diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile
index 5f298f00a82e..df2c05a545d8 100644
--- a/drivers/firmware/arm_scmi/Makefile
+++ b/drivers/firmware/arm_scmi/Makefile
@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
-obj-y	= scmi-bus.o scmi-driver.o scmi-protocols.o
+obj-y	= scmi-bus.o scmi-driver.o scmi-protocols.o scmi-transport.o
 scmi-bus-y = bus.o
 scmi-driver-y = driver.o
+scmi-transport-y = mailbox.o
 scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o
 obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 5237c2ff79fe..fc3e427eb2cc 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -13,6 +13,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/scmi_protocol.h>
+#include <linux/stddef.h>
 #include <linux/types.h>
 
 #include <asm/unaligned.h>
@@ -111,3 +112,90 @@ void scmi_setup_protocol_implemented(const struct scmi_handle *handle,
 				     u8 *prot_imp);
 
 int scmi_base_protocol_init(struct scmi_handle *h);
+
+/* SCMI Transport */
+
+/*
+ * SCMI specification requires all parameters, message headers, return
+ * arguments or any protocol data to be expressed in little endian
+ * format only.
+ */
+struct scmi_shared_mem {
+	__le32 reserved;
+	__le32 channel_status;
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR	BIT(1)
+#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE	BIT(0)
+	__le32 reserved1[2];
+	__le32 flags;
+#define SCMI_SHMEM_FLAG_INTR_ENABLED	BIT(0)
+	__le32 length;
+	__le32 msg_header;
+	u8 msg_payload[0];
+};
+
+/* Offset of fields within the above structure */
+#define SHMEM_CHANNEL_STATUS		offsetof(struct scmi_shared_mem, channel_status)
+#define SHMEM_FLAGS			offsetof(struct scmi_shared_mem, flags)
+#define SHMEM_LENGTH			offsetof(struct scmi_shared_mem, length)
+#define SHMEM_MSG_HEADER		offsetof(struct scmi_shared_mem, msg_header)
+#define SHMEM_MSG_PAYLOAD		offsetof(struct scmi_shared_mem, msg_payload)
+
+struct scmi_info;
+
+/**
+ * struct scmi_chan_info - Structure representing a SCMI channel information
+ *
+ * @payload: Transmit/Receive payload area
+ * @dev: Reference to device in the SCMI hierarchy corresponding to this
+ *	 channel
+ * @handle: Pointer to SCMI entity handle
+ * @transport_info: Transport layer related information
+ */
+struct scmi_chan_info {
+	struct scmi_info *info;
+	struct device *dev;
+	struct scmi_handle *handle;
+	void *transport_info;
+};
+
+/**
+ * struct scmi_transport_ops - Structure representing a SCMI transport ops
+ *
+ * @send_message: Callback to send a message
+ * @mark_txdone: Callback to mark tx as done
+ * @chan_setup: Callback to allocate and setup a channel
+ * @chan_free: Callback to free a channel
+ */
+struct scmi_transport_ops {
+	bool (*chan_available)(struct device *dev, int idx);
+	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev, bool tx);
+	int (*chan_free)(int id, void *p, void *data);
+	int (*send_message)(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer);
+	void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
+	u32 (*read32)(struct scmi_chan_info *cinfo, unsigned int offset);
+	void (*write32)(struct scmi_chan_info *cinfo, u32 val, unsigned int offset);
+	void (*memcpy_from)(struct scmi_chan_info *cinfo, void *to, unsigned int offset, long len);
+	void (*memcpy_to)(struct scmi_chan_info *cinfo, unsigned int offset, void *from, long len);
+
+};
+
+/**
+ * struct scmi_desc - Description of SoC integration
+ *
+ * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
+ * @max_msg: Maximum number of messages that can be pending
+ *	simultaneously in the system
+ * @max_msg_size: Maximum size of data per message that can be handled.
+ */
+struct scmi_desc {
+	struct scmi_transport_ops *ops;
+	int max_rx_timeout_ms;
+	int max_msg;
+	int max_msg_size;
+};
+
+extern const struct scmi_desc scmi_mailbox_desc;
+
+void scmi_tx_prepare(struct scmi_chan_info *cinfo, struct scmi_xfer *t);
+void scmi_rx_callback(struct scmi_chan_info *cinfo, struct scmi_xfer *t);
+void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id);
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 3eb0382491ce..c34b283685c5 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -19,7 +19,6 @@
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/ktime.h>
-#include <linux/mailbox_client.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
@@ -77,38 +76,6 @@ struct scmi_xfers_info {
 	spinlock_t xfer_lock;
 };
 
