Re: [PATCH 1/9] dt-bindings: reset: Add a binding for the RPi Firmware USB reset

[Florian Fainelli <f.fainelli@gmail.com>]

On 6/8/2020 12:26 PM, Nicolas Saenz Julienne wrote:
> The firmware running on the RPi VideoCore can be used to reset and
> initialize the board's xHCI controller. The reset controller is passed
> to the PCI device through the DT, hence this binding.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
> ---
>  .../arm/bcm/raspberrypi,bcm2835-firmware.yaml | 21 +++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> index b48ed875eb8e..8f9d0986c28f 100644
> --- a/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> +++ b/Documentation/devicetree/bindings/arm/bcm/raspberrypi,bcm2835-firmware.yaml
> @@ -39,6 +39,22 @@ properties:
>        - compatible
>        - "#clock-cells"
>  
> +  usb-reset:
> +    type: object
> +
> +    properties:
> +      compatible:
> +        const: raspberrypi,firmware-usb-reset

I would make this less USB centric, even if this is the only consumer of
the reset controller for now, there could, in premise be other blocks
that require a reset (e.g.: V3D) that would involve going to the VPU
firmware because of various requirements (security, register blocking etc.).

> +
> +      "#clock-cells":

Did not you mean #reset-cells here?


> +        const: 0
> +        description: >
> +          There is only one reset line available, so no need for cell decoding.
> +
> +    required:
> +      - compatible
> +      - "#reset-cells"
> +
>      additionalProperties: false
>  
>  required:
> @@ -55,5 +71,10 @@ examples:
>              compatible = "raspberrypi,firmware-clocks";
>              #clock-cells = <1>;
>          };
> +
> +        usb_reset: usb-reset {
> +            compatible = "raspberrypi,firmware-usb-reset";
> +            #reset-cells = <0>;
> +        };
>      };
>  ...
> 

-- 
Florian