On Tue, Nov 25, 2014 at 11:40 AM, Scott Branden <[email protected]> wrote: > From: Arun Ramamurthy <[email protected]> > > The pwm core code requires a separate call for enabling the channel > and hence the driver does not need to set pwm_trigger after a > polarity change
The framework does restrict when polarity changes can occur but it isn't clear to me that there is any reason to delay applying the polarity change. Keep in mind that polarity matters even when a PWM is disabled. While disabled, the output should be equivalent to an enabled configuration with zero duty. Thus for normal polarity the output is constant low and for inversed polarity the output is constant high. I believe there is an expectation that the output is updated to reflect the requested polarity change prior to returning to the caller. > > Signed-off-by: Arun Ramamurthy <[email protected]> > Reviewed-by: Ray Jui <[email protected]> > Signed-off-by: Scott Branden <[email protected]> > --- > drivers/pwm/pwm-bcm-kona.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/drivers/pwm/pwm-bcm-kona.c b/drivers/pwm/pwm-bcm-kona.c > index 29eef9e..fa0b5bf 100644 > --- a/drivers/pwm/pwm-bcm-kona.c > +++ b/drivers/pwm/pwm-bcm-kona.c > @@ -173,11 +173,6 @@ static int kona_pwmc_set_polarity(struct pwm_chip *chip, > struct pwm_device *pwm, > > writel(value, kp->base + PWM_CONTROL_OFFSET); > > - kona_pwmc_apply_settings(kp, chan); > - > - /* Wait for waveform to settle before gating off the clock */ > - ndelay(400); > - > clk_disable_unprepare(kp->clk); > > return 0; > -- > 2.1.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-pwm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
