diff --git a/drivers/net/wireless/realtek/rtw89/ser.c b/drivers/net/wireless/realtek/rtw89/ser.c
new file mode 100644
index 000000000000..887edd6dd2b0
--- /dev/null
+++ b/drivers/net/wireless/realtek/rtw89/ser.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/* Copyright(c) 2019-2020  Realtek Corporation
+ */
+
+#include "cam.h"
+#include "debug.h"
+#include "mac.h"
+#include "ps.h"
+#include "ser.h"
+#include "util.h"
+
+#define SER_RECFG_TIMEOUT 1000
+
+enum ser_evt {
+	SER_EV_NONE,
+	SER_EV_STATE_IN,
+	SER_EV_STATE_OUT,
+	SER_EV_L1_RESET, /* M1 */
+	SER_EV_DO_RECOVERY, /* M3 */
+	SER_EV_MAC_RESET_DONE, /* M5 */
+	SER_EV_L2_RESET,
+	SER_EV_L2_RECFG_DONE,
+	SER_EV_L2_RECFG_TIMEOUT,
+	SER_EV_M3_TIMEOUT,
+	SER_EV_FW_M5_TIMEOUT,
+	SER_EV_L0_RESET,
+	SER_EV_MAXX
+};
+
+enum ser_state {
+	SER_IDLE_ST,
+	SER_RESET_TRX_ST,
+	SER_DO_HCI_ST,
+	SER_L2_RESET_ST,
+	SER_ST_MAX_ST
+};
+
+struct ser_msg {
+	struct list_head list;
+	u8 event;
+};
+
+struct state_ent {
+	u8 state;
+	char *name;
+	void (*st_func)(struct rtw89_ser *ser, u8 event);
+};
+
+struct event_ent {
+	u8 event;
+	char *name;
+};
+
+static char *ser_ev_name(struct rtw89_ser *ser, u8 event)
+{
+	if (event < SER_EV_MAXX)
+		return ser->ev_tbl[event].name;
+
+	return "err_ev_name";
+}
+
+static char *ser_st_name(struct rtw89_ser *ser)
+{
+	if (ser->state < SER_ST_MAX_ST)
+		return ser->st_tbl[ser->state].name;
+
+	return "err_st_name";
+}
+
+static void ser_state_run(struct rtw89_ser *ser, u8 evt)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	rtw89_debug(rtwdev, RTW89_DBG_SER, "ser: %s receive %s\n",
+		    ser_st_name(ser), ser_ev_name(ser, evt));
+
+	rtw89_leave_lps(rtwdev, false);
+	ser->st_tbl[ser->state].st_func(ser, evt);
+}
+
+static void ser_state_goto(struct rtw89_ser *ser, u8 new_state)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	if (ser->state == new_state || new_state >= SER_ST_MAX_ST)
+		return;
+	ser_state_run(ser, SER_EV_STATE_OUT);
+
+	rtw89_debug(rtwdev, RTW89_DBG_SER, "ser: %s goto -> %s\n",
+		    ser_st_name(ser), ser->st_tbl[new_state].name);
+
+	ser->state = new_state;
+	ser_state_run(ser, SER_EV_STATE_IN);
+}
+
+static struct ser_msg *__rtw89_ser_dequeue_msg(struct rtw89_ser *ser)
+{
+	struct ser_msg *msg;
+
+	spin_lock_irq(&ser->msg_q_lock);
+	msg = list_first_entry_or_null(&ser->msg_q, struct ser_msg, list);
+	if (msg)
+		list_del(&msg->list);
+	spin_unlock_irq(&ser->msg_q_lock);
+
+	return msg;
+}
+
+static void rtw89_ser_hdl_work(struct work_struct *work)
+{
+	struct ser_msg *msg;
+	struct rtw89_ser *ser = container_of(work, struct rtw89_ser,
+					     ser_hdl_work);
+
+	while ((msg = __rtw89_ser_dequeue_msg(ser))) {
+		ser_state_run(ser, msg->event);
+		kfree(msg);
+	}
+}
+
+static int ser_send_msg(struct rtw89_ser *ser, u8 event)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+	struct ser_msg *msg = NULL;
+
+	if (test_bit(RTW89_SER_DRV_STOP_RUN, ser->flags))
+		return -EIO;
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	if (!msg)
+		return -ENOMEM;
+
