diff mbox series

drm/panel: s6e63m0: Support max-brightness

Message ID 20201214222210.238081-1-linus.walleij@linaro.org
State Accepted
Commit 1f20bf5921de420071fdb1d55cda7550ae137bcd
Headers show
Series drm/panel: s6e63m0: Support max-brightness | expand

Commit Message

Linus Walleij Dec. 14, 2020, 10:22 p.m. UTC
The "max-brightness" is a standard backlight property that
we need to support for the Samsung GT-I8190 Golden because
the display will go black if we crank up the brightness
too high.

As the platform needs this ability to give picture this is
a regression fix along with the addition of the property
to the GT-I8190 device tree.

Cc: Stephan Gerhold <stephan@gerhold.net>
Fixes: 9c3f0a0dd6a1 ("drm/panel: s6e63m0: Implement 28 backlight levels")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
 drivers/gpu/drm/panel/panel-samsung-s6e63m0.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

-- 
2.29.2

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Comments

Sam Ravnborg Dec. 15, 2020, 5:44 a.m. UTC | #1
Hi Linus.
On Mon, Dec 14, 2020 at 11:22:10PM +0100, Linus Walleij wrote:
> The "max-brightness" is a standard backlight property that

> we need to support for the Samsung GT-I8190 Golden because

> the display will go black if we crank up the brightness

> too high.

> 

> As the platform needs this ability to give picture this is

> a regression fix along with the addition of the property

> to the GT-I8190 device tree.

> 

> Cc: Stephan Gerhold <stephan@gerhold.net>

> Fixes: 9c3f0a0dd6a1 ("drm/panel: s6e63m0: Implement 28 backlight levels")

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>


Looks good. backlight_properties.max_brightness is an int, but this
looks like a sub-optimal type so the use of u32 in this patch is fine.

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>


As we are in the merge window it should be drm-next-fixes material,
but you may have to wait until -rc2 before the drm-next-fixes branched
is ready.

	Sam

> ---

>  drivers/gpu/drm/panel/panel-samsung-s6e63m0.c | 17 +++++++++++++----

>  1 file changed, 13 insertions(+), 4 deletions(-)

> 

> diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c

> index bf6d704d4d27..603c5dfe8768 100644

> --- a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c

> +++ b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c

> @@ -692,12 +692,12 @@ static const struct backlight_ops s6e63m0_backlight_ops = {

>  	.update_status	= s6e63m0_set_brightness,

>  };

>  

> -static int s6e63m0_backlight_register(struct s6e63m0 *ctx)

> +static int s6e63m0_backlight_register(struct s6e63m0 *ctx, u32 max_brightness)

>  {

>  	struct backlight_properties props = {

>  		.type		= BACKLIGHT_RAW,

> -		.brightness	= MAX_BRIGHTNESS,

> -		.max_brightness = MAX_BRIGHTNESS

> +		.brightness	= max_brightness,

> +		.max_brightness = max_brightness,

>  	};

>  	struct device *dev = ctx->dev;

>  	int ret = 0;

> @@ -719,6 +719,7 @@ int s6e63m0_probe(struct device *dev,

>  		  bool dsi_mode)

>  {

>  	struct s6e63m0 *ctx;

> +	u32 max_brightness;

>  	int ret;

>  

>  	ctx = devm_kzalloc(dev, sizeof(struct s6e63m0), GFP_KERNEL);

> @@ -734,6 +735,14 @@ int s6e63m0_probe(struct device *dev,

>  	ctx->enabled = false;

>  	ctx->prepared = false;

>  

> +	ret = device_property_read_u32(dev, "max-brightness", &max_brightness);

> +	if (ret)

> +		max_brightness = MAX_BRIGHTNESS;

> +	if (max_brightness > MAX_BRIGHTNESS) {

> +		dev_err(dev, "illegal max brightness specified\n");

> +		max_brightness = MAX_BRIGHTNESS;

> +	}

> +

>  	ctx->supplies[0].supply = "vdd3";

>  	ctx->supplies[1].supply = "vci";

>  	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),

> @@ -753,7 +762,7 @@ int s6e63m0_probe(struct device *dev,

>  		       dsi_mode ? DRM_MODE_CONNECTOR_DSI :

>  		       DRM_MODE_CONNECTOR_DPI);

>  

> -	ret = s6e63m0_backlight_register(ctx);

> +	ret = s6e63m0_backlight_register(ctx, max_brightness);

>  	if (ret < 0)

>  		return ret;

>  

> -- 

> 2.29.2

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diff mbox series

Patch

diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
index bf6d704d4d27..603c5dfe8768 100644
--- a/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e63m0.c
@@ -692,12 +692,12 @@  static const struct backlight_ops s6e63m0_backlight_ops = {
 	.update_status	= s6e63m0_set_brightness,
 };
 
-static int s6e63m0_backlight_register(struct s6e63m0 *ctx)
+static int s6e63m0_backlight_register(struct s6e63m0 *ctx, u32 max_brightness)
 {
 	struct backlight_properties props = {
 		.type		= BACKLIGHT_RAW,
-		.brightness	= MAX_BRIGHTNESS,
-		.max_brightness = MAX_BRIGHTNESS
+		.brightness	= max_brightness,
+		.max_brightness = max_brightness,
 	};
 	struct device *dev = ctx->dev;
 	int ret = 0;
@@ -719,6 +719,7 @@  int s6e63m0_probe(struct device *dev,
 		  bool dsi_mode)
 {
 	struct s6e63m0 *ctx;
+	u32 max_brightness;
 	int ret;
 
 	ctx = devm_kzalloc(dev, sizeof(struct s6e63m0), GFP_KERNEL);
@@ -734,6 +735,14 @@  int s6e63m0_probe(struct device *dev,
 	ctx->enabled = false;
 	ctx->prepared = false;
 
+	ret = device_property_read_u32(dev, "max-brightness", &max_brightness);
+	if (ret)
+		max_brightness = MAX_BRIGHTNESS;
+	if (max_brightness > MAX_BRIGHTNESS) {
+		dev_err(dev, "illegal max brightness specified\n");
+		max_brightness = MAX_BRIGHTNESS;
+	}
+
 	ctx->supplies[0].supply = "vdd3";
 	ctx->supplies[1].supply = "vci";
 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
@@ -753,7 +762,7 @@  int s6e63m0_probe(struct device *dev,
 		       dsi_mode ? DRM_MODE_CONNECTOR_DSI :
 		       DRM_MODE_CONNECTOR_DPI);
 
-	ret = s6e63m0_backlight_register(ctx);
+	ret = s6e63m0_backlight_register(ctx, max_brightness);
 	if (ret < 0)
 		return ret;