Re: [RFC PATCH 1/6] dt-bindings: display/bridge: Add binding for input mux bridge

[Rob Herring]

On Fri, May 15, 2020 at 03:12:10PM +0200, Guido Günther wrote:
> The bridge allows to select the input source via a mux controller.
> 
> Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>
> ---
>  .../display/bridge/mux-input-bridge.yaml      | 123 ++++++++++++++++++
>  1 file changed, 123 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/display/bridge/mux-input-bridge.yaml
> 
> diff --git a/Documentation/devicetree/bindings/display/bridge/mux-input-bridge.yaml b/Documentation/devicetree/bindings/display/bridge/mux-input-bridge.yaml
> new file mode 100644
> index 000000000000..4029cf63ee5c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/bridge/mux-input-bridge.yaml
> @@ -0,0 +1,123 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/bridge/mux-input-bridge.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: DRM input source selection via multiplexer

DRM is not a hardware thing.

The graph binding is already designed to support muxing. Generally, 
multiple endpoints on an input node is a mux. So either the device with 
the input ports knows how to select the input, or you just need a 
mux-control property for the port to have some other device implement 
the control.

You could do it like you have below. That would be appropriate if 
there's a separate h/w device controlling the muxing. Say for example 
some board level device controlled by i2c.

Rob