Linux on AT91RM9200

Hello,

I'm designing a system based on ATMEL AT91RM9200 SOC.

The system will run under Linux.

I've couple of quetsion regarding processor initialisation code.

I'm trying to find this code in the linux 2.4 kernel sources and unable to
locate it.
In particular i'm looking for the code initializing the processor internal
PLLs and selecting the master clock source.

Looking in the include/asm-arm/arch-at91rm9200/at91rm9200dk.h

i see following code and comments

 #define AT91C_MAIN_CLOCK       179712000       /* from 18.432 MHz crystal (18432000 / 
4
* 39) */
 #define AT91C_MASTER_CLOCK      59904000       /* peripheral clock
(AT91C_MASTER_CLOCK / 3) */

BTW the second comment id erroneous it should be  /* peripheral clock
(AT91C_MAIN_CLOCK / 3) */


These 4 and 39 constants are apparently parameters for PLL divider and
multiplyer
But i'm unable to locate the code where these values are actually programmed
into the PLL control registers.

My hardware will be a subset of  at91rm9200dk with a twist. I'd like to
scrap the 50 MHZ oscilator
used to drive RMII REFCLK and istead to connect the at91rm9200 to the 25 Mhz
crystal and derive then
the 50MHZ from one of the PMC outputs.

Any suggestions or pointers?
Thanks
Vadim Lebedev
CTO
7Chips