Re: [PATCH v4 7/8] dt-bindings: iio: adc: add docs for AD7606C-{16,18} parts

[David Lechner <dlechner@xxxxxxxxxxxx>]

On 9/5/24 3:24 AM, Alexandru Ardelean wrote:
> The driver will support the AD7606C-16 and AD7606C-18.
> This change adds the compatible strings for these devices.
> 
> The AD7606C-16,18 channels also support these (individually configurable)
> types of channels:
>  - bipolar single-ended
>  - unipolar single-ended
>  - bipolar differential
> 
> Signed-off-by: Alexandru Ardelean <aardelean@xxxxxxxxxxxx>
> ---
>  .../bindings/iio/adc/adi,ad7606.yaml          | 109 ++++++++++++++++++
>  1 file changed, 109 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> index 69408cae3db9..57537ab0ec82 100644
> --- a/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7606.yaml
> @@ -14,6 +14,8 @@ description: |
>    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7605-4.pdf
>    https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606_7606-6_7606-4.pdf
>    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7606B.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606c-16.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad7606c-18.pdf
>    https://www.analog.com/media/en/technical-documentation/data-sheets/AD7616.pdf
>  
>  properties:
> @@ -24,11 +26,19 @@ properties:
>        - adi,ad7606-6
>        - adi,ad7606-8  # Referred to as AD7606 (without -8) in the datasheet
>        - adi,ad7606b
> +      - adi,ad7606c-16
> +      - adi,ad7606c-18
>        - adi,ad7616
>  
>    reg:
>      maxItems: 1
>  
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
>    spi-cpha: true
>  
>    spi-cpol: true
> @@ -114,6 +124,46 @@ properties:
>        assumed that the pins are hardwired to VDD.
>      type: boolean
>  
> +patternProperties:
> +  "^channel@[1-8]$":
> +    type: object
> +    $ref: adc.yaml
> +    unevaluatedProperties: false
> +
> +    properties:
> +      reg:
> +        description:
> +          The channel number, as specified in the datasheet (from 1 to 8).
> +        minimum: 1
> +        maximum: 8
> +
> +      diff-channels:
> +        description:
> +          Each channel can be configured as a differential bipolar channel.
> +          The ADC uses the same positive and negative inputs for this.
> +          This property must be specified as 'reg' (or the channel number) for
> +          both positive and negative inputs (i.e. diff-channels = <reg reg>).
> +        items:
> +          minimum: 1
> +          maximum: 8
> +
> +      bipolar:
> +        description:
> +          Each channel can be configured as a unipolar or bipolar single-ended.
> +          When this property is not specified, it's unipolar, so the ADC will
> +          have only the positive input wired.
> +          For this ADC the 'diff-channels' & 'bipolar' properties are mutually
> +          exclusive.
> +
> +    required:
> +      - reg
> +
> +    oneOf:
> +      - required:
> +          - diff-channels
> +      - required:
> +          - bipolar

The datasheet (ad7606c-18.pdf) lists the following combinations:

* Bipolar single-ended
* Unipolar single-ended
* Bipolar differential

The logic in the oneOf: doesn't match this.

This I think this would be sufficient:

- if:
    required: [diff-channels]
  then:
    required: [bipolar]

> +
>  required:
>    - compatible
>    - reg
> @@ -170,6 +220,17 @@ allOf:
>          adi,conversion-start-gpios:
>            maxItems: 1
>  
> +  - if:
> +      not:
> +        properties:
> +          compatible:
> +            enum:
> +              - adi,ad7606c-16
> +              - adi,ad7606c-18
> +    then:
> +      patternProperties:
> +        "^channel@[1-8]$": false
> +
>  unevaluatedProperties: false
>  
>  examples:
> @@ -202,4 +263,52 @@ examples:
>              standby-gpios = <&gpio 24 GPIO_ACTIVE_LOW>;
>          };
>      };
> +  - |
> +    #include <dt-bindings/gpio/gpio.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    spi {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@0 {
> +            compatible = "adi,ad7606c-18";
> +            reg = <0>;
> +
> +            #address-cells = <1>;
> +            #size-cells = <0>;
> +
> +            spi-max-frequency = <1000000>;
> +            spi-cpol;
> +            spi-cpha;
> +
> +            avcc-supply = <&adc_vref>;
> +            vdrive-supply = <&vdd_supply>;
> +
> +            interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
> +            interrupt-parent = <&gpio>;
> +
> +            adi,conversion-start-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
> +            reset-gpios = <&gpio 27 GPIO_ACTIVE_HIGH>;
> +            adi,first-data-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
> +            standby-gpios = <&gpio 24 GPIO_ACTIVE_LOW>;
> +
> +            adi,sw-mode;
> +
> +            channel@1 {
> +                reg = <1>;
> +                diff-channels = <1 1>;

                   bipolar;

> +            };
> +
> +            channel@3 {
> +                reg = <3>;
> +                bipolar;
> +            };
> +
> +            channel@8 {
> +                reg = <8>;
> +                diff-channels = <8 8>;

                   bipolar;

> +            };
> +
> +        };
> +    };
>  ...