arch/powerpc/cpu/mpc86xx/speed.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright 2004 Freescale Semiconductor.
   4  * Jeff Brown
   5  * Srikanth Srinivasan (srikanth.srinivasan@freescale.com)
   6  *
   7  * (C) Copyright 2000-2002
   8  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   9  */
  10
  11 #include <common.h>
  12 #include <clock_legacy.h>
  13 #include <mpc86xx.h>
  14 #include <asm/global_data.h>
  15 #include <asm/processor.h>
  16 #include <asm/io.h>
  17
  18 DECLARE_GLOBAL_DATA_PTR;
  19
  20 /* used in some defintiions of CONFIG_SYS_CLK_FREQ */
  21 extern unsigned long get_board_sys_clk(unsigned long dummy);
  22
  23 void get_sys_info(sys_info_t *sys_info)
  24 {
  25         volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
  26         volatile ccsr_gur_t *gur = &immap->im_gur;
  27         uint plat_ratio, e600_ratio;
  28
  29         plat_ratio = (gur->porpllsr) & 0x0000003e;
  30         plat_ratio >>= 1;
  31
  32         switch (plat_ratio) {
  33         case 0x0:
  34                 sys_info->freq_systembus = 16 * CONFIG_SYS_CLK_FREQ;
  35                 break;
  36         case 0x02:
  37         case 0x03:
  38         case 0x04:
  39         case 0x05:
  40         case 0x06:
  41         case 0x08:
  42         case 0x09:
  43         case 0x0a:
  44         case 0x0c:
  45         case 0x10:
  46                 sys_info->freq_systembus = plat_ratio * CONFIG_SYS_CLK_FREQ;
  47                 break;
  48         default:
  49                 sys_info->freq_systembus = 0;
  50                 break;
  51         }
  52
  53         e600_ratio = (gur->porpllsr) & 0x003f0000;
  54         e600_ratio >>= 16;
  55
  56         switch (e600_ratio) {
  57         case 0x10:
  58                 sys_info->freq_processor = 2 * sys_info->freq_systembus;
  59                 break;
  60         case 0x19:
  61                 sys_info->freq_processor = 5 * sys_info->freq_systembus / 2;
  62                 break;
  63         case 0x20:
  64                 sys_info->freq_processor = 3 * sys_info->freq_systembus;
  65                 break;
  66         case 0x39:
  67                 sys_info->freq_processor = 7 * sys_info->freq_systembus / 2;
  68                 break;
  69         case 0x28:
  70                 sys_info->freq_processor = 4 * sys_info->freq_systembus;
  71                 break;
  72         case 0x1d:
  73                 sys_info->freq_processor = 9 * sys_info->freq_systembus / 2;
  74                 break;
  75         default:
  76                 sys_info->freq_processor = e600_ratio +
  77                                                 sys_info->freq_systembus;
  78                 break;
  79         }
  80
  81         sys_info->freq_localbus = sys_info->freq_systembus;
  82 }
  83
  84
  85 /*
  86  * Measure CPU clock speed (core clock GCLK1, GCLK2)
  87  * (Approx. GCLK frequency in Hz)
  88  */
  89
  90 int get_clocks(void)
  91 {
  92         sys_info_t sys_info;
  93
  94         get_sys_info(&sys_info);
  95         gd->cpu_clk = sys_info.freq_processor;
  96         gd->bus_clk = sys_info.freq_systembus;
  97         gd->arch.lbc_clk = sys_info.freq_localbus;
  98
  99         /*
 100          * The base clock for I2C depends on the actual SOC.  Unfortunately,
 101          * there is no pattern that can be used to determine the frequency, so
 102          * the only choice is to look up the actual SOC number and use the value
 103          * for that SOC. This information is taken from application note
 104          * AN2919.
 105          */
 106 #ifdef CONFIG_ARCH_MPC8610
 107         gd->arch.i2c1_clk = sys_info.freq_systembus;
 108 #else
 109         gd->arch.i2c1_clk = sys_info.freq_systembus / 2;
 110 #endif
 111         gd->arch.i2c2_clk = gd->arch.i2c1_clk;
 112
 113         if (gd->cpu_clk != 0)
 114                 return 0;
 115         else
 116                 return 1;
 117 }
 118
 119
 120 /*
 121  * get_bus_freq
 122  *      Return system bus freq in Hz
 123  */
 124
 125 ulong get_bus_freq(ulong dummy)
 126 {
 127         ulong val;
 128         sys_info_t sys_info;
 129
 130         get_sys_info(&sys_info);
 131         val = sys_info.freq_systembus;
 132
 133         return val;
 134 }