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Commit | Line | Data |
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5fafdf24 | 1 | /* |
0ff596d0 PB |
2 | * QEMU I2C bus interface. |
3 | * | |
4 | * Copyright (c) 2007 CodeSourcery. | |
5 | * Written by Paul Brook | |
6 | * | |
7 | * This code is licenced under the LGPL. | |
8 | */ | |
9 | ||
87ecb68b | 10 | #include "i2c.h" |
0ff596d0 PB |
11 | |
12 | struct i2c_bus | |
13 | { | |
02e2da45 | 14 | BusState qbus; |
0ff596d0 PB |
15 | i2c_slave *current_dev; |
16 | i2c_slave *dev; | |
5b7f5327 | 17 | uint8_t saved_address; |
0ff596d0 PB |
18 | }; |
19 | ||
10c4c98a GH |
20 | static struct BusInfo i2c_bus_info = { |
21 | .name = "I2C", | |
22 | .size = sizeof(i2c_bus), | |
ee6847d1 | 23 | .props = (Property[]) { |
5b7f5327 | 24 | DEFINE_PROP_UINT8("address", struct i2c_slave, address, 0), |
368eb5d4 | 25 | DEFINE_PROP_END_OF_LIST(), |
ee6847d1 | 26 | } |
10c4c98a GH |
27 | }; |
28 | ||
8d0eb050 | 29 | static void i2c_bus_pre_save(void *opaque) |
c701b35b | 30 | { |
8d0eb050 | 31 | i2c_bus *bus = opaque; |
c701b35b | 32 | |
8d0eb050 | 33 | bus->saved_address = bus->current_dev ? bus->current_dev->address : -1; |
c701b35b PB |
34 | } |
35 | ||
8d0eb050 | 36 | static int i2c_bus_post_load(void *opaque, int version_id) |
c701b35b | 37 | { |
8d0eb050 | 38 | i2c_bus *bus = opaque; |
c701b35b PB |
39 | |
40 | /* The bus is loaded before attached devices, so load and save the | |
41 | current device id. Devices will check themselves as loaded. */ | |
c701b35b | 42 | bus->current_dev = NULL; |
c701b35b PB |
43 | return 0; |
44 | } | |
45 | ||
8d0eb050 JQ |
46 | static const VMStateDescription vmstate_i2c_bus = { |
47 | .name = "i2c_bus", | |
48 | .version_id = 1, | |
49 | .minimum_version_id = 1, | |
50 | .minimum_version_id_old = 1, | |
51 | .pre_save = i2c_bus_pre_save, | |
52 | .post_load = i2c_bus_post_load, | |
53 | .fields = (VMStateField []) { | |
54 | VMSTATE_UINT8(saved_address, i2c_bus), | |
55 | VMSTATE_END_OF_LIST() | |
56 | } | |
57 | }; | |
58 | ||
0ff596d0 | 59 | /* Create a new I2C bus. */ |
02e2da45 | 60 | i2c_bus *i2c_init_bus(DeviceState *parent, const char *name) |
0ff596d0 PB |
61 | { |
62 | i2c_bus *bus; | |
63 | ||
10c4c98a | 64 | bus = FROM_QBUS(i2c_bus, qbus_create(&i2c_bus_info, parent, name)); |
8d0eb050 | 65 | vmstate_register(-1, &vmstate_i2c_bus, bus); |
0ff596d0 PB |
66 | return bus; |
67 | } | |
68 | ||
5b7f5327 | 69 | void i2c_set_slave_address(i2c_slave *dev, uint8_t address) |
0ff596d0 PB |
70 | { |
71 | dev->address = address; | |
72 | } | |
73 | ||
74 | /* Return nonzero if bus is busy. */ | |
75 | int i2c_bus_busy(i2c_bus *bus) | |
76 | { | |
77 | return bus->current_dev != NULL; | |
78 | } | |
79 | ||
4a2c8ac2 | 80 | /* Returns non-zero if the address is not valid. */ |
0ff596d0 | 81 | /* TODO: Make this handle multiple masters. */ |
5b7f5327 | 82 | int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv) |
0ff596d0 | 83 | { |
02e2da45 PB |
84 | DeviceState *qdev; |
85 | i2c_slave *slave = NULL; | |
0ff596d0 | 86 | |
72cf2d4f | 87 | QLIST_FOREACH(qdev, &bus->qbus.children, sibling) { |
02e2da45 PB |
88 | slave = I2C_SLAVE_FROM_QDEV(qdev); |
89 | if (slave->address == address) | |
0ff596d0 PB |
90 | break; |
91 | } | |
