diff --git a/drivers/net/wireless/ath/ath12k/mhi.c b/drivers/net/wireless/ath/ath12k/mhi.c
new file mode 100644
index 000000000000..42f1140baa4f
--- /dev/null
+++ b/drivers/net/wireless/ath/ath12k/mhi.c
@@ -0,0 +1,616 @@
+// SPDX-License-Identifier: BSD-3-Clause-Clear
+/*
+ * Copyright (c) 2020-2021 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#include <linux/msi.h>
+#include <linux/pci.h>
+
+#include "core.h"
+#include "debug.h"
+#include "mhi.h"
+#include "pci.h"
+
+#define MHI_TIMEOUT_DEFAULT_MS	90000
+
+static const struct mhi_channel_config ath12k_mhi_channels_qcn9274[] = {
+	{
+		.num = 0,
+		.name = "LOOPBACK",
+		.num_elements = 32,
+		.event_ring = 1,
+		.dir = DMA_TO_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 1,
+		.name = "LOOPBACK",
+		.num_elements = 32,
+		.event_ring = 1,
+		.dir = DMA_FROM_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 20,
+		.name = "IPCR",
+		.num_elements = 32,
+		.event_ring = 1,
+		.dir = DMA_TO_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 21,
+		.name = "IPCR",
+		.num_elements = 32,
+		.event_ring = 1,
+		.dir = DMA_FROM_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = true,
+	},
+};
+
+static struct mhi_event_config ath12k_mhi_events_qcn9274[] = {
+	{
+		.num_elements = 32,
+		.irq_moderation_ms = 0,
+		.irq = 1,
+		.data_type = MHI_ER_CTRL,
+		.mode = MHI_DB_BRST_DISABLE,
+		.hardware_event = false,
+		.client_managed = false,
+		.offload_channel = false,
+	},
+	{
+		.num_elements = 256,
+		.irq_moderation_ms = 1,
+		.irq = 2,
+		.mode = MHI_DB_BRST_DISABLE,
+		.priority = 1,
+		.hardware_event = false,
+		.client_managed = false,
+		.offload_channel = false,
+	},
+};
+
+const struct mhi_controller_config ath12k_mhi_config_qcn9274 = {
+	.max_channels = 30,
+	.timeout_ms = 10000,
+	.use_bounce_buf = false,
+	.buf_len = 0,
+	.num_channels = ARRAY_SIZE(ath12k_mhi_channels_qcn9274),
+	.ch_cfg = ath12k_mhi_channels_qcn9274,
+	.num_events = ARRAY_SIZE(ath12k_mhi_events_qcn9274),
+	.event_cfg = ath12k_mhi_events_qcn9274,
+};
+
+static const struct mhi_channel_config ath12k_mhi_channels_wcn7850[] = {
+	{
+		.num = 0,
+		.name = "LOOPBACK",
+		.num_elements = 32,
+		.event_ring = 0,
+		.dir = DMA_TO_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 1,
+		.name = "LOOPBACK",
+		.num_elements = 32,
+		.event_ring = 0,
+		.dir = DMA_FROM_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 20,
+		.name = "IPCR",
+		.num_elements = 64,
+		.event_ring = 1,
+		.dir = DMA_TO_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = false,
+	},
+	{
+		.num = 21,
+		.name = "IPCR",
+		.num_elements = 64,
+		.event_ring = 1,
+		.dir = DMA_FROM_DEVICE,
+		.ee_mask = 0x4,
+		.pollcfg = 0,
+		.doorbell = MHI_DB_BRST_DISABLE,
+		.lpm_notify = false,
+		.offload_channel = false,
