Re: [PATCH v2 2/9] devicetree: bindings: Document qcom,kpss-acc

From: Mark Rutland
Date: Wed Jan 08 2014 - 09:33:12 EST


On Wed, Jan 08, 2014 at 02:25:41PM +0000, Mark Rutland wrote:
> On Tue, Dec 24, 2013 at 12:39:46AM +0000, Stephen Boyd wrote:
> > The kpss acc binding describes the clock, reset, and power domain
> > controller for a Krait CPU.
> >
> > Cc: <devicetree@xxxxxxxxxxxxxxx>
> > Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
> > ---
> > .../devicetree/bindings/arm/msm/qcom,kpss-acc.txt | 30 ++++++++++++++++++++++
> > 1 file changed, 30 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
> >
> > diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
> > new file mode 100644
> > index 0000000..1333db9
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/arm/msm/qcom,kpss-acc.txt
> > @@ -0,0 +1,30 @@
> > +Krait Processor Sub-system (KPSS) Application Clock Controller (ACC)
> > +
> > +The KPSS ACC provides clock, power domain, and reset control to a Krait CPU.
> > +There is one ACC register region per CPU within the KPSS remapped region as
> > +well as an alias register region that remaps accesses to the ACC associated
> > +with the CPU accessing the region.
>
> Is the mapping of ACC register to a specific processor well-defined? I
> assume it's just in order of MPIDR.Aff0.
>
> To maintain our collective sanity in the face of possible future
> implementations, do you have an idea as to whether this might need to be
> extended in future for multiple clusters / reordered IDs and so on?
>
> I assume we'd just allocate a new compatible string if those get a
> little crazy.

Actually, I'm getting too hung-up on future-proofing. Assuming the
mapping is well-defined for current implementations we can always add an
additional property later if required.

Acked-by: Mark Rutland <mark.rutland@xxxxxxx>

Thanks,
Mark.
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