[PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[Marek Vasut]

Decoder input LVDS format is a property of the decoder chip or even
its strapping. Add DT property data-mapping the same way lvds-panel
does, to define the LVDS data mapping.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: devicetree@vger.kernel.org
To: dri-devel@lists.freedesktop.org
---
V2: - Use allOf
    - Move the data-mapping to endpoint
V3: - Rebase on V2 submitted a while ago, reinstate changelog
    - Drop the allOf and un-rebase on previous pclk patch
V4: - port@1, remove $ref: /schemas/graph.yaml#/properties/port and
      add $ref: /schemas/graph.yaml#/$defs/port-base
---
 .../bindings/display/bridge/lvds-codec.yaml   | 33 ++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
index 304a1367faaa7..c0400c60f272a 100644
--- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
@@ -55,11 +55,26 @@ properties:
           For LVDS decoders, port 0 is the LVDS input
 
       port@1:
-        $ref: /schemas/graph.yaml#/properties/port
+        $ref: /schemas/graph.yaml#/$defs/port-base
         description: |
           For LVDS encoders, port 1 is the LVDS output
           For LVDS decoders, port 1 is the parallel output
 
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-mapping:
+                enum:
+                  - jeida-18
+                  - jeida-24
+                  - vesa-24
+                description: |
+                  The color signals mapping order. See details in
+                  Documentation/devicetree/bindings/display/panel/lvds.yaml
+
     required:
       - port@0
       - port@1
@@ -71,6 +86,22 @@ properties:
 
   power-supply: true
 
+if:
+  not:
+    properties:
+      compatible:
+        contains:
+          const: lvds-decoder
+then:
+  properties:
+    ports:
+      properties:
+        port@1:
+          properties:
+            endpoint:
+              properties:
+                data-mapping: false
+
 required:
   - compatible
   - ports
-- 
2.30.2

[PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[Marek Vasut]

Decoder input LVDS format is a property of the decoder chip or even
its strapping. Add DT property data-mapping the same way lvds-panel
does, to define the LVDS data mapping.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: devicetree@vger.kernel.org
To: dri-devel@lists.freedesktop.org
---
V2: - Use allOf
    - Move the data-mapping to endpoint
V3: - Rebase on V2 submitted a while ago, reinstate changelog
    - Drop the allOf and un-rebase on previous pclk patch
V4: - port@1, remove $ref: /schemas/graph.yaml#/properties/port and
      add $ref: /schemas/graph.yaml#/$defs/port-base
---
 .../bindings/display/bridge/lvds-codec.yaml   | 33 ++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
index 304a1367faaa7..c0400c60f272a 100644
--- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
+++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
@@ -55,11 +55,26 @@ properties:
           For LVDS decoders, port 0 is the LVDS input
 
       port@1:
-        $ref: /schemas/graph.yaml#/properties/port
+        $ref: /schemas/graph.yaml#/$defs/port-base
         description: |
           For LVDS encoders, port 1 is the LVDS output
           For LVDS decoders, port 1 is the parallel output
 
+        properties:
+          endpoint:
+            $ref: /schemas/media/video-interfaces.yaml#
+            unevaluatedProperties: false
+
+            properties:
+              data-mapping:
+                enum:
+                  - jeida-18
+                  - jeida-24
+                  - vesa-24
+                description: |
+                  The color signals mapping order. See details in
+                  Documentation/devicetree/bindings/display/panel/lvds.yaml
+
     required:
       - port@0
       - port@1
@@ -71,6 +86,22 @@ properties:
 
   power-supply: true
 
+if:
+  not:
+    properties:
+      compatible:
+        contains:
+          const: lvds-decoder
+then:
+  properties:
+    ports:
+      properties:
+        port@1:
+          properties:
+            endpoint:
+              properties:
+                data-mapping: false
+
 required:
   - compatible
   - ports
-- 
2.30.2

[PATCH V4 2/2] drm/bridge: lvds-codec: Add support for LVDS data mapping select

[Marek Vasut]

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
---
V2: - Move the data-mapping to endpoint
V3: - Rebase on V2 submitted a while ago, reinstate changelog
    - Use .atomic_get_input_bus_fmts for the decoder, separate funcs for encoder
V4: - No change
---
 drivers/gpu/drm/bridge/lvds-codec.c | 76 ++++++++++++++++++++++++++++-
 1 file changed, 75 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
index dcf579a4cf833..afa7ce7ea01e8 100644
--- a/drivers/gpu/drm/bridge/lvds-codec.c
+++ b/drivers/gpu/drm/bridge/lvds-codec.c
@@ -12,6 +12,7 @@
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_bridge.h>
 #include <drm/drm_panel.h>
 
@@ -22,6 +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)
@@ -74,12 +76,50 @@ static const struct drm_bridge_funcs funcs = {
 	.disable = lvds_codec_disable,
 };
 
+#define MAX_INPUT_SEL_FORMATS 1
+static u32 *
+lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
+				     struct drm_bridge_state *bridge_state,
+				     struct drm_crtc_state *crtc_state,
+				     struct drm_connector_state *conn_state,
+				     u32 output_fmt,
+				     unsigned int *num_input_fmts)
+{
+	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
+	u32 *input_fmts;
+
+	*num_input_fmts = 0;
+
+	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
+			     GFP_KERNEL);
+	if (!input_fmts)
+		return NULL;
+
+	input_fmts[0] = lvds_codec->bus_format;
+	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
+
+	return input_fmts;
+}
+
+static const struct drm_bridge_funcs funcs_decoder = {
+	.attach = lvds_codec_attach,
+	.enable = lvds_codec_enable,
+	.disable = lvds_codec_disable,
+	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
+	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
+	.atomic_reset = drm_atomic_helper_bridge_reset,
+	.atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
+};
+
 static int lvds_codec_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *panel_node;
+	struct device_node *bus_node;
 	struct drm_panel *panel;
 	struct lvds_codec *lvds_codec;
+	const char *mapping;
+	int ret;
 
 	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
 	if (!lvds_codec)
@@ -119,13 +159,47 @@ static int lvds_codec_probe(struct platform_device *pdev)
 	if (IS_ERR(lvds_codec->panel_bridge))
 		return PTR_ERR(lvds_codec->panel_bridge);
 
+	lvds_codec->bridge.funcs = &funcs;
+
+	/*
+	 * 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) {
+		bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
+		if (!bus_node) {
+			dev_dbg(dev, "bus DT node not found\n");
+			return -ENXIO;
+		}
+
+		ret = of_property_read_string(bus_node, "data-mapping",
+					      &mapping);
+		of_node_put(bus_node);
+		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;
+			}
+			lvds_codec->bridge.funcs = &funcs_decoder;
+		}
+	}
+
 	/*
 	 * 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
 	 * to look up.
 	 */
 	lvds_codec->bridge.of_node = dev->of_node;
-	lvds_codec->bridge.funcs = &funcs;
 	drm_bridge_add(&lvds_codec->bridge);
 
 	platform_set_drvdata(pdev, lvds_codec);
-- 
2.30.2

Re: [PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[Rob Herring]

On Tue, 27 Jul 2021 18:13:56 +0200, Marek Vasut wrote:
> Decoder input LVDS format is a property of the decoder chip or even
> its strapping. Add DT property data-mapping the same way lvds-panel
> does, to define the LVDS data mapping.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: devicetree@vger.kernel.org
> To: dri-devel@lists.freedesktop.org
> ---
> V2: - Use allOf
>     - Move the data-mapping to endpoint
> V3: - Rebase on V2 submitted a while ago, reinstate changelog
>     - Drop the allOf and un-rebase on previous pclk patch
> V4: - port@1, remove $ref: /schemas/graph.yaml#/properties/port and
>       add $ref: /schemas/graph.yaml#/$defs/port-base
> ---
>  .../bindings/display/bridge/lvds-codec.yaml   | 33 ++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH V4 2/2] drm/bridge: lvds-codec: Add support for LVDS data mapping select

[Marek Vasut]

