[PATCH 0/2] pwm-backlight: switch to gpiod interface (part 1)

[PATCH 0/2] pwm-backlight: switch to gpiod interface (part 1)

[Alexandre Courbot]

These two patches initiate the switch of the pwm-backlight driver to
the gpiod GPIO interface, as it considerably simplifies the code.

For compatibility with current users of the driver, it is still possible
to pass the enable GPIO number as platform data. Two platforms are still
relying on this feature (pxa/palmtc and shmobile/armadillo800eva) which
will be removed as soon as its last users are switched to GPIO mapping
tables.

Alexandre Courbot (2):
  ARM: SAMSUNG: remove gpio flags in dev-backlight
  pwm-backlight: switch to gpiod interface

 arch/arm/plat-samsung/dev-backlight.c |  2 -
 drivers/video/backlight/pwm_bl.c      | 72 +++++++++++++++--------------------
 include/linux/pwm_backlight.h         |  5 +--
 3 files changed, 32 insertions(+), 47 deletions(-)

-- 
1.9.0

[PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Alexandre Courbot]

The pwm-backlight driver is moving to use the gpiod interface,
which has its own mapping mechanism for platform data GPIOs.
These mappings carry GPIO properties like active low so they don't have
to be explicitly handled by GPIO consumers.

Because of this change, the enable_gpio_flags member of
platform_pwm_backlight_data is going away. dev-backlight was passing
this member, but had no user making use of it, so it can safely be
removed. Further GPIOs used by pwm-backlight are expected to be
defined using the mechanisms provided by the gpiod API.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 arch/arm/plat-samsung/dev-backlight.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c
index be4ad0b21c08..2157c5b539e6 100644
--- a/arch/arm/plat-samsung/dev-backlight.c
+++ b/arch/arm/plat-samsung/dev-backlight.c
@@ -124,8 +124,6 @@ void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
 		samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
 	if (bl_data->enable_gpio >= 0)
 		samsung_bl_data->enable_gpio = bl_data->enable_gpio;
-	if (bl_data->enable_gpio_flags)
-		samsung_bl_data->enable_gpio_flags = bl_data->enable_gpio_flags;
 	if (bl_data->init)
 		samsung_bl_data->init = bl_data->init;
 	if (bl_data->notify)
-- 
1.9.0

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Alexandre Courbot]

Ping, can I have the Samsung folks review and ,aybe even merge this
patch? enable_gpio_flags is never used in any code, is replaced by
gpiod, and we would like to remove it altogether from pwm_bl. Thanks!

Alex.

On Thu, Feb 27, 2014 at 2:53 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> The pwm-backlight driver is moving to use the gpiod interface,
> which has its own mapping mechanism for platform data GPIOs.
> These mappings carry GPIO properties like active low so they don't have
> to be explicitly handled by GPIO consumers.
>
> Because of this change, the enable_gpio_flags member of
> platform_pwm_backlight_data is going away. dev-backlight was passing
> this member, but had no user making use of it, so it can safely be
> removed. Further GPIOs used by pwm-backlight are expected to be
> defined using the mechanisms provided by the gpiod API.
>
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  arch/arm/plat-samsung/dev-backlight.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c
> index be4ad0b21c08..2157c5b539e6 100644
> --- a/arch/arm/plat-samsung/dev-backlight.c
> +++ b/arch/arm/plat-samsung/dev-backlight.c
> @@ -124,8 +124,6 @@ void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
>                 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
>         if (bl_data->enable_gpio >= 0)
>                 samsung_bl_data->enable_gpio = bl_data->enable_gpio;
> -       if (bl_data->enable_gpio_flags)
> -               samsung_bl_data->enable_gpio_flags = bl_data->enable_gpio_flags;
>         if (bl_data->init)
>                 samsung_bl_data->init = bl_data->init;
>         if (bl_data->notify)
> --
> 1.9.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Jingoo Han]

On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
> 
> Ping, can I have the Samsung folks review and ,aybe even merge this
> patch? enable_gpio_flags is never used in any code, is replaced by
> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!

OK, I see. It looks good.

As far as I know, 'enable_gpio_flags' has not been being used
for Samsung platform. So, there will be no side effect,
if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
directory.

