[RFC v2 5/6] drivers: boot_constraint: Add initial DT bindings

Rob Herring robh at kernel.org
Mon Jul 17 10:34:07 PDT 2017


On Thu, Jul 13, 2017 at 03:06:08PM +0530, Viresh Kumar wrote:
> On 12-07-17, 16:28, Rob Herring wrote:
> > Display is a pretty well known use case here. Do you have other
> > examples in mind?
> 
> No, I don't.
> 
> @Stephen: Do you have more cases like this for your Qcom products ?
> 
> > Other cases I've seen are automotive with keeping
> > the backup camera going and CAN bus handling. Though my new car has a
> > flicker shortly after coming on, so I guess the handoff doesn't have
> > to be completely seemless. :)
> 
> :)
> 
> > [...]
> > 
> > > +       mmc: mmc at 0x0 {
> > > +               ...
> > > +               ...
> > > +               vmmc-supply = <&twl_reg1>;
> > > +               vmmcaux-supply = <&twl_reg2>;
> > > +               boot-constraint-supplies = "vmmc", "vmmcaux";
> > > +               boot-constraint-uV = <1800000 2000000>, /* vmmc */
> > > +                                    <2000000 2000000>; /* vmmcaux */
> > 
> > No. I don't like how this is going to extend to all the other bindings
> > people are going to want constraints for. We don't need a parallel set
> > of properties for each type of binding.
> 
> Fair enough.
> 
> > I'm not convinced that we need a general solution for what's probably
> > a handful of things that need a handoff versus just re-initialize.
> 
> What about keeping the first four patches (mostly) as it is and adding
> these constraints from a platform specific constraints driver ?
> 
> Will that be acceptable ?

Meaning no DT binding? Then I don't care (from a DT perspective).

Rob



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