Re: [PATCH 1/2] dt-bindings: iio: adc: Add Nuvoton MA35D1 EADC

[Chi-Wen Weng]

Hi David,

Thanks for the clarification.

> We always want the devicetree to be as complete as possible even
> if the drier doesn't use all of the information.
>
> So for trivial/well-known bindings like dmas, we should be able to
> add it now.

Understood. I will add optional DMA properties in v2.

The hardware supports PDMA for EADC transfers, so I will describe it in
the binding even though the initial driver does not use DMA yet.

I plan to add:

  dmas:
    maxItems: 1

  dma-names:
    const: rx

These properties will not be required.

> Same reasoning as above, we want the binding to be as complete as
> possible, so we should not omit diff-channels since we know what
> the bindings should look like already.

Understood. I will keep diff-channels in the binding.

I will still limit the DT child channel nodes to the external ADC input
channels 0 to 7, since channel 8 is the fixed internal VBAT input and
does not describe board wiring.

For differential inputs, I will keep diff-channels in the channel child
node schema and restrict it to valid external ADC input channels. I will
also check the hardware-supported differential pair constraints and
encode them in the schema if the hardware only supports fixed pairs.

For v2, I will update the binding to:
- allow up to four interrupt entries for ADINT0 to ADINT3,
- add optional vref-supply,
- add optional dmas and dma-names,
- keep diff-channels,
- limit DT child channel nodes to external channels 0 to 7,
- keep the internal VBAT channel out of the DT child nodes.

Thanks,
Chi-Wen