Re: [PATCH] devicetree: Add video bus switch

Rob Herring
2017-02-08T22:10:27Z

On Fri, Feb 03, 2017 at 01:35:08PM +0100, Pavel Machek wrote:
>
> N900 contains front and back camera, with a switch between the
> two. This adds support for the switch component, and it is now
> possible to select between front and back cameras during runtime.
>
> This adds documentation for the devicetree binding.
>
> Signed-off-by: Sebastian Reichel <sre@kernel.org>
> Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
> Signed-off-by: Pavel Machek <pavel@ucw.cz>
>
>
> diff --git a/Documentation/devicetree/bindings/media/video-bus-switch.txt b/Documentation/devicetree/bindings/media/video-bus-switch.txt
> new file mode 100644
> index 0000000..1b9f8e0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/video-bus-switch.txt
> @@ -0,0 +1,63 @@
> +Video Bus Switch Binding
> +========================

I'd call it a mux rather than switch.

BTW, there's a new mux-controller binding under review you might look
at. It would only be needed here if the mux ctrl also controls other
things.

> +
> +This is a binding for a gpio controlled switch for camera interfaces. Such a
> +device is used on some embedded devices to connect two cameras to the same
> +interface of a image signal processor.
> +
> +Required properties
> +===================
> +
> +compatible : must contain "video-bus-switch"

video-bus-gpio-mux

> +switch-gpios : GPIO specifier for the gpio, which can toggle the

mux-gpios to align with existing GPIO controlled muxes.

> + selected camera. The GPIO should be configured, so
> + that a disabled GPIO means, that the first port is
> + selected.
> +
> +Required Port nodes
> +===================
> +
> +More documentation on these bindings is available in
> +video-interfaces.txt in the same directory.
> +
> +reg : The interface:
> + 0 - port for image signal processor
> + 1 - port for first camera sensor
> + 2 - port for second camera sensor

This could be used for display side as well. So describe these just as
inputs and outputs.

Rob