Re: [PATCH v3 5/9] staging: iio: ad2s1200: Add documentation for device tree binding

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 27 Apr 2018 09:48:20 -0500
Rob Herring <robh@kernel.org> wrote:

> On Mon, Apr 23, 2018 at 12:03:47AM +0200, David Veenstra wrote:
> > Add documentation for the added device tree bindings.
> > 
> > Signed-off-by: David Veenstra <davidjulianveenstra@gmail.com>
> > ---
> > Changes in v3:
> >  - Documentation is added to Documentation/devicetree/bindings/iio/resolver
> >    instead of staging directory.
> >  - Add mention to ad2s1205 device.
> > 
> >  .../devicetree/bindings/iio/resolver/ad2s1200.txt        | 16 ++++++++++++++++
> >  1 file changed, 16 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt b/Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt
> > new file mode 100644
> > index 000000000000..46b51db38368
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/resolver/ad2s1200.txt
> > @@ -0,0 +1,16 @@
> > +Analog Devices AD2S1200 and AD2S1205 Resolver-to-Digital Converter
> > +
> > +Required properties:
> > + - compatible : should be "adi,ad2s1200" or "adi,ad2s1205"
> > + - reg : the SPI chip select number of the device
> > + - sample-gpios : The GPIO pin connected to the SAMPLE line of the AD2S1200
> > + - rdvel-gpios : The GPIO pin connected to the RDVEL line of the AD2S1200  
> 
> Are these gpios something that would be common to resolvers (whatever 
> that is) or specific to this chip. For the latter, you need vendor 
> prefixes.

They are pretty chip specific I think, so prefixes needed.

I'd not really registered that gpios should be vendor prefixed for some reason
(kind of obvious now you mention it).  We have only a few from a quick grep
of the bindings for IIO devices (there are loads elsewhere that aren't and
are clearly very much part specific).  Ah well, will try and do better moving
forward on this!

Jonathan


> 
> > +
> > +Example:
> > +
> > +	resolver {  
> 
> Missing unit address.
> 
> > +		compatible = "adi,ad2s1200";
> > +		reg = <4>;
> > +		sample-gpios = <&gpio 5 GPIO_ACTIVE_HIGH>;
> > +		rdvel-gpios = <&gpio 6 GPIO_ACTIVE_HIGH>;
> > +	};
> > -- 
> > 2.16.2
> >