Re: [PATCH] ARM: OMAP2+: timer: remove CONFIG_OMAP_32K_TIMER

[Igor Grinberg <grinberg@compulab.co.il>]

On 11/12/12 21:15, Jon Hunter wrote:
> 
> On 11/11/2012 05:28 AM, Igor Grinberg wrote:
>>
>>
>> On 11/08/12 21:16, Jon Hunter wrote:
>>>
>>> On 11/08/2012 12:59 PM, Hiremath, Vaibhav wrote:
>>>> On Fri, Nov 09, 2012 at 00:24:23, Hunter, Jon wrote:
>>>>>
>>>>> On 11/08/2012 01:59 AM, Igor Grinberg wrote:
>>>>>
>>>>> [snip]
>>>>>
>>>>>> There is no reliable way to determine which source should be used in runtime
>>>>>> for boards that do not have the 32k oscillator wired.
>>>>>
>>>>> So thinking about this some more and given that we are moving away from
>>>>> board files, if a board does not provide a 32kHz clock source, then this
>>>>> should be reflected in the device-tree source file for that board.
>>>>> Hence, at boot time we should be able to determine if a 32kHz clock
>>>>> source can be used.
>>>>>
>>>>
>>>> Let me feed some more thoughts here :)
>>>>
>>>> The way it is being detected currently is based on timer idle status bit.
>>>> I am worried that, this is the only option we have.
>>>
>>> Why not use device-tree to indicate the presence of a 32k clock source?
>>> This seems like a board level configuration and so device-tree seems to
>>> be the perfect place for this IMO.
>>
>> Well, that is what my commit message says...
> 
> Sorry, but that was not clear to me from whats in the commit message.

>From the commit message:
"1) Timer structures and initialization functions are named by the platform
   name and the clock source in use. The decision which timer is
   used is done statically from the machine_desc structure. In the
   future it should come from DT."

The last sentence has it.
The transition to DT is not immediate and we can't (still) neglect
the non-DT setups.

> 
> Should we be doing this now instead of adding all these static timer
> init functions?

I don't see this as "adding ...", I see this as expanding the setup
which was previously hidden by the CONFIG_OMAP_32K_TIMER option.

> 
> Are there any boards today (supported in the kernel that is), that don't
> support a 32k?

Yes, starting from revision 1.2, CM-T3517 does not have the 32k.

[...]

-- 
Regards,
Igor.