| 1 | |
| 2 | |
| 3 | * RTC subsystem, interface functions
|
| 4 | *
|
| 5 | * Copyright (C) 2005 Tower Technologies
|
| 6 | * Author: Alessandro Zummo <[email protected]>
|
| 7 | *
|
| 8 | * based on arch/arm/common/rtctime.c
|
| 9 |
|
| 10 |
|
| 11 | #include <linux/rtc.h>
|
| 12 | #include <linux/sched.h>
|
| 13 | #include <linux/module.h>
|
| 14 | #include <linux/log2.h>
|
| 15 | #include <linux/workqueue.h>
|
| 16 |
|
| 17 | #define CREATE_TRACE_POINTS
|
| 18 | #include <trace/events/rtc.h>
|
| 19 |
|
| 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 |
|
| 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 |
|
| 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);
|
| 71 | time64_t range_min = rtc->set_start_time ? rtc->start_secs :
|
| 72 | rtc->range_min;
|
| 73 | timeu64_t range_max = rtc->set_start_time ?
|
| 74 | (rtc->start_secs + rtc->range_max - rtc->range_min) :
|
| 75 | rtc->range_max;
|
| 76 |
|
| 77 | if (time < range_min || time > range_max)
|
| 78 | return -ERANGE;
|
| 79 | }
|
| 80 |
|
| 81 | return 0;
|
| 82 | }
|
| 83 |
|
| 84 | static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
|
| 85 | {
|
| 86 | int err;
|
| 87 |
|
| 88 | if (!rtc->ops) {
|
| 89 | err = -ENODEV;
|
| 90 | } else if (!rtc->ops->read_time) {
|
| 91 | err = -EINVAL;
|
| 92 | } else {
|
| 93 | memset(tm, 0, sizeof(struct rtc_time));
|
| 94 | err = rtc->ops->read_time(rtc->dev.parent, tm);
|
| 95 | if (err < 0) {
|
| 96 | dev_dbg(&rtc->dev, "read_time: fail to read: %d\n",
|
| 97 | err);
|
| 98 | return err;
|
| 99 | }
|
| 100 |
|
| 101 | rtc_add_offset(rtc, tm);
|
| 102 |
|
| 103 | err = rtc_valid_tm(tm);
|
| 104 | if (err < 0)
|
| 105 | dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n");
|
| 106 | }
|
| 107 | return err;
|
| 108 | }
|
| 109 |
|
| 110 | int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
|
| 111 | {
|
| 112 | int err;
|
| 113 |
|
| 114 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 115 | if (err)
|
| 116 | return err;
|
| 117 |
|
| 118 | err = __rtc_read_time(rtc, tm);
|
| 119 | mutex_unlock(&rtc->ops_lock);
|
| 120 |
|
| 121 | trace_rtc_read_time(rtc_tm_to_time64(tm), err);
|
| 122 | return err;
|
| 123 | }
|
| 124 | EXPORT_SYMBOL_GPL(rtc_read_time);
|
| 125 |
|
| 126 | int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
|
| 127 | {
|
| 128 | int err, uie;
|
| 129 |
|
| 130 | err = rtc_valid_tm(tm);
|
| 131 | if (err != 0)
|
| 132 | return err;
|
| 133 |
|
| 134 | err = rtc_valid_range(rtc, tm);
|
| 135 | if (err)
|
| 136 | return err;
|
| 137 |
|
| 138 | rtc_subtract_offset(rtc, tm);
|
| 139 |
|
| 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 |
|
| 151 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 152 | if (err)
|
| 153 | return err;
|
| 154 |
|
| 155 | if (!rtc->ops)
|
| 156 | err = -ENODEV;
|
| 157 | else if (rtc->ops->set_time)
|
| 158 | err = rtc->ops->set_time(rtc->dev.parent, tm);
|
| 159 | else
|
| 160 | err = -EINVAL;
|
| 161 |
|
| 162 | pm_stay_awake(rtc->dev.parent);
|
| 163 | mutex_unlock(&rtc->ops_lock);
|
| 164 |
|
| 165 | schedule_work(&rtc->irqwork);
|
| 166 |
|
| 167 | if (uie) {
|
| 168 | err = rtc_update_irq_enable(rtc, 1);
|
| 169 | if (err)
|
| 170 | return err;
|
| 171 | }
|
| 172 |
|
| 173 | trace_rtc_set_time(rtc_tm_to_time64(tm), err);
|
| 174 | return err;
|
| 175 | }
|
| 176 | EXPORT_SYMBOL_GPL(rtc_set_time);
|
| 177 |
|
| 178 | static int rtc_read_alarm_internal(struct rtc_device *rtc,
|
| 179 | struct rtc_wkalrm *alarm)
|
| 180 | {
|
| 181 | int err;
|
| 182 |
|
| 183 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 184 | if (err)
|
| 185 | return err;
|
| 186 |
|
| 187 | if (!rtc->ops) {
|
| 188 | err = -ENODEV;
|
| 189 | } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->read_alarm) {
|
| 190 | err = -EINVAL;
|
| 191 | } else {
|
| 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;
|
| 203 | err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
|
| 204 | }
|
| 205 |
|
| 206 | mutex_unlock(&rtc->ops_lock);
|
| 207 |
|
| 208 | trace_rtc_read_alarm(err?0:rtc_tm_to_time64(&alarm->time), err);
|
| 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;
|
| 217 | time64_t t_now, t_alm;
|
| 218 | enum { none, day, month, year } missing = none;
|
| 219 | unsigned int days;
|
| 220 |
|
| 221 | |
| 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,
|
| 259 | * then it's probably best to do it here instead of there..
