#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_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)
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;
}
}
EXPORT_SYMBOL_GPL(rtc_set_mmss);
-static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
+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));
- err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
- }
-
+ alarm->enabled = rtc->aie_timer.enabled;
+ if (alarm->enabled)
+ alarm->time = rtc_ktime_to_tm(rtc->aie_timer.node.expires);
mutex_unlock(&rtc->ops_lock);
- return err;
+
+ return 0;
}
+EXPORT_SYMBOL_GPL(rtc_read_alarm);
-int rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
+int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
+ struct rtc_time tm;
+ long now, scheduled;
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 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)
+ err = rtc_valid_tm(&alarm->time);
+ if (err)
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;
- if (!alarm->enabled)
- return 0;
-
- /* 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 = now.tm_mday;
- missing = day;
- }
- if (alarm->time.tm_mon == -1) {
- 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;
- }
-
- /* 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) {
+ rtc_tm_to_time(&alarm->time, &scheduled);
- /* 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.
+ /* 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.
*/
- 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 (rtc_valid_tm(&alarm->time) != 0);
- break;
-
- default:
- dev_warn(&rtc->dev, "alarm rollover not handled\n");
- }
-done:
- return 0;
+ 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;
}
-EXPORT_SYMBOL_GPL(rtc_read_alarm);
int rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
err = mutex_lock_interruptible(&rtc->ops_lock);
if (err)
return err;
-
- if (!rtc->ops)
- err = -ENODEV;
- else if (!rtc->ops->set_alarm)
- err = -EINVAL;
- else
- err = rtc->ops->set_alarm(rtc->dev.parent, alarm);
-
+ if (rtc->aie_timer.enabled) {
+ rtc_timer_remove(rtc, &rtc->aie_timer);
+ rtc->aie_timer.enabled = 0;
+ }
+ rtc->aie_timer.node.expires = rtc_tm_to_ktime(alarm->time);
+ rtc->aie_timer.period = ktime_set(0, 0);
+ if (alarm->enabled) {
+ rtc->aie_timer.enabled = 1;
+ rtc_timer_enqueue(rtc, &rtc->aie_timer);
+ }
mutex_unlock(&rtc->ops_lock);
- return err;
+ return 0;
}
EXPORT_SYMBOL_GPL(rtc_set_alarm);
if (err)
return err;
+ if (rtc->aie_timer.enabled != enabled) {
+ if (enabled) {
+ rtc->aie_timer.enabled = 1;
+ rtc_timer_enqueue(rtc, &rtc->aie_timer);
+ } else {
+ rtc_timer_remove(rtc, &rtc->aie_timer);
+ rtc->aie_timer.enabled = 0;
+ }
+ }
+
if (!rtc->ops)
err = -ENODEV;
else if (!rtc->ops->alarm_irq_enable)
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, enabled);
+ /* 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);
+ rtc->uie_rtctimer.enabled = 1;
+ rtc_timer_enqueue(rtc, &rtc->uie_rtctimer);
+ } else {
+ rtc_timer_remove(rtc, &rtc->uie_rtctimer);
+ rtc->uie_rtctimer.enabled = 0;
}
-#endif
-
- 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
- * 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: 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)
+static 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);
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)
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;
}
int err = 0;
unsigned long flags;
- if (rtc->ops->irq_set_freq == 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_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.
+ *
+ * Must hold ops_lock for proper serialization of timerqueue
+ */
+void rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
+{
+ 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);
+ }
+}
+
+/**
+ * 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.
+ *
+ * Must hold ops_lock for proper serialization of timerqueue
+ */
+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);
+
+ 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;
+
+ timer->enabled = 1;
+ 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);
+ timer->enabled = 0;
+ mutex_unlock(&rtc->ops_lock);
+ return ret;
+}
+
+
projects / cascardo / linux.git / commitdiff