src/southbridge/intel/i82371eb/wakeup.c

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