Re: [PATCH v3 1/2] iio: document ti-dac8554 devicetree bindings

[Nikolaus Schulz <nikolaus.schulz-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>]

On Mon, Dec 15, 2014 at 01:02:48PM +0000, Mark Rutland wrote:
> On Mon, Dec 15, 2014 at 11:39:56AM +0000, Nikolaus Schulz wrote:
> > Signed-off-by: Nikolaus Schulz <nikolaus.schulz-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org>
> > ---
> >  .../devicetree/bindings/iio/dac/ti-dac8554.txt     | 22 ++++++++++++++++++++++
> >  1 file changed, 22 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/iio/dac/ti-dac8554.txt
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/dac/ti-dac8554.txt b/Documentation/devicetree/bindings/iio/dac/ti-dac8554.txt
> > new file mode 100644
> > index 0000000..32e96859
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/dac/ti-dac8554.txt
> > @@ -0,0 +1,22 @@
> > +TI DAC8554 Digital to Analog Converter
> > +
> > +This driver supports the SPI bus.
> 
> The binding need not refer to the driver, this sentence can go. It might
> be worth adding "(SPI)" to the first line.

OK

> > +
> > +Required properties:
> > +	- compatible: must be "ti,dac8554"
> > +	- vref-supply: the vref power supply
> > +	- ti,address: the additional 2-bit chip address
> > +
> > +For required properties on SPI, please consult
> > +Documentation/devicetree/bindings/spi/spi-bus.txt
> > +
> > +Example:
> > +
> > +	dac8554@0 {
> > +		compatible = "ti,dac8554";
> > +		reg = <0>;
> > +		spi-max-frequency = <50000000>;
> > +
> > +		vref-supply = <&vdd_vref>;
> > +		ti,address = <0>;
> 
> What's this property used for?

The DAC8554 has its own addressing scheme, where each chip is assigned a
two-bit address, defined by the state of two pins. So up to 4 DAC8554
can be operated independently on the same SPI bus.

> > +	};
> 
> Otherwise this looks sane to me.
> 
> Mark.

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