diff mbox series

[2/2] drm/bridge: lvds-codec: Add support for LVDS data mapping select

Message ID 20210515204656.367442-2-marex@denx.de (mailing list archive)
State New, archived
Headers show
Series [1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select | expand

Commit Message

Marek Vasut May 15, 2021, 8:46 p.m. UTC
Decoder input LVDS format is a property of the decoder chip or even
its strapping. Handle data-mapping the same way lvds-panel does. In
case data-mapping is not present, do nothing, since there are still
legacy bindings which do not specify this property.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
To: dri-devel@lists.freedesktop.org
---
 drivers/gpu/drm/bridge/lvds-codec.c | 50 +++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

Comments

Laurent Pinchart May 17, 2021, 11:03 p.m. UTC | #1
Hi Marek,

Thank you for the patch.

On Sat, May 15, 2021 at 10:46:56PM +0200, Marek Vasut wrote:
> Decoder input LVDS format is a property of the decoder chip or even
> its strapping. Handle data-mapping the same way lvds-panel does. In
> case data-mapping is not present, do nothing, since there are still
> legacy bindings which do not specify this property.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> To: dri-devel@lists.freedesktop.org
> ---
>  drivers/gpu/drm/bridge/lvds-codec.c | 50 +++++++++++++++++++++++++++++
>  1 file changed, 50 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> index 8a7cb267ab14..33f992d52902 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -23,6 +23,7 @@ struct lvds_codec {
>  	struct regulator *vcc;
>  	struct gpio_desc *powerdown_gpio;
>  	u32 connector_type;
> +	unsigned int bus_format;
>  };
>  
>  static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
> @@ -69,10 +70,33 @@ static void lvds_codec_disable(struct drm_bridge *bridge)
>  			"Failed to disable regulator \"vcc\": %d\n", ret);
>  }
>  
> +static bool lvds_codec_mode_fixup(struct drm_bridge *bridge,
> +				const struct drm_display_mode *mode,
> +				struct drm_display_mode *adj)
> +{
> +	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
> +	struct drm_encoder *encoder = bridge->encoder;
> +	struct drm_device *ddev = encoder->dev;
> +	struct drm_connector *connector;
> +
> +	/* If 'data-mapping' was not specified, do nothing. */
> +	if (!lvds_codec->bus_format)
> +		return true;
> +
> +	/* Patch in the LVDS format */
> +	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
> +		drm_display_info_set_bus_formats(&connector->display_info,
> +						 &lvds_codec->bus_format, 1);
> +	}

This part bothers me, as the format at the input of the LVDS decoder
doesn't match the format on the connector. Shouldn't you implement
.atomic_get_output_bus_fmts() instead ?

> +
> +	return true;
> +}
> +
>  static const struct drm_bridge_funcs funcs = {
>  	.attach = lvds_codec_attach,
>  	.enable = lvds_codec_enable,
>  	.disable = lvds_codec_disable,
> +	.mode_fixup = lvds_codec_mode_fixup,
>  };
>  
>  static int lvds_codec_probe(struct platform_device *pdev)
> @@ -81,6 +105,7 @@ static int lvds_codec_probe(struct platform_device *pdev)
>  	struct device_node *panel_node;
>  	struct drm_panel *panel;
>  	struct lvds_codec *lvds_codec;
> +	const char *mapping;

I would have moved this variable to the if () { ... } below, but maybe
that's just me.

>  	u32 val;
>  
>  	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
> @@ -133,6 +158,31 @@ static int lvds_codec_probe(struct platform_device *pdev)
>  			DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
>  	}
>  
> +	/*
> +	 * Decoder input LVDS format is a property of the decoder chip or even
> +	 * its strapping. Handle data-mapping the same way lvds-panel does. In
> +	 * case data-mapping is not present, do nothing, since there are still
> +	 * legacy bindings which do not specify this property.
> +	 */
> +	if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
> +		ret = of_property_read_string(dev->of_node, "data-mapping",
> +					      &mapping);
> +		if (ret < 0) {
> +			dev_err(dev, "missing 'data-mapping' DT property\n");
> +		} else {
> +			if (!strcmp(mapping, "jeida-18")) {
> +				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
> +			} else if (!strcmp(mapping, "jeida-24")) {
> +				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
> +			} else if (!strcmp(mapping, "vesa-24")) {
> +				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
> +			} else {
> +				dev_err(dev, "invalid 'data-mapping' DT property\n");
> +				return -EINVAL;
> +			}
> +		}
> +	}
> +
>  	/*
>  	 * The panel_bridge bridge is attached to the panel's of_node,
>  	 * but we need a bridge attached to our of_node for our user
Marek Vasut May 25, 2021, 10:38 a.m. UTC | #2
On 5/18/21 1:03 AM, Laurent Pinchart wrote:

Hi,

[...]

>> @@ -69,10 +70,33 @@ static void lvds_codec_disable(struct drm_bridge *bridge)
>>   			"Failed to disable regulator \"vcc\": %d\n", ret);
>>   }
>>   
>> +static bool lvds_codec_mode_fixup(struct drm_bridge *bridge,
>> +				const struct drm_display_mode *mode,
>> +				struct drm_display_mode *adj)
>> +{
>> +	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
>> +	struct drm_encoder *encoder = bridge->encoder;
>> +	struct drm_device *ddev = encoder->dev;
>> +	struct drm_connector *connector;
>> +
>> +	/* If 'data-mapping' was not specified, do nothing. */
>> +	if (!lvds_codec->bus_format)
>> +		return true;
>> +
>> +	/* Patch in the LVDS format */
>> +	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
>> +		drm_display_info_set_bus_formats(&connector->display_info,
>> +						 &lvds_codec->bus_format, 1);
>> +	}
> 
> This part bothers me, as the format at the input of the LVDS decoder
> doesn't match the format on the connector. Shouldn't you implement
> .atomic_get_output_bus_fmts() instead ?

