root / hw / i2c.c @ d8c6d07f
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1 | 5fafdf24 | ths | /*
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2 | 0ff596d0 | pbrook | * QEMU I2C bus interface.
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3 | 0ff596d0 | pbrook | *
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4 | 0ff596d0 | pbrook | * Copyright (c) 2007 CodeSourcery.
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5 | 0ff596d0 | pbrook | * Written by Paul Brook
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6 | 0ff596d0 | pbrook | *
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7 | 8e31bf38 | Matthew Fernandez | * This code is licensed under the LGPL.
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8 | 0ff596d0 | pbrook | */
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9 | 0ff596d0 | pbrook | |
10 | 87ecb68b | pbrook | #include "i2c.h" |
11 | 0ff596d0 | pbrook | |
12 | 0ff596d0 | pbrook | struct i2c_bus
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13 | 0ff596d0 | pbrook | { |
14 | 02e2da45 | Paul Brook | BusState qbus; |
15 | 9e07bdf8 | Anthony Liguori | I2CSlave *current_dev; |
16 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev; |
17 | 5b7f5327 | Juan Quintela | uint8_t saved_address; |
18 | 0ff596d0 | pbrook | }; |
19 | 0ff596d0 | pbrook | |
20 | 3cb75a7c | Paolo Bonzini | static Property i2c_props[] = {
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21 | 3cb75a7c | Paolo Bonzini | DEFINE_PROP_UINT8("address", struct I2CSlave, address, 0), |
22 | 3cb75a7c | Paolo Bonzini | DEFINE_PROP_END_OF_LIST(), |
23 | 3cb75a7c | Paolo Bonzini | }; |
24 | 3cb75a7c | Paolo Bonzini | |
25 | 0d936928 | Anthony Liguori | #define TYPE_I2C_BUS "i2c-bus" |
26 | 0d936928 | Anthony Liguori | #define I2C_BUS(obj) OBJECT_CHECK(i2c_bus, (obj), TYPE_I2C_BUS)
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27 | 0d936928 | Anthony Liguori | |
28 | 0d936928 | Anthony Liguori | static const TypeInfo i2c_bus_info = { |
29 | 0d936928 | Anthony Liguori | .name = TYPE_I2C_BUS, |
30 | 0d936928 | Anthony Liguori | .parent = TYPE_BUS, |
31 | 0d936928 | Anthony Liguori | .instance_size = sizeof(i2c_bus),
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32 | 10c4c98a | Gerd Hoffmann | }; |
33 | 10c4c98a | Gerd Hoffmann | |
34 | 8d0eb050 | Juan Quintela | static void i2c_bus_pre_save(void *opaque) |
35 | c701b35b | pbrook | { |
36 | 8d0eb050 | Juan Quintela | i2c_bus *bus = opaque; |
37 | c701b35b | pbrook | |
38 | 8d0eb050 | Juan Quintela | bus->saved_address = bus->current_dev ? bus->current_dev->address : -1;
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39 | c701b35b | pbrook | } |
40 | c701b35b | pbrook | |
41 | 8d0eb050 | Juan Quintela | static int i2c_bus_post_load(void *opaque, int version_id) |
42 | c701b35b | pbrook | { |
43 | 8d0eb050 | Juan Quintela | i2c_bus *bus = opaque; |
44 | c701b35b | pbrook | |
45 | c701b35b | pbrook | /* The bus is loaded before attached devices, so load and save the
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46 | c701b35b | pbrook | current device id. Devices will check themselves as loaded. */
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47 | c701b35b | pbrook | bus->current_dev = NULL;
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48 | c701b35b | pbrook | return 0; |
49 | c701b35b | pbrook | } |
50 | c701b35b | pbrook | |
51 | 8d0eb050 | Juan Quintela | static const VMStateDescription vmstate_i2c_bus = { |
52 | 8d0eb050 | Juan Quintela | .name = "i2c_bus",
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53 | 8d0eb050 | Juan Quintela | .version_id = 1,
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54 | 8d0eb050 | Juan Quintela | .minimum_version_id = 1,
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55 | 8d0eb050 | Juan Quintela | .minimum_version_id_old = 1,
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56 | 8d0eb050 | Juan Quintela | .pre_save = i2c_bus_pre_save, |
