cpufreq: frequency scaling spec in DT node
Mason
slash.tmp at free.fr
Wed Jul 12 04:25:11 PDT 2017
On 12/07/2017 12:09, Viresh Kumar wrote:
> On 12-07-17, 11:58, Mason wrote:
>> I would object to the characterization of "just a PLL" :-)
>>
>> The PLL outputs "garbage" before actually "locking" a target
>> frequency. It is not possible for the CPU to blindly change
>> the PLL settings, because that crashes the system.
>>
>> The bootloader implements the steps required to change said
>> settings, so the strategy has been: have Linux use whatever
>> PLL frequency the bootloader programs.
>>
>> Behind the PLL, there is a glitch-free divider, which is able
>> to divide the PLL output without crashing the system. I've
>> been using that divider for DFS.
>>
>> drivers/clk/clk-tango4.c
>
> Okay, got it now.
>
> Yes, you *really* need to create these OPPs dynamically.
> I am convinced now :)
I will test your patch on my 4.9 branch.
Does tango-cpufreq.c look acceptable to you?
(I am aware the patch needs work in the the Kconfig/Makefile part.
That was quick and dirty.)
Regards.
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