Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 1 | /* |
Uwe Hermann | c6a1062 | 2010-10-17 19:30:58 +0000 | [diff] [blame] | 2 | * This file is part of the coreboot project. |
| 3 | * |
| 4 | * Copyright (C) 2005 AMD |
| 5 | * Written by Yinghai Lu <yinghai.lu@amd.com> for AMD. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; version 2 of the License. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 15 | */ |
Uwe Hermann | c6a1062 | 2010-10-17 19:30:58 +0000 | [diff] [blame] | 16 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 17 | #include <device/smbus_def.h> |
| 18 | |
| 19 | #define SMBHSTSTAT 0x0 |
| 20 | #define SMBSLVSTAT 0x1 |
| 21 | #define SMBHSTCTRL 0x2 |
| 22 | #define SMBHSTCMD 0x3 |
| 23 | #define SMBHSTADDR 0x4 |
| 24 | #define SMBHSTDAT0 0x5 |
| 25 | #define SMBHSTDAT1 0x6 |
| 26 | #define SMBHSTBLKDAT 0x7 |
| 27 | |
| 28 | #define SMBSLVCTRL 0x8 |
| 29 | #define SMBSLVCMD_SHADOW 0x9 |
| 30 | #define SMBSLVEVT 0xa |
| 31 | #define SMBSLVDAT 0xc |
| 32 | |
| 33 | |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 34 | /* Between 1-10 seconds, We should never timeout normally |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 35 | * Longer than this is just painful when a timeout condition occurs. |
| 36 | */ |
| 37 | #define SMBUS_TIMEOUT (100*1000*10) |
| 38 | |
| 39 | static inline void smbus_delay(void) |
| 40 | { |
| 41 | outb(0x80, 0x80); |
| 42 | } |
| 43 | |
| 44 | static int smbus_wait_until_ready(unsigned smbus_io_base) |
| 45 | { |
| 46 | unsigned long loops; |
| 47 | loops = SMBUS_TIMEOUT; |
| 48 | do { |
| 49 | unsigned char val; |
| 50 | val = inb(smbus_io_base + SMBHSTSTAT); |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 51 | val &= 0x1f; |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 52 | if (val == 0) { // ready now |
| 53 | return 0; |
| 54 | } |
| 55 | outb(val, smbus_io_base + SMBHSTSTAT); |
| 56 | } while(--loops); |
| 57 | return -2; // time out |
| 58 | } |
| 59 | |
| 60 | static int smbus_wait_until_done(unsigned smbus_io_base) |
| 61 | { |
| 62 | unsigned long loops; |
| 63 | loops = SMBUS_TIMEOUT; |
| 64 | do { |
| 65 | unsigned char val; |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 66 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 67 | val = inb(smbus_io_base + SMBHSTSTAT); |
| 68 | val &= 0x1f; // mask off reserved bits |
| 69 | if ( val & 0x1c) { |
| 70 | return -5; // error |
| 71 | } |
| 72 | if ( val == 0x02) { |
| 73 | outb(val, smbus_io_base + SMBHSTSTAT); // clear status |
| 74 | return 0; // |
| 75 | } |
| 76 | } while(--loops); |
| 77 | return -3; // timeout |
| 78 | } |
| 79 | |
| 80 | static int do_smbus_recv_byte(unsigned smbus_io_base, unsigned device) |
| 81 | { |
| 82 | uint8_t byte; |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 83 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 84 | if (smbus_wait_until_ready(smbus_io_base) < 0) { |
| 85 | return -2; // not ready |
| 86 | } |
| 87 | |
| 88 | /* set the device I'm talking too */ |
| 89 | outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBHSTADDR); |
| 90 | |
| 91 | byte = inb(smbus_io_base + SMBHSTCTRL); |
| 92 | byte &= 0xe3; // Clear [4:2] |
| 93 | byte |= (1<<2) | (1<<6); // Byte data read/write command, start the command |
| 94 | outb(byte, smbus_io_base + SMBHSTCTRL); |
| 95 | |
| 96 | /* poll for transaction completion */ |
| 97 | if (smbus_wait_until_done(smbus_io_base) < 0) { |
| 98 | return -3; // timeout or error |
| 99 | } |
| 100 | |
| 101 | /* read results of transaction */ |
| 102 | byte = inb(smbus_io_base + SMBHSTCMD); |
| 103 | |