On 7/27/21 6:13 PM, 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
> ---
> V2: - Move the data-mapping to endpoint
> V3: - Rebase on V2 submitted a while ago, reinstate changelog
>      - Use .atomic_get_input_bus_fmts for the decoder, separate funcs for encoder
> V4: - No change
> ---
>   drivers/gpu/drm/bridge/lvds-codec.c | 76 ++++++++++++++++++++++++++++-
>   1 file changed, 75 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> index dcf579a4cf833..afa7ce7ea01e8 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -12,6 +12,7 @@
>   #include <linux/platform_device.h>
>   #include <linux/regulator/consumer.h>
>   
> +#include <drm/drm_atomic_helper.h>
>   #include <drm/drm_bridge.h>
>   #include <drm/drm_panel.h>
>   
> @@ -22,6 +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)
> @@ -74,12 +76,50 @@ static const struct drm_bridge_funcs funcs = {
>   	.disable = lvds_codec_disable,
>   };
>   
> +#define MAX_INPUT_SEL_FORMATS 1
> +static u32 *
> +lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +				     struct drm_bridge_state *bridge_state,
> +				     struct drm_crtc_state *crtc_state,
> +				     struct drm_connector_state *conn_state,
> +				     u32 output_fmt,
> +				     unsigned int *num_input_fmts)
> +{
> +	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
> +	u32 *input_fmts;
> +
> +	*num_input_fmts = 0;
> +
> +	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
> +			     GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	input_fmts[0] = lvds_codec->bus_format;
> +	*num_input_fmts = MAX_INPUT_SEL_FORMATS;
> +
> +	return input_fmts;
> +}
> +
> +static const struct drm_bridge_funcs funcs_decoder = {
> +	.attach = lvds_codec_attach,
> +	.enable = lvds_codec_enable,
> +	.disable = lvds_codec_disable,
> +	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +	.atomic_reset = drm_atomic_helper_bridge_reset,
> +	.atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
> +};
> +
>   static int lvds_codec_probe(struct platform_device *pdev)
>   {
>   	struct device *dev = &pdev->dev;
>   	struct device_node *panel_node;
> +	struct device_node *bus_node;
>   	struct drm_panel *panel;
>   	struct lvds_codec *lvds_codec;
> +	const char *mapping;
> +	int ret;
>   
>   	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
>   	if (!lvds_codec)
> @@ -119,13 +159,47 @@ static int lvds_codec_probe(struct platform_device *pdev)
>   	if (IS_ERR(lvds_codec->panel_bridge))
>   		return PTR_ERR(lvds_codec->panel_bridge);
>   
> +	lvds_codec->bridge.funcs = &funcs;
> +
> +	/*
> +	 * 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) {
> +		bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);
> +		if (!bus_node) {
> +			dev_dbg(dev, "bus DT node not found\n");
> +			return -ENXIO;
> +		}
> +
> +		ret = of_property_read_string(bus_node, "data-mapping",
> +					      &mapping);
> +		of_node_put(bus_node);
> +		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;
> +			}
> +			lvds_codec->bridge.funcs = &funcs_decoder;
> +		}
> +	}
> +
>   	/*
>   	 * 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
>   	 * to look up.
>   	 */
>   	lvds_codec->bridge.of_node = dev->of_node;
> -	lvds_codec->bridge.funcs = &funcs;
>   	drm_bridge_add(&lvds_codec->bridge);
>   
>   	platform_set_drvdata(pdev, lvds_codec);

It has been two months since this patch was posted and I still received 
zero feedback. Bump ?

Re: [PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[Laurent Pinchart]

Hi Marek,

Thank you for the patch.

On Tue, Jul 27, 2021 at 06:13:56PM +0200, Marek Vasut wrote:
> Decoder input LVDS format is a property of the decoder chip or even
> its strapping. Add DT property data-mapping the same way lvds-panel
> does, to define the LVDS data mapping.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Sam Ravnborg <sam@ravnborg.org>
> Cc: devicetree@vger.kernel.org
> To: dri-devel@lists.freedesktop.org

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

And all my apologies for the delay.

> ---
> V2: - Use allOf
>     - Move the data-mapping to endpoint
> V3: - Rebase on V2 submitted a while ago, reinstate changelog
>     - Drop the allOf and un-rebase on previous pclk patch
> V4: - port@1, remove $ref: /schemas/graph.yaml#/properties/port and
>       add $ref: /schemas/graph.yaml#/$defs/port-base
> ---
>  .../bindings/display/bridge/lvds-codec.yaml   | 33 ++++++++++++++++++-
>  1 file changed, 32 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> index 304a1367faaa7..c0400c60f272a 100644
> --- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> +++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> @@ -55,11 +55,26 @@ properties:
>            For LVDS decoders, port 0 is the LVDS input
>  
>        port@1:
> -        $ref: /schemas/graph.yaml#/properties/port
> +        $ref: /schemas/graph.yaml#/$defs/port-base
>          description: |
>            For LVDS encoders, port 1 is the LVDS output
>            For LVDS decoders, port 1 is the parallel output
>  
> +        properties:
> +          endpoint:
> +            $ref: /schemas/media/video-interfaces.yaml#
> +            unevaluatedProperties: false
> +
> +            properties:
> +              data-mapping:
> +                enum:
> +                  - jeida-18
> +                  - jeida-24
> +                  - vesa-24
> +                description: |
> +                  The color signals mapping order. See details in
> +                  Documentation/devicetree/bindings/display/panel/lvds.yaml
> +
>      required:
>        - port@0
>        - port@1
> @@ -71,6 +86,22 @@ properties:
>  
>    power-supply: true
>  
> +if:
> +  not:
> +    properties:
> +      compatible:
> +        contains:
> +          const: lvds-decoder
> +then:
> +  properties:
> +    ports:
> +      properties:
> +        port@1:
> +          properties:
> +            endpoint:
> +              properties:
> +                data-mapping: false
> +
>  required:
>    - compatible
>    - ports

