On 10 September 2014 11:59, Thomas Petazzoni
[off-list ref] wrote:

A compile time conditional does not work, as it isn't compatible with
multiplatform: what if in the same kernel you want to support two
platforms that use cpufreq-dt, one having a single clock for all CPUs,
and one having one clock per CPU.

Yeah, that's a known problem. Should have mentioned this in logs.

I'm still confused as to what is the problem with the DT binding
surrounding this driver. Isn't it simply a matter of adding a clocks =
<...> property to all CPUs, and that's it?

Viresh told me there was an issue related to comparing the clocks in
the driver to find out which CPUs share which clocks. But that is not a
DT binding issue, it's an implementation detail. Since the driver is
purely for DT platforms (as its name suggest), comparing phandles could
work as a temporary solution. And since it's just an implementation
detail that doesn't affect the DT binding, we could change the
implementation later to use a proper clock API like clk_is_same(clk1,
clk2) that would tell us if the clocks are the same.

But I have probably missed some of the complexity of this.

(Couldn't give you these links yesterday as I was done for the day and
was replying from my phone (In our private chat))

https://lkml.org/lkml/2014/6/26/577
https://lkml.org/lkml/2014/7/1/565
https://lkml.org/lkml/2014/7/3/813
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/275520.html

So these are few mails I could pick, specially from Mike, where he pointed
out why getting a clk-API for this is a bad idea.

--
viresh