rtc: at91rm9200: clear RTC alarm status flag prior to suspending

As said in the SAMA5D2 datasheet, "Prior to instructing the device
to enter ULP mode 1, ... and the internal sources of wake-up must
be cleared."

This patch is to clear the RTC alarm status flag prior to suspending
to avoid the erroneous wake-up activity, as it is often used as
the wake-up source for the ULP mode 1.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c
index cb62e214b52a0066f0a0402c7d89d8b0de74b4fb..b60fd477778f7fed1e8c1a510d80646f47d8373f 100644 (file)
--- a/drivers/rtc/rtc-at91rm9200.c
+++ b/drivers/rtc/rtc-at91rm9200.c
@@ -495,6 +495,8 @@ static int at91_rtc_suspend(struct device *dev)
        /* this IRQ is shared with DBGU and other hardware which isn't
         * necessarily doing PM like we are...
         */
+       at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);
+
        at91_rtc_imr = at91_rtc_read_imr()
                        & (AT91_RTC_ALARM|AT91_RTC_SECEV);
        if (at91_rtc_imr) {