cpu/sa1100/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
  36 #ifdef CONFIG_USE_IRQ
  37 DECLARE_GLOBAL_DATA_PTR;
  38 #endif
  39
  40 int cpu_init (void)
  41 {
  42         /*
  43          * setup up stacks if necessary
  44          */
  45 #ifdef CONFIG_USE_IRQ
  46         IRQ_STACK_START = _armboot_start - CONFIG_SYS_MALLOC_LEN - CONFIG_SYS_GBL_DATA_SIZE - 4;
  47         FIQ_STACK_START = IRQ_STACK_START - CONFIG_STACKSIZE_IRQ;
  48 #endif
  49         return 0;
  50 }
  51
  52 int cleanup_before_linux (void)
  53 {
  54         /*
  55          * this function is called just before we call linux
  56          * it prepares the processor for linux
  57          *
  58          * just disable everything that can disturb booting linux
  59          */
  60
  61         unsigned long i;
  62
  63         disable_interrupts ();
  64
  65         /* turn off I-cache */
  66         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
  67         i &= ~0x1000;
  68         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
  69
  70         /* flush I-cache */
  71         asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i));
  72
  73         return (0);
  74 }
  75
  76 int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
  77 {
  78         printf ("resetting ...\n");
  79
  80         udelay (50000);                         /* wait 50 ms */
  81         disable_interrupts ();
  82         reset_cpu (0);
  83
  84         /*NOTREACHED*/
  85         return (0);
  86 }
  87
  88 /* taken from blob */
  89 void icache_enable (void)
  90 {
  91         register u32 i;
  92
  93         /* read control register */
  94         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
  95
  96         /* set i-cache */
  97         i |= 0x1000;
  98
  99         /* write back to control register */
 100         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
 101 }
 102
 103 void icache_disable (void)
 104 {
 105         register u32 i;
 106
 107         /* read control register */
 108         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
 109
 110         /* clear i-cache */
 111         i &= ~0x1000;
 112
 113         /* write back to control register */
 114         asm ("mcr p15, 0, %0, c1, c0, 0": :"r" (i));
 115
 116         /* flush i-cache */
 117         asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i));
 118 }
 119
 120 int icache_status (void)
 121 {
 122         register u32 i;
 123
 124         /* read control register */
 125         asm ("mrc p15, 0, %0, c1, c0, 0":"=r" (i));
 126
 127         /* return bit */
 128         return (i & 0x1000);
 129 }
 130
 131 /* we will never enable dcache, because we have to setup MMU first */
 132 void dcache_enable (void)
 133 {
 134         return;
 135 }
 136
 137 void dcache_disable (void)
 138 {
 139         return;
 140 }
 141
 142 int dcache_status (void)
 143 {
 144         return 0;                                       /* always off */
 145 }