dell_uart_bl_command
return dell_uart_bl_command(dell_bl, set_brightness, SET_CMD_LEN, resp, SET_RESP_LEN);
ret = dell_uart_bl_command(dell_bl, get_brightness, GET_CMD_LEN, resp, GET_RESP_LEN);
ret = dell_uart_bl_command(dell_bl, set_power, SET_CMD_LEN, resp, SET_RESP_LEN);
ret = dell_uart_bl_command(dell_bl, get_version, GET_CMD_LEN, resp, MAX_RESP_LEN);