| 104 | return byte; |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 105 | } |
Uwe Hermann | c6a1062 | 2010-10-17 19:30:58 +0000 | [diff] [blame] | 106 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 107 | static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device, unsigned char val) |
| 108 | { |
| 109 | uint8_t byte; |
| 110 | |
| 111 | if (smbus_wait_until_ready(smbus_io_base) < 0) { |
| 112 | return -2; // not ready |
| 113 | } |
| 114 | |
| 115 | /* set the command... */ |
| 116 | outb(val, smbus_io_base + SMBHSTCMD); |
| 117 | |
| 118 | /* set the device I'm talking too */ |
| 119 | outb(((device & 0x7f) << 1)|0 , smbus_io_base + SMBHSTADDR); |
| 120 | |
| 121 | byte = inb(smbus_io_base + SMBHSTCTRL); |
| 122 | byte &= 0xe3; // Clear [4:2] |
| 123 | byte |= (1<<2) | (1<<6); // Byte data read/write command, start the command |
| 124 | outb(byte, smbus_io_base + SMBHSTCTRL); |
| 125 | |
| 126 | /* poll for transaction completion */ |
| 127 | if (smbus_wait_until_done(smbus_io_base) < 0) { |
| 128 | return -3; // timeout or error |
| 129 | } |
| 130 | |
| 131 | return 0; |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 132 | } |
| 133 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 134 | static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address) |
| 135 | { |
| 136 | uint8_t byte; |
| 137 | |
| 138 | if (smbus_wait_until_ready(smbus_io_base) < 0) { |
| 139 | return -2; // not ready |
| 140 | } |
Stefan Reinauer | 14e2277 | 2010-04-27 06:56:47 +0000 | [diff] [blame] | 141 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 142 | /* set the command/address... */ |
| 143 | outb(address & 0xff, smbus_io_base + SMBHSTCMD); |
| 144 | |
| 145 | /* set the device I'm talking too */ |
| 146 | outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBHSTADDR); |
| 147 | |
| 148 | byte = inb(smbus_io_base + SMBHSTCTRL); |
| 149 | byte &= 0xe3; // Clear [4:2] |
| 150 | byte |= (1<<3) | (1<<6); // Byte data read/write command, start the command |
| 151 | outb(byte, smbus_io_base + SMBHSTCTRL); |
| 152 | |
| 153 | /* poll for transaction completion */ |
| 154 | if (smbus_wait_until_done(smbus_io_base) < 0) { |
| 155 | return -3; // timeout or error |
| 156 | } |
| 157 | |
| 158 | /* read results of transaction */ |
| 159 | byte = inb(smbus_io_base + SMBHSTDAT0); |
| 160 | |
| 161 | return byte; |
| 162 | } |
Uwe Hermann | c6a1062 | 2010-10-17 19:30:58 +0000 | [diff] [blame] | 163 | |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 164 | static int do_smbus_write_byte(unsigned smbus_io_base, unsigned device, unsigned address, unsigned char val) |
| 165 | { |
| 166 | uint8_t byte; |
| 167 | |
| 168 | if (smbus_wait_until_ready(smbus_io_base) < 0) { |
| 169 | return -2; // not ready |
| 170 | } |
| 171 | |
| 172 | /* set the command/address... */ |
| 173 | outb(address & 0xff, smbus_io_base + SMBHSTCMD); |
| 174 | |
| 175 | /* set the device I'm talking too */ |
| 176 | outb(((device & 0x7f) << 1)|0 , smbus_io_base + SMBHSTADDR); |
| 177 | |
| 178 | /* output value */ |
| 179 | outb(val, smbus_io_base + SMBHSTDAT0); |
| 180 | |
| 181 | byte = inb(smbus_io_base + SMBHSTCTRL); |
| 182 | byte &= 0xe3; // Clear [4:2] |
| 183 | byte |= (1<<3) | (1<<6); // Byte data read/write command, start the command |
| 184 | outb(byte, smbus_io_base + SMBHSTCTRL); |
| 185 | |
| 186 | /* poll for transaction completion */ |
| 187 | if (smbus_wait_until_done(smbus_io_base) < 0) { |
| 188 | return -3; // timeout or error |
| 189 | } |
| 190 | |
| 191 | return 0; |
Yinghai Lu | afd34e6 | 2006-02-16 17:22:19 +0000 | [diff] [blame] | 192 | } |