Re: [RFC 1/2] dt-bindings: usb: dwc3: Add support for multiport related properties

Rob Herring
2022-05-23T12:26:00Z

On Thu, May 19, 2022 at 06:04:54PM +0530, Harsh Agarwal wrote:
> Added support for multiport, mport, num-ssphy and num-hsphy
> properties. These properties are used to support devices having
> a multiport controller.
>
> Signed-off-by: Harsh Agarwal <quic_harshq@quicinc.com>
> ---
> .../devicetree/bindings/usb/snps,dwc3.yaml | 55 ++++++++++++++++++++++
> 1 file changed, 55 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> index f4471f8..39c61483 100644
> --- a/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> +++ b/Documentation/devicetree/bindings/usb/snps,dwc3.yaml
> @@ -341,6 +341,35 @@ properties:
> This port is used with the 'usb-role-switch' property to connect the
> dwc3 to type C connector.
>
> + multiport:
> + description:
> + If a single USB controller supports multiple ports, then it's referred to as
> + a multiport controller. Each port of the multiport controller can support
> + either High Speed or Super Speed or both and have their own PHY phandles. Each
> + port is represented by "mport" node and all the "mport" nodes are grouped
> + together inside the "multiport" node where individual "mport" node defines the
> + PHYs supported by that port.
> + required:
> + - mport
> +
> + num-hsphy:
> + description: Total number of HS-PHYs defined by the multiport controller.
> + $ref: /schemas/types.yaml#/definitions/uint32
> +
> + num-ssphy:
> + description: Total number of SS-PHYs defined by the multiport controller.
> + $ref: /schemas/types.yaml#/definitions/uint32

These seem redundant. Can't you count ports/phys?

> +
> + mport:
> + description: Each mport node represents one port of the multiport controller.
> + patternProperties: "^mport@[0-9a-f]+$"

Think about how the USB device binding fits into this. A hub vs.
multiple root ports doesn't seem much different.

Rob