+	msg->event = event;
+
+	spin_lock_irq(&ser->msg_q_lock);
+	list_add(&msg->list, &ser->msg_q);
+	spin_unlock_irq(&ser->msg_q_lock);
+
+	ieee80211_queue_work(rtwdev->hw, &ser->ser_hdl_work);
+	return 0;
+}
+
+static void rtw89_ser_alarm_work(struct work_struct *work)
+{
+	struct rtw89_ser *ser = container_of(work, struct rtw89_ser,
+					     ser_alarm_work.work);
+
+	ser_send_msg(ser, ser->alarm_event);
+	ser->alarm_event = SER_EV_NONE;
+}
+
+static void ser_set_alarm(struct rtw89_ser *ser, u32 ms, u8 event)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	if (test_bit(RTW89_SER_DRV_STOP_RUN, ser->flags))
+		return;
+
+	ser->alarm_event = event;
+	ieee80211_queue_delayed_work(rtwdev->hw, &ser->ser_alarm_work,
+				     msecs_to_jiffies(ms));
+}
+
+static void ser_del_alarm(struct rtw89_ser *ser)
+{
+	cancel_delayed_work(&ser->ser_alarm_work);
+	ser->alarm_event = SER_EV_NONE;
+}
+
+/* driver function */
+static void drv_stop_tx(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	ieee80211_stop_queues(rtwdev->hw);
+	set_bit(RTW89_SER_DRV_STOP_TX, ser->flags);
+}
+
+static void drv_stop_rx(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	clear_bit(RTW89_FLAG_RUNNING, rtwdev->flags);
+	set_bit(RTW89_SER_DRV_STOP_RX, ser->flags);
+}
+
+static void drv_trx_reset(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	rtw89_hci_reset(rtwdev);
+}
+
+static void drv_resume_tx(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	if (!test_bit(RTW89_SER_DRV_STOP_TX, ser->flags))
+		return;
+
+	ieee80211_wake_queues(rtwdev->hw);
+	clear_bit(RTW89_SER_DRV_STOP_TX, ser->flags);
+}
+
+static void drv_resume_rx(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	if (!test_bit(RTW89_SER_DRV_STOP_RX, ser->flags))
+		return;
+
+	set_bit(RTW89_FLAG_RUNNING, rtwdev->flags);
+	clear_bit(RTW89_SER_DRV_STOP_RX, ser->flags);
+}
+
+static void ser_reset_vif_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
+{
+	struct rtw89_dev *rtwdev = (struct rtw89_dev *)data;
+	struct rtw89_vif *rtwvif = (struct rtw89_vif *)vif->drv_priv;
+
+	rtw89_core_release_bit_map(rtwdev->hw_port, rtwvif->port);
+	rtwvif->net_type = RTW89_NET_TYPE_NO_LINK;
+	rtwvif->trigger = false;
+}
+
+static void ser_reset_mac_binding(struct rtw89_dev *rtwdev)
+{
+	rtw89_cam_reset_keys(rtwdev);
+	rtw89_core_release_all_bits_map(rtwdev->mac_id_map, RTW89_MAX_MAC_ID_NUM);
+	rtw89_iterate_vifs(rtwdev, ser_reset_vif_iter, rtwdev, false);
+}
+
+/* hal function */
+static int hal_enable_dma(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+	int ret;
+
+	if (!test_bit(RTW89_SER_HAL_STOP_DMA, ser->flags))
+		return 0;
+
+	if (!rtwdev->hci.ops->mac_lv1_rcvy)
+		return -EIO;
+
+	ret = rtwdev->hci.ops->mac_lv1_rcvy(rtwdev, RTW89_LV1_RCVY_STEP_2);
+	if (!ret)
+		clear_bit(RTW89_SER_HAL_STOP_DMA, ser->flags);
+
+	return ret;
+}
+
+static int hal_stop_dma(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+	int ret;
+
+	if (!rtwdev->hci.ops->mac_lv1_rcvy)
+		return -EIO;
+
+	ret = rtwdev->hci.ops->mac_lv1_rcvy(rtwdev, RTW89_LV1_RCVY_STEP_1);
