Re: [PATCH v2 1/2] dt-bindings: iio: adc: ti,ads1298: add ADS1299 EEG ADC variants

[Jonathan Cameron]

On Mon,  6 Jul 2026 14:26:13 +0300
Md Shofiqul Islam <shofiqtest@xxxxxxxxx> wrote:

> The ADS1299, ADS1299-4, and ADS1299-6 share the same SPI interface

Given mention of 3 parts, this description should say why only
one compatible is needed.

> 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.
That comment needs an update seeing as now it is removing description

rather than documenting the ADS1299 description.

Note Sashiko identified something was wrong around both of these -
glad it reads patch descriptions more closely than I do!

> 
> Signed-off-by: Md Shofiqul Islam <shofiqtest@xxxxxxxxx>
> ---
>  .../devicetree/bindings/iio/adc/ti,ads1298.yaml   | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads1298.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads1298.yaml
> index 71f9f9b745cbc..202776cee73ff 100644
> --- a/Documentation/devicetree/bindings/iio/adc/ti,ads1298.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1298.yaml
> @@ -4,11 +4,15 @@
>  $id: http://devicetree.org/schemas/iio/adc/ti,ads1298.yaml#
>  $schema: http://devicetree.org/meta-schemas/core.yaml#
>  
> -title: Texas Instruments' ads1298 medical ADC chips
> +title: Texas Instruments ADS1298/ADS1299 biopotential ADC chips
>  
>  description: |
> -  Datasheet at: https://www.ti.com/product/ADS1298
> -  Bindings for this chip aren't complete.
> +  ADS1298/ADS1298R: 8-channel, 24-bit ECG ADC. Max 12x PGA gain.
> +  Datasheet: https://www.ti.com/product/ADS1298
> +
> +  ADS1299: 4/6/8-channel, 24-bit EEG/biopotential ADC. Max 24x PGA gain.
> +  Channel count is discoverable from the ID register at runtime.
> +  Datasheet: https://www.ti.com/product/ADS1299
>  
>  maintainers:
>    - Mike Looijmans <mike.looijmans@xxxxxxxx>
Make sure to +CC Mike (added)

> @@ -17,6 +21,7 @@ properties:
>    compatible:
>      enum:
>        - ti,ads1298
> +      - ti,ads1299
>  
>    reg:
>      maxItems: 1
> @@ -33,8 +38,7 @@ properties:
>  
>    vref-supply:
>      description:
> -      Optional reference voltage. If omitted, internal reference is used,
> -      which is 2.4V when analog supply is below 4.4V, 4V otherwise.
> +      Optional reference voltage. If omitted, internal reference is used.
>  
>    clocks:
>      description: Optional 2.048 MHz external source clock on CLK pin
> @@ -75,5 +79,6 @@ examples:
>            spi-max-frequency = <20000000>;
>            spi-cpha;
>          };
> +
Unrelated change.  Make sure to clean these out before sending a series.

Jonathan

>      };
>  ...