Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

35 files changed, 17953 insertions, 0 deletions

diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
new file mode 100644
index 000000000..05d6fae80
--- /dev/null
+++ b/drivers/mailbox/Kconfig
@@ -0,0 +1,297 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig MAILBOX
+	bool "Mailbox Hardware Support"
+	help
+	  Mailbox is a framework to control hardware communication between
+	  on-chip processors through queued messages and interrupt driven
+	  signals. Say Y if your platform supports hardware mailboxes.
+
+if MAILBOX
+
+config APPLE_MAILBOX
+	tristate "Apple Mailbox driver"
+	depends on ARCH_APPLE || (ARM64 && COMPILE_TEST)
+	default ARCH_APPLE
+	help
+	  Apple SoCs have various co-processors required for certain
+	  peripherals to work (NVMe, display controller, etc.). This
+	  driver adds support for the mailbox controller used to
+	  communicate with those.
+
+	  Say Y here if you have a Apple SoC.
+
+config ARM_MHU
+	tristate "ARM MHU Mailbox"
+	depends on ARM_AMBA
+	help
+	  Say Y here if you want to build the ARM MHU controller driver.
+	  The controller has 3 mailbox channels, the last of which can be
+	  used in Secure mode only.
+
+config ARM_MHU_V2
+	tristate "ARM MHUv2 Mailbox"
+	depends on ARM_AMBA
+	help
+	  Say Y here if you want to build the ARM MHUv2 controller driver,
+	  which provides unidirectional mailboxes between processing elements.
+
+config IMX_MBOX
+	tristate "i.MX Mailbox"
+	depends on ARCH_MXC || COMPILE_TEST
+	help
+	  Mailbox implementation for i.MX Messaging Unit (MU).
+
+config PLATFORM_MHU
+	tristate "Platform MHU Mailbox"
+	depends on OF
+	depends on HAS_IOMEM
+	help
+	  Say Y here if you want to build a platform specific variant MHU
+	  controller driver.
+	  The controller has a maximum of 3 mailbox channels, the last of
+	  which can be used in Secure mode only.
+
+config PL320_MBOX
+	bool "ARM PL320 Mailbox"
+	depends on ARM_AMBA
+	help
+	  An implementation of the ARM PL320 Interprocessor Communication
+	  Mailbox (IPCM), tailored for the Calxeda Highbank. It is used to
+	  send short messages between Highbank's A9 cores and the EnergyCore
+	  Management Engine, primarily for cpufreq. Say Y here if you want
+	  to use the PL320 IPCM support.
+
+config ARMADA_37XX_RWTM_MBOX
+	tristate "Armada 37xx rWTM BIU Mailbox"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	help
+	  Mailbox implementation for communication with the the firmware
+	  running on the Cortex-M3 rWTM secure processor of the Armada 37xx
+	  SOC. Say Y here if you are building for such a device (for example
+	  the Turris Mox router).
+
+config OMAP2PLUS_MBOX
+	tristate "OMAP2+ Mailbox framework support"
+	depends on ARCH_OMAP2PLUS || ARCH_K3
+	help
+	  Mailbox implementation for OMAP family chips with hardware for
+	  interprocessor communication involving DSP, IVA1.0 and IVA2 in
+	  OMAP2/3; or IPU, IVA HD and DSP in OMAP4/5. Say Y here if you
+	  want to use OMAP2+ Mailbox framework support.
+
+config OMAP_MBOX_KFIFO_SIZE
+	int "Mailbox kfifo default buffer size (bytes)"
+	depends on OMAP2PLUS_MBOX
+	default 256
+	help
+	  Specify the default size of mailbox's kfifo buffers (bytes).
+	  This can also be changed at runtime (via the mbox_kfifo_size
+	  module parameter).
+
+config ROCKCHIP_MBOX
+	bool "Rockchip Soc Integrated Mailbox Support"
+	depends on ARCH_ROCKCHIP || COMPILE_TEST
+	help
+	  This driver provides support for inter-processor communication
+	  between CPU cores and MCU processor on Some Rockchip SOCs.
+	  Please check it that the Soc you use have Mailbox hardware.
+	  Say Y here if you want to use the Rockchip Mailbox support.
+
+config PCC
+	bool "Platform Communication Channel Driver"
+	depends on ACPI
+	default n
+	help
+	  ACPI 5.0+ spec defines a generic mode of communication
+	  between the OS and a platform such as the BMC. This medium
+	  (PCC) is typically used by CPPC (ACPI CPU Performance management),
+	  RAS (ACPI reliability protocol) and MPST (ACPI Memory power
+	  states). Select this driver if your platform implements the
+	  PCC clients mentioned above.
+
+config ALTERA_MBOX
+	tristate "Altera Mailbox"
+	depends on HAS_IOMEM
+	help
+	  An implementation of the Altera Mailbox soft core. It is used
+	  to send message between processors. Say Y here if you want to use the
+	  Altera mailbox support.
+
+config BCM2835_MBOX
+	tristate "BCM2835 Mailbox"
+	depends on ARCH_BCM2835
+	help
+	  An implementation of the BCM2385 Mailbox.  It is used to invoke
+	  the services of the Videocore. Say Y here if you want to use the
+	  BCM2835 Mailbox.
+
+config STI_MBOX
+	tristate "STI Mailbox framework support"
+	depends on ARCH_STI && OF
+	help
+	  Mailbox implementation for STMicroelectonics family chips with
+	  hardware for interprocessor communication.
+
+config TI_MESSAGE_MANAGER
+	tristate "Texas Instruments Message Manager Driver"
+	depends on ARCH_KEYSTONE || ARCH_K3
+	help
+	  An implementation of Message Manager slave driver for Keystone
+	  and K3 architecture SoCs from Texas Instruments. Message Manager
+	  is a communication entity found on few of Texas Instrument's keystone
+	  and K3 architecture SoCs. These may be used for communication between
+	  multiple processors within the SoC. Select this driver if your
+	  platform has support for the hardware block.
+
+config HI3660_MBOX
+	tristate "Hi3660 Mailbox" if EXPERT
+	depends on (ARCH_HISI || COMPILE_TEST)
+	depends on OF
+	default ARCH_HISI
+	help
+	  An implementation of the hi3660 mailbox. It is used to send message
+	  between application processors and other processors/MCU/DSP. Select
+	  Y here if you want to use Hi3660 mailbox controller.
+
+config HI6220_MBOX
+	tristate "Hi6220 Mailbox" if EXPERT
+	depends on (ARCH_HISI || COMPILE_TEST)
+	depends on OF
+	default ARCH_HISI
+	help
+	  An implementation of the hi6220 mailbox. It is used to send message
+	  between application processors and MCU. Say Y here if you want to
+	  build Hi6220 mailbox controller driver.
+
+config MAILBOX_TEST
+	tristate "Mailbox Test Client"
+	depends on OF
+	depends on HAS_IOMEM
+	help
+	  Test client to help with testing new Controller driver
+	  implementations.
+
+config POLARFIRE_SOC_MAILBOX
+	tristate "PolarFire SoC (MPFS) Mailbox"
+	depends on HAS_IOMEM
+	depends on SOC_MICROCHIP_POLARFIRE || COMPILE_TEST
+	help
+	  This driver adds support for the PolarFire SoC (MPFS) mailbox controller.
+
+	  To compile this driver as a module, choose M here. the
+	  module will be called mailbox-mpfs.
+
+	  If unsure, say N.
+
+config QCOM_APCS_IPC
+	tristate "Qualcomm APCS IPC driver"
+	depends on ARCH_QCOM || COMPILE_TEST
+	help
+	  Say y here to enable support for the APCS IPC mailbox driver,
+	  providing an interface for invoking the inter-process communication
+	  signals from the application processor to other masters.
+
+config TEGRA_HSP_MBOX
+	bool "Tegra HSP (Hardware Synchronization Primitives) Driver"
+	depends on ARCH_TEGRA
+	help
+	  The Tegra HSP driver is used for the interprocessor communication
+	  between different remote processors and host processors on Tegra186
+	  and later SoCs. Say Y here if you want to have this support.
+	  If unsure say N.
+
+config XGENE_SLIMPRO_MBOX
+	tristate "APM SoC X-Gene SLIMpro Mailbox Controller"
+	depends on ARCH_XGENE
+	help
+	  An implementation of the APM X-Gene Interprocessor Communication
+	  Mailbox (IPCM) between the ARM 64-bit cores and SLIMpro controller.
+	  It is used to send short messages between ARM64-bit cores and
+	  the SLIMpro Management Engine, primarily for PM. Say Y here if you
+	  want to use the APM X-Gene SLIMpro IPCM support.
+
+config BCM_PDC_MBOX
+	tristate "Broadcom FlexSparx DMA Mailbox"
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	help
+	  Mailbox implementation for the Broadcom FlexSparx DMA ring manager,
+	  which provides access to various offload engines on Broadcom
+	  SoCs, including FA2/FA+ on Northstar Plus and PDC on Northstar 2.
+
+config BCM_FLEXRM_MBOX
+	tristate "Broadcom FlexRM Mailbox"
+	depends on ARM64
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	select GENERIC_MSI_IRQ_DOMAIN
+	default m if ARCH_BCM_IPROC
+	help
+	  Mailbox implementation of the Broadcom FlexRM ring manager,
+	  which provides access to various offload engines on Broadcom
+	  SoCs. Say Y here if you want to use the Broadcom FlexRM.
+
+config STM32_IPCC
+	tristate "STM32 IPCC Mailbox"
+	depends on MACH_STM32MP157 || COMPILE_TEST
+	help
+	  Mailbox implementation for STMicroelectonics STM32 family chips
+	  with hardware for Inter-Processor Communication Controller (IPCC)
+	  between processors. Say Y here if you want to have this support.
+
+config MTK_ADSP_MBOX
+	tristate "MediaTek ADSP Mailbox Controller"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	help
+          Say yes here to add support for "MediaTek ADSP Mailbox Controller.
+          This mailbox driver is used to send notification or short message
+          between processors with ADSP. It will place the message to share
+	  buffer and will access the ipc control.
+
+config MTK_CMDQ_MBOX
+	tristate "MediaTek CMDQ Mailbox Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select MTK_INFRACFG
+	help
+	  Say yes here to add support for the MediaTek Command Queue (CMDQ)
+	  mailbox driver. The CMDQ is used to help read/write registers with
+	  critical time limitation, such as updating display configuration
+	  during the vblank.
+
+config ZYNQMP_IPI_MBOX
+	bool "Xilinx ZynqMP IPI Mailbox"
+	depends on ARCH_ZYNQMP && OF
+	help
+	  Say yes here to add support for Xilinx IPI mailbox driver.
+	  This mailbox driver is used to send notification or short message
+	  between processors with Xilinx ZynqMP IPI. It will place the
+	  message to the IPI buffer and will access the IPI control
+	  registers to kick the other processor or enquire status.
+
+config SUN6I_MSGBOX
+	tristate "Allwinner sun6i/sun8i/sun9i/sun50i Message Box"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	default ARCH_SUNXI
+	help
+	  Mailbox implementation for the hardware message box present in
+	  various Allwinner SoCs. This mailbox is used for communication
+	  between the application CPUs and the power management coprocessor.
+
+config SPRD_MBOX
+	tristate "Spreadtrum Mailbox"
+	depends on ARCH_SPRD || COMPILE_TEST
+	help
+	  Mailbox driver implementation for the Spreadtrum platform. It is used
+	  to send message between application processors and MCU. Say Y here if
+	  you want to build the Spreatrum mailbox controller driver.
+
+config QCOM_IPCC
+	tristate "Qualcomm Technologies, Inc. IPCC driver"
+	depends on ARCH_QCOM || COMPILE_TEST
+	help
+	  Qualcomm Technologies, Inc. Inter-Processor Communication Controller
+	  (IPCC) driver for MSM devices. The driver provides mailbox support for
+	  sending interrupts to the clients. On the other hand, the driver also
+	  acts as an interrupt controller for receiving interrupts from clients.
+	  Say Y here if you want to build this driver.
+
+endif
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
new file mode 100644
index 000000000..fc9376117
--- /dev/null
+++ b/drivers/mailbox/Makefile
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0
+# Generic MAILBOX API
+
+obj-$(CONFIG_MAILBOX)		+= mailbox.o
+
+obj-$(CONFIG_MAILBOX_TEST)	+= mailbox-test.o
+
+obj-$(CONFIG_ARM_MHU)	+= arm_mhu.o arm_mhu_db.o
+
+obj-$(CONFIG_ARM_MHU_V2)	+= arm_mhuv2.o
+
+obj-$(CONFIG_IMX_MBOX)	+= imx-mailbox.o
+
+obj-$(CONFIG_ARMADA_37XX_RWTM_MBOX)	+= armada-37xx-rwtm-mailbox.o
+
+obj-$(CONFIG_PLATFORM_MHU)	+= platform_mhu.o
+
+obj-$(CONFIG_PL320_MBOX)	+= pl320-ipc.o
+
+obj-$(CONFIG_OMAP2PLUS_MBOX)	+= omap-mailbox.o
+
+obj-$(CONFIG_ROCKCHIP_MBOX)	+= rockchip-mailbox.o
+
+obj-$(CONFIG_PCC)		+= pcc.o
+
+obj-$(CONFIG_ALTERA_MBOX)	+= mailbox-altera.o
+
+obj-$(CONFIG_BCM2835_MBOX)	+= bcm2835-mailbox.o
+
+obj-$(CONFIG_STI_MBOX)		+= mailbox-sti.o
+
+obj-$(CONFIG_TI_MESSAGE_MANAGER) += ti-msgmgr.o
+
+obj-$(CONFIG_XGENE_SLIMPRO_MBOX) += mailbox-xgene-slimpro.o
+
+obj-$(CONFIG_HI3660_MBOX)	+= hi3660-mailbox.o
+
+obj-$(CONFIG_HI6220_MBOX)	+= hi6220-mailbox.o
+
+obj-$(CONFIG_BCM_PDC_MBOX)	+= bcm-pdc-mailbox.o
+
+obj-$(CONFIG_BCM_FLEXRM_MBOX)	+= bcm-flexrm-mailbox.o
+
+obj-$(CONFIG_POLARFIRE_SOC_MAILBOX)	+= mailbox-mpfs.o
+
+obj-$(CONFIG_QCOM_APCS_IPC)	+= qcom-apcs-ipc-mailbox.o
+
+obj-$(CONFIG_TEGRA_HSP_MBOX)	+= tegra-hsp.o
+
+obj-$(CONFIG_STM32_IPCC) 	+= stm32-ipcc.o
+
+obj-$(CONFIG_MTK_ADSP_MBOX)	+= mtk-adsp-mailbox.o
+
+obj-$(CONFIG_MTK_CMDQ_MBOX)	+= mtk-cmdq-mailbox.o
+
+obj-$(CONFIG_ZYNQMP_IPI_MBOX)	+= zynqmp-ipi-mailbox.o
+
+obj-$(CONFIG_SUN6I_MSGBOX)	+= sun6i-msgbox.o
+
+obj-$(CONFIG_SPRD_MBOX)		+= sprd-mailbox.o
+
+obj-$(CONFIG_QCOM_IPCC)		+= qcom-ipcc.o
+
+obj-$(CONFIG_APPLE_MAILBOX)	+= apple-mailbox.o
diff --git a/drivers/mailbox/apple-mailbox.c b/drivers/mailbox/apple-mailbox.c
new file mode 100644
index 000000000..2a3e8d8ff
--- /dev/null
+++ b/drivers/mailbox/apple-mailbox.c
@@ -0,0 +1,441 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple mailbox driver
+ *
+ * Copyright (C) 2021 The Asahi Linux Contributors
+ *
+ * This driver adds support for two mailbox variants (called ASC and M3 by
+ * Apple) found in Apple SoCs such as the M1. It consists of two FIFOs used to
+ * exchange 64+32 bit messages between the main CPU and a co-processor.
+ * Various coprocessors implement different IPC protocols based on these simple
+ * messages and shared memory buffers.
+ *
+ * Both the main CPU and the co-processor see the same set of registers but
+ * the first FIFO (A2I) is always used to transfer messages from the application
+ * processor (us) to the I/O processor and the second one (I2A) for the
+ * other direction.
+ */
+
+#include <linux/apple-mailbox.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/gfp.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#define APPLE_ASC_MBOX_CONTROL_FULL  BIT(16)
+#define APPLE_ASC_MBOX_CONTROL_EMPTY BIT(17)
+
+#define APPLE_ASC_MBOX_A2I_CONTROL 0x110
+#define APPLE_ASC_MBOX_A2I_SEND0   0x800
+#define APPLE_ASC_MBOX_A2I_SEND1   0x808
+#define APPLE_ASC_MBOX_A2I_RECV0   0x810
+#define APPLE_ASC_MBOX_A2I_RECV1   0x818
+
+#define APPLE_ASC_MBOX_I2A_CONTROL 0x114
+#define APPLE_ASC_MBOX_I2A_SEND0   0x820
+#define APPLE_ASC_MBOX_I2A_SEND1   0x828
+#define APPLE_ASC_MBOX_I2A_RECV0   0x830
+#define APPLE_ASC_MBOX_I2A_RECV1   0x838
+
+#define APPLE_M3_MBOX_CONTROL_FULL  BIT(16)
+#define APPLE_M3_MBOX_CONTROL_EMPTY BIT(17)
+
+#define APPLE_M3_MBOX_A2I_CONTROL 0x50
+#define APPLE_M3_MBOX_A2I_SEND0	  0x60
+#define APPLE_M3_MBOX_A2I_SEND1	  0x68
+#define APPLE_M3_MBOX_A2I_RECV0	  0x70
+#define APPLE_M3_MBOX_A2I_RECV1	  0x78
+
+#define APPLE_M3_MBOX_I2A_CONTROL 0x80
+#define APPLE_M3_MBOX_I2A_SEND0	  0x90
+#define APPLE_M3_MBOX_I2A_SEND1	  0x98
+#define APPLE_M3_MBOX_I2A_RECV0	  0xa0
+#define APPLE_M3_MBOX_I2A_RECV1	  0xa8
+
+#define APPLE_M3_MBOX_IRQ_ENABLE	0x48
+#define APPLE_M3_MBOX_IRQ_ACK		0x4c
+#define APPLE_M3_MBOX_IRQ_A2I_EMPTY	BIT(0)
+#define APPLE_M3_MBOX_IRQ_A2I_NOT_EMPTY BIT(1)
+#define APPLE_M3_MBOX_IRQ_I2A_EMPTY	BIT(2)
+#define APPLE_M3_MBOX_IRQ_I2A_NOT_EMPTY BIT(3)
+
+#define APPLE_MBOX_MSG1_OUTCNT GENMASK(56, 52)
+#define APPLE_MBOX_MSG1_INCNT  GENMASK(51, 48)
+#define APPLE_MBOX_MSG1_OUTPTR GENMASK(47, 44)
+#define APPLE_MBOX_MSG1_INPTR  GENMASK(43, 40)
+#define APPLE_MBOX_MSG1_MSG    GENMASK(31, 0)
+
+struct apple_mbox_hw {
+	unsigned int control_full;
+	unsigned int control_empty;
+
+	unsigned int a2i_control;
+	unsigned int a2i_send0;
+	unsigned int a2i_send1;
+
+	unsigned int i2a_control;
+	unsigned int i2a_recv0;
+	unsigned int i2a_recv1;
+
+	bool has_irq_controls;
+	unsigned int irq_enable;
+	unsigned int irq_ack;
+	unsigned int irq_bit_recv_not_empty;
+	unsigned int irq_bit_send_empty;
+};
+
+struct apple_mbox {
+	void __iomem *regs;
+	const struct apple_mbox_hw *hw;
+
+	int irq_recv_not_empty;
+	int irq_send_empty;
+
+	struct mbox_chan chan;
+
+	struct device *dev;
+	struct mbox_controller controller;
+	spinlock_t rx_lock;
+};
+
+static const struct of_device_id apple_mbox_of_match[];
+
+static bool apple_mbox_hw_can_send(struct apple_mbox *apple_mbox)
+{
+	u32 mbox_ctrl =
+		readl_relaxed(apple_mbox->regs + apple_mbox->hw->a2i_control);
+
+	return !(mbox_ctrl & apple_mbox->hw->control_full);
+}
+
+static bool apple_mbox_hw_send_empty(struct apple_mbox *apple_mbox)
+{
+	u32 mbox_ctrl =
+		readl_relaxed(apple_mbox->regs + apple_mbox->hw->a2i_control);
+
+	return mbox_ctrl & apple_mbox->hw->control_empty;
+}
+
+static int apple_mbox_hw_send(struct apple_mbox *apple_mbox,
+			      struct apple_mbox_msg *msg)
+{
+	if (!apple_mbox_hw_can_send(apple_mbox))
+		return -EBUSY;
+
+	dev_dbg(apple_mbox->dev, "> TX %016llx %08x\n", msg->msg0, msg->msg1);
+
+	writeq_relaxed(msg->msg0, apple_mbox->regs + apple_mbox->hw->a2i_send0);
+	writeq_relaxed(FIELD_PREP(APPLE_MBOX_MSG1_MSG, msg->msg1),
+		       apple_mbox->regs + apple_mbox->hw->a2i_send1);
+
+	return 0;
+}
+
+static bool apple_mbox_hw_can_recv(struct apple_mbox *apple_mbox)
+{
+	u32 mbox_ctrl =
+		readl_relaxed(apple_mbox->regs + apple_mbox->hw->i2a_control);
+
+	return !(mbox_ctrl & apple_mbox->hw->control_empty);
+}
+
+static int apple_mbox_hw_recv(struct apple_mbox *apple_mbox,
+			      struct apple_mbox_msg *msg)
+{
+	if (!apple_mbox_hw_can_recv(apple_mbox))
+		return -ENOMSG;
+
+	msg->msg0 = readq_relaxed(apple_mbox->regs + apple_mbox->hw->i2a_recv0);
+	msg->msg1 = FIELD_GET(
+		APPLE_MBOX_MSG1_MSG,
+		readq_relaxed(apple_mbox->regs + apple_mbox->hw->i2a_recv1));
+
+	dev_dbg(apple_mbox->dev, "< RX %016llx %08x\n", msg->msg0, msg->msg1);
+
+	return 0;
+}
+
+static int apple_mbox_chan_send_data(struct mbox_chan *chan, void *data)
+{
+	struct apple_mbox *apple_mbox = chan->con_priv;
+	struct apple_mbox_msg *msg = data;
+	int ret;
+
+	ret = apple_mbox_hw_send(apple_mbox, msg);
+	if (ret)
+		return ret;
+
+	/*
+	 * The interrupt is level triggered and will keep firing as long as the
+	 * FIFO is empty. It will also keep firing if the FIFO was empty
+	 * at any point in the past until it has been acknowledged at the
+	 * mailbox level. By acknowledging it here we can ensure that we will
+	 * only get the interrupt once the FIFO has been cleared again.
+	 * If the FIFO is already empty before the ack it will fire again
+	 * immediately after the ack.
+	 */
+	if (apple_mbox->hw->has_irq_controls) {
+		writel_relaxed(apple_mbox->hw->irq_bit_send_empty,
+			       apple_mbox->regs + apple_mbox->hw->irq_ack);
+	}
+	enable_irq(apple_mbox->irq_send_empty);
+
+	return 0;
+}
+
+static irqreturn_t apple_mbox_send_empty_irq(int irq, void *data)
+{
+	struct apple_mbox *apple_mbox = data;
+
+	/*
+	 * We don't need to acknowledge the interrupt at the mailbox level
+	 * here even if supported by the hardware. It will keep firing but that
+	 * doesn't matter since it's disabled at the main interrupt controller.
+	 * apple_mbox_chan_send_data will acknowledge it before enabling
+	 * it at the main controller again.
+	 */
+	disable_irq_nosync(apple_mbox->irq_send_empty);
+	mbox_chan_txdone(&apple_mbox->chan, 0);
+	return IRQ_HANDLED;
+}
+
+static int apple_mbox_poll(struct apple_mbox *apple_mbox)
+{
+	struct apple_mbox_msg msg;
+	int ret = 0;
+
+	while (apple_mbox_hw_recv(apple_mbox, &msg) == 0) {
+		mbox_chan_received_data(&apple_mbox->chan, (void *)&msg);
+		ret++;
+	}
+
+	/*
+	 * The interrupt will keep firing even if there are no more messages
+	 * unless we also acknowledge it at the mailbox level here.
+	 * There's no race if a message comes in between the check in the while
+	 * loop above and the ack below: If a new messages arrives inbetween
+	 * those two the interrupt will just fire again immediately after the
+	 * ack since it's level triggered.
+	 */
+	if (apple_mbox->hw->has_irq_controls) {
+		writel_relaxed(apple_mbox->hw->irq_bit_recv_not_empty,
+			       apple_mbox->regs + apple_mbox->hw->irq_ack);
+	}
+
+	return ret;
+}
+
+static irqreturn_t apple_mbox_recv_irq(int irq, void *data)
+{
+	struct apple_mbox *apple_mbox = data;
+
+	spin_lock(&apple_mbox->rx_lock);
+	apple_mbox_poll(apple_mbox);
+	spin_unlock(&apple_mbox->rx_lock);
+
+	return IRQ_HANDLED;
+}
+
+static bool apple_mbox_chan_peek_data(struct mbox_chan *chan)
+{
+	struct apple_mbox *apple_mbox = chan->con_priv;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&apple_mbox->rx_lock, flags);
+	ret = apple_mbox_poll(apple_mbox);
+	spin_unlock_irqrestore(&apple_mbox->rx_lock, flags);
+
+	return ret > 0;
+}
+
+static int apple_mbox_chan_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+	struct apple_mbox *apple_mbox = chan->con_priv;
+	unsigned long deadline = jiffies + msecs_to_jiffies(timeout);
+
+	while (time_before(jiffies, deadline)) {
+		if (apple_mbox_hw_send_empty(apple_mbox)) {
+			mbox_chan_txdone(&apple_mbox->chan, 0);
+			return 0;
+		}
+
+		udelay(1);
+	}
+
+	return -ETIME;
+}
+
+static int apple_mbox_chan_startup(struct mbox_chan *chan)
+{
+	struct apple_mbox *apple_mbox = chan->con_priv;
+
+	/*
+	 * Only some variants of this mailbox HW provide interrupt control
+	 * at the mailbox level. We therefore need to handle enabling/disabling
+	 * interrupts at the main interrupt controller anyway for hardware that
+	 * doesn't. Just always keep the interrupts we care about enabled at
+	 * the mailbox level so that both hardware revisions behave almost
+	 * the same.
+	 */
+	if (apple_mbox->hw->has_irq_controls) {
+		writel_relaxed(apple_mbox->hw->irq_bit_recv_not_empty |
+				       apple_mbox->hw->irq_bit_send_empty,
+			       apple_mbox->regs + apple_mbox->hw->irq_enable);
+	}
+
+	enable_irq(apple_mbox->irq_recv_not_empty);
+	return 0;
+}
+
+static void apple_mbox_chan_shutdown(struct mbox_chan *chan)
+{
+	struct apple_mbox *apple_mbox = chan->con_priv;
+
+	disable_irq(apple_mbox->irq_recv_not_empty);
+}
+
+static const struct mbox_chan_ops apple_mbox_ops = {
+	.send_data = apple_mbox_chan_send_data,
+	.peek_data = apple_mbox_chan_peek_data,
+	.flush = apple_mbox_chan_flush,
+	.startup = apple_mbox_chan_startup,
+	.shutdown = apple_mbox_chan_shutdown,
+};
+
+static struct mbox_chan *apple_mbox_of_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *args)
+{
+	if (args->args_count != 0)
+		return ERR_PTR(-EINVAL);
+
+	return &mbox->chans[0];
+}
+
+static int apple_mbox_probe(struct platform_device *pdev)
+{
+	int ret;
+	const struct of_device_id *match;
+	char *irqname;
+	struct apple_mbox *mbox;
+	struct device *dev = &pdev->dev;
+
+	match = of_match_node(apple_mbox_of_match, pdev->dev.of_node);
+	if (!match)
+		return -EINVAL;
+	if (!match->data)
+		return -EINVAL;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, mbox);
+
+	mbox->dev = dev;
+	mbox->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->regs))
+		return PTR_ERR(mbox->regs);
+
+	mbox->hw = match->data;
+	mbox->irq_recv_not_empty =
+		platform_get_irq_byname(pdev, "recv-not-empty");
+	if (mbox->irq_recv_not_empty < 0)
+		return -ENODEV;
+
+	mbox->irq_send_empty = platform_get_irq_byname(pdev, "send-empty");
+	if (mbox->irq_send_empty < 0)
+		return -ENODEV;
+
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = &mbox->chan;
+	mbox->controller.ops = &apple_mbox_ops;
+	mbox->controller.txdone_irq = true;
+	mbox->controller.of_xlate = apple_mbox_of_xlate;
+	mbox->chan.con_priv = mbox;
+	spin_lock_init(&mbox->rx_lock);
+
+	irqname = devm_kasprintf(dev, GFP_KERNEL, "%s-recv", dev_name(dev));
+	if (!irqname)
+		return -ENOMEM;
+
+	ret = devm_request_threaded_irq(dev, mbox->irq_recv_not_empty, NULL,
+					apple_mbox_recv_irq,
+					IRQF_NO_AUTOEN | IRQF_ONESHOT, irqname,
+					mbox);
+	if (ret)
+		return ret;
+
+	irqname = devm_kasprintf(dev, GFP_KERNEL, "%s-send", dev_name(dev));
+	if (!irqname)
+		return -ENOMEM;
+
+	ret = devm_request_irq(dev, mbox->irq_send_empty,
+			       apple_mbox_send_empty_irq, IRQF_NO_AUTOEN,
+			       irqname, mbox);
+	if (ret)
+		return ret;
+
+	return devm_mbox_controller_register(dev, &mbox->controller);
+}
+
+static const struct apple_mbox_hw apple_mbox_asc_hw = {
+	.control_full = APPLE_ASC_MBOX_CONTROL_FULL,
+	.control_empty = APPLE_ASC_MBOX_CONTROL_EMPTY,
+
+	.a2i_control = APPLE_ASC_MBOX_A2I_CONTROL,
+	.a2i_send0 = APPLE_ASC_MBOX_A2I_SEND0,
+	.a2i_send1 = APPLE_ASC_MBOX_A2I_SEND1,
+
+	.i2a_control = APPLE_ASC_MBOX_I2A_CONTROL,
+	.i2a_recv0 = APPLE_ASC_MBOX_I2A_RECV0,
+	.i2a_recv1 = APPLE_ASC_MBOX_I2A_RECV1,
+
+	.has_irq_controls = false,
+};
+
+static const struct apple_mbox_hw apple_mbox_m3_hw = {
+	.control_full = APPLE_M3_MBOX_CONTROL_FULL,
+	.control_empty = APPLE_M3_MBOX_CONTROL_EMPTY,
+
+	.a2i_control = APPLE_M3_MBOX_A2I_CONTROL,
+	.a2i_send0 = APPLE_M3_MBOX_A2I_SEND0,
+	.a2i_send1 = APPLE_M3_MBOX_A2I_SEND1,
+
+	.i2a_control = APPLE_M3_MBOX_I2A_CONTROL,
+	.i2a_recv0 = APPLE_M3_MBOX_I2A_RECV0,
+	.i2a_recv1 = APPLE_M3_MBOX_I2A_RECV1,
+
+	.has_irq_controls = true,
+	.irq_enable = APPLE_M3_MBOX_IRQ_ENABLE,
+	.irq_ack = APPLE_M3_MBOX_IRQ_ACK,
+	.irq_bit_recv_not_empty = APPLE_M3_MBOX_IRQ_I2A_NOT_EMPTY,
+	.irq_bit_send_empty = APPLE_M3_MBOX_IRQ_A2I_EMPTY,
+};
+
+static const struct of_device_id apple_mbox_of_match[] = {
+	{ .compatible = "apple,asc-mailbox-v4", .data = &apple_mbox_asc_hw },
+	{ .compatible = "apple,m3-mailbox-v2", .data = &apple_mbox_m3_hw },
+	{}
+};
+MODULE_DEVICE_TABLE(of, apple_mbox_of_match);
+
+static struct platform_driver apple_mbox_driver = {
+	.driver = {
+		.name = "apple-mailbox",
+		.of_match_table = apple_mbox_of_match,
+	},
+	.probe = apple_mbox_probe,
+};
+module_platform_driver(apple_mbox_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_DESCRIPTION("Apple Mailbox driver");
diff --git a/drivers/mailbox/arm_mhu.c b/drivers/mailbox/arm_mhu.c
new file mode 100644
index 000000000..22243cabe
--- /dev/null
+++ b/drivers/mailbox/arm_mhu.c
@@ -0,0 +1,175 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Jassi Brar <jaswinder.singh@linaro.org>
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+
+#define INTR_STAT_OFS	0x0
+#define INTR_SET_OFS	0x8
+#define INTR_CLR_OFS	0x10
+
+#define MHU_LP_OFFSET	0x0
+#define MHU_HP_OFFSET	0x20
+#define MHU_SEC_OFFSET	0x200
+#define TX_REG_OFFSET	0x100
+
+#define MHU_CHANS	3
+
+struct mhu_link {
+	unsigned irq;
+	void __iomem *tx_reg;
+	void __iomem *rx_reg;
+};
+
+struct arm_mhu {
+	void __iomem *base;
+	struct mhu_link mlink[MHU_CHANS];
+	struct mbox_chan chan[MHU_CHANS];
+	struct mbox_controller mbox;
+};
+
+static irqreturn_t mhu_rx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = p;
+	struct mhu_link *mlink = chan->con_priv;
+	u32 val;
+
+	val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+	if (!val)
+		return IRQ_NONE;
+
+	mbox_chan_received_data(chan, (void *)&val);
+
+	writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+
+	return IRQ_HANDLED;
+}
+
+static bool mhu_last_tx_done(struct mbox_chan *chan)
+{
+	struct mhu_link *mlink = chan->con_priv;
+	u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+
+	return (val == 0);
+}
+
+static int mhu_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mhu_link *mlink = chan->con_priv;
+	u32 *arg = data;
+
+	writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+
+	return 0;
+}
+
+static int mhu_startup(struct mbox_chan *chan)
+{
+	struct mhu_link *mlink = chan->con_priv;
+	u32 val;
+	int ret;
+
+	val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+	writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
+
+	ret = request_irq(mlink->irq, mhu_rx_interrupt,
+			  IRQF_SHARED, "mhu_link", chan);
+	if (ret) {
+		dev_err(chan->mbox->dev,
+			"Unable to acquire IRQ %d\n", mlink->irq);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void mhu_shutdown(struct mbox_chan *chan)
+{
+	struct mhu_link *mlink = chan->con_priv;
+
+	free_irq(mlink->irq, chan);
+}
+
+static const struct mbox_chan_ops mhu_ops = {
+	.send_data = mhu_send_data,
+	.startup = mhu_startup,
+	.shutdown = mhu_shutdown,
+	.last_tx_done = mhu_last_tx_done,
+};
+
+static int mhu_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int i, err;
+	struct arm_mhu *mhu;
+	struct device *dev = &adev->dev;
+	int mhu_reg[MHU_CHANS] = {MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET};
+
+	if (!of_device_is_compatible(dev->of_node, "arm,mhu"))
+		return -ENODEV;
+
+	/* Allocate memory for device */
+	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+	if (!mhu)
+		return -ENOMEM;
+
+	mhu->base = devm_ioremap_resource(dev, &adev->res);
+	if (IS_ERR(mhu->base))
+		return PTR_ERR(mhu->base);
+
+	for (i = 0; i < MHU_CHANS; i++) {
+		mhu->chan[i].con_priv = &mhu->mlink[i];
+		mhu->mlink[i].irq = adev->irq[i];
+		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+	}
+
+	mhu->mbox.dev = dev;
+	mhu->mbox.chans = &mhu->chan[0];
+	mhu->mbox.num_chans = MHU_CHANS;
+	mhu->mbox.ops = &mhu_ops;
+	mhu->mbox.txdone_irq = false;
+	mhu->mbox.txdone_poll = true;
+	mhu->mbox.txpoll_period = 1;
+
+	amba_set_drvdata(adev, mhu);
+
+	err = devm_mbox_controller_register(dev, &mhu->mbox);
+	if (err) {
+		dev_err(dev, "Failed to register mailboxes %d\n", err);
+		return err;
+	}
+
+	dev_info(dev, "ARM MHU Mailbox registered\n");
+	return 0;
+}
+
+static struct amba_id mhu_ids[] = {
+	{
+		.id	= 0x1bb098,
+		.mask	= 0xffffff,
+	},
+	{ 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, mhu_ids);
+
+static struct amba_driver arm_mhu_driver = {
+	.drv = {
+		.name	= "mhu",
+	},
+	.id_table	= mhu_ids,
+	.probe		= mhu_probe,
+};
+module_amba_driver(arm_mhu_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ARM MHU Driver");
+MODULE_AUTHOR("Jassi Brar <jassisinghbrar@gmail.com>");
diff --git a/drivers/mailbox/arm_mhu_db.c b/drivers/mailbox/arm_mhu_db.c
new file mode 100644
index 000000000..aa0a4d838
--- /dev/null
+++ b/drivers/mailbox/arm_mhu_db.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Based on ARM MHU driver by Jassi Brar <jaswinder.singh@linaro.org>
+ * Copyright (C) 2020 ARM Ltd.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#define INTR_STAT_OFS	0x0
+#define INTR_SET_OFS	0x8
+#define INTR_CLR_OFS	0x10
+
+#define MHU_LP_OFFSET	0x0
+#define MHU_HP_OFFSET	0x20
+#define MHU_SEC_OFFSET	0x200
+#define TX_REG_OFFSET	0x100
+
+#define MHU_CHANS	3	/* Secure, Non-Secure High and Low Priority */
+#define MHU_CHAN_MAX	20	/* Max channels to save on unused RAM */
+#define MHU_NUM_DOORBELLS	32
+
+struct mhu_db_link {
+	unsigned int irq;
+	void __iomem *tx_reg;
+	void __iomem *rx_reg;
+};
+
+struct arm_mhu {
+	void __iomem *base;
+	struct mhu_db_link mlink[MHU_CHANS];
+	struct mbox_controller mbox;
+	struct device *dev;
+};
+
+/**
+ * struct mhu_db_channel - ARM MHU Mailbox allocated channel information
+ *
+ * @mhu: Pointer to parent mailbox device
+ * @pchan: Physical channel within which this doorbell resides in
+ * @doorbell: doorbell number pertaining to this channel
+ */
+struct mhu_db_channel {
+	struct arm_mhu *mhu;
+	unsigned int pchan;
+	unsigned int doorbell;
+};
+
+static inline struct mbox_chan *
+mhu_db_mbox_to_channel(struct mbox_controller *mbox, unsigned int pchan,
+		       unsigned int doorbell)
+{
+	int i;
+	struct mhu_db_channel *chan_info;
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+		if (chan_info && chan_info->pchan == pchan &&
+		    chan_info->doorbell == doorbell)
+			return &mbox->chans[i];
+	}
+
+	return NULL;
+}
+
+static void mhu_db_mbox_clear_irq(struct mbox_chan *chan)
+{
+	struct mhu_db_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg;
+
+	writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS);
+}
+
+static unsigned int mhu_db_mbox_irq_to_pchan_num(struct arm_mhu *mhu, int irq)
+{
+	unsigned int pchan;
+
+	for (pchan = 0; pchan < MHU_CHANS; pchan++)
+		if (mhu->mlink[pchan].irq == irq)
+			break;
+	return pchan;
+}
+
+static struct mbox_chan *
+mhu_db_mbox_irq_to_channel(struct arm_mhu *mhu, unsigned int pchan)
+{
+	unsigned long bits;
+	unsigned int doorbell;
+	struct mbox_chan *chan = NULL;
+	struct mbox_controller *mbox = &mhu->mbox;
+	void __iomem *base = mhu->mlink[pchan].rx_reg;
+
+	bits = readl_relaxed(base + INTR_STAT_OFS);
+	if (!bits)
+		/* No IRQs fired in specified physical channel */
+		return NULL;
+
+	/* An IRQ has fired, find the associated channel */
+	for (doorbell = 0; bits; doorbell++) {
+		if (!test_and_clear_bit(doorbell, &bits))
+			continue;
+
+		chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);
+		if (chan)
+			break;
+		dev_err(mbox->dev,
+			"Channel not registered: pchan: %d doorbell: %d\n",
+			pchan, doorbell);
+	}
+
+	return chan;
+}
+
+static irqreturn_t mhu_db_mbox_rx_handler(int irq, void *data)
+{
+	struct mbox_chan *chan;
+	struct arm_mhu *mhu = data;
+	unsigned int pchan = mhu_db_mbox_irq_to_pchan_num(mhu, irq);
+
+	while (NULL != (chan = mhu_db_mbox_irq_to_channel(mhu, pchan))) {
+		mbox_chan_received_data(chan, NULL);
+		mhu_db_mbox_clear_irq(chan);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static bool mhu_db_last_tx_done(struct mbox_chan *chan)
+{
+	struct mhu_db_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+	if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell))
+		return false;
+
+	return true;
+}
+
+static int mhu_db_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mhu_db_channel *chan_info = chan->con_priv;
+	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;
+
+	/* Send event to co-processor */
+	writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS);
+
+	return 0;
+}
+
+static int mhu_db_startup(struct mbox_chan *chan)
+{
+	mhu_db_mbox_clear_irq(chan);
+	return 0;
+}
+
+static void mhu_db_shutdown(struct mbox_chan *chan)
+{
+	struct mhu_db_channel *chan_info = chan->con_priv;
+	struct mbox_controller *mbox = &chan_info->mhu->mbox;
+	int i;
+
+	for (i = 0; i < mbox->num_chans; i++)
+		if (chan == &mbox->chans[i])
+			break;
+
+	if (mbox->num_chans == i) {
+		dev_warn(mbox->dev, "Request to free non-existent channel\n");
+		return;
+	}
+
+	/* Reset channel */
+	mhu_db_mbox_clear_irq(chan);
+	devm_kfree(mbox->dev, chan->con_priv);
+	chan->con_priv = NULL;
+}
+
+static struct mbox_chan *mhu_db_mbox_xlate(struct mbox_controller *mbox,
+					   const struct of_phandle_args *spec)
+{
+	struct arm_mhu *mhu = dev_get_drvdata(mbox->dev);
+	struct mhu_db_channel *chan_info;
+	struct mbox_chan *chan;
+	unsigned int pchan = spec->args[0];
+	unsigned int doorbell = spec->args[1];
+	int i;
+
+	/* Bounds checking */
+	if (pchan >= MHU_CHANS || doorbell >= MHU_NUM_DOORBELLS) {
+		dev_err(mbox->dev,
+			"Invalid channel requested pchan: %d doorbell: %d\n",
+			pchan, doorbell);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Is requested channel free? */
+	chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);
+	if (chan) {
+		dev_err(mbox->dev, "Channel in use: pchan: %d doorbell: %d\n",
+			pchan, doorbell);
+		return ERR_PTR(-EBUSY);
+	}
+
+	/* Find the first free slot */
+	for (i = 0; i < mbox->num_chans; i++)
+		if (!mbox->chans[i].con_priv)
+			break;
+
+	if (mbox->num_chans == i) {
+		dev_err(mbox->dev, "No free channels left\n");
+		return ERR_PTR(-EBUSY);
+	}
+
+	chan = &mbox->chans[i];
+
+	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
+	if (!chan_info)
+		return ERR_PTR(-ENOMEM);
+
+	chan_info->mhu = mhu;
+	chan_info->pchan = pchan;
+	chan_info->doorbell = doorbell;
+
+	chan->con_priv = chan_info;
+
+	dev_dbg(mbox->dev, "mbox: created channel phys: %d doorbell: %d\n",
+		pchan, doorbell);
+
+	return chan;
+}
+
+static const struct mbox_chan_ops mhu_db_ops = {
+	.send_data = mhu_db_send_data,
+	.startup = mhu_db_startup,
+	.shutdown = mhu_db_shutdown,
+	.last_tx_done = mhu_db_last_tx_done,
+};
+
+static int mhu_db_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	u32 cell_count;
+	int i, err, max_chans;
+	struct arm_mhu *mhu;
+	struct mbox_chan *chans;
+	struct device *dev = &adev->dev;
+	struct device_node *np = dev->of_node;
+	int mhu_reg[MHU_CHANS] = {
+		MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET,
+	};
+
+	if (!of_device_is_compatible(np, "arm,mhu-doorbell"))
+		return -ENODEV;
+
+	err = of_property_read_u32(np, "#mbox-cells", &cell_count);
+	if (err) {
+		dev_err(dev, "failed to read #mbox-cells in '%pOF'\n", np);
+		return err;
+	}
+
+	if (cell_count == 2) {
+		max_chans = MHU_CHAN_MAX;
+	} else {
+		dev_err(dev, "incorrect value of #mbox-cells in '%pOF'\n", np);
+		return -EINVAL;
+	}
+
+	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+	if (!mhu)
+		return -ENOMEM;
+
+	mhu->base = devm_ioremap_resource(dev, &adev->res);
+	if (IS_ERR(mhu->base))
+		return PTR_ERR(mhu->base);
+
+	chans = devm_kcalloc(dev, max_chans, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mhu->dev = dev;
+	mhu->mbox.dev = dev;
+	mhu->mbox.chans = chans;
+	mhu->mbox.num_chans = max_chans;
+	mhu->mbox.txdone_irq = false;
+	mhu->mbox.txdone_poll = true;
+	mhu->mbox.txpoll_period = 1;
+
+	mhu->mbox.of_xlate = mhu_db_mbox_xlate;
+	amba_set_drvdata(adev, mhu);
+
+	mhu->mbox.ops = &mhu_db_ops;
+
+	err = devm_mbox_controller_register(dev, &mhu->mbox);
+	if (err) {
+		dev_err(dev, "Failed to register mailboxes %d\n", err);
+		return err;
+	}
+
+	for (i = 0; i < MHU_CHANS; i++) {
+		int irq = mhu->mlink[i].irq = adev->irq[i];
+
+		if (irq <= 0) {
+			dev_dbg(dev, "No IRQ found for Channel %d\n", i);
+			continue;
+		}
+
+		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];
+		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+
+		err = devm_request_threaded_irq(dev, irq, NULL,
+						mhu_db_mbox_rx_handler,
+						IRQF_ONESHOT, "mhu_db_link", mhu);
+		if (err) {
+			dev_err(dev, "Can't claim IRQ %d\n", irq);
+			mbox_controller_unregister(&mhu->mbox);
+			return err;
+		}
+	}
+
+	dev_info(dev, "ARM MHU Doorbell mailbox registered\n");
+	return 0;
+}
+
+static struct amba_id mhu_ids[] = {
+	{
+		.id	= 0x1bb098,
+		.mask	= 0xffffff,
+	},
+	{ 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, mhu_ids);
+
+static struct amba_driver arm_mhu_db_driver = {
+	.drv = {
+		.name	= "mhu-doorbell",
+	},
+	.id_table	= mhu_ids,
+	.probe		= mhu_db_probe,
+};
+module_amba_driver(arm_mhu_db_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ARM MHU Doorbell Driver");
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
diff --git a/drivers/mailbox/arm_mhuv2.c b/drivers/mailbox/arm_mhuv2.c
new file mode 100644
index 000000000..c6d4957c4
--- /dev/null
+++ b/drivers/mailbox/arm_mhuv2.c
@@ -0,0 +1,1137 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM Message Handling Unit Version 2 (MHUv2) driver.
+ *
+ * Copyright (C) 2020 ARM Ltd.
+ * Copyright (C) 2020 Linaro Ltd.
+ *
+ * An MHUv2 mailbox controller can provide up to 124 channel windows (each 32
+ * bit long) and the driver allows any combination of both the transport
+ * protocol modes: data-transfer and doorbell, to be used on those channel
+ * windows.
+ *
+ * The transport protocols should be specified in the device tree entry for the
+ * device. The transport protocols determine how the underlying hardware
+ * resources of the device are utilized when transmitting data. Refer to the
+ * device tree bindings of the ARM MHUv2 controller for more details.
+ *
+ * The number of registered mailbox channels is dependent on both the underlying
+ * hardware - mainly the number of channel windows implemented by the platform,
+ * as well as the selected transport protocols.
+ *
+ * The MHUv2 controller can work both as a sender and receiver, but the driver
+ * and the DT bindings support unidirectional transfers for better allocation of
+ * the channels. That is, this driver will be probed for two separate devices
+ * for each mailbox controller, a sender device and a receiver device.
+ */
+
+#include <linux/amba/bus.h>
+#include <linux/interrupt.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/arm_mhuv2_message.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+/* ====== MHUv2 Registers ====== */
+
+/* Maximum number of channel windows */
+#define MHUV2_CH_WN_MAX			124
+/* Number of combined interrupt status registers */
+#define MHUV2_CMB_INT_ST_REG_CNT	4
+#define MHUV2_STAT_BYTES		(sizeof(u32))
+#define MHUV2_STAT_BITS			(MHUV2_STAT_BYTES * __CHAR_BIT__)
+
+#define LSB_MASK(n)			((1 << (n * __CHAR_BIT__)) - 1)
+#define MHUV2_PROTOCOL_PROP		"arm,mhuv2-protocols"
+
+/* Register Message Handling Unit Configuration fields */
+struct mhu_cfg_t {
+	u32 num_ch : 7;
+	u32 pad : 25;
+} __packed;
+
+/* register Interrupt Status fields */
+struct int_st_t {
+	u32 nr2r : 1;
+	u32 r2nr : 1;
+	u32 pad : 30;
+} __packed;
+
+/* Register Interrupt Clear fields */
+struct int_clr_t {
+	u32 nr2r : 1;
+	u32 r2nr : 1;
+	u32 pad : 30;
+} __packed;
+
+/* Register Interrupt Enable fields */
+struct int_en_t {
+	u32 r2nr : 1;
+	u32 nr2r : 1;
+	u32 chcomb : 1;
+	u32 pad : 29;
+} __packed;
+
+/* Register Implementer Identification fields */
+struct iidr_t {
+	u32 implementer : 12;
+	u32 revision : 4;
+	u32 variant : 4;
+	u32 product_id : 12;
+} __packed;
+
+/* Register Architecture Identification Register fields */
+struct aidr_t {
+	u32 arch_minor_rev : 4;
+	u32 arch_major_rev : 4;
+	u32 pad : 24;
+} __packed;
+
+/* Sender Channel Window fields */
+struct mhu2_send_ch_wn_reg {
+	u32 stat;
+	u8 pad1[0x0C - 0x04];
+	u32 stat_set;
+	u32 int_st;
+	u32 int_clr;
+	u32 int_en;
+	u8 pad2[0x20 - 0x1C];
+} __packed;
+
+/* Sender frame register fields */
+struct mhu2_send_frame_reg {
+	struct mhu2_send_ch_wn_reg ch_wn[MHUV2_CH_WN_MAX];
+	struct mhu_cfg_t mhu_cfg;
+	u32 resp_cfg;
+	u32 access_request;
+	u32 access_ready;
+	struct int_st_t int_st;
+	struct int_clr_t int_clr;
+	struct int_en_t int_en;
+	u32 reserved0;
+	u32 chcomb_int_st[MHUV2_CMB_INT_ST_REG_CNT];
+	u8 pad[0xFC8 - 0xFB0];
+	struct iidr_t iidr;
+	struct aidr_t aidr;
+} __packed;
+
+/* Receiver Channel Window fields */
+struct mhu2_recv_ch_wn_reg {
+	u32 stat;
+	u32 stat_masked;
+	u32 stat_clear;
+	u8 reserved0[0x10 - 0x0C];
+	u32 mask;
+	u32 mask_set;
+	u32 mask_clear;
+	u8 pad[0x20 - 0x1C];
+} __packed;
+
+/* Receiver frame register fields */
+struct mhu2_recv_frame_reg {
+	struct mhu2_recv_ch_wn_reg ch_wn[MHUV2_CH_WN_MAX];
+	struct mhu_cfg_t mhu_cfg;
+	u8 reserved0[0xF90 - 0xF84];
+	struct int_st_t int_st;
+	struct int_clr_t int_clr;
+	struct int_en_t int_en;
+	u32 pad;
+	u32 chcomb_int_st[MHUV2_CMB_INT_ST_REG_CNT];
+	u8 reserved2[0xFC8 - 0xFB0];
+	struct iidr_t iidr;
+	struct aidr_t aidr;
+} __packed;
+
+
+/* ====== MHUv2 data structures ====== */
+
+enum mhuv2_transport_protocol {
+	DOORBELL = 0,
+	DATA_TRANSFER = 1
+};
+
+enum mhuv2_frame {
+	RECEIVER_FRAME,
+	SENDER_FRAME
+};
+
+/**
+ * struct mhuv2 - MHUv2 mailbox controller data
+ *
+ * @mbox:	Mailbox controller belonging to the MHU frame.
+ * @send:	Base address of the register mapping region.
+ * @recv:	Base address of the register mapping region.
+ * @frame:	Frame type: RECEIVER_FRAME or SENDER_FRAME.
+ * @irq:	Interrupt.
+ * @windows:	Channel windows implemented by the platform.
+ * @minor:	Minor version of the controller.
+ * @length:	Length of the protocols array in bytes.
+ * @protocols:	Raw protocol information, derived from device tree.
+ * @doorbell_pending_lock: spinlock required for correct operation of Tx
+ *		interrupt for doorbells.
+ */
+struct mhuv2 {
+	struct mbox_controller mbox;
+	union {
+		struct mhu2_send_frame_reg __iomem *send;
+		struct mhu2_recv_frame_reg __iomem *recv;
+	};
+	enum mhuv2_frame frame;
+	unsigned int irq;
+	unsigned int windows;
+	unsigned int minor;
+	unsigned int length;
+	u32 *protocols;
+
+	spinlock_t doorbell_pending_lock;
+};
+
+#define mhu_from_mbox(_mbox) container_of(_mbox, struct mhuv2, mbox)
+
+/**
+ * struct mhuv2_protocol_ops - MHUv2 operations
+ *
+ * Each transport protocol must provide an implementation of the operations
+ * provided here.
+ *
+ * @rx_startup: Startup callback for receiver.
+ * @rx_shutdown: Shutdown callback for receiver.
+ * @read_data: Reads and clears newly available data.
+ * @tx_startup: Startup callback for receiver.
+ * @tx_shutdown: Shutdown callback for receiver.
+ * @last_tx_done: Report back if the last tx is completed or not.
+ * @send_data: Send data to the receiver.
+ */
+struct mhuv2_protocol_ops {
+	int (*rx_startup)(struct mhuv2 *mhu, struct mbox_chan *chan);
+	void (*rx_shutdown)(struct mhuv2 *mhu, struct mbox_chan *chan);
+	void *(*read_data)(struct mhuv2 *mhu, struct mbox_chan *chan);
+
+	void (*tx_startup)(struct mhuv2 *mhu, struct mbox_chan *chan);
+	void (*tx_shutdown)(struct mhuv2 *mhu, struct mbox_chan *chan);
+	int (*last_tx_done)(struct mhuv2 *mhu, struct mbox_chan *chan);
+	int (*send_data)(struct mhuv2 *mhu, struct mbox_chan *chan, void *arg);
+};
+
+/*
+ * MHUv2 mailbox channel's private information
+ *
+ * @ops:	protocol specific ops for the channel.
+ * @ch_wn_idx:	Channel window index allocated to the channel.
+ * @windows:	Total number of windows consumed by the channel, only relevant
+ *		in DATA_TRANSFER protocol.
+ * @doorbell:	Doorbell bit number within the ch_wn_idx window, only relevant
+ *		in DOORBELL protocol.
+ * @pending:	Flag indicating pending doorbell interrupt, only relevant in
+ *		DOORBELL protocol.
+ */
+struct mhuv2_mbox_chan_priv {
+	const struct mhuv2_protocol_ops *ops;
+	u32 ch_wn_idx;
+	union {
+		u32 windows;
+		struct {
+			u32 doorbell;
+			u32 pending;
+		};
+	};
+};
+
+/* Macro for reading a bitfield within a physically mapped packed struct */
+#define readl_relaxed_bitfield(_regptr, _type, _field)			\
+	({								\
+		u32 _regval;						\
+		_regval = readl_relaxed((_regptr));			\
+		(*(_type *)(&_regval))._field;				\
+	})
+
+/* Macro for writing a bitfield within a physically mapped packed struct */
+#define writel_relaxed_bitfield(_value, _regptr, _type, _field)		\
+	({								\
+		u32 _regval;						\
+		_regval = readl_relaxed(_regptr);			\
+		(*(_type *)(&_regval))._field = _value;			\
+		writel_relaxed(_regval, _regptr);			\
+	})
+
+
+/* =================== Doorbell transport protocol operations =============== */
+
+static int mhuv2_doorbell_rx_startup(struct mhuv2 *mhu, struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	writel_relaxed(BIT(priv->doorbell),
+		       &mhu->recv->ch_wn[priv->ch_wn_idx].mask_clear);
+	return 0;
+}
+
+static void mhuv2_doorbell_rx_shutdown(struct mhuv2 *mhu,
+				       struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	writel_relaxed(BIT(priv->doorbell),
+		       &mhu->recv->ch_wn[priv->ch_wn_idx].mask_set);
+}
+
+static void *mhuv2_doorbell_read_data(struct mhuv2 *mhu, struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	writel_relaxed(BIT(priv->doorbell),
+		       &mhu->recv->ch_wn[priv->ch_wn_idx].stat_clear);
+	return NULL;
+}
+
+static int mhuv2_doorbell_last_tx_done(struct mhuv2 *mhu,
+				       struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	return !(readl_relaxed(&mhu->send->ch_wn[priv->ch_wn_idx].stat) &
+		 BIT(priv->doorbell));
+}
+
+static int mhuv2_doorbell_send_data(struct mhuv2 *mhu, struct mbox_chan *chan,
+				    void *arg)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	unsigned long flags;
+
+	spin_lock_irqsave(&mhu->doorbell_pending_lock, flags);
+
+	priv->pending = 1;
+	writel_relaxed(BIT(priv->doorbell),
+		       &mhu->send->ch_wn[priv->ch_wn_idx].stat_set);
+
+	spin_unlock_irqrestore(&mhu->doorbell_pending_lock, flags);
+
+	return 0;
+}
+
+static const struct mhuv2_protocol_ops mhuv2_doorbell_ops = {
+	.rx_startup = mhuv2_doorbell_rx_startup,
+	.rx_shutdown = mhuv2_doorbell_rx_shutdown,
+	.read_data = mhuv2_doorbell_read_data,
+	.last_tx_done = mhuv2_doorbell_last_tx_done,
+	.send_data = mhuv2_doorbell_send_data,
+};
+#define IS_PROTOCOL_DOORBELL(_priv) (_priv->ops == &mhuv2_doorbell_ops)
+
+/* ============= Data transfer transport protocol operations ================ */
+
+static int mhuv2_data_transfer_rx_startup(struct mhuv2 *mhu,
+					  struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int i = priv->ch_wn_idx + priv->windows - 1;
+
+	/*
+	 * The protocol mandates that all but the last status register must be
+	 * masked.
+	 */
+	writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[i].mask_clear);
+	return 0;
+}
+
+static void mhuv2_data_transfer_rx_shutdown(struct mhuv2 *mhu,
+					    struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int i = priv->ch_wn_idx + priv->windows - 1;
+
+	writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[i].mask_set);
+}
+
+static void *mhuv2_data_transfer_read_data(struct mhuv2 *mhu,
+					   struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	const int windows = priv->windows;
+	struct arm_mhuv2_mbox_msg *msg;
+	u32 *data;
+	int i, idx;
+
+	msg = kzalloc(sizeof(*msg) + windows * MHUV2_STAT_BYTES, GFP_KERNEL);
+	if (!msg)
+		return ERR_PTR(-ENOMEM);
+
+	data = msg->data = msg + 1;
+	msg->len = windows * MHUV2_STAT_BYTES;
+
+	/*
+	 * Messages are expected in order of most significant word to least
+	 * significant word. Refer mhuv2_data_transfer_send_data() for more
+	 * details.
+	 *
+	 * We also need to read the stat register instead of stat_masked, as we
+	 * masked all but the last window.
+	 *
+	 * Last channel window must be cleared as the final operation. Upon
+	 * clearing the last channel window register, which is unmasked in
+	 * data-transfer protocol, the interrupt is de-asserted.
+	 */
+	for (i = 0; i < windows; i++) {
+		idx = priv->ch_wn_idx + i;
+		data[windows - 1 - i] = readl_relaxed(&mhu->recv->ch_wn[idx].stat);
+		writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[idx].stat_clear);
+	}
+
+	return msg;
+}
+
+static void mhuv2_data_transfer_tx_startup(struct mhuv2 *mhu,
+					   struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int i = priv->ch_wn_idx + priv->windows - 1;
+
+	/* Enable interrupts only for the last window */
+	if (mhu->minor) {
+		writel_relaxed(0x1, &mhu->send->ch_wn[i].int_clr);
+		writel_relaxed(0x1, &mhu->send->ch_wn[i].int_en);
+	}
+}
+
+static void mhuv2_data_transfer_tx_shutdown(struct mhuv2 *mhu,
+					    struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int i = priv->ch_wn_idx + priv->windows - 1;
+
+	if (mhu->minor)
+		writel_relaxed(0x0, &mhu->send->ch_wn[i].int_en);
+}
+
+static int mhuv2_data_transfer_last_tx_done(struct mhuv2 *mhu,
+					    struct mbox_chan *chan)
+{
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int i = priv->ch_wn_idx + priv->windows - 1;
+
+	/* Just checking the last channel window should be enough */
+	return !readl_relaxed(&mhu->send->ch_wn[i].stat);
+}
+
+/*
+ * Message will be transmitted from most significant to least significant word.
+ * This is to allow for messages shorter than channel windows to still trigger
+ * the receiver interrupt which gets activated when the last stat register is
+ * written. As an example, a 6-word message is to be written on a 4-channel MHU
+ * connection: Registers marked with '*' are masked, and will not generate an
+ * interrupt on the receiver side once written.
+ *
+ * u32 *data =	[0x00000001], [0x00000002], [0x00000003], [0x00000004],
+ *		[0x00000005], [0x00000006]
+ *
+ * ROUND 1:
+ * stat reg		To write	Write sequence
+ * [ stat 3 ]	<-	[0x00000001]	4 <- triggers interrupt on receiver
+ * [ stat 2 ]	<-	[0x00000002]	3
+ * [ stat 1 ]	<-	[0x00000003]	2
+ * [ stat 0 ]	<-	[0x00000004]	1
+ *
+ * data += 4 // Increment data pointer by number of stat regs
+ *
+ * ROUND 2:
+ * stat reg		To write	Write sequence
+ * [ stat 3 ]	<-	[0x00000005]	2 <- triggers interrupt on receiver
+ * [ stat 2 ]	<-	[0x00000006]	1
+ * [ stat 1 ]	<-	[0x00000000]
+ * [ stat 0 ]	<-	[0x00000000]
+ */
+static int mhuv2_data_transfer_send_data(struct mhuv2 *mhu,
+					 struct mbox_chan *chan, void *arg)
+{
+	const struct arm_mhuv2_mbox_msg *msg = arg;
+	int bytes_left = msg->len, bytes_to_send, bytes_in_round, i;
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+	int windows = priv->windows;
+	u32 *data = msg->data, word;
+
+	while (bytes_left) {
+		if (!data[0]) {
+			dev_err(mhu->mbox.dev, "Data aligned at first window can't be zero to guarantee interrupt generation at receiver");
+			return -EINVAL;
+		}
+
+		while(!mhuv2_data_transfer_last_tx_done(mhu, chan))
+			continue;
+
+		bytes_in_round = min(bytes_left, (int)(windows * MHUV2_STAT_BYTES));
+
+		for (i = windows - 1; i >= 0; i--) {
+			/* Data less than windows can transfer ? */
+			if (unlikely(bytes_in_round <= i * MHUV2_STAT_BYTES))
+				continue;
+
+			word = data[i];
+			bytes_to_send = bytes_in_round & (MHUV2_STAT_BYTES - 1);
+			if (unlikely(bytes_to_send))
+				word &= LSB_MASK(bytes_to_send);
+			else
+				bytes_to_send = MHUV2_STAT_BYTES;
+
+			writel_relaxed(word, &mhu->send->ch_wn[priv->ch_wn_idx + windows - 1 - i].stat_set);
+			bytes_left -= bytes_to_send;
+			bytes_in_round -= bytes_to_send;
+		}
+
+		data += windows;
+	}
+
+	return 0;
+}
+
+static const struct mhuv2_protocol_ops mhuv2_data_transfer_ops = {
+	.rx_startup = mhuv2_data_transfer_rx_startup,
+	.rx_shutdown = mhuv2_data_transfer_rx_shutdown,
+	.read_data = mhuv2_data_transfer_read_data,
+	.tx_startup = mhuv2_data_transfer_tx_startup,
+	.tx_shutdown = mhuv2_data_transfer_tx_shutdown,
+	.last_tx_done = mhuv2_data_transfer_last_tx_done,
+	.send_data = mhuv2_data_transfer_send_data,
+};
+
+/* Interrupt handlers */
+
+static struct mbox_chan *get_irq_chan_comb(struct mhuv2 *mhu, u32 __iomem *reg)
+{
+	struct mbox_chan *chans = mhu->mbox.chans;
+	int channel = 0, i, offset = 0, windows, protocol, ch_wn;
+	u32 stat;
+
+	for (i = 0; i < MHUV2_CMB_INT_ST_REG_CNT; i++) {
+		stat = readl_relaxed(reg + i);
+		if (!stat)
+			continue;
+
+		ch_wn = i * MHUV2_STAT_BITS + __builtin_ctz(stat);
+
+		for (i = 0; i < mhu->length; i += 2) {
+			protocol = mhu->protocols[i];
+			windows = mhu->protocols[i + 1];
+
+			if (ch_wn >= offset + windows) {
+				if (protocol == DOORBELL)
+					channel += MHUV2_STAT_BITS * windows;
+				else
+					channel++;
+
+				offset += windows;
+				continue;
+			}
+
+			/* Return first chan of the window in doorbell mode */
+			if (protocol == DOORBELL)
+				channel += MHUV2_STAT_BITS * (ch_wn - offset);
+
+			return &chans[channel];
+		}
+	}
+
+	return ERR_PTR(-EIO);
+}
+
+static irqreturn_t mhuv2_sender_interrupt(int irq, void *data)
+{
+	struct mhuv2 *mhu = data;
+	struct device *dev = mhu->mbox.dev;
+	struct mhuv2_mbox_chan_priv *priv;
+	struct mbox_chan *chan;
+	unsigned long flags;
+	int i, found = 0;
+	u32 stat;
+
+	chan = get_irq_chan_comb(mhu, mhu->send->chcomb_int_st);
+	if (IS_ERR(chan)) {
+		dev_warn(dev, "Failed to find channel for the Tx interrupt\n");
+		return IRQ_NONE;
+	}
+	priv = chan->con_priv;
+
+	if (!IS_PROTOCOL_DOORBELL(priv)) {
+		writel_relaxed(1, &mhu->send->ch_wn[priv->ch_wn_idx + priv->windows - 1].int_clr);
+
+		if (chan->cl) {
+			mbox_chan_txdone(chan, 0);
+			return IRQ_HANDLED;
+		}
+
+		dev_warn(dev, "Tx interrupt Received on channel (%u) not currently attached to a mailbox client\n",
+			 priv->ch_wn_idx);
+		return IRQ_NONE;
+	}
+
+	/* Clear the interrupt first, so we don't miss any doorbell later */
+	writel_relaxed(1, &mhu->send->ch_wn[priv->ch_wn_idx].int_clr);
+
+	/*
+	 * In Doorbell mode, make sure no new transitions happen while the
+	 * interrupt handler is trying to find the finished doorbell tx
+	 * operations, else we may think few of the transfers were complete
+	 * before they actually were.
+	 */
+	spin_lock_irqsave(&mhu->doorbell_pending_lock, flags);
+
+	/*
+	 * In case of doorbell mode, the first channel of the window is returned
+	 * by get_irq_chan_comb(). Find all the pending channels here.
+	 */
+	stat = readl_relaxed(&mhu->send->ch_wn[priv->ch_wn_idx].stat);
+
+	for (i = 0; i < MHUV2_STAT_BITS; i++) {
+		priv = chan[i].con_priv;
+
+		/* Find cases where pending was 1, but stat's bit is cleared */
+		if (priv->pending ^ ((stat >> i) & 0x1)) {
+			BUG_ON(!priv->pending);
+
+			if (!chan->cl) {
+				dev_warn(dev, "Tx interrupt received on doorbell (%u : %u) channel not currently attached to a mailbox client\n",
+					 priv->ch_wn_idx, i);
+				continue;
+			}
+
+			mbox_chan_txdone(&chan[i], 0);
+			priv->pending = 0;
+			found++;
+		}
+	}
+
+	spin_unlock_irqrestore(&mhu->doorbell_pending_lock, flags);
+
+	if (!found) {
+		/*
+		 * We may have already processed the doorbell in the previous
+		 * iteration if the interrupt came right after we cleared it but
+		 * before we read the stat register.
+		 */
+		dev_dbg(dev, "Couldn't find the doorbell (%u) for the Tx interrupt interrupt\n",
+			priv->ch_wn_idx);
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct mbox_chan *get_irq_chan_comb_rx(struct mhuv2 *mhu)
+{
+	struct mhuv2_mbox_chan_priv *priv;
+	struct mbox_chan *chan;
+	u32 stat;
+
+	chan = get_irq_chan_comb(mhu, mhu->recv->chcomb_int_st);
+	if (IS_ERR(chan))
+		return chan;
+
+	priv = chan->con_priv;
+	if (!IS_PROTOCOL_DOORBELL(priv))
+		return chan;
+
+	/*
+	 * In case of doorbell mode, the first channel of the window is returned
+	 * by the routine. Find the exact channel here.
