Re: [PATCH v4 1/3] dt-bindings: iio: dac: AD5766 yaml documentation

From: Jonathan Cameron
Date: Tue Dec 29 2020 - 11:20:41 EST


On Mon, 21 Dec 2020 11:44:34 -0700
Rob Herring <robh@xxxxxxxxxx> wrote:

> On Fri, Dec 18, 2020 at 07:12:29PM +0200, Cristian Pop wrote:
> > This adds device tree bindings for the AD5766 DAC.
> >
> > Signed-off-by: Cristian Pop <cristian.pop@xxxxxxxxxx>
> > ---
> > Changelog v4:
> > - Add range selection
> > - Reset is GPIO_ACTIVE_LOW
> >
> > .../bindings/iio/dac/adi,ad5766.yaml | 64 +++++++++++++++++++
> > 1 file changed, 64 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/iio/dac/adi,ad5766.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/iio/dac/adi,ad5766.yaml b/Documentation/devicetree/bindings/iio/dac/adi,ad5766.yaml
> > new file mode 100644
> > index 000000000000..846b5ee50761
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/dac/adi,ad5766.yaml
> > @@ -0,0 +1,64 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +# Copyright 2020 Analog Devices Inc.
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/dac/adi,ad5766.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices AD5766 DAC device driver
> > +
> > +maintainers:
> > + - Cristian Pop <cristian.pop@xxxxxxxxxx>
> > +
> > +description: |
> > + Bindings for the Analog Devices AD5766 current DAC device. Datasheet can be
> > + found here:
> > + https://www.analog.com/media/en/technical-documentation/data-sheets/ad5766-5767.pdf
> > +
> > +properties:
> > + compatible:
> > + enum:
> > + - adi,ad5766
> > + - adi,ad5767
> > +
> > + output-range:
> > + description: Select converter output range.
>
> Something standard for DACs? If not needs a vendor prefix and type.

Hmm. It's a common enough thing that we could think about standardizing
it but it would need units in the naming.

output-range-volts

and promoting to a higher level in the DT bindings docs than the individual
driver.

We almost certainly have a bunch of preexisting bindings using manufacturer
specific equivalents. I've not be completely consistent on this so have
encouraged separate max / min attributes but with hind sight I two value
version like this probably makes more sense in a DT binding (not so much
if userspace is controlling it).


>
> > +
> > + reg:
> > + maxItems: 1
> > +
> > + spi-max-frequency:
> > + maximum: 1000000
> > +
> > + spi-cpol: true
> > +
> > + reset-gpios:
> > + description: GPIO spec for the RESET pin. If specified, it will be asserted
> > + during driver probe. As the line is active low, it should be marked
> > + GPIO_ACTIVE_LOW.
> > + maxItems: 1
> > +
> > +required:
> > + - compatible
> > + - output-range
> > + - reg
> > + - spi-max-frequency
> > + - spi-cpol
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > + - |
> > + spi {
> > + #address-cells = <1>;
> > + #size-cells = <0>;
> > +
> > + ad5766@0 {
> > + compatible = "adi,ad5766";
> > + output-range = <(-5) 5>;
> > + reg = <0>;
> > + spi-cpol;
> > + spi-max-frequency = <1000000>;
> > + reset-gpios = <&gpio 22 0>;
> > + };
> > + };
> > --
> > 2.17.1
> >