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

[Hiremath, Vaibhav]

On Sun, Nov 11, 2012 at 17:05:07, Igor Grinberg wrote:
> 
> 
> On 11/08/12 20:34, Jon Hunter wrote:
> > 
> > On 11/08/2012 12:17 PM, Paul Walmsley wrote:
> >> On Thu, 8 Nov 2012, Jon Hunter wrote:
> >>
> >>> On 11/08/2012 11:58 AM, Paul Walmsley wrote:
> >>>> On Thu, 8 Nov 2012, Jon Hunter wrote:
> >>>>
> >>>>> Igor was mentioning a h/w scenario where the 32kHz source is not
> >>>>> present. However, I am not sure which devices support this and is
> >>>>> applicable too.
> >>>>
> >>>> Pretty sure Igor is referring to the AM3517/3505.  This is very poorly 
> >>>> documented, but can be observed in the AM3517 TRM Rev B (SPRUGR0B) Figure 
> >>>> 4-23 "PRM Clock Generator" and the AM3517 DM Rev C (SPRS550C) Section 4 
> >>>> "Clock Specifications".
> >>>
> >>> But AFAICT, even in that h/w configuration the internal 32k
> >>> oscillator will be used
> >>
> >> Just to clarify, there's no internal 32k oscillator used on the 3517/3505; 
> >> just a divider from the HF clock.
> > 
> > Ah yes I see that now!
> > 
> >>> and so the gptimer will still have a 32k clock source.
> >>
> >> That's a good question and you might want to check with Igor on that one,
> >> the AM3517 TRM conflicts with the DM as to whether it's available to the 
> >> GPTIMER or not :-(
> > 
> > Well the external 32k and internal divided down version go through the
> > same mux and so that seems to imply either they are both available to
> > the gptimer or neither is.
> 
> Yep, but the /800 do not get you the 32768...
> and that makes the timer suck.
> Of course this can be dealt with in the clock subsystem
> (I remember Paul said that he will look into that), but it will take time.
> 
> Also, what about having the sys_clk instead of 32k for higher precision?
> Is that possible already (without my patch)?
> 

Yes, it is possible. You can choose it through bootargs.

Thanks,
Vaibhav

> 
> -- 
> Regards,
> Igor.
>