Subject: [PATCH V2 01/14] ARM: OMAP: Add DMTIMER definitions for posted mode

From: [email-masked] (Jon Hunter)
Date: Wed, 7 Nov 2012 16:11:37 -0600

On 11/07/2012 04:04 PM, Santosh Shilimkar wrote:
> On Wednesday 07 November 2012 01:01 PM, Jon Hunter wrote:
>> For OMAP2+ devices, when using DMTIMERs for system timers
>> (clock-events and
>> clock-source) the posted mode configuration of the timers is used. To
>> allow
>> the compiler to optimise the functions for configuring and reading the
>> system
>> timers, the posted flag variable is hard-coded with the value 1. To
>> make it
>> clear that posted mode is being used add some definitions so that it
>> is more
>> readable.
>>
>> Add separate definitions for the clock-events and clock-source timers
>> so that
>> we can change the posted mode of clock-events and clock-source
>> independently.
>>
>> Signed-off-by: Jon Hunter <[email-masked]>
>> ---
>>   arch/arm/mach-omap2/timer.c               |   26
>> +++++++++++++++++++-------
>>   arch/arm/plat-omap/include/plat/dmtimer.h |    4 ++++
>>   2 files changed, 23 insertions(+), 7 deletions(-)
>>
>> diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
>> index 0758bae..28c6078 100644
>> --- a/arch/arm/mach-omap2/timer.c
>> +++ b/arch/arm/mach-omap2/timer.c
>> @@ -82,6 +82,13 @@
>>   #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET        0x14
>>   #define NUMERATOR_DENUMERATOR_MASK            0xfffff000
>>
>> +/*
>> + * For clock-events timer, always use posted mode to
>> + * minimise CPU overhead for configuring the timer.
>> + */
>> +#define OMAP_CLKEVT_POSTEDMODE    OMAP_TIMER_POSTED
>> +#define OMAP_CLKSRC_POSTEDMODE    OMAP_TIMER_POSTED
>> +
> I don't see need of above defines. Just use OMAP_TIMER_POSTED directly
> with API. Rest of the patch looks fine.

Yes that's possible, however, in patch #2, I am disabling posted mode
for clock-source (see changelog of patch #2 for details). Having these
#defines makes it easier to change the posted configuration. That was
the real motivation here.

Cheers
Jon