[PATCH RFC] clk: add support for automatic parent handling

Saravana Kannan skannan at codeaurora.org
Fri Apr 22 20:48:23 EDT 2011


On 04/22/2011 03:55 PM, Thomas Gleixner wrote:
> On Fri, 22 Apr 2011, Saravana Kannan wrote:
>
>> On 04/22/2011 09:57 AM, Thomas Gleixner wrote:
>>> On Fri, 22 Apr 2011, Colin Cross wrote:
>>>
>>>> On Fri, Apr 22, 2011 at 2:51 AM, Thomas Gleixner<tglx at linutronix.de>
>>>> wrote:
>>>>> Another thing I'm pondering is to provide the ability to maintain
>>>>> separate clk trees. So you can have individual domains which have
>>>>> their per clk tree locking. Would that make sense ?
>>>>
>>>> Clock trees are likely to be linked somewhere - an external clock chip
>>>> that drives the main clock input on the SoC, or an SoC clock output
>>>> that drives a chip with an internal clock tree.  Domains would have to
>>>> be dynamically managed to ensure two clocks from different clock chips
>>>> that become linked are moved under the same clock lock.  Probably
>>>> easier to keep a global lock.
>>>
>>> Ok. It's easy enough to split later if the need arises.
>>
>> MSM certainly has the need for having independent clock trees. I would like
>> support for this to be in from the start otherwise it's going to really screw
>> clocks in one of the trees.
>
> Are they completely independent or do you need a global
> synchronization mechanism between those clock trees as well ?
>
> Thanks,
>
> 	tglx

They are completely independent. No synchronization is needed between 
these clock trees. It's basically a bunch of clocks controlled by 
another processor that has it's own set of PLLs, etc.

-Saravana

-- 
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