Re: [PATCH 1/2] dt-bindings: iio: adc: add TI ADS1299

[Krzysztof Kozlowski <krzk@kernel.org>]

On Sun, Oct 18, 2026 at 09:12:46PM -0300, Stephan Costa Barros wrote:
> The ADS1299 is an 8-channel, 24-bit, simultaneous-sampling biopotential
> (EEG) analog front-end with an SPI interface. The ADS1299-6 and ADS1299-4
> are the same part with six and four channels.
> 
> One converter can drive its clock out of its CLK pin to the others
> (#clock-cells), and converters sharing a chip select in daisy-chain mode
> are described as one node with #daisy-chained-devices.
> 
> Signed-off-by: Stephan Costa Barros <stephanbrrs8@gmail.com>
> ---
>  .../bindings/iio/adc/ti,ads1299.yaml          | 221 ++++++++++++++++++
>  MAINTAINERS                                   |   6 +
>  2 files changed, 227 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/ti,ads1299.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads1299.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads1299.yaml
> new file mode 100644
> index 000000000..a8966cd07
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads1299.yaml
> @@ -0,0 +1,221 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/ti,ads1299.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Texas Instruments ADS1299 biopotential analog front-end
> +
> +maintainers:
> +  - Stephan Costa Barros <stephanbrrs8@gmail.com>
> +
> +description: |
> +  Texas Instruments ADS1299 family: low-noise, 24-bit, simultaneous-sampling
> +  biopotential (EEG) analog front-ends with an SPI interface. The ADS1299 has
> +  eight channels, the ADS1299-6 six and the ADS1299-4 four.
> +
> +  Each channel has its own programmable gain amplifier and a multiplexer that
> +  can select the electrode inputs, a shorted input, the internal test signal,
> +  the supply or the temperature sensor. The part also provides lead-off
> +  detection and a bias drive amplifier for the driven reference electrode.
> +
> +  The converter signals a completed conversion on its DRDY output and is read
> +  over SPI in mode 1 (CPOL=0, CPHA=1).
> +
> +  Several converters can share one SPI bus in two ways. In cascaded mode each
> +  has its own chip select and its own node; one of them can drive its internal
> +  oscillator out of its CLK pin (#clock-cells) for the others to use as their
> +  external clock. In daisy-chain mode they share the chip select and DIN, the
> +  DOUT of each one feeds the DAISY_IN of the one before it, and the chain is a
> +  single node with #daisy-chained-devices. A daisy chain shares DIN, so every
> +  register write reaches every device: the devices run with one configuration
> +  and from one external clock, and the bias drive amplifier cannot be used.
> +
> +  https://www.ti.com/lit/gpn/ads1299
> +
> +properties:
> +  compatible:
> +    enum:
> +      - ti,ads1299

This should be then "-8" variant?

> +      - ti,ads1299-4
> +      - ti,ads1299-6
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +    description:
> +      The DRDY output of the converter, asserted low when a conversion is
> +      ready to be read.
> +
> +  reset-gpios:
> +    maxItems: 1
> +    description: The active-low RESET input of the converter.
> +
> +  powerdown-gpios:
> +    maxItems: 1
> +    description:
> +      The active-low PWDN input.
> +
> +  clocks:
> +    maxItems: 1
> +    description:
> +      External clock on the CLK pin, used when the CLKSEL pin selects an
> +      external clock. Omit when the part runs from its internal oscillator.
> +
> +  clock-names:
> +    const: clk

Drop clock-names

> +
> +  '#clock-cells':
> +    const: 0
> +    description:
> +      The CLK pin as a clock output, for a part whose CLKSEL pin selects the
> +      internal oscillator.
> +
> +  clock-output-names:
> +    maxItems: 1

Best regards,
Krzysztof