|
| 260 |
|
| 261 |
|
| 262 |
|
| 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 |
|
| 272 | err = rtc_read_alarm_internal(rtc, alarm);
|
| 273 | if (err)
|
| 274 | return err;
|
| 275 |
|
| 276 |
|
| 277 | err = rtc_valid_tm(&alarm->time);
|
| 278 | if (!err)
|
| 279 | goto done;
|
| 280 |
|
| 281 |
|
| 282 | err = rtc_read_time(rtc, &now);
|
| 283 | if (err < 0)
|
| 284 | return err;
|
| 285 |
|
| 286 |
|
| 287 | } while (before.tm_min != now.tm_min ||
|
| 288 | before.tm_hour != now.tm_hour ||
|
| 289 | before.tm_mon != now.tm_mon ||
|
| 290 | before.tm_year != now.tm_year);
|
| 291 |
|
| 292 | |
| 293 | * know there's at least one since alarm->time is invalid.
|
| 294 |
|
| 295 | if (alarm->time.tm_sec == -1)
|
| 296 | alarm->time.tm_sec = now.tm_sec;
|
| 297 | if (alarm->time.tm_min == -1)
|
| 298 | alarm->time.tm_min = now.tm_min;
|
| 299 | if (alarm->time.tm_hour == -1)
|
| 300 | alarm->time.tm_hour = now.tm_hour;
|
| 301 |
|
| 302 |
|
| 303 | if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) {
|
| 304 | alarm->time.tm_mday = now.tm_mday;
|
| 305 | missing = day;
|
| 306 | }
|
| 307 | if ((unsigned int)alarm->time.tm_mon >= 12) {
|
| 308 | alarm->time.tm_mon = now.tm_mon;
|
| 309 | if (missing == none)
|
| 310 | missing = month;
|
| 311 | }
|
| 312 | if (alarm->time.tm_year == -1) {
|
| 313 | alarm->time.tm_year = now.tm_year;
|
| 314 | if (missing == none)
|
| 315 | missing = year;
|
| 316 | }
|
| 317 |
|
| 318 | |
| 319 | * missing fields.
|
| 320 |
|
| 321 | err = rtc_valid_tm(&alarm->time);
|
| 322 | if (err)
|
| 323 | goto done;
|
| 324 |
|
| 325 |
|
| 326 | t_now = rtc_tm_to_time64(&now);
|
| 327 | t_alm = rtc_tm_to_time64(&alarm->time);
|
| 328 | if (t_now < t_alm)
|
| 329 | goto done;
|
| 330 |
|
| 331 | switch (missing) {
|
| 332 | |
| 333 | * that will trigger at 5am will do so at 5am Tuesday, which
|
| 334 | * could also be in the next month or year. This is a common
|
| 335 | * case, especially for PCs.
|
| 336 |
|
| 337 | case day:
|
| 338 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
|
| 339 | t_alm += 24 * 60 * 60;
|
| 340 | rtc_time64_to_tm(t_alm, &alarm->time);
|
| 341 | break;
|
| 342 |
|
| 343 | |
| 344 | * be next month. An alarm matching on the 30th, 29th, or 28th
|
| 345 | * may end up in the month after that! Many newer PCs support
|
| 346 | * this type of alarm.
|
| 347 |
|
| 348 | case month:
|
| 349 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month");
|
| 350 | do {
|
| 351 | if (alarm->time.tm_mon < 11) {
|
| 352 | alarm->time.tm_mon++;
|
| 353 | } else {
|
| 354 | alarm->time.tm_mon = 0;
|
| 355 | alarm->time.tm_year++;
|
| 356 | }
|
| 357 | days = rtc_month_days(alarm->time.tm_mon,
|
| 358 | alarm->time.tm_year);
|
| 359 | } while (days < alarm->time.tm_mday);
|
| 360 | break;
|
| 361 |
|
| 362 |
|
| 363 | case year:
|
| 364 | dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year");
|
| 365 | do {
|
| 366 | alarm->time.tm_year++;
|
| 367 | } while (!is_leap_year(alarm->time.tm_year + 1900) &&
|
| 368 | rtc_valid_tm(&alarm->time) != 0);
|
| 369 | break;
|
| 370 |
|
| 371 | default:
|
| 372 | dev_warn(&rtc->dev, "alarm rollover not handled\n");
|
| 373 | }
|
| 374 |
|
| 375 | err = rtc_valid_tm(&alarm->time);
|
| 376 |
|
| 377 | done:
|
| 378 | if (err && alarm->enabled)
|
| 379 | dev_warn(&rtc->dev, "invalid alarm value: %ptR\n",
|
| 380 | &alarm->time);
|
| 381 | else
|
| 382 | rtc_add_offset(rtc, &alarm->time);
|
| 383 |
|
| 384 | return err;
|
| 385 | }
|
| 386 |
|
| 387 | |
| 388 | * rtc_read_next_alarm - read the next expiring alarm
|
| 389 | * @rtc: RTC device
|
| 390 | * @alarm: storage for the alarm information
|
| 391 | *
|
| 392 | * Read the next expiring alarm from the RTC timerqueue. This returns
|
| 393 | * the alarm that will actually fire next, which may be different from
|
| 394 | * rtc_read_alarm() if multiple timers are queued (e.g., alarmtimer
|
| 395 | * and wakealarm sysfs both active).
