cpu/ixp/cpu.c

   1 /*
   2  * (C) Copyright 2002
   3  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   4  * Marius Groeger <mgroeger@sysgo.de>
   5  *
   6  * (C) Copyright 2002
   7  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
   8  * Alex Zuepke <azu@sysgo.de>
   9  *
  10  * See file CREDITS for list of people who contributed to this
  11  * project.
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License as
  15  * published by the Free Software Foundation; either version 2 of
  16  * the License, or (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program; if not, write to the Free Software
  25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  26  * MA 02111-1307 USA
  27  */
  28
  29 /*
  30  * CPU specific code
  31  */
  32
  33 #include <common.h>
  34 #include <command.h>
  35 #include <asm/arch/ixp425.h>
  36
  37 #ifdef CONFIG_USE_IRQ
  38 DECLARE_GLOBAL_DATA_PTR;
  39 #endif
  40
  41 int cpu_init (void)
  42 {
  43         /*
  44          * setup up stacks if necessary
  45          */
  46 #ifdef CONFIG_USE_IRQ
  47         IRQ_STACK_START = _armboot_start - CFG_MALLOC_LEN - CFG_GBL_DATA_SIZE - 4;
  48         FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
  49 #endif
  50
  51         pci_init();
  52         return 0;
  53 }
  54
  55 int cleanup_before_linux (void)
  56 {
  57         /*
  58          * this function is called just before we call linux
  59          * it prepares the processor for linux
  60          *
  61          * just disable everything that can disturb booting linux
  62          */
  63
  64         unsigned long i;
  65
  66         disable_interrupts ();
  67
  68         /* turn off I-cache */
  69         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
  70         i &= ~0x1000;
  71         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
  72
  73         /* flush I-cache */
  74         asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i));
  75
  76         return (0);
  77 }
  78
  79 int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
  80 {
  81         printf ("resetting ...\n");
  82
  83         udelay (50000);                         /* wait 50 ms */
  84         disable_interrupts ();
  85         reset_cpu (0);
  86
  87         /*NOTREACHED*/
  88         return (0);
  89 }
  90
  91 /* taken from blob */
  92 void icache_enable (void)
  93 {
  94         register u32 i;
  95
  96         /* read control register */
  97         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
  98
  99         /* set i-cache */
 100         i |= 0x1000;
 101
 102         /* write back to control register */
 103         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
 104 }
 105
 106 void icache_disable (void)
 107 {
 108         register u32 i;
 109
 110         /* read control register */
 111         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
 112
 113         /* clear i-cache */
 114         i &= ~0x1000;
 115
 116         /* write back to control register */
 117         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
 118
 119         /* flush i-cache */
 120         asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i));
 121 }
 122
 123 int icache_status (void)
 124 {
 125         register u32 i;
 126
 127         /* read control register */
 128         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
 129
 130         /* return bit */
 131         return (i & 0x1000);
 132 }
 133
 134 /* we will never enable dcache, because we have to setup MMU first */
 135 void dcache_enable (void)
 136 {
 137         return;
 138 }
 139
 140 void dcache_disable (void)
 141 {
 142         return;
 143 }
 144
 145 int dcache_status (void)
 146 {
 147         return 0;                                       /* always off */
 148 }
 149
 150 /* FIXME */
 151 /*
 152 void pci_init(void)
 153 {
 154         return;
 155 }
 156 */