-/**
- * struct scmi_desc - Description of SoC integration
- *
- * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)
- * @max_msg: Maximum number of messages that can be pending
- *	simultaneously in the system
- * @max_msg_size: Maximum size of data per message that can be handled.
- */
-struct scmi_desc {
-	int max_rx_timeout_ms;
-	int max_msg;
-	int max_msg_size;
-};
-
-/**
- * struct scmi_chan_info - Structure representing a SCMI channel information
- *
- * @cl: Mailbox Client
- * @chan: Transmit/Receive mailbox channel
- * @payload: Transmit/Receive mailbox channel payload area
- * @dev: Reference to device in the SCMI hierarchy corresponding to this
- *	 channel
- * @handle: Pointer to SCMI entity handle
- */
-struct scmi_chan_info {
-	struct mbox_client cl;
-	struct mbox_chan *chan;
-	void __iomem *payload;
-	struct device *dev;
-	struct scmi_handle *handle;
-};
-
 /**
  * struct scmi_info - Structure representing a SCMI instance
  *
@@ -138,27 +105,8 @@ struct scmi_info {
 	int users;
 };
 
-#define client_to_scmi_chan_info(c) container_of(c, struct scmi_chan_info, cl)
 #define handle_to_scmi_info(h)	container_of(h, struct scmi_info, handle)
 
-/*
- * SCMI specification requires all parameters, message headers, return
- * arguments or any protocol data to be expressed in little endian
- * format only.
- */
-struct scmi_shared_mem {
-	__le32 reserved;
-	__le32 channel_status;
-#define SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR	BIT(1)
-#define SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE	BIT(0)
-	__le32 reserved1[2];
-	__le32 flags;
-#define SCMI_SHMEM_FLAG_INTR_ENABLED	BIT(0)
-	__le32 length;
-	__le32 msg_header;
-	u8 msg_payload[0];
-};
-
 static const int scmi_linux_errmap[] = {
 	/* better than switch case as long as return value is continuous */
 	0,			/* SCMI_SUCCESS */
@@ -194,15 +142,17 @@ static inline void scmi_dump_header_dbg(struct device *dev,
 		hdr->id, hdr->seq, hdr->protocol_id);
 }
 
-static void scmi_fetch_response(struct scmi_xfer *xfer,
-				struct scmi_shared_mem __iomem *mem)
+static void scmi_fetch_response(struct scmi_chan_info *cinfo,
+				struct scmi_xfer *xfer)
 {
-	xfer->hdr.status = ioread32(mem->msg_payload);
+	struct scmi_transport_ops *ops = cinfo->info->desc->ops;
+
+	xfer->hdr.status = ops->read32(cinfo, SHMEM_MSG_PAYLOAD);
 	/* Skip the length of header and status in payload area i.e 8 bytes */
-	xfer->rx.len = min_t(size_t, xfer->rx.len, ioread32(&mem->length) - 8);
+	xfer->rx.len = min_t(size_t, xfer->rx.len, ops->read32(cinfo, SHMEM_LENGTH) - 8);
 
 	/* Take a copy to the rx buffer.. */
-	memcpy_fromio(xfer->rx.buf, mem->msg_payload + 4, xfer->rx.len);
+	ops->memcpy_from(cinfo, xfer->rx.buf, SHMEM_MSG_PAYLOAD + 4, xfer->rx.len);
 }
 
 /**
@@ -233,19 +183,17 @@ static inline void unpack_scmi_header(u32 msg_hdr, struct scmi_msg_hdr *hdr)
 }
 