+	 */
+	stat = readl_relaxed(&mhu->recv->ch_wn[priv->ch_wn_idx].stat_masked);
+	BUG_ON(!stat);
+
+	return chan + __builtin_ctz(stat);
+}
+
+static struct mbox_chan *get_irq_chan_stat_rx(struct mhuv2 *mhu)
+{
+	struct mbox_chan *chans = mhu->mbox.chans;
+	struct mhuv2_mbox_chan_priv *priv;
+	u32 stat;
+	int i = 0;
+
+	while (i < mhu->mbox.num_chans) {
+		priv = chans[i].con_priv;
+		stat = readl_relaxed(&mhu->recv->ch_wn[priv->ch_wn_idx].stat_masked);
+
+		if (stat) {
+			if (IS_PROTOCOL_DOORBELL(priv))
+				i += __builtin_ctz(stat);
+			return &chans[i];
+		}
+
+		i += IS_PROTOCOL_DOORBELL(priv) ? MHUV2_STAT_BITS : 1;
+	}
+
+	return ERR_PTR(-EIO);
+}
+
+static struct mbox_chan *get_irq_chan_rx(struct mhuv2 *mhu)
+{
+	if (!mhu->minor)
+		return get_irq_chan_stat_rx(mhu);
+
+	return get_irq_chan_comb_rx(mhu);
+}
+
+static irqreturn_t mhuv2_receiver_interrupt(int irq, void *arg)
+{
+	struct mhuv2 *mhu = arg;
+	struct mbox_chan *chan = get_irq_chan_rx(mhu);
+	struct device *dev = mhu->mbox.dev;
+	struct mhuv2_mbox_chan_priv *priv;
+	int ret = IRQ_NONE;
+	void *data;
+
+	if (IS_ERR(chan)) {
+		dev_warn(dev, "Failed to find channel for the rx interrupt\n");
+		return IRQ_NONE;
+	}
+	priv = chan->con_priv;
+
+	/* Read and clear the data first */
+	data = priv->ops->read_data(mhu, chan);
+
+	if (!chan->cl) {
+		dev_warn(dev, "Received data on channel (%u) not currently attached to a mailbox client\n",
+			 priv->ch_wn_idx);
+	} else if (IS_ERR(data)) {
+		dev_err(dev, "Failed to read data: %lu\n", PTR_ERR(data));
+	} else {
+		mbox_chan_received_data(chan, data);
+		ret = IRQ_HANDLED;
+	}
+
+	if (!IS_ERR(data))
+		kfree(data);
+
+	return ret;
+}
+
+/* Sender and receiver ops */
+static bool mhuv2_sender_last_tx_done(struct mbox_chan *chan)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	return priv->ops->last_tx_done(mhu, chan);
+}
+
+static int mhuv2_sender_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	if (!priv->ops->last_tx_done(mhu, chan))
+		return -EBUSY;
+
+	return priv->ops->send_data(mhu, chan, data);
+}
+
+static int mhuv2_sender_startup(struct mbox_chan *chan)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	if (priv->ops->tx_startup)
+		priv->ops->tx_startup(mhu, chan);
+	return 0;
+}
+
+static void mhuv2_sender_shutdown(struct mbox_chan *chan)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	if (priv->ops->tx_shutdown)
+		priv->ops->tx_shutdown(mhu, chan);
+}
+
+static const struct mbox_chan_ops mhuv2_sender_ops = {
+	.send_data = mhuv2_sender_send_data,
+	.startup = mhuv2_sender_startup,
+	.shutdown = mhuv2_sender_shutdown,
+	.last_tx_done = mhuv2_sender_last_tx_done,
+};
+
+static int mhuv2_receiver_startup(struct mbox_chan *chan)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	return priv->ops->rx_startup(mhu, chan);
+}
+
+static void mhuv2_receiver_shutdown(struct mbox_chan *chan)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(chan->mbox);
+	struct mhuv2_mbox_chan_priv *priv = chan->con_priv;
+
+	priv->ops->rx_shutdown(mhu, chan);
+}
+
+static int mhuv2_receiver_send_data(struct mbox_chan *chan, void *data)
+{
+	dev_err(chan->mbox->dev,
+		"Trying to transmit on a receiver MHU frame\n");
+	return -EIO;
+}
+
+static bool mhuv2_receiver_last_tx_done(struct mbox_chan *chan)
+{
+	dev_err(chan->mbox->dev, "Trying to Tx poll on a receiver MHU frame\n");
+	return true;
+}
+
+static const struct mbox_chan_ops mhuv2_receiver_ops = {
+	.send_data = mhuv2_receiver_send_data,
+	.startup = mhuv2_receiver_startup,
+	.shutdown = mhuv2_receiver_shutdown,
+	.last_tx_done = mhuv2_receiver_last_tx_done,
+};
+
+static struct mbox_chan *mhuv2_mbox_of_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *pa)
+{
+	struct mhuv2 *mhu = mhu_from_mbox(mbox);
+	struct mbox_chan *chans = mbox->chans;
+	int channel = 0, i, offset, doorbell, protocol, windows;
+
+	if (pa->args_count != 2)
+		return ERR_PTR(-EINVAL);
+
+	offset = pa->args[0];
+	doorbell = pa->args[1];
+	if (doorbell >= MHUV2_STAT_BITS)
+		goto out;
+
+	for (i = 0; i < mhu->length; i += 2) {
+		protocol = mhu->protocols[i];
+		windows = mhu->protocols[i + 1];
+
+		if (protocol == DOORBELL) {
+			if (offset < windows)
+				return &chans[channel + MHUV2_STAT_BITS * offset + doorbell];
+
+			channel += MHUV2_STAT_BITS * windows;
+			offset -= windows;
+		} else {
+			if (offset == 0) {
+				if (doorbell)
+					goto out;
+
+				return &chans[channel];
+			}
+
+			channel++;
+			offset--;
+		}
+	}
+
+out:
+	dev_err(mbox->dev, "Couldn't xlate to a valid channel (%d: %d)\n",
+		pa->args[0], doorbell);
+	return ERR_PTR(-ENODEV);
+}
+
+static int mhuv2_verify_protocol(struct mhuv2 *mhu)
+{
+	struct device *dev = mhu->mbox.dev;
+	int protocol, windows, channels = 0, total_windows = 0, i;
+
+	for (i = 0; i < mhu->length; i += 2) {
+		protocol = mhu->protocols[i];
+		windows = mhu->protocols[i + 1];
+
+		if (!windows) {
+			dev_err(dev, "Window size can't be zero (%d)\n", i);
+			return -EINVAL;
+		}
+		total_windows += windows;
+
+		if (protocol == DOORBELL) {
+			channels += MHUV2_STAT_BITS * windows;
+		} else if (protocol == DATA_TRANSFER) {
+			channels++;
+		} else {
+			dev_err(dev, "Invalid protocol (%d) present in %s property at index %d\n",
+				protocol, MHUV2_PROTOCOL_PROP, i);
+			return -EINVAL;
+		}
+	}
+
+	if (total_windows > mhu->windows) {
+		dev_err(dev, "Channel windows can't be more than what's implemented by the hardware ( %d: %d)\n",
+			total_windows, mhu->windows);
+		return -EINVAL;
+	}
+
+	mhu->mbox.num_chans = channels;
+	return 0;
+}
+
+static int mhuv2_allocate_channels(struct mhuv2 *mhu)
+{
+	struct mbox_controller *mbox = &mhu->mbox;
+	struct mhuv2_mbox_chan_priv *priv;
+	struct device *dev = mbox->dev;
+	struct mbox_chan *chans;
+	int protocol, windows = 0, next_window = 0, i, j, k;
+
+	chans = devm_kcalloc(dev, mbox->num_chans, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mbox->chans = chans;
+
+	for (i = 0; i < mhu->length; i += 2) {
+		next_window += windows;
+
+		protocol = mhu->protocols[i];
+		windows = mhu->protocols[i + 1];
+
+		if (protocol == DATA_TRANSFER) {
+			priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+			if (!priv)
+				return -ENOMEM;
+
+			priv->ch_wn_idx = next_window;
+			priv->ops = &mhuv2_data_transfer_ops;
+			priv->windows = windows;
+			chans++->con_priv = priv;
+			continue;
+		}
+
+		for (j = 0; j < windows; j++) {
+			for (k = 0; k < MHUV2_STAT_BITS; k++) {
+				priv = devm_kmalloc(dev, sizeof(*priv), GFP_KERNEL);
+				if (!priv)
+					return -ENOMEM;
+
+				priv->ch_wn_idx = next_window + j;
+				priv->ops = &mhuv2_doorbell_ops;
+				priv->doorbell = k;
+				chans++->con_priv = priv;
+			}
+
+			/*
+			 * Permanently enable interrupt as we can't
+			 * control it per doorbell.
+			 */
+			if (mhu->frame == SENDER_FRAME && mhu->minor)
+				writel_relaxed(0x1, &mhu->send->ch_wn[priv->ch_wn_idx].int_en);
+		}
+	}
+
+	/* Make sure we have initialized all channels */
+	BUG_ON(chans - mbox->chans != mbox->num_chans);
+
+	return 0;
+}
+
+static int mhuv2_parse_channels(struct mhuv2 *mhu)
+{
+	struct device *dev = mhu->mbox.dev;
+	const struct device_node *np = dev->of_node;
+	int ret, count;
+	u32 *protocols;
+
+	count = of_property_count_u32_elems(np, MHUV2_PROTOCOL_PROP);
+	if (count <= 0 || count % 2) {
+		dev_err(dev, "Invalid %s property (%d)\n", MHUV2_PROTOCOL_PROP,
+			count);
+		return -EINVAL;
+	}
+
+	protocols = devm_kmalloc_array(dev, count, sizeof(*protocols), GFP_KERNEL);
+	if (!protocols)
+		return -ENOMEM;
+
+	ret = of_property_read_u32_array(np, MHUV2_PROTOCOL_PROP, protocols, count);
+	if (ret) {
+		dev_err(dev, "Failed to read %s property: %d\n",
+			MHUV2_PROTOCOL_PROP, ret);
+		return ret;
+	}
+
+	mhu->protocols = protocols;
+	mhu->length = count;
+
+	ret = mhuv2_verify_protocol(mhu);
+	if (ret)
+		return ret;
+
+	return mhuv2_allocate_channels(mhu);
+}
+
+static int mhuv2_tx_init(struct amba_device *adev, struct mhuv2 *mhu,
+			 void __iomem *reg)
+{
+	struct device *dev = mhu->mbox.dev;
+	int ret, i;
+
+	mhu->frame = SENDER_FRAME;
+	mhu->mbox.ops = &mhuv2_sender_ops;
+	mhu->send = reg;
+
+	mhu->windows = readl_relaxed_bitfield(&mhu->send->mhu_cfg, struct mhu_cfg_t, num_ch);
+	mhu->minor = readl_relaxed_bitfield(&mhu->send->aidr, struct aidr_t, arch_minor_rev);
+
+	spin_lock_init(&mhu->doorbell_pending_lock);
+
+	/*
+	 * For minor version 1 and forward, tx interrupt is provided by
+	 * the controller.
+	 */
+	if (mhu->minor && adev->irq[0]) {
+		ret = devm_request_threaded_irq(dev, adev->irq[0], NULL,
+						mhuv2_sender_interrupt,
+						IRQF_ONESHOT, "mhuv2-tx", mhu);
+		if (ret) {
+			dev_err(dev, "Failed to request tx IRQ, fallback to polling mode: %d\n",
+				ret);
+		} else {
+			mhu->mbox.txdone_irq = true;
+			mhu->mbox.txdone_poll = false;
+			mhu->irq = adev->irq[0];
+
+			writel_relaxed_bitfield(1, &mhu->send->int_en, struct int_en_t, chcomb);
+
+			/* Disable all channel interrupts */
+			for (i = 0; i < mhu->windows; i++)
+				writel_relaxed(0x0, &mhu->send->ch_wn[i].int_en);
+
+			goto out;
+		}
+	}
+
+	mhu->mbox.txdone_irq = false;
+	mhu->mbox.txdone_poll = true;
+	mhu->mbox.txpoll_period = 1;
+
+out:
+	/* Wait for receiver to be ready */
+	writel_relaxed(0x1, &mhu->send->access_request);
+	while (!readl_relaxed(&mhu->send->access_ready))
+		continue;
+
+	return 0;
+}
+
+static int mhuv2_rx_init(struct amba_device *adev, struct mhuv2 *mhu,
+			 void __iomem *reg)
+{
+	struct device *dev = mhu->mbox.dev;
+	int ret, i;
+
+	mhu->frame = RECEIVER_FRAME;
+	mhu->mbox.ops = &mhuv2_receiver_ops;
+	mhu->recv = reg;
+
+	mhu->windows = readl_relaxed_bitfield(&mhu->recv->mhu_cfg, struct mhu_cfg_t, num_ch);
+	mhu->minor = readl_relaxed_bitfield(&mhu->recv->aidr, struct aidr_t, arch_minor_rev);
+
+	mhu->irq = adev->irq[0];
+	if (!mhu->irq) {
+		dev_err(dev, "Missing receiver IRQ\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_threaded_irq(dev, mhu->irq, NULL,
+					mhuv2_receiver_interrupt, IRQF_ONESHOT,
+					"mhuv2-rx", mhu);
+	if (ret) {
+		dev_err(dev, "Failed to request rx IRQ\n");
+		return ret;
+	}
+
+	/* Mask all the channel windows */
+	for (i = 0; i < mhu->windows; i++)
+		writel_relaxed(0xFFFFFFFF, &mhu->recv->ch_wn[i].mask_set);
+
+	if (mhu->minor)
+		writel_relaxed_bitfield(1, &mhu->recv->int_en, struct int_en_t, chcomb);
+
+	return 0;
+}
+
+static int mhuv2_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	struct device *dev = &adev->dev;
+	const struct device_node *np = dev->of_node;
+	struct mhuv2 *mhu;
+	void __iomem *reg;
+	int ret = -EINVAL;
+
+	reg = devm_of_iomap(dev, dev->of_node, 0, NULL);
+	if (IS_ERR(reg))
+		return PTR_ERR(reg);
+
+	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+	if (!mhu)
+		return -ENOMEM;
+
+	mhu->mbox.dev = dev;
+	mhu->mbox.of_xlate = mhuv2_mbox_of_xlate;
+
+	if (of_device_is_compatible(np, "arm,mhuv2-tx"))
+		ret = mhuv2_tx_init(adev, mhu, reg);
+	else if (of_device_is_compatible(np, "arm,mhuv2-rx"))
+		ret = mhuv2_rx_init(adev, mhu, reg);
+	else
+		dev_err(dev, "Invalid compatible property\n");
+
+	if (ret)
+		return ret;
+
+	/* Channel windows can't be 0 */
+	BUG_ON(!mhu->windows);
+
+	ret = mhuv2_parse_channels(mhu);
+	if (ret)
+		return ret;
+
+	amba_set_drvdata(adev, mhu);
+
+	ret = devm_mbox_controller_register(dev, &mhu->mbox);
+	if (ret)
+		dev_err(dev, "failed to register ARM MHUv2 driver %d\n", ret);
+
+	return ret;
+}
+
+static void mhuv2_remove(struct amba_device *adev)
+{
+	struct mhuv2 *mhu = amba_get_drvdata(adev);
+
+	if (mhu->frame == SENDER_FRAME)
+		writel_relaxed(0x0, &mhu->send->access_request);
+}
+
+static struct amba_id mhuv2_ids[] = {
+	{
+		/* 2.0 */
+		.id = 0xbb0d1,
+		.mask = 0xfffff,
+	},
+	{
+		/* 2.1 */
+		.id = 0xbb076,
+		.mask = 0xfffff,
+	},
+	{ 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, mhuv2_ids);
+
+static struct amba_driver mhuv2_driver = {
+	.drv = {
+		.name	= "arm-mhuv2",
+	},
+	.id_table	= mhuv2_ids,
+	.probe		= mhuv2_probe,
+	.remove		= mhuv2_remove,
+};
+module_amba_driver(mhuv2_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ARM MHUv2 Driver");
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_AUTHOR("Tushar Khandelwal <tushar.khandelwal@arm.com>");
diff --git a/drivers/mailbox/armada-37xx-rwtm-mailbox.c b/drivers/mailbox/armada-37xx-rwtm-mailbox.c
new file mode 100644
index 000000000..456a117a6
--- /dev/null
+++ b/drivers/mailbox/armada-37xx-rwtm-mailbox.c
@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * rWTM BIU Mailbox driver for Armada 37xx
+ *
+ * Author: Marek Behún <kabel@kernel.org>
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/armada-37xx-rwtm-mailbox.h>
+
+#define DRIVER_NAME	"armada-37xx-rwtm-mailbox"
+
+/* relative to rWTM BIU Mailbox Registers */
+#define RWTM_MBOX_PARAM(i)		(0x0 + ((i) << 2))
+#define RWTM_MBOX_COMMAND		0x40
+#define RWTM_MBOX_RETURN_STATUS		0x80
+#define RWTM_MBOX_STATUS(i)		(0x84 + ((i) << 2))
+#define RWTM_MBOX_FIFO_STATUS		0xc4
+#define FIFO_STS_RDY			0x100
+#define FIFO_STS_CNTR_MASK		0x7
+#define FIFO_STS_CNTR_MAX		4
+
+#define RWTM_HOST_INT_RESET		0xc8
+#define RWTM_HOST_INT_MASK		0xcc
+#define SP_CMD_COMPLETE			BIT(0)
+#define SP_CMD_QUEUE_FULL_ACCESS	BIT(17)
+#define SP_CMD_QUEUE_FULL		BIT(18)
+
+struct a37xx_mbox {
+	struct device *dev;
+	struct mbox_controller controller;
+	void __iomem *base;
+	int irq;
+};
+
+static void a37xx_mbox_receive(struct mbox_chan *chan)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	struct armada_37xx_rwtm_rx_msg rx_msg;
+	int i;
+
+	rx_msg.retval = readl(mbox->base + RWTM_MBOX_RETURN_STATUS);
+	for (i = 0; i < 16; ++i)
+		rx_msg.status[i] = readl(mbox->base + RWTM_MBOX_STATUS(i));
+
+	mbox_chan_received_data(chan, &rx_msg);
+}
+
+static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+	struct a37xx_mbox *mbox = chan->con_priv;
+	u32 reg;
+
+	reg = readl(mbox->base + RWTM_HOST_INT_RESET);
+
+	if (reg & SP_CMD_COMPLETE)
+		a37xx_mbox_receive(chan);
+
+	if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL))
+		dev_err(mbox->dev, "Secure processor command queue full\n");
+
+	writel(reg, mbox->base + RWTM_HOST_INT_RESET);
+	if (reg)
+		mbox_chan_txdone(chan, 0);
+
+	return reg ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	struct armada_37xx_rwtm_tx_msg *msg = data;
+	int i;
+	u32 reg;
+
+	if (!data)
+		return -EINVAL;
+
+	reg = readl(mbox->base + RWTM_MBOX_FIFO_STATUS);
+	if (!(reg & FIFO_STS_RDY))
+		dev_warn(mbox->dev, "Secure processor not ready\n");
+
+	if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) {
+		dev_err(mbox->dev, "Secure processor command queue full\n");
+		return -EBUSY;
+	}
+
+	for (i = 0; i < 16; ++i)
+		writel(msg->args[i], mbox->base + RWTM_MBOX_PARAM(i));
+	writel(msg->command, mbox->base + RWTM_MBOX_COMMAND);
+
+	return 0;
+}
+
+static int a37xx_mbox_startup(struct mbox_chan *chan)
+{
+	struct a37xx_mbox *mbox = chan->con_priv;
+	u32 reg;
+	int ret;
+
+	ret = devm_request_irq(mbox->dev, mbox->irq, a37xx_mbox_irq_handler, 0,
+			       DRIVER_NAME, chan);
+	if (ret < 0) {
+		dev_err(mbox->dev, "Cannot request irq\n");
+		return ret;
+	}
+
+	/* enable IRQ generation */
+	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
+	reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL);
+	writel(reg, mbox->base + RWTM_HOST_INT_MASK);
+
+	return 0;
+}
+
+static void a37xx_mbox_shutdown(struct mbox_chan *chan)
+{
+	u32 reg;
+	struct a37xx_mbox *mbox = chan->con_priv;
+
+	/* disable interrupt generation */
+	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
+	reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL;
+	writel(reg, mbox->base + RWTM_HOST_INT_MASK);
+
+	devm_free_irq(mbox->dev, mbox->irq, chan);
+}
+
+static const struct mbox_chan_ops a37xx_mbox_ops = {
+	.send_data	= a37xx_mbox_send_data,
+	.startup	= a37xx_mbox_startup,
+	.shutdown	= a37xx_mbox_shutdown,
+};
+
+static int armada_37xx_mbox_probe(struct platform_device *pdev)
+{
+	struct a37xx_mbox *mbox;
+	struct mbox_chan *chans;
+	int ret;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	/* Allocated one channel */
+	chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mbox->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->base))
+		return PTR_ERR(mbox->base);
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq < 0)
+		return mbox->irq;
+
+	mbox->dev = &pdev->dev;
+
+	/* Hardware supports only one channel. */
+	chans[0].con_priv = mbox;
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = chans;
+	mbox->controller.ops = &a37xx_mbox_ops;
+	mbox->controller.txdone_irq = true;
+
+	ret = devm_mbox_controller_register(mbox->dev, &mbox->controller);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register mailbox controller\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	return ret;
+}
+
+
+static const struct of_device_id armada_37xx_mbox_match[] = {
+	{ .compatible = "marvell,armada-3700-rwtm-mailbox" },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match);
+
+static struct platform_driver armada_37xx_mbox_driver = {
+	.probe	= armada_37xx_mbox_probe,
+	.driver	= {
+		.name		= DRIVER_NAME,
+		.of_match_table	= armada_37xx_mbox_match,
+	},
+};
+
+module_platform_driver(armada_37xx_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx");
+MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
diff --git a/drivers/mailbox/bcm-flexrm-mailbox.c b/drivers/mailbox/bcm-flexrm-mailbox.c
new file mode 100644
index 000000000..bf6e86b0e
--- /dev/null
+++ b/drivers/mailbox/bcm-flexrm-mailbox.c
@@ -0,0 +1,1690 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (C) 2017 Broadcom
+
+/*
+ * Broadcom FlexRM Mailbox Driver
+ *
+ * Each Broadcom FlexSparx4 offload engine is implemented as an
+ * extension to Broadcom FlexRM ring manager. The FlexRM ring
+ * manager provides a set of rings which can be used to submit
+ * work to a FlexSparx4 offload engine.
+ *
+ * This driver creates a mailbox controller using a set of FlexRM
+ * rings where each mailbox channel represents a separate FlexRM ring.
+ */
+
+#include <asm/barrier.h>
+#include <asm/byteorder.h>
+#include <linux/atomic.h>
+#include <linux/bitmap.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/mailbox/brcm-message.h>
+#include <linux/module.h>
+#include <linux/msi.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+/* ====== FlexRM register defines ===== */
+
+/* FlexRM configuration */
+#define RING_REGS_SIZE					0x10000
+#define RING_DESC_SIZE					8
+#define RING_DESC_INDEX(offset)				\
+			((offset) / RING_DESC_SIZE)
+#define RING_DESC_OFFSET(index)				\
+			((index) * RING_DESC_SIZE)
+#define RING_MAX_REQ_COUNT				1024
+#define RING_BD_ALIGN_ORDER				12
+#define RING_BD_ALIGN_CHECK(addr)			\
+			(!((addr) & ((0x1 << RING_BD_ALIGN_ORDER) - 1)))
+#define RING_BD_TOGGLE_INVALID(offset)			\
+			(((offset) >> RING_BD_ALIGN_ORDER) & 0x1)
+#define RING_BD_TOGGLE_VALID(offset)			\
+			(!RING_BD_TOGGLE_INVALID(offset))
+#define RING_BD_DESC_PER_REQ				32
+#define RING_BD_DESC_COUNT				\
+			(RING_MAX_REQ_COUNT * RING_BD_DESC_PER_REQ)
+#define RING_BD_SIZE					\
+			(RING_BD_DESC_COUNT * RING_DESC_SIZE)
+#define RING_CMPL_ALIGN_ORDER				13
+#define RING_CMPL_DESC_COUNT				RING_MAX_REQ_COUNT
+#define RING_CMPL_SIZE					\
+			(RING_CMPL_DESC_COUNT * RING_DESC_SIZE)
+#define RING_VER_MAGIC					0x76303031
+
+/* Per-Ring register offsets */
+#define RING_VER					0x000
+#define RING_BD_START_ADDR				0x004
+#define RING_BD_READ_PTR				0x008
+#define RING_BD_WRITE_PTR				0x00c
+#define RING_BD_READ_PTR_DDR_LS				0x010
+#define RING_BD_READ_PTR_DDR_MS				0x014
+#define RING_CMPL_START_ADDR				0x018
+#define RING_CMPL_WRITE_PTR				0x01c
+#define RING_NUM_REQ_RECV_LS				0x020
+#define RING_NUM_REQ_RECV_MS				0x024
+#define RING_NUM_REQ_TRANS_LS				0x028
+#define RING_NUM_REQ_TRANS_MS				0x02c
+#define RING_NUM_REQ_OUTSTAND				0x030
+#define RING_CONTROL					0x034
+#define RING_FLUSH_DONE					0x038
+#define RING_MSI_ADDR_LS				0x03c
+#define RING_MSI_ADDR_MS				0x040
+#define RING_MSI_CONTROL				0x048
+#define RING_BD_READ_PTR_DDR_CONTROL			0x04c
+#define RING_MSI_DATA_VALUE				0x064
+
+/* Register RING_BD_START_ADDR fields */
+#define BD_LAST_UPDATE_HW_SHIFT				28
+#define BD_LAST_UPDATE_HW_MASK				0x1
+#define BD_START_ADDR_VALUE(pa)				\
+	((u32)((((dma_addr_t)(pa)) >> RING_BD_ALIGN_ORDER) & 0x0fffffff))
+#define BD_START_ADDR_DECODE(val)			\
+	((dma_addr_t)((val) & 0x0fffffff) << RING_BD_ALIGN_ORDER)
+
+/* Register RING_CMPL_START_ADDR fields */
+#define CMPL_START_ADDR_VALUE(pa)			\
+	((u32)((((u64)(pa)) >> RING_CMPL_ALIGN_ORDER) & 0x07ffffff))
+
+/* Register RING_CONTROL fields */
+#define CONTROL_MASK_DISABLE_CONTROL			12
+#define CONTROL_FLUSH_SHIFT				5
+#define CONTROL_ACTIVE_SHIFT				4
+#define CONTROL_RATE_ADAPT_MASK				0xf
+#define CONTROL_RATE_DYNAMIC				0x0
+#define CONTROL_RATE_FAST				0x8
+#define CONTROL_RATE_MEDIUM				0x9
+#define CONTROL_RATE_SLOW				0xa
+#define CONTROL_RATE_IDLE				0xb
+
+/* Register RING_FLUSH_DONE fields */
+#define FLUSH_DONE_MASK					0x1
+
+/* Register RING_MSI_CONTROL fields */
+#define MSI_TIMER_VAL_SHIFT				16
+#define MSI_TIMER_VAL_MASK				0xffff
+#define MSI_ENABLE_SHIFT				15
+#define MSI_ENABLE_MASK					0x1
+#define MSI_COUNT_SHIFT					0
+#define MSI_COUNT_MASK					0x3ff
+
+/* Register RING_BD_READ_PTR_DDR_CONTROL fields */
+#define BD_READ_PTR_DDR_TIMER_VAL_SHIFT			16
+#define BD_READ_PTR_DDR_TIMER_VAL_MASK			0xffff
+#define BD_READ_PTR_DDR_ENABLE_SHIFT			15
+#define BD_READ_PTR_DDR_ENABLE_MASK			0x1
+
+/* ====== FlexRM ring descriptor defines ===== */
+
+/* Completion descriptor format */
+#define CMPL_OPAQUE_SHIFT			0
+#define CMPL_OPAQUE_MASK			0xffff
+#define CMPL_ENGINE_STATUS_SHIFT		16
+#define CMPL_ENGINE_STATUS_MASK			0xffff
+#define CMPL_DME_STATUS_SHIFT			32
+#define CMPL_DME_STATUS_MASK			0xffff
+#define CMPL_RM_STATUS_SHIFT			48
+#define CMPL_RM_STATUS_MASK			0xffff
+
+/* Completion DME status code */
+#define DME_STATUS_MEM_COR_ERR			BIT(0)
+#define DME_STATUS_MEM_UCOR_ERR			BIT(1)
+#define DME_STATUS_FIFO_UNDERFLOW		BIT(2)
+#define DME_STATUS_FIFO_OVERFLOW		BIT(3)
+#define DME_STATUS_RRESP_ERR			BIT(4)
+#define DME_STATUS_BRESP_ERR			BIT(5)
+#define DME_STATUS_ERROR_MASK			(DME_STATUS_MEM_COR_ERR | \
+						 DME_STATUS_MEM_UCOR_ERR | \
+						 DME_STATUS_FIFO_UNDERFLOW | \
+						 DME_STATUS_FIFO_OVERFLOW | \
+						 DME_STATUS_RRESP_ERR | \
+						 DME_STATUS_BRESP_ERR)
+
+/* Completion RM status code */
+#define RM_STATUS_CODE_SHIFT			0
+#define RM_STATUS_CODE_MASK			0x3ff
+#define RM_STATUS_CODE_GOOD			0x0
+#define RM_STATUS_CODE_AE_TIMEOUT		0x3ff
+
+/* General descriptor format */
+#define DESC_TYPE_SHIFT				60
+#define DESC_TYPE_MASK				0xf
+#define DESC_PAYLOAD_SHIFT			0
+#define DESC_PAYLOAD_MASK			0x0fffffffffffffff
+
+/* Null descriptor format  */
+#define NULL_TYPE				0
+#define NULL_TOGGLE_SHIFT			58
+#define NULL_TOGGLE_MASK			0x1
+
+/* Header descriptor format */
+#define HEADER_TYPE				1
+#define HEADER_TOGGLE_SHIFT			58
+#define HEADER_TOGGLE_MASK			0x1
+#define HEADER_ENDPKT_SHIFT			57
+#define HEADER_ENDPKT_MASK			0x1
+#define HEADER_STARTPKT_SHIFT			56
+#define HEADER_STARTPKT_MASK			0x1
+#define HEADER_BDCOUNT_SHIFT			36
+#define HEADER_BDCOUNT_MASK			0x1f
+#define HEADER_BDCOUNT_MAX			HEADER_BDCOUNT_MASK
+#define HEADER_FLAGS_SHIFT			16
+#define HEADER_FLAGS_MASK			0xffff
+#define HEADER_OPAQUE_SHIFT			0
+#define HEADER_OPAQUE_MASK			0xffff
+
+/* Source (SRC) descriptor format */
+#define SRC_TYPE				2
+#define SRC_LENGTH_SHIFT			44
+#define SRC_LENGTH_MASK				0xffff
+#define SRC_ADDR_SHIFT				0
+#define SRC_ADDR_MASK				0x00000fffffffffff
+
+/* Destination (DST) descriptor format */
+#define DST_TYPE				3
+#define DST_LENGTH_SHIFT			44
+#define DST_LENGTH_MASK				0xffff
+#define DST_ADDR_SHIFT				0
+#define DST_ADDR_MASK				0x00000fffffffffff
+
+/* Immediate (IMM) descriptor format */
+#define IMM_TYPE				4
+#define IMM_DATA_SHIFT				0
+#define IMM_DATA_MASK				0x0fffffffffffffff
+
+/* Next pointer (NPTR) descriptor format */
+#define NPTR_TYPE				5
+#define NPTR_TOGGLE_SHIFT			58
+#define NPTR_TOGGLE_MASK			0x1
+#define NPTR_ADDR_SHIFT				0
+#define NPTR_ADDR_MASK				0x00000fffffffffff
+
+/* Mega source (MSRC) descriptor format */
+#define MSRC_TYPE				6
+#define MSRC_LENGTH_SHIFT			44
+#define MSRC_LENGTH_MASK			0xffff
+#define MSRC_ADDR_SHIFT				0
+#define MSRC_ADDR_MASK				0x00000fffffffffff
+
+/* Mega destination (MDST) descriptor format */
+#define MDST_TYPE				7
+#define MDST_LENGTH_SHIFT			44
+#define MDST_LENGTH_MASK			0xffff
+#define MDST_ADDR_SHIFT				0
+#define MDST_ADDR_MASK				0x00000fffffffffff
+
+/* Source with tlast (SRCT) descriptor format */
+#define SRCT_TYPE				8
+#define SRCT_LENGTH_SHIFT			44
+#define SRCT_LENGTH_MASK			0xffff
+#define SRCT_ADDR_SHIFT				0
+#define SRCT_ADDR_MASK				0x00000fffffffffff
+
+/* Destination with tlast (DSTT) descriptor format */
+#define DSTT_TYPE				9
+#define DSTT_LENGTH_SHIFT			44
+#define DSTT_LENGTH_MASK			0xffff
+#define DSTT_ADDR_SHIFT				0
+#define DSTT_ADDR_MASK				0x00000fffffffffff
+
+/* Immediate with tlast (IMMT) descriptor format */
+#define IMMT_TYPE				10
+#define IMMT_DATA_SHIFT				0
+#define IMMT_DATA_MASK				0x0fffffffffffffff
+
+/* Descriptor helper macros */
+#define DESC_DEC(_d, _s, _m)			(((_d) >> (_s)) & (_m))
+#define DESC_ENC(_d, _v, _s, _m)		\
+			do { \
+				(_d) &= ~((u64)(_m) << (_s)); \
+				(_d) |= (((u64)(_v) & (_m)) << (_s)); \
+			} while (0)
+
+/* ====== FlexRM data structures ===== */
+
+struct flexrm_ring {
+	/* Unprotected members */
+	int num;
+	struct flexrm_mbox *mbox;
+	void __iomem *regs;
+	bool irq_requested;
+	unsigned int irq;
+	cpumask_t irq_aff_hint;
+	unsigned int msi_timer_val;
+	unsigned int msi_count_threshold;
+	struct brcm_message *requests[RING_MAX_REQ_COUNT];
+	void *bd_base;
+	dma_addr_t bd_dma_base;
+	u32 bd_write_offset;
+	void *cmpl_base;
+	dma_addr_t cmpl_dma_base;
+	/* Atomic stats */
+	atomic_t msg_send_count;
+	atomic_t msg_cmpl_count;
+	/* Protected members */
+	spinlock_t lock;
+	DECLARE_BITMAP(requests_bmap, RING_MAX_REQ_COUNT);
+	u32 cmpl_read_offset;
+};
+
+struct flexrm_mbox {
+	struct device *dev;
+	void __iomem *regs;
+	u32 num_rings;
+	struct flexrm_ring *rings;
+	struct dma_pool *bd_pool;
+	struct dma_pool *cmpl_pool;
+	struct dentry *root;
+	struct mbox_controller controller;
+};
+
+/* ====== FlexRM ring descriptor helper routines ===== */
+
+static u64 flexrm_read_desc(void *desc_ptr)
+{
+	return le64_to_cpu(*((u64 *)desc_ptr));
+}
+
+static void flexrm_write_desc(void *desc_ptr, u64 desc)
+{
+	*((u64 *)desc_ptr) = cpu_to_le64(desc);
+}
+
+static u32 flexrm_cmpl_desc_to_reqid(u64 cmpl_desc)
+{
+	return (u32)(cmpl_desc & CMPL_OPAQUE_MASK);
+}
+
+static int flexrm_cmpl_desc_to_error(u64 cmpl_desc)
+{
+	u32 status;
+
+	status = DESC_DEC(cmpl_desc, CMPL_DME_STATUS_SHIFT,
+			  CMPL_DME_STATUS_MASK);
+	if (status & DME_STATUS_ERROR_MASK)
+		return -EIO;
+
+	status = DESC_DEC(cmpl_desc, CMPL_RM_STATUS_SHIFT,
+			  CMPL_RM_STATUS_MASK);
+	status &= RM_STATUS_CODE_MASK;
+	if (status == RM_STATUS_CODE_AE_TIMEOUT)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static bool flexrm_is_next_table_desc(void *desc_ptr)
+{
+	u64 desc = flexrm_read_desc(desc_ptr);
+	u32 type = DESC_DEC(desc, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+
+	return (type == NPTR_TYPE) ? true : false;
+}
+
+static u64 flexrm_next_table_desc(u32 toggle, dma_addr_t next_addr)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, NPTR_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, toggle, NPTR_TOGGLE_SHIFT, NPTR_TOGGLE_MASK);
+	DESC_ENC(desc, next_addr, NPTR_ADDR_SHIFT, NPTR_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_null_desc(u32 toggle)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, NULL_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, toggle, NULL_TOGGLE_SHIFT, NULL_TOGGLE_MASK);
+
+	return desc;
+}
+
+static u32 flexrm_estimate_header_desc_count(u32 nhcnt)
+{
+	u32 hcnt = nhcnt / HEADER_BDCOUNT_MAX;
+
+	if (!(nhcnt % HEADER_BDCOUNT_MAX))
+		hcnt += 1;
+
+	return hcnt;
+}
+
+static void flexrm_flip_header_toggle(void *desc_ptr)
+{
+	u64 desc = flexrm_read_desc(desc_ptr);
+
+	if (desc & ((u64)0x1 << HEADER_TOGGLE_SHIFT))
+		desc &= ~((u64)0x1 << HEADER_TOGGLE_SHIFT);
+	else
+		desc |= ((u64)0x1 << HEADER_TOGGLE_SHIFT);
+
+	flexrm_write_desc(desc_ptr, desc);
+}
+
+static u64 flexrm_header_desc(u32 toggle, u32 startpkt, u32 endpkt,
+			       u32 bdcount, u32 flags, u32 opaque)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, HEADER_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, toggle, HEADER_TOGGLE_SHIFT, HEADER_TOGGLE_MASK);
+	DESC_ENC(desc, startpkt, HEADER_STARTPKT_SHIFT, HEADER_STARTPKT_MASK);
+	DESC_ENC(desc, endpkt, HEADER_ENDPKT_SHIFT, HEADER_ENDPKT_MASK);
+	DESC_ENC(desc, bdcount, HEADER_BDCOUNT_SHIFT, HEADER_BDCOUNT_MASK);
+	DESC_ENC(desc, flags, HEADER_FLAGS_SHIFT, HEADER_FLAGS_MASK);
+	DESC_ENC(desc, opaque, HEADER_OPAQUE_SHIFT, HEADER_OPAQUE_MASK);
+
+	return desc;
+}
+
+static void flexrm_enqueue_desc(u32 nhpos, u32 nhcnt, u32 reqid,
+				 u64 desc, void **desc_ptr, u32 *toggle,
+				 void *start_desc, void *end_desc)
+{
+	u64 d;
+	u32 nhavail, _toggle, _startpkt, _endpkt, _bdcount;
+
+	/* Sanity check */
+	if (nhcnt <= nhpos)
+		return;
+
+	/*
+	 * Each request or packet start with a HEADER descriptor followed
+	 * by one or more non-HEADER descriptors (SRC, SRCT, MSRC, DST,
+	 * DSTT, MDST, IMM, and IMMT). The number of non-HEADER descriptors
+	 * following a HEADER descriptor is represented by BDCOUNT field
+	 * of HEADER descriptor. The max value of BDCOUNT field is 31 which
+	 * means we can only have 31 non-HEADER descriptors following one
+	 * HEADER descriptor.
+	 *
+	 * In general use, number of non-HEADER descriptors can easily go
+	 * beyond 31. To tackle this situation, we have packet (or request)
+	 * extension bits (STARTPKT and ENDPKT) in the HEADER descriptor.
+	 *
+	 * To use packet extension, the first HEADER descriptor of request
+	 * (or packet) will have STARTPKT=1 and ENDPKT=0. The intermediate
+	 * HEADER descriptors will have STARTPKT=0 and ENDPKT=0. The last
+	 * HEADER descriptor will have STARTPKT=0 and ENDPKT=1. Also, the
+	 * TOGGLE bit of the first HEADER will be set to invalid state to
+	 * ensure that FlexRM does not start fetching descriptors till all
+	 * descriptors are enqueued. The user of this function will flip
+	 * the TOGGLE bit of first HEADER after all descriptors are
+	 * enqueued.
+	 */
+
+	if ((nhpos % HEADER_BDCOUNT_MAX == 0) && (nhcnt - nhpos)) {
+		/* Prepare the header descriptor */
+		nhavail = (nhcnt - nhpos);
+		_toggle = (nhpos == 0) ? !(*toggle) : (*toggle);
+		_startpkt = (nhpos == 0) ? 0x1 : 0x0;
+		_endpkt = (nhavail <= HEADER_BDCOUNT_MAX) ? 0x1 : 0x0;
+		_bdcount = (nhavail <= HEADER_BDCOUNT_MAX) ?
+				nhavail : HEADER_BDCOUNT_MAX;
+		if (nhavail <= HEADER_BDCOUNT_MAX)
+			_bdcount = nhavail;
+		else
+			_bdcount = HEADER_BDCOUNT_MAX;
+		d = flexrm_header_desc(_toggle, _startpkt, _endpkt,
+					_bdcount, 0x0, reqid);
+
+		/* Write header descriptor */
+		flexrm_write_desc(*desc_ptr, d);
+
+		/* Point to next descriptor */
+		*desc_ptr += sizeof(desc);
+		if (*desc_ptr == end_desc)
+			*desc_ptr = start_desc;
+
+		/* Skip next pointer descriptors */
+		while (flexrm_is_next_table_desc(*desc_ptr)) {
+			*toggle = (*toggle) ? 0 : 1;
+			*desc_ptr += sizeof(desc);
+			if (*desc_ptr == end_desc)
+				*desc_ptr = start_desc;
+		}
+	}
+
+	/* Write desired descriptor */
+	flexrm_write_desc(*desc_ptr, desc);
+
+	/* Point to next descriptor */
+	*desc_ptr += sizeof(desc);
+	if (*desc_ptr == end_desc)
+		*desc_ptr = start_desc;
+
+	/* Skip next pointer descriptors */
+	while (flexrm_is_next_table_desc(*desc_ptr)) {
+		*toggle = (*toggle) ? 0 : 1;
+		*desc_ptr += sizeof(desc);
+		if (*desc_ptr == end_desc)
+			*desc_ptr = start_desc;
+	}
+}
+
+static u64 flexrm_src_desc(dma_addr_t addr, unsigned int length)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, SRC_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length, SRC_LENGTH_SHIFT, SRC_LENGTH_MASK);
+	DESC_ENC(desc, addr, SRC_ADDR_SHIFT, SRC_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_msrc_desc(dma_addr_t addr, unsigned int length_div_16)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, MSRC_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length_div_16, MSRC_LENGTH_SHIFT, MSRC_LENGTH_MASK);
+	DESC_ENC(desc, addr, MSRC_ADDR_SHIFT, MSRC_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_dst_desc(dma_addr_t addr, unsigned int length)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, DST_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length, DST_LENGTH_SHIFT, DST_LENGTH_MASK);
+	DESC_ENC(desc, addr, DST_ADDR_SHIFT, DST_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_mdst_desc(dma_addr_t addr, unsigned int length_div_16)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, MDST_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length_div_16, MDST_LENGTH_SHIFT, MDST_LENGTH_MASK);
+	DESC_ENC(desc, addr, MDST_ADDR_SHIFT, MDST_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_imm_desc(u64 data)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, IMM_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, data, IMM_DATA_SHIFT, IMM_DATA_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_srct_desc(dma_addr_t addr, unsigned int length)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, SRCT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length, SRCT_LENGTH_SHIFT, SRCT_LENGTH_MASK);
+	DESC_ENC(desc, addr, SRCT_ADDR_SHIFT, SRCT_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_dstt_desc(dma_addr_t addr, unsigned int length)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, DSTT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, length, DSTT_LENGTH_SHIFT, DSTT_LENGTH_MASK);
+	DESC_ENC(desc, addr, DSTT_ADDR_SHIFT, DSTT_ADDR_MASK);
+
+	return desc;
+}
+
+static u64 flexrm_immt_desc(u64 data)
+{
+	u64 desc = 0;
+
+	DESC_ENC(desc, IMMT_TYPE, DESC_TYPE_SHIFT, DESC_TYPE_MASK);
+	DESC_ENC(desc, data, IMMT_DATA_SHIFT, IMMT_DATA_MASK);
+
+	return desc;
+}
+
+static bool flexrm_spu_sanity_check(struct brcm_message *msg)
+{
+	struct scatterlist *sg;
+
+	if (!msg->spu.src || !msg->spu.dst)
+		return false;
+	for (sg = msg->spu.src; sg; sg = sg_next(sg)) {
+		if (sg->length & 0xf) {
+			if (sg->length > SRC_LENGTH_MASK)
+				return false;
+		} else {
+			if (sg->length > (MSRC_LENGTH_MASK * 16))
+				return false;
+		}
+	}
+	for (sg = msg->spu.dst; sg; sg = sg_next(sg)) {
+		if (sg->length & 0xf) {
+			if (sg->length > DST_LENGTH_MASK)
+				return false;
+		} else {
+			if (sg->length > (MDST_LENGTH_MASK * 16))
+				return false;
+		}
+	}
+
+	return true;
+}
+
+static u32 flexrm_spu_estimate_nonheader_desc_count(struct brcm_message *msg)
+{
+	u32 cnt = 0;
+	unsigned int dst_target = 0;
+	struct scatterlist *src_sg = msg->spu.src, *dst_sg = msg->spu.dst;
+
+	while (src_sg || dst_sg) {
+		if (src_sg) {
+			cnt++;
+			dst_target = src_sg->length;
+			src_sg = sg_next(src_sg);
+		} else
+			dst_target = UINT_MAX;
+
+		while (dst_target && dst_sg) {
+			cnt++;
+			if (dst_sg->length < dst_target)
+				dst_target -= dst_sg->length;
+			else
+				dst_target = 0;
+			dst_sg = sg_next(dst_sg);
+		}
+	}
+
+	return cnt;
+}
+
+static int flexrm_spu_dma_map(struct device *dev, struct brcm_message *msg)
+{
+	int rc;
+
+	rc = dma_map_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
+			DMA_TO_DEVICE);
+	if (!rc)
+		return -EIO;
+
+	rc = dma_map_sg(dev, msg->spu.dst, sg_nents(msg->spu.dst),
+			DMA_FROM_DEVICE);
+	if (!rc) {
+		dma_unmap_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
+			     DMA_TO_DEVICE);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void flexrm_spu_dma_unmap(struct device *dev, struct brcm_message *msg)
+{
+	dma_unmap_sg(dev, msg->spu.dst, sg_nents(msg->spu.dst),
+		     DMA_FROM_DEVICE);
+	dma_unmap_sg(dev, msg->spu.src, sg_nents(msg->spu.src),
+		     DMA_TO_DEVICE);
+}
+
+static void *flexrm_spu_write_descs(struct brcm_message *msg, u32 nhcnt,
+				     u32 reqid, void *desc_ptr, u32 toggle,
+				     void *start_desc, void *end_desc)
+{
+	u64 d;
+	u32 nhpos = 0;
+	void *orig_desc_ptr = desc_ptr;
+	unsigned int dst_target = 0;
+	struct scatterlist *src_sg = msg->spu.src, *dst_sg = msg->spu.dst;
+
+	while (src_sg || dst_sg) {
+		if (src_sg) {
+			if (sg_dma_len(src_sg) & 0xf)
+				d = flexrm_src_desc(sg_dma_address(src_sg),
+						     sg_dma_len(src_sg));
+			else
+				d = flexrm_msrc_desc(sg_dma_address(src_sg),
+						      sg_dma_len(src_sg)/16);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+			dst_target = sg_dma_len(src_sg);
+			src_sg = sg_next(src_sg);
+		} else
+			dst_target = UINT_MAX;
+
+		while (dst_target && dst_sg) {
+			if (sg_dma_len(dst_sg) & 0xf)
+				d = flexrm_dst_desc(sg_dma_address(dst_sg),
+						     sg_dma_len(dst_sg));
+			else
+				d = flexrm_mdst_desc(sg_dma_address(dst_sg),
+						      sg_dma_len(dst_sg)/16);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+			if (sg_dma_len(dst_sg) < dst_target)
+				dst_target -= sg_dma_len(dst_sg);
+			else
+				dst_target = 0;
+			dst_sg = sg_next(dst_sg);
+		}
+	}
+
+	/* Null descriptor with invalid toggle bit */
+	flexrm_write_desc(desc_ptr, flexrm_null_desc(!toggle));
+
+	/* Ensure that descriptors have been written to memory */
+	wmb();
+
+	/* Flip toggle bit in header */
+	flexrm_flip_header_toggle(orig_desc_ptr);
+
+	return desc_ptr;
+}
+
+static bool flexrm_sba_sanity_check(struct brcm_message *msg)
+{
+	u32 i;
+
+	if (!msg->sba.cmds || !msg->sba.cmds_count)
+		return false;
+
+	for (i = 0; i < msg->sba.cmds_count; i++) {
+		if (((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) ||
+		     (msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C)) &&
+		    (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT))
+			return false;
+		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) &&
+		    (msg->sba.cmds[i].data_len > SRCT_LENGTH_MASK))
+			return false;
+		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C) &&
+		    (msg->sba.cmds[i].data_len > SRCT_LENGTH_MASK))
+			return false;
+		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_RESP) &&
+		    (msg->sba.cmds[i].resp_len > DSTT_LENGTH_MASK))
+			return false;
+		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT) &&
+		    (msg->sba.cmds[i].data_len > DSTT_LENGTH_MASK))
+			return false;
+	}
+
+	return true;
+}
+
+static u32 flexrm_sba_estimate_nonheader_desc_count(struct brcm_message *msg)
+{
+	u32 i, cnt;
+
+	cnt = 0;
+	for (i = 0; i < msg->sba.cmds_count; i++) {
+		cnt++;
+
+		if ((msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_B) ||
+		    (msg->sba.cmds[i].flags & BRCM_SBA_CMD_TYPE_C))
+			cnt++;
+
+		if (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_RESP)
+			cnt++;
+
+		if (msg->sba.cmds[i].flags & BRCM_SBA_CMD_HAS_OUTPUT)
+			cnt++;
+	}
+
+	return cnt;
+}
+
+static void *flexrm_sba_write_descs(struct brcm_message *msg, u32 nhcnt,
+				     u32 reqid, void *desc_ptr, u32 toggle,
+				     void *start_desc, void *end_desc)
+{
+	u64 d;
+	u32 i, nhpos = 0;
+	struct brcm_sba_command *c;
+	void *orig_desc_ptr = desc_ptr;
+
+	/* Convert SBA commands into descriptors */
+	for (i = 0; i < msg->sba.cmds_count; i++) {
+		c = &msg->sba.cmds[i];
+
+		if ((c->flags & BRCM_SBA_CMD_HAS_RESP) &&
+		    (c->flags & BRCM_SBA_CMD_HAS_OUTPUT)) {
+			/* Destination response descriptor */
+			d = flexrm_dst_desc(c->resp, c->resp_len);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		} else if (c->flags & BRCM_SBA_CMD_HAS_RESP) {
+			/* Destination response with tlast descriptor */
+			d = flexrm_dstt_desc(c->resp, c->resp_len);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		}
+
+		if (c->flags & BRCM_SBA_CMD_HAS_OUTPUT) {
+			/* Destination with tlast descriptor */
+			d = flexrm_dstt_desc(c->data, c->data_len);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		}
+
+		if (c->flags & BRCM_SBA_CMD_TYPE_B) {
+			/* Command as immediate descriptor */
+			d = flexrm_imm_desc(c->cmd);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		} else {
+			/* Command as immediate descriptor with tlast */
+			d = flexrm_immt_desc(c->cmd);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		}
+
+		if ((c->flags & BRCM_SBA_CMD_TYPE_B) ||
+		    (c->flags & BRCM_SBA_CMD_TYPE_C)) {
+			/* Source with tlast descriptor */
+			d = flexrm_srct_desc(c->data, c->data_len);
+			flexrm_enqueue_desc(nhpos, nhcnt, reqid,
+					     d, &desc_ptr, &toggle,
+					     start_desc, end_desc);
+			nhpos++;
+		}
+	}
+
+	/* Null descriptor with invalid toggle bit */
+	flexrm_write_desc(desc_ptr, flexrm_null_desc(!toggle));
+
+	/* Ensure that descriptors have been written to memory */
+	wmb();
+
+	/* Flip toggle bit in header */
+	flexrm_flip_header_toggle(orig_desc_ptr);
+
+	return desc_ptr;
+}
+
+static bool flexrm_sanity_check(struct brcm_message *msg)
+{
+	if (!msg)
+		return false;
+
+	switch (msg->type) {
+	case BRCM_MESSAGE_SPU:
+		return flexrm_spu_sanity_check(msg);
+	case BRCM_MESSAGE_SBA:
+		return flexrm_sba_sanity_check(msg);
+	default:
+		return false;
+	};
+}
+
+static u32 flexrm_estimate_nonheader_desc_count(struct brcm_message *msg)
+{
+	if (!msg)
+		return 0;
+
+	switch (msg->type) {
+	case BRCM_MESSAGE_SPU:
+		return flexrm_spu_estimate_nonheader_desc_count(msg);
+	case BRCM_MESSAGE_SBA:
+		return flexrm_sba_estimate_nonheader_desc_count(msg);
+	default:
+		return 0;
+	};
+}
+
+static int flexrm_dma_map(struct device *dev, struct brcm_message *msg)
+{
+	if (!dev || !msg)
+		return -EINVAL;
+
+	switch (msg->type) {
+	case BRCM_MESSAGE_SPU:
+		return flexrm_spu_dma_map(dev, msg);
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static void flexrm_dma_unmap(struct device *dev, struct brcm_message *msg)
+{
+	if (!dev || !msg)
+		return;
+
+	switch (msg->type) {
+	case BRCM_MESSAGE_SPU:
+		flexrm_spu_dma_unmap(dev, msg);
+		break;
+	default:
+		break;
+	}
+}
+
+static void *flexrm_write_descs(struct brcm_message *msg, u32 nhcnt,
+				u32 reqid, void *desc_ptr, u32 toggle,
+				void *start_desc, void *end_desc)
+{
+	if (!msg || !desc_ptr || !start_desc || !end_desc)
+		return ERR_PTR(-ENOTSUPP);
+
+	if ((desc_ptr < start_desc) || (end_desc <= desc_ptr))
+		return ERR_PTR(-ERANGE);
+
+	switch (msg->type) {
+	case BRCM_MESSAGE_SPU:
+		return flexrm_spu_write_descs(msg, nhcnt, reqid,
+					       desc_ptr, toggle,
+					       start_desc, end_desc);
+	case BRCM_MESSAGE_SBA:
+		return flexrm_sba_write_descs(msg, nhcnt, reqid,
+					       desc_ptr, toggle,
+					       start_desc, end_desc);
+	default:
+		return ERR_PTR(-ENOTSUPP);
+	};
+}
+
+/* ====== FlexRM driver helper routines ===== */
+
+static void flexrm_write_config_in_seqfile(struct flexrm_mbox *mbox,
+					   struct seq_file *file)
+{
+	int i;
+	const char *state;
+	struct flexrm_ring *ring;
+
+	seq_printf(file, "%-5s %-9s %-18s %-10s %-18s %-10s\n",
+		   "Ring#", "State", "BD_Addr", "BD_Size",
+		   "Cmpl_Addr", "Cmpl_Size");
+
+	for (i = 0; i < mbox->num_rings; i++) {
+		ring = &mbox->rings[i];
+		if (readl(ring->regs + RING_CONTROL) &
+		    BIT(CONTROL_ACTIVE_SHIFT))
+			state = "active";
+		else
+			state = "inactive";
+		seq_printf(file,
+			   "%-5d %-9s 0x%016llx 0x%08x 0x%016llx 0x%08x\n",
+			   ring->num, state,
+			   (unsigned long long)ring->bd_dma_base,
+			   (u32)RING_BD_SIZE,
+			   (unsigned long long)ring->cmpl_dma_base,
+			   (u32)RING_CMPL_SIZE);
+	}
+}
+
+static void flexrm_write_stats_in_seqfile(struct flexrm_mbox *mbox,
+					  struct seq_file *file)
+{
+	int i;
+	u32 val, bd_read_offset;
+	struct flexrm_ring *ring;
+
+	seq_printf(file, "%-5s %-10s %-10s %-10s %-11s %-11s\n",
+		   "Ring#", "BD_Read", "BD_Write",
+		   "Cmpl_Read", "Submitted", "Completed");
+
+	for (i = 0; i < mbox->num_rings; i++) {
+		ring = &mbox->rings[i];
+		bd_read_offset = readl_relaxed(ring->regs + RING_BD_READ_PTR);
+		val = readl_relaxed(ring->regs + RING_BD_START_ADDR);
+		bd_read_offset *= RING_DESC_SIZE;
+		bd_read_offset += (u32)(BD_START_ADDR_DECODE(val) -
+					ring->bd_dma_base);
+		seq_printf(file, "%-5d 0x%08x 0x%08x 0x%08x %-11d %-11d\n",
+			   ring->num,
+			   (u32)bd_read_offset,
+			   (u32)ring->bd_write_offset,
+			   (u32)ring->cmpl_read_offset,
+			   (u32)atomic_read(&ring->msg_send_count),
+			   (u32)atomic_read(&ring->msg_cmpl_count));
+	}
+}
+
+static int flexrm_new_request(struct flexrm_ring *ring,
+				struct brcm_message *batch_msg,
+				struct brcm_message *msg)
+{
+	void *next;
+	unsigned long flags;
+	u32 val, count, nhcnt;
+	u32 read_offset, write_offset;
+	bool exit_cleanup = false;
+	int ret = 0, reqid;
+
+	/* Do sanity check on message */
+	if (!flexrm_sanity_check(msg))
+		return -EIO;
+	msg->error = 0;
+
+	/* If no requests possible then save data pointer and goto done. */
+	spin_lock_irqsave(&ring->lock, flags);
+	reqid = bitmap_find_free_region(ring->requests_bmap,
+					RING_MAX_REQ_COUNT, 0);
+	spin_unlock_irqrestore(&ring->lock, flags);
+	if (reqid < 0)
+		return -ENOSPC;
+	ring->requests[reqid] = msg;
+
+	/* Do DMA mappings for the message */
+	ret = flexrm_dma_map(ring->mbox->dev, msg);
+	if (ret < 0) {
+		ring->requests[reqid] = NULL;
+		spin_lock_irqsave(&ring->lock, flags);
+		bitmap_release_region(ring->requests_bmap, reqid, 0);
+		spin_unlock_irqrestore(&ring->lock, flags);
+		return ret;
+	}
+
+	/* Determine current HW BD read offset */
+	read_offset = readl_relaxed(ring->regs + RING_BD_READ_PTR);
+	val = readl_relaxed(ring->regs + RING_BD_START_ADDR);
+	read_offset *= RING_DESC_SIZE;
+	read_offset += (u32)(BD_START_ADDR_DECODE(val) - ring->bd_dma_base);
+
+	/*
+	 * Number required descriptors = number of non-header descriptors +
+	 *				 number of header descriptors +
+	 *				 1x null descriptor
+	 */
+	nhcnt = flexrm_estimate_nonheader_desc_count(msg);
+	count = flexrm_estimate_header_desc_count(nhcnt) + nhcnt + 1;
+
+	/* Check for available descriptor space. */
+	write_offset = ring->bd_write_offset;
+	while (count) {
+		if (!flexrm_is_next_table_desc(ring->bd_base + write_offset))
+			count--;
+		write_offset += RING_DESC_SIZE;
+		if (write_offset == RING_BD_SIZE)
+			write_offset = 0x0;
+		if (write_offset == read_offset)
+			break;
+	}
+	if (count) {
+		ret = -ENOSPC;
+		exit_cleanup = true;
+		goto exit;
+	}
+
+	/* Write descriptors to ring */
+	next = flexrm_write_descs(msg, nhcnt, reqid,
+			ring->bd_base + ring->bd_write_offset,
+			RING_BD_TOGGLE_VALID(ring->bd_write_offset),
+			ring->bd_base, ring->bd_base + RING_BD_SIZE);
+	if (IS_ERR(next)) {
+		ret = PTR_ERR(next);
+		exit_cleanup = true;
+		goto exit;
+	}
+
+	/* Save ring BD write offset */
+	ring->bd_write_offset = (unsigned long)(next - ring->bd_base);
+
+	/* Increment number of messages sent */
+	atomic_inc_return(&ring->msg_send_count);
+
+exit:
+	/* Update error status in message */
+	msg->error = ret;
+
+	/* Cleanup if we failed */
+	if (exit_cleanup) {
+		flexrm_dma_unmap(ring->mbox->dev, msg);
+		ring->requests[reqid] = NULL;
+		spin_lock_irqsave(&ring->lock, flags);
+		bitmap_release_region(ring->requests_bmap, reqid, 0);
+		spin_unlock_irqrestore(&ring->lock, flags);
+	}
+
+	return ret;
+}
+
+static int flexrm_process_completions(struct flexrm_ring *ring)
+{
+	u64 desc;
+	int err, count = 0;
+	unsigned long flags;
+	struct brcm_message *msg = NULL;
+	u32 reqid, cmpl_read_offset, cmpl_write_offset;
+	struct mbox_chan *chan = &ring->mbox->controller.chans[ring->num];
+
+	spin_lock_irqsave(&ring->lock, flags);
+
+	/*
+	 * Get current completion read and write offset
+	 *
+	 * Note: We should read completion write pointer at least once
+	 * after we get a MSI interrupt because HW maintains internal
+	 * MSI status which will allow next MSI interrupt only after
+	 * completion write pointer is read.
+	 */
+	cmpl_write_offset = readl_relaxed(ring->regs + RING_CMPL_WRITE_PTR);
+	cmpl_write_offset *= RING_DESC_SIZE;
+	cmpl_read_offset = ring->cmpl_read_offset;
+	ring->cmpl_read_offset = cmpl_write_offset;
+
+	spin_unlock_irqrestore(&ring->lock, flags);
+
+	/* For each completed request notify mailbox clients */
+	reqid = 0;
+	while (cmpl_read_offset != cmpl_write_offset) {
+		/* Dequeue next completion descriptor */
+		desc = *((u64 *)(ring->cmpl_base + cmpl_read_offset));
+
+		/* Next read offset */
+		cmpl_read_offset += RING_DESC_SIZE;
+		if (cmpl_read_offset == RING_CMPL_SIZE)
+			cmpl_read_offset = 0;
+
+		/* Decode error from completion descriptor */
+		err = flexrm_cmpl_desc_to_error(desc);
+		if (err < 0) {
+			dev_warn(ring->mbox->dev,
+			"ring%d got completion desc=0x%lx with error %d\n",
+			ring->num, (unsigned long)desc, err);
+		}
+
+		/* Determine request id from completion descriptor */
+		reqid = flexrm_cmpl_desc_to_reqid(desc);
+
+		/* Determine message pointer based on reqid */
+		msg = ring->requests[reqid];
+		if (!msg) {
+			dev_warn(ring->mbox->dev,
+			"ring%d null msg pointer for completion desc=0x%lx\n",
+			ring->num, (unsigned long)desc);
+			continue;
+		}
+
+		/* Release reqid for recycling */
+		ring->requests[reqid] = NULL;
+		spin_lock_irqsave(&ring->lock, flags);
+		bitmap_release_region(ring->requests_bmap, reqid, 0);
+		spin_unlock_irqrestore(&ring->lock, flags);
+
+		/* Unmap DMA mappings */
+		flexrm_dma_unmap(ring->mbox->dev, msg);
+
+		/* Give-back message to mailbox client */
+		msg->error = err;
+		mbox_chan_received_data(chan, msg);
+
+		/* Increment number of completions processed */
+		atomic_inc_return(&ring->msg_cmpl_count);
+		count++;
+	}
+
+	return count;
+}
+
+/* ====== FlexRM Debugfs callbacks ====== */
+
+static int flexrm_debugfs_conf_show(struct seq_file *file, void *offset)
+{
+	struct flexrm_mbox *mbox = dev_get_drvdata(file->private);
+
+	/* Write config in file */
+	flexrm_write_config_in_seqfile(mbox, file);
+
+	return 0;
+}
+
+static int flexrm_debugfs_stats_show(struct seq_file *file, void *offset)
+{
+	struct flexrm_mbox *mbox = dev_get_drvdata(file->private);
+
+	/* Write stats in file */
+	flexrm_write_stats_in_seqfile(mbox, file);
+
+	return 0;
+}
+
+/* ====== FlexRM interrupt handler ===== */
+
+static irqreturn_t flexrm_irq_event(int irq, void *dev_id)
+{
+	/* We only have MSI for completions so just wakeup IRQ thread */
+	/* Ring related errors will be informed via completion descriptors */
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t flexrm_irq_thread(int irq, void *dev_id)
+{
+	flexrm_process_completions(dev_id);
+
+	return IRQ_HANDLED;
+}
+
+/* ====== FlexRM mailbox callbacks ===== */
+
+static int flexrm_send_data(struct mbox_chan *chan, void *data)
+{
+	int i, rc;
+	struct flexrm_ring *ring = chan->con_priv;
+	struct brcm_message *msg = data;
+
+	if (msg->type == BRCM_MESSAGE_BATCH) {
+		for (i = msg->batch.msgs_queued;
+		     i < msg->batch.msgs_count; i++) {
+			rc = flexrm_new_request(ring, msg,
+						 &msg->batch.msgs[i]);
+			if (rc) {
+				msg->error = rc;
+				return rc;
+			}
+			msg->batch.msgs_queued++;
+		}
+		return 0;
+	}
+
+	return flexrm_new_request(ring, NULL, data);
+}
+
+static bool flexrm_peek_data(struct mbox_chan *chan)
+{
+	int cnt = flexrm_process_completions(chan->con_priv);
+
+	return (cnt > 0) ? true : false;
+}
+
+static int flexrm_startup(struct mbox_chan *chan)
+{
+	u64 d;
+	u32 val, off;
+	int ret = 0;
+	dma_addr_t next_addr;
+	struct flexrm_ring *ring = chan->con_priv;
+
+	/* Allocate BD memory */
+	ring->bd_base = dma_pool_alloc(ring->mbox->bd_pool,
+				       GFP_KERNEL, &ring->bd_dma_base);
+	if (!ring->bd_base) {
+		dev_err(ring->mbox->dev,
+			"can't allocate BD memory for ring%d\n",
+			ring->num);
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/* Configure next table pointer entries in BD memory */
+	for (off = 0; off < RING_BD_SIZE; off += RING_DESC_SIZE) {
+		next_addr = off + RING_DESC_SIZE;
+		if (next_addr == RING_BD_SIZE)
+			next_addr = 0;
+		next_addr += ring->bd_dma_base;
+		if (RING_BD_ALIGN_CHECK(next_addr))
+			d = flexrm_next_table_desc(RING_BD_TOGGLE_VALID(off),
+						    next_addr);
+		else
+			d = flexrm_null_desc(RING_BD_TOGGLE_INVALID(off));
+		flexrm_write_desc(ring->bd_base + off, d);
+	}
+
+	/* Allocate completion memory */
+	ring->cmpl_base = dma_pool_zalloc(ring->mbox->cmpl_pool,
+					 GFP_KERNEL, &ring->cmpl_dma_base);
+	if (!ring->cmpl_base) {
+		dev_err(ring->mbox->dev,
+			"can't allocate completion memory for ring%d\n",
+			ring->num);
+		ret = -ENOMEM;
+		goto fail_free_bd_memory;
+	}
+
+	/* Request IRQ */
+	if (ring->irq == UINT_MAX) {
+		dev_err(ring->mbox->dev,
+			"ring%d IRQ not available\n", ring->num);
+		ret = -ENODEV;
+		goto fail_free_cmpl_memory;
+	}
+	ret = request_threaded_irq(ring->irq,
+				   flexrm_irq_event,
+				   flexrm_irq_thread,
+				   0, dev_name(ring->mbox->dev), ring);
+	if (ret) {
+		dev_err(ring->mbox->dev,
+			"failed to request ring%d IRQ\n", ring->num);
+		goto fail_free_cmpl_memory;
+	}
+	ring->irq_requested = true;
+
+	/* Set IRQ affinity hint */
+	ring->irq_aff_hint = CPU_MASK_NONE;
+	val = ring->mbox->num_rings;
+	val = (num_online_cpus() < val) ? val / num_online_cpus() : 1;
+	cpumask_set_cpu((ring->num / val) % num_online_cpus(),
+			&ring->irq_aff_hint);
+	ret = irq_update_affinity_hint(ring->irq, &ring->irq_aff_hint);
+	if (ret) {
+		dev_err(ring->mbox->dev,
+			"failed to set IRQ affinity hint for ring%d\n",
+			ring->num);
+		goto fail_free_irq;
+	}
+
+	/* Disable/inactivate ring */
+	writel_relaxed(0x0, ring->regs + RING_CONTROL);
+
+	/* Program BD start address */
+	val = BD_START_ADDR_VALUE(ring->bd_dma_base);
+	writel_relaxed(val, ring->regs + RING_BD_START_ADDR);
+
+	/* BD write pointer will be same as HW write pointer */
+	ring->bd_write_offset =
+			readl_relaxed(ring->regs + RING_BD_WRITE_PTR);
+	ring->bd_write_offset *= RING_DESC_SIZE;
+
+	/* Program completion start address */
+	val = CMPL_START_ADDR_VALUE(ring->cmpl_dma_base);
+	writel_relaxed(val, ring->regs + RING_CMPL_START_ADDR);
+
+	/* Completion read pointer will be same as HW write pointer */
+	ring->cmpl_read_offset =
+			readl_relaxed(ring->regs + RING_CMPL_WRITE_PTR);
+	ring->cmpl_read_offset *= RING_DESC_SIZE;
+
+	/* Read ring Tx, Rx, and Outstanding counts to clear */
+	readl_relaxed(ring->regs + RING_NUM_REQ_RECV_LS);
+	readl_relaxed(ring->regs + RING_NUM_REQ_RECV_MS);
+	readl_relaxed(ring->regs + RING_NUM_REQ_TRANS_LS);
+	readl_relaxed(ring->regs + RING_NUM_REQ_TRANS_MS);
+	readl_relaxed(ring->regs + RING_NUM_REQ_OUTSTAND);
+
+	/* Configure RING_MSI_CONTROL */
+	val = 0;
+	val |= (ring->msi_timer_val << MSI_TIMER_VAL_SHIFT);
+	val |= BIT(MSI_ENABLE_SHIFT);
+	val |= (ring->msi_count_threshold & MSI_COUNT_MASK) << MSI_COUNT_SHIFT;
+	writel_relaxed(val, ring->regs + RING_MSI_CONTROL);
+
+	/* Enable/activate ring */
+	val = BIT(CONTROL_ACTIVE_SHIFT);
+	writel_relaxed(val, ring->regs + RING_CONTROL);
+
+	/* Reset stats to zero */
+	atomic_set(&ring->msg_send_count, 0);
+	atomic_set(&ring->msg_cmpl_count, 0);
+
+	return 0;
+
+fail_free_irq:
+	free_irq(ring->irq, ring);
+	ring->irq_requested = false;
+fail_free_cmpl_memory:
+	dma_pool_free(ring->mbox->cmpl_pool,
+		      ring->cmpl_base, ring->cmpl_dma_base);
+	ring->cmpl_base = NULL;
+fail_free_bd_memory:
+	dma_pool_free(ring->mbox->bd_pool,
+		      ring->bd_base, ring->bd_dma_base);
+	ring->bd_base = NULL;
+fail:
+	return ret;
+}
+
+static void flexrm_shutdown(struct mbox_chan *chan)
+{
+	u32 reqid;
+	unsigned int timeout;
+	struct brcm_message *msg;
+	struct flexrm_ring *ring = chan->con_priv;
+
+	/* Disable/inactivate ring */
+	writel_relaxed(0x0, ring->regs + RING_CONTROL);
+
+	/* Set ring flush state */
+	timeout = 1000; /* timeout of 1s */
+	writel_relaxed(BIT(CONTROL_FLUSH_SHIFT),
+			ring->regs + RING_CONTROL);
+	do {
+		if (readl_relaxed(ring->regs + RING_FLUSH_DONE) &
+		    FLUSH_DONE_MASK)
+			break;
+		mdelay(1);
+	} while (--timeout);
+	if (!timeout)
+		dev_err(ring->mbox->dev,
+			"setting ring%d flush state timedout\n", ring->num);
+
+	/* Clear ring flush state */
+	timeout = 1000; /* timeout of 1s */
+	writel_relaxed(0x0, ring->regs + RING_CONTROL);
+	do {
+		if (!(readl_relaxed(ring->regs + RING_FLUSH_DONE) &
+		      FLUSH_DONE_MASK))
+			break;
+		mdelay(1);
+	} while (--timeout);
+	if (!timeout)
+		dev_err(ring->mbox->dev,
+			"clearing ring%d flush state timedout\n", ring->num);
+
+	/* Abort all in-flight requests */
+	for (reqid = 0; reqid < RING_MAX_REQ_COUNT; reqid++) {
+		msg = ring->requests[reqid];
+		if (!msg)
+			continue;
+
+		/* Release reqid for recycling */
+		ring->requests[reqid] = NULL;
+
+		/* Unmap DMA mappings */
+		flexrm_dma_unmap(ring->mbox->dev, msg);
+
+		/* Give-back message to mailbox client */
+		msg->error = -EIO;
+		mbox_chan_received_data(chan, msg);
+	}
+
+	/* Clear requests bitmap */
+	bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);
+
+	/* Release IRQ */
+	if (ring->irq_requested) {
+		irq_update_affinity_hint(ring->irq, NULL);
+		free_irq(ring->irq, ring);
+		ring->irq_requested = false;
+	}
+
+	/* Free-up completion descriptor ring */
+	if (ring->cmpl_base) {
+		dma_pool_free(ring->mbox->cmpl_pool,
+			      ring->cmpl_base, ring->cmpl_dma_base);
+		ring->cmpl_base = NULL;
+	}
+
+	/* Free-up BD descriptor ring */
+	if (ring->bd_base) {
+		dma_pool_free(ring->mbox->bd_pool,
+			      ring->bd_base, ring->bd_dma_base);
+		ring->bd_base = NULL;
+	}
+}
+
+static const struct mbox_chan_ops flexrm_mbox_chan_ops = {
+	.send_data	= flexrm_send_data,
+	.startup	= flexrm_startup,
+	.shutdown	= flexrm_shutdown,
+	.peek_data	= flexrm_peek_data,
+};
+
+static struct mbox_chan *flexrm_mbox_of_xlate(struct mbox_controller *cntlr,
+					const struct of_phandle_args *pa)
+{
+	struct mbox_chan *chan;
+	struct flexrm_ring *ring;
+
+	if (pa->args_count < 3)
+		return ERR_PTR(-EINVAL);
+
+	if (pa->args[0] >= cntlr->num_chans)
+		return ERR_PTR(-ENOENT);
+
+	if (pa->args[1] > MSI_COUNT_MASK)
+		return ERR_PTR(-EINVAL);
+
+	if (pa->args[2] > MSI_TIMER_VAL_MASK)
+		return ERR_PTR(-EINVAL);
+
+	chan = &cntlr->chans[pa->args[0]];
+	ring = chan->con_priv;
+	ring->msi_count_threshold = pa->args[1];
+	ring->msi_timer_val = pa->args[2];
+
+	return chan;
+}
+
+/* ====== FlexRM platform driver ===== */
+
+static void flexrm_mbox_msi_write(struct msi_desc *desc, struct msi_msg *msg)
+{
+	struct device *dev = msi_desc_to_dev(desc);
+	struct flexrm_mbox *mbox = dev_get_drvdata(dev);
+	struct flexrm_ring *ring = &mbox->rings[desc->msi_index];
+
+	/* Configure per-Ring MSI registers */
+	writel_relaxed(msg->address_lo, ring->regs + RING_MSI_ADDR_LS);
+	writel_relaxed(msg->address_hi, ring->regs + RING_MSI_ADDR_MS);
+	writel_relaxed(msg->data, ring->regs + RING_MSI_DATA_VALUE);
+}
+
+static int flexrm_mbox_probe(struct platform_device *pdev)
+{
+	int index, ret = 0;
+	void __iomem *regs;
+	void __iomem *regs_end;
+	struct resource *iomem;
+	struct flexrm_ring *ring;
+	struct flexrm_mbox *mbox;
+	struct device *dev = &pdev->dev;
+
+	/* Allocate driver mailbox struct */
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+	mbox->dev = dev;
+	platform_set_drvdata(pdev, mbox);
+
+	/* Get resource for registers */
+	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!iomem || (resource_size(iomem) < RING_REGS_SIZE)) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	/* Map registers of all rings */
+	mbox->regs = devm_ioremap_resource(&pdev->dev, iomem);
+	if (IS_ERR(mbox->regs)) {
+		ret = PTR_ERR(mbox->regs);
+		goto fail;
+	}
+	regs_end = mbox->regs + resource_size(iomem);
+
+	/* Scan and count available rings */
+	mbox->num_rings = 0;
+	for (regs = mbox->regs; regs < regs_end; regs += RING_REGS_SIZE) {
+		if (readl_relaxed(regs + RING_VER) == RING_VER_MAGIC)
+			mbox->num_rings++;
+	}
+	if (!mbox->num_rings) {
+		ret = -ENODEV;
+		goto fail;
+	}
+
+	/* Allocate driver ring structs */
+	ring = devm_kcalloc(dev, mbox->num_rings, sizeof(*ring), GFP_KERNEL);
+	if (!ring) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+	mbox->rings = ring;
+
+	/* Initialize members of driver ring structs */
+	regs = mbox->regs;
+	for (index = 0; index < mbox->num_rings; index++) {
+		ring = &mbox->rings[index];
+		ring->num = index;
+		ring->mbox = mbox;
+		while ((regs < regs_end) &&
+		       (readl_relaxed(regs + RING_VER) != RING_VER_MAGIC))
+			regs += RING_REGS_SIZE;
+		if (regs_end <= regs) {
+			ret = -ENODEV;
+			goto fail;
+		}
+		ring->regs = regs;
+		regs += RING_REGS_SIZE;
+		ring->irq = UINT_MAX;
+		ring->irq_requested = false;
+		ring->msi_timer_val = MSI_TIMER_VAL_MASK;
+		ring->msi_count_threshold = 0x1;
+		memset(ring->requests, 0, sizeof(ring->requests));
+		ring->bd_base = NULL;
+		ring->bd_dma_base = 0;
+		ring->cmpl_base = NULL;
+		ring->cmpl_dma_base = 0;
+		atomic_set(&ring->msg_send_count, 0);
+		atomic_set(&ring->msg_cmpl_count, 0);
+		spin_lock_init(&ring->lock);
+		bitmap_zero(ring->requests_bmap, RING_MAX_REQ_COUNT);
+		ring->cmpl_read_offset = 0;
+	}
+
+	/* FlexRM is capable of 40-bit physical addresses only */
+	ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(40));
+	if (ret) {
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+		if (ret)
+			goto fail;
+	}
+
+	/* Create DMA pool for ring BD memory */
+	mbox->bd_pool = dma_pool_create("bd", dev, RING_BD_SIZE,
+					1 << RING_BD_ALIGN_ORDER, 0);
+	if (!mbox->bd_pool) {
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	/* Create DMA pool for ring completion memory */
+	mbox->cmpl_pool = dma_pool_create("cmpl", dev, RING_CMPL_SIZE,
+					  1 << RING_CMPL_ALIGN_ORDER, 0);
+	if (!mbox->cmpl_pool) {
+		ret = -ENOMEM;
+		goto fail_destroy_bd_pool;
+	}
+
+	/* Allocate platform MSIs for each ring */
+	ret = platform_msi_domain_alloc_irqs(dev, mbox->num_rings,
+						flexrm_mbox_msi_write);
+	if (ret)
+		goto fail_destroy_cmpl_pool;
+
+	/* Save alloced IRQ numbers for each ring */
+	for (index = 0; index < mbox->num_rings; index++)
+		mbox->rings[index].irq = msi_get_virq(dev, index);
+
+	/* Check availability of debugfs */
+	if (!debugfs_initialized())
+		goto skip_debugfs;
+
+	/* Create debugfs root entry */
+	mbox->root = debugfs_create_dir(dev_name(mbox->dev), NULL);
+
+	/* Create debugfs config entry */
+	debugfs_create_devm_seqfile(mbox->dev, "config", mbox->root,
+				    flexrm_debugfs_conf_show);
+
+	/* Create debugfs stats entry */
+	debugfs_create_devm_seqfile(mbox->dev, "stats", mbox->root,
+				    flexrm_debugfs_stats_show);
+
+skip_debugfs:
+
+	/* Initialize mailbox controller */
+	mbox->controller.txdone_irq = false;
+	mbox->controller.txdone_poll = false;
+	mbox->controller.ops = &flexrm_mbox_chan_ops;
+	mbox->controller.dev = dev;
+	mbox->controller.num_chans = mbox->num_rings;
+	mbox->controller.of_xlate = flexrm_mbox_of_xlate;
+	mbox->controller.chans = devm_kcalloc(dev, mbox->num_rings,
+				sizeof(*mbox->controller.chans), GFP_KERNEL);
+	if (!mbox->controller.chans) {
+		ret = -ENOMEM;
+		goto fail_free_debugfs_root;
+	}
+	for (index = 0; index < mbox->num_rings; index++)
+		mbox->controller.chans[index].con_priv = &mbox->rings[index];
+
+	/* Register mailbox controller */
+	ret = devm_mbox_controller_register(dev, &mbox->controller);
+	if (ret)
+		goto fail_free_debugfs_root;
+
+	dev_info(dev, "registered flexrm mailbox with %d channels\n",
+			mbox->controller.num_chans);
+
+	return 0;
+
+fail_free_debugfs_root:
+	debugfs_remove_recursive(mbox->root);
+	platform_msi_domain_free_irqs(dev);
+fail_destroy_cmpl_pool:
+	dma_pool_destroy(mbox->cmpl_pool);
+fail_destroy_bd_pool:
+	dma_pool_destroy(mbox->bd_pool);
+fail:
+	return ret;
+}
+
+static int flexrm_mbox_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct flexrm_mbox *mbox = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(mbox->root);
+
+	platform_msi_domain_free_irqs(dev);
+
+	dma_pool_destroy(mbox->cmpl_pool);
+	dma_pool_destroy(mbox->bd_pool);
+
+	return 0;
+}
+
+static const struct of_device_id flexrm_mbox_of_match[] = {
+	{ .compatible = "brcm,iproc-flexrm-mbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, flexrm_mbox_of_match);
+
+static struct platform_driver flexrm_mbox_driver = {
+	.driver = {
+		.name = "brcm-flexrm-mbox",
+		.of_match_table = flexrm_mbox_of_match,
+	},
+	.probe		= flexrm_mbox_probe,
+	.remove		= flexrm_mbox_remove,
+};
+module_platform_driver(flexrm_mbox_driver);
+
+MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom FlexRM mailbox driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/bcm-pdc-mailbox.c b/drivers/mailbox/bcm-pdc-mailbox.c
new file mode 100644
index 000000000..8d3a4c1fe
--- /dev/null
+++ b/drivers/mailbox/bcm-pdc-mailbox.c
@@ -0,0 +1,1645 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2016 Broadcom
+ */
+
+/*
+ * Broadcom PDC Mailbox Driver
+ * The PDC provides a ring based programming interface to one or more hardware
+ * offload engines. For example, the PDC driver works with both SPU-M and SPU2
+ * cryptographic offload hardware. In some chips the PDC is referred to as MDE,
+ * and in others the FA2/FA+ hardware is used with this PDC driver.
