src/southbridge/intel/i82371eb/wakeup.c

   1 /* This file is part of the coreboot project. */
   2 /* SPDX-License-Identifier: GPL-2.0-or-later */
   3
   4 #include <stdint.h>
   5 #include <acpi/acpi.h>
   6 #include <arch/io.h>
   7 #include <console/console.h>
   8 #include "i82371eb.h"
   9
  10 /*
  11  * Intel 82371EB (PIIX4E) datasheet, section 7.2.3, page 142
  12  *
  13  * 0: soft off/suspend to disk                                  S5
  14  * 1: suspend to ram                                            S3
  15  * 2: powered on suspend, context lost                          S2
  16  *    Note: 'context lost' means the CPU restarts at the reset
  17  *          vector
  18  * 3: powered on suspend, CPU context lost                      S1
  19  *    Note: Looks like 'CPU context lost' does _not_ mean the
  20  *          CPU restarts at the reset vector. Most likely only
  21  *          caches are lost, so both 0x3 and 0x4 map to acpi S1
  22  * 4: powered on suspend, context maintained                    S1
  23  * 5: working (clock control)                                   S0
  24  * 6: reserved
  25  * 7: reserved
  26  */
  27 static const u8 acpi_sus_to_slp_typ[8] = {
  28         5, 3, 2, 1, 1, 0, 0, 0
  29 };
  30
  31 int acpi_get_sleep_type(void)
  32 {
  33         u16 reg, result;
  34
  35         reg = inw(DEFAULT_PMBASE + PMCNTRL);
  36         result = acpi_sus_to_slp_typ[(reg >> 10) & 7];
  37
  38         printk(BIOS_DEBUG, "Wakeup from ACPI sleep type S%d (PMCNTRL=%04x)\n", result, reg);
  39
  40         return result;
  41 }