| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2004 Tyan Computer |
| * Written by Yinghai Lu <yhlu@tyan.com> for Tyan Computer. |
| * Copyright (C) 2006,2007 AMD |
| * Written by Yinghai Lu <yinghai.lu@amd.com> for AMD. |
| * |
| * 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. |
| */ |
| |
| #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); |
| } |
| |
| 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; |
| } |
| static int do_smbus_recv_byte(unsigned smbus_io_base, unsigned device) |
| { |
| unsigned char global_status_register; |
| unsigned char byte; |
| |
| /* set the device I'm talking too */ |
| outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBXMITADD); |
| 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; |
| } |
| |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ |
| |
| /* read results of transaction */ |
| byte = inb(smbus_io_base + SMBHSTCMD); |
| |
| if (global_status_register != 0x80) { // lose check, otherwise it should be 0 |
| return -1; |
| } |
| return byte; |
| } |
| static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device, unsigned char val) |
| { |
| unsigned global_status_register; |
| |
| outb(val, smbus_io_base + SMBHSTDAT0); |
| smbus_delay(); |
| |
| /* set the command... */ |
| outb(val, smbus_io_base + SMBHSTCMD); |
| smbus_delay(); |
| |
| /* set the device I'm talking too */ |
| outb(((device & 0x7f) << 1) | 0, smbus_io_base + SMBXMITADD); |
| 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; |
| } |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ |
| |
| if (global_status_register != 0x80) { |
| return -1; |
| } |
| return 0; |
| } |
| static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address) |
| { |
| unsigned char global_status_register; |
| unsigned char byte; |
| |
| /* set the device I'm talking too */ |
| 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; |
| } |
| |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ |
| |
| /* read results of transaction */ |
| byte = inb(smbus_io_base + SMBHSTDAT0); |
| |
| if (global_status_register != 0x80) { // lose check, otherwise it should be 0 |
| 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; |
| |
| outb(val, smbus_io_base + SMBHSTDAT0); |
| smbus_delay(); |
| |
| /* set the device I'm talking too */ |
| 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; |
| } |
| global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ |
| |
| if (global_status_register != 0x80) { |
| return -1; |
| } |
| return 0; |
| } |