57 | 8d0eb050 | Juan Quintela | .post_load = i2c_bus_post_load, |
58 | 8d0eb050 | Juan Quintela | .fields = (VMStateField []) { |
59 | 8d0eb050 | Juan Quintela | VMSTATE_UINT8(saved_address, i2c_bus), |
60 | 8d0eb050 | Juan Quintela | VMSTATE_END_OF_LIST() |
61 | 8d0eb050 | Juan Quintela | } |
62 | 8d0eb050 | Juan Quintela | }; |
63 | 8d0eb050 | Juan Quintela | |
64 | 0ff596d0 | pbrook | /* Create a new I2C bus. */
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65 | 02e2da45 | Paul Brook | i2c_bus *i2c_init_bus(DeviceState *parent, const char *name) |
66 | 0ff596d0 | pbrook | { |
67 | 0ff596d0 | pbrook | i2c_bus *bus; |
68 | 0ff596d0 | pbrook | |
69 | 0d936928 | Anthony Liguori | bus = FROM_QBUS(i2c_bus, qbus_create(TYPE_I2C_BUS, parent, name)); |
70 | 0be71e32 | Alex Williamson | vmstate_register(NULL, -1, &vmstate_i2c_bus, bus); |
71 | 0ff596d0 | pbrook | return bus;
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72 | 0ff596d0 | pbrook | } |
73 | 0ff596d0 | pbrook | |
74 | 9e07bdf8 | Anthony Liguori | void i2c_set_slave_address(I2CSlave *dev, uint8_t address)
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75 | 0ff596d0 | pbrook | { |
76 | 0ff596d0 | pbrook | dev->address = address; |
77 | 0ff596d0 | pbrook | } |
78 | 0ff596d0 | pbrook | |
79 | 0ff596d0 | pbrook | /* Return nonzero if bus is busy. */
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80 | 0ff596d0 | pbrook | int i2c_bus_busy(i2c_bus *bus)
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81 | 0ff596d0 | pbrook | { |
82 | 0ff596d0 | pbrook | return bus->current_dev != NULL; |
83 | 0ff596d0 | pbrook | } |
84 | 0ff596d0 | pbrook | |
85 | 4a2c8ac2 | balrog | /* Returns non-zero if the address is not valid. */
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86 | 0ff596d0 | pbrook | /* TODO: Make this handle multiple masters. */
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87 | 5b7f5327 | Juan Quintela | int i2c_start_transfer(i2c_bus *bus, uint8_t address, int recv) |
88 | 0ff596d0 | pbrook | { |
89 | 0866aca1 | Anthony Liguori | BusChild *kid; |
90 | 9e07bdf8 | Anthony Liguori | I2CSlave *slave = NULL;
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91 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc; |
92 | 0ff596d0 | pbrook | |
93 | 0866aca1 | Anthony Liguori | QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { |
94 | 0866aca1 | Anthony Liguori | DeviceState *qdev = kid->child; |
95 | 9e07bdf8 | Anthony Liguori | I2CSlave *candidate = I2C_SLAVE_FROM_QDEV(qdev); |
96 | b3a21988 | Juha Riihimäki | if (candidate->address == address) {
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97 | b3a21988 | Juha Riihimäki | slave = candidate; |
98 | 0ff596d0 | pbrook | break;
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99 | b3a21988 | Juha Riihimäki | } |
100 | 0ff596d0 | pbrook | } |
101 | 0ff596d0 | pbrook | |
102 | b5ea9327 | Anthony Liguori | if (!slave) {
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103 | 0ff596d0 | pbrook | return 1; |
104 | b5ea9327 | Anthony Liguori | } |
105 | 0ff596d0 | pbrook | |
106 | b5ea9327 | Anthony Liguori | sc = I2C_SLAVE_GET_CLASS(slave); |
107 | 0ff596d0 | pbrook | /* If the bus is already busy, assume this is a repeated
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108 | 0ff596d0 | pbrook | start condition. */
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109 | 02e2da45 | Paul Brook | bus->current_dev = slave; |
110 | b5ea9327 | Anthony Liguori | if (sc->event) {
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111 | b5ea9327 | Anthony Liguori | sc->event(slave, recv ? I2C_START_RECV : I2C_START_SEND); |
112 | b5ea9327 | Anthony Liguori | } |
113 | 0ff596d0 | pbrook | return 0; |
114 | 0ff596d0 | pbrook | } |
115 | 0ff596d0 | pbrook | |
116 | 0ff596d0 | pbrook | void i2c_end_transfer(i2c_bus *bus)
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117 | 0ff596d0 | pbrook | { |
118 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev = bus->current_dev; |
