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
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
|
/*
* QEMU SMBus device emulation.
*
* This code is a helper for SMBus device emulation. It implements an
* I2C device inteface and runs the SMBus protocol from the device
* point of view and maps those to simple calls to emulate.
*
* Copyright (c) 2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licensed under the LGPL.
*/
/* TODO: Implement PEC. */
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/i2c/i2c.h"
#include "hw/i2c/smbus_slave.h"
//#define DEBUG_SMBUS 1
#ifdef DEBUG_SMBUS
#define DPRINTF(fmt, ...) \
do { printf("smbus(%02x): " fmt , dev->i2c.address, ## __VA_ARGS__); } while (0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__); exit(1);} while (0)
#else
#define DPRINTF(fmt, ...) do {} while(0)
#define BADF(fmt, ...) \
do { fprintf(stderr, "smbus: error: " fmt , ## __VA_ARGS__);} while (0)
#endif
enum {
SMBUS_IDLE,
SMBUS_WRITE_DATA,
SMBUS_RECV_BYTE,
SMBUS_READ_DATA,
SMBUS_DONE,
SMBUS_CONFUSED = -1
};
static void smbus_do_quick_cmd(SMBusDevice *dev, int recv)
{
SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
DPRINTF("Quick Command %d\n", recv);
if (sc->quick_cmd) {
sc->quick_cmd(dev, recv);
}
}
static void smbus_do_write(SMBusDevice *dev)
{
SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
if (dev->data_len == 0) {
smbus_do_quick_cmd(dev, 0);
} else if (dev->data_len == 1) {
DPRINTF("Send Byte\n");
if (sc->send_byte) {
sc->send_byte(dev, dev->data_buf[0]);
}
} else {
dev->command = dev->data_buf[0];
DPRINTF("Command %d len %d\n", dev->command, dev->data_len - 1);
if (sc->write_data) {
sc->write_data(dev, dev->command, dev->data_buf + 1,
dev->data_len - 1);
}
}
}
static int smbus_i2c_event(I2CSlave *s, enum i2c_event event)
{
SMBusDevice *dev = SMBUS_DEVICE(s);
switch (event) {
case I2C_START_SEND:
switch (dev->mode) {
case SMBUS_IDLE:
DPRINTF("Incoming data\n");
dev->mode = SMBUS_WRITE_DATA;
break;
default:
BADF("Unexpected send start condition in state %d\n", dev->mode);
dev->mode = SMBUS_CONFUSED;
break;
}
break;
case I2C_START_RECV:
switch (dev->mode) {
case SMBUS_IDLE:
DPRINTF("Read mode\n");
dev->mode = SMBUS_RECV_BYTE;
break;
case SMBUS_WRITE_DATA:
if (dev->data_len == 0) {
BADF("Read after write with no data\n");
dev->mode = SMBUS_CONFUSED;
} else {
if (dev->data_len > 1) {
smbus_do_write(dev);
} else {
dev->command = dev->data_buf[0];
DPRINTF("%02x: Command %d\n", dev->i2c.address,
dev->command);
}
DPRINTF("Read mode\n");
dev->data_len = 0;
dev->mode = SMBUS_READ_DATA;
}
break;
default:
BADF("Unexpected recv start condition in state %d\n", dev->mode);
dev->mode = SMBUS_CONFUSED;
break;
}
break;
case I2C_FINISH:
switch (dev->mode) {
case SMBUS_WRITE_DATA:
smbus_do_write(dev);
break;
case SMBUS_RECV_BYTE:
smbus_do_quick_cmd(dev, 1);
break;
case SMBUS_READ_DATA:
BADF("Unexpected stop during receive\n");
break;
default:
/* Nothing to do. */
break;
}
dev->mode = SMBUS_IDLE;
dev->data_len = 0;
break;
case I2C_NACK:
switch (dev->mode) {
case SMBUS_DONE:
/* Nothing to do. */
break;
case SMBUS_READ_DATA:
dev->mode = SMBUS_DONE;
break;
default:
BADF("Unexpected NACK in state %d\n", dev->mode);
dev->mode = SMBUS_CONFUSED;
break;
}
}
return 0;
}
static int smbus_i2c_recv(I2CSlave *s)
{
SMBusDevice *dev = SMBUS_DEVICE(s);
SMBusDeviceClass *sc = SMBUS_DEVICE_GET_CLASS(dev);
int ret;
switch (dev->mode) {
case SMBUS_RECV_BYTE:
if (sc->receive_byte) {
ret = sc->receive_byte(dev);
} else {
ret = 0;
}
DPRINTF("Receive Byte %02x\n", ret);
dev->mode = SMBUS_DONE;
break;
case SMBUS_READ_DATA:
if (sc->read_data) {
ret = sc->read_data(dev, dev->command, dev->data_len);
dev->data_len++;
} else {
ret = 0;
}
DPRINTF("Read data %02x\n", ret);
break;
default:
BADF("Unexpected read in state %d\n", dev->mode);
dev->mode = SMBUS_CONFUSED;
ret = 0;
break;
}
return ret;
}
static int smbus_i2c_send(I2CSlave *s, uint8_t data)
{
SMBusDevice *dev = SMBUS_DEVICE(s);
switch (dev->mode) {
case SMBUS_WRITE_DATA:
DPRINTF("Write data %02x\n", data);
if (dev->data_len >= sizeof(dev->data_buf)) {
BADF("Too many bytes sent\n");
} else {
dev->data_buf[dev->data_len++] = data;
}
break;
default:
BADF("Unexpected write in state %d\n", dev->mode);
break;
}
return 0;
}
static void smbus_device_class_init(ObjectClass *klass, void *data)
{
I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass);
sc->event = smbus_i2c_event;
sc->recv = smbus_i2c_recv;
sc->send = smbus_i2c_send;
}
static const TypeInfo smbus_device_type_info = {
.name = TYPE_SMBUS_DEVICE,
.parent = TYPE_I2C_SLAVE,
.instance_size = sizeof(SMBusDevice),
.abstract = true,
.class_size = sizeof(SMBusDeviceClass),
.class_init = smbus_device_class_init,
};
static void smbus_device_register_types(void)
{
type_register_static(&smbus_device_type_info);
}
type_init(smbus_device_register_types)
|
