RTC: Fix the cross interrupt issue on rtc-test.

The rtc-test driver is meant to provide a test/debug code for the RTC
subsystem.

The rtc-test driver simulates specific interrupts by echoing to the
sys interface. Those were the update, alarm and periodic interrupts.

As a side effect of the new implementation, any interrupt generated in
the rtc-test driver would trigger the same code path in the generic
code, and thus the distinction among interrupts gets lost.

This patch preserves the previous behaviour of the rtc-test driver,
where e.g. an update interrupt would not trigger an alarm or periodic
interrupt, and vice-versa. In real world RTC drivers, this is not an
issue, but in the rtc-test driver it may be interesting to distinguish
these interrupts for testing purposes.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
CC: rtc-linux@googlegroups.com
Signed-off-by: Marcelo Roberto Jimenez <mroberto@cpti.cetuc.puc-rio.br>
Signed-off-by: John Stultz <john.stultz@linaro.org>

drivers/rtc/rtc-test.c

@@ -78,11 +78,16 @@ static ssize_t test_irq_store(struct device *dev,
 	struct rtc_device *rtc = platform_get_drvdata(plat_dev);
 
 	retval = count;
-	if (strncmp(buf, "tick", 4) == 0)
+	if (strncmp(buf, "tick", 4) == 0 && rtc->pie_enabled)
 		rtc_update_irq(rtc, 1, RTC_PF | RTC_IRQF);
-	else if (strncmp(buf, "alarm", 5) == 0)
-		rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
-	else if (strncmp(buf, "update", 6) == 0)
+	else if (strncmp(buf, "alarm", 5) == 0) {
+		struct rtc_wkalrm alrm;
+		int err = rtc_read_alarm(rtc, &alrm);
+
+		if (!err && alrm.enabled)
+			rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);
+
+	} else if (strncmp(buf, "update", 6) == 0 && rtc->uie_rtctimer.enabled)
 		rtc_update_irq(rtc, 1, RTC_UF | RTC_IRQF);
 	else
 		retval = -EINVAL;