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Message-Id: <20220613094853.880833714@linuxfoundation.org>
Date: Mon, 13 Jun 2022 12:09:34 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>,
Thierry Reding <thierry.reding@...il.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.10 014/172] pwm: lp3943: Fix duty calculation in case period was clamped
From: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
[ Upstream commit 5e3b07ca5cc78cd4a987e78446849e41288d87cb ]
The hardware only supports periods <= 1.6 ms and if a bigger period is
requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger
than 1.6 ms and then the duty cycle register is written with a value
bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly.
Fixes: af66b3c0934e ("pwm: Add LP3943 PWM driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@...il.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/pwm/pwm-lp3943.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/pwm/pwm-lp3943.c b/drivers/pwm/pwm-lp3943.c
index bf3f14fb5f24..05e4120fd702 100644
--- a/drivers/pwm/pwm-lp3943.c
+++ b/drivers/pwm/pwm-lp3943.c
@@ -125,6 +125,7 @@ static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
if (err)
return err;
+ duty_ns = min(duty_ns, period_ns);
val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns);
return lp3943_write_byte(lp3943, reg_duty, val);
--
2.35.1
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