[Freedreno] [PATCH v6 2/2] arm64: dts: sdm845: Add gpu and gmu device nodes

[Stephen Boyd]

Quoting Rob Herring (2018-12-19 15:47:25)
> On Wed, Dec 19, 2018 at 4:40 PM Doug Anderson <dianders at chromium.org> wrote:
> > On Wed, Dec 19, 2018 at 12:40 PM Doug Anderson <dianders at chromium.org> wrote:
> > > On Wed, Dec 19, 2018 at 12:09 PM Rob Herring <robh at kernel.org> wrote:
> > > ...but it does have a frequency, doesn't it?
> > >
> > > +   compatible = "operating-points-v2-qcom-level";
> > > +
> > > +   opp-710000000 {
> > > +     opp-hz = /bits/ 64 <710000000>;
> > > +     qcom,level = <RPMH_REGULATOR_LEVEL_TURBO_L1>;
> > > +   };
> >
> > Ah, I perhaps see the confusion.  So Rajendra's usage of
> > "operating-points-v2-qcom-level" [1] doesn't have a frequency but
> > Jordan's do.  So I guess it makes sense that Jordan's have the
> > fallback compatible but Rajendra's don't?
> 
> Is having it useful to s/w that doesn't understand
> "operating-points-v2-qcom-level"? If so, then add
> "operating-points-v2". If not, then don't.

The only benefit I see in having "operating-points-v2" is that we don't
need to update the of_skipped_node_table[] in drivers/platform/of.c to
have all the variants of operating-points-v2-* when they decide to not
use anything from the "base" binding.

If that fails to work because opp-hz is required for the
"operating-points-v2" binding but sometimes
operating-points-v2-qcom-level doesn't require it I guess we need to
update the skip table or make some generic property like
'this-is-not-a-device' that these various data tables in DT can be
marked with so we don't make platform devices for them.

Regardless of the above, we should update the binding for
operating-points-v2-qcom-level to say that opp-hz isn't always required
when the qcom-level compatible is present. It looks like it just says
that it builds on top of the opp binding so that's not obvious.