Re: [PATCH v2 1/2] dt-bindings: adc: add AD7173

From: Conor Dooley <conor@kernel.org>
To: Dumitru Ceclan <mitrutzceclan@gmail.com>
Cc: linus.walleij@linaro.org, brgl@bgdev.pl, andy@kernel.org,
	linux-gpio@vger.kernel.org,
	"Lars-Peter Clausen" <lars@metafoo.de>,
	"Jonathan Cameron" <jic23@kernel.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
	"Conor Dooley" <conor+dt@kernel.org>,
	"Michael Walle" <michael@walle.cc>,
	"Andy Shevchenko" <andy.shevchenko@gmail.com>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"ChiaEn Wu" <chiaen_wu@richtek.com>,
	"Niklas Schnelle" <schnelle@linux.ibm.com>,
	"Leonard Göhrs" <l.goehrs@pengutronix.de>,
	"Mike Looijmans" <mike.looijmans@topic.nl>,
	"Haibo Chen" <haibo.chen@nxp.com>,
	"Hugo Villeneuve" <hvilleneuve@dimonoff.com>,
	"Ceclan Dumitru" <dumitru.ceclan@analog.com>,
	linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: adc: add AD7173
Date: Sat, 30 Sep 2023 10:45:17 +0100	[thread overview]
Message-ID: <20230930-grief-clapper-1c8f4d058969@spud> (raw)
In-Reply-To: <20230928125443.615006-1-mitrutzceclan@gmail.com>

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Hey,

On Thu, Sep 28, 2023 at 03:54:42PM +0300, Dumitru Ceclan 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>
> ---
>  .../bindings/iio/adc/adi,ad7173.yaml          | 139 ++++++++++++++++++
>  1 file changed, 139 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..a0f437297a23
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7173.yaml
> @@ -0,0 +1,139 @@
> +# 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
> +
> +  required:
> +    - compatible
> +    - reg
> +    - interrupts
> +
> +patternProperties:
> +  "^channel@[0-9a-f]$":
> +    type: object
> +    $ref: adc.yaml
> +    unevaluatedProperties: false
> +
> +    properties:
> +      reg:
> +        description: Channel number
> +        minimum: 0
> +        maximum: 15
> +
> +      diff-channels:
> +        description:
> +          Analog input pins

These descriptions are redundant AFAICT, since youre just constraining
properties defined in adc.yaml.

> +        items:
> +          minimum: 0
> +          maximum: 31
> +
> +      adi,bipolar:
> +        description: Specify if the channel should measure in bipolar mode.
> +        type: boolean

You have a ref here to adc.yaml, but do not appear to be making use of
"bipolar" property:
  bipolar:
    $ref: /schemas/types.yaml#/definitions/flag
    description: If provided, the channel is to be used in bipolar mode.

> +
> +    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>;
> +          adi,bipolar;
> +

Why the odd newlines?

Mostly looks good to me, cheers,
Conor.

> +          diff-channels = <0 1>;
> +        };
> +
> +        channel@1 {
> +          reg = <1>;
> +
> +          diff-channels = <2 3>;
> +        };
> +
> +        channel@2 {
> +          reg = <2>;
> +          adi,bipolar;
> +
> +          diff-channels = <4 5>;
> +        };
> +
> +        channel@3 {
> +          reg = <3>;
> +          adi,bipolar;
> +
> +          diff-channels = <6 7>;
> +        };
> +
> +        channel@4 {
> +          reg = <4>;
> +
> +          diff-channels = <8 9>;
> +        };
> +      };
> +    };
> -- 
> 2.39.2
> 

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