[PATCH] pwm: use div64_u64() instead of do_div()

[Qing Wang]

From: Wang Qing <wangqing@xxxxxxxx>

do_div() does a 64-by-32 division.
When the divisor is u64, do_div() truncates it to 32 bits, this means it
can test non-zero and be truncated to zero for division.

fix do_div.cocci warning:
do_div() does a 64-by-32 division, please consider using div64_u64 instead.

Signed-off-by: Wang Qing <wangqing@xxxxxxxx>
---
 drivers/pwm/pwm-berlin.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-berlin.c b/drivers/pwm/pwm-berlin.c
index e157273..15b10cb3
--- a/drivers/pwm/pwm-berlin.c
+++ b/drivers/pwm/pwm-berlin.c
@@ -109,7 +109,7 @@ static int berlin_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	period = cycles;
 	cycles *= duty_ns;
-	do_div(cycles, period_ns);
+	div64_u64(cycles, period_ns);
 	duty = cycles;
 
 	value = berlin_pwm_readl(bpc, pwm->hwpwm, BERLIN_PWM_CONTROL);
-- 
2.7.4