[PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[Shobhit Kukreti]

Port the sky81452-backlight driver to adhere to new gpio descriptor based
APIs. Modified the file sky81452-backlight.c and sky81452-backlight.h.
The gpio descriptor property in device tree should be "sky81452-en-gpios"

Removed unnecessary header files "linux/gpio.h" and "linux/of_gpio.h".

Signed-off-by: Shobhit Kukreti <shobhitkukreti@gmail.com>
---
 drivers/video/backlight/sky81452-backlight.c     | 24 ++++++++++++------------
 include/linux/platform_data/sky81452-backlight.h |  4 +++-
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
index d414c7a..12ef628 100644
--- a/drivers/video/backlight/sky81452-backlight.c
+++ b/drivers/video/backlight/sky81452-backlight.c
@@ -19,12 +19,10 @@
 
 #include <linux/backlight.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/platform_data/sky81452-backlight.h>
@@ -193,7 +191,6 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
 	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
 	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
 	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
-	pdata->gpio_enable = of_get_gpio(np, 0);
 
 	ret = of_property_count_u32_elems(np, "led-sources");
 	if (ret < 0) {
@@ -274,13 +271,17 @@ static int sky81452_bl_probe(struct platform_device *pdev)
 		if (IS_ERR(pdata))
 			return PTR_ERR(pdata);
 	}
-
-	if (gpio_is_valid(pdata->gpio_enable)) {
-		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
-					GPIOF_OUT_INIT_HIGH, "sky81452-en");
-		if (ret < 0) {
-			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
-			return ret;
+	pdata->gpiod_enable = devm_gpiod_get(dev, "sk81452-en", GPIOD_OUT_HIGH);
+	if (IS_ERR(pdata->gpiod_enable)) {
+		long ret = PTR_ERR(pdata->gpiod_enable);
+
+		/**
+		 * gpiod_enable is optional in device tree.
+		 * Return error only if gpio was assigned in device tree
+		 */
+		if (ret != -ENOENT) {
+			dev_err(dev, "failed to request GPIO. err=%ld\n", ret);
+			return PTR_ERR(pdata->gpiod_enable);
 		}
 	}
 
@@ -323,8 +324,7 @@ static int sky81452_bl_remove(struct platform_device *pdev)
 	bd->props.brightness = 0;
 	backlight_update_status(bd);
 
-	if (gpio_is_valid(pdata->gpio_enable))
-		gpio_set_value_cansleep(pdata->gpio_enable, 0);
+	gpiod_set_value_cansleep(pdata->gpiod_enable, 0);
 
 	return 0;
 }
diff --git a/include/linux/platform_data/sky81452-backlight.h b/include/linux/platform_data/sky81452-backlight.h
index 1231e9b..dc4cb85 100644
--- a/include/linux/platform_data/sky81452-backlight.h
+++ b/include/linux/platform_data/sky81452-backlight.h
@@ -20,6 +20,8 @@
 #ifndef _SKY81452_BACKLIGHT_H
 #define _SKY81452_BACKLIGHT_H
 
+#include <linux/gpio/consumer.h>
+
 /**
  * struct sky81452_platform_data
  * @name:	backlight driver name.
@@ -34,7 +36,7 @@
  */
 struct sky81452_bl_platform_data {
 	const char *name;
-	int gpio_enable;
+	struct gpio_desc *gpiod_enable;
 	unsigned int enable;
 	bool ignore_pwm;
 	bool dpwm_mode;
-- 
2.7.4

Re: [PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[Daniel Thompson]

Hi Shobhit

Thanks for the patch. Feedback below...


On Tue, Jun 11, 2019 at 09:32:32PM -0700, Shobhit Kukreti wrote:
> Port the sky81452-backlight driver to adhere to new gpio descriptor based
> APIs. Modified the file sky81452-backlight.c and sky81452-backlight.h.
> The gpio descriptor property in device tree should be "sky81452-en-gpios"

That is contradicted by the device tree bindings. The property should
remain "gpios" as it was before this conversion.


> Removed unnecessary header files "linux/gpio.h" and "linux/of_gpio.h".
> 
> Signed-off-by: Shobhit Kukreti <shobhitkukreti@gmail.com>

What level of testing have you done? Is this a fix for hardware you own
or a cleanup after searching the sources?


