cpu/mpc5xx/cpu.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:                cpu.c
  25  *
  26  * Discription:         Some cpu specific function for watchdog,
  27  *                      cpu version test, clock setting ...
  28  *
  29  */
  30
  31
  32 #include <common.h>
  33 #include <watchdog.h>
  34 #include <command.h>
  35 #include <mpc5xx.h>
  36
  37
  38 #if (defined(CONFIG_MPC555))
  39 #  define       ID_STR  "MPC555/556"
  40
  41 /*
  42  * Check version of cpu with Processor Version Register (PVR)
  43  */
  44 static int check_cpu_version (long clock, uint pvr, uint immr)
  45 {
  46     char buf[32];
  47         /* The highest 16 bits should be 0x0002 for a MPC555/556 */
  48         if ((pvr >> 16) == 0x0002) {
  49                 printf (" " ID_STR " Version %x", (pvr >> 16));
  50                 printf (" at %s MHz:", strmhz (buf, clock));
  51         } else {
  52                 printf ("Not supported cpu version");
  53                 return -1;
  54         }
  55         return 0;
  56 }
  57 #endif /* CONFIG_MPC555 */
  58
  59
  60 /*
  61  * Check version of mpc5xx
  62  */
  63 int checkcpu (void)
  64 {
  65         DECLARE_GLOBAL_DATA_PTR;
  66
  67         ulong clock = gd->cpu_clk;
  68         uint immr = get_immr (0);       /* Return full IMMR contents */
  69         uint pvr = get_pvr ();          /* Retrieve PVR register */
  70
  71         puts ("CPU:   ");
  72
  73         return check_cpu_version (clock, pvr, immr);
  74 }
  75
  76 /*
  77  * Called by macro WATCHDOG_RESET
  78  */
  79 #if defined(CONFIG_WATCHDOG)
  80 void watchdog_reset (void)
  81 {
  82         int re_enable = disable_interrupts ();
  83
  84         reset_5xx_watchdog ((immap_t *) CFG_IMMR);
  85         if (re_enable)
  86                 enable_interrupts ();
  87 }
  88
  89 /*
  90  * Will clear software reset
  91  */
  92 void reset_5xx_watchdog (volatile immap_t * immr)
  93 {
  94         /* Use the MPC5xx Internal Watchdog */
  95         immr->im_siu_conf.sc_swsr = 0x556c;     /* Prevent SW time-out */
  96         immr->im_siu_conf.sc_swsr = 0xaa39;
  97 }
  98
  99 #endif /* CONFIG_WATCHDOG */
 100
 101
 102 /*
 103  * Get timebase clock frequency
 104  */
 105 unsigned long get_tbclk (void)
 106 {
 107         DECLARE_GLOBAL_DATA_PTR;
 108         volatile immap_t *immr = (volatile immap_t *) CFG_IMMR;
 109         ulong oscclk, factor;
 110
 111         if (immr->im_clkrst.car_sccr & SCCR_TBS) {
 112                 return (gd->cpu_clk / 16);
 113         }
 114
 115         factor = (((CFG_PLPRCR) & PLPRCR_MF_MSK) >> PLPRCR_MF_SHIFT) + 1;
 116
 117         oscclk = gd->cpu_clk / factor;
 118
 119         if ((immr->im_clkrst.car_sccr & SCCR_RTSEL) == 0 || factor > 2) {
 120                 return (oscclk / 4);
 121         }
 122         return (oscclk / 16);
 123 }
 124
 125
 126 /*
 127  * Reset board
 128  */
 129 int do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
 130 {
 131         ulong addr;
 132
 133         /* Interrupts off, enable reset */
 134         __asm__ volatile        ("  mtspr       81, %r0         \n\t"
 135                                  "  mfmsr       %r3             \n\t"
 136                                  "  rlwinm      %r31,%r3,0,25,23\n\t"
 137                                  "  mtmsr       %r31            \n\t");
 138         /*
 139          * Trying to execute the next instruction at a non-existing address
 140          * should cause a machine check, resulting in reset
 141          */
 142 #ifdef CFG_RESET_ADDRESS
 143         addr = CFG_RESET_ADDRESS;
 144 #else
 145         /*
 146          * note: when CFG_MONITOR_BASE points to a RAM address, CFG_MONITOR_BASE         * - sizeof (ulong) is usually a valid address. Better pick an address
 147          * known to be invalid on your system and assign it to CFG_RESET_ADDRESS.
 148          * "(ulong)-1" used to be a good choice for many systems...
 149          */
 150         addr = CFG_MONITOR_BASE - sizeof (ulong);
 151 #endif
 152         ((void (*) (void)) addr) ();
 153         return 1;
 154 }