diff options
Diffstat (limited to 'drivers/rtc/interface.c')
| -rw-r--r-- | drivers/rtc/interface.c | 711 |
1 files changed, 641 insertions, 70 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index 7e3ad4f3b34..5813fa52c3d 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -12,16 +12,17 @@ */ #include <linux/rtc.h> +#include <linux/sched.h> +#include <linux/module.h> #include <linux/log2.h> +#include <linux/workqueue.h> -int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) +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 int __rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) { int err; - - err = mutex_lock_interruptible(&rtc->ops_lock); - if (err) - return -EBUSY; - if (!rtc->ops) err = -ENODEV; else if (!rtc->ops->read_time) @@ -30,7 +31,18 @@ int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm) memset(tm, 0, sizeof(struct rtc_time)); err = rtc->ops->read_time(rtc->dev.parent, tm); } + 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); return err; } @@ -46,16 +58,24 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm) err = mutex_lock_interruptible(&rtc->ops_lock); if (err) - return -EBUSY; + return err; if (!rtc->ops) err = -ENODEV; - else if (!rtc->ops->set_time) - err = -EINVAL; - else + else if (rtc->ops->set_time) err = rtc->ops->set_time(rtc->dev.parent, tm); + else if (rtc->ops->set_mmss) { + unsigned long secs; + err = rtc_tm_to_time(tm, &secs); + if (err == 0) + err = rtc->ops->set_mmss(rtc->dev.parent, secs); + } else + err = -EINVAL; + pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); + /* A timer might have just expired */ + schedule_work(&rtc->irqwork); return err; } EXPORT_SYMBOL_GPL(rtc_set_time); @@ -66,7 +86,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) err = mutex_lock_interruptible(&rtc->ops_lock); if (err) - return -EBUSY; + return err; if (!rtc->ops) err = -ENODEV; @@ -90,11 +110,14 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs) err = rtc->ops->set_time(rtc->dev.parent, &new); } - } - else + } else { err = -EINVAL; + } + pm_stay_awake(rtc->dev.parent); mutex_unlock(&rtc->ops_lock); + /* A timer might have just expired */ + schedule_work(&rtc->irqwork); return err; } @@ -106,7 +129,7 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al err = mutex_lock_interruptible(&rtc->ops_lock); if (err) - return -EBUSY; + return err; if (rtc->ops == NULL) err = -ENODEV; @@ -121,17 +144,30 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al return err; } -int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) +int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; struct rtc_time before, now; int first_time = 1; + unsigned long t_now, t_alm; + enum { none, day, month, year } missing = none; + unsigned days; - /* The lower level RTC driver may not be capable of filling - * in all fields of the rtc_time struct (eg. rtc-cmos), - * and so might instead return -1 in some fields. - * We deal with that here by grabbing a current RTC timestamp - * and using values from that for any missing (-1) values. + /* 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, @@ -171,7 +207,9 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) err = rtc_read_alarm_internal(rtc, alarm); if (err) return err; - if (!alarm->enabled) + + /* 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 */ @@ -183,26 +221,153 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) } 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 - || before.tm_isdst != now.tm_isdst); + || before.tm_year != now.tm_year); - /* Fill in any missing alarm fields using the timestamp */ + /* 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; - if (alarm->time.tm_mday == -1) + + /* 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; - if (alarm->time.tm_mon == -1) + missing = day; + } + if ((unsigned)alarm->time.tm_mon >= 12) { alarm->time.tm_mon = now.tm_mon; - if (alarm->time.tm_year == -1) + if (missing == none) + missing = month; + } + if (alarm->time.tm_year == -1) { alarm->time.tm_year = now.tm_year; - return 0; + if (missing == none) + missing = year; + } + + /* with luck, no rollover is needed */ + rtc_tm_to_time(&now, &t_now); + rtc_tm_to_time(&alarm->time, &t_alm); + 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_time_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"); + } + +done: + err = rtc_valid_tm(&alarm->time); + + 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); + + 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; + long now, scheduled; + int err; + + err = rtc_valid_tm(&alarm->time); + if (err) + return err; + rtc_tm_to_time(&alarm->time, &scheduled); + + /* Make sure we're not setting alarms in the past */ + err = __rtc_read_time(rtc, &tm); + rtc_tm_to_time(&tm, &now); + 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); + + return err; +} + int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; @@ -213,59 +378,245 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) err = mutex_lock_interruptible(&rtc->ops_lock); if (err) - return -EBUSY; + return err; + if (rtc->aie_timer.enabled) + rtc_timer_remove(rtc, &rtc->aie_timer); - if (!rtc->ops) + rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time); + rtc->aie_timer.period = ktime_set(0, 0); + if (alarm->enabled) + err = rtc_timer_enqueue(rtc, &rtc->aie_timer); + + mutex_unlock(&rtc->ops_lock); + 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 = ktime_set(0, 0); + + /* Alarm has to be enabled & in the futrure for us to enqueue it */ + if (alarm->enabled && (rtc_tm_to_ktime(now).tv64 < + rtc->aie_timer.node.expires.tv64)) { + + rtc->aie_timer.enabled = 1; + timerqueue_add(&rtc->timerqueue, &rtc->aie_timer.node); + } + 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->set_alarm) + else if (!rtc->ops->alarm_irq_enable) err = -EINVAL; else - err = rtc->ops->set_alarm(rtc->dev.parent, alarm); + err = rtc->ops->alarm_irq_enable(rtc->dev.parent, enabled); mutex_unlock(&rtc->ops_lock); return err; } -EXPORT_SYMBOL_GPL(rtc_set_alarm); +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_update_irq - report RTC periodic, alarm, and/or update irqs - * @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: in_interrupt(), irqs blocked + * 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_update_irq(struct rtc_device *rtc, - unsigned long num, unsigned long events) +void rtc_handle_legacy_irq(struct rtc_device *rtc, int num, int mode) { - spin_lock(&rtc->irq_lock); - rtc->irq_data = (rtc->irq_data + (num << 8)) | events; - spin_unlock(&rtc->irq_lock); + 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); - spin_lock(&rtc->irq_task_lock); + /* 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(&rtc->irq_task_lock); + 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 = ktime_set(0, 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 (unlikely(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, void *data) +static int __rtc_match(struct device *dev, const void *data) { - char *name = (char *)data; + const char *name = data; - if (strncmp(dev->bus_id, name, BUS_ID_SIZE) == 0) + if (strcmp(dev_name(dev), name) == 0) return 1; return 0; } -struct rtc_device *rtc_class_open(char *name) +struct rtc_device *rtc_class_open(const char *name) { struct device *dev; struct rtc_device *rtc = NULL; - dev = class_find_device(rtc_class, name, __rtc_match); + dev = class_find_device(rtc_class, NULL, name, __rtc_match); if (dev) rtc = to_rtc_device(dev); @@ -320,6 +671,29 @@ void rtc_irq_unregister(struct rtc_device *rtc, struct rtc_task *task) } EXPORT_SYMBOL_GPL(rtc_irq_unregister); +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 = ktime_set(0, 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 @@ -335,19 +709,21 @@ int rtc_irq_set_state(struct rtc_device *rtc, struct rtc_task *task, int enabled int err = 0; unsigned long flags; - if (rtc->ops->irq_set_state == NULL) - return -ENXIO; - +retry: spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; - if (rtc->irq_task != task) + 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); - - if (err == 0) - err = rtc->ops->irq_set_state(rtc->dev.parent, enabled); - return err; } EXPORT_SYMBOL_GPL(rtc_irq_set_state); @@ -367,24 +743,219 @@ int rtc_irq_set_freq(struct rtc_device *rtc, struct rtc_task *task, int freq) int err = 0; unsigned long flags; - if (rtc->ops->irq_set_freq == NULL) - return -ENXIO; - - if (!is_power_of_2(freq)) + 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; - if (rtc->irq_task != task) + else if (rtc->irq_task != task) err = -EACCES; - spin_unlock_irqrestore(&rtc->irq_task_lock, flags); - - if (err == 0) { - err = rtc->ops->irq_set_freq(rtc->dev.parent, freq); - if (err == 0) - rtc->irq_freq = freq; + 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); 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) +{ + timer->enabled = 1; + timerqueue_add(&rtc->timerqueue, &timer->node); + if (&timer->node == timerqueue_getnext(&rtc->timerqueue)) { + 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); + 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); +} + +/** + * 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); + 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.tv64 > now.tv64) + break; + + /* expire timer */ + timer = container_of(next, struct rtc_timer, node); + timerqueue_del(&rtc->timerqueue, &timer->node); + timer->enabled = 0; + if (timer->task.func) + timer->task.func(timer->task.private_data); + + /* 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); + } + } + + /* Set next alarm */ + if (next) { + struct rtc_wkalrm alarm; + int err; + alarm.time = rtc_ktime_to_tm(next->expires); + alarm.enabled = 1; + err = __rtc_set_alarm(rtc, &alarm); + if (err == -ETIME) + 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 + */ +int rtc_timer_cancel(struct rtc_device *rtc, struct rtc_timer *timer) +{ + int ret = 0; + mutex_lock(&rtc->ops_lock); + if (timer->enabled) + rtc_timer_remove(rtc, timer); + mutex_unlock(&rtc->ops_lock); + return ret; +} + + |