[PATCH] pwm: imx: Port "pwm: imx: support output polarity inversion" to Linux v4.7

[Stefan Agner]

On 2016-09-29 23:49, Lukasz Majewski wrote:
> Dear all,
> 
>> Dear Lothar, Stefan,
>>
>> > This patch ports "pwm: imx: support output polarity inversion" patch
>> > set written by Lothar Wassmann (v6 from 10.2014).
>> >
>>
>> I've read the e-mail from Stefan regarding missing support for pwm-imx
>> polarity inversion feature.
>>
>> I also would like to see it in ML. Hence, my patch. Lothar, please
>> feel free to squash it to your patches when you (I hope :-) ) will
>> prepare v7 of this feature.
>>
>> I hope that this would help.
> 
> Was there any decision about those patches?

Bhuvan here at Toradex is preparing an updated patchset...

> 
> Would they be included to main line anytime soon?

I don't think that there were fundamental issues with the patchset, so I
hope they make it once upon a time...

--
Stefan

> 
> Best regards,
> Łukasz Majewski
> 
>>
>> Best regards,
>> Łukasz Majewski
>>
>> > It is used to control backlight of panels via inverted PWM signal.
>> >
>> > The "inversion" of PWM output is not an issue at such devices, since
>> > separate GPIO pin is responsible for enabling and disabling the
>> > panel's backlight.
>> >
>> > This patch should be put on top of:
>> >
>> > https://patchwork.kernel.org/patch/5065841/
>> > https://patchwork.kernel.org/patch/5065821/
>> > https://patchwork.kernel.org/patch/5065811/
>> >
>> >
>> > Signed-off-by: Lukasz Majewski <l.majewski at majess.pl>
>> > ---
>> >  drivers/pwm/pwm-imx.c | 20 ++++++++++++++------
>> >  1 file changed, 14 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c
>> > index 471a99e..c37d223 100644
>> > --- a/drivers/pwm/pwm-imx.c
>> > +++ b/drivers/pwm/pwm-imx.c
>> > @@ -181,7 +181,7 @@ static int imx_pwm_config_v2(struct pwm_chip
>> > *chip, if (enable)
>> >  		cr |= MX3_PWMCR_EN;
>> >
>> > -	if (pwm->polarity == PWM_POLARITY_INVERSED)
>> > +	if (pwm->args.polarity == PWM_POLARITY_INVERSED)
>> >  		cr |= MX3_PWMCR_POUTC;
>> >
>> >  	writel(cr, imx->mmio_base + MX3_PWMCR);
>> > @@ -201,11 +201,6 @@ static void imx_pwm_set_enable_v2(struct
>> > pwm_chip *chip, bool enable) else
>> >  		val &= ~MX3_PWMCR_EN;
>> >
>> > -	if (chip->pwms[0].polarity == PWM_POLARITY_INVERSED)
>> > -		val |= MX3_PWMCR_POUTC;
>> > -	else
>> > -		val &= ~MX3_PWMCR_POUTC;
>> > -
>> >  	writel(val, imx->mmio_base + MX3_PWMCR);
>> >  }
>> >
>> > @@ -253,6 +248,19 @@ static int imx_pwm_set_polarity(struct pwm_chip
>> > *chip, struct pwm_device *pwm, enum pwm_polarity polarity)
>> >  {
>> >  	struct imx_chip *imx = to_imx_chip(chip);
>> > +	u32 val;
>> > +
>> > +	if (polarity == pwm->args.polarity)
>> > +		return 0;
>> > +
>> > +	val = readl(imx->mmio_base + MX3_PWMCR);
>> > +
>> > +	if (polarity == PWM_POLARITY_INVERSED)
>> > +		val |= MX3_PWMCR_POUTC;
>> > +	else
>> > +		val &= ~MX3_PWMCR_POUTC;
>> > +
>> > +	writel(val, imx->mmio_base + MX3_PWMCR);
>> >
>> >  	dev_dbg(imx->chip.dev, "%s: polarity set to %s\n",
>> > __func__, polarity == PWM_POLARITY_INVERSED ? "inverted" :
>> > "normal");
>>