Re: [PATCH 1/4] dt-bindings: iio: adc: add ti,ads122c14

[David Lechner]

On 6/15/26 7:26 PM, Kurt Borja wrote:
> On Mon Jun 15, 2026 at 4:59 PM -05, David Lechner (TI) wrote:
>> Add new bindings for ti,ads122c14 and similar devices.
>>
>> This is an ADC that is primarily intended for use with temperature
>> sensors. There are a few unusual properties because of this. In
>> particular, the reference voltage source and current output requirements
>> can be different for each measurement, so these are included in the
>> channel bindings.
>>
>> The REFP/REFN reference voltage is usually just connected to a resistor
>> that is being driven by the ADC's current outputs, so there is special
>> property for this case rather than requiring a regulator to be defined
>> to represent that.
>>
>> ti,vref-source is reused from ti,tlv320adcx140.yaml (otherwise might
>> have preferred an enum of strings).
>>
>> Signed-off-by: David Lechner (TI) <dlechner@xxxxxxxxxxxx>
>> ---
>>  .../devicetree/bindings/iio/adc/ti,ads112c14.yaml  | 224 +++++++++++++++++++++
>>  MAINTAINERS                                        |   7 +
>>  include/dt-bindings/iio/adc/ti,ads112c14.h         |  11 +
>>  3 files changed, 242 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads112c14.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads112c14.yaml
>> new file mode 100644
>> index 000000000000..dc7f37cad772
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c14.yaml
>> @@ -0,0 +1,224 @@
> 
> [...]
> 
>> +patternProperties:
>> +  ^channel@[0-7]$:
>> +    $ref: adc.yaml
>> +
>> +    unevaluatedProperties: false
>> +
>> +    properties:
>> +      reg:
>> +        maximum: 16 # arbitrary limit, channel@ can be any combination of AIN0-AIN7
>> +
>> +      single-channel:
>> +        maximum: 7
>> +
>> +      diff-channels:
>> +        items:
>> +          maximum: 7
>> +
>> +      bipolar:
>> +        description:
>> +          Set this flag if the differential input can be negative.
>> +
>> +      excitation-channels:
> 
> I noticed this doesn't have the "ti," prefix. Is your plan to add this
> to adc.yaml?

I hadn't really though about it. I guess it could make sense.

> 
> Also, do you think excitation-pins might be a better name?

I used -channels to match e.g. diff-channels. The same values apply to
both properties.

> 
>> +        description: AINx pins used as current output.
>> +        $ref: /schemas/types.yaml#/definitions/uint32-array
>> +        minItems: 1
>> +        maxItems: 2
>> +        items:
>> +          maximum: 7
>> +
>> +      excitation-current-microamp:
>> +        description: The current output of the excitation channels in microamps.
>> +        minimum: 1
>> +        maximum: 1000
>> +
>> +      current-chopping:
> 
> If you agree with the above comment, I think this too should be added.
> In that case, can we call this something like
> excitation-current-rotation for less ambiguity?

I think excitation-channel-rotation would be fine.

> 
> I say this because my device has an "IDAC rotation mode", but it also has
> a "Chop Mode" which rotates analog inputs and averages consecutive
> conversions.

And this one sounds like it could be named input-channel-rotation. Would
this also need a 2nd set of single-channel or diff-channels to the extra
inputs?

> 
>> +        $ref: /schemas/types.yaml#/definitions/flag
>> +        description:
>> +          If provided, the two excitation channels are to be used with current
>> +          chopping enabled.
>> +
>> +      ti,vref-source:
>> +        description: |
>> +          Indicates the source for the reference voltage for this channel.
>> +          0 - Internal 2.5V reference
>> +          1 - Internal 1.25V reference
>> +          2 - External reference (REFP-REFN)
>> +          3 - AVDD as reference
>> +
>> +          For convenience, macros for these values are available in
>> +          dt-bindings/iio/adc/ti,ads112c14.h.
>> +        $ref: /schemas/types.yaml#/definitions/uint32
>> +        maximum: 3
>> +        default: 0
>> +
>> +    dependencies:
>> +      excitation-channels: [ excitation-current-microamp ]
>> +      excitation-current-microamp: [ excitation-channels ]
>> +      current-chopping: [ excitation-channels ]
>> +
>> +    oneOf:
>> +      - required: [ single-channel ]
>> +      - required: [ diff-channels ]
> 
> [...]
>