src/southbridge/intel/i82371eb/wakeup.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <stdint.h>
#include <arch/io.h>
#include <console/console.h>
#include "i82371eb.h"

int acpi_get_sleep_type(void);

/*
 * Intel 82371EB (PIIX4E) datasheet, section 7.2.3, page 142
 *
 * 0: soft off/suspend to disk					S5
 * 1: suspend to ram						S3
 * 2: powered on suspend, context lost				S2
 *    Note: 'context lost' means the CPU restarts at the reset
 *          vector
 * 3: powered on suspend, CPU context lost			S1
 *    Note: Looks like 'CPU context lost' does _not_ mean the
 *          CPU restarts at the reset vector. Most likely only
 *          caches are lost, so both 0x3 and 0x4 map to acpi S1
 * 4: powered on suspend, context maintained			S1
 * 5: working (clock control)					S0
 * 6: reserved
 * 7: reserved
 */
static const u8 acpi_sus_to_slp_typ[8] = {
	5, 3, 2, 1, 1, 0, 0, 0
};

int acpi_get_sleep_type(void)
{
	u16 reg, result;

	reg = inw(DEFAULT_PMBASE + PMCNTRL);
	result = acpi_sus_to_slp_typ[(reg >> 10) & 7];

	printk(BIOS_DEBUG, "Wakeup from ACPI sleep type S%d (PMCNTRL=%04x)\n", result, reg);

	return result;
}