|
| 396 | *
|
| 397 | * Returns: 0 on success, -ENOENT if no alarm is pending, or other error.
|
| 398 |
|
| 399 | int rtc_read_next_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
| 400 | {
|
| 401 | struct timerqueue_node *next;
|
| 402 | int err;
|
| 403 |
|
| 404 | if (!rtc || !alarm)
|
| 405 | return -EINVAL;
|
| 406 |
|
| 407 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 408 | if (err)
|
| 409 | return err;
|
| 410 |
|
| 411 | next = timerqueue_getnext(&rtc->timerqueue);
|
| 412 | if (!next) {
|
| 413 | err = -ENOENT;
|
| 414 | goto unlock;
|
| 415 | }
|
| 416 |
|
| 417 | memset(alarm, 0, sizeof(struct rtc_wkalrm));
|
| 418 | alarm->time = rtc_ktime_to_tm(next->expires);
|
| 419 | alarm->enabled = 1;
|
| 420 |
|
| 421 | unlock:
|
| 422 | mutex_unlock(&rtc->ops_lock);
|
| 423 | return err;
|
| 424 | }
|
| 425 | EXPORT_SYMBOL_GPL(rtc_read_next_alarm);
|
| 426 |
|
| 427 | int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
| 428 | {
|
| 429 | int err;
|
| 430 |
|
| 431 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 432 | if (err)
|
| 433 | return err;
|
| 434 | if (!rtc->ops) {
|
| 435 | err = -ENODEV;
|
| 436 | } else if (!test_bit(RTC_FEATURE_ALARM, rtc->features)) {
|
| 437 | err = -EINVAL;
|
| 438 | } else {
|
| 439 | memset(alarm, 0, sizeof(struct rtc_wkalrm));
|
| 440 | alarm->enabled = rtc->aie_timer.enabled;
|
| 441 | alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
|
| 442 | }
|
| 443 | mutex_unlock(&rtc->ops_lock);
|
| 444 |
|
| 445 | trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err);
|
| 446 | return err;
|
| 447 | }
|
| 448 | EXPORT_SYMBOL_GPL(rtc_read_alarm);
|
| 449 |
|
| 450 | static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
| 451 | {
|
| 452 | struct rtc_time tm;
|
| 453 | time64_t now, scheduled;
|
| 454 | int err;
|
| 455 |
|
| 456 | err = rtc_valid_tm(&alarm->time);
|
| 457 | if (err)
|
| 458 | return err;
|
| 459 |
|
| 460 | scheduled = rtc_tm_to_time64(&alarm->time);
|
| 461 |
|
| 462 |
|
| 463 | err = __rtc_read_time(rtc, &tm);
|
| 464 | if (err)
|
| 465 | return err;
|
| 466 | now = rtc_tm_to_time64(&tm);
|
| 467 |
|
| 468 | if (scheduled <= now)
|
| 469 | return -ETIME;
|
| 470 | |
| 471 | * XXX - We just checked to make sure the alarm time is not
|
| 472 | * in the past, but there is still a race window where if
|
| 473 | * the is alarm set for the next second and the second ticks
|
| 474 | * over right here, before we set the alarm.
|
| 475 |
|
| 476 |
|
| 477 | rtc_subtract_offset(rtc, &alarm->time);
|
| 478 |
|
| 479 | if (!rtc->ops)
|
| 480 | err = -ENODEV;
|
| 481 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
|
| 482 | err = -EINVAL;
|
| 483 | else
|
| 484 | err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
|
| 485 |
|
| 486 | |
| 487 | * Check for potential race described above. If the waiting for next
|
| 488 | * second, and the second just ticked since the check above, either
|
| 489 | *
|
| 490 | * 1) It ticked after the alarm was set, and an alarm irq should be
|
| 491 | * generated.
|
| 492 | *
|
| 493 | * 2) It ticked before the alarm was set, and alarm irq most likely will
|
| 494 | * not be generated.
|
| 495 | *
|
| 496 | * While we cannot easily check for which of these two scenarios we
|
| 497 | * are in, we can return -ETIME to signal that the timer has already
|
| 498 | * expired, which is true in both cases.
