/* * RTC subsystem, interface functions * * Copyright (C) 2005 Tower Technologies * Author: Alessandro Zummo * * based on arch/arm/common/rtctime.c * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include #include #include #include #include #define CREATE_TRACE_POINTS #include static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer); static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer); static void rtc_add_offset(struct rtc_device *rtc, struct rtc_time *tm) { time64_t secs; if (!rtc->offset_secs) return; secs = rtc_tm_to_time64(tm); /* * Since the reading time values from RTC device are always in the RTC * original valid range, but we need to skip the overlapped region * between expanded range and original range, which is no need to add * the offset. */ if ((rtc->start_secs > rtc->range_min && secs >= rtc->start_secs) || (rtc->start_secs < rtc->range_min && secs <= (rtc->start_secs + rtc->range_max - rtc->range_min))) return; rtc_time64_to_tm(secs + rtc->offset_secs, tm); } static void rtc_subtract_offset(struct rtc_device *rtc, struct rtc_time *tm) { time64_t secs; if (!rtc->offset_secs) return; secs = rtc_tm_to_time64(tm); /* * If the setting time values are in the valid range of RTC hardware * device, then no need to subtract the offset when setting time to RTC * device. Otherwise we need to subtract the offset to make the time * values are valid for RTC hardware device. */ if (secs >= rtc->range_min && secs <= rtc->range_max) return; rtc_time64_to_tm(secs - rtc->offset_secs, tm); } static int rtc_valid_range(struct rtc_device *rtc, struct rtc_time *tm) { if (rtc->range_min != rtc->range_max) { time64_t time = rtc_tm_to_time64(tm); time64_t range_min = rtc->set_start_time ? rtc->start_secs : rtc->range_min; time64_t range_max = rtc->set_start_time ? (rtc->start_secs + rtc->range_max - rtc->range_min) : rtc->range_max; if (time < range_min || time > range_max) return -ERANGE; } return 0; } static int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) { int err; if (!rtc->ops) err = -ENODEV; else if (!rtc->ops->read_time) err = -EINVAL; else { memset(tm, 0, sizeof(struct rtc_time)); err = rtc->ops->read_time(rtc->dev.parent, tm); if (err < 0) { dev_dbg(&rtc->dev, "read_time: fail to read: %d\n", err); return err; } rtc_add_offset(rtc, tm); err = rtc_valid_tm(tm); if (err < 0) dev_dbg(&rtc->dev, "read_time: rtc_time isn't valid\n"); } return err; } int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) { int err; err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; err = __rtc_read_time(rtc, tm); mutex_unlock(&rtc->ops_lock); trace_rtc_read_time(rtc_tm_to_time64(tm), err); return err; } EXPORT_SYMBOL_GPL(rtc_read_time); int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) { int err; err = rtc_valid_tm(tm); if (err != 0) return err; err = rtc_valid_range(rtc, tm); if (err) return err; rtc_subtract_offset(rtc, tm); err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (!rtc->ops) err = -ENODEV; else if (rtc->ops->set_time) err = rtc->ops->set_time(rtc->dev.parent, tm); else if (rtc->ops->set_mmss64) { time64_t secs64 = rtc_tm_to_time64(tm); err = rtc->ops->set_mmss64(rtc->dev.parent, secs64); } else if (rtc->ops->set_mmss) { time64_t secs64 = rtc_tm_to_time64(tm); err = rtc->ops->set_mmss(rtc->dev.parent, secs64); } else err = -EINVAL; pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); /* A timer might have just expired */ schedule_work(&rtc->irqwork); trace_rtc_set_time(rtc_tm_to_time64(tm), err); return err; } EXPORT_SYMBOL_GPL(rtc_set_time); static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (rtc->ops == NULL) err = -ENODEV; else if (!rtc->ops->read_alarm) err = -EINVAL; else { alarm->enabled = 0; alarm->pending = 0; alarm->time.tm_sec = -1; alarm->time.tm_min = -1; alarm->time.tm_hour = -1; alarm->time.tm_mday = -1; alarm->time.tm_mon = -1; alarm->time.tm_year = -1; alarm->time.tm_wday = -1; alarm->time.tm_yday = -1; alarm->time.tm_isdst = -1; err = rtc->ops->read_alarm(rtc->dev.parent, alarm); } mutex_unlock(&rtc->ops_lock); trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err); return err; } int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; struct rtc_time before, now; int first_time = 1; time64_t t_now, t_alm; enum { none, day, month, year } missing = none; unsigned days; /* The lower level RTC driver may return -1 in some fields, * creating invalid alarm->time values, for reasons like: * * - The hardware may not be capable of filling them in; * many alarms match only on time-of-day fields, not * day/month/year calendar data. * * - Some hardware uses illegal values as "wildcard" match * values, which non-Linux firmware (like a BIOS) may try * to set up as e.g. "alarm 15 minutes after each hour". * Linux uses only oneshot alarms. * * When we see that here, we deal with it by using values from * a current RTC timestamp for any missing (-1) values. The * RTC driver prevents "periodic alarm" modes. * * But this can be racey, because some fields of the RTC timestamp * may have wrapped in the interval since we read the RTC alarm, * which would lead to us inserting inconsistent values in place * of the -1 fields. * * Reading the alarm and timestamp in the reverse sequence * would have the same race condition, and not solve the issue. * * So, we must first read the RTC timestamp, * then read the RTC alarm value, * and then read a second RTC timestamp. * * If any fields of the second timestamp have changed * when compared with the first timestamp, then we know * our timestamp may be inconsistent with that used by * the low-level rtc_read_alarm_internal() function. * * So, when the two timestamps disagree, we just loop and do * the process again to get a fully consistent set of values. * * This could all instead be done in the lower level driver, * but since more than one lower level RTC implementation needs it, * then it's probably best best to do it here instead of there.. */ /* Get the "before" timestamp */ err = rtc_read_time(rtc, &before); if (err < 0) return err; do { if (!first_time) memcpy(&before, &now, sizeof(struct rtc_time)); first_time = 0; /* get the RTC alarm values, which may be incomplete */ err = rtc_read_alarm_internal(rtc, alarm); if (err) return err; /* full-function RTCs won't have such missing fields */ if (rtc_valid_tm(&alarm->time) == 0) return 0; /* get the "after" timestamp, to detect wrapped fields */ err = rtc_read_time(rtc, &now); if (err < 0) return err; /* note that tm_sec is a "don't care" value here: */ } while ( before.tm_min != now.tm_min || before.tm_hour != now.tm_hour || before.tm_mon != now.tm_mon || before.tm_year != now.tm_year); /* Fill in the missing alarm fields using the timestamp; we * know there's at least one since alarm->time is invalid. */ if (alarm->time.tm_sec == -1) alarm->time.tm_sec = now.tm_sec; if (alarm->time.tm_min == -1) alarm->time.tm_min = now.tm_min; if (alarm->time.tm_hour == -1) alarm->time.tm_hour = now.tm_hour; /* For simplicity, only support date rollover for now */ if (alarm->time.tm_mday < 1 || alarm->time.tm_mday > 31) { alarm->time.tm_mday = now.tm_mday; missing = day; } if ((unsigned)alarm->time.tm_mon >= 12) { alarm->time.tm_mon = now.tm_mon; if (missing == none) missing = month; } if (alarm->time.tm_year == -1) { alarm->time.tm_year = now.tm_year; if (missing == none) missing = year; } /* Can't