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Date:   Tue, 16 Mar 2021 16:19:34 -0600
From:   Rob Herring <robh@kernel.org>
To:     =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-usb@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>
Subject: Re: [PATCH robh next] dt-bindings: usb: add USB controller port
Message-ID: <20210316221934.GA3768880@robh.at.kernel.org>
References: <20210309121311.7263-1-zajec5@gmail.com>
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On Tue, Mar 09, 2021 at 01:13:11PM +0100, Rafał Miłecki wrote:
> From: Rafał Miłecki <rafal@milecki.pl>
> 
> USB bindings already allow specifying USB device hard wired to a
> specific controller port but they don't allow describing port on its
> own.
> 
> This fixes:
> arch/arm/boot/dts/bcm4708-buffalo-wzr-1750dhp.dt.yaml: usb@23000: port@1: 'compatible' is a required property
>         From schema: Documentation/devicetree/bindings/usb/generic-xhci.yaml
> 
> Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
> ---
> Please check if I got the $nodename part right. Somehow I don't see any
> errors / warnings when using:
> 
> something@1 {
> 	reg = <1>;
> };

$nodename may not work in child nodes of a schema.

> ---
>  .../devicetree/bindings/usb/usb-hcd.yaml      |  4 +-
>  .../devicetree/bindings/usb/usb-port.yaml     | 39 +++++++++++++++++++
>  2 files changed, 42 insertions(+), 1 deletion(-)
>  create mode 100644 Documentation/devicetree/bindings/usb/usb-port.yaml
> 
> diff --git a/Documentation/devicetree/bindings/usb/usb-hcd.yaml b/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> index 56853c17af66..b0c6a79cad57 100644
> --- a/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> +++ b/Documentation/devicetree/bindings/usb/usb-hcd.yaml
> @@ -33,7 +33,9 @@ patternProperties:
>    "^.*@[0-9a-f]{1,2}$":
>      description: The hard wired USB devices
>      type: object
> -    $ref: /usb/usb-device.yaml
> +    oneOf:
> +      - $ref: /usb/usb-port.yaml
> +      - $ref: /usb/usb-device.yaml
>  
>  additionalProperties: true
>  
> diff --git a/Documentation/devicetree/bindings/usb/usb-port.yaml b/Documentation/devicetree/bindings/usb/usb-port.yaml
> new file mode 100644
> index 000000000000..68fe16c8703e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/usb-port.yaml
> @@ -0,0 +1,39 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/usb-port.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: USB port on USB controller
> +
> +maintainers:
> +  - Rafał Miłecki <rafal@milecki.pl>
> +
> +description: |
> +  This binding describes a single USB controller port that doesn't have any
> +  device hard wired.
> +
> +properties:
> +  $nodename:
> +    pattern: "^port@[0-9a-f]{1,2}$"

Unfortunately, 'port' is used elsewhere, so this would be applied 
any node that matches. That's not really a problem as this is simple 
enough, but then what does it buy us?

I'd be fine just dropping 'compatible' as required in usb-device.yaml.

> +
> +  reg:
> +    description: number of USB controller port
> +    maxItems: 1
> +
> +required:
> +  - reg
> +
> +additionalProperties: true
> +
> +examples:
> +  - |
> +    usb@11270000 {
> +        reg = <0x11270000 0x1000>;
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        port@1 {
> +            reg = <1>;
> +        };
> +    };
> -- 
> 2.26.2
>