|
| 499 |
|
| 500 | if (!err && (scheduled - now) <= 1) {
|
| 501 | err = __rtc_read_time(rtc, &tm);
|
| 502 | if (err)
|
| 503 | return err;
|
| 504 | now = rtc_tm_to_time64(&tm);
|
| 505 | if (scheduled <= now)
|
| 506 | return -ETIME;
|
| 507 | }
|
| 508 |
|
| 509 | trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err);
|
| 510 | return err;
|
| 511 | }
|
| 512 |
|
| 513 | int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
| 514 | {
|
| 515 | ktime_t alarm_time;
|
| 516 | int err;
|
| 517 |
|
| 518 | if (!rtc->ops)
|
| 519 | return -ENODEV;
|
| 520 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features))
|
| 521 | return -EINVAL;
|
| 522 |
|
| 523 | err = rtc_valid_tm(&alarm->time);
|
| 524 | if (err != 0)
|
| 525 | return err;
|
| 526 |
|
| 527 | err = rtc_valid_range(rtc, &alarm->time);
|
| 528 | if (err)
|
| 529 | return err;
|
| 530 |
|
| 531 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 532 | if (err)
|
| 533 | return err;
|
| 534 | if (rtc->aie_timer.enabled)
|
| 535 | rtc_timer_remove(rtc, &rtc->aie_timer);
|
| 536 |
|
| 537 | alarm_time = rtc_tm_to_ktime(alarm->time);
|
| 538 | |
| 539 | * Round down so we never miss a deadline, checking for past deadline is
|
| 540 | * done in __rtc_set_alarm
|
| 541 |
|
| 542 | if (test_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features))
|
| 543 | alarm_time = ktime_sub_ns(alarm_time, (u64)alarm->time.tm_sec * NSEC_PER_SEC);
|
| 544 |
|
| 545 | rtc->aie_timer.node.expires = alarm_time;
|
| 546 | rtc->aie_timer.period = 0;
|
| 547 | if (alarm->enabled)
|
| 548 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
|
| 549 |
|
| 550 | mutex_unlock(&rtc->ops_lock);
|
| 551 |
|
| 552 | return err;
|
| 553 | }
|
| 554 | EXPORT_SYMBOL_GPL(rtc_set_alarm);
|
| 555 |
|
| 556 |
|
| 557 | int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
|
| 558 | {
|
| 559 | int err;
|
| 560 | struct rtc_time now;
|
| 561 |
|
| 562 | err = rtc_valid_tm(&alarm->time);
|
| 563 | if (err != 0)
|
| 564 | return err;
|
| 565 |
|
| 566 | err = rtc_read_time(rtc, &now);
|
| 567 | if (err)
|
| 568 | return err;
|
| 569 |
|
| 570 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 571 | if (err)
|
| 572 | return err;
|
| 573 |
|
| 574 | rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
|
| 575 | rtc->aie_timer.period = 0;
|
| 576 |
|
| 577 |
|
| 578 | if (alarm->enabled && (rtc_tm_to_ktime(now) <
|
| 579 | rtc->aie_timer.node.expires)) {
|
| 580 | rtc->aie_timer.enabled = 1;
|
| 581 | timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node);
|
| 582 | trace_rtc_timer_enqueue(&rtc->aie_timer);
|
| 583 | }
|
| 584 | mutex_unlock(&rtc->ops_lock);
|
| 585 | return err;
|
| 586 | }
|
| 587 | EXPORT_SYMBOL_GPL(rtc_initialize_alarm);
|
| 588 |
|
| 589 | int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled)
|
| 590 | {
|
| 591 | int err;
|
| 592 |
|
| 593 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 594 | if (err)
|
| 595 | return err;
|
| 596 |
|
| 597 | if (rtc->aie_timer.enabled != enabled) {
|
| 598 | if (enabled)
|
| 599 | err = rtc_timer_enqueue(rtc, &rtc->aie_timer);
|
| 600 | else
|
| 601 | rtc_timer_remove(rtc, &rtc->aie_timer);
|
| 602 | }
|
| 603 |
|
| 604 | if (err)
|
| 605 | ;
|
| 606 | else if (!rtc->ops)
|
| 607 | err = -ENODEV;
|
| 608 | else if (!test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
|
| 609 | err = -EINVAL;
|
| 610 | else
|
| 611 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled);
|
| 612 |
|
| 613 | mutex_unlock(&rtc->ops_lock);
|
| 614 |
|
| 615 | trace_rtc_alarm_irq_enable(enabled, err);
|
| 616 | return err;
|
| 617 | }
|
| 618 | EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable);
|
| 619 |
|
| 620 | int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
|
| 621 | {
|
| 622 | int err;
|
| 623 |
|
| 624 | err = mutex_lock_interruptible(&rtc->ops_lock);
|
| 625 | if (err)
|
| 626 | return err;
|
| 627 |
|
| 628 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
|
| 629 | if (enabled == 0 && rtc->uie_irq_active) {
|
| 630 | mutex_unlock(&rtc->ops_lock);
|
| 631 | return rtc_dev_update_irq_enable_emul(rtc, 0);
|
| 632 | }
|
| 633 | #endif
|
| 634 |
|
| 635 | if (rtc->uie_rtctimer.enabled == enabled)
|
| 636 | goto out;
|
| 637 |
|
| 638 | if (!test_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features) ||
|
| 639 | !test_bit(RTC_FEATURE_ALARM, rtc->features)) {
|
| 640 | mutex_unlock(&rtc->ops_lock);
|
| 641 | #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
|
| 642 | return rtc_dev_update_irq_enable_emul(rtc, enabled);
|
| 643 | #else
|
| 644 | return -EINVAL;
|
| 645 | #endif
|
| 646 | }
|
| 647 |
|
| 648 | if (enabled) {
|
| 649 | struct rtc_time tm;
|
| 650 | ktime_t now, onesec;
|
| 651 |
|
| 652 | err = __rtc_read_time(rtc, &tm);
|
| 653 | if (err)
|
| 654 | goto out;
|
| 655 | onesec = ktime_set(1, 0);
|
| 656 | now = rtc_tm_to_ktime(tm);
|
| 657 | rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
|
| 658 | rtc->uie_rtctimer.period = ktime_set(1, 0);
|
| 659 | err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
|
| 660 | if (!err && rtc->ops && rtc->ops->alarm_irq_enable)
|
| 661 | err = rtc->ops->alarm_irq_enable(rtc->dev.parent, 1);
|
| 662 | if (err)
|
| 663 | goto out;
|
| 664 | } else {
|
| 665 | rtc_timer_remove(rtc, &rtc->uie_rtctimer);
|
| 666 | }
|
| 667 |
|
| 668 | out:
|
| 669 | mutex_unlock(&rtc->ops_lock);
|
| 670 |
|
| 671 | return err;
|
| 672 | }
|
| 673 | EXPORT_SYMBOL_GPL(rtc_update_irq_enable);
|
| 674 |
|
| 675 | |
| 676 | * rtc_handle_legacy_irq - AIE, UIE and PIE event hook
|
| 677 | * @rtc: pointer to the rtc device
|
| 678 | * @num: number of occurrence of the event
|
| 679 | * @mode: type of the event, RTC_AF, RTC_UF or RTC_PF
|
| 680 | *
|
| 681 | * This function is called when an AIE, UIE or PIE mode interrupt
|
| 682 | * has occurred (or been emulated).
