1 #ifndef QEMU_I2C_H 2 #define QEMU_I2C_H 3 4 #include "hw/qdev.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 11 enum i2c_event { 12 I2C_START_RECV, 13 I2C_START_SEND, 14 I2C_FINISH, 15 I2C_NACK /* Masker NACKed a receive byte. */ 16 }; 17 18 typedef 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 28 typedef struct I2CSlaveClass { 29 DeviceClass parent_class; 30 31 /* Callbacks provided by the device. */ 32 int (*init)(I2CSlave *dev); 33 34 /* Master to slave. Returns non-zero for a NAK, 0 for success. */ 35 int (*send)(I2CSlave *s, uint8_t data); 36 37 /* 38 * Slave to master. This cannot fail, the device should always 39 * return something here. Negative values probably result in 0xff 40 * and a possible log from the driver, and shouldn't be used. 41 */ 42 int (*recv)(I2CSlave *s); 43 44 /* 45 * Notify the slave of a bus state change. For start event, 46 * returns non-zero to NAK an operation. For other events the 47 * return code is not used and should be zero. 48 */ 49 int (*event)(I2CSlave *s, enum i2c_event event); 50 } I2CSlaveClass; 51 52 struct I2CSlave { 53 DeviceState qdev; 54 55 /* Remaining fields for internal use by the I2C code. */ 56 uint8_t address; 57 }; 58 59 I2CBus *i2c_init_bus(DeviceState *parent, const char *name); 60 void i2c_set_slave_address(I2CSlave *dev, uint8_t address); 61 int i2c_bus_busy(I2CBus *bus); 62 int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv); 63 void i2c_end_transfer(I2CBus *bus); 64 void i2c_nack(I2CBus *bus); 65 int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send); 66 int i2c_send(I2CBus *bus, uint8_t data); 67 int i2c_recv(I2CBus *bus); 68 69 DeviceState *i2c_create_slave(I2CBus *bus, const char *name, uint8_t addr); 70 71 /* lm832x.c */ 72 void lm832x_key_event(DeviceState *dev, int key, int state); 73 74 extern const VMStateDescription vmstate_i2c_slave; 75 76 #define VMSTATE_I2C_SLAVE(_field, _state) { \ 77 .name = (stringify(_field)), \ 78 .size = sizeof(I2CSlave), \ 79 .vmsd = &vmstate_i2c_slave, \ 80 .flags = VMS_STRUCT, \ 81 .offset = vmstate_offset_value(_state, _field, I2CSlave), \ 82 } 83 84 #endif 85