u-boot/cpu/mpc85xx/speed.c
Andy Fleming 66ed6cca3f Reworked 85xx speed detection code
Changed the code to read the registers and calculate the clock
rates, rather than using a "switch" statement.

Idea from Andrew Klossner <andrew@cesa.opbu.xerox.com>

Signed-off-by: Andy Fleming <afleming@freescale.com>
2007-04-23 19:58:28 -05:00

96 lines
2.6 KiB
C

/*
* Copyright 2004 Freescale Semiconductor.
* (C) Copyright 2003 Motorola Inc.
* Xianghua Xiao, (X.Xiao@motorola.com)
*
* (C) Copyright 2000
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <ppc_asm.tmpl>
#include <asm/processor.h>
DECLARE_GLOBAL_DATA_PTR;
/* --------------------------------------------------------------- */
void get_sys_info (sys_info_t * sysInfo)
{
volatile immap_t *immap = (immap_t *)CFG_IMMR;
volatile ccsr_gur_t *gur = &immap->im_gur;
uint plat_ratio,e500_ratio,half_freqSystemBus;
plat_ratio = (gur->porpllsr) & 0x0000003e;
plat_ratio >>= 1;
sysInfo->freqSystemBus = plat_ratio * CONFIG_SYS_CLK_FREQ;
e500_ratio = (gur->porpllsr) & 0x003f0000;
e500_ratio >>= 16;
/* Divide before multiply to avoid integer
* overflow for processor speeds above 2GHz */
half_freqSystemBus = sysInfo->freqSystemBus/2;
sysInfo->freqProcessor = e500_ratio*half_freqSystemBus;
}
int get_clocks (void)
{
sys_info_t sys_info;
#if defined(CONFIG_CPM2)
volatile immap_t *immap = (immap_t *) CFG_IMMR;
uint sccr, dfbrg;
/* set VCO = 4 * BRG */
immap->im_cpm.im_cpm_intctl.sccr &= 0xfffffffc;
sccr = immap->im_cpm.im_cpm_intctl.sccr;
dfbrg = (sccr & SCCR_DFBRG_MSK) >> SCCR_DFBRG_SHIFT;
#endif
get_sys_info (&sys_info);
gd->cpu_clk = sys_info.freqProcessor;
gd->bus_clk = sys_info.freqSystemBus;
#if defined(CONFIG_CPM2)
gd->vco_out = 2*sys_info.freqSystemBus;
gd->cpm_clk = gd->vco_out / 2;
gd->scc_clk = gd->vco_out / 4;
gd->brg_clk = gd->vco_out / (1 << (2 * (dfbrg + 1)));
#endif
if(gd->cpu_clk != 0) return (0);
else return (1);
}
/********************************************
* get_bus_freq
* return system bus freq in Hz
*********************************************/
ulong get_bus_freq (ulong dummy)
{
ulong val;
sys_info_t sys_info;
get_sys_info (&sys_info);
val = sys_info.freqSystemBus;
return val;
}