> ---
>  drivers/video/backlight/sky81452-backlight.c     | 24 ++++++++++++------------
>  include/linux/platform_data/sky81452-backlight.h |  4 +++-
>  2 files changed, 15 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
> index d414c7a..12ef628 100644
> --- a/drivers/video/backlight/sky81452-backlight.c
> +++ b/drivers/video/backlight/sky81452-backlight.c
> @@ -19,12 +19,10 @@
>  
>  #include <linux/backlight.h>
>  #include <linux/err.h>
> -#include <linux/gpio.h>
>  #include <linux/init.h>
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> -#include <linux/of_gpio.h>
>  #include <linux/platform_device.h>
>  #include <linux/regmap.h>
>  #include <linux/platform_data/sky81452-backlight.h>
> @@ -193,7 +191,6 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
>  	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
>  	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
>  	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
> -	pdata->gpio_enable = of_get_gpio(np, 0);
>  
>  	ret = of_property_count_u32_elems(np, "led-sources");
>  	if (ret < 0) {
> @@ -274,13 +271,17 @@ static int sky81452_bl_probe(struct platform_device *pdev)
>  		if (IS_ERR(pdata))
>  			return PTR_ERR(pdata);
>  	}
> -
> -	if (gpio_is_valid(pdata->gpio_enable)) {
> -		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
> -					GPIOF_OUT_INIT_HIGH, "sky81452-en");
> -		if (ret < 0) {
> -			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
> -			return ret;
> +	pdata->gpiod_enable = devm_gpiod_get(dev, "sk81452-en", GPIOD_OUT_HIGH);

As above... I think the second argument here needs to be NULL in order
to preserve the current DT bindings.


> +	if (IS_ERR(pdata->gpiod_enable)) {
> +		long ret = PTR_ERR(pdata->gpiod_enable);
> +
> +		/**

Nitpicking... but no second star here. That's a trigger symbold for
documentation processors.

> +		 * gpiod_enable is optional in device tree.
> +		 * Return error only if gpio was assigned in device tree

Also nitpicking but I had to read this a few times because
gpiod_enable is not in device tree, gpios is.

This is a common pattern so the comment can be very short. Something
like:

    This DT property is optional so no need to propagate ENOENT


> +		 */
> +		if (ret != -ENOENT) {
> +			dev_err(dev, "failed to request GPIO. err=%ld\n", ret);
> +			return PTR_ERR(pdata->gpiod_enable);
>  		}
>  	}
>  
> @@ -323,8 +324,7 @@ static int sky81452_bl_remove(struct platform_device *pdev)
>  	bd->props.brightness = 0;
>  	backlight_update_status(bd);
>  
> -	if (gpio_is_valid(pdata->gpio_enable))
> -		gpio_set_value_cansleep(pdata->gpio_enable, 0);
> +	gpiod_set_value_cansleep(pdata->gpiod_enable, 0);
>  
>  	return 0;
>  }
> diff --git a/include/linux/platform_data/sky81452-backlight.h b/include/linux/platform_data/sky81452-backlight.h
> index 1231e9b..dc4cb85 100644
> --- a/include/linux/platform_data/sky81452-backlight.h
> +++ b/include/linux/platform_data/sky81452-backlight.h
> @@ -20,6 +20,8 @@
>  #ifndef _SKY81452_BACKLIGHT_H
>  #define _SKY81452_BACKLIGHT_H
>  
> +#include <linux/gpio/consumer.h>
> +

This heaer file should be included from the C file... it is not required
to parse the header.


Daniel.


>  /**
>   * struct sky81452_platform_data
>   * @name:	backlight driver name.
> @@ -34,7 +36,7 @@
>   */
>  struct sky81452_bl_platform_data {
>  	const char *name;
> -	int gpio_enable;
> +	struct gpio_desc *gpiod_enable;
>  	unsigned int enable;
>  	bool ignore_pwm;
>  	bool dpwm_mode;
> -- 
> 2.7.4
> 

Re: [PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[Sam Ravnborg]

Hi Shobhit

> -	if (gpio_is_valid(pdata->gpio_enable)) {
> -		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
> -					GPIOF_OUT_INIT_HIGH, "sky81452-en");


> +	pdata->gpiod_enable = devm_gpiod_get(dev, "sk81452-en", GPIOD_OUT_HIGH);
> +	if (IS_ERR(pdata->gpiod_enable)) {
> +		long ret = PTR_ERR(pdata->gpiod_enable);

In the old code the property was named "sky81452-en".
In the new code the property is named "sk81452-en".

Most likely a bug.

	Sam

Re: [PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[Shobhit Kukreti]

On Wed, Jun 12, 2019 at 11:26:15AM +0100, Daniel Thompson wrote:
> Hi Shobhit
> 
> Thanks for the patch. Feedback below...

