Since DDC version 2, introduced in 1996, VGA monitors have exposed EDID data over an I2C bus. The bus is also used to detect the presence of a connected monitor by trying to read the EDID data.
Some devices where the VGA display is integrated in the device and always connected do not connect the DDC pins. Some development boards, such as the Renesas M3N Salvator-XS, also do not connect the DDC pins. To support those, add the ability to provide hardcoded EDID data in the device tree. This is mutually exclusive with specifying a DDC bus, and can only be done when the VGA display is guaranteed to be always connected. Signed-off-by: Laurent Pinchart <[email protected]> --- .../bindings/display/connector/vga-connector.yaml | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/devicetree/bindings/display/connector/vga-connector.yaml b/Documentation/devicetree/bindings/display/connector/vga-connector.yaml index 25f868002000..7e1b8e798e5b 100644 --- a/Documentation/devicetree/bindings/display/connector/vga-connector.yaml +++ b/Documentation/devicetree/bindings/display/connector/vga-connector.yaml @@ -19,10 +19,25 @@ properties: description: phandle link to the I2C controller used for DDC EDID probing $ref: /schemas/types.yaml#/definitions/phandle + edid: + $ref: /schemas/types.yaml#/definitions/uint8-array + description: + When the DDC signals are not wired to the connector, and the connected + display is not removable, this property is used to supply a binary EDID + blob for the display. + port: $ref: /schemas/graph.yaml#/properties/port description: Connection to controller providing VGA signals +allOf: + - if: + required: + - ddc-i2c-bus + then: + properties: + edid: false + required: - compatible - port -- Regards, Laurent Pinchart
