Extending OPP bindings

[Mark Brown]

On Tue, Feb 04, 2014 at 01:28:20PM -0600, Nishanth Menon wrote:
> On 02/04/2014 12:22 PM, Mark Brown wrote:

> > You're assuming that the frequency is a unique key here.  That may not
> > be the case, for example two OPPs might have the same CPU clock
> > (assuming that's the frequency you're referring to) but different bus
> > clocking and of course the CPUs or CPU clusters might be individually
> > scalable (this is common in big.LITTLE designs I think).

> Which is why OPPs are maintained per device, bus OPPs belong to bus
> device (in TI terminology, we'd be talking of cross domain dependency
> here for maintaining asynchronous bridge timing closure constraints -
> but ofcourse, other SoCs may or maynot have such constraints). For
> scaling bus frequency, we already have infrastructure in place - clock
> notifiers - discussion of using that is much deeper topic of it's own.

> for each processor that is uniquely transitioning, we'd have it's own
> sets of OPPs - the correct representation of the device node is the
> key there.

I've seen some SoCs characterised over the whole device rather than with
individual parts of the SoC done separately.
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