2019-06-12 07:56:52

by Shobhit Kukreti

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

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 <[email protected]>
---
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


2019-06-12 14:38:33

by Daniel Thompson

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

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 <[email protected]>

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
>

2019-06-12 18:03:57

by Sam Ravnborg

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

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

2019-06-12 18:05:56

by Shobhit Kukreti

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

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 <[email protected]>
>
> 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
> >

2019-06-13 15:35:16

by Daniel Thompson

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

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 <[email protected]>
> >
> > 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
> > >