Re: [PATCH 1/2] dt-bindings: iio: adc: ti,ads1298: add ADS1299 EEG ADC variants

[Jonathan Cameron]

On Tue, 30 Jun 2026 17:03:10 +0300
Md Shofiqul Islam <shofiqtest@xxxxxxxxx> wrote:

> The ADS1299, ADS1299-4, and ADS1299-6 share the same SPI interface
> and register map as the ADS1298 ECG ADC family but are designed for
> EEG and biopotential measurement.  Key differences from ADS1298:
> - PGA gain up to 24x (vs 12x for ADS1298)
> - Internal reference is always 2.4V (no 4V option)
> 
> Add compatible strings and update the vref-supply description to
> document the ADS1299 reference voltage behaviour.
> 
> Signed-off-by: Md Shofiqul Islam <shofiqtest@xxxxxxxxx>

>  
>  maintainers:
>    - Mike Looijmans <mike.looijmans@xxxxxxxx>
> @@ -17,6 +22,9 @@ properties:
>    compatible:
>      enum:
>        - ti,ads1298
> +      - ti,ads1299
> +      - ti,ads1299-4
> +      - ti,ads1299-6

As the channel count is a discoverable feature (encoded as a field in the
ID Register, I think we can use just the one compatible).  FWIW it is
nice to see a manufacturer making this discoverable!  I'd expect any
future drop in parts to vary the other part of the ID, but this field
should be respected - as such this doesn't fall into the stuff I've been
discussing with DT maintainers about fallback compatibles needing to
be specific (I'm way behind so not sure where that thread got to!)

Jonathan