Reviewed-by: Jingoo Han <jg1.han@samsung.com>

Best regards,
Jingoo Han

> 
> Alex.
> 
> On Thu, Feb 27, 2014 at 2:53 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> > The pwm-backlight driver is moving to use the gpiod interface,
> > which has its own mapping mechanism for platform data GPIOs.
> > These mappings carry GPIO properties like active low so they don't have
> > to be explicitly handled by GPIO consumers.
> >
> > Because of this change, the enable_gpio_flags member of
> > platform_pwm_backlight_data is going away. dev-backlight was passing
> > this member, but had no user making use of it, so it can safely be
> > removed. Further GPIOs used by pwm-backlight are expected to be
> > defined using the mechanisms provided by the gpiod API.
> >
> > Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> > ---
> >  arch/arm/plat-samsung/dev-backlight.c | 2 --
> >  1 file changed, 2 deletions(-)
> >
> > diff --git a/arch/arm/plat-samsung/dev-backlight.c b/arch/arm/plat-samsung/dev-backlight.c
> > index be4ad0b21c08..2157c5b539e6 100644
> > --- a/arch/arm/plat-samsung/dev-backlight.c
> > +++ b/arch/arm/plat-samsung/dev-backlight.c
> > @@ -124,8 +124,6 @@ void __init samsung_bl_set(struct samsung_bl_gpio_info *gpio_info,
> >                 samsung_bl_data->pwm_period_ns = bl_data->pwm_period_ns;
> >         if (bl_data->enable_gpio >= 0)
> >                 samsung_bl_data->enable_gpio = bl_data->enable_gpio;
> > -       if (bl_data->enable_gpio_flags)
> > -               samsung_bl_data->enable_gpio_flags = bl_data->enable_gpio_flags;
> >         if (bl_data->init)
> >                 samsung_bl_data->init = bl_data->init;
> >         if (bl_data->notify)
> > --
> > 1.9.0

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Alexandre Courbot]

On Thu, Apr 10, 2014 at 6:51 PM, Jingoo Han <jg1.han@samsung.com> wrote:
> On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
>>
>> Ping, can I have the Samsung folks review and ,aybe even merge this
>> patch? enable_gpio_flags is never used in any code, is replaced by
>> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!
>
> OK, I see. It looks good.
>
> As far as I know, 'enable_gpio_flags' has not been being used
> for Samsung platform. So, there will be no side effect,
> if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
> directory.
>
> Reviewed-by: Jingoo Han <jg1.han@samsung.com>

Great, thanks. Ben, Kukjin, could we have your Acked-by?

Thierry, if the Samsung maintainers are ok with it, and 2/2 of this
series is also ok for you (you merged the same for simple-panel
already), can you take both into your tree?

Thanks,
Alex.

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Alexandre Courbot]

On Thu, Apr 10, 2014 at 11:14 PM, Alexandre Courbot <gnurou@gmail.com> wrote:
> On Thu, Apr 10, 2014 at 6:51 PM, Jingoo Han <jg1.han@samsung.com> wrote:
>> On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
>>>
>>> Ping, can I have the Samsung folks review and ,aybe even merge this
>>> patch? enable_gpio_flags is never used in any code, is replaced by
>>> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!
>>
>> OK, I see. It looks good.
>>
>> As far as I know, 'enable_gpio_flags' has not been being used
>> for Samsung platform. So, there will be no side effect,
>> if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
>> directory.
>>
>> Reviewed-by: Jingoo Han <jg1.han@samsung.com>
>
> Great, thanks. Ben, Kukjin, could we have your Acked-by?
>
> Thierry, if the Samsung maintainers are ok with it, and 2/2 of this
> series is also ok for you (you merged the same for simple-panel
> already), can you take both into your tree?

Last call - could we have a Acked-by from Ben or Kukjin and merge this
through Thierry's tree? Otherwise I will just have to drop this
series, which would be sad.

RE: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Kukjin Kim]

Alexandre Courbot wrote:
> 
> On Thu, Apr 10, 2014 at 11:14 PM, Alexandre Courbot <gnurou@gmail.com>
> wrote:
> > On Thu, Apr 10, 2014 at 6:51 PM, Jingoo Han <jg1.han@samsung.com> wrote:
> >> On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
> >>>
> >>> Ping, can I have the Samsung folks review and ,aybe even merge this
> >>> patch? enable_gpio_flags is never used in any code, is replaced by
> >>> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!
> >>
> >> OK, I see. It looks good.
> >>
> >> As far as I know, 'enable_gpio_flags' has not been being used
> >> for Samsung platform. So, there will be no side effect,
> >> if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
> >> directory.
> >>
> >> Reviewed-by: Jingoo Han <jg1.han@samsung.com>
> >
> > Great, thanks. Ben, Kukjin, could we have your Acked-by?
> >
> > Thierry, if the Samsung maintainers are ok with it, and 2/2 of this
> > series is also ok for you (you merged the same for simple-panel
> > already), can you take both into your tree?
> 
> Last call - could we have a Acked-by from Ben or Kukjin and merge this
> through Thierry's tree? Otherwise I will just have to drop this
> series, which would be sad.

