u-boot/cpu/mpc5xx/speed.c

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/*
* (C) Copyright 2003
* Martin Winistoerfer, martinwinistoerfer@gmx.ch.
*
* 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,
*/
/*
* File: speed.c
*
* Discription: Provides cpu speed calculation
*
*/
#include <common.h>
#include <mpc5xx.h>
#include <asm/processor.h>
/*
* Get cpu and bus clock
*/
int get_clocks (void)
{
DECLARE_GLOBAL_DATA_PTR;
volatile immap_t *immr = (immap_t *) CFG_IMMR;
#ifndef CONFIG_5xx_GCLK_FREQ
uint divf = (immr->im_clkrst.car_plprcr & PLPRCR_DIVF_MSK);
uint mf = ((immr->im_clkrst.car_plprcr & PLPRCR_MF_MSK) >> PLPRCR_MF_SHIFT);
ulong vcoout;
vcoout = (CFG_OSC_CLK / (divf + 1)) * (mf + 1) * 2;
if(immr->im_clkrst.car_plprcr & PLPRCR_CSRC_MSK) {
gd->cpu_clk = vcoout / (2^(((immr->im_clkrst.car_sccr & SCCR_DFNL_MSK) >> SCCR_DFNL_SHIFT) + 1));
} else {
gd->cpu_clk = vcoout / (2^(immr->im_clkrst.car_sccr & SCCR_DFNH_MSK));
}
#else /* CONFIG_5xx_GCLK_FREQ */
gd->bus_clk = CONFIG_5xx_GCLK_FREQ;
#endif /* CONFIG_5xx_GCLK_FREQ */
if ((immr->im_clkrst.car_sccr & SCCR_EBDF11) == 0) {
/* No Bus Divider active */
gd->bus_clk = gd->cpu_clk;
} else {
/* CLKOUT is GCLK / 2 */
gd->bus_clk = gd->cpu_clk / 2;
}
return (0);
}