cpu/mpc86xx/speed.c

   1 /*
   2  * Copyright 2004 Freescale Semiconductor.
   3  * Jeff Brown
   4  * Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
   5  *
   6  * (C) Copyright 2000-2002
   7  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   8  *
   9  * See file CREDITS for list of people who contributed to this
  10  * project.
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License as
  14  * published by the Free Software Foundation; either version 2 of
  15  * the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  25  * MA 02111-1307 USA
  26  */
  27
  28 #include <common.h>
  29 #include <mpc86xx.h>
  30 #include <asm/processor.h>
  31
  32 DECLARE_GLOBAL_DATA_PTR;
  33
  34 /* used in some defintiions of CONFIG_SYS_CLK_FREQ */
  35 extern unsigned long get_board_sys_clk(unsigned long dummy);
  36
  37 void get_sys_info(sys_info_t *sysInfo)
  38 {
  39         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  40         volatile ccsr_gur_t *gur = &immap->im_gur;
  41         uint plat_ratio, e600_ratio;
  42
  43         plat_ratio = (gur->porpllsr) & 0x0000003e;
  44         plat_ratio >>= 1;
  45
  46         switch (plat_ratio) {
  47         case 0x0:
  48                 sysInfo->freqSystemBus = 16 * CONFIG_SYS_CLK_FREQ;
  49                 break;
  50         case 0x02:
  51         case 0x03:
  52         case 0x04:
  53         case 0x05:
  54         case 0x06:
  55         case 0x08:
  56         case 0x09:
  57         case 0x0a:
  58         case 0x0c:
  59         case 0x10:
  60                 sysInfo->freqSystemBus = plat_ratio * CONFIG_SYS_CLK_FREQ;
  61                 break;
  62         default:
  63                 sysInfo->freqSystemBus = 0;
  64                 break;
  65         }
  66
  67         e600_ratio = (gur->porpllsr) & 0x003f0000;
  68         e600_ratio >>= 16;
  69
  70         switch (e600_ratio) {
  71         case 0x10:
  72                 sysInfo->freqProcessor = 2 * sysInfo->freqSystemBus;
  73                 break;
  74         case 0x19:
  75                 sysInfo->freqProcessor = 5 * sysInfo->freqSystemBus / 2;
  76                 break;
  77         case 0x20:
  78                 sysInfo->freqProcessor = 3 * sysInfo->freqSystemBus;
  79                 break;
  80         case 0x39:
  81                 sysInfo->freqProcessor = 7 * sysInfo->freqSystemBus / 2;
  82                 break;
  83         case 0x28:
  84                 sysInfo->freqProcessor = 4 * sysInfo->freqSystemBus;
  85                 break;
  86         case 0x1d:
  87                 sysInfo->freqProcessor = 9 * sysInfo->freqSystemBus / 2;
  88                 break;
  89         default:
  90                 sysInfo->freqProcessor = e600_ratio + sysInfo->freqSystemBus;
  91                 break;
  92         }
  93 }
  94
  95
  96 /*
  97  * Measure CPU clock speed (core clock GCLK1, GCLK2)
  98  * (Approx. GCLK frequency in Hz)
  99  */
 100
 101 int get_clocks(void)
 102 {
 103         sys_info_t sys_info;
 104
 105         get_sys_info(&sys_info);
 106         gd->cpu_clk = sys_info.freqProcessor;
 107         gd->bus_clk = sys_info.freqSystemBus;
 108
 109         /*
 110          * The base clock for I2C depends on the actual SOC.  Unfortunately,
 111          * there is no pattern that can be used to determine the frequency, so
 112          * the only choice is to look up the actual SOC number and use the value
 113          * for that SOC. This information is taken from application note
 114          * AN2919.
 115          */
 116 #ifdef CONFIG_MPC8610
 117         gd->i2c1_clk = sys_info.freqSystemBus;
 118 #else
 119         gd->i2c1_clk = sys_info.freqSystemBus / 2;
 120 #endif
 121         gd->i2c2_clk = gd->i2c1_clk;
 122
 123         if (gd->cpu_clk != 0)
 124                 return 0;
 125         else
 126                 return 1;
 127 }
 128
 129
 130 /*
 131  * get_bus_freq
 132  *      Return system bus freq in Hz
 133  */
 134
 135 ulong get_bus_freq(ulong dummy)
 136 {
 137         ulong val;
 138         sys_info_t sys_info;
 139
 140         get_sys_info(&sys_info);
 141         val = sys_info.freqSystemBus;
 142
 143         return val;
 144 }