Very sorry for late response. I missed... :(

Looks good to me, so please go ahead with my ack.

Thanks,
Kukjin

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Alexandre Courbot]

On Tue, May 6, 2014 at 1:59 PM, Kukjin Kim <kgene.kim@samsung.com> wrote:
> Alexandre Courbot wrote:
>>
>> On Thu, Apr 10, 2014 at 11:14 PM, Alexandre Courbot <gnurou@gmail.com>
>> wrote:
>> > On Thu, Apr 10, 2014 at 6:51 PM, Jingoo Han <jg1.han@samsung.com> wrote:
>> >> On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
>> >>>
>> >>> Ping, can I have the Samsung folks review and ,aybe even merge this
>> >>> patch? enable_gpio_flags is never used in any code, is replaced by
>> >>> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!
>> >>
>> >> OK, I see. It looks good.
>> >>
>> >> As far as I know, 'enable_gpio_flags' has not been being used
>> >> for Samsung platform. So, there will be no side effect,
>> >> if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
>> >> directory.
>> >>
>> >> Reviewed-by: Jingoo Han <jg1.han@samsung.com>
>> >
>> > Great, thanks. Ben, Kukjin, could we have your Acked-by?
>> >
>> > Thierry, if the Samsung maintainers are ok with it, and 2/2 of this
>> > series is also ok for you (you merged the same for simple-panel
>> > already), can you take both into your tree?
>>
>> Last call - could we have a Acked-by from Ben or Kukjin and merge this
>> through Thierry's tree? Otherwise I will just have to drop this
>> series, which would be sad.
>
> Very sorry for late response. I missed... :(
>
> Looks good to me, so please go ahead with my ack.

Thanks Kukjin!

Thierry, do you want me to rebase and resend these (now old) patches?
I haven't heard anything from you about them yet.

Cheers,
Alex.

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1807 bytes --]

On Tue, May 06, 2014 at 11:33:00PM +0900, Alexandre Courbot wrote:
> On Tue, May 6, 2014 at 1:59 PM, Kukjin Kim <kgene.kim@samsung.com> wrote:
> > Alexandre Courbot wrote:
> >>
> >> On Thu, Apr 10, 2014 at 11:14 PM, Alexandre Courbot <gnurou@gmail.com>
> >> wrote:
> >> > On Thu, Apr 10, 2014 at 6:51 PM, Jingoo Han <jg1.han@samsung.com> wrote:
> >> >> On Thursday, April 10, 2014 1:17 PM, Alexandre Courbot wrote:
> >> >>>
> >> >>> Ping, can I have the Samsung folks review and ,aybe even merge this
> >> >>> patch? enable_gpio_flags is never used in any code, is replaced by
> >> >>> gpiod, and we would like to remove it altogether from pwm_bl. Thanks!
> >> >>
> >> >> OK, I see. It looks good.
> >> >>
> >> >> As far as I know, 'enable_gpio_flags' has not been being used
> >> >> for Samsung platform. So, there will be no side effect,
> >> >> if 'enable_gpio_flags' is removed from 'arch/arm/plat-samsung'
> >> >> directory.
> >> >>
> >> >> Reviewed-by: Jingoo Han <jg1.han@samsung.com>
> >> >
> >> > Great, thanks. Ben, Kukjin, could we have your Acked-by?
> >> >
> >> > Thierry, if the Samsung maintainers are ok with it, and 2/2 of this
> >> > series is also ok for you (you merged the same for simple-panel
> >> > already), can you take both into your tree?
> >>
> >> Last call - could we have a Acked-by from Ben or Kukjin and merge this
> >> through Thierry's tree? Otherwise I will just have to drop this
> >> series, which would be sad.
> >
> > Very sorry for late response. I missed... :(
> >
> > Looks good to me, so please go ahead with my ack.
> 
> Thanks Kukjin!
> 
> Thierry, do you want me to rebase and resend these (now old) patches?
> I haven't heard anything from you about them yet.

