Re: [PATCH RFC 1/4] dt-bindings: iio: adc: ad7380: add adaq4370-4 and adaq4380-4 compatible parts

Jonathan Cameron
2024-10-18T18:09:45Z

On Fri, 18 Oct 2024 09:36:52 +0200
Julien Stephan <jstephan@baylibre.com> wrote:

> Le jeu. 17 oct. 2024 à 20:05, Jonathan Cameron <jic23@kernel.org> a écrit :
> >
> > On Tue, 15 Oct 2024 11:09:06 +0200
> > Julien Stephan <jstephan@baylibre.com> wrote:
> >
> > > adaq4370-4 (2MSPS) and adaq4380-4 (4MSPS) are quad-channel precision data
> > > acquisition signal chain μModule solutions compatible with the ad738x
> > > family, with the following differences:
> > >
> > > - configurable gain in front of each 4 adc
> > > - internal reference is 3V derived from refin-supply (5V)
> >
> > Now I'm confused.
> >
> > The earlier refin-supply change appears unused in this patch.
> > I was expecting it to be required for the additional devices.
> > With additions to the docs from the fix to explain the new
> > cases. I'm not seeing that in here.
> >
> >
> > > - additional supplies
> > >
> > > To configure the gain a new patternProperties is added to describe each
> > > channel. It is restricted to adaq devices.
> > >
> > > Signed-off-by: Julien Stephan <jstephan@baylibre.com>
> > > ---
> > > .../devicetree/bindings/iio/adc/adi,ad7380.yaml | 117 +++++++++++++++++++++
> > > 1 file changed, 117 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
> > > index 74d82721637c..3007d8e39684 100644
> > > --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
> > > +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
> > > @@ -25,6 +25,8 @@ description: |
> > > * https://www.analog.com/en/products/ad7386-4.html
> > > * https://www.analog.com/en/products/ad7387-4.html
> > > * https://www.analog.com/en/products/ad7388-4.html
> > > + * https://www.analog.com/en/products/adaq4370-4.html
> > > + * https://www.analog.com/en/products/adaq4380-4.html
> > >
> > >
> > > $ref: /schemas/spi/spi-peripheral-props.yaml#
> > > @@ -46,6 +48,8 @@ properties:
> > > - adi,ad7386-4
> > > - adi,ad7387-4
> > > - adi,ad7388-4
> > > + - adi,adaq4370-4
> > > + - adi,adaq4380-4
> > >
> > > reg:
> > > maxItems: 1
> > > @@ -59,6 +63,9 @@ properties:
> > > vlogic-supply: true
> > > refio-supply: true
> > > refin-supply: true
> > > + vs-p-supply: true
> > > + vs-n-supply: true
> > > + ldo-supply: true
> > >
> > > aina-supply:
> > > description:
> > > @@ -86,12 +93,43 @@ properties:
> > > specify the ALERT interrupt.
> > > maxItems: 1
> > >
> > > + '#address-cells':
> > > + const: 1
> > > +
> > > + '#size-cells':
> > > + const: 0
> > > +
> > > required:
> > > - compatible
> > > - reg
> > > - vcc-supply
> > > - vlogic-supply
> > >
> > > +patternProperties:
> > > + "^channel@([0-3])$":
> > > + $ref: adc.yaml
> > > + type: object
> > > +
> > > + properties:
> > > + reg:
> > > + description:
> > > + The channel number. From 0 to 3 corresponding to channels A,B,C,D
> > > + items:
> > > + minimum: 0
> > > + maximum: 3
> > > +
> > > + adi,gain-milli:
> > > + description:
> > > + The hardware gain applied to the ADC input (in milli units).
> > > + If not present, default to 1000 (no actual gain applied).
> > > + $ref: /schemas/types.yaml#/definitions/uint32
> > > + default: 1000
> > > +
> > > + required:
> > > + - reg
> > > +
> > > + additionalProperties: false
> > > +
> > > unevaluatedProperties: false
> > >
> > > allOf:
> > > @@ -128,7 +166,21 @@ allOf:
> > > ainc-supply: false
> > > aind-supply: false
> > >
> > > + # Using channel to declare gain property only applies to adaq devices
> > > + - if:
> > > + properties:
> > > + compatible:
> > > + not:
> > > + contains:
> > > + enum:
> > > + - adi,adaq4370-4
> > > + - adi,adaq4380-4
> > > + then:
> > > + patternProperties:
> > > + "^channel@([0-3])$": false
> > > +
> > > # ad7380-4 uses refin-supply as external reference.
> > > + # adaq devices use internal reference only, derived from refin-supply
>
> Hi Jonathan,
>
> here I add a quick description on how adaq devices are using refin-supply ...
>
> > > # All other chips from ad738x family use refio as optional external reference.
> > > # When refio-supply is omitted, internal reference is used.
> > > - if:
> > > @@ -136,6 +188,8 @@ allOf:
> > > compatible:
> > > enum:
> > > - adi,ad7380-4
> > > + - adi,adaq4370-4
> > > + - adi,adaq4380-4
>
> ... and adaq devices are added here to require refin-supply.
>
> Maybe I am missing your point? or I still need to improve the description?
Nope. I just misread the diff! Thanks for pointing out the key bits.

Jonathan

>
> Cheers
> Julien
>
> > > then:
> > > properties:
> > > refio-supply: false
> > > @@ -145,6 +199,24 @@ allOf:
> > > properties:
> > > refin-supply: false
> > >
> > > + # adaq devices need more supplies
> > > + - if:
> > > + properties:
> > > + compatible:
> > > + enum:
> > > + - adi,adaq4370-4
> > > + - adi,adaq4380-4
> > > + then:
> > > + required:
> > > + - vs-p-supply
> > > + - vs-n-supply
> > > + - ldo-supply
> > > + else:
> > > + properties:
> > > + vs-p-supply: false
> > > + vs-n-supply: false
> > > + ldo-supply: false
> > > +
> > > examples:
> > > - |
> > > #include <dt-bindings/interrupt-controller/irq.h>
> > > @@ -169,3 +241,48 @@ examples:
> > > refio-supply = <&supply_2_5V>;
> > > };
> > > };
> > > +
> > > + - |
> > > + #include <dt-bindings/interrupt-controller/irq.h>
> > > +
> > > + spi {
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> > > + adc@0 {
> > > + compatible = "adi,adaq4380-4";
> > > + reg = <0>;
> > > +
> > > + spi-cpol;
> > > + spi-cpha;
> > > + spi-max-frequency = <80000000>;
> > > +
> > > + interrupts = <27 IRQ_TYPE_EDGE_FALLING>;
> > > + interrupt-parent = <&gpio0>;
> > > +
> > > + vcc-supply = <&supply_3_3V>;
> > > + vlogic-supply = <&supply_3_3V>;
> > > + refin-supply = <&supply_5V>;
> > > + vs-p-supply = <&supply_5V>;
> > > + vs-n-supply = <&supply_0V>;
> > > + ldo-supply = <&supply_5V>;
> > > +
> > > + #address-cells = <1>;
> > > + #size-cells = <0>;
> > > +
> > > + channel@0 {
> > > + reg = <0>;
> > > + adi,gain-milli = <300>;
> > > + };
> > > +
> > > + channel@2 {
> > > + reg = <2>;
> > > + adi,gain-milli = <600>;
> > > + };
> > > +
> > > + channel@3 {
> > > + reg = <3>;
> > > + adi,gain-milli = <1000>;
> > > + };
> > > + };
> > > + };
> > >
> >