[PATCH 3/4] dt-bindings: display: imx: add binding for i.MX8MP HDMI PAI

[Shengjiu Wang]

On Tue, Jul 22, 2025 at 3:16 PM Liu Ying <victor.liu at nxp.com> wrote:
>
> Hi Shengjiu,
>
> On 07/18/2025, Shengjiu Wang wrote:
> > Add binding for the i.MX8MP HDMI parallel Audio interface block.
> > As this port is linked to imx8mp-hdmi-tx, add port at 2 in
> > fsl,imx8mp-hdmi-tx.yaml document.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
> > ---
> >  .../display/bridge/fsl,imx8mp-hdmi-tx.yaml    | 13 ++++
> >  .../display/imx/fsl,imx8mp-hdmi-pai.yaml      | 61 +++++++++++++++++++
> >  2 files changed, 74 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
>
> Usually, to add a new driver, a DT binding patch comes first.

ok, will move it to first patch

>
> >
> > diff --git a/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
> > index 05442d437755..cf810b277557 100644
> > --- a/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
> > +++ b/Documentation/devicetree/bindings/display/bridge/fsl,imx8mp-hdmi-tx.yaml
> > @@ -49,9 +49,14 @@ properties:
> >          $ref: /schemas/graph.yaml#/properties/port
> >          description: HDMI output port
> >
> > +      port at 2:
> > +        $ref: /schemas/graph.yaml#/properties/port
> > +        description: Parallel audio input port
> > +
> >      required:
> >        - port at 0
> >        - port at 1
> > +      - port at 2
>
> Can port at 2 be optional?
> Note that video output can work with only port at 0 and port at 1.

yes, it can be optional

>
> >
> >  required:
> >    - compatible
> > @@ -98,5 +103,13 @@ examples:
> >                      remote-endpoint = <&hdmi0_con>;
> >                  };
> >              };
> > +
> > +            port at 2 {
> > +                reg = <2>;
> > +
> > +                endpoint {
> > +                    remote-endpoint = <&pai_to_hdmi_tx>;
> > +                };
> > +            };
> >          };
> >      };
> > diff --git a/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
> > new file mode 100644
> > index 000000000000..d2d723935032
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/display/imx/fsl,imx8mp-hdmi-pai.yaml
> > @@ -0,0 +1,61 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/display/imx/fsl,imx8mp-hdmi-pai.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Freescale i.MX8MP HDMI Parallel Audio Interface
> > +
> > +maintainers:
> > +  - Shengjiu Wang <shengjiu.wang at nxp.com>
> > +
> > +description:
> > +  The HDMI TX Parallel Audio Interface (HTX_PAI) is a digital module that acts as the
> > +  bridge between the Audio Subsystem to the HDMI TX Controller.
> > +
> > +properties:
>
> In i.MX8MP TRM, HTX_PAI block diagram mentions an APB interface.
> Does it mean a clock is needed?

The APB clock is bound with the power domain, so no need to add it here.

>
> > +  compatible:
> > +    const: fsl,imx8mp-hdmi-pai
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  power-domains:
> > +    maxItems: 1
> > +
> > +  port:
> > +    $ref: /schemas/graph.yaml#/properties/port
> > +    description: Output to the HDMI TX controller.
> > +    unevaluatedProperties: false
>
> Why do you need this line?

per my understanding, this line can be added or removed.

>
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - interrupts
> > +  - power-domains
> > +  - port
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/irq.h>
>
> Unused. Drop.

Ok.
>
> > +    #include <dt-bindings/power/imx8mp-power.h>
> > +
> > +    hdmi at 32fc4800 {
> > +        compatible = "fsl,imx8mp-hdmi-pai";
> > +        reg = <0x32fc4800 0x800>;
> > +        interrupt-parent = <&irqsteer_hdmi>;
> > +        interrupts = <14>;
> > +        power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_PAI>;
> > +
> > +        port {
> > +
>
> Drop this blank line.

Ok.

Best regards
Shengjiu Wang
>
> > +            pai_to_hdmi_tx: endpoint {
> > +                remote-endpoint = <&hdmi_tx_from_pai>;
> > +            };
> > +        };
> > +    };
>
> --
> Regards,
> Liu Ying