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
|
/*
* This file is part of the coreboot project.
*
* Copyright (C) 2005 Yinghai Lu <yinghailu@gmail.com>
* Copyright (C) 2009 coresystems GmbH
*
* 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>
#include "i82801ix.h"
static void smbus_delay(void)
{
inb(0x80);
}
static int smbus_wait_until_ready(u16 smbus_base)
{
unsigned loops = SMBUS_TIMEOUT;
unsigned char byte;
do {
smbus_delay();
if (--loops == 0)
break;
byte = inb(smbus_base + SMBHSTSTAT);
} while (byte & 1);
return loops ? 0 : -1;
}
static int smbus_wait_until_done(u16 smbus_base)
{
unsigned loops = SMBUS_TIMEOUT;
unsigned char byte;
do {
smbus_delay();
if (--loops == 0)
break;
byte = inb(smbus_base + SMBHSTSTAT);
} while ((byte & 1) || (byte & ~((1 << 6) | (1 << 0))) == 0);
return loops ? 0 : -1;
}
static int do_smbus_read_byte(unsigned smbus_base, unsigned device, unsigned address)
{
unsigned char global_status_register;
unsigned char byte;
if (smbus_wait_until_ready(smbus_base) < 0) {
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
}
/* Setup transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & (~1), smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(address & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a byte data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | (0x2 << 2),
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Clear the data byte... */
outb(0, smbus_base + SMBHSTDAT0);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | 0x40),
smbus_base + SMBHSTCTL);
/* Poll for transaction completion */
if (smbus_wait_until_done(smbus_base) < 0) {
return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
}
global_status_register = inb(smbus_base + SMBHSTSTAT);
/* Ignore the "In Use" status... */
global_status_register &= ~(3 << 5);
/* Read results of transaction */
byte = inb(smbus_base + SMBHSTDAT0);
if (global_status_register != (1 << 1)) {
return SMBUS_ERROR;
}
return byte;
}
#ifndef __PRE_RAM__
static int do_smbus_write_byte(unsigned smbus_base, unsigned device, unsigned address, unsigned data)
{
unsigned char global_status_register;
if (smbus_wait_until_ready(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
/* Setup transaction */
/* Disable interrupts */
outb(inb(smbus_base + SMBHSTCTL) & (~1), smbus_base + SMBHSTCTL);
/* Set the device I'm talking too */
outb(((device & 0x7f) << 1) & ~0x01, smbus_base + SMBXMITADD);
/* Set the command/address... */
outb(address & 0xff, smbus_base + SMBHSTCMD);
/* Set up for a byte data read */
outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | (0x2 << 2),
(smbus_base + SMBHSTCTL));
/* Clear any lingering errors, so the transaction will run */
outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
/* Clear the data byte... */
outb(data, smbus_base + SMBHSTDAT0);
/* Start the command */
outb((inb(smbus_base + SMBHSTCTL) | 0x40),
smbus_base + SMBHSTCTL);
/* Poll for transaction completion */
if (smbus_wait_until_done(smbus_base) < 0)
return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
global_status_register = inb(smbus_base + SMBHSTSTAT);
/* Ignore the "In Use" status... */
global_status_register &= ~(3 << 5);
/* Read results of transaction */
if (global_status_register != (1 << 1))
return SMBUS_ERROR;
return 0;
}
#endif
|
