1#ifndef QEMU_I2C_H
2#define QEMU_I2C_H
3
4#include "hw/qdev-core.h"
5
6/* The QEMU I2C implementation only supports simple transfers that complete
7 immediately. It does not support slave devices that need to be able to
8 defer their response (eg. CPU slave interfaces where the data is supplied
9 by the device driver in response to an interrupt). */
10
11enum i2c_event {
12 I2C_START_RECV,
13 I2C_START_SEND,
14 I2C_FINISH,
15 I2C_NACK /* Masker NACKed a receive byte. */
16};
17
18typedef struct I2CSlave I2CSlave;
19
20#define TYPE_I2C_SLAVE "i2c-slave"
21#define I2C_SLAVE(obj) \
22 OBJECT_CHECK(I2CSlave, (obj), TYPE_I2C_SLAVE)
23#define I2C_SLAVE_CLASS(klass) \
24 OBJECT_CLASS_CHECK(I2CSlaveClass, (klass), TYPE_I2C_SLAVE)
25#define I2C_SLAVE_GET_CLASS(obj) \
26 OBJECT_GET_CLASS(I2CSlaveClass, (obj), TYPE_I2C_SLAVE)
27
28typedef struct I2CSlaveClass {
29 DeviceClass parent_class;
30
31 /* Master to slave. Returns non-zero for a NAK, 0 for success. */
32 int (*send)(I2CSlave *s, uint8_t data);
33
34 /*
35 * Slave to master. This cannot fail, the device should always
36 * return something here.
37 */
38 uint8_t (*recv)(I2CSlave *s);
39
40 /*
41 * Notify the slave of a bus state change. For start event,
42 * returns non-zero to NAK an operation. For other events the
43 * return code is not used and should be zero.
44 */
45 int (*event)(I2CSlave *s, enum i2c_event event);
46} I2CSlaveClass;
47
48struct I2CSlave {
49 DeviceState qdev;
50
51 /* Remaining fields for internal use by the I2C code. */
52 uint8_t address;
53};
54
55#define TYPE_I2C_BUS "i2c-bus"
56#define I2C_BUS(obj) OBJECT_CHECK(I2CBus, (obj), TYPE_I2C_BUS)
57
58typedef struct I2CNode I2CNode;
59
60struct I2CNode {
61 I2CSlave *elt;
62 QLIST_ENTRY(I2CNode) next;
63};
64
65struct I2CBus {
66 BusState qbus;
67 QLIST_HEAD(, I2CNode) current_devs;
68 uint8_t saved_address;
69 bool broadcast;
70};
71
72I2CBus *i2c_init_bus(DeviceState *parent, const char *name);
73void i2c_set_slave_address(I2CSlave *dev, uint8_t address);
74int i2c_bus_busy(I2CBus *bus);
75int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv);
76void i2c_end_transfer(I2CBus *bus);
77void i2c_nack(I2CBus *bus);
78int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send);
79int i2c_send(I2CBus *bus, uint8_t data);
80uint8_t i2c_recv(I2CBus *bus);
81
82DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr);
83
84/* lm832x.c */
85void lm832x_key_event(DeviceState *dev, int key, int state);
86
87extern const VMStateDescription vmstate_i2c_slave;
88
89#define VMSTATE_I2C_SLAVE(_field, _state) { \
90 .name = (stringify(_field)), \
91 .size = sizeof(I2CSlave), \
92 .vmsd = &vmstate_i2c_slave, \
93 .flags = VMS_STRUCT, \
94 .offset = vmstate_offset_value(_state, _field, I2CSlave), \
95}
96
97#endif
98