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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 | * | |
8e31bf38 | 7 | * This code is licensed under the LGPL. |
0ff596d0 PB |
8 | */ |
9 | ||
0d09e41a | 10 | #include "hw/i2c/i2c.h" |
0ff596d0 PB |
11 | |
12 | struct i2c_bus | |
13 | { | |
02e2da45 | 14 | BusState qbus; |
9e07bdf8 AL |
15 | I2CSlave *current_dev; |
16 | I2CSlave *dev; | |
5b7f5327 | 17 | uint8_t saved_address; |
0ff596d0 PB |
18 | }; |
19 | ||
3cb75a7c PB |
20 | static Property i2c_props[] = { |
21 | DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0), | |
22 | DEFINE_PROP_END_OF_LIST(), | |
23 | }; | |
24 | ||
0d936928 AL |
25 | #define TYPE_I2C_BUS "i2c-bus" |
26 | #define I2C_BUS(obj) OBJECT_CHECK(i2c_bus, (obj), TYPE_I2C_BUS) | |
27 | ||
28 | static const TypeInfo i2c_bus_info = { | |
29 | .name = TYPE_I2C_BUS, | |
30 | .parent = TYPE_BUS, | |
31 | .instance_size = sizeof(i2c_bus), | |
10c4c98a GH |
32 | }; |
33 | ||
8d0eb050 | 34 | static void i2c_bus_pre_save(void *opaque) |
c701b35b | 35 | { |
8d0eb050 | 36 | i2c_bus *bus = opaque; |
c701b35b | 37 | |
8d0eb050 | 38 | bus->saved_address = bus->current_dev ? bus->current_dev->address : -1; |
c701b35b PB |
39 | } |
40 | ||
8d0eb050 | 41 | static int i2c_bus_post_load(void *opaque, int version_id) |
c701b35b | 42 | { |
8d0eb050 | 43 | i2c_bus *bus = opaque; |
c701b35b PB |
44 | |
45 | /* The bus is loaded before attached devices, so load and save the | |
46 | current device id. Devices will check themselves as loaded. */ | |
c701b35b | 47 | bus->current_dev = NULL; |
c701b35b PB |
48 | return 0; |
49 | } | |
50 | ||
8d0eb050 JQ |
51 | static const VMStateDescription vmstate_i2c_bus = { |
52 | .name = "i2c_bus", | |
53 | .version_id = 1, | |
54 | .minimum_version_id = 1, | |
55 | .minimum_version_id_old = 1, | |
56 | .pre_save = i2c_bus_pre_save, | |
57 | .post_load = i2c_bus_post_load, | |
58 | .fields = (VMStateField []) { | |
59 | VMSTATE_UINT8(saved_address, i2c_bus), | |
60 | VMSTATE_END_OF_LIST() | |
61 | } | |
62 | }; | |
63 | ||
0ff596d0 | 64 | /* Create a new I2C bus. */ |
02e2da45 | 65 | i2c_bus *i2c_init_bus(DeviceState *parent, const char *name) |
0ff596d0 PB |
66 | { |
67 | i2c_bus *bus; | |
68 | ||
fef7fbc9 | 69 | bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name)); |
0be71e32 | 70 | vmstate_register(NULL, -1, &vmstate_i2c_bus, bus); |
0ff596d0 PB |
71 | return bus; |
72 | } | |
73 | ||
9e07bdf8 | 74 | void i2c_set_slave_address(I2CSlave *dev, uint8_t address) |
0ff596d0 PB |
75 | { |
76 | dev->address = address; | |
77 | } | |
78 | ||
79 | /* Return nonzero if bus is busy. */ | |
80 | int i2c_bus_busy(i2c_bus *bus) | |
81 | { | |
82 | return bus->current_dev != NULL; | |
83 | } | |
84 | ||
