[PATCH V4 1/3] OPP: Redefine bindings to overcome shortcomings

Rob Herring robherring2 at gmail.com
Fri May 22 09:04:49 PDT 2015

On Fri, May 22, 2015 at 9:04 AM, Viresh Kumar <viresh.kumar at linaro.org> wrote:
> On 21-05-15, 01:02, Nishanth Menon wrote:
>> This argues that clock is an input to the cpu, this is not in-correct,
>> but, it could also be argued that OPP tables are clock dependent.

What piece of h/w is the clock an input to then?

>> For example, with multiple clock source options that a device might
>> choose to select from internally(by some means.. lets not just restrict
>> ourselves to just CPUs here for a moment), the tables might be
>> different. We can always debate that this then is the responsibility of
>> the driver handling the description for that device and we might want
>> possibility of vice versa as well - same OPP table used by different
>> clock source selections as well.
> @Rob: Any inputs ?

If you are going to describe this clock mux in DT, then that mux
should be part of the h/w block that controls it. You could always add
entries that describe what parent clock must be used for a given OPP,
but that is a new binding and not part of the existing clock binding.

If things get too complicated, then don't try to describe this in DT.
That is always an option.


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