  Hi Daneil, 	

  You provided some valuable feedback. Thank you for your time and
  effort.	
> 
> 
> On Tue, Jun 11, 2019 at 09:32:32PM -0700, Shobhit Kukreti wrote:
> > Port the sky81452-backlight driver to adhere to new gpio descriptor based
> > APIs. Modified the file sky81452-backlight.c and sky81452-backlight.h.
> > The gpio descriptor property in device tree should be "sky81452-en-gpios"
> 
> That is contradicted by the device tree bindings. The property should
> remain "gpios" as it was before this conversion.

 You are correct. 	
> 
> 
> > Removed unnecessary header files "linux/gpio.h" and "linux/of_gpio.h".
> > 
> > Signed-off-by: Shobhit Kukreti <shobhitkukreti@gmail.com>
> 
> What level of testing have you done? Is this a fix for hardware you own
> or a cleanup after searching the sources?
> 
  I did not the test on actual hardware. I was trying to do a clean up and boot on 
  QEMU/rock960 board. I will drop the patch until I can find  the  sk81452 
  hardware to test it.
  
> 
> > ---
> >  drivers/video/backlight/sky81452-backlight.c     | 24 ++++++++++++------------
> >  include/linux/platform_data/sky81452-backlight.h |  4 +++-
> >  2 files changed, 15 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
> > index d414c7a..12ef628 100644
> > --- a/drivers/video/backlight/sky81452-backlight.c
> > +++ b/drivers/video/backlight/sky81452-backlight.c
> > @@ -19,12 +19,10 @@
> >  
> >  #include <linux/backlight.h>
> >  #include <linux/err.h>
> > -#include <linux/gpio.h>
> >  #include <linux/init.h>
> >  #include <linux/kernel.h>
> >  #include <linux/module.h>
> >  #include <linux/of.h>
> > -#include <linux/of_gpio.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/regmap.h>
> >  #include <linux/platform_data/sky81452-backlight.h>
> > @@ -193,7 +191,6 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
> >  	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
> >  	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
> >  	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
> > -	pdata->gpio_enable = of_get_gpio(np, 0);
> >  
> >  	ret = of_property_count_u32_elems(np, "led-sources");
> >  	if (ret < 0) {
> > @@ -274,13 +271,17 @@ static int sky81452_bl_probe(struct platform_device *pdev)
> >  		if (IS_ERR(pdata))
> >  			return PTR_ERR(pdata);
> >  	}
> > -
> > -	if (gpio_is_valid(pdata->gpio_enable)) {
> > -		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
> > -					GPIOF_OUT_INIT_HIGH, "sky81452-en");
> > -		if (ret < 0) {
> > -			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
> > -			return ret;
> > +	pdata->gpiod_enable = devm_gpiod_get(dev, "sk81452-en", GPIOD_OUT_HIGH);
> 
> As above... I think the second argument here needs to be NULL in order
> to preserve the current DT bindings.
  
  You are correct. I was testing this driver with a custom dtb in rock960 board and named
  the property as above in the dts. It should be NULL.

> 
> > +	if (IS_ERR(pdata->gpiod_enable)) {
> > +		long ret = PTR_ERR(pdata->gpiod_enable);
> > +
> > +		/**
> 
> Nitpicking... but no second star here. That's a trigger symbold for
> documentation processors.

  That is a great feedback. I will keep that in mind.
> 
> > +		 * gpiod_enable is optional in device tree.
> > +		 * Return error only if gpio was assigned in device tree
> 
> Also nitpicking but I had to read this a few times because
> gpiod_enable is not in device tree, gpios is.

  You are correct. I will make necessary changes.
> 
> This is a common pattern so the comment can be very short. Something
> like:
> 
>     This DT property is optional so no need to propagate ENOENT