4a2c8ac2 | 85 | /* Returns non-zero if the address is not valid. */ |
0ff596d0 | 86 | /* TODO: Make this handle multiple masters. */ |
5b7f5327 | 87 | int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv) |
0ff596d0 | 88 | { |
0866aca1 | 89 | BusChild *kid; |
9e07bdf8 | 90 | I2CSlave *slave = NULL; |
b5ea9327 | 91 | I2CSlaveClass *sc; |
0ff596d0 | 92 | |
0866aca1 AL |
93 | QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { |
94 | DeviceState *qdev = kid->child; | |
8aae84a1 | 95 | I2CSlave *candidate = I2C_SLAVE(qdev); |
b3a21988 JR |
96 | if (candidate->address == address) { |
97 | slave = candidate; | |
0ff596d0 | 98 | break; |
b3a21988 | 99 | } |
0ff596d0 PB |
100 | } |
101 | ||
b5ea9327 | 102 | if (!slave) { |
0ff596d0 | 103 | return 1; |
b5ea9327 | 104 | } |
0ff596d0 | 105 | |
b5ea9327 | 106 | sc = I2C_SLAVE_GET_CLASS(slave); |
0ff596d0 PB |
107 | /* If the bus is already busy, assume this is a repeated |
108 | start condition. */ | |
02e2da45 | 109 | bus->current_dev = slave; |
b5ea9327 AL |
110 | if (sc->event) { |
111 | sc->event(slave, recv ? I2C_START_RECV : I2C_START_SEND); | |
112 | } | |
0ff596d0 PB |
113 | return 0; |
114 | } | |
115 | ||
116 | void i2c_end_transfer(i2c_bus *bus) | |
117 | { | |
9e07bdf8 | 118 | I2CSlave *dev = bus->current_dev; |
b5ea9327 | 119 | I2CSlaveClass *sc; |
0ff596d0 | 120 | |
b5ea9327 | 121 | if (!dev) { |
0ff596d0 | 122 | return; |
b5ea9327 | 123 | } |
0ff596d0 | 124 | |
b5ea9327 AL |
125 | sc = I2C_SLAVE_GET_CLASS(dev); |
126 | if (sc->event) { | |
127 | sc->event(dev, I2C_FINISH); | |
128 | } | |
0ff596d0 PB |
129 | |
130 | bus->current_dev = NULL; | |
131 | } | |
132 | ||
133 | int i2c_send(i2c_bus *bus, uint8_t data) | |
134 | { | |
9e07bdf8 | 135 | I2CSlave *dev = bus->current_dev; |
b5ea9327 | 136 | I2CSlaveClass *sc; |
0ff596d0 | 137 | |
b5ea9327 | 138 | if (!dev) { |
0ff596d0 | 139 | return -1; |
b5ea9327 | 140 | } |
0ff596d0 | 141 | |
b5ea9327 AL |
142 | sc = I2C_SLAVE_GET_CLASS(dev); |
143 | if (sc->send) { | |
144 | return sc->send(dev, data); | |
145 | } | |
146 | ||
147 | return -1; | |
0ff596d0 PB |
148 | } |
149 | ||
150 | int i2c_recv(i2c_bus *bus) | |
151 | { | |
9e07bdf8 | 152 | I2CSlave *dev = bus->current_dev; |
b5ea9327 | 153 | I2CSlaveClass *sc; |
0ff596d0 | 154 | |
b5ea9327 | 155 | if (!dev) { |
0ff596d0 | 156 | return -1; |
b5ea9327 AL |
157 | } |
158 | ||
159 | sc = I2C_SLAVE_GET_CLASS(dev); | |
160 | if (sc->recv) { | |
161 | return sc->recv(dev); | |
162 | } | |
0ff596d0 | 163 | |
b5ea9327 | 164 | return -1; |
0ff596d0 PB |
165 | } |
166 | ||
167 | void i2c_nack(i2c_bus *bus) | |
168 | { | |
9e07bdf8 | 169 | I2CSlave *dev = bus->current_dev; |
b5ea9327 | 170 | I2CSlaveClass *sc; |
0ff596d0 | 171 | |
b5ea9327 | 172 | if (!dev) { |
