[U-Boot-Users] [PATCH 4/4] TQM885D: Use the OSCM, feeded by EXTAL = 10 MHz.

[Martin Krause]

u-boot-users-bounces at lists.sourceforge.net wrote on :
> wd at denx.de wrote on Monday, July 30, 2007 5:42 PM:
> > In message <20070724085849.20151.20950.stgit at tq-sewsrv-4.tq-net.de>
> > you wrote:
> > > From: Jens Gehrlein <jens.gehrlein at tqs.de>
> > > 
> > > This makes it necessary to prescale PITCLK by 512.
> > > 
> > > This patch is necessary for revision 102 and above of the TQM885D.
> > > Revisions 100 and 101 of the TQM885D will not work with this patch
> > > applied. But this should not be a problem, since there are only
> > > a few prototypes of this revisions floating around.
> > > 
> > > Signed-off-by: Jens Gehrlein <jens.gehrlein at tqs.de>
> > > Signed-off-by: Martin Krause <martin.krause at tqs.de>
> > 
> > NAK by Wolfgang Denk.
> > 
> > > diff --git a/cpu/mpc8xx/speed.c b/cpu/mpc8xx/speed.c
> > > index 101d5f9..4173092 100644
> > > --- a/cpu/mpc8xx/speed.c
> > > +++ b/cpu/mpc8xx/speed.c
> > > @@ -93,11 +93,23 @@ unsigned long measure_gclk(void)  	ulong
> > > msr_val; 
> > > 
> > >  #ifdef CFG_8XX_XIN
> > > +#ifdef CONFIG_TQM885D
> > 
> > I don't allow for board specific code in that file (and please get
> > rid 
> 
> Does this mean, I should make the code cpu specific instead (like
> #ifdef CONFIG_MPC885)?
> 
> Our TQM885D board uses an external 10 MHz oscillator on EXTAL
> (-> OSCM = 10 MHz). But measure_gclk() is assumeing that, if OSCM
> is used as clock source, it has a frequency of 32768 Hz (wich seems
> to be true for all other MPC8xx boards).

I found a solution, where we don't need to modify speed.c at all.
We don't need to measure cpuclk - the value could be calculated
by the PLL configuration registers.

Best Regards,
Martin Krause

--
TQ-Systems GmbH
Muehlstrasse 2, Gut Delling, D-82229 Seefeld
Amtsgericht Muenchen, HRB 105 018, UST-IdNr. DE 811 607 913
Geschaeftsfuehrer: Dipl.-Ing. (FH) Detlef Schneider, Dipl.-Ing. (FH) Ruediger Stahl
http://www.tq-group.com