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

[Krzysztof Kozlowski]

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?

> +    };
> -- 
> 2.43.0
>