1
2
3
4
5
6
7
8
9
10#include "qemu/osdep.h"
11#include "hw/i2c/i2c.h"
12
13#define I2C_BROADCAST 0x00
14
15static Property i2c_props[] = {
16 DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
17 DEFINE_PROP_END_OF_LIST(),
18};
19
20static const TypeInfo i2c_bus_info = {
21 .name = TYPE_I2C_BUS,
22 .parent = TYPE_BUS,
23 .instance_size = sizeof(I2CBus),
24};
25
26static int i2c_bus_pre_save(void *opaque)
27{
28 I2CBus *bus = opaque;
29
30 bus->saved_address = -1;
31 if (!QLIST_EMPTY(&bus->current_devs)) {
32 if (!bus->broadcast) {
33 bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
34 } else {
35 bus->saved_address = I2C_BROADCAST;
36 }
37 }
38
39 return 0;
40}
41
42static const VMStateDescription vmstate_i2c_bus = {
43 .name = "i2c_bus",
44 .version_id = 1,
45 .minimum_version_id = 1,
46 .pre_save = i2c_bus_pre_save,
47 .fields = (VMStateField[]) {
48 VMSTATE_UINT8(saved_address, I2CBus),
49 VMSTATE_END_OF_LIST()
50 }
51};
52
53
54I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
55{
56 I2CBus *bus;
57
58 bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
59 QLIST_INIT(&bus->current_devs);
60 vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
61 return bus;
62}
63
64void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
65{
66 dev->address = address;
67}
68
69
70int i2c_bus_busy(I2CBus *bus)
71{
72 return !QLIST_EMPTY(&bus->current_devs);
73}
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
90{
91 BusChild *kid;
92 I2CSlaveClass *sc;
93 I2CNode *node;
94 bool bus_scanned = false;
95
96 if (address == I2C_BROADCAST) {
97
98
99
100
101 bus->broadcast = true;
102 }
103
104
105
106
107
108
109
110
111
112 if (QLIST_EMPTY(&bus->current_devs)) {
113 QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
114 DeviceState *qdev = kid->child;
115 I2CSlave *candidate = I2C_SLAVE(qdev);
116 if ((candidate->address == address) || (bus->broadcast)) {
117 node = g_malloc(sizeof(struct I2CNode));
118 node->elt = candidate;
119 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
120 if (!bus->broadcast) {
121 break;
122 }
123 }
124 }
125 bus_scanned = true;
126 }
127
128 if (QLIST_EMPTY(&bus->current_devs)) {
129 return 1;
130 }
131
132 QLIST_FOREACH(node, &bus->current_devs, next) {
133 int rv;
134
135 sc = I2C_SLAVE_GET_CLASS(node->elt);
136
137
138
139 if (sc->event) {
140 rv = sc->event(node->elt, recv ? I2C_START_RECV : I2C_START_SEND);
141 if (rv && !bus->broadcast) {
142 if (bus_scanned) {
143
144 i2c_end_transfer(bus);
145 }
146 return rv;
147 }
148 }
149 }
150 return 0;
151}
152
153void i2c_end_transfer(I2CBus *bus)
154{
155 I2CSlaveClass *sc;
156 I2CNode *node, *next;
157
158 QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
159 sc = I2C_SLAVE_GET_CLASS(node->elt);
160 if (sc->event) {
161 sc->event(node->elt, I2C_FINISH);
162 }
163 QLIST_REMOVE(node, next);
164 g_free(node);
165 }
166 bus->broadcast = false;
167}
168
169int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
170{
171 I2CSlaveClass *sc;
172 I2CNode *node;
173 int ret = 0;
174
175 if (send) {
176 QLIST_FOREACH(node, &bus->current_devs, next) {
177 sc = I2C_SLAVE_GET_CLASS(node->elt);
178 if (sc->send) {
179 ret = ret || sc->send(node->elt, *data);
180 } else {
181 ret = -1;
182 }
183 }
184 return ret ? -1 : 0;
185 } else {
186 if ((QLIST_EMPTY(&bus->current_devs)) || (bus->broadcast)) {
187 return -1;
188 }
189
190 sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
191 if (sc->recv) {
192 ret = sc->recv(QLIST_FIRST(&bus->current_devs)->elt);
193 if (ret < 0) {
194 return ret;
195 } else {
196 *data = ret;
197 return 0;
198 }
199 }
200 return -1;
201 }
202}
203
204int i2c_send(I2CBus *bus, uint8_t data)
205{
206 return i2c_send_recv(bus, &data, true);
207}
208
209int i2c_recv(I2CBus *bus)
210{
211 uint8_t data;
212 int ret = i2c_send_recv(bus, &data, false);
213
214 return ret < 0 ? ret : data;
215}
216
217void i2c_nack(I2CBus *bus)
218{
219 I2CSlaveClass *sc;
220 I2CNode *node;
221
222 if (QLIST_EMPTY(&bus->current_devs)) {
223 return;
224 }
225
226 QLIST_FOREACH(node, &bus->current_devs, next) {
227 sc = I2C_SLAVE_GET_CLASS(node->elt);
228 if (sc->event) {
229 sc->event(node->elt, I2C_NACK);
230 }
231 }
232}
233
234static int i2c_slave_post_load(void *opaque, int version_id)
235{
236 I2CSlave *dev = opaque;
237 I2CBus *bus;
238 I2CNode *node;
239
240 bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
241 if ((bus->saved_address == dev->address) ||
242 (bus->saved_address == I2C_BROADCAST)) {
243 node = g_malloc(sizeof(struct I2CNode));
244 node->elt = dev;
245 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
246 }
247 return 0;
248}
249
250const VMStateDescription vmstate_i2c_slave = {
251 .name = "I2CSlave",
252 .version_id = 1,
253 .minimum_version_id = 1,
254 .post_load = i2c_slave_post_load,
255 .fields = (VMStateField[]) {
256 VMSTATE_UINT8(address, I2CSlave),
257 VMSTATE_END_OF_LIST()
258 }
259};
260
261static int i2c_slave_qdev_init(DeviceState *dev)
262{
263 I2CSlave *s = I2C_SLAVE(dev);
264 I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s);
265
266 if (sc->init) {
267 return sc->init(s);
268 }
269
270 return 0;
271}
272
273DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr)
274{
275 DeviceState *dev;
276
277 dev = qdev_create(&bus->qbus, name);
278 qdev_prop_set_uint8(dev, "address", addr);
279 qdev_init_nofail(dev);
280 return dev;
281}
282
283static void i2c_slave_class_init(ObjectClass *klass, void *data)
284{
285 DeviceClass *k = DEVICE_CLASS(klass);
286 k->init = i2c_slave_qdev_init;
287 set_bit(DEVICE_CATEGORY_MISC, k->categories);
288 k->bus_type = TYPE_I2C_BUS;
289 k->props = i2c_props;
290}
291
292static const TypeInfo i2c_slave_type_info = {
293 .name = TYPE_I2C_SLAVE,
294 .parent = TYPE_DEVICE,
295 .instance_size = sizeof(I2CSlave),
296 .abstract = true,
297 .class_size = sizeof(I2CSlaveClass),
298 .class_init = i2c_slave_class_init,
299};
300
301static void i2c_slave_register_types(void)
302{
303 type_register_static(&i2c_bus_info);
304 type_register_static(&i2c_slave_type_info);
305}
306
307type_init(i2c_slave_register_types)
308