src/southbridge/intel/i82371eb/wakeup.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  */
  16
  17 #include <stdint.h>
  18 #include <arch/acpi.h>
  19 #include <arch/io.h>
  20 #include <console/console.h>
  21 #include "i82371eb.h"
  22
  23 /*
  24  * Intel 82371EB (PIIX4E) datasheet, section 7.2.3, page 142
  25  *
  26  * 0: soft off/suspend to disk                                  S5
  27  * 1: suspend to ram                                            S3
  28  * 2: powered on suspend, context lost                          S2
  29  *    Note: 'context lost' means the CPU restarts at the reset
  30  *          vector
  31  * 3: powered on suspend, CPU context lost                      S1
  32  *    Note: Looks like 'CPU context lost' does _not_ mean the
  33  *          CPU restarts at the reset vector. Most likely only
  34  *          caches are lost, so both 0x3 and 0x4 map to acpi S1
  35  * 4: powered on suspend, context maintained                    S1
  36  * 5: working (clock control)                                   S0
  37  * 6: reserved
  38  * 7: reserved
  39  */
  40 static const u8 acpi_sus_to_slp_typ[8] = {
  41         5, 3, 2, 1, 1, 0, 0, 0
  42 };
  43
  44 int acpi_get_sleep_type(void)
  45 {
  46         u16 reg, result;
  47
  48         reg = inw(DEFAULT_PMBASE + PMCNTRL);
  49         result = acpi_sus_to_slp_typ[(reg >> 10) & 7];
  50
  51         printk(BIOS_DEBUG, "Wakeup from ACPI sleep type S%d (PMCNTRL=%04x)\n", result, reg);
  52
  53         return result;
  54 }