|
| 683 | *
|
| 684 |
|
| 685 | void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode)
|
| 686 | {
|
| 687 | unsigned long flags;
|
| 688 |
|
| 689 |
|
| 690 | spin_lock_irqsave(&rtc->irq_lock, flags);
|
| 691 | rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF | mode);
|
| 692 | spin_unlock_irqrestore(&rtc->irq_lock, flags);
|
| 693 |
|
| 694 | wake_up_interruptible(&rtc->irq_queue);
|
| 695 | kill_fasync(&rtc->async_queue, SIGIO, POLL_IN);
|
| 696 | }
|
| 697 |
|
| 698 | |
| 699 | * rtc_aie_update_irq - AIE mode rtctimer hook
|
| 700 | * @rtc: pointer to the rtc_device
|
| 701 | *
|
| 702 | * This functions is called when the aie_timer expires.
|
| 703 |
|
| 704 | void rtc_aie_update_irq(struct rtc_device *rtc)
|
| 705 | {
|
| 706 | rtc_handle_legacy_irq(rtc, 1, RTC_AF);
|
| 707 | }
|
| 708 |
|
| 709 | |
| 710 | * rtc_uie_update_irq - UIE mode rtctimer hook
|
| 711 | * @rtc: pointer to the rtc_device
|
| 712 | *
|
| 713 | * This functions is called when the uie_timer expires.
|
| 714 |
|
| 715 | void rtc_uie_update_irq(struct rtc_device *rtc)
|
| 716 | {
|
| 717 | rtc_handle_legacy_irq(rtc, 1, RTC_UF);
|
| 718 | }
|
| 719 |
|
| 720 | |
| 721 | * rtc_pie_update_irq - PIE mode hrtimer hook
|
| 722 | * @timer: pointer to the pie mode hrtimer
|
| 723 | *
|
| 724 | * This function is used to emulate PIE mode interrupts
|
| 725 | * using an hrtimer. This function is called when the periodic
|
| 726 | * hrtimer expires.
|
| 727 |
|
| 728 | enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer)
|
| 729 | {
|
| 730 | struct rtc_device *rtc;
|
| 731 | ktime_t period;
|
| 732 | u64 count;
|
| 733 |
|
| 734 | rtc = container_of(timer, struct rtc_device, pie_timer);
|
| 735 |
|
| 736 | period = NSEC_PER_SEC / rtc->irq_freq;
|
| 737 | count = hrtimer_forward_now(timer, period);
|
| 738 |
|
| 739 | rtc_handle_legacy_irq(rtc, count, RTC_PF);
|
| 740 |
|
| 741 | return HRTIMER_RESTART;
|
| 742 | }
|
| 743 |
|
| 744 | |
| 745 | * rtc_update_irq - Triggered when a RTC interrupt occurs.
|
| 746 | * @rtc: the rtc device
|
| 747 | * @num: how many irqs are being reported (usually one)
|
| 748 | * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF
|
| 749 | * Context: any
|
| 750 |
|
| 751 | void rtc_update_irq(struct rtc_device *rtc,
|
| 752 | unsigned long num, unsigned long events)
|
| 753 | {
|
| 754 | if (IS_ERR_OR_NULL(rtc))
|
| 755 | return;
|
| 756 |
|
| 757 | pm_stay_awake(rtc->dev.parent);
|
| 758 | schedule_work(&rtc->irqwork);
|
| 759 | }
|
| 760 | EXPORT_SYMBOL_GPL(rtc_update_irq);
|
| 761 |
|
| 762 | struct rtc_device *rtc_class_open(const char *name)
|
| 763 | {
|
| 764 | struct device *dev;
|
| 765 | struct rtc_device *rtc = NULL;
|
| 766 |
|
| 767 | dev = class_find_device_by_name(&rtc_class, name);
|
| 768 | if (dev)
|
| 769 | rtc = to_rtc_device(dev);
|
| 770 |
|
| 771 | if (rtc) {
|
| 772 | if (!try_module_get(rtc->owner)) {
|
| 773 | put_device(dev);
|
| 774 | rtc = NULL;
|
| 775 | }
|
| 776 | }
|
| 777 |
|
| 778 | return rtc;
|
| 779 | }
|
| 780 | EXPORT_SYMBOL_GPL(rtc_class_open);
|
| 781 |
|
| 782 | void rtc_class_close(struct rtc_device *rtc)
|
| 783 | {
|
| 784 | module_put(rtc->owner);
|
| 785 | put_device(&rtc->dev);
|
| 786 | }
|
| 787 | EXPORT_SYMBOL_GPL(rtc_class_close);
|
| 788 |
|
| 789 | static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled)
|
| 790 | {
|
| 791 | |
| 792 | * We always cancel the timer here first, because otherwise
|
| 793 | * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK);
|
| 794 | * when we manage to start the timer before the callback
|
| 795 | * returns HRTIMER_RESTART.