+	if (!ret)
+		set_bit(RTW89_SER_HAL_STOP_DMA, ser->flags);
+
+	return ret;
+}
+
+static void hal_send_m2_event(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	rtw89_mac_set_err_status(rtwdev, MAC_AX_ERR_L1_DISABLE_EN);
+}
+
+static void hal_send_m4_event(struct rtw89_ser *ser)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	rtw89_mac_set_err_status(rtwdev, MAC_AX_ERR_L1_RCVY_EN);
+}
+
+/* state handler */
+static void ser_idle_st_hdl(struct rtw89_ser *ser, u8 evt)
+{
+	switch (evt) {
+	case SER_EV_STATE_IN:
+		break;
+	case SER_EV_L1_RESET:
+		ser_state_goto(ser, SER_RESET_TRX_ST);
+		break;
+	case SER_EV_L2_RESET:
+		ser_state_goto(ser, SER_L2_RESET_ST);
+		break;
+	case SER_EV_STATE_OUT:
+	default:
+		break;
+	}
+}
+
+static void ser_reset_trx_st_hdl(struct rtw89_ser *ser, u8 evt)
+{
+	switch (evt) {
+	case SER_EV_STATE_IN:
+		drv_stop_tx(ser);
+
+		if (hal_stop_dma(ser)) {
+			ser_state_goto(ser, SER_L2_RESET_ST);
+			break;
+		}
+
+		drv_stop_rx(ser);
+		drv_trx_reset(ser);
+
+		/* wait m3 */
+		hal_send_m2_event(ser);
+
+		/* set alarm to prevent FW response timeout */
+		ser_set_alarm(ser, 1000, SER_EV_M3_TIMEOUT);
+		break;
+
+	case SER_EV_DO_RECOVERY:
+		ser_state_goto(ser, SER_DO_HCI_ST);
+		break;
+
+	case SER_EV_M3_TIMEOUT:
+		ser_state_goto(ser, SER_L2_RESET_ST);
+		break;
+
+	case SER_EV_STATE_OUT:
+		ser_del_alarm(ser);
+		hal_enable_dma(ser);
+		drv_resume_rx(ser);
+		drv_resume_tx(ser);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void ser_do_hci_st_hdl(struct rtw89_ser *ser, u8 evt)
+{
+	switch (evt) {
+	case SER_EV_STATE_IN:
+		/* wait m5 */
+		hal_send_m4_event(ser);
+
+		/* prevent FW response timeout */
+		ser_set_alarm(ser, 1000, SER_EV_FW_M5_TIMEOUT);
+		break;
+
+	case SER_EV_FW_M5_TIMEOUT:
+		ser_state_goto(ser, SER_L2_RESET_ST);
+		break;
+
+	case SER_EV_MAC_RESET_DONE:
+		ser_state_goto(ser, SER_IDLE_ST);
+		break;
+
+	case SER_EV_STATE_OUT:
+		ser_del_alarm(ser);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static void ser_l2_reset_st_hdl(struct rtw89_ser *ser, u8 evt)
+{
+	struct rtw89_dev *rtwdev = container_of(ser, struct rtw89_dev, ser);
+
+	switch (evt) {
+	case SER_EV_STATE_IN:
+		mutex_lock(&rtwdev->mutex);
+		ser_reset_mac_binding(rtwdev);
+		rtw89_core_stop(rtwdev);
+		mutex_unlock(&rtwdev->mutex);
+
+		ieee80211_restart_hw(rtwdev->hw);
+		ser_set_alarm(ser, SER_RECFG_TIMEOUT, SER_EV_L2_RECFG_TIMEOUT);
+		break;
+
+	case SER_EV_L2_RECFG_TIMEOUT:
+		rtw89_info(rtwdev, "Err: ser L2 re-config timeout\n");
+		fallthrough;
+	case SER_EV_L2_RECFG_DONE:
+		ser_state_goto(ser, SER_IDLE_ST);
+		break;
+
+	case SER_EV_STATE_OUT:
+		ser_del_alarm(ser);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static struct event_ent ser_ev_tbl[] = {
+	{SER_EV_NONE, "SER_EV_NONE"},
+	{SER_EV_STATE_IN, "SER_EV_STATE_IN"},
+	{SER_EV_STATE_OUT, "SER_EV_STATE_OUT"},
+	{SER_EV_L1_RESET, "SER_EV_L1_RESET"},
+	{SER_EV_DO_RECOVERY, "SER_EV_DO_RECOVERY m3"},
+	{SER_EV_MAC_RESET_DONE, "SER_EV_MAC_RESET_DONE m5"},
