Re: [PATCH v5 2/6] dt-bindings: usb: add binding for Type-B GPIO connector driver

Rob Herring
2019-05-14T18:12:25Z

On Tue, May 14, 2019 at 04:47:19PM +0800, Chunfeng Yun wrote:
> It's used to support dual role switch via GPIO when use Type-B
> receptacle, typically the USB ID pin is connected to an input
> GPIO pin
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
> v5 changes:
> 1. treat type-B connector as child device of USB controller's, but not
> as a separate virtual device, suggested by Rob
> 2. put connector's port node under connector node, suggested by Rob
>
> v4 no changes
>
> v3 changes:
> 1. treat type-B connector as a virtual device, but not child device of
> USB controller's
>
> v2 changes:
> 1. new patch to make binding clear suggested by Hans
> ---
> .../bindings/usb/typeb-conn-gpio.txt | 42 +++++++++++++++++++
> 1 file changed, 42 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/usb/typeb-conn-gpio.txt
>
> diff --git a/Documentation/devicetree/bindings/usb/typeb-conn-gpio.txt b/Documentation/devicetree/bindings/usb/typeb-conn-gpio.txt
> new file mode 100644
> index 000000000000..20dd3499a348
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/typeb-conn-gpio.txt
> @@ -0,0 +1,42 @@
> +USB Type-B GPIO Connector
> +
> +This is used to switch dual role mode from the USB ID pin connected to
> +an input GPIO pin.
> +
> +Required properties:
> +- compatible : should include "linux,typeb-conn-gpio" and "usb-b-connector".

I don't think we need "linux,typeb-conn-gpio". A driver can decide to
handle GPIO lines if they present or we assume the parent device handles
ID and/or Vbus if they are not present.

> +- id-gpios, vbus-gpios : either one of them must be present, and both
> + can be present as well.

Please clarify that vbus-gpios is an input to sense Vbus presence as an
output it should be modelled as a regulator only.

These should be added to usb-connector.txt.

The result of all this is you don't need this file. Just additions to
usb-connector.txt.

> +- vbus-supply : can be present if needed when supports dual role mode or
> + host mode.
> + see connector/usb-connector.txt
> +
> +Sub-nodes:
> +- port : should be present.
> + see graph.txt
> +
> +Example:
> +
> +&mtu3 {
> + status = "okay";

Don't show status in examples.

> +
> + connector {
> + compatible = "linux,typeb-conn-gpio", "usb-b-connector";
> + label = "micro-USB";
> + type = "micro";
> + id-gpios = <&pio 12 GPIO_ACTIVE_HIGH>;
> + vbus-supply = <&usb_p0_vbus>;
> +
> + port {
> + bconn_ep: endpoint@0 {
> + remote-endpoint = <&usb_role_sw>;
> + };
> + };
> + };
> +
> + port {
> + usb_role_sw: endpoint@0 {
> + remote-endpoint = <&bconn_ep>;
> + };
> + };

When the host controller is the parent of the connector, you don't need
the graph unless you're describing the alternate modes in Type-C.

> +};
> --
> 2.21.0
>