|
| 796 | *
|
| 797 | * We cannot use hrtimer_cancel() here as a running callback
|
| 798 | * could be blocked on rtc->irq_task_lock and hrtimer_cancel()
|
| 799 | * would spin forever.
|
| 800 |
|
| 801 | if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0)
|
| 802 | return -1;
|
| 803 |
|
| 804 | if (enabled) {
|
| 805 | ktime_t period = NSEC_PER_SEC / rtc->irq_freq;
|
| 806 |
|
| 807 | hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL);
|
| 808 | }
|
| 809 | return 0;
|
| 810 | }
|
| 811 |
|
| 812 | |
| 813 | * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs
|
| 814 | * @rtc: the rtc device
|
| 815 | * @enabled: true to enable periodic IRQs
|
| 816 | * Context: any
|
| 817 | *
|
| 818 | * Note that rtc_irq_set_freq() should previously have been used to
|
| 819 | * specify the desired frequency of periodic IRQ.
|
| 820 |
|
| 821 | int rtc_irq_set_state(struct rtc_device *rtc, int enabled)
|
| 822 | {
|
| 823 | int err = 0;
|
| 824 |
|
| 825 | while (rtc_update_hrtimer(rtc, enabled) < 0)
|
| 826 | cpu_relax();
|
| 827 |
|
| 828 | rtc->pie_enabled = enabled;
|
| 829 |
|
| 830 | trace_rtc_irq_set_state(enabled, err);
|
| 831 | return err;
|
| 832 | }
|
| 833 |
|
| 834 | |
| 835 | * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ
|
| 836 | * @rtc: the rtc device
|
| 837 | * @freq: positive frequency
|
| 838 | * Context: any
|
| 839 | *
|
| 840 | * Note that rtc_irq_set_state() is used to enable or disable the
|
| 841 | * periodic IRQs.
|
| 842 |
|
| 843 | int rtc_irq_set_freq(struct rtc_device *rtc, int freq)
|
| 844 | {
|
| 845 | int err = 0;
|
| 846 |
|
| 847 | if (freq <= 0 || freq > RTC_MAX_FREQ)
|
| 848 | return -EINVAL;
|
| 849 |
|
| 850 | rtc->irq_freq = freq;
|
| 851 | while (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0)
|
| 852 | cpu_relax();
|
| 853 |
|
| 854 | trace_rtc_irq_set_freq(freq, err);
|
| 855 | return err;
|
| 856 | }
|
| 857 |
|
| 858 | |
| 859 | * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue
|
| 860 | * @rtc: rtc device
|
| 861 | * @timer: timer being added.
|
| 862 | *
|
| 863 | * Enqueues a timer onto the rtc devices timerqueue and sets
|
| 864 | * the next alarm event appropriately.
|
| 865 | *
|
| 866 | * Sets the enabled bit on the added timer.
|
| 867 | *
|
| 868 | * Must hold ops_lock for proper serialization of timerqueue
|
| 869 |
|
| 870 | static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
|
| 871 | {
|
| 872 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
|
| 873 | struct rtc_time tm;
|
| 874 | ktime_t now;
|
| 875 | int err;
|
| 876 |
|
| 877 | err = __rtc_read_time(rtc, &tm);
|
| 878 | if (err)
|
| 879 | return err;
|
| 880 |
|
| 881 | timer->enabled = 1;
|
| 882 | now = rtc_tm_to_ktime(tm);
|
| 883 |
|
| 884 |
|
| 885 | while (next) {
|
| 886 | if (next->expires >= now)
|
| 887 | break;
|
| 888 | next = timerqueue_iterate_next(next);
|
| 889 | }
|
| 890 |
|
| 891 | timerqueue_add(&rtc->timerqueue, &timer->node);
|
| 892 | trace_rtc_timer_enqueue(timer);
|
| 893 | if (!next || ktime_before(timer->node.expires, next->expires)) {
|
| 894 | struct rtc_wkalrm alarm;
|
| 895 |
|
| 896 | alarm.time = rtc_ktime_to_tm(timer->node.expires);
|
| 897 | alarm.enabled = 1;
|
| 898 | err = __rtc_set_alarm(rtc, &alarm);
|
| 899 | if (err == -ETIME) {
|
| 900 | pm_stay_awake(rtc->dev.parent);
|
| 901 | schedule_work(&rtc->irqwork);
|
| 902 | } else if (err) {
|
| 903 | timerqueue_del(&rtc->timerqueue, &timer->node);
|
| 904 | trace_rtc_timer_dequeue(timer);
|
| 905 | timer->enabled = 0;
|
| 906 | return err;
|
| 907 | }
|
| 908 | }
|
| 909 | return 0;
|
| 910 | }
|
| 911 |
|
| 912 | static void rtc_alarm_disable(struct rtc_device *rtc)
|
| 913 | {
|
| 914 | if (!rtc->ops || !test_bit(RTC_FEATURE_ALARM, rtc->features) || !rtc->ops->alarm_irq_enable)
|
| 915 | return;
|
| 916 |
|
| 917 | rtc->ops->alarm_irq_enable(rtc->dev.parent, false);
|
| 918 | trace_rtc_alarm_irq_enable(0, 0);
|
| 919 | }
|
| 920 |
|
| 921 | |
| 922 | * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue
|
| 923 | * @rtc: rtc device
|
| 924 | * @timer: timer being removed.
