Re: [Aarch64-laptops] [PATCH 1/4] dt-bindings: display: panel: document panel-id

Hi Rob.

The panel-id can be used to help in several usecase. With a few nits pointed out below fixed: Reviewed-by: Sam Ravnborg sam@ravnborg.org

Sam

On Sat, Dec 07, 2019 at 12:35:50PM -0800, Rob Clark wrote:

From: Rob Clark robdclark@chromium.org

For devices that have one of several possible panels installed, the panel-id property gives firmware a generic way to locate and enable the panel node corresponding to the installed panel. Example of how to use this property:

ivo_panel {
    compatible = "ivo,m133nwf4-r0";
    panel-id = <0xc5>;
    status = "disabled";

    ports {
        port {
            ivo_panel_in_edp: endpoint {
                remote-endpoint = <&sn65dsi86_out_ivo>;
            };
        };
    };
};

boe_panel {
    compatible = "boe,nv133fhm-n61";
    panel-id = <0xc4>;
    status = "disabled";

    ports {
        port {
            boe_panel_in_edp: endpoint {
                remote-endpoint = <&sn65dsi86_out_boe>;
            };
        };
    };
};

sn65dsi86: bridge@2c {
    compatible = "ti,sn65dsi86";

    ports {
        #address-cells = <1>;
        #size-cells = <0>;

        port@0 {
            reg = <0>;
            sn65dsi86_in_a: endpoint {
                remote-endpoint = <&dsi0_out>;
            };
        };

        port@1 {
            reg = <1>;

            sn65dsi86_out_boe: endpoint@c4 {
                remote-endpoint = <&boe_panel_in_edp>;
            };

            sn65dsi86_out_ivo: endpoint@c5 {
                remote-endpoint = <&ivo_panel_in_edp>;
            };
        };
    };
};

Signed-off-by: Rob Clark robdclark@chromium.org

.../bindings/display/panel/panel-common.yaml | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/panel/panel-common.yaml b/Documentation/devicetree/bindings/display/panel/panel-common.yaml index ef8d8cdfcede..6113319b91dd 100644 --- a/Documentation/devicetree/bindings/display/panel/panel-common.yaml +++ b/Documentation/devicetree/bindings/display/panel/panel-common.yaml @@ -75,6 +75,32 @@ properties: in the device graph bindings defined in Documentation/devicetree/bindings/graph.txt.

• panel-id:
• description:

•  To support the case where one of several different panels can be installed
  

•  on a device, the panel-id property can be used by the firmware to identify
  

•  which panel should have it's status changed to "ok".  This property is not
  

Use "okay" as this is waht is specified in the CT files.

•  used by the HLOS itself.
  

Spell out HLOS - it is not obvious for all what it is.

•  For a device with multiple potential panels, a node for each potential
  

•  should be defined with status = "disabled", and an appropriate panel-id
  

"potential panel should"

•  property.  The video data producer should be setup with endpoints going to
  

•  each possible panel.  The firmware will find the dt node with a panel-id
  

•  matching the actual panel installed, and change it's status to "ok".
  

•  The exact method the firmware uses to determine the panel-id of the installed
  

•  panel is outside the scope of this binding, but a few examples are
  

•  1) u-boot module reading a value from a u-boot env var
  

•  2) EFI driver module reading a value from an EFI variable
  

•  3) device specific firmware reading some device specific GPIOs or
  

•     e-fuse
  

•  The panel-id values are an opaque integer.  They can be sparse.  The only
  

•  important thing is that each possible panel in the system has a unique
  

•  panel-id, and that the values configured in the device's DTB match the
  

•  values that the firmware is looking for.
  

• ddc-i2c-bus: $ref: /schemas/types.yaml#/definitions/phandle description:

-- 2.23.0

---

dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel