[U-Boot] [PATCH resend] armv7/ltimer: Add support for local timer on armv7 cpus

Vipin Kumar vipin.kumar at st.com
Mon Dec 17 05:24:48 CET 2012


On 12/16/2012 1:14 PM, Dennis Lan (dlan) wrote:
> Hi
>
>
> On Sat, Dec 15, 2012 at 6:20 AM, Wolfgang Denk <wd at denx.de
> <mailto:wd at denx.de>> wrote:
>
>     Dear Vipin Kumar,
>
>     In message <50CAF0CB.1050108 at st.com
>     <mailto:50CAF0CB.1050108 at st.com>> you wrote:
>      > ping again
>
>     pong ;-)
>
>      > On 12/6/2012 2:52 PM, Vipin KUMAR wrote:
>      > > Certain ARMV7 cpus eg. CortexA9 contains a local and a global
>     timer within the
>      > > CPU core itself.  This patch adds generic support for local timer.
>
>     What would be the use of such timer support?  Is there any code that
>     actually needs it, and why does it need anything beyond the existing
>     timer support we have?
>
> Hi wolfgang:
>    I think vipin here is trying to provide a generic timer support for
> ARMV7 architecture,
> which contains private(local) and global timer. It's general a good
> thing which means we can maximize the code usage..
>    Actually I was planing to test the code, but haven't find the time
> yet ;-)
>

Hello Wolfgang

Dennis is right. I am trying to provide the armv7 local timer support.

> Hi vipin:
>    why you only support local timer(private)? shouldn't it different to
> support global timer too?
>

Well, actually the local timer was used in the spear13xx support which 
is to be added later on. The global timer was not used and hence the 
driver was not needed (at least by us). but I agree that such a driver 
would be useful for a lot of people using armv7 cores and CPU timers

The global timer support, even if it is added, would be added as a 
separate driver so this is infact complete in its own

Regards
Vipin


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