Subject: [PATCH V4] ARM: OMAP5/DRA7: realtime_counter: Configure CNTFRQ register

From: [email-masked] (Sricharan R)
Date: Wed, 9 Oct 2013 18:46:42 +0530

On Wednesday 09 October 2013 06:45 PM, Sricharan R wrote:
> Santosh,
>
> On Wednesday 09 October 2013 03:35 AM, Santosh Shilimkar wrote:
>> On Tuesday 08 October 2013 05:45 PM, Tony Lindgren wrote:
>>> * Sricharan R <[email-masked]> [131003 03:27]:
>>>> On Wednesday 18 September 2013 09:32 PM, Sricharan R wrote:
>>>>> --- a/arch/arm/boot/dts/omap5.dtsi
>>>>> +++ b/arch/arm/boot/dts/omap5.dtsi
>>>>> @@ -52,7 +52,6 @@
>>>>>  			     <GIC_PPI 14 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>,
>>>>>  			     <GIC_PPI 11 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>,
>>>>>  			     <GIC_PPI 10 (GIC_CPU_MASK_RAW(3) | IRQ_TYPE_LEVEL_LOW)>;
>>>>> -		clock-frequency = <6144000>;
>>>>>  	};
>>>>>  
>>>>>  	gic: interrupt-controller at 48211000 {
>>> Can the above be done later on in a separate clean-up patch?
>>> If so I can drop that part as that removes a dependency to the
>>> .dts patches queued by Benoit.
>>>
>> This can be applied separately. 
>>
>>  
>>>>> --- a/arch/arm/mach-omap2/omap-smp.c
>>>>> +++ b/arch/arm/mach-omap2/omap-smp.c
>>>>> @@ -41,6 +41,8 @@
>>>>>  
>>>>>  u16 pm44xx_errata;
>>>>>  
>>>>> +extern unsigned long arch_timer_freq;
>>>>> +
>>>>>  /* SCU base address */
>>>>>  static void __iomem *scu_base;
>>>>>  
>>> No externs in *.c files please, checkpatch.pl and sparse should warn
>>> about this.
>>>
>>>>  Are you planning to pull this patch and the below $subject patch as well? They are
>>>>  acked and tested.
>>>>
>>>>  ARM: DRA7: realtime_counter: Add ratio registers for 20MHZ sys-clk frequency
>>>>
>>>>   http://www.spinics.net/lists/linux-omap/msg97281.html
>>> The 20MHz patch I've applied, just noticed the above things
>>> when was about to apply this.
>>>
>> Now re-looking at the patch, I think this extern stuff can be and
>> should be avoided. It needs order change though like below. Not
>> tested but should work.
>>
>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
>> index fa74a06..c8d8308 100644
>> --- a/arch/arm/mach-omap2/timer.c
>> +++ b/arch/arm/mach-omap2/timer.c
>> @@ -631,10 +631,9 @@ void __init omap4_local_timer_init(void)
>>  #ifdef CONFIG_SOC_OMAP5
>>  void __init omap5_realtime_timer_init(void)
>>  {
>> -	omap4_sync32k_timer_init();
>>  	realtime_counter_init();
>> -
>>  	clocksource_of_init();
>> +	omap4_sync32k_timer_init();
>>  }
>>  #endif /* CONFIG_SOC_OMAP5 */
>>  
>> Then, the CNTFREQ programming needs to be moved to
>> realtime_counter_init(). It should be actually part of that
>> first place instead of timer_init().
>>
>> On secondary CPU then a simple asm accessor can
>> read the CNTFREQ and pass that to SMC.
> Sorry,  I did not quite get you here. You mean an asm accessor to
>  the read the variable that is set in timer.c ?
 Also, is it not ok to move the extern to a .h file instead ?

Regards,
 Sricharan