+ *
+ * The PDC driver registers with the Linux mailbox framework as a mailbox
+ * controller, once for each PDC instance. Ring 0 for each PDC is registered as
+ * a mailbox channel. The PDC driver uses interrupts to determine when data
+ * transfers to and from an offload engine are complete. The PDC driver uses
+ * threaded IRQs so that response messages are handled outside of interrupt
+ * context.
+ *
+ * The PDC driver allows multiple messages to be pending in the descriptor
+ * rings. The tx_msg_start descriptor index indicates where the last message
+ * starts. The txin_numd value at this index indicates how many descriptor
+ * indexes make up the message. Similar state is kept on the receive side. When
+ * an rx interrupt indicates a response is ready, the PDC driver processes numd
+ * descriptors from the tx and rx ring, thus processing one response at a time.
+ */
+
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/wait.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/brcm-message.h>
+#include <linux/scatterlist.h>
+#include <linux/dma-direction.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+
+#define PDC_SUCCESS  0
+
+#define RING_ENTRY_SIZE   sizeof(struct dma64dd)
+
+/* # entries in PDC dma ring */
+#define PDC_RING_ENTRIES  512
+/*
+ * Minimum number of ring descriptor entries that must be free to tell mailbox
+ * framework that it can submit another request
+ */
+#define PDC_RING_SPACE_MIN  15
+
+#define PDC_RING_SIZE    (PDC_RING_ENTRIES * RING_ENTRY_SIZE)
+/* Rings are 8k aligned */
+#define RING_ALIGN_ORDER  13
+#define RING_ALIGN        BIT(RING_ALIGN_ORDER)
+
+#define RX_BUF_ALIGN_ORDER  5
+#define RX_BUF_ALIGN	    BIT(RX_BUF_ALIGN_ORDER)
+
+/* descriptor bumping macros */
+#define XXD(x, max_mask)              ((x) & (max_mask))
+#define TXD(x, max_mask)              XXD((x), (max_mask))
+#define RXD(x, max_mask)              XXD((x), (max_mask))
+#define NEXTTXD(i, max_mask)          TXD((i) + 1, (max_mask))
+#define PREVTXD(i, max_mask)          TXD((i) - 1, (max_mask))
+#define NEXTRXD(i, max_mask)          RXD((i) + 1, (max_mask))
+#define PREVRXD(i, max_mask)          RXD((i) - 1, (max_mask))
+#define NTXDACTIVE(h, t, max_mask)    TXD((t) - (h), (max_mask))
+#define NRXDACTIVE(h, t, max_mask)    RXD((t) - (h), (max_mask))
+
+/* Length of BCM header at start of SPU msg, in bytes */
+#define BCM_HDR_LEN  8
+
+/*
+ * PDC driver reserves ringset 0 on each SPU for its own use. The driver does
+ * not currently support use of multiple ringsets on a single PDC engine.
+ */
+#define PDC_RINGSET  0
+
+/*
+ * Interrupt mask and status definitions. Enable interrupts for tx and rx on
+ * ring 0
+ */
+#define PDC_RCVINT_0         (16 + PDC_RINGSET)
+#define PDC_RCVINTEN_0       BIT(PDC_RCVINT_0)
+#define PDC_INTMASK	     (PDC_RCVINTEN_0)
+#define PDC_LAZY_FRAMECOUNT  1
+#define PDC_LAZY_TIMEOUT     10000
+#define PDC_LAZY_INT  (PDC_LAZY_TIMEOUT | (PDC_LAZY_FRAMECOUNT << 24))
+#define PDC_INTMASK_OFFSET   0x24
+#define PDC_INTSTATUS_OFFSET 0x20
+#define PDC_RCVLAZY0_OFFSET  (0x30 + 4 * PDC_RINGSET)
+#define FA_RCVLAZY0_OFFSET   0x100
+
+/*
+ * For SPU2, configure MDE_CKSUM_CONTROL to write 17 bytes of metadata
+ * before frame
+ */
+#define PDC_SPU2_RESP_HDR_LEN  17
+#define PDC_CKSUM_CTRL         BIT(27)
+#define PDC_CKSUM_CTRL_OFFSET  0x400
+
+#define PDC_SPUM_RESP_HDR_LEN  32
+
+/*
+ * Sets the following bits for write to transmit control reg:
+ * 11    - PtyChkDisable - parity check is disabled
+ * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory
+ */
+#define PDC_TX_CTL		0x000C0800
+
+/* Bit in tx control reg to enable tx channel */
+#define PDC_TX_ENABLE		0x1
+
+/*
+ * Sets the following bits for write to receive control reg:
+ * 7:1   - RcvOffset - size in bytes of status region at start of rx frame buf
+ * 9     - SepRxHdrDescEn - place start of new frames only in descriptors
+ *                          that have StartOfFrame set
+ * 10    - OflowContinue - on rx FIFO overflow, clear rx fifo, discard all
+ *                         remaining bytes in current frame, report error
+ *                         in rx frame status for current frame
+ * 11    - PtyChkDisable - parity check is disabled
+ * 20:18 - BurstLen = 3 -> 2^7 = 128 byte data reads from memory
+ */
+#define PDC_RX_CTL		0x000C0E00
+
+/* Bit in rx control reg to enable rx channel */
+#define PDC_RX_ENABLE		0x1
+
+#define CRYPTO_D64_RS0_CD_MASK   ((PDC_RING_ENTRIES * RING_ENTRY_SIZE) - 1)
+
+/* descriptor flags */
+#define D64_CTRL1_EOT   BIT(28)	/* end of descriptor table */
+#define D64_CTRL1_IOC   BIT(29)	/* interrupt on complete */
+#define D64_CTRL1_EOF   BIT(30)	/* end of frame */
+#define D64_CTRL1_SOF   BIT(31)	/* start of frame */
+
+#define RX_STATUS_OVERFLOW       0x00800000
+#define RX_STATUS_LEN            0x0000FFFF
+
+#define PDC_TXREGS_OFFSET  0x200
+#define PDC_RXREGS_OFFSET  0x220
+
+/* Maximum size buffer the DMA engine can handle */
+#define PDC_DMA_BUF_MAX 16384
+
+enum pdc_hw {
+	FA_HW,		/* FA2/FA+ hardware (i.e. Northstar Plus) */
+	PDC_HW		/* PDC/MDE hardware (i.e. Northstar 2, Pegasus) */
+};
+
+struct pdc_dma_map {
+	void *ctx;          /* opaque context associated with frame */
+};
+
+/* dma descriptor */
+struct dma64dd {
+	u32 ctrl1;      /* misc control bits */
+	u32 ctrl2;      /* buffer count and address extension */
+	u32 addrlow;    /* memory address of the date buffer, bits 31:0 */
+	u32 addrhigh;   /* memory address of the date buffer, bits 63:32 */
+};
+
+/* dma registers per channel(xmt or rcv) */
+struct dma64_regs {
+	u32  control;   /* enable, et al */
+	u32  ptr;       /* last descriptor posted to chip */
+	u32  addrlow;   /* descriptor ring base address low 32-bits */
+	u32  addrhigh;  /* descriptor ring base address bits 63:32 */
+	u32  status0;   /* last rx descriptor written by hw */
+	u32  status1;   /* driver does not use */
+};
+
+/* cpp contortions to concatenate w/arg prescan */
+#ifndef PAD
+#define _PADLINE(line)  pad ## line
+#define _XSTR(line)     _PADLINE(line)
+#define PAD             _XSTR(__LINE__)
+#endif  /* PAD */
+
+/* dma registers. matches hw layout. */
+struct dma64 {
+	struct dma64_regs dmaxmt;  /* dma tx */
+	u32          PAD[2];
+	struct dma64_regs dmarcv;  /* dma rx */
+	u32          PAD[2];
+};
+
+/* PDC registers */
+struct pdc_regs {
+	u32  devcontrol;             /* 0x000 */
+	u32  devstatus;              /* 0x004 */
+	u32  PAD;
+	u32  biststatus;             /* 0x00c */
+	u32  PAD[4];
+	u32  intstatus;              /* 0x020 */
+	u32  intmask;                /* 0x024 */
+	u32  gptimer;                /* 0x028 */
+
+	u32  PAD;
+	u32  intrcvlazy_0;           /* 0x030 (Only in PDC, not FA2) */
+	u32  intrcvlazy_1;           /* 0x034 (Only in PDC, not FA2) */
+	u32  intrcvlazy_2;           /* 0x038 (Only in PDC, not FA2) */
+	u32  intrcvlazy_3;           /* 0x03c (Only in PDC, not FA2) */
+
+	u32  PAD[48];
+	u32  fa_intrecvlazy;         /* 0x100 (Only in FA2, not PDC) */
+	u32  flowctlthresh;          /* 0x104 */
+	u32  wrrthresh;              /* 0x108 */
+	u32  gmac_idle_cnt_thresh;   /* 0x10c */
+
+	u32  PAD[4];
+	u32  ifioaccessaddr;         /* 0x120 */
+	u32  ifioaccessbyte;         /* 0x124 */
+	u32  ifioaccessdata;         /* 0x128 */
+
+	u32  PAD[21];
+	u32  phyaccess;              /* 0x180 */
+	u32  PAD;
+	u32  phycontrol;             /* 0x188 */
+	u32  txqctl;                 /* 0x18c */
+	u32  rxqctl;                 /* 0x190 */
+	u32  gpioselect;             /* 0x194 */
+	u32  gpio_output_en;         /* 0x198 */
+	u32  PAD;                    /* 0x19c */
+	u32  txq_rxq_mem_ctl;        /* 0x1a0 */
+	u32  memory_ecc_status;      /* 0x1a4 */
+	u32  serdes_ctl;             /* 0x1a8 */
+	u32  serdes_status0;         /* 0x1ac */
+	u32  serdes_status1;         /* 0x1b0 */
+	u32  PAD[11];                /* 0x1b4-1dc */
+	u32  clk_ctl_st;             /* 0x1e0 */
+	u32  hw_war;                 /* 0x1e4 (Only in PDC, not FA2) */
+	u32  pwrctl;                 /* 0x1e8 */
+	u32  PAD[5];
+
+#define PDC_NUM_DMA_RINGS   4
+	struct dma64 dmaregs[PDC_NUM_DMA_RINGS];  /* 0x0200 - 0x2fc */
+
+	/* more registers follow, but we don't use them */
+};
+
+/* structure for allocating/freeing DMA rings */
+struct pdc_ring_alloc {
+	dma_addr_t  dmabase; /* DMA address of start of ring */
+	void	   *vbase;   /* base kernel virtual address of ring */
+	u32	    size;    /* ring allocation size in bytes */
+};
+
+/*
+ * context associated with a receive descriptor.
+ * @rxp_ctx: opaque context associated with frame that starts at each
+ *           rx ring index.
+ * @dst_sg:  Scatterlist used to form reply frames beginning at a given ring
+ *           index. Retained in order to unmap each sg after reply is processed.
+ * @rxin_numd: Number of rx descriptors associated with the message that starts
+ *             at a descriptor index. Not set for every index. For example,
+ *             if descriptor index i points to a scatterlist with 4 entries,
+ *             then the next three descriptor indexes don't have a value set.
+ * @resp_hdr: Virtual address of buffer used to catch DMA rx status
+ * @resp_hdr_daddr: physical address of DMA rx status buffer
+ */
+struct pdc_rx_ctx {
+	void *rxp_ctx;
+	struct scatterlist *dst_sg;
+	u32  rxin_numd;
+	void *resp_hdr;
+	dma_addr_t resp_hdr_daddr;
+};
+
+/* PDC state structure */
+struct pdc_state {
+	/* Index of the PDC whose state is in this structure instance */
+	u8 pdc_idx;
+
+	/* Platform device for this PDC instance */
+	struct platform_device *pdev;
+
+	/*
+	 * Each PDC instance has a mailbox controller. PDC receives request
+	 * messages through mailboxes, and sends response messages through the
+	 * mailbox framework.
+	 */
+	struct mbox_controller mbc;
+
+	unsigned int pdc_irq;
+
+	/* tasklet for deferred processing after DMA rx interrupt */
+	struct tasklet_struct rx_tasklet;
+
+	/* Number of bytes of receive status prior to each rx frame */
+	u32 rx_status_len;
+	/* Whether a BCM header is prepended to each frame */
+	bool use_bcm_hdr;
+	/* Sum of length of BCM header and rx status header */
+	u32 pdc_resp_hdr_len;
+
+	/* The base virtual address of DMA hw registers */
+	void __iomem *pdc_reg_vbase;
+
+	/* Pool for allocation of DMA rings */
+	struct dma_pool *ring_pool;
+
+	/* Pool for allocation of metadata buffers for response messages */
+	struct dma_pool *rx_buf_pool;
+
+	/*
+	 * The base virtual address of DMA tx/rx descriptor rings. Corresponding
+	 * DMA address and size of ring allocation.
+	 */
+	struct pdc_ring_alloc tx_ring_alloc;
+	struct pdc_ring_alloc rx_ring_alloc;
+
+	struct pdc_regs *regs;    /* start of PDC registers */
+
+	struct dma64_regs *txregs_64; /* dma tx engine registers */
+	struct dma64_regs *rxregs_64; /* dma rx engine registers */
+
+	/*
+	 * Arrays of PDC_RING_ENTRIES descriptors
+	 * To use multiple ringsets, this needs to be extended
+	 */
+	struct dma64dd   *txd_64;  /* tx descriptor ring */
+	struct dma64dd   *rxd_64;  /* rx descriptor ring */
+
+	/* descriptor ring sizes */
+	u32      ntxd;       /* # tx descriptors */
+	u32      nrxd;       /* # rx descriptors */
+	u32      nrxpost;    /* # rx buffers to keep posted */
+	u32      ntxpost;    /* max number of tx buffers that can be posted */
+
+	/*
+	 * Index of next tx descriptor to reclaim. That is, the descriptor
+	 * index of the oldest tx buffer for which the host has yet to process
+	 * the corresponding response.
+	 */
+	u32  txin;
+
+	/*
+	 * Index of the first receive descriptor for the sequence of
+	 * message fragments currently under construction. Used to build up
+	 * the rxin_numd count for a message. Updated to rxout when the host
+	 * starts a new sequence of rx buffers for a new message.
+	 */
+	u32  tx_msg_start;
+
+	/* Index of next tx descriptor to post. */
+	u32  txout;
+
+	/*
+	 * Number of tx descriptors associated with the message that starts
+	 * at this tx descriptor index.
+	 */
+	u32      txin_numd[PDC_RING_ENTRIES];
+
+	/*
+	 * Index of next rx descriptor to reclaim. This is the index of
+	 * the next descriptor whose data has yet to be processed by the host.
+	 */
+	u32  rxin;
+
+	/*
+	 * Index of the first receive descriptor for the sequence of
+	 * message fragments currently under construction. Used to build up
+	 * the rxin_numd count for a message. Updated to rxout when the host
+	 * starts a new sequence of rx buffers for a new message.
+	 */
+	u32  rx_msg_start;
+
+	/*
+	 * Saved value of current hardware rx descriptor index.
+	 * The last rx buffer written by the hw is the index previous to
+	 * this one.
+	 */
+	u32  last_rx_curr;
+
+	/* Index of next rx descriptor to post. */
+	u32  rxout;
+
+	struct pdc_rx_ctx rx_ctx[PDC_RING_ENTRIES];
+
+	/*
+	 * Scatterlists used to form request and reply frames beginning at a
+	 * given ring index. Retained in order to unmap each sg after reply
+	 * is processed
+	 */
+	struct scatterlist *src_sg[PDC_RING_ENTRIES];
+
+	/* counters */
+	u32  pdc_requests;     /* number of request messages submitted */
+	u32  pdc_replies;      /* number of reply messages received */
+	u32  last_tx_not_done; /* too few tx descriptors to indicate done */
+	u32  tx_ring_full;     /* unable to accept msg because tx ring full */
+	u32  rx_ring_full;     /* unable to accept msg because rx ring full */
+	u32  txnobuf;          /* unable to create tx descriptor */
+	u32  rxnobuf;          /* unable to create rx descriptor */
+	u32  rx_oflow;         /* count of rx overflows */
+
+	/* hardware type - FA2 or PDC/MDE */
+	enum pdc_hw hw_type;
+};
+
+/* Global variables */
+
+struct pdc_globals {
+	/* Actual number of SPUs in hardware, as reported by device tree */
+	u32 num_spu;
+};
+
+static struct pdc_globals pdcg;
+
+/* top level debug FS directory for PDC driver */
+static struct dentry *debugfs_dir;
+
+static ssize_t pdc_debugfs_read(struct file *filp, char __user *ubuf,
+				size_t count, loff_t *offp)
+{
+	struct pdc_state *pdcs;
+	char *buf;
+	ssize_t ret, out_offset, out_count;
+
+	out_count = 512;
+
+	buf = kmalloc(out_count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	pdcs = filp->private_data;
+	out_offset = 0;
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "SPU %u stats:\n", pdcs->pdc_idx);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "PDC requests....................%u\n",
+			       pdcs->pdc_requests);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "PDC responses...................%u\n",
+			       pdcs->pdc_replies);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Tx not done.....................%u\n",
+			       pdcs->last_tx_not_done);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Tx ring full....................%u\n",
+			       pdcs->tx_ring_full);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Rx ring full....................%u\n",
+			       pdcs->rx_ring_full);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Tx desc write fail. Ring full...%u\n",
+			       pdcs->txnobuf);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Rx desc write fail. Ring full...%u\n",
+			       pdcs->rxnobuf);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Receive overflow................%u\n",
+			       pdcs->rx_oflow);
+	out_offset += scnprintf(buf + out_offset, out_count - out_offset,
+			       "Num frags in rx ring............%u\n",
+			       NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr,
+					  pdcs->nrxpost));
+
+	if (out_offset > out_count)
+		out_offset = out_count;
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset);
+	kfree(buf);
+	return ret;
+}
+
+static const struct file_operations pdc_debugfs_stats = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = pdc_debugfs_read,
+};
+
+/**
+ * pdc_setup_debugfs() - Create the debug FS directories. If the top-level
+ * directory has not yet been created, create it now. Create a stats file in
+ * this directory for a SPU.
+ * @pdcs: PDC state structure
+ */
+static void pdc_setup_debugfs(struct pdc_state *pdcs)
+{
+	char spu_stats_name[16];
+
+	if (!debugfs_initialized())
+		return;
+
+	snprintf(spu_stats_name, 16, "pdc%d_stats", pdcs->pdc_idx);
+	if (!debugfs_dir)
+		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	/* S_IRUSR == 0400 */
+	debugfs_create_file(spu_stats_name, 0400, debugfs_dir, pdcs,
+			    &pdc_debugfs_stats);
+}
+
+static void pdc_free_debugfs(void)
+{
+	debugfs_remove_recursive(debugfs_dir);
+	debugfs_dir = NULL;
+}
+
+/**
+ * pdc_build_rxd() - Build DMA descriptor to receive SPU result.
+ * @pdcs:      PDC state for SPU that will generate result
+ * @dma_addr:  DMA address of buffer that descriptor is being built for
+ * @buf_len:   Length of the receive buffer, in bytes
+ * @flags:     Flags to be stored in descriptor
+ */
+static inline void
+pdc_build_rxd(struct pdc_state *pdcs, dma_addr_t dma_addr,
+	      u32 buf_len, u32 flags)
+{
+	struct device *dev = &pdcs->pdev->dev;
+	struct dma64dd *rxd = &pdcs->rxd_64[pdcs->rxout];
+
+	dev_dbg(dev,
+		"Writing rx descriptor for PDC %u at index %u with length %u. flags %#x\n",
+		pdcs->pdc_idx, pdcs->rxout, buf_len, flags);
+
+	rxd->addrlow = cpu_to_le32(lower_32_bits(dma_addr));
+	rxd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr));
+	rxd->ctrl1 = cpu_to_le32(flags);
+	rxd->ctrl2 = cpu_to_le32(buf_len);
+
+	/* bump ring index and return */
+	pdcs->rxout = NEXTRXD(pdcs->rxout, pdcs->nrxpost);
+}
+
+/**
+ * pdc_build_txd() - Build a DMA descriptor to transmit a SPU request to
+ * hardware.
+ * @pdcs:        PDC state for the SPU that will process this request
+ * @dma_addr:    DMA address of packet to be transmitted
+ * @buf_len:     Length of tx buffer, in bytes
+ * @flags:       Flags to be stored in descriptor
+ */
+static inline void
+pdc_build_txd(struct pdc_state *pdcs, dma_addr_t dma_addr, u32 buf_len,
+	      u32 flags)
+{
+	struct device *dev = &pdcs->pdev->dev;
+	struct dma64dd *txd = &pdcs->txd_64[pdcs->txout];
+
+	dev_dbg(dev,
+		"Writing tx descriptor for PDC %u at index %u with length %u, flags %#x\n",
+		pdcs->pdc_idx, pdcs->txout, buf_len, flags);
+
+	txd->addrlow = cpu_to_le32(lower_32_bits(dma_addr));
+	txd->addrhigh = cpu_to_le32(upper_32_bits(dma_addr));
+	txd->ctrl1 = cpu_to_le32(flags);
+	txd->ctrl2 = cpu_to_le32(buf_len);
+
+	/* bump ring index and return */
+	pdcs->txout = NEXTTXD(pdcs->txout, pdcs->ntxpost);
+}
+
+/**
+ * pdc_receive_one() - Receive a response message from a given SPU.
+ * @pdcs:    PDC state for the SPU to receive from
+ *
+ * When the return code indicates success, the response message is available in
+ * the receive buffers provided prior to submission of the request.
+ *
+ * Return:  PDC_SUCCESS if one or more receive descriptors was processed
+ *          -EAGAIN indicates that no response message is available
+ *          -EIO an error occurred
+ */
+static int
+pdc_receive_one(struct pdc_state *pdcs)
+{
+	struct device *dev = &pdcs->pdev->dev;
+	struct mbox_controller *mbc;
+	struct mbox_chan *chan;
+	struct brcm_message mssg;
+	u32 len, rx_status;
+	u32 num_frags;
+	u8 *resp_hdr;    /* virtual addr of start of resp message DMA header */
+	u32 frags_rdy;   /* number of fragments ready to read */
+	u32 rx_idx;      /* ring index of start of receive frame */
+	dma_addr_t resp_hdr_daddr;
+	struct pdc_rx_ctx *rx_ctx;
+
+	mbc = &pdcs->mbc;
+	chan = &mbc->chans[0];
+	mssg.type = BRCM_MESSAGE_SPU;
+
+	/*
+	 * return if a complete response message is not yet ready.
+	 * rxin_numd[rxin] is the number of fragments in the next msg
+	 * to read.
+	 */
+	frags_rdy = NRXDACTIVE(pdcs->rxin, pdcs->last_rx_curr, pdcs->nrxpost);
+	if ((frags_rdy == 0) ||
+	    (frags_rdy < pdcs->rx_ctx[pdcs->rxin].rxin_numd))
+		/* No response ready */
+		return -EAGAIN;
+
+	num_frags = pdcs->txin_numd[pdcs->txin];
+	WARN_ON(num_frags == 0);
+
+	dma_unmap_sg(dev, pdcs->src_sg[pdcs->txin],
+		     sg_nents(pdcs->src_sg[pdcs->txin]), DMA_TO_DEVICE);
+
+	pdcs->txin = (pdcs->txin + num_frags) & pdcs->ntxpost;
+
+	dev_dbg(dev, "PDC %u reclaimed %d tx descriptors",
+		pdcs->pdc_idx, num_frags);
+
+	rx_idx = pdcs->rxin;
+	rx_ctx = &pdcs->rx_ctx[rx_idx];
+	num_frags = rx_ctx->rxin_numd;
+	/* Return opaque context with result */
+	mssg.ctx = rx_ctx->rxp_ctx;
+	rx_ctx->rxp_ctx = NULL;
+	resp_hdr = rx_ctx->resp_hdr;
+	resp_hdr_daddr = rx_ctx->resp_hdr_daddr;
+	dma_unmap_sg(dev, rx_ctx->dst_sg, sg_nents(rx_ctx->dst_sg),
+		     DMA_FROM_DEVICE);
+
+	pdcs->rxin = (pdcs->rxin + num_frags) & pdcs->nrxpost;
+
+	dev_dbg(dev, "PDC %u reclaimed %d rx descriptors",
+		pdcs->pdc_idx, num_frags);
+
+	dev_dbg(dev,
+		"PDC %u txin %u, txout %u, rxin %u, rxout %u, last_rx_curr %u\n",
+		pdcs->pdc_idx, pdcs->txin, pdcs->txout, pdcs->rxin,
+		pdcs->rxout, pdcs->last_rx_curr);
+
+	if (pdcs->pdc_resp_hdr_len == PDC_SPUM_RESP_HDR_LEN) {
+		/*
+		 * For SPU-M, get length of response msg and rx overflow status.
+		 */
+		rx_status = *((u32 *)resp_hdr);
+		len = rx_status & RX_STATUS_LEN;
+		dev_dbg(dev,
+			"SPU response length %u bytes", len);
+		if (unlikely(((rx_status & RX_STATUS_OVERFLOW) || (!len)))) {
+			if (rx_status & RX_STATUS_OVERFLOW) {
+				dev_err_ratelimited(dev,
+						    "crypto receive overflow");
+				pdcs->rx_oflow++;
+			} else {
+				dev_info_ratelimited(dev, "crypto rx len = 0");
+			}
+			return -EIO;
+		}
+	}
+
+	dma_pool_free(pdcs->rx_buf_pool, resp_hdr, resp_hdr_daddr);
+
+	mbox_chan_received_data(chan, &mssg);
+
+	pdcs->pdc_replies++;
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_receive() - Process as many responses as are available in the rx ring.
+ * @pdcs:  PDC state
+ *
+ * Called within the hard IRQ.
+ * Return:
+ */
+static int
+pdc_receive(struct pdc_state *pdcs)
+{
+	int rx_status;
+
+	/* read last_rx_curr from register once */
+	pdcs->last_rx_curr =
+	    (ioread32((const void __iomem *)&pdcs->rxregs_64->status0) &
+	     CRYPTO_D64_RS0_CD_MASK) / RING_ENTRY_SIZE;
+
+	do {
+		/* Could be many frames ready */
+		rx_status = pdc_receive_one(pdcs);
+	} while (rx_status == PDC_SUCCESS);
+
+	return 0;
+}
+
+/**
+ * pdc_tx_list_sg_add() - Add the buffers in a scatterlist to the transmit
+ * descriptors for a given SPU. The scatterlist buffers contain the data for a
+ * SPU request message.
+ * @spu_idx:   The index of the SPU to submit the request to, [0, max_spu)
+ * @sg:        Scatterlist whose buffers contain part of the SPU request
+ *
+ * If a scatterlist buffer is larger than PDC_DMA_BUF_MAX, multiple descriptors
+ * are written for that buffer, each <= PDC_DMA_BUF_MAX byte in length.
+ *
+ * Return: PDC_SUCCESS if successful
+ *         < 0 otherwise
+ */
+static int pdc_tx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg)
+{
+	u32 flags = 0;
+	u32 eot;
+	u32 tx_avail;
+
+	/*
+	 * Num descriptors needed. Conservatively assume we need a descriptor
+	 * for every entry in sg.
+	 */
+	u32 num_desc;
+	u32 desc_w = 0;	/* Number of tx descriptors written */
+	u32 bufcnt;	/* Number of bytes of buffer pointed to by descriptor */
+	dma_addr_t databufptr;	/* DMA address to put in descriptor */
+
+	num_desc = (u32)sg_nents(sg);
+
+	/* check whether enough tx descriptors are available */
+	tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout,
+					      pdcs->ntxpost);
+	if (unlikely(num_desc > tx_avail)) {
+		pdcs->txnobuf++;
+		return -ENOSPC;
+	}
+
+	/* build tx descriptors */
+	if (pdcs->tx_msg_start == pdcs->txout) {
+		/* Start of frame */
+		pdcs->txin_numd[pdcs->tx_msg_start] = 0;
+		pdcs->src_sg[pdcs->txout] = sg;
+		flags = D64_CTRL1_SOF;
+	}
+
+	while (sg) {
+		if (unlikely(pdcs->txout == (pdcs->ntxd - 1)))
+			eot = D64_CTRL1_EOT;
+		else
+			eot = 0;
+
+		/*
+		 * If sg buffer larger than PDC limit, split across
+		 * multiple descriptors
+		 */
+		bufcnt = sg_dma_len(sg);
+		databufptr = sg_dma_address(sg);
+		while (bufcnt > PDC_DMA_BUF_MAX) {
+			pdc_build_txd(pdcs, databufptr, PDC_DMA_BUF_MAX,
+				      flags | eot);
+			desc_w++;
+			bufcnt -= PDC_DMA_BUF_MAX;
+			databufptr += PDC_DMA_BUF_MAX;
+			if (unlikely(pdcs->txout == (pdcs->ntxd - 1)))
+				eot = D64_CTRL1_EOT;
+			else
+				eot = 0;
+		}
+		sg = sg_next(sg);
+		if (!sg)
+			/* Writing last descriptor for frame */
+			flags |= (D64_CTRL1_EOF | D64_CTRL1_IOC);
+		pdc_build_txd(pdcs, databufptr, bufcnt, flags | eot);
+		desc_w++;
+		/* Clear start of frame after first descriptor */
+		flags &= ~D64_CTRL1_SOF;
+	}
+	pdcs->txin_numd[pdcs->tx_msg_start] += desc_w;
+
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_tx_list_final() - Initiate DMA transfer of last frame written to tx
+ * ring.
+ * @pdcs:  PDC state for SPU to process the request
+ *
+ * Sets the index of the last descriptor written in both the rx and tx ring.
+ *
+ * Return: PDC_SUCCESS
+ */
+static int pdc_tx_list_final(struct pdc_state *pdcs)
+{
+	/*
+	 * write barrier to ensure all register writes are complete
+	 * before chip starts to process new request
+	 */
+	wmb();
+	iowrite32(pdcs->rxout << 4, &pdcs->rxregs_64->ptr);
+	iowrite32(pdcs->txout << 4, &pdcs->txregs_64->ptr);
+	pdcs->pdc_requests++;
+
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_rx_list_init() - Start a new receive descriptor list for a given PDC.
+ * @pdcs:   PDC state for SPU handling request
+ * @dst_sg: scatterlist providing rx buffers for response to be returned to
+ *	    mailbox client
+ * @ctx:    Opaque context for this request
+ *
+ * Posts a single receive descriptor to hold the metadata that precedes a
+ * response. For example, with SPU-M, the metadata is a 32-byte DMA header and
+ * an 8-byte BCM header. Moves the msg_start descriptor indexes for both tx and
+ * rx to indicate the start of a new message.
+ *
+ * Return:  PDC_SUCCESS if successful
+ *          < 0 if an error (e.g., rx ring is full)
+ */
+static int pdc_rx_list_init(struct pdc_state *pdcs, struct scatterlist *dst_sg,
+			    void *ctx)
+{
+	u32 flags = 0;
+	u32 rx_avail;
+	u32 rx_pkt_cnt = 1;	/* Adding a single rx buffer */
+	dma_addr_t daddr;
+	void *vaddr;
+	struct pdc_rx_ctx *rx_ctx;
+
+	rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+					      pdcs->nrxpost);
+	if (unlikely(rx_pkt_cnt > rx_avail)) {
+		pdcs->rxnobuf++;
+		return -ENOSPC;
+	}
+
+	/* allocate a buffer for the dma rx status */
+	vaddr = dma_pool_zalloc(pdcs->rx_buf_pool, GFP_ATOMIC, &daddr);
+	if (unlikely(!vaddr))
+		return -ENOMEM;
+
+	/*
+	 * Update msg_start indexes for both tx and rx to indicate the start
+	 * of a new sequence of descriptor indexes that contain the fragments
+	 * of the same message.
+	 */
+	pdcs->rx_msg_start = pdcs->rxout;
+	pdcs->tx_msg_start = pdcs->txout;
+
+	/* This is always the first descriptor in the receive sequence */
+	flags = D64_CTRL1_SOF;
+	pdcs->rx_ctx[pdcs->rx_msg_start].rxin_numd = 1;
+
+	if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+		flags |= D64_CTRL1_EOT;
+
+	rx_ctx = &pdcs->rx_ctx[pdcs->rxout];
+	rx_ctx->rxp_ctx = ctx;
+	rx_ctx->dst_sg = dst_sg;
+	rx_ctx->resp_hdr = vaddr;
+	rx_ctx->resp_hdr_daddr = daddr;
+	pdc_build_rxd(pdcs, daddr, pdcs->pdc_resp_hdr_len, flags);
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_rx_list_sg_add() - Add the buffers in a scatterlist to the receive
+ * descriptors for a given SPU. The caller must have already DMA mapped the
+ * scatterlist.
+ * @spu_idx:    Indicates which SPU the buffers are for
+ * @sg:         Scatterlist whose buffers are added to the receive ring
+ *
+ * If a receive buffer in the scatterlist is larger than PDC_DMA_BUF_MAX,
+ * multiple receive descriptors are written, each with a buffer <=
+ * PDC_DMA_BUF_MAX.
+ *
+ * Return: PDC_SUCCESS if successful
+ *         < 0 otherwise (e.g., receive ring is full)
+ */
+static int pdc_rx_list_sg_add(struct pdc_state *pdcs, struct scatterlist *sg)
+{
+	u32 flags = 0;
+	u32 rx_avail;
+
+	/*
+	 * Num descriptors needed. Conservatively assume we need a descriptor
+	 * for every entry from our starting point in the scatterlist.
+	 */
+	u32 num_desc;
+	u32 desc_w = 0;	/* Number of tx descriptors written */
+	u32 bufcnt;	/* Number of bytes of buffer pointed to by descriptor */
+	dma_addr_t databufptr;	/* DMA address to put in descriptor */
+
+	num_desc = (u32)sg_nents(sg);
+
+	rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+					      pdcs->nrxpost);
+	if (unlikely(num_desc > rx_avail)) {
+		pdcs->rxnobuf++;
+		return -ENOSPC;
+	}
+
+	while (sg) {
+		if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+			flags = D64_CTRL1_EOT;
+		else
+			flags = 0;
+
+		/*
+		 * If sg buffer larger than PDC limit, split across
+		 * multiple descriptors
+		 */
+		bufcnt = sg_dma_len(sg);
+		databufptr = sg_dma_address(sg);
+		while (bufcnt > PDC_DMA_BUF_MAX) {
+			pdc_build_rxd(pdcs, databufptr, PDC_DMA_BUF_MAX, flags);
+			desc_w++;
+			bufcnt -= PDC_DMA_BUF_MAX;
+			databufptr += PDC_DMA_BUF_MAX;
+			if (unlikely(pdcs->rxout == (pdcs->nrxd - 1)))
+				flags = D64_CTRL1_EOT;
+			else
+				flags = 0;
+		}
+		pdc_build_rxd(pdcs, databufptr, bufcnt, flags);
+		desc_w++;
+		sg = sg_next(sg);
+	}
+	pdcs->rx_ctx[pdcs->rx_msg_start].rxin_numd += desc_w;
+
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_irq_handler() - Interrupt handler called in interrupt context.
+ * @irq:      Interrupt number that has fired
+ * @data:     device struct for DMA engine that generated the interrupt
+ *
+ * We have to clear the device interrupt status flags here. So cache the
+ * status for later use in the thread function. Other than that, just return
+ * WAKE_THREAD to invoke the thread function.
+ *
+ * Return: IRQ_WAKE_THREAD if interrupt is ours
+ *         IRQ_NONE otherwise
+ */
+static irqreturn_t pdc_irq_handler(int irq, void *data)
+{
+	struct device *dev = (struct device *)data;
+	struct pdc_state *pdcs = dev_get_drvdata(dev);
+	u32 intstatus = ioread32(pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
+
+	if (unlikely(intstatus == 0))
+		return IRQ_NONE;
+
+	/* Disable interrupts until soft handler runs */
+	iowrite32(0, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
+
+	/* Clear interrupt flags in device */
+	iowrite32(intstatus, pdcs->pdc_reg_vbase + PDC_INTSTATUS_OFFSET);
+
+	/* Wakeup IRQ thread */
+	tasklet_schedule(&pdcs->rx_tasklet);
+	return IRQ_HANDLED;
+}
+
+/**
+ * pdc_tasklet_cb() - Tasklet callback that runs the deferred processing after
+ * a DMA receive interrupt. Reenables the receive interrupt.
+ * @data: PDC state structure
+ */
+static void pdc_tasklet_cb(struct tasklet_struct *t)
+{
+	struct pdc_state *pdcs = from_tasklet(pdcs, t, rx_tasklet);
+
+	pdc_receive(pdcs);
+
+	/* reenable interrupts */
+	iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
+}
+
+/**
+ * pdc_ring_init() - Allocate DMA rings and initialize constant fields of
+ * descriptors in one ringset.
+ * @pdcs:    PDC instance state
+ * @ringset: index of ringset being used
+ *
+ * Return: PDC_SUCCESS if ring initialized
+ *         < 0 otherwise
+ */
+static int pdc_ring_init(struct pdc_state *pdcs, int ringset)
+{
+	int i;
+	int err = PDC_SUCCESS;
+	struct dma64 *dma_reg;
+	struct device *dev = &pdcs->pdev->dev;
+	struct pdc_ring_alloc tx;
+	struct pdc_ring_alloc rx;
+
+	/* Allocate tx ring */
+	tx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &tx.dmabase);
+	if (unlikely(!tx.vbase)) {
+		err = -ENOMEM;
+		goto done;
+	}
+
+	/* Allocate rx ring */
+	rx.vbase = dma_pool_zalloc(pdcs->ring_pool, GFP_KERNEL, &rx.dmabase);
+	if (unlikely(!rx.vbase)) {
+		err = -ENOMEM;
+		goto fail_dealloc;
+	}
+
+	dev_dbg(dev, " - base DMA addr of tx ring      %pad", &tx.dmabase);
+	dev_dbg(dev, " - base virtual addr of tx ring  %p", tx.vbase);
+	dev_dbg(dev, " - base DMA addr of rx ring      %pad", &rx.dmabase);
+	dev_dbg(dev, " - base virtual addr of rx ring  %p", rx.vbase);
+
+	memcpy(&pdcs->tx_ring_alloc, &tx, sizeof(tx));
+	memcpy(&pdcs->rx_ring_alloc, &rx, sizeof(rx));
+
+	pdcs->rxin = 0;
+	pdcs->rx_msg_start = 0;
+	pdcs->last_rx_curr = 0;
+	pdcs->rxout = 0;
+	pdcs->txin = 0;
+	pdcs->tx_msg_start = 0;
+	pdcs->txout = 0;
+
+	/* Set descriptor array base addresses */
+	pdcs->txd_64 = (struct dma64dd *)pdcs->tx_ring_alloc.vbase;
+	pdcs->rxd_64 = (struct dma64dd *)pdcs->rx_ring_alloc.vbase;
+
+	/* Tell device the base DMA address of each ring */
+	dma_reg = &pdcs->regs->dmaregs[ringset];
+
+	/* But first disable DMA and set curptr to 0 for both TX & RX */
+	iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
+	iowrite32((PDC_RX_CTL + (pdcs->rx_status_len << 1)),
+		  &dma_reg->dmarcv.control);
+	iowrite32(0, &dma_reg->dmaxmt.ptr);
+	iowrite32(0, &dma_reg->dmarcv.ptr);
+
+	/* Set base DMA addresses */
+	iowrite32(lower_32_bits(pdcs->tx_ring_alloc.dmabase),
+		  &dma_reg->dmaxmt.addrlow);
+	iowrite32(upper_32_bits(pdcs->tx_ring_alloc.dmabase),
+		  &dma_reg->dmaxmt.addrhigh);
+
+	iowrite32(lower_32_bits(pdcs->rx_ring_alloc.dmabase),
+		  &dma_reg->dmarcv.addrlow);
+	iowrite32(upper_32_bits(pdcs->rx_ring_alloc.dmabase),
+		  &dma_reg->dmarcv.addrhigh);
+
+	/* Re-enable DMA */
+	iowrite32(PDC_TX_CTL | PDC_TX_ENABLE, &dma_reg->dmaxmt.control);
+	iowrite32((PDC_RX_CTL | PDC_RX_ENABLE | (pdcs->rx_status_len << 1)),
+		  &dma_reg->dmarcv.control);
+
+	/* Initialize descriptors */
+	for (i = 0; i < PDC_RING_ENTRIES; i++) {
+		/* Every tx descriptor can be used for start of frame. */
+		if (i != pdcs->ntxpost) {
+			iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF,
+				  &pdcs->txd_64[i].ctrl1);
+		} else {
+			/* Last descriptor in ringset. Set End of Table. */
+			iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOF |
+				  D64_CTRL1_EOT, &pdcs->txd_64[i].ctrl1);
+		}
+
+		/* Every rx descriptor can be used for start of frame */
+		if (i != pdcs->nrxpost) {
+			iowrite32(D64_CTRL1_SOF,
+				  &pdcs->rxd_64[i].ctrl1);
+		} else {
+			/* Last descriptor in ringset. Set End of Table. */
+			iowrite32(D64_CTRL1_SOF | D64_CTRL1_EOT,
+				  &pdcs->rxd_64[i].ctrl1);
+		}
+	}
+	return PDC_SUCCESS;
+
+fail_dealloc:
+	dma_pool_free(pdcs->ring_pool, tx.vbase, tx.dmabase);
+done:
+	return err;
+}
+
+static void pdc_ring_free(struct pdc_state *pdcs)
+{
+	if (pdcs->tx_ring_alloc.vbase) {
+		dma_pool_free(pdcs->ring_pool, pdcs->tx_ring_alloc.vbase,
+			      pdcs->tx_ring_alloc.dmabase);
+		pdcs->tx_ring_alloc.vbase = NULL;
+	}
+
+	if (pdcs->rx_ring_alloc.vbase) {
+		dma_pool_free(pdcs->ring_pool, pdcs->rx_ring_alloc.vbase,
+			      pdcs->rx_ring_alloc.dmabase);
+		pdcs->rx_ring_alloc.vbase = NULL;
+	}
+}
+
+/**
+ * pdc_desc_count() - Count the number of DMA descriptors that will be required
+ * for a given scatterlist. Account for the max length of a DMA buffer.
+ * @sg:    Scatterlist to be DMA'd
+ * Return: Number of descriptors required
+ */
+static u32 pdc_desc_count(struct scatterlist *sg)
+{
+	u32 cnt = 0;
+
+	while (sg) {
+		cnt += ((sg->length / PDC_DMA_BUF_MAX) + 1);
+		sg = sg_next(sg);
+	}
+	return cnt;
+}
+
+/**
+ * pdc_rings_full() - Check whether the tx ring has room for tx_cnt descriptors
+ * and the rx ring has room for rx_cnt descriptors.
+ * @pdcs:  PDC state
+ * @tx_cnt: The number of descriptors required in the tx ring
+ * @rx_cnt: The number of descriptors required i the rx ring
+ *
+ * Return: true if one of the rings does not have enough space
+ *         false if sufficient space is available in both rings
+ */
+static bool pdc_rings_full(struct pdc_state *pdcs, int tx_cnt, int rx_cnt)
+{
+	u32 rx_avail;
+	u32 tx_avail;
+	bool full = false;
+
+	/* Check if the tx and rx rings are likely to have enough space */
+	rx_avail = pdcs->nrxpost - NRXDACTIVE(pdcs->rxin, pdcs->rxout,
+					      pdcs->nrxpost);
+	if (unlikely(rx_cnt > rx_avail)) {
+		pdcs->rx_ring_full++;
+		full = true;
+	}
+
+	if (likely(!full)) {
+		tx_avail = pdcs->ntxpost - NTXDACTIVE(pdcs->txin, pdcs->txout,
+						      pdcs->ntxpost);
+		if (unlikely(tx_cnt > tx_avail)) {
+			pdcs->tx_ring_full++;
+			full = true;
+		}
+	}
+	return full;
+}
+
+/**
+ * pdc_last_tx_done() - If both the tx and rx rings have at least
+ * PDC_RING_SPACE_MIN descriptors available, then indicate that the mailbox
+ * framework can submit another message.
+ * @chan:  mailbox channel to check
+ * Return: true if PDC can accept another message on this channel
+ */
+static bool pdc_last_tx_done(struct mbox_chan *chan)
+{
+	struct pdc_state *pdcs = chan->con_priv;
+	bool ret;
+
+	if (unlikely(pdc_rings_full(pdcs, PDC_RING_SPACE_MIN,
+				    PDC_RING_SPACE_MIN))) {
+		pdcs->last_tx_not_done++;
+		ret = false;
+	} else {
+		ret = true;
+	}
+	return ret;
+}
+
+/**
+ * pdc_send_data() - mailbox send_data function
+ * @chan:	The mailbox channel on which the data is sent. The channel
+ *              corresponds to a DMA ringset.
+ * @data:	The mailbox message to be sent. The message must be a
+ *              brcm_message structure.
+ *
+ * This function is registered as the send_data function for the mailbox
+ * controller. From the destination scatterlist in the mailbox message, it
+ * creates a sequence of receive descriptors in the rx ring. From the source
+ * scatterlist, it creates a sequence of transmit descriptors in the tx ring.
+ * After creating the descriptors, it writes the rx ptr and tx ptr registers to
+ * initiate the DMA transfer.
+ *
+ * This function does the DMA map and unmap of the src and dst scatterlists in
+ * the mailbox message.
+ *
+ * Return: 0 if successful
+ *	   -ENOTSUPP if the mailbox message is a type this driver does not
+ *			support
+ *         < 0 if an error
+ */
+static int pdc_send_data(struct mbox_chan *chan, void *data)
+{
+	struct pdc_state *pdcs = chan->con_priv;
+	struct device *dev = &pdcs->pdev->dev;
+	struct brcm_message *mssg = data;
+	int err = PDC_SUCCESS;
+	int src_nent;
+	int dst_nent;
+	int nent;
+	u32 tx_desc_req;
+	u32 rx_desc_req;
+
+	if (unlikely(mssg->type != BRCM_MESSAGE_SPU))
+		return -ENOTSUPP;
+
+	src_nent = sg_nents(mssg->spu.src);
+	if (likely(src_nent)) {
+		nent = dma_map_sg(dev, mssg->spu.src, src_nent, DMA_TO_DEVICE);
+		if (unlikely(nent == 0))
+			return -EIO;
+	}
+
+	dst_nent = sg_nents(mssg->spu.dst);
+	if (likely(dst_nent)) {
+		nent = dma_map_sg(dev, mssg->spu.dst, dst_nent,
+				  DMA_FROM_DEVICE);
+		if (unlikely(nent == 0)) {
+			dma_unmap_sg(dev, mssg->spu.src, src_nent,
+				     DMA_TO_DEVICE);
+			return -EIO;
+		}
+	}
+
+	/*
+	 * Check if the tx and rx rings have enough space. Do this prior to
+	 * writing any tx or rx descriptors. Need to ensure that we do not write
+	 * a partial set of descriptors, or write just rx descriptors but
+	 * corresponding tx descriptors don't fit. Note that we want this check
+	 * and the entire sequence of descriptor to happen without another
+	 * thread getting in. The channel spin lock in the mailbox framework
+	 * ensures this.
+	 */
+	tx_desc_req = pdc_desc_count(mssg->spu.src);
+	rx_desc_req = pdc_desc_count(mssg->spu.dst);
+	if (unlikely(pdc_rings_full(pdcs, tx_desc_req, rx_desc_req + 1)))
+		return -ENOSPC;
+
+	/* Create rx descriptors to SPU catch response */
+	err = pdc_rx_list_init(pdcs, mssg->spu.dst, mssg->ctx);
+	err |= pdc_rx_list_sg_add(pdcs, mssg->spu.dst);
+
+	/* Create tx descriptors to submit SPU request */
+	err |= pdc_tx_list_sg_add(pdcs, mssg->spu.src);
+	err |= pdc_tx_list_final(pdcs);	/* initiate transfer */
+
+	if (unlikely(err))
+		dev_err(&pdcs->pdev->dev,
+			"%s failed with error %d", __func__, err);
+
+	return err;
+}
+
+static int pdc_startup(struct mbox_chan *chan)
+{
+	return pdc_ring_init(chan->con_priv, PDC_RINGSET);
+}
+
+static void pdc_shutdown(struct mbox_chan *chan)
+{
+	struct pdc_state *pdcs = chan->con_priv;
+
+	if (!pdcs)
+		return;
+
+	dev_dbg(&pdcs->pdev->dev,
+		"Shutdown mailbox channel for PDC %u", pdcs->pdc_idx);
+	pdc_ring_free(pdcs);
+}
+
+/**
+ * pdc_hw_init() - Use the given initialization parameters to initialize the
+ * state for one of the PDCs.
+ * @pdcs:  state of the PDC
+ */
+static
+void pdc_hw_init(struct pdc_state *pdcs)
+{
+	struct platform_device *pdev;
+	struct device *dev;
+	struct dma64 *dma_reg;
+	int ringset = PDC_RINGSET;
+
+	pdev = pdcs->pdev;
+	dev = &pdev->dev;
+
+	dev_dbg(dev, "PDC %u initial values:", pdcs->pdc_idx);
+	dev_dbg(dev, "state structure:                   %p",
+		pdcs);
+	dev_dbg(dev, " - base virtual addr of hw regs    %p",
+		pdcs->pdc_reg_vbase);
+
+	/* initialize data structures */
+	pdcs->regs = (struct pdc_regs *)pdcs->pdc_reg_vbase;
+	pdcs->txregs_64 = (struct dma64_regs *)
+	    (((u8 *)pdcs->pdc_reg_vbase) +
+		     PDC_TXREGS_OFFSET + (sizeof(struct dma64) * ringset));
+	pdcs->rxregs_64 = (struct dma64_regs *)
+	    (((u8 *)pdcs->pdc_reg_vbase) +
+		     PDC_RXREGS_OFFSET + (sizeof(struct dma64) * ringset));
+
+	pdcs->ntxd = PDC_RING_ENTRIES;
+	pdcs->nrxd = PDC_RING_ENTRIES;
+	pdcs->ntxpost = PDC_RING_ENTRIES - 1;
+	pdcs->nrxpost = PDC_RING_ENTRIES - 1;
+	iowrite32(0, &pdcs->regs->intmask);
+
+	dma_reg = &pdcs->regs->dmaregs[ringset];
+
+	/* Configure DMA but will enable later in pdc_ring_init() */
+	iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
+
+	iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
+		  &dma_reg->dmarcv.control);
+
+	/* Reset current index pointers after making sure DMA is disabled */
+	iowrite32(0, &dma_reg->dmaxmt.ptr);
+	iowrite32(0, &dma_reg->dmarcv.ptr);
+
+	if (pdcs->pdc_resp_hdr_len == PDC_SPU2_RESP_HDR_LEN)
+		iowrite32(PDC_CKSUM_CTRL,
+			  pdcs->pdc_reg_vbase + PDC_CKSUM_CTRL_OFFSET);
+}
+
+/**
+ * pdc_hw_disable() - Disable the tx and rx control in the hw.
+ * @pdcs: PDC state structure
+ *
+ */
+static void pdc_hw_disable(struct pdc_state *pdcs)
+{
+	struct dma64 *dma_reg;
+
+	dma_reg = &pdcs->regs->dmaregs[PDC_RINGSET];
+	iowrite32(PDC_TX_CTL, &dma_reg->dmaxmt.control);
+	iowrite32(PDC_RX_CTL + (pdcs->rx_status_len << 1),
+		  &dma_reg->dmarcv.control);
+}
+
+/**
+ * pdc_rx_buf_pool_create() - Pool of receive buffers used to catch the metadata
+ * header returned with each response message.
+ * @pdcs: PDC state structure
+ *
+ * The metadata is not returned to the mailbox client. So the PDC driver
+ * manages these buffers.
+ *
+ * Return: PDC_SUCCESS
+ *         -ENOMEM if pool creation fails
+ */
+static int pdc_rx_buf_pool_create(struct pdc_state *pdcs)
+{
+	struct platform_device *pdev;
+	struct device *dev;
+
+	pdev = pdcs->pdev;
+	dev = &pdev->dev;
+
+	pdcs->pdc_resp_hdr_len = pdcs->rx_status_len;
+	if (pdcs->use_bcm_hdr)
+		pdcs->pdc_resp_hdr_len += BCM_HDR_LEN;
+
+	pdcs->rx_buf_pool = dma_pool_create("pdc rx bufs", dev,
+					    pdcs->pdc_resp_hdr_len,
+					    RX_BUF_ALIGN, 0);
+	if (!pdcs->rx_buf_pool)
+		return -ENOMEM;
+
+	return PDC_SUCCESS;
+}
+
+/**
+ * pdc_interrupts_init() - Initialize the interrupt configuration for a PDC and
+ * specify a threaded IRQ handler for deferred handling of interrupts outside of
+ * interrupt context.
+ * @pdcs:   PDC state
+ *
+ * Set the interrupt mask for transmit and receive done.
+ * Set the lazy interrupt frame count to generate an interrupt for just one pkt.
+ *
+ * Return:  PDC_SUCCESS
+ *          <0 if threaded irq request fails
+ */
+static int pdc_interrupts_init(struct pdc_state *pdcs)
+{
+	struct platform_device *pdev = pdcs->pdev;
+	struct device *dev = &pdev->dev;
+	struct device_node *dn = pdev->dev.of_node;
+	int err;
+
+	/* interrupt configuration */
+	iowrite32(PDC_INTMASK, pdcs->pdc_reg_vbase + PDC_INTMASK_OFFSET);
+
+	if (pdcs->hw_type == FA_HW)
+		iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase +
+			  FA_RCVLAZY0_OFFSET);
+	else
+		iowrite32(PDC_LAZY_INT, pdcs->pdc_reg_vbase +
+			  PDC_RCVLAZY0_OFFSET);
+
+	/* read irq from device tree */
+	pdcs->pdc_irq = irq_of_parse_and_map(dn, 0);
+	dev_dbg(dev, "pdc device %s irq %u for pdcs %p",
+		dev_name(dev), pdcs->pdc_irq, pdcs);
+
+	err = devm_request_irq(dev, pdcs->pdc_irq, pdc_irq_handler, 0,
+			       dev_name(dev), dev);
+	if (err) {
+		dev_err(dev, "IRQ %u request failed with err %d\n",
+			pdcs->pdc_irq, err);
+		return err;
+	}
+	return PDC_SUCCESS;
+}
+
+static const struct mbox_chan_ops pdc_mbox_chan_ops = {
+	.send_data = pdc_send_data,
+	.last_tx_done = pdc_last_tx_done,
+	.startup = pdc_startup,
+	.shutdown = pdc_shutdown
+};
+
+/**
+ * pdc_mb_init() - Initialize the mailbox controller.
+ * @pdcs:  PDC state
+ *
+ * Each PDC is a mailbox controller. Each ringset is a mailbox channel. Kernel
+ * driver only uses one ringset and thus one mb channel. PDC uses the transmit
+ * complete interrupt to determine when a mailbox message has successfully been
+ * transmitted.
+ *
+ * Return: 0 on success
+ *         < 0 if there is an allocation or registration failure
+ */
+static int pdc_mb_init(struct pdc_state *pdcs)
+{
+	struct device *dev = &pdcs->pdev->dev;
+	struct mbox_controller *mbc;
+	int chan_index;
+	int err;
+
+	mbc = &pdcs->mbc;
+	mbc->dev = dev;
+	mbc->ops = &pdc_mbox_chan_ops;
+	mbc->num_chans = 1;
+	mbc->chans = devm_kcalloc(dev, mbc->num_chans, sizeof(*mbc->chans),
+				  GFP_KERNEL);
+	if (!mbc->chans)
+		return -ENOMEM;
+
+	mbc->txdone_irq = false;
+	mbc->txdone_poll = true;
+	mbc->txpoll_period = 1;
+	for (chan_index = 0; chan_index < mbc->num_chans; chan_index++)
+		mbc->chans[chan_index].con_priv = pdcs;
+
+	/* Register mailbox controller */
+	err = devm_mbox_controller_register(dev, mbc);
+	if (err) {
+		dev_crit(dev,
+			 "Failed to register PDC mailbox controller. Error %d.",
+			 err);
+		return err;
+	}
+	return 0;
+}
+
+/* Device tree API */
+static const int pdc_hw = PDC_HW;
+static const int fa_hw = FA_HW;
+
+static const struct of_device_id pdc_mbox_of_match[] = {
+	{.compatible = "brcm,iproc-pdc-mbox", .data = &pdc_hw},
+	{.compatible = "brcm,iproc-fa2-mbox", .data = &fa_hw},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, pdc_mbox_of_match);
+
+/**
+ * pdc_dt_read() - Read application-specific data from device tree.
+ * @pdev:  Platform device
+ * @pdcs:  PDC state
+ *
+ * Reads the number of bytes of receive status that precede each received frame.
+ * Reads whether transmit and received frames should be preceded by an 8-byte
+ * BCM header.
+ *
+ * Return: 0 if successful
+ *         -ENODEV if device not available
+ */
+static int pdc_dt_read(struct platform_device *pdev, struct pdc_state *pdcs)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *dn = pdev->dev.of_node;
+	const struct of_device_id *match;
+	const int *hw_type;
+	int err;
+
+	err = of_property_read_u32(dn, "brcm,rx-status-len",
+				   &pdcs->rx_status_len);
+	if (err < 0)
+		dev_err(dev,
+			"%s failed to get DMA receive status length from device tree",
+			__func__);
+
+	pdcs->use_bcm_hdr = of_property_read_bool(dn, "brcm,use-bcm-hdr");
+
+	pdcs->hw_type = PDC_HW;
+
+	match = of_match_device(of_match_ptr(pdc_mbox_of_match), dev);
+	if (match != NULL) {
+		hw_type = match->data;
+		pdcs->hw_type = *hw_type;
+	}
+
+	return 0;
+}
+
+/**
+ * pdc_probe() - Probe function for PDC driver.
+ * @pdev:   PDC platform device
+ *
+ * Reserve and map register regions defined in device tree.
+ * Allocate and initialize tx and rx DMA rings.
+ * Initialize a mailbox controller for each PDC.
+ *
+ * Return: 0 if successful
+ *         < 0 if an error
+ */
+static int pdc_probe(struct platform_device *pdev)
+{
+	int err = 0;
+	struct device *dev = &pdev->dev;
+	struct resource *pdc_regs;
+	struct pdc_state *pdcs;
+
+	/* PDC state for one SPU */
+	pdcs = devm_kzalloc(dev, sizeof(*pdcs), GFP_KERNEL);
+	if (!pdcs) {
+		err = -ENOMEM;
+		goto cleanup;
+	}
+
+	pdcs->pdev = pdev;
+	platform_set_drvdata(pdev, pdcs);
+	pdcs->pdc_idx = pdcg.num_spu;
+	pdcg.num_spu++;
+
+	err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(39));
+	if (err) {
+		dev_warn(dev, "PDC device cannot perform DMA. Error %d.", err);
+		goto cleanup;
+	}
+
+	/* Create DMA pool for tx ring */
+	pdcs->ring_pool = dma_pool_create("pdc rings", dev, PDC_RING_SIZE,
+					  RING_ALIGN, 0);
+	if (!pdcs->ring_pool) {
+		err = -ENOMEM;
+		goto cleanup;
+	}
+
+	err = pdc_dt_read(pdev, pdcs);
+	if (err)
+		goto cleanup_ring_pool;
+
+	pdc_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!pdc_regs) {
+		err = -ENODEV;
+		goto cleanup_ring_pool;
+	}
+	dev_dbg(dev, "PDC register region res.start = %pa, res.end = %pa",
+		&pdc_regs->start, &pdc_regs->end);
+
+	pdcs->pdc_reg_vbase = devm_ioremap_resource(&pdev->dev, pdc_regs);
+	if (IS_ERR(pdcs->pdc_reg_vbase)) {
+		err = PTR_ERR(pdcs->pdc_reg_vbase);
+		goto cleanup_ring_pool;
+	}
+
+	/* create rx buffer pool after dt read to know how big buffers are */
+	err = pdc_rx_buf_pool_create(pdcs);
+	if (err)
+		goto cleanup_ring_pool;
+
+	pdc_hw_init(pdcs);
+
+	/* Init tasklet for deferred DMA rx processing */
+	tasklet_setup(&pdcs->rx_tasklet, pdc_tasklet_cb);
+
+	err = pdc_interrupts_init(pdcs);
+	if (err)
+		goto cleanup_buf_pool;
+
+	/* Initialize mailbox controller */
+	err = pdc_mb_init(pdcs);
+	if (err)
+		goto cleanup_buf_pool;
+
+	pdc_setup_debugfs(pdcs);
+
+	dev_dbg(dev, "pdc_probe() successful");
+	return PDC_SUCCESS;
+
+cleanup_buf_pool:
+	tasklet_kill(&pdcs->rx_tasklet);
+	dma_pool_destroy(pdcs->rx_buf_pool);
+
+cleanup_ring_pool:
+	dma_pool_destroy(pdcs->ring_pool);
+
+cleanup:
+	return err;
+}
+
+static int pdc_remove(struct platform_device *pdev)
+{
+	struct pdc_state *pdcs = platform_get_drvdata(pdev);
+
+	pdc_free_debugfs();
+
+	tasklet_kill(&pdcs->rx_tasklet);
+
+	pdc_hw_disable(pdcs);
+
+	dma_pool_destroy(pdcs->rx_buf_pool);
+	dma_pool_destroy(pdcs->ring_pool);
+	return 0;
+}
+
+static struct platform_driver pdc_mbox_driver = {
+	.probe = pdc_probe,
+	.remove = pdc_remove,
+	.driver = {
+		   .name = "brcm-iproc-pdc-mbox",
+		   .of_match_table = of_match_ptr(pdc_mbox_of_match),
+		   },
+};
+module_platform_driver(pdc_mbox_driver);
+
+MODULE_AUTHOR("Rob Rice <rob.rice@broadcom.com>");
+MODULE_DESCRIPTION("Broadcom PDC mailbox driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/bcm2835-mailbox.c b/drivers/mailbox/bcm2835-mailbox.c
new file mode 100644
index 000000000..fbfd02020
--- /dev/null
+++ b/drivers/mailbox/bcm2835-mailbox.c
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2010,2015 Broadcom
+ *  Copyright (C) 2013-2014 Lubomir Rintel
+ *  Copyright (C) 2013 Craig McGeachie
+ *
+ * Parts of the driver are based on:
+ *  - arch/arm/mach-bcm2708/vcio.c file written by Gray Girling that was
+ *    obtained from branch "rpi-3.6.y" of git://github.com/raspberrypi/
+ *    linux.git
+ *  - drivers/mailbox/bcm2835-ipc.c by Lubomir Rintel at
+ *    https://github.com/hackerspace/rpi-linux/blob/lr-raspberry-pi/drivers/
+ *    mailbox/bcm2835-ipc.c
+ *  - documentation available on the following web site:
+ *    https://github.com/raspberrypi/firmware/wiki/Mailbox-property-interface
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+/* Mailboxes */
+#define ARM_0_MAIL0	0x00
+#define ARM_0_MAIL1	0x20
+
+/*
+ * Mailbox registers. We basically only support mailbox 0 & 1. We
+ * deliver to the VC in mailbox 1, it delivers to us in mailbox 0. See
+ * BCM2835-ARM-Peripherals.pdf section 1.3 for an explanation about
+ * the placement of memory barriers.
