Ok .
=============================================
Case arch = powerpc
I saw that cdm is modified in two fields.
arch/powerpc/platforms/mpc52xx_common.c file, in function:
mpc52xx_setup_cpu(void)
.....
/* Use internal 48 Mhz */
out_8(&cdm->ext_48mhz_en, 0x00);
out_8(&cdm->fd_enable, 0x01);
if (in_be32(&cdm->rstcfg) & 0x40) /* Assumes 33Mhz clock */
out_be16(&cdm->fd_counters, 0x0001);
else
out_be16(&cdm->fd_counters, 0x5555);
.....
and in file arch/powerpc/platforms/52xx/lite5200.c , function:
void __init lite5200_calibrate_decr(void)
{
ppc_tb_freq = 0x1F78A40; /* hardcoded default */
/* CPU FREQUENCY FORCED TO 396 MHz VALUE */
ppc_proc_freq = 0x179A7B00; /* hardcoded default */
..........
=============================================
Case arch = ppc
The code is equal but obviously the path change
(arch/ppc/syslib/mpc52xx_setup.c). Funtion: mpc52xx_setup_cpu(void)
.....
/* Use internal 48 Mhz */
out_8(&cdm->ext_48mhz_en, 0x00);
out_8(&cdm->fd_enable, 0x01);
if (in_be32(&cdm->rstcfg) & 0x40) /* Assumes 33Mhz clock */
out_be16(&cdm->fd_counters, 0x0001);
else
out_be16(&cdm->fd_counters, 0x5555);
.....
And in function: mpc52xx_calibrate_decr(void)
.....
xlbfreq = __res.bi_busfreq;
/* if bootloader didn't pass bus frequencies, calculate them */
if (xlbfreq == 0) {
...........
/* Compute all frequency from that & CDM settings */
xlbfreq = (tbl_end - tbl_start) << 8;
cpufreq = (xlbfreq * core_mult[in_be32(&cdm->rstcfg)&0x1f])/10;
ipbfreq = (in_8(&cdm->ipb_clk_sel) & 1) ?
xlbfreq / 2 : xlbfreq;
switch (in_8(&cdm->pci_clk_sel) & 3) {
case 0:
pcifreq = ipbfreq;
break;
case 1:
pcifreq = ipbfreq / 2;
break;
default:
pcifreq = xlbfreq / 4;
break;
}
.....
=============================================
What do you think about this?
Thanks in advance,
@ngel
--- Ven 5/12/08, Jon Smirl <[EMAIL PROTECTED]> ha scritto:
Da: Jon Smirl <[EMAIL PROTECTED]>
Oggetto: Re: R: Installation on a MPC5200 based custom board
A: "Juergen Beisert" <[EMAIL PROTECTED]>
Cc: linuxppc-dev@ozlabs.org, [EMAIL PROTECTED], "Gary Thomas" <[EMAIL
PROTECTED]>, [EMAIL PROTECTED]
Data: Venerdì 5 dicembre 2008, 20:33
The attachment is from Freescale and shows how the divider works.
--
Jon Smirl
[EMAIL PROTECTED]
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