[PATCH v2] dt-bindings: display: imx: Document fsl,pcr

[PATCH v2] dt-bindings: display: imx: Document fsl,pcr

[Fabio Estevam]

Some i.MX25 and i.MX27 devicetree display nodes contain fsl,pcr, but
the property has no schema type. As a result, dt-core.yaml reports
its raw bytes as an invalid property:

  imx27-phytec-phycard-s-rdk.dtb: display: fsl,pcr:
  b'\xf0\xc8\x80\x80' is not of type
  'object', 'integer', 'array', 'boolean', 'null'

Document fsl,pcr as a uint32. The property belongs to the display node
referenced by the display phandle and is not valid on the LCD controller
node.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
Changes since v1:
- Explicitly forbid fsl,pcr on the controller through allOf, addressing
  the Sashiko review, while retaining its uint32 type for decoding the
  property in legacy display nodes.

 .../devicetree/bindings/display/imx/fsl,imx-lcdc.yaml  | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml b/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
index 84610b5690c4..450f95098c99 100644
--- a/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
+++ b/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
@@ -65,7 +65,17 @@ properties:
     description:
       LCDC Sharp Configuration Register value.
 
+  fsl,pcr:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      LCDC Panel Configuration Register value used in the display node
+      referenced by the display property.
+
 allOf:
+  # Define the type above for decoding, but forbid it on the controller.
+  - properties:
+      fsl,pcr: false
+
   - if:
       properties:
         compatible:

Re: [PATCH v2] dt-bindings: display: imx: Document fsl,pcr

[Rob Herring]

On Mon, Nov 9, 2026 at 8:34 PM Fabio Estevam <festevam@gmail.com> wrote:
>
> Some i.MX25 and i.MX27 devicetree display nodes contain fsl,pcr, but
> the property has no schema type. As a result, dt-core.yaml reports
> its raw bytes as an invalid property:
>
>   imx27-phytec-phycard-s-rdk.dtb: display: fsl,pcr:
>   b'\xf0\xc8\x80\x80' is not of type
>   'object', 'integer', 'array', 'boolean', 'null'
>
> Document fsl,pcr as a uint32. The property belongs to the display node
> referenced by the display phandle and is not valid on the LCD controller
> node.
>
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
> Changes since v1:
> - Explicitly forbid fsl,pcr on the controller through allOf, addressing
>   the Sashiko review, while retaining its uint32 type for decoding the
>   property in legacy display nodes.
>
>  .../devicetree/bindings/display/imx/fsl,imx-lcdc.yaml  | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml b/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
> index 84610b5690c4..450f95098c99 100644
> --- a/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
> +++ b/Documentation/devicetree/bindings/display/imx/fsl,imx-lcdc.yaml
> @@ -65,7 +65,17 @@ properties:
>      description:
>        LCDC Sharp Configuration Register value.
>
> +  fsl,pcr:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description:
> +      LCDC Panel Configuration Register value used in the display node
> +      referenced by the display property.
> +
>  allOf:
> +  # Define the type above for decoding, but forbid it on the controller.
> +  - properties:
> +      fsl,pcr: false

That does fix the warning, but still leaves display nodes unvalidated.
This needs to go in a new schema. Since there's no compatible on these
nodes, we need something like this to apply the schema:

select:
  required:
    - fsl,pcr

Then the schema is this property, model, bits-per-pixel and a $ref to
panel-common.yaml.

Rob