 /**
- * scmi_tx_prepare() - mailbox client callback to prepare for the transfer
+ * scmi_tx_prepare() - callback to prepare for the transfer
  *
- * @cl: client pointer
- * @m: mailbox message
+ * @cinfo: SCMI channel info
+ * @t: transfer message
  *
  * This function prepares the shared memory which contains the header and the
  * payload.
  */
-static void scmi_tx_prepare(struct mbox_client *cl, void *m)
+void scmi_tx_prepare(struct scmi_chan_info *cinfo, struct scmi_xfer *t)
 {
-	struct scmi_xfer *t = m;
-	struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
-	struct scmi_shared_mem __iomem *mem = cinfo->payload;
+	struct scmi_transport_ops *ops = cinfo->info->desc->ops;
 
 	/*
 	 * Ideally channel must be free by now unless OS timeout last
@@ -253,16 +201,17 @@ static void scmi_tx_prepare(struct mbox_client *cl, void *m)
 	 * until it releases the shared memory, otherwise we may endup
 	 * overwriting its response with new message payload or vice-versa
 	 */
-	spin_until_cond(ioread32(&mem->channel_status) &
+	spin_until_cond(ops->read32(cinfo, SHMEM_CHANNEL_STATUS) &
 			SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
 	/* Mark channel busy + clear error */
-	iowrite32(0x0, &mem->channel_status);
-	iowrite32(t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,
-		  &mem->flags);
-	iowrite32(sizeof(mem->msg_header) + t->tx.len, &mem->length);
-	iowrite32(pack_scmi_header(&t->hdr), &mem->msg_header);
+	ops->write32(cinfo, 0x0, SHMEM_CHANNEL_STATUS);
+	ops->write32(cinfo,
+		     t->hdr.poll_completion ? 0 : SCMI_SHMEM_FLAG_INTR_ENABLED,
+		     SHMEM_FLAGS);
+	ops->write32(cinfo, sizeof(((struct scmi_shared_mem *)0)->msg_header) + t->tx.len, SHMEM_LENGTH);
+	ops->write32(cinfo, pack_scmi_header(&t->hdr), SHMEM_MSG_HEADER);
 	if (t->tx.buf)
-		memcpy_toio(mem->msg_payload, t->tx.buf, t->tx.len);
+		ops->memcpy_to(cinfo, SHMEM_MSG_PAYLOAD, t->tx.buf, t->tx.len);
 }
 
 /**
@@ -332,10 +281,10 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
 }
 
 /**
- * scmi_rx_callback() - mailbox client callback for receive messages
+ * scmi_rx_callback() - callback for receiving messages
  *
- * @cl: client pointer
- * @m: mailbox message
+ * @cinfo: SCMI channel info
+ * @t: transfer message
  *
  * Processes one received message to appropriate transfer information and
  * signals completion of the transfer.
@@ -343,19 +292,17 @@ __scmi_xfer_put(struct scmi_xfers_info *minfo, struct scmi_xfer *xfer)
  * NOTE: This function will be invoked in IRQ context, hence should be
  * as optimal as possible.
  */
-static void scmi_rx_callback(struct mbox_client *cl, void *m)
+void scmi_rx_callback(struct scmi_chan_info *cinfo, struct scmi_xfer *t)
 {
 	u8 msg_type;
 	u32 msg_hdr;
 	u16 xfer_id;
 	struct scmi_xfer *xfer;
-	struct scmi_chan_info *cinfo = client_to_scmi_chan_info(cl);
 	struct device *dev = cinfo->dev;
 	struct scmi_info *info = handle_to_scmi_info(cinfo->handle);
 	struct scmi_xfers_info *minfo = &info->tx_minfo;
-	struct scmi_shared_mem __iomem *mem = cinfo->payload;
 
-	msg_hdr = ioread32(&mem->msg_header);
+	msg_hdr = cinfo->info->desc->ops->read32(cinfo, SHMEM_MSG_HEADER);
 	msg_type = MSG_XTRACT_TYPE(msg_hdr);
 	xfer_id = MSG_XTRACT_TOKEN(msg_hdr);
 
