Re: [PATCH v2 3/3] dt-bindings: iio: imu: st_lsm6dsx: add asm330lhhxg1

[Rob Herring <robh@kernel.org>]

On Mon, Jan 29, 2024 at 02:30:27PM +0100, Lorenzo Bianconi wrote:
> > On 28/01/2024 12:25, Lorenzo Bianconi wrote:
> > > Add device bindings for asm330lhhxg1 IMU sensor.
> > > Use asm330lhhx as fallback device for asm330lhhxg1 since it implements
> > > all the features currently supported by asm330lhhxg1.
> > > 
> > > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > > ---
> > >  Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml | 3 +++
> > >  1 file changed, 3 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> > > index 28b667a9cb76..7ba3de66a2e1 100644
> > > --- a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> > > +++ b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> > > @@ -49,6 +49,9 @@ properties:
> > >        - items:
> > >            - const: st,asm330lhb
> > >            - const: st,asm330lhh
> > > +      - items:
> > > +          - const: st,asm330lhhxg1
> > > +          - const: st,asm330lhhx
> > 
> > lhhx is compatible with st,lsm6dsr, so some explanation would be useful
> > why it is not included here.
> > 
> > Best regards,
> > Krzysztof
> > 
> 
> Do you mean something like:
> 
> diff --git a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> index 7ba3de66a2e1..92feba6e2427 100644
> --- a/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> +++ b/Documentation/devicetree/bindings/iio/imu/st,lsm6dsx.yaml
> @@ -35,6 +35,7 @@ properties:
>            - st,lsm6dsv
>            - st,lsm6dso16is
>        - items:
> +          - const: st,asm330lhhxg1
>            - const: st,asm330lhhx
>            - const: st,lsm6dsr

No, that's not right because you just changed the existing user.

You need to explain why "st,lsm6dsr" is not needed as a fallback or you 
need your original change with "st,lsm6dsr" added on the end. (And group 
it next to the original entry, not at the end.)

The question to ask is whether software that only understands what 
"st,lsm6dsr" is will work with this newer device.

Rob