1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2005 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; 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.
*/
#include <device/smbus_def.h>
#define SMBHSTSTAT 0x0
#define SMBSLVSTAT 0x1
#define SMBHSTCTRL 0x2
#define SMBHSTCMD 0x3
#define SMBHSTADDR 0x4
#define SMBHSTDAT0 0x5
#define SMBHSTDAT1 0x6
#define SMBHSTBLKDAT 0x7
#define SMBSLVCTRL 0x8
#define SMBSLVCMD_SHADOW 0x9
#define SMBSLVEVT 0xa
#define SMBSLVDAT 0xc
/* 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_ready(unsigned smbus_io_base)
{
unsigned long loops;
loops = SMBUS_TIMEOUT;
do {
unsigned char val;
val = inb(smbus_io_base + SMBHSTSTAT);
val &= 0x1f;
if (val == 0) { // ready now
return 0;
}
outb(val, smbus_io_base + SMBHSTSTAT);
} while (--loops);
return -2; // time out
}
static int smbus_wait_until_done(unsigned smbus_io_base)
{
unsigned long loops;
loops = SMBUS_TIMEOUT;
do {
unsigned char val;
val = inb(smbus_io_base + SMBHSTSTAT);
val &= 0x1f; // mask off reserved bits
if ( val & 0x1c) {
return -5; // error
}
if ( val == 0x02) {
outb(val, smbus_io_base + SMBHSTSTAT); // clear status
return 0; //
}
} while (--loops);
return -3; // timeout
}
static int do_smbus_recv_byte(unsigned smbus_io_base, unsigned device)
{
uint8_t byte;
if (smbus_wait_until_ready(smbus_io_base) < 0) {
return -2; // not ready
}
/* set the device I'm talking to */
outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBHSTADDR);
byte = inb(smbus_io_base + SMBHSTCTRL);
byte &= 0xe3; // Clear [4:2]
byte |= (1<<2) | (1<<6); // Byte data read/write command, start the command
outb(byte, smbus_io_base + SMBHSTCTRL);
/* poll for transaction completion */
if (smbus_wait_until_done(smbus_io_base) < 0) {
return -3; // timeout or error
}
/* read results of transaction */
byte = inb(smbus_io_base + SMBHSTCMD);
return byte;
}
static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device, unsigned char val)
{
uint8_t byte;
if (smbus_wait_until_ready(smbus_io_base) < 0) {
return -2; // not ready
}
/* set the command... */
outb(val, smbus_io_base + SMBHSTCMD);
/* set the device I'm talking to */
outb(((device & 0x7f) << 1)|0 , smbus_io_base + SMBHSTADDR);
byte = inb(smbus_io_base + SMBHSTCTRL);
byte &= 0xe3; // Clear [4:2]
byte |= (1<<2) | (1<<6); // Byte data read/write command, start the command
outb(byte, smbus_io_base + SMBHSTCTRL);
/* poll for transaction completion */
if (smbus_wait_until_done(smbus_io_base) < 0) {
return -3; // timeout or error
}
return 0;
}
static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address)
{
uint8_t byte;
if (smbus_wait_until_ready(smbus_io_base) < 0) {
return -2; // not ready
}
/* set the command/address... */
outb(address & 0xff, smbus_io_base + SMBHSTCMD);
/* set the device I'm talking to */
outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBHSTADDR);
byte = inb(smbus_io_base + SMBHSTCTRL);
byte &= 0xe3; // Clear [4:2]
byte |= (1<<3) | (1<<6); // Byte data read/write command, start the command
outb(byte, smbus_io_base + SMBHSTCTRL);
/* poll for transaction completion */
if (smbus_wait_until_done(smbus_io_base) < 0) {
return -3; // timeout or error
}
/* read results of transaction */
byte = inb(smbus_io_base + SMBHSTDAT0);
return byte;
}
static int do_smbus_write_byte(unsigned smbus_io_base, unsigned device, unsigned address, unsigned char val)
{
uint8_t byte;
if (smbus_wait_until_ready(smbus_io_base) < 0) {
return -2; // not ready
}
/* set the command/address... */
outb(address & 0xff, smbus_io_base + SMBHSTCMD);
/* set the device I'm talking to */
outb(((device & 0x7f) << 1)|0 , smbus_io_base + SMBHSTADDR);
/* output value */
outb(val, smbus_io_base + SMBHSTDAT0);
byte = inb(smbus_io_base + SMBHSTCTRL);
byte &= 0xe3; // Clear [4:2]
byte |= (1<<3) | (1<<6); // Byte data read/write command, start the command
outb(byte, smbus_io_base + SMBHSTCTRL);
/* poll for transaction completion */
if (smbus_wait_until_done(smbus_io_base) < 0) {
return -3; // timeout or error
}
return 0;
}
|