proceed if alarm is still invalid after replacing * missing fields. */ err = rtc_valid_tm(&alarm->time); if (err) goto done; /* with luck, no rollover is needed */ t_now = rtc_tm_to_time64(&now); t_alm = rtc_tm_to_time64(&alarm->time); if (t_now < t_alm) goto done; switch (missing) { /* 24 hour rollover ... if it's now 10am Monday, an alarm that * that will trigger at 5am will do so at 5am Tuesday, which * could also be in the next month or year. This is a common * case, especially for PCs. */ case day: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day"); t_alm += 24 * 60 * 60; rtc_time64_to_tm(t_alm, &alarm->time); break; /* Month rollover ... if it's the 31th, an alarm on the 3rd will * be next month. An alarm matching on the 30th, 29th, or 28th * may end up in the month after that! Many newer PCs support * this type of alarm. */ case month: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "month"); do { if (alarm->time.tm_mon < 11) alarm->time.tm_mon++; else { alarm->time.tm_mon = 0; alarm->time.tm_year++; } days = rtc_month_days(alarm->time.tm_mon, alarm->time.tm_year); } while (days < alarm->time.tm_mday); break; /* Year rollover ... easy except for leap years! */ case year: dev_dbg(&rtc->dev, "alarm rollover: %s\n", "year"); do { alarm->time.tm_year++; } while (!is_leap_year(alarm->time.tm_year + 1900) && rtc_valid_tm(&alarm->time) != 0); break; default: dev_warn(&rtc->dev, "alarm rollover not handled\n"); } err = rtc_valid_tm(&alarm->time); done: if (err) { dev_warn(&rtc->dev, "invalid alarm value: %d-%d-%d %d:%d:%d\n", alarm->time.tm_year + 1900, alarm->time.tm_mon + 1, alarm->time.tm_mday, alarm->time.tm_hour, alarm->time.tm_min, alarm->time.tm_sec); } return err; } int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (rtc->ops == NULL) err = -ENODEV; else if (!rtc->ops->read_alarm) err = -EINVAL; else { memset(alarm, 0, sizeof(struct rtc_wkalrm)); alarm->enabled = rtc->aie_timer.enabled; alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires); } mutex_unlock(&rtc->ops_lock); trace_rtc_read_alarm(rtc_tm_to_time64(&alarm->time), err); return err; } EXPORT_SYMBOL_GPL(rtc_read_alarm); static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { struct rtc_time tm; time64_t now, scheduled; int err; err = rtc_valid_tm(&alarm->time); if (err) return err; rtc_subtract_offset(rtc, &alarm->time); scheduled = rtc_tm_to_time64(&alarm->time); /* Make sure we're not setting alarms in the past */ err = __rtc_read_time(rtc, &tm); if (err) return err; now = rtc_tm_to_time64(&tm); if (scheduled <= now) return -ETIME; /* * XXX - We just checked to make sure the alarm time is not * in the past, but there is still a race window where if * the is alarm set for the next second and the second ticks * over right here, before we set the alarm. */ if (!rtc->ops) err = -ENODEV; else if (!rtc->ops->set_alarm) err = -EINVAL; else err = rtc->ops->set_alarm(rtc->dev.parent, alarm); trace_rtc_set_alarm(rtc_tm_to_time64(&alarm->time), err); return err; } int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; if (!rtc->ops) return -ENODEV; else if (!rtc->ops->set_alarm) return -EINVAL; err = rtc_valid_tm(&alarm->time); if (err != 0) return err; err = rtc_valid_range(rtc, &alarm->time); if (err) return err; err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (rtc->aie_timer.enabled) rtc_timer_remove(rtc, &rtc->aie_timer); rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); rtc->aie_timer.period = 0; if (alarm->enabled) err = rtc_timer_enqueue(rtc, &rtc->aie_timer); mutex_unlock(&rtc->ops_lock); rtc_add_offset(rtc, &alarm->time); return err; } EXPORT_SYMBOL_GPL(rtc_set_alarm); /* Called once per device from