Re: [PATCH] nokia n900: update dts with camera support

Sakari Ailus
2017-08-16T21:23:44Z

On Wed, Aug 16, 2017 at 10:59:15PM +0200, Pavel Machek wrote:
> > Hi,
> >
> > On Wed, Aug 16, 2017 at 12:03:49AM +0200, Pavel Machek wrote:
> > > diff --git a/Documentation/devicetree/bindings/media/video-interfaces.txt b/Documentation/devicetree/bindings/media/video-interfaces.txt
> > > index 852041a..aade681 100644
> > > --- a/Documentation/devicetree/bindings/media/video-interfaces.txt
> > > +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt
> > > @@ -119,6 +119,8 @@ Optional endpoint properties
> > > as 0 (normal). This property is valid for serial busses only.
> > > - strobe: Whether the clock signal is used as clock (0) or strobe (1). Used
> > > with CCP2, for instance.
> > > +- clock-inv: polarity of clock/strobe signal. 0 - not inverted, 1 - inverted
> > > +- crc: crc is in use
> >
> > booleans in DT are not done with <0> and <1>, but as properties without
> > values. True = property exists, False = property does not exist.

Now that you mention it, I remember that now.

>
> Well, strobe property above already uses = <0>/<1> format, as do
> others.
>
> Problem with "false = property does not exist" is that you don't know
> if it is "someone forgot to define it" or "someone made a typo" or
> "dts is too old to know about this property" or "the property indeed
> should be false"...

As this is an established practice, I think we should follow it for bool
properties.

We could change the existing ones, too, and leave some extra checks in
place to handle old dtbs.

--
Regards,

Sakari Ailus
e-mail: sakari.ailus@iki.fi