src/southbridge/intel/i82801dx/early_smbus.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2004 Ronald G. Minnich
 *
 * 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 <device/pci_def.h>
#include <console/console.h>
#include <southbridge/intel/common/smbus.h>

#include "i82801dx.h"

void enable_smbus(void)
{
	pci_devfn_t dev = PCI_DEV(0x0, 0x1f, 0x3);

	printk(BIOS_DEBUG, "SMBus controller enabled\n");
	/* set smbus iobase */
	pci_write_config32(dev, 0x20, SMBUS_IO_BASE | 1);
	/* Set smbus enable */
	pci_write_config8(dev, 0x40, 0x01);
	/* Set smbus iospace enable */
	pci_write_config16(dev, 0x4, 0x01);
	/* Disable interrupt generation */
	outb(0, SMBUS_IO_BASE + SMBHSTCTL);
	/* clear any lingering errors, so the transaction will run */
	outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
}

int smbus_read_byte(unsigned int device, unsigned int address)
{
	return do_smbus_read_byte(SMBUS_IO_BASE, device, address);
}