	Noted.
> 
> 
> > +		 */
> > +		if (ret != -ENOENT) {
> > +			dev_err(dev, "failed to request GPIO. err=%ld\n", ret);
> > +			return PTR_ERR(pdata->gpiod_enable);
> >  		}
> >  	}
> >  
> > @@ -323,8 +324,7 @@ static int sky81452_bl_remove(struct platform_device *pdev)
> >  	bd->props.brightness = 0;
> >  	backlight_update_status(bd);
> >  
> > -	if (gpio_is_valid(pdata->gpio_enable))
> > -		gpio_set_value_cansleep(pdata->gpio_enable, 0);
> > +	gpiod_set_value_cansleep(pdata->gpiod_enable, 0);
> >  
> >  	return 0;
> >  }
> > diff --git a/include/linux/platform_data/sky81452-backlight.h b/include/linux/platform_data/sky81452-backlight.h
> > index 1231e9b..dc4cb85 100644
> > --- a/include/linux/platform_data/sky81452-backlight.h
> > +++ b/include/linux/platform_data/sky81452-backlight.h
> > @@ -20,6 +20,8 @@
> >  #ifndef _SKY81452_BACKLIGHT_H
> >  #define _SKY81452_BACKLIGHT_H
> >  
> > +#include <linux/gpio/consumer.h>
> > +
> 
> This heaer file should be included from the C file... it is not required
> to parse the header.
 
  I appreciate the feedback. I will keep that in mind to avoid future
  errors. 
> 
> 
> Daniel.
> 
> 
> >  /**
> >   * struct sky81452_platform_data
> >   * @name:	backlight driver name.
> > @@ -34,7 +36,7 @@
> >   */
> >  struct sky81452_bl_platform_data {
> >  	const char *name;
> > -	int gpio_enable;
> > +	struct gpio_desc *gpiod_enable;
> >  	unsigned int enable;
> >  	bool ignore_pwm;
> >  	bool dpwm_mode;
> > -- 
> > 2.7.4
> > 

Re: [PATCH] video: backlight: Replace old GPIO APIs with GPIO Consumer APIs for sky81542-backlight driver

[Daniel Thompson]

On Wed, Jun 12, 2019 at 08:24:34AM -0700, Shobhit Kukreti wrote:
> On Wed, Jun 12, 2019 at 11:26:15AM +0100, Daniel Thompson wrote:
> > Hi Shobhit
> > 
> > Thanks for the patch. Feedback below...
> 
>   Hi Daneil, 	
> 
>   You provided some valuable feedback. Thank you for your time and
>   effort.	
> > 
> > 
> > On Tue, Jun 11, 2019 at 09:32:32PM -0700, Shobhit Kukreti wrote:
> > > Port the sky81452-backlight driver to adhere to new gpio descriptor based
> > > APIs. Modified the file sky81452-backlight.c and sky81452-backlight.h.
> > > The gpio descriptor property in device tree should be "sky81452-en-gpios"
> > 
> > That is contradicted by the device tree bindings. The property should
> > remain "gpios" as it was before this conversion.
> 
>  You are correct. 	
> > 
> > 
> > > Removed unnecessary header files "linux/gpio.h" and "linux/of_gpio.h".
> > > 
> > > Signed-off-by: Shobhit Kukreti <shobhitkukreti@gmail.com>
> > 
> > What level of testing have you done? Is this a fix for hardware you own
> > or a cleanup after searching the sources?
> > 
>   I did not the test on actual hardware. I was trying to do a clean up and boot on 
>   QEMU/rock960 board. I will drop the patch until I can find  the  sk81452 
>   hardware to test it.

Blind bug fixes are not prohibited by any means. However a clean up
without no (intentional) functional changes will certainly attract much
closer review and might also need more care when constructing a Cc: list
for the patch (e.g. to include the original author for their review or
testing, etc).


Daniel.

