LXR linux/arch/arm/mach-s3c24xx/sleep.S

   1/* linux/arch/arm/plat-s3c24xx/sleep.S
   2 *
   3 * Copyright (c) 2004 Simtec Electronics
   4 *      Ben Dooks <ben@simtec.co.uk>
   5 *
   6 * S3C2410 Power Manager (Suspend-To-RAM) support
   7 *
   8 * Based on PXA/SA1100 sleep code by:
   9 *      Nicolas Pitre, (c) 2002 Monta Vista Software Inc
  10 *      Cliff Brake, (c) 2001
  11 *
  12 * This program is free software; you can redistribute it and/or modify
  13 * it under the terms of the GNU General Public License as published by
  14 * the Free Software Foundation; either version 2 of the License, or
  15 * (at your option) any later version.
  16 *
  17 * This program is distributed in the hope that it will be useful,
  18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 * GNU General Public License for more details.
  21 *
  22 * You should have received a copy of the GNU General Public License
  23 * along with this program; if not, write to the Free Software
  24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25*/
  26
  27#include <linux/linkage.h>
  28#include <linux/serial_s3c.h>
  29#include <asm/assembler.h>
  30#include <mach/hardware.h>
  31#include <mach/map.h>
  32
  33#include <mach/regs-gpio.h>
  34#include <mach/regs-clock.h>
  35
  36/* CONFIG_DEBUG_RESUME is dangerous if your bootloader does not
  37 * reset the UART configuration, only enable if you really need this!
  38*/
  39//#define CONFIG_DEBUG_RESUME
  40
  41        .text
  42
  43        /* sleep magic, to allow the bootloader to check for an valid
  44         * image to resume to. Must be the first word before the
  45         * s3c_cpu_resume entry.
  46        */
  47
  48        .word   0x2bedf00d
  49
  50        /* s3c_cpu_resume
  51         *
  52         * resume code entry for bootloader to call
  53        */
  54
  55ENTRY(s3c_cpu_resume)
  56        mov     r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE
  57        msr     cpsr_c, r0
  58
  59        @@ load UART to allow us to print the two characters for
  60        @@ resume debug
  61
  62        mov     r2, #S3C24XX_PA_UART & 0xff000000
  63        orr     r2, r2, #S3C24XX_PA_UART & 0xff000
  64
  65#if 0
  66        /* SMDK2440 LED set */
  67        mov     r14, #S3C24XX_PA_GPIO
  68        ldr     r12, [ r14, #0x54 ]
  69        bic     r12, r12, #3<<4
  70        orr     r12, r12, #1<<7
  71        str     r12, [ r14, #0x54 ]
  72#endif
  73
  74#ifdef CONFIG_DEBUG_RESUME
  75        mov     r3, #'L'
  76        strb    r3, [ r2, #S3C2410_UTXH ]
  771001:
  78        ldrb    r14, [ r3, #S3C2410_UTRSTAT ]
  79        tst     r14, #S3C2410_UTRSTAT_TXE
  80        beq     1001b
  81#endif /* CONFIG_DEBUG_RESUME */
  82
  83        b       cpu_resume
  84