-- 
Regards,

Laurent Pinchart

Re: [PATCH V4 1/2] dt-bindings: display: bridge: lvds-codec: Document LVDS data mapping select

[Laurent Pinchart]

On Tue, Oct 05, 2021 at 03:03:40AM +0300, Laurent Pinchart wrote:
> Hi Marek,
> 
> Thank you for the patch.
> 
> On Tue, Jul 27, 2021 at 06:13:56PM +0200, Marek Vasut wrote:
> > Decoder input LVDS format is a property of the decoder chip or even
> > its strapping. Add DT property data-mapping the same way lvds-panel
> > does, to define the LVDS data mapping.
> > 
> > Signed-off-by: Marek Vasut <marex@denx.de>
> > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Sam Ravnborg <sam@ravnborg.org>
> > Cc: devicetree@vger.kernel.org
> > To: dri-devel@lists.freedesktop.org
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I think I have to retract this, see below :-(

> And all my apologies for the delay.
> 
> > ---
> > V2: - Use allOf
> >     - Move the data-mapping to endpoint
> > V3: - Rebase on V2 submitted a while ago, reinstate changelog
> >     - Drop the allOf and un-rebase on previous pclk patch
> > V4: - port@1, remove $ref: /schemas/graph.yaml#/properties/port and
> >       add $ref: /schemas/graph.yaml#/$defs/port-base
> > ---
> >  .../bindings/display/bridge/lvds-codec.yaml   | 33 ++++++++++++++++++-
> >  1 file changed, 32 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> > index 304a1367faaa7..c0400c60f272a 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/lvds-codec.yaml
> > @@ -55,11 +55,26 @@ properties:
> >            For LVDS decoders, port 0 is the LVDS input
> >  
> >        port@1:
> > -        $ref: /schemas/graph.yaml#/properties/port
> > +        $ref: /schemas/graph.yaml#/$defs/port-base
> >          description: |
> >            For LVDS encoders, port 1 is the LVDS output
> >            For LVDS decoders, port 1 is the parallel output
> >  
> > +        properties:
> > +          endpoint:
> > +            $ref: /schemas/media/video-interfaces.yaml#
> > +            unevaluatedProperties: false
> > +
> > +            properties:
> > +              data-mapping:
> > +                enum:
> > +                  - jeida-18
> > +                  - jeida-24
> > +                  - vesa-24
> > +                description: |
> > +                  The color signals mapping order. See details in
> > +                  Documentation/devicetree/bindings/display/panel/lvds.yaml
> > +

Shouldn't this be for port 0 ? For decoders, port 1 is the parallel
side, not the LVDS side.

With this fixed, you can retain the

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> >      required:
> >        - port@0
> >        - port@1
> > @@ -71,6 +86,22 @@ properties:
> >  
> >    power-supply: true
> >  
> > +if:
> > +  not:
> > +    properties:
> > +      compatible:
> > +        contains:
> > +          const: lvds-decoder
> > +then:
> > +  properties:
> > +    ports:
> > +      properties:
> > +        port@1:
> > +          properties:
> > +            endpoint:
> > +              properties:
> > +                data-mapping: false
> > +
> >  required:
> >    - compatible
> >    - ports

-- 
Regards,

Laurent Pinchart

Re: [PATCH V4 2/2] drm/bridge: lvds-codec: Add support for LVDS data mapping select

[Laurent Pinchart]

Hi Marek,

Thank you for the patch, and all my apologies for the delay.

