Re: [PATCH v2 1/4] dt-bindings: Add cros-ec Type C port driver

From: Rob Herring
Date: Tue Feb 11 2020 - 18:25:29 EST


On Fri, Feb 7, 2020 at 2:39 PM Prashant Malani <pmalani@xxxxxxxxxxxx> wrote:
>
> Some Chrome OS devices with Embedded Controllers (EC) can read and
> modify Type C port state.
>
> Add an entry in the DT Bindings documentation that lists out the logical
> device and describes the relevant port information, to be used by the
> corresponding driver.
>
> Signed-off-by: Prashant Malani <pmalani@xxxxxxxxxxxx>
> ---
>
> Changes in v2:
> - No changes. Patch first introduced in v2 of series.
>
> .../bindings/chrome/google,cros-ec-typec.yaml | 77 +++++++++++++++++++
> 1 file changed, 77 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
>
> diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
> new file mode 100644
> index 00000000000000..46ebcbe76db3c2
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
> @@ -0,0 +1,77 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/chrome/google,cros-ec-typec.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Google Chrome OS EC(Embedded Controller) Type C port driver.
> +
> +maintainers:
> + - Benson Leung <bleung@xxxxxxxxxxxx>
> + - Prashant Malani <pmalani@xxxxxxxxxxxx>
> +
> +description:
> + Chrome OS devices have an Embedded Controller(EC) which has access to
> + Type C port state. This node is intended to allow the host to read and
> + control the Type C ports. The node for this device should be under a
> + cros-ec node like google,cros-ec-spi.
> +
> +properties:
> + compatible:
> + const: google,cros-ec-typec
> +
> + port:
> + description: A node that represents a physical Type C port on the
> + device.
> + type: object
> + properties:
> + port-number:
> + description: The number used by the Chrome OS EC to identify
> + this type C port.
> + $ref: /schemas/types.yaml#/definitions/uint32
> + power-role:
> + description: Determines the power role that the Type C port will
> + adopt.
> + oneOf:
> + - items:
> + - const: sink
> + - const: source
> + - const: dual
> + data-role:
> + description: Determines the data role that the Type C port will
> + adopt.
> + oneOf:
> + - items:
> + - const: host
> + - const: device
> + - const: dual
> + try-power-role:
> + description: Determines the preferred power role of the Type C port.
> + oneOf:
> + - items:
> + - const: sink
> + - const: source
> + - const: dual
> +
> + required:
> + - port-number
> + - power-role
> + - data-role
> + - try-power-role
> +
> +required:
> + - compatible
> + - port
> +
> +examples:
> + - |+
> + typec {
> + compatible = "google,cros-ec-typec";
> +
> + port@0 {

'port' is reserved for OF graph binding which this is not.

> + port-number = <0>;
> + power-role = "dual";
> + data-role = "dual";
> + try-power-role = "source";

These are usb-connector binding properties, but this is not a
usb-connector node. However, I think it should be. The main thing to
work out seems to be have multiple connectors.

With your binding, how does one associate the USB host controller with
each port/connector? That's a solved problem with the connector
binding.

Rob