target/ppc: Fix slbia TLB invalidation gap
[qemu.git] / hw / i2c / core.c
1 /*
2 * QEMU I2C bus interface.
3 *
4 * Copyright (c) 2007 CodeSourcery.
5 * Written by Paul Brook
6 *
7 * This code is licensed under the LGPL.
8 */
9
10 #include "qemu/osdep.h"
11 #include "hw/i2c/i2c.h"
12 #include "hw/qdev-properties.h"
13 #include "migration/vmstate.h"
14 #include "qemu/module.h"
15 #include "trace.h"
16
17 #define I2C_BROADCAST 0x00
18
19 static Property i2c_props[] = {
20 DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0),
21 DEFINE_PROP_END_OF_LIST(),
22 };
23
24 static const TypeInfo i2c_bus_info = {
25 .name = TYPE_I2C_BUS,
26 .parent = TYPE_BUS,
27 .instance_size = sizeof(I2CBus),
28 };
29
30 static int i2c_bus_pre_save(void *opaque)
31 {
32 I2CBus *bus = opaque;
33
34 bus->saved_address = -1;
35 if (!QLIST_EMPTY(&bus->current_devs)) {
36 if (!bus->broadcast) {
37 bus->saved_address = QLIST_FIRST(&bus->current_devs)->elt->address;
38 } else {
39 bus->saved_address = I2C_BROADCAST;
40 }
41 }
42
43 return 0;
44 }
45
46 static const VMStateDescription vmstate_i2c_bus = {
47 .name = "i2c_bus",
48 .version_id = 1,
49 .minimum_version_id = 1,
50 .pre_save = i2c_bus_pre_save,
51 .fields = (VMStateField[]) {
52 VMSTATE_UINT8(saved_address, I2CBus),
53 VMSTATE_END_OF_LIST()
54 }
55 };
56
57 /* Create a new I2C bus. */
58 I2CBus *i2c_init_bus(DeviceState *parent, const char *name)
59 {
60 I2CBus *bus;
61
62 bus = I2C_BUS(qbus_create(TYPE_I2C_BUS, parent, name));
63 QLIST_INIT(&bus->current_devs);
64 vmstate_register(NULL, VMSTATE_INSTANCE_ID_ANY, &vmstate_i2c_bus, bus);
65 return bus;
66 }
67
68 void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
69 {
70 dev->address = address;
71 }
72
73 /* Return nonzero if bus is busy. */
74 int i2c_bus_busy(I2CBus *bus)
75 {
76 return !QLIST_EMPTY(&bus->current_devs);
77 }
78
79 /* TODO: Make this handle multiple masters. */
80 /*
81 * Start or continue an i2c transaction. When this is called for the
82 * first time or after an i2c_end_transfer(), if it returns an error
83 * the bus transaction is terminated (or really never started). If
84 * this is called after another i2c_start_transfer() without an
85 * intervening i2c_end_transfer(), and it returns an error, the
86 * transaction will not be terminated. The caller must do it.
87 *
88 * This corresponds with the way real hardware works. The SMBus
89 * protocol uses a start transfer to switch from write to read mode
90 * without releasing the bus. If that fails, the bus is still
91 * in a transaction.
92 */
93 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv)
94 {
95 BusChild *kid;
96 I2CSlaveClass *sc;
97 I2CNode *node;
98 bool bus_scanned = false;
99
100 if (address == I2C_BROADCAST) {
101 /*
102 * This is a broadcast, the current_devs will be all the devices of the
103 * bus.
104 */
105 bus->broadcast = true;
106 }
107
108 /*
109 * If there are already devices in the list, that means we are in
110 * the middle of a transaction and we shouldn't rescan the bus.
111 *
112 * This happens with any SMBus transaction, even on a pure I2C
113 * device. The interface does a transaction start without
114 * terminating the previous transaction.
