Re: [PATCH v5 1/2] dt-bindings: iio: adc: ti,ads112c04: Add binding for ADS112C04

On Fri, Aug 14, 2026 at 12:57 AM Rob Herring <[email protected]> wrote:
>
> On Thu, Aug 13, 2026 at 11:06:02AM +0800, Kyle Hsieh wrote:
> > Add device tree binding documentation for Texas Instruments ADS112C04
> > I2C Analog-to-Digital Converters.
> >
> > These devices provide 4-channel, 16-bit delta-sigma ADCs with an I2C
> > interface, programmable gain amplifier (PGA), and data-ready (DRDY)
> > interrupt output.
> >
> > The binding uses child nodes to dynamically define the connected
> > single-ended or differential channels.
> >
> > Excitation current, burn-out current, and reference source properties
> > are also included to fully describe the chip's hardware capabilities,
> > aligned with the ti,ads112c14 binding conventions.
> >
> > Reviewed-by: David Lechner <[email protected]>
> > Acked-by: Conor Dooley <[email protected]>
> > Signed-off-by: Kyle Hsieh <[email protected]>
> > ---
> >  .../devicetree/bindings/iio/adc/ti,ads112c04.yaml  | 148 +++++++++++++++++++++
> >  MAINTAINERS                                        |   6 +
> >  2 files changed, 154 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
> > new file mode 100644
> > index 000000000000..68a0df21cedd
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/iio/adc/ti,ads112c04.yaml
> > @@ -0,0 +1,148 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/iio/adc/ti,ads112c04.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Texas Instruments ADS112C04 ADC
> > +
> > +maintainers:
> > +  - Kyle Hsieh <[email protected]>
> > +
> > +description:
> > +  The ADS112C04 (16-bit) are precision analog-to-digital converters (ADCs)
> > +  with an I2C interface. They feature a flexible input multiplexer, a
> > +  low-noise programmable gain amplifier (PGA), two programmable excitation
> > +  current sources, a voltage reference, and a precision temperature sensor.
> > +
> > +properties:
> > +  compatible:
> > +    enum:
> > +      - ti,ads112c04
> > +
> > +  reg:
> > +    maxItems: 1
> > +    description: I2C address of the device.
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +    description: Data ready (DRDY) interrupt output.
> > +
> > +  "#address-cells":
> > +    const: 1
> > +
> > +  "#size-cells":
> > +    const: 0
> > +
> > +  reset-gpios:
> > +    maxItems: 1
> > +    description: GPIO connected to the RESET pin. Active low.
> > +
> > +  avdd-supply: true
> > +  dvdd-supply: true
> > +
> > +  refp-supply: true
> > +  refn-supply: true
> > +
> > +  ti,refp-refn-resistor-ohms:
> > +    description: Resistance of the external resistor between REFP and REFN.
> > +
> > +patternProperties:
> > +  "^channel@[0-9a-b]$":
> > +    $ref: adc.yaml
> > +    unevaluatedProperties: false
> > +    properties:
> > +      reg:
> > +        items:
> > +          - maximum: 11
> > +
> > +      single-channel:
> > +        maximum: 3
> > +
> > +      diff-channels:
> > +        items:
> > +          maximum: 3
> > +
> > +      excitation-channels:
> > +        maxItems: 2
> > +        items:
> > +          maximum: 5
> > +        description:
> > +          Additionally to AIN0-AIN3, IDAC1/IDAC2 can also be routed to
> > +          REFP0 (4) and REFN0 (5).
> > +
> > +      excitation-current-nanoamp:
> > +        items:
> > +          - enum: [10000, 50000, 100000, 250000, 500000, 1000000, 1500000]
>
> Drop 'items'. Just enum is enough.
>
> > +
> > +      burn-out-current-nanoamp:
> > +        items:
> > +          - const: 10000
>
> Just 'const'
>
> > +
> > +      reference-sources:
> > +        items:
> > +          - enum: [internal, external, avdd]
> > +            default: internal
>
> default for an items entry doesn't make sense as the entry has to be
> present. Instead (at the same level as 'items'):
>
> default: [ internal ]
>

Will fix all three in v6, thanks.

> > +
> > +    dependencies:
> > +      excitation-channels: [ excitation-current-nanoamp ]
> > +      excitation-current-nanoamp: [ excitation-channels ]
> > +
> > +    oneOf:
> > +      - required: [ single-channel ]
> > +      - required: [ diff-channels ]
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - avdd-supply
> > +  - dvdd-supply
> > +
> > +dependencies:
> > +  refn-supply: [ refp-supply ]
> > +
> > +oneOf:
> > +  - required:
> > +      - refp-supply
>
> Just to make sure, refp-supply is allowed without refn-supply? If not,
> either this should be refn or the dependencies reversed.

Yes - refp-supply alone is valid when REFN is tied to AVSS/ground, which
is the common single-ended case (and what my board does). The
dependency is one-directional on purpose: refn-supply requires
refp-supply, but not the other way round.

Kyle Hsieh