[PATCH-V6 0/3] ARM: OMAP: Make OMAP clocksource source selection runtime

Cousson, Benoit b-cousson at ti.com
Mon May 7 08:39:55 EDT 2012


On 5/3/2012 8:19 PM, Jon Hunter wrote:
> Hi Vaibhav,
>
> On 05/03/2012 12:07 AM, Hiremath, Vaibhav wrote:
>> On Thu, May 03, 2012 at 01:26:18, Hunter, Jon wrote:
>>> Hi Vaibhav,
>>>
>>> On 05/02/2012 08:56 AM, Vaibhav Hiremath wrote:
>>>> Current OMAP code supports couple of clocksource options based
>>>> on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
>>>> and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz)
>>>>
>>>> This patch series cleans up the existing 32k-sync timer implementation,
>>>> movind SoC init code to respective files (mach-omap1/timer32k.c and
>>>> mach-omap2/timer.c) and uses kernel parameter to override the default
>>>> clocksource of "counter_32k", also in order to support some OMAP based
>>>> derivative SoCs like AM33XX which doesn't have 32K sync-timer hardware IP,
>>>> adds hwmod lookup for omap2+ devices, and if lookup fails then
>>>> fall back to gp-timer.
>>>>
>>>> if(use_gptimer_clksrc == true)
>>>> 	gptimer clocksource init;
>>>> else if (counter_32 init == false)
>>>> 	/* Fallback to gptimer */
>>>> 	gptimer clocksource init(;
>>>>
>>>> With this, we should be able to support multi-omap boot
>>>> including devices with/without 32k-sync timer.
>>>>
>>>> This patch-series has been boot tested on AM37xEVM platform, it
>>>> would be helpful if somebody help me to validate it on OMAP1/2
>>>> platforms.
>>>>
>>>> The patches are also available at (based on linux-omap/master) -
>>>> https://github.com/hvaibhav/am335x-linux   32ksync-timer-cleanup
>>>
>>> I was testing on OMAP4 and I found that the gptimer was always being set by default. I noticed that currently the HWMOD for counter_32k on OMAP4 is commented and hence was not being found. Please can you include the following with your series?
>>>
>>
>> The 32kcounter hwmod entry is already enabled in linux-omap/master branch.
>>
>> Your baseline looks pretty old to me, are you not using linux-omap/master?
>
> Ha! My "old" baseline is the latest mainline kernel ;-)
>
> I guess this is a bit out-dated in terms of omap now. Sorry I missed
> that fact your patches were on top of the omap kernel in the changelog.

Yeah, in fact Paul submitted a big series to clean / re-organize and add 
missing hwmod for 3.5. So any change on hwmod should be done on top of 
Paul's branch.

Regards,
Benoit



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