2 * This file is part of the coreboot project.
4 * Copyright (C) 2005 Tyan Computer
5 * (Written by Yinghai Lu <yinghailu@gmail.com> for Tyan Computer)
6 * Copyright (C) 2007 Corey Osgood <corey.osgood@gmail.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 #include <device/pci_ids.h>
25 #include "i82801bx_smbus.h"
27 static void enable_smbus(void)
32 /* Set the SMBus device statically. */
33 dev = PCI_DEV(0x0, 0x1f, 0x3);
35 /* Check to make sure we've got the right device. */
36 device_id = pci_read_config16(dev, 0x2);
38 /* Clear bits 7-4 (the only bits that vary between models). */
41 if (device_id != 0x2403) {
42 die("Device not found, Corey probably screwed up!");
45 /* Set SMBus I/O base. */
46 pci_write_config32(dev, SMB_BASE,
47 SMBUS_IO_BASE | PCI_BASE_ADDRESS_SPACE_IO);
49 /* Set SMBus enable. */
50 pci_write_config8(dev, HOSTC, HST_EN);
52 /* Set SMBus I/O space enable. */
53 pci_write_config16(dev, PCI_COMMAND, PCI_COMMAND_IO);
55 /* Disable interrupt generation. */
56 outb(0, SMBUS_IO_BASE + SMBHSTCTL);
58 /* Clear any lingering errors, so transactions can run. */
59 outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
61 print_debug("SMBus controller enabled\n");
64 static inline int smbus_read_byte(unsigned device, unsigned address)
66 return do_smbus_read_byte(device, address);