Re: [RFC PATCH v2 1/6] dt-bindings: add bindings for USB physical connector

[Rob Herring]

On Thu, Feb 15, 2018 at 11:39:15AM +0100, Andrzej Hajda wrote:
> These bindings allow to describe most known standard USB connectors
> and it should be possible to extend it if necessary.
> USB connectors, beside USB can be used to route other protocols,
> for example UART, Audio, MHL. In such case every device passing data
> through the connector should have appropriate graph bindings.
> 
> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> ---
> v3:
> - removed MHL port (samsung connector will have separate bindings),
> - added 2nd example for USB-C,
> - improved formatting
> v2:
> - moved connector type(A,B,C) to compatible string (Rob),
> - renamed size property to type (Rob),
> - changed type description to be less confusing (Laurent),
> - removed vendor specific compatibles (implied by graph port number),
> - added requirement of connector being a child of IC (Rob),
> - removed max-mode (subtly suggested by Rob, it should be detected anyway
>   by USB Controller in runtime, downside is that device is not able to
>   report its real capabilities, maybe better would be to make it optional(?)),
> - assigned port numbers to data buses (Rob).
> 
> Regards
> Andrzej
> 
> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
> 
> dt-bindings: add bindings for USB physical connector v3
> ---
>  .../bindings/connector/usb-connector.txt           | 74 ++++++++++++++++++++++
>  1 file changed, 74 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/connector/usb-connector.txt
> 
> diff --git a/Documentation/devicetree/bindings/connector/usb-connector.txt b/Documentation/devicetree/bindings/connector/usb-connector.txt
> new file mode 100644
> index 000000000000..1efda92639da
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/connector/usb-connector.txt
> @@ -0,0 +1,74 @@
> +USB Connector
> +=============
> +
> +USB connector node represents physical USB connector. It should be
> +a child of USB interface controller.
> +
> +Required properties:
> +- compatible: describes type of the connector, must be one of:
> +    "usb-a-connector",
> +    "usb-b-connector",
> +    "usb-c-connector".
> +
> +Optional properties:
> +- label: symbolic name for the connector,
> +- type: size of the connector, should be specified in case of USB-A, USB-B
> +  non-standard (large) connector sizes: "mini", "micro".

The smaller connectors are standard too. Perhaps "non-fullsize connector 
sizes".

We're missing a micro-AB connector, but I think those are actually 
pretty rare. Most phones are micro-B connectors, but do both host and 
device.

> +
> +Required nodes:
> +- any data bus to the connector should be modeled using the OF graph bindings
> +  specified in bindings/graph.txt, unless the bus is between parent node and
> +  the connector. Since single connector can have multpile data buses every bus
> +  has assigned OF graph port number as follows:
> +    0: High Speed (HS), present in all connectors,
> +    1: Super Speed (SS), present in SS capable connectors,

This should also say endpoint 0 is USB-SS, endpoint 1 (and higher?) is 
Alternate Mode. And show in the example.

> +    2: Sideband use (SBU), present in USB-C.
> +
> +Examples
> +--------
> +
> +1. Micro-USB connector with HS lines routed via controller (MUIC):
> +
> +muic-max77843@66 {
> +	...
> +	usb_con: connector {
> +		compatible = "usb-b-connector";
> +		label = "micro-USB";
> +		type = "micro";
> +	};
> +};
> +
> +2. USB-C connector attached to CC controller (s2mm005), HS lines routed
> +to companion PMIC (max77865), SS lines to USB3 PHY and SBU to DisplayPort:

Having SBU to DP but no DP video path connection is wrong.

> +
> +ccic: s2mm005@33 {
> +	...
> +	usb_con: connector {
> +		compatible = "usb-c-connector";
> +		label = "USB-C";
> +
> +		ports {
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			port@0 {
> +				reg = <0>;
> +				usb_con_hs: endpoint {
> +					remote-endpoint = <&max77865_usbc_hs>;
> +				};
> +			};
> +			port@1 {
> +				reg = <1>;
> +				usb_con_ss: endpoint {
> +					remote-endpoint = <&usbdrd_phy_ss>;
> +				};
> +			};
> +			port@2 {
> +				reg = <2>;
> +				usb_con_sbu: endpoint {
> +					remote-endpoint = <&dp_aux>;
> +				};
> +			};
> +		};
> +	};
> +};
> -- 
> 2.16.1
>