+		.doorbell_mode_switch = false,
+		.auto_queue = true,
+	},
+};
+
+static struct mhi_event_config ath12k_mhi_events_wcn7850[] = {
+	{
+		.num_elements = 32,
+		.irq_moderation_ms = 0,
+		.irq = 1,
+		.mode = MHI_DB_BRST_DISABLE,
+		.data_type = MHI_ER_CTRL,
+		.hardware_event = false,
+		.client_managed = false,
+		.offload_channel = false,
+	},
+	{
+		.num_elements = 256,
+		.irq_moderation_ms = 1,
+		.irq = 2,
+		.mode = MHI_DB_BRST_DISABLE,
+		.priority = 1,
+		.hardware_event = false,
+		.client_managed = false,
+		.offload_channel = false,
+	},
+};
+
+const struct mhi_controller_config ath12k_mhi_config_wcn7850 = {
+	.max_channels = 128,
+	.timeout_ms = 2000,
+	.use_bounce_buf = false,
+	.buf_len = 0,
+	.num_channels = ARRAY_SIZE(ath12k_mhi_channels_wcn7850),
+	.ch_cfg = ath12k_mhi_channels_wcn7850,
+	.num_events = ARRAY_SIZE(ath12k_mhi_events_wcn7850),
+	.event_cfg = ath12k_mhi_events_wcn7850,
+};
+
+void ath12k_mhi_set_mhictrl_reset(struct ath12k_base *ab)
+{
+	u32 val;
+
+	val = ath12k_pci_read32(ab, MHISTATUS);
+
+	ath12k_dbg(ab, ATH12K_DBG_PCI, "MHISTATUS 0x%x\n", val);
+
+	/* Observed on some targets that after SOC_GLOBAL_RESET, MHISTATUS
+	 * has SYSERR bit set and thus need to set MHICTRL_RESET
+	 * to clear SYSERR.
+	 */
+	ath12k_pci_write32(ab, MHICTRL, MHICTRL_RESET_MASK);
+
+	mdelay(10);
+}
+
+static void ath12k_mhi_reset_txvecdb(struct ath12k_base *ab)
+{
+	ath12k_pci_write32(ab, PCIE_TXVECDB, 0);
+}
+
+static void ath12k_mhi_reset_txvecstatus(struct ath12k_base *ab)
+{
+	ath12k_pci_write32(ab, PCIE_TXVECSTATUS, 0);
+}
+
+static void ath12k_mhi_reset_rxvecdb(struct ath12k_base *ab)
+{
+	ath12k_pci_write32(ab, PCIE_RXVECDB, 0);
+}
+
+static void ath12k_mhi_reset_rxvecstatus(struct ath12k_base *ab)
+{
+	ath12k_pci_write32(ab, PCIE_RXVECSTATUS, 0);
+}
+
+void ath12k_mhi_clear_vector(struct ath12k_base *ab)
+{
+	ath12k_mhi_reset_txvecdb(ab);
+	ath12k_mhi_reset_txvecstatus(ab);
+	ath12k_mhi_reset_rxvecdb(ab);
+	ath12k_mhi_reset_rxvecstatus(ab);
+}
+
+static int ath12k_mhi_get_msi(struct ath12k_pci *ab_pci)
+{
+	struct ath12k_base *ab = ab_pci->ab;
+	u32 user_base_data, base_vector;
+	int ret, num_vectors, i;
+	int *irq;
+
+	ret = ath12k_pci_get_user_msi_assignment(ab,
+						 "MHI", &num_vectors,
+						 &user_base_data, &base_vector);
+	if (ret)
+		return ret;
+
+	ath12k_dbg(ab, ATH12K_DBG_PCI, "Number of assigned MSI for MHI is %d, base vector is %d\n",
+		   num_vectors, base_vector);
+
+	irq = kcalloc(num_vectors, sizeof(*irq), GFP_KERNEL);
+	if (!irq)
+		return -ENOMEM;
+
+	for (i = 0; i < num_vectors; i++)
+		irq[i] = ath12k_pci_get_msi_irq(ab->dev,
+						base_vector + i);
+
+	ab_pci->mhi_ctrl->irq = irq;
+	ab_pci->mhi_ctrl->nr_irqs = num_vectors;
+
+	return 0;
+}
+
+static int ath12k_mhi_op_runtime_get(struct mhi_controller *mhi_cntrl)
