src/southbridge/intel/i82801gx/early_lpc.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2008-2009 coresystems GmbH
 *
 * 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; version 2 of
 * the License.
 *
 * 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.
 */

#include <arch/io.h>
#include <console/console.h>
#include <arch/acpi.h>
#include "i82801gx.h"

int southbridge_detect_s3_resume(void)
{
	u32 reg32;

	/* Read PM1_CNT */
	reg32 = inl(DEFAULT_PMBASE + 0x04);
	printk(BIOS_DEBUG, "PM1_CNT: %08x\n", reg32);
	if (((reg32 >> 10) & 7) == 5) {
		if (!acpi_s3_resume_allowed()) {
			printk(BIOS_DEBUG, "Resume from S3 detected, but disabled.\n");
		} else {
			printk(BIOS_DEBUG, "Resume from S3 detected.\n");
			/* Clear SLP_TYPE. This will break stage2 but
			 * we care for that when we get there.
			 */
			outl(reg32 & ~(7 << 10), DEFAULT_PMBASE + 0x04);
			return 1;
		}
	}

	return 0;
}