[PATCH v3 2/2] dt-bindings: drm/bridge: Document Cadence DSI bridge bindings

[Andrzej Hajda]

On 31.08.2017 17:55, Boris Brezillon wrote:
> Document the bindings used for the Cadence DSI bridge.
>
> Signed-off-by: Boris Brezillon <boris.brezillon at free-electrons.com>
> ---
> Changes in v3:
> - Fix clock names in the example
> - Document how to represent DSI devices that are controller through
>   an external bus like I2C or SPI
>
> Changes in v2:
> - None
> ---
>  .../bindings/display/bridge/cdns,dsi.txt           | 109 +++++++++++++++++++++
>  1 file changed, 109 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt b/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt
> new file mode 100644
> index 000000000000..c70008bd8c0d
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/cdns,dsi.txt
> @@ -0,0 +1,109 @@
> +Cadence DSI bridge
> +==================
> +
> +The Cadence DSI bridge is a DPI to DSI bridge supporting up to 4 DSI lanes.
> +
> +Required properties:
> +- compatible: should be set to "cdns,dsi-1.3.1".
> +- reg: physical base address and length of the controller's registers.
> +- interrupts: interrupt line connected to the DSI bridge.
> +- clocks: DSI bridge clocks.
> +- clock-names: must contain "pclk" and "sysclk".
> +- phys: phandle link to the MIPI D-PHY controller.
> +- phy-names: must contain "dphy".
> +- #address-cells: must be set to 1.
> +- #size-cells: must be set to 0.
> +
> +Required subnodes:
> +- ports: Ports as described in Documentation/devicetree/bindings/graph.txt.
> +  2 ports are available:
> +  * port 0: this port is only needed if some of your DSI devices are
> +	    controlled through  an external bus like I2C or SPI. Can have at
> +	    most 4 endpoints. The endpoint number is directly encoding the
> +	    DSI virtual channel used by this device.
> +  * port 1: represents the DPI input.
> +  Other ports will be added later to support the new kind of inputs.

I think usual practice is to use lower numbers for input ports, higher
for output ports.
Is there a reason to do it this way?

Regards
Andrzej

> +
> +- one subnode per DSI device connected on the DSI bus. Each DSI device should
> +  contain a reg property encoding its virtual channel.
> +
> +Example:
> +
> +	dsi0: dsi at fd0c0000 {
> +		compatible = "cdns,dsi-1.3.1";
> +		reg = <0x0 0xfd0c0000 0x0 0x1000>;
> +		clocks = <&pclk>, <&sysclk>;
> +		clock-names = "pclk", "sysclk";
> +		interrupts = <1>;
> +		phys = <&dphy1>;
> +		phy-names = "dphy";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			port at 1 {
> +				reg = <1>;
> +				dsi0_dpi_input: endpoint {
> +					remote-endpoint = <&xxx_dpi_output>;
> +				};
> +			};
> +		};
> +
> +		panel: dsi-dev at 0 {
> +			compatible = "<vendor,panel>";
> +			reg = <0>;
> +		};
> +	};
> +
> +or
> +
> +	dsi0: dsi at fd0c0000 {
> +		compatible = "cdns,dsi";
> +		reg = <0x0 0xfd0c0000 0x0 0x1000>;
> +		clocks = <&pclk>, <&sysclk>;
> +		clock-names = "pclk", "sysclk";
> +		interrupts = <1>;
> +		phys = <&dphy1>;
> +		phy-names = "dphy";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			port at 0 {
> +				reg = <0>;
> +				#address-cells = <1>;
> +				#size-cells = <0>;
> +
> +				dsi0_output: endpoint at 0 {
> +					reg = <0>;
> +					remote-endpoint = <&dsi_panel_input>;
> +				};
> +			};
> +
> +			port at 1 {
> +				reg = <1>;
> +				dsi0_dpi_input: endpoint {
> +					remote-endpoint = <&xxx_dpi_output>;
> +				};
> +			};
> +		};
> +	};
> +
> +	i2c at xxx {
> +		panel: panel at 59 {
> +			compatible = "<vendor,panel>";
> +			reg = <0x59>;
> +
> +			port {
> +				dsi_panel_input: endpoint {
> +					remote-endpoint = <&dsi0_output>;
> +				};
> +			};
> +		};
> +	};