On 03/05/2023 15:39, Michal Simek wrote:
> The Microchip usb5744 is a SS/HS USB 3.0 hub controller with 4 ports.
> The binding describes USB related aspects of the USB5744 hub, it as
> well cover the option of connecting the controller as an i2c slave.
> When i2c interface is connected hub needs to be initialized first.
> Hub itself has fixed i2c address 0x2D but hardcoding address is not good
> idea because address can be shifted by i2c address translator in the
> middle.
>
> Signed-off-by: Piyush Mehta <piyush.mehta@xxxxxxx>
> Signed-off-by: Michal Simek <michal.simek@xxxxxxx>
> ---
>
> It looks like that usb8041 has also an optional i2c interface which is not
> covered. But it is mentioned at commit 40e58a8a7ca6 ("dt-bindings: usb:
> Add binding for TI USB8041 hub controller").
>
> i2c-bus name property was suggested by Rob at
> https://lore.kernel.org/all/CAL_JsqJedhX6typpUKbnzV7CLK6UZVjq3CyG9iY_j5DLPqvVdw@xxxxxxxxxxxxxx/
> and
> https://lore.kernel.org/all/CAL_JsqJZBbu+UXqUNdZwg-uv0PAsNg55026PTwhKr5wQtxCjVQ@xxxxxxxxxxxxxx/
>
> the question is if adding address like this is acceptable.
> But it must be specified.
Why? phandle points it explicitly.
>
> Driver will follow based on final dt-binding.
>
> ---
> .../bindings/usb/microchip,usb5744.yaml | 85 +++++++++++++++++++
> 1 file changed, 85 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
>
> diff --git a/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
> new file mode 100644
> index 000000000000..fafe275a35df
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/microchip,usb5744.yaml
> @@ -0,0 +1,85 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/microchip,usb5744.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Microchip USB5744 4-port Hub Controller
> +
> +description:
> + Microchip's USB5744 SmartHubTM IC is a 4 port, SuperSpeed (SS)/Hi-Speed (HS),
> + low power, low pin count configurable and fully compliant with the USB 3.1
> + Gen 1 specification. The USB5744 also supports Full Speed (FS) and Low Speed
> + (LS) USB signaling, offering complete coverage of all defined USB operating
> + speeds. The new SuperSpeed hubs operate in parallel with the USB 2.0
> + controller, so 5 Gbps SuperSpeed data transfers are not affected by slower
> + USB 2.0 traffic.
> +
> +maintainers:
> + - Piyush Mehta <piyush.mehta@xxxxxxx>
> + - Michal Simek <michal.simek@xxxxxxx>
> +
> +allOf:
> + - $ref: usb-device.yaml#
> +
> +properties:
> + compatible:
> + enum:
> + - usb424,5744
> + - usb424,2744
Keep the list ordered, so 2744 before 5744.
> +
> + reg: true
> +
> + reset-gpios:
> + maxItems: 1
> + description:
> + GPIO controlling the GRST# pin.
> +
> + vdd-supply:
> + description:
> + VDD power supply to the hub
> +
> + peer-hub:
> + $ref: /schemas/types.yaml#/definitions/phandle
> + description:
> + phandle to the peer hub on the controller.
> +
> + i2c-bus:
> + maxItems: 1
> + description:
> + phandle of an I2C controller to link usb-hub for usb attach and reset
> + followed by i2c address.
> +
> +required:
> + - compatible
> + - reg
> + - peer-hub
> +
> +additionalProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> +
> + usb {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + /* 2.0 hub on port 1 */
> + hub_2_0: hub@1 {
> + compatible = "usb424,5744";
Mixed indentation, use four spaces here as well.
> + reg = <1>;
> + peer-hub = <&hub_3_0>;
> + i2c-bus = <&i2c 0x2d>;
> + reset-gpios = <&gpio 3 GPIO_ACTIVE_LOW>;
> + };
Krzysztof
