[PATCH 1/2] ARM: simplify timer initialisation and remove arm_timer.h inclusion

Sudeep Holla sudeep.holla at arm.com
Mon May 18 03:44:24 PDT 2015


On 18/05/15 11:42, Russell King - ARM Linux wrote:
> On Thu, Apr 30, 2015 at 03:19:01PM +0100, Sudeep Holla wrote:
>>
>>
>> On 30/04/15 15:09, Rob Herring wrote:
>>> On Thu, Apr 30, 2015 at 5:44 AM, Sudeep Holla <sudeep.holla at arm.com> wrote:
>>>> The header asm/hardware/arm_timer.h is included in various machine
>>>> specific files to access TIMER_CTRL and initialise to a known state.
>>>> However that's not required as the clock{source,event} driver timer-sp
>>>> initialises all the timer being used.
>>>
>>> I believe the idea is not to initialize the timers being used, but the
>>> ones not being used and perhaps left running by the bootloader. Cases
>>> where the interrupt is shared could cause a problem.
>>>
>>
>> Ah OK, makes sense. I will wait for Russell to confirm. The main idea
>> was to keep the header file having offsets local to driver/clocksource
>> and avoid sharing it in include/linux but looks like that's not possible.
>
> An alternative would be to have a new function, something like
> sp804_disable() which takes the virtual address of the timer.
> That'd still allow the platforms to disable all timers, but
> without exposing the register stuff to them.
>

Yes that's much better, will re-spin the patch accordingly.

Regards,
Sudeep



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