Re: [PATCH v21 3/8] dt-bindings: display: bridge: Add Cadence MHDP8501

[Laurentiu Palcu]

On Wed, Apr 08, 2026 at 08:42:09AM +0200, Krzysztof Kozlowski wrote:
> On Tue, Apr 07, 2026 at 02:31:27PM +0000, Laurentiu Palcu wrote:
> > From: Sandor Yu <Sandor.yu@xxxxxxx>
> > 
> > Add bindings for Cadence MHDP8501 DisplayPort/HDMI bridge.
> > 
> > Signed-off-by: Sandor Yu <Sandor.yu@xxxxxxx>
> > Signed-off-by: Laurentiu Palcu <laurentiu.palcu@xxxxxxxxxxx>
> > ---
> >  .../bindings/display/bridge/cdns,mhdp8501.yaml     | 131 +++++++++++++++++++++
> >  1 file changed, 131 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml
> > new file mode 100644
> > index 0000000000000..77e16ee9d855d
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/bridge/cdns,mhdp8501.yaml
> > @@ -0,0 +1,131 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/bridge/cdns,mhdp8501.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Cadence MHDP8501 DP/HDMI bridge
> > +
> > +maintainers:
> > +  - Sandor Yu <Sandor.yu@xxxxxxx>
> > +
> > +description:
> > +  Cadence MHDP8501 DisplayPort/HDMI interface.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - fsl,imx8mq-mhdp8501
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    maxItems: 1
> > +    description: MHDP8501 DP/HDMI APB clock.
> > +
> > +  phys:
> > +    maxItems: 1
> > +    description:
> > +      phandle to the DP/HDMI PHY
> > +
> > +  interrupts:
> > +    items:
> > +      - description: Hotplug cable plugin.
> > +      - description: Hotplug cable plugout.
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: plug_in
> > +      - const: plug_out
> > +
> > +  cdns,bridge-type:
> 
> Drop property. Graph defines what is connected on the other side. And if
> this is for different devices then compatible tells what bridge is that.

Initially, Sandor did use the remote compatible to decide the bridge
type but he assumed the remote is always the connector. However, as
Dmitry pointed out [1], this is not reliable as we can have another bridge
in-between this one and the connector.

[1] https://lore.kernel.org/all/dpj333mzr5azqhrgw3cxd7x5kiwxms4iomwy74uqfhr2zu4ocr@36rkth27d2jc/

-- 
Thanks,
Laurentiu