On Tue, Jul 27, 2021 at 06:13:57PM +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
> ---
> V2: - Move the data-mapping to endpoint
> V3: - Rebase on V2 submitted a while ago, reinstate changelog
>     - Use .atomic_get_input_bus_fmts for the decoder, separate funcs for encoder
> V4: - No change
> ---
>  drivers/gpu/drm/bridge/lvds-codec.c | 76 ++++++++++++++++++++++++++++-
>  1 file changed, 75 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/bridge/lvds-codec.c b/drivers/gpu/drm/bridge/lvds-codec.c
> index dcf579a4cf833..afa7ce7ea01e8 100644
> --- a/drivers/gpu/drm/bridge/lvds-codec.c
> +++ b/drivers/gpu/drm/bridge/lvds-codec.c
> @@ -12,6 +12,7 @@
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
>  
> +#include <drm/drm_atomic_helper.h>
>  #include <drm/drm_bridge.h>
>  #include <drm/drm_panel.h>
>  
> @@ -22,6 +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)
> @@ -74,12 +76,50 @@ static const struct drm_bridge_funcs funcs = {
>  	.disable = lvds_codec_disable,
>  };
>  
> +#define MAX_INPUT_SEL_FORMATS 1
> +static u32 *
> +lvds_codec_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
> +				     struct drm_bridge_state *bridge_state,
> +				     struct drm_crtc_state *crtc_state,
> +				     struct drm_connector_state *conn_state,
> +				     u32 output_fmt,
> +				     unsigned int *num_input_fmts)
> +{
> +	struct lvds_codec *lvds_codec = to_lvds_codec(bridge);
> +	u32 *input_fmts;
> +
> +	*num_input_fmts = 0;
> +
> +	input_fmts = kcalloc(MAX_INPUT_SEL_FORMATS, sizeof(*input_fmts),
> +			     GFP_KERNEL);
> +	if (!input_fmts)
> +		return NULL;
> +
> +	input_fmts[0] = lvds_codec->bus_format;
> +	*num_input_fmts = MAX_INPUT_SEL_FORMATS;

Are there cases where the input format would depend on the output format
? For instance, a 24-bit RGB output that could also work in RGB666 mode,
where we would select between MEDIA_BUS_FMT_RGB666_1X7X3_SPWG and
MEDIA_BUS_FMT_RGB888_1X7X4_SPWG depending on whether the output is
RGB666 or RGB888 ? I don't think we need to handle this now, and I
believe it will be possible to do this in a backward-compatible way if
the need ever arises. A confirmation that I'm not missing something
obvious would be nice.

> +
> +	return input_fmts;
> +}
> +
> +static const struct drm_bridge_funcs funcs_decoder = {
> +	.attach = lvds_codec_attach,
> +	.enable = lvds_codec_enable,
> +	.disable = lvds_codec_disable,
> +	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
> +	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
> +	.atomic_reset = drm_atomic_helper_bridge_reset,
> +	.atomic_get_input_bus_fmts = lvds_codec_atomic_get_input_bus_fmts,
> +};
> +
>  static int lvds_codec_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct device_node *panel_node;
> +	struct device_node *bus_node;
>  	struct drm_panel *panel;
>  	struct lvds_codec *lvds_codec;
> +	const char *mapping;
> +	int ret;
>  
>  	lvds_codec = devm_kzalloc(dev, sizeof(*lvds_codec), GFP_KERNEL);
>  	if (!lvds_codec)
> @@ -119,13 +159,47 @@ static int lvds_codec_probe(struct platform_device *pdev)
>  	if (IS_ERR(lvds_codec->panel_bridge))
>  		return PTR_ERR(lvds_codec->panel_bridge);
>  
> +	lvds_codec->bridge.funcs = &funcs;
> +
> +	/*
> +	 * 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) {
> +		bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 1, 0);

I think this should be

		bus_node = of_graph_get_endpoint_by_regs(dev->of_node, 0, 0);

(see the comment on patch 1/2).

> +		if (!bus_node) {
> +			dev_dbg(dev, "bus DT node not found\n");
> +			return -ENXIO;
> +		}
> +
> +		ret = of_property_read_string(bus_node, "data-mapping",
> +					      &mapping);
> +		of_node_put(bus_node);
> +		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;
> +			}
> +			lvds_codec->bridge.funcs = &funcs_decoder;
> +		}

I may have split this to a separate function to reduce line length and
simplify error handling, up to you.

With at least the port number fix above (unless I'm mistaken of course),

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	}
> +
>  	/*
>  	 * 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
>  	 * to look up.
>  	 */
>  	lvds_codec->bridge.of_node = dev->of_node;
> -	lvds_codec->bridge.funcs = &funcs;
>  	drm_bridge_add(&lvds_codec->bridge);
>  
>  	platform_set_drvdata(pdev, lvds_codec);

-- 
Regards,

Laurent Pinchart