LXR uboot/arch/mips/cpu/mips32/incaip/incaip

   1/*
   2 * (C) Copyright 2003
   3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   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, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23
  24#include <common.h>
  25#include <asm/inca-ip.h>
  26
  27
  28/*******************************************************************************
  29*
  30* get_cpuclk - returns the frequency of the CPU.
  31*
  32* Gets the value directly from the INCA-IP hardware.
  33*
  34* RETURNS:
  35*          150.000.000 for 150 MHz
  36*          133.333.333 for 133 MHz (= 400MHz/3)
  37*          100.000.000 for 100 MHz (= 400MHz/4)
  38* NOTE:
  39*   This functions should be used by the hardware driver to get the correct
  40*   frequency of the CPU. Don't use the macros, which are set to init the CPU
  41*   frequency in the ROM code.
  42*/
  43uint incaip_get_cpuclk (void)
  44{
  45        /*-------------------------------------------------------------------------*/
  46        /* CPU Clock Input Multiplexer (MUX I)                                     */
  47        /* Multiplexer MUX I selects the maximum input clock to the CPU.           */
  48        /*-------------------------------------------------------------------------*/
  49        if (*((volatile ulong *) INCA_IP_CGU_CGU_MUXCR) &
  50            INCA_IP_CGU_CGU_MUXCR_MUXI) {
  51                /* MUX I set to 150 MHz clock */
  52                return 150000000;
  53        } else {
  54                /* MUX I set to 100/133 MHz clock */
  55                if (*((volatile ulong *) INCA_IP_CGU_CGU_DIVCR) & 0x40) {
  56                        /* Division value is 1/3, maximum CPU operating */
  57                        /* frequency is 133.3 MHz                       */
  58                        return 133333333;
  59                } else {
  60                        /* Division value is 1/4, maximum CPU operating */
  61                        /* frequency is 100 MHz                         */
  62                        return 100000000;
  63                }
  64        }
  65}
  66
  67/*******************************************************************************
  68*
  69* get_fpiclk - returns the frequency of the FPI bus.
  70*
  71* Gets the value directly from the INCA-IP hardware.
  72*
  73* RETURNS: Frquency in Hz
  74*
  75* NOTE:
  76*   This functions should be used by the hardware driver to get the correct
  77*   frequency of the CPU. Don't use the macros, which are set to init the CPU
  78*   frequency in the ROM code.
  79*   The calculation for the
  80*/
  81uint incaip_get_fpiclk (void)
  82{
  83        uint clkCPU;
  84
  85        clkCPU = incaip_get_cpuclk ();
  86
  87        switch (*((volatile ulong *) INCA_IP_CGU_CGU_DIVCR) & 0xC) {
  88        case 0x4:
  89                return clkCPU >> 1;     /* devided by 2 */
  90                break;
  91        case 0x8:
  92                return clkCPU >> 2;     /* devided by 4 */
  93                break;
  94        default:
  95                return clkCPU;
  96                break;
  97        }
  98}
  99
 100int incaip_set_cpuclk (void)
 101{
 102        extern void ebu_init(long);
 103        extern void cgu_init(long);
 104        extern void sdram_init(long);
 105        char tmp[64];
 106        ulong cpuclk;
 107
 108        if (getenv_f("cpuclk", tmp, sizeof (tmp)) > 0) {
 109                cpuclk = simple_strtoul (tmp, NULL, 10) * 1000000;
 110                cgu_init (cpuclk);
 111                ebu_init (cpuclk);
 112                sdram_init (cpuclk);
 113        }
 114
 115        return 0;
 116}
 117