Re: [PATCH 1/2] dt-bindings: it6251: add bindings for IT6251 LVDS-to-eDP bridge

Hi Richard,

Thank you for the patch.

On Sat, May 09, 2020 at 01:17:31PM +0200, srk@48.io wrote:

From: Marek Vasut marex@denx.de

Add DT bindings for ITE IT6251 LVDS-to-eDP bridge.

Signed-off-by: Marek Vasut marex@denx.de Signed-off-by: Richard Marko srk@48.io Cc: Daniel Vetter daniel@ffwll.ch Cc: Rob Herring robh+dt@kernel.org Cc: Sean Cross xobs@kosagi.com Cc: devicetree@vger.kernel.org To: dri-devel@lists.freedesktop.org

---

.../bindings/display/bridge/ite,it6251.yaml | 97 +++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 Documentation/devicetree/bindings/display/bridge/ite,it6251.yaml

diff --git a/Documentation/devicetree/bindings/display/bridge/ite,it6251.yaml b/Documentation/devicetree/bindings/display/bridge/ite,it6251.yaml new file mode 100644 index 000000000000..8daa44a30fa1 --- /dev/null +++ b/Documentation/devicetree/bindings/display/bridge/ite,it6251.yaml @@ -0,0 +1,97 @@ +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/display/bridge/ite,it6251.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml#

+title: ITE IT6251 LVDS-to-eDP bridge bindings

+maintainers:

• • Marek Vasut marex@denx.de
• • Richard Marko srk@48.io

+description: |

• The IT6251 is a high-performance single-chip
• De-SSC LVDS to DisplayPort converter.
• Combined with LVDS receiver and DisplayPort Transmitter,
• the IT6251 supports LVDS input and DisplayPort 1.1a
• output by conversion function.

You could reflow this to the 80 columns limit. It also sounds like marketing material copied from the datasheet, with "by conversion function" likely a bad translation.

+properties:

• compatible:
• const: ite,it6251
• reg:
• items:

•  - description: I2C address of the bridge
  

•  - description: I2C address of the LVDS part
  

• reg-names:
• items:

•  - const: bridge
  

•  - const: lvds
  

• ports:
• type: object
• properties:

•  "#address-cells":
  

•    const: 1
  

•  "#size-cells":
  

•    const: 0
  

•  port@0:
  

•    type: object
  

•    description: |
  

•     Video port for eDP output (typically panel).
  

•  port@1:
  

•    type: object
  

•    description: |
  

•      Video port for LVDS input.
  

We traditionally use port 0 for the input and port 1 for the output. I'd rather do the same here to remain consistent, and allow generic code to operate on this device.

• required:

•  - port@0
  

•  - port@1
  

• additionalProperties: false
• power-supply: true

There are multiple power supplies for the chip, shouldn't we have multiple properties ? I would also name the properties according to the supply name.

The chip has an HPD input. I would recommend already documenting an optional boolean no-hpd property to report when the HPD input is not connected.

+required:

• • compatible
• • reg
• • reg-names
• • power-supply
• • ports

+additionalProperties: false

+examples:

• • |
• it6251@5c {

•  compatible = "ite,it6251";
  

•  reg = <0x5c>, <0x5e>;
  

•  reg-names = "bridge", "lvds";
  

•  power-supply = <&reg_display>;
  

•  ports {
  

•    #address-cells = <1>;
  

•    #size-cells = <0>;
  

•    port@0 {
  

•      reg = <0>;
  

•      bridge_out_edp0: endpoint {
  

•        remote-endpoint = <&panel_in_edp0>;
  

•      };
  

•    };
  

•    port@1 {
  

•      reg = <1>;
  

•      bridge_in_lvds0: endpoint {
  

•        remote-endpoint = <&lvds0_out>;
  

•      };
  

•    };
  

•  };
  

• };