vl6180_read_byte
ret = vl6180_read_byte(client, VL6180_INTR_STATUS);
vl6180_read_byte(client, vl6180_chan_regs_table[addr].value_reg);
ret = vl6180_read_byte(data->client,
ret = vl6180_read_byte(client, VL6180_MODEL_ID);
ret = vl6180_read_byte(client, VL6180_OUT_OF_RESET);