From: Guru Das Srinagesh <gurus@codeaurora.org>
To: linux-pwm@vger.kernel.org
Cc: "Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Subbaraman Narayanamurthy" <subbaram@codeaurora.org>,
linux-kernel@vger.kernel.org,
"Guru Das Srinagesh" <gurus@codeaurora.org>,
"Alexander Shiyan" <shc_work@mail.ru>,
"Arnd Bergmann" <arnd@arndb.de>
Subject: [PATCH v11 04/12] pwm: clps711x: Cast period to u32 before use as divisor
Date: Thu, 19 Mar 2020 18:41:15 -0700 [thread overview]
Message-ID: <3dc95ebc6539066cc58bc44c0e6e53ac979fe9a9.1584667964.git.gurus@codeaurora.org> (raw)
In-Reply-To: <cover.1584667964.git.gurus@codeaurora.org>
In-Reply-To: <cover.1584667964.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 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@mail.ru>
Cc: Arnd Bergmann <arnd@arndb.de>
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..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)
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-03-20 1:42 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1584667964.git.gurus@codeaurora.org>
2020-03-20 1:41 ` [PATCH v11 01/12] drm/i915: Use 64-bit division macro Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 02/12] hwmon: pwm-fan: " Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 03/12] ir-rx51: " Guru Das Srinagesh
2020-03-20 1:41 ` Guru Das Srinagesh [this message]
2020-03-20 17:11 ` [PATCH v11 04/12] pwm: clps711x: Cast period to u32 before use as divisor Arnd Bergmann
2020-04-07 0:26 ` Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 05/12] pwm: pwm-imx-tpm: Use 64-bit division macro Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 06/12] pwm: imx27: Use 64-bit division macro and function Guru Das Srinagesh
2020-03-20 17:09 ` Arnd Bergmann
2020-03-30 20:43 ` Guru Das Srinagesh
2020-03-31 15:24 ` Arnd Bergmann
2020-03-31 20:20 ` Guru Das Srinagesh
2020-03-31 20:49 ` Thierry Reding
2020-04-02 20:16 ` Guru Das Srinagesh
2020-04-02 20:55 ` Guru Das Srinagesh
2020-04-02 21:16 ` Arnd Bergmann
2020-04-03 17:37 ` Guru Das Srinagesh
2020-04-03 19:13 ` Arnd Bergmann
2020-03-20 1:41 ` [PATCH v11 07/12] pwm: sifive: Use 64-bit division macro Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 08/12] pwm: stm32-lp: Use %llu format specifier for period Guru Das Srinagesh
2020-03-20 10:45 ` Joe Perches
2020-03-30 19:30 ` Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 09/12] pwm: sun4i: Use 64-bit division function Guru Das Srinagesh
2020-03-20 17:02 ` Arnd Bergmann
2020-03-20 1:41 ` [PATCH v11 10/12] backlight: pwm_bl: " Guru Das Srinagesh
2020-03-20 13:31 ` Lee Jones
2020-03-24 11:07 ` Lee Jones
2020-03-24 12:57 ` Uwe Kleine-König
2020-03-24 13:04 ` Daniel Thompson
2020-03-24 14:24 ` Lee Jones
2020-03-24 14:43 ` Uwe Kleine-König
2020-04-15 9:26 ` Lee Jones
2020-03-20 1:41 ` [PATCH v11 11/12] clk: pwm: Assign u64 divisor to unsigned int before use Guru Das Srinagesh
2020-03-20 17:00 ` Arnd Bergmann
2020-03-20 18:42 ` David Laight
2020-04-07 2:40 ` Guru Das Srinagesh
2020-03-20 1:41 ` [PATCH v11 12/12] pwm: core: Convert period and duty cycle to u64 Guru Das Srinagesh
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