Re: [PATCH 1/2] dt-bindings: iio: adc: ti,ads7038: Add description for ADS7038

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 5 Oct 2023 05:51:40 +0200
werneazc <werneazc@gmail.com> wrote:

> Dear Mr. Herring,
> 
> On Wed, Oct 4, 2023 at 5:11 PM Rob Herring <robh@kernel.org> wrote:
> >
> > On Wed, Oct 04, 2023 at 12:23:29PM +0200, werneazc@gmail.com wrote:  
> > > From: Andre Werner <andre.werner@systec-electronic.com>
> > >  
> >
> > Needs a commit message.  
> 
> Added in an upcoming commit.
> 
> >  
> > > Signed-off-by: Andre Werner <andre.werner@systec-electronic.com>
> > > ---
> > >  .../bindings/iio/adc/ti,ads7038.yaml          | 51 +++++++++++++++++++
> > >  1 file changed, 51 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads7038.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads7038.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads7038.yaml
> > > new file mode 100644
> > > index 000000000000..37fbae95c8e6
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads7038.yaml
> > > @@ -0,0 +1,51 @@
> > > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/iio/adc/ti,ads7038.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Texas Instruments ADS7038 and similar ADCs
> > > +
> > > +maintainers:
> > > +  - Andre Werner <andre.werner@systec-electronic.com>
> > > +
> > > +description: |
> > > +  Family of 7 channel, 12 bit ADCs with SPI/I2C interface.
> > > +
> > > +  Datasheet: https://www.ti.com/lit/gpn/ads7038
> > > +
> > > +properties:
> > > +  compatible:
> > > +    enum:
> > > +      - ti,ads7038
> > > +      - ti,ads7138
> > > +
> > > +  reg:
> > > +    maxItems: 1
> > > +
> > > +  spi-max-frequency:
> > > +    maximum: 60000000
> > > +
> > > +  vref-supply:
> > > +    description: Supplies the 2.5V or 5V reference voltage  
> >
> > I don't see that in the datasheet. It has AVDD and DVDD.  
> 
> Yes, that was a copy-and-paste error from another description used as
> a template.
> 
> >
> > Also, looks like there are GPIOs. Those aren't ever exposed to the OS?  
> 
> Yes, you are right. This is a fundamental implementation of the driver
> to support the chip family. I want to add further functionalities in
> upcoming commits.
> I wanted to get some feedback when the first steps are done to not
> reinvent everything from the beginning if something is generally
> wrong in the driver structure and the way I had used the APIs.

Device tree binding should fully describe the hardware, not what
the driver currently implements.

So add the GPIOs for v3.
> 
> >  
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - vref-supply
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    spi {
> > > +        #address-cells = <1>;
> > > +        #size-cells = <0>;
> > > +
> > > +        adc@0 {
> > > +            compatible = "ti,ads7038";
> > > +            reg = <0>;
> > > +            vref-supply = <&refin_supply>;
> > > +            spi-max-frequency = <10000000>;
> > > +        };
> > > +    };
> > > --
> > > 2.42.0
> > >  
> 
> Regards,
> 
> André