@@ -372,7 +319,7 @@ static void scmi_rx_callback(struct mbox_client *cl, void *m)
 
 	scmi_dump_header_dbg(dev, &xfer->hdr);
 
-	scmi_fetch_response(xfer, mem);
+	scmi_fetch_response(cinfo, xfer);
 
 	if (msg_type == MSG_TYPE_DELAYED_RESP)
 		complete(xfer->async_done);
@@ -394,22 +341,22 @@ void scmi_xfer_put(const struct scmi_handle *handle, struct scmi_xfer *xfer)
 }
 
 static bool
-scmi_xfer_poll_done(const struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
+scmi_xfer_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer)
 {
-	struct scmi_shared_mem __iomem *mem = cinfo->payload;
-	u16 xfer_id = MSG_XTRACT_TOKEN(ioread32(&mem->msg_header));
+	struct scmi_transport_ops *ops = cinfo->info->desc->ops;
+	u16 xfer_id = MSG_XTRACT_TOKEN(ops->read32(cinfo, SHMEM_MSG_HEADER));
 
 	if (xfer->hdr.seq != xfer_id)
 		return false;
 
-	return ioread32(&mem->channel_status) &
+	return ops->read32(cinfo, SHMEM_CHANNEL_STATUS) &
 		(SCMI_SHMEM_CHAN_STAT_CHANNEL_ERROR |
 		SCMI_SHMEM_CHAN_STAT_CHANNEL_FREE);
 }
 
 #define SCMI_MAX_POLL_TO_NS	(100 * NSEC_PER_USEC)
 
-static bool scmi_xfer_done_no_timeout(const struct scmi_chan_info *cinfo,
+static bool scmi_xfer_done_no_timeout(struct scmi_chan_info *cinfo,
 				      struct scmi_xfer *xfer, ktime_t stop)
 {
 	ktime_t __cur = ktime_get();
@@ -439,29 +386,26 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
 	if (unlikely(!cinfo))
 		return -EINVAL;
 
-	ret = mbox_send_message(cinfo->chan, xfer);
+	ret = info->desc->ops->send_message(cinfo, xfer);
 	if (ret < 0) {
-		dev_dbg(dev, "mbox send fail %d\n", ret);
+		dev_dbg(dev, "Failed to send message %d\n", ret);
 		return ret;
 	}
 
-	/* mbox_send_message returns non-negative value on success, so reset */
-	ret = 0;
-
 	if (xfer->hdr.poll_completion) {
 		ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS);
 
 		spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
 
 		if (ktime_before(ktime_get(), stop))
-			scmi_fetch_response(xfer, cinfo->payload);
+			scmi_fetch_response(cinfo, xfer);
 		else
 			ret = -ETIMEDOUT;
 	} else {
 		/* And we wait for the response. */
 		timeout = msecs_to_jiffies(info->desc->max_rx_timeout_ms);
 		if (!wait_for_completion_timeout(&xfer->done, timeout)) {
-			dev_err(dev, "mbox timed out in resp(caller: %pS)\n",
+			dev_err(dev, "timed out in resp(caller: %pS)\n",
 				(void *)_RET_IP_);
 			ret = -ETIMEDOUT;
 		}
@@ -470,13 +414,7 @@ int scmi_do_xfer(const struct scmi_handle *handle, struct scmi_xfer *xfer)
 	if (!ret && xfer->hdr.status)
 		ret = scmi_to_linux_errno(xfer->hdr.status);
 
-	/*
-	 * NOTE: we might prefer not to need the mailbox ticker to manage the
-	 * transfer queueing since the protocol layer queues things by itself.
-	 * Unfortunately, we have to kick the mailbox framework after we have
-	 * received our message.
-	 */
-	mbox_client_txdone(cinfo->chan, ret);
+	info->desc->ops->mark_txdone(cinfo, ret);
 
 	return ret;
 }
@@ -713,29 +651,18 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
 	return 0;
 }
 
