]>
Commit | Line | Data |
---|---|---|
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 | ||
0430891c | 10 | #include "qemu/osdep.h" |
0d09e41a | 11 | #include "hw/i2c/i2c.h" |
d6454270 | 12 | #include "migration/vmstate.h" |
0b8fa32f | 13 | #include "qemu/module.h" |
08bb9b34 | 14 | #include "trace.h" |
0ff596d0 | 15 | |
71ae65e5 IM |
16 | #define I2C_BROADCAST 0x00 |
17 | ||
3cb75a7c PB |
18 | static Property i2c_props[] = { |
19 | DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0), | |
20 | DEFINE_PROP_END_OF_LIST(), | |
21 | }; | |
22 | ||
0d936928 AL |
23 | static const TypeInfo i2c_bus_info = { |
24 | .name = TYPE_I2C_BUS, | |
25 | .parent = TYPE_BUS, | |
a5c82852 | 26 | .instance_size = sizeof(I2CBus), |
10c4c98a GH |
27 | }; |
28 | ||
44b1ff31 | 29 | static int i2c_bus_pre_save(void *opaque) |
c701b35b | 30 | { |
a5c82852 | 31 | I2CBus *bus = opaque; |
c701b35b | 32 | |
2293c27f FK |
33 | bus->saved_address = -1; |
34 | if (!QLIST_EMPTY(&bus->current_devs)) { | |
35 | if (!bus->broadcast) { | |
36 | bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address; | |
71ae65e5 IM |
37 | } else { |
38 | bus->saved_address = I2C_BROADCAST; | |
2293c27f FK |
39 | } |
40 | } | |
44b1ff31 DDAG |
41 | |
42 | return 0; | |
c701b35b PB |
43 | } |
44 | ||
8d0eb050 JQ |
45 | static const VMStateDescription vmstate_i2c_bus = { |
46 | .name = "i2c_bus", | |
47 | .version_id = 1, | |
48 | .minimum_version_id = 1, | |
8d0eb050 | 49 | .pre_save = i2c_bus_pre_save, |
35d08458 | 50 | .fields = (VMStateField[]) { |
a5c82852 | 51 | VMSTATE_UINT8(saved_address, I2CBus), |
8d0eb050 JQ |
52 | VMSTATE_END_OF_LIST() |
53 | } | |
54 | }; | |
55 | ||
0ff596d0 | 56 | /* Create a new I2C bus. */ |
a5c82852 | 57 | I2CBus *i2c_init_bus(DeviceState *parent, const char *name) |
0ff596d0 | 58 | { |
a5c82852 | 59 | I2CBus *bus; |
0ff596d0 | 60 | |
fef7fbc9 | 61 | bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name)); |
2293c27f | 62 | QLIST_INIT(&bus->current_devs); |
0be71e32 | 63 | vmstate_register(NULL, -1, &vmstate_i2c_bus, bus); |
0ff596d0 PB |
64 | return bus; |
65 | } | |
66 | ||
9e07bdf8 | 67 | void i2c_set_slave_address(I2CSlave *dev, uint8_t address) |
0ff596d0 PB |
68 | { |
69 | dev->address = address; | |
70 | } | |
71 | ||
72 | /* Return nonzero if bus is busy. */ | |
a5c82852 | 73 | int i2c_bus_busy(I2CBus *bus) |
0ff596d0 | 74 | { |
2293c27f | 75 | return !QLIST_EMPTY(&bus->current_devs); |
0ff596d0 PB |
76 | } |
77 | ||
d307c28c | 78 | /* TODO: Make this handle multiple masters. */ |
cc083d8a | 79 | /* |
d307c28c CM |
80 | * Start or continue an i2c transaction. When this is called for the |
81 | * first time or after an i2c_end_transfer(), if it returns an error | |
82 | * the bus transaction is terminated (or really never started). If | |
83 | * this is called after another i2c_start_transfer() without an | |
84 | * intervening i2c_end_transfer(), and it returns an error, the | |
85 | * transaction will not be terminated. The caller must do it. | |
86 | * | |
87 | * This corresponds with the way real hardware works. The SMBus | |
88 | * protocol uses a start transfer to switch from write to read mode | |
89 | * without releasing the bus. If that fails, the bus is still | |
90 | * in a transaction. | |
cc083d8a | 91 | */ |
a5c82852 | 92 | int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv) |
0ff596d0 | 93 | { |
0866aca1 | 94 | BusChild *kid; |
b5ea9327 | 95 | I2CSlaveClass *sc; |
2293c27f | 96 | I2CNode *node; |
d307c28c | 97 | bool bus_scanned = false; |
2293c27f | 98 | |
71ae65e5 | 99 | if (address == I2C_BROADCAST) { |
2293c27f FK |
100 | /* |
