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Commit | Line | Data |
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5fafdf24 | 1 | /* |
0ff596d0 PB |
2 | * QEMU I2C bus interface. |
3 | * | |
4 | * Copyright (c) 2007 CodeSourcery. | |
5 | * Written by Paul Brook | |
6 | * | |
7 | * This code is licenced under the LGPL. | |
8 | */ | |
9 | ||
87ecb68b | 10 | #include "i2c.h" |
0ff596d0 PB |
11 | |
12 | struct i2c_bus | |
13 | { | |
02e2da45 | 14 | BusState qbus; |
0ff596d0 PB |
15 | i2c_slave *current_dev; |
16 | i2c_slave *dev; | |
c701b35b | 17 | int saved_address; |
0ff596d0 PB |
18 | }; |
19 | ||
10c4c98a GH |
20 | static struct BusInfo i2c_bus_info = { |
21 | .name = "I2C", | |
22 | .size = sizeof(i2c_bus), | |
ee6847d1 GH |
23 | .props = (Property[]) { |
24 | { | |
25 | .name = "address", | |
26 | .info = &qdev_prop_uint32, | |
27 | .offset = offsetof(struct i2c_slave, address), | |
28 | }, | |
29 | {/* end of list */} | |
30 | } | |
10c4c98a GH |
31 | }; |
32 | ||
c701b35b PB |
33 | static void i2c_bus_save(QEMUFile *f, void *opaque) |
34 | { | |
35 | i2c_bus *bus = (i2c_bus *)opaque; | |
36 | ||
37 | qemu_put_byte(f, bus->current_dev ? bus->current_dev->address : -1); | |
38 | } | |
39 | ||
40 | static int i2c_bus_load(QEMUFile *f, void *opaque, int version_id) | |
41 | { | |
42 | i2c_bus *bus = (i2c_bus *)opaque; | |
43 | ||
44 | if (version_id != 1) | |
45 | return -EINVAL; | |
46 | ||
47 | /* The bus is loaded before attached devices, so load and save the | |
48 | current device id. Devices will check themselves as loaded. */ | |
d0c22f49 | 49 | bus->saved_address = (int8_t) qemu_get_byte(f); |
c701b35b PB |
50 | bus->current_dev = NULL; |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
0ff596d0 | 55 | /* Create a new I2C bus. */ |
02e2da45 | 56 | i2c_bus *i2c_init_bus(DeviceState *parent, const char *name) |
0ff596d0 PB |
57 | { |
58 | i2c_bus *bus; | |
59 | ||
10c4c98a | 60 | bus = FROM_QBUS(i2c_bus, qbus_create(&i2c_bus_info, parent, name)); |
c701b35b | 61 | register_savevm("i2c_bus", -1, 1, i2c_bus_save, i2c_bus_load, bus); |
0ff596d0 PB |
62 | return bus; |
63 | } | |
64 | ||
0ff596d0 PB |
65 | void i2c_set_slave_address(i2c_slave *dev, int address) |
66 | { | |
67 | dev->address = address; | |
68 | } | |
69 | ||
70 | /* Return nonzero if bus is busy. */ | |
71 | int i2c_bus_busy(i2c_bus *bus) | |
72 | { | |
73 | return bus->current_dev != NULL; | |
74 | } | |
75 | ||
4a2c8ac2 | 76 | /* Returns non-zero if the address is not valid. */ |
0ff596d0 PB |
77 | /* TODO: Make this handle multiple masters. */ |
78 | int i2c_start_transfer(i2c_bus *bus, int address, int recv) | |
79 | { | |
02e2da45 PB |
80 | DeviceState *qdev; |
81 | i2c_slave *slave = NULL; | |
0ff596d0 | 82 | |
02e2da45 PB |
83 | LIST_FOREACH(qdev, &bus->qbus.children, sibling) { |
84 | slave = I2C_SLAVE_FROM_QDEV(qdev); | |
85 | if (slave->address == address) | |
0ff596d0 PB |
86 | break; |
87 | } | |
88 | ||
02e2da45 | 89 | if (!slave) |
0ff596d0 PB |
90 | return 1; |
91 | ||
92 | /* If the bus is already busy, assume this is a repeated | |
93 | start condition. */ | |
02e2da45 PB |
94 | bus->current_dev = slave; |
95 | slave->info->event(slave, recv ? I2C_START_RECV : I2C_START_SEND); | |
0ff596d0 PB |
96 | return 0; |
97 | } | |
98 | ||
99 | void i2c_end_transfer(i2c_bus *bus) | |
100 | { | |
101 | i2c_slave *dev = bus->current_dev; | |
102 | ||
103 | if (!dev) | |
104 | return; | |
105 | ||
fe8de492 | 106 | dev->info->event(dev, I2C_FINISH); |
0ff596d0 PB |
107 | |
108 | bus->current_dev = NULL; | |
109 | } | |
110 | ||
111 | int i2c_send(i2c_bus *bus, uint8_t data) | |
112 | { | |
113 | i2c_slave *dev = bus->current_dev; | |
114 | ||
115 | if (!dev) | |
116 | return -1; | |
117 | ||
fe8de492 | 118 | return dev->info->send(dev, data); |
0ff596d0 PB |
119 | } |
120 | ||
121 | int i2c_recv(i2c_bus *bus) | |
122 | { | |
123 | i2c_slave *dev = bus->current_dev; | |
124 | ||
125 | if (!dev) | |
126 | return -1; | |
127 | ||
fe8de492 | 128 | return dev->info->recv(dev); |
0ff596d0 PB |
129 | } |
130 | ||
131 | void i2c_nack(i2c_bus *bus) | |
132 | { | |
133 | i2c_slave *dev = bus->current_dev; | |
134 | ||
135 | if (!dev) | |
136 | return; | |
137 | ||
fe8de492 | 138 | dev->info->event(dev, I2C_NACK); |
0ff596d0 PB |
139 | } |
140 | ||
aa941b94 AZ |
141 | void i2c_slave_save(QEMUFile *f, i2c_slave *dev) |
142 | { | |
143 | qemu_put_byte(f, dev->address); | |
144 | } | |
145 | ||
146 | void i2c_slave_load(QEMUFile *f, i2c_slave *dev) | |
147 | { | |
fe8de492 | 148 | i2c_bus *bus; |
02e2da45 | 149 | bus = FROM_QBUS(i2c_bus, qdev_get_parent_bus(&dev->qdev)); |
aa941b94 | 150 | dev->address = qemu_get_byte(f); |
fe8de492 PB |
151 | if (bus->saved_address == dev->address) { |
152 | bus->current_dev = dev; | |
153 | } | |
154 | } | |
155 | ||
02e2da45 | 156 | static void i2c_slave_qdev_init(DeviceState *dev, DeviceInfo *base) |
fe8de492 | 157 | { |
02e2da45 | 158 | I2CSlaveInfo *info = container_of(base, I2CSlaveInfo, qdev); |
fe8de492 PB |
159 | i2c_slave *s = I2C_SLAVE_FROM_QDEV(dev); |
160 | ||
161 | s->info = info; | |
fe8de492 | 162 | |
fe8de492 PB |
163 | info->init(s); |
164 | } | |
165 | ||
074f2fff | 166 | void i2c_register_slave(I2CSlaveInfo *info) |
fe8de492 | 167 | { |
074f2fff | 168 | assert(info->qdev.size >= sizeof(i2c_slave)); |
02e2da45 | 169 | info->qdev.init = i2c_slave_qdev_init; |
10c4c98a | 170 | info->qdev.bus_info = &i2c_bus_info; |
074f2fff | 171 | qdev_register(&info->qdev); |
fe8de492 PB |
172 | } |
173 | ||
174 | DeviceState *i2c_create_slave(i2c_bus *bus, const char *name, int addr) | |
175 | { | |
176 | DeviceState *dev; | |
177 | ||
02e2da45 | 178 | dev = qdev_create(&bus->qbus, name); |
ee6847d1 | 179 | qdev_prop_set_uint32(dev, "address", addr); |
fe8de492 PB |
180 | qdev_init(dev); |
181 | return dev; | |
aa941b94 | 182 | } |