Re: [PATCH v3 1/2] dt-bindings: adc: add AD7173

Jonathan Cameron
2023-10-05T16:40:19Z

On Thu, 5 Oct 2023 13:59:21 +0300
Dumitru Ceclan <mitrutzceclan@gmail.com> wrote:

> The AD7173 family offer a complete integrated Sigma-Delta ADC solution
> which can be used in high precision, low noise single channel applications
> or higher speed multiplexed applications. The Sigma-Delta ADC is intended
> primarily for measurement of signals close to DC but also delivers
> outstanding performance with input bandwidths out to ~10kHz.
>
> Signed-off-by: Dumitru Ceclan <mitrutzceclan@gmail.com>

Seems the family is a bit wider than covered here as there is at least
an ad7172-4 device. It might be nice to support that if not too hard.

> ---
> V2 -> V3
> - remove redundant descriptions
> - use referenced 'bipolar' property
> - remove newlines from example
>
> .../bindings/iio/adc/adi,ad7173.yaml | 130 ++++++++++++++++++
> 1 file changed, 130 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
> new file mode 100644
> index 000000000000..bf9e3cbf842e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
> @@ -0,0 +1,130 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +# Copyright 2023 Analog Devices Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad7173.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD7173 ADC device driver
> +
> +maintainers:
> + - Ceclan Dumitru <dumitru.ceclan@analog.com>
> +
> +description: |
> + Bindings for the Analog Devices AD717X ADC's. Datasheets for supported chips:
> + https://www.analog.com/media/en/technical-documentation/data-sheets/AD7172-2.pdf
> + https://www.analog.com/media/en/technical-documentation/data-sheets/AD7173-8.pdf
> + https://www.analog.com/media/en/technical-documentation/data-sheets/AD7175-2.pdf
> + https://www.analog.com/media/en/technical-documentation/data-sheets/AD7176-2.pdf
> +
> +properties:
> + compatible:
> + enum:
> + - adi,ad7172-2
> + - adi,ad7173-8
> + - adi,ad7175-2
> + - adi,ad7176-2
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 1
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> + spi-max-frequency:
> + maximum: 20000000
> +
> + spi-cpol:
> + type: boolean
> +
> + spi-cpha:
> + type: boolean

I'd like to see supplies listed here as well.

> +
> + required:
> + - compatible
> + - reg
> + - interrupts
> +
> +patternProperties:
> + "^channel@[0-9a-f]$":
> + type: object
> + $ref: adc.yaml
> + unevaluatedProperties: false
> +
> + properties:
> + reg:
> + minimum: 0
> + maximum: 15
> +
> + diff-channels:
> + items:
> + minimum: 0
> + maximum: 31

How can this go to 31? Do we have devices with 32 input lines?

> +
> + bipolar:
> + type: boolean
> +
> + required:
> + - reg
> + - diff-channels
> +
> +allOf:
> + - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/gpio/gpio.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> +
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + adc@0 {
> + compatible = "adi,ad7173-8";
> + reg = <0>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
> + interrupt-parent = <&gpio>;
> + spi-max-frequency = <5000000>;
> +
> + channel@0 {
> + reg = <0>;
> + bipolar;
> + diff-channels = <0 1>;
> + };
> +
> + channel@1 {
> + reg = <1>;
> + diff-channels = <2 3>;
> + };
> +
> + channel@2 {
> + reg = <2>;
> + bipolar;
> + diff-channels = <4 5>;
> + };
> +
> + channel@3 {
> + reg = <3>;
> + bipolar;
> + diff-channels = <6 7>;
> + };
> +
> + channel@4 {
> + reg = <4>;
> + diff-channels = <8 9>;
> + };
> + };
> + };