Re: [PATCH 2/6] dt-bindings: iio: adc: ad7380: fix ad7380-4 reference supply

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 15 Oct 2024 11:10:52 +0200
Julien Stephan <jstephan@baylibre.com> wrote:

> Le lun. 14 oct. 2024 à 20:37, Jonathan Cameron <jic23@kernel.org> a écrit :
> >
> > On Mon, 14 Oct 2024 11:00:39 +0200
> > Julien Stephan <jstephan@baylibre.com> wrote:
> >  
> > > Le jeu. 10 oct. 2024 à 20:22, Jonathan Cameron <jic23@kernel.org> a écrit :  
> > > >
> > > > On Tue, 8 Oct 2024 09:52:50 +0200
> > > > Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > > >  
> > > > > On Mon, Oct 07, 2024 at 05:45:45PM +0200, Julien Stephan wrote:  
> > > > > > ad7380-4 is the only device from ad738x family that doesn't have an
> > > > > > internal reference. Moreover its external reference is called REFIN in
> > > > > > the datasheet while all other use REFIO as an optional external
> > > > > > reference. If refio-supply is omitted the internal reference is
> > > > > > used.
> > > > > >
> > > > > > Fix the binding by adding refin-supply and makes it required for
> > > > > > ad7380-4 only.  
> > > > >
> > > > > Maybe let's just use refio as refin? Reference-IO fits here well.
> > > > > Otherwise you have two supplies for the same.  
> > > > Whilst it is ugly, the effort this series is going to in order
> > > > to paper over a naming mismatch makes me agree with Krzysztof.
> > > >
> > > > I think adding a comment to the dt-binding would be sensible
> > > > though as people might fall into this hole.
> > > >  
> > >
> > > Hi Jonathan and Krzysztof,
> > >
> > > I am currently adding support for another chip to this family
> > > (ADAQ4380-4) and it also uses REFIN.. but in another way ad7380-4
> > > does..
> > > So:
> > > - ad7380-4 does not have any internal reference and use a mandatory
> > > refin supply as external reference
> > > - adaq4380-4 does not have external reference but uses a 3V internal
> > > reference derived from a 5V mandatory refin supply
> > > - all others (AFAIK) use an optional refio external reference. If
> > > omitted, use an internal 2.5V reference.
> > >
> > > I am not sure using a single refio-supply for all will make things
> > > clearer.. What do you think? Should I also send the adaq series now to
> > > bring more context? (I wanted feedback on this series first).
> > >  
> >
> > Sounds like that context would be useful if you have it more or less
> > ready to send anyway.  I don't have particularly strong views on this
> > either way.  If we 'fix' the case you have here, old bindings should
> > continue to work for the part you are moving over (though no need
> > to have them in the dt-bindings file).
> >  
> 
> Hi Jonathan,
> 
> Just sent the new series with an RFC tag.
https://lore.kernel.org/all/20241015-ad7380-add-adaq4380-4-support-v1-1-d2e1a95fb248@baylibre.com/

Examples in there look strong enough reason that we are going to need
refin-supply in the binding anyway shortly. So might as well use it for this
part as well.

Just include a reference to that patch under the --- in v2.
+ see if you can keep the description from patch 1 and fix the assignment issue
the bot found.


Thanks,

Jonathan



> 
> 
> Cheers
> Julien
> 
> > Jonathan
> >  
> > > Cheers
> > > Julien
> > >  
> > > > Other than the missing ret =, rest of series looks fine to me
> > > >
> > > > Jonathan
> > > >  
> > > > >
> > > > > Best regards,
> > > > > Krzysztof
> > > > >  
> > > >  
> >