[RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare

[bilhuang@nvidia.com (Bill Huang)]

On Fri, 2013-03-15 at 20:33 +0800, Ulf Hansson wrote:
> I guess you did not fully got what I meant with "dvfs clock type". It
> will not affect the clock API. But instead the dvfs is handled by
> implementing a specific clk hw type. So the same thing is accomplished
> as with clk notifiers, no changes should be needed to device drivers.
> 
> The difference is only that no notifiers will be needed, and all the
> dvfs stuff will be handled in the clk hw instead. It will mean that we
> will bundle dvfs stuff into the clock drivers, instead of separating
> the code outside the clock drivers. But, on the other hand no
> notifiers will be needed.
> 
Oh yes I misunderstand your origin point, but my thought is using
existing devfreq framework as frequency/voltage policy driver instead of
creating another one in clock driver and that's why I think we need the
notifier work. 

By the way, some centralized DVFS implementation like Tegra's VDD_CORE
rail has association with tens of clocks which will need to be taken
care specially if we're doing those in clock driver I think.

> Kind regards
> Ulf Hansson