No, that's fine. I can handle them.

Thanks,
Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

Re: [PATCH 1/2] ARM: SAMSUNG: remove gpio flags in dev-backlight

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 858 bytes --]

On Thu, Feb 27, 2014 at 02:53:33PM +0900, Alexandre Courbot wrote:
> The pwm-backlight driver is moving to use the gpiod interface,
> which has its own mapping mechanism for platform data GPIOs.
> These mappings carry GPIO properties like active low so they don't have
> to be explicitly handled by GPIO consumers.
> 
> Because of this change, the enable_gpio_flags member of
> platform_pwm_backlight_data is going away. dev-backlight was passing
> this member, but had no user making use of it, so it can safely be
> removed. Further GPIOs used by pwm-backlight are expected to be
> defined using the mechanisms provided by the gpiod API.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  arch/arm/plat-samsung/dev-backlight.c | 2 --
>  1 file changed, 2 deletions(-)

Applied with Kukjin's Acked-by, thanks.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

[PATCH 2/2] pwm-backlight: switch to gpiod interface

[Alexandre Courbot]

Switch to the new gpiod interface, which allows to handle GPIO
properties such as active low transparently and removes a whole bunch of
code.

There are still a couple of users of this driver that rely on passing
the enable GPIO number through platform data, so a fallback mechanism
using a GPIO number is still available to avoid breaking them. It will
be removed once current users have switched to the GPIO lookup tables
provided by the gpiod interface.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/video/backlight/pwm_bl.c | 72 +++++++++++++++++-----------------------
 include/linux/pwm_backlight.h    |  5 +--
 2 files changed, 32 insertions(+), 45 deletions(-)

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index b75201ff46f6..533057688d93 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -10,8 +10,8 @@
  * published by the Free Software Foundation.
  */
 
+#include <linux/gpio/consumer.h>
 #include <linux/gpio.h>
-#include <linux/of_gpio.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
@@ -32,8 +32,7 @@ struct pwm_bl_data {
 	unsigned int		*levels;
 	bool			enabled;
 	struct regulator	*power_supply;
-	int			enable_gpio;
-	unsigned long		enable_gpio_flags;
+	struct gpio_desc	*enable_gpio;
 	unsigned int		scale;
 	int			(*notify)(struct device *,
 					  int brightness);
@@ -54,12 +53,8 @@ static void pwm_backlight_power_on(struct pwm_bl_data *pb, int brightness)
 	if (err < 0)
 		dev_err(pb->dev, "failed to enable power supply\n");
 
-	if (gpio_is_valid(pb->enable_gpio)) {
-		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
-			gpio_set_value(pb->enable_gpio, 0);
-		else
-			gpio_set_value(pb->enable_gpio, 1);
-	}
+	if (pb->enable_gpio)
+		gpiod_set_value(pb->enable_gpio, 1);
 
 	pwm_enable(pb->pwm);
 	pb->enabled = true;
@@ -73,12 +68,8 @@ static void pwm_backlight_power_off(struct pwm_bl_data *pb)
 	pwm_config(pb->pwm, 0, pb->period);
 	pwm_disable(pb->pwm);
 
-	if (gpio_is_valid(pb->enable_gpio)) {
-		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
-			gpio_set_value(pb->enable_gpio, 1);
-		else
-			gpio_set_value(pb->enable_gpio, 0);
-	}
+	if (pb->enable_gpio)
+		gpiod_set_value(pb->enable_gpio, 0);
 
 	regulator_disable(pb->power_supply);
 	pb->enabled = false;
@@ -148,7 +139,6 @@ static int pwm_backlight_parse_dt(struct device *dev,
 				  struct platform_pwm_backlight_data *data)
 {
 	struct device_node *node = dev->of_node;
-	enum of_gpio_flags flags;
 	struct property *prop;
 	int length;
 	u32 value;
@@ -189,14 +179,6 @@ static int pwm_backlight_parse_dt(struct device *dev,
 		data->max_brightness--;
 	}
 
