v4l2_ctrl_s_ctrl_string
v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, "");
v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, "");
v4l2_ctrl_s_ctrl_string(dev->rds_ps_name, text_buffer);
v4l2_ctrl_s_ctrl_string(dev->rds_radio_test, text_buffer + 1);
v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_psname, ctrl->p_new.p_char);
v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_radiotext, ctrl->p_new.p_char);
v4l2_ctrl_s_ctrl_string(dev->radio_tx_rds_psname, "VIVID-TX");
v4l2_ctrl_s_ctrl_string(dev->radio_tx_rds_radiotext,
v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_psname, rds->psname);
v4l2_ctrl_s_ctrl_string(dev->radio_rx_rds_radiotext, rds->radiotext);