rtc-at32ap700x: fix bug in at32_rtc_readalarm()

alarm->pending indicates whether there's an alarm that has actually been
triggered, not whether we're waiting for it.  alarm->enabled indicates
that.

Also add missing locking around reading the RTC registers.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/rtc-at32ap700x.c

@@ -94,8 +94,11 @@ static int at32_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct rtc_at32ap700x *rtc = dev_get_drvdata(dev);
 
+	spin_lock_irq(&rtc->lock);
 	rtc_time_to_tm(rtc->alarm_time, &alrm->time);
-	alrm->pending = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
+	alrm->enabled = rtc_readl(rtc, IMR) & RTC_BIT(IMR_TOPI) ? 1 : 0;
+	alrm->pending = rtc_readl(rtc, ISR) & RTC_BIT(ISR_TOPI) ? 1 : 0;
+	spin_unlock_irq(&rtc->lock);
 
 	return 0;
 }
@@ -119,7 +122,7 @@ static int at32_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
 	spin_lock_irq(&rtc->lock);
 	rtc->alarm_time = alarm_unix_time;
 	rtc_writel(rtc, TOP, rtc->alarm_time);
-	if (alrm->pending)
+	if (alrm->enabled)
 		rtc_writel(rtc, CTRL, rtc_readl(rtc, CTRL)
 				| RTC_BIT(CTRL_TOPEN));
 	else