Re: [PATCH v4 02/10] dt-bindings: iio: adc: support the TI ADS126x ADC family

[Kurt Borja]

On Fri Aug 28, 2026 at 1:39 PM -03, Conor Dooley wrote:
> On Fri, Aug 28, 2026 at 01:38:17AM -0500, Kurt Borja wrote:
>> The ADS1262 and ADS1263 are 32-bit, 38.4-kSPS delta-sigma ADCs with an
>> integrated PGA, internal reference, excitation and burn-out current
>> sources for sensor biasing and diagnostics. The ADS1263 is compatible
>> with ADS1262, but includes a second auxiliary ADC (ADC2) to perform main
>> channel (ADC1) cross-checking measurements, system background
>> measurements, or temperature compensation of the primary sensor.
>> 
>> Both parts can configure per-channel voltage reference source,
>> excitation current sources (IDAC), plus input and IDAC chopping for
>> offset and IDAC mismatch cancellation. This lets the device drive and
>> ratiometrically measure RTDs and other resistive sensors.
>> 
>> Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
>> ---
>>  .../devicetree/bindings/iio/adc/ti,ads1262.yaml    | 376 +++++++++++++++++++++
>>  MAINTAINERS                                        |   6 +
>>  2 files changed, 382 insertions(+)
>> 
>> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads1262.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads1262.yaml
>> new file mode 100644
>> index 000000000000..7e26572388e4
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1262.yaml
>> @@ -0,0 +1,376 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/iio/adc/ti,ads1262.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: TI ADS1262/ADS1263 analog to digital converter
>> +
>> +maintainers:
>> +  - Kurt Borja <kuurtb@xxxxxxxxx>
>> +
>> +description: |
>> +  The ADS1262 and ADS1263 are 38.4-kSPS, delta-sigma (ΔΣ) ADCs with an
>> +  integrated PGA, reference, and internal fault monitors. The ADS1263 integrates
>> +  an auxiliary, 24-bit, ΔΣ ADC intended for background measurements.
>> +
>> +  Datasheets:
>> +    - ADS126x: https://www.ti.com/lit/ds/symlink/ads1262.pdf
>> +
>> +properties:
>> +  compatible:
>> +    oneOf:
>> +      - const: ti,ads1262
>> +      - items:
>> +          - const: ti,ads1263
>> +          - const: ti,ads1262
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  '#address-cells':
>> +    const: 1
>> +
>> +  '#size-cells':
>> +    const: 0
>> +
>> +  spi-max-frequency:
>> +    maximum: 8000000
>> +
>> +  spi-cpha: true
>> +
>> +  interrupts:
>> +    minItems: 1
>> +    maxItems: 2
>> +    description: Data ready (DRDY) interrupt lines.
>> +
>> +  interrupt-names:
>> +    description:
>> +      The data ready (DRDY) signal has two independent interrupt lines. A
>> +      dedicated DRDY pin and a pin shared with the serial interface MISO pin,
>> +      which is called DOUT/DRDY.
>> +    minItems: 1
>> +    maxItems: 2
>> +    items:
>> +      enum: [drdy, doutdrdy]
>> +
>> +  start-gpios:
>> +    description: Start conversion control.
>> +    maxItems: 1
>> +
>> +  reset-gpios:
>> +    maxItems: 1
>> +
>> +  dvdd-supply:
>> +    description: Digital power supply.
>> +
>> +  avdd-supply:
>> +    description:
>> +      Analog power supply. In bipolar supply configurations, the reported
>> +      voltage should be in reference to DGND.
>> +
>> +  avss-supply:
>> +    description:
>> +      Negative analog power supply for bipolar configurations. AVSS can only be
>> +      at or below the ground reference (DGND). If not described, AVSS is assumed
>> +      to be connected to ground (0V).
>> +
>> +  clocks:
>> +    maxItems: 1
>
> clock doesn't appear mandatory, what does it do?

Its not mandatory because the chip has an internal clock too. If an
external clock is wired, the chip also has an autodetection mechanism
so we just describe it here so we can enable it.

>
>> +
>> +  '#io-channel-cells':
>> +    minimum: 1
>> +    maximum: 2
>
> What's the use case for actually setting this as a single cell? Kinda
> confused by it.

As Jonathan said this is part dependent but we can also just make it
'const: 2' and validate the second cell's value.

>
> Otherwise, quite frankly, the binding is too complicated for me! I'll
> have to leave it up to the IIO folks to cover whether what's being done
> is sane.
>
> Cheers,
> Conor.

...

-- 
Thanks,
 ~ Kurt