| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2004 Tyan Computer |
| * Written by Yinghai Lu <yhlu@tyan.com> for Tyan Computer. |
| * |
| * 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. |
| * |
| * 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/smbus_def.h> |
| |
| #define SMBHSTSTAT 0x1 |
| #define SMBHSTPRTCL 0x0 |
| #define SMBHSTCMD 0x3 |
| #define SMBXMITADD 0x2 |
| #define SMBHSTDAT0 0x4 |
| #define SMBHSTDAT1 0x5 |
| |
| /* |
| * Between 1-10 seconds, We should never timeout normally. |
| * Longer than this is just painful when a timeout condition occurs. |
| */ |
| #define SMBUS_TIMEOUT (100 * 1000 * 10) |
| |
| static inline void smbus_delay(void) |
| { |
| outb(0x80, 0x80); |
| } |
| |
| #if 0 |
| /* Not needed, upon write to PRTCL, the status will be auto-cleared. */ |
| static int smbus_wait_until_ready(unsigned smbus_io_base) |
| { |
| unsigned long loops; |
| loops = SMBUS_TIMEOUT; |
| do { |
| unsigned char val; |
| smbus_delay(); |
| val = inb(smbus_io_base + SMBHSTSTAT); |
| val &= 0x1f; |
| if (val == 0) |
| return 0; |
| outb(val, smbus_io_base + SMBHSTSTAT); |
| } while (--loops); |
| return -2; |
| } |
| #endif |
| |
| static int smbus_wait_until_done(unsigned smbus_io_base) |
| { |
| unsigned long loops; |
| loops = SMBUS_TIMEOUT; |
| do { |
| unsigned char val; |
| smbus_delay(); |
| val = inb(smbus_io_base + SMBHSTSTAT); |
| if ((val & 0xff) != 0) |
| return 0; |
| } while (--loops); |
| return -3; |
| } |
| |
| #ifndef __PRE_RAM__ |
| static int do_smbus_recv_byte(unsigned smbus_io_base, unsigned device) |
| { |
| unsigned char global_status_register, byte; |
| |
| #if 0 |
| /* Not needed, upon write to PRTCL, the status will be auto-cleared. */ |
| if (smbus_wait_until_ready(smbus_io_base) < 0) |
| return -2; |
| #endif |
| |
| /* Set the device I'm talking to. */ |
| outb(((device & 0x7f) << 1) | 1, smbus_io_base + SMBXMITADD); |
| smbus_delay(); |
| |
| /* Set the command/address. */ |
| outb(0, smbus_io_base + SMBHSTCMD); |
| smbus_delay(); |
| |
| /* Byte data recv. */ |
| outb(0x05, smbus_io_base + SMBHSTPRTCL); |
| smbus_delay(); |
| |
| /* Poll for transaction completion. */ |
| if (smbus_wait_until_done(smbus_io_base) < 0) |
| return -3; |
| |
| /* Lose check. */ |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; |
| |
| /* Read results of transaction. */ |
| byte = inb(smbus_io_base + SMBHSTDAT0); |
| |
| /* Lose check, otherwise it should be 0. */ |
| if (global_status_register != 0x80) |
| return -1; |
| |
| return byte; |
| } |
| |
| static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device, |
| unsigned char val) |
| { |
| unsigned global_status_register; |
| |
| #if 0 |
| /* Not needed, upon write to PRTCL, the status will be auto-cleared. */ |
| if (smbus_wait_until_ready(smbus_io_base) < 0) |
| return -2; |
| #endif |
| |
| outb(val, smbus_io_base + SMBHSTDAT0); |
| smbus_delay(); |
| |
| /* Set the device I'm talking to. */ |
| outb(((device & 0x7f) << 1) | 0, smbus_io_base + SMBXMITADD); |
| smbus_delay(); |
| |
| outb(0, smbus_io_base + SMBHSTCMD); |
| smbus_delay(); |
| |
| /* Set up for a byte data write. */ |
| outb(0x04, smbus_io_base + SMBHSTPRTCL); |
| smbus_delay(); |
| |
| /* Poll for transaction completion. */ |
| if (smbus_wait_until_done(smbus_io_base) < 0) |
| return -3; |
| |
| /* Lose check. */ |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; |
| |
| if (global_status_register != 0x80) |
| return -1; |
| |
| return 0; |
| } |
| #endif |
| |
| static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, |
| unsigned address) |
| { |
| unsigned char global_status_register, byte; |
| |
| #if 0 |
| /* Not needed, upon write to PRTCL, the status will be auto-cleared. */ |
| if (smbus_wait_until_ready(smbus_io_base) < 0) |
| return -2; |
| #endif |
| |
| /* Set the device I'm talking to. */ |
| outb(((device & 0x7f) << 1) | 1, smbus_io_base + SMBXMITADD); |
| smbus_delay(); |
| |
| /* Set the command/address. */ |
| outb(address & 0xff, smbus_io_base + SMBHSTCMD); |
| smbus_delay(); |
| |
| /* Byte data read. */ |
| outb(0x07, smbus_io_base + SMBHSTPRTCL); |
| smbus_delay(); |
| |
| /* Poll for transaction completion. */ |
| if (smbus_wait_until_done(smbus_io_base) < 0) |
| return -3; |
| |
| /* Lose check. */ |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; |
| |
| /* Read results of transaction. */ |
| byte = inb(smbus_io_base + SMBHSTDAT0); |
| |
| /* Lose check, otherwise it should be 0. */ |
| if (global_status_register != 0x80) |
| return -1; |
| |
| return byte; |
| } |
| |
| static int do_smbus_write_byte(unsigned smbus_io_base, unsigned device, |
| unsigned address, unsigned char val) |
| { |
| unsigned global_status_register; |
| |
| #if 0 |
| /* Not needed, upon write to PRTCL, the status will be auto-cleared. */ |
| if (smbus_wait_until_ready(smbus_io_base) < 0) |
| return -2; |
| #endif |
| |
| outb(val, smbus_io_base + SMBHSTDAT0); |
| smbus_delay(); |
| |
| /* Set the device I'm talking to. */ |
| outb(((device & 0x7f) << 1) | 0, smbus_io_base + SMBXMITADD); |
| smbus_delay(); |
| |
| outb(address & 0xff, smbus_io_base + SMBHSTCMD); |
| smbus_delay(); |
| |
| /* Set up for a byte data write. */ |
| outb(0x06, smbus_io_base + SMBHSTPRTCL); |
| smbus_delay(); |
| |
| /* Poll for transaction completion. */ |
| if (smbus_wait_until_done(smbus_io_base) < 0) |
| return -3; |
| |
| /* Lose check. */ |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; |
| |
| if (global_status_register != 0x80) |
| return -1; |
| |
| return 0; |
| } |