No, I tried that option before this solution and that didn't work. The 
atomic stuff seems to be separate from what I need to pass here, i.e. 
without this, e.g. the mxsfb scanout engine still receives the wrong format.

[...]
Laurent Pinchart June 14, 2021, 6:02 p.m. UTC | #3
Hi Marek,

On Tue, May 25, 2021 at 12:38:47PM +0200, Marek Vasut wrote:
> On 5/18/21 1:03 AM, Laurent Pinchart wrote:
> 
> Hi,
> 
> [...]
> 
> >> @@ -69,10 +70,33 @@ static void lvds_codec_disable(struct drm_bridge *bridge)
> >>   			"Failed to disable regulator \"vcc\": %d\n", ret);
> >>   }
> >>   
> >> +static bool lvds_codec_mode_fixup(struct drm_bridge *bridge,
> >> +				const struct drm_display_mode *mode,
> >> +				struct drm_display_mode *adj)
> >> +{
> >> +	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
> >> +	struct drm_encoder *encoder = bridge->encoder;
> >> +	struct drm_device *ddev = encoder->dev;
> >> +	struct drm_connector *connector;
> >> +
> >> +	/* If 'data-mapping' was not specified, do nothing. */
> >> +	if (!lvds_codec->bus_format)
> >> +		return true;
> >> +
> >> +	/* Patch in the LVDS format */
> >> +	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
> >> +		drm_display_info_set_bus_formats(&connector->display_info,
> >> +						 &lvds_codec->bus_format, 1);
> >> +	}
> > 
> > This part bothers me, as the format at the input of the LVDS decoder
> > doesn't match the format on the connector. Shouldn't you implement
> > .atomic_get_output_bus_fmts() instead ?
> 
> No, I tried that option before this solution and that didn't work. The 
> atomic stuff seems to be separate from what I need to pass here, i.e. 
> without this, e.g. the mxsfb scanout engine still receives the wrong format.

I fear this needs to be investigated then, as the connected format isn't
the same as the LVDS decoder input format, so the above isn't right.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
index 8a7cb267ab14..33f992d52902 100644
--- a/drivers/gpu/drm/bridge/lvds-codec.c
+++ b/drivers/gpu/drm/bridge/lvds-codec.c
@@ -23,6 +23,7 @@  struct lvds_codec {
 	struct regulator *vcc;
 	struct gpio_desc *powerdown_gpio;
 	u32 connector_type;
+	unsigned int bus_format;
 };
 
 static inline struct lvds_codec *to_lvds_codec(struct drm_bridge *bridge)
@@ -69,10 +70,33 @@  static void lvds_codec_disable(struct drm_bridge *bridge)
 			"Failed to disable regulator \"vcc\": %d\n", ret);
 }
 
+static bool lvds_codec_mode_fixup(struct drm_bridge *bridge,
+				const struct drm_display_mode *mode,
+				struct drm_display_mode *adj)
+{
+	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
+	struct drm_encoder *encoder = bridge->encoder;
+	struct drm_device *ddev = encoder->dev;
+	struct drm_connector *connector;
+
+	/* If 'data-mapping' was not specified, do nothing. */
+	if (!lvds_codec->bus_format)
+		return true;
+
+	/* Patch in the LVDS format */
+	list_for_each_entry(connector, &ddev->mode_config.connector_list, head) {
+		drm_display_info_set_bus_formats(&connector->display_info,
+						 &lvds_codec->bus_format, 1);
+	}
+
+	return true;
+}
+
 static const struct drm_bridge_funcs funcs = {
 	.attach = lvds_codec_attach,
 	.enable = lvds_codec_enable,
 	.disable = lvds_codec_disable,
+	.mode_fixup = lvds_codec_mode_fixup,
 };
 
 static int lvds_codec_probe(struct platform_device *pdev)
@@ -81,6 +105,7 @@  static int lvds_codec_probe(struct platform_device *pdev)
 	struct device_node *panel_node;
 	struct drm_panel *panel;
 	struct lvds_codec *lvds_codec;
+	const char *mapping;
 	u32 val;
 
 	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
@@ -133,6 +158,31 @@  static int lvds_codec_probe(struct platform_device *pdev)
 			DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
 	}
 
+	/*
+	 * Decoder input LVDS format is a property of the decoder chip or even
+	 * its strapping. Handle data-mapping the same way lvds-panel does. In
+	 * case data-mapping is not present, do nothing, since there are still
+	 * legacy bindings which do not specify this property.
+	 */
+	if (lvds_codec->connector_type != DRM_MODE_CONNECTOR_LVDS) {
+		ret = of_property_read_string(dev->of_node, "data-mapping",
+					      &mapping);
+		if (ret < 0) {
+			dev_err(dev, "missing 'data-mapping' DT property\n");
+		} else {
+			if (!strcmp(mapping, "jeida-18")) {
+				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
+			} else if (!strcmp(mapping, "jeida-24")) {
+				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
+			} else if (!strcmp(mapping, "vesa-24")) {
+				lvds_codec->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
+			} else {
+				dev_err(dev, "invalid 'data-mapping' DT property\n");
+				return -EINVAL;
+			}
+		}
+	}
+
 	/*
 	 * The panel_bridge bridge is attached to the panel's of_node,
 	 * but we need a bridge attached to our of_node for our user