>   
> > 
> > > ---
> > >  drivers/video/backlight/sky81452-backlight.c     | 24 ++++++++++++------------
> > >  include/linux/platform_data/sky81452-backlight.h |  4 +++-
> > >  2 files changed, 15 insertions(+), 13 deletions(-)
> > > 
> > > diff --git a/drivers/video/backlight/sky81452-backlight.c b/drivers/video/backlight/sky81452-backlight.c
> > > index d414c7a..12ef628 100644
> > > --- a/drivers/video/backlight/sky81452-backlight.c
> > > +++ b/drivers/video/backlight/sky81452-backlight.c
> > > @@ -19,12 +19,10 @@
> > >  
> > >  #include <linux/backlight.h>
> > >  #include <linux/err.h>
> > > -#include <linux/gpio.h>
> > >  #include <linux/init.h>
> > >  #include <linux/kernel.h>
> > >  #include <linux/module.h>
> > >  #include <linux/of.h>
> > > -#include <linux/of_gpio.h>
> > >  #include <linux/platform_device.h>
> > >  #include <linux/regmap.h>
> > >  #include <linux/platform_data/sky81452-backlight.h>
> > > @@ -193,7 +191,6 @@ static struct sky81452_bl_platform_data *sky81452_bl_parse_dt(
> > >  	pdata->ignore_pwm = of_property_read_bool(np, "skyworks,ignore-pwm");
> > >  	pdata->dpwm_mode = of_property_read_bool(np, "skyworks,dpwm-mode");
> > >  	pdata->phase_shift = of_property_read_bool(np, "skyworks,phase-shift");
> > > -	pdata->gpio_enable = of_get_gpio(np, 0);
> > >  
> > >  	ret = of_property_count_u32_elems(np, "led-sources");
> > >  	if (ret < 0) {
> > > @@ -274,13 +271,17 @@ static int sky81452_bl_probe(struct platform_device *pdev)
> > >  		if (IS_ERR(pdata))
> > >  			return PTR_ERR(pdata);
> > >  	}
> > > -
> > > -	if (gpio_is_valid(pdata->gpio_enable)) {
> > > -		ret = devm_gpio_request_one(dev, pdata->gpio_enable,
> > > -					GPIOF_OUT_INIT_HIGH, "sky81452-en");
> > > -		if (ret < 0) {
> > > -			dev_err(dev, "failed to request GPIO. err=%d\n", ret);
> > > -			return ret;
> > > +	pdata->gpiod_enable = devm_gpiod_get(dev, "sk81452-en", GPIOD_OUT_HIGH);
> > 
> > As above... I think the second argument here needs to be NULL in order
> > to preserve the current DT bindings.
>   
>   You are correct. I was testing this driver with a custom dtb in rock960 board and named
>   the property as above in the dts. It should be NULL.
> 
> > 
> > > +	if (IS_ERR(pdata->gpiod_enable)) {
> > > +		long ret = PTR_ERR(pdata->gpiod_enable);
> > > +
> > > +		/**
> > 
> > Nitpicking... but no second star here. That's a trigger symbold for
> > documentation processors.
> 
>   That is a great feedback. I will keep that in mind.
> > 
> > > +		 * gpiod_enable is optional in device tree.
> > > +		 * Return error only if gpio was assigned in device tree
> > 
> > Also nitpicking but I had to read this a few times because
> > gpiod_enable is not in device tree, gpios is.
> 
>   You are correct. I will make necessary changes.
> > 
> > This is a common pattern so the comment can be very short. Something
> > like:
> > 
> >     This DT property is optional so no need to propagate ENOENT
> 
> 	Noted.
> > 
> > 
> > > +		 */
> > > +		if (ret != -ENOENT) {
> > > +			dev_err(dev, "failed to request GPIO. err=%ld\n", ret);
> > > +			return PTR_ERR(pdata->gpiod_enable);
> > >  		}
> > >  	}
> > >  
> > > @@ -323,8 +324,7 @@ static int sky81452_bl_remove(struct platform_device *pdev)
> > >  	bd->props.brightness = 0;
> > >  	backlight_update_status(bd);
> > >  
> > > -	if (gpio_is_valid(pdata->gpio_enable))
> > > -		gpio_set_value_cansleep(pdata->gpio_enable, 0);
> > > +	gpiod_set_value_cansleep(pdata->gpiod_enable, 0);
> > >  
> > >  	return 0;
> > >  }
> > > diff --git a/include/linux/platform_data/sky81452-backlight.h b/include/linux/platform_data/sky81452-backlight.h
> > > index 1231e9b..dc4cb85 100644
> > > --- a/include/linux/platform_data/sky81452-backlight.h
> > > +++ b/include/linux/platform_data/sky81452-backlight.h
> > > @@ -20,6 +20,8 @@
> > >  #ifndef _SKY81452_BACKLIGHT_H
> > >  #define _SKY81452_BACKLIGHT_H
> > >  
> > > +#include <linux/gpio/consumer.h>
> > > +
> > 
> > This heaer file should be included from the C file... it is not required
> > to parse the header.
>  
>   I appreciate the feedback. I will keep that in mind to avoid future
>   errors. 
> > 
> > 
> > Daniel.
> > 
> > 
> > >  /**
> > >   * struct sky81452_platform_data
> > >   * @name:	backlight driver name.
> > > @@ -34,7 +36,7 @@
> > >   */
> > >  struct sky81452_bl_platform_data {
> > >  	const char *name;
> > > -	int gpio_enable;
> > > +	struct gpio_desc *gpiod_enable;
> > >  	unsigned int enable;
> > >  	bool ignore_pwm;
> > >  	bool dpwm_mode;
> > > -- 
> > > 2.7.4
> > >