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10#include "qemu/osdep.h"
11#include "hw/i2c/i2c.h"
12#include "qemu/module.h"
13#include "trace.h"
14
15#define I2C_BROADCAST 0x00
16
17static Property i2c_props[] = {
18 DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
19 DEFINE_PROP_END_OF_LIST(),
20};
21
22static const TypeInfo i2c_bus_info = {
23 .name = TYPE_I2C_BUS,
24 .parent = TYPE_BUS,
25 .instance_size = sizeof(I2CBus),
26};
27
28static int i2c_bus_pre_save(void *opaque)
29{
30 I2CBus *bus = opaque;
31
32 bus->saved_address = -1;
33 if (!QLIST_EMPTY(&bus->current_devs)) {
34 if (!bus->broadcast) {
35 bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
36 } else {
37 bus->saved_address = I2C_BROADCAST;
38 }
39 }
40
41 return 0;
42}
43
44static const VMStateDescription vmstate_i2c_bus = {
45 .name = "i2c_bus",
46 .version_id = 1,
47 .minimum_version_id = 1,
48 .pre_save = i2c_bus_pre_save,
49 .fields = (VMStateField[]) {
50 VMSTATE_UINT8(saved_address, I2CBus),
51 VMSTATE_END_OF_LIST()
52 }
53};
54
55
56I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
57{
58 I2CBus *bus;
59
60 bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
61 QLIST_INIT(&bus->current_devs);
62 vmstate_register(NULL, -1, &vmstate_i2c_bus, bus);
63 return bus;
64}
65
66void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
67{
68 dev->address = address;
69}
70
71
72int i2c_bus_busy(I2CBus *bus)
73{
74 return !QLIST_EMPTY(&bus->current_devs);
75}
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90
91int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
92{
93 BusChild *kid;
94 I2CSlaveClass *sc;
95 I2CNode *node;
96 bool bus_scanned = false;
97
98 if (address == I2C_BROADCAST) {
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100
101
102
103 bus->broadcast = true;
104 }
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112
113
114 if (QLIST_EMPTY(&bus->current_devs)) {
115 QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
116 DeviceState *qdev = kid->child;
117 I2CSlave *candidate = I2C_SLAVE(qdev);
118 if ((candidate->address == address) || (bus->broadcast)) {
119 node = g_malloc(sizeof(struct I2CNode));
120 node->elt = candidate;
121 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
122 if (!bus->broadcast) {
123 break;
124 }
125 }
126 }
127 bus_scanned = true;
128 }
129
130 if (QLIST_EMPTY(&bus->current_devs)) {
131 return 1;
132 }
133
134 QLIST_FOREACH(node, &bus->current_devs, next) {
135 I2CSlave *s = node->elt;
136 int rv;
137
138 sc = I2C_SLAVE_GET_CLASS(s);
139
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141
142 if (sc->event) {
143 trace_i2c_event("start", s->address);
144 rv = sc->event(s, recv ? I2C_START_RECV : I2C_START_SEND);
145 if (rv && !bus->broadcast) {
146 if (bus_scanned) {
147
148 i2c_end_transfer(bus);
149 }
150 return rv;
151 }
152 }
153 }
154 return 0;
155}
156
157void i2c_end_transfer(I2CBus *bus)
158{
159 I2CSlaveClass *sc;
160 I2CNode *node, *next;
161
162 QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
163 I2CSlave *s = node->elt;
164 sc = I2C_SLAVE_GET_CLASS(s);
165 if (sc->event) {
166 trace_i2c_event("finish", s->address);
167 sc->event(s, I2C_FINISH);
168 }
169 QLIST_REMOVE(node, next);
170 g_free(node);
171 }
172 bus->broadcast = false;
173}
174
175int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
176{
177 I2CSlaveClass *sc;
178 I2CSlave *s;
179 I2CNode *node;
180 int ret = 0;
181
182 if (send) {
183 QLIST_FOREACH(node, &bus->current_devs, next) {
184 s = node->elt;
185 sc = I2C_SLAVE_GET_CLASS(s);
186 if (sc->send) {
187 trace_i2c_send(s->address, *data);
188 ret = ret || sc->send(s, *data);
189 } else {
190 ret = -1;
191 }
192 }
193 return ret ? -1 : 0;
194 } else {
195 ret = 0xff;
196 if (!QLIST_EMPTY(&bus->current_devs) && !bus->broadcast) {
197 sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
198 if (sc->recv) {
199 s = QLIST_FIRST(&bus->current_devs)->elt;
200 ret = sc->recv(s);
201 trace_i2c_recv(s->address, ret);
202 }
203 }
204 *data = ret;
205 return 0;
206 }
207}
208
209int i2c_send(I2CBus *bus, uint8_t data)
210{
211 return i2c_send_recv(bus, &data, true);
212}
213
214uint8_t i2c_recv(I2CBus *bus)
215{
216 uint8_t data = 0xff;
217
218 i2c_send_recv(bus, &data, false);
219 return data;
220}
221
222void i2c_nack(I2CBus *bus)
223{
224 I2CSlaveClass *sc;
225 I2CNode *node;
226
227 if (QLIST_EMPTY(&bus->current_devs)) {
228 return;
229 }
230
231 QLIST_FOREACH(node, &bus->current_devs, next) {
232 sc = I2C_SLAVE_GET_CLASS(node->elt);
233 if (sc->event) {
234 trace_i2c_event("nack", node->elt->address);
235 sc->event(node->elt, I2C_NACK);
236 }
237 }
238}
239
240static int i2c_slave_post_load(void *opaque, int version_id)
241{
242 I2CSlave *dev = opaque;
243 I2CBus *bus;
244 I2CNode *node;
245
246 bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
247 if ((bus->saved_address == dev->address) ||
248 (bus->saved_address == I2C_BROADCAST)) {
249 node = g_malloc(sizeof(struct I2CNode));
250 node->elt = dev;
251 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
252 }
253 return 0;
254}
255
256const VMStateDescription vmstate_i2c_slave = {
257 .name = "I2CSlave",
258 .version_id = 1,
259 .minimum_version_id = 1,
260 .post_load = i2c_slave_post_load,
261 .fields = (VMStateField[]) {
262 VMSTATE_UINT8(address, I2CSlave),
263 VMSTATE_END_OF_LIST()
264 }
265};
266
267DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr)
268{
269 DeviceState *dev;
270
271 dev = qdev_create(&bus->qbus, name);
272 qdev_prop_set_uint8(dev, "address", addr);
273 qdev_init_nofail(dev);
274 return dev;
275}
276
277static void i2c_slave_class_init(ObjectClass *klass, void *data)
278{
279 DeviceClass *k = DEVICE_CLASS(klass);
280 set_bit(DEVICE_CATEGORY_MISC, k->categories);
281 k->bus_type = TYPE_I2C_BUS;
282 k->props = i2c_props;
283}
284
285static const TypeInfo i2c_slave_type_info = {
286 .name = TYPE_I2C_SLAVE,
287 .parent = TYPE_DEVICE,
288 .instance_size = sizeof(I2CSlave),
289 .abstract = true,
290 .class_size = sizeof(I2CSlaveClass),
291 .class_init = i2c_slave_class_init,
292};
293
294static void i2c_slave_register_types(void)
295{
296 type_register_static(&i2c_bus_info);
297 type_register_static(&i2c_slave_type_info);
298}
299
300type_init(i2c_slave_register_types)
301