Initialization of Timer Clock on the MPC8260

Initialization of Timer Clock on the MPC8260

[annamaya]

I am not sure if this is the right place to ask this
question since this may be a U-Boot question. I am
trying to understand how the source for the timer
clock is selected on this processor. Figure 4-3 tries
to explain this but I am unable to find code in U-Boot
that actually sets either BRG1 or one of the GPIO pins
to act as inputs for the timer clock generation. Can
someone point me to the right place in the code where
this is done? I think I  know how to do it but I fail
to understand where this is being actually done. All I
see is the settings of PISCR and TMCNT registers in
cpu initialization code. Thanks for your help in advance.

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Re: Initialization of Timer Clock on the MPC8260

[Wolfgang Denk]

In message <20041214230712.79751.qmail@web53805.mail.yahoo.com> you wrote:
> I am not sure if this is the right place to ask this
> question since this may be a U-Boot question. I am

Why do you ask here and not on the U-Boot mailing list then?

> trying to understand how the source for the timer
> clock is selected on this processor. Figure 4-3 tries
> to explain this but I am unable to find code in U-Boot
> that actually sets either BRG1 or one of the GPIO pins
> to act as inputs for the timer clock generation. Can
> someone point me to the right place in the code where

Well, did you check the place where all GPIO pins
get initialized, i. e. board/<name>/<name>.c ?

Best regards,

Wolfgang Denk

-- 
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
"To take a significant step forward, you must make a series of finite
improvements." - Donald J. Atwood, General Motors

Re: Initialization of Timer Clock on the MPC8260

[annamaya]

Hello Wolfgang,

I will surely post this in the U-Boot forums. I just
did not know where it was but I think I've found it
now. I still had the address to the PPCBOOT mailist
lists. I miss the good old days. :-)

And to answer you questions, yes, I did look at the
GPIO pins for all the 8260 boards and not one of them
was configured to be a clock. And I was unable to find
the setbrg() routine elsewhere to set brgc1 to be the
input for timerclk.

-Navin.

--- Wolfgang Denk <wd@denx.de> wrote:

> In message
> <20041214230712.79751.qmail@web53805.mail.yahoo.com>
> you wrote:
> > I am not sure if this is the right place to ask
> this
> > question since this may be a U-Boot question. I am
> 
> Why do you ask here and not on the U-Boot mailing
> list then?
> 
> > trying to understand how the source for the timer
> > clock is selected on this processor. Figure 4-3
> tries
> > to explain this but I am unable to find code in
> U-Boot
> > that actually sets either BRG1 or one of the GPIO
> pins
> > to act as inputs for the timer clock generation.
> Can
> > someone point me to the right place in the code
> where
> 
> Well, did you check the place where all GPIO pins
> get initialized, i. e. board/<name>/<name>.c ?
> 
> Best regards,
> 
> Wolfgang Denk
> 
> -- 
> Software Engineering:  Embedded and Realtime
> Systems,  Embedded Linux
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80
> Email: wd@denx.de
> "To take a significant step forward, you must make a
> series of finite
> improvements." - Donald J. Atwood, General Motors
> 



		
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Re: Initialization of Timer Clock on the MPC8260

[annamaya]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=us-ascii, Size: 2779 bytes --]

OK Wolfgang. Noone has posted an answer to this
question in the U-Boot mailing list. So, I still need
help with this. :-)

I am looking at the support for one of your own
boards, the TQM8260. I dont see PC25, PC27 and PC26
being configured anywhere. And PC29 is configured as
an SCC1 CLSN signal. Therefore, I think the internal
BRGCLK is used as an input to the timerclk. Now, if
this was true, BRGC1 should have been programmed to
generate either 4MHz or 32KHz clock. But I dont see
this being done anywhere else in the code. I am
missing something and I am not sure what that is.

Thanks much for your help.


--- annamaya <annamaya@yahoo.com> wrote:

> Hello Wolfgang,
> 
> I will surely post this in the U-Boot forums. I just
> did not know where it was but I think I've found it
> now. I still had the address to the PPCBOOT mailist
> lists. I miss the good old days. :-)
> 
> And to answer you questions, yes, I did look at the
> GPIO pins for all the 8260 boards and not one of
> them
> was configured to be a clock. And I was unable to
> find
> the setbrg() routine elsewhere to set brgc1 to be
> the
> input for timerclk.
> 
> -Navin.
> 
> --- Wolfgang Denk <wd@denx.de> wrote:
> 
> > In message
> >
> <20041214230712.79751.qmail@web53805.mail.yahoo.com>
> > you wrote:
> > > I am not sure if this is the right place to ask
> > this
> > > question since this may be a U-Boot question. I
> am
> > 
> > Why do you ask here and not on the U-Boot mailing
> > list then?
> > 
> > > trying to understand how the source for the
> timer
> > > clock is selected on this processor. Figure 4-3
> > tries
> > > to explain this but I am unable to find code in
> > U-Boot
> > > that actually sets either BRG1 or one of the
> GPIO
> > pins
> > > to act as inputs for the timer clock generation.
> > Can
> > > someone point me to the right place in the code
> > where
> > 
> > Well, did you check the place where all GPIO pins
> > get initialized, i. e. board/<name>/<name>.c ?
> > 
> > Best regards,
> > 
> > Wolfgang Denk
> > 
> > -- 
> > Software Engineering:  Embedded and Realtime
> > Systems,  Embedded Linux
> > Phone: (+49)-8142-66989-10 Fax:
> (+49)-8142-66989-80
> > Email: wd@denx.de
> > "To take a significant step forward, you must make
> a
> > series of finite
> > improvements." - Donald J. Atwood, General Motors
> > 
> 
> 
> 
> 		
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