LXR uboot/cpu/mpc5xx/speed.c

   1/*
   2 * (C) Copyright 2003
   3 * Martin Winistoerfer, martinwinistoerfer@gmx.ch.
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation,
  21 */
  22
  23/*
  24 * File:                speed.c
  25 *
  26 * Discription:         Provides cpu speed calculation
  27 *
  28 */
  29
  30#include <common.h>
  31#include <mpc5xx.h>
  32#include <asm/processor.h>
  33
  34DECLARE_GLOBAL_DATA_PTR;
  35
  36/*
  37 * Get cpu and bus clock
  38 */
  39int get_clocks (void)
  40{
  41        volatile immap_t *immr = (immap_t *) CONFIG_SYS_IMMR;
  42
  43#ifndef CONFIG_5xx_GCLK_FREQ
  44        uint divf = (immr->im_clkrst.car_plprcr & PLPRCR_DIVF_MSK);
  45        uint mf = ((immr->im_clkrst.car_plprcr & PLPRCR_MF_MSK) >> PLPRCR_MF_SHIFT);
  46        ulong vcoout;
  47
  48        vcoout = (CONFIG_SYS_OSC_CLK / (divf + 1)) * (mf + 1) * 2;
  49        if(immr->im_clkrst.car_plprcr & PLPRCR_CSRC_MSK) {
  50                gd->cpu_clk = vcoout / (2^(((immr->im_clkrst.car_sccr & SCCR_DFNL_MSK) >> SCCR_DFNL_SHIFT) + 1));
  51        } else {
  52                gd->cpu_clk = vcoout / (2^(immr->im_clkrst.car_sccr & SCCR_DFNH_MSK));
  53        }
  54
  55#else /* CONFIG_5xx_GCLK_FREQ */
  56        gd->bus_clk = CONFIG_5xx_GCLK_FREQ;
  57#endif /* CONFIG_5xx_GCLK_FREQ */
  58
  59        if ((immr->im_clkrst.car_sccr & SCCR_EBDF11) == 0) {
  60                /* No Bus Divider active */
  61                gd->bus_clk = gd->cpu_clk;
  62        } else {
  63                /* CLKOUT is GCLK / 2 */
  64                gd->bus_clk = gd->cpu_clk / 2;
  65        }
  66        return (0);
  67}
  68