+{
+	return 0;
+}
+
+static void ath12k_mhi_op_runtime_put(struct mhi_controller *mhi_cntrl)
+{
+}
+
+static char *ath12k_mhi_op_callback_to_str(enum mhi_callback reason)
+{
+	switch (reason) {
+	case MHI_CB_IDLE:
+		return "MHI_CB_IDLE";
+	case MHI_CB_PENDING_DATA:
+		return "MHI_CB_PENDING_DATA";
+	case MHI_CB_LPM_ENTER:
+		return "MHI_CB_LPM_ENTER";
+	case MHI_CB_LPM_EXIT:
+		return "MHI_CB_LPM_EXIT";
+	case MHI_CB_EE_RDDM:
+		return "MHI_CB_EE_RDDM";
+	case MHI_CB_EE_MISSION_MODE:
+		return "MHI_CB_EE_MISSION_MODE";
+	case MHI_CB_SYS_ERROR:
+		return "MHI_CB_SYS_ERROR";
+	case MHI_CB_FATAL_ERROR:
+		return "MHI_CB_FATAL_ERROR";
+	case MHI_CB_BW_REQ:
+		return "MHI_CB_BW_REQ";
+	default:
+		return "UNKNOWN";
+	}
+}
+
+static void ath12k_mhi_op_status_cb(struct mhi_controller *mhi_cntrl,
+				    enum mhi_callback cb)
+{
+	struct ath12k_base *ab = dev_get_drvdata(mhi_cntrl->cntrl_dev);
+
+	ath12k_dbg(ab, ATH12K_DBG_BOOT, "mhi notify status reason %s\n",
+		   ath12k_mhi_op_callback_to_str(cb));
+
+	switch (cb) {
+	case MHI_CB_SYS_ERROR:
+		ath12k_warn(ab, "firmware crashed: MHI_CB_SYS_ERROR\n");
+		break;
+	case MHI_CB_EE_RDDM:
+		if (!(test_bit(ATH12K_FLAG_UNREGISTERING, &ab->dev_flags)))
+			queue_work(ab->workqueue_aux, &ab->reset_work);
+		break;
+	default:
+		break;
+	}
+}
+
+static int ath12k_mhi_op_read_reg(struct mhi_controller *mhi_cntrl,
+				  void __iomem *addr,
+				  u32 *out)
+{
+	*out = readl(addr);
+
+	return 0;
+}
+
+static void ath12k_mhi_op_write_reg(struct mhi_controller *mhi_cntrl,
+				    void __iomem *addr,
+				    u32 val)
+{
+	writel(val, addr);
+}
+
+int ath12k_mhi_register(struct ath12k_pci *ab_pci)
+{
+	struct ath12k_base *ab = ab_pci->ab;
+	struct mhi_controller *mhi_ctrl;
+	int ret;
+
+	mhi_ctrl = mhi_alloc_controller();
+	if (!mhi_ctrl)
+		return -ENOMEM;
+
+	ath12k_core_create_firmware_path(ab, ATH12K_AMSS_FILE,
+					 ab_pci->amss_path,
+					 sizeof(ab_pci->amss_path));
+
+	ab_pci->mhi_ctrl = mhi_ctrl;
+	mhi_ctrl->cntrl_dev = ab->dev;
+	mhi_ctrl->fw_image = ab_pci->amss_path;
+	mhi_ctrl->regs = ab->mem;
+	mhi_ctrl->reg_len = ab->mem_len;
+
+	ret = ath12k_mhi_get_msi(ab_pci);
+	if (ret) {
+		ath12k_err(ab, "failed to get msi for mhi\n");
+		mhi_free_controller(mhi_ctrl);
+		return ret;
+	}
+
+	mhi_ctrl->iova_start = 0;
+	mhi_ctrl->iova_stop = 0xffffffff;
+	mhi_ctrl->sbl_size = SZ_512K;
+	mhi_ctrl->seg_len = SZ_512K;
+	mhi_ctrl->fbc_download = true;
+	mhi_ctrl->runtime_get = ath12k_mhi_op_runtime_get;
+	mhi_ctrl->runtime_put = ath12k_mhi_op_runtime_put;
+	mhi_ctrl->status_cb = ath12k_mhi_op_status_cb;
+	mhi_ctrl->read_reg = ath12k_mhi_op_read_reg;
+	mhi_ctrl->write_reg = ath12k_mhi_op_write_reg;
+
+	ret = mhi_register_controller(mhi_ctrl, ab->hw_params->mhi_config);
+	if (ret) {