-static int scmi_mailbox_check(struct device_node *np, int idx)
-{
-	return of_parse_phandle_with_args(np, "mboxes", "#mbox-cells",
-					  idx, NULL);
-}
-
-static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev,
-				int prot_id, bool tx)
+static int scmi_chan_setup(struct scmi_info *info, struct device *dev,
+			   int prot_id, bool tx)
 {
 	int ret, idx;
-	struct resource res;
-	resource_size_t size;
-	struct device_node *shmem, *np = dev->of_node;
 	struct scmi_chan_info *cinfo;
-	struct mbox_client *cl;
 	struct idr *idr;
-	const char *desc = tx ? "Tx" : "Rx";
 
 	/* Transmit channel is first entry i.e. index 0 */
 	idx = tx ? 0 : 1;
 	idr = tx ? &info->tx_idr : &info->rx_idr;
 
-	if (scmi_mailbox_check(np, idx)) {
+	if (!info->desc->ops->chan_available(dev, idx)) {
 		cinfo = idr_find(idr, SCMI_PROTOCOL_BASE);
 		if (unlikely(!cinfo)) /* Possible only if platform has no Rx */
 			return -EINVAL;
@@ -747,37 +674,11 @@ static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev,
 		return -ENOMEM;
 
 	cinfo->dev = dev;
+	cinfo->info = info;
 
-	cl = &cinfo->cl;
-	cl->dev = dev;
-	cl->rx_callback = scmi_rx_callback;
-	cl->tx_prepare = tx ? scmi_tx_prepare : NULL;
-	cl->tx_block = false;
-	cl->knows_txdone = tx;
-
-	shmem = of_parse_phandle(np, "shmem", idx);
-	ret = of_address_to_resource(shmem, 0, &res);
-	of_node_put(shmem);
-	if (ret) {
-		dev_err(dev, "failed to get SCMI %s payload memory\n", desc);
-		return ret;
-	}
-
-	size = resource_size(&res);
-	cinfo->payload = devm_ioremap(info->dev, res.start, size);
-	if (!cinfo->payload) {
-		dev_err(dev, "failed to ioremap SCMI %s payload\n", desc);
-		return -EADDRNOTAVAIL;
-	}
-
-	cinfo->chan = mbox_request_channel(cl, idx);
-	if (IS_ERR(cinfo->chan)) {
-		ret = PTR_ERR(cinfo->chan);
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "failed to request SCMI %s mailbox\n",
-				desc);
+	ret = info->desc->ops->chan_setup(cinfo, info->dev, tx);
+	if (ret)
 		return ret;
-	}
 
 idr_alloc:
 	ret = idr_alloc(idr, cinfo, prot_id, prot_id + 1, GFP_KERNEL);
@@ -791,12 +692,12 @@ static int scmi_mbox_chan_setup(struct scmi_info *info, struct device *dev,
 }
 
 static inline int
-scmi_mbox_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
+scmi_txrx_setup(struct scmi_info *info, struct device *dev, int prot_id)
 {
-	int ret = scmi_mbox_chan_setup(info, dev, prot_id, true);
+	int ret = scmi_chan_setup(info, dev, prot_id, true);
 
 	if (!ret) /* Rx is optional, hence no error check */
-		scmi_mbox_chan_setup(info, dev, prot_id, false);
+		scmi_chan_setup(info, dev, prot_id, false);
 
 	return ret;
 }
@@ -814,7 +715,7 @@ scmi_create_protocol_device(struct device_node *np, struct scmi_info *info,
 		return;
 	}
 
-	if (scmi_mbox_txrx_setup(info, &sdev->dev, prot_id)) {
+	if (scmi_txrx_setup(info, &sdev->dev, prot_id)) {
 		dev_err(&sdev->dev, "failed to setup transport\n");
 		scmi_device_destroy(sdev);
 		return;
@@ -833,12 +734,6 @@ static int scmi_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
 
-	/* Only mailbox method supported, check for the presence of one */
-	if (scmi_mailbox_check(np, 0)) {
-		dev_err(dev, "no mailbox found in %pOF\n", np);
-		return -EINVAL;
-	}
-
 	desc = of_device_get_match_data(dev);
 	if (!desc)
 		return -EINVAL;
@@ -863,7 +758,7 @@ static int scmi_probe(struct platform_device *pdev)
 	handle->dev = info->dev;
 	handle->version = &info->version;
 
