Re: [PATCH v10 1/3] dt-bindings: soc: imx93-media-blk-ctrl: Add PDFC subnode to schema and example

On 26-03-03, Liu Ying wrote:

On Mon, Mar 02, 2026 at 05:10:40PM +0100, Marco Felsch wrote:

quoted

From: Liu Ying <victor.liu@nxp.com>

i.MX93 SoC mediamix blk-ctrl contains one DISPLAY_MUX register which
configures parallel display format by using the "PARALLEL_DISP_FORMAT"
field. Document the Parallel Display Format Configuration(PDFC) subnode
and add the subnode to example.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
[m.felsch@pengutronix.de: port to v7.0-rc1]
[m.felsch@pengutronix.de: add bus-width]
Signed-off-by: Marco Felsch <redacted>
---
 .../bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml | 78 ++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml b/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml
index 34aea58094e55365a2f9c86092f637e533f954ff..d828c2e82965c7a4cd69a67136047d83c96b0a35 100644
--- a/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml
+++ b/Documentation/devicetree/bindings/soc/imx/fsl,imx93-media-blk-ctrl.yaml

@@ -40,6 +40,58 @@ properties:
     minItems: 8
     maxItems: 10
 
+  dpi-bridge:

Cc'ing Frank.

fsl,ldb.yaml documents fsl,imx6sx-ldb, fsl,imx8mp-ldb and fsl,imx93-ldb
with a reg property.  Since all of them are child devices of either GPR
or BLK_CTRL and this dpi-bridge is a child device of BLK_CTRL without a
reg property, how can we handle the inconsistency?  At least, with this
patch and the current fsl,ldb.yaml, we cannot add an i.MX93 LDB child
node.

This reg property was longly discussed and there should be no reg
because this 'reg' covers not only the PDFC register fields. Please see
the discussion:

- https://lore.kernel.org/all/PAXPR04MB84599D676EC1E3879694579688B2A@PAXPR04MB8459.eurprd04.prod.outlook.com/ (local)

The LDB node shouldn't have a reg property in the first place. There are
a few registers within BLK-CTRL which belong to only one "IP" like the
LDB. But these are the exception rather than the rule. To make it
possible to abstract _all_ sub-devices within the BLK control you need
to drop the reg property. The subdevice drivers need to handle the
offsets within the BLK-CTRL accordingly, like the LDB driver already
does. So removing the reg property from the LDB dt-bindings is the
correct fix.

Regards,
  Marco

quoted

+    type: object
+    additionalProperties: false
+
+    properties:
+      compatible:
+        enum:
+          - nxp,imx91-pdfc
+          - nxp,imx93-pdfc
+
+      ports:
+        $ref: /schemas/graph.yaml#/properties/ports
+
+        properties:
+          port@0:
+            $ref: /schemas/graph.yaml#/properties/port
+            description: Input port node to receive pixel data.
+
+          port@1:
+            $ref: /schemas/graph.yaml#/$defs/port-base
+            unevaluatedProperties: false
+            description: Output port node to downstream pixel data receivers.
+
+            properties:
+              endpoint:
+                $ref: /schemas/media/video-interfaces.yaml#
+                unevaluatedProperties: false
+
+                properties:
+                  bus-width:
+                    enum: [ 16, 18, 24 ]
+                    description:
+                      Specify the physical parallel bus width.
+
+                      This property is optional if the display bus-width
+                      matches the SoC bus-width, e.g. a 18-bit RGB666 (display)
+                      is connected and all 18-bit data lines are muxed to the
+                      parallel-output pads.
+
+                      This property must be set to 18 to cut only the LSBs
+                      instead of the MSBs in case a 24-bit RGB888 display is
+                      connected and only the lower 18-bit data lanes are muxed
+                      to the parallel-output pads.
+
+        required:
+          - port@0
+          - port@1
+
+    required:
+      - compatible
+      - ports
+
 allOf:
   - if:
       properties:

@@ -112,4 +164,30 @@ examples:
                clock-names = "apb", "axi", "nic", "disp", "cam",
                              "pxp", "lcdif", "isi", "csi", "dsi";
       #power-domain-cells = <1>;
+
+      dpi-bridge {
+        compatible = "nxp,imx93-pdfc";
+
+        ports {
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          port@0 {
+            reg = <0>;
+
+            pdfc_from_lcdif: endpoint {
+              remote-endpoint = <&lcdif_to_pdfc>;
+            };
+          };
+
+          port@1 {
+            reg = <1>;
+
+            pdfc_to_panel: endpoint {
+              remote-endpoint = <&panel_from_pdfc>;
+              bus-width = <18>;
+            };
+          };
+        };
+      };
     };

-- 
Regards,
Liu Ying

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