Running 'make dt_binding_check' gives following warnings:
iio/addac/adi,ad74115.example.dtb:
addac@0: adi,conv2-range-microvolt: 'oneOf' conditional failed, one must
be fixed:
        4282967296 is not one of [-2500000, 0]
        4282967296 is not one of [-12000000, 0]
        -2500000 was expected
        -104000 was expected
        625000 was expected

addac@0: Unevaluated properties are not allowed
('adi,conv2-range-microvolt' was unexpected)
        From schema: iio/addac/adi,ad74115.yaml

As every property with standard suffix has inferred type of array of
cells, adi,conv2-range-microvolt is required by meta-schemas/cell.yaml
to have maxItems >= 2. Fix these errors by setting maxItems to 2.

Signed-off-by: Michał Grzelak <mchl.grzlk@gmail.com>
---
 Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml b/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
index 72d2e910f206..cdeb04184f5a 100644
--- a/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
+++ b/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
@@ -87,6 +87,7 @@ properties:
 
   adi,conv2-range-microvolt:
     description: Conversion range for ADC conversion 2.
+    maxItems: 2
     oneOf:
       - items:
           - enum: [-2500000, 0]
-- 
2.37.3

On Sun, Jan 15, 2023 at 03:25:58AM +0100, Michał Grzelak wrote:
> Running 'make dt_binding_check' gives following warnings:
> iio/addac/adi,ad74115.example.dtb:
> addac@0: adi,conv2-range-microvolt: 'oneOf' conditional failed, one must
> be fixed:
>         4282967296 is not one of [-2500000, 0]
>         4282967296 is not one of [-12000000, 0]
>         -2500000 was expected
>         -104000 was expected
>         625000 was expected
> 
> addac@0: Unevaluated properties are not allowed
> ('adi,conv2-range-microvolt' was unexpected)
>         From schema: iio/addac/adi,ad74115.yaml

I think your dtschema version is out of date. I don't see this issue. 
The issue has to do with signed types and there have been some fixes 
related to them.

> As every property with standard suffix has inferred type of array of
> cells, adi,conv2-range-microvolt is required by meta-schemas/cell.yaml
> to have maxItems >= 2. Fix these errors by setting maxItems to 2.

The meta-schemas have nothing to do with warnings in examples. It's like 
this: meta-schemas check schemas check examples

> 
> Signed-off-by: Michał Grzelak <mchl.grzlk@gmail.com>
> ---
>  Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml b/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
> index 72d2e910f206..cdeb04184f5a 100644
> --- a/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
> +++ b/Documentation/devicetree/bindings/iio/addac/adi,ad74115.yaml
> @@ -87,6 +87,7 @@ properties:
>  
>    adi,conv2-range-microvolt:
>      description: Conversion range for ADC conversion 2.
> +    maxItems: 2
>      oneOf:
>        - items:
>            - enum: [-2500000, 0]
> -- 
> 2.37.3
> 

On Tue, 17 Jan 2023, Rob Herring wrote:

> On Sun, Jan 15, 2023 at 03:25:58AM +0100, Michał Grzelak wrote:
>> Running 'make dt_binding_check' gives following warnings:
>> iio/addac/adi,ad74115.example.dtb:
>> addac@0: adi,conv2-range-microvolt: 'oneOf' conditional failed, one must
>> be fixed:
>>         4282967296 is not one of [-2500000, 0]
>>         4282967296 is not one of [-12000000, 0]
>>         -2500000 was expected
>>         -104000 was expected
>>         625000 was expected
>>
>> addac@0: Unevaluated properties are not allowed
>> ('adi,conv2-range-microvolt' was unexpected)
>>         From schema: iio/addac/adi,ad74115.yaml
>
> I think your dtschema version is out of date. I don't see this issue.
> The issue has to do with signed types and there have been some fixes
> related to them.
>

Right. Issue vanished after upgrade, sorry for unnecessary noise.

Best regards,
Michał