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
|
/*
* QEMU I2C bus interface.
*
* Copyright (c) 2007 CodeSourcery.
* Written by Paul Brook
*
* This code is licenced under the LGPL.
*/
#include "i2c.h"
struct i2c_bus
{
BusState qbus;
i2c_slave *current_dev;
i2c_slave *dev;
uint8_t saved_address;
};
static struct BusInfo i2c_bus_info = {
.name = "I2C",
.size = sizeof(i2c_bus),
.props = (Property[]) {
DEFINE_PROP_UINT8("address", struct i2c_slave, address, 0),
DEFINE_PROP_END_OF_LIST(),
}
};
static void i2c_bus_pre_save(void *opaque)
{
i2c_bus *bus = opaque;
bus->saved_address = bus->current_dev ? bus->current_dev->address : -1;
}
static int i2c_bus_post_load(void *opaque, int version_id)
{
i2c_bus *bus = opaque;
/* The bus is loaded before attached devices, so load and save the
current device id. Devices will check themselves as loaded. */
bus->current_dev = NULL;
return 0;
}
static const VMStateDescription vmstate_i2c_bus = {
.name = "i2c_bus",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.pre_save = i2c_bus_pre_save,
.post_load = i2c_bus_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT8(saved_address, i2c_bus),
VMSTATE_END_OF_LIST()
}
};
/* Create a new I2C bus. */
i2c_bus *i2c_init_bus(DeviceState *parent, const char *name)
{
i2c_bus *bus;
bus = FROM_QBUS(i2c_bus, qbus_create(&i2c_bus_info, parent, name));
vmstate_register(-1, &vmstate_i2c_bus, bus);
return bus;
}
void i2c_set_slave_address(i2c_slave *dev, uint8_t address)
{
dev->address = address;
}
/* Return nonzero if bus is busy. */
int i2c_bus_busy(i2c_bus *bus)
{
return bus->current_dev != NULL;
}
/* Returns non-zero if the address is not valid. */
/* TODO: Make this handle multiple masters. */
int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv)
{
DeviceState *qdev;
i2c_slave *slave = NULL;
QLIST_FOREACH(qdev, &bus->qbus.children, sibling) {
i2c_slave *candidate = I2C_SLAVE_FROM_QDEV(qdev);
if (candidate->address == address) {
slave = candidate;
break;
}
}
if (!slave)
return 1;
/* If the bus is already busy, assume this is a repeated
start condition. */
bus->current_dev = slave;
slave->info->event(slave, recv ? I2C_START_RECV : I2C_START_SEND);
return 0;
}
void i2c_end_transfer(i2c_bus *bus)
{
i2c_slave *dev = bus->current_dev;
if (!dev)
return;
dev->info->event(dev, I2C_FINISH);
bus->current_dev = NULL;
}
int i2c_send(i2c_bus *bus, uint8_t data)
{
i2c_slave *dev = bus->current_dev;
if (!dev)
return -1;
return dev->info->send(dev, data);
}
int i2c_recv(i2c_bus *bus)
{
i2c_slave *dev = bus->current_dev;
if (!dev)
return -1;
return dev->info->recv(dev);
}
void i2c_nack(i2c_bus *bus)
{
i2c_slave *dev = bus->current_dev;
if (!dev)
return;
dev->info->event(dev, I2C_NACK);
}
static int i2c_slave_post_load(void *opaque, int version_id)
{
i2c_slave *dev = opaque;
i2c_bus *bus;
bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev));
if (bus->saved_address == dev->address) {
bus->current_dev = dev;
}
return 0;
}
const VMStateDescription vmstate_i2c_slave = {
.name = "i2c_slave",
.version_id = 1,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.post_load = i2c_slave_post_load,
.fields = (VMStateField []) {
VMSTATE_UINT8(address, i2c_slave),
VMSTATE_END_OF_LIST()
}
};
static int i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base)
{
I2CSlaveInfo *info = container_of(base, I2CSlaveInfo, qdev);
i2c_slave *s = I2C_SLAVE_FROM_QDEV(dev);
s->info = info;
return info->init(s);
}
void i2c_register_slave(I2CSlaveInfo *info)
{
assert(info->qdev.size >= sizeof(i2c_slave));
info->qdev.init = i2c_slave_qdev_init;
info->qdev.bus_info = &i2c_bus_info;
qdev_register(&info->qdev);
}
DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr)
{
DeviceState *dev;
dev = qdev_create(&bus->qbus, name);
qdev_prop_set_uint8(dev, "address", addr);
qdev_init_nofail(dev);
return dev;
}
|
