Re: [PATCH v4 7/8] dt-bindings: iio: adc: adi,ad4030: Add ADAQ4216 and ADAQ4224

[Conor Dooley <conor@kernel.org>]

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On Wed, Oct 08, 2025 at 10:51:37AM -0300, Marcelo Schmitt wrote:
> ADAQ4216 and ADAQ4224 are similar to AD4030 except that ADAQ devices have a
> PGA (programmable gain amplifier) that scales the input signal prior to it
> reaching the ADC inputs. The PGA is controlled through a couple of pins (A0
> and A1) that set one of four possible signal gain configurations.
> 
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> ---
> Change log v3 -> v4
> - Now only documenting GPIO setup to control ADAQ PGA pins.
> 
> Pin strapped/hardwired connections to PGA pins may benefit from a "fixed-gpios"
> driver which may (or may not?) use the shared GPIO abstraction layer [1]. I may
> propose support for pin-strapped/hardwired connections when I get a working
> fixed-gpios implementation.

What is a "fixed-gpio" as compared to a hog, from a dt point of view?
Is it purely a software change?

This looks fine other than the potential oversight I pointed out in the
other mail.

Cheers,
COnor

> 
> [1]: https://lore.kernel.org/linux-gpio/CAMRc=Mdb_cUG+hKq8GyfUP1SYBh0p19J+4dFG7G3JSuZTr4n8Q@mail.gmail.com/T/#t
> 
>  .../bindings/iio/adc/adi,ad4030.yaml          | 71 +++++++++++++++++--
>  1 file changed, 66 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
> index 564b6f67a96e..d0e8452598d4 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4030.yaml
> @@ -19,6 +19,8 @@ description: |
>    * https://www.analog.com/media/en/technical-documentation/data-sheets/ad4030-24-4032-24.pdf
>    * https://www.analog.com/media/en/technical-documentation/data-sheets/ad4630-24_ad4632-24.pdf
>    * https://www.analog.com/media/en/technical-documentation/data-sheets/ad4630-16-4632-16.pdf
> +  * https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4216.pdf
> +  * https://www.analog.com/media/en/technical-documentation/data-sheets/adaq4224.pdf
>  
>  $ref: /schemas/spi/spi-peripheral-props.yaml#
>  
> @@ -31,6 +33,8 @@ properties:
>        - adi,ad4630-24
>        - adi,ad4632-16
>        - adi,ad4632-24
> +      - adi,adaq4216
> +      - adi,adaq4224
>  
>    reg:
>      maxItems: 1
> @@ -54,6 +58,14 @@ properties:
>      description:
>        Internal buffered Reference. Used when ref-supply is not connected.
>  
> +  vddh-supply:
> +    description:
> +      PGIA Positive Power Supply.
> +
> +  vdd-fda-supply:
> +    description:
> +      FDA Positive Power Supply.
> +
>    cnv-gpios:
>      description:
>        The Convert Input (CNV). It initiates the sampling conversions.
> @@ -64,6 +76,13 @@ properties:
>        The Reset Input (/RST). Used for asynchronous device reset.
>      maxItems: 1
>  
> +  pga-gpios:
> +    description:
> +      A0 and A1 pins for gain selection. For devices that have PGA configuration
> +      input pins, pga-gpios should be defined.
> +    minItems: 2
> +    maxItems: 2
> +
>    pwms:
>      description: PWM signal connected to the CNV pin.
>      maxItems: 1
> @@ -86,11 +105,30 @@ required:
>    - vio-supply
>    - cnv-gpios
>  
> -oneOf:
> -  - required:
> -      - ref-supply
> -  - required:
> -      - refin-supply
> +allOf:
> +  - oneOf:
> +      - required:
> +          - ref-supply
> +      - required:
> +          - refin-supply
> +  # ADAQ devices require a gain property to indicate how hardware PGA is set
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            pattern: ^adi,adaq
> +    then:
> +      required:
> +        - vddh-supply
> +        - vdd-fda-supply
> +        - pga-gpios
> +      properties:
> +        ref-supply: false
> +    else:
> +      properties:
> +        adi,pga-value: false
> +        pga-gpios: false
> +
>  
>  unevaluatedProperties: false
>  
> @@ -114,3 +152,26 @@ examples:
>              reset-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>;
>          };
>      };
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@0 {
> +            compatible = "adi,adaq4216";
> +            reg = <0>;
> +            spi-max-frequency = <80000000>;
> +            vdd-5v-supply = <&supply_5V>;
> +            vdd-1v8-supply = <&supply_1_8V>;
> +            vio-supply = <&supply_1_8V>;
> +            refin-supply = <&refin_sup>;
> +            vddh-supply = <&vddh>;
> +            vdd-fda-supply = <&vdd_fda>;
> +            cnv-gpios = <&gpio0 0 GPIO_ACTIVE_HIGH>;
> +            reset-gpios = <&gpio0 1 GPIO_ACTIVE_LOW>;
> +            pga-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>,
> +                        <&gpio0 3 GPIO_ACTIVE_HIGH>;
> +        };
> +    };
> +...
> -- 
> 2.39.2
> 

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