-	data->enable_gpio = of_get_named_gpio_flags(node, "enable-gpios", 0,
-						    &flags);
-	if (data->enable_gpio == -EPROBE_DEFER)
-		return -EPROBE_DEFER;
-
-	if (gpio_is_valid(data->enable_gpio) && (flags & OF_GPIO_ACTIVE_LOW))
-		data->enable_gpio_flags |= PWM_BACKLIGHT_GPIO_ACTIVE_LOW;
-
 	return 0;
 }
 
@@ -256,8 +238,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	} else
 		pb->scale = data->max_brightness;
 
-	pb->enable_gpio = data->enable_gpio;
-	pb->enable_gpio_flags = data->enable_gpio_flags;
 	pb->notify = data->notify;
 	pb->notify_after = data->notify_after;
 	pb->check_fb = data->check_fb;
@@ -265,26 +245,39 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	pb->dev = &pdev->dev;
 	pb->enabled = false;
 
-	if (gpio_is_valid(pb->enable_gpio)) {
-		unsigned long flags;
-
-		if (pb->enable_gpio_flags & PWM_BACKLIGHT_GPIO_ACTIVE_LOW)
-			flags = GPIOF_OUT_INIT_HIGH;
-		else
-			flags = GPIOF_OUT_INIT_LOW;
+	pb->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
+	if (IS_ERR(pb->enable_gpio)) {
+		ret = PTR_ERR(pb->enable_gpio);
+		if (ret == -ENOENT) {
+			pb->enable_gpio = NULL;
+			ret = 0;
+		} else {
+			goto err_alloc;
+		}
+	}
 
-		ret = gpio_request_one(pb->enable_gpio, flags, "enable");
+	/*
+	 * Compatibility fallback for drivers still using the integer GPIO
+	 * platform data. Must go away soon.
+	 */
+	if (pb->enable_gpio == NULL && gpio_is_valid(data->enable_gpio)) {
+		ret = devm_gpio_request_one(&pdev->dev, data->enable_gpio,
+					    GPIOF_OUT_INIT_HIGH, "enable");
 		if (ret < 0) {
 			dev_err(&pdev->dev, "failed to request GPIO#%d: %d\n",
-				pb->enable_gpio, ret);
+				data->enable_gpio, ret);
 			goto err_alloc;
 		}
+		pb->enable_gpio = gpio_to_desc(data->enable_gpio);
 	}
 
+	if (pb->enable_gpio)
+		gpiod_direction_output(pb->enable_gpio, 1);
+
 	pb->power_supply = devm_regulator_get(&pdev->dev, "power");
 	if (IS_ERR(pb->power_supply)) {
 		ret = PTR_ERR(pb->power_supply);
-		goto err_gpio;
+		goto err_alloc;
 	}
 
 	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
@@ -295,7 +288,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 		if (IS_ERR(pb->pwm)) {
 			dev_err(&pdev->dev, "unable to request legacy PWM\n");
 			ret = PTR_ERR(pb->pwm);
-			goto err_gpio;
+			goto err_alloc;
 		}
 	}
 
@@ -320,7 +313,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	if (IS_ERR(bl)) {
 		dev_err(&pdev->dev, "failed to register backlight\n");
 		ret = PTR_ERR(bl);
-		goto err_gpio;
+		goto err_alloc;
 	}
 
 	if (data->dft_brightness > data->max_brightness) {
@@ -336,9 +329,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, bl);
 	return 0;
 
-err_gpio:
-	if (gpio_is_valid(pb->enable_gpio))
-		gpio_free(pb->enable_gpio);
 err_alloc:
 	if (data->exit)
 		data->exit(&pdev->dev);
diff --git a/include/linux/pwm_backlight.h b/include/linux/pwm_backlight.h
index 2de2e275b2cb..efdd9227a49c 100644
--- a/include/linux/pwm_backlight.h
+++ b/include/linux/pwm_backlight.h
@@ -6,9 +6,6 @@
 
 #include <linux/backlight.h>
 
-/* TODO: convert to gpiod_*() API once it has been merged */
-#define PWM_BACKLIGHT_GPIO_ACTIVE_LOW	(1 << 0)
-
 struct platform_pwm_backlight_data {
 	int pwm_id;
 	unsigned int max_brightness;
@@ -16,8 +13,8 @@ struct platform_pwm_backlight_data {
 	unsigned int lth_brightness;
 	unsigned int pwm_period_ns;
 	unsigned int *levels;
+	/* TODO remove once all users are switched to gpiod_* API */
 	int enable_gpio;
-	unsigned long enable_gpio_flags;
 	int (*init)(struct device *dev);
 	int (*notify)(struct device *dev, int brightness);
 	void (*notify_after)(struct device *dev, int brightness);
-- 
1.9.0

