diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index 05b1009e2820..378ebd5a7933 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -254,4 +254,16 @@ config QCOM_IPCC
 	  acts as an interrupt controller for receiving interrupts from clients.
 	  Say Y here if you want to build this driver.
 
+config BRCMSTB_MBOX
+	tristate "Broadcom STB Mailbox"
+	depends on ARM64 || ARM
+	depends on ARM_SCMI_PROTOCOL && ARCH_BRCMSTB
+	default ARM_SCMI_PROTOCOL && ARCH_BRCMSTB
+        help
+          Mailbox implementation of the Broadcom STB for the sole purposes
+          of SCMI communication.  This is used by the SCMI drivers to
+	  communicate with FW that runs in EL3.  This mailbox only implements
+	  the agent-to-platform channgel of SCMI but may be augmented in
+	  the future to add the platform-to-agent channel.
+
 endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index 60d224b723a1..a74efd02eece 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -54,3 +54,5 @@ obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
 obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
 
 obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
+
+obj-$(CONFIG_BRCMSTB_MBOX)	+= brcmstb-mailbox.o
diff --git a/drivers/mailbox/brcmstb-mailbox.c b/drivers/mailbox/brcmstb-mailbox.c
new file mode 100644
index 000000000000..27d87938b08c
--- /dev/null
+++ b/drivers/mailbox/brcmstb-mailbox.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017, Broadcom */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#if defined(CONFIG_ARM64) || defined(CONFIG_ARM)
+#include <linux/arm-smccc.h>
+#endif
+
+#define BRCM_SCMI_SMC_OEM_FUNC	0x400
+#define BRCM_SCMI_MBOX_NUM	0
+#define BRCM_FID(ch) ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
+			IS_ENABLED(CONFIG_ARM64), \
+			ARM_SMCCC_OWNER_OEM, \
+			BRCM_SCMI_SMC_OEM_FUNC + (ch))
+enum {
+	A2P_CHAN = 0,
+	NUM_CHAN
+};
+
+struct chan_priv {
+	unsigned int mbox_num;
+	unsigned int ch;
+};
+
+struct brcm_mbox {
+	struct mbox_controller controller;
+	int irqs[NUM_CHAN];
+};
+
+static struct mbox_chan *brcm_mbox_of_xlate(struct mbox_controller *controller,
+					    const struct of_phandle_args *sp)
+{
+	unsigned int ch = sp->args[0];
+	struct brcm_mbox *mbox
+		= container_of(controller, struct brcm_mbox, controller);
+
+	if (!mbox || ch >= NUM_CHAN)
+		return ERR_PTR(-ENOENT);
+
+	return &mbox->controller.chans[ch];
+}
+
+#if defined(CONFIG_ARM64) || defined(CONFIG_ARM)
+static int announce_msg(unsigned int mbox_num, unsigned int ch)
+{
+	struct arm_smccc_res res;
+
+	if (ch >= NUM_CHAN)
+		return -EIO;
+	arm_smccc_smc(BRCM_FID(ch), mbox_num, 0, 0, 0, 0, 0, 0, &res);
+	if (res.a0)
+		return -EIO;
+	return 0;
+}
+#else
+#error Func announce_msg() not defined for the current ARCH
+#endif
+
+static int brcm_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct chan_priv *priv = chan->con_priv;
+
+	return announce_msg(priv->mbox_num, priv->ch);
+}
+
+static int brcm_mbox_startup(struct mbox_chan *chan)
+{
+	return 0;
+}
+
+static const struct mbox_chan_ops brcm_mbox_ops = {
+	.send_data = brcm_mbox_send_data,
+	.startup = brcm_mbox_startup,
+};
+
+static irqreturn_t brcm_a2p_isr(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+
+	mbox_chan_received_data(chan, NULL);
+	return IRQ_HANDLED;
+}
+
+static int brcm_mbox_probe(struct platform_device *pdev)
+{
+	struct brcm_mbox *mbox;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct chan_priv *chan_priv;
+	int ret;
+
+	if (!np)
+		return -EINVAL;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	/* Allocate channels */
+	mbox->controller.chans = devm_kzalloc(
+		&pdev->dev, NUM_CHAN * sizeof(struct mbox_chan), GFP_KERNEL);
+	if (!mbox->controller.chans)
+		return -ENOMEM;
+	chan_priv = devm_kzalloc(
+		&pdev->dev, NUM_CHAN * sizeof(struct chan_priv), GFP_KERNEL);
+	if (!chan_priv)
+		return -ENOMEM;
+
+	mbox->irqs[A2P_CHAN] = platform_get_irq(pdev, 0);
+	ret = devm_request_irq(&pdev->dev, mbox->irqs[A2P_CHAN], brcm_a2p_isr,
+				IRQF_NO_SUSPEND, "brcm: SCMI a2p intr",
+				&mbox->controller.chans[A2P_CHAN]);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to setup SCMI a2p isr\n");
+		return ret;
+	}
+	chan_priv[A2P_CHAN].mbox_num = BRCM_SCMI_MBOX_NUM;
+	chan_priv[A2P_CHAN].ch = A2P_CHAN;
+	mbox->controller.chans[A2P_CHAN].con_priv = &chan_priv[A2P_CHAN];
+	mbox->controller.num_chans++;
+	mbox->controller.dev = &pdev->dev;
+	mbox->controller.ops = &brcm_mbox_ops;
+	mbox->controller.of_xlate = brcm_mbox_of_xlate;
+	ret = mbox_controller_register(&mbox->controller);
+	if (ret) {
+		dev_err(dev, "failed to register BrcmSTB mbox\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	return 0;
+}
+
+static int brcm_mbox_remove(struct platform_device *pdev)
+{
+	struct brcm_mbox *mbox = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&mbox->controller);
+
+	return 0;
+}
+
+static const struct of_device_id brcm_mbox_of_match[] = {
+	{ .compatible = "brcm,brcmstb-mbox", },
+	{}
+};
+MODULE_DEVICE_TABLE(of, brcm_mbox_of_match);
+
+static struct platform_driver brcm_mbox_driver = {
+	.probe = brcm_mbox_probe,
+	.remove = brcm_mbox_remove,
+	.driver = {
+		.name = "brcm_mbox",
+		.of_match_table = brcm_mbox_of_match,
+	},
+};
+
+module_platform_driver(brcm_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Broadcom STB SCMI Mailbox driver");
+MODULE_AUTHOR("Broadcom");