0ff596d0 | 173 | return; |
b5ea9327 | 174 | } |
0ff596d0 | 175 | |
b5ea9327 AL |
176 | sc = I2C_SLAVE_GET_CLASS(dev); |
177 | if (sc->event) { | |
178 | sc->event(dev, I2C_NACK); | |
179 | } | |
0ff596d0 PB |
180 | } |
181 | ||
bcbe8068 | 182 | static int i2c_slave_post_load(void *opaque, int version_id) |
aa941b94 | 183 | { |
9e07bdf8 | 184 | I2CSlave *dev = opaque; |
fe8de492 | 185 | i2c_bus *bus; |
fef7fbc9 | 186 | bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev))); |
fe8de492 PB |
187 | if (bus->saved_address == dev->address) { |
188 | bus->current_dev = dev; | |
189 | } | |
bcbe8068 JQ |
190 | return 0; |
191 | } | |
192 | ||
1894839f | 193 | const VMStateDescription vmstate_i2c_slave = { |
9e07bdf8 | 194 | .name = "I2CSlave", |
bcbe8068 JQ |
195 | .version_id = 1, |
196 | .minimum_version_id = 1, | |
197 | .minimum_version_id_old = 1, | |
198 | .post_load = i2c_slave_post_load, | |
199 | .fields = (VMStateField []) { | |
9e07bdf8 | 200 | VMSTATE_UINT8(address, I2CSlave), |
bcbe8068 JQ |
201 | VMSTATE_END_OF_LIST() |
202 | } | |
203 | }; | |
204 | ||
d307af79 | 205 | static int i2c_slave_qdev_init(DeviceState *dev) |
fe8de492 | 206 | { |
8aae84a1 | 207 | I2CSlave *s = I2C_SLAVE(dev); |
b5ea9327 | 208 | I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s); |
fe8de492 | 209 | |
b5ea9327 AL |
210 | return sc->init(s); |
211 | } | |
fe8de492 | 212 | |
5b7f5327 | 213 | DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr) |
fe8de492 PB |
214 | { |
215 | DeviceState *dev; | |
216 | ||
02e2da45 | 217 | dev = qdev_create(&bus->qbus, name); |
5b7f5327 | 218 | qdev_prop_set_uint8(dev, "address", addr); |
e23a1b33 | 219 | qdev_init_nofail(dev); |
fe8de492 | 220 | return dev; |
aa941b94 | 221 | } |
b5ea9327 | 222 | |
39bffca2 AL |
223 | static void i2c_slave_class_init(ObjectClass *klass, void *data) |
224 | { | |
225 | DeviceClass *k = DEVICE_CLASS(klass); | |
226 | k->init = i2c_slave_qdev_init; | |
125ee0ed | 227 | set_bit(DEVICE_CATEGORY_MISC, k->categories); |
0d936928 | 228 | k->bus_type = TYPE_I2C_BUS; |
bce54474 | 229 | k->props = i2c_props; |
39bffca2 AL |
230 | } |
231 | ||
8c43a6f0 | 232 | static const TypeInfo i2c_slave_type_info = { |
b5ea9327 AL |
233 | .name = TYPE_I2C_SLAVE, |
234 | .parent = TYPE_DEVICE, | |
235 | .instance_size = sizeof(I2CSlave), | |
236 | .abstract = true, | |
237 | .class_size = sizeof(I2CSlaveClass), | |
39bffca2 | 238 | .class_init = i2c_slave_class_init, |
b5ea9327 AL |
239 | }; |
240 | ||
83f7d43a | 241 | static void i2c_slave_register_types(void) |
b5ea9327 | 242 | { |
0d936928 | 243 | type_register_static(&i2c_bus_info); |
b5ea9327 AL |
244 | type_register_static(&i2c_slave_type_info); |
245 | } | |
246 | ||
83f7d43a | 247 | type_init(i2c_slave_register_types) |