Re: [PATCH v8 1/2] dt-bindings: drm/bridge: anx7625: MIPI to DP transmitter binding

Sam Ravnborg
2020-04-27T18:49:23Z

Hi Xin Ji

On Mon, Apr 27, 2020 at 02:17:46PM +0800, Xin Ji wrote:
> The ANX7625 is an ultra-low power 4K Mobile HD Transmitter designed
> for portable device. It converts MIPI to DisplayPort 1.3 4K.

Thanks for providing this binding.
When you re-submit please also send to devicetree@vger.kernel.org.

Running the binding through dt_binding_check gives me:

/home/sam/drm/linux.git/Documentation/devicetree/bindings/display/bridge/anx7625.yaml: ignoring, error in schema:
warning: no schema found in file: /home/sam/drm/linux.git/Documentation/devicetree/bindings/display/bridge/anx7625.yaml
make[2]: *** [/home/sam/drm/linux.git/Documentation/devicetree/bindings/Makefile:42: Documentation/devicetree/bindings/processed-schema.yaml] Error 255
make[2]: *** Waiting for unfinished jobs....
/home/sam/drm/linux.git/Documentation/devicetree/bindings/display/bridge/anx7625.yaml: Additional properties are not allowed ('example' was unexpected)
/home/sam/drm/linux.git/Documentation/devicetree/bindings/display/bridge/anx7625.yaml: Additional properties are not allowed ('example' was unexpected)

See writing-schemas.rst for instruction installing tools etc.

>
> You can add support to your board with binding.
>
> Example:
> anx7625_bridge: encoder@58 {
> compatible = "analogix,anx7625";
> reg = <0x58>;
> status = "okay";
> panel-flags = <1>;
> enable-gpios = <&pio 45 GPIO_ACTIVE_HIGH>;
> reset-gpios = <&pio 73 GPIO_ACTIVE_HIGH>;
> #address-cells = <1>;
> #size-cells = <0>;
>
> port@0 {
> reg = <0>;
> anx_1_in: endpoint {
> remote-endpoint = <&mipi_dsi>;
> };
> };
>
> port@2 {
> reg = <2>;
> anx_1_out: endpoint {
> remote-endpoint = <&panel_in>;
> };
> };
> };
>
> Signed-off-by: Xin Ji <xji@analogixsemi.com>
> ---
> .../bindings/display/bridge/anx7625.yaml | 91 ++++++++++++++++++++++
> 1 file changed, 91 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/display/bridge/anx7625.yaml
>
> diff --git a/Documentation/devicetree/bindings/display/bridge/anx7625.yaml b/Documentation/devicetree/bindings/display/bridge/anx7625.yaml
> new file mode 100644
> index 0000000..1149ebb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/anx7625.yaml

Name the file "analogix,anx7625.yaml".
(We should rename anx6345.yaml, so others do not omit the company name)

> @@ -0,0 +1,91 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2019 Analogix Semiconductor, Inc.
> +%YAML 1.2
> +---
> +$id: "http://devicetree.org/schemas/display/bridge/anx7625.yaml#"
> +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> +
> +title: Analogix ANX7625 SlimPort (4K Mobile HD Transmitter)
> +
> +maintainers:
> + - Xin Ji <xji@analogixsemi.com>
> +
> +description: |
> + The ANX7625 is an ultra-low power 4K Mobile HD Transmitter
> + designed for portable devices.
> +
> +properties:
> + "#address-cells": true
> + "#size-cells": true
> +
> + compatible:
> + items:
> + - const: analogix,anx7625
> +
> + reg:
> + maxItems: 1
> +
> + panel-flags:
> + description: indicate the panel is internal or external.
> + maxItems: 1
This property hint at something needs to be modelled in a different way.
I do not recall other bindings need similar info.

> +
> + interrupts:
> + maxItems: 1
A description would be nice.

> +
> + enable-gpios:
> + description: used for power on chip control, POWER_EN pin D2.
> + maxItems: 1
> +
> + reset-gpios:
> + description: used for reset chip control, RESET_N pin B7.
> + maxItems: 1
> +
> + port@0:
> + type: object
> + description:
> + A port node pointing to MIPI DSI host port node.
> +
> + port@1:
> + type: object
> + description:
> + A port node pointing to MIPI DPI host port node.
Maybe explain how it differs from port@0 and why it is optional.

> +
> + port@2:
> + type: object
> + description:
> + A port node pointing to panel port node.
Unless there is a good reason not to then please use a ports node, like
you see in almost (all?) other bridge bindings.

> +
> +required:
> + - "#address-cells"
> + - "#size-cells"
> + - compatible
> + - reg
> + - port@0
> + - port@2

additionalProperties: false??

> +
> +example:
It must be named "examples:" - this is what dt_binding_check complains
about.

> + - |
> + anx7625_bridge: encoder@58 {
> + compatible = "analogix,anx7625";
> + reg = <0x58>;
> + status = "okay";
No status in examples.

> + panel-flags = <1>;
> + enable-gpios = <&pio 45 GPIO_ACTIVE_HIGH>;
You need to include a header file to pull in GPIO_ACTIVE_HIGH - see what
other bindings do.
> + reset-gpios = <&pio 73 GPIO_ACTIVE_HIGH>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + port@0 {
> + reg = <0>;
Be consistent with indent. My personal preference is 4 spaces.

> + anx_1_in: endpoint {
> + remote-endpoint = <&mipi_dsi>;
> + };
> + };
> +
> + port@2 {
> + reg = <2>;
> + anx_1_out: endpoint {
> + remote-endpoint = <&panel_in>;
> + };
> + };
> + };

Lot's of small comments. But if this is your first binding then this is
expected.
Looks forward for v2.

Sam