rtc: use set_mmss when set_time is not available

Drivers should only need to implement either set_mmss (counter based RTCs)
or set_time (most RTCs).  The RTC subsystem will handle them
appropriately.

Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 8 insertions, 3 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 50482d1321e8..4348c4b0d453 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -50,10 +50,15 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 
         if (!rtc->ops)
                 err = -ENODEV;
-        else if (!rtc->ops->set_time)
-                err = -EINVAL;
-        else
+        else if (rtc->ops->set_time)
                 err = rtc->ops->set_time(rtc->dev.parent, tm);
+        else if (rtc->ops->set_mmss) {
+                unsigned long secs;
+                err = rtc_tm_to_time(tm, &secs);
+                if (err == 0)
+                        err = rtc->ops->set_mmss(rtc->dev.parent, secs);
+        } else
+                err = -EINVAL;
 
         mutex_unlock(&rtc->ops_lock);
         return err;