+		ath12k_err(ab, "failed to register to mhi bus, err = %d\n", ret);
+		mhi_free_controller(mhi_ctrl);
+		return ret;
+	}
+
+	return 0;
+}
+
+void ath12k_mhi_unregister(struct ath12k_pci *ab_pci)
+{
+	struct mhi_controller *mhi_ctrl = ab_pci->mhi_ctrl;
+
+	mhi_unregister_controller(mhi_ctrl);
+	kfree(mhi_ctrl->irq);
+	mhi_free_controller(mhi_ctrl);
+	ab_pci->mhi_ctrl = NULL;
+}
+
+static char *ath12k_mhi_state_to_str(enum ath12k_mhi_state mhi_state)
+{
+	switch (mhi_state) {
+	case ATH12K_MHI_INIT:
+		return "INIT";
+	case ATH12K_MHI_DEINIT:
+		return "DEINIT";
+	case ATH12K_MHI_POWER_ON:
+		return "POWER_ON";
+	case ATH12K_MHI_POWER_OFF:
+		return "POWER_OFF";
+	case ATH12K_MHI_FORCE_POWER_OFF:
+		return "FORCE_POWER_OFF";
+	case ATH12K_MHI_SUSPEND:
+		return "SUSPEND";
+	case ATH12K_MHI_RESUME:
+		return "RESUME";
+	case ATH12K_MHI_TRIGGER_RDDM:
+		return "TRIGGER_RDDM";
+	case ATH12K_MHI_RDDM_DONE:
+		return "RDDM_DONE";
+	default:
+		return "UNKNOWN";
+	}
+};
+
+static void ath12k_mhi_set_state_bit(struct ath12k_pci *ab_pci,
+				     enum ath12k_mhi_state mhi_state)
+{
+	struct ath12k_base *ab = ab_pci->ab;
+
+	switch (mhi_state) {
+	case ATH12K_MHI_INIT:
+		set_bit(ATH12K_MHI_INIT, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_DEINIT:
+		clear_bit(ATH12K_MHI_INIT, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_POWER_ON:
+		set_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_POWER_OFF:
+	case ATH12K_MHI_FORCE_POWER_OFF:
+		clear_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state);
+		clear_bit(ATH12K_MHI_TRIGGER_RDDM, &ab_pci->mhi_state);
+		clear_bit(ATH12K_MHI_RDDM_DONE, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_SUSPEND:
+		set_bit(ATH12K_MHI_SUSPEND, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_RESUME:
+		clear_bit(ATH12K_MHI_SUSPEND, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_TRIGGER_RDDM:
+		set_bit(ATH12K_MHI_TRIGGER_RDDM, &ab_pci->mhi_state);
+		break;
+	case ATH12K_MHI_RDDM_DONE:
+		set_bit(ATH12K_MHI_RDDM_DONE, &ab_pci->mhi_state);
+		break;
+	default:
+		ath12k_err(ab, "unhandled mhi state (%d)\n", mhi_state);
+	}
+}
+
+static int ath12k_mhi_check_state_bit(struct ath12k_pci *ab_pci,
+				      enum ath12k_mhi_state mhi_state)
+{
+	struct ath12k_base *ab = ab_pci->ab;
+
+	switch (mhi_state) {
+	case ATH12K_MHI_INIT:
+		if (!test_bit(ATH12K_MHI_INIT, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_DEINIT:
+	case ATH12K_MHI_POWER_ON:
+		if (test_bit(ATH12K_MHI_INIT, &ab_pci->mhi_state) &&
+		    !test_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_FORCE_POWER_OFF:
+		if (test_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_POWER_OFF:
+	case ATH12K_MHI_SUSPEND:
+		if (test_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state) &&
+		    !test_bit(ATH12K_MHI_SUSPEND, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_RESUME:
