Re: [PATCH v22 5/8] dt-bindings: phy: Add Freescale iMX8MQ DP and HDMI PHY

Laurentiu Palcu
2026-04-27T14:35:51Z

Hi Luca,

On Mon, Apr 27, 2026 at 02:59:47PM +0200, Luca Ceresoli wrote:
> Hello Laurentiu,
>
> On Fri Apr 24, 2026 at 1:07 PM CEST, Laurentiu Palcu wrote:
> > From: Sandor Yu <Sandor.yu@nxp.com>
> >
> > Add bindings for Freescale iMX8MQ DP and HDMI PHY.
> >
> > Signed-off-by: Sandor Yu <Sandor.yu@nxp.com>
> > Signed-off-by: Laurentiu Palcu <laurentiu.palcu@oss.nxp.com>
> > ---
> > .../bindings/phy/fsl,imx8mq-hdptx-phy.yaml | 80 ++++++++++++++++++++++
> > 1 file changed, 80 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/phy/fsl,imx8mq-hdptx-phy.yaml b/Documentation/devicetree/bindings/phy/fsl,imx8mq-hdptx-phy.yaml
> > new file mode 100644
> > index 0000000000000..a24435139b8b3
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/phy/fsl,imx8mq-hdptx-phy.yaml
> > @@ -0,0 +1,80 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/phy/fsl,imx8mq-hdptx-phy.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Cadence HDP-TX DP/HDMI PHY for Freescale i.MX8MQ SoC
> > +
> > +maintainers:
> > + - Sandor Yu <sandor.yu@nxp.com>
>
> Based on what you said in the cover, I guess this line will have to be
> changed. Are you willing to maintain this binding?

Yes, I'll update it in the next iteration.

>
> > +description:
> > + The Cadence HDP-TX DP/HDMI PHY is a child node of the MHDP8501 bridge,
> > + sharing the same MMIO region as the parent bridge node.
> > +
> > +properties:
> > + compatible:
> > + const: fsl,imx8mq-hdptx-phy
> > +
> > + clocks:
> > + items:
> > + - description: PHY reference clock.
> > + - description: APB clock.
> > +
> > + clock-names:
> > + items:
> > + - const: ref
> > + - const: apb
> > +
> > + "#phy-cells":
> > + const: 0
> > +
> > +required:
> > + - compatible
> > + - clocks
> > + - clock-names
> > + - "#phy-cells"
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/clock/imx8mq-clock.h>
> > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +
> > + display-bridge@32c00000 {
> > + compatible = "fsl,imx8mq-mhdp8501";
> > + reg = <0x32c00000 0x100000>;
> > + interrupts = <GIC_SPI 16 IRQ_TYPE_LEVEL_HIGH>,
> > + <GIC_SPI 25 IRQ_TYPE_LEVEL_HIGH>;
> > + interrupt-names = "plug_in", "plug_out";
> > + clocks = <&clk IMX8MQ_CLK_DISP_APB_ROOT>;
> > + phys = <&dp_phy>;
> > +
> > + ports {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
>
> The ports are not mentioned in the properties. I'm not a DT maintainer, but
> I think they should, e.g. to mention which port is the input and which is
> the output.
>
> > +
> > + port@0 {
> > + reg = <0>;
> > + endpoint {
> > + remote-endpoint = <&dcss_out>;
> > + };
> > + };
> > +
> > + port@1 {
> > + reg = <1>;
> > + endpoint {
> > + data-lanes = <2 1 0 3>;
>
> Having a remote-endpoint property would be nice here, to make the example
> more complete.

The ports and the remote endpoints are documented in the bridge binding...

However, I believe I screwed this example up by adding the entire bridge node,
instead of just a simple:

mhdp {
phy {
compatible = "fsl,imx8mq-hdptx-phy";
#phy-cells = <0>;
clocks = <&hdmi_phy_27m>, <&clk IMX8MQ_CLK_DISP_APB_ROOT>;
clock-names = "ref", "apb";
};
};

I'll simplify the example in the next iteration.

--
Thanks,
Laurentiu