From: Guru Das Srinagesh <gurus@codeaurora.org>
To: linux-pwm@vger.kernel.org,
"Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <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>,
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>,
Guru Das Srinagesh <gurus@codeaurora.org>
Subject: [RESEND PATCH v14 04/11] pwm: clps711x: Cast period to u32 before use as divisor
Date: Mon, 4 May 2020 11:50:10 -0700 [thread overview]
Message-ID: <1d6918c3fc2976bdbdb687bf54a2ef09fc1558db.1588616856.git.gurus@codeaurora.org> (raw)
In-Reply-To: <cover.1588616856.git.gurus@codeaurora.org>
In-Reply-To: <cover.1588616856.git.gurus@codeaurora.org>
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)
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-05-04 18:50 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-13 0:39 [RESEND PATCH v14 00/11] Convert PWM period and duty cycle to u64 Guru Das Srinagesh
2020-05-04 18:50 ` Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 01/11] drm/i915: Use 64-bit division macro Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 02/11] hwmon: pwm-fan: " Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 03/11] ir-rx51: " Guru Das Srinagesh
2020-05-04 18:50 ` Guru Das Srinagesh [this message]
2020-05-04 18:50 ` [RESEND PATCH v14 05/11] pwm: pwm-imx-tpm: " Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 06/11] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 07/11] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 08/11] pwm: sun4i: Use nsecs_to_jiffies to avoid a division Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 09/11] backlight: pwm_bl: Use 64-bit division function Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 10/11] clk: pwm: " Guru Das Srinagesh
2020-05-04 18:50 ` [RESEND PATCH v14 11/11] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 00/11] Convert PWM " Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 01/11] drm/i915: Use 64-bit division macro Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 02/11] hwmon: pwm-fan: " Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 03/11] ir-rx51: " Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 04/11] pwm: clps711x: Cast period to u32 before use as divisor Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-21 10:19 ` Daniel Thompson
2020-05-21 20:25 ` Guru Das Srinagesh
2020-05-22 9:37 ` Daniel Thompson
2020-05-22 23:19 ` Guru Das Srinagesh
2020-05-23 17:08 ` Daniel Thompson
2020-05-13 0:39 ` [RESEND PATCH v14 05/11] pwm: pwm-imx-tpm: Use 64-bit division macro Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 06/11] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
2020-05-20 22:55 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 07/11] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
2020-05-20 22:56 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 08/11] pwm: sun4i: Use nsecs_to_jiffies to avoid a division Guru Das Srinagesh
2020-05-20 22:56 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 09/11] backlight: pwm_bl: Use 64-bit division function Guru Das Srinagesh
2020-05-20 22:56 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 10/11] clk: pwm: " Guru Das Srinagesh
2020-05-20 22:56 ` Guru Das Srinagesh
2020-05-13 0:39 ` [RESEND PATCH v14 11/11] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh
2020-05-20 22:56 ` Guru Das Srinagesh
2020-05-20 22:55 ` [RESEND PATCH v14 00/11] Convert PWM " Guru Das Srinagesh
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