|
| 925 | *
|
| 926 | * Removes a timer onto the rtc devices timerqueue and sets
|
| 927 | * the next alarm event appropriately.
|
| 928 | *
|
| 929 | * Clears the enabled bit on the removed timer.
|
| 930 | *
|
| 931 | * Must hold ops_lock for proper serialization of timerqueue
|
| 932 |
|
| 933 | static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer)
|
| 934 | {
|
| 935 | struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue);
|
| 936 |
|
| 937 | timerqueue_del(&rtc->timerqueue, &timer->node);
|
| 938 | trace_rtc_timer_dequeue(timer);
|
| 939 | timer->enabled = 0;
|
| 940 | if (next == &timer->node) {
|
| 941 | struct rtc_wkalrm alarm;
|
| 942 | int err;
|
| 943 |
|
| 944 | next = timerqueue_getnext(&rtc->timerqueue);
|
| 945 | if (!next) {
|
| 946 | rtc_alarm_disable(rtc);
|
| 947 | return;
|
| 948 | }
|
| 949 | alarm.time = rtc_ktime_to_tm(next->expires);
|
| 950 | alarm.enabled = 1;
|
| 951 | err = __rtc_set_alarm(rtc, &alarm);
|
| 952 | if (err == -ETIME) {
|
| 953 | pm_stay_awake(rtc->dev.parent);
|
| 954 | schedule_work(&rtc->irqwork);
|
| 955 | }
|
| 956 | }
|
| 957 | }
|
| 958 |
|
| 959 | |
| 960 | * rtc_timer_do_work - Expires rtc timers
|
| 961 | * @work: work item
|
| 962 | *
|
| 963 | * Expires rtc timers. Reprograms next alarm event if needed.
|
| 964 | * Called via worktask.
|
| 965 | *
|
| 966 | * Serializes access to timerqueue via ops_lock mutex
|
| 967 |
|
| 968 | void rtc_timer_do_work(struct work_struct *work)
|
| 969 | {
|
| 970 | struct rtc_timer *timer;
|
| 971 | struct timerqueue_node *next;
|
| 972 | ktime_t now;
|
| 973 | struct rtc_time tm;
|
| 974 | int err;
|
| 975 |
|
| 976 | struct rtc_device *rtc =
|
| 977 | container_of(work, struct rtc_device, irqwork);
|
| 978 |
|
| 979 | mutex_lock(&rtc->ops_lock);
|
| 980 | again:
|
| 981 | err = __rtc_read_time(rtc, &tm);
|
| 982 | if (err) {
|
| 983 | mutex_unlock(&rtc->ops_lock);
|
| 984 | return;
|
| 985 | }
|
| 986 | now = rtc_tm_to_ktime(tm);
|
| 987 | while ((next = timerqueue_getnext(&rtc->timerqueue))) {
|
| 988 | if (next->expires > now)
|
| 989 | break;
|
| 990 |
|
| 991 |
|
| 992 | timer = container_of(next, struct rtc_timer, node);
|
| 993 | timerqueue_del(&rtc->timerqueue, &timer->node);
|
| 994 | trace_rtc_timer_dequeue(timer);
|
| 995 | timer->enabled = 0;
|
| 996 | if (timer->func)
|
| 997 | timer->func(timer->rtc);
|
| 998 |
|
| 999 | trace_rtc_timer_fired(timer);
|
| 1000 |
|
| 1001 | if (ktime_to_ns(timer->period)) {
|
| 1002 | timer->node.expires = ktime_add(timer->node.expires,
|
| 1003 | timer->period);
|
| 1004 | timer->enabled = 1;
|
| 1005 | timerqueue_add(&rtc->timerqueue, &timer->node);
|
| 1006 | trace_rtc_timer_enqueue(timer);
|
| 1007 | }
|
| 1008 | }
|
| 1009 |
|
| 1010 |
|
| 1011 | if (next) {
|
| 1012 | struct rtc_wkalrm alarm;
|
| 1013 | int err;
|
| 1014 | int retry = 3;
|
| 1015 |
|
| 1016 | alarm.time = rtc_ktime_to_tm(next->expires);
|
| 1017 | alarm.enabled = 1;
|
| 1018 | reprogram:
|
| 1019 | err = __rtc_set_alarm(rtc, &alarm);
|
| 1020 | if (err == -ETIME) {
|
| 1021 | goto again;
|
| 1022 | } else if (err) {
|
| 1023 | if (retry-- > 0)
|
| 1024 | goto reprogram;
|
| 1025 |
|
| 1026 | timer = container_of(next, struct rtc_timer, node);
|
| 1027 | timerqueue_del(&rtc->timerqueue, &timer->node);
|
| 1028 | trace_rtc_timer_dequeue(timer);
|
| 1029 | timer->enabled = 0;
|
| 1030 | dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err);
|
| 1031 | goto again;
|
| 1032 | }
|
| 1033 | } else {
|
| 1034 | rtc_alarm_disable(rtc);
|
| 1035 | }
|
| 1036 |
|
| 1037 | pm_relax(rtc->dev.parent);
|
| 1038 | mutex_unlock(&rtc->ops_lock);
|
| 1039 | }
|
| 1040 |
|
| 1041 | |
| 1042 | * @timer: timer to be intiialized
|
| 1043 | * @f: function pointer to be called when timer fires
|
| 1044 | * @rtc: pointer to the rtc_device
|
| 1045 | *
|
| 1046 | * Kernel interface to initializing an rtc_timer.
