[PATCH 11/15] ARM: OMAP: timer: Interchange clksrc and clkevt for AM33XX

Kevin Hilman khilman at deeprootsystems.com
Sat Nov 3 09:04:30 EDT 2012


T
On 11/03/2012 12:47 PM, Bedia, Vaibhav wrote:
> Hi Kevin,
>
> On Sat, Nov 03, 2012 at 17:13:54, Kevin Hilman wrote:
>> On 11/02/2012 01:32 PM, Vaibhav Bedia wrote:
>>> AM33XX has only one usable timer in the WKUP domain.
>>> Currently the timer instance in WKUP domain is used
>>> as the clockevent and the timer in non-WKUP domain
>>> as the clocksource. The timer in WKUP domain can keep
>>> running in suspend from a 32K clock and hence serve
>>> as the persistent clock. To enable this, interchange
>>> the timers used as clocksource and clockevent for
>>> AM33XX.
>>
>> Doesn't this also mean that you won't get timer wakeups
>> in idle?  Or are you keeping the domain where the clockevent is
>> on during idle?
>>
>
> The lowest idle state that we are targeting will have MPU powered
> off with external memory in self-refresh mode. Peripheral domain
> with the clockevent will be kept on.

Is this a limitation of the hardware?  or the software?

Kevin

P.S.  I haven't yet made my way through the TRM, so I'll probably figure
this out when I read it, but having this summarized in the changelog would
be helpful since even after I read the TRM, I'll forget.  I'm saving the 
TRM
reading for entertainment on upcoming flight home from Linaro Connect.



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