get_cur_ctl_value
err = get_cur_ctl_value(cval, cval->control << 8, &val);
err = get_cur_ctl_value(cval, cval->control << 8, &oval);
err = get_cur_ctl_value(cval, cval->control << 8, &val);
err = get_cur_ctl_value(cval, cval->control << 8, &val);
err = get_cur_ctl_value(cval, cval->control << 8, &oval);