Re: [PATCH 1/8] dt-bindings: iio: adc: stm32-adc: add support for stm32mp23 and stm32mp25

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 11 Sep 2026 17:51:23 +0200
Fabrice Gasnier <fabrice.gasnier@foss.st.com> wrote:

> Add stm32mp23 and stm32mp25 compatibles. Three ADCs can be found on
> these SoCs, split into two blocks:
> - ADC12 are tightly coupled (common registers).
> - ADC3 is managed independently.
> Each ADC is a 12-bits successive approximation analog-to-digital converter,
> with up to 20 multiplexed channels that can be configured as single ended
> or differential.
> 
> New property "st,adc-trigger-sel " allow to make the difference between
> the ADCs and to apply the correct trigger configuration.
> 
> STM32 ADC may be in a power domain: allow a single 'power-domains'.
> 
> Restrict the last channel (19), as it is wired directly to ADC Vref+.
> It's meaningless to have direct measurement. Internal Vref with
> calibration data from bsec (nvmem) must be used instead e.g. vrefint.
> Restrict deprecated properties (st,adc-channels, st,adc-diff-channels,
> st,min-sample-time-nsecs).
> 
> Co-developed-by: Cheick Traore <cheick.traore-ext@st.com>
> Signed-off-by: Cheick Traore <cheick.traore-ext@st.com>
> Co-developed-by: Olivier Moysan <olivier.moysan@foss.st.com>
> Signed-off-by: Olivier Moysan <olivier.moysan@foss.st.com>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>

Hi Fabrice, all,

> ---
>  .../devicetree/bindings/iio/adc/st,stm32-adc.yaml  | 106 ++++++++++++++++++---
>  1 file changed, 94 insertions(+), 12 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml
> index c4c4575d3fa9..0e0ceaa3d8d6 100644
> --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml
> +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.yaml
> @@ -23,11 +23,18 @@ maintainers:
>  
>  properties:
>    compatible:
> -    enum:
> -      - st,stm32f4-adc-core
> -      - st,stm32h7-adc-core
> -      - st,stm32mp1-adc-core
> -      - st,stm32mp13-adc-core
> +    oneOf:
> +      - items:
> +          - enum:
> +              - st,stm32f4-adc-core
> +              - st,stm32h7-adc-core
> +              - st,stm32mp1-adc-core
> +              - st,stm32mp13-adc-core
> +      - items:
> +          - enum:
> +              - st,stm32mp23-adc-core
> +              - st,stm32mp25-adc-core
> +          - const: st,stm32-adc-core

What is this?  Given these all vary in features
why would we fallback to a generic match for
these new compatibles?



>  additionalProperties: false
>  
>  required:
> @@ -239,11 +276,18 @@ patternProperties:
>  
>      properties:
>        compatible:
> -        enum:
> -          - st,stm32f4-adc
> -          - st,stm32h7-adc
> -          - st,stm32mp1-adc
> -          - st,stm32mp13-adc
> +        oneOf:
> +          - items:
> +              - enum:
> +                  - st,stm32f4-adc
> +                  - st,stm32h7-adc
> +                  - st,stm32mp1-adc
> +                  - st,stm32mp13-adc
> +          - items:
> +              - enum:
> +                  - st,stm32mp23-adc
> +                  - st,stm32mp25-adc
> +              - const: st,stm32-adc

Similar to above, what is this?


> @@ -344,6 +388,12 @@ patternProperties:
>          items:
>            - const: vrefint
>  
> +      st,adc-trigger-sel:
> +        description: Selects the HW trigger configuration available on this ADC
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        enum: [0, 1]

Magic value that is meaningless to see in a dts.  If they
are effectively not compatible, give them different compatibles and
drop this property.  I'm unconvinced this property is more
useful than that given just how opaque the description is.