arch/powerpc/cpu/mpc5xx/cpu.c

   1 /*
   2  * (C) Copyright 2003
   3  * Martin Winistoerfer, martinwinistoerfer@gmx.ch.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * File:                cpu.c
  10  *
  11  * Discription:         Some cpu specific function for watchdog,
  12  *                      cpu version test, clock setting ...
  13  *
  14  */
  15
  16
  17 #include <common.h>
  18 #include <watchdog.h>
  19 #include <command.h>
  20 #include <mpc5xx.h>
  21
  22 DECLARE_GLOBAL_DATA_PTR;
  23
  24 #if (defined(CONFIG_MPC555))
  25 #  define       ID_STR  "MPC555/556"
  26
  27 /*
  28  * Check version of cpu with Processor Version Register (PVR)
  29  */
  30 static int check_cpu_version (long clock, uint pvr, uint immr)
  31 {
  32     char buf[32];
  33         /* The highest 16 bits should be 0x0002 for a MPC555/556 */
  34         if ((pvr >> 16) == 0x0002) {
  35                 printf (" " ID_STR " Version %x", (pvr >> 16));
  36                 printf (" at %s MHz:", strmhz (buf, clock));
  37         } else {
  38                 printf ("Not supported cpu version");
  39                 return -1;
  40         }
  41         return 0;
  42 }
  43 #endif /* CONFIG_MPC555 */
  44
  45
  46 /*
  47  * Check version of mpc5xx
  48  */
  49 int checkcpu (void)
  50 {
  51         ulong clock = gd->cpu_clk;
  52         uint immr = get_immr (0);       /* Return full IMMR contents */
  53         uint pvr = get_pvr ();          /* Retrieve PVR register */
  54
  55         puts ("CPU:   ");
  56
  57         return check_cpu_version (clock, pvr, immr);
  58 }
  59
  60 /*
  61  * Called by macro WATCHDOG_RESET
  62  */
  63 #if defined(CONFIG_WATCHDOG)
  64 void watchdog_reset (void)
  65 {
  66         int re_enable = disable_interrupts ();
  67
  68         reset_5xx_watchdog ((immap_t *) CONFIG_SYS_IMMR);
  69         if (re_enable)
  70                 enable_interrupts ();
  71 }
  72
  73 /*
  74  * Will clear software reset
  75  */
  76 void reset_5xx_watchdog (volatile immap_t * immr)
  77 {
  78         /* Use the MPC5xx Internal Watchdog */
  79         immr->im_siu_conf.sc_swsr = 0x556c;     /* Prevent SW time-out */
  80         immr->im_siu_conf.sc_swsr = 0xaa39;
  81 }
  82
  83 #endif /* CONFIG_WATCHDOG */
  84
  85
  86 /*
  87  * Get timebase clock frequency
  88  */
  89 unsigned long get_tbclk (void)
  90 {
  91         volatile immap_t *immr = (volatile immap_t *) CONFIG_SYS_IMMR;
  92         ulong oscclk, factor;
  93
  94         if (immr->im_clkrst.car_sccr & SCCR_TBS) {
  95                 return (gd->cpu_clk / 16);
  96         }
  97
  98         factor = (((CONFIG_SYS_PLPRCR) & PLPRCR_MF_MSK) >> PLPRCR_MF_SHIFT) + 1;
  99
 100         oscclk = gd->cpu_clk / factor;
 101
 102         if ((immr->im_clkrst.car_sccr & SCCR_RTSEL) == 0 || factor > 2) {
 103                 return (oscclk / 4);
 104         }
 105         return (oscclk / 16);
 106 }
 107
 108 void dcache_enable (void)
 109 {
 110         return;
 111 }
 112
 113 void dcache_disable (void)
 114 {
 115         return;
 116 }
 117
 118 int dcache_status (void)
 119 {
 120         return 0;       /* always off */
 121 }
 122
 123 /*
 124  * Reset board
 125  */
 126 int do_reset (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
 127 {
 128 #if defined(CONFIG_PATI)
 129         volatile ulong *addr = (ulong *) CONFIG_SYS_RESET_ADDRESS;
 130         *addr = 1;
 131 #else
 132         ulong addr;
 133
 134         /* Interrupts off, enable reset */
 135         __asm__ volatile        ("  mtspr       81, %r0         \n\t"
 136                                  "  mfmsr       %r3             \n\t"
 137                                  "  rlwinm      %r31,%r3,0,25,23\n\t"
 138                                  "  mtmsr       %r31            \n\t");
 139         /*
 140          * Trying to execute the next instruction at a non-existing address
 141          * should cause a machine check, resulting in reset
 142          */
 143 #ifdef CONFIG_SYS_RESET_ADDRESS
 144         addr = CONFIG_SYS_RESET_ADDRESS;
 145 #else
 146         /*
 147          * note: when CONFIG_SYS_MONITOR_BASE points to a RAM address, CONFIG_SYS_MONITOR_BASE         * - sizeof (ulong) is usually a valid address. Better pick an address
 148          * known to be invalid on your system and assign it to CONFIG_SYS_RESET_ADDRESS.
 149          * "(ulong)-1" used to be a good choice for many systems...
 150          */
 151         addr = CONFIG_SYS_MONITOR_BASE - sizeof (ulong);
 152 #endif
 153         ((void (*) (void)) addr) ();
 154 #endif  /* #if defined(CONFIG_PATI) */
 155         return 1;
 156 }