Re: [PATCH v2 2/2] dt-bindings: iio: adc: Add DT docs for AD7292

[Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>]

Hi Rob

Thanks for the review.

I'm having some trouble with the DTC.
I installed the DT tool from https://github.com/robherring/dt-schema.
Running make -k dt_binding_check goes through all the checks (CHKDT), producing
the .example.dts files but then gives errors like:

  DTC     Documentation/devicetree/bindings/arm/calxeda.example.dt.yaml
FATAL ERROR: Unknown output format "yaml"
make[1]: *** [scripts/Makefile.lib:314: Documentation/devicetree/bindings/arm/calxeda.example.dt.yaml] Error 1
make[1]: *** Deleting file 'Documentation/devicetree/bindings/arm/calxeda.example.dt.yaml'

My pip3 installation has:
jsonschema jsonschema-3.1.2.dev6+g0d827f3
rfc3987 1.3.8

$HOME/.local/bin is listed in my shell's PATH variable.

I was trying to follow the documentation at:
Documentation/devicetree/writing-schema.rst

Are there any other DTC dependencies that I am missing?

On 10/17, Rob Herring wrote:
> On Tue, Oct 15, 2019 at 11:52:23PM -0300, Marcelo Schmitt wrote:
> > Add a device tree binding doc for AD7292 monitor and control system.
> > 
> > Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>
> > ---
> >  .../bindings/iio/adc/adi,ad7292.yaml          | 107 ++++++++++++++++++
> >  MAINTAINERS                                   |   1 +
> >  2 files changed, 108 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> > new file mode 100644
> > index 000000000000..40028332d9e2
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> > @@ -0,0 +1,107 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Analog Devices AD7292 10-Bit Monitor and Control System
> > +
> > +maintainers:
> > +  - Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>
> > +
> > +description: |
> > +  Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs,
> > +  Temperature Sensor, and GPIOs
> > +
> > +  Specifications about the part can be found at:
> > +    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - adi,ad7292
> > +
> > +  reg:
> > +    maxItems: 1
> > +
> > +  vref-supply:
> > +    description: |
> > +      The regulator supply for ADC and DAC reference voltage.
> > +    maxItems: 1
> 
> Not necessary, regulator supplies are always 1 item, so drop maxItems.
> 
> > +
> > +  spi-cpha:
> > +    description: |
> > +      See Documentation/devicetree/bindings/spi/spi-controller.yaml
> > +    maxItems: 1
> 
> This is just wrong because spi-cpha is a boolean. Just 'spi-cpha: true' 
> is sufficient. If this device needs this property, then it should 
> probably be required.
> 
> > +
> > +  '#address-cells':
> > +    const: 1
> > +
> > +  '#size-cells':
> > +    const: 0
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +
> > +patternProperties:
> > +  "^channel@[0-7]$":
> > +    type: object
> > +    description: |
> > +      Represents the external channels which are connected to the ADC.
> > +      See Documentation/devicetree/bindings/iio/adc/adc.txt.
> > +
> > +    properties:
> > +      reg:
> > +        description: |
> > +          The channel number. It can have up to 8 channels numbered from 0 to 7.
> > +        maxItems: 1
> > +
> > +      diff-channels:
> > +        description: see Documentation/devicetree/bindings/iio/adc/adc.txt
> > +        maxItems: 1
> > +
> > +    required:
> > +      - reg
> > +
> > +examples:
> > +  - |
> > +    spi {
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +
> > +      ad7292: ad7292@0 {
> 
> adc@0
> 
> > +        compatible = "adi,ad7292";
> > +        reg = <0>;
> > +
> > +        #address-cells = <1>;
> > +        #size-cells = <0>;
> > +
> > +        spi-max-frequency = <25000000>;
> > +        vref-supply = <&adc_vref>;
> > +        spi-cpha;
> > +
> > +        channel@0 {
> > +          reg = <0>;
> > +          diff-channels = <0 1>;
> > +        };
> > +        channel@2 {
> > +          reg = <2>;
> > +        };
> > +        channel@3 {
> > +          reg = <3>;
> > +        };
> > +        channel@4 {
> > +          reg = <4>;
> > +        };
> > +        channel@5 {
> > +          reg = <5>;
> > +        };
> > +        channel@6 {
> > +          reg = <6>;
> > +        };
> > +        channel@7 {
> > +          reg = <7>;
> > +        };
> > +      };
> > +    }
> 
> Missing ';'. Make sure this builds with 'make -k dt_binding_check'. The 
> '-k' is due to some other breakage ATM.
> 
> Rob