Re: [PATCH v2 1/4] dt-bindings: display: imx: add binding for i.MX8MP HDMI TX

[Rob Herring <robh@kernel.org>]

On Sat, Dec 17, 2022 at 03:40:24PM +0800, Liu Ying wrote:
> Hi Lucas,
> 
> On Fri, 2022-12-16 at 22:07 +0100, Lucas Stach wrote:
> > The HDMI TX controller on the i.MX8MP SoC is a Synopsys designware IP
> > core with a little bit of SoC integration around it.
> > 
> > Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
> > ---
> >  .../bindings/display/imx/fsl,imx8mp-hdmi.yaml | 69
> > +++++++++++++++++++
> >  1 file changed, 69 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi.yaml
> > 
> > diff --git
> > a/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi.yaml
> > b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi.yaml
> > new file mode 100644
> > index 000000000000..75ebeaa8c9d5
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-
> > hdmi.yaml
> > @@ -0,0 +1,69 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/imx/fsl,imx8mp-hdmi.yaml#
> 
> Better to put the binding documentation under the display/bridge
> umbrella as the corresponding linux driver is a DRM bridge driver, not
> a DRM encoder driver.

Bridge vs. encoder is not a distinction I would make for bindings. It 
would be better if all the HDMI encoders/bridges were grouped together 
rather than in vendor silos/directories. But that's a much bigger 
restructuring and fsl,imx6-hdmi.yaml is already here.

> 
> Regarding the file name, I would use 'fsl,imx8mp-hdmi-tx.yaml' to
> explicitly tell it's a TX controller(not a RX controller), which
> matches the chapter name 'HDMI TX controller' in i.MX8mp RM.
> 
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Freescale i.MX8MP DWC HDMI TX Encoder
> > +
> > +maintainers:
> > +  - Lucas Stach <l.stach@pengutronix.de>
> > +
> > +description: |
> > +  The i.MX8MP HDMI transmitter is a Synopsys DesignWare
> > +  HDMI 2.0 TX controller IP.
> 
> i.MX8mp RM says it is compatible with the HDMI v2.0a spec, so better to
> mention 2.0a instead of 2.0.
> 
> > +
> > +allOf:
> > +  - $ref: ../bridge/synopsys,dw-hdmi.yaml#
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - fsl,imx8mp-hdmi
> 
> Like the file name, I would use 'fsl,imx8mp-hdmi-tx'.
> 
> It seems that the i.MX6q DW HDMI TX controller will not easily use this
> binding since it's corresponding driver is a DRM encoder driver, and no
> other i.MX SoCs embed the controller, so use const instead of enum(It
> can be changed to enum when necessary later.)?

That shouldn't matter for bindings. I do expect the 'ports' will be a 
bit different, so probably not worth trying to combine the schema.

Rob