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From:   Guru Das Srinagesh <gurus@codeaurora.org>
To:     linux-pwm@vger.kernel.org,
        Thierry Reding <thierry.reding@gmail.com>,
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        <u.kleine-koenig@pengutronix.de>
Cc:     Subbaraman Narayanamurthy <subbaram@codeaurora.org>,
        David Collins <collinsd@codeaurora.org>,
        linux-kernel@vger.kernel.org, Joe Perches <joe@perches.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Lee Jones <lee.jones@linaro.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Guenter Roeck <linux@roeck-us.net>,
        Daniel Thompson <daniel.thompson@linaro.org>,
        Dan Carpenter <dan.carpenter@oracle.com>,
        linux-arm-kernel@lists.infradead.org,
        Guru Das Srinagesh <gurus@codeaurora.org>
Subject: [RESEND PATCH v14 04/11] pwm: clps711x: Cast period to u32 before use as divisor
Date:   Tue, 12 May 2020 17:39:38 -0700
Message-Id: <1d6918c3fc2976bdbdb687bf54a2ef09fc1558db.1589330178.git.gurus@codeaurora.org>
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Precedence: bulk

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@codeaurora.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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