diff mbox

backlight: pwm: reject legacy pwm request for device defined in dt

Message ID 1434292172-22129-1-git-send-email-vladimir_zapolskiy@mentor.com (mailing list archive)
State New, archived
Headers show

Commit Message

Vladimir Zapolskiy June 14, 2015, 2:29 p.m. UTC
Platform PWM backlight data provided by board's device tree should be
complete enough to successfully request a pwm device using pwm_get()
API. This change fixes a bug, when an arbitrary (first found) PWM is
connected to a "pwm-backlight" compatible device, when explicit PWM
device reference is not given.

Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
already describes "pwms" as a required property, instead of blind
selection of a potentially wrong PWM reject legacy PWM device
registration request, leave legacy API only for non-dt cases.

Based on initial implementation done by Dmitry Eremin-Solenikov.

Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
---
 drivers/video/backlight/pwm_bl.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

Comments

Vladimir Zapolskiy Sept. 21, 2015, 3:16 p.m. UTC | #1
Lee, Thierry,

On 14.06.2015 17:29, Vladimir Zapolskiy wrote:
> Platform PWM backlight data provided by board's device tree should be
> complete enough to successfully request a pwm device using pwm_get()
> API. This change fixes a bug, when an arbitrary (first found) PWM is
> connected to a "pwm-backlight" compatible device, when explicit PWM
> device reference is not given.
> 
> Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> already describes "pwms" as a required property, instead of blind
> selection of a potentially wrong PWM reject legacy PWM device
> registration request, leave legacy API only for non-dt cases.
> 
> Based on initial implementation done by Dmitry Eremin-Solenikov.
> 
> Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
> Acked-by: Thierry Reding <thierry.reding@gmail.com>
> ---
>  drivers/video/backlight/pwm_bl.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 57cb9ec..9991cdb 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -271,15 +271,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
>  	}
>  
>  	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
> -	if (IS_ERR(pb->pwm)) {
> +	if (IS_ERR(pb->pwm) && !pdev->dev.of_node) {
>  		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
>  		pb->legacy = true;
>  		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
> -		if (IS_ERR(pb->pwm)) {
> -			dev_err(&pdev->dev, "unable to request legacy PWM\n");
> -			ret = PTR_ERR(pb->pwm);
> -			goto err_alloc;
> -		}
> +	}
> +
> +	if (IS_ERR(pb->pwm)) {
> +		dev_err(&pdev->dev, "unable to request PWM\n");
> +		ret = PTR_ERR(pb->pwm);
> +		goto err_alloc;
>  	}
>  
>  	dev_dbg(&pdev->dev, "got pwm for backlight\n");
> 


could you please apply this reviewed and acked change?

Thank you in advance.

--
With best wishes,
Vladimir
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Lee Jones Sept. 21, 2015, 11:22 p.m. UTC | #2
On Sun, 14 Jun 2015, Vladimir Zapolskiy wrote:

> Platform PWM backlight data provided by board's device tree should be
> complete enough to successfully request a pwm device using pwm_get()
> API. This change fixes a bug, when an arbitrary (first found) PWM is
> connected to a "pwm-backlight" compatible device, when explicit PWM
> device reference is not given.
> 
> Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> already describes "pwms" as a required property, instead of blind
> selection of a potentially wrong PWM reject legacy PWM device
> registration request, leave legacy API only for non-dt cases.
> 
> Based on initial implementation done by Dmitry Eremin-Solenikov.
> 
> Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
> Acked-by: Thierry Reding <thierry.reding@gmail.com>
> ---
>  drivers/video/backlight/pwm_bl.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)

Applied, thanks.

> diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> index 57cb9ec..9991cdb 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -271,15 +271,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
>  	}
>  
>  	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
> -	if (IS_ERR(pb->pwm)) {
> +	if (IS_ERR(pb->pwm) && !pdev->dev.of_node) {
>  		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
>  		pb->legacy = true;
>  		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
> -		if (IS_ERR(pb->pwm)) {
> -			dev_err(&pdev->dev, "unable to request legacy PWM\n");
> -			ret = PTR_ERR(pb->pwm);
> -			goto err_alloc;
> -		}
> +	}
> +
> +	if (IS_ERR(pb->pwm)) {
> +		dev_err(&pdev->dev, "unable to request PWM\n");
> +		ret = PTR_ERR(pb->pwm);
> +		goto err_alloc;
>  	}
>  
>  	dev_dbg(&pdev->dev, "got pwm for backlight\n");
Lee Jones Oct. 5, 2015, 12:46 p.m. UTC | #3
On Tue, 22 Sep 2015, Lee Jones wrote:

> On Sun, 14 Jun 2015, Vladimir Zapolskiy wrote:
> 
> > Platform PWM backlight data provided by board's device tree should be
> > complete enough to successfully request a pwm device using pwm_get()
> > API. This change fixes a bug, when an arbitrary (first found) PWM is
> > connected to a "pwm-backlight" compatible device, when explicit PWM
> > device reference is not given.
> > 
> > Documentation/devicetree/bindings/video/backlight/pwm-backlight.txt
> > already describes "pwms" as a required property, instead of blind
> > selection of a potentially wrong PWM reject legacy PWM device
> > registration request, leave legacy API only for non-dt cases.
> > 
> > Based on initial implementation done by Dmitry Eremin-Solenikov.
> > 
> > Reported-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> > Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
> > Acked-by: Thierry Reding <thierry.reding@gmail.com>
> > ---
> >  drivers/video/backlight/pwm_bl.c | 13 +++++++------
> >  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> Applied, thanks.

Slight change of plan, as the patch does not apply.

Please rebase it on top of the backlight tree and resubmit with my
Ack.

> > diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
> > index 57cb9ec..9991cdb 100644
> > --- a/drivers/video/backlight/pwm_bl.c
> > +++ b/drivers/video/backlight/pwm_bl.c
> > @@ -271,15 +271,16 @@ static int pwm_backlight_probe(struct platform_device *pdev)
> >  	}
> >  
> >  	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
> > -	if (IS_ERR(pb->pwm)) {
> > +	if (IS_ERR(pb->pwm) && !pdev->dev.of_node) {
> >  		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
> >  		pb->legacy = true;
> >  		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
> > -		if (IS_ERR(pb->pwm)) {
> > -			dev_err(&pdev->dev, "unable to request legacy PWM\n");
> > -			ret = PTR_ERR(pb->pwm);
> > -			goto err_alloc;
> > -		}
> > +	}
> > +
> > +	if (IS_ERR(pb->pwm)) {
> > +		dev_err(&pdev->dev, "unable to request PWM\n");
> > +		ret = PTR_ERR(pb->pwm);
> > +		goto err_alloc;
> >  	}
> >  
> >  	dev_dbg(&pdev->dev, "got pwm for backlight\n");
>
diff mbox

Patch

diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index 57cb9ec..9991cdb 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -271,15 +271,16 @@  static int pwm_backlight_probe(struct platform_device *pdev)
 	}
 
 	pb->pwm = devm_pwm_get(&pdev->dev, NULL);
-	if (IS_ERR(pb->pwm)) {
+	if (IS_ERR(pb->pwm) && !pdev->dev.of_node) {
 		dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
 		pb->legacy = true;
 		pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
-		if (IS_ERR(pb->pwm)) {
-			dev_err(&pdev->dev, "unable to request legacy PWM\n");
-			ret = PTR_ERR(pb->pwm);
-			goto err_alloc;
-		}
+	}
+
+	if (IS_ERR(pb->pwm)) {
+		dev_err(&pdev->dev, "unable to request PWM\n");
+		ret = PTR_ERR(pb->pwm);
+		goto err_alloc;
 	}
 
 	dev_dbg(&pdev->dev, "got pwm for backlight\n");