Re: [RFC PATCH 1/2] dt-bindings: pincfg-node: Introduce an overridable way to set bias on pins

From: Rob Herring
Date: Tue Jan 31 2023 - 20:57:38 EST


On Tue, Jan 31, 2023 at 02:21:38PM +0100, Linus Walleij wrote:
> On Tue, Jan 31, 2023 at 12:50 AM Konrad Dybcio <konrad.dybcio@xxxxxxxxxx> wrote:
>
> > > +#define DRIVE_STRENGTH 9
> > > +#define DRIVE_STRENGTH_UA 10
> > >
> > > drive-strength = <8>; // 8mA drive strength
> > >
> > > bias-type = <DRIVE_STRENGTH>;
> > >
> > > OK where do I put my 8 mA now?
> > >
> > If you look at the 2/2 patch, this property only reads BIAS_
> > values, which can't coexist anyway.
>
> Well the DT bindings have to be consistent and clear on their
> own, no matter how Linux implements it.
>
> But I'm sure you can make YAML verification such that it is
> impossible to use both schemes at the same time, and it's not
> like I don't understand what you're getting at.

We already don't enforce mutually exclusive combinations. Perhaps
someone wants to fix that first?

> What I need as input is mainly the DT bindings people opinion
> on introducing another orthogonal way of doing something
> that is already possible to do another way, just more convenient.
> Because that is essentially what is happening here.

It's really a 3rd way we're adding because the existing properties have
2 forms which IMO is worse than 2 disjoint ways of doing it. And since
this new way can't represent some cases, I don't think it is an
improvement.

Rob