rtc_device_register */ int rtc_initialize_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; struct rtc_time now; err = rtc_valid_tm(&alarm->time); if (err != 0) return err; err = rtc_read_time(rtc, &now); if (err) return err; err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); rtc->aie_timer.period = 0; /* Alarm has to be enabled & in the future for us to enqueue it */ if (alarm->enabled && (rtc_tm_to_ktime(now) < rtc->aie_timer.node.expires)) { rtc->aie_timer.enabled = 1; timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); trace_rtc_timer_enqueue(&rtc->aie_timer); } mutex_unlock(&rtc->ops_lock); return err; } EXPORT_SYMBOL_GPL(rtc_initialize_alarm); int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) { int err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; if (rtc->aie_timer.enabled != enabled) { if (enabled) err = rtc_timer_enqueue(rtc, &rtc->aie_timer); else rtc_timer_remove(rtc, &rtc->aie_timer); } if (err) /* nothing */; else if (!rtc->ops) err = -ENODEV; else if (!rtc->ops->alarm_irq_enable) err = -EINVAL; else err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); mutex_unlock(&rtc->ops_lock); trace_rtc_alarm_irq_enable(enabled, err); return err; } EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) { int err = mutex_lock_interruptible(&rtc->ops_lock); if (err) return err; #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL if (enabled == 0 && rtc->uie_irq_active) { mutex_unlock(&rtc->ops_lock); return rtc_dev_update_irq_enable_emul(rtc, 0); } #endif /* make sure we're changing state */ if (rtc->uie_rtctimer.enabled == enabled) goto out; if (rtc->uie_unsupported) { err = -EINVAL; goto out; } if (enabled) { struct rtc_time tm; ktime_t now, onesec; __rtc_read_time(rtc, &tm); onesec = ktime_set(1, 0); now = rtc_tm_to_ktime(tm); rtc->uie_rtctimer.node.expires = ktime_add(now, onesec); rtc->uie_rtctimer.period = ktime_set(1, 0); err = rtc_timer_enqueue(rtc, &rtc->uie_rtctimer); } else rtc_timer_remove(rtc, &rtc->uie_rtctimer); out: mutex_unlock(&rtc->ops_lock); #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL /* * Enable emulation if the driver did not provide * the update_irq_enable function pointer or if returned * -EINVAL to signal that it has been configured without * interrupts or that are not available at the moment. */ if (err == -EINVAL) err = rtc_dev_update_irq_enable_emul(rtc, enabled); #endif return err; } EXPORT_SYMBOL_GPL(rtc_update_irq_enable); /** * rtc_handle_legacy_irq - AIE, UIE and PIE event hook * @rtc: pointer to the rtc device * * This function is called when an AIE, UIE or PIE mode interrupt * has occurred (or been emulated). * * Triggers the registered irq_task function callback. */ void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) { unsigned long flags; /* mark one irq of the appropriate mode */ spin_lock_irqsave(&rtc->irq_lock, flags); rtc->irq_data = (rtc->irq_data + (num << 8)) | (RTC_IRQF|mode); spin_unlock_irqrestore(&rtc->irq_lock, flags); /* call the task func */ spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task) rtc->irq_task->func(rtc->irq_task->private_data); spin_unlock_irqrestore(&rtc->irq_task_lock, flags); wake_up_interruptible(&rtc->irq_queue); kill_fasync(&rtc->async_queue, SIGIO, POLL_IN); } /** * rtc_aie_update_irq - AIE mode rtctimer hook * @private: pointer to the rtc_device * * This functions is called when the aie_timer expires. */ void rtc_aie_update_irq(void *private) { struct rtc_device *rtc = (struct rtc_device *)private; rtc_handle_legacy_irq(rtc, 1, RTC_AF); } /** * rtc_uie_update_irq - UIE mode rtctimer hook * @private: pointer to the rtc_device * * This functions is called when the uie_timer