int smbus_read_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data);
void smbus_write_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data,
int len);
int smbus_read_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data);
void smbus_write_block(i2c_bus *bus, int addr, uint8_t command, uint8_t *data,
int len);