+#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
+/*
+ * Routine to poll RTC seconds field for change as often as possible,
+ * after first RTC_UIE use timer to reduce polling
+ */
+static void rtc_uie_task(void *data)
+{
+ struct rtc_device *rtc = data;
+ struct rtc_time tm;
+ int num = 0;
+ int err;
+
+ err = rtc_read_time(&rtc->class_dev, &tm);
+ spin_lock_irq(&rtc->irq_lock);
+ if (rtc->stop_uie_polling || err) {
+ rtc->uie_task_active = 0;
+ } else if (rtc->oldsecs != tm.tm_sec) {
+ num = (tm.tm_sec + 60 - rtc->oldsecs) % 60;
+ rtc->oldsecs = tm.tm_sec;
+ rtc->uie_timer.expires = jiffies + HZ - (HZ/10);
+ rtc->uie_timer_active = 1;
+ rtc->uie_task_active = 0;
+ add_timer(&rtc->uie_timer);
+ } else if (schedule_work(&rtc->uie_task) == 0) {
+ rtc->uie_task_active = 0;
+ }
+ spin_unlock_irq(&rtc->irq_lock);
+ if (num)
+ rtc_update_irq(&rtc->class_dev, num, RTC_UF | RTC_IRQF);
+}
+
+static void rtc_uie_timer(unsigned long data)
+{
+ struct rtc_device *rtc = (struct rtc_device *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc->irq_lock, flags);
+ rtc->uie_timer_active = 0;
+ rtc->uie_task_active = 1;
+ if ((schedule_work(&rtc->uie_task) == 0))
+ rtc->uie_task_active = 0;
+ spin_unlock_irqrestore(&rtc->irq_lock, flags);
+}
+
+static void clear_uie(struct rtc_device *rtc)
+{
+ spin_lock_irq(&rtc->irq_lock);
+ if (rtc->irq_active) {
+ rtc->stop_uie_polling = 1;
+ if (rtc->uie_timer_active) {
+ spin_unlock_irq(&rtc->irq_lock);
+ del_timer_sync(&rtc->uie_timer);
+ spin_lock_irq(&rtc->irq_lock);
+ rtc->uie_timer_active = 0;
+ }
+ if (rtc->uie_task_active) {
+ spin_unlock_irq(&rtc->irq_lock);
+ flush_scheduled_work();
+ spin_lock_irq(&rtc->irq_lock);
+ }
+ rtc->irq_active = 0;
+ }
+ spin_unlock_irq(&rtc->irq_lock);
+}
+
+static int set_uie(struct rtc_device *rtc)
+{
+ struct rtc_time tm;
+ int err;
+
+ err = rtc_read_time(&rtc->class_dev, &tm);
+ if (err)
+ return err;
+ spin_lock_irq(&rtc->irq_lock);
+ if (!rtc->irq_active) {
+ rtc->irq_active = 1;
+ rtc->stop_uie_polling = 0;
+ rtc->oldsecs = tm.tm_sec;
+ rtc->uie_task_active = 1;
+ if (schedule_work(&rtc->uie_task) == 0)
+ rtc->uie_task_active = 0;
+ }
+ rtc->irq_data = 0;
+ spin_unlock_irq(&rtc->irq_lock);
+ return 0;
+}
+#endif /* CONFIG_RTC_INTF_DEV_UIE_EMUL */