diff options
Diffstat (limited to 'drivers/rtc/interface.c')
| -rw-r--r-- | drivers/rtc/interface.c | 425 |
1 files changed, 380 insertions, 45 deletions
diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c index a0c816238aa..8ec6b069a7f 100644 --- a/drivers/rtc/interface.c +++ b/drivers/rtc/interface.c @@ -14,15 +14,14 @@ #include <linux/rtc.h> #include <linux/sched.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 err; - if (!rtc->ops) err = -ENODEV; else if (!rtc->ops->read_time) @@ -31,7 +30,18 @@ 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; } @@ -127,7 +137,7 @@ 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; @@ -190,8 +200,6 @@ 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) - return 0; /* full-function RTCs won't have such missing fields */ if (rtc_valid_tm(&alarm->time) == 0) @@ -287,19 +295,51 @@ int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) done: return 0; } -EXPORT_SYMBOL_GPL(rtc_read_alarm); -int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) +int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) { int err; - err = rtc_valid_tm(&alarm->time); - if (err != 0) + 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); - err = mutex_lock_interruptible(&rtc->ops_lock); + return err; +} +EXPORT_SYMBOL_GPL(rtc_read_alarm); + +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; @@ -308,6 +348,28 @@ int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm) 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; + + err = rtc_valid_tm(&alarm->time); + if (err != 0) + 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 = ktime_set(0, 0); + if (alarm->enabled) { + err = rtc_timer_enqueue(rtc, &rtc->aie_timer); + } mutex_unlock(&rtc->ops_lock); return err; } @@ -319,7 +381,16 @@ int rtc_alarm_irq_enable(struct rtc_device *rtc, unsigned int enabled) if (err) return err; - if (!rtc->ops) + 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; @@ -340,19 +411,28 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) #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, enabled); + 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 (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); - if (!rtc->ops) - err = -ENODEV; - else if (!rtc->ops->update_irq_enable) - err = -EINVAL; - else - err = rtc->ops->update_irq_enable(rtc->dev.parent, enabled); - +out: mutex_unlock(&rtc->ops_lock); - #ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL /* * Enable emulation if the driver did not provide @@ -364,25 +444,30 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 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: any + * 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 occured (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) { 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)) | events; + 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); @@ -391,6 +476,69 @@ void rtc_update_irq(struct rtc_device *rtc, 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) +{ + schedule_work(&rtc->irqwork); +} EXPORT_SYMBOL_GPL(rtc_update_irq); static int __rtc_match(struct device *dev, void *data) @@ -477,18 +625,20 @@ 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; - spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; if (rtc->irq_task != task) err = -EACCES; - spin_unlock_irqrestore(&rtc->irq_task_lock, flags); - if (err == 0) - err = rtc->ops->irq_set_state(rtc->dev.parent, enabled); + if (enabled) { + ktime_t period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); + hrtimer_start(&rtc->pie_timer, period, HRTIMER_MODE_REL); + } else { + hrtimer_cancel(&rtc->pie_timer); + } + rtc->pie_enabled = enabled; + spin_unlock_irqrestore(&rtc->irq_task_lock, flags); return err; } @@ -509,21 +659,206 @@ 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 (freq <= 0) + return -EINVAL; spin_lock_irqsave(&rtc->irq_task_lock, flags); if (rtc->irq_task != NULL && task == NULL) err = -EBUSY; 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; + rtc->irq_freq = freq; + if (rtc->pie_enabled) { + ktime_t period; + hrtimer_cancel(&rtc->pie_timer); + period = ktime_set(0, NSEC_PER_SEC/rtc->irq_freq); + hrtimer_start(&rtc->pie_timer, period, + HRTIMER_MODE_REL); + } } + 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) + schedule_work(&rtc->irqwork); + else if (err) { + timerqueue_del(&rtc->timerqueue, &timer->node); + timer->enabled = 0; + return err; + } + } + return 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); + timer->enabled = 0; + if (next == &timer->node) { + struct rtc_wkalrm alarm; + int err; + next = timerqueue_getnext(&rtc->timerqueue); + if (!next) + return; + alarm.time = rtc_ktime_to_tm(next->expires); + alarm.enabled = 1; + err = __rtc_set_alarm(rtc, &alarm); + if (err == -ETIME) + 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; + } + + 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; +} + + |