[PATCH RFC v2 0/3] dt-bindings: iio: adc: Add reference, excitation and burn-out properties

[Kurt Borja]

Hi all,

After submitting a patch series adding support for TI ADS126X ADCs [1],
I was made aware by David [2] that at least two more chip families,
ads1220 [3] and ads1x2c14, share very similar features (though these
chips are not really compatible between them). After that, I found one
more chip with the same features which is already upstream, the
AD4170-4.

As David explained in [2], these chips are intended to be used with
RTDs, thermocouples or other resistive sensors so they share the
following per-channel features:

  - Configurable reference selection
  - Burn-out Current Sources (BOCS) for diagnostic purpuses
  - Excitation current sources (usually called IDACs TI) for sensor
    current biasing

Given that these three features are present in all four devices and
three of these drivers are still under review, my proposal is to have
these features be described in adc.yaml and have this series merged
before the three others [1] [2] [3].

This series is sent as RFC because I still don't have much experience
with dt-bindings and I don't know if this approach or the properties are
general enough to be described like this.

No dependencies between properties were provided because not all devices
may be able to configure each one of them.

[1] https://lore.kernel.org/linux-iio/20260612-ads126x-v1-0-894c788d03ed@xxxxxxxxx/
[2] https://lore.kernel.org/linux-iio/20260615-iio-adc-ti-ads122c14-v1-0-e6bdadf7cb2b@xxxxxxxxxxxx/
[3] https://lore.kernel.org/linux-iio/20260610151342.44274-1-zizuzacker@xxxxxxxxx/

Signed-off-by: Kurt Borja <kuurtb@xxxxxxxxx>
---
v2:
  - reference-source is now a string-array and now presents a couple of
    quick examples
  - excitation-* properties now do not enforce arbitrary limits
  - Dropped burn-out-current-polarity because it was not general enough
  - I kept burn-out-current-microamp because the discussion around it is
    still ongoing

v1: https://patch.msgid.link/20260618-new-channel-props-v1-0-963c1b5cf40a@xxxxxxxxx

---
Kurt Borja (3):
      dt-bindings: iio: adc: Add reference-source property
      dt-bindings: iio: adc: Add excitation current sources properties
      dt-bindings: iio: adc: Add burn-out current properties

 Documentation/devicetree/bindings/iio/adc/adc.yaml | 38 ++++++++++++++++++++++
 1 file changed, 38 insertions(+)
---
base-commit: a50909aa46dec46de3c73235fc15a7d6f763d996
change-id: 20260618-new-channel-props-4fbd52020da2

-- 
Thanks, 
 ~ Kurt