115 */
116 if (QLIST_EMPTY(&bus->current_devs)) {
117 QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) {
118 DeviceState *qdev = kid->child;
119 I2CSlave *candidate = I2C_SLAVE(qdev);
120 if ((candidate->address == address) || (bus->broadcast)) {
121 node = g_malloc(sizeof(struct I2CNode));
122 node->elt = candidate;
123 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
124 if (!bus->broadcast) {
125 break;
126 }
127 }
128 }
129 bus_scanned = true;
130 }
131
132 if (QLIST_EMPTY(&bus->current_devs)) {
133 return 1;
134 }
135
136 QLIST_FOREACH(node, &bus->current_devs, next) {
137 I2CSlave *s = node->elt;
138 int rv;
139
140 sc = I2C_SLAVE_GET_CLASS(s);
141 /* If the bus is already busy, assume this is a repeated
142 start condition. */
143
144 if (sc->event) {
145 trace_i2c_event("start", s->address);
146 rv = sc->event(s, recv ? I2C_START_RECV : I2C_START_SEND);
147 if (rv && !bus->broadcast) {
148 if (bus_scanned) {
149 /* First call, terminate the transfer. */
150 i2c_end_transfer(bus);
151 }
152 return rv;
153 }
154 }
155 }
156 return 0;
157 }
158
159 void i2c_end_transfer(I2CBus *bus)
160 {
161 I2CSlaveClass *sc;
162 I2CNode *node, *next;
163
164 QLIST_FOREACH_SAFE(node, &bus->current_devs, next, next) {
165 I2CSlave *s = node->elt;
166 sc = I2C_SLAVE_GET_CLASS(s);
167 if (sc->event) {
168 trace_i2c_event("finish", s->address);
169 sc->event(s, I2C_FINISH);
170 }
171 QLIST_REMOVE(node, next);
172 g_free(node);
173 }
174 bus->broadcast = false;
175 }
176
177 int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send)
178 {
179 I2CSlaveClass *sc;
180 I2CSlave *s;
181 I2CNode *node;
182 int ret = 0;
183
184 if (send) {
185 QLIST_FOREACH(node, &bus->current_devs, next) {
186 s = node->elt;
187 sc = I2C_SLAVE_GET_CLASS(s);
188 if (sc->send) {
189 trace_i2c_send(s->address, *data);
190 ret = ret || sc->send(s, *data);
191 } else {
192 ret = -1;
193 }
194 }
195 return ret ? -1 : 0;
196 } else {
197 ret = 0xff;
198 if (!QLIST_EMPTY(&bus->current_devs) && !bus->broadcast) {
199 sc = I2C_SLAVE_GET_CLASS(QLIST_FIRST(&bus->current_devs)->elt);
200 if (sc->recv) {
201 s = QLIST_FIRST(&bus->current_devs)->elt;
202 ret = sc->recv(s);
203 trace_i2c_recv(s->address, ret);
204 }
205 }
206 *data = ret;
207 return 0;
208 }
209 }
210
211 int i2c_send(I2CBus *bus, uint8_t data)
212 {
213 return i2c_send_recv(bus, &data, true);
214 }
215
216 uint8_t i2c_recv(I2CBus *bus)
217 {
218 uint8_t data = 0xff;
219
220 i2c_send_recv(bus, &data, false);
221 return data;
222 }
223
224 void i2c_nack(I2CBus *bus)
225 {
226 I2CSlaveClass *sc;
227 I2CNode *node;
228
229 if (QLIST_EMPTY(&bus->current_devs)) {
230 return;
231 }
232
233 QLIST_FOREACH(node, &bus->current_devs, next) {
234 sc = I2C_SLAVE_GET_CLASS(node->elt);
235 if (sc->event) {
236 trace_i2c_event("nack", node->elt->address);
237 sc->event(node->elt, I2C_NACK);
238 }
239 }
240 }
241
242 static int i2c_slave_post_load(void *opaque, int version_id)
243 {
244 I2CSlave *dev = opaque;
245 I2CBus *bus;
246 I2CNode *node;
247
248 bus = I2C_BUS(qdev_get_parent_bus(DEVICE(dev)));
249 if ((bus->saved_address == dev->address) ||
250 (bus->saved_address == I2C_BROADCAST)) {
251 node = g_malloc(sizeof(struct I2CNode));
252 node->elt = dev;
253 QLIST_INSERT_HEAD(&bus->current_devs, node, next);
254 }
255 return 0;
256 }
257
258 const VMStateDescription vmstate_i2c_slave = {
259 .name = "I2CSlave",
260 .version_id = 1,
261 .minimum_version_id = 1,
262 .post_load = i2c_slave_post_load,
263 .fields = (VMStateField[]) {
264 VMSTATE_UINT8(address, I2CSlave),
265 VMSTATE_END_OF_LIST()
266 }
267 };
268
269 DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr)
270 {
271 DeviceState *dev;
272
273 dev = qdev_create(&bus->qbus, name);
274 qdev_prop_set_uint8(dev, "address", addr);
275 qdev_init_nofail(dev);
276 return dev;
277 }
278
279 static void i2c_slave_class_init(ObjectClass *klass, void *data)
280 {
281 DeviceClass *k = DEVICE_CLASS(klass);
282 set_bit(DEVICE_CATEGORY_MISC, k->categories);
283 k->bus_type = TYPE_I2C_BUS;
284 device_class_set_props(k, i2c_props);
285 }
286
287 static const TypeInfo i2c_slave_type_info = {
288 .name = TYPE_I2C_SLAVE,
289 .parent = TYPE_DEVICE,
290 .instance_size = sizeof(I2CSlave),
291 .abstract = true,
292 .class_size = sizeof(I2CSlaveClass),
293 .class_init = i2c_slave_class_init,
294 };
295
296 static void i2c_slave_register_types(void)
297 {
298 type_register_static(&i2c_bus_info);
299 type_register_static(&i2c_slave_type_info);
300 }
301
302 type_init(i2c_slave_register_types)