expires. */ void rtc_uie_update_irq(void *private) { struct rtc_device *rtc = (struct rtc_device *)private; rtc_handle_legacy_irq(rtc, 1, RTC_UF); } /** * rtc_pie_update_irq - PIE mode hrtimer hook * @timer: pointer to the pie mode hrtimer * * This function is used to emulate PIE mode interrupts * using an hrtimer. This function is called when the periodic * hrtimer expires. */ enum hrtimer_restart rtc_pie_update_irq(struct hrtimer *timer) { struct rtc_device *rtc; ktime_t period; int count; rtc = container_of(timer, struct rtc_device, pie_timer); period = NSEC_PER_SEC / rtc->irq_freq; count = hrtimer_forward_now(timer, period); rtc_handle_legacy_irq(rtc, count, RTC_PF); return HRTIMER_RESTART; } /** * rtc_update_irq - Triggered when a RTC interrupt occurs. * @rtc: the rtc device * @num: how many irqs are being reported (usually one) * @events: mask of RTC_IRQF with one or more of RTC_PF, RTC_AF, RTC_UF * Context: any */ void rtc_update_irq(struct rtc_device *rtc, unsigned long num, unsigned long events) { if (IS_ERR_OR_NULL(rtc)) return; pm_stay_awake(rtc->dev.parent); schedule_work(&rtc->irqwork); } EXPORT_SYMBOL_GPL(rtc_update_irq); static int __rtc_match(struct device *dev, const void *data) { const char *name = data; if (strcmp(dev_name(dev), name) == 0) return 1; return 0; } struct rtc_device *rtc_class_open(const char *name) { struct device *dev; struct rtc_device *rtc = NULL; dev = class_find_device(rtc_class, NULL, name, __rtc_match); if (dev) rtc = to_rtc_device(dev); if (rtc) { if (!try_module_get(rtc->owner)) { put_device(dev); rtc = NULL; } } return rtc; } EXPORT_SYMBOL_GPL(rtc_class_open); void rtc_class_close(struct rtc_device *rtc) { module_put(rtc->owner); put_device(&rtc->dev); } EXPORT_SYMBOL_GPL(rtc_class_close); static int rtc_update_hrtimer(struct rtc_device *rtc, int enabled) { /* * We always cancel the timer here first, because otherwise * we could run into BUG_ON(timer->state != HRTIMER_STATE_CALLBACK); * when we manage to start the timer before the callback * returns HRTIMER_RESTART. * * We cannot use hrtimer_cancel() here as a running callback * could be blocked on rtc->irq_task_lock and hrtimer_cancel() * would spin forever. */ if (hrtimer_try_to_cancel(&rtc->pie_timer) < 0) return -1; if (enabled) { ktime_t period = NSEC_PER_SEC / rtc->irq_freq; hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); } return 0; } /** * rtc_irq_set_state - enable/disable 2^N Hz periodic IRQs * @rtc: the rtc device * @task: currently registered with rtc_irq_register() * @enabled: true to enable periodic IRQs * Context: any * * Note that rtc_irq_set_freq() should previously have been used to * specify the desired frequency of periodic IRQ task->func() callbacks. */ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled) { int err = 0; unsigned long flags; retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; else if (rtc->irq_task != task) err = -EACCES; else { if (rtc_update_hrtimer(rtc, enabled) < 0) { spin_unlock_irqrestore(&rtc->irq_task_lock, flags); cpu_relax(); goto retry; } rtc->pie_enabled = enabled; } spin_unlock_irqrestore(&rtc->irq_task_lock, flags); trace_rtc_irq_set_state(enabled, err); return err; } EXPORT_SYMBOL_GPL(rtc_irq_set_state); /** * rtc_irq_set_freq - set 2^N Hz periodic IRQ frequency for IRQ * @rtc: the rtc device * @task: currently registered with rtc_irq_register() * @freq: positive frequency with which task->func() will be called * Context: any * * Note that rtc_irq_set_state() is used to enable or disable the * periodic IRQs. */ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) { int err = 0; unsigned long flags; if (freq <= 0 || freq > RTC_MAX_FREQ) return -EINVAL; retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; else if (rtc->irq_task != task) err = -EACCES; else { rtc->irq_freq = freq; if (rtc->pie_enabled && rtc_update_hrtimer(rtc, 1) < 0) { spin_unlock_irqrestore(&rtc->irq_task_lock, flags); cpu_relax(); goto retry; } } spin_unlock_irqrestore(&rtc->irq_task_lock, flags); trace_rtc_irq_set_freq(freq, err); return err; } EXPORT_SYMBOL_GPL(rtc_irq_set_freq); /** * rtc_timer_enqueue - Adds a rtc_timer to the rtc_device timerqueue * @rtc rtc device * @timer timer being added. * * Enqueues a timer onto the rtc devices timerqueue and sets * the next alarm event appropriately. * * Sets the enabled bit on the added timer. * * Must hold ops_lock for proper serialization of timerqueue */ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer) { struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); struct rtc_time tm; ktime_t now; timer->enabled = 1; __rtc_read_time(rtc, &tm); now = rtc_tm_to_ktime(tm); /* Skip over expired timers */ while (next) { if (next->expires >= now) break; next = timerqueue_iterate_next(next); } timerqueue_add(&rtc->timerqueue, &timer->node); trace_rtc_timer_enqueue(timer); if (!next || ktime_before(timer->node.expires, next->expires)) { struct rtc_wkalrm alarm; int err; alarm.time = rtc_ktime_to_tm(timer->node.expires); alarm.enabled = 1; err = __rtc_set_alarm(rtc, &alarm); if (err == -ETIME) { pm_stay_awake(rtc->dev.parent); schedule_work(&rtc->irqwork); } else if (err) { timerqueue_del(&rtc->timerqueue, &timer->node); trace_rtc_timer_dequeue(timer); timer->enabled = 0; return err; } } return 0; } static void rtc_alarm_disable(struct rtc_device *rtc) { if (!rtc->ops || !rtc->ops->alarm_irq_enable) return; rtc->ops->alarm_irq_enable(rtc->dev.parent, false); trace_rtc_alarm_irq_enable(0, 0); } /** * rtc_timer_remove - Removes a rtc_timer from the rtc_device timerqueue * @rtc rtc device * @timer timer being removed. * * Removes a timer onto the rtc devices timerqueue and sets * the next alarm event appropriately. * * Clears the enabled bit on the removed timer. * * Must hold ops_lock for proper serialization of timerqueue */ static void rtc_timer_remove(struct rtc_device *rtc, struct rtc_timer *timer) { struct timerqueue_node *next = timerqueue_getnext(&rtc->timerqueue); timerqueue_del(&rtc->timerqueue, &timer->node); trace_rtc_timer_dequeue(timer); timer->enabled = 0; if (next == &timer->node) { struct rtc_wkalrm alarm; int err; next = timerqueue_getnext(&rtc->timerqueue); if (!next) { rtc_alarm_disable(rtc); return; } alarm.time = rtc_ktime_to_tm(next->expires); alarm.enabled = 1; err = __rtc_set_alarm(rtc, &alarm); if (err == -ETIME) { pm_stay_awake(rtc->dev.parent); schedule_work(&rtc->irqwork); } } } /** * rtc_timer_do_work - Expires rtc timers * @rtc rtc device * @timer timer being removed. * * Expires rtc timers. Reprograms next alarm event if needed. * Called via worktask. * * Serializes access to timerqueue via ops_lock mutex */ void rtc_timer_do_work(struct work_struct *work) { struct rtc_timer *timer; struct timerqueue_node *next; ktime_t now; struct rtc_time tm; struct rtc_device *rtc = container_of(work, struct rtc_device, irqwork); mutex_lock(&rtc->ops_lock); again: __rtc_read_time(rtc, &tm); now = rtc_tm_to_ktime(tm); while ((next = timerqueue_getnext(&rtc->timerqueue))) { if (next->expires > now) break; /* expire timer */ timer = container_of(next, struct rtc_timer, node); timerqueue_del(&rtc->timerqueue, &timer->node); trace_rtc_timer_dequeue(timer); timer->enabled = 0; if (timer->task.func) timer->task.func(timer->task.private_data); trace_rtc_timer_fired(timer); /* Re-add/fwd periodic timers */ if (ktime_to_ns(timer->period)) { timer->node.expires = ktime_add(timer->node.expires, timer->period); timer->enabled = 1; timerqueue_add(&rtc->timerqueue, &timer->node); trace_rtc_timer_enqueue(timer); } } /* Set next alarm */ if (next) { struct rtc_wkalrm alarm; int err; int retry = 3; alarm.time = rtc_ktime_to_tm(next->expires); alarm.enabled = 1; reprogram: err = __rtc_set_alarm(rtc, &alarm); if (err == -ETIME) goto again; else if (err) { if (retry-- > 0) goto reprogram; timer = container_of(next, struct rtc_timer, node); timerqueue_del(&rtc->timerqueue, &timer->node); trace_rtc_timer_dequeue(timer); timer->enabled = 0; dev_err(&rtc->dev, "__rtc_set_alarm: err=%d\n", err); goto again; } } else rtc_alarm_disable(rtc); pm_relax(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); } /* rtc_timer_init - Initializes an rtc_timer * @timer: timer to be intiialized * @f: function pointer to be called when timer fires * @data: private data passed to function pointer * * Kernel interface to initializing an rtc_timer. */ void rtc_timer_init(struct rtc_timer *timer, void (*f)(void *p), void *data) { timerqueue_init(&timer->node); timer->enabled = 0; timer->task.func = f; timer->task.private_data = data; } /* rtc_timer_start - Sets an rtc_timer to fire in the future * @ rtc: rtc device to be used * @ timer: timer being set * @ expires: time at which to expire the timer * @ period: period that the timer will recur * * Kernel interface to set an rtc_timer */ int rtc_timer_start(struct rtc_device *rtc, struct rtc_timer *timer, ktime_t expires, ktime_t period) { int ret = 0; mutex_lock(&rtc->ops_lock); if (timer->enabled) rtc_timer_remove(rtc, timer); timer->node.expires = expires; timer->period = period; ret = rtc_timer_enqueue(rtc, timer); mutex_unlock(&rtc->ops_lock); return ret; } /* rtc_timer_cancel - Stops an rtc_timer * @ rtc: rtc device to be used * @ timer: timer being set * * Kernel interface to cancel an rtc_timer */ void rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) { mutex_lock(&rtc->ops_lock); if (timer->enabled) rtc_timer_remove(rtc, timer); mutex_unlock(&rtc->ops_lock); } /** * rtc_read_offset - Read the amount of rtc offset in parts per billion * @ rtc: rtc device to be used * @ offset: the offset in parts per billion * * see below for details. * * Kernel interface to read rtc clock offset * Returns 0 on success, or a negative number on error. * If read_offset() is not implemented for the rtc, return -EINVAL */ int rtc_read_offset(struct rtc_device *rtc, long *offset) { int ret; if (!rtc->ops) return -ENODEV; if (!rtc->ops->read_offset) return -EINVAL; mutex_lock(&rtc->ops_lock); ret = rtc->ops->read_offset(rtc->dev.parent, offset); mutex_unlock(&rtc->ops_lock); trace_rtc_read_offset(*offset, ret); return ret; } /** * rtc_set_offset - Adjusts the duration of the average second * @ rtc: rtc device to be used * @ offset: the offset in parts per billion * * Some rtc's allow an adjustment to the average duration of a second * to compensate for differences in the actual clock rate due to temperature, * the crystal, capacitor, etc. * * The adjustment applied is as follows: * t = t0 * (1 + offset * 1e-9) * where t0 is the measured length of 1 RTC second with offset = 0 * * Kernel interface to adjust an rtc clock offset. * Return 0 on success, or a negative number on error. * If the rtc offset is not setable (or not implemented), return -EINVAL */ int rtc_set_offset(struct rtc_device *rtc, long offset) { int ret; if (!rtc->ops) return -ENODEV; if (!rtc->ops->set_offset) return -EINVAL; mutex_lock(&rtc->ops_lock); ret = rtc->ops->set_offset(rtc->dev.parent, offset); mutex_unlock(&rtc->ops_lock); trace_rtc_set_offset(offset, ret); return ret; }