101 | * This is a broadcast, the current_devs will be all the devices of the | |
102 | * bus. | |
103 | */ | |
104 | bus->broadcast = true; | |
105 | } | |
0ff596d0 | 106 | |
0fa758c3 CM |
107 | /* |
108 | * If there are already devices in the list, that means we are in | |
109 | * the middle of a transaction and we shouldn't rescan the bus. | |
110 | * | |
111 | * This happens with any SMBus transaction, even on a pure I2C | |
112 | * device. The interface does a transaction start without | |
113 | * terminating the previous transaction. | |
114 | */ | |
115 | if (QLIST_EMPTY(&bus->current_devs)) { | |
116 | QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { | |
117 | DeviceState *qdev = kid->child; | |
118 | I2CSlave *candidate = I2C_SLAVE(qdev); | |
119 | if ((candidate->address == address) || (bus->broadcast)) { | |
120 | node = g_malloc(sizeof(struct I2CNode)); | |
121 | node->elt = candidate; | |
122 | QLIST_INSERT_HEAD(&bus->current_devs, node, next); | |
123 | if (!bus->broadcast) { | |
124 | break; | |
125 | } | |
2293c27f | 126 | } |
b3a21988 | 127 | } |
d307c28c | 128 | bus_scanned = true; |
0ff596d0 PB |
129 | } |
130 | ||
2293c27f | 131 | if (QLIST_EMPTY(&bus->current_devs)) { |
0ff596d0 | 132 | return 1; |
b5ea9327 | 133 | } |
0ff596d0 | 134 | |
2293c27f | 135 | QLIST_FOREACH(node, &bus->current_devs, next) { |
08bb9b34 | 136 | I2CSlave *s = node->elt; |
d307c28c CM |
137 | int rv; |
138 | ||
08bb9b34 | 139 | sc = I2C_SLAVE_GET_CLASS(s); |
2293c27f FK |
140 | /* If the bus is already busy, assume this is a repeated |
141 | start condition. */ | |
d307c28c | 142 | |
2293c27f | 143 | if (sc->event) { |
08bb9b34 PMD |
144 | trace_i2c_event("start", s->address); |
145 | rv = sc->event(s, recv ? I2C_START_RECV : I2C_START_SEND); | |
d307c28c CM |
146 | if (rv && !bus->broadcast) { |
147 | if (bus_scanned) { | |
148 | /* First call, terminate the transfer. */ | |
149 | i2c_end_transfer(bus); | |
150 | } | |
151 | return rv; | |
152 | } | |
2293c27f | 153 | } |
b5ea9327 | 154 | } |
0ff596d0 PB |
155 | return 0; |
156 | } | |
157 | ||
a5c82852 | 158 | void i2c_end_transfer(I2CBus *bus) |
0ff596d0 | 159 | { |
b5ea9327 | 160 | I2CSlaveClass *sc; |
2293c27f | 161 | I2CNode *node, *next; |
0ff596d0 | 162 | |
2293c27f | 163 | QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) { |
08bb9b34 PMD |
164 | I2CSlave *s = node->elt; |
165 | sc = I2C_SLAVE_GET_CLASS(s); | |
2293c27f | 166 | if (sc->event) { |
08bb9b34 PMD |
167 | trace_i2c_event("finish", s->address); |
168 | sc->event(s, I2C_FINISH); | |
2293c27f FK |
169 | } |
170 | QLIST_REMOVE(node, next); | |
171 | g_free(node); | |
b5ea9327 | 172 | } |
2293c27f | 173 | bus->broadcast = false; |
0ff596d0 PB |
174 | } |
175 | ||
056fca7b | 176 | int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send) |
0ff596d0 | 177 | { |
b5ea9327 | 178 | I2CSlaveClass *sc; |
08bb9b34 | 179 | I2CSlave *s; |
2293c27f FK |
180 | I2CNode *node; |
181 | int ret = 0; | |
182 | ||
056fca7b PC |
183 | if (send) { |
184 | QLIST_FOREACH(node, &bus->current_devs, next) { | |
08bb9b34 PMD |
185 | s = node->elt; |
186 | sc = I2C_SLAVE_GET_CLASS(s); | |
056fca7b | 187 | if (sc->send) { |
08bb9b34 PMD |
188 | trace_i2c_send(s->address, *data); |
189 | ret = ret || sc->send(s, *data); | |
056fca7b PC |
190 | } else { |
191 | ret = -1; | |
192 | } | |
193 | } | |
194 | return ret ? -1 : 0; | |
195 | } else { | |
2ac4c5f4 CM |
196 | ret = 0xff; |
197 | if (!QLIST_EMPTY(&bus->current_devs) && !bus->broadcast) { | |
198 | sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt); | |
199 | if (sc->recv) { | |
200 | s = QLIST_FIRST(&bus->current_devs)->elt; | |
