| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2013 Alexandru Gagniuc <mr.nuke.me@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, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include "via_early_smbus.h" |
| |
| /** |
| * \brief Read a byte from the SMBus. |
| * |
| * @param smbus_dev The base SMBus IO port |
| * @param addr The address location of the DIMM on the SMBus. |
| * @param offset The offset the data is located at. |
| */ |
| u8 smbus_read_byte(u32 smbus_dev, u8 addr, u8 offset) |
| { |
| u8 val; |
| |
| /* Initialize SMBus sequence */ |
| smbus_reset(smbus_dev); |
| /* Clear host data port. */ |
| outb(0x00, SMBHSTDAT0(smbus_dev)); |
| |
| smbus_wait_until_ready(smbus_dev); |
| |
| /* Actual addr to reg format. */ |
| addr = (addr << 1); |
| addr |= 1; /* read command */ |
| outb(addr, SMBXMITADD(smbus_dev)); |
| outb(offset, SMBHSTCMD(smbus_dev)); |
| /* Start transaction, byte data read. */ |
| outb(0x48, SMBHSTCTL(smbus_dev)); |
| smbus_wait_until_ready(smbus_dev); |
| |
| val = inb(SMBHSTDAT0(smbus_dev)); |
| return val; |
| } |