire in the future |
6610e089 JS |
985 | * @ rtc: rtc device to be used |
986 | * @ timer: timer being set | |
987 | * @ expires: time at which to expire the timer | |
988 | * @ period: period that the timer will recur | |
989 | * | |
990 | * Kernel interface to set an rtc_timer | |
991 | */ | |
3ff2e13c | 992 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, |
606cc43c | 993 | ktime_t expires, ktime_t period) |
6610e089 JS |
994 | { |
995 | int ret = 0; | |
606cc43c | 996 | |
6610e089 JS |
997 | mutex_lock(&rtc->ops_lock); |
998 | if (timer->enabled) | |
96c8f06a | 999 | rtc_timer_remove(rtc, timer); |
6610e089 JS |
1000 | |
1001 | timer->node.expires = expires; | |
1002 | timer->period = period; | |
1003 | ||
aa0be0f4 | 1004 | ret = rtc_timer_enqueue(rtc, timer); |
6610e089 JS |
1005 | |
1006 | mutex_unlock(&rtc->ops_lock); | |
1007 | return ret; | |
1008 | } | |
1009 | ||
96c8f06a | 1010 | /* rtc_timer_cancel - Stops an rtc_timer |
6610e089 JS |
1011 | * @ rtc: rtc device to be used |
1012 | * @ timer: timer being set | |
1013 | * | |
1014 | * Kernel interface to cancel an rtc_timer | |
1015 | */ | |
73744a64 | 1016 | void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) |
6610e089 | 1017 | { |
6610e089 JS |
1018 | mutex_lock(&rtc->ops_lock); |
1019 | if (timer->enabled) | |
96c8f06a | 1020 | rtc_timer_remove(rtc, timer); |
6610e089 | 1021 | mutex_unlock(&rtc->ops_lock); |
6610e089 JS |
1022 | } |
1023 | ||
b3967067 JC |
1024 | /** |
1025 | * rtc_read_offset - Read the amount of rtc offset in parts per billion | |
55dcf7a2 AB |
1026 | * @rtc: rtc device to be used |
1027 | * @offset: the offset in parts per billion | |
b3967067 JC |
1028 | * |
1029 | * see below for details. | |
1030 | * | |
1031 | * Kernel interface to read rtc clock offset | |
1032 | * Returns 0 on success, or a negative number on error. | |
1033 | * If read_offset() is not implemented for the rtc, return -EINVAL | |
1034 | */ | |
1035 | int rtc_read_offset(struct rtc_device *rtc, long *offset) | |
1036 | { | |
1037 | int ret; | |
1038 | ||
1039 | if (!rtc->ops) | |
1040 | return -ENODEV; | |
1041 | ||
1042 | if (!rtc->ops->read_offset) | |
1043 | return -EINVAL; | |
1044 | ||
1045 | mutex_lock(&rtc->ops_lock); | |
1046 | ret = rtc->ops->read_offset(rtc->dev.parent, offset); | |
1047 | mutex_unlock(&rtc->ops_lock); | |
29a1f599 BW |
1048 | |
1049 | trace_rtc_read_offset(*offset, ret); | |
b3967067 JC |
1050 | return ret; |
1051 | } | |
6610e089 | 1052 | |
b3967067 JC |
1053 | /** |
1054 | * rtc_set_offset - Adjusts the duration of the average second | |
55dcf7a2 AB |
1055 | * @rtc: rtc device to be used |
1056 | * @offset: the offset in parts per billion | |
b3967067 JC |
1057 | * |
1058 | * Some rtc's allow an adjustment to the average duration of a second | |
1059 | * to compensate for differences in the actual clock rate due to temperature, | |
1060 | * the crystal, capacitor, etc. | |
1061 | * | |
8a25c8f6 RK |
1062 | * The adjustment applied is as follows: |
1063 | * t = t0 * (1 + offset * 1e-9) | |
1064 | * where t0 is the measured length of 1 RTC second with offset = 0 | |
1065 | * | |
b3967067 JC |
1066 | * Kernel interface to adjust an rtc clock offset. |
1067 | * Return 0 on success, or a negative number on error. | |
1068 | * If the rtc offset is not setable (or not implemented), return -EINVAL | |
1069 | */ | |
1070 | int rtc_set_offset(struct rtc_device *rtc, long offset) | |
1071 | { | |
1072 | int ret; | |
1073 | ||
1074 | if (!rtc->ops) | |
1075 | return -ENODEV; | |
1076 | ||
1077 | if (!rtc->ops->set_offset) | |
1078 | return -EINVAL; | |
1079 | ||
1080 | mutex_lock(&rtc->ops_lock); | |
1081 | ret = rtc->ops->set_offset(rtc->dev.parent, offset); | |
1082 | mutex_unlock(&rtc->ops_lock); | |
29a1f599 BW |
1083 | |
1084 | trace_rtc_set_offset(offset, ret); | |
b3967067 JC |
1085 | return ret; |
1086 | } |