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

[Kurt Borja]

On Fri Jun 19, 2026 at 9:23 AM -05, David Lechner wrote:
> On 6/18/26 7:33 PM, Kurt Borja wrote:
>> 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.
>
> Generally, we don't propose bindings without users in the same series.
> I was going to wait to see what feedback Jonathan gave on my series
> before proposing this.

Makes sense. In this case I think it would be useful for the three
series to have this first, but not up to me.

>
>> 
>> 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>
>> ---
>> 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 | 47 ++++++++++++++++++++++
>>  1 file changed, 47 insertions(+)
>> ---
>> base-commit: a50909aa46dec46de3c73235fc15a7d6f763d996
>> change-id: 20260618-new-channel-props-4fbd52020da2
>> 

-- 
Thanks,
 ~ Kurt