i2c_ctrl_discover_step
while ((iret = i2c_ctrl_discover_step(iter, &disc)) == I2C_ITER_VALID) {
extern i2c_iter_t i2c_ctrl_discover_step(i2c_ctrl_iter_t *,
while ((ret = i2c_ctrl_discover_step(iter, &disc)) == I2C_ITER_VALID) {