Re: [PATCHv5 3/4] dt-bindings: wiegand: add GPIO bitbanged Wiegand controller

[Rob Herring <robh@kernel.org>]

On Thu, Aug 24, 2023 at 01:10:14PM +0200, Martin Zaťovič wrote:
> GPIO bitbanged Wiegand controller requires definitions of GPIO lines to be
> used on top of the common Wiegand properties. Wiegand utilizes two such
> lines - DATA0(low data line) and DATA1(high data line).
> 
> Acked-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Martin Zaťovič <m.zatovic1@gmail.com>
> ---
>  .../bindings/wiegand/wiegand-gpio.yaml        | 46 +++++++++++++++++++
>  MAINTAINERS                                   |  5 ++
>  2 files changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/wiegand/wiegand-gpio.yaml
> 
> diff --git a/Documentation/devicetree/bindings/wiegand/wiegand-gpio.yaml b/Documentation/devicetree/bindings/wiegand/wiegand-gpio.yaml
> new file mode 100644
> index 000000000000..cf2cb938de02
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/wiegand/wiegand-gpio.yaml
> @@ -0,0 +1,46 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/wiegand/wiegand-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: GPIO bitbanged Wiegand interface properties
> +
> +maintainers:
> +  - Martin Zaťovič <m.zatovic1@gmail.com>
> +
> +description:
> +  This represents the GPIO lines used for bit-banged Wiegand on dedicated GPIO
> +  lines.
> +
> +allOf:
> +  - $ref: /schemas/wiegand/wiegand-controller.yaml#
> +
> +properties:
> +  compatible:
> +    const: wiegand-gpio
> +
> +  data-gpios:
> +    description: GPIOs used as Wiegand data lines, DATA0 and DATA1 respectivelly.
> +    maxItems: 2
> +
> +required:
> +  - compatible
> +  - data-gpios
> +
> +unevaluatedProperties: false

You'll find this fails if you add an actual child node. Assuming you go 
with only 1 child node allowed, then you need:

unevaluatedProperties:
  type: object

(There's not any way to say only 1 child, but multiple would have 
constraints in the common binding as I explained.)

Rob