[PATCH v10 04/12] pwm: clps711x: Cast period to u32 before use as divisor
From: Guru Das Srinagesh
Date: Thu Mar 19 2020 - 16:51:08 EST
Since the PWM framework is switching struct pwm_args.period's datatype
to u64, prepare for this transition by typecasting it to u32.
Also, since the dividend is still a 32-bit number, any divisor greater
than UINT_MAX will cause the quotient to be zero, so return 0 in that
case to efficiently skip the division.
Cc: Alexander Shiyan <shc_work@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Guru Das Srinagesh <gurus@xxxxxxxxxxxxxx>
---
drivers/pwm/pwm-clps711x.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/pwm/pwm-clps711x.c b/drivers/pwm/pwm-clps711x.c
index 924d39a..f34f1f3 100644
--- a/drivers/pwm/pwm-clps711x.c
+++ b/drivers/pwm/pwm-clps711x.c
@@ -43,7 +43,10 @@ static void clps711x_pwm_update_val(struct clps711x_chip *priv, u32 n, u32 v)
static unsigned int clps711x_get_duty(struct pwm_device *pwm, unsigned int v)
{
/* Duty cycle 0..15 max */
- return DIV_ROUND_CLOSEST(v * 0xf, pwm->args.period);
+ if (pwm->args.period > UINT_MAX)
+ return 0;
+
+ return DIV_ROUND_CLOSEST(v * 0xf, (u32)pwm->args.period);
}
static int clps711x_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
--
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