On 07/11/12 16:25, Alban Bedel wrote:
> Signed-off-by: Alban Bedel <alban.be...@avionic-design.de>
> ---
> drivers/pwm/pwm-lpc32xx.c | 6 +++++-
> 1 files changed, 5 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c
> index adb87f0..0dc278d 100644
> --- a/drivers/pwm/pwm-lpc32xx.c
> +++ b/drivers/pwm/pwm-lpc32xx.c
> @@ -51,7 +51,11 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip,
> struct pwm_device *pwm,
>
> c = 256 * duty_ns;
> do_div(c, period_ns);
> - duty_cycles = c;
> + if (c == 0)
> + c = 256;
> + if (c > 255)
> + c = 255;
> + duty_cycles = 256 - c;
Except for the range check (for the original c > 255), this results in:
duty_cycles = 256 - c
except for (c == 0) where
duty_cycles = 1
which actually is
duty_cycles = (256 - c) - 255
(think with the original c)
i.e. nearly a polarity inversion in the case of (c == 0).
Why is the case (c == 0) so special here? Maybe you can document this,
if it is really intended?
>
> writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles),
> lpc32xx->base + (pwm->hwpwm << 2));
--
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