RKCANFD_REG_MODE_RXSTX_MODE |
                RKCANFD_REG_MODE_WORK_MODE;
 
+       if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
+               priv->reg_mode_default |= RKCANFD_REG_MODE_LBACK_MODE |
+                       RKCANFD_REG_MODE_SILENT_MODE |
+                       RKCANFD_REG_MODE_SELF_TEST;
+
        /* mask, i.e. ignore:
         * - TIMESTAMP_COUNTER_OVERFLOW_INT - timestamp counter overflow interrupt
         * - TX_ARBIT_FAIL_INT - TX arbitration fail interrupt
        priv->can.clock.freq = clk_get_rate(priv->clks[0].clk);
        priv->can.bittiming_const = &rkcanfd_bittiming_const;
        priv->can.data_bittiming_const = &rkcanfd_data_bittiming_const;
-       priv->can.ctrlmode_supported = 0;
+       priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK;
        if (!(priv->devtype_data.quirks & RKCANFD_QUIRK_CANFD_BROKEN))
                priv->can.ctrlmode_supported |= CAN_CTRLMODE_FD;
        priv->can.do_set_mode = rkcanfd_set_mode;