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. > -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
