Re: [PATCH v6 2/8] dt-bindings: display: bridge: Add Cadence MHDP8501 HDMI and DP

From: Rob Herring
Date: Tue Jun 20 2023 - 11:49:05 EST


On Thu, Jun 15, 2023 at 09:38:12AM +0800, Sandor Yu wrote:
> Add bindings for Cadence MHDP8501 DisplayPort and HDMI driver.

Bindings are for h/w, not a driver.

>
> Signed-off-by: Sandor Yu <Sandor.yu@xxxxxxx>
> ---
> .../display/bridge/cdns,mhdp8501.yaml | 105 ++++++++++++++++++
> 1 file changed, 105 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml
> new file mode 100644
> index 000000000000..a54756815e6f
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml
> @@ -0,0 +1,105 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/cdns,mhdp8501.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Cadence MHDP8501 Displayport bridge
> +
> +maintainers:
> + - Sandor Yu <Sandor.yu@xxxxxxx>
> +
> +description:
> + The Cadence MHDP8501 Displayport/HDMI TX interface.
> +
> +properties:
> + compatible:
> + enum:
> + - cdns,mhdp8501-dp
> + - cdns,mhdp8501-hdmi
> + - fsl,imx8mq-mhdp8501-dp
> + - fsl,imx8mq-mhdp8501-hdmi

Is DP vs. HDMI fixed for a particular SoC implementation or it's a board
level decision. In the latter case, the type of connector should
determine the mode, not compatible.

> +
> + reg:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> + description: MHDP8501 DP/HDMI APB clock.

Seems odd there's no clock tied to the pixel/serdes clock.

> +
> + phys:
> + maxItems: 1
> +
> + interrupts:
> + items:
> + - description: Hotplug cable plugin.
> + - description: Hotplug cable plugout.
> +
> + interrupt-names:
> + items:
> + - const: plug_in
> + - const: plug_out
> +
> + ports:
> + $ref: /schemas/graph.yaml#/properties/ports
> +
> + properties:
> + port@0:
> + $ref: /schemas/graph.yaml#/properties/port
> + description:
> + Input port from display controller output.
> + port@1:
> + $ref: /schemas/graph.yaml#/properties/port
> + description:
> + Output port to DP/HDMI connector.
> +
> + required:
> + - port@0
> + - port@1
> +
> +required:
> + - compatible
> + - reg
> + - clocks
> + - interrupts
> + - interrupt-names
> + - phys
> + - ports
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/imx8mq-clock.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> + mhdp_dp: dp-bridge@32c00000 {
> + compatible = "fsl,imx8mq-mhdp8501-dp";
> + reg = <0x32c00000 0x100000>;
> + interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
> + interrupt-names = "plug_in", "plug_out";
> + clocks = <&clk IMX8MQ_CLK_DISP_APB_ROOT>;
> + phys = <&dp_phy>;
> +
> + ports {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
> +
> + mhdp_in: endpoint {
> + remote-endpoint = <&dcss_out>;
> + };
> + };
> +
> + port@1 {
> + reg = <1>;
> +
> + mhdp_out: endpoint {
> + remote-endpoint = <&dp_con>;
> + };
> + };
> + };
> + };
> --
> 2.34.1
>