Re: [PATCH] devicetree: Add video bus switch

From: Pavel Machek
Date: Wed Feb 08 2017 - 17:30:25 EST


On Wed 2017-02-08 15:36:09, Rob Herring wrote:
> 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@xxxxxxxxxx>
> > Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@xxxxxxxxx>
> > Signed-off-by: Pavel Machek <pavel@xxxxxx>
> >
> >
> > 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.

It is a switch, not a multiplexor (
https://en.wikipedia.org/wiki/Multiplexing ). Only one camera can
operate at a time.

> 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.

Do you have a pointer?

> > +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.

I'd prefer not to confuse people. I guess that would be 0 -- output
port, 1, 2 -- input ports... But this is media data, are you sure it
is good idea to change this?

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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