+	{SER_EV_L2_RESET, "SER_EV_L2_RESET"},
+	{SER_EV_L2_RECFG_DONE, "SER_EV_L2_RECFG_DONE"},
+	{SER_EV_L2_RECFG_TIMEOUT, "SER_EV_L2_RECFG_TIMEOUT"},
+	{SER_EV_M3_TIMEOUT, "SER_EV_M3_TIMEOUT"},
+	{SER_EV_FW_M5_TIMEOUT, "SER_EV_FW_M5_TIMEOUT"},
+	{SER_EV_L0_RESET, "SER_EV_L0_RESET"},
+	{SER_EV_MAXX, "SER_EV_MAX"}
+};
+
+static struct state_ent ser_st_tbl[] = {
+	{SER_IDLE_ST, "SER_IDLE_ST", ser_idle_st_hdl},
+	{SER_RESET_TRX_ST, "SER_RESET_TRX_ST", ser_reset_trx_st_hdl},
+	{SER_DO_HCI_ST, "SER_DO_HCI_ST", ser_do_hci_st_hdl},
+	{SER_L2_RESET_ST, "SER_L2_RESET_ST", ser_l2_reset_st_hdl}
+};
+
+int rtw89_ser_init(struct rtw89_dev *rtwdev)
+{
+	struct rtw89_ser *ser = &rtwdev->ser;
+
+	memset(ser, 0, sizeof(*ser));
+	INIT_LIST_HEAD(&ser->msg_q);
+	ser->state = SER_IDLE_ST;
+	ser->st_tbl = ser_st_tbl;
+	ser->ev_tbl = ser_ev_tbl;
+
+	bitmap_zero(ser->flags, RTW89_NUM_OF_SER_FLAGS);
+	spin_lock_init(&ser->msg_q_lock);
+	INIT_WORK(&ser->ser_hdl_work, rtw89_ser_hdl_work);
+	INIT_DELAYED_WORK(&ser->ser_alarm_work, rtw89_ser_alarm_work);
+	return 0;
+}
+
+int rtw89_ser_deinit(struct rtw89_dev *rtwdev)
+{
+	struct rtw89_ser *ser = (struct rtw89_ser *)&rtwdev->ser;
+
+	set_bit(RTW89_SER_DRV_STOP_RUN, ser->flags);
+	cancel_delayed_work_sync(&ser->ser_alarm_work);
+	cancel_work_sync(&ser->ser_hdl_work);
+	clear_bit(RTW89_SER_DRV_STOP_RUN, ser->flags);
+	return 0;
+}
+
+void rtw89_ser_recfg_done(struct rtw89_dev *rtwdev)
+{
+	ser_send_msg(&rtwdev->ser, SER_EV_L2_RECFG_DONE);
+}
+
+int rtw89_ser_notify(struct rtw89_dev *rtwdev, u32 err)
+{
+	u8 event = SER_EV_NONE;
+
+	rtw89_info(rtwdev, "ser event = 0x%04x\n", err);
+
+	switch (err) {
+	case MAC_AX_ERR_L1_ERR_DMAC:
+	case MAC_AX_ERR_L0_PROMOTE_TO_L1:
+		event = SER_EV_L1_RESET; /* M1 */
+		break;
+	case MAC_AX_ERR_L1_RESET_DISABLE_DMAC_DONE:
+		event = SER_EV_DO_RECOVERY; /* M3 */
+		break;
+	case MAC_AX_ERR_L1_RESET_RECOVERY_DONE:
+		event = SER_EV_MAC_RESET_DONE; /* M5 */
+		break;
+	case MAC_AX_ERR_L0_ERR_CMAC0:
+	case MAC_AX_ERR_L0_ERR_CMAC1:
+	case MAC_AX_ERR_L0_RESET_DONE:
+		event = SER_EV_L0_RESET;
+		break;
+	default:
+		if (err == MAC_AX_ERR_L1_PROMOTE_TO_L2 ||
+		    (err >= MAC_AX_ERR_L2_ERR_AH_DMA &&
+		     err <= MAC_AX_GET_ERR_MAX))
+			event = SER_EV_L2_RESET;
+		break;
+	}
+
+	if (event == SER_EV_NONE)
+		return -EINVAL;
+
+	ser_send_msg(&rtwdev->ser, event);
+	return 0;
+}
+EXPORT_SYMBOL(rtw89_ser_notify);
diff --git a/drivers/net/wireless/realtek/rtw89/ser.h b/drivers/net/wireless/realtek/rtw89/ser.h
new file mode 100644
index 000000000000..6b8e62019942
--- /dev/null
+++ b/drivers/net/wireless/realtek/rtw89/ser.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+ * Copyright(c) 2019-2020  Realtek Corporation
+ */
+#ifndef __SER_H__
+#define __SER_H__
+
+#include "core.h"
+
+int rtw89_ser_init(struct rtw89_dev *rtwdev);
+int rtw89_ser_deinit(struct rtw89_dev *rtwdev);
+int rtw89_ser_notify(struct rtw89_dev *rtwdev, u32 err);
+void rtw89_ser_recfg_done(struct rtw89_dev *rtwdev);
+
+#endif /* __SER_H__*/
+