119 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc; |
120 | 0ff596d0 | pbrook | |
121 | b5ea9327 | Anthony Liguori | if (!dev) {
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122 | 0ff596d0 | pbrook | return;
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123 | b5ea9327 | Anthony Liguori | } |
124 | 0ff596d0 | pbrook | |
125 | b5ea9327 | Anthony Liguori | sc = I2C_SLAVE_GET_CLASS(dev); |
126 | b5ea9327 | Anthony Liguori | if (sc->event) {
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127 | b5ea9327 | Anthony Liguori | sc->event(dev, I2C_FINISH); |
128 | b5ea9327 | Anthony Liguori | } |
129 | 0ff596d0 | pbrook | |
130 | 0ff596d0 | pbrook | bus->current_dev = NULL;
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131 | 0ff596d0 | pbrook | } |
132 | 0ff596d0 | pbrook | |
133 | 0ff596d0 | pbrook | int i2c_send(i2c_bus *bus, uint8_t data)
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134 | 0ff596d0 | pbrook | { |
135 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev = bus->current_dev; |
136 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc; |
137 | 0ff596d0 | pbrook | |
138 | b5ea9327 | Anthony Liguori | if (!dev) {
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139 | 0ff596d0 | pbrook | return -1; |
140 | b5ea9327 | Anthony Liguori | } |
141 | 0ff596d0 | pbrook | |
142 | b5ea9327 | Anthony Liguori | sc = I2C_SLAVE_GET_CLASS(dev); |
143 | b5ea9327 | Anthony Liguori | if (sc->send) {
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144 | b5ea9327 | Anthony Liguori | return sc->send(dev, data);
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145 | b5ea9327 | Anthony Liguori | } |
146 | b5ea9327 | Anthony Liguori | |
147 | b5ea9327 | Anthony Liguori | return -1; |
148 | 0ff596d0 | pbrook | } |
149 | 0ff596d0 | pbrook | |
150 | 0ff596d0 | pbrook | int i2c_recv(i2c_bus *bus)
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151 | 0ff596d0 | pbrook | { |
152 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev = bus->current_dev; |
153 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc; |
154 | 0ff596d0 | pbrook | |
155 | b5ea9327 | Anthony Liguori | if (!dev) {
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156 | 0ff596d0 | pbrook | return -1; |
157 | b5ea9327 | Anthony Liguori | } |
158 | b5ea9327 | Anthony Liguori | |
159 | b5ea9327 | Anthony Liguori | sc = I2C_SLAVE_GET_CLASS(dev); |
160 | b5ea9327 | Anthony Liguori | if (sc->recv) {
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161 | b5ea9327 | Anthony Liguori | return sc->recv(dev);
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162 | b5ea9327 | Anthony Liguori | } |
163 | 0ff596d0 | pbrook | |
164 | b5ea9327 | Anthony Liguori | return -1; |
165 | 0ff596d0 | pbrook | } |
166 | 0ff596d0 | pbrook | |
167 | 0ff596d0 | pbrook | void i2c_nack(i2c_bus *bus)
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168 | 0ff596d0 | pbrook | { |
169 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev = bus->current_dev; |
170 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc; |
171 | 0ff596d0 | pbrook | |
172 | b5ea9327 | Anthony Liguori | if (!dev) {
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173 | 0ff596d0 | pbrook | return;
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174 | b5ea9327 | Anthony Liguori | } |
175 | 0ff596d0 | pbrook | |
176 | b5ea9327 | Anthony Liguori | sc = I2C_SLAVE_GET_CLASS(dev); |
177 | b5ea9327 | Anthony Liguori | if (sc->event) {
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178 | b5ea9327 | Anthony Liguori | sc->event(dev, I2C_NACK); |
179 | b5ea9327 | Anthony Liguori | } |
180 | 0ff596d0 | pbrook | } |
181 | 0ff596d0 | pbrook | |
182 | bcbe8068 | Juan Quintela | static int i2c_slave_post_load(void *opaque, int version_id) |
183 | aa941b94 | balrog | { |
184 | 9e07bdf8 | Anthony Liguori | I2CSlave *dev = opaque; |
185 | fe8de492 | Paul Brook | i2c_bus *bus; |
186 | 02e2da45 | Paul Brook | bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev)); |
