rtc: initialize output parameter for read alarm to "uninitialized"

rtc drivers are supposed to set values they don't support to -1. To
simplify this for drivers and also make it harder for them to get it
wrong initialize the values to -1.

Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 9ef5f6f89f98..99475908e556 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -104,7 +104,17 @@ static int rtc_read_alarm_internal(struct rtc_device *rtc, struct rtc_wkalrm *al
         else if (!rtc->ops->read_alarm)
                 err = -EINVAL;
         else {
-                memset(alarm, 0, sizeof(struct rtc_wkalrm));
+                alarm->enabled = 0;
+                alarm->pending = 0;
+                alarm->time.tm_sec = -1;
+                alarm->time.tm_min = -1;
+                alarm->time.tm_hour = -1;
+                alarm->time.tm_mday = -1;
+                alarm->time.tm_mon = -1;
+                alarm->time.tm_year = -1;
+                alarm->time.tm_wday = -1;
+                alarm->time.tm_yday = -1;
+                alarm->time.tm_isdst = -1;
                 err = rtc->ops->read_alarm(rtc->dev.parent, alarm);
         }