+		if (test_bit(ATH12K_MHI_SUSPEND, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_TRIGGER_RDDM:
+		if (test_bit(ATH12K_MHI_POWER_ON, &ab_pci->mhi_state) &&
+		    !test_bit(ATH12K_MHI_TRIGGER_RDDM, &ab_pci->mhi_state))
+			return 0;
+		break;
+	case ATH12K_MHI_RDDM_DONE:
+		return 0;
+	default:
+		ath12k_err(ab, "unhandled mhi state: %s(%d)\n",
+			   ath12k_mhi_state_to_str(mhi_state), mhi_state);
+	}
+
+	ath12k_err(ab, "failed to set mhi state %s(%d) in current mhi state (0x%lx)\n",
+		   ath12k_mhi_state_to_str(mhi_state), mhi_state,
+		   ab_pci->mhi_state);
+
+	return -EINVAL;
+}
+
+static int ath12k_mhi_set_state(struct ath12k_pci *ab_pci,
+				enum ath12k_mhi_state mhi_state)
+{
+	struct ath12k_base *ab = ab_pci->ab;
+	int ret;
+
+	ret = ath12k_mhi_check_state_bit(ab_pci, mhi_state);
+	if (ret)
+		goto out;
+
+	ath12k_dbg(ab, ATH12K_DBG_PCI, "setting mhi state: %s(%d)\n",
+		   ath12k_mhi_state_to_str(mhi_state), mhi_state);
+
+	switch (mhi_state) {
+	case ATH12K_MHI_INIT:
+		ret = mhi_prepare_for_power_up(ab_pci->mhi_ctrl);
+		break;
+	case ATH12K_MHI_DEINIT:
+		mhi_unprepare_after_power_down(ab_pci->mhi_ctrl);
+		ret = 0;
+		break;
+	case ATH12K_MHI_POWER_ON:
+		ret = mhi_async_power_up(ab_pci->mhi_ctrl);
+		break;
+	case ATH12K_MHI_POWER_OFF:
+		mhi_power_down(ab_pci->mhi_ctrl, true);
+		ret = 0;
+		break;
+	case ATH12K_MHI_FORCE_POWER_OFF:
+		mhi_power_down(ab_pci->mhi_ctrl, false);
+		ret = 0;
+		break;
+	case ATH12K_MHI_SUSPEND:
+		ret = mhi_pm_suspend(ab_pci->mhi_ctrl);
+		break;
+	case ATH12K_MHI_RESUME:
+		ret = mhi_pm_resume(ab_pci->mhi_ctrl);
+		break;
+	case ATH12K_MHI_TRIGGER_RDDM:
+		ret = mhi_force_rddm_mode(ab_pci->mhi_ctrl);
+		break;
+	case ATH12K_MHI_RDDM_DONE:
+		break;
+	default:
+		ath12k_err(ab, "unhandled MHI state (%d)\n", mhi_state);
+		ret = -EINVAL;
+	}
+
+	if (ret)
+		goto out;
+
+	ath12k_mhi_set_state_bit(ab_pci, mhi_state);
+
+	return 0;
+
+out:
+	ath12k_err(ab, "failed to set mhi state: %s(%d)\n",
+		   ath12k_mhi_state_to_str(mhi_state), mhi_state);
+	return ret;
+}
+
+int ath12k_mhi_start(struct ath12k_pci *ab_pci)
+{
+	int ret;
+
+	ab_pci->mhi_ctrl->timeout_ms = MHI_TIMEOUT_DEFAULT_MS;
+
+	ret = ath12k_mhi_set_state(ab_pci, ATH12K_MHI_INIT);
+	if (ret)
+		goto out;
+
+	ret = ath12k_mhi_set_state(ab_pci, ATH12K_MHI_POWER_ON);
+	if (ret)
+		goto out;
+
+	return 0;
+
+out:
+	return ret;
+}
+
+void ath12k_mhi_stop(struct ath12k_pci *ab_pci)
+{
+	ath12k_mhi_set_state(ab_pci, ATH12K_MHI_POWER_OFF);
+	ath12k_mhi_set_state(ab_pci, ATH12K_MHI_DEINIT);
+}
+
+void ath12k_mhi_suspend(struct ath12k_pci *ab_pci)
+{
+	ath12k_mhi_set_state(ab_pci, ATH12K_MHI_SUSPEND);
+}
+
+void ath12k_mhi_resume(struct ath12k_pci *ab_pci)
+{
+	ath12k_mhi_set_state(ab_pci, ATH12K_MHI_RESUME);
+}
