Re: [PATCH 1/2] dt-bindings: iio: adc: Add TI ADS1018/ADS1118

[Krzysztof Kozlowski <krzk@kernel.org>]

On 21/11/2025 18:16, Kurt Borja wrote:
> Add documentation for Texas Instruments ADS1018 and ADS1118
> analog-to-digital converters.
> 
> Signed-off-by: Kurt Borja <kuurtb@gmail.com>

You did not test it before sending, so no full review but few nits to
save you one round of reviews:

> ---
>  .../devicetree/bindings/iio/adc/ti,ads1118.yaml    | 132 +++++++++++++++++++++
>  1 file changed, 132 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads1118.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads1118.yaml
> new file mode 100644
> index 000000000000..eb7228ed6ddb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1118.yaml
> @@ -0,0 +1,132 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/ti,ads1118.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: TI ADS1018/ADS1118 SPI analog to digital converter
> +
> +maintainers:
> +  - Kurt Borja <kuurtb@gmail.com>
> +
> +description: |
> +  The ADS1018/ADS1118 is a precision, low-power, 12-bit or 16-bit, noise-free,
> +  analog-to-digital converter (ADC). It integrates a programmable gain amplifier
> +  (PGA), voltage reference, oscillator and high-accuracy temperature sensor.
> +
> +  Datasheets:
> +    - ADS1018: https://www.ti.com/lit/ds/symlink/ads1018.pdf
> +    - ADS1118: https://www.ti.com/lit/ds/symlink/ads1118.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ti,ads1018
> +      - ti,ads1118
> +
> +  reg:
> +    maxitems: 1
> +
> +  interrupts:
> +    description: DOUT/DRDY (Data Out/Data Ready) line.
> +    maxitems: 1
> +
> +  drdy-gpios:
> +    description:
> +      Extra GPIO line connected to DOUT/DRDY (Data Out/Data Ready). This allows
> +      distinguishing between latched and real DRDY IRQs.

I have feeling that you miss proper handling of IRQs (e.g. active level)
on your board.

> +    maxitems: 1
> +
> +  '#address-cells':
> +    const: 1
> +
> +  '#size-cells':
> +    const: 0
> +
> +  '#io-channel-cells':
> +    const: 1
> +
> +required:

This goes after patternProperties.

> +  - compatible
> +  - reg
> +  - drdy-gpios
> +  - '#address-cells'
> +  - '#size-cells'
> +
> +patternProperties:
> +  "^channel@[0-7]$":
> +    type: object
> +    $ref: /schemas/iio/adc/adc.yaml#
> +    description: Properties for a single ADC channel.
> +
> +    properties:
> +      reg:
> +        minimum: 0
> +        maximum: 7
> +        description: The channel index (0-7).
> +
> +      ti,gain:

Use common property units.

https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/property-units.yaml

> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        minimum: 0
> +        maximum: 5
> +        description:
> +          Programmable gain amplifier configuration, as described in the PGA
> +          Config Register Field description. If not present, the default is
> +          used.
> +
> +      ti,datarate:

Use common property units.

> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        minimum: 0
> +        maximum: 7
> +        description:
> +          Data rate configuration, as described in the DR Config Register Field
> +          description. If not present, the default is used.

default:

> +
> +    required:
> +      - reg
> +
> +    additionalProperties: false
> +
> +allOf:
> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
> +
> +  - if:
> +    properties:
> +      compatible:
> +        contains:
> +          const: ti,ads1018
> +    then:
> +      patternProperties:
> +        "^channel@[0-7]$":
> +          properties:
> +            ti,datarate:
> +              maximum: 6
> +
> +unevaluatedProperties: false
> +
> +examples:
> +  - |
> +    spi0 {

spi

> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        ads1118@0 {


Node names should be generic. See also an explanation and list of
examples (not exhaustive) in DT specification:
https://devicetree-specification.readthedocs.io/en/latest/chapter2-devicetree-basics.html#generic-names-recommendation
If you cannot find a name matching your device, please check in kernel
sources for similar cases or you can grow the spec (via pull request to
DT spec repo).

e.g. adc


> +            compatible = "ti,ads1118";
Best regards,
Krzysztof