From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guru Das Srinagesh Subject: [PATCH v12 04/11] pwm: clps711x: Cast period to u32 before use as divisor Date: Wed, 8 Apr 2020 23:52:33 -0700 Message-ID: References: Return-path: Received: from alexa-out-sd-01.qualcomm.com ([199.106.114.38]:42559 "EHLO alexa-out-sd-01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725783AbgDIGwz (ORCPT ); Thu, 9 Apr 2020 02:52:55 -0400 In-Reply-To: In-Reply-To: References: Sender: linux-pwm-owner@vger.kernel.org List-Id: linux-pwm@vger.kernel.org To: linux-pwm@vger.kernel.org Cc: Thierry Reding , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Subbaraman Narayanamurthy , David Collins , linux-kernel@vger.kernel.org, Guru Das Srinagesh , Alexander Shiyan , Arnd Bergmann 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. Cc: Alexander Shiyan Cc: Arnd Bergmann Signed-off-by: Guru Das Srinagesh --- 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..0d368ac 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 ((u32)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) -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project