+ */
+#define MAIL0_RD	(ARM_0_MAIL0 + 0x00)
+#define MAIL0_POL	(ARM_0_MAIL0 + 0x10)
+#define MAIL0_STA	(ARM_0_MAIL0 + 0x18)
+#define MAIL0_CNF	(ARM_0_MAIL0 + 0x1C)
+#define MAIL1_WRT	(ARM_0_MAIL1 + 0x00)
+#define MAIL1_STA	(ARM_0_MAIL1 + 0x18)
+
+/* Status register: FIFO state. */
+#define ARM_MS_FULL		BIT(31)
+#define ARM_MS_EMPTY		BIT(30)
+
+/* Configuration register: Enable interrupts. */
+#define ARM_MC_IHAVEDATAIRQEN	BIT(0)
+
+struct bcm2835_mbox {
+	void __iomem *regs;
+	spinlock_t lock;
+	struct mbox_controller controller;
+};
+
+static struct bcm2835_mbox *bcm2835_link_mbox(struct mbox_chan *link)
+{
+	return container_of(link->mbox, struct bcm2835_mbox, controller);
+}
+
+static irqreturn_t bcm2835_mbox_irq(int irq, void *dev_id)
+{
+	struct bcm2835_mbox *mbox = dev_id;
+	struct device *dev = mbox->controller.dev;
+	struct mbox_chan *link = &mbox->controller.chans[0];
+
+	while (!(readl(mbox->regs + MAIL0_STA) & ARM_MS_EMPTY)) {
+		u32 msg = readl(mbox->regs + MAIL0_RD);
+		dev_dbg(dev, "Reply 0x%08X\n", msg);
+		mbox_chan_received_data(link, &msg);
+	}
+	return IRQ_HANDLED;
+}
+
+static int bcm2835_send_data(struct mbox_chan *link, void *data)
+{
+	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);
+	u32 msg = *(u32 *)data;
+
+	spin_lock(&mbox->lock);
+	writel(msg, mbox->regs + MAIL1_WRT);
+	dev_dbg(mbox->controller.dev, "Request 0x%08X\n", msg);
+	spin_unlock(&mbox->lock);
+	return 0;
+}
+
+static int bcm2835_startup(struct mbox_chan *link)
+{
+	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);
+
+	/* Enable the interrupt on data reception */
+	writel(ARM_MC_IHAVEDATAIRQEN, mbox->regs + MAIL0_CNF);
+
+	return 0;
+}
+
+static void bcm2835_shutdown(struct mbox_chan *link)
+{
+	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);
+
+	writel(0, mbox->regs + MAIL0_CNF);
+}
+
+static bool bcm2835_last_tx_done(struct mbox_chan *link)
+{
+	struct bcm2835_mbox *mbox = bcm2835_link_mbox(link);
+	bool ret;
+
+	spin_lock(&mbox->lock);
+	ret = !(readl(mbox->regs + MAIL1_STA) & ARM_MS_FULL);
+	spin_unlock(&mbox->lock);
+	return ret;
+}
+
+static const struct mbox_chan_ops bcm2835_mbox_chan_ops = {
+	.send_data	= bcm2835_send_data,
+	.startup	= bcm2835_startup,
+	.shutdown	= bcm2835_shutdown,
+	.last_tx_done	= bcm2835_last_tx_done
+};
+
+static struct mbox_chan *bcm2835_mbox_index_xlate(struct mbox_controller *mbox,
+		    const struct of_phandle_args *sp)
+{
+	if (sp->args_count != 0)
+		return ERR_PTR(-EINVAL);
+
+	return &mbox->chans[0];
+}
+
+static int bcm2835_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int ret = 0;
+	struct bcm2835_mbox *mbox;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (mbox == NULL)
+		return -ENOMEM;
+	spin_lock_init(&mbox->lock);
+
+	ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0),
+			       bcm2835_mbox_irq, 0, dev_name(dev), mbox);
+	if (ret) {
+		dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
+			ret);
+		return -ENODEV;
+	}
+
+	mbox->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->regs)) {
+		ret = PTR_ERR(mbox->regs);
+		return ret;
+	}
+
+	mbox->controller.txdone_poll = true;
+	mbox->controller.txpoll_period = 5;
+	mbox->controller.ops = &bcm2835_mbox_chan_ops;
+	mbox->controller.of_xlate = &bcm2835_mbox_index_xlate;
+	mbox->controller.dev = dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = devm_kzalloc(dev,
+		sizeof(*mbox->controller.chans), GFP_KERNEL);
+	if (!mbox->controller.chans)
+		return -ENOMEM;
+
+	ret = devm_mbox_controller_register(dev, &mbox->controller);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, mbox);
+	dev_info(dev, "mailbox enabled\n");
+
+	return ret;
+}
+
+static const struct of_device_id bcm2835_mbox_of_match[] = {
+	{ .compatible = "brcm,bcm2835-mbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_mbox_of_match);
+
+static struct platform_driver bcm2835_mbox_driver = {
+	.driver = {
+		.name = "bcm2835-mbox",
+		.of_match_table = bcm2835_mbox_of_match,
+	},
+	.probe		= bcm2835_mbox_probe,
+};
+module_platform_driver(bcm2835_mbox_driver);
+
+MODULE_AUTHOR("Lubomir Rintel <lkundrak@v3.sk>");
+MODULE_DESCRIPTION("BCM2835 mailbox IPC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c
new file mode 100644
index 000000000..ab24e731a
--- /dev/null
+++ b/drivers/mailbox/hi3660-mailbox.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2017-2018 HiSilicon Limited.
+// Copyright (c) 2017-2018 Linaro Limited.
+
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "mailbox.h"
+
+#define MBOX_CHAN_MAX			32
+
+#define MBOX_RX				0x0
+#define MBOX_TX				0x1
+
+#define MBOX_BASE(mbox, ch)		((mbox)->base + ((ch) * 0x40))
+#define MBOX_SRC_REG			0x00
+#define MBOX_DST_REG			0x04
+#define MBOX_DCLR_REG			0x08
+#define MBOX_DSTAT_REG			0x0c
+#define MBOX_MODE_REG			0x10
+#define MBOX_IMASK_REG			0x14
+#define MBOX_ICLR_REG			0x18
+#define MBOX_SEND_REG			0x1c
+#define MBOX_DATA_REG			0x20
+
+#define MBOX_IPC_LOCK_REG		0xa00
+#define MBOX_IPC_UNLOCK			0x1acce551
+
+#define MBOX_AUTOMATIC_ACK		1
+
+#define MBOX_STATE_IDLE			BIT(4)
+#define MBOX_STATE_READY		BIT(5)
+#define MBOX_STATE_ACK			BIT(7)
+
+#define MBOX_MSG_LEN			8
+
+/**
+ * struct hi3660_chan_info - Hi3660 mailbox channel information
+ * @dst_irq:	Interrupt vector for remote processor
+ * @ack_irq:	Interrupt vector for local processor
+ *
+ * A channel can be used for TX or RX, it can trigger remote
+ * processor interrupt to notify remote processor and can receive
+ * interrupt if it has an incoming message.
+ */
+struct hi3660_chan_info {
+	unsigned int dst_irq;
+	unsigned int ack_irq;
+};
+
+/**
+ * struct hi3660_mbox - Hi3660 mailbox controller data
+ * @dev:	Device to which it is attached
+ * @base:	Base address of the register mapping region
+ * @chan:	Representation of channels in mailbox controller
+ * @mchan:	Representation of channel info
+ * @controller:	Representation of a communication channel controller
+ *
+ * Mailbox controller includes 32 channels and can allocate
+ * channel for message transferring.
+ */
+struct hi3660_mbox {
+	struct device *dev;
+	void __iomem *base;
+	struct mbox_chan chan[MBOX_CHAN_MAX];
+	struct hi3660_chan_info mchan[MBOX_CHAN_MAX];
+	struct mbox_controller controller;
+};
+
+static struct hi3660_mbox *to_hi3660_mbox(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct hi3660_mbox, controller);
+}
+
+static int hi3660_mbox_check_state(struct mbox_chan *chan)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	unsigned long val;
+	unsigned int ret;
+
+	/* Mailbox is ready to use */
+	if (readl(base + MBOX_MODE_REG) & MBOX_STATE_READY)
+		return 0;
+
+	/* Wait for acknowledge from remote */
+	ret = readx_poll_timeout_atomic(readl, base + MBOX_MODE_REG,
+			val, (val & MBOX_STATE_ACK), 1000, 300000);
+	if (ret) {
+		dev_err(mbox->dev, "%s: timeout for receiving ack\n", __func__);
+		return ret;
+	}
+
+	/* clear ack state, mailbox will get back to ready state */
+	writel(BIT(mchan->ack_irq), base + MBOX_ICLR_REG);
+
+	return 0;
+}
+
+static int hi3660_mbox_unlock(struct mbox_chan *chan)
+{
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	unsigned int val, retry = 3;
+
+	do {
+		writel(MBOX_IPC_UNLOCK, mbox->base + MBOX_IPC_LOCK_REG);
+
+		val = readl(mbox->base + MBOX_IPC_LOCK_REG);
+		if (!val)
+			break;
+
+		udelay(10);
+	} while (retry--);
+
+	if (val)
+		dev_err(mbox->dev, "%s: failed to unlock mailbox\n", __func__);
+
+	return (!val) ? 0 : -ETIMEDOUT;
+}
+
+static int hi3660_mbox_acquire_channel(struct mbox_chan *chan)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	unsigned int val, retry;
+
+	for (retry = 10; retry; retry--) {
+		/* Check if channel is in idle state */
+		if (readl(base + MBOX_MODE_REG) & MBOX_STATE_IDLE) {
+			writel(BIT(mchan->ack_irq), base + MBOX_SRC_REG);
+
+			/* Check ack bit has been set successfully */
+			val = readl(base + MBOX_SRC_REG);
+			if (val & BIT(mchan->ack_irq))
+				break;
+		}
+	}
+
+	if (!retry)
+		dev_err(mbox->dev, "%s: failed to acquire channel\n", __func__);
+
+	return retry ? 0 : -ETIMEDOUT;
+}
+
+static int hi3660_mbox_startup(struct mbox_chan *chan)
+{
+	int ret;
+
+	ret = hi3660_mbox_unlock(chan);
+	if (ret)
+		return ret;
+
+	ret = hi3660_mbox_acquire_channel(chan);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int hi3660_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	unsigned long ch = (unsigned long)chan->con_priv;
+	struct hi3660_mbox *mbox = to_hi3660_mbox(chan->mbox);
+	struct hi3660_chan_info *mchan = &mbox->mchan[ch];
+	void __iomem *base = MBOX_BASE(mbox, ch);
+	u32 *buf = msg;
+	unsigned int i;
+	int ret;
+
+	ret = hi3660_mbox_check_state(chan);
+	if (ret)
+		return ret;
+
+	/* Clear mask for destination interrupt */
+	writel_relaxed(~BIT(mchan->dst_irq), base + MBOX_IMASK_REG);
+
+	/* Config destination for interrupt vector */
+	writel_relaxed(BIT(mchan->dst_irq), base + MBOX_DST_REG);
+
+	/* Automatic acknowledge mode */
+	writel_relaxed(MBOX_AUTOMATIC_ACK, base + MBOX_MODE_REG);
+
+	/* Fill message data */
+	for (i = 0; i < MBOX_MSG_LEN; i++)
+		writel_relaxed(buf[i], base + MBOX_DATA_REG + i * 4);
+
+	/* Trigger data transferring */
+	writel(BIT(mchan->ack_irq), base + MBOX_SEND_REG);
+	return 0;
+}
+
+static const struct mbox_chan_ops hi3660_mbox_ops = {
+	.startup	= hi3660_mbox_startup,
+	.send_data	= hi3660_mbox_send_data,
+};
+
+static struct mbox_chan *hi3660_mbox_xlate(struct mbox_controller *controller,
+					   const struct of_phandle_args *spec)
+{
+	struct hi3660_mbox *mbox = to_hi3660_mbox(controller);
+	struct hi3660_chan_info *mchan;
+	unsigned int ch = spec->args[0];
+
+	if (ch >= MBOX_CHAN_MAX) {
+		dev_err(mbox->dev, "Invalid channel idx %d\n", ch);
+		return ERR_PTR(-EINVAL);
+	}
+
+	mchan = &mbox->mchan[ch];
+	mchan->dst_irq = spec->args[1];
+	mchan->ack_irq = spec->args[2];
+
+	return &mbox->chan[ch];
+}
+
+static const struct of_device_id hi3660_mbox_of_match[] = {
+	{ .compatible = "hisilicon,hi3660-mbox", },
+	{},
+};
+
+MODULE_DEVICE_TABLE(of, hi3660_mbox_of_match);
+
+static int hi3660_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct hi3660_mbox *mbox;
+	struct mbox_chan *chan;
+	unsigned long ch;
+	int err;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->base))
+		return PTR_ERR(mbox->base);
+
+	mbox->dev = dev;
+	mbox->controller.dev = dev;
+	mbox->controller.chans = mbox->chan;
+	mbox->controller.num_chans = MBOX_CHAN_MAX;
+	mbox->controller.ops = &hi3660_mbox_ops;
+	mbox->controller.of_xlate = hi3660_mbox_xlate;
+
+	/* Initialize mailbox channel data */
+	chan = mbox->chan;
+	for (ch = 0; ch < MBOX_CHAN_MAX; ch++)
+		chan[ch].con_priv = (void *)ch;
+
+	err = devm_mbox_controller_register(dev, &mbox->controller);
+	if (err) {
+		dev_err(dev, "Failed to register mailbox %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	dev_info(dev, "Mailbox enabled\n");
+	return 0;
+}
+
+static struct platform_driver hi3660_mbox_driver = {
+	.probe  = hi3660_mbox_probe,
+	.driver = {
+		.name = "hi3660-mbox",
+		.of_match_table = hi3660_mbox_of_match,
+	},
+};
+
+static int __init hi3660_mbox_init(void)
+{
+	return platform_driver_register(&hi3660_mbox_driver);
+}
+core_initcall(hi3660_mbox_init);
+
+static void __exit hi3660_mbox_exit(void)
+{
+	platform_driver_unregister(&hi3660_mbox_driver);
+}
+module_exit(hi3660_mbox_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Hisilicon Hi3660 Mailbox Controller");
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
diff --git a/drivers/mailbox/hi6220-mailbox.c b/drivers/mailbox/hi6220-mailbox.c
new file mode 100644
index 000000000..fca61f531
--- /dev/null
+++ b/drivers/mailbox/hi6220-mailbox.c
@@ -0,0 +1,373 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Hisilicon's Hi6220 mailbox driver
+ *
+ * Copyright (c) 2015 HiSilicon Limited.
+ * Copyright (c) 2015 Linaro Limited.
+ *
+ * Author: Leo Yan <leo.yan@linaro.org>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kfifo.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define MBOX_CHAN_MAX			32
+
+#define MBOX_TX				0x1
+
+/* Mailbox message length: 8 words */
+#define MBOX_MSG_LEN			8
+
+/* Mailbox Registers */
+#define MBOX_OFF(m)			(0x40 * (m))
+#define MBOX_MODE_REG(m)		(MBOX_OFF(m) + 0x0)
+#define MBOX_DATA_REG(m)		(MBOX_OFF(m) + 0x4)
+
+#define MBOX_STATE_MASK			(0xF << 4)
+#define MBOX_STATE_IDLE			(0x1 << 4)
+#define MBOX_STATE_TX			(0x2 << 4)
+#define MBOX_STATE_RX			(0x4 << 4)
+#define MBOX_STATE_ACK			(0x8 << 4)
+#define MBOX_ACK_CONFIG_MASK		(0x1 << 0)
+#define MBOX_ACK_AUTOMATIC		(0x1 << 0)
+#define MBOX_ACK_IRQ			(0x0 << 0)
+
+/* IPC registers */
+#define ACK_INT_RAW_REG(i)		((i) + 0x400)
+#define ACK_INT_MSK_REG(i)		((i) + 0x404)
+#define ACK_INT_STAT_REG(i)		((i) + 0x408)
+#define ACK_INT_CLR_REG(i)		((i) + 0x40c)
+#define ACK_INT_ENA_REG(i)		((i) + 0x500)
+#define ACK_INT_DIS_REG(i)		((i) + 0x504)
+#define DST_INT_RAW_REG(i)		((i) + 0x420)
+
+
+struct hi6220_mbox_chan {
+
+	/*
+	 * Description for channel's hardware info:
+	 *  - direction: tx or rx
+	 *  - dst irq: peer core's irq number
+	 *  - ack irq: local irq number
+	 *  - slot number
+	 */
+	unsigned int dir, dst_irq, ack_irq;
+	unsigned int slot;
+
+	struct hi6220_mbox *parent;
+};
+
+struct hi6220_mbox {
+	struct device *dev;
+
+	int irq;
+
+	/* flag of enabling tx's irq mode */
+	bool tx_irq_mode;
+
+	/* region for ipc event */
+	void __iomem *ipc;
+
+	/* region for mailbox */
+	void __iomem *base;
+
+	unsigned int chan_num;
+	struct hi6220_mbox_chan *mchan;
+
+	void *irq_map_chan[MBOX_CHAN_MAX];
+	struct mbox_chan *chan;
+	struct mbox_controller controller;
+};
+
+static void mbox_set_state(struct hi6220_mbox *mbox,
+			   unsigned int slot, u32 val)
+{
+	u32 status;
+
+	status = readl(mbox->base + MBOX_MODE_REG(slot));
+	status = (status & ~MBOX_STATE_MASK) | val;
+	writel(status, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static void mbox_set_mode(struct hi6220_mbox *mbox,
+			  unsigned int slot, u32 val)
+{
+	u32 mode;
+
+	mode = readl(mbox->base + MBOX_MODE_REG(slot));
+	mode = (mode & ~MBOX_ACK_CONFIG_MASK) | val;
+	writel(mode, mbox->base + MBOX_MODE_REG(slot));
+}
+
+static bool hi6220_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+	u32 state;
+
+	/* Only set idle state for polling mode */
+	BUG_ON(mbox->tx_irq_mode);
+
+	state = readl(mbox->base + MBOX_MODE_REG(mchan->slot));
+	return ((state & MBOX_STATE_MASK) == MBOX_STATE_IDLE);
+}
+
+static int hi6220_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+	unsigned int slot = mchan->slot;
+	u32 *buf = msg;
+	int i;
+
+	/* indicate as a TX channel */
+	mchan->dir = MBOX_TX;
+
+	mbox_set_state(mbox, slot, MBOX_STATE_TX);
+
+	if (mbox->tx_irq_mode)
+		mbox_set_mode(mbox, slot, MBOX_ACK_IRQ);
+	else
+		mbox_set_mode(mbox, slot, MBOX_ACK_AUTOMATIC);
+
+	for (i = 0; i < MBOX_MSG_LEN; i++)
+		writel(buf[i], mbox->base + MBOX_DATA_REG(slot) + i * 4);
+
+	/* trigger remote request */
+	writel(BIT(mchan->dst_irq), DST_INT_RAW_REG(mbox->ipc));
+	return 0;
+}
+
+static irqreturn_t hi6220_mbox_interrupt(int irq, void *p)
+{
+	struct hi6220_mbox *mbox = p;
+	struct hi6220_mbox_chan *mchan;
+	struct mbox_chan *chan;
+	unsigned int state, intr_bit, i;
+	u32 msg[MBOX_MSG_LEN];
+
+	state = readl(ACK_INT_STAT_REG(mbox->ipc));
+	if (!state) {
+		dev_warn(mbox->dev, "%s: spurious interrupt\n",
+			 __func__);
+		return IRQ_HANDLED;
+	}
+
+	while (state) {
+		intr_bit = __ffs(state);
+		state &= (state - 1);
+
+		chan = mbox->irq_map_chan[intr_bit];
+		if (!chan) {
+			dev_warn(mbox->dev, "%s: unexpected irq vector %d\n",
+				 __func__, intr_bit);
+			continue;
+		}
+
+		mchan = chan->con_priv;
+		if (mchan->dir == MBOX_TX)
+			mbox_chan_txdone(chan, 0);
+		else {
+			for (i = 0; i < MBOX_MSG_LEN; i++)
+				msg[i] = readl(mbox->base +
+					MBOX_DATA_REG(mchan->slot) + i * 4);
+
+			mbox_chan_received_data(chan, (void *)msg);
+		}
+
+		/* clear IRQ source */
+		writel(BIT(mchan->ack_irq), ACK_INT_CLR_REG(mbox->ipc));
+		mbox_set_state(mbox, mchan->slot, MBOX_STATE_IDLE);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int hi6220_mbox_startup(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+
+	mchan->dir = 0;
+
+	/* enable interrupt */
+	writel(BIT(mchan->ack_irq), ACK_INT_ENA_REG(mbox->ipc));
+	return 0;
+}
+
+static void hi6220_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct hi6220_mbox_chan *mchan = chan->con_priv;
+	struct hi6220_mbox *mbox = mchan->parent;
+
+	/* disable interrupt */
+	writel(BIT(mchan->ack_irq), ACK_INT_DIS_REG(mbox->ipc));
+	mbox->irq_map_chan[mchan->ack_irq] = NULL;
+}
+
+static const struct mbox_chan_ops hi6220_mbox_ops = {
+	.send_data    = hi6220_mbox_send_data,
+	.startup      = hi6220_mbox_startup,
+	.shutdown     = hi6220_mbox_shutdown,
+	.last_tx_done = hi6220_mbox_last_tx_done,
+};
+
+static struct mbox_chan *hi6220_mbox_xlate(struct mbox_controller *controller,
+					   const struct of_phandle_args *spec)
+{
+	struct hi6220_mbox *mbox = dev_get_drvdata(controller->dev);
+	struct hi6220_mbox_chan *mchan;
+	struct mbox_chan *chan;
+	unsigned int i = spec->args[0];
+	unsigned int dst_irq = spec->args[1];
+	unsigned int ack_irq = spec->args[2];
+
+	/* Bounds checking */
+	if (i >= mbox->chan_num || dst_irq >= mbox->chan_num ||
+	    ack_irq >= mbox->chan_num) {
+		dev_err(mbox->dev,
+			"Invalid channel idx %d dst_irq %d ack_irq %d\n",
+			i, dst_irq, ack_irq);
+		return ERR_PTR(-EINVAL);
+	}
+
+	/* Is requested channel free? */
+	chan = &mbox->chan[i];
+	if (mbox->irq_map_chan[ack_irq] == (void *)chan) {
+		dev_err(mbox->dev, "Channel in use\n");
+		return ERR_PTR(-EBUSY);
+	}
+
+	mchan = chan->con_priv;
+	mchan->dst_irq = dst_irq;
+	mchan->ack_irq = ack_irq;
+
+	mbox->irq_map_chan[ack_irq] = (void *)chan;
+	return chan;
+}
+
+static const struct of_device_id hi6220_mbox_of_match[] = {
+	{ .compatible = "hisilicon,hi6220-mbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hi6220_mbox_of_match);
+
+static int hi6220_mbox_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct hi6220_mbox *mbox;
+	int i, err;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->dev = dev;
+	mbox->chan_num = MBOX_CHAN_MAX;
+	mbox->mchan = devm_kcalloc(dev,
+		mbox->chan_num, sizeof(*mbox->mchan), GFP_KERNEL);
+	if (!mbox->mchan)
+		return -ENOMEM;
+
+	mbox->chan = devm_kcalloc(dev,
+		mbox->chan_num, sizeof(*mbox->chan), GFP_KERNEL);
+	if (!mbox->chan)
+		return -ENOMEM;
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq < 0)
+		return mbox->irq;
+
+	mbox->ipc = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->ipc)) {
+		dev_err(dev, "ioremap ipc failed\n");
+		return PTR_ERR(mbox->ipc);
+	}
+
+	mbox->base = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(mbox->base)) {
+		dev_err(dev, "ioremap buffer failed\n");
+		return PTR_ERR(mbox->base);
+	}
+
+	err = devm_request_irq(dev, mbox->irq, hi6220_mbox_interrupt, 0,
+			dev_name(dev), mbox);
+	if (err) {
+		dev_err(dev, "Failed to register a mailbox IRQ handler: %d\n",
+			err);
+		return -ENODEV;
+	}
+
+	mbox->controller.dev = dev;
+	mbox->controller.chans = &mbox->chan[0];
+	mbox->controller.num_chans = mbox->chan_num;
+	mbox->controller.ops = &hi6220_mbox_ops;
+	mbox->controller.of_xlate = hi6220_mbox_xlate;
+
+	for (i = 0; i < mbox->chan_num; i++) {
+		mbox->chan[i].con_priv = &mbox->mchan[i];
+		mbox->irq_map_chan[i] = NULL;
+
+		mbox->mchan[i].parent = mbox;
+		mbox->mchan[i].slot   = i;
+	}
+
+	/* mask and clear all interrupt vectors */
+	writel(0x0,  ACK_INT_MSK_REG(mbox->ipc));
+	writel(~0x0, ACK_INT_CLR_REG(mbox->ipc));
+
+	/* use interrupt for tx's ack */
+	if (of_find_property(node, "hi6220,mbox-tx-noirq", NULL))
+		mbox->tx_irq_mode = false;
+	else
+		mbox->tx_irq_mode = true;
+
+	if (mbox->tx_irq_mode)
+		mbox->controller.txdone_irq = true;
+	else {
+		mbox->controller.txdone_poll = true;
+		mbox->controller.txpoll_period = 5;
+	}
+
+	err = devm_mbox_controller_register(dev, &mbox->controller);
+	if (err) {
+		dev_err(dev, "Failed to register mailbox %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+	dev_info(dev, "Mailbox enabled\n");
+	return 0;
+}
+
+static struct platform_driver hi6220_mbox_driver = {
+	.driver = {
+		.name = "hi6220-mbox",
+		.of_match_table = hi6220_mbox_of_match,
+	},
+	.probe	= hi6220_mbox_probe,
+};
+
+static int __init hi6220_mbox_init(void)
+{
+	return platform_driver_register(&hi6220_mbox_driver);
+}
+core_initcall(hi6220_mbox_init);
+
+static void __exit hi6220_mbox_exit(void)
+{
+	platform_driver_unregister(&hi6220_mbox_driver);
+}
+module_exit(hi6220_mbox_exit);
+
+MODULE_AUTHOR("Leo Yan <leo.yan@linaro.org>");
+MODULE_DESCRIPTION("Hi6220 mailbox driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
new file mode 100644
index 000000000..20f2ec880
--- /dev/null
+++ b/drivers/mailbox/imx-mailbox.c
@@ -0,0 +1,1057 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Pengutronix, Oleksij Rempel <o.rempel@pengutronix.de>
+ * Copyright 2022 NXP, Peng Fan <peng.fan@nxp.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/firmware/imx/ipc.h>
+#include <linux/firmware/imx/s4.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/suspend.h>
+#include <linux/slab.h>
+
+#define IMX_MU_CHANS		17
+/* TX0/RX0/RXDB[0-3] */
+#define IMX_MU_SCU_CHANS	6
+/* TX0/RX0 */
+#define IMX_MU_S4_CHANS		2
+#define IMX_MU_CHAN_NAME_SIZE	20
+
+#define IMX_MU_NUM_RR		4
+
+#define IMX_MU_SECO_TX_TOUT (msecs_to_jiffies(3000))
+#define IMX_MU_SECO_RX_TOUT (msecs_to_jiffies(3000))
+
+/* Please not change TX & RX */
+enum imx_mu_chan_type {
+	IMX_MU_TYPE_TX		= 0, /* Tx */
+	IMX_MU_TYPE_RX		= 1, /* Rx */
+	IMX_MU_TYPE_TXDB	= 2, /* Tx doorbell */
+	IMX_MU_TYPE_RXDB	= 3, /* Rx doorbell */
+	IMX_MU_TYPE_RST		= 4, /* Reset */
+};
+
+enum imx_mu_xcr {
+	IMX_MU_CR,
+	IMX_MU_GIER,
+	IMX_MU_GCR,
+	IMX_MU_TCR,
+	IMX_MU_RCR,
+	IMX_MU_xCR_MAX,
+};
+
+enum imx_mu_xsr {
+	IMX_MU_SR,
+	IMX_MU_GSR,
+	IMX_MU_TSR,
+	IMX_MU_RSR,
+	IMX_MU_xSR_MAX,
+};
+
+struct imx_sc_rpc_msg_max {
+	struct imx_sc_rpc_msg hdr;
+	u32 data[30];
+};
+
+struct imx_s4_rpc_msg_max {
+	struct imx_s4_rpc_msg hdr;
+	u32 data[254];
+};
+
+struct imx_mu_con_priv {
+	unsigned int		idx;
+	char			irq_desc[IMX_MU_CHAN_NAME_SIZE];
+	enum imx_mu_chan_type	type;
+	struct mbox_chan	*chan;
+	struct tasklet_struct	txdb_tasklet;
+};
+
+struct imx_mu_priv {
+	struct device		*dev;
+	void __iomem		*base;
+	void			*msg;
+	spinlock_t		xcr_lock; /* control register lock */
+
+	struct mbox_controller	mbox;
+	struct mbox_chan	mbox_chans[IMX_MU_CHANS];
+
+	struct imx_mu_con_priv  con_priv[IMX_MU_CHANS];
+	const struct imx_mu_dcfg	*dcfg;
+	struct clk		*clk;
+	int			irq[IMX_MU_CHANS];
+	bool			suspend;
+
+	u32 xcr[IMX_MU_xCR_MAX];
+
+	bool			side_b;
+};
+
+enum imx_mu_type {
+	IMX_MU_V1,
+	IMX_MU_V2 = BIT(1),
+	IMX_MU_V2_S4 = BIT(15),
+	IMX_MU_V2_IRQ = BIT(16),
+};
+
+struct imx_mu_dcfg {
+	int (*tx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data);
+	int (*rx)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
+	int (*rxdb)(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp);
+	void (*init)(struct imx_mu_priv *priv);
+	enum imx_mu_type type;
+	u32	xTR;		/* Transmit Register0 */
+	u32	xRR;		/* Receive Register0 */
+	u32	xSR[IMX_MU_xSR_MAX];	/* Status Registers */
+	u32	xCR[IMX_MU_xCR_MAX];	/* Control Registers */
+};
+
+#define IMX_MU_xSR_GIPn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
+#define IMX_MU_xSR_RFn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+#define IMX_MU_xSR_TEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
+
+/* General Purpose Interrupt Enable */
+#define IMX_MU_xCR_GIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(28 + (3 - (x))))
+/* Receive Interrupt Enable */
+#define IMX_MU_xCR_RIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(24 + (3 - (x))))
+/* Transmit Interrupt Enable */
+#define IMX_MU_xCR_TIEn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(20 + (3 - (x))))
+/* General Purpose Interrupt Request */
+#define IMX_MU_xCR_GIRn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(16 + (3 - (x))))
+/* MU reset */
+#define IMX_MU_xCR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(5))
+#define IMX_MU_xSR_RST(type)	(type & IMX_MU_V2 ? BIT(0) : BIT(7))
+
+
+static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct imx_mu_priv, mbox);
+}
+
+static void imx_mu_write(struct imx_mu_priv *priv, u32 val, u32 offs)
+{
+	iowrite32(val, priv->base + offs);
+}
+
+static u32 imx_mu_read(struct imx_mu_priv *priv, u32 offs)
+{
+	return ioread32(priv->base + offs);
+}
+
+static int imx_mu_tx_waiting_write(struct imx_mu_priv *priv, u32 val, u32 idx)
+{
+	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_TX_TOUT;
+	u32 status;
+	u32 can_write;
+
+	dev_dbg(priv->dev, "Trying to write %.8x to idx %d\n", val, idx);
+
+	do {
+		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
+		can_write = status & IMX_MU_xSR_TEn(priv->dcfg->type, idx % 4);
+	} while (!can_write && time_is_after_jiffies64(timeout_time));
+
+	if (!can_write) {
+		dev_err(priv->dev, "timeout trying to write %.8x at %d(%.8x)\n",
+			val, idx, status);
+		return -ETIME;
+	}
+
+	imx_mu_write(priv, val, priv->dcfg->xTR + (idx % 4) * 4);
+
+	return 0;
+}
+
+static int imx_mu_rx_waiting_read(struct imx_mu_priv *priv, u32 *val, u32 idx)
+{
+	u64 timeout_time = get_jiffies_64() + IMX_MU_SECO_RX_TOUT;
+	u32 status;
+	u32 can_read;
+
+	dev_dbg(priv->dev, "Trying to read from idx %d\n", idx);
+
+	do {
+		status = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
+		can_read = status & IMX_MU_xSR_RFn(priv->dcfg->type, idx % 4);
+	} while (!can_read && time_is_after_jiffies64(timeout_time));
+
+	if (!can_read) {
+		dev_err(priv->dev, "timeout trying to read idx %d (%.8x)\n",
+			idx, status);
+		return -ETIME;
+	}
+
+	*val = imx_mu_read(priv, priv->dcfg->xRR + (idx % 4) * 4);
+	dev_dbg(priv->dev, "Read %.8x\n", *val);
+
+	return 0;
+}
+
+static u32 imx_mu_xcr_rmw(struct imx_mu_priv *priv, enum imx_mu_xcr type, u32 set, u32 clr)
+{
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&priv->xcr_lock, flags);
+	val = imx_mu_read(priv, priv->dcfg->xCR[type]);
+	val &= ~clr;
+	val |= set;
+	imx_mu_write(priv, val, priv->dcfg->xCR[type]);
+	spin_unlock_irqrestore(&priv->xcr_lock, flags);
+
+	return val;
+}
+
+static int imx_mu_generic_tx(struct imx_mu_priv *priv,
+			     struct imx_mu_con_priv *cp,
+			     void *data)
+{
+	u32 *arg = data;
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_TX:
+		imx_mu_write(priv, *arg, priv->dcfg->xTR + cp->idx * 4);
+		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
+		break;
+	case IMX_MU_TYPE_TXDB:
+		imx_mu_xcr_rmw(priv, IMX_MU_GCR, IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
+		tasklet_schedule(&cp->txdb_tasklet);
+		break;
+	default:
+		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int imx_mu_generic_rx(struct imx_mu_priv *priv,
+			     struct imx_mu_con_priv *cp)
+{
+	u32 dat;
+
+	dat = imx_mu_read(priv, priv->dcfg->xRR + (cp->idx) * 4);
+	mbox_chan_received_data(cp->chan, (void *)&dat);
+
+	return 0;
+}
+
+static int imx_mu_generic_rxdb(struct imx_mu_priv *priv,
+			       struct imx_mu_con_priv *cp)
+{
+	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
+		     priv->dcfg->xSR[IMX_MU_GSR]);
+	mbox_chan_received_data(cp->chan, NULL);
+
+	return 0;
+}
+
+static int imx_mu_specific_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp, void *data)
+{
+	u32 *arg = data;
+	int i, ret;
+	u32 xsr;
+	u32 size, max_size, num_tr;
+
+	if (priv->dcfg->type & IMX_MU_V2_S4) {
+		size = ((struct imx_s4_rpc_msg_max *)data)->hdr.size;
+		max_size = sizeof(struct imx_s4_rpc_msg_max);
+		num_tr = 8;
+	} else {
+		size = ((struct imx_sc_rpc_msg_max *)data)->hdr.size;
+		max_size = sizeof(struct imx_sc_rpc_msg_max);
+		num_tr = 4;
+	}
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_TX:
+		/*
+		 * msg->hdr.size specifies the number of u32 words while
+		 * sizeof yields bytes.
+		 */
+
+		if (size > max_size / 4) {
+			/*
+			 * The real message size can be different to
+			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
+			 */
+			dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on TX; got: %i bytes\n", max_size, size << 2);
+			return -EINVAL;
+		}
+
+		for (i = 0; i < num_tr && i < size; i++)
+			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
+		for (; i < size; i++) {
+			ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_TSR],
+						 xsr,
+						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
+						 0, 5 * USEC_PER_SEC);
+			if (ret) {
+				dev_err(priv->dev, "Send data index: %d timeout\n", i);
+				return ret;
+			}
+			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % num_tr) * 4);
+		}
+
+		imx_mu_xcr_rmw(priv, IMX_MU_TCR, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx), 0);
+		break;
+	default:
+		dev_warn_ratelimited(priv->dev, "Send data on wrong channel type: %d\n", cp->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
+{
+	u32 *data;
+	int i, ret;
+	u32 xsr;
+	u32 size, max_size;
+
+	data = (u32 *)priv->msg;
+
+	imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, 0));
+	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
+
+	if (priv->dcfg->type & IMX_MU_V2_S4) {
+		size = ((struct imx_s4_rpc_msg_max *)priv->msg)->hdr.size;
+		max_size = sizeof(struct imx_s4_rpc_msg_max);
+	} else {
+		size = ((struct imx_sc_rpc_msg_max *)priv->msg)->hdr.size;
+		max_size = sizeof(struct imx_sc_rpc_msg_max);
+	}
+
+	if (size > max_size / 4) {
+		dev_err(priv->dev, "Maximal message size (%u bytes) exceeded on RX; got: %i bytes\n", max_size, size << 2);
+		return -EINVAL;
+	}
+
+	for (i = 1; i < size; i++) {
+		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_RSR], xsr,
+					 xsr & IMX_MU_xSR_RFn(priv->dcfg->type, i % 4), 0,
+					 5 * USEC_PER_SEC);
+		if (ret) {
+			dev_err(priv->dev, "timeout read idx %d\n", i);
+			return ret;
+		}
+		*data++ = imx_mu_read(priv, priv->dcfg->xRR + (i % 4) * 4);
+	}
+
+	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
+	mbox_chan_received_data(cp->chan, (void *)priv->msg);
+
+	return 0;
+}
+
+static int imx_mu_seco_tx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp,
+			  void *data)
+{
+	struct imx_sc_rpc_msg_max *msg = data;
+	u32 *arg = data;
+	u32 byte_size;
+	int err;
+	int i;
+
+	dev_dbg(priv->dev, "Sending message\n");
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_TXDB:
+		byte_size = msg->hdr.size * sizeof(u32);
+		if (byte_size > sizeof(*msg)) {
+			/*
+			 * The real message size can be different to
+			 * struct imx_sc_rpc_msg_max size
+			 */
+			dev_err(priv->dev,
+				"Exceed max msg size (%zu) on TX, got: %i\n",
+				sizeof(*msg), byte_size);
+			return -EINVAL;
+		}
+
+		print_hex_dump_debug("from client ", DUMP_PREFIX_OFFSET, 4, 4,
+				     data, byte_size, false);
+
+		/* Send first word */
+		dev_dbg(priv->dev, "Sending header\n");
+		imx_mu_write(priv, *arg++, priv->dcfg->xTR);
+
+		/* Send signaling */
+		dev_dbg(priv->dev, "Sending signaling\n");
+		imx_mu_xcr_rmw(priv, IMX_MU_GCR,
+			       IMX_MU_xCR_GIRn(priv->dcfg->type, cp->idx), 0);
+
+		/* Send words to fill the mailbox */
+		for (i = 1; i < 4 && i < msg->hdr.size; i++) {
+			dev_dbg(priv->dev, "Sending word %d\n", i);
+			imx_mu_write(priv, *arg++,
+				     priv->dcfg->xTR + (i % 4) * 4);
+		}
+
+		/* Send rest of message waiting for remote read */
+		for (; i < msg->hdr.size; i++) {
+			dev_dbg(priv->dev, "Sending word %d\n", i);
+			err = imx_mu_tx_waiting_write(priv, *arg++, i);
+			if (err) {
+				dev_err(priv->dev, "Timeout tx %d\n", i);
+				return err;
+			}
+		}
+
+		/* Simulate hack for mbox framework */
+		tasklet_schedule(&cp->txdb_tasklet);
+
+		break;
+	default:
+		dev_warn_ratelimited(priv->dev,
+				     "Send data on wrong channel type: %d\n",
+				     cp->type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int imx_mu_seco_rxdb(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
+{
+	struct imx_sc_rpc_msg_max msg;
+	u32 *data = (u32 *)&msg;
+	u32 byte_size;
+	int err = 0;
+	int i;
+
+	dev_dbg(priv->dev, "Receiving message\n");
+
+	/* Read header */
+	dev_dbg(priv->dev, "Receiving header\n");
+	*data++ = imx_mu_read(priv, priv->dcfg->xRR);
+	byte_size = msg.hdr.size * sizeof(u32);
+	if (byte_size > sizeof(msg)) {
+		dev_err(priv->dev, "Exceed max msg size (%zu) on RX, got: %i\n",
+			sizeof(msg), byte_size);
+		err = -EINVAL;
+		goto error;
+	}
+
+	/* Read message waiting they are written */
+	for (i = 1; i < msg.hdr.size; i++) {
+		dev_dbg(priv->dev, "Receiving word %d\n", i);
+		err = imx_mu_rx_waiting_read(priv, data++, i);
+		if (err) {
+			dev_err(priv->dev, "Timeout rx %d\n", i);
+			goto error;
+		}
+	}
+
+	/* Clear GIP */
+	imx_mu_write(priv, IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx),
+		     priv->dcfg->xSR[IMX_MU_GSR]);
+
+	print_hex_dump_debug("to client ", DUMP_PREFIX_OFFSET, 4, 4,
+			     &msg, byte_size, false);
+
+	/* send data to client */
+	dev_dbg(priv->dev, "Sending message to client\n");
+	mbox_chan_received_data(cp->chan, (void *)&msg);
+
+	goto exit;
+
+error:
+	mbox_chan_received_data(cp->chan, ERR_PTR(err));
+
+exit:
+	return err;
+}
+
+static void imx_mu_txdb_tasklet(unsigned long data)
+{
+	struct imx_mu_con_priv *cp = (struct imx_mu_con_priv *)data;
+
+	mbox_chan_txdone(cp->chan, 0);
+}
+
+static irqreturn_t imx_mu_isr(int irq, void *p)
+{
+	struct mbox_chan *chan = p;
+	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
+	struct imx_mu_con_priv *cp = chan->con_priv;
+	u32 val, ctrl;
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_TX:
+		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_TCR]);
+		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_TSR]);
+		val &= IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx) &
+			(ctrl & IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RX:
+		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_RCR]);
+		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_RSR]);
+		val &= IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx) &
+			(ctrl & IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RXDB:
+		ctrl = imx_mu_read(priv, priv->dcfg->xCR[IMX_MU_GIER]);
+		val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
+		val &= IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx) &
+			(ctrl & IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RST:
+		return IRQ_NONE;
+	default:
+		dev_warn_ratelimited(priv->dev, "Unhandled channel type %d\n",
+				     cp->type);
+		return IRQ_NONE;
+	}
+
+	if (!val)
+		return IRQ_NONE;
+
+	if ((val == IMX_MU_xSR_TEn(priv->dcfg->type, cp->idx)) &&
+	    (cp->type == IMX_MU_TYPE_TX)) {
+		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
+		mbox_chan_txdone(chan, 0);
+	} else if ((val == IMX_MU_xSR_RFn(priv->dcfg->type, cp->idx)) &&
+		   (cp->type == IMX_MU_TYPE_RX)) {
+		priv->dcfg->rx(priv, cp);
+	} else if ((val == IMX_MU_xSR_GIPn(priv->dcfg->type, cp->idx)) &&
+		   (cp->type == IMX_MU_TYPE_RXDB)) {
+		priv->dcfg->rxdb(priv, cp);
+	} else {
+		dev_warn_ratelimited(priv->dev, "Not handled interrupt\n");
+		return IRQ_NONE;
+	}
+
+	if (priv->suspend)
+		pm_system_wakeup();
+
+	return IRQ_HANDLED;
+}
+
+static int imx_mu_send_data(struct mbox_chan *chan, void *data)
+{
+	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
+	struct imx_mu_con_priv *cp = chan->con_priv;
+
+	return priv->dcfg->tx(priv, cp, data);
+}
+
+static int imx_mu_startup(struct mbox_chan *chan)
+{
+	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
+	struct imx_mu_con_priv *cp = chan->con_priv;
+	unsigned long irq_flag = 0;
+	int ret;
+
+	pm_runtime_get_sync(priv->dev);
+	if (cp->type == IMX_MU_TYPE_TXDB) {
+		/* Tx doorbell don't have ACK support */
+		tasklet_init(&cp->txdb_tasklet, imx_mu_txdb_tasklet,
+			     (unsigned long)cp);
+		return 0;
+	}
+
+	/* IPC MU should be with IRQF_NO_SUSPEND set */
+	if (!priv->dev->pm_domain)
+		irq_flag |= IRQF_NO_SUSPEND;
+
+	if (!(priv->dcfg->type & IMX_MU_V2_IRQ))
+		irq_flag |= IRQF_SHARED;
+
+	ret = request_irq(priv->irq[cp->type], imx_mu_isr, irq_flag, cp->irq_desc, chan);
+	if (ret) {
+		dev_err(priv->dev, "Unable to acquire IRQ %d\n", priv->irq[cp->type]);
+		return ret;
+	}
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_RX:
+		imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx), 0);
+		break;
+	case IMX_MU_TYPE_RXDB:
+		imx_mu_xcr_rmw(priv, IMX_MU_GIER, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx), 0);
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static void imx_mu_shutdown(struct mbox_chan *chan)
+{
+	struct imx_mu_priv *priv = to_imx_mu_priv(chan->mbox);
+	struct imx_mu_con_priv *cp = chan->con_priv;
+	int ret;
+	u32 sr;
+
+	if (cp->type == IMX_MU_TYPE_TXDB) {
+		tasklet_kill(&cp->txdb_tasklet);
+		pm_runtime_put_sync(priv->dev);
+		return;
+	}
+
+	switch (cp->type) {
+	case IMX_MU_TYPE_TX:
+		imx_mu_xcr_rmw(priv, IMX_MU_TCR, 0, IMX_MU_xCR_TIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RX:
+		imx_mu_xcr_rmw(priv, IMX_MU_RCR, 0, IMX_MU_xCR_RIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RXDB:
+		imx_mu_xcr_rmw(priv, IMX_MU_GIER, 0, IMX_MU_xCR_GIEn(priv->dcfg->type, cp->idx));
+		break;
+	case IMX_MU_TYPE_RST:
+		imx_mu_xcr_rmw(priv, IMX_MU_CR, IMX_MU_xCR_RST(priv->dcfg->type), 0);
+		ret = readl_poll_timeout(priv->base + priv->dcfg->xSR[IMX_MU_SR], sr,
+					 !(sr & IMX_MU_xSR_RST(priv->dcfg->type)), 1, 5);
+		if (ret)
+			dev_warn(priv->dev, "RST channel timeout\n");
+		break;
+	default:
+		break;
+	}
+
+	free_irq(priv->irq[cp->type], chan);
+	pm_runtime_put_sync(priv->dev);
+}
+
+static const struct mbox_chan_ops imx_mu_ops = {
+	.send_data = imx_mu_send_data,
+	.startup = imx_mu_startup,
+	.shutdown = imx_mu_shutdown,
+};
+
+static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
+					       const struct of_phandle_args *sp)
+{
+	u32 type, idx, chan;
+
+	if (sp->args_count != 2) {
+		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
+		return ERR_PTR(-EINVAL);
+	}
+
+	type = sp->args[0]; /* channel type */
+	idx = sp->args[1]; /* index */
+
+	switch (type) {
+	case IMX_MU_TYPE_TX:
+	case IMX_MU_TYPE_RX:
+		if (idx != 0)
+			dev_err(mbox->dev, "Invalid chan idx: %d\n", idx);
+		chan = type;
+		break;
+	case IMX_MU_TYPE_RXDB:
+		chan = 2 + idx;
+		break;
+	default:
+		dev_err(mbox->dev, "Invalid chan type: %d\n", type);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (chan >= mbox->num_chans) {
+		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return &mbox->chans[chan];
+}
+
+static struct mbox_chan * imx_mu_xlate(struct mbox_controller *mbox,
+				       const struct of_phandle_args *sp)
+{
+	u32 type, idx, chan;
+
+	if (sp->args_count != 2) {
+		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
+		return ERR_PTR(-EINVAL);
+	}
+
+	type = sp->args[0]; /* channel type */
+	idx = sp->args[1]; /* index */
+	chan = type * 4 + idx;
+
+	if (chan >= mbox->num_chans) {
+		dev_err(mbox->dev, "Not supported channel number: %d. (type: %d, idx: %d)\n", chan, type, idx);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return &mbox->chans[chan];
+}
+
+static struct mbox_chan *imx_mu_seco_xlate(struct mbox_controller *mbox,
+					   const struct of_phandle_args *sp)
+{
+	u32 type;
+
+	if (sp->args_count < 1) {
+		dev_err(mbox->dev, "Invalid argument count %d\n", sp->args_count);
+		return ERR_PTR(-EINVAL);
+	}
+
+	type = sp->args[0]; /* channel type */
+
+	/* Only supports TXDB and RXDB */
+	if (type == IMX_MU_TYPE_TX || type == IMX_MU_TYPE_RX) {
+		dev_err(mbox->dev, "Invalid type: %d\n", type);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return imx_mu_xlate(mbox, sp);
+}
+
+static void imx_mu_init_generic(struct imx_mu_priv *priv)
+{
+	unsigned int i;
+	unsigned int val;
+
+	for (i = 0; i < IMX_MU_CHANS; i++) {
+		struct imx_mu_con_priv *cp = &priv->con_priv[i];
+
+		cp->idx = i % 4;
+		cp->type = i >> 2;
+		cp->chan = &priv->mbox_chans[i];
+		priv->mbox_chans[i].con_priv = cp;
+		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
+			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
+	}
+
+	priv->mbox.num_chans = IMX_MU_CHANS;
+	priv->mbox.of_xlate = imx_mu_xlate;
+
+	if (priv->side_b)
+		return;
+
+	/* Set default MU configuration */
+	for (i = 0; i < IMX_MU_xCR_MAX; i++)
+		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
+
+	/* Clear any pending GIP */
+	val = imx_mu_read(priv, priv->dcfg->xSR[IMX_MU_GSR]);
+	imx_mu_write(priv, val, priv->dcfg->xSR[IMX_MU_GSR]);
+
+	/* Clear any pending RSR */
+	for (i = 0; i < IMX_MU_NUM_RR; i++)
+		imx_mu_read(priv, priv->dcfg->xRR + (i % 4) * 4);
+}
+
+static void imx_mu_init_specific(struct imx_mu_priv *priv)
+{
+	unsigned int i;
+	int num_chans = priv->dcfg->type & IMX_MU_V2_S4 ? IMX_MU_S4_CHANS : IMX_MU_SCU_CHANS;
+
+	for (i = 0; i < num_chans; i++) {
+		struct imx_mu_con_priv *cp = &priv->con_priv[i];
+
+		cp->idx = i < 2 ? 0 : i - 2;
+		cp->type = i < 2 ? i : IMX_MU_TYPE_RXDB;
+		cp->chan = &priv->mbox_chans[i];
+		priv->mbox_chans[i].con_priv = cp;
+		snprintf(cp->irq_desc, sizeof(cp->irq_desc),
+			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
+	}
+
+	priv->mbox.num_chans = num_chans;
+	priv->mbox.of_xlate = imx_mu_specific_xlate;
+
+	/* Set default MU configuration */
+	for (i = 0; i < IMX_MU_xCR_MAX; i++)
+		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
+}
+
+static void imx_mu_init_seco(struct imx_mu_priv *priv)
+{
+	imx_mu_init_generic(priv);
+	priv->mbox.of_xlate = imx_mu_seco_xlate;
+}
+
+static int imx_mu_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct imx_mu_priv *priv;
+	const struct imx_mu_dcfg *dcfg;
+	int i, ret;
+	u32 size;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	dcfg = of_device_get_match_data(dev);
+	if (!dcfg)
+		return -EINVAL;
+	priv->dcfg = dcfg;
+	if (priv->dcfg->type & IMX_MU_V2_IRQ) {
+		priv->irq[IMX_MU_TYPE_TX] = platform_get_irq_byname(pdev, "tx");
+		if (priv->irq[IMX_MU_TYPE_TX] < 0)
+			return priv->irq[IMX_MU_TYPE_TX];
+		priv->irq[IMX_MU_TYPE_RX] = platform_get_irq_byname(pdev, "rx");
+		if (priv->irq[IMX_MU_TYPE_RX] < 0)
+			return priv->irq[IMX_MU_TYPE_RX];
+	} else {
+		ret = platform_get_irq(pdev, 0);
+		if (ret < 0)
+			return ret;
+
+		for (i = 0; i < IMX_MU_CHANS; i++)
+			priv->irq[i] = ret;
+	}
+
+	if (priv->dcfg->type & IMX_MU_V2_S4)
+		size = sizeof(struct imx_s4_rpc_msg_max);
+	else
+		size = sizeof(struct imx_sc_rpc_msg_max);
+
+	priv->msg = devm_kzalloc(dev, size, GFP_KERNEL);
+	if (!priv->msg)
+		return -ENOMEM;
+
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		if (PTR_ERR(priv->clk) != -ENOENT)
+			return PTR_ERR(priv->clk);
+
+		priv->clk = NULL;
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	priv->side_b = of_property_read_bool(np, "fsl,mu-side-b");
+
+	priv->dcfg->init(priv);
+
+	spin_lock_init(&priv->xcr_lock);
+
+	priv->mbox.dev = dev;
+	priv->mbox.ops = &imx_mu_ops;
+	priv->mbox.chans = priv->mbox_chans;
+	priv->mbox.txdone_irq = true;
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = devm_mbox_controller_register(dev, &priv->mbox);
+	if (ret) {
+		clk_disable_unprepare(priv->clk);
+		return ret;
+	}
+
+	pm_runtime_enable(dev);
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0)
+		goto disable_runtime_pm;
+
+	ret = pm_runtime_put_sync(dev);
+	if (ret < 0)
+		goto disable_runtime_pm;
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+
+disable_runtime_pm:
+	pm_runtime_disable(dev);
+	clk_disable_unprepare(priv->clk);
+	return ret;
+}
+
+static int imx_mu_remove(struct platform_device *pdev)
+{
+	struct imx_mu_priv *priv = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(priv->dev);
+
+	return 0;
+}
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx6sx = {
+	.tx	= imx_mu_generic_tx,
+	.rx	= imx_mu_generic_rx,
+	.rxdb	= imx_mu_generic_rxdb,
+	.init	= imx_mu_init_generic,
+	.xTR	= 0x0,
+	.xRR	= 0x10,
+	.xSR	= {0x20, 0x20, 0x20, 0x20},
+	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx7ulp = {
+	.tx	= imx_mu_generic_tx,
+	.rx	= imx_mu_generic_rx,
+	.rxdb	= imx_mu_generic_rxdb,
+	.init	= imx_mu_init_generic,
+	.xTR	= 0x20,
+	.xRR	= 0x40,
+	.xSR	= {0x60, 0x60, 0x60, 0x60},
+	.xCR	= {0x64, 0x64, 0x64, 0x64, 0x64},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
+	.tx	= imx_mu_generic_tx,
+	.rx	= imx_mu_generic_rx,
+	.rxdb	= imx_mu_generic_rxdb,
+	.init	= imx_mu_init_generic,
+	.type	= IMX_MU_V2,
+	.xTR	= 0x200,
+	.xRR	= 0x280,
+	.xSR	= {0xC, 0x118, 0x124, 0x12C},
+	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp_s4 = {
+	.tx	= imx_mu_specific_tx,
+	.rx	= imx_mu_specific_rx,
+	.init	= imx_mu_init_specific,
+	.type	= IMX_MU_V2 | IMX_MU_V2_S4,
+	.xTR	= 0x200,
+	.xRR	= 0x280,
+	.xSR	= {0xC, 0x118, 0x124, 0x12C},
+	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx93_s4 = {
+	.tx	= imx_mu_specific_tx,
+	.rx	= imx_mu_specific_rx,
+	.init	= imx_mu_init_specific,
+	.type	= IMX_MU_V2 | IMX_MU_V2_S4 | IMX_MU_V2_IRQ,
+	.xTR	= 0x200,
+	.xRR	= 0x280,
+	.xSR	= {0xC, 0x118, 0x124, 0x12C},
+	.xCR	= {0x8, 0x110, 0x114, 0x120, 0x128},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
+	.tx	= imx_mu_specific_tx,
+	.rx	= imx_mu_specific_rx,
+	.init	= imx_mu_init_specific,
+	.rxdb	= imx_mu_generic_rxdb,
+	.xTR	= 0x0,
+	.xRR	= 0x10,
+	.xSR	= {0x20, 0x20, 0x20, 0x20},
+	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
+};
+
+static const struct imx_mu_dcfg imx_mu_cfg_imx8_seco = {
+	.tx	= imx_mu_seco_tx,
+	.rx	= imx_mu_generic_rx,
+	.rxdb	= imx_mu_seco_rxdb,
+	.init	= imx_mu_init_seco,
+	.xTR	= 0x0,
+	.xRR	= 0x10,
+	.xSR	= {0x20, 0x20, 0x20, 0x20},
+	.xCR	= {0x24, 0x24, 0x24, 0x24, 0x24},
+};
+
+static const struct of_device_id imx_mu_dt_ids[] = {
+	{ .compatible = "fsl,imx7ulp-mu", .data = &imx_mu_cfg_imx7ulp },
+	{ .compatible = "fsl,imx6sx-mu", .data = &imx_mu_cfg_imx6sx },
+	{ .compatible = "fsl,imx8ulp-mu", .data = &imx_mu_cfg_imx8ulp },
+	{ .compatible = "fsl,imx8ulp-mu-s4", .data = &imx_mu_cfg_imx8ulp_s4 },
+	{ .compatible = "fsl,imx93-mu-s4", .data = &imx_mu_cfg_imx93_s4 },
+	{ .compatible = "fsl,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
+	{ .compatible = "fsl,imx8-mu-seco", .data = &imx_mu_cfg_imx8_seco },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, imx_mu_dt_ids);
+
+static int __maybe_unused imx_mu_suspend_noirq(struct device *dev)
+{
+	struct imx_mu_priv *priv = dev_get_drvdata(dev);
+	int i;
+
+	if (!priv->clk) {
+		for (i = 0; i < IMX_MU_xCR_MAX; i++)
+			priv->xcr[i] = imx_mu_read(priv, priv->dcfg->xCR[i]);
+	}
+
+	priv->suspend = true;
+
+	return 0;
+}
+
+static int __maybe_unused imx_mu_resume_noirq(struct device *dev)
+{
+	struct imx_mu_priv *priv = dev_get_drvdata(dev);
+	int i;
+
+	/*
+	 * ONLY restore MU when context lost, the TIE could
+	 * be set during noirq resume as there is MU data
+	 * communication going on, and restore the saved
+	 * value will overwrite the TIE and cause MU data
+	 * send failed, may lead to system freeze. This issue
+	 * is observed by testing freeze mode suspend.
+	 */
+	if (!priv->clk && !imx_mu_read(priv, priv->dcfg->xCR[0])) {
+		for (i = 0; i < IMX_MU_xCR_MAX; i++)
+			imx_mu_write(priv, priv->xcr[i], priv->dcfg->xCR[i]);
+	}
+
+	priv->suspend = false;
+
+	return 0;
+}
+
+static int __maybe_unused imx_mu_runtime_suspend(struct device *dev)
+{
+	struct imx_mu_priv *priv = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static int __maybe_unused imx_mu_runtime_resume(struct device *dev)
+{
+	struct imx_mu_priv *priv = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		dev_err(dev, "failed to enable clock\n");
+
+	return ret;
+}
+
+static const struct dev_pm_ops imx_mu_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_mu_suspend_noirq,
+				      imx_mu_resume_noirq)
+	SET_RUNTIME_PM_OPS(imx_mu_runtime_suspend,
+			   imx_mu_runtime_resume, NULL)
+};
+
+static struct platform_driver imx_mu_driver = {
+	.probe		= imx_mu_probe,
+	.remove		= imx_mu_remove,
+	.driver = {
+		.name	= "imx_mu",
+		.of_match_table = imx_mu_dt_ids,
+		.pm = &imx_mu_pm_ops,
+	},
+};
+module_platform_driver(imx_mu_driver);
+
+MODULE_AUTHOR("Oleksij Rempel <o.rempel@pengutronix.de>");
+MODULE_DESCRIPTION("Message Unit driver for i.MX");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/mailbox-altera.c b/drivers/mailbox/mailbox-altera.c
new file mode 100644
index 000000000..afb320e9d
--- /dev/null
+++ b/drivers/mailbox/mailbox-altera.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright Altera Corporation (C) 2013-2014. All rights reserved
+ */
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME	"altera-mailbox"
+
+#define MAILBOX_CMD_REG			0x00
+#define MAILBOX_PTR_REG			0x04
+#define MAILBOX_STS_REG			0x08
+#define MAILBOX_INTMASK_REG		0x0C
+
+#define INT_PENDING_MSK			0x1
+#define INT_SPACE_MSK			0x2
+
+#define STS_PENDING_MSK			0x1
+#define STS_FULL_MSK			0x2
+#define STS_FULL_OFT			0x1
+
+#define MBOX_PENDING(status)	(((status) & STS_PENDING_MSK))
+#define MBOX_FULL(status)	(((status) & STS_FULL_MSK) >> STS_FULL_OFT)
+
+enum altera_mbox_msg {
+	MBOX_CMD = 0,
+	MBOX_PTR,
+};
+
+#define MBOX_POLLING_MS		5	/* polling interval 5ms */
+
+struct altera_mbox {
+	bool is_sender;		/* 1-sender, 0-receiver */
+	bool intr_mode;
+	int irq;
+	void __iomem *mbox_base;
+	struct device *dev;
+	struct mbox_controller controller;
+
+	/* If the controller supports only RX polling mode */
+	struct timer_list rxpoll_timer;
+	struct mbox_chan *chan;
+};
+
+static struct altera_mbox *mbox_chan_to_altera_mbox(struct mbox_chan *chan)
+{
+	if (!chan || !chan->con_priv)
+		return NULL;
+
+	return (struct altera_mbox *)chan->con_priv;
+}
+
+static inline int altera_mbox_full(struct altera_mbox *mbox)
+{
+	u32 status;
+
+	status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
+	return MBOX_FULL(status);
+}
+
+static inline int altera_mbox_pending(struct altera_mbox *mbox)
+{
+	u32 status;
+
+	status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
+	return MBOX_PENDING(status);
+}
+
+static void altera_mbox_rx_intmask(struct altera_mbox *mbox, bool enable)
+{
+	u32 mask;
+
+	mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
+	if (enable)
+		mask |= INT_PENDING_MSK;
+	else
+		mask &= ~INT_PENDING_MSK;
+	writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
+}
+
+static void altera_mbox_tx_intmask(struct altera_mbox *mbox, bool enable)
+{
+	u32 mask;
+
+	mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
+	if (enable)
+		mask |= INT_SPACE_MSK;
+	else
+		mask &= ~INT_SPACE_MSK;
+	writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
+}
+
+static bool altera_mbox_is_sender(struct altera_mbox *mbox)
+{
+	u32 reg;
+	/* Write a magic number to PTR register and read back this register.
+	 * This register is read-write if it is a sender.
+	 */
+	#define MBOX_MAGIC	0xA5A5AA55
+	writel_relaxed(MBOX_MAGIC, mbox->mbox_base + MAILBOX_PTR_REG);
+	reg = readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
+	if (reg == MBOX_MAGIC) {
+		/* Clear to 0 */
+		writel_relaxed(0, mbox->mbox_base + MAILBOX_PTR_REG);
+		return true;
+	}
+	return false;
+}
+
+static void altera_mbox_rx_data(struct mbox_chan *chan)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+	u32 data[2];
+
+	if (altera_mbox_pending(mbox)) {
+		data[MBOX_PTR] =
+			readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
+		data[MBOX_CMD] =
+			readl_relaxed(mbox->mbox_base + MAILBOX_CMD_REG);
+		mbox_chan_received_data(chan, (void *)data);
+	}
+}
+
+static void altera_mbox_poll_rx(struct timer_list *t)
+{
+	struct altera_mbox *mbox = from_timer(mbox, t, rxpoll_timer);
+
+	altera_mbox_rx_data(mbox->chan);
+
+	mod_timer(&mbox->rxpoll_timer,
+		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
+}
+
+static irqreturn_t altera_mbox_tx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = (struct mbox_chan *)p;
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	altera_mbox_tx_intmask(mbox, false);
+	mbox_chan_txdone(chan, 0);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t altera_mbox_rx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = (struct mbox_chan *)p;
+
+	altera_mbox_rx_data(chan);
+	return IRQ_HANDLED;
+}
+
+static int altera_mbox_startup_sender(struct mbox_chan *chan)
+{
+	int ret;
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	if (mbox->intr_mode) {
+		ret = request_irq(mbox->irq, altera_mbox_tx_interrupt, 0,
+				  DRIVER_NAME, chan);
+		if (unlikely(ret)) {
+			dev_err(mbox->dev,
+				"failed to register mailbox interrupt:%d\n",
+				ret);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int altera_mbox_startup_receiver(struct mbox_chan *chan)
+{
+	int ret;
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	if (mbox->intr_mode) {
+		ret = request_irq(mbox->irq, altera_mbox_rx_interrupt, 0,
+				  DRIVER_NAME, chan);
+		if (unlikely(ret)) {
+			mbox->intr_mode = false;
+			goto polling; /* use polling if failed */
+		}
+
+		altera_mbox_rx_intmask(mbox, true);
+		return 0;
+	}
+
+polling:
+	/* Setup polling timer */
+	mbox->chan = chan;
+	timer_setup(&mbox->rxpoll_timer, altera_mbox_poll_rx, 0);
+	mod_timer(&mbox->rxpoll_timer,
+		  jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
+
+	return 0;
+}
+
+static int altera_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+	u32 *udata = (u32 *)data;
+
+	if (!mbox || !data)
+		return -EINVAL;
+	if (!mbox->is_sender) {
+		dev_warn(mbox->dev,
+			 "failed to send. This is receiver mailbox.\n");
+		return -EINVAL;
+	}
+
+	if (altera_mbox_full(mbox))
+		return -EBUSY;
+
+	/* Enable interrupt before send */
+	if (mbox->intr_mode)
+		altera_mbox_tx_intmask(mbox, true);
+
+	/* Pointer register must write before command register */
+	writel_relaxed(udata[MBOX_PTR], mbox->mbox_base + MAILBOX_PTR_REG);
+	writel_relaxed(udata[MBOX_CMD], mbox->mbox_base + MAILBOX_CMD_REG);
+
+	return 0;
+}
+
+static bool altera_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	/* Return false if mailbox is full */
+	return altera_mbox_full(mbox) ? false : true;
+}
+
+static bool altera_mbox_peek_data(struct mbox_chan *chan)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	return altera_mbox_pending(mbox) ? true : false;
+}
+
+static int altera_mbox_startup(struct mbox_chan *chan)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+	int ret = 0;
+
+	if (!mbox)
+		return -EINVAL;
+
+	if (mbox->is_sender)
+		ret = altera_mbox_startup_sender(chan);
+	else
+		ret = altera_mbox_startup_receiver(chan);
+
+	return ret;
+}
+
+static void altera_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
+
+	if (mbox->intr_mode) {
+		/* Unmask all interrupt masks */
+		writel_relaxed(~0, mbox->mbox_base + MAILBOX_INTMASK_REG);
+		free_irq(mbox->irq, chan);
+	} else if (!mbox->is_sender) {
+		del_timer_sync(&mbox->rxpoll_timer);
+	}
+}
+
+static const struct mbox_chan_ops altera_mbox_ops = {
+	.send_data = altera_mbox_send_data,
+	.startup = altera_mbox_startup,
+	.shutdown = altera_mbox_shutdown,
+	.last_tx_done = altera_mbox_last_tx_done,
+	.peek_data = altera_mbox_peek_data,
+};
+
+static int altera_mbox_probe(struct platform_device *pdev)
+{
+	struct altera_mbox *mbox;
+	struct mbox_chan *chans;
+	int ret;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox),
+			    GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	/* Allocated one channel */
+	chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mbox->mbox_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->mbox_base))
+		return PTR_ERR(mbox->mbox_base);
+
+	/* Check is it a sender or receiver? */
+	mbox->is_sender = altera_mbox_is_sender(mbox);
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq >= 0)
+		mbox->intr_mode = true;
+
+	mbox->dev = &pdev->dev;
+
+	/* Hardware supports only one channel. */
+	chans[0].con_priv = mbox;
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = chans;
+	mbox->controller.ops = &altera_mbox_ops;
+
+	if (mbox->is_sender) {
+		if (mbox->intr_mode) {
+			mbox->controller.txdone_irq = true;
+		} else {
+			mbox->controller.txdone_poll = true;
+			mbox->controller.txpoll_period = MBOX_POLLING_MS;
+		}
+	}
+
+	ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
+	if (ret) {
+		dev_err(&pdev->dev, "Register mailbox failed\n");
+		goto err;
+	}
+
+	platform_set_drvdata(pdev, mbox);
+err:
+	return ret;
+}
+
+static const struct of_device_id altera_mbox_match[] = {
+	{ .compatible = "altr,mailbox-1.0" },
+	{ /* Sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, altera_mbox_match);
+
+static struct platform_driver altera_mbox_driver = {
+	.probe	= altera_mbox_probe,
+	.driver	= {
+		.name	= DRIVER_NAME,
+		.of_match_table	= altera_mbox_match,
+	},
+};
+
+module_platform_driver(altera_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Altera mailbox specific functions");
+MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
+MODULE_ALIAS("platform:altera-mailbox");
diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c
new file mode 100644
index 000000000..08aa840cc
--- /dev/null
+++ b/drivers/mailbox/mailbox-mpfs.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver
+ *
+ * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved.
