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Message-Id: <1d6918c3fc2976bdbdb687bf54a2ef09fc1558db.1588616856.git.gurus@codeaurora.org>
Date: Mon, 4 May 2020 11:50:10 -0700
From: Guru Das Srinagesh <gurus@...eaurora.org>
To: linux-pwm@...r.kernel.org,
Thierry Reding <thierry.reding@...il.com>,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>
Cc: Subbaraman Narayanamurthy <subbaram@...eaurora.org>,
David Collins <collinsd@...eaurora.org>,
linux-kernel@...r.kernel.org, Joe Perches <joe@...ches.com>,
Arnd Bergmann <arnd@...db.de>,
Geert Uytterhoeven <geert@...ux-m68k.org>,
Guenter Roeck <linux@...ck-us.net>,
Daniel Thompson <daniel.thompson@...aro.org>,
Dan Carpenter <dan.carpenter@...cle.com>,
Guru Das Srinagesh <gurus@...eaurora.org>
Subject: [RESEND PATCH v14 04/11] pwm: clps711x: Cast period to u32 before use as divisor
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 the numerator will cause the quotient to be zero, so return 0 in
that case to efficiently skip the division.
Signed-off-by: Guru Das Srinagesh <gurus@...eaurora.org>
---
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..da771b1 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 > (v * 0xf))
+ 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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