Re: [PATCH 2/2] pwm-backlight: switch to gpiod interface

[Thierry Reding]

[-- Attachment #1: Type: text/plain, Size: 1824 bytes --]

On Thu, Feb 27, 2014 at 02:53:34PM +0900, Alexandre Courbot wrote:
> Switch to the new gpiod interface, which allows to handle GPIO
> properties such as active low transparently and removes a whole bunch of
> code.
> 
> There are still a couple of users of this driver that rely on passing
> the enable GPIO number through platform data, so a fallback mechanism
> using a GPIO number is still available to avoid breaking them. It will
> be removed once current users have switched to the GPIO lookup tables
> provided by the gpiod interface.
> 
> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
> ---
>  drivers/video/backlight/pwm_bl.c | 72 +++++++++++++++++-----------------------
>  include/linux/pwm_backlight.h    |  5 +--
>  2 files changed, 32 insertions(+), 45 deletions(-)

I've applied this with two tiny changes, see below. Please shout if you
think that's a bad idea.

> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
[...]
> @@ -256,8 +238,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
[...]
> +	pb->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
> +	if (IS_ERR(pb->enable_gpio)) {
> +		ret = PTR_ERR(pb->enable_gpio);
> +		if (ret == -ENOENT) {
> +			pb->enable_gpio = NULL;
> +			ret = 0;
> +		} else {
> +			goto err_alloc;
> +		}

I dropped the ret = 0 here because all error paths set it explicitly and
the non-error path never uses it. Now all branches have a single
statement and therefore the braces can be dropped.

> +	/*
> +	 * Compatibility fallback for drivers still using the integer GPIO
> +	 * platform data. Must go away soon.
> +	 */
> +	if (pb->enable_gpio == NULL && gpio_is_valid(data->enable_gpio)) {

Changed the first condition to !pb->enable_gpio for consistency.

Thierry

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

Re: [PATCH 2/2] pwm-backlight: switch to gpiod interface

[Alexandre Courbot]

On Wed, May 7, 2014 at 5:18 PM, Thierry Reding <thierry.reding@gmail.com> wrote:
> On Thu, Feb 27, 2014 at 02:53:34PM +0900, Alexandre Courbot wrote:
>> Switch to the new gpiod interface, which allows to handle GPIO
>> properties such as active low transparently and removes a whole bunch of
>> code.
>>
>> There are still a couple of users of this driver that rely on passing
>> the enable GPIO number through platform data, so a fallback mechanism
>> using a GPIO number is still available to avoid breaking them. It will
>> be removed once current users have switched to the GPIO lookup tables
>> provided by the gpiod interface.
>>
>> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
>> ---
>>  drivers/video/backlight/pwm_bl.c | 72 +++++++++++++++++-----------------------
>>  include/linux/pwm_backlight.h    |  5 +--
>>  2 files changed, 32 insertions(+), 45 deletions(-)
>
> I've applied this with two tiny changes, see below. Please shout if you
> think that's a bad idea.

I'm fine with both changes. Thanks for picking these two guys!

Alex.

>
>> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> [...]
>> @@ -256,8 +238,6 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> [...]
>> +     pb->enable_gpio = devm_gpiod_get(&pdev->dev, "enable");
>> +     if (IS_ERR(pb->enable_gpio)) {
>> +             ret = PTR_ERR(pb->enable_gpio);
>> +             if (ret == -ENOENT) {
>> +                     pb->enable_gpio = NULL;
>> +                     ret = 0;
>> +             } else {
>> +                     goto err_alloc;
>> +             }
>
> I dropped the ret = 0 here because all error paths set it explicitly and
> the non-error path never uses it. Now all branches have a single
> statement and therefore the braces can be dropped.
>
>> +     /*
>> +      * Compatibility fallback for drivers still using the integer GPIO
>> +      * platform data. Must go away soon.
>> +      */
>> +     if (pb->enable_gpio == NULL && gpio_is_valid(data->enable_gpio)) {
>
> Changed the first condition to !pb->enable_gpio for consistency.
>
> Thierry

Re: [PATCH 0/2] pwm-backlight: switch to gpiod interface (part 1)

[Alexandre Courbot]

Ping Thierry, can you have a look at this series? It is quite similar
to the same change you merged for panel-simple (although I cannot see
it in -next neither).