201 | ret = sc->recv(s); | |
202 | trace_i2c_recv(s->address, ret); | |
056fca7b PC |
203 | } |
204 | } | |
2ac4c5f4 CM |
205 | *data = ret; |
206 | return 0; | |
b5ea9327 | 207 | } |
0ff596d0 PB |
208 | } |
209 | ||
056fca7b | 210 | int i2c_send(I2CBus *bus, uint8_t data) |
0ff596d0 | 211 | { |
056fca7b PC |
212 | return i2c_send_recv(bus, &data, true); |
213 | } | |
0ff596d0 | 214 | |
2ac4c5f4 | 215 | uint8_t i2c_recv(I2CBus *bus) |
056fca7b | 216 | { |
2ac4c5f4 | 217 | uint8_t data = 0xff; |
b5ea9327 | 218 | |
2ac4c5f4 CM |
219 | i2c_send_recv(bus, &data, false); |
220 | return data; | |
0ff596d0 PB |
221 | } |
222 | ||
a5c82852 | 223 | void i2c_nack(I2CBus *bus) |
0ff596d0 | 224 | { |
b5ea9327 | 225 | I2CSlaveClass *sc; |
2293c27f | 226 | I2CNode *node; |
0ff596d0 | 227 | |
2293c27f | 228 | if (QLIST_EMPTY(&bus->current_devs)) { |
0ff596d0 | 229 | return; |
b5ea9327 | 230 | } |
0ff596d0 | 231 | |
2293c27f FK |
232 | QLIST_FOREACH(node, &bus->current_devs, next) { |
233 | sc = I2C_SLAVE_GET_CLASS(node->elt); | |
234 | if (sc->event) { | |
08bb9b34 | 235 | trace_i2c_event("nack", node->elt->address); |
2293c27f FK |
236 | sc->event(node->elt, I2C_NACK); |
237 | } | |
b5ea9327 | 238 | } |
0ff596d0 PB |
239 | } |
240 | ||
bcbe8068 | 241 | static int i2c_slave_post_load(void *opaque, int version_id) |
aa941b94 | 242 | { |
9e07bdf8 | 243 | I2CSlave *dev = opaque; |
a5c82852 | 244 | I2CBus *bus; |
2293c27f FK |
245 | I2CNode *node; |
246 | ||
fef7fbc9 | 247 | bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev))); |
71ae65e5 IM |
248 | if ((bus->saved_address == dev->address) || |
249 | (bus->saved_address == I2C_BROADCAST)) { | |
2293c27f FK |
250 | node = g_malloc(sizeof(struct I2CNode)); |
251 | node->elt = dev; | |
252 | QLIST_INSERT_HEAD(&bus->current_devs, node, next); | |
fe8de492 | 253 | } |
bcbe8068 JQ |
254 | return 0; |
255 | } | |
256 | ||
1894839f | 257 | const VMStateDescription vmstate_i2c_slave = { |
9e07bdf8 | 258 | .name = "I2CSlave", |
bcbe8068 JQ |
259 | .version_id = 1, |
260 | .minimum_version_id = 1, | |
bcbe8068 | 261 | .post_load = i2c_slave_post_load, |
35d08458 | 262 | .fields = (VMStateField[]) { |
9e07bdf8 | 263 | VMSTATE_UINT8(address, I2CSlave), |
bcbe8068 JQ |
264 | VMSTATE_END_OF_LIST() |
265 | } | |
266 | }; | |
267 | ||
a5c82852 | 268 | DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr) |
fe8de492 PB |
269 | { |
270 | DeviceState *dev; | |
271 | ||
02e2da45 | 272 | dev = qdev_create(&bus->qbus, name); |
5b7f5327 | 273 | qdev_prop_set_uint8(dev, "address", addr); |
e23a1b33 | 274 | qdev_init_nofail(dev); |
fe8de492 | 275 | return dev; |
aa941b94 | 276 | } |
b5ea9327 | 277 | |
39bffca2 AL |
278 | static void i2c_slave_class_init(ObjectClass *klass, void *data) |
279 | { | |
280 | DeviceClass *k = DEVICE_CLASS(klass); | |
125ee0ed | 281 | set_bit(DEVICE_CATEGORY_MISC, k->categories); |
0d936928 | 282 | k->bus_type = TYPE_I2C_BUS; |
bce54474 | 283 | k->props = i2c_props; |
39bffca2 AL |
284 | } |
285 | ||
8c43a6f0 | 286 | static const TypeInfo i2c_slave_type_info = { |
b5ea9327 AL |
287 | .name = TYPE_I2C_SLAVE, |
288 | .parent = TYPE_DEVICE, | |
289 | .instance_size = sizeof(I2CSlave), | |
290 | .abstract = true, | |
291 | .class_size = sizeof(I2CSlaveClass), | |
39bffca2 | 292 | .class_init = i2c_slave_class_init, |
b5ea9327 AL |
293 | }; |
294 | ||
83f7d43a | 295 | static void i2c_slave_register_types(void) |
b5ea9327 | 296 | { |
0d936928 | 297 | type_register_static(&i2c_bus_info); |
b5ea9327 AL |
298 | type_register_static(&i2c_slave_type_info); |
299 | } | |
300 | ||
83f7d43a | 301 | type_init(i2c_slave_register_types) |