src/southbridge/intel/i82801xx/i82801xx_early_smbus.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright (C) 2005 Tyan Computer
 * (Written by Yinghai Lu <yinghailu@gmail.com> for Tyan Computer)
 * Copyright (C) 2007 Corey Osgood <corey.osgood@gmail.com>
 *
 * 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 <device/pci_ids.h>
#include "i82801xx.h"
#include "i82801xx_smbus.h"

static void enable_smbus(void)
{
	device_t dev;
	uint16_t device_id;

	/* Set the SMBus device statically. */
	dev = PCI_DEV(0x0, 0x1f, 0x3);

	/* Check to make sure we've got the right device. */
	device_id = pci_read_config16(dev, 0x2);

	/* Clear bits 7-4 (the only bits that vary between models). */
	device_id &= 0xff0f;

	if (device_id != 0x2403) {
		die("Device not found, Corey probably screwed up!");
	}

	/* Set SMBus I/O base. */
	pci_write_config32(dev, SMB_BASE,
			   SMBUS_IO_BASE | PCI_BASE_ADDRESS_SPACE_IO);

	/* Set SMBus enable. */
	pci_write_config8(dev, HOSTC, HST_EN);

	/* Set SMBus I/O space enable. */
	pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_IO);

	/* Disable interrupt generation. */
	outb(0, SMBUS_IO_BASE + SMBHSTCTL);

	/* Clear any lingering errors, so transactions can run. */
	outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);

	print_debug("SMBus controller enabled\r\n");
}

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

static void smbus_write_byte(unsigned device, unsigned address,
			     unsigned char val)
{
	print_err("Unimplemented smbus_write_byte() called\r\n");
	return;
}

static inline int smbus_write_block(unsigned device, unsigned length,
				    unsigned cmd, unsigned data1,
				    unsigned data2)
{
	return do_smbus_write_block(device, length, cmd, data1, data2);
}