92 | ||
02e2da45 | 93 | if (!slave) |
0ff596d0 PB |
94 | return 1; |
95 | ||
96 | /* If the bus is already busy, assume this is a repeated | |
97 | start condition. */ | |
02e2da45 PB |
98 | bus->current_dev = slave; |
99 | slave->info->event(slave, recv ? I2C_START_RECV : I2C_START_SEND); | |
0ff596d0 PB |
100 | return 0; |
101 | } | |
102 | ||
103 | void i2c_end_transfer(i2c_bus *bus) | |
104 | { | |
105 | i2c_slave *dev = bus->current_dev; | |
106 | ||
107 | if (!dev) | |
108 | return; | |
109 | ||
fe8de492 | 110 | dev->info->event(dev, I2C_FINISH); |
0ff596d0 PB |
111 | |
112 | bus->current_dev = NULL; | |
113 | } | |
114 | ||
115 | int i2c_send(i2c_bus *bus, uint8_t data) | |
116 | { | |
117 | i2c_slave *dev = bus->current_dev; | |
118 | ||
119 | if (!dev) | |
120 | return -1; | |
121 | ||
fe8de492 | 122 | return dev->info->send(dev, data); |
0ff596d0 PB |
123 | } |
124 | ||
125 | int i2c_recv(i2c_bus *bus) | |
126 | { | |
127 | i2c_slave *dev = bus->current_dev; | |
128 | ||
129 | if (!dev) | |
130 | return -1; | |
131 | ||
fe8de492 | 132 | return dev->info->recv(dev); |
0ff596d0 PB |
133 | } |
134 | ||
135 | void i2c_nack(i2c_bus *bus) | |
136 | { | |
137 | i2c_slave *dev = bus->current_dev; | |
138 | ||
139 | if (!dev) | |
140 | return; | |
141 | ||
fe8de492 | 142 | dev->info->event(dev, I2C_NACK); |
0ff596d0 PB |
143 | } |
144 | ||
bcbe8068 | 145 | static int i2c_slave_post_load(void *opaque, int version_id) |
aa941b94 | 146 | { |
bcbe8068 | 147 | i2c_slave *dev = opaque; |
fe8de492 | 148 | i2c_bus *bus; |
02e2da45 | 149 | bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev)); |
fe8de492 PB |
150 | if (bus->saved_address == dev->address) { |
151 | bus->current_dev = dev; | |
152 | } | |
bcbe8068 JQ |
153 | return 0; |
154 | } | |
155 | ||
1894839f | 156 | const VMStateDescription vmstate_i2c_slave = { |
bcbe8068 JQ |
157 | .name = "i2c_slave", |
158 | .version_id = 1, | |
159 | .minimum_version_id = 1, | |
160 | .minimum_version_id_old = 1, | |
161 | .post_load = i2c_slave_post_load, | |
162 | .fields = (VMStateField []) { | |
163 | VMSTATE_UINT8(address, i2c_slave), | |
164 | VMSTATE_END_OF_LIST() | |
165 | } | |
166 | }; | |
167 | ||
81a322d4 | 168 | static int i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base) |
fe8de492 | 169 | { |
02e2da45 | 170 | I2CSlaveInfo *info = container_of(base, I2CSlaveInfo, qdev); |
fe8de492 PB |
171 | i2c_slave *s = I2C_SLAVE_FROM_QDEV(dev); |
172 | ||
173 | s->info = info; | |
fe8de492 | 174 | |
81a322d4 | 175 | return info->init(s); |
fe8de492 PB |
176 | } |
177 | ||
074f2fff | 178 | void i2c_register_slave(I2CSlaveInfo *info) |
fe8de492 | 179 | { |
074f2fff | 180 | assert(info->qdev.size >= sizeof(i2c_slave)); |
02e2da45 | 181 | info->qdev.init = i2c_slave_qdev_init; |
10c4c98a | 182 | info->qdev.bus_info = &i2c_bus_info; |
074f2fff | 183 | qdev_register(&info->qdev); |
fe8de492 PB |
184 | } |
185 | ||
5b7f5327 | 186 | DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr) |
fe8de492 PB |
187 | { |
188 | DeviceState *dev; | |
189 | ||
02e2da45 | 190 | dev = qdev_create(&bus->qbus, name); |
5b7f5327 | 191 | qdev_prop_set_uint8(dev, "address", addr); |
e23a1b33 | 192 | qdev_init_nofail(dev); |
fe8de492 | 193 | return dev; |
aa941b94 | 194 | } |