187 | fe8de492 | Paul Brook | if (bus->saved_address == dev->address) {
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188 | fe8de492 | Paul Brook | bus->current_dev = dev; |
189 | fe8de492 | Paul Brook | } |
190 | bcbe8068 | Juan Quintela | return 0; |
191 | bcbe8068 | Juan Quintela | } |
192 | bcbe8068 | Juan Quintela | |
193 | 1894839f | Juan Quintela | const VMStateDescription vmstate_i2c_slave = {
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194 | 9e07bdf8 | Anthony Liguori | .name = "I2CSlave",
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195 | bcbe8068 | Juan Quintela | .version_id = 1,
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196 | bcbe8068 | Juan Quintela | .minimum_version_id = 1,
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197 | bcbe8068 | Juan Quintela | .minimum_version_id_old = 1,
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198 | bcbe8068 | Juan Quintela | .post_load = i2c_slave_post_load, |
199 | bcbe8068 | Juan Quintela | .fields = (VMStateField []) { |
200 | 9e07bdf8 | Anthony Liguori | VMSTATE_UINT8(address, I2CSlave), |
201 | bcbe8068 | Juan Quintela | VMSTATE_END_OF_LIST() |
202 | bcbe8068 | Juan Quintela | } |
203 | bcbe8068 | Juan Quintela | }; |
204 | bcbe8068 | Juan Quintela | |
205 | d307af79 | Anthony Liguori | static int i2c_slave_qdev_init(DeviceState *dev) |
206 | fe8de492 | Paul Brook | { |
207 | 9e07bdf8 | Anthony Liguori | I2CSlave *s = I2C_SLAVE_FROM_QDEV(dev); |
208 | b5ea9327 | Anthony Liguori | I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(s); |
209 | fe8de492 | Paul Brook | |
210 | b5ea9327 | Anthony Liguori | return sc->init(s);
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211 | b5ea9327 | Anthony Liguori | } |
212 | fe8de492 | Paul Brook | |
213 | 5b7f5327 | Juan Quintela | DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, uint8_t addr) |
214 | fe8de492 | Paul Brook | { |
215 | fe8de492 | Paul Brook | DeviceState *dev; |
216 | fe8de492 | Paul Brook | |
217 | 02e2da45 | Paul Brook | dev = qdev_create(&bus->qbus, name); |
218 | 5b7f5327 | Juan Quintela | qdev_prop_set_uint8(dev, "address", addr);
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219 | e23a1b33 | Markus Armbruster | qdev_init_nofail(dev); |
220 | fe8de492 | Paul Brook | return dev;
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221 | aa941b94 | balrog | } |
222 | b5ea9327 | Anthony Liguori | |
223 | 39bffca2 | Anthony Liguori | static void i2c_slave_class_init(ObjectClass *klass, void *data) |
224 | 39bffca2 | Anthony Liguori | { |
225 | 39bffca2 | Anthony Liguori | DeviceClass *k = DEVICE_CLASS(klass); |
226 | 39bffca2 | Anthony Liguori | k->init = i2c_slave_qdev_init; |
227 | 0d936928 | Anthony Liguori | k->bus_type = TYPE_I2C_BUS; |
228 | bce54474 | Paolo Bonzini | k->props = i2c_props; |
229 | 39bffca2 | Anthony Liguori | } |
230 | 39bffca2 | Anthony Liguori | |
231 | 8c43a6f0 | Andreas Färber | static const TypeInfo i2c_slave_type_info = { |
232 | b5ea9327 | Anthony Liguori | .name = TYPE_I2C_SLAVE, |
233 | b5ea9327 | Anthony Liguori | .parent = TYPE_DEVICE, |
234 | b5ea9327 | Anthony Liguori | .instance_size = sizeof(I2CSlave),
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235 | b5ea9327 | Anthony Liguori | .abstract = true,
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236 | b5ea9327 | Anthony Liguori | .class_size = sizeof(I2CSlaveClass),
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237 | 39bffca2 | Anthony Liguori | .class_init = i2c_slave_class_init, |
238 | b5ea9327 | Anthony Liguori | }; |
239 | b5ea9327 | Anthony Liguori | |
240 | 83f7d43a | Andreas Färber | static void i2c_slave_register_types(void) |
241 | b5ea9327 | Anthony Liguori | { |
242 | 0d936928 | Anthony Liguori | type_register_static(&i2c_bus_info); |
243 | b5ea9327 | Anthony Liguori | type_register_static(&i2c_slave_type_info); |
244 | b5ea9327 | Anthony Liguori | } |
245 | b5ea9327 | Anthony Liguori | |
246 | 83f7d43a | Andreas Färber | type_init(i2c_slave_register_types) |