Re: [PATCH v4 1/2] dt-bindings: iio: adc: Add the Ingenic X1600 ADC

[H. Nikolaus Schaller]

Hi Olivier, Conor,

> Am 02.11.2026 um 21:48 schrieb Conor Dooley <conor@xxxxxxxxxx>:
> 
> On Mon, Nov 02, 2026 at 09:11:54PM +0100, Olivier Louvignes wrote:
>> The X1600's SAR ADC has four auxiliary channels and none of the
>> touchscreen or battery engines of the JZ47xx ADCs in ingenic,adc.yaml,
>> so it gets a binding of its own.
>> 
>> Signed-off-by: Olivier Louvignes <olivier@xxxxxxxxx>
>> ---
>> .../bindings/iio/adc/ingenic,x1600-adc.yaml   | 53 +++++++++++++++++++
>> MAINTAINERS                                   |  5 ++
>> 2 files changed, 58 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml
>> 
>> diff --git a/Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml b/Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml
>> new file mode 100644
>> index 000000000000..f6356ea97980
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml
>> @@ -0,0 +1,53 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/iio/adc/ingenic,x1600-adc.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Ingenic X1600 ADC
>> +
>> +maintainers:
>> +  - Olivier Louvignes <olivier@xxxxxxxxx>
>> +
>> +description:
>> +  The SAR ADC of the Ingenic X1600 SoC, with four auxiliary input channels
>> +  measured against a 3.3 V reference.
> 
> The wording here makes me wonder if a 3v3 supply is missing here? Or is
> this some internal supply on the soc?

It is an external SADC_VREFP input pin (ball P12) which is usually connected to
the 3v3 supply. But it is specified to be min=0V .. typical=3.3V ... max=VADC
voltage levels.

VADC is indeed the power supply for the SADC on a separate ball. It must
be in the range of 2.97V .. 3.3V .. 3.63V so that it is extremely likely to be
connected to the system 3.3V rail.

Therefore I do not see a necessity to require a separate regulator reference here.

I would suggest:

  The SAR ADC of the Ingenic X1600 SoC, with four auxiliary input channels
  measured against an external SADC_VREFP reference (typically 3.3 V).

> 
> Otherwise, this looks fine really.
> 
>> +
>> +properties:
>> +  compatible:
>> +    const: ingenic,x1600-adc
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    maxItems: 1
>> +
>> +  interrupts:
>> +    maxItems: 1
>> +
>> +  '#io-channel-cells':
>> +    const: 1
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - clocks
>> +  - interrupts
>> +  - '#io-channel-cells'
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    adc@10070000 {
>> +        compatible = "ingenic,x1600-adc";
>> +        reg = <0x10070000 0x30>;
> 
> That said, the 0x30 looks suspiciously small - but the region is aligned
> neatly so I suppose it's probably not problematic..
> 
> Cheers,
> Conor.
> 
>> +
>> +        clocks = <&cgu 28>;
>> +
>> +        interrupt-parent = <&intc>;
>> +        interrupts = <11>;
>> +
>> +        #io-channel-cells = <1>;
>> +    };
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ecc22d1149d1..fd4bb5c6bf16 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -12925,6 +12925,11 @@ F: include/linux/mfd/ingenic-tcu.h
>> F: sound/soc/codecs/jz47*
>> F: sound/soc/jz4740/
>> 
>> +INGENIC X1600 ADC DRIVER
>> +M: Olivier Louvignes <olivier@xxxxxxxxx>
>> +S: Maintained
>> +F: Documentation/devicetree/bindings/iio/adc/ingenic,x1600-adc.yaml
>> +
>> INJOINIC IP5xxx POWER BANK IC DRIVER
>> M: Samuel Holland <samuel@xxxxxxxxxxxx>
>> S: Maintained
>> -- 
>> 2.54.0
>> 

BR and thanks,
Nikolaus