rtc: tps6586x: Fix error in RTC tick calculations

In the TPS6586x PMU/PMIC RTC support code, when
converting from seconds to ticks using a shift
operator, the most significant bits were being lost
due to seconds being a 32-bit value and ticks being
a 64-bit value.  A hard cast was added to avoid this
loss.

Reviewed-by: Lowell Dennis <ldennis@nvidia.com>
Tested-by: Lowell Dennis <ldennis@nvidia.com>
Reviewed-by: Jonathan Mayo <jmayo@nvidia.com>
Reviewed-by: Peter Zu <pzu@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>
Signed-off-by: Robert Morell <rmorell@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>

diff --git a/drivers/rtc/rtc-tps6586x.c b/drivers/rtc/rtc-tps6586x.c
index 9ab93cb9de0eb173b1ddc937abbff05a00ecb67e..ca6138bbda4b1ed73f5a353f4186feedfdf77fe3 100644 (file)
--- a/drivers/rtc/rtc-tps6586x.c
+++ b/drivers/rtc/rtc-tps6586x.c
@@ -95,7 +95,7 @@ static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 
        seconds -= rtc->epoch_start;
 
-       ticks = seconds << 10;
+       ticks = (unsigned long long)seconds << 10;
        buff[0] = (ticks >> 32) & 0xff;
        buff[1] = (ticks >> 24) & 0xff;
        buff[2] = (ticks >> 16) & 0xff;
@@ -148,7 +148,7 @@ static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
        }
 
        seconds -= rtc->epoch_start;
-       ticks = (seconds << 10) & 0xffffff;
+       ticks = (unsigned long long)seconds << 10;
 
        buff[0] = (ticks >> 16) & 0xff;
        buff[1] = (ticks >> 8) & 0xff;