Re: [PATCH v7 1/8] dt-bindings: soc: qcom: eud: Add per-path child nodes for UTMI routing

[Bjorn Andersson <andersson@kernel.org>]

On Sun, Aug 30, 2026 at 08:01:40PM -0700, Elson Serrao wrote:
> The Qualcomm Embedded USB Debugger (EUD) can intercept one or two
> High-Speed UTMI paths depending on the SoC. For example, SC7280 supports
> EUD on the primary UTMI path only, while SM8350 supports EUD on both
> primary and secondary UTMI paths.
> 
> Each UTMI path connects an independent USB controller/connector pair and
> forms its own role-switch domain. EUD routes traffic based on USB role.
> In device role the debug hub is inserted, while in host role it is
> bypassed.
> 
> The existing binding models EUD using a flattened ports representation.
> While sufficient for fixed device-role configurations, it cannot naturally
> associate a controller, connector, and role switch with a specific
> EUD-routable path. This is problematic for role-switch capable ports and
> becomes more pronounced on SoCs with multiple paths. In such cases, each
> path forms an independent role-switch domain and requires per-path role
> awareness.
> 
> Model each UTMI path as a separate child node with its own OF graph. This
> representation is used for role-aware EUD routing regardless of whether a
> SoC exposes one or two UTMI paths. Add an SM8350 compatible for
> dual-path EUD topologies. Retain support for the legacy flat ports
> representation on SC7280 for backward compatibility.
> 

Acked-by: Bjorn Andersson <andersson@kernel.org>

Please merge this together with the driver changes.

Regards,
Bjorn

> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
> Signed-off-by: Elson Serrao <elson.serrao@oss.qualcomm.com>
> ---
>  .../bindings/soc/qcom/qcom,eud.yaml           | 134 +++++++++++++++++-
>  1 file changed, 133 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/soc/qcom/qcom,eud.yaml b/Documentation/devicetree/bindings/soc/qcom/qcom,eud.yaml
> index 84218636c0d8..c377a77d623c 100644
> --- a/Documentation/devicetree/bindings/soc/qcom/qcom,eud.yaml
> +++ b/Documentation/devicetree/bindings/soc/qcom/qcom,eud.yaml
> @@ -18,6 +18,7 @@ properties:
>      items:
>        - enum:
>            - qcom,sc7280-eud
> +          - qcom,sm8350-eud
>        - const: qcom,eud
>  
>    reg:
> @@ -45,10 +46,88 @@ properties:
>          $ref: /schemas/graph.yaml#/properties/port
>          description: This port is to be attached to the type C connector.
>  
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +patternProperties:
> +  "^eud-path@[0-1]$":
> +    type: object
> +    description:
> +      Represents one High-Speed UTMI path that EUD intercepts. Use eud-path nodes
> +      to associate role-switching behavior with specific port connections, allowing
> +      EUD to manage role transitions independently for each UTMI path.
> +
> +    properties:
> +      reg:
> +        maxItems: 1
> +        description: Path number
> +
> +      usb-role-switch:
> +        type: boolean
> +        description:
> +          Indicates that EUD relays USB role-switch events for this path and
> +          performs role-dependent UTMI routing accordingly. In device role,
> +          the EUD hub is inserted into this path to enable debug
> +          functionality. In host role, the EUD hub is bypassed and UTMI
> +          traffic flows directly between the PHY and the USB controller.
> +
> +      ports:
> +        $ref: /schemas/graph.yaml#/properties/ports
> +        description:
> +          These ports are to be attached to the endpoint of the USB controller node
> +          and USB connector node.
> +
> +        properties:
> +          port@0:
> +            $ref: /schemas/graph.yaml#/properties/port
> +            description: This port is to be attached to the USB controller.
> +
> +          port@1:
> +            $ref: /schemas/graph.yaml#/properties/port
> +            description: This port is to be attached to the USB connector.
> +
> +    required:
> +      - reg
> +      - ports
> +
> +    additionalProperties: false
> +
>  required:
>    - compatible
>    - reg
> -  - ports
> +
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: qcom,sc7280-eud
> +    then:
> +      oneOf:
> +        - required:
> +            - ports
> +          properties:
> +            eud-path@0: false
> +            eud-path@1: false
> +        - required:
> +            - eud-path@0
> +          properties:
> +            ports: false
> +            eud-path@1: false
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: qcom,sm8350-eud
> +    then:
> +      required:
> +        - eud-path@0
> +        - eud-path@1
> +      properties:
> +        ports: false
>  
>  additionalProperties: false
>  
> @@ -77,3 +156,56 @@ examples:
>              };
>          };
>      };
> +  - |
> +    eud@88e0000 {
> +        compatible = "qcom,sm8350-eud", "qcom,eud";
> +        reg = <0x88e0000 0x2000>,
> +              <0x88e2000 0x1000>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        eud-path@0 {
> +            reg = <0>;
> +            usb-role-switch;
> +
> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +                port@0 {
> +                    reg = <0>;
> +                    eud_usb0: endpoint {
> +                        remote-endpoint = <&usb_1_dwc3_hs>;
> +                    };
> +                };
> +
> +                port@1 {
> +                    reg = <1>;
> +                    eud_con0: endpoint {
> +                        remote-endpoint = <&pmic_glink_hs_in>;
> +                    };
> +                };
> +            };
> +        };
> +
> +        eud-path@1 {
> +            reg = <1>;
> +
> +            ports {
> +                #address-cells = <1>;
> +                #size-cells = <0>;
> +                port@0 {
> +                    reg = <0>;
> +                    eud_usb1: endpoint {
> +                        remote-endpoint = <&usb_2_dwc3_hs>;
> +                    };
> +                };
> +
> +                port@1 {
> +                    reg = <1>;
> +                    eud_con1: endpoint {
> +                        remote-endpoint = <&conn_2_hs_in>;
> +                    };
> +                };
> +            };
> +        };
> +    };
> -- 
> 2.34.1
>