Hi Mike,

Am Freitag, 11. M?rz 2016, 08:51:52 schrieb Michael Turquette:

Quoting Jisheng Zhang (2016-03-08 23:24:20)

quoted

I have the following clk case which I dunno the elegant solution:


cpuclk have two parents: cpupll and refclk. When set the cpuclk freq, we
have to set its parent's freq, I.E cpupll freq. But before changing the
cpupll's freq, we should set its refclk as its parent firstly.

AFAIK, this is a common case, I have seen such requirement in rockchip,
samsung clk driver. They solve this by notifier, but as pointed out by
Michael in
http://lists.infradead.org/pipermail/linux-arm-kernel/2015-June/351565.ht
ml

"This is also a hack and it points towards some missing infrastructure in
the clock framework."

I also don't like the notifier solution, I believe the elegant solution
could be using the coordinated clock infrastructure. So what's the status
of this infrastructure? I can test, and I can even add some code to make
it be ready to be merged if you guide me ;)

Thanks for the email. I hope to finish that feature before ELC. I have
Cc'd Pi-Cheng Chen from Mediatek who is also interested in coordinated
clock rates.

pulling this up again, did this materialize yet? :-)

Because it looks like on Rockchip we're getting yet another clock that needs 
special handling (set_rate needs to go through the trusted-firmware, while 
reading stays the same) which might profit from that as well.


Heiko