hw/i2c.h

   1 #ifndef QEMU_I2C_H
   2 #define QEMU_I2C_H
   3
   4 /* The QEMU I2C implementation only supports simple transfers that complete
   5    immediately.  It does not support slave devices that need to be able to
   6    defer their response (eg. CPU slave interfaces where the data is supplied
   7    by the device driver in response to an interrupt).  */
   8
   9 enum i2c_event {
  10     I2C_START_RECV,
  11     I2C_START_SEND,
  12     I2C_FINISH,
  13     I2C_NACK /* Masker NACKed a recieve byte.  */
  14 };
  15
  16 typedef struct i2c_slave i2c_slave;
  17
  18 /* Master to slave.  */
  19 typedef int (*i2c_send_cb)(i2c_slave *s, uint8_t data);
  20 /* Slave to master.  */
  21 typedef int (*i2c_recv_cb)(i2c_slave *s);
  22 /* Notify the slave of a bus state change.  */
  23 typedef void (*i2c_event_cb)(i2c_slave *s, enum i2c_event event);
  24
  25 struct i2c_slave
  26 {
  27     /* Callbacks to be set by the device.  */
  28     i2c_event_cb event;
  29     i2c_recv_cb recv;
  30     i2c_send_cb send;
  31
  32     /* Remaining fields for internal use by the I2C code.  */
  33     int address;
  34     void *next;
  35 };
  36
  37 typedef struct i2c_bus i2c_bus;
  38
  39 i2c_bus *i2c_init_bus(void);
  40 i2c_slave *i2c_slave_init(i2c_bus *bus, int address, int size);
  41 void i2c_set_slave_address(i2c_slave *dev, int address);
  42 int i2c_bus_busy(i2c_bus *bus);
  43 int i2c_start_transfer(i2c_bus *bus, int address, int recv);
  44 void i2c_end_transfer(i2c_bus *bus);
  45 void i2c_nack(i2c_bus *bus);
  46 int i2c_send(i2c_bus *bus, uint8_t data);
  47 int i2c_recv(i2c_bus *bus);
  48
  49 #endif