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

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

[Lukasz Majewski]

This patch ports "pwm: imx: support output polarity inversion" patch set
written by Lothar Wassmann (v6 from 10.2014).

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@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");
-- 
2.1.4

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

[Lukasz Majewski]

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.

Best regards,
?ukasz 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@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");

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

[Lukasz Majewski]

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?

Would they be included to main line anytime soon?

Best regards,
?ukasz Majewski

> 
> Best regards,
> ?ukasz 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@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");
> 

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[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,
> ?ukasz Majewski
> 
>>
>> Best regards,
>> ?ukasz 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@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");
>>