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; 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); 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; }
int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) { int err; 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 returned -EINVAL to signal that it has * been configured without interrupts or they are not available at the * moment. */ if (err == -EINVAL) err = rtc_dev_update_irq_enable_emul(rtc, enabled); #endif return err; }
/** * 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; }
/** * 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->func) timer->func(timer->rtc); 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 {