+ *
+ * Author: Conor Dooley <conor.dooley@microchip.com>
+ *
+ */
+
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+#include <soc/microchip/mpfs.h>
+
+#define SERVICES_CR_OFFSET		0x50u
+#define SERVICES_SR_OFFSET		0x54u
+#define MAILBOX_REG_OFFSET		0x800u
+#define MSS_SYS_MAILBOX_DATA_OFFSET	0u
+#define SCB_MASK_WIDTH			16u
+
+/* SCBCTRL service control register */
+
+#define SCB_CTRL_REQ (0)
+#define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ)
+
+#define SCB_CTRL_BUSY (1)
+#define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY)
+
+#define SCB_CTRL_ABORT (2)
+#define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT)
+
+#define SCB_CTRL_NOTIFY (3)
+#define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY)
+
+#define SCB_CTRL_POS (16)
+#define SCB_CTRL_MASK GENMASK_ULL(SCB_CTRL_POS + SCB_MASK_WIDTH, SCB_CTRL_POS)
+
+/* SCBCTRL service status register */
+
+#define SCB_STATUS_REQ (0)
+#define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ)
+
+#define SCB_STATUS_BUSY (1)
+#define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY)
+
+#define SCB_STATUS_ABORT (2)
+#define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT)
+
+#define SCB_STATUS_NOTIFY (3)
+#define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY)
+
+#define SCB_STATUS_POS (16)
+#define SCB_STATUS_MASK GENMASK(SCB_STATUS_POS + SCB_MASK_WIDTH - 1, SCB_STATUS_POS)
+
+struct mpfs_mbox {
+	struct mbox_controller controller;
+	struct device *dev;
+	int irq;
+	void __iomem *ctrl_base;
+	void __iomem *mbox_base;
+	void __iomem *int_reg;
+	struct mbox_chan chans[1];
+	struct mpfs_mss_response *response;
+	u16 resp_offset;
+};
+
+static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
+{
+	u32 status;
+
+	status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET);
+
+	return status & SCB_STATUS_BUSY_MASK;
+}
+
+static bool mpfs_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+	return !mpfs_mbox_busy(mbox);
+}
+
+static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+	struct mpfs_mss_msg *msg = data;
+	u32 tx_trigger;
+	u16 opt_sel;
+	u32 val = 0u;
+
+	mbox->response = msg->response;
+	mbox->resp_offset = msg->resp_offset;
+
+	if (mpfs_mbox_busy(mbox))
+		return -EBUSY;
+
+	if (msg->cmd_data_size) {
+		u32 index;
+		u8 extra_bits = msg->cmd_data_size & 3;
+		u32 *word_buf = (u32 *)msg->cmd_data;
+
+		for (index = 0; index < (msg->cmd_data_size / 4); index++)
+			writel_relaxed(word_buf[index],
+				       mbox->mbox_base + msg->mbox_offset + index * 0x4);
+		if (extra_bits) {
+			u8 i;
+			u8 byte_off = ALIGN_DOWN(msg->cmd_data_size, 4);
+			u8 *byte_buf = msg->cmd_data + byte_off;
+
+			val = readl_relaxed(mbox->mbox_base + msg->mbox_offset + index * 0x4);
+
+			for (i = 0u; i < extra_bits; i++) {
+				val &= ~(0xffu << (i * 8u));
+				val |= (byte_buf[i] << (i * 8u));
+			}
+
+			writel_relaxed(val, mbox->mbox_base + msg->mbox_offset + index * 0x4);
+		}
+	}
+
+	opt_sel = ((msg->mbox_offset << 7u) | (msg->cmd_opcode & 0x7fu));
+	tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK;
+	tx_trigger |= SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK;
+	writel_relaxed(tx_trigger, mbox->ctrl_base + SERVICES_CR_OFFSET);
+
+	return 0;
+}
+
+static void mpfs_mbox_rx_data(struct mbox_chan *chan)
+{
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+	struct mpfs_mss_response *response = mbox->response;
+	u16 num_words = ALIGN((response->resp_size), (4)) / 4U;
+	u32 i, status;
+
+	if (!response->resp_msg) {
+		dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM);
+		return;
+	}
+
+	/*
+	 * The status is stored in bits 31:16 of the SERVICES_SR register.
+	 * It is only valid when BUSY == 0.
+	 * We should *never* get an interrupt while the controller is
+	 * still in the busy state. If we do, something has gone badly
+	 * wrong & the content of the mailbox would not be valid.
+	 */
+	if (mpfs_mbox_busy(mbox)) {
+		dev_err(mbox->dev, "got an interrupt but system controller is busy\n");
+		response->resp_status = 0xDEAD;
+		return;
+	}
+
+	status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET);
+
+	/*
+	 * If the status of the individual servers is non-zero, the service has
+	 * failed. The contents of the mailbox at this point are not be valid,
+	 * so don't bother reading them. Set the status so that the driver
+	 * implementing the service can handle the result.
+	 */
+	response->resp_status = (status & SCB_STATUS_MASK) >> SCB_STATUS_POS;
+	if (response->resp_status)
+		return;
+
+	if (!mpfs_mbox_busy(mbox)) {
+		for (i = 0; i < num_words; i++) {
+			response->resp_msg[i] =
+				readl_relaxed(mbox->mbox_base
+					      + mbox->resp_offset + i * 0x4);
+		}
+	}
+
+	mbox_chan_received_data(chan, response);
+}
+
+static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+	writel_relaxed(0, mbox->int_reg);
+
+	mpfs_mbox_rx_data(chan);
+
+	return IRQ_HANDLED;
+}
+
+static int mpfs_mbox_startup(struct mbox_chan *chan)
+{
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+	int ret = 0;
+
+	if (!mbox)
+		return -EINVAL;
+
+	ret = devm_request_irq(mbox->dev, mbox->irq, mpfs_mbox_inbox_isr, 0, "mpfs-mailbox", chan);
+	if (ret)
+		dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", ret);
+
+	return ret;
+}
+
+static void mpfs_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv;
+
+	devm_free_irq(mbox->dev, mbox->irq, chan);
+}
+
+static const struct mbox_chan_ops mpfs_mbox_ops = {
+	.send_data = mpfs_mbox_send_data,
+	.startup = mpfs_mbox_startup,
+	.shutdown = mpfs_mbox_shutdown,
+	.last_tx_done = mpfs_mbox_last_tx_done,
+};
+
+static int mpfs_mbox_probe(struct platform_device *pdev)
+{
+	struct mpfs_mbox *mbox;
+	struct resource *regs;
+	int ret;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->ctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, &regs);
+	if (IS_ERR(mbox->ctrl_base))
+		return PTR_ERR(mbox->ctrl_base);
+
+	mbox->int_reg = devm_platform_get_and_ioremap_resource(pdev, 1, &regs);
+	if (IS_ERR(mbox->int_reg))
+		return PTR_ERR(mbox->int_reg);
+
+	mbox->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 2, &regs);
+	if (IS_ERR(mbox->mbox_base)) // account for the old dt-binding w/ 2 regs
+		mbox->mbox_base = mbox->ctrl_base + MAILBOX_REG_OFFSET;
+
+	mbox->irq = platform_get_irq(pdev, 0);
+	if (mbox->irq < 0)
+		return mbox->irq;
+
+	mbox->dev = &pdev->dev;
+
+	mbox->chans[0].con_priv = mbox;
+	mbox->controller.dev = mbox->dev;
+	mbox->controller.num_chans = 1;
+	mbox->controller.chans = mbox->chans;
+	mbox->controller.ops = &mpfs_mbox_ops;
+	mbox->controller.txdone_poll = true;
+	mbox->controller.txpoll_period = 10u;
+
+	ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
+	if (ret) {
+		dev_err(&pdev->dev, "Registering MPFS mailbox controller failed\n");
+		return ret;
+	}
+	dev_info(&pdev->dev, "Registered MPFS mailbox controller driver\n");
+
+	return 0;
+}
+
+static const struct of_device_id mpfs_mbox_of_match[] = {
+	{.compatible = "microchip,mpfs-mailbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mpfs_mbox_of_match);
+
+static struct platform_driver mpfs_mbox_driver = {
+	.driver = {
+		.name = "mpfs-mailbox",
+		.of_match_table = mpfs_mbox_of_match,
+	},
+	.probe = mpfs_mbox_probe,
+};
+module_platform_driver(mpfs_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
+MODULE_DESCRIPTION("MPFS mailbox controller driver");
diff --git a/drivers/mailbox/mailbox-sti.c b/drivers/mailbox/mailbox-sti.c
new file mode 100644
index 000000000..823061dd8
--- /dev/null
+++ b/drivers/mailbox/mailbox-sti.c
@@ -0,0 +1,497 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * STi Mailbox
+ *
+ * Copyright (C) 2015 ST Microelectronics
+ *
+ * Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics
+ *
+ * Based on the original driver written by;
+ *   Alexandre Torgue, Olivier Lebreton and Loic Pallardy
+ */
+
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include "mailbox.h"
+
+#define STI_MBOX_INST_MAX	4      /* RAM saving: Max supported instances */
+#define STI_MBOX_CHAN_MAX	20     /* RAM saving: Max supported channels  */
+
+#define STI_IRQ_VAL_OFFSET	0x04   /* Read interrupt status	              */
+#define STI_IRQ_SET_OFFSET	0x24   /* Generate a Tx channel interrupt     */
+#define STI_IRQ_CLR_OFFSET	0x44   /* Clear pending Rx interrupts	      */
+#define STI_ENA_VAL_OFFSET	0x64   /* Read enable status		      */
+#define STI_ENA_SET_OFFSET	0x84   /* Enable a channel		      */
+#define STI_ENA_CLR_OFFSET	0xa4   /* Disable a channel		      */
+
+#define MBOX_BASE(mdev, inst)   ((mdev)->base + ((inst) * 4))
+
+/**
+ * struct sti_mbox_device - STi Mailbox device data
+ *
+ * @dev:	Device to which it is attached
+ * @mbox:	Representation of a communication channel controller
+ * @base:	Base address of the register mapping region
+ * @name:	Name of the mailbox
+ * @enabled:	Local copy of enabled channels
+ * @lock:	Mutex protecting enabled status
+ *
+ * An IP Mailbox is currently composed of 4 instances
+ * Each instance is currently composed of 32 channels
+ * This means that we have 128 channels per Mailbox
+ * A channel an be used for TX or RX
+ */
+struct sti_mbox_device {
+	struct device		*dev;
+	struct mbox_controller	*mbox;
+	void __iomem		*base;
+	const char		*name;
+	u32			enabled[STI_MBOX_INST_MAX];
+	spinlock_t		lock;
+};
+
+/**
+ * struct sti_mbox_pdata - STi Mailbox platform specific configuration
+ *
+ * @num_inst:	Maximum number of instances in one HW Mailbox
+ * @num_chan:	Maximum number of channel per instance
+ */
+struct sti_mbox_pdata {
+	unsigned int		num_inst;
+	unsigned int		num_chan;
+};
+
+/**
+ * struct sti_channel - STi Mailbox allocated channel information
+ *
+ * @mdev:	Pointer to parent Mailbox device
+ * @instance:	Instance number channel resides in
+ * @channel:	Channel number pertaining to this container
+ */
+struct sti_channel {
+	struct sti_mbox_device	*mdev;
+	unsigned int		instance;
+	unsigned int		channel;
+};
+
+static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+
+	return mdev->enabled[instance] & BIT(channel);
+}
+
+static inline
+struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox,
+				      unsigned int instance,
+				      unsigned int channel)
+{
+	struct sti_channel *chan_info;
+	int i;
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+		if (chan_info &&
+		    chan_info->instance == instance &&
+		    chan_info->channel == channel)
+			return &mbox->chans[i];
+	}
+
+	dev_err(mbox->dev,
+		"Channel not registered: instance: %d channel: %d\n",
+		instance, channel);
+
+	return NULL;
+}
+
+static void sti_mbox_enable_channel(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	unsigned long flags;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	spin_lock_irqsave(&mdev->lock, flags);
+	mdev->enabled[instance] |= BIT(channel);
+	writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET);
+	spin_unlock_irqrestore(&mdev->lock, flags);
+}
+
+static void sti_mbox_disable_channel(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	unsigned long flags;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	spin_lock_irqsave(&mdev->lock, flags);
+	mdev->enabled[instance] &= ~BIT(channel);
+	writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET);
+	spin_unlock_irqrestore(&mdev->lock, flags);
+}
+
+static void sti_mbox_clear_irq(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET);
+}
+
+static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev,
+						 unsigned int instance)
+{
+	struct mbox_controller *mbox = mdev->mbox;
+	struct mbox_chan *chan = NULL;
+	unsigned int channel;
+	unsigned long bits;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET);
+	if (!bits)
+		/* No IRQs fired in specified instance */
+		return NULL;
+
+	/* An IRQ has fired, find the associated channel */
+	for (channel = 0; bits; channel++) {
+		if (!test_and_clear_bit(channel, &bits))
+			continue;
+
+		chan = sti_mbox_to_channel(mbox, instance, channel);
+		if (chan) {
+			dev_dbg(mbox->dev,
+				"IRQ fired on instance: %d channel: %d\n",
+				instance, channel);
+			break;
+		}
+	}
+
+	return chan;
+}
+
+static irqreturn_t sti_mbox_thread_handler(int irq, void *data)
+{
+	struct sti_mbox_device *mdev = data;
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct mbox_chan *chan;
+	unsigned int instance;
+
+	for (instance = 0; instance < pdata->num_inst; instance++) {
+keep_looking:
+		chan = sti_mbox_irq_to_channel(mdev, instance);
+		if (!chan)
+			continue;
+
+		mbox_chan_received_data(chan, NULL);
+		sti_mbox_clear_irq(chan);
+		sti_mbox_enable_channel(chan);
+		goto keep_looking;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sti_mbox_irq_handler(int irq, void *data)
+{
+	struct sti_mbox_device *mdev = data;
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct sti_channel *chan_info;
+	struct mbox_chan *chan;
+	unsigned int instance;
+	int ret = IRQ_NONE;
+
+	for (instance = 0; instance < pdata->num_inst; instance++) {
+		chan = sti_mbox_irq_to_channel(mdev, instance);
+		if (!chan)
+			continue;
+		chan_info = chan->con_priv;
+
+		if (!sti_mbox_channel_is_enabled(chan)) {
+			dev_warn(mdev->dev,
+				 "Unexpected IRQ: %s\n"
+				 "  instance: %d: channel: %d [enabled: %x]\n",
+				 mdev->name, chan_info->instance,
+				 chan_info->channel, mdev->enabled[instance]);
+
+			/* Only handle IRQ if no other valid IRQs were found */
+			if (ret == IRQ_NONE)
+				ret = IRQ_HANDLED;
+			continue;
+		}
+
+		sti_mbox_disable_channel(chan);
+		ret = IRQ_WAKE_THREAD;
+	}
+
+	if (ret == IRQ_NONE)
+		dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n");
+
+	return ret;
+}
+
+static bool sti_mbox_tx_is_ready(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) {
+		dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n",
+			mdev->name, instance, channel);
+		return false;
+	}
+
+	if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) {
+		dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n",
+			mdev->name, instance, channel);
+		return false;
+	}
+
+	return true;
+}
+
+static int sti_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct sti_mbox_device *mdev = chan_info->mdev;
+	unsigned int instance = chan_info->instance;
+	unsigned int channel = chan_info->channel;
+	void __iomem *base = MBOX_BASE(mdev, instance);
+
+	/* Send event to co-processor */
+	writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET);
+
+	dev_dbg(mdev->dev,
+		"Sent via Mailbox %s: instance: %d channel: %d\n",
+		mdev->name, instance, channel);
+
+	return 0;
+}
+
+static int sti_mbox_startup_chan(struct mbox_chan *chan)
+{
+	sti_mbox_clear_irq(chan);
+	sti_mbox_enable_channel(chan);
+
+	return 0;
+}
+
+static void sti_mbox_shutdown_chan(struct mbox_chan *chan)
+{
+	struct sti_channel *chan_info = chan->con_priv;
+	struct mbox_controller *mbox = chan_info->mdev->mbox;
+	int i;
+
+	for (i = 0; i < mbox->num_chans; i++)
+		if (chan == &mbox->chans[i])
+			break;
+
+	if (mbox->num_chans == i) {
+		dev_warn(mbox->dev, "Request to free non-existent channel\n");
+		return;
+	}
+
+	/* Reset channel */
+	sti_mbox_disable_channel(chan);
+	sti_mbox_clear_irq(chan);
+	chan->con_priv = NULL;
+}
+
+static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox,
+					const struct of_phandle_args *spec)
+{
+	struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev);
+	struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev);
+	struct sti_channel *chan_info;
+	struct mbox_chan *chan = NULL;
+	unsigned int instance  = spec->args[0];
+	unsigned int channel   = spec->args[1];
+	int i;
+
+	/* Bounds checking */
+	if (instance >= pdata->num_inst || channel  >= pdata->num_chan) {
+		dev_err(mbox->dev,
+			"Invalid channel requested instance: %d channel: %d\n",
+			instance, channel);
+		return ERR_PTR(-EINVAL);
+	}
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan_info = mbox->chans[i].con_priv;
+
+		/* Is requested channel free? */
+		if (chan_info &&
+		    mbox->dev == chan_info->mdev->dev &&
+		    instance == chan_info->instance &&
+		    channel == chan_info->channel) {
+
+			dev_err(mbox->dev, "Channel in use\n");
+			return ERR_PTR(-EBUSY);
+		}
+
+		/*
+		 * Find the first free slot, then continue checking
+		 * to see if requested channel is in use
+		 */
+		if (!chan && !chan_info)
+			chan = &mbox->chans[i];
+	}
+
+	if (!chan) {
+		dev_err(mbox->dev, "No free channels left\n");
+		return ERR_PTR(-EBUSY);
+	}
+
+	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);
+	if (!chan_info)
+		return ERR_PTR(-ENOMEM);
+
+	chan_info->mdev		= mdev;
+	chan_info->instance	= instance;
+	chan_info->channel	= channel;
+
+	chan->con_priv = chan_info;
+
+	dev_info(mbox->dev,
+		 "Mbox: %s: Created channel: instance: %d channel: %d\n",
+		 mdev->name, instance, channel);
+
+	return chan;
+}
+
+static const struct mbox_chan_ops sti_mbox_ops = {
+	.startup	= sti_mbox_startup_chan,
+	.shutdown	= sti_mbox_shutdown_chan,
+	.send_data	= sti_mbox_send_data,
+	.last_tx_done	= sti_mbox_tx_is_ready,
+};
+
+static const struct sti_mbox_pdata mbox_stih407_pdata = {
+	.num_inst	= 4,
+	.num_chan	= 32,
+};
+
+static const struct of_device_id sti_mailbox_match[] = {
+	{
+		.compatible = "st,stih407-mailbox",
+		.data = (void *)&mbox_stih407_pdata
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sti_mailbox_match);
+
+static int sti_mbox_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct mbox_controller *mbox;
+	struct sti_mbox_device *mdev;
+	struct device_node *np = pdev->dev.of_node;
+	struct mbox_chan *chans;
+	int irq;
+	int ret;
+
+	match = of_match_device(sti_mailbox_match, &pdev->dev);
+	if (!match) {
+		dev_err(&pdev->dev, "No configuration found\n");
+		return -ENODEV;
+	}
+	pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data;
+
+	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, mdev);
+
+	mdev->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mdev->base))
+		return PTR_ERR(mdev->base);
+
+	ret = of_property_read_string(np, "mbox-name", &mdev->name);
+	if (ret)
+		mdev->name = np->full_name;
+
+	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	chans = devm_kcalloc(&pdev->dev,
+			     STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	mdev->dev		= &pdev->dev;
+	mdev->mbox		= mbox;
+
+	spin_lock_init(&mdev->lock);
+
+	/* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */
+	mbox->txdone_irq	= false;
+	mbox->txdone_poll	= true;
+	mbox->txpoll_period	= 100;
+	mbox->ops		= &sti_mbox_ops;
+	mbox->dev		= mdev->dev;
+	mbox->of_xlate		= sti_mbox_xlate;
+	mbox->chans		= chans;
+	mbox->num_chans		= STI_MBOX_CHAN_MAX;
+
+	ret = devm_mbox_controller_register(&pdev->dev, mbox);
+	if (ret)
+		return ret;
+
+	/* It's okay for Tx Mailboxes to not supply IRQs */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_info(&pdev->dev,
+			 "%s: Registered Tx only Mailbox\n", mdev->name);
+		return 0;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, irq,
+					sti_mbox_irq_handler,
+					sti_mbox_thread_handler,
+					IRQF_ONESHOT, mdev->name, mdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq);
+		return -EINVAL;
+	}
+
+	dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name);
+
+	return 0;
+}
+
+static struct platform_driver sti_mbox_driver = {
+	.probe = sti_mbox_probe,
+	.driver = {
+		.name = "sti-mailbox",
+		.of_match_table = sti_mailbox_match,
+	},
+};
+module_platform_driver(sti_mbox_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
+MODULE_ALIAS("platform:mailbox-sti");
diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
new file mode 100644
index 000000000..abcee58e8
--- /dev/null
+++ b/drivers/mailbox/mailbox-test.c
@@ -0,0 +1,454 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2015 ST Microelectronics
+ *
+ * Author: Lee Jones <lee.jones@linaro.org>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/err.h>
+#include <linux/fs.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_client.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/sched/signal.h>
+
+#define MBOX_MAX_SIG_LEN	8
+#define MBOX_MAX_MSG_LEN	128
+#define MBOX_BYTES_PER_LINE	16
+#define MBOX_HEXDUMP_LINE_LEN	((MBOX_BYTES_PER_LINE * 4) + 2)
+#define MBOX_HEXDUMP_MAX_LEN	(MBOX_HEXDUMP_LINE_LEN *		\
+				 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
+
+static bool mbox_data_ready;
+
+struct mbox_test_device {
+	struct device		*dev;
+	void __iomem		*tx_mmio;
+	void __iomem		*rx_mmio;
+	struct mbox_chan	*tx_channel;
+	struct mbox_chan	*rx_channel;
+	char			*rx_buffer;
+	char			*signal;
+	char			*message;
+	spinlock_t		lock;
+	struct mutex		mutex;
+	wait_queue_head_t	waitq;
+	struct fasync_struct	*async_queue;
+	struct dentry		*root_debugfs_dir;
+};
+
+static ssize_t mbox_test_signal_write(struct file *filp,
+				       const char __user *userbuf,
+				       size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+
+	if (!tdev->tx_channel) {
+		dev_err(tdev->dev, "Channel cannot do Tx\n");
+		return -EINVAL;
+	}
+
+	if (count > MBOX_MAX_SIG_LEN) {
+		dev_err(tdev->dev,
+			"Signal length %zd greater than max allowed %d\n",
+			count, MBOX_MAX_SIG_LEN);
+		return -EINVAL;
+	}
+
+	/* Only allocate memory if we need to */
+	if (!tdev->signal) {
+		tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
+		if (!tdev->signal)
+			return -ENOMEM;
+	}
+
+	if (copy_from_user(tdev->signal, userbuf, count)) {
+		kfree(tdev->signal);
+		tdev->signal = NULL;
+		return -EFAULT;
+	}
+
+	return count;
+}
+
+static const struct file_operations mbox_test_signal_ops = {
+	.write	= mbox_test_signal_write,
+	.open	= simple_open,
+	.llseek	= generic_file_llseek,
+};
+
+static int mbox_test_message_fasync(int fd, struct file *filp, int on)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+
+	return fasync_helper(fd, filp, on, &tdev->async_queue);
+}
+
+static ssize_t mbox_test_message_write(struct file *filp,
+				       const char __user *userbuf,
+				       size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+	char *message;
+	void *data;
+	int ret;
+
+	if (!tdev->tx_channel) {
+		dev_err(tdev->dev, "Channel cannot do Tx\n");
+		return -EINVAL;
+	}
+
+	if (count > MBOX_MAX_MSG_LEN) {
+		dev_err(tdev->dev,
+			"Message length %zd greater than max allowed %d\n",
+			count, MBOX_MAX_MSG_LEN);
+		return -EINVAL;
+	}
+
+	message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
+	if (!message)
+		return -ENOMEM;
+
+	mutex_lock(&tdev->mutex);
+
+	tdev->message = message;
+	ret = copy_from_user(tdev->message, userbuf, count);
+	if (ret) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	/*
+	 * A separate signal is only of use if there is
+	 * MMIO to subsequently pass the message through
+	 */
+	if (tdev->tx_mmio && tdev->signal) {
+		print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
+				     tdev->signal, MBOX_MAX_SIG_LEN);
+
+		data = tdev->signal;
+	} else
+		data = tdev->message;
+
+	print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
+			     tdev->message, MBOX_MAX_MSG_LEN);
+
+	ret = mbox_send_message(tdev->tx_channel, data);
+	if (ret < 0)
+		dev_err(tdev->dev, "Failed to send message via mailbox\n");
+
+out:
+	kfree(tdev->signal);
+	kfree(tdev->message);
+	tdev->signal = NULL;
+
+	mutex_unlock(&tdev->mutex);
+
+	return ret < 0 ? ret : count;
+}
+
+static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
+{
+	bool data_ready;
+	unsigned long flags;
+
+	spin_lock_irqsave(&tdev->lock, flags);
+	data_ready = mbox_data_ready;
+	spin_unlock_irqrestore(&tdev->lock, flags);
+
+	return data_ready;
+}
+
+static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
+				      size_t count, loff_t *ppos)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+	unsigned long flags;
+	char *touser, *ptr;
+	int l = 0;
+	int ret;
+
+	DECLARE_WAITQUEUE(wait, current);
+
+	touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
+	if (!touser)
+		return -ENOMEM;
+
+	if (!tdev->rx_channel) {
+		ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
+		ret = simple_read_from_buffer(userbuf, count, ppos,
+					      touser, ret);
+		goto kfree_err;
+	}
+
+	add_wait_queue(&tdev->waitq, &wait);
+
+	do {
+		__set_current_state(TASK_INTERRUPTIBLE);
+
+		if (mbox_test_message_data_ready(tdev))
+			break;
+
+		if (filp->f_flags & O_NONBLOCK) {
+			ret = -EAGAIN;
+			goto waitq_err;
+		}
+
+		if (signal_pending(current)) {
+			ret = -ERESTARTSYS;
+			goto waitq_err;
+		}
+		schedule();
+
+	} while (1);
+
+	spin_lock_irqsave(&tdev->lock, flags);
+
+	ptr = tdev->rx_buffer;
+	while (l < MBOX_HEXDUMP_MAX_LEN) {
+		hex_dump_to_buffer(ptr,
+				   MBOX_BYTES_PER_LINE,
+				   MBOX_BYTES_PER_LINE, 1, touser + l,
+				   MBOX_HEXDUMP_LINE_LEN, true);
+
+		ptr += MBOX_BYTES_PER_LINE;
+		l += MBOX_HEXDUMP_LINE_LEN;
+		*(touser + (l - 1)) = '\n';
+	}
+	*(touser + l) = '\0';
+
+	memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
+	mbox_data_ready = false;
+
+	spin_unlock_irqrestore(&tdev->lock, flags);
+
+	ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
+waitq_err:
+	__set_current_state(TASK_RUNNING);
+	remove_wait_queue(&tdev->waitq, &wait);
+kfree_err:
+	kfree(touser);
+	return ret;
+}
+
+static __poll_t
+mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
+{
+	struct mbox_test_device *tdev = filp->private_data;
+
+	poll_wait(filp, &tdev->waitq, wait);
+
+	if (mbox_test_message_data_ready(tdev))
+		return EPOLLIN | EPOLLRDNORM;
+	return 0;
+}
+
+static const struct file_operations mbox_test_message_ops = {
+	.write	= mbox_test_message_write,
+	.read	= mbox_test_message_read,
+	.fasync	= mbox_test_message_fasync,
+	.poll	= mbox_test_message_poll,
+	.open	= simple_open,
+	.llseek	= generic_file_llseek,
+};
+
+static int mbox_test_add_debugfs(struct platform_device *pdev,
+				 struct mbox_test_device *tdev)
+{
+	if (!debugfs_initialized())
+		return 0;
+
+	tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL);
+	if (!tdev->root_debugfs_dir) {
+		dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
+		return -EINVAL;
+	}
+
+	debugfs_create_file("message", 0600, tdev->root_debugfs_dir,
+			    tdev, &mbox_test_message_ops);
+
+	debugfs_create_file("signal", 0200, tdev->root_debugfs_dir,
+			    tdev, &mbox_test_signal_ops);
+
+	return 0;
+}
+
+static void mbox_test_receive_message(struct mbox_client *client, void *message)
+{
+	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&tdev->lock, flags);
+	if (tdev->rx_mmio) {
+		memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
+		print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
+				     tdev->rx_buffer, MBOX_MAX_MSG_LEN);
+	} else if (message) {
+		print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
+				     message, MBOX_MAX_MSG_LEN);
+		memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
+	}
+	mbox_data_ready = true;
+	spin_unlock_irqrestore(&tdev->lock, flags);
+
+	wake_up_interruptible(&tdev->waitq);
+
+	kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
+}
+
+static void mbox_test_prepare_message(struct mbox_client *client, void *message)
+{
+	struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
+
+	if (tdev->tx_mmio) {
+		if (tdev->signal)
+			memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
+		else
+			memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
+	}
+}
+
+static void mbox_test_message_sent(struct mbox_client *client,
+				   void *message, int r)
+{
+	if (r)
+		dev_warn(client->dev,
+			 "Client: Message could not be sent: %d\n", r);
+	else
+		dev_info(client->dev,
+			 "Client: Message sent\n");
+}
+
+static struct mbox_chan *
+mbox_test_request_channel(struct platform_device *pdev, const char *name)
+{
+	struct mbox_client *client;
+	struct mbox_chan *channel;
+
+	client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return ERR_PTR(-ENOMEM);
+
+	client->dev		= &pdev->dev;
+	client->rx_callback	= mbox_test_receive_message;
+	client->tx_prepare	= mbox_test_prepare_message;
+	client->tx_done		= mbox_test_message_sent;
+	client->tx_block	= true;
+	client->knows_txdone	= false;
+	client->tx_tout		= 500;
+
+	channel = mbox_request_channel_byname(client, name);
+	if (IS_ERR(channel)) {
+		dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
+		return NULL;
+	}
+
+	return channel;
+}
+
+static int mbox_test_probe(struct platform_device *pdev)
+{
+	struct mbox_test_device *tdev;
+	struct resource *res;
+	resource_size_t size;
+	int ret;
+
+	tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
+	if (!tdev)
+		return -ENOMEM;
+
+	/* It's okay for MMIO to be NULL */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
+		/* if reserved area in SRAM, try just ioremap */
+		size = resource_size(res);
+		tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
+	} else if (IS_ERR(tdev->tx_mmio)) {
+		tdev->tx_mmio = NULL;
+	}
+
+	/* If specified, second reg entry is Rx MMIO */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
+		size = resource_size(res);
+		tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
+	} else if (IS_ERR(tdev->rx_mmio)) {
+		tdev->rx_mmio = tdev->tx_mmio;
+	}
+
+	tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
+	tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
+
+	if (!tdev->tx_channel && !tdev->rx_channel)
+		return -EPROBE_DEFER;
+
+	/* If Rx is not specified but has Rx MMIO, then Rx = Tx */
+	if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
+		tdev->rx_channel = tdev->tx_channel;
+
+	tdev->dev = &pdev->dev;
+	platform_set_drvdata(pdev, tdev);
+
+	spin_lock_init(&tdev->lock);
+	mutex_init(&tdev->mutex);
+
+	if (tdev->rx_channel) {
+		tdev->rx_buffer = devm_kzalloc(&pdev->dev,
+					       MBOX_MAX_MSG_LEN, GFP_KERNEL);
+		if (!tdev->rx_buffer)
+			return -ENOMEM;
+	}
+
+	ret = mbox_test_add_debugfs(pdev, tdev);
+	if (ret)
+		return ret;
+
+	init_waitqueue_head(&tdev->waitq);
+	dev_info(&pdev->dev, "Successfully registered\n");
+
+	return 0;
+}
+
+static int mbox_test_remove(struct platform_device *pdev)
+{
+	struct mbox_test_device *tdev = platform_get_drvdata(pdev);
+
+	debugfs_remove_recursive(tdev->root_debugfs_dir);
+
+	if (tdev->tx_channel)
+		mbox_free_channel(tdev->tx_channel);
+	if (tdev->rx_channel)
+		mbox_free_channel(tdev->rx_channel);
+
+	return 0;
+}
+
+static const struct of_device_id mbox_test_match[] = {
+	{ .compatible = "mailbox-test" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mbox_test_match);
+
+static struct platform_driver mbox_test_driver = {
+	.driver = {
+		.name = "mailbox_test",
+		.of_match_table = mbox_test_match,
+	},
+	.probe  = mbox_test_probe,
+	.remove = mbox_test_remove,
+};
+module_platform_driver(mbox_test_driver);
+
+MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
+MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
new file mode 100644
index 000000000..946ea773e
--- /dev/null
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -0,0 +1,260 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * APM X-Gene SLIMpro MailBox Driver
+ *
+ * Copyright (c) 2015, Applied Micro Circuits Corporation
+ * Author: Feng Kan fkan@apm.com
+ */
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#define MBOX_CON_NAME			"slimpro-mbox"
+#define MBOX_REG_SET_OFFSET		0x1000
+#define MBOX_CNT			8
+#define MBOX_STATUS_AVAIL_MASK		BIT(16)
+#define MBOX_STATUS_ACK_MASK		BIT(0)
+
+/* Configuration and Status Registers */
+#define REG_DB_IN		0x00
+#define REG_DB_DIN0		0x04
+#define REG_DB_DIN1		0x08
+#define REG_DB_OUT		0x10
+#define REG_DB_DOUT0		0x14
+#define REG_DB_DOUT1		0x18
+#define REG_DB_STAT		0x20
+#define REG_DB_STATMASK		0x24
+
+/**
+ * X-Gene SlimPRO mailbox channel information
+ *
+ * @dev:	Device to which it is attached
+ * @chan:	Pointer to mailbox communication channel
+ * @reg:	Base address to access channel registers
+ * @irq:	Interrupt number of the channel
+ * @rx_msg:	Received message storage
+ */
+struct slimpro_mbox_chan {
+	struct device		*dev;
+	struct mbox_chan	*chan;
+	void __iomem		*reg;
+	int			irq;
+	u32			rx_msg[3];
+};
+
+/**
+ * X-Gene SlimPRO Mailbox controller data
+ *
+ * X-Gene SlimPRO Mailbox controller has 8 communication channels.
+ * Each channel has a separate IRQ number assigned to it.
+ *
+ * @mb_ctrl:	Representation of the communication channel controller
+ * @mc:		Array of SlimPRO mailbox channels of the controller
+ * @chans:	Array of mailbox communication channels
+ *
+ */
+struct slimpro_mbox {
+	struct mbox_controller		mb_ctrl;
+	struct slimpro_mbox_chan	mc[MBOX_CNT];
+	struct mbox_chan		chans[MBOX_CNT];
+};
+
+static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
+{
+	writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
+	writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
+	writel(msg[0], mb_chan->reg + REG_DB_OUT);
+}
+
+static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
+{
+	mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
+	mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
+	mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
+}
+
+static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_ACK_MASK) {
+		writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
+{
+	u32 val = readl(mb_chan->reg + REG_DB_STAT);
+
+	if (val & MBOX_STATUS_AVAIL_MASK) {
+		mb_chan_recv_msg(mb_chan);
+		writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
+		return 1;
+	}
+	return 0;
+}
+
+static irqreturn_t slimpro_mbox_irq(int irq, void *id)
+{
+	struct slimpro_mbox_chan *mb_chan = id;
+
+	if (mb_chan_status_ack(mb_chan))
+		mbox_chan_txdone(mb_chan->chan, 0);
+
+	if (mb_chan_status_avail(mb_chan))
+		mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
+
+	return IRQ_HANDLED;
+}
+
+static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+
+	mb_chan_send_msg(mb_chan, msg);
+	return 0;
+}
+
+static int slimpro_mbox_startup(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	int rc;
+	u32 val;
+
+	rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
+			      MBOX_CON_NAME, mb_chan);
+	if (unlikely(rc)) {
+		dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
+			mb_chan->irq);
+		return rc;
+	}
+
+	/* Enable HW interrupt */
+	writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
+	       mb_chan->reg + REG_DB_STAT);
+	/* Unmask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	return 0;
+}
+
+static void slimpro_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct slimpro_mbox_chan *mb_chan = chan->con_priv;
+	u32 val;
+
+	/* Mask doorbell status interrupt */
+	val = readl(mb_chan->reg + REG_DB_STATMASK);
+	val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
+	writel(val, mb_chan->reg + REG_DB_STATMASK);
+
+	devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
+}
+
+static const struct mbox_chan_ops slimpro_mbox_ops = {
+	.send_data = slimpro_mbox_send_data,
+	.startup = slimpro_mbox_startup,
+	.shutdown = slimpro_mbox_shutdown,
+};
+
+static int slimpro_mbox_probe(struct platform_device *pdev)
+{
+	struct slimpro_mbox *ctx;
+	void __iomem *mb_base;
+	int rc;
+	int i;
+
+	ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ctx);
+
+	mb_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mb_base))
+		return PTR_ERR(mb_base);
+
+	/* Setup mailbox links */
+	for (i = 0; i < MBOX_CNT; i++) {
+		ctx->mc[i].irq = platform_get_irq(pdev, i);
+		if (ctx->mc[i].irq < 0) {
+			if (i == 0) {
+				dev_err(&pdev->dev, "no available IRQ\n");
+				return -EINVAL;
+			}
+			dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
+			break;
+		}
+
+		ctx->mc[i].dev = &pdev->dev;
+		ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
+		ctx->mc[i].chan = &ctx->chans[i];
+		ctx->chans[i].con_priv = &ctx->mc[i];
+	}
+
+	/* Setup mailbox controller */
+	ctx->mb_ctrl.dev = &pdev->dev;
+	ctx->mb_ctrl.chans = ctx->chans;
+	ctx->mb_ctrl.txdone_irq = true;
+	ctx->mb_ctrl.ops = &slimpro_mbox_ops;
+	ctx->mb_ctrl.num_chans = i;
+
+	rc = devm_mbox_controller_register(&pdev->dev, &ctx->mb_ctrl);
+	if (rc) {
+		dev_err(&pdev->dev,
+			"APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
+		return rc;
+	}
+
+	dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
+	return 0;
+}
+
+static const struct of_device_id slimpro_of_match[] = {
+	{.compatible = "apm,xgene-slimpro-mbox" },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, slimpro_of_match);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id slimpro_acpi_ids[] = {
+	{"APMC0D01", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
+#endif
+
+static struct platform_driver slimpro_mbox_driver = {
+	.probe	= slimpro_mbox_probe,
+	.driver	= {
+		.name = "xgene-slimpro-mbox",
+		.of_match_table = of_match_ptr(slimpro_of_match),
+		.acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
+	},
+};
+
+static int __init slimpro_mbox_init(void)
+{
+	return platform_driver_register(&slimpro_mbox_driver);
+}
+
+static void __exit slimpro_mbox_exit(void)
+{
+	platform_driver_unregister(&slimpro_mbox_driver);
+}
+
+subsys_initcall(slimpro_mbox_init);
+module_exit(slimpro_mbox_exit);
+
+MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
new file mode 100644
index 000000000..4229b9b5d
--- /dev/null
+++ b/drivers/mailbox/mailbox.c
@@ -0,0 +1,625 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Mailbox: Common code for Mailbox controllers and users
+ *
+ * Copyright (C) 2013-2014 Linaro Ltd.
+ * Author: Jassi Brar <jassisinghbrar@gmail.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/bitops.h>
+#include <linux/mailbox_client.h>
+#include <linux/mailbox_controller.h>
+
+#include "mailbox.h"
+
+static LIST_HEAD(mbox_cons);
+static DEFINE_MUTEX(con_mutex);
+
+static int add_to_rbuf(struct mbox_chan *chan, void *mssg)
+{
+	int idx;
+	unsigned long flags;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	/* See if there is any space left */
+	if (chan->msg_count == MBOX_TX_QUEUE_LEN) {
+		spin_unlock_irqrestore(&chan->lock, flags);
+		return -ENOBUFS;
+	}
+
+	idx = chan->msg_free;
+	chan->msg_data[idx] = mssg;
+	chan->msg_count++;
+
+	if (idx == MBOX_TX_QUEUE_LEN - 1)
+		chan->msg_free = 0;
+	else
+		chan->msg_free++;
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	return idx;
+}
+
+static void msg_submit(struct mbox_chan *chan)
+{
+	unsigned count, idx;
+	unsigned long flags;
+	void *data;
+	int err = -EBUSY;
+
+	spin_lock_irqsave(&chan->lock, flags);
+
+	if (!chan->msg_count || chan->active_req)
+		goto exit;
+
+	count = chan->msg_count;
+	idx = chan->msg_free;
+	if (idx >= count)
+		idx -= count;
+	else
+		idx += MBOX_TX_QUEUE_LEN - count;
+
+	data = chan->msg_data[idx];
+
+	if (chan->cl->tx_prepare)
+		chan->cl->tx_prepare(chan->cl, data);
+	/* Try to submit a message to the MBOX controller */
+	err = chan->mbox->ops->send_data(chan, data);
+	if (!err) {
+		chan->active_req = data;
+		chan->msg_count--;
+	}
+exit:
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	if (!err && (chan->txdone_method & TXDONE_BY_POLL)) {
+		/* kick start the timer immediately to avoid delays */
+		spin_lock_irqsave(&chan->mbox->poll_hrt_lock, flags);
+		hrtimer_start(&chan->mbox->poll_hrt, 0, HRTIMER_MODE_REL);
+		spin_unlock_irqrestore(&chan->mbox->poll_hrt_lock, flags);
+	}
+}
+
+static void tx_tick(struct mbox_chan *chan, int r)
+{
+	unsigned long flags;
+	void *mssg;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	mssg = chan->active_req;
+	chan->active_req = NULL;
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	/* Submit next message */
+	msg_submit(chan);
+
+	if (!mssg)
+		return;
+
+	/* Notify the client */
+	if (chan->cl->tx_done)
+		chan->cl->tx_done(chan->cl, mssg, r);
+
+	if (r != -ETIME && chan->cl->tx_block)
+		complete(&chan->tx_complete);
+}
+
+static enum hrtimer_restart txdone_hrtimer(struct hrtimer *hrtimer)
+{
+	struct mbox_controller *mbox =
+		container_of(hrtimer, struct mbox_controller, poll_hrt);
+	bool txdone, resched = false;
+	int i;
+	unsigned long flags;
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		struct mbox_chan *chan = &mbox->chans[i];
+
+		if (chan->active_req && chan->cl) {
+			txdone = chan->mbox->ops->last_tx_done(chan);
+			if (txdone)
+				tx_tick(chan, 0);
+			else
+				resched = true;
+		}
+	}
+
+	if (resched) {
+		spin_lock_irqsave(&mbox->poll_hrt_lock, flags);
+		if (!hrtimer_is_queued(hrtimer))
+			hrtimer_forward_now(hrtimer, ms_to_ktime(mbox->txpoll_period));
+		spin_unlock_irqrestore(&mbox->poll_hrt_lock, flags);
+
+		return HRTIMER_RESTART;
+	}
+	return HRTIMER_NORESTART;
+}
+
+/**
+ * mbox_chan_received_data - A way for controller driver to push data
+ *				received from remote to the upper layer.
+ * @chan: Pointer to the mailbox channel on which RX happened.
+ * @mssg: Client specific message typecasted as void *
+ *
+ * After startup and before shutdown any data received on the chan
+ * is passed on to the API via atomic mbox_chan_received_data().
+ * The controller should ACK the RX only after this call returns.
+ */
+void mbox_chan_received_data(struct mbox_chan *chan, void *mssg)
+{
+	/* No buffering the received data */
+	if (chan->cl->rx_callback)
+		chan->cl->rx_callback(chan->cl, mssg);
+}
+EXPORT_SYMBOL_GPL(mbox_chan_received_data);
+
+/**
+ * mbox_chan_txdone - A way for controller driver to notify the
+ *			framework that the last TX has completed.
+ * @chan: Pointer to the mailbox chan on which TX happened.
+ * @r: Status of last TX - OK or ERROR
+ *
+ * The controller that has IRQ for TX ACK calls this atomic API
+ * to tick the TX state machine. It works only if txdone_irq
+ * is set by the controller.
+ */
+void mbox_chan_txdone(struct mbox_chan *chan, int r)
+{
+	if (unlikely(!(chan->txdone_method & TXDONE_BY_IRQ))) {
+		dev_err(chan->mbox->dev,
+		       "Controller can't run the TX ticker\n");
+		return;
+	}
+
+	tx_tick(chan, r);
+}
+EXPORT_SYMBOL_GPL(mbox_chan_txdone);
+
+/**
+ * mbox_client_txdone - The way for a client to run the TX state machine.
+ * @chan: Mailbox channel assigned to this client.
+ * @r: Success status of last transmission.
+ *
+ * The client/protocol had received some 'ACK' packet and it notifies
+ * the API that the last packet was sent successfully. This only works
+ * if the controller can't sense TX-Done.
+ */
+void mbox_client_txdone(struct mbox_chan *chan, int r)
+{
+	if (unlikely(!(chan->txdone_method & TXDONE_BY_ACK))) {
+		dev_err(chan->mbox->dev, "Client can't run the TX ticker\n");
+		return;
+	}
+
+	tx_tick(chan, r);
+}
+EXPORT_SYMBOL_GPL(mbox_client_txdone);
+
+/**
+ * mbox_client_peek_data - A way for client driver to pull data
+ *			received from remote by the controller.
+ * @chan: Mailbox channel assigned to this client.
+ *
+ * A poke to controller driver for any received data.
+ * The data is actually passed onto client via the
+ * mbox_chan_received_data()
+ * The call can be made from atomic context, so the controller's
+ * implementation of peek_data() must not sleep.
+ *
+ * Return: True, if controller has, and is going to push after this,
+ *          some data.
+ *         False, if controller doesn't have any data to be read.
+ */
+bool mbox_client_peek_data(struct mbox_chan *chan)
+{
+	if (chan->mbox->ops->peek_data)
+		return chan->mbox->ops->peek_data(chan);
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(mbox_client_peek_data);
+
+/**
+ * mbox_send_message -	For client to submit a message to be
+ *				sent to the remote.
+ * @chan: Mailbox channel assigned to this client.
+ * @mssg: Client specific message typecasted.
+ *
+ * For client to submit data to the controller destined for a remote
+ * processor. If the client had set 'tx_block', the call will return
+ * either when the remote receives the data or when 'tx_tout' millisecs
+ * run out.
+ *  In non-blocking mode, the requests are buffered by the API and a
+ * non-negative token is returned for each queued request. If the request
+ * is not queued, a negative token is returned. Upon failure or successful
+ * TX, the API calls 'tx_done' from atomic context, from which the client
+ * could submit yet another request.
+ * The pointer to message should be preserved until it is sent
+ * over the chan, i.e, tx_done() is made.
+ * This function could be called from atomic context as it simply
+ * queues the data and returns a token against the request.
+ *
+ * Return: Non-negative integer for successful submission (non-blocking mode)
+ *	or transmission over chan (blocking mode).
+ *	Negative value denotes failure.
+ */
+int mbox_send_message(struct mbox_chan *chan, void *mssg)
+{
+	int t;
+
+	if (!chan || !chan->cl)
+		return -EINVAL;
+
+	t = add_to_rbuf(chan, mssg);
+	if (t < 0) {
+		dev_err(chan->mbox->dev, "Try increasing MBOX_TX_QUEUE_LEN\n");
+		return t;
+	}
+
+	msg_submit(chan);
+
+	if (chan->cl->tx_block) {
+		unsigned long wait;
+		int ret;
+
+		if (!chan->cl->tx_tout) /* wait forever */
+			wait = msecs_to_jiffies(3600000);
+		else
+			wait = msecs_to_jiffies(chan->cl->tx_tout);
+
+		ret = wait_for_completion_timeout(&chan->tx_complete, wait);
+		if (ret == 0) {
+			t = -ETIME;
+			tx_tick(chan, t);
+		}
+	}
+
+	return t;
+}
+EXPORT_SYMBOL_GPL(mbox_send_message);
+
+/**
+ * mbox_flush - flush a mailbox channel
+ * @chan: mailbox channel to flush
+ * @timeout: time, in milliseconds, to allow the flush operation to succeed
+ *
+ * Mailbox controllers that need to work in atomic context can implement the
+ * ->flush() callback to busy loop until a transmission has been completed.
+ * The implementation must call mbox_chan_txdone() upon success. Clients can
+ * call the mbox_flush() function at any time after mbox_send_message() to
+ * flush the transmission. After the function returns success, the mailbox
+ * transmission is guaranteed to have completed.
+ *
+ * Returns: 0 on success or a negative error code on failure.
+ */
+int mbox_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+	int ret;
+
+	if (!chan->mbox->ops->flush)
+		return -ENOTSUPP;
+
+	ret = chan->mbox->ops->flush(chan, timeout);
+	if (ret < 0)
+		tx_tick(chan, ret);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(mbox_flush);
+
+/**
+ * mbox_request_channel - Request a mailbox channel.
+ * @cl: Identity of the client requesting the channel.
+ * @index: Index of mailbox specifier in 'mboxes' property.
+ *
+ * The Client specifies its requirements and capabilities while asking for
+ * a mailbox channel. It can't be called from atomic context.
+ * The channel is exclusively allocated and can't be used by another
+ * client before the owner calls mbox_free_channel.
+ * After assignment, any packet received on this channel will be
+ * handed over to the client via the 'rx_callback'.
+ * The framework holds reference to the client, so the mbox_client
+ * structure shouldn't be modified until the mbox_free_channel returns.
+ *
+ * Return: Pointer to the channel assigned to the client if successful.
+ *		ERR_PTR for request failure.
+ */
+struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
+{
+	struct device *dev = cl->dev;
+	struct mbox_controller *mbox;
+	struct of_phandle_args spec;
+	struct mbox_chan *chan;
+	unsigned long flags;
+	int ret;
+
+	if (!dev || !dev->of_node) {
+		pr_debug("%s: No owner device node\n", __func__);
+		return ERR_PTR(-ENODEV);
+	}
+
+	mutex_lock(&con_mutex);
+
+	if (of_parse_phandle_with_args(dev->of_node, "mboxes",
+				       "#mbox-cells", index, &spec)) {
+		dev_dbg(dev, "%s: can't parse \"mboxes\" property\n", __func__);
+		mutex_unlock(&con_mutex);
+		return ERR_PTR(-ENODEV);
+	}
+
+	chan = ERR_PTR(-EPROBE_DEFER);
+	list_for_each_entry(mbox, &mbox_cons, node)
+		if (mbox->dev->of_node == spec.np) {
+			chan = mbox->of_xlate(mbox, &spec);
+			if (!IS_ERR(chan))
+				break;
+		}
+
+	of_node_put(spec.np);
+
+	if (IS_ERR(chan)) {
+		mutex_unlock(&con_mutex);
+		return chan;
+	}
+
+	if (chan->cl || !try_module_get(mbox->dev->driver->owner)) {
+		dev_dbg(dev, "%s: mailbox not free\n", __func__);
+		mutex_unlock(&con_mutex);
+		return ERR_PTR(-EBUSY);
+	}
+
+	spin_lock_irqsave(&chan->lock, flags);
+	chan->msg_free = 0;
+	chan->msg_count = 0;
+	chan->active_req = NULL;
+	chan->cl = cl;
+	init_completion(&chan->tx_complete);
+
+	if (chan->txdone_method	== TXDONE_BY_POLL && cl->knows_txdone)
+		chan->txdone_method = TXDONE_BY_ACK;
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	if (chan->mbox->ops->startup) {
+		ret = chan->mbox->ops->startup(chan);
+
+		if (ret) {
+			dev_err(dev, "Unable to startup the chan (%d)\n", ret);
+			mbox_free_channel(chan);
+			chan = ERR_PTR(ret);
+		}
+	}
+
+	mutex_unlock(&con_mutex);
+	return chan;
+}
+EXPORT_SYMBOL_GPL(mbox_request_channel);
+
+struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
+					      const char *name)
+{
+	struct device_node *np = cl->dev->of_node;
+	struct property *prop;
+	const char *mbox_name;
+	int index = 0;
+
+	if (!np) {
+		dev_err(cl->dev, "%s() currently only supports DT\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!of_get_property(np, "mbox-names", NULL)) {
+		dev_err(cl->dev,
+			"%s() requires an \"mbox-names\" property\n", __func__);
+		return ERR_PTR(-EINVAL);
+	}
+
+	of_property_for_each_string(np, "mbox-names", prop, mbox_name) {
+		if (!strncmp(name, mbox_name, strlen(name)))
+			return mbox_request_channel(cl, index);
+		index++;
+	}
+
+	dev_err(cl->dev, "%s() could not locate channel named \"%s\"\n",
+		__func__, name);
+	return ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL_GPL(mbox_request_channel_byname);
+
+/**
+ * mbox_free_channel - The client relinquishes control of a mailbox
+ *			channel by this call.
+ * @chan: The mailbox channel to be freed.
+ */
+void mbox_free_channel(struct mbox_chan *chan)
+{
+	unsigned long flags;
+
+	if (!chan || !chan->cl)
+		return;
+
+	if (chan->mbox->ops->shutdown)
+		chan->mbox->ops->shutdown(chan);
+
+	/* The queued TX requests are simply aborted, no callbacks are made */
+	spin_lock_irqsave(&chan->lock, flags);
+	chan->cl = NULL;
+	chan->active_req = NULL;
+	if (chan->txdone_method == TXDONE_BY_ACK)
+		chan->txdone_method = TXDONE_BY_POLL;
+
+	module_put(chan->mbox->dev->driver->owner);
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+EXPORT_SYMBOL_GPL(mbox_free_channel);
+
+static struct mbox_chan *
+of_mbox_index_xlate(struct mbox_controller *mbox,
+		    const struct of_phandle_args *sp)
+{
+	int ind = sp->args[0];
+
+	if (ind >= mbox->num_chans)
+		return ERR_PTR(-EINVAL);
+
+	return &mbox->chans[ind];
+}
+
+/**
+ * mbox_controller_register - Register the mailbox controller
+ * @mbox:	Pointer to the mailbox controller.
+ *
+ * The controller driver registers its communication channels
+ */
+int mbox_controller_register(struct mbox_controller *mbox)
+{
+	int i, txdone;
+
+	/* Sanity check */
+	if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)
+		return -EINVAL;
+
+	if (mbox->txdone_irq)
+		txdone = TXDONE_BY_IRQ;
+	else if (mbox->txdone_poll)
+		txdone = TXDONE_BY_POLL;
+	else /* It has to be ACK then */
+		txdone = TXDONE_BY_ACK;
+
+	if (txdone == TXDONE_BY_POLL) {
+
+		if (!mbox->ops->last_tx_done) {
+			dev_err(mbox->dev, "last_tx_done method is absent\n");
+			return -EINVAL;
+		}
+
+		hrtimer_init(&mbox->poll_hrt, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_REL);
+		mbox->poll_hrt.function = txdone_hrtimer;
+		spin_lock_init(&mbox->poll_hrt_lock);
+	}
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		struct mbox_chan *chan = &mbox->chans[i];
+
+		chan->cl = NULL;
+		chan->mbox = mbox;
+		chan->txdone_method = txdone;
+		spin_lock_init(&chan->lock);
+	}
+
+	if (!mbox->of_xlate)
+		mbox->of_xlate = of_mbox_index_xlate;
+
+	mutex_lock(&con_mutex);
+	list_add_tail(&mbox->node, &mbox_cons);
+	mutex_unlock(&con_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(mbox_controller_register);
+
+/**
+ * mbox_controller_unregister - Unregister the mailbox controller
+ * @mbox:	Pointer to the mailbox controller.
+ */
+void mbox_controller_unregister(struct mbox_controller *mbox)
+{
+	int i;
+
+	if (!mbox)
+		return;
+
+	mutex_lock(&con_mutex);
+
+	list_del(&mbox->node);
+
+	for (i = 0; i < mbox->num_chans; i++)
+		mbox_free_channel(&mbox->chans[i]);
+
+	if (mbox->txdone_poll)
+		hrtimer_cancel(&mbox->poll_hrt);
+
+	mutex_unlock(&con_mutex);
+}
+EXPORT_SYMBOL_GPL(mbox_controller_unregister);
+
+static void __devm_mbox_controller_unregister(struct device *dev, void *res)
+{
+	struct mbox_controller **mbox = res;
+
+	mbox_controller_unregister(*mbox);
+}
+
+static int devm_mbox_controller_match(struct device *dev, void *res, void *data)
+{
+	struct mbox_controller **mbox = res;
+
+	if (WARN_ON(!mbox || !*mbox))
+		return 0;
+
+	return *mbox == data;
+}
+
+/**
+ * devm_mbox_controller_register() - managed mbox_controller_register()
+ * @dev: device owning the mailbox controller being registered
+ * @mbox: mailbox controller being registered
+ *
+ * This function adds a device-managed resource that will make sure that the
+ * mailbox controller, which is registered using mbox_controller_register()
+ * as part of this function, will be unregistered along with the rest of
+ * device-managed resources upon driver probe failure or driver removal.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int devm_mbox_controller_register(struct device *dev,
+				  struct mbox_controller *mbox)
+{
+	struct mbox_controller **ptr;
+	int err;
+
+	ptr = devres_alloc(__devm_mbox_controller_unregister, sizeof(*ptr),
+			   GFP_KERNEL);
+	if (!ptr)
+		return -ENOMEM;
+
+	err = mbox_controller_register(mbox);
+	if (err < 0) {
+		devres_free(ptr);
+		return err;
+	}
+
+	devres_add(dev, ptr);
+	*ptr = mbox;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_register);
+
+/**
+ * devm_mbox_controller_unregister() - managed mbox_controller_unregister()
+ * @dev: device owning the mailbox controller being unregistered
+ * @mbox: mailbox controller being unregistered
+ *
+ * This function unregisters the mailbox controller and removes the device-
+ * managed resource that was set up to automatically unregister the mailbox
+ * controller on driver probe failure or driver removal. It's typically not
+ * necessary to call this function.
+ */
+void devm_mbox_controller_unregister(struct device *dev, struct mbox_controller *mbox)
+{
+	WARN_ON(devres_release(dev, __devm_mbox_controller_unregister,
+			       devm_mbox_controller_match, mbox));
+}
+EXPORT_SYMBOL_GPL(devm_mbox_controller_unregister);
diff --git a/drivers/mailbox/mailbox.h b/drivers/mailbox/mailbox.h
new file mode 100644
index 000000000..046d6d258
--- /dev/null
+++ b/drivers/mailbox/mailbox.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __MAILBOX_H
+#define __MAILBOX_H
+
+#define TXDONE_BY_IRQ	BIT(0) /* controller has remote RTR irq */
+#define TXDONE_BY_POLL	BIT(1) /* controller can read status of last TX */
+#define TXDONE_BY_ACK	BIT(2) /* S/W ACK received by Client ticks the TX */
+
+#endif /* __MAILBOX_H */
diff --git a/drivers/mailbox/mtk-adsp-mailbox.c b/drivers/mailbox/mtk-adsp-mailbox.c
new file mode 100644
index 000000000..14bc0057d
--- /dev/null
+++ b/drivers/mailbox/mtk-adsp-mailbox.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2022 MediaTek Corporation. All rights reserved.
+ * Author: Allen-KH Cheng <allen-kh.cheng@mediatek.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+
+struct mtk_adsp_mbox_priv {
+	struct device *dev;
+	struct mbox_controller mbox;
+	void __iomem *va_mboxreg;
+	const struct mtk_adsp_mbox_cfg *cfg;
+};
+
+struct mtk_adsp_mbox_cfg {
+	u32 set_in;
+	u32 set_out;
+	u32 clr_in;
+	u32 clr_out;
+};
+
+static inline struct mtk_adsp_mbox_priv *get_mtk_adsp_mbox_priv(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct mtk_adsp_mbox_priv, mbox);
+}
+
+static irqreturn_t mtk_adsp_mbox_irq(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
+	u32 op = readl(priv->va_mboxreg + priv->cfg->set_out);
+
+	writel(op, priv->va_mboxreg + priv->cfg->clr_out);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t mtk_adsp_mbox_isr(int irq, void *data)
+{
+	struct mbox_chan *chan = data;
+
+	mbox_chan_received_data(chan, NULL);
+
+	return IRQ_HANDLED;
+}
+
+static struct mbox_chan *mtk_adsp_mbox_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *sp)
+{
+	return mbox->chans;
+}
+
+static int mtk_adsp_mbox_startup(struct mbox_chan *chan)
+{
+	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
+
+	/* Clear ADSP mbox command */
+	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in);
+	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out);
+
+	return 0;
+}
+
+static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
+
+	/* Clear ADSP mbox command */
+	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_in);
+	writel(0xFFFFFFFF, priv->va_mboxreg + priv->cfg->clr_out);
+}
+
+static int mtk_adsp_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
+	u32 *msg = data;
+
+	writel(*msg, priv->va_mboxreg + priv->cfg->set_in);
+
+	return 0;
+}
+
+static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct mtk_adsp_mbox_priv *priv = get_mtk_adsp_mbox_priv(chan->mbox);
+
+	return readl(priv->va_mboxreg + priv->cfg->set_in) == 0;
+}
+
+static const struct mbox_chan_ops mtk_adsp_mbox_chan_ops = {
+	.send_data	= mtk_adsp_mbox_send_data,
+	.startup	= mtk_adsp_mbox_startup,
+	.shutdown	= mtk_adsp_mbox_shutdown,
+	.last_tx_done	= mtk_adsp_mbox_last_tx_done,
+};
+
+static int mtk_adsp_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_adsp_mbox_priv *priv;
+	const struct mtk_adsp_mbox_cfg *cfg;
+	struct mbox_controller *mbox;
+	int ret, irq;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	mbox = &priv->mbox;
+	mbox->dev = dev;
+	mbox->ops = &mtk_adsp_mbox_chan_ops;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = true;
+	mbox->of_xlate = mtk_adsp_mbox_xlate;
+	mbox->num_chans = 1;
+	mbox->chans = devm_kzalloc(dev, sizeof(*mbox->chans), GFP_KERNEL);
+	if (!mbox->chans)
+		return -ENOMEM;
+
+	priv->va_mboxreg = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->va_mboxreg))
+		return PTR_ERR(priv->va_mboxreg);
+
+	cfg = of_device_get_match_data(dev);
+	if (!cfg)
+		return -EINVAL;
+	priv->cfg = cfg;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	ret = devm_request_threaded_irq(dev, irq, mtk_adsp_mbox_irq,
+					mtk_adsp_mbox_isr, IRQF_TRIGGER_NONE,
+					dev_name(dev), mbox->chans);
+	if (ret < 0)
+		return ret;
+
+	platform_set_drvdata(pdev, priv);
+
+	return devm_mbox_controller_register(dev, &priv->mbox);
+}
+
+static const struct mtk_adsp_mbox_cfg mt8186_adsp_mbox_cfg = {
+	.set_in		= 0x00,
+	.set_out	= 0x04,
+	.clr_in		= 0x08,
+	.clr_out	= 0x0C,
+};
+
+static const struct mtk_adsp_mbox_cfg mt8195_adsp_mbox_cfg = {
+	.set_in		= 0x00,
+	.set_out	= 0x1c,
+	.clr_in		= 0x04,
+	.clr_out	= 0x20,
+};
+
+static const struct of_device_id mtk_adsp_mbox_of_match[] = {
+	{ .compatible = "mediatek,mt8186-adsp-mbox", .data = &mt8186_adsp_mbox_cfg },
+	{ .compatible = "mediatek,mt8195-adsp-mbox", .data = &mt8195_adsp_mbox_cfg },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_adsp_mbox_of_match);
+
+static struct platform_driver mtk_adsp_mbox_driver = {
+	.probe		= mtk_adsp_mbox_probe,
+	.driver = {
+		.name	= "mtk_adsp_mbox",
+		.of_match_table = mtk_adsp_mbox_of_match,
+	},
+};
+module_platform_driver(mtk_adsp_mbox_driver);
+
+MODULE_AUTHOR("Allen-KH Cheng <Allen-KH.Cheng@mediatek.com>");
+MODULE_DESCRIPTION("MTK ADSP Mailbox Controller");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
new file mode 100644
index 000000000..9465f9081
--- /dev/null
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -0,0 +1,695 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2018 MediaTek Inc.
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/mtk-cmdq-mailbox.h>
+#include <linux/of_device.h>
+
+#define CMDQ_OP_CODE_MASK		(0xff << CMDQ_OP_CODE_SHIFT)
+#define CMDQ_NUM_CMD(t)			(t->cmd_buf_size / CMDQ_INST_SIZE)
+#define CMDQ_GCE_NUM_MAX		(2)
+
+#define CMDQ_CURR_IRQ_STATUS		0x10
+#define CMDQ_SYNC_TOKEN_UPDATE		0x68
+#define CMDQ_THR_SLOT_CYCLES		0x30
+#define CMDQ_THR_BASE			0x100
+#define CMDQ_THR_SIZE			0x80
+#define CMDQ_THR_WARM_RESET		0x00
+#define CMDQ_THR_ENABLE_TASK		0x04
+#define CMDQ_THR_SUSPEND_TASK		0x08
+#define CMDQ_THR_CURR_STATUS		0x0c
+#define CMDQ_THR_IRQ_STATUS		0x10
+#define CMDQ_THR_IRQ_ENABLE		0x14
+#define CMDQ_THR_CURR_ADDR		0x20
+#define CMDQ_THR_END_ADDR		0x24
+#define CMDQ_THR_WAIT_TOKEN		0x30
+#define CMDQ_THR_PRIORITY		0x40
+
+#define GCE_GCTL_VALUE			0x48
+
+#define CMDQ_THR_ACTIVE_SLOT_CYCLES	0x3200
+#define CMDQ_THR_ENABLED		0x1
+#define CMDQ_THR_DISABLED		0x0
+#define CMDQ_THR_SUSPEND		0x1
+#define CMDQ_THR_RESUME			0x0
+#define CMDQ_THR_STATUS_SUSPENDED	BIT(1)
+#define CMDQ_THR_DO_WARM_RESET		BIT(0)
+#define CMDQ_THR_IRQ_DONE		0x1
+#define CMDQ_THR_IRQ_ERROR		0x12
+#define CMDQ_THR_IRQ_EN			(CMDQ_THR_IRQ_ERROR | CMDQ_THR_IRQ_DONE)
+#define CMDQ_THR_IS_WAITING		BIT(31)
+
+#define CMDQ_JUMP_BY_OFFSET		0x10000000
+#define CMDQ_JUMP_BY_PA			0x10000001
+
+struct cmdq_thread {
+	struct mbox_chan	*chan;
+	void __iomem		*base;
+	struct list_head	task_busy_list;
+	u32			priority;
+};
+
+struct cmdq_task {
+	struct cmdq		*cmdq;
+	struct list_head	list_entry;
+	dma_addr_t		pa_base;
+	struct cmdq_thread	*thread;
+	struct cmdq_pkt		*pkt; /* the packet sent from mailbox client */
+};
+
+struct cmdq {
+	struct mbox_controller	mbox;
+	void __iomem		*base;
+	int			irq;
+	u32			thread_nr;
+	u32			irq_mask;
+	struct cmdq_thread	*thread;
+	struct clk_bulk_data	clocks[CMDQ_GCE_NUM_MAX];
+	bool			suspended;
+	u8			shift_pa;
+	bool			control_by_sw;
+	u32			gce_num;
+};
+
+struct gce_plat {
+	u32 thread_nr;
+	u8 shift;
+	bool control_by_sw;
+	u32 gce_num;
+};
+
+u8 cmdq_get_shift_pa(struct mbox_chan *chan)
+{
+	struct cmdq *cmdq = container_of(chan->mbox, struct cmdq, mbox);
+
+	return cmdq->shift_pa;
+}
+EXPORT_SYMBOL(cmdq_get_shift_pa);
+
+static int cmdq_thread_suspend(struct cmdq *cmdq, struct cmdq_thread *thread)
+{
+	u32 status;
+
+	writel(CMDQ_THR_SUSPEND, thread->base + CMDQ_THR_SUSPEND_TASK);
+
+	/* If already disabled, treat as suspended successful. */
+	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
+		return 0;
+
+	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_CURR_STATUS,
+			status, status & CMDQ_THR_STATUS_SUSPENDED, 0, 10)) {
+		dev_err(cmdq->mbox.dev, "suspend GCE thread 0x%x failed\n",
+			(u32)(thread->base - cmdq->base));
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static void cmdq_thread_resume(struct cmdq_thread *thread)
+{
+	writel(CMDQ_THR_RESUME, thread->base + CMDQ_THR_SUSPEND_TASK);
+}
+
+static void cmdq_init(struct cmdq *cmdq)
+{
+	int i;
+
+	WARN_ON(clk_bulk_enable(cmdq->gce_num, cmdq->clocks));
+	if (cmdq->control_by_sw)
+		writel(0x7, cmdq->base + GCE_GCTL_VALUE);
+	writel(CMDQ_THR_ACTIVE_SLOT_CYCLES, cmdq->base + CMDQ_THR_SLOT_CYCLES);
+	for (i = 0; i <= CMDQ_MAX_EVENT; i++)
+		writel(i, cmdq->base + CMDQ_SYNC_TOKEN_UPDATE);
+	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+}
+
+static int cmdq_thread_reset(struct cmdq *cmdq, struct cmdq_thread *thread)
+{
+	u32 warm_reset;
+
+	writel(CMDQ_THR_DO_WARM_RESET, thread->base + CMDQ_THR_WARM_RESET);
+	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_WARM_RESET,
+			warm_reset, !(warm_reset & CMDQ_THR_DO_WARM_RESET),
+			0, 10)) {
+		dev_err(cmdq->mbox.dev, "reset GCE thread 0x%x failed\n",
+			(u32)(thread->base - cmdq->base));
+		return -EFAULT;
+	}
+
+	return 0;
+}
+
+static void cmdq_thread_disable(struct cmdq *cmdq, struct cmdq_thread *thread)
+{
+	cmdq_thread_reset(cmdq, thread);
+	writel(CMDQ_THR_DISABLED, thread->base + CMDQ_THR_ENABLE_TASK);
+}
+
+/* notify GCE to re-fetch commands by setting GCE thread PC */
+static void cmdq_thread_invalidate_fetched_data(struct cmdq_thread *thread)
+{
+	writel(readl(thread->base + CMDQ_THR_CURR_ADDR),
+	       thread->base + CMDQ_THR_CURR_ADDR);
+}
+
+static void cmdq_task_insert_into_thread(struct cmdq_task *task)
+{
+	struct device *dev = task->cmdq->mbox.dev;
+	struct cmdq_thread *thread = task->thread;
+	struct cmdq_task *prev_task = list_last_entry(
+			&thread->task_busy_list, typeof(*task), list_entry);
+	u64 *prev_task_base = prev_task->pkt->va_base;
+
+	/* let previous task jump to this task */
+	dma_sync_single_for_cpu(dev, prev_task->pa_base,
+				prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
+	prev_task_base[CMDQ_NUM_CMD(prev_task->pkt) - 1] =
+		(u64)CMDQ_JUMP_BY_PA << 32 |
+		(task->pa_base >> task->cmdq->shift_pa);
+	dma_sync_single_for_device(dev, prev_task->pa_base,
+				   prev_task->pkt->cmd_buf_size, DMA_TO_DEVICE);
+
+	cmdq_thread_invalidate_fetched_data(thread);
+}
+
+static bool cmdq_thread_is_in_wfe(struct cmdq_thread *thread)
+{
+	return readl(thread->base + CMDQ_THR_WAIT_TOKEN) & CMDQ_THR_IS_WAITING;
+}
+
+static void cmdq_task_exec_done(struct cmdq_task *task, int sta)
+{
+	struct cmdq_cb_data data;
+
+	data.sta = sta;
+	data.pkt = task->pkt;
+	mbox_chan_received_data(task->thread->chan, &data);
+
+	list_del(&task->list_entry);
+}
+
+static void cmdq_task_handle_error(struct cmdq_task *task)
+{
+	struct cmdq_thread *thread = task->thread;
+	struct cmdq_task *next_task;
+	struct cmdq *cmdq = task->cmdq;
+
+	dev_err(cmdq->mbox.dev, "task 0x%p error\n", task);
+	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
+	next_task = list_first_entry_or_null(&thread->task_busy_list,
+			struct cmdq_task, list_entry);
+	if (next_task)
+		writel(next_task->pa_base >> cmdq->shift_pa,
+		       thread->base + CMDQ_THR_CURR_ADDR);
+	cmdq_thread_resume(thread);
+}
+
+static void cmdq_thread_irq_handler(struct cmdq *cmdq,
+				    struct cmdq_thread *thread)
+{
+	struct cmdq_task *task, *tmp, *curr_task = NULL;
+	u32 curr_pa, irq_flag, task_end_pa;
+	bool err;
+
+	irq_flag = readl(thread->base + CMDQ_THR_IRQ_STATUS);
+	writel(~irq_flag, thread->base + CMDQ_THR_IRQ_STATUS);
+
+	/*
+	 * When ISR call this function, another CPU core could run
+	 * "release task" right before we acquire the spin lock, and thus
+	 * reset / disable this GCE thread, so we need to check the enable
+	 * bit of this GCE thread.
