Re: [PATCH 2/4] dt-bindings: iio: adc: Add adi,ad4052

[Jonathan Cameron <jic23@kernel.org>]

On Thu, 6 Mar 2025 15:03:15 +0100
Jorge Marques <jorge.marques@analog.com> wrote:

> Add dt-bindings for AD4052 family, devices AD4050/AD4052/AD4056/AD4058,
> low-power with monitor capabilities SAR ADCs.
> Contain selectable oversampling and sample rate, the latter for both
> oversampling and monitor mode.
> The monitor capability is exposed as an IIO threshold either direction
> event.
> 
> Signed-off-by: Jorge Marques <jorge.marques@analog.com>
> ---
>  .../devicetree/bindings/iio/adc/adi,ad4052.yaml    | 80 ++++++++++++++++++++++
>  MAINTAINERS                                        |  6 ++
>  2 files changed, 86 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..4602f1f0184d58f33883852ff6d76933758825f1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad4052.yaml
> @@ -0,0 +1,80 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +# Copyright 2025 Analog Devices Inc.
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad4052.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD4052 ADC family device driver
> +
> +maintainers:
> +  - Jorge Marques <jorge.marques@analog.com>
> +
> +description: |
> +  Analog Devices AD4052 Single Channel Precision SAR ADC family
> +
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4050.pdf
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/ad4052.pdf
It's this data sheet that I opened.  Seems it describes things a bit
different that you have here.

> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad4050
> +      - adi,ad4052
> +      - adi,ad4056
> +      - adi,ad4058
> +
> +  reg:
> +    maxItems: 1
> +
> +  clocks:
> +    description:
> +      Reference clock
> +    maxItems: 1
> +
> +  interrupts:
> +    items:
> +      - description: threshold events.
> +      - description: device ready and data ready.

People have a nasty habit of wiring just one. So use
interrupt-names and let them come in any order.  The driver can require
both or a specific one if it likes, but in future we may need to make it
more flexible and the dt-binding should allow that.

They seem to be GP0 and GP1 on datasheet and don't have fixed roles
like this implies.

> +
> +  cnv-gpios:

Not the most self explanatory of names. I'd suggest a bit of help
text for this one.

> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    maximum: 62500000
> +
> +  vdd-supply: true
> +  vdd_1_8-supply: true
As per other thread, supplies like this normally required and this
one at least doesn't seem to exist in the datasheet I randomly picked.

> +  vio-supply: true
> +
> +required:
> +  - compatible
> +  - reg
> +  - interrupts
> +