[PATCH 1/4] dt_bindings: rs485: Add binding for GPIO that controls Rx enable during Tx

[Rob Herring]

On Wed, Oct 26, 2022 at 06:50:46PM +0200, Christoph Niedermaier wrote:
> Add the binding for a generic definition of a GPIO, that controls whether Rx
> is connected or disconnected by an electrical circuit to have the ability
> to receive the signals on the bus during sending or disable receiving during
> sending.
> 
> Signed-off-by: Christoph Niedermaier <cniedermaier at dh-electronics.com>
> ---
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Rob Herring <robh+dt at kernel.org>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski+dt at linaro.org>
> Cc: Marek Vasut <marex at denx.de>
> Cc: devicetree at vger.kernel.org
> To: linux-serial at vger.kernel.org
> To: linux-arm-kernel at lists.infradead.org
> ---
>  Documentation/devicetree/bindings/serial/rs485.yaml | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/rs485.yaml b/Documentation/devicetree/bindings/serial/rs485.yaml
> index 90a1bab40f05..0ebd7690f85d 100644
> --- a/Documentation/devicetree/bindings/serial/rs485.yaml
> +++ b/Documentation/devicetree/bindings/serial/rs485.yaml
> @@ -51,6 +51,10 @@ properties:
>      description: GPIO pin to enable RS485 bus termination.
>      maxItems: 1
>  
> +  rs485-rx-during-tx-gpios:
> +    description: GPIO pin to control RS485 Rx enable during Tx.

Active state means do what? And inactive? This is an output gating the 
RX signal or an input telling the receiver what to do during tx? The 
description is not adequate.

How does this property relate to 'rs485-rx-during-tx' Any combination of 
the 2 being present or not is okay? If not, you need some constraints.

Rob