Re: [PATCH v2 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04

[David Lechner <dlechner@baylibre.com>]

On 8/2/26 9:32 PM, Kyle Hsieh wrote:
> On Fri, Jul 31, 2026 at 9:52 PM David Lechner <dlechner@baylibre.com> wrote:
>>
>> On 7/30/26 9:58 PM, Kyle Hsieh wrote:
>>> Add device tree binding documentation for Texas Instruments ADS112C04
>>> I2C Analog-to-Digital Converters.
>>>
>>> These devices provide 4-channel, 16-bit delta-sigma ADCs with an I2C
>>> interface, programmable gain amplifier (PGA), and data-ready (DRDY)
>>> interrupt output.
>>>
>>> The binding uses child nodes to dynamically define the connected
>>> single-ended or differential channels.
>>>
>>> Signed-off-by: Kyle Hsieh <kylehsieh1995@gmail.com>
>>> ---
>>>  .../devicetree/bindings/iio/adc/ti,ads112c04.yaml  | 122 +++++++++++++++++++++
>>>  1 file changed, 122 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
>>> new file mode 100644
>>> index 000000000000..6a5ffda84b80
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
>>> @@ -0,0 +1,122 @@
>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>> +%YAML 1.2
>>> +---
>>> +$id: http://devicetree.org/schemas/iio/adc/ti,ads112c04.yaml#
>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>> +
>>> +title: Texas Instruments ADS112C04 ADC
>>> +
>>> +maintainers:
>>> +  - Kyle Hsieh <kylehsieh1995@gmail.com>
>>> +
>>> +description: |
>>
>> The | isn't needed in this case. (It is only needed if we needed
>> to preserve formatting, or if there is a : in the text that would
>> be interpreted as a dict key.)
> Understood. I will remove the `|` from in v3.
>>
>>> +  The ADS112C04 (16-bit) are precision analog-to-digital converters (ADCs)
>>> +  with an I2C interface. They feature a flexible input multiplexer, a
>>> +  low-noise programmable gain amplifier (PGA), two programmable excitation
>>> +  current sources, a voltage reference, and a precision temperature sensor.
>>> +
>>> +properties:
>>> +  compatible:
>>> +    enum:
>>> +      - ti,ads112c04
>>> +
>>> +  reg:
>>> +    maxItems: 1
>>> +    description: I2C address of the device.
>>> +
>>> +  interrupts:
>>> +    maxItems: 1
>>> +    description: Data ready (DRDY) interrupt output.
>>> +
>>> +  "#address-cells":
>>> +    const: 1
>>> +
>>> +  "#size-cells":
>>> +    const: 0
>>> +
>>> +  reset-gpios:
>>> +    maxItems: 1
>>> +    description: GPIO connected to the RESET pin. Active low.
>>> +
>>> +  avdd-supply: true
>>> +  dvdd-supply: true
>>> +
>>> +  refp-supply: true
>>> +  refn-supply: true
>>> +
>>> +  ti,refp-refn-resistor-ohms:
>>> +    $ref: /schemas/types.yaml#/definitions/uint32
>>
>> As the bot said, don't need $ref here because it is a standard unit.
>> (So don't forget to run `make dt_binding_check DT_SCHEMA_FILES=ads112c04`
>> before sending.)
> Yes, the `dt_binding_check` robot caught this right away. I will
> removed the redundant `$ref` and resolved the warning locally.
>>
>>> +    description: Resistance of the external resistor between REFP and REFN.
>>> +
>>> +patternProperties:
>>> +  "^channel@[0-9a-f]$":
>>> +    $ref: adc.yaml
>>> +    unevaluatedProperties: false
>>> +    properties:
>>> +      reg:
>>> +        items:
>>> +          - maximum: 15
>>
>> This chip doesn't allow arbitrary combinations, so there
>> are actually only 12 possible single-channel + diff-channels
>> values. So maximum: 11 and channel@[0-9a-b] would make sense.
> I will update the regex and set the reg maximum to 11 to strictly reflect
> the 12 possible MUX configurations supported by the hardware.
>>
>>> +
>>> +      single-channel:
>>> +        maximum: 3
>>> +
>>> +      diff-channels:
>>> +        items:
>>> +          maximum: 3
>>
>> For this chip, we should also have excitation-channels, excitation-current-nanoamp,
>> and reference-sources.
> I will add these properties to the binding to fully describe
> the hardware capabilities.
>>
>>> +
>>> +    oneOf:
>>> +      - required: [ single-channel ]
>>> +      - required: [ diff-channels ]
>>> +

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