On Thu, Feb 27, 2014 at 2:53 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> These two patches initiate the switch of the pwm-backlight driver to
> the gpiod GPIO interface, as it considerably simplifies the code.
>
> For compatibility with current users of the driver, it is still possible
> to pass the enable GPIO number as platform data. Two platforms are still
> relying on this feature (pxa/palmtc and shmobile/armadillo800eva) which
> will be removed as soon as its last users are switched to GPIO mapping
> tables.
>
> Alexandre Courbot (2):
>   ARM: SAMSUNG: remove gpio flags in dev-backlight
>   pwm-backlight: switch to gpiod interface
>
>  arch/arm/plat-samsung/dev-backlight.c |  2 -
>  drivers/video/backlight/pwm_bl.c      | 72 +++++++++++++++--------------------
>  include/linux/pwm_backlight.h         |  5 +--
>  3 files changed, 32 insertions(+), 47 deletions(-)
>
> --
> 1.9.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 0/2] pwm-backlight: switch to gpiod interface (part 1)

[Bryan Wu]

On Tue, Mar 25, 2014 at 10:01 PM, Alexandre Courbot <gnurou@gmail.com> wrote:
> Ping Thierry, can you have a look at this series? It is quite similar
> to the same change you merged for panel-simple (although I cannot see
> it in -next neither).
>

I think Jingoo can help to review this as well. Jingoo, can you help
to review. Actually it looks good to me.

-Bryan

> On Thu, Feb 27, 2014 at 2:53 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
>> These two patches initiate the switch of the pwm-backlight driver to
>> the gpiod GPIO interface, as it considerably simplifies the code.
>>
>> For compatibility with current users of the driver, it is still possible
>> to pass the enable GPIO number as platform data. Two platforms are still
>> relying on this feature (pxa/palmtc and shmobile/armadillo800eva) which
>> will be removed as soon as its last users are switched to GPIO mapping
>> tables.
>>
>> Alexandre Courbot (2):
>>   ARM: SAMSUNG: remove gpio flags in dev-backlight
>>   pwm-backlight: switch to gpiod interface
>>
>>  arch/arm/plat-samsung/dev-backlight.c |  2 -
>>  drivers/video/backlight/pwm_bl.c      | 72 +++++++++++++++--------------------
>>  include/linux/pwm_backlight.h         |  5 +--
>>  3 files changed, 32 insertions(+), 47 deletions(-)
>>
>> --
>> 1.9.0
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-gpio" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH 0/2] pwm-backlight: switch to gpiod interface (part 1)

[Jingoo Han]

On Thursday, March 27, 2014 9:09 AM, Bryan Wu wrote:
> On Tue, Mar 25, 2014 at 10:01 PM, Alexandre Courbot <gnurou@gmail.com> wrote:
> > Ping Thierry, can you have a look at this series? It is quite similar
> > to the same change you merged for panel-simple (although I cannot see
> > it in -next neither).
> >
> 
> I think Jingoo can help to review this as well. Jingoo, can you help
> to review. Actually it looks good to me.

Sorry, I cannot review this pwm-backlight code, I don't have
knowledge about pwm-backlight and gpiod. I think that Thierry
will review this correctly.

Best regards,
Jingoo Han

> 
> -Bryan
> 
> > On Thu, Feb 27, 2014 at 2:53 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> >> These two patches initiate the switch of the pwm-backlight driver to
> >> the gpiod GPIO interface, as it considerably simplifies the code.
> >>
> >> For compatibility with current users of the driver, it is still possible
> >> to pass the enable GPIO number as platform data. Two platforms are still
> >> relying on this feature (pxa/palmtc and shmobile/armadillo800eva) which
> >> will be removed as soon as its last users are switched to GPIO mapping
> >> tables.
> >>
> >> Alexandre Courbot (2):
> >>   ARM: SAMSUNG: remove gpio flags in dev-backlight
> >>   pwm-backlight: switch to gpiod interface
> >>
> >>  arch/arm/plat-samsung/dev-backlight.c |  2 -
> >>  drivers/video/backlight/pwm_bl.c      | 72 +++++++++++++++--------------------
> >>  include/linux/pwm_backlight.h         |  5 +--
> >>  3 files changed, 32 insertions(+), 47 deletions(-)
> >>
> >> --
> >> 1.9.0