Re: [PATCH 01/22] dt-bindings: gpio: Add binding for ChromeOS EC GPIO controller

[Rob Herring <robh@kernel.org>]

On Fri, Feb 09, 2024 at 11:09:12PM -0800, Stephen Boyd wrote:
> The ChromeOS embedded controller (EC) supports setting the state of
> GPIOs when the system is unlocked, and getting the state of GPIOs in all
> cases. The GPIOs are on the EC itself, so the EC acts similar to a GPIO
> expander. Add a binding to describe these GPIOs in DT so that other
> devices described in DT can read the GPIOs on the EC.
> 
> Cc: Linus Walleij <linus.walleij@linaro.org>
> Cc: Bartosz Golaszewski <brgl@bgdev.pl>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Lee Jones <lee@kernel.org>
> Cc: Benson Leung <bleung@chromium.org>
> Cc: Guenter Roeck <groeck@chromium.org>
> Cc: <linux-gpio@vger.kernel.org>
> Cc: <devicetree@vger.kernel.org>
> Cc: <chrome-platform@lists.linux.dev>
> Cc: Pin-yen Lin <treapking@chromium.org>
> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
> ---
>  .../bindings/gpio/google,cros-ec-gpio.yaml    | 49 +++++++++++++++++++
>  .../bindings/mfd/google,cros-ec.yaml          |  3 ++
>  2 files changed, 52 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/google,cros-ec-gpio.yaml
> 
> diff --git a/Documentation/devicetree/bindings/gpio/google,cros-ec-gpio.yaml b/Documentation/devicetree/bindings/gpio/google,cros-ec-gpio.yaml
> new file mode 100644
> index 000000000000..a9f1d7784070
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/google,cros-ec-gpio.yaml
> @@ -0,0 +1,49 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/google,cros-ec-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: GPIOs controlled by ChromeOS EC
> +
> +maintainers:
> +  - Stephen Boyd <swboyd@chromium.org>
> +
> +description:
> +  Google's ChromeOS EC has a gpio controller inside the Embedded Controller
> +  (EC) and controlled via a host-command interface. The node for this
> +  device should be under a cros-ec node like google,cros-ec-spi.

Why do we need a child node here? 

Rob