|
| 1047 |
|
| 1048 | void rtc_timer_init(struct rtc_timer *timer, void (*f)(struct rtc_device *r),
|
| 1049 | struct rtc_device *rtc)
|
| 1050 | {
|
| 1051 | timerqueue_init(&timer->node);
|
| 1052 | timer->enabled = 0;
|
| 1053 | timer->func = f;
|
| 1054 | timer->rtc = rtc;
|
| 1055 | }
|
| 1056 |
|
| 1057 | |
| 1058 | * @ rtc: rtc device to be used
|
| 1059 | * @ timer: timer being set
|
| 1060 | * @ expires: time at which to expire the timer
|
| 1061 | * @ period: period that the timer will recur
|
| 1062 | *
|
| 1063 | * Kernel interface to set an rtc_timer
|
| 1064 |
|
| 1065 | int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer,
|
| 1066 | ktime_t expires, ktime_t period)
|
| 1067 | {
|
| 1068 | int ret = 0;
|
| 1069 |
|
| 1070 | mutex_lock(&rtc->ops_lock);
|
| 1071 | if (timer->enabled)
|
| 1072 | rtc_timer_remove(rtc, timer);
|
| 1073 |
|
| 1074 | timer->node.expires = expires;
|
| 1075 | timer->period = period;
|
| 1076 |
|
| 1077 | ret = rtc_timer_enqueue(rtc, timer);
|
| 1078 |
|
| 1079 | mutex_unlock(&rtc->ops_lock);
|
| 1080 | return ret;
|
| 1081 | }
|
| 1082 |
|
| 1083 | |
| 1084 | * @ rtc: rtc device to be used
|
| 1085 | * @ timer: timer being set
|
| 1086 | *
|
| 1087 | * Kernel interface to cancel an rtc_timer
|
| 1088 |
|
| 1089 | void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer)
|
| 1090 | {
|
| 1091 | mutex_lock(&rtc->ops_lock);
|
| 1092 | if (timer->enabled)
|
| 1093 | rtc_timer_remove(rtc, timer);
|
| 1094 | mutex_unlock(&rtc->ops_lock);
|
| 1095 | }
|
| 1096 |
|
| 1097 | |
| 1098 | * rtc_read_offset - Read the amount of rtc offset in parts per billion
|
| 1099 | * @rtc: rtc device to be used
|
| 1100 | * @offset: the offset in parts per billion
|
| 1101 | *
|
| 1102 | * see below for details.
|
| 1103 | *
|
| 1104 | * Kernel interface to read rtc clock offset
|
| 1105 | * Returns 0 on success, or a negative number on error.
|
| 1106 | * If read_offset() is not implemented for the rtc, return -EINVAL
|
| 1107 |
|
| 1108 | int rtc_read_offset(struct rtc_device *rtc, long *offset)
|
| 1109 | {
|
| 1110 | int ret;
|
| 1111 |
|
| 1112 | if (!rtc->ops)
|
| 1113 | return -ENODEV;
|
| 1114 |
|
| 1115 | if (!rtc->ops->read_offset)
|
| 1116 | return -EINVAL;
|
| 1117 |
|
| 1118 | mutex_lock(&rtc->ops_lock);
|
| 1119 | ret = rtc->ops->read_offset(rtc->dev.parent, offset);
|
| 1120 | mutex_unlock(&rtc->ops_lock);
|
| 1121 |
|
| 1122 | trace_rtc_read_offset(*offset, ret);
|
| 1123 | return ret;
|
| 1124 | }
|
| 1125 |
|
| 1126 | |
| 1127 | * rtc_set_offset - Adjusts the duration of the average second
|
| 1128 | * @rtc: rtc device to be used
|
| 1129 | * @offset: the offset in parts per billion
|
| 1130 | *
|
| 1131 | * Some rtc's allow an adjustment to the average duration of a second
|
| 1132 | * to compensate for differences in the actual clock rate due to temperature,
|
| 1133 | * the crystal, capacitor, etc.
|
| 1134 | *
|
| 1135 | * The adjustment applied is as follows:
|
| 1136 | * t = t0 * (1 + offset * 1e-9)
|
| 1137 | * where t0 is the measured length of 1 RTC second with offset = 0
|
| 1138 | *
|
| 1139 | * Kernel interface to adjust an rtc clock offset.
|
| 1140 | * Return 0 on success, or a negative number on error.
|
| 1141 | * If the rtc offset is not setable (or not implemented), return -EINVAL
|
| 1142 |
|
| 1143 | int rtc_set_offset(struct rtc_device *rtc, long offset)
|
| 1144 | {
|
| 1145 | int ret;
|
| 1146 |
|
| 1147 | if (!rtc->ops)
|
| 1148 | return -ENODEV;
|
| 1149 |
|
| 1150 | if (!rtc->ops->set_offset)
|
| 1151 | return -EINVAL;
|
| 1152 |
|
| 1153 | mutex_lock(&rtc->ops_lock);
|
| 1154 | ret = rtc->ops->set_offset(rtc->dev.parent, offset);
|
| 1155 | mutex_unlock(&rtc->ops_lock);
|
| 1156 |
|
| 1157 | trace_rtc_set_offset(offset, ret);
|
| 1158 | return ret;
|
| 1159 | }
|