-	ret = scmi_mbox_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
+	ret = scmi_txrx_setup(info, dev, SCMI_PROTOCOL_BASE);
 	if (ret)
 		return ret;
 
@@ -898,19 +793,9 @@ static int scmi_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int scmi_mbox_free_channel(int id, void *p, void *data)
+void scmi_free_channel(struct scmi_chan_info *cinfo, struct idr *idr, int id)
 {
-	struct scmi_chan_info *cinfo = p;
-	struct idr *idr = data;
-
-	if (!IS_ERR_OR_NULL(cinfo->chan)) {
-		mbox_free_channel(cinfo->chan);
-		cinfo->chan = NULL;
-	}
-
 	idr_remove(idr, id);
-
-	return 0;
 }
 
 static int scmi_remove(struct platform_device *pdev)
@@ -930,25 +815,19 @@ static int scmi_remove(struct platform_device *pdev)
 		return ret;
 
 	/* Safe to free channels since no more users */
-	ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
+	ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
 	idr_destroy(&info->tx_idr);
 
 	idr = &info->rx_idr;
-	ret = idr_for_each(idr, scmi_mbox_free_channel, idr);
+	ret = idr_for_each(idr, info->desc->ops->chan_free, idr);
 	idr_destroy(&info->rx_idr);
 
 	return ret;
 }
 
-static const struct scmi_desc scmi_generic_desc = {
-	.max_rx_timeout_ms = 30,	/* We may increase this if required */
-	.max_msg = 20,		/* Limited by MBOX_TX_QUEUE_LEN */
-	.max_msg_size = 128,
-};
-
 /* Each compatible listed below must have descriptor associated with it */
 static const struct of_device_id scmi_of_match[] = {
-	{ .compatible = "arm,scmi", .data = &scmi_generic_desc },
+	{ .compatible = "arm,scmi", .data = &scmi_mailbox_desc },
 	{ /* Sentinel */ },
 };
 
diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
new file mode 100644
index 000000000000..7509e7eb262a
--- /dev/null
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -0,0 +1,202 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * System Control and Management Interface (SCMI) Message Mailbox Transport
+ * driver.
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ */
+
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/mailbox_client.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "common.h"
+
+/**
+ * struct scmi_mailbox - Structure representing a SCMI mailbox transport
+ *
+ * @cl: Mailbox Client
+ * @chan: Transmit/Receive mailbox channel
+ * @cinfo: SCMI channel info
+ */
+struct scmi_mailbox {
+	struct mbox_client cl;
+	struct mbox_chan *chan;
+	struct scmi_chan_info *cinfo;
+	void __iomem *payload;
+};
+
+#define client_to_scmi_mailbox(c) container_of(c, struct scmi_mailbox, cl)
+
+static bool mailbox_chan_available(struct device *dev, int idx)
+{
+	return !of_parse_phandle_with_args(dev->of_node, "mboxes",
+					   "#mbox-cells", idx, NULL);
+}
+
+static void mailbox_tx_prepare(struct mbox_client *cl, void *m)
+{
+	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+	struct scmi_chan_info *cinfo = smbox->cinfo;
+
+	scmi_tx_prepare(cinfo, m);
+}
+
+static void mailbox_rx_callback(struct mbox_client *cl, void *m)
+{
+	struct scmi_mailbox *smbox = client_to_scmi_mailbox(cl);
+	struct scmi_chan_info *cinfo = smbox->cinfo;
+
+	scmi_rx_callback(cinfo, m);
+}
+
+static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
+			      bool tx)
+{
+	const char *desc = tx ? "Tx" : "Rx";
+	struct device *cdev = cinfo->dev;
+	struct scmi_mailbox *smbox;
+	struct device_node *shmem;
+	int ret, idx = tx ? 0 : 1;
+	struct mbox_client *cl;
+	resource_size_t size;
+	struct resource res;
+
+	smbox = devm_kzalloc(cdev, sizeof(*smbox), GFP_KERNEL);
+	if (!smbox)
+		return -ENOMEM;
+
+	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);
+	ret = of_address_to_resource(shmem, 0, &res);
+	of_node_put(shmem);
+	if (ret) {
+		dev_err(cdev, "failed to get SCMI %s payload memory\n", desc);
+		return ret;
+	}
+
+	size = resource_size(&res);
+	smbox->payload = devm_ioremap(dev, res.start, size);
+	if (!smbox->payload) {
+		dev_err(dev, "failed to ioremap SCMI %s payload\n", desc);
+		return -EADDRNOTAVAIL;
+	}
+
+	cl = &smbox->cl;
+	cl->dev = cdev;
+	cl->tx_prepare = tx ? mailbox_tx_prepare : NULL;
+	cl->rx_callback = mailbox_rx_callback;
+	cl->tx_block = false;
+	cl->knows_txdone = tx;
+
+	smbox->chan = mbox_request_channel(cl, tx ? 0 : 1);
+	if (IS_ERR(smbox->chan)) {
+		ret = PTR_ERR(smbox->chan);
+		if (ret != -EPROBE_DEFER)
+			dev_err(cdev, "failed to request SCMI %s mailbox\n",
+				tx ? "Tx" : "Rx");
+		return ret;
+	}
+
+	cinfo->transport_info = smbox;
+	smbox->cinfo = cinfo;
+
+	return 0;
+}
+
+static int mailbox_chan_free(int id, void *p, void *data)
+{
+	struct scmi_chan_info *cinfo = p;
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	if (!IS_ERR(smbox->chan)) {
+		mbox_free_channel(smbox->chan);
+		cinfo->transport_info = NULL;
+		smbox->chan = NULL;
+		smbox->cinfo = NULL;
+	}
+
+	scmi_free_channel(cinfo, data, id);
+
+	return 0;
+}
+
+static int mailbox_send_message(struct scmi_chan_info *cinfo,
+				struct scmi_xfer *xfer)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+	int ret;
+
+	ret = mbox_send_message(smbox->chan, xfer);
+
+	/* mbox_send_message returns non-negative value on success, so reset */
+	if (ret > 0)
+		ret = 0;
+
+	return ret;
+}
+
+static void mailbox_mark_txdone(struct scmi_chan_info *cinfo, int ret)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	/*
+	 * NOTE: we might prefer not to need the mailbox ticker to manage the
+	 * transfer queueing since the protocol layer queues things by itself.
+	 * Unfortunately, we have to kick the mailbox framework after we have
+	 * received our message.
+	 */
+	mbox_client_txdone(smbox->chan, ret);
+}
+
+static u32 mailbox_read32(struct scmi_chan_info *cinfo, unsigned int offset)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	return ioread32(smbox->payload + offset);
+}
+
+static void mailbox_write32(struct scmi_chan_info *cinfo, u32 val,
+			    unsigned int offset)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	iowrite32(val, smbox->payload + offset);
+}
+
+static void mailbox_memcpy_from(struct scmi_chan_info *cinfo, void *to,
+				unsigned int offset, long len)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	memcpy_fromio(to, smbox->payload + offset, len);
+}
+
+static void mailbox_memcpy_to(struct scmi_chan_info *cinfo, unsigned int offset,
+			      void *from, long len)
+{
+	struct scmi_mailbox *smbox = cinfo->transport_info;
+
+	memcpy_toio(smbox->payload + offset, from, len);
+}
+
+static struct scmi_transport_ops scmi_mailbox_ops = {
+	.chan_available = mailbox_chan_available,
+	.chan_setup = mailbox_chan_setup,
+	.chan_free = mailbox_chan_free,
+	.send_message = mailbox_send_message,
+	.mark_txdone = mailbox_mark_txdone,
+	.read32 = mailbox_read32,
+	.write32 = mailbox_write32,
+	.memcpy_from = mailbox_memcpy_from,
+	.memcpy_to = mailbox_memcpy_to,
+};
+
+const struct scmi_desc scmi_mailbox_desc = {
+	.ops = &scmi_mailbox_ops,
+	.max_rx_timeout_ms = 30, /* We may increase this if required */
+	.max_msg = 20, /* Limited by MBOX_TX_QUEUE_LEN */
+	.max_msg_size = 128,
+};
