Re: [PATCH v2 1/2] dt-bindings: iio: adc: avia-hx711: add avia,hx710b compatible

[Piyush Patle]

On Tue, Apr 21, 2026 at 1:53 PM Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
>
> On Sun, Apr 19, 2026 at 11:16:39PM +0530, Piyush Patle wrote:
> >  description: |
> > -  Bit-banging driver using two GPIOs:
> > -  - sck-gpio gives a clock to the sensor with 24 cycles for data retrieval
> > -    and up to 3 cycles for selection of the input channel and gain for the
> > -    next measurement
> > -  - dout-gpio is the sensor data the sensor responds to the clock
> > +  The HX711 is a 24-bit ADC with selectable gain (32/64/128) and two
> > +  differential input channels. Channel A supports gain 64 and 128;
> > +  channel B supports gain 32.
> >
> > -  Specifications about the driver can be found at:
> > -  http://www.aviaic.com/ENProducts.aspx
> > +  The HX710B is a 24-bit ADC with fixed gain of 128. Channel 0 is the
> > +  differential input and channel 1 measures the DVDD-AVDD supply
> > +  voltage difference.
> >
> >  properties:
> >    compatible:
> >      enum:
> > +      - avia,hx710b
> >        - avia,hx711
> >
> >    sck-gpios:
> > @@ -40,13 +40,45 @@ properties:
> >
> >    avdd-supply:
> >      description:
> > -      Definition of the regulator used as analog supply
> > +      Analog supply voltage (AVDD). Also serves as the voltage reference on
> > +      both chips; no separate vref-supply is required.
>
> There is no such thing as vref-supply.
>
> > +
> > +  dvdd-supply:
> > +    description:
> > +      Digital supply voltage (DVDD). HX711 only.
> > +
> > +  vsup-supply:
> > +    description:
> > +      Supply voltage for the on-chip regulator (VSUP). HX711 only.
> > +
> > +  rate-gpios:
> > +    description:
> > +      GPIO connected to the RATE pin (HX711 only). When driven low the
> > +      output data rate is 10 SPS; when driven high it is 80 SPS. If
> > +      omitted the RATE pin state is determined by the board wiring.
> > +    maxItems: 1
> >
> >    clock-frequency:
> > +    description:
> > +      Controls the SCK bit-bang timing. The value is used to derive the
> > +      delay between SCK edges; keep the SCK high time below 60 us to
> > +      avoid triggering chip power-down mode. Defaults to 400 kHz if not
> > +      specified.
>
> Don't repeat constraints in free form text. Drop last sentence.
>
> >      minimum: 20000
> >      maximum: 2500000
> >      default: 400000
> >
> > +allOf:
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          const: avia,hx710b
> > +    then:
> > +      properties:
> > +        vsup-supply: false
> > +        dvdd-supply: false
> > +        rate-gpios: false
> > +
> >  required:
> >    - compatible
> >    - sck-gpios
> > @@ -58,10 +90,19 @@ additionalProperties: false
> >  examples:
> >    - |
> >      #include <dt-bindings/gpio/gpio.h>
> > -    weight {
> > +    weight0 {
>
> Don't change the node names.
>
> >          compatible = "avia,hx711";
> >          sck-gpios = <&gpio3 10 GPIO_ACTIVE_HIGH>;
> >          dout-gpios = <&gpio0 7 GPIO_ACTIVE_HIGH>;
> > +        rate-gpios = <&gpio0 9 GPIO_ACTIVE_HIGH>;
> >          avdd-supply = <&avdd>;
> >          clock-frequency = <100000>;
> >      };
> > +  - |
> > +    #include <dt-bindings/gpio/gpio.h>
> > +    weight1 {
> > +        compatible = "avia,hx710b";
> > +        sck-gpios = <&gpio3 11 GPIO_ACTIVE_HIGH>;
> > +        dout-gpios = <&gpio0 8 GPIO_ACTIVE_HIGH>;
> > +        avdd-supply = <&avdd>;
>
> Why no clock-frequency? So basically difference is one property? Then no
> need for new example, less code to maintain.
>
> But OTOH, where is vsup and dvdd?

dvdd-supply and vsup-supply are optional HX711 properties and
arenot present on all boards (e.g. DVDD tied to AVDD or use of the
on-chip regulator without a separate supply node).
The example shows a minimal working configuration.

I will remove the example for HX710B.
>
> > +    };
> > --
> > 2.43.0
> >

Thanks for the review.

I'll fix the schema issues you pointed out in v3
Will share v3 shortly

Regards
Piyush Patle