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    Subject[PATCH 5.4 292/411] pwm: lp3943: Fix duty calculation in case period was clamped
    Date
    From: Uwe Kleine-König <u.kleine-koenig@pengutronix.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@pengutronix.de>
    Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
    Signed-off-by: Sasha Levin <sashal@kernel.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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