+	 */
+	if (!(readl(thread->base + CMDQ_THR_ENABLE_TASK) & CMDQ_THR_ENABLED))
+		return;
+
+	if (irq_flag & CMDQ_THR_IRQ_ERROR)
+		err = true;
+	else if (irq_flag & CMDQ_THR_IRQ_DONE)
+		err = false;
+	else
+		return;
+
+	curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) << cmdq->shift_pa;
+
+	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
+				 list_entry) {
+		task_end_pa = task->pa_base + task->pkt->cmd_buf_size;
+		if (curr_pa >= task->pa_base && curr_pa < task_end_pa)
+			curr_task = task;
+
+		if (!curr_task || curr_pa == task_end_pa - CMDQ_INST_SIZE) {
+			cmdq_task_exec_done(task, 0);
+			kfree(task);
+		} else if (err) {
+			cmdq_task_exec_done(task, -ENOEXEC);
+			cmdq_task_handle_error(curr_task);
+			kfree(task);
+		}
+
+		if (curr_task)
+			break;
+	}
+
+	if (list_empty(&thread->task_busy_list)) {
+		cmdq_thread_disable(cmdq, thread);
+		clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+	}
+}
+
+static irqreturn_t cmdq_irq_handler(int irq, void *dev)
+{
+	struct cmdq *cmdq = dev;
+	unsigned long irq_status, flags = 0L;
+	int bit;
+
+	irq_status = readl(cmdq->base + CMDQ_CURR_IRQ_STATUS) & cmdq->irq_mask;
+	if (!(irq_status ^ cmdq->irq_mask))
+		return IRQ_NONE;
+
+	for_each_clear_bit(bit, &irq_status, cmdq->thread_nr) {
+		struct cmdq_thread *thread = &cmdq->thread[bit];
+
+		spin_lock_irqsave(&thread->chan->lock, flags);
+		cmdq_thread_irq_handler(cmdq, thread);
+		spin_unlock_irqrestore(&thread->chan->lock, flags);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int cmdq_suspend(struct device *dev)
+{
+	struct cmdq *cmdq = dev_get_drvdata(dev);
+	struct cmdq_thread *thread;
+	int i;
+	bool task_running = false;
+
+	cmdq->suspended = true;
+
+	for (i = 0; i < cmdq->thread_nr; i++) {
+		thread = &cmdq->thread[i];
+		if (!list_empty(&thread->task_busy_list)) {
+			task_running = true;
+			break;
+		}
+	}
+
+	if (task_running)
+		dev_warn(dev, "exist running task(s) in suspend\n");
+
+	clk_bulk_unprepare(cmdq->gce_num, cmdq->clocks);
+
+	return 0;
+}
+
+static int cmdq_resume(struct device *dev)
+{
+	struct cmdq *cmdq = dev_get_drvdata(dev);
+
+	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
+	cmdq->suspended = false;
+	return 0;
+}
+
+static int cmdq_remove(struct platform_device *pdev)
+{
+	struct cmdq *cmdq = platform_get_drvdata(pdev);
+
+	clk_bulk_unprepare(cmdq->gce_num, cmdq->clocks);
+	return 0;
+}
+
+static int cmdq_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct cmdq_pkt *pkt = (struct cmdq_pkt *)data;
+	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
+	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
+	struct cmdq_task *task;
+	unsigned long curr_pa, end_pa;
+
+	/* Client should not flush new tasks if suspended. */
+	WARN_ON(cmdq->suspended);
+
+	task = kzalloc(sizeof(*task), GFP_ATOMIC);
+	if (!task)
+		return -ENOMEM;
+
+	task->cmdq = cmdq;
+	INIT_LIST_HEAD(&task->list_entry);
+	task->pa_base = pkt->pa_base;
+	task->thread = thread;
+	task->pkt = pkt;
+
+	if (list_empty(&thread->task_busy_list)) {
+		WARN_ON(clk_bulk_enable(cmdq->gce_num, cmdq->clocks));
+
+		/*
+		 * The thread reset will clear thread related register to 0,
+		 * including pc, end, priority, irq, suspend and enable. Thus
+		 * set CMDQ_THR_ENABLED to CMDQ_THR_ENABLE_TASK will enable
+		 * thread and make it running.
+		 */
+		WARN_ON(cmdq_thread_reset(cmdq, thread) < 0);
+
+		writel(task->pa_base >> cmdq->shift_pa,
+		       thread->base + CMDQ_THR_CURR_ADDR);
+		writel((task->pa_base + pkt->cmd_buf_size) >> cmdq->shift_pa,
+		       thread->base + CMDQ_THR_END_ADDR);
+
+		writel(thread->priority, thread->base + CMDQ_THR_PRIORITY);
+		writel(CMDQ_THR_IRQ_EN, thread->base + CMDQ_THR_IRQ_ENABLE);
+		writel(CMDQ_THR_ENABLED, thread->base + CMDQ_THR_ENABLE_TASK);
+	} else {
+		WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
+		curr_pa = readl(thread->base + CMDQ_THR_CURR_ADDR) <<
+			cmdq->shift_pa;
+		end_pa = readl(thread->base + CMDQ_THR_END_ADDR) <<
+			cmdq->shift_pa;
+		/* check boundary */
+		if (curr_pa == end_pa - CMDQ_INST_SIZE ||
+		    curr_pa == end_pa) {
+			/* set to this task directly */
+			writel(task->pa_base >> cmdq->shift_pa,
+			       thread->base + CMDQ_THR_CURR_ADDR);
+		} else {
+			cmdq_task_insert_into_thread(task);
+			smp_mb(); /* modify jump before enable thread */
+		}
+		writel((task->pa_base + pkt->cmd_buf_size) >> cmdq->shift_pa,
+		       thread->base + CMDQ_THR_END_ADDR);
+		cmdq_thread_resume(thread);
+	}
+	list_move_tail(&task->list_entry, &thread->task_busy_list);
+
+	return 0;
+}
+
+static int cmdq_mbox_startup(struct mbox_chan *chan)
+{
+	return 0;
+}
+
+static void cmdq_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
+	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
+	struct cmdq_task *task, *tmp;
+	unsigned long flags;
+
+	spin_lock_irqsave(&thread->chan->lock, flags);
+	if (list_empty(&thread->task_busy_list))
+		goto done;
+
+	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
+
+	/* make sure executed tasks have success callback */
+	cmdq_thread_irq_handler(cmdq, thread);
+	if (list_empty(&thread->task_busy_list))
+		goto done;
+
+	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
+				 list_entry) {
+		cmdq_task_exec_done(task, -ECONNABORTED);
+		kfree(task);
+	}
+
+	cmdq_thread_disable(cmdq, thread);
+	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+
+done:
+	/*
+	 * The thread->task_busy_list empty means thread already disable. The
+	 * cmdq_mbox_send_data() always reset thread which clear disable and
+	 * suspend statue when first pkt send to channel, so there is no need
+	 * to do any operation here, only unlock and leave.
+	 */
+	spin_unlock_irqrestore(&thread->chan->lock, flags);
+}
+
+static int cmdq_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+	struct cmdq_thread *thread = (struct cmdq_thread *)chan->con_priv;
+	struct cmdq_cb_data data;
+	struct cmdq *cmdq = dev_get_drvdata(chan->mbox->dev);
+	struct cmdq_task *task, *tmp;
+	unsigned long flags;
+	u32 enable;
+
+	spin_lock_irqsave(&thread->chan->lock, flags);
+	if (list_empty(&thread->task_busy_list))
+		goto out;
+
+	WARN_ON(cmdq_thread_suspend(cmdq, thread) < 0);
+	if (!cmdq_thread_is_in_wfe(thread))
+		goto wait;
+
+	list_for_each_entry_safe(task, tmp, &thread->task_busy_list,
+				 list_entry) {
+		data.sta = -ECONNABORTED;
+		data.pkt = task->pkt;
+		mbox_chan_received_data(task->thread->chan, &data);
+		list_del(&task->list_entry);
+		kfree(task);
+	}
+
+	cmdq_thread_resume(thread);
+	cmdq_thread_disable(cmdq, thread);
+	clk_bulk_disable(cmdq->gce_num, cmdq->clocks);
+
+out:
+	spin_unlock_irqrestore(&thread->chan->lock, flags);
+	return 0;
+
+wait:
+	cmdq_thread_resume(thread);
+	spin_unlock_irqrestore(&thread->chan->lock, flags);
+	if (readl_poll_timeout_atomic(thread->base + CMDQ_THR_ENABLE_TASK,
+				      enable, enable == 0, 1, timeout)) {
+		dev_err(cmdq->mbox.dev, "Fail to wait GCE thread 0x%x done\n",
+			(u32)(thread->base - cmdq->base));
+
+		return -EFAULT;
+	}
+	return 0;
+}
+
+static const struct mbox_chan_ops cmdq_mbox_chan_ops = {
+	.send_data = cmdq_mbox_send_data,
+	.startup = cmdq_mbox_startup,
+	.shutdown = cmdq_mbox_shutdown,
+	.flush = cmdq_mbox_flush,
+};
+
+static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
+		const struct of_phandle_args *sp)
+{
+	int ind = sp->args[0];
+	struct cmdq_thread *thread;
+
+	if (ind >= mbox->num_chans)
+		return ERR_PTR(-EINVAL);
+
+	thread = (struct cmdq_thread *)mbox->chans[ind].con_priv;
+	thread->priority = sp->args[1];
+	thread->chan = &mbox->chans[ind];
+
+	return &mbox->chans[ind];
+}
+
+static int cmdq_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cmdq *cmdq;
+	int err, i;
+	struct gce_plat *plat_data;
+	struct device_node *phandle = dev->of_node;
+	struct device_node *node;
+	int alias_id = 0;
+	static const char * const clk_name = "gce";
+	static const char * const clk_names[] = { "gce0", "gce1" };
+
+	cmdq = devm_kzalloc(dev, sizeof(*cmdq), GFP_KERNEL);
+	if (!cmdq)
+		return -ENOMEM;
+
+	cmdq->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(cmdq->base))
+		return PTR_ERR(cmdq->base);
+
+	cmdq->irq = platform_get_irq(pdev, 0);
+	if (cmdq->irq < 0)
+		return cmdq->irq;
+
+	plat_data = (struct gce_plat *)of_device_get_match_data(dev);
+	if (!plat_data) {
+		dev_err(dev, "failed to get match data\n");
+		return -EINVAL;
+	}
+
+	cmdq->thread_nr = plat_data->thread_nr;
+	cmdq->shift_pa = plat_data->shift;
+	cmdq->control_by_sw = plat_data->control_by_sw;
+	cmdq->gce_num = plat_data->gce_num;
+	cmdq->irq_mask = GENMASK(cmdq->thread_nr - 1, 0);
+	err = devm_request_irq(dev, cmdq->irq, cmdq_irq_handler, IRQF_SHARED,
+			       "mtk_cmdq", cmdq);
+	if (err < 0) {
+		dev_err(dev, "failed to register ISR (%d)\n", err);
+		return err;
+	}
+
+	dev_dbg(dev, "cmdq device: addr:0x%p, va:0x%p, irq:%d\n",
+		dev, cmdq->base, cmdq->irq);
+
+	if (cmdq->gce_num > 1) {
+		for_each_child_of_node(phandle->parent, node) {
+			alias_id = of_alias_get_id(node, clk_name);
+			if (alias_id >= 0 && alias_id < cmdq->gce_num) {
+				cmdq->clocks[alias_id].id = clk_names[alias_id];
+				cmdq->clocks[alias_id].clk = of_clk_get(node, 0);
+				if (IS_ERR(cmdq->clocks[alias_id].clk)) {
+					of_node_put(node);
+					return dev_err_probe(dev,
+							     PTR_ERR(cmdq->clocks[alias_id].clk),
+							     "failed to get gce clk: %d\n",
+							     alias_id);
+				}
+			}
+		}
+	} else {
+		cmdq->clocks[alias_id].id = clk_name;
+		cmdq->clocks[alias_id].clk = devm_clk_get(&pdev->dev, clk_name);
+		if (IS_ERR(cmdq->clocks[alias_id].clk)) {
+			return dev_err_probe(dev, PTR_ERR(cmdq->clocks[alias_id].clk),
+					     "failed to get gce clk\n");
+		}
+	}
+
+	cmdq->mbox.dev = dev;
+	cmdq->mbox.chans = devm_kcalloc(dev, cmdq->thread_nr,
+					sizeof(*cmdq->mbox.chans), GFP_KERNEL);
+	if (!cmdq->mbox.chans)
+		return -ENOMEM;
+
+	cmdq->mbox.num_chans = cmdq->thread_nr;
+	cmdq->mbox.ops = &cmdq_mbox_chan_ops;
+	cmdq->mbox.of_xlate = cmdq_xlate;
+
+	/* make use of TXDONE_BY_ACK */
+	cmdq->mbox.txdone_irq = false;
+	cmdq->mbox.txdone_poll = false;
+
+	cmdq->thread = devm_kcalloc(dev, cmdq->thread_nr,
+					sizeof(*cmdq->thread), GFP_KERNEL);
+	if (!cmdq->thread)
+		return -ENOMEM;
+
+	for (i = 0; i < cmdq->thread_nr; i++) {
+		cmdq->thread[i].base = cmdq->base + CMDQ_THR_BASE +
+				CMDQ_THR_SIZE * i;
+		INIT_LIST_HEAD(&cmdq->thread[i].task_busy_list);
+		cmdq->mbox.chans[i].con_priv = (void *)&cmdq->thread[i];
+	}
+
+	err = devm_mbox_controller_register(dev, &cmdq->mbox);
+	if (err < 0) {
+		dev_err(dev, "failed to register mailbox: %d\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, cmdq);
+
+	WARN_ON(clk_bulk_prepare(cmdq->gce_num, cmdq->clocks));
+
+	cmdq_init(cmdq);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cmdq_pm_ops = {
+	.suspend = cmdq_suspend,
+	.resume = cmdq_resume,
+};
+
+static const struct gce_plat gce_plat_v2 = {
+	.thread_nr = 16,
+	.shift = 0,
+	.control_by_sw = false,
+	.gce_num = 1
+};
+
+static const struct gce_plat gce_plat_v3 = {
+	.thread_nr = 24,
+	.shift = 0,
+	.control_by_sw = false,
+	.gce_num = 1
+};
+
+static const struct gce_plat gce_plat_v4 = {
+	.thread_nr = 24,
+	.shift = 3,
+	.control_by_sw = false,
+	.gce_num = 1
+};
+
+static const struct gce_plat gce_plat_v5 = {
+	.thread_nr = 24,
+	.shift = 3,
+	.control_by_sw = true,
+	.gce_num = 1
+};
+
+static const struct gce_plat gce_plat_v6 = {
+	.thread_nr = 24,
+	.shift = 3,
+	.control_by_sw = true,
+	.gce_num = 2
+};
+
+static const struct of_device_id cmdq_of_ids[] = {
+	{.compatible = "mediatek,mt8173-gce", .data = (void *)&gce_plat_v2},
+	{.compatible = "mediatek,mt8183-gce", .data = (void *)&gce_plat_v3},
+	{.compatible = "mediatek,mt6779-gce", .data = (void *)&gce_plat_v4},
+	{.compatible = "mediatek,mt8192-gce", .data = (void *)&gce_plat_v5},
+	{.compatible = "mediatek,mt8195-gce", .data = (void *)&gce_plat_v6},
+	{}
+};
+
+static struct platform_driver cmdq_drv = {
+	.probe = cmdq_probe,
+	.remove = cmdq_remove,
+	.driver = {
+		.name = "mtk_cmdq",
+		.pm = &cmdq_pm_ops,
+		.of_match_table = cmdq_of_ids,
+	}
+};
+
+static int __init cmdq_drv_init(void)
+{
+	return platform_driver_register(&cmdq_drv);
+}
+
+static void __exit cmdq_drv_exit(void)
+{
+	platform_driver_unregister(&cmdq_drv);
+}
+
+subsys_initcall(cmdq_drv_init);
+module_exit(cmdq_drv_exit);
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
new file mode 100644
index 000000000..098c82d87
--- /dev/null
+++ b/drivers/mailbox/omap-mailbox.c
@@ -0,0 +1,933 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * OMAP mailbox driver
+ *
+ * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
+ * Copyright (C) 2013-2021 Texas Instruments Incorporated - https://www.ti.com
+ *
+ * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *          Suman Anna <s-anna@ti.com>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/kfifo.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/omap-mailbox.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+
+#include "mailbox.h"
+
+#define MAILBOX_REVISION		0x000
+#define MAILBOX_MESSAGE(m)		(0x040 + 4 * (m))
+#define MAILBOX_FIFOSTATUS(m)		(0x080 + 4 * (m))
+#define MAILBOX_MSGSTATUS(m)		(0x0c0 + 4 * (m))
+
+#define OMAP2_MAILBOX_IRQSTATUS(u)	(0x100 + 8 * (u))
+#define OMAP2_MAILBOX_IRQENABLE(u)	(0x104 + 8 * (u))
+
+#define OMAP4_MAILBOX_IRQSTATUS(u)	(0x104 + 0x10 * (u))
+#define OMAP4_MAILBOX_IRQENABLE(u)	(0x108 + 0x10 * (u))
+#define OMAP4_MAILBOX_IRQENABLE_CLR(u)	(0x10c + 0x10 * (u))
+
+#define MAILBOX_IRQSTATUS(type, u)	(type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
+						OMAP2_MAILBOX_IRQSTATUS(u))
+#define MAILBOX_IRQENABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE(u) : \
+						OMAP2_MAILBOX_IRQENABLE(u))
+#define MAILBOX_IRQDISABLE(type, u)	(type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
+						: OMAP2_MAILBOX_IRQENABLE(u))
+
+#define MAILBOX_IRQ_NEWMSG(m)		(1 << (2 * (m)))
+#define MAILBOX_IRQ_NOTFULL(m)		(1 << (2 * (m) + 1))
+
+/* Interrupt register configuration types */
+#define MBOX_INTR_CFG_TYPE1		0
+#define MBOX_INTR_CFG_TYPE2		1
+
+struct omap_mbox_fifo {
+	unsigned long msg;
+	unsigned long fifo_stat;
+	unsigned long msg_stat;
+	unsigned long irqenable;
+	unsigned long irqstatus;
+	unsigned long irqdisable;
+	u32 intr_bit;
+};
+
+struct omap_mbox_queue {
+	spinlock_t		lock;
+	struct kfifo		fifo;
+	struct work_struct	work;
+	struct omap_mbox	*mbox;
+	bool full;
+};
+
+struct omap_mbox_match_data {
+	u32 intr_type;
+};
+
+struct omap_mbox_device {
+	struct device *dev;
+	struct mutex cfg_lock;
+	void __iomem *mbox_base;
+	u32 *irq_ctx;
+	u32 num_users;
+	u32 num_fifos;
+	u32 intr_type;
+	struct omap_mbox **mboxes;
+	struct mbox_controller controller;
+	struct list_head elem;
+};
+
+struct omap_mbox_fifo_info {
+	int tx_id;
+	int tx_usr;
+	int tx_irq;
+
+	int rx_id;
+	int rx_usr;
+	int rx_irq;
+
+	const char *name;
+	bool send_no_irq;
+};
+
+struct omap_mbox {
+	const char		*name;
+	int			irq;
+	struct omap_mbox_queue	*rxq;
+	struct device		*dev;
+	struct omap_mbox_device *parent;
+	struct omap_mbox_fifo	tx_fifo;
+	struct omap_mbox_fifo	rx_fifo;
+	u32			intr_type;
+	struct mbox_chan	*chan;
+	bool			send_no_irq;
+};
+
+/* global variables for the mailbox devices */
+static DEFINE_MUTEX(omap_mbox_devices_lock);
+static LIST_HEAD(omap_mbox_devices);
+
+static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
+module_param(mbox_kfifo_size, uint, S_IRUGO);
+MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
+
+static struct omap_mbox *mbox_chan_to_omap_mbox(struct mbox_chan *chan)
+{
+	if (!chan || !chan->con_priv)
+		return NULL;
+
+	return (struct omap_mbox *)chan->con_priv;
+}
+
+static inline
+unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
+{
+	return __raw_readl(mdev->mbox_base + ofs);
+}
+
+static inline
+void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
+{
+	__raw_writel(val, mdev->mbox_base + ofs);
+}
+
+/* Mailbox FIFO handle functions */
+static u32 mbox_fifo_read(struct omap_mbox *mbox)
+{
+	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
+
+	return mbox_read_reg(mbox->parent, fifo->msg);
+}
+
+static void mbox_fifo_write(struct omap_mbox *mbox, u32 msg)
+{
+	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
+
+	mbox_write_reg(mbox->parent, msg, fifo->msg);
+}
+
+static int mbox_fifo_empty(struct omap_mbox *mbox)
+{
+	struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
+
+	return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
+}
+
+static int mbox_fifo_full(struct omap_mbox *mbox)
+{
+	struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
+
+	return mbox_read_reg(mbox->parent, fifo->fifo_stat);
+}
+
+/* Mailbox IRQ handle functions */
+static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
+				&mbox->tx_fifo : &mbox->rx_fifo;
+	u32 bit = fifo->intr_bit;
+	u32 irqstatus = fifo->irqstatus;
+
+	mbox_write_reg(mbox->parent, bit, irqstatus);
+
+	/* Flush posted write for irq status to avoid spurious interrupts */
+	mbox_read_reg(mbox->parent, irqstatus);
+}
+
+static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
+				&mbox->tx_fifo : &mbox->rx_fifo;
+	u32 bit = fifo->intr_bit;
+	u32 irqenable = fifo->irqenable;
+	u32 irqstatus = fifo->irqstatus;
+
+	u32 enable = mbox_read_reg(mbox->parent, irqenable);
+	u32 status = mbox_read_reg(mbox->parent, irqstatus);
+
+	return (int)(enable & status & bit);
+}
+
+static void _omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	u32 l;
+	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
+				&mbox->tx_fifo : &mbox->rx_fifo;
+	u32 bit = fifo->intr_bit;
+	u32 irqenable = fifo->irqenable;
+
+	l = mbox_read_reg(mbox->parent, irqenable);
+	l |= bit;
+	mbox_write_reg(mbox->parent, l, irqenable);
+}
+
+static void _omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
+{
+	struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
+				&mbox->tx_fifo : &mbox->rx_fifo;
+	u32 bit = fifo->intr_bit;
+	u32 irqdisable = fifo->irqdisable;
+
+	/*
+	 * Read and update the interrupt configuration register for pre-OMAP4.
+	 * OMAP4 and later SoCs have a dedicated interrupt disabling register.
+	 */
+	if (!mbox->intr_type)
+		bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;
+
+	mbox_write_reg(mbox->parent, bit, irqdisable);
+}
+
+void omap_mbox_enable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
+{
+	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
+
+	if (WARN_ON(!mbox))
+		return;
+
+	_omap_mbox_enable_irq(mbox, irq);
+}
+EXPORT_SYMBOL(omap_mbox_enable_irq);
+
+void omap_mbox_disable_irq(struct mbox_chan *chan, omap_mbox_irq_t irq)
+{
+	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
+
+	if (WARN_ON(!mbox))
+		return;
+
+	_omap_mbox_disable_irq(mbox, irq);
+}
+EXPORT_SYMBOL(omap_mbox_disable_irq);
+
+/*
+ * Message receiver(workqueue)
+ */
+static void mbox_rx_work(struct work_struct *work)
+{
+	struct omap_mbox_queue *mq =
+			container_of(work, struct omap_mbox_queue, work);
+	mbox_msg_t data;
+	u32 msg;
+	int len;
+
+	while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
+		len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+		WARN_ON(len != sizeof(msg));
+		data = msg;
+
+		mbox_chan_received_data(mq->mbox->chan, (void *)data);
+		spin_lock_irq(&mq->lock);
+		if (mq->full) {
+			mq->full = false;
+			_omap_mbox_enable_irq(mq->mbox, IRQ_RX);
+		}
+		spin_unlock_irq(&mq->lock);
+	}
+}
+
+/*
+ * Mailbox interrupt handler
+ */
+static void __mbox_tx_interrupt(struct omap_mbox *mbox)
+{
+	_omap_mbox_disable_irq(mbox, IRQ_TX);
+	ack_mbox_irq(mbox, IRQ_TX);
+	mbox_chan_txdone(mbox->chan, 0);
+}
+
+static void __mbox_rx_interrupt(struct omap_mbox *mbox)
+{
+	struct omap_mbox_queue *mq = mbox->rxq;
+	u32 msg;
+	int len;
+
+	while (!mbox_fifo_empty(mbox)) {
+		if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
+			_omap_mbox_disable_irq(mbox, IRQ_RX);
+			mq->full = true;
+			goto nomem;
+		}
+
+		msg = mbox_fifo_read(mbox);
+
+		len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
+		WARN_ON(len != sizeof(msg));
+	}
+
+	/* no more messages in the fifo. clear IRQ source. */
+	ack_mbox_irq(mbox, IRQ_RX);
+nomem:
+	schedule_work(&mbox->rxq->work);
+}
+
+static irqreturn_t mbox_interrupt(int irq, void *p)
+{
+	struct omap_mbox *mbox = p;
+
+	if (is_mbox_irq(mbox, IRQ_TX))
+		__mbox_tx_interrupt(mbox);
+
+	if (is_mbox_irq(mbox, IRQ_RX))
+		__mbox_rx_interrupt(mbox);
+
+	return IRQ_HANDLED;
+}
+
+static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
+					void (*work)(struct work_struct *))
+{
+	struct omap_mbox_queue *mq;
+
+	if (!work)
+		return NULL;
+
+	mq = kzalloc(sizeof(*mq), GFP_KERNEL);
+	if (!mq)
+		return NULL;
+
+	spin_lock_init(&mq->lock);
+
+	if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
+		goto error;
+
+	INIT_WORK(&mq->work, work);
+	return mq;
+
+error:
+	kfree(mq);
+	return NULL;
+}
+
+static void mbox_queue_free(struct omap_mbox_queue *q)
+{
+	kfifo_free(&q->fifo);
+	kfree(q);
+}
+
+static int omap_mbox_startup(struct omap_mbox *mbox)
+{
+	int ret = 0;
+	struct omap_mbox_queue *mq;
+
+	mq = mbox_queue_alloc(mbox, mbox_rx_work);
+	if (!mq)
+		return -ENOMEM;
+	mbox->rxq = mq;
+	mq->mbox = mbox;
+
+	ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
+			  mbox->name, mbox);
+	if (unlikely(ret)) {
+		pr_err("failed to register mailbox interrupt:%d\n", ret);
+		goto fail_request_irq;
+	}
+
+	if (mbox->send_no_irq)
+		mbox->chan->txdone_method = TXDONE_BY_ACK;
+
+	_omap_mbox_enable_irq(mbox, IRQ_RX);
+
+	return 0;
+
+fail_request_irq:
+	mbox_queue_free(mbox->rxq);
+	return ret;
+}
+
+static void omap_mbox_fini(struct omap_mbox *mbox)
+{
+	_omap_mbox_disable_irq(mbox, IRQ_RX);
+	free_irq(mbox->irq, mbox);
+	flush_work(&mbox->rxq->work);
+	mbox_queue_free(mbox->rxq);
+}
+
+static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
+					       const char *mbox_name)
+{
+	struct omap_mbox *_mbox, *mbox = NULL;
+	struct omap_mbox **mboxes = mdev->mboxes;
+	int i;
+
+	if (!mboxes)
+		return NULL;
+
+	for (i = 0; (_mbox = mboxes[i]); i++) {
+		if (!strcmp(_mbox->name, mbox_name)) {
+			mbox = _mbox;
+			break;
+		}
+	}
+	return mbox;
+}
+
+struct mbox_chan *omap_mbox_request_channel(struct mbox_client *cl,
+					    const char *chan_name)
+{
+	struct device *dev = cl->dev;
+	struct omap_mbox *mbox = NULL;
+	struct omap_mbox_device *mdev;
+	struct mbox_chan *chan;
+	unsigned long flags;
+	int ret;
+
+	if (!dev)
+		return ERR_PTR(-ENODEV);
+
+	if (dev->of_node) {
+		pr_err("%s: please use mbox_request_channel(), this API is supported only for OMAP non-DT usage\n",
+		       __func__);
+		return ERR_PTR(-ENODEV);
+	}
+
+	mutex_lock(&omap_mbox_devices_lock);
+	list_for_each_entry(mdev, &omap_mbox_devices, elem) {
+		mbox = omap_mbox_device_find(mdev, chan_name);
+		if (mbox)
+			break;
+	}
+	mutex_unlock(&omap_mbox_devices_lock);
+
+	if (!mbox || !mbox->chan)
+		return ERR_PTR(-ENOENT);
+
+	chan = mbox->chan;
+	spin_lock_irqsave(&chan->lock, flags);
+	chan->msg_free = 0;
+	chan->msg_count = 0;
+	chan->active_req = NULL;
+	chan->cl = cl;
+	init_completion(&chan->tx_complete);
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	ret = chan->mbox->ops->startup(chan);
+	if (ret) {
+		pr_err("Unable to startup the chan (%d)\n", ret);
+		mbox_free_channel(chan);
+		chan = ERR_PTR(ret);
+	}
+
+	return chan;
+}
+EXPORT_SYMBOL(omap_mbox_request_channel);
+
+static struct class omap_mbox_class = { .name = "mbox", };
+
+static int omap_mbox_register(struct omap_mbox_device *mdev)
+{
+	int ret;
+	int i;
+	struct omap_mbox **mboxes;
+
+	if (!mdev || !mdev->mboxes)
+		return -EINVAL;
+
+	mboxes = mdev->mboxes;
+	for (i = 0; mboxes[i]; i++) {
+		struct omap_mbox *mbox = mboxes[i];
+
+		mbox->dev = device_create(&omap_mbox_class, mdev->dev,
+					0, mbox, "%s", mbox->name);
+		if (IS_ERR(mbox->dev)) {
+			ret = PTR_ERR(mbox->dev);
+			goto err_out;
+		}
+	}
+
+	mutex_lock(&omap_mbox_devices_lock);
+	list_add(&mdev->elem, &omap_mbox_devices);
+	mutex_unlock(&omap_mbox_devices_lock);
+
+	ret = devm_mbox_controller_register(mdev->dev, &mdev->controller);
+
+err_out:
+	if (ret) {
+		while (i--)
+			device_unregister(mboxes[i]->dev);
+	}
+	return ret;
+}
+
+static int omap_mbox_unregister(struct omap_mbox_device *mdev)
+{
+	int i;
+	struct omap_mbox **mboxes;
+
+	if (!mdev || !mdev->mboxes)
+		return -EINVAL;
+
+	mutex_lock(&omap_mbox_devices_lock);
+	list_del(&mdev->elem);
+	mutex_unlock(&omap_mbox_devices_lock);
+
+	mboxes = mdev->mboxes;
+	for (i = 0; mboxes[i]; i++)
+		device_unregister(mboxes[i]->dev);
+	return 0;
+}
+
+static int omap_mbox_chan_startup(struct mbox_chan *chan)
+{
+	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
+	struct omap_mbox_device *mdev = mbox->parent;
+	int ret = 0;
+
+	mutex_lock(&mdev->cfg_lock);
+	pm_runtime_get_sync(mdev->dev);
+	ret = omap_mbox_startup(mbox);
+	if (ret)
+		pm_runtime_put_sync(mdev->dev);
+	mutex_unlock(&mdev->cfg_lock);
+	return ret;
+}
+
+static void omap_mbox_chan_shutdown(struct mbox_chan *chan)
+{
+	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
+	struct omap_mbox_device *mdev = mbox->parent;
+
+	mutex_lock(&mdev->cfg_lock);
+	omap_mbox_fini(mbox);
+	pm_runtime_put_sync(mdev->dev);
+	mutex_unlock(&mdev->cfg_lock);
+}
+
+static int omap_mbox_chan_send_noirq(struct omap_mbox *mbox, u32 msg)
+{
+	int ret = -EBUSY;
+
+	if (!mbox_fifo_full(mbox)) {
+		_omap_mbox_enable_irq(mbox, IRQ_RX);
+		mbox_fifo_write(mbox, msg);
+		ret = 0;
+		_omap_mbox_disable_irq(mbox, IRQ_RX);
+
+		/* we must read and ack the interrupt directly from here */
+		mbox_fifo_read(mbox);
+		ack_mbox_irq(mbox, IRQ_RX);
+	}
+
+	return ret;
+}
+
+static int omap_mbox_chan_send(struct omap_mbox *mbox, u32 msg)
+{
+	int ret = -EBUSY;
+
+	if (!mbox_fifo_full(mbox)) {
+		mbox_fifo_write(mbox, msg);
+		ret = 0;
+	}
+
+	/* always enable the interrupt */
+	_omap_mbox_enable_irq(mbox, IRQ_TX);
+	return ret;
+}
+
+static int omap_mbox_chan_send_data(struct mbox_chan *chan, void *data)
+{
+	struct omap_mbox *mbox = mbox_chan_to_omap_mbox(chan);
+	int ret;
+	u32 msg = omap_mbox_message(data);
+
+	if (!mbox)
+		return -EINVAL;
+
+	if (mbox->send_no_irq)
+		ret = omap_mbox_chan_send_noirq(mbox, msg);
+	else
+		ret = omap_mbox_chan_send(mbox, msg);
+
+	return ret;
+}
+
+static const struct mbox_chan_ops omap_mbox_chan_ops = {
+	.startup        = omap_mbox_chan_startup,
+	.send_data      = omap_mbox_chan_send_data,
+	.shutdown       = omap_mbox_chan_shutdown,
+};
+
+#ifdef CONFIG_PM_SLEEP
+static int omap_mbox_suspend(struct device *dev)
+{
+	struct omap_mbox_device *mdev = dev_get_drvdata(dev);
+	u32 usr, fifo, reg;
+
+	if (pm_runtime_status_suspended(dev))
+		return 0;
+
+	for (fifo = 0; fifo < mdev->num_fifos; fifo++) {
+		if (mbox_read_reg(mdev, MAILBOX_MSGSTATUS(fifo))) {
+			dev_err(mdev->dev, "fifo %d has unexpected unread messages\n",
+				fifo);
+			return -EBUSY;
+		}
+	}
+
+	for (usr = 0; usr < mdev->num_users; usr++) {
+		reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
+		mdev->irq_ctx[usr] = mbox_read_reg(mdev, reg);
+	}
+
+	return 0;
+}
+
+static int omap_mbox_resume(struct device *dev)
+{
+	struct omap_mbox_device *mdev = dev_get_drvdata(dev);
+	u32 usr, reg;
+
+	if (pm_runtime_status_suspended(dev))
+		return 0;
+
+	for (usr = 0; usr < mdev->num_users; usr++) {
+		reg = MAILBOX_IRQENABLE(mdev->intr_type, usr);
+		mbox_write_reg(mdev, mdev->irq_ctx[usr], reg);
+	}
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops omap_mbox_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(omap_mbox_suspend, omap_mbox_resume)
+};
+
+static const struct omap_mbox_match_data omap2_data = { MBOX_INTR_CFG_TYPE1 };
+static const struct omap_mbox_match_data omap4_data = { MBOX_INTR_CFG_TYPE2 };
+
+static const struct of_device_id omap_mailbox_of_match[] = {
+	{
+		.compatible	= "ti,omap2-mailbox",
+		.data		= &omap2_data,
+	},
+	{
+		.compatible	= "ti,omap3-mailbox",
+		.data		= &omap2_data,
+	},
+	{
+		.compatible	= "ti,omap4-mailbox",
+		.data		= &omap4_data,
+	},
+	{
+		.compatible	= "ti,am654-mailbox",
+		.data		= &omap4_data,
+	},
+	{
+		.compatible	= "ti,am64-mailbox",
+		.data		= &omap4_data,
+	},
+	{
+		/* end */
+	},
+};
+MODULE_DEVICE_TABLE(of, omap_mailbox_of_match);
+
+static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
+					    const struct of_phandle_args *sp)
+{
+	phandle phandle = sp->args[0];
+	struct device_node *node;
+	struct omap_mbox_device *mdev;
+	struct omap_mbox *mbox;
+
+	mdev = container_of(controller, struct omap_mbox_device, controller);
+	if (WARN_ON(!mdev))
+		return ERR_PTR(-EINVAL);
+
+	node = of_find_node_by_phandle(phandle);
+	if (!node) {
+		pr_err("%s: could not find node phandle 0x%x\n",
+		       __func__, phandle);
+		return ERR_PTR(-ENODEV);
+	}
+
+	mbox = omap_mbox_device_find(mdev, node->name);
+	of_node_put(node);
+	return mbox ? mbox->chan : ERR_PTR(-ENOENT);
+}
+
+static int omap_mbox_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct mbox_chan *chnls;
+	struct omap_mbox **list, *mbox, *mboxblk;
+	struct omap_mbox_fifo_info *finfo, *finfoblk;
+	struct omap_mbox_device *mdev;
+	struct omap_mbox_fifo *fifo;
+	struct device_node *node = pdev->dev.of_node;
+	struct device_node *child;
+	const struct omap_mbox_match_data *match_data;
+	u32 intr_type, info_count;
+	u32 num_users, num_fifos;
+	u32 tmp[3];
+	u32 l;
+	int i;
+
+	if (!node) {
+		pr_err("%s: only DT-based devices are supported\n", __func__);
+		return -ENODEV;
+	}
+
+	match_data = of_device_get_match_data(&pdev->dev);
+	if (!match_data)
+		return -ENODEV;
+	intr_type = match_data->intr_type;
+
+	if (of_property_read_u32(node, "ti,mbox-num-users", &num_users))
+		return -ENODEV;
+
+	if (of_property_read_u32(node, "ti,mbox-num-fifos", &num_fifos))
+		return -ENODEV;
+
+	info_count = of_get_available_child_count(node);
+	if (!info_count) {
+		dev_err(&pdev->dev, "no available mbox devices found\n");
+		return -ENODEV;
+	}
+
+	finfoblk = devm_kcalloc(&pdev->dev, info_count, sizeof(*finfoblk),
+				GFP_KERNEL);
+	if (!finfoblk)
+		return -ENOMEM;
+
+	finfo = finfoblk;
+	child = NULL;
+	for (i = 0; i < info_count; i++, finfo++) {
+		child = of_get_next_available_child(node, child);
+		ret = of_property_read_u32_array(child, "ti,mbox-tx", tmp,
+						 ARRAY_SIZE(tmp));
+		if (ret)
+			return ret;
+		finfo->tx_id = tmp[0];
+		finfo->tx_irq = tmp[1];
+		finfo->tx_usr = tmp[2];
+
+		ret = of_property_read_u32_array(child, "ti,mbox-rx", tmp,
+						 ARRAY_SIZE(tmp));
+		if (ret)
+			return ret;
+		finfo->rx_id = tmp[0];
+		finfo->rx_irq = tmp[1];
+		finfo->rx_usr = tmp[2];
+
+		finfo->name = child->name;
+
+		if (of_find_property(child, "ti,mbox-send-noirq", NULL))
+			finfo->send_no_irq = true;
+
+		if (finfo->tx_id >= num_fifos || finfo->rx_id >= num_fifos ||
+		    finfo->tx_usr >= num_users || finfo->rx_usr >= num_users)
+			return -EINVAL;
+	}
+
+	mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
+	if (!mdev)
+		return -ENOMEM;
+
+	mdev->mbox_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mdev->mbox_base))
+		return PTR_ERR(mdev->mbox_base);
+
+	mdev->irq_ctx = devm_kcalloc(&pdev->dev, num_users, sizeof(u32),
+				     GFP_KERNEL);
+	if (!mdev->irq_ctx)
+		return -ENOMEM;
+
+	/* allocate one extra for marking end of list */
+	list = devm_kcalloc(&pdev->dev, info_count + 1, sizeof(*list),
+			    GFP_KERNEL);
+	if (!list)
+		return -ENOMEM;
+
+	chnls = devm_kcalloc(&pdev->dev, info_count + 1, sizeof(*chnls),
+			     GFP_KERNEL);
+	if (!chnls)
+		return -ENOMEM;
+
+	mboxblk = devm_kcalloc(&pdev->dev, info_count, sizeof(*mbox),
+			       GFP_KERNEL);
+	if (!mboxblk)
+		return -ENOMEM;
+
+	mbox = mboxblk;
+	finfo = finfoblk;
+	for (i = 0; i < info_count; i++, finfo++) {
+		fifo = &mbox->tx_fifo;
+		fifo->msg = MAILBOX_MESSAGE(finfo->tx_id);
+		fifo->fifo_stat = MAILBOX_FIFOSTATUS(finfo->tx_id);
+		fifo->intr_bit = MAILBOX_IRQ_NOTFULL(finfo->tx_id);
+		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->tx_usr);
+		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->tx_usr);
+		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->tx_usr);
+
+		fifo = &mbox->rx_fifo;
+		fifo->msg = MAILBOX_MESSAGE(finfo->rx_id);
+		fifo->msg_stat =  MAILBOX_MSGSTATUS(finfo->rx_id);
+		fifo->intr_bit = MAILBOX_IRQ_NEWMSG(finfo->rx_id);
+		fifo->irqenable = MAILBOX_IRQENABLE(intr_type, finfo->rx_usr);
+		fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, finfo->rx_usr);
+		fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, finfo->rx_usr);
+
+		mbox->send_no_irq = finfo->send_no_irq;
+		mbox->intr_type = intr_type;
+
+		mbox->parent = mdev;
+		mbox->name = finfo->name;
+		mbox->irq = platform_get_irq(pdev, finfo->tx_irq);
+		if (mbox->irq < 0)
+			return mbox->irq;
+		mbox->chan = &chnls[i];
+		chnls[i].con_priv = mbox;
+		list[i] = mbox++;
+	}
+
+	mutex_init(&mdev->cfg_lock);
+	mdev->dev = &pdev->dev;
+	mdev->num_users = num_users;
+	mdev->num_fifos = num_fifos;
+	mdev->intr_type = intr_type;
+	mdev->mboxes = list;
+
+	/*
+	 * OMAP/K3 Mailbox IP does not have a Tx-Done IRQ, but rather a Tx-Ready
+	 * IRQ and is needed to run the Tx state machine
+	 */
+	mdev->controller.txdone_irq = true;
+	mdev->controller.dev = mdev->dev;
+	mdev->controller.ops = &omap_mbox_chan_ops;
+	mdev->controller.chans = chnls;
+	mdev->controller.num_chans = info_count;
+	mdev->controller.of_xlate = omap_mbox_of_xlate;
+	ret = omap_mbox_register(mdev);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, mdev);
+	pm_runtime_enable(mdev->dev);
+
+	ret = pm_runtime_resume_and_get(mdev->dev);
+	if (ret < 0)
+		goto unregister;
+
+	/*
+	 * just print the raw revision register, the format is not
+	 * uniform across all SoCs
+	 */
+	l = mbox_read_reg(mdev, MAILBOX_REVISION);
+	dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
+
+	ret = pm_runtime_put_sync(mdev->dev);
+	if (ret < 0 && ret != -ENOSYS)
+		goto unregister;
+
+	devm_kfree(&pdev->dev, finfoblk);
+	return 0;
+
+unregister:
+	pm_runtime_disable(mdev->dev);
+	omap_mbox_unregister(mdev);
+	return ret;
+}
+
+static int omap_mbox_remove(struct platform_device *pdev)
+{
+	struct omap_mbox_device *mdev = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(mdev->dev);
+	omap_mbox_unregister(mdev);
+
+	return 0;
+}
+
+static struct platform_driver omap_mbox_driver = {
+	.probe	= omap_mbox_probe,
+	.remove	= omap_mbox_remove,
+	.driver	= {
+		.name = "omap-mailbox",
+		.pm = &omap_mbox_pm_ops,
+		.of_match_table = of_match_ptr(omap_mailbox_of_match),
+	},
+};
+
+static int __init omap_mbox_init(void)
+{
+	int err;
+
+	err = class_register(&omap_mbox_class);
+	if (err)
+		return err;
+
+	/* kfifo size sanity check: alignment and minimal size */
+	mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(u32));
+	mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size, sizeof(u32));
+
+	err = platform_driver_register(&omap_mbox_driver);
+	if (err)
+		class_unregister(&omap_mbox_class);
+
+	return err;
+}
+subsys_initcall(omap_mbox_init);
+
+static void __exit omap_mbox_exit(void)
+{
+	platform_driver_unregister(&omap_mbox_driver);
+	class_unregister(&omap_mbox_class);
+}
+module_exit(omap_mbox_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
+MODULE_AUTHOR("Toshihiro Kobayashi");
+MODULE_AUTHOR("Hiroshi DOYU");
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
new file mode 100644
index 000000000..105d46c98
--- /dev/null
+++ b/drivers/mailbox/pcc.c
@@ -0,0 +1,758 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Copyright (C) 2014 Linaro Ltd.
+ *	Author:	Ashwin Chaugule <ashwin.chaugule@linaro.org>
+ *
+ *  PCC (Platform Communication Channel) is defined in the ACPI 5.0+
+ *  specification. It is a mailbox like mechanism to allow clients
+ *  such as CPPC (Collaborative Processor Performance Control), RAS
+ *  (Reliability, Availability and Serviceability) and MPST (Memory
+ *  Node Power State Table) to talk to the platform (e.g. BMC) through
+ *  shared memory regions as defined in the PCC table entries. The PCC
+ *  specification supports a Doorbell mechanism for the PCC clients
+ *  to notify the platform about new data. This Doorbell information
+ *  is also specified in each PCC table entry.
+ *
+ *  Typical high level flow of operation is:
+ *
+ *  PCC Reads:
+ *  * Client tries to acquire a channel lock.
+ *  * After it is acquired it writes READ cmd in communication region cmd
+ *		address.
+ *  * Client issues mbox_send_message() which rings the PCC doorbell
+ *		for its PCC channel.
+ *  * If command completes, then client has control over channel and
+ *		it can proceed with its reads.
+ *  * Client releases lock.
+ *
+ *  PCC Writes:
+ *  * Client tries to acquire channel lock.
+ *  * Client writes to its communication region after it acquires a
+ *		channel lock.
+ *  * Client writes WRITE cmd in communication region cmd address.
+ *  * Client issues mbox_send_message() which rings the PCC doorbell
+ *		for its PCC channel.
+ *  * If command completes, then writes have succeeded and it can release
+ *		the channel lock.
+ *
+ *  There is a Nominal latency defined for each channel which indicates
+ *  how long to wait until a command completes. If command is not complete
+ *  the client needs to retry or assume failure.
+ *
+ *	For more details about PCC, please see the ACPI specification from
+ *  http://www.uefi.org/ACPIv5.1 Section 14.
+ *
+ *  This file implements PCC as a Mailbox controller and allows for PCC
+ *  clients to be implemented as its Mailbox Client Channels.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/list.h>
+#include <linux/log2.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox_client.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <acpi/pcc.h>
+
+#include "mailbox.h"
+
+#define MBOX_IRQ_NAME		"pcc-mbox"
+
+/**
+ * struct pcc_chan_reg - PCC register bundle
+ *
+ * @vaddr: cached virtual address for this register
+ * @gas: pointer to the generic address structure for this register
+ * @preserve_mask: bitmask to preserve when writing to this register
+ * @set_mask: bitmask to set when writing to this register
+ * @status_mask: bitmask to determine and/or update the status for this register
+ */
+struct pcc_chan_reg {
+	void __iomem *vaddr;
+	struct acpi_generic_address *gas;
+	u64 preserve_mask;
+	u64 set_mask;
+	u64 status_mask;
+};
+
+/**
+ * struct pcc_chan_info - PCC channel specific information
+ *
+ * @chan: PCC channel information with Shared Memory Region info
+ * @db: PCC register bundle for the doorbell register
+ * @plat_irq_ack: PCC register bundle for the platform interrupt acknowledge
+ *	register
+ * @cmd_complete: PCC register bundle for the command complete check register
+ * @cmd_update: PCC register bundle for the command complete update register
+ * @error: PCC register bundle for the error status register
+ * @plat_irq: platform interrupt
+ */
+struct pcc_chan_info {
+	struct pcc_mbox_chan chan;
+	struct pcc_chan_reg db;
+	struct pcc_chan_reg plat_irq_ack;
+	struct pcc_chan_reg cmd_complete;
+	struct pcc_chan_reg cmd_update;
+	struct pcc_chan_reg error;
+	int plat_irq;
+};
+
+#define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan)
+static struct pcc_chan_info *chan_info;
+static int pcc_chan_count;
+
+/*
+ * PCC can be used with perf critical drivers such as CPPC
+ * So it makes sense to locally cache the virtual address and
+ * use it to read/write to PCC registers such as doorbell register
+ *
+ * The below read_register and write_registers are used to read and
+ * write from perf critical registers such as PCC doorbell register
+ */
+static void read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
+{
+	switch (bit_width) {
+	case 8:
+		*val = readb(vaddr);
+		break;
+	case 16:
+		*val = readw(vaddr);
+		break;
+	case 32:
+		*val = readl(vaddr);
+		break;
+	case 64:
+		*val = readq(vaddr);
+		break;
+	}
+}
+
+static void write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
+{
+	switch (bit_width) {
+	case 8:
+		writeb(val, vaddr);
+		break;
+	case 16:
+		writew(val, vaddr);
+		break;
+	case 32:
+		writel(val, vaddr);
+		break;
+	case 64:
+		writeq(val, vaddr);
+		break;
+	}
+}
+
+static int pcc_chan_reg_read(struct pcc_chan_reg *reg, u64 *val)
+{
+	int ret = 0;
+
+	if (!reg->gas) {
+		*val = 0;
+		return 0;
+	}
+
+	if (reg->vaddr)
+		read_register(reg->vaddr, val, reg->gas->bit_width);
+	else
+		ret = acpi_read(val, reg->gas);
+
+	return ret;
+}
+
+static int pcc_chan_reg_write(struct pcc_chan_reg *reg, u64 val)
+{
+	int ret = 0;
+
+	if (!reg->gas)
+		return 0;
+
+	if (reg->vaddr)
+		write_register(reg->vaddr, val, reg->gas->bit_width);
+	else
+		ret = acpi_write(val, reg->gas);
+
+	return ret;
+}
+
+static int pcc_chan_reg_read_modify_write(struct pcc_chan_reg *reg)
+{
+	int ret = 0;
+	u64 val;
+
+	ret = pcc_chan_reg_read(reg, &val);
+	if (ret)
+		return ret;
+
+	val &= reg->preserve_mask;
+	val |= reg->set_mask;
+
+	return pcc_chan_reg_write(reg, val);
+}
+
+/**
+ * pcc_map_interrupt - Map a PCC subspace GSI to a linux IRQ number
+ * @interrupt: GSI number.
+ * @flags: interrupt flags
+ *
+ * Returns: a valid linux IRQ number on success
+ *		0 or -EINVAL on failure
+ */
+static int pcc_map_interrupt(u32 interrupt, u32 flags)
+{
+	int trigger, polarity;
+
+	if (!interrupt)
+		return 0;
+
+	trigger = (flags & ACPI_PCCT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+			: ACPI_LEVEL_SENSITIVE;
+
+	polarity = (flags & ACPI_PCCT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+			: ACPI_ACTIVE_HIGH;
+
+	return acpi_register_gsi(NULL, interrupt, trigger, polarity);
+}
+
+/**
+ * pcc_mbox_irq - PCC mailbox interrupt handler
+ * @irq:	interrupt number
+ * @p: data/cookie passed from the caller to identify the channel
+ *
+ * Returns: IRQ_HANDLED if interrupt is handled or IRQ_NONE if not
+ */
+static irqreturn_t pcc_mbox_irq(int irq, void *p)
+{
+	struct pcc_chan_info *pchan;
+	struct mbox_chan *chan = p;
+	u64 val;
+	int ret;
+
+	pchan = chan->con_priv;
+
+	ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
+	if (ret)
+		return IRQ_NONE;
+
+	if (val) { /* Ensure GAS exists and value is non-zero */
+		val &= pchan->cmd_complete.status_mask;
+		if (!val)
+			return IRQ_NONE;
+	}
+
+	ret = pcc_chan_reg_read(&pchan->error, &val);
+	if (ret)
+		return IRQ_NONE;
+	val &= pchan->error.status_mask;
+	if (val) {
+		val &= ~pchan->error.status_mask;
+		pcc_chan_reg_write(&pchan->error, val);
+		return IRQ_NONE;
+	}
+
+	if (pcc_chan_reg_read_modify_write(&pchan->plat_irq_ack))
+		return IRQ_NONE;
+
+	mbox_chan_received_data(chan, NULL);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * pcc_mbox_request_channel - PCC clients call this function to
+ *		request a pointer to their PCC subspace, from which they
+ *		can get the details of communicating with the remote.
+ * @cl: Pointer to Mailbox client, so we know where to bind the
+ *		Channel.
+ * @subspace_id: The PCC Subspace index as parsed in the PCC client
+ *		ACPI package. This is used to lookup the array of PCC
+ *		subspaces as parsed by the PCC Mailbox controller.
+ *
+ * Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
+ */
+struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
+{
+	struct pcc_chan_info *pchan;
+	struct mbox_chan *chan;
+	struct device *dev;
+	unsigned long flags;
+
+	if (subspace_id < 0 || subspace_id >= pcc_chan_count)
+		return ERR_PTR(-ENOENT);
+
+	pchan = chan_info + subspace_id;
+	chan = pchan->chan.mchan;
+	if (IS_ERR(chan) || chan->cl) {
+		pr_err("Channel not found for idx: %d\n", subspace_id);
+		return ERR_PTR(-EBUSY);
+	}
+	dev = chan->mbox->dev;
+
+	spin_lock_irqsave(&chan->lock, flags);
+	chan->msg_free = 0;
+	chan->msg_count = 0;
+	chan->active_req = NULL;
+	chan->cl = cl;
+	init_completion(&chan->tx_complete);
+
+	if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
+		chan->txdone_method = TXDONE_BY_ACK;
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+
+	if (pchan->plat_irq > 0) {
+		int rc;
+
+		rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, 0,
+				      MBOX_IRQ_NAME, chan);
+		if (unlikely(rc)) {
+			dev_err(dev, "failed to register PCC interrupt %d\n",
+				pchan->plat_irq);
+			pcc_mbox_free_channel(&pchan->chan);
+			return ERR_PTR(rc);
+		}
+	}
+
+	return &pchan->chan;
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
+
+/**
+ * pcc_mbox_free_channel - Clients call this to free their Channel.
+ *
+ * @pchan: Pointer to the PCC mailbox channel as returned by
+ *	   pcc_mbox_request_channel()
+ */
+void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
+{
+	struct pcc_chan_info *pchan_info = to_pcc_chan_info(pchan);
+	struct mbox_chan *chan = pchan->mchan;
+	unsigned long flags;
+
+	if (!chan || !chan->cl)
+		return;
+
+	if (pchan_info->plat_irq > 0)
+		devm_free_irq(chan->mbox->dev, pchan_info->plat_irq, chan);
+
+	spin_lock_irqsave(&chan->lock, flags);
+	chan->cl = NULL;
+	chan->active_req = NULL;
+	if (chan->txdone_method == TXDONE_BY_ACK)
+		chan->txdone_method = TXDONE_BY_POLL;
+
+	spin_unlock_irqrestore(&chan->lock, flags);
+}
+EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
+
+/**
+ * pcc_send_data - Called from Mailbox Controller code. Used
+ *		here only to ring the channel doorbell. The PCC client
+ *		specific read/write is done in the client driver in
+ *		order to maintain atomicity over PCC channel once
+ *		OS has control over it. See above for flow of operations.
+ * @chan: Pointer to Mailbox channel over which to send data.
+ * @data: Client specific data written over channel. Used here
+ *		only for debug after PCC transaction completes.
+ *
+ * Return: Err if something failed else 0 for success.
+ */
+static int pcc_send_data(struct mbox_chan *chan, void *data)
+{
+	int ret;
+	struct pcc_chan_info *pchan = chan->con_priv;
+
+	ret = pcc_chan_reg_read_modify_write(&pchan->cmd_update);
+	if (ret)
+		return ret;
+
+	return pcc_chan_reg_read_modify_write(&pchan->db);
+}
+
+static const struct mbox_chan_ops pcc_chan_ops = {
+	.send_data = pcc_send_data,
+};
+
+/**
+ * parse_pcc_subspace - Count PCC subspaces defined
+ * @header: Pointer to the ACPI subtable header under the PCCT.
+ * @end: End of subtable entry.
+ *
+ * Return: If we find a PCC subspace entry of a valid type, return 0.
+ *	Otherwise, return -EINVAL.
+ *
+ * This gets called for each entry in the PCC table.
+ */
+static int parse_pcc_subspace(union acpi_subtable_headers *header,
+		const unsigned long end)
+{
+	struct acpi_pcct_subspace *ss = (struct acpi_pcct_subspace *) header;
+
+	if (ss->header.type < ACPI_PCCT_TYPE_RESERVED)
+		return 0;
+
+	return -EINVAL;
+}
+
+static int
+pcc_chan_reg_init(struct pcc_chan_reg *reg, struct acpi_generic_address *gas,
+		  u64 preserve_mask, u64 set_mask, u64 status_mask, char *name)
+{
+	if (gas->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+		if (!(gas->bit_width >= 8 && gas->bit_width <= 64 &&
+		      is_power_of_2(gas->bit_width))) {
+			pr_err("Error: Cannot access register of %u bit width",
+			       gas->bit_width);
+			return -EFAULT;
+		}
+
+		reg->vaddr = acpi_os_ioremap(gas->address, gas->bit_width / 8);
+		if (!reg->vaddr) {
+			pr_err("Failed to ioremap PCC %s register\n", name);
+			return -ENOMEM;
+		}
+	}
+	reg->gas = gas;
+	reg->preserve_mask = preserve_mask;
+	reg->set_mask = set_mask;
+	reg->status_mask = status_mask;
+	return 0;
+}
+
+/**
+ * pcc_parse_subspace_irq - Parse the PCC IRQ and PCC ACK register
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ * Return: 0 for Success, else errno.
+ *
+ * There should be one entry per PCC channel. This gets called for each
+ * entry in the PCC table. This uses PCCY Type1 structure for all applicable
+ * types(Type 1-4) to fetch irq
+ */
+static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
+				  struct acpi_subtable_header *pcct_entry)
+{
+	int ret = 0;
+	struct acpi_pcct_hw_reduced *pcct_ss;
+
+	if (pcct_entry->type < ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
+	    pcct_entry->type > ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE)
+		return 0;
+
+	pcct_ss = (struct acpi_pcct_hw_reduced *)pcct_entry;
+	pchan->plat_irq = pcc_map_interrupt(pcct_ss->platform_interrupt,
+					    (u32)pcct_ss->flags);
+	if (pchan->plat_irq <= 0) {
+		pr_err("PCC GSI %d not registered\n",
+		       pcct_ss->platform_interrupt);
+		return -EINVAL;
+	}
+
+	if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+		struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
+
+		ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
+					&pcct2_ss->platform_ack_register,
+					pcct2_ss->ack_preserve_mask,
+					pcct2_ss->ack_write_mask, 0,
+					"PLAT IRQ ACK");
+
+	} else if (pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_MASTER_SUBSPACE ||
+		   pcct_ss->header.type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE) {
+		struct acpi_pcct_ext_pcc_master *pcct_ext = (void *)pcct_ss;
+
+		ret = pcc_chan_reg_init(&pchan->plat_irq_ack,
+					&pcct_ext->platform_ack_register,
+					pcct_ext->ack_preserve_mask,
+					pcct_ext->ack_set_mask, 0,
+					"PLAT IRQ ACK");
+	}
+
+	return ret;
+}
+
+/**
+ * pcc_parse_subspace_db_reg - Parse the PCC doorbell register
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ * Return: 0 for Success, else errno.
+ */
+static int pcc_parse_subspace_db_reg(struct pcc_chan_info *pchan,
+				     struct acpi_subtable_header *pcct_entry)
+{
+	int ret = 0;
+
+	if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+		struct acpi_pcct_subspace *pcct_ss;
+
+		pcct_ss = (struct acpi_pcct_subspace *)pcct_entry;
+
+		ret = pcc_chan_reg_init(&pchan->db,
+					&pcct_ss->doorbell_register,
+					pcct_ss->preserve_mask,
+					pcct_ss->write_mask, 0,	"Doorbell");
+
+	} else {
+		struct acpi_pcct_ext_pcc_master *pcct_ext;
+
+		pcct_ext = (struct acpi_pcct_ext_pcc_master *)pcct_entry;
+
+		ret = pcc_chan_reg_init(&pchan->db,
+					&pcct_ext->doorbell_register,
+					pcct_ext->preserve_mask,
+					pcct_ext->write_mask, 0, "Doorbell");
+		if (ret)
+			return ret;
+
+		ret = pcc_chan_reg_init(&pchan->cmd_complete,
+					&pcct_ext->cmd_complete_register,
+					0, 0, pcct_ext->cmd_complete_mask,
+					"Command Complete Check");
+		if (ret)
+			return ret;
+
+		ret = pcc_chan_reg_init(&pchan->cmd_update,
+					&pcct_ext->cmd_update_register,
+					pcct_ext->cmd_update_preserve_mask,
+					pcct_ext->cmd_update_set_mask, 0,
+					"Command Complete Update");
+		if (ret)
+			return ret;
+
+		ret = pcc_chan_reg_init(&pchan->error,
+					&pcct_ext->error_status_register,
+					0, 0, pcct_ext->error_status_mask,
+					"Error Status");
+	}
+	return ret;
+}
+
+/**
+ * pcc_parse_subspace_shmem - Parse the PCC Shared Memory Region information
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
+ *
+ */
+static void pcc_parse_subspace_shmem(struct pcc_chan_info *pchan,
+				     struct acpi_subtable_header *pcct_entry)
+{
+	if (pcct_entry->type <= ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+		struct acpi_pcct_subspace *pcct_ss =
+			(struct acpi_pcct_subspace *)pcct_entry;
+
+		pchan->chan.shmem_base_addr = pcct_ss->base_address;
+		pchan->chan.shmem_size = pcct_ss->length;
+		pchan->chan.latency = pcct_ss->latency;
+		pchan->chan.max_access_rate = pcct_ss->max_access_rate;
+		pchan->chan.min_turnaround_time = pcct_ss->min_turnaround_time;
+	} else {
+		struct acpi_pcct_ext_pcc_master *pcct_ext =
+			(struct acpi_pcct_ext_pcc_master *)pcct_entry;
+
+		pchan->chan.shmem_base_addr = pcct_ext->base_address;
+		pchan->chan.shmem_size = pcct_ext->length;
+		pchan->chan.latency = pcct_ext->latency;
+		pchan->chan.max_access_rate = pcct_ext->max_access_rate;
+		pchan->chan.min_turnaround_time = pcct_ext->min_turnaround_time;
+	}
+}
+
+/**
+ * acpi_pcc_probe - Parse the ACPI tree for the PCCT.
+ *
+ * Return: 0 for Success, else errno.
+ */
+static int __init acpi_pcc_probe(void)
+{
+	int count, i, rc = 0;
+	acpi_status status;
+	struct acpi_table_header *pcct_tbl;
+	struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
+
+	status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
+	if (ACPI_FAILURE(status) || !pcct_tbl)
+		return -ENODEV;
+
+	/* Set up the subtable handlers */
+	for (i = ACPI_PCCT_TYPE_GENERIC_SUBSPACE;
+	     i < ACPI_PCCT_TYPE_RESERVED; i++) {
+		proc[i].id = i;
+		proc[i].count = 0;
+		proc[i].handler = parse_pcc_subspace;
+	}
+
+	count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
+			sizeof(struct acpi_table_pcct), proc,
+			ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
+	if (count <= 0 || count > MAX_PCC_SUBSPACES) {
+		if (count < 0)
+			pr_warn("Error parsing PCC subspaces from PCCT\n");
+		else
+			pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
+
+		rc = -EINVAL;
+	} else {
+		pcc_chan_count = count;
+	}
+
+	acpi_put_table(pcct_tbl);
+
+	return rc;
+}
+
+/**
+ * pcc_mbox_probe - Called when we find a match for the
+ *	PCCT platform device. This is purely used to represent
+ *	the PCCT as a virtual device for registering with the
+ *	generic Mailbox framework.
+ *
+ * @pdev: Pointer to platform device returned when a match
+ *	is found.
+ *
+ *	Return: 0 for Success, else errno.
+ */
+static int pcc_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mbox_controller *pcc_mbox_ctrl;
+	struct mbox_chan *pcc_mbox_channels;
+	struct acpi_table_header *pcct_tbl;
+	struct acpi_subtable_header *pcct_entry;
+	struct acpi_table_pcct *acpi_pcct_tbl;
+	acpi_status status = AE_OK;
+	int i, rc, count = pcc_chan_count;
+
+	/* Search for PCCT */
+	status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
+
+	if (ACPI_FAILURE(status) || !pcct_tbl)
+		return -ENODEV;
+
+	pcc_mbox_channels = devm_kcalloc(dev, count, sizeof(*pcc_mbox_channels),
+					 GFP_KERNEL);
+	if (!pcc_mbox_channels) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	chan_info = devm_kcalloc(dev, count, sizeof(*chan_info), GFP_KERNEL);
+	if (!chan_info) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	pcc_mbox_ctrl = devm_kzalloc(dev, sizeof(*pcc_mbox_ctrl), GFP_KERNEL);
+	if (!pcc_mbox_ctrl) {
+		rc = -ENOMEM;
+		goto err;
+	}
+
+	/* Point to the first PCC subspace entry */
+	pcct_entry = (struct acpi_subtable_header *) (
+		(unsigned long) pcct_tbl + sizeof(struct acpi_table_pcct));
+
+	acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
+	if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
+		pcc_mbox_ctrl->txdone_irq = true;
+
+	for (i = 0; i < count; i++) {
+		struct pcc_chan_info *pchan = chan_info + i;
+
+		pcc_mbox_channels[i].con_priv = pchan;
+		pchan->chan.mchan = &pcc_mbox_channels[i];
+
+		if (pcct_entry->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE &&
+		    !pcc_mbox_ctrl->txdone_irq) {
+			pr_err("Platform Interrupt flag must be set to 1");
+			rc = -EINVAL;
+			goto err;
+		}
+
+		if (pcc_mbox_ctrl->txdone_irq) {
+			rc = pcc_parse_subspace_irq(pchan, pcct_entry);
+			if (rc < 0)
+				goto err;
+		}
+		rc = pcc_parse_subspace_db_reg(pchan, pcct_entry);
+		if (rc < 0)
+			goto err;
+
+		pcc_parse_subspace_shmem(pchan, pcct_entry);
+
+		pcct_entry = (struct acpi_subtable_header *)
+			((unsigned long) pcct_entry + pcct_entry->length);
+	}
+
+	pcc_mbox_ctrl->num_chans = count;
+
+	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl->num_chans);
+
+	pcc_mbox_ctrl->chans = pcc_mbox_channels;
+	pcc_mbox_ctrl->ops = &pcc_chan_ops;
+	pcc_mbox_ctrl->dev = dev;
+
+	pr_info("Registering PCC driver as Mailbox controller\n");
+	rc = mbox_controller_register(pcc_mbox_ctrl);
+	if (rc)
+		pr_err("Err registering PCC as Mailbox controller: %d\n", rc);
+	else
+		return 0;
+err:
+	acpi_put_table(pcct_tbl);
+	return rc;
+}
+
+static struct platform_driver pcc_mbox_driver = {
+	.probe = pcc_mbox_probe,
+	.driver = {
+		.name = "PCCT",
+	},
+};
+
+static int __init pcc_init(void)
+{
+	int ret;
+	struct platform_device *pcc_pdev;
+
+	if (acpi_disabled)
+		return -ENODEV;
+
+	/* Check if PCC support is available. */
+	ret = acpi_pcc_probe();
+
+	if (ret) {
+		pr_debug("ACPI PCC probe failed.\n");
+		return -ENODEV;
+	}
+
+	pcc_pdev = platform_create_bundle(&pcc_mbox_driver,
+			pcc_mbox_probe, NULL, 0, NULL, 0);
+
+	if (IS_ERR(pcc_pdev)) {
+		pr_debug("Err creating PCC platform bundle\n");
+		pcc_chan_count = 0;
+		return PTR_ERR(pcc_pdev);
+	}
+
+	return 0;
+}
+
+/*
+ * Make PCC init postcore so that users of this mailbox
+ * such as the ACPI Processor driver have it available
+ * at their init.
+ */
+postcore_initcall(pcc_init);
diff --git a/drivers/mailbox/pl320-ipc.c b/drivers/mailbox/pl320-ipc.c
new file mode 100644
index 000000000..fbcf07930
--- /dev/null
+++ b/drivers/mailbox/pl320-ipc.c
@@ -0,0 +1,187 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2012 Calxeda, Inc.
+ */
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/amba/bus.h>
+
+#include <linux/pl320-ipc.h>
+
+#define IPCMxSOURCE(m)		((m) * 0x40)
+#define IPCMxDSET(m)		(((m) * 0x40) + 0x004)
+#define IPCMxDCLEAR(m)		(((m) * 0x40) + 0x008)
+#define IPCMxDSTATUS(m)		(((m) * 0x40) + 0x00C)
+#define IPCMxMODE(m)		(((m) * 0x40) + 0x010)
+#define IPCMxMSET(m)		(((m) * 0x40) + 0x014)
+#define IPCMxMCLEAR(m)		(((m) * 0x40) + 0x018)
+#define IPCMxMSTATUS(m)		(((m) * 0x40) + 0x01C)
+#define IPCMxSEND(m)		(((m) * 0x40) + 0x020)
+#define IPCMxDR(m, dr)		(((m) * 0x40) + ((dr) * 4) + 0x024)
+
+#define IPCMMIS(irq)		(((irq) * 8) + 0x800)
+#define IPCMRIS(irq)		(((irq) * 8) + 0x804)
+
+#define MBOX_MASK(n)		(1 << (n))
+#define IPC_TX_MBOX		1
+#define IPC_RX_MBOX		2
+
+#define CHAN_MASK(n)		(1 << (n))
+#define A9_SOURCE		1
+#define M3_SOURCE		0
+
+static void __iomem *ipc_base;
+static int ipc_irq;
+static DEFINE_MUTEX(ipc_m1_lock);
+static DECLARE_COMPLETION(ipc_completion);
+static ATOMIC_NOTIFIER_HEAD(ipc_notifier);
+
+static inline void set_destination(int source, int mbox)
+{
+	writel_relaxed(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox));
+	writel_relaxed(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox));
+}
+
+static inline void clear_destination(int source, int mbox)
+{
+	writel_relaxed(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox));
+	writel_relaxed(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox));
+}
+
+static void __ipc_send(int mbox, u32 *data)
+{
+	int i;
+	for (i = 0; i < 7; i++)
+		writel_relaxed(data[i], ipc_base + IPCMxDR(mbox, i));
+	writel_relaxed(0x1, ipc_base + IPCMxSEND(mbox));
+}
+
+static u32 __ipc_rcv(int mbox, u32 *data)
+{
+	int i;
+	for (i = 0; i < 7; i++)
+		data[i] = readl_relaxed(ipc_base + IPCMxDR(mbox, i));
+	return data[1];
+}
+
+/* blocking implementation from the A9 side, not usable in interrupts! */
+int pl320_ipc_transmit(u32 *data)
+{
+	int ret;
+
+	mutex_lock(&ipc_m1_lock);
+
+	init_completion(&ipc_completion);
+	__ipc_send(IPC_TX_MBOX, data);
+	ret = wait_for_completion_timeout(&ipc_completion,
+					  msecs_to_jiffies(1000));
+	if (ret == 0) {
+		ret = -ETIMEDOUT;
+		goto out;
+	}
+
+	ret = __ipc_rcv(IPC_TX_MBOX, data);
+out:
+	mutex_unlock(&ipc_m1_lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_transmit);
+
+static irqreturn_t ipc_handler(int irq, void *dev)
+{
+	u32 irq_stat;
+	u32 data[7];
+
+	irq_stat = readl_relaxed(ipc_base + IPCMMIS(1));
+	if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) {
+		writel_relaxed(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
+		complete(&ipc_completion);
+	}
+	if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) {
+		__ipc_rcv(IPC_RX_MBOX, data);
+		atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1);
+		writel_relaxed(2, ipc_base + IPCMxSEND(IPC_RX_MBOX));
+	}
+
+	return IRQ_HANDLED;
+}
+
+int pl320_ipc_register_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&ipc_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier);
+
+int pl320_ipc_unregister_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&ipc_notifier, nb);
+}
+EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier);
+
+static int pl320_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	int ret;
+
+	ipc_base = ioremap(adev->res.start, resource_size(&adev->res));
+	if (ipc_base == NULL)
+		return -ENOMEM;
+
+	writel_relaxed(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
+
+	ipc_irq = adev->irq[0];
+	ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL);
+	if (ret < 0)
+		goto err;
+
+	/* Init slow mailbox */
+	writel_relaxed(CHAN_MASK(A9_SOURCE),
+		       ipc_base + IPCMxSOURCE(IPC_TX_MBOX));
+	writel_relaxed(CHAN_MASK(M3_SOURCE),
+		       ipc_base + IPCMxDSET(IPC_TX_MBOX));
+	writel_relaxed(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
+		       ipc_base + IPCMxMSET(IPC_TX_MBOX));
+
+	/* Init receive mailbox */
+	writel_relaxed(CHAN_MASK(M3_SOURCE),
+		       ipc_base + IPCMxSOURCE(IPC_RX_MBOX));
+	writel_relaxed(CHAN_MASK(A9_SOURCE),
+		       ipc_base + IPCMxDSET(IPC_RX_MBOX));
+	writel_relaxed(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
+		       ipc_base + IPCMxMSET(IPC_RX_MBOX));
+
+	return 0;
+err:
+	iounmap(ipc_base);
+	return ret;
+}
+
+static struct amba_id pl320_ids[] = {
+	{
+		.id	= 0x00041320,
+		.mask	= 0x000fffff,
+	},
+	{ 0, 0 },
+};
+
+static struct amba_driver pl320_driver = {
+	.drv = {
+		.name	= "pl320",
+	},
+	.id_table	= pl320_ids,
+	.probe		= pl320_probe,
+};
+
+static int __init ipc_init(void)
+{
+	return amba_driver_register(&pl320_driver);
+}
+subsys_initcall(ipc_init);
diff --git a/drivers/mailbox/platform_mhu.c b/drivers/mailbox/platform_mhu.c
new file mode 100644
index 000000000..a5922ac0b
--- /dev/null
+++ b/drivers/mailbox/platform_mhu.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2016 BayLibre SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ * Synchronised with arm_mhu.c from :
+ * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
+ * Copyright (C) 2015 Linaro Ltd.
+ * Author: Jassi Brar <jaswinder.singh@linaro.org>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/mailbox_controller.h>
+
+#define INTR_SET_OFS	0x0
+#define INTR_STAT_OFS	0x4
+#define INTR_CLR_OFS	0x8
+
+#define MHU_SEC_OFFSET	0x0
+#define MHU_LP_OFFSET	0xc
+#define MHU_HP_OFFSET	0x18
+#define TX_REG_OFFSET	0x24
+
+#define MHU_CHANS	3
+
+struct platform_mhu_link {
+	int irq;
+	void __iomem *tx_reg;
+	void __iomem *rx_reg;
+};
+
+struct platform_mhu {
+	void __iomem *base;
+	struct platform_mhu_link mlink[MHU_CHANS];
+	struct mbox_chan chan[MHU_CHANS];
+	struct mbox_controller mbox;
+};
+
+static irqreturn_t platform_mhu_rx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = p;
+	struct platform_mhu_link *mlink = chan->con_priv;
+	u32 val;
+
+	val = readl_relaxed(mlink->rx_reg + INTR_STAT_OFS);
+	if (!val)
+		return IRQ_NONE;
+
+	mbox_chan_received_data(chan, (void *)&val);
+
+	writel_relaxed(val, mlink->rx_reg + INTR_CLR_OFS);
+
+	return IRQ_HANDLED;
+}
+
+static bool platform_mhu_last_tx_done(struct mbox_chan *chan)
+{
+	struct platform_mhu_link *mlink = chan->con_priv;
+	u32 val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+
+	return (val == 0);
+}
+
+static int platform_mhu_send_data(struct mbox_chan *chan, void *data)
+{
+	struct platform_mhu_link *mlink = chan->con_priv;
+	u32 *arg = data;
+
+	writel_relaxed(*arg, mlink->tx_reg + INTR_SET_OFS);
+
+	return 0;
+}
+
+static int platform_mhu_startup(struct mbox_chan *chan)
+{
+	struct platform_mhu_link *mlink = chan->con_priv;
+	u32 val;
+	int ret;
+
+	val = readl_relaxed(mlink->tx_reg + INTR_STAT_OFS);
+	writel_relaxed(val, mlink->tx_reg + INTR_CLR_OFS);
+
+	ret = request_irq(mlink->irq, platform_mhu_rx_interrupt,
+			  IRQF_SHARED, "platform_mhu_link", chan);
+	if (ret) {
+		dev_err(chan->mbox->dev,
+			"Unable to acquire IRQ %d\n", mlink->irq);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void platform_mhu_shutdown(struct mbox_chan *chan)
+{
+	struct platform_mhu_link *mlink = chan->con_priv;
+
+	free_irq(mlink->irq, chan);
+}
+
+static const struct mbox_chan_ops platform_mhu_ops = {
+	.send_data = platform_mhu_send_data,
+	.startup = platform_mhu_startup,
+	.shutdown = platform_mhu_shutdown,
+	.last_tx_done = platform_mhu_last_tx_done,
+};
+
+static int platform_mhu_probe(struct platform_device *pdev)
+{
+	int i, err;
+	struct platform_mhu *mhu;
+	struct device *dev = &pdev->dev;
+	int platform_mhu_reg[MHU_CHANS] = {
+		MHU_SEC_OFFSET, MHU_LP_OFFSET, MHU_HP_OFFSET
+	};
+
+	/* Allocate memory for device */
+	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);
+	if (!mhu)
+		return -ENOMEM;
+
+	mhu->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mhu->base)) {
+		dev_err(dev, "ioremap failed\n");
+		return PTR_ERR(mhu->base);
+	}
+
+	for (i = 0; i < MHU_CHANS; i++) {
+		mhu->chan[i].con_priv = &mhu->mlink[i];
+		mhu->mlink[i].irq = platform_get_irq(pdev, i);
+		if (mhu->mlink[i].irq < 0) {
+			dev_err(dev, "failed to get irq%d\n", i);
+			return mhu->mlink[i].irq;
+		}
+		mhu->mlink[i].rx_reg = mhu->base + platform_mhu_reg[i];
+		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;
+	}
+
+	mhu->mbox.dev = dev;
+	mhu->mbox.chans = &mhu->chan[0];
+	mhu->mbox.num_chans = MHU_CHANS;
+	mhu->mbox.ops = &platform_mhu_ops;
+	mhu->mbox.txdone_irq = false;
+	mhu->mbox.txdone_poll = true;
+	mhu->mbox.txpoll_period = 1;
+
+	platform_set_drvdata(pdev, mhu);
+
+	err = devm_mbox_controller_register(dev, &mhu->mbox);
+	if (err) {
+		dev_err(dev, "Failed to register mailboxes %d\n", err);
+		return err;
+	}
+
+	dev_info(dev, "Platform MHU Mailbox registered\n");
+	return 0;
+}
+
+static const struct of_device_id platform_mhu_dt_ids[] = {
+	{ .compatible = "amlogic,meson-gxbb-mhu", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, platform_mhu_dt_ids);
+
+static struct platform_driver platform_mhu_driver = {
+	.probe	= platform_mhu_probe,
+	.driver = {
+		.name = "platform-mhu",
+		.of_match_table	= platform_mhu_dt_ids,
+	},
+};
+
+module_platform_driver(platform_mhu_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:platform-mhu");
+MODULE_DESCRIPTION("Platform MHU Driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
diff --git a/drivers/mailbox/qcom-apcs-ipc-mailbox.c b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
new file mode 100644
index 000000000..f1f0e87a7
--- /dev/null
+++ b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017, Linaro Ltd
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mailbox_controller.h>
+
+#define QCOM_APCS_IPC_BITS	32
+
+struct qcom_apcs_ipc {
+	struct mbox_controller mbox;
+	struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
+
+	struct regmap *regmap;
+	unsigned long offset;
+	struct platform_device *clk;
+};
+
+struct qcom_apcs_ipc_data {
+	int offset;
+	char *clk_name;
+};
+
+static const struct qcom_apcs_ipc_data ipq6018_apcs_data = {
+	.offset = 8, .clk_name = "qcom,apss-ipq6018-clk"
+};
+
+static const struct qcom_apcs_ipc_data msm8916_apcs_data = {
+	.offset = 8, .clk_name = "qcom-apcs-msm8916-clk"
+};
+
+static const struct qcom_apcs_ipc_data msm8994_apcs_data = {
+	.offset = 8, .clk_name = NULL
+};
+
+static const struct qcom_apcs_ipc_data msm8996_apcs_data = {
+	.offset = 16, .clk_name = NULL
+};
+
+static const struct qcom_apcs_ipc_data apps_shared_apcs_data = {
+	.offset = 12, .clk_name = NULL
+};
+
+static const struct qcom_apcs_ipc_data sdx55_apcs_data = {
+	.offset = 0x1008, .clk_name = "qcom-sdx55-acps-clk"
+};
+
+static const struct regmap_config apcs_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = 0x1008,
+	.fast_io = true,
+};
+
+static int qcom_apcs_ipc_send_data(struct mbox_chan *chan, void *data)
+{
+	struct qcom_apcs_ipc *apcs = container_of(chan->mbox,
+						  struct qcom_apcs_ipc, mbox);
+	unsigned long idx = (unsigned long)chan->con_priv;
+
+	return regmap_write(apcs->regmap, apcs->offset, BIT(idx));
+}
+
+static const struct mbox_chan_ops qcom_apcs_ipc_ops = {
+	.send_data = qcom_apcs_ipc_send_data,
+};
+
+static int qcom_apcs_ipc_probe(struct platform_device *pdev)
+{
+	struct qcom_apcs_ipc *apcs;
+	const struct qcom_apcs_ipc_data *apcs_data;
+	struct regmap *regmap;
+	void __iomem *base;
+	unsigned long i;
+	int ret;
+
+	apcs = devm_kzalloc(&pdev->dev, sizeof(*apcs), GFP_KERNEL);
+	if (!apcs)
+		return -ENOMEM;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	regmap = devm_regmap_init_mmio(&pdev->dev, base, &apcs_regmap_config);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	apcs_data = of_device_get_match_data(&pdev->dev);
+
+	apcs->regmap = regmap;
+	apcs->offset = apcs_data->offset;
+
+	/* Initialize channel identifiers */
+	for (i = 0; i < ARRAY_SIZE(apcs->mbox_chans); i++)
+		apcs->mbox_chans[i].con_priv = (void *)i;
+
+	apcs->mbox.dev = &pdev->dev;
+	apcs->mbox.ops = &qcom_apcs_ipc_ops;
+	apcs->mbox.chans = apcs->mbox_chans;
+	apcs->mbox.num_chans = ARRAY_SIZE(apcs->mbox_chans);
+
+	ret = devm_mbox_controller_register(&pdev->dev, &apcs->mbox);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register APCS IPC controller\n");
+		return ret;
+	}
+
+	if (apcs_data->clk_name) {
+		apcs->clk = platform_device_register_data(&pdev->dev,
+							  apcs_data->clk_name,
+							  PLATFORM_DEVID_AUTO,
+							  NULL, 0);
+		if (IS_ERR(apcs->clk))
+			dev_err(&pdev->dev, "failed to register APCS clk\n");
+	}
+
+	platform_set_drvdata(pdev, apcs);
+
+	return 0;
+}
+
+static int qcom_apcs_ipc_remove(struct platform_device *pdev)
+{
+	struct qcom_apcs_ipc *apcs = platform_get_drvdata(pdev);
+	struct platform_device *clk = apcs->clk;
+
+	platform_device_unregister(clk);
+
+	return 0;
+}
+
+/* .data is the offset of the ipc register within the global block */
+static const struct of_device_id qcom_apcs_ipc_of_match[] = {
+	{ .compatible = "qcom,ipq6018-apcs-apps-global", .data = &ipq6018_apcs_data },
+	{ .compatible = "qcom,ipq8074-apcs-apps-global", .data = &ipq6018_apcs_data },
+	{ .compatible = "qcom,msm8916-apcs-kpss-global", .data = &msm8916_apcs_data },
+	{ .compatible = "qcom,msm8939-apcs-kpss-global", .data = &msm8916_apcs_data },
+	{ .compatible = "qcom,msm8953-apcs-kpss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,msm8976-apcs-kpss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,msm8994-apcs-kpss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,msm8996-apcs-hmss-global", .data = &msm8996_apcs_data },
+	{ .compatible = "qcom,msm8998-apcs-hmss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,qcm2290-apcs-hmss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,qcs404-apcs-apps-global", .data = &msm8916_apcs_data },
+	{ .compatible = "qcom,sc7180-apss-shared", .data = &apps_shared_apcs_data },
+	{ .compatible = "qcom,sc8180x-apss-shared", .data = &apps_shared_apcs_data },
+	{ .compatible = "qcom,sdm660-apcs-hmss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,sdm845-apss-shared", .data = &apps_shared_apcs_data },
+	{ .compatible = "qcom,sm6125-apcs-hmss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,sm8150-apss-shared", .data = &apps_shared_apcs_data },
+	{ .compatible = "qcom,sm6115-apcs-hmss-global", .data = &msm8994_apcs_data },
+	{ .compatible = "qcom,sdx55-apcs-gcc", .data = &sdx55_apcs_data },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_apcs_ipc_of_match);
+
+static struct platform_driver qcom_apcs_ipc_driver = {
+	.probe = qcom_apcs_ipc_probe,
+	.remove = qcom_apcs_ipc_remove,
+	.driver = {
+		.name = "qcom_apcs_ipc",
+		.of_match_table = qcom_apcs_ipc_of_match,
+	},
+};
+
+static int __init qcom_apcs_ipc_init(void)
+{
+	return platform_driver_register(&qcom_apcs_ipc_driver);
+}
+postcore_initcall(qcom_apcs_ipc_init);
+
+static void __exit qcom_apcs_ipc_exit(void)
+{
+	platform_driver_unregister(&qcom_apcs_ipc_driver);
+}
+module_exit(qcom_apcs_ipc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm APCS IPC driver");
diff --git a/drivers/mailbox/qcom-ipcc.c b/drivers/mailbox/qcom-ipcc.c
new file mode 100644
index 000000000..f597a1bd5
--- /dev/null
+++ b/drivers/mailbox/qcom-ipcc.c
@@ -0,0 +1,369 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2018-2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <dt-bindings/mailbox/qcom-ipcc.h>
+
+/* IPCC Register offsets */
+#define IPCC_REG_SEND_ID		0x0c
+#define IPCC_REG_RECV_ID		0x10
+#define IPCC_REG_RECV_SIGNAL_ENABLE	0x14
+#define IPCC_REG_RECV_SIGNAL_DISABLE	0x18
+#define IPCC_REG_RECV_SIGNAL_CLEAR	0x1c
+#define IPCC_REG_CLIENT_CLEAR		0x38
+
+#define IPCC_SIGNAL_ID_MASK		GENMASK(15, 0)
+#define IPCC_CLIENT_ID_MASK		GENMASK(31, 16)
+
+#define IPCC_NO_PENDING_IRQ		GENMASK(31, 0)
+
+/**
+ * struct qcom_ipcc_chan_info - Per-mailbox-channel info
+ * @client_id:	The client-id to which the interrupt has to be triggered
+ * @signal_id:	The signal-id to which the interrupt has to be triggered
+ */
+struct qcom_ipcc_chan_info {
+	u16 client_id;
+	u16 signal_id;
+};
+
+/**
+ * struct qcom_ipcc - Holder for the mailbox driver
+ * @dev:		Device associated with this instance
+ * @base:		Base address of the IPCC frame associated to APSS
+ * @irq_domain:		The irq_domain associated with this instance
+ * @chans:		The mailbox channels array
+ * @mchan:		The per-mailbox channel info array
+ * @mbox:		The mailbox controller
+ * @num_chans:		Number of @chans elements
+ * @irq:		Summary irq
+ */
+struct qcom_ipcc {
+	struct device *dev;
+	void __iomem *base;
+	struct irq_domain *irq_domain;
+	struct mbox_chan *chans;
+	struct qcom_ipcc_chan_info *mchan;
+	struct mbox_controller mbox;
+	int num_chans;
+	int irq;
+};
+
+static inline struct qcom_ipcc *to_qcom_ipcc(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct qcom_ipcc, mbox);
+}
+
+static inline u32 qcom_ipcc_get_hwirq(u16 client_id, u16 signal_id)
+{
+	return FIELD_PREP(IPCC_CLIENT_ID_MASK, client_id) |
+	       FIELD_PREP(IPCC_SIGNAL_ID_MASK, signal_id);
+}
+
+static irqreturn_t qcom_ipcc_irq_fn(int irq, void *data)
+{
+	struct qcom_ipcc *ipcc = data;
+	u32 hwirq;
+	int virq;
+
+	for (;;) {
+		hwirq = readl(ipcc->base + IPCC_REG_RECV_ID);
+		if (hwirq == IPCC_NO_PENDING_IRQ)
+			break;
+
+		virq = irq_find_mapping(ipcc->irq_domain, hwirq);
+		writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_CLEAR);
+		generic_handle_irq(virq);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static void qcom_ipcc_mask_irq(struct irq_data *irqd)
+{
+	struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
+
+	writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_DISABLE);
+}
+
+static void qcom_ipcc_unmask_irq(struct irq_data *irqd)
+{
+	struct qcom_ipcc *ipcc = irq_data_get_irq_chip_data(irqd);
+	irq_hw_number_t hwirq = irqd_to_hwirq(irqd);
+
+	writel(hwirq, ipcc->base + IPCC_REG_RECV_SIGNAL_ENABLE);
+}
+
+static struct irq_chip qcom_ipcc_irq_chip = {
+	.name = "ipcc",
+	.irq_mask = qcom_ipcc_mask_irq,
+	.irq_unmask = qcom_ipcc_unmask_irq,
+	.flags = IRQCHIP_SKIP_SET_WAKE,
+};
+
+static int qcom_ipcc_domain_map(struct irq_domain *d, unsigned int irq,
+				irq_hw_number_t hw)
+{
+	struct qcom_ipcc *ipcc = d->host_data;
+
+	irq_set_chip_and_handler(irq, &qcom_ipcc_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, ipcc);
+	irq_set_noprobe(irq);
+
+	return 0;
+}
+
+static int qcom_ipcc_domain_xlate(struct irq_domain *d,
+				  struct device_node *node, const u32 *intspec,
+				  unsigned int intsize,
+				  unsigned long *out_hwirq,
+				  unsigned int *out_type)
+{
+	if (intsize != 3)
+		return -EINVAL;
+
+	*out_hwirq = qcom_ipcc_get_hwirq(intspec[0], intspec[1]);
+	*out_type = intspec[2] & IRQ_TYPE_SENSE_MASK;
+
+	return 0;
+}
+
+static const struct irq_domain_ops qcom_ipcc_irq_ops = {
+	.map = qcom_ipcc_domain_map,
+	.xlate = qcom_ipcc_domain_xlate,
+};
+
+static int qcom_ipcc_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct qcom_ipcc *ipcc = to_qcom_ipcc(chan->mbox);
+	struct qcom_ipcc_chan_info *mchan = chan->con_priv;
+	u32 hwirq;
+
+	hwirq = qcom_ipcc_get_hwirq(mchan->client_id, mchan->signal_id);
+	writel(hwirq, ipcc->base + IPCC_REG_SEND_ID);
+
+	return 0;
+}
+
+static void qcom_ipcc_mbox_shutdown(struct mbox_chan *chan)
+{
+	chan->con_priv = NULL;
+}
+
+static struct mbox_chan *qcom_ipcc_mbox_xlate(struct mbox_controller *mbox,
+					const struct of_phandle_args *ph)
+{
+	struct qcom_ipcc *ipcc = to_qcom_ipcc(mbox);
+	struct qcom_ipcc_chan_info *mchan;
+	struct mbox_chan *chan;
+	struct device *dev;
+	int chan_id;
+
+	dev = ipcc->dev;
+
+	if (ph->args_count != 2)
+		return ERR_PTR(-EINVAL);
+
+	for (chan_id = 0; chan_id < mbox->num_chans; chan_id++) {
+		chan = &ipcc->chans[chan_id];
+		mchan = chan->con_priv;
+
+		if (!mchan)
+			break;
+		else if (mchan->client_id == ph->args[0] &&
+				mchan->signal_id == ph->args[1])
+			return ERR_PTR(-EBUSY);
+	}
+
+	if (chan_id >= mbox->num_chans)
+		return ERR_PTR(-EBUSY);
+
+	mchan = devm_kzalloc(dev, sizeof(*mchan), GFP_KERNEL);
+	if (!mchan)
+		return ERR_PTR(-ENOMEM);
+
+	mchan->client_id = ph->args[0];
+	mchan->signal_id = ph->args[1];
+	chan->con_priv = mchan;
+
+	return chan;
+}
+
+static const struct mbox_chan_ops ipcc_mbox_chan_ops = {
+	.send_data = qcom_ipcc_mbox_send_data,
+	.shutdown = qcom_ipcc_mbox_shutdown,
+};
+
+static int qcom_ipcc_setup_mbox(struct qcom_ipcc *ipcc,
+				struct device_node *controller_dn)
+{
+	struct of_phandle_args curr_ph;
+	struct device_node *client_dn;
+	struct mbox_controller *mbox;
+	struct device *dev = ipcc->dev;
+	int i, j, ret;
+
+	/*
+	 * Find out the number of clients interested in this mailbox
+	 * and create channels accordingly.
+	 */
+	ipcc->num_chans = 0;
+	for_each_node_with_property(client_dn, "mboxes") {
+		if (!of_device_is_available(client_dn))
+			continue;
+		i = of_count_phandle_with_args(client_dn,
+						"mboxes", "#mbox-cells");
+		for (j = 0; j < i; j++) {
+			ret = of_parse_phandle_with_args(client_dn, "mboxes",
+						"#mbox-cells", j, &curr_ph);
+			of_node_put(curr_ph.np);
+			if (!ret && curr_ph.np == controller_dn)
+				ipcc->num_chans++;
+		}
+	}
+
+	/* If no clients are found, skip registering as a mbox controller */
+	if (!ipcc->num_chans)
+		return 0;
+
+	ipcc->chans = devm_kcalloc(dev, ipcc->num_chans,
+					sizeof(struct mbox_chan), GFP_KERNEL);
+	if (!ipcc->chans)
+		return -ENOMEM;
+
+	mbox = &ipcc->mbox;
+	mbox->dev = dev;
+	mbox->num_chans = ipcc->num_chans;
+	mbox->chans = ipcc->chans;
+	mbox->ops = &ipcc_mbox_chan_ops;
+	mbox->of_xlate = qcom_ipcc_mbox_xlate;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = false;
+
+	return devm_mbox_controller_register(dev, mbox);
+}
+
+static int qcom_ipcc_pm_resume(struct device *dev)
+{
+	struct qcom_ipcc *ipcc = dev_get_drvdata(dev);
+	u32 hwirq;
+	int virq;
+
+	hwirq = readl(ipcc->base + IPCC_REG_RECV_ID);
+	if (hwirq == IPCC_NO_PENDING_IRQ)
+		return 0;
+
+	virq = irq_find_mapping(ipcc->irq_domain, hwirq);
+
+	dev_dbg(dev, "virq: %d triggered client-id: %ld; signal-id: %ld\n", virq,
+		FIELD_GET(IPCC_CLIENT_ID_MASK, hwirq), FIELD_GET(IPCC_SIGNAL_ID_MASK, hwirq));
+
+	return 0;
+}
+
+static int qcom_ipcc_probe(struct platform_device *pdev)
+{
+	struct qcom_ipcc *ipcc;
+	static int id;
+	char *name;
+	int ret;
+
+	ipcc = devm_kzalloc(&pdev->dev, sizeof(*ipcc), GFP_KERNEL);
+	if (!ipcc)
+		return -ENOMEM;
+
+	ipcc->dev = &pdev->dev;
+
+	ipcc->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ipcc->base))
+		return PTR_ERR(ipcc->base);
+
+	ipcc->irq = platform_get_irq(pdev, 0);
+	if (ipcc->irq < 0)
+		return ipcc->irq;
+
+	name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "ipcc_%d", id++);
+	if (!name)
+		return -ENOMEM;
+
+	ipcc->irq_domain = irq_domain_add_tree(pdev->dev.of_node,
+					       &qcom_ipcc_irq_ops, ipcc);
+	if (!ipcc->irq_domain)
+		return -ENOMEM;
+
+	ret = qcom_ipcc_setup_mbox(ipcc, pdev->dev.of_node);
+	if (ret)
+		goto err_mbox;
+
+	ret = devm_request_irq(&pdev->dev, ipcc->irq, qcom_ipcc_irq_fn,
+			       IRQF_TRIGGER_HIGH | IRQF_NO_SUSPEND |
+			       IRQF_NO_THREAD, name, ipcc);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register the irq: %d\n", ret);
+		goto err_req_irq;
+	}
+
+	platform_set_drvdata(pdev, ipcc);
+
+	return 0;
+
+err_req_irq:
+	if (ipcc->num_chans)
+		mbox_controller_unregister(&ipcc->mbox);
+err_mbox:
+	irq_domain_remove(ipcc->irq_domain);
+
+	return ret;
+}
+
+static int qcom_ipcc_remove(struct platform_device *pdev)
+{
+	struct qcom_ipcc *ipcc = platform_get_drvdata(pdev);
+
+	disable_irq_wake(ipcc->irq);
+	irq_domain_remove(ipcc->irq_domain);
+
+	return 0;
+}
+
+static const struct of_device_id qcom_ipcc_of_match[] = {
+	{ .compatible = "qcom,ipcc"},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qcom_ipcc_of_match);
+
+static const struct dev_pm_ops qcom_ipcc_dev_pm_ops = {
+	NOIRQ_SYSTEM_SLEEP_PM_OPS(NULL, qcom_ipcc_pm_resume)
+};
+
+static struct platform_driver qcom_ipcc_driver = {
+	.probe = qcom_ipcc_probe,
+	.remove = qcom_ipcc_remove,
+	.driver = {
+		.name = "qcom-ipcc",
+		.of_match_table = qcom_ipcc_of_match,
+		.suppress_bind_attrs = true,
+		.pm = pm_sleep_ptr(&qcom_ipcc_dev_pm_ops),
+	},
+};
+
+static int __init qcom_ipcc_init(void)
+{
+	return platform_driver_register(&qcom_ipcc_driver);
+}
+arch_initcall(qcom_ipcc_init);
+
+MODULE_AUTHOR("Venkata Narendra Kumar Gutta <vnkgutta@codeaurora.org>");
+MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
+MODULE_DESCRIPTION("Qualcomm Technologies, Inc. IPCC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/rockchip-mailbox.c b/drivers/mailbox/rockchip-mailbox.c
new file mode 100644
index 000000000..979acc810
--- /dev/null
+++ b/drivers/mailbox/rockchip-mailbox.c
@@ -0,0 +1,262 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015, Fuzhou Rockchip Electronics Co., Ltd
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#define MAILBOX_A2B_INTEN		0x00
+#define MAILBOX_A2B_STATUS		0x04
+#define MAILBOX_A2B_CMD(x)		(0x08 + (x) * 8)
+#define MAILBOX_A2B_DAT(x)		(0x0c + (x) * 8)
+
+#define MAILBOX_B2A_INTEN		0x28
+#define MAILBOX_B2A_STATUS		0x2C
+#define MAILBOX_B2A_CMD(x)		(0x30 + (x) * 8)
+#define MAILBOX_B2A_DAT(x)		(0x34 + (x) * 8)
+
+struct rockchip_mbox_msg {
+	u32 cmd;
+	int rx_size;
+};
+
+struct rockchip_mbox_data {
+	int num_chans;
+};
+
+struct rockchip_mbox_chan {
+	int idx;
+	int irq;
+	struct rockchip_mbox_msg *msg;
+	struct rockchip_mbox *mb;
+};
+
+struct rockchip_mbox {
+	struct mbox_controller mbox;
+	struct clk *pclk;
+	void __iomem *mbox_base;
+
+	/* The maximum size of buf for each channel */
+	u32 buf_size;
+
+	struct rockchip_mbox_chan *chans;
+};
+
+static int rockchip_mbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
+	struct rockchip_mbox_msg *msg = data;
+	struct rockchip_mbox_chan *chans = mb->chans;
+
+	if (!msg)
+		return -EINVAL;
+
+	if (msg->rx_size > mb->buf_size) {
+		dev_err(mb->mbox.dev, "Transmit size over buf size(%d)\n",
+			mb->buf_size);
+		return -EINVAL;
+	}
+
+	dev_dbg(mb->mbox.dev, "Chan[%d]: A2B message, cmd 0x%08x\n",
+		chans->idx, msg->cmd);
+
+	mb->chans[chans->idx].msg = msg;
+
+	writel_relaxed(msg->cmd, mb->mbox_base + MAILBOX_A2B_CMD(chans->idx));
+	writel_relaxed(msg->rx_size, mb->mbox_base +
+		       MAILBOX_A2B_DAT(chans->idx));
+
+	return 0;
+}
+
+static int rockchip_mbox_startup(struct mbox_chan *chan)
+{
+	struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
+
+	/* Enable all B2A interrupts */
+	writel_relaxed((1 << mb->mbox.num_chans) - 1,
+		       mb->mbox_base + MAILBOX_B2A_INTEN);
+
+	return 0;
+}
+
+static void rockchip_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct rockchip_mbox *mb = dev_get_drvdata(chan->mbox->dev);
+	struct rockchip_mbox_chan *chans = mb->chans;
+
+	/* Disable all B2A interrupts */
+	writel_relaxed(0, mb->mbox_base + MAILBOX_B2A_INTEN);
+
+	mb->chans[chans->idx].msg = NULL;
+}
+
+static const struct mbox_chan_ops rockchip_mbox_chan_ops = {
+	.send_data	= rockchip_mbox_send_data,
+	.startup	= rockchip_mbox_startup,
+	.shutdown	= rockchip_mbox_shutdown,
+};
+
+static irqreturn_t rockchip_mbox_irq(int irq, void *dev_id)
+{
+	int idx;
+	struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
+	u32 status = readl_relaxed(mb->mbox_base + MAILBOX_B2A_STATUS);
+
+	for (idx = 0; idx < mb->mbox.num_chans; idx++) {
+		if ((status & (1 << idx)) && (irq == mb->chans[idx].irq)) {
+			/* Clear mbox interrupt */
+			writel_relaxed(1 << idx,
+				       mb->mbox_base + MAILBOX_B2A_STATUS);
+			return IRQ_WAKE_THREAD;
+		}
+	}
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t rockchip_mbox_isr(int irq, void *dev_id)
+{
+	int idx;
+	struct rockchip_mbox_msg *msg = NULL;
+	struct rockchip_mbox *mb = (struct rockchip_mbox *)dev_id;
+
+	for (idx = 0; idx < mb->mbox.num_chans; idx++) {
+		if (irq != mb->chans[idx].irq)
+			continue;
+
+		msg = mb->chans[idx].msg;
+		if (!msg) {
+			dev_err(mb->mbox.dev,
+				"Chan[%d]: B2A message is NULL\n", idx);
+			break; /* spurious */
+		}
+
+		mbox_chan_received_data(&mb->mbox.chans[idx], msg);
+		mb->chans[idx].msg = NULL;
+
+		dev_dbg(mb->mbox.dev, "Chan[%d]: B2A message, cmd 0x%08x\n",
+			idx, msg->cmd);
+
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static const struct rockchip_mbox_data rk3368_drv_data = {
+	.num_chans = 4,
+};
+
+static const struct of_device_id rockchip_mbox_of_match[] = {
+	{ .compatible = "rockchip,rk3368-mailbox", .data = &rk3368_drv_data},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, rockchp_mbox_of_match);
+
+static int rockchip_mbox_probe(struct platform_device *pdev)
+{
+	struct rockchip_mbox *mb;
+	const struct of_device_id *match;
+	const struct rockchip_mbox_data *drv_data;
+	struct resource *res;
+	int ret, irq, i;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	match = of_match_node(rockchip_mbox_of_match, pdev->dev.of_node);
+	drv_data = (const struct rockchip_mbox_data *)match->data;
+
+	mb = devm_kzalloc(&pdev->dev, sizeof(*mb), GFP_KERNEL);
+	if (!mb)
+		return -ENOMEM;
+
+	mb->chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
+				 sizeof(*mb->chans), GFP_KERNEL);
+	if (!mb->chans)
+		return -ENOMEM;
+
+	mb->mbox.chans = devm_kcalloc(&pdev->dev, drv_data->num_chans,
+				      sizeof(*mb->mbox.chans), GFP_KERNEL);
+	if (!mb->mbox.chans)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, mb);
+
+	mb->mbox.dev = &pdev->dev;
+	mb->mbox.num_chans = drv_data->num_chans;
+	mb->mbox.ops = &rockchip_mbox_chan_ops;
+	mb->mbox.txdone_irq = true;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	mb->mbox_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mb->mbox_base))
+		return PTR_ERR(mb->mbox_base);
+
+	/* Each channel has two buffers for A2B and B2A */
+	mb->buf_size = (size_t)resource_size(res) / (drv_data->num_chans * 2);
+
+	mb->pclk = devm_clk_get(&pdev->dev, "pclk_mailbox");
+	if (IS_ERR(mb->pclk)) {
+		ret = PTR_ERR(mb->pclk);
+		dev_err(&pdev->dev, "failed to get pclk_mailbox clock: %d\n",
+			ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(mb->pclk);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable pclk: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < mb->mbox.num_chans; i++) {
+		irq = platform_get_irq(pdev, i);
+		if (irq < 0)
+			return irq;
+
+		ret = devm_request_threaded_irq(&pdev->dev, irq,
+						rockchip_mbox_irq,
+						rockchip_mbox_isr, IRQF_ONESHOT,
+						dev_name(&pdev->dev), mb);
+		if (ret < 0)
+			return ret;
+
+		mb->chans[i].idx = i;
+		mb->chans[i].irq = irq;
+		mb->chans[i].mb = mb;
+		mb->chans[i].msg = NULL;
+	}
+
+	ret = devm_mbox_controller_register(&pdev->dev, &mb->mbox);
+	if (ret < 0)
+		dev_err(&pdev->dev, "Failed to register mailbox: %d\n", ret);
+
+	return ret;
+}
+
+static struct platform_driver rockchip_mbox_driver = {
+	.probe	= rockchip_mbox_probe,
+	.driver = {
+		.name = "rockchip-mailbox",
+		.of_match_table = of_match_ptr(rockchip_mbox_of_match),
+	},
+};
+
+module_platform_driver(rockchip_mbox_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Rockchip mailbox: communicate between CPU cores and MCU");
+MODULE_AUTHOR("Addy Ke <addy.ke@rock-chips.com>");
+MODULE_AUTHOR("Caesar Wang <wxt@rock-chips.com>");
diff --git a/drivers/mailbox/sprd-mailbox.c b/drivers/mailbox/sprd-mailbox.c
new file mode 100644
index 000000000..e3c899abe
--- /dev/null
+++ b/drivers/mailbox/sprd-mailbox.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Spreadtrum mailbox driver
+ *
+ * Copyright (c) 2020 Spreadtrum Communications Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#define SPRD_MBOX_ID		0x0
+#define SPRD_MBOX_MSG_LOW	0x4
+#define SPRD_MBOX_MSG_HIGH	0x8
+#define SPRD_MBOX_TRIGGER	0xc
+#define SPRD_MBOX_FIFO_RST	0x10
+#define SPRD_MBOX_FIFO_STS	0x14
+#define SPRD_MBOX_IRQ_STS	0x18
+#define SPRD_MBOX_IRQ_MSK	0x1c
+#define SPRD_MBOX_LOCK		0x20
+#define SPRD_MBOX_FIFO_DEPTH	0x24
+
+/* Bit and mask definition for inbox's SPRD_MBOX_FIFO_STS register */
+#define SPRD_INBOX_FIFO_DELIVER_MASK		GENMASK(23, 16)
+#define SPRD_INBOX_FIFO_OVERLOW_MASK		GENMASK(15, 8)
+#define SPRD_INBOX_FIFO_DELIVER_SHIFT		16
+#define SPRD_INBOX_FIFO_BUSY_MASK		GENMASK(7, 0)
+
+/* Bit and mask definition for SPRD_MBOX_IRQ_STS register */
+#define SPRD_MBOX_IRQ_CLR			BIT(0)
+
+/* Bit and mask definition for outbox's SPRD_MBOX_FIFO_STS register */
+#define SPRD_OUTBOX_FIFO_FULL			BIT(2)
+#define SPRD_OUTBOX_FIFO_WR_SHIFT		16
+#define SPRD_OUTBOX_FIFO_RD_SHIFT		24
+#define SPRD_OUTBOX_FIFO_POS_MASK		GENMASK(7, 0)
+
+/* Bit and mask definition for inbox's SPRD_MBOX_IRQ_MSK register */
+#define SPRD_INBOX_FIFO_BLOCK_IRQ		BIT(0)
+#define SPRD_INBOX_FIFO_OVERFLOW_IRQ		BIT(1)
+#define SPRD_INBOX_FIFO_DELIVER_IRQ		BIT(2)
+#define SPRD_INBOX_FIFO_IRQ_MASK		GENMASK(2, 0)
+
+/* Bit and mask definition for outbox's SPRD_MBOX_IRQ_MSK register */
+#define SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ		BIT(0)
+#define SPRD_OUTBOX_FIFO_IRQ_MASK		GENMASK(4, 0)
+
+#define SPRD_OUTBOX_BASE_SPAN			0x1000
+#define SPRD_MBOX_CHAN_MAX			8
+#define SPRD_SUPP_INBOX_ID_SC9863A		7
+
+struct sprd_mbox_priv {
+	struct mbox_controller	mbox;
+	struct device		*dev;
+	void __iomem		*inbox_base;
+	void __iomem		*outbox_base;
+	/*  Base register address for supplementary outbox */
+	void __iomem		*supp_base;
+	struct clk		*clk;
+	u32			outbox_fifo_depth;
+
+	struct mutex		lock;
+	u32			refcnt;
+	struct mbox_chan	chan[SPRD_MBOX_CHAN_MAX];
+};
+
+static struct sprd_mbox_priv *to_sprd_mbox_priv(struct mbox_controller *mbox)
+{
+	return container_of(mbox, struct sprd_mbox_priv, mbox);
+}
+
+static u32 sprd_mbox_get_fifo_len(struct sprd_mbox_priv *priv, u32 fifo_sts)
+{
+	u32 wr_pos = (fifo_sts >> SPRD_OUTBOX_FIFO_WR_SHIFT) &
+		SPRD_OUTBOX_FIFO_POS_MASK;
+	u32 rd_pos = (fifo_sts >> SPRD_OUTBOX_FIFO_RD_SHIFT) &
+		SPRD_OUTBOX_FIFO_POS_MASK;
+	u32 fifo_len;
+
+	/*
+	 * If the read pointer is equal with write pointer, which means the fifo
+	 * is full or empty.
+	 */
+	if (wr_pos == rd_pos) {
+		if (fifo_sts & SPRD_OUTBOX_FIFO_FULL)
+			fifo_len = priv->outbox_fifo_depth;
+		else
+			fifo_len = 0;
+	} else if (wr_pos > rd_pos) {
+		fifo_len = wr_pos - rd_pos;
+	} else {
+		fifo_len = priv->outbox_fifo_depth - rd_pos + wr_pos;
+	}
+
+	return fifo_len;
+}
+
+static irqreturn_t do_outbox_isr(void __iomem *base, struct sprd_mbox_priv *priv)
+{
+	struct mbox_chan *chan;
+	u32 fifo_sts, fifo_len, msg[2];
+	int i, id;
+
+	fifo_sts = readl(base + SPRD_MBOX_FIFO_STS);
+
+	fifo_len = sprd_mbox_get_fifo_len(priv, fifo_sts);
+	if (!fifo_len) {
+		dev_warn_ratelimited(priv->dev, "spurious outbox interrupt\n");
+		return IRQ_NONE;
+	}
+
+	for (i = 0; i < fifo_len; i++) {
+		msg[0] = readl(base + SPRD_MBOX_MSG_LOW);
+		msg[1] = readl(base + SPRD_MBOX_MSG_HIGH);
+		id = readl(base + SPRD_MBOX_ID);
+
+		chan = &priv->chan[id];
+		if (chan->cl)
+			mbox_chan_received_data(chan, (void *)msg);
+		else
+			dev_warn_ratelimited(priv->dev,
+				    "message's been dropped at ch[%d]\n", id);
+
+		/* Trigger to update outbox FIFO pointer */
+		writel(0x1, base + SPRD_MBOX_TRIGGER);
+	}
+
+	/* Clear irq status after reading all message. */
+	writel(SPRD_MBOX_IRQ_CLR, base + SPRD_MBOX_IRQ_STS);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t sprd_mbox_outbox_isr(int irq, void *data)
+{
+	struct sprd_mbox_priv *priv = data;
+
+	return do_outbox_isr(priv->outbox_base, priv);
+}
+
+static irqreturn_t sprd_mbox_supp_isr(int irq, void *data)
+{
+	struct sprd_mbox_priv *priv = data;
+
+	return do_outbox_isr(priv->supp_base, priv);
+}
+
+static irqreturn_t sprd_mbox_inbox_isr(int irq, void *data)
+{
+	struct sprd_mbox_priv *priv = data;
+	struct mbox_chan *chan;
+	u32 fifo_sts, send_sts, busy, id;
+
+	fifo_sts = readl(priv->inbox_base + SPRD_MBOX_FIFO_STS);
+
+	/* Get the inbox data delivery status */
+	send_sts = (fifo_sts & SPRD_INBOX_FIFO_DELIVER_MASK) >>
+		SPRD_INBOX_FIFO_DELIVER_SHIFT;
+	if (!send_sts) {
+		dev_warn_ratelimited(priv->dev, "spurious inbox interrupt\n");
+		return IRQ_NONE;
+	}
+
+	while (send_sts) {
+		id = __ffs(send_sts);
+		send_sts &= (send_sts - 1);
+
+		chan = &priv->chan[id];
+
+		/*
+		 * Check if the message was fetched by remote target, if yes,
+		 * that means the transmission has been completed.
+		 */
+		busy = fifo_sts & SPRD_INBOX_FIFO_BUSY_MASK;
+		if (!(busy & BIT(id)))
+			mbox_chan_txdone(chan, 0);
+	}
+
+	/* Clear FIFO delivery and overflow status */
+	writel(fifo_sts &
+	       (SPRD_INBOX_FIFO_DELIVER_MASK | SPRD_INBOX_FIFO_OVERLOW_MASK),
+	       priv->inbox_base + SPRD_MBOX_FIFO_RST);
+
+	/* Clear irq status */
+	writel(SPRD_MBOX_IRQ_CLR, priv->inbox_base + SPRD_MBOX_IRQ_STS);
+
+	return IRQ_HANDLED;
+}
+
+static int sprd_mbox_send_data(struct mbox_chan *chan, void *msg)
+{
+	struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox);
+	unsigned long id = (unsigned long)chan->con_priv;
+	u32 *data = msg;
+
+	/* Write data into inbox FIFO, and only support 8 bytes every time */
+	writel(data[0], priv->inbox_base + SPRD_MBOX_MSG_LOW);
+	writel(data[1], priv->inbox_base + SPRD_MBOX_MSG_HIGH);
+
+	/* Set target core id */
+	writel(id, priv->inbox_base + SPRD_MBOX_ID);
+
+	/* Trigger remote request */
+	writel(0x1, priv->inbox_base + SPRD_MBOX_TRIGGER);
+
+	return 0;
+}
+
+static int sprd_mbox_flush(struct mbox_chan *chan, unsigned long timeout)
+{
+	struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox);
+	unsigned long id = (unsigned long)chan->con_priv;
+	u32 busy;
+
+	timeout = jiffies + msecs_to_jiffies(timeout);
+
+	while (time_before(jiffies, timeout)) {
+		busy = readl(priv->inbox_base + SPRD_MBOX_FIFO_STS) &
+			SPRD_INBOX_FIFO_BUSY_MASK;
+		if (!(busy & BIT(id))) {
+			mbox_chan_txdone(chan, 0);
+			return 0;
+		}
+
+		udelay(1);
+	}
+
+	return -ETIME;
+}
+
+static int sprd_mbox_startup(struct mbox_chan *chan)
+{
+	struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox);
+	u32 val;
+
+	mutex_lock(&priv->lock);
+	if (priv->refcnt++ == 0) {
+		/* Select outbox FIFO mode and reset the outbox FIFO status */
+		writel(0x0, priv->outbox_base + SPRD_MBOX_FIFO_RST);
+
+		/* Enable inbox FIFO overflow and delivery interrupt */
+		val = readl(priv->inbox_base + SPRD_MBOX_IRQ_MSK);
+		val &= ~(SPRD_INBOX_FIFO_OVERFLOW_IRQ | SPRD_INBOX_FIFO_DELIVER_IRQ);
+		writel(val, priv->inbox_base + SPRD_MBOX_IRQ_MSK);
+
+		/* Enable outbox FIFO not empty interrupt */
+		val = readl(priv->outbox_base + SPRD_MBOX_IRQ_MSK);
+		val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
+		writel(val, priv->outbox_base + SPRD_MBOX_IRQ_MSK);
+
+		/* Enable supplementary outbox as the fundamental one */
+		if (priv->supp_base) {
+			writel(0x0, priv->supp_base + SPRD_MBOX_FIFO_RST);
+			val = readl(priv->supp_base + SPRD_MBOX_IRQ_MSK);
+			val &= ~SPRD_OUTBOX_FIFO_NOT_EMPTY_IRQ;
+			writel(val, priv->supp_base + SPRD_MBOX_IRQ_MSK);
+		}
+	}
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static void sprd_mbox_shutdown(struct mbox_chan *chan)
+{
+	struct sprd_mbox_priv *priv = to_sprd_mbox_priv(chan->mbox);
+
+	mutex_lock(&priv->lock);
+	if (--priv->refcnt == 0) {
+		/* Disable inbox & outbox interrupt */
+		writel(SPRD_INBOX_FIFO_IRQ_MASK, priv->inbox_base + SPRD_MBOX_IRQ_MSK);
+		writel(SPRD_OUTBOX_FIFO_IRQ_MASK, priv->outbox_base + SPRD_MBOX_IRQ_MSK);
+
+		if (priv->supp_base)
+			writel(SPRD_OUTBOX_FIFO_IRQ_MASK,
+			       priv->supp_base + SPRD_MBOX_IRQ_MSK);
+	}
+	mutex_unlock(&priv->lock);
+}
+
+static const struct mbox_chan_ops sprd_mbox_ops = {
+	.send_data	= sprd_mbox_send_data,
+	.flush		= sprd_mbox_flush,
+	.startup	= sprd_mbox_startup,
+	.shutdown	= sprd_mbox_shutdown,
+};
+
+static void sprd_mbox_disable(void *data)
+{
+	struct sprd_mbox_priv *priv = data;
+
+	clk_disable_unprepare(priv->clk);
+}
+
+static int sprd_mbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sprd_mbox_priv *priv;
+	int ret, inbox_irq, outbox_irq, supp_irq;
+	unsigned long id, supp;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	mutex_init(&priv->lock);
+
+	/*
+	 * Unisoc mailbox uses an inbox to send messages to the target
+	 * core, and uses (an) outbox(es) to receive messages from other
+	 * cores.
+	 *
+	 * Thus in general the mailbox controller supplies 2 different
+	 * register addresses and IRQ numbers for inbox and outbox.
+	 *
+	 * If necessary, a supplementary inbox could be enabled optionally
+	 * with an independent FIFO and an extra interrupt.
+	 */
+	priv->inbox_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->inbox_base))
+		return PTR_ERR(priv->inbox_base);
+
+	priv->outbox_base = devm_platform_ioremap_resource(pdev, 1);
+	if (IS_ERR(priv->outbox_base))
+		return PTR_ERR(priv->outbox_base);
+
+	priv->clk = devm_clk_get(dev, "enable");
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to get mailbox clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, sprd_mbox_disable, priv);
+	if (ret) {
+		dev_err(dev, "failed to add mailbox disable action\n");
+		return ret;
+	}
+
+	inbox_irq = platform_get_irq_byname(pdev, "inbox");
+	if (inbox_irq < 0)
+		return inbox_irq;
+
+	ret = devm_request_irq(dev, inbox_irq, sprd_mbox_inbox_isr,
+			       IRQF_NO_SUSPEND, dev_name(dev), priv);
+	if (ret) {
+		dev_err(dev, "failed to request inbox IRQ: %d\n", ret);
+		return ret;
+	}
+
+	outbox_irq = platform_get_irq_byname(pdev, "outbox");
+	if (outbox_irq < 0)
+		return outbox_irq;
+
+	ret = devm_request_irq(dev, outbox_irq, sprd_mbox_outbox_isr,
+			       IRQF_NO_SUSPEND, dev_name(dev), priv);
+	if (ret) {
+		dev_err(dev, "failed to request outbox IRQ: %d\n", ret);
+		return ret;
+	}
+
+	/* Supplementary outbox IRQ is optional */
+	supp_irq = platform_get_irq_byname(pdev, "supp-outbox");
+	if (supp_irq > 0) {
+		ret = devm_request_irq(dev, supp_irq, sprd_mbox_supp_isr,
+				       IRQF_NO_SUSPEND, dev_name(dev), priv);
+		if (ret) {
+			dev_err(dev, "failed to request outbox IRQ: %d\n", ret);
+			return ret;
+		}
+
+		supp = (unsigned long) of_device_get_match_data(dev);
+		if (!supp) {
+			dev_err(dev, "no supplementary outbox specified\n");
+			return -ENODEV;
+		}
+		priv->supp_base = priv->outbox_base + (SPRD_OUTBOX_BASE_SPAN * supp);
+	}
+
+	/* Get the default outbox FIFO depth */
+	priv->outbox_fifo_depth =
+		readl(priv->outbox_base + SPRD_MBOX_FIFO_DEPTH) + 1;
+	priv->mbox.dev = dev;
+	priv->mbox.chans = &priv->chan[0];
+	priv->mbox.num_chans = SPRD_MBOX_CHAN_MAX;
+	priv->mbox.ops = &sprd_mbox_ops;
+	priv->mbox.txdone_irq = true;
+
+	for (id = 0; id < SPRD_MBOX_CHAN_MAX; id++)
+		priv->chan[id].con_priv = (void *)id;
+
+	ret = devm_mbox_controller_register(dev, &priv->mbox);
+	if (ret) {
+		dev_err(dev, "failed to register mailbox: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id sprd_mbox_of_match[] = {
+	{ .compatible = "sprd,sc9860-mailbox" },
+	{ .compatible = "sprd,sc9863a-mailbox",
+	  .data = (void *)SPRD_SUPP_INBOX_ID_SC9863A },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, sprd_mbox_of_match);
+
+static struct platform_driver sprd_mbox_driver = {
+	.driver = {
+		.name = "sprd-mailbox",
+		.of_match_table = sprd_mbox_of_match,
+	},
+	.probe	= sprd_mbox_probe,
+};
+module_platform_driver(sprd_mbox_driver);
+
+MODULE_AUTHOR("Baolin Wang <baolin.wang@unisoc.com>");
+MODULE_DESCRIPTION("Spreadtrum mailbox driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
new file mode 100644
index 000000000..15d538fe2
--- /dev/null
+++ b/drivers/mailbox/stm32-ipcc.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
+ * Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
+ *          Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_wakeirq.h>
+
+#define IPCC_XCR		0x000
+#define XCR_RXOIE		BIT(0)
+#define XCR_TXOIE		BIT(16)
+
+#define IPCC_XMR		0x004
+#define IPCC_XSCR		0x008
+#define IPCC_XTOYSR		0x00c
+
+#define IPCC_PROC_OFFST		0x010
+
+#define IPCC_HWCFGR		0x3f0
+#define IPCFGR_CHAN_MASK	GENMASK(7, 0)
+
+#define IPCC_VER		0x3f4
+#define VER_MINREV_MASK		GENMASK(3, 0)
+#define VER_MAJREV_MASK		GENMASK(7, 4)
+
+#define RX_BIT_MASK		GENMASK(15, 0)
+#define RX_BIT_CHAN(chan)	BIT(chan)
+#define TX_BIT_SHIFT		16
+#define TX_BIT_MASK		GENMASK(31, 16)
+#define TX_BIT_CHAN(chan)	BIT(TX_BIT_SHIFT + (chan))
+
+#define STM32_MAX_PROCS		2
+
+enum {
+	IPCC_IRQ_RX,
+	IPCC_IRQ_TX,
+	IPCC_IRQ_NUM,
+};
+
+struct stm32_ipcc {
+	struct mbox_controller controller;
+	void __iomem *reg_base;
+	void __iomem *reg_proc;
+	struct clk *clk;
+	spinlock_t lock; /* protect access to IPCC registers */
+	int irqs[IPCC_IRQ_NUM];
+	u32 proc_id;
+	u32 n_chans;
+	u32 xcr;
+	u32 xmr;
+};
+
+static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg,
+				       u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	writel_relaxed(readl_relaxed(reg) | mask, reg);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg,
+				       u32 mask)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(lock, flags);
+	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+	spin_unlock_irqrestore(lock, flags);
+}
+
+static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
+{
+	struct stm32_ipcc *ipcc = data;
+	struct device *dev = ipcc->controller.dev;
+	u32 status, mr, tosr, chan;
+	irqreturn_t ret = IRQ_NONE;
+	int proc_offset;
+
+	/* read 'channel occupied' status from other proc */
+	proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST;
+	tosr = readl_relaxed(ipcc->reg_proc + proc_offset + IPCC_XTOYSR);
+	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+
+	/* search for unmasked 'channel occupied' */
+	status = tosr & FIELD_GET(RX_BIT_MASK, ~mr);
+
+	for (chan = 0; chan < ipcc->n_chans; chan++) {
+		if (!(status & (1 << chan)))
+			continue;
+
+		dev_dbg(dev, "%s: chan:%d rx\n", __func__, chan);
+
+		mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);
+
+		stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
+				    RX_BIT_CHAN(chan));
+
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
+{
+	struct stm32_ipcc *ipcc = data;
+	struct device *dev = ipcc->controller.dev;
+	u32 status, mr, tosr, chan;
+	irqreturn_t ret = IRQ_NONE;
+
+	tosr = readl_relaxed(ipcc->reg_proc + IPCC_XTOYSR);
+	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+
+	/* search for unmasked 'channel free' */
+	status = ~tosr & FIELD_GET(TX_BIT_MASK, ~mr);
+
+	for (chan = 0; chan < ipcc->n_chans ; chan++) {
+		if (!(status & (1 << chan)))
+			continue;
+
+		dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);
+
+		/* mask 'tx channel free' interrupt */
+		stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+				    TX_BIT_CHAN(chan));
+
+		mbox_chan_txdone(&ipcc->controller.chans[chan], 0);
+
+		ret = IRQ_HANDLED;
+	}
+
+	return ret;
+}
+
+static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+
+	dev_dbg(ipcc->controller.dev, "%s: chan:%lu\n", __func__, chan);
+
+	/* set channel n occupied */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
+			    TX_BIT_CHAN(chan));
+
+	/* unmask 'tx channel free' interrupt */
+	stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    TX_BIT_CHAN(chan));
+
+	return 0;
+}
+
+static int stm32_ipcc_startup(struct mbox_chan *link)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+	int ret;
+
+	ret = clk_prepare_enable(ipcc->clk);
+	if (ret) {
+		dev_err(ipcc->controller.dev, "can not enable the clock\n");
+		return ret;
+	}
+
+	/* unmask 'rx channel occupied' interrupt */
+	stm32_ipcc_clr_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_CHAN(chan));
+
+	return 0;
+}
+
+static void stm32_ipcc_shutdown(struct mbox_chan *link)
+{
+	unsigned long chan = (unsigned long)link->con_priv;
+	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
+					       controller);
+
+	/* mask rx/tx interrupt */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan));
+
+	clk_disable_unprepare(ipcc->clk);
+}
+
+static const struct mbox_chan_ops stm32_ipcc_ops = {
+	.send_data	= stm32_ipcc_send_data,
+	.startup	= stm32_ipcc_startup,
+	.shutdown	= stm32_ipcc_shutdown,
+};
+
+static int stm32_ipcc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct stm32_ipcc *ipcc;
+	unsigned long i;
+	int ret;
+	u32 ip_ver;
+	static const char * const irq_name[] = {"rx", "tx"};
+	irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq};
+
+	if (!np) {
+		dev_err(dev, "No DT found\n");
+		return -ENODEV;
+	}
+
+	ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL);
+	if (!ipcc)
+		return -ENOMEM;
+
+	spin_lock_init(&ipcc->lock);
+
+	/* proc_id */
+	if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
+		dev_err(dev, "Missing st,proc-id\n");
+		return -ENODEV;
+	}
+
+	if (ipcc->proc_id >= STM32_MAX_PROCS) {
+		dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
+		return -EINVAL;
+	}
+
+	/* regs */
+	ipcc->reg_base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ipcc->reg_base))
+		return PTR_ERR(ipcc->reg_base);
+
+	ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;
+
+	/* clock */
+	ipcc->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ipcc->clk))
+		return PTR_ERR(ipcc->clk);
+
+	ret = clk_prepare_enable(ipcc->clk);
+	if (ret) {
+		dev_err(dev, "can not enable the clock\n");
+		return ret;
+	}
+
+	/* irq */
+	for (i = 0; i < IPCC_IRQ_NUM; i++) {
+		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
+		if (ipcc->irqs[i] < 0) {
+			ret = ipcc->irqs[i];
+			goto err_clk;
+		}
+
+		ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL,
+						irq_thread[i], IRQF_ONESHOT,
+						dev_name(dev), ipcc);
+		if (ret) {
+			dev_err(dev, "failed to request irq %lu (%d)\n", i, ret);
+			goto err_clk;
+		}
+	}
+
+	/* mask and enable rx/tx irq */
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XMR,
+			    RX_BIT_MASK | TX_BIT_MASK);
+	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR,
+			    XCR_RXOIE | XCR_TXOIE);
+
+	/* wakeup */
+	if (of_property_read_bool(np, "wakeup-source")) {
+		device_set_wakeup_capable(dev, true);
+
+		ret = dev_pm_set_wake_irq(dev, ipcc->irqs[IPCC_IRQ_RX]);
+		if (ret) {
+			dev_err(dev, "Failed to set wake up irq\n");
+			goto err_init_wkp;
+		}
+	}
+
+	/* mailbox controller */
+	ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR);
+	ipcc->n_chans &= IPCFGR_CHAN_MASK;
+
+	ipcc->controller.dev = dev;
+	ipcc->controller.txdone_irq = true;
+	ipcc->controller.ops = &stm32_ipcc_ops;
+	ipcc->controller.num_chans = ipcc->n_chans;
+	ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans,
+					      sizeof(*ipcc->controller.chans),
+					      GFP_KERNEL);
+	if (!ipcc->controller.chans) {
+		ret = -ENOMEM;
+		goto err_irq_wkp;
+	}
+
+	for (i = 0; i < ipcc->controller.num_chans; i++)
+		ipcc->controller.chans[i].con_priv = (void *)i;
+
+	ret = devm_mbox_controller_register(dev, &ipcc->controller);
+	if (ret)
+		goto err_irq_wkp;
+
+	platform_set_drvdata(pdev, ipcc);
+
+	ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER);
+
+	dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n",
+		 FIELD_GET(VER_MAJREV_MASK, ip_ver),
+		 FIELD_GET(VER_MINREV_MASK, ip_ver),
+		 ipcc->controller.num_chans, ipcc->proc_id);
+
+	clk_disable_unprepare(ipcc->clk);
+	return 0;
+
+err_irq_wkp:
+	if (of_property_read_bool(np, "wakeup-source"))
+		dev_pm_clear_wake_irq(dev);
+err_init_wkp:
+	device_set_wakeup_capable(dev, false);
+err_clk:
+	clk_disable_unprepare(ipcc->clk);
+	return ret;
+}
+
+static int stm32_ipcc_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	if (of_property_read_bool(dev->of_node, "wakeup-source"))
+		dev_pm_clear_wake_irq(&pdev->dev);
+
+	device_set_wakeup_capable(dev, false);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stm32_ipcc_suspend(struct device *dev)
+{
+	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
+
+	ipcc->xmr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
+	ipcc->xcr = readl_relaxed(ipcc->reg_proc + IPCC_XCR);
+
+	return 0;
+}
+
+static int stm32_ipcc_resume(struct device *dev)
+{
+	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
+
+	writel_relaxed(ipcc->xmr, ipcc->reg_proc + IPCC_XMR);
+	writel_relaxed(ipcc->xcr, ipcc->reg_proc + IPCC_XCR);
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stm32_ipcc_pm_ops,
+			 stm32_ipcc_suspend, stm32_ipcc_resume);
+
+static const struct of_device_id stm32_ipcc_of_match[] = {
+	{ .compatible = "st,stm32mp1-ipcc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32_ipcc_of_match);
+
+static struct platform_driver stm32_ipcc_driver = {
+	.driver = {
+		.name = "stm32-ipcc",
+		.pm = &stm32_ipcc_pm_ops,
+		.of_match_table = stm32_ipcc_of_match,
+	},
+	.probe		= stm32_ipcc_probe,
+	.remove		= stm32_ipcc_remove,
+};
+
+module_platform_driver(stm32_ipcc_driver);
+
+MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
+MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
+MODULE_DESCRIPTION("STM32 IPCC driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/sun6i-msgbox.c b/drivers/mailbox/sun6i-msgbox.c
new file mode 100644
index 000000000..7f8d93104
--- /dev/null
+++ b/drivers/mailbox/sun6i-msgbox.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2017-2019 Samuel Holland <samuel@sholland.org>
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+
+#define NUM_CHANS		8
+
+#define CTRL_REG(n)		(0x0000 + 0x4 * ((n) / 4))
+#define CTRL_RX(n)		BIT(0 + 8 * ((n) % 4))
+#define CTRL_TX(n)		BIT(4 + 8 * ((n) % 4))
+
+#define REMOTE_IRQ_EN_REG	0x0040
+#define REMOTE_IRQ_STAT_REG	0x0050
+#define LOCAL_IRQ_EN_REG	0x0060
+#define LOCAL_IRQ_STAT_REG	0x0070
+
+#define RX_IRQ(n)		BIT(0 + 2 * (n))
+#define RX_IRQ_MASK		0x5555
+#define TX_IRQ(n)		BIT(1 + 2 * (n))
+#define TX_IRQ_MASK		0xaaaa
+
+#define FIFO_STAT_REG(n)	(0x0100 + 0x4 * (n))
+#define FIFO_STAT_MASK		GENMASK(0, 0)
+
+#define MSG_STAT_REG(n)		(0x0140 + 0x4 * (n))
+#define MSG_STAT_MASK		GENMASK(2, 0)
+
+#define MSG_DATA_REG(n)		(0x0180 + 0x4 * (n))
+
+#define mbox_dbg(mbox, ...)	dev_dbg((mbox)->controller.dev, __VA_ARGS__)
+
+struct sun6i_msgbox {
+	struct mbox_controller controller;
+	struct clk *clk;
+	spinlock_t lock;
+	void __iomem *regs;
+};
+
+static bool sun6i_msgbox_last_tx_done(struct mbox_chan *chan);
+static bool sun6i_msgbox_peek_data(struct mbox_chan *chan);
+
+static inline int channel_number(struct mbox_chan *chan)
+{
+	return chan - chan->mbox->chans;
+}
+
+static inline struct sun6i_msgbox *to_sun6i_msgbox(struct mbox_chan *chan)
+{
+	return chan->con_priv;
+}
+
+static irqreturn_t sun6i_msgbox_irq(int irq, void *dev_id)
+{
+	struct sun6i_msgbox *mbox = dev_id;
+	uint32_t status;
+	int n;
+
+	/* Only examine channels that are currently enabled. */
+	status = readl(mbox->regs + LOCAL_IRQ_EN_REG) &
+		 readl(mbox->regs + LOCAL_IRQ_STAT_REG);
+
+	if (!(status & RX_IRQ_MASK))
+		return IRQ_NONE;
+
+	for (n = 0; n < NUM_CHANS; ++n) {
+		struct mbox_chan *chan = &mbox->controller.chans[n];
+
+		if (!(status & RX_IRQ(n)))
+			continue;
+
+		while (sun6i_msgbox_peek_data(chan)) {
+			uint32_t msg = readl(mbox->regs + MSG_DATA_REG(n));
+
+			mbox_dbg(mbox, "Channel %d received 0x%08x\n", n, msg);
+			mbox_chan_received_data(chan, &msg);
+		}
+
+		/* The IRQ can be cleared only once the FIFO is empty. */
+		writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int sun6i_msgbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
+	int n = channel_number(chan);
+	uint32_t msg = *(uint32_t *)data;
+
+	/* Using a channel backwards gets the hardware into a bad state. */
+	if (WARN_ON_ONCE(!(readl(mbox->regs + CTRL_REG(n)) & CTRL_TX(n))))
+		return 0;
+
+	writel(msg, mbox->regs + MSG_DATA_REG(n));
+	mbox_dbg(mbox, "Channel %d sent 0x%08x\n", n, msg);
+
+	return 0;
+}
+
+static int sun6i_msgbox_startup(struct mbox_chan *chan)
+{
+	struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
+	int n = channel_number(chan);
+
+	/* The coprocessor is responsible for setting channel directions. */
+	if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
+		/* Flush the receive FIFO. */
+		while (sun6i_msgbox_peek_data(chan))
+			readl(mbox->regs + MSG_DATA_REG(n));
+		writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+
+		/* Enable the receive IRQ. */
+		spin_lock(&mbox->lock);
+		writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) | RX_IRQ(n),
+		       mbox->regs + LOCAL_IRQ_EN_REG);
+		spin_unlock(&mbox->lock);
+	}
+
+	mbox_dbg(mbox, "Channel %d startup complete\n", n);
+
+	return 0;
+}
+
+static void sun6i_msgbox_shutdown(struct mbox_chan *chan)
+{
+	struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
+	int n = channel_number(chan);
+
+	if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
+		/* Disable the receive IRQ. */
+		spin_lock(&mbox->lock);
+		writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) & ~RX_IRQ(n),
+		       mbox->regs + LOCAL_IRQ_EN_REG);
+		spin_unlock(&mbox->lock);
+
+		/* Attempt to flush the FIFO until the IRQ is cleared. */
+		do {
+			while (sun6i_msgbox_peek_data(chan))
+				readl(mbox->regs + MSG_DATA_REG(n));
+			writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
+		} while (readl(mbox->regs + LOCAL_IRQ_STAT_REG) & RX_IRQ(n));
+	}
+
+	mbox_dbg(mbox, "Channel %d shutdown complete\n", n);
+}
+
+static bool sun6i_msgbox_last_tx_done(struct mbox_chan *chan)
+{
+	struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
+	int n = channel_number(chan);
+
+	/*
+	 * The hardware allows snooping on the remote user's IRQ statuses.
+	 * We consider a message to be acknowledged only once the receive IRQ
+	 * for that channel is cleared. Since the receive IRQ for a channel
+	 * cannot be cleared until the FIFO for that channel is empty, this
+	 * ensures that the message has actually been read. It also gives the
+	 * recipient an opportunity to perform minimal processing before
+	 * acknowledging the message.
+	 */
+	return !(readl(mbox->regs + REMOTE_IRQ_STAT_REG) & RX_IRQ(n));
+}
+
+static bool sun6i_msgbox_peek_data(struct mbox_chan *chan)
+{
+	struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
+	int n = channel_number(chan);
+
+	return readl(mbox->regs + MSG_STAT_REG(n)) & MSG_STAT_MASK;
+}
+
+static const struct mbox_chan_ops sun6i_msgbox_chan_ops = {
+	.send_data    = sun6i_msgbox_send_data,
+	.startup      = sun6i_msgbox_startup,
+	.shutdown     = sun6i_msgbox_shutdown,
+	.last_tx_done = sun6i_msgbox_last_tx_done,
+	.peek_data    = sun6i_msgbox_peek_data,
+};
+
+static int sun6i_msgbox_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mbox_chan *chans;
+	struct reset_control *reset;
+	struct sun6i_msgbox *mbox;
+	int i, ret;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	chans = devm_kcalloc(dev, NUM_CHANS, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+
+	for (i = 0; i < NUM_CHANS; ++i)
+		chans[i].con_priv = mbox;
+
+	mbox->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(mbox->clk)) {
+		ret = PTR_ERR(mbox->clk);
+		dev_err(dev, "Failed to get clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(mbox->clk);
+	if (ret) {
+		dev_err(dev, "Failed to enable clock: %d\n", ret);
+		return ret;
+	}
+
+	reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(reset)) {
+		ret = PTR_ERR(reset);
+		dev_err(dev, "Failed to get reset control: %d\n", ret);
+		goto err_disable_unprepare;
+	}
+
+	/*
+	 * NOTE: We rely on platform firmware to preconfigure the channel
+	 * directions, and we share this hardware block with other firmware
+	 * that runs concurrently with Linux (e.g. a trusted monitor).
+	 *
+	 * Therefore, we do *not* assert the reset line if probing fails or
+	 * when removing the device.
+	 */
+	ret = reset_control_deassert(reset);
+	if (ret) {
+		dev_err(dev, "Failed to deassert reset: %d\n", ret);
+		goto err_disable_unprepare;
+	}
+
+	mbox->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->regs)) {
+		ret = PTR_ERR(mbox->regs);
+		dev_err(dev, "Failed to map MMIO resource: %d\n", ret);
+		goto err_disable_unprepare;
+	}
+
+	/* Disable all IRQs for this end of the msgbox. */
+	writel(0, mbox->regs + LOCAL_IRQ_EN_REG);
+
+	ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0),
+			       sun6i_msgbox_irq, 0, dev_name(dev), mbox);
+	if (ret) {
+		dev_err(dev, "Failed to register IRQ handler: %d\n", ret);
+		goto err_disable_unprepare;
+	}
+
+	mbox->controller.dev           = dev;
+	mbox->controller.ops           = &sun6i_msgbox_chan_ops;
+	mbox->controller.chans         = chans;
+	mbox->controller.num_chans     = NUM_CHANS;
+	mbox->controller.txdone_irq    = false;
+	mbox->controller.txdone_poll   = true;
+	mbox->controller.txpoll_period = 5;
+
+	spin_lock_init(&mbox->lock);
+	platform_set_drvdata(pdev, mbox);
+
+	ret = mbox_controller_register(&mbox->controller);
+	if (ret) {
+		dev_err(dev, "Failed to register controller: %d\n", ret);
+		goto err_disable_unprepare;
+	}
+
+	return 0;
+
+err_disable_unprepare:
+	clk_disable_unprepare(mbox->clk);
+
+	return ret;
+}
+
+static int sun6i_msgbox_remove(struct platform_device *pdev)
+{
+	struct sun6i_msgbox *mbox = platform_get_drvdata(pdev);
+
+	mbox_controller_unregister(&mbox->controller);
+	/* See the comment in sun6i_msgbox_probe about the reset line. */
+	clk_disable_unprepare(mbox->clk);
+
+	return 0;
+}
+
+static const struct of_device_id sun6i_msgbox_of_match[] = {
+	{ .compatible = "allwinner,sun6i-a31-msgbox", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sun6i_msgbox_of_match);
+
+static struct platform_driver sun6i_msgbox_driver = {
+	.driver = {
+		.name = "sun6i-msgbox",
+		.of_match_table = sun6i_msgbox_of_match,
+	},
+	.probe  = sun6i_msgbox_probe,
+	.remove = sun6i_msgbox_remove,
+};
+module_platform_driver(sun6i_msgbox_driver);
+
+MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
+MODULE_DESCRIPTION("Allwinner sun6i/sun8i/sun9i/sun50i Message Box");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mailbox/tegra-hsp.c b/drivers/mailbox/tegra-hsp.c
new file mode 100644
index 000000000..573481e43
--- /dev/null
+++ b/drivers/mailbox/tegra-hsp.c
@@ -0,0 +1,954 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016-2018, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mailbox_controller.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+
+#include <soc/tegra/fuse.h>
+
+#include <dt-bindings/mailbox/tegra186-hsp.h>
+
+#include "mailbox.h"
+
+#define HSP_INT_IE(x)		(0x100 + ((x) * 4))
+#define HSP_INT_IV		0x300
+#define HSP_INT_IR		0x304
+
+#define HSP_INT_EMPTY_SHIFT	0
+#define HSP_INT_EMPTY_MASK	0xff
+#define HSP_INT_FULL_SHIFT	8
+#define HSP_INT_FULL_MASK	0xff
+
+#define HSP_INT_DIMENSIONING	0x380
+#define HSP_nSM_SHIFT		0
+#define HSP_nSS_SHIFT		4
+#define HSP_nAS_SHIFT		8
+#define HSP_nDB_SHIFT		12
+#define HSP_nSI_SHIFT		16
+#define HSP_nINT_MASK		0xf
+
+#define HSP_DB_TRIGGER	0x0
+#define HSP_DB_ENABLE	0x4
+#define HSP_DB_RAW	0x8
+#define HSP_DB_PENDING	0xc
+
+#define HSP_SM_SHRD_MBOX	0x0
+#define HSP_SM_SHRD_MBOX_FULL	BIT(31)
+#define HSP_SM_SHRD_MBOX_FULL_INT_IE	0x04
+#define HSP_SM_SHRD_MBOX_EMPTY_INT_IE	0x08
+
+#define HSP_SHRD_MBOX_TYPE1_TAG		0x40
+#define HSP_SHRD_MBOX_TYPE1_DATA0	0x48
+#define HSP_SHRD_MBOX_TYPE1_DATA1	0x4c
+#define HSP_SHRD_MBOX_TYPE1_DATA2	0x50
+#define HSP_SHRD_MBOX_TYPE1_DATA3	0x54
+
+#define HSP_DB_CCPLEX		1
+#define HSP_DB_BPMP		3
+#define HSP_DB_MAX		7
+
+#define HSP_MBOX_TYPE_MASK	0xff
+
+struct tegra_hsp_channel;
+struct tegra_hsp;
+
+struct tegra_hsp_channel {
+	struct tegra_hsp *hsp;
+	struct mbox_chan *chan;
+	void __iomem *regs;
+};
+
+struct tegra_hsp_doorbell {
+	struct tegra_hsp_channel channel;
+	struct list_head list;
+	const char *name;
+	unsigned int master;
+	unsigned int index;
+};
+
+struct tegra_hsp_sm_ops {
+	void (*send)(struct tegra_hsp_channel *channel, void *data);
+	void (*recv)(struct tegra_hsp_channel *channel);
+};
+
+struct tegra_hsp_mailbox {
+	struct tegra_hsp_channel channel;
+	const struct tegra_hsp_sm_ops *ops;
+	unsigned int index;
+	bool producer;
+};
+
+struct tegra_hsp_db_map {
+	const char *name;
+	unsigned int master;
+	unsigned int index;
+};
+
+struct tegra_hsp_soc {
+	const struct tegra_hsp_db_map *map;
+	bool has_per_mb_ie;
+	bool has_128_bit_mb;
+};
+
+struct tegra_hsp {
+	struct device *dev;
+	const struct tegra_hsp_soc *soc;
+	struct mbox_controller mbox_db;
+	struct mbox_controller mbox_sm;
+	void __iomem *regs;
+	unsigned int doorbell_irq;
+	unsigned int *shared_irqs;
+	unsigned int shared_irq;
+	unsigned int num_sm;
+	unsigned int num_as;
+	unsigned int num_ss;
+	unsigned int num_db;
+	unsigned int num_si;
+
+	spinlock_t lock;
+	struct lock_class_key lock_key;
+
+	struct list_head doorbells;
+	struct tegra_hsp_mailbox *mailboxes;
+
+	unsigned long mask;
+};
+
+static inline u32 tegra_hsp_readl(struct tegra_hsp *hsp, unsigned int offset)
+{
+	return readl(hsp->regs + offset);
+}
+
+static inline void tegra_hsp_writel(struct tegra_hsp *hsp, u32 value,
+				    unsigned int offset)
+{
+	writel(value, hsp->regs + offset);
+}
+
+static inline u32 tegra_hsp_channel_readl(struct tegra_hsp_channel *channel,
+					  unsigned int offset)
+{
+	return readl(channel->regs + offset);
+}
+
+static inline void tegra_hsp_channel_writel(struct tegra_hsp_channel *channel,
+					    u32 value, unsigned int offset)
+{
+	writel(value, channel->regs + offset);
+}
+
+static bool tegra_hsp_doorbell_can_ring(struct tegra_hsp_doorbell *db)
+{
+	u32 value;
+
+	value = tegra_hsp_channel_readl(&db->channel, HSP_DB_ENABLE);
+
+	return (value & BIT(TEGRA_HSP_DB_MASTER_CCPLEX)) != 0;
+}
+
+static struct tegra_hsp_doorbell *
+__tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+	struct tegra_hsp_doorbell *entry;
+
+	list_for_each_entry(entry, &hsp->doorbells, list)
+		if (entry->master == master)
+			return entry;
+
+	return NULL;
+}
+
+static struct tegra_hsp_doorbell *
+tegra_hsp_doorbell_get(struct tegra_hsp *hsp, unsigned int master)
+{
+	struct tegra_hsp_doorbell *db;
+	unsigned long flags;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+	db = __tegra_hsp_doorbell_get(hsp, master);
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return db;
+}
+
+static irqreturn_t tegra_hsp_doorbell_irq(int irq, void *data)
+{
+	struct tegra_hsp *hsp = data;
+	struct tegra_hsp_doorbell *db;
+	unsigned long master, value;
+
+	db = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!db)
+		return IRQ_NONE;
+
+	value = tegra_hsp_channel_readl(&db->channel, HSP_DB_PENDING);
+	tegra_hsp_channel_writel(&db->channel, value, HSP_DB_PENDING);
+
+	spin_lock(&hsp->lock);
+
+	for_each_set_bit(master, &value, hsp->mbox_db.num_chans) {
+		struct tegra_hsp_doorbell *db;
+
+		db = __tegra_hsp_doorbell_get(hsp, master);
+		/*
+		 * Depending on the bootloader chain, the CCPLEX doorbell will
+		 * have some doorbells enabled, which means that requesting an
+		 * interrupt will immediately fire.
+		 *
+		 * In that case, db->channel.chan will still be NULL here and
+		 * cause a crash if not properly guarded.
+		 *
+		 * It remains to be seen if ignoring the doorbell in that case
+		 * is the correct solution.
+		 */
+		if (db && db->channel.chan)
+			mbox_chan_received_data(db->channel.chan, NULL);
+	}
+
+	spin_unlock(&hsp->lock);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t tegra_hsp_shared_irq(int irq, void *data)
+{
+	struct tegra_hsp *hsp = data;
+	unsigned long bit, mask;
+	u32 status;
+
+	status = tegra_hsp_readl(hsp, HSP_INT_IR) & hsp->mask;
+
+	/* process EMPTY interrupts first */
+	mask = (status >> HSP_INT_EMPTY_SHIFT) & HSP_INT_EMPTY_MASK;
+
+	for_each_set_bit(bit, &mask, hsp->num_sm) {
+		struct tegra_hsp_mailbox *mb = &hsp->mailboxes[bit];
+
+		if (mb->producer) {
+			/*
+			 * Disable EMPTY interrupts until data is sent with
+			 * the next message. These interrupts are level-
+			 * triggered, so if we kept them enabled they would
+			 * constantly trigger until we next write data into
+			 * the message.
+			 */
+			spin_lock(&hsp->lock);
+
+			hsp->mask &= ~BIT(HSP_INT_EMPTY_SHIFT + mb->index);
+			tegra_hsp_writel(hsp, hsp->mask,
+					 HSP_INT_IE(hsp->shared_irq));
+
+			spin_unlock(&hsp->lock);
+
+			mbox_chan_txdone(mb->channel.chan, 0);
+		}
+	}
+
+	/* process FULL interrupts */
+	mask = (status >> HSP_INT_FULL_SHIFT) & HSP_INT_FULL_MASK;
+
+	for_each_set_bit(bit, &mask, hsp->num_sm) {
+		struct tegra_hsp_mailbox *mb = &hsp->mailboxes[bit];
+
+		if (!mb->producer)
+			mb->ops->recv(&mb->channel);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct tegra_hsp_channel *
+tegra_hsp_doorbell_create(struct tegra_hsp *hsp, const char *name,
+			  unsigned int master, unsigned int index)
+{
+	struct tegra_hsp_doorbell *db;
+	unsigned int offset;
+	unsigned long flags;
+
+	db = devm_kzalloc(hsp->dev, sizeof(*db), GFP_KERNEL);
+	if (!db)
+		return ERR_PTR(-ENOMEM);
+
+	offset = (1 + (hsp->num_sm / 2) + hsp->num_ss + hsp->num_as) * SZ_64K;
+	offset += index * 0x100;
+
+	db->channel.regs = hsp->regs + offset;
+	db->channel.hsp = hsp;
+
+	db->name = devm_kstrdup_const(hsp->dev, name, GFP_KERNEL);
+	db->master = master;
+	db->index = index;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+	list_add_tail(&db->list, &hsp->doorbells);
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return &db->channel;
+}
+
+static int tegra_hsp_doorbell_send_data(struct mbox_chan *chan, void *data)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+
+	tegra_hsp_channel_writel(&db->channel, 1, HSP_DB_TRIGGER);
+
+	return 0;
+}
+
+static int tegra_hsp_doorbell_startup(struct mbox_chan *chan)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+	struct tegra_hsp *hsp = db->channel.hsp;
+	struct tegra_hsp_doorbell *ccplex;
+	unsigned long flags;
+	u32 value;
+
+	if (db->master >= chan->mbox->num_chans) {
+		dev_err(chan->mbox->dev,
+			"invalid master ID %u for HSP channel\n",
+			db->master);
+		return -EINVAL;
+	}
+
+	ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!ccplex)
+		return -ENODEV;
+
+	/*
+	 * On simulation platforms the BPMP hasn't had a chance yet to mark
+	 * the doorbell as ringable by the CCPLEX, so we want to skip extra
+	 * checks here.
+	 */
+	if (tegra_is_silicon() && !tegra_hsp_doorbell_can_ring(db))
+		return -ENODEV;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+	value |= BIT(db->master);
+	tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return 0;
+}
+
+static void tegra_hsp_doorbell_shutdown(struct mbox_chan *chan)
+{
+	struct tegra_hsp_doorbell *db = chan->con_priv;
+	struct tegra_hsp *hsp = db->channel.hsp;
+	struct tegra_hsp_doorbell *ccplex;
+	unsigned long flags;
+	u32 value;
+
+	ccplex = tegra_hsp_doorbell_get(hsp, TEGRA_HSP_DB_MASTER_CCPLEX);
+	if (!ccplex)
+		return;
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	value = tegra_hsp_channel_readl(&ccplex->channel, HSP_DB_ENABLE);
+	value &= ~BIT(db->master);
+	tegra_hsp_channel_writel(&ccplex->channel, value, HSP_DB_ENABLE);
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static const struct mbox_chan_ops tegra_hsp_db_ops = {
+	.send_data = tegra_hsp_doorbell_send_data,
+	.startup = tegra_hsp_doorbell_startup,
+	.shutdown = tegra_hsp_doorbell_shutdown,
+};
+
+static void tegra_hsp_sm_send32(struct tegra_hsp_channel *channel, void *data)
+{
+	u32 value;
+
+	/* copy data and mark mailbox full */
+	value = (u32)(unsigned long)data;
+	value |= HSP_SM_SHRD_MBOX_FULL;
+
+	tegra_hsp_channel_writel(channel, value, HSP_SM_SHRD_MBOX);
+}
+
+static void tegra_hsp_sm_recv32(struct tegra_hsp_channel *channel)
+{
+	u32 value;
+	void *msg;
+
+	value = tegra_hsp_channel_readl(channel, HSP_SM_SHRD_MBOX);
+	value &= ~HSP_SM_SHRD_MBOX_FULL;
+	msg = (void *)(unsigned long)value;
+	mbox_chan_received_data(channel->chan, msg);
+
+	/*
+	 * Need to clear all bits here since some producers, such as TCU, depend
+	 * on fields in the register getting cleared by the consumer.
+	 *
+	 * The mailbox API doesn't give the consumers a way of doing that
+	 * explicitly, so we have to make sure we cover all possible cases.
+	 */
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SM_SHRD_MBOX);
+}
+
+static const struct tegra_hsp_sm_ops tegra_hsp_sm_32bit_ops = {
+	.send = tegra_hsp_sm_send32,
+	.recv = tegra_hsp_sm_recv32,
+};
+
+static void tegra_hsp_sm_send128(struct tegra_hsp_channel *channel, void *data)
+{
+	u32 value[4];
+
+	memcpy(value, data, sizeof(value));
+
+	/* Copy data */
+	tegra_hsp_channel_writel(channel, value[0], HSP_SHRD_MBOX_TYPE1_DATA0);
+	tegra_hsp_channel_writel(channel, value[1], HSP_SHRD_MBOX_TYPE1_DATA1);
+	tegra_hsp_channel_writel(channel, value[2], HSP_SHRD_MBOX_TYPE1_DATA2);
+	tegra_hsp_channel_writel(channel, value[3], HSP_SHRD_MBOX_TYPE1_DATA3);
+
+	/* Update tag to mark mailbox full */
+	tegra_hsp_channel_writel(channel, HSP_SM_SHRD_MBOX_FULL,
+				 HSP_SHRD_MBOX_TYPE1_TAG);
+}
+
+static void tegra_hsp_sm_recv128(struct tegra_hsp_channel *channel)
+{
+	u32 value[4];
+	void *msg;
+
+	value[0] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA0);
+	value[1] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA1);
+	value[2] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA2);
+	value[3] = tegra_hsp_channel_readl(channel, HSP_SHRD_MBOX_TYPE1_DATA3);
+
+	msg = (void *)(unsigned long)value;
+	mbox_chan_received_data(channel->chan, msg);
+
+	/*
+	 * Clear data registers and tag.
+	 */
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA0);
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA1);
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA2);
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_DATA3);
+	tegra_hsp_channel_writel(channel, 0x0, HSP_SHRD_MBOX_TYPE1_TAG);
+}
+
+static const struct tegra_hsp_sm_ops tegra_hsp_sm_128bit_ops = {
+	.send = tegra_hsp_sm_send128,
+	.recv = tegra_hsp_sm_recv128,
+};
+
+static int tegra_hsp_mailbox_send_data(struct mbox_chan *chan, void *data)
+{
+	struct tegra_hsp_mailbox *mb = chan->con_priv;
+	struct tegra_hsp *hsp = mb->channel.hsp;
+	unsigned long flags;
+
+	if (WARN_ON(!mb->producer))
+		return -EPERM;
+
+	mb->ops->send(&mb->channel, data);
+
+	/* enable EMPTY interrupt for the shared mailbox */
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	hsp->mask |= BIT(HSP_INT_EMPTY_SHIFT + mb->index);
+	tegra_hsp_writel(hsp, hsp->mask, HSP_INT_IE(hsp->shared_irq));
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return 0;
+}
+
+static int tegra_hsp_mailbox_flush(struct mbox_chan *chan,
+				   unsigned long timeout)
+{
+	struct tegra_hsp_mailbox *mb = chan->con_priv;
+	struct tegra_hsp_channel *ch = &mb->channel;
+	u32 value;
+
+	timeout = jiffies + msecs_to_jiffies(timeout);
+
+	while (time_before(jiffies, timeout)) {
+		value = tegra_hsp_channel_readl(ch, HSP_SM_SHRD_MBOX);
+		if ((value & HSP_SM_SHRD_MBOX_FULL) == 0) {
+			mbox_chan_txdone(chan, 0);
+
+			/* Wait until channel is empty */
+			if (chan->active_req != NULL)
+				continue;
+
+			return 0;
+		}
+
+		udelay(1);
+	}
+
+	return -ETIME;
+}
+
+static int tegra_hsp_mailbox_startup(struct mbox_chan *chan)
+{
+	struct tegra_hsp_mailbox *mb = chan->con_priv;
+	struct tegra_hsp_channel *ch = &mb->channel;
+	struct tegra_hsp *hsp = mb->channel.hsp;
+	unsigned long flags;
+
+	chan->txdone_method = TXDONE_BY_IRQ;
+
+	/*
+	 * Shared mailboxes start out as consumers by default. FULL and EMPTY
+	 * interrupts are coalesced at the same shared interrupt.
+	 *
+	 * Keep EMPTY interrupts disabled at startup and only enable them when
+	 * the mailbox is actually full. This is required because the FULL and
+	 * EMPTY interrupts are level-triggered, so keeping EMPTY interrupts
+	 * enabled all the time would cause an interrupt storm while mailboxes
+	 * are idle.
+	 */
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	if (mb->producer)
+		hsp->mask &= ~BIT(HSP_INT_EMPTY_SHIFT + mb->index);
+	else
+		hsp->mask |= BIT(HSP_INT_FULL_SHIFT + mb->index);
+
+	tegra_hsp_writel(hsp, hsp->mask, HSP_INT_IE(hsp->shared_irq));
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	if (hsp->soc->has_per_mb_ie) {
+		if (mb->producer)
+			tegra_hsp_channel_writel(ch, 0x0,
+						 HSP_SM_SHRD_MBOX_EMPTY_INT_IE);
+		else
+			tegra_hsp_channel_writel(ch, 0x1,
+						 HSP_SM_SHRD_MBOX_FULL_INT_IE);
+	}
+
+	return 0;
+}
+
+static void tegra_hsp_mailbox_shutdown(struct mbox_chan *chan)
+{
+	struct tegra_hsp_mailbox *mb = chan->con_priv;
+	struct tegra_hsp_channel *ch = &mb->channel;
+	struct tegra_hsp *hsp = mb->channel.hsp;
+	unsigned long flags;
+
+	if (hsp->soc->has_per_mb_ie) {
+		if (mb->producer)
+			tegra_hsp_channel_writel(ch, 0x0,
+						 HSP_SM_SHRD_MBOX_EMPTY_INT_IE);
+		else
+			tegra_hsp_channel_writel(ch, 0x0,
+						 HSP_SM_SHRD_MBOX_FULL_INT_IE);
+	}
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	if (mb->producer)
+		hsp->mask &= ~BIT(HSP_INT_EMPTY_SHIFT + mb->index);
+	else
+		hsp->mask &= ~BIT(HSP_INT_FULL_SHIFT + mb->index);
+
+	tegra_hsp_writel(hsp, hsp->mask, HSP_INT_IE(hsp->shared_irq));
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+}
+
+static const struct mbox_chan_ops tegra_hsp_sm_ops = {
+	.send_data = tegra_hsp_mailbox_send_data,
+	.flush = tegra_hsp_mailbox_flush,
+	.startup = tegra_hsp_mailbox_startup,
+	.shutdown = tegra_hsp_mailbox_shutdown,
+};
+
+static struct mbox_chan *tegra_hsp_db_xlate(struct mbox_controller *mbox,
+					    const struct of_phandle_args *args)
+{
+	struct tegra_hsp *hsp = container_of(mbox, struct tegra_hsp, mbox_db);
+	unsigned int type = args->args[0], master = args->args[1];
+	struct tegra_hsp_channel *channel = ERR_PTR(-ENODEV);
+	struct tegra_hsp_doorbell *db;
+	struct mbox_chan *chan;
+	unsigned long flags;
+	unsigned int i;
+
+	if (type != TEGRA_HSP_MBOX_TYPE_DB || !hsp->doorbell_irq)
+		return ERR_PTR(-ENODEV);
+
+	db = tegra_hsp_doorbell_get(hsp, master);
+	if (db)
+		channel = &db->channel;
+
+	if (IS_ERR(channel))
+		return ERR_CAST(channel);
+
+	spin_lock_irqsave(&hsp->lock, flags);
+
+	for (i = 0; i < mbox->num_chans; i++) {
+		chan = &mbox->chans[i];
+		if (!chan->con_priv) {
+			channel->chan = chan;
+			chan->con_priv = db;
+			break;
+		}
+
+		chan = NULL;
+	}
+
+	spin_unlock_irqrestore(&hsp->lock, flags);
+
+	return chan ?: ERR_PTR(-EBUSY);
+}
+
+static struct mbox_chan *tegra_hsp_sm_xlate(struct mbox_controller *mbox,
+					    const struct of_phandle_args *args)
+{
+	struct tegra_hsp *hsp = container_of(mbox, struct tegra_hsp, mbox_sm);
+	unsigned int type = args->args[0], index;
+	struct tegra_hsp_mailbox *mb;
+
+	index = args->args[1] & TEGRA_HSP_SM_MASK;
+
+	if ((type & HSP_MBOX_TYPE_MASK) != TEGRA_HSP_MBOX_TYPE_SM ||
+	    !hsp->shared_irqs || index >= hsp->num_sm)
+		return ERR_PTR(-ENODEV);
+
+	mb = &hsp->mailboxes[index];
+
+	if (type & TEGRA_HSP_MBOX_TYPE_SM_128BIT) {
+		if (!hsp->soc->has_128_bit_mb)
+			return ERR_PTR(-ENODEV);
+
+		mb->ops = &tegra_hsp_sm_128bit_ops;
+	} else {
+		mb->ops = &tegra_hsp_sm_32bit_ops;
+	}
+
+	if ((args->args[1] & TEGRA_HSP_SM_FLAG_TX) == 0)
+		mb->producer = false;
+	else
+		mb->producer = true;
+
+	return mb->channel.chan;
+}
+
+static int tegra_hsp_add_doorbells(struct tegra_hsp *hsp)
+{
+	const struct tegra_hsp_db_map *map = hsp->soc->map;
+	struct tegra_hsp_channel *channel;
+
+	while (map->name) {
+		channel = tegra_hsp_doorbell_create(hsp, map->name,
+						    map->master, map->index);
+		if (IS_ERR(channel))
+			return PTR_ERR(channel);
+
+		map++;
+	}
+
+	return 0;
+}
+
+static int tegra_hsp_add_mailboxes(struct tegra_hsp *hsp, struct device *dev)
+{
+	int i;
+
+	hsp->mailboxes = devm_kcalloc(dev, hsp->num_sm, sizeof(*hsp->mailboxes),
+				      GFP_KERNEL);
+	if (!hsp->mailboxes)
+		return -ENOMEM;
+
+	for (i = 0; i < hsp->num_sm; i++) {
+		struct tegra_hsp_mailbox *mb = &hsp->mailboxes[i];
+
+		mb->index = i;
+
+		mb->channel.hsp = hsp;
+		mb->channel.regs = hsp->regs + SZ_64K + i * SZ_32K;
+		mb->channel.chan = &hsp->mbox_sm.chans[i];
+		mb->channel.chan->con_priv = mb;
+	}
+
+	return 0;
+}
+
+static int tegra_hsp_request_shared_irq(struct tegra_hsp *hsp)
+{
+	unsigned int i, irq = 0;
+	int err;
+
+	for (i = 0; i < hsp->num_si; i++) {
+		irq = hsp->shared_irqs[i];
+		if (irq <= 0)
+			continue;
+
+		err = devm_request_irq(hsp->dev, irq, tegra_hsp_shared_irq, 0,
+				       dev_name(hsp->dev), hsp);
+		if (err < 0) {
+			dev_err(hsp->dev, "failed to request interrupt: %d\n",
+				err);
+			continue;
+		}
+
+		hsp->shared_irq = i;
+
+		/* disable all interrupts */
+		tegra_hsp_writel(hsp, 0, HSP_INT_IE(hsp->shared_irq));
+
+		dev_dbg(hsp->dev, "interrupt requested: %u\n", irq);
+
+		break;
+	}
+
+	if (i == hsp->num_si) {
+		dev_err(hsp->dev, "failed to find available interrupt\n");
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int tegra_hsp_probe(struct platform_device *pdev)
+{
+	struct tegra_hsp *hsp;
+	struct resource *res;
+	unsigned int i;
+	u32 value;
+	int err;
+
+	hsp = devm_kzalloc(&pdev->dev, sizeof(*hsp), GFP_KERNEL);
+	if (!hsp)
+		return -ENOMEM;
+
+	hsp->dev = &pdev->dev;
+	hsp->soc = of_device_get_match_data(&pdev->dev);
+	INIT_LIST_HEAD(&hsp->doorbells);
+	spin_lock_init(&hsp->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	hsp->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(hsp->regs))
+		return PTR_ERR(hsp->regs);
+
+	value = tegra_hsp_readl(hsp, HSP_INT_DIMENSIONING);
+	hsp->num_sm = (value >> HSP_nSM_SHIFT) & HSP_nINT_MASK;
+	hsp->num_ss = (value >> HSP_nSS_SHIFT) & HSP_nINT_MASK;
+	hsp->num_as = (value >> HSP_nAS_SHIFT) & HSP_nINT_MASK;
+	hsp->num_db = (value >> HSP_nDB_SHIFT) & HSP_nINT_MASK;
+	hsp->num_si = (value >> HSP_nSI_SHIFT) & HSP_nINT_MASK;
+
+	err = platform_get_irq_byname_optional(pdev, "doorbell");
+	if (err >= 0)
+		hsp->doorbell_irq = err;
+
+	if (hsp->num_si > 0) {
+		unsigned int count = 0;
+
+		hsp->shared_irqs = devm_kcalloc(&pdev->dev, hsp->num_si,
+						sizeof(*hsp->shared_irqs),
+						GFP_KERNEL);
+		if (!hsp->shared_irqs)
+			return -ENOMEM;
+
+		for (i = 0; i < hsp->num_si; i++) {
+			char *name;
+
+			name = kasprintf(GFP_KERNEL, "shared%u", i);
+			if (!name)
+				return -ENOMEM;
+
+			err = platform_get_irq_byname_optional(pdev, name);
+			if (err >= 0) {
+				hsp->shared_irqs[i] = err;
+				count++;
+			}
+
+			kfree(name);
+		}
+
+		if (count == 0) {
+			devm_kfree(&pdev->dev, hsp->shared_irqs);
+			hsp->shared_irqs = NULL;
+		}
+	}
+
+	/* setup the doorbell controller */
+	hsp->mbox_db.of_xlate = tegra_hsp_db_xlate;
+	hsp->mbox_db.num_chans = 32;
+	hsp->mbox_db.dev = &pdev->dev;
+	hsp->mbox_db.ops = &tegra_hsp_db_ops;
+
+	hsp->mbox_db.chans = devm_kcalloc(&pdev->dev, hsp->mbox_db.num_chans,
+					  sizeof(*hsp->mbox_db.chans),
+					  GFP_KERNEL);
+	if (!hsp->mbox_db.chans)
+		return -ENOMEM;
+
+	if (hsp->doorbell_irq) {
+		err = tegra_hsp_add_doorbells(hsp);
+		if (err < 0) {
+			dev_err(&pdev->dev, "failed to add doorbells: %d\n",
+			        err);
+			return err;
+		}
+	}
+
+	err = devm_mbox_controller_register(&pdev->dev, &hsp->mbox_db);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register doorbell mailbox: %d\n",
+			err);
+		return err;
+	}
+
+	/* setup the shared mailbox controller */
+	hsp->mbox_sm.of_xlate = tegra_hsp_sm_xlate;
+	hsp->mbox_sm.num_chans = hsp->num_sm;
+	hsp->mbox_sm.dev = &pdev->dev;
+	hsp->mbox_sm.ops = &tegra_hsp_sm_ops;
+
+	hsp->mbox_sm.chans = devm_kcalloc(&pdev->dev, hsp->mbox_sm.num_chans,
+					  sizeof(*hsp->mbox_sm.chans),
+					  GFP_KERNEL);
+	if (!hsp->mbox_sm.chans)
+		return -ENOMEM;
+
+	if (hsp->shared_irqs) {
+		err = tegra_hsp_add_mailboxes(hsp, &pdev->dev);
+		if (err < 0) {
+			dev_err(&pdev->dev, "failed to add mailboxes: %d\n",
+			        err);
+			return err;
+		}
+	}
+
+	err = devm_mbox_controller_register(&pdev->dev, &hsp->mbox_sm);
+	if (err < 0) {
+		dev_err(&pdev->dev, "failed to register shared mailbox: %d\n",
+			err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, hsp);
+
+	if (hsp->doorbell_irq) {
+		err = devm_request_irq(&pdev->dev, hsp->doorbell_irq,
+				       tegra_hsp_doorbell_irq, IRQF_NO_SUSPEND,
+				       dev_name(&pdev->dev), hsp);
+		if (err < 0) {
+			dev_err(&pdev->dev,
+			        "failed to request doorbell IRQ#%u: %d\n",
+				hsp->doorbell_irq, err);
+			return err;
+		}
+	}
+
+	if (hsp->shared_irqs) {
+		err = tegra_hsp_request_shared_irq(hsp);
+		if (err < 0)
+			return err;
+	}
+
+	lockdep_register_key(&hsp->lock_key);
+	lockdep_set_class(&hsp->lock, &hsp->lock_key);
+
+	return 0;
+}
+
+static int tegra_hsp_remove(struct platform_device *pdev)
+{
+	struct tegra_hsp *hsp = platform_get_drvdata(pdev);
+
+	lockdep_unregister_key(&hsp->lock_key);
+
+	return 0;
+}
+
+static int __maybe_unused tegra_hsp_resume(struct device *dev)
+{
+	struct tegra_hsp *hsp = dev_get_drvdata(dev);
+	unsigned int i;
+	struct tegra_hsp_doorbell *db;
+
+	list_for_each_entry(db, &hsp->doorbells, list) {
+		if (db->channel.chan)
+			tegra_hsp_doorbell_startup(db->channel.chan);
+	}
+
+	if (hsp->mailboxes) {
+		for (i = 0; i < hsp->num_sm; i++) {
+			struct tegra_hsp_mailbox *mb = &hsp->mailboxes[i];
+
+			if (mb->channel.chan->cl)
+				tegra_hsp_mailbox_startup(mb->channel.chan);
+		}
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops tegra_hsp_pm_ops = {
+	.resume_noirq = tegra_hsp_resume,
+};
+
+static const struct tegra_hsp_db_map tegra186_hsp_db_map[] = {
+	{ "ccplex", TEGRA_HSP_DB_MASTER_CCPLEX, HSP_DB_CCPLEX, },
+	{ "bpmp",   TEGRA_HSP_DB_MASTER_BPMP,   HSP_DB_BPMP,   },
+	{ /* sentinel */ }
+};
+
+static const struct tegra_hsp_soc tegra186_hsp_soc = {
+	.map = tegra186_hsp_db_map,
+	.has_per_mb_ie = false,
+	.has_128_bit_mb = false,
+};
+
+static const struct tegra_hsp_soc tegra194_hsp_soc = {
+	.map = tegra186_hsp_db_map,
+	.has_per_mb_ie = true,
+	.has_128_bit_mb = false,
+};
+
+static const struct tegra_hsp_soc tegra234_hsp_soc = {
+	.map = tegra186_hsp_db_map,
+	.has_per_mb_ie = false,
+	.has_128_bit_mb = true,
+};
+
+static const struct of_device_id tegra_hsp_match[] = {
+	{ .compatible = "nvidia,tegra186-hsp", .data = &tegra186_hsp_soc },
+	{ .compatible = "nvidia,tegra194-hsp", .data = &tegra194_hsp_soc },
+	{ .compatible = "nvidia,tegra234-hsp", .data = &tegra234_hsp_soc },
+	{ }
+};
+
+static struct platform_driver tegra_hsp_driver = {
+	.driver = {
+		.name = "tegra-hsp",
+		.of_match_table = tegra_hsp_match,
+		.pm = &tegra_hsp_pm_ops,
+	},
+	.probe = tegra_hsp_probe,
+	.remove = tegra_hsp_remove,
+};
+
+static int __init tegra_hsp_init(void)
+{
+	return platform_driver_register(&tegra_hsp_driver);
+}
+core_initcall(tegra_hsp_init);
diff --git a/drivers/mailbox/ti-msgmgr.c b/drivers/mailbox/ti-msgmgr.c
new file mode 100644
index 000000000..03048cbda
--- /dev/null
+++ b/drivers/mailbox/ti-msgmgr.c
@@ -0,0 +1,944 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Texas Instruments' Message Manager Driver
+ *
+ * Copyright (C) 2015-2022 Texas Instruments Incorporated - https://www.ti.com/
+ *	Nishanth Menon
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/soc/ti/ti-msgmgr.h>
+
+#define Q_DATA_OFFSET(proxy, queue, reg)	\
+		     ((0x10000 * (proxy)) + (0x80 * (queue)) + ((reg) * 4))
+#define Q_STATE_OFFSET(queue)			((queue) * 0x4)
+#define Q_STATE_ENTRY_COUNT_MASK		(0xFFF000)
+
+#define SPROXY_THREAD_OFFSET(tid) (0x1000 * (tid))
+#define SPROXY_THREAD_DATA_OFFSET(tid, reg) \
+	(SPROXY_THREAD_OFFSET(tid) + ((reg) * 0x4) + 0x4)
+
+#define SPROXY_THREAD_STATUS_OFFSET(tid) (SPROXY_THREAD_OFFSET(tid))
+
+#define SPROXY_THREAD_STATUS_COUNT_MASK (0xFF)
+
+#define SPROXY_THREAD_CTRL_OFFSET(tid) (0x1000 + SPROXY_THREAD_OFFSET(tid))
+#define SPROXY_THREAD_CTRL_DIR_MASK (0x1 << 31)
+
+/**
+ * struct ti_msgmgr_valid_queue_desc - SoC valid queues meant for this processor
+ * @queue_id:	Queue Number for this path
+ * @proxy_id:	Proxy ID representing the processor in SoC
+ * @is_tx:	Is this a receive path?
+ */
+struct ti_msgmgr_valid_queue_desc {
+	u8 queue_id;
+	u8 proxy_id;
+	bool is_tx;
+};
+
+/**
+ * struct ti_msgmgr_desc - Description of message manager integration
+ * @queue_count:	Number of Queues
+ * @max_message_size:	Message size in bytes
+ * @max_messages:	Number of messages
+ * @data_first_reg:	First data register for proxy data region
+ * @data_last_reg:	Last data register for proxy data region
+ * @status_cnt_mask:	Mask for getting the status value
+ * @status_err_mask:	Mask for getting the error value, if applicable
+ * @tx_polled:		Do I need to use polled mechanism for tx
+ * @tx_poll_timeout_ms: Timeout in ms if polled
+ * @valid_queues:	List of Valid queues that the processor can access
+ * @data_region_name:	Name of the proxy data region
+ * @status_region_name:	Name of the proxy status region
+ * @ctrl_region_name:	Name of the proxy control region
+ * @num_valid_queues:	Number of valid queues
+ * @is_sproxy:		Is this an Secure Proxy instance?
+ *
+ * This structure is used in of match data to describe how integration
+ * for a specific compatible SoC is done.
+ */
+struct ti_msgmgr_desc {
+	u8 queue_count;
+	u8 max_message_size;
+	u8 max_messages;
+	u8 data_first_reg;
+	u8 data_last_reg;
+	u32 status_cnt_mask;
+	u32 status_err_mask;
+	bool tx_polled;
+	int tx_poll_timeout_ms;
+	const struct ti_msgmgr_valid_queue_desc *valid_queues;
+	const char *data_region_name;
+	const char *status_region_name;
+	const char *ctrl_region_name;
+	int num_valid_queues;
+	bool is_sproxy;
+};
+
+/**
+ * struct ti_queue_inst - Description of a queue instance
+ * @name:	Queue Name
+ * @queue_id:	Queue Identifier as mapped on SoC
+ * @proxy_id:	Proxy Identifier as mapped on SoC
+ * @irq:	IRQ for Rx Queue
+ * @is_tx:	'true' if transmit queue, else, 'false'
+ * @queue_buff_start: First register of Data Buffer
+ * @queue_buff_end: Last (or confirmation) register of Data buffer
+ * @queue_state: Queue status register
+ * @queue_ctrl: Queue Control register
+ * @chan:	Mailbox channel
+ * @rx_buff:	Receive buffer pointer allocated at probe, max_message_size
+ * @polled_rx_mode: Use polling for rx instead of interrupts
+ */
+struct ti_queue_inst {
+	char name[30];
+	u8 queue_id;
+	u8 proxy_id;
+	int irq;
+	bool is_tx;
+	void __iomem *queue_buff_start;
+	void __iomem *queue_buff_end;
+	void __iomem *queue_state;
+	void __iomem *queue_ctrl;
+	struct mbox_chan *chan;
+	u32 *rx_buff;
+	bool polled_rx_mode;
+};
+
+/**
+ * struct ti_msgmgr_inst - Description of a Message Manager Instance
+ * @dev:	device pointer corresponding to the Message Manager instance
+ * @desc:	Description of the SoC integration
+ * @queue_proxy_region:	Queue proxy region where queue buffers are located
+ * @queue_state_debug_region:	Queue status register regions
+ * @queue_ctrl_region:	Queue Control register regions
+ * @num_valid_queues:	Number of valid queues defined for the processor
+ *		Note: other queues are probably reserved for other processors
+ *		in the SoC.
+ * @qinsts:	Array of valid Queue Instances for the Processor
+ * @mbox:	Mailbox Controller
+ * @chans:	Array for channels corresponding to the Queue Instances.
+ */
+struct ti_msgmgr_inst {
+	struct device *dev;
+	const struct ti_msgmgr_desc *desc;
+	void __iomem *queue_proxy_region;
+	void __iomem *queue_state_debug_region;
+	void __iomem *queue_ctrl_region;
+	u8 num_valid_queues;
+	struct ti_queue_inst *qinsts;
+	struct mbox_controller mbox;
+	struct mbox_chan *chans;
+};
+
+/**
+ * ti_msgmgr_queue_get_num_messages() - Get the number of pending messages
+ * @d:		Description of message manager
+ * @qinst:	Queue instance for which we check the number of pending messages
+ *
+ * Return: number of messages pending in the queue (0 == no pending messages)
+ */
+static inline int
+ti_msgmgr_queue_get_num_messages(const struct ti_msgmgr_desc *d,
+				 struct ti_queue_inst *qinst)
+{
+	u32 val;
+	u32 status_cnt_mask = d->status_cnt_mask;
+
+	/*
+	 * We cannot use relaxed operation here - update may happen
+	 * real-time.
+	 */
+	val = readl(qinst->queue_state) & status_cnt_mask;
+	val >>= __ffs(status_cnt_mask);
+
+	return val;
+}
+
+/**
+ * ti_msgmgr_queue_is_error() - Check to see if there is queue error
+ * @d:		Description of message manager
+ * @qinst:	Queue instance for which we check the number of pending messages
+ *
+ * Return: true if error, else false
+ */
+static inline bool ti_msgmgr_queue_is_error(const struct ti_msgmgr_desc *d,
+					    struct ti_queue_inst *qinst)
+{
+	u32 val;
+
+	/* Msgmgr has no error detection */
+	if (!d->is_sproxy)
+		return false;
+
+	/*
+	 * We cannot use relaxed operation here - update may happen
+	 * real-time.
+	 */
+	val = readl(qinst->queue_state) & d->status_err_mask;
+
+	return val ? true : false;
+}
+
+static int ti_msgmgr_queue_rx_data(struct mbox_chan *chan, struct ti_queue_inst *qinst,
+				   const struct ti_msgmgr_desc *desc)
+{
+	int num_words;
+	struct ti_msgmgr_message message;
+	void __iomem *data_reg;
+	u32 *word_data;
+
+	/*
+	 * I have no idea about the protocol being used to communicate with the
+	 * remote producer - 0 could be valid data, so I wont make a judgement
+	 * of how many bytes I should be reading. Let the client figure this
+	 * out.. I just read the full message and pass it on..
+	 */
+	message.len = desc->max_message_size;
+	message.buf = (u8 *)qinst->rx_buff;
+
+	/*
+	 * NOTE about register access involved here:
+	 * the hardware block is implemented with 32bit access operations and no
+	 * support for data splitting.  We don't want the hardware to misbehave
+	 * with sub 32bit access - For example: if the last register read is
+	 * split into byte wise access, it can result in the queue getting
+	 * stuck or indeterminate behavior. An out of order read operation may
+	 * result in weird data results as well.
+	 * Hence, we do not use memcpy_fromio or __ioread32_copy here, instead
+	 * we depend on readl for the purpose.
+	 *
+	 * Also note that the final register read automatically marks the
+	 * queue message as read.
+	 */
+	for (data_reg = qinst->queue_buff_start, word_data = qinst->rx_buff,
+	     num_words = (desc->max_message_size / sizeof(u32));
+	     num_words; num_words--, data_reg += sizeof(u32), word_data++)
+		*word_data = readl(data_reg);
+
+	/*
+	 * Last register read automatically clears the IRQ if only 1 message
+	 * is pending - so send the data up the stack..
+	 * NOTE: Client is expected to be as optimal as possible, since
+	 * we invoke the handler in IRQ context.
+	 */
+	mbox_chan_received_data(chan, (void *)&message);
+
+	return 0;
+}
+
+static int ti_msgmgr_queue_rx_poll_timeout(struct mbox_chan *chan, int timeout_us)
+{
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	struct ti_queue_inst *qinst = chan->con_priv;
+	const struct ti_msgmgr_desc *desc = inst->desc;
+	int msg_count;
+	int ret;
+
+	ret = readl_poll_timeout_atomic(qinst->queue_state, msg_count,
+					(msg_count & desc->status_cnt_mask),
+					10, timeout_us);
+	if (ret != 0)
+		return ret;
+
+	ti_msgmgr_queue_rx_data(chan, qinst, desc);
+
+	return 0;
+}
+
+/**
+ * ti_msgmgr_queue_rx_interrupt() - Interrupt handler for receive Queue
+ * @irq:	Interrupt number
+ * @p:		Channel Pointer
+ *
+ * Return: -EINVAL if there is no instance
+ * IRQ_NONE if the interrupt is not ours.
+ * IRQ_HANDLED if the rx interrupt was successfully handled.
+ */
+static irqreturn_t ti_msgmgr_queue_rx_interrupt(int irq, void *p)
+{
+	struct mbox_chan *chan = p;
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	struct ti_queue_inst *qinst = chan->con_priv;
+	const struct ti_msgmgr_desc *desc;
+	int msg_count;
+
+	if (WARN_ON(!inst)) {
+		dev_err(dev, "no platform drv data??\n");
+		return -EINVAL;
+	}
+
+	/* Do I have an invalid interrupt source? */
+	if (qinst->is_tx) {
+		dev_err(dev, "Cannot handle rx interrupt on tx channel %s\n",
+			qinst->name);
+		return IRQ_NONE;
+	}
+
+	desc = inst->desc;
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on Rx channel %s\n", qinst->name);
+		return IRQ_NONE;
+	}
+
+	/* Do I actually have messages to read? */
+	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
+	if (!msg_count) {
+		/* Shared IRQ? */
+		dev_dbg(dev, "Spurious event - 0 pending data!\n");
+		return IRQ_NONE;
+	}
+
+	ti_msgmgr_queue_rx_data(chan, qinst, desc);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * ti_msgmgr_queue_peek_data() - Peek to see if there are any rx messages.
+ * @chan:	Channel Pointer
+ *
+ * Return: 'true' if there is pending rx data, 'false' if there is none.
+ */
+static bool ti_msgmgr_queue_peek_data(struct mbox_chan *chan)
+{
+	struct ti_queue_inst *qinst = chan->con_priv;
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	const struct ti_msgmgr_desc *desc = inst->desc;
+	int msg_count;
+
+	if (qinst->is_tx)
+		return false;
+
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
+	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
+
+	return msg_count ? true : false;
+}
+
+/**
+ * ti_msgmgr_last_tx_done() - See if all the tx messages are sent
+ * @chan:	Channel pointer
+ *
+ * Return: 'true' is no pending tx data, 'false' if there are any.
+ */
+static bool ti_msgmgr_last_tx_done(struct mbox_chan *chan)
+{
+	struct ti_queue_inst *qinst = chan->con_priv;
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	const struct ti_msgmgr_desc *desc = inst->desc;
+	int msg_count;
+
+	if (!qinst->is_tx)
+		return false;
+
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
+	msg_count = ti_msgmgr_queue_get_num_messages(desc, qinst);
+
+	if (desc->is_sproxy) {
+		/* In secure proxy, msg_count indicates how many we can send */
+		return msg_count ? true : false;
+	}
+
+	/* if we have any messages pending.. */
+	return msg_count ? false : true;
+}
+
+static bool ti_msgmgr_chan_has_polled_queue_rx(struct mbox_chan *chan)
+{
+	struct ti_queue_inst *qinst;
+
+	if (!chan)
+		return false;
+
+	qinst = chan->con_priv;
+	return qinst->polled_rx_mode;
+}
+
+/**
+ * ti_msgmgr_send_data() - Send data
+ * @chan:	Channel Pointer
+ * @data:	ti_msgmgr_message * Message Pointer
+ *
+ * Return: 0 if all goes good, else appropriate error messages.
+ */
+static int ti_msgmgr_send_data(struct mbox_chan *chan, void *data)
+{
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	const struct ti_msgmgr_desc *desc;
+	struct ti_queue_inst *qinst = chan->con_priv;
+	int num_words, trail_bytes;
+	struct ti_msgmgr_message *message = data;
+	void __iomem *data_reg;
+	u32 *word_data;
+	int ret = 0;
+
+	if (WARN_ON(!inst)) {
+		dev_err(dev, "no platform drv data??\n");
+		return -EINVAL;
+	}
+	desc = inst->desc;
+
+	if (ti_msgmgr_queue_is_error(desc, qinst)) {
+		dev_err(dev, "Error on channel %s\n", qinst->name);
+		return false;
+	}
+
+	if (desc->max_message_size < message->len) {
+		dev_err(dev, "Queue %s message length %zu > max %d\n",
+			qinst->name, message->len, desc->max_message_size);
+		return -EINVAL;
+	}
+
+	/* NOTE: Constraints similar to rx path exists here as well */
+	for (data_reg = qinst->queue_buff_start,
+	     num_words = message->len / sizeof(u32),
+	     word_data = (u32 *)message->buf;
+	     num_words; num_words--, data_reg += sizeof(u32), word_data++)
+		writel(*word_data, data_reg);
+
+	trail_bytes = message->len % sizeof(u32);
+	if (trail_bytes) {
+		u32 data_trail = *word_data;
+
+		/* Ensure all unused data is 0 */
+		data_trail &= 0xFFFFFFFF >> (8 * (sizeof(u32) - trail_bytes));
+		writel(data_trail, data_reg);
+		data_reg += sizeof(u32);
+	}
+
+	/*
+	 * 'data_reg' indicates next register to write. If we did not already
+	 * write on tx complete reg(last reg), we must do so for transmit
+	 * In addition, we also need to make sure all intermediate data
+	 * registers(if any required), are reset to 0 for TISCI backward
+	 * compatibility to be maintained.
+	 */
+	while (data_reg <= qinst->queue_buff_end) {
+		writel(0, data_reg);
+		data_reg += sizeof(u32);
+	}
+
+	/* If we are in polled mode, wait for a response before proceeding */
+	if (ti_msgmgr_chan_has_polled_queue_rx(message->chan_rx))
+		ret = ti_msgmgr_queue_rx_poll_timeout(message->chan_rx,
+						      message->timeout_rx_ms * 1000);
+
+	return ret;
+}
+
+/**
+ *  ti_msgmgr_queue_rx_irq_req() - RX IRQ request
+ *  @dev:	device pointer
+ *  @d:		descriptor for ti_msgmgr
+ *  @qinst:	Queue instance
+ *  @chan:	Channel pointer
+ */
+static int ti_msgmgr_queue_rx_irq_req(struct device *dev,
+				      const struct ti_msgmgr_desc *d,
+				      struct ti_queue_inst *qinst,
+				      struct mbox_chan *chan)
+{
+	int ret = 0;
+	char of_rx_irq_name[7];
+	struct device_node *np;
+
+	snprintf(of_rx_irq_name, sizeof(of_rx_irq_name),
+		 "rx_%03d", d->is_sproxy ? qinst->proxy_id : qinst->queue_id);
+
+	/* Get the IRQ if not found */
+	if (qinst->irq < 0) {
+		np = of_node_get(dev->of_node);
+		if (!np)
+			return -ENODATA;
+		qinst->irq = of_irq_get_byname(np, of_rx_irq_name);
+		of_node_put(np);
+
+		if (qinst->irq < 0) {
+			dev_err(dev,
+				"QID %d PID %d:No IRQ[%s]: %d\n",
+				qinst->queue_id, qinst->proxy_id,
+				of_rx_irq_name, qinst->irq);
+			return qinst->irq;
+		}
+	}
+
+	/* With the expectation that the IRQ might be shared in SoC */
+	ret = request_irq(qinst->irq, ti_msgmgr_queue_rx_interrupt,
+			  IRQF_SHARED, qinst->name, chan);
+	if (ret) {
+		dev_err(dev, "Unable to get IRQ %d on %s(res=%d)\n",
+			qinst->irq, qinst->name, ret);
+	}
+
+	return ret;
+}
+
+/**
+ * ti_msgmgr_queue_startup() - Startup queue
+ * @chan:	Channel pointer
+ *
+ * Return: 0 if all goes good, else return corresponding error message
+ */
+static int ti_msgmgr_queue_startup(struct mbox_chan *chan)
+{
+	struct device *dev = chan->mbox->dev;
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	struct ti_queue_inst *qinst = chan->con_priv;
+	const struct ti_msgmgr_desc *d = inst->desc;
+	int ret;
+	int msg_count;
+
+	/*
+	 * If sproxy is starting and can send messages, we are a Tx thread,
+	 * else Rx
+	 */
+	if (d->is_sproxy) {
+		qinst->is_tx = (readl(qinst->queue_ctrl) &
+				SPROXY_THREAD_CTRL_DIR_MASK) ? false : true;
+
+		msg_count = ti_msgmgr_queue_get_num_messages(d, qinst);
+
+		if (!msg_count && qinst->is_tx) {
+			dev_err(dev, "%s: Cannot transmit with 0 credits!\n",
+				qinst->name);
+			return -EINVAL;
+		}
+	}
+
+	if (!qinst->is_tx) {
+		/* Allocate usage buffer for rx */
+		qinst->rx_buff = kzalloc(d->max_message_size, GFP_KERNEL);
+		if (!qinst->rx_buff)
+			return -ENOMEM;
+		/* Request IRQ */
+		ret = ti_msgmgr_queue_rx_irq_req(dev, d, qinst, chan);
+		if (ret) {
+			kfree(qinst->rx_buff);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * ti_msgmgr_queue_shutdown() - Shutdown the queue
+ * @chan:	Channel pointer
+ */
+static void ti_msgmgr_queue_shutdown(struct mbox_chan *chan)
+{
+	struct ti_queue_inst *qinst = chan->con_priv;
+
+	if (!qinst->is_tx) {
+		free_irq(qinst->irq, chan);
+		kfree(qinst->rx_buff);
+	}
+}
+
+/**
+ * ti_msgmgr_of_xlate() - Translation of phandle to queue
+ * @mbox:	Mailbox controller
+ * @p:		phandle pointer
+ *
+ * Return: Mailbox channel corresponding to the queue, else return error
+ * pointer.
+ */
+static struct mbox_chan *ti_msgmgr_of_xlate(struct mbox_controller *mbox,
+					    const struct of_phandle_args *p)
+{
+	struct ti_msgmgr_inst *inst;
+	int req_qid, req_pid;
+	struct ti_queue_inst *qinst;
+	const struct ti_msgmgr_desc *d;
+	int i, ncells;
+
+	inst = container_of(mbox, struct ti_msgmgr_inst, mbox);
+	if (WARN_ON(!inst))
+		return ERR_PTR(-EINVAL);
+
+	d = inst->desc;
+
+	if (d->is_sproxy)
+		ncells = 1;
+	else
+		ncells = 2;
+	if (p->args_count != ncells) {
+		dev_err(inst->dev, "Invalid arguments in dt[%d]. Must be %d\n",
+			p->args_count, ncells);
+		return ERR_PTR(-EINVAL);
+	}
+	if (ncells == 1) {
+		req_qid = 0;
+		req_pid = p->args[0];
+	} else {
+		req_qid = p->args[0];
+		req_pid = p->args[1];
+	}
+
+	if (d->is_sproxy) {
+		if (req_pid >= d->num_valid_queues)
+			goto err;
+		qinst = &inst->qinsts[req_pid];
+		return qinst->chan;
+	}
+
+	for (qinst = inst->qinsts, i = 0; i < inst->num_valid_queues;
+	     i++, qinst++) {
+		if (req_qid == qinst->queue_id && req_pid == qinst->proxy_id)
+			return qinst->chan;
+	}
+
+err:
+	dev_err(inst->dev, "Queue ID %d, Proxy ID %d is wrong on %pOFn\n",
+		req_qid, req_pid, p->np);
+	return ERR_PTR(-ENOENT);
+}
+
+/**
+ * ti_msgmgr_queue_setup() - Setup data structures for each queue instance
+ * @idx:	index of the queue
+ * @dev:	pointer to the message manager device
+ * @np:		pointer to the of node
+ * @inst:	Queue instance pointer
+ * @d:		Message Manager instance description data
+ * @qd:		Queue description data
+ * @qinst:	Queue instance pointer
+ * @chan:	pointer to mailbox channel
+ *
+ * Return: 0 if all went well, else return corresponding error
+ */
+static int ti_msgmgr_queue_setup(int idx, struct device *dev,
+				 struct device_node *np,
+				 struct ti_msgmgr_inst *inst,
+				 const struct ti_msgmgr_desc *d,
+				 const struct ti_msgmgr_valid_queue_desc *qd,
+				 struct ti_queue_inst *qinst,
+				 struct mbox_chan *chan)
+{
+	char *dir;
+
+	qinst->proxy_id = qd->proxy_id;
+	qinst->queue_id = qd->queue_id;
+
+	if (qinst->queue_id > d->queue_count) {
+		dev_err(dev, "Queue Data [idx=%d] queuid %d > %d\n",
+			idx, qinst->queue_id, d->queue_count);
+		return -ERANGE;
+	}
+
+	if (d->is_sproxy) {
+		qinst->queue_buff_start = inst->queue_proxy_region +
+		    SPROXY_THREAD_DATA_OFFSET(qinst->proxy_id,
+					      d->data_first_reg);
+		qinst->queue_buff_end = inst->queue_proxy_region +
+		    SPROXY_THREAD_DATA_OFFSET(qinst->proxy_id,
+					      d->data_last_reg);
+		qinst->queue_state = inst->queue_state_debug_region +
+		    SPROXY_THREAD_STATUS_OFFSET(qinst->proxy_id);
+		qinst->queue_ctrl = inst->queue_ctrl_region +
+		    SPROXY_THREAD_CTRL_OFFSET(qinst->proxy_id);
+
+		/* XXX: DONOT read registers here!.. Some may be unusable */
+		dir = "thr";
+		snprintf(qinst->name, sizeof(qinst->name), "%s %s_%03d",
+			 dev_name(dev), dir, qinst->proxy_id);
+	} else {
+		qinst->queue_buff_start = inst->queue_proxy_region +
+		    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id,
+				  d->data_first_reg);
+		qinst->queue_buff_end = inst->queue_proxy_region +
+		    Q_DATA_OFFSET(qinst->proxy_id, qinst->queue_id,
+				  d->data_last_reg);
+		qinst->queue_state =
+		    inst->queue_state_debug_region +
+		    Q_STATE_OFFSET(qinst->queue_id);
+		qinst->is_tx = qd->is_tx;
+		dir = qinst->is_tx ? "tx" : "rx";
+		snprintf(qinst->name, sizeof(qinst->name), "%s %s_%03d_%03d",
+			 dev_name(dev), dir, qinst->queue_id, qinst->proxy_id);
+	}
+
+	qinst->chan = chan;
+
+	/* Setup an error value for IRQ - Lazy allocation */
+	qinst->irq = -EINVAL;
+
+	chan->con_priv = qinst;
+
+	dev_dbg(dev, "[%d] qidx=%d pidx=%d irq=%d q_s=%p q_e = %p\n",
+		idx, qinst->queue_id, qinst->proxy_id, qinst->irq,
+		qinst->queue_buff_start, qinst->queue_buff_end);
+	return 0;
+}
+
+static int ti_msgmgr_queue_rx_set_polled_mode(struct ti_queue_inst *qinst, bool enable)
+{
+	if (enable) {
+		disable_irq(qinst->irq);
+		qinst->polled_rx_mode = true;
+	} else {
+		enable_irq(qinst->irq);
+		qinst->polled_rx_mode = false;
+	}
+
+	return 0;
+}
+
+static int ti_msgmgr_suspend(struct device *dev)
+{
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	struct ti_queue_inst *qinst;
+	int i;
+
+	/*
+	 * We must switch operation to polled mode now as drivers and the genpd
+	 * layer may make late TI SCI calls to change clock and device states
+	 * from the noirq phase of suspend.
+	 */
+	for (qinst = inst->qinsts, i = 0; i < inst->num_valid_queues; qinst++, i++) {
+		if (!qinst->is_tx)
+			ti_msgmgr_queue_rx_set_polled_mode(qinst, true);
+	}
+
+	return 0;
+}
+
+static int ti_msgmgr_resume(struct device *dev)
+{
+	struct ti_msgmgr_inst *inst = dev_get_drvdata(dev);
+	struct ti_queue_inst *qinst;
+	int i;
+
+	for (qinst = inst->qinsts, i = 0; i < inst->num_valid_queues; qinst++, i++) {
+		if (!qinst->is_tx)
+			ti_msgmgr_queue_rx_set_polled_mode(qinst, false);
+	}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ti_msgmgr_pm_ops, ti_msgmgr_suspend, ti_msgmgr_resume);
+
+/* Queue operations */
+static const struct mbox_chan_ops ti_msgmgr_chan_ops = {
+	.startup = ti_msgmgr_queue_startup,
+	.shutdown = ti_msgmgr_queue_shutdown,
+	.peek_data = ti_msgmgr_queue_peek_data,
+	.last_tx_done = ti_msgmgr_last_tx_done,
+	.send_data = ti_msgmgr_send_data,
+};
+
+/* Keystone K2G SoC integration details */
+static const struct ti_msgmgr_valid_queue_desc k2g_valid_queues[] = {
+	{.queue_id = 0, .proxy_id = 0, .is_tx = true,},
+	{.queue_id = 1, .proxy_id = 0, .is_tx = true,},
+	{.queue_id = 2, .proxy_id = 0, .is_tx = true,},
+	{.queue_id = 3, .proxy_id = 0, .is_tx = true,},
+	{.queue_id = 5, .proxy_id = 2, .is_tx = false,},
+	{.queue_id = 56, .proxy_id = 1, .is_tx = true,},
+	{.queue_id = 57, .proxy_id = 2, .is_tx = false,},
+	{.queue_id = 58, .proxy_id = 3, .is_tx = true,},
+	{.queue_id = 59, .proxy_id = 4, .is_tx = true,},
+	{.queue_id = 60, .proxy_id = 5, .is_tx = true,},
+	{.queue_id = 61, .proxy_id = 6, .is_tx = true,},
+};
+
+static const struct ti_msgmgr_desc k2g_desc = {
+	.queue_count = 64,
+	.max_message_size = 64,
+	.max_messages = 128,
+	.data_region_name = "queue_proxy_region",
+	.status_region_name = "queue_state_debug_region",
+	.data_first_reg = 16,
+	.data_last_reg = 31,
+	.status_cnt_mask = Q_STATE_ENTRY_COUNT_MASK,
+	.tx_polled = false,
+	.valid_queues = k2g_valid_queues,
+	.num_valid_queues = ARRAY_SIZE(k2g_valid_queues),
+	.is_sproxy = false,
+};
+
+static const struct ti_msgmgr_desc am654_desc = {
+	.queue_count = 190,
+	.num_valid_queues = 190,
+	.max_message_size = 60,
+	.data_region_name = "target_data",
+	.status_region_name = "rt",
+	.ctrl_region_name = "scfg",
+	.data_first_reg = 0,
+	.data_last_reg = 14,
+	.status_cnt_mask = SPROXY_THREAD_STATUS_COUNT_MASK,
+	.tx_polled = false,
+	.is_sproxy = true,
+};
+
+static const struct of_device_id ti_msgmgr_of_match[] = {
+	{.compatible = "ti,k2g-message-manager", .data = &k2g_desc},
+	{.compatible = "ti,am654-secure-proxy", .data = &am654_desc},
+	{ /* Sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, ti_msgmgr_of_match);
+
+static int ti_msgmgr_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct of_device_id *of_id;
+	struct device_node *np;
+	struct resource *res;
+	const struct ti_msgmgr_desc *desc;
+	struct ti_msgmgr_inst *inst;
+	struct ti_queue_inst *qinst;
+	struct mbox_controller *mbox;
+	struct mbox_chan *chans;
+	int queue_count;
+	int i;
+	int ret = -EINVAL;
+	const struct ti_msgmgr_valid_queue_desc *queue_desc;
+
+	if (!dev->of_node) {
+		dev_err(dev, "no OF information\n");
+		return -EINVAL;
+	}
+	np = dev->of_node;
+
+	of_id = of_match_device(ti_msgmgr_of_match, dev);
+	if (!of_id) {
+		dev_err(dev, "OF data missing\n");
+		return -EINVAL;
+	}
+	desc = of_id->data;
+
+	inst = devm_kzalloc(dev, sizeof(*inst), GFP_KERNEL);
+	if (!inst)
+		return -ENOMEM;
+
+	inst->dev = dev;
+	inst->desc = desc;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   desc->data_region_name);
+	inst->queue_proxy_region = devm_ioremap_resource(dev, res);
+	if (IS_ERR(inst->queue_proxy_region))
+		return PTR_ERR(inst->queue_proxy_region);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					   desc->status_region_name);
+	inst->queue_state_debug_region = devm_ioremap_resource(dev, res);
+	if (IS_ERR(inst->queue_state_debug_region))
+		return PTR_ERR(inst->queue_state_debug_region);
+
+	if (desc->is_sproxy) {
+		res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+						   desc->ctrl_region_name);
+		inst->queue_ctrl_region = devm_ioremap_resource(dev, res);
+		if (IS_ERR(inst->queue_ctrl_region))
+			return PTR_ERR(inst->queue_ctrl_region);
+	}
+
+	dev_dbg(dev, "proxy region=%p, queue_state=%p\n",
+		inst->queue_proxy_region, inst->queue_state_debug_region);
+
+	queue_count = desc->num_valid_queues;
+	if (!queue_count || queue_count > desc->queue_count) {
+		dev_crit(dev, "Invalid Number of queues %d. Max %d\n",
+			 queue_count, desc->queue_count);
+		return -ERANGE;
+	}
+	inst->num_valid_queues = queue_count;
+
+	qinst = devm_kcalloc(dev, queue_count, sizeof(*qinst), GFP_KERNEL);
+	if (!qinst)
+		return -ENOMEM;
+	inst->qinsts = qinst;
+
+	chans = devm_kcalloc(dev, queue_count, sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+	inst->chans = chans;
+
+	if (desc->is_sproxy) {
+		struct ti_msgmgr_valid_queue_desc sproxy_desc;
+
+		/* All proxies may be valid in Secure Proxy instance */
+		for (i = 0; i < queue_count; i++, qinst++, chans++) {
+			sproxy_desc.queue_id = 0;
+			sproxy_desc.proxy_id = i;
+			ret = ti_msgmgr_queue_setup(i, dev, np, inst,
+						    desc, &sproxy_desc, qinst,
+						    chans);
+			if (ret)
+				return ret;
+		}
+	} else {
+		/* Only Some proxies are valid in Message Manager */
+		for (i = 0, queue_desc = desc->valid_queues;
+		     i < queue_count; i++, qinst++, chans++, queue_desc++) {
+			ret = ti_msgmgr_queue_setup(i, dev, np, inst,
+						    desc, queue_desc, qinst,
+						    chans);
+			if (ret)
+				return ret;
+		}
+	}
+
+	mbox = &inst->mbox;
+	mbox->dev = dev;
+	mbox->ops = &ti_msgmgr_chan_ops;
+	mbox->chans = inst->chans;
+	mbox->num_chans = inst->num_valid_queues;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = desc->tx_polled;
+	if (desc->tx_polled)
+		mbox->txpoll_period = desc->tx_poll_timeout_ms;
+	mbox->of_xlate = ti_msgmgr_of_xlate;
+
+	platform_set_drvdata(pdev, inst);
+	ret = devm_mbox_controller_register(dev, mbox);
+	if (ret)
+		dev_err(dev, "Failed to register mbox_controller(%d)\n", ret);
+
+	return ret;
+}
+
+static struct platform_driver ti_msgmgr_driver = {
+	.probe = ti_msgmgr_probe,
+	.driver = {
+		   .name = "ti-msgmgr",
+		   .of_match_table = of_match_ptr(ti_msgmgr_of_match),
+		   .pm = &ti_msgmgr_pm_ops,
+	},
+};
+module_platform_driver(ti_msgmgr_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("TI message manager driver");
+MODULE_AUTHOR("Nishanth Menon");
+MODULE_ALIAS("platform:ti-msgmgr");
diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
new file mode 100644
index 000000000..d097f45b0
--- /dev/null
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -0,0 +1,726 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xilinx Inter Processor Interrupt(IPI) Mailbox Driver
+ *
+ * Copyright (C) 2018 Xilinx, Inc.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mailbox_controller.h>
+#include <linux/mailbox/zynqmp-ipi-message.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+
+/* IPI agent ID any */
+#define IPI_ID_ANY 0xFFUL
+
+/* indicate if ZynqMP IPI mailbox driver uses SMC calls or HVC calls */
+#define USE_SMC 0
+#define USE_HVC 1
+
+/* Default IPI SMC function IDs */
+#define SMC_IPI_MAILBOX_OPEN		0x82001000U
+#define SMC_IPI_MAILBOX_RELEASE		0x82001001U
+#define SMC_IPI_MAILBOX_STATUS_ENQUIRY	0x82001002U
+#define SMC_IPI_MAILBOX_NOTIFY		0x82001003U
+#define SMC_IPI_MAILBOX_ACK		0x82001004U
+#define SMC_IPI_MAILBOX_ENABLE_IRQ	0x82001005U
+#define SMC_IPI_MAILBOX_DISABLE_IRQ	0x82001006U
+
+/* IPI SMC Macros */
+#define IPI_SMC_ENQUIRY_DIRQ_MASK	0x00000001UL /* Flag to indicate if
+						      * notification interrupt
+						      * to be disabled.
+						      */
+#define IPI_SMC_ACK_EIRQ_MASK		0x00000001UL /* Flag to indicate if
+						      * notification interrupt
+						      * to be enabled.
+						      */
+
+/* IPI mailbox status */
+#define IPI_MB_STATUS_IDLE		0
+#define IPI_MB_STATUS_SEND_PENDING	1
+#define IPI_MB_STATUS_RECV_PENDING	2
+
+#define IPI_MB_CHNL_TX	0 /* IPI mailbox TX channel */
+#define IPI_MB_CHNL_RX	1 /* IPI mailbox RX channel */
+
+/**
+ * struct zynqmp_ipi_mchan - Description of a Xilinx ZynqMP IPI mailbox channel
+ * @is_opened: indicate if the IPI channel is opened
+ * @req_buf: local to remote request buