On 14/03/2014 15:19, Alexandre Belloni :
>>From the datasheet, the actual duty cycle is:
> (period - (1/clk) * CDTY)/period
>
> This actually correct the polarity of the PWM and solves the issue that
> pwm-leds
> exhibits: when setting a duty cycle of 0 and then disabling a channel, the
> level
> was wrong (1 when the polarity was normal and 0 when the polarity was
> inversed).
>
> Signed-off-by: Alexandre Belloni <alexandre.bell...@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.fe...@atmel.com>
> ---
> drivers/pwm/pwm-atmel.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
> index 2d69e9c431dd..0adc952cc4ef 100644
> --- a/drivers/pwm/pwm-atmel.c
> +++ b/drivers/pwm/pwm-atmel.c
> @@ -133,7 +133,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct
> pwm_device *pwm,
> prd = div;
> div *= duty_ns;
> do_div(div, period_ns);
> - dty = div;
> + dty = prd - div;
>
> ret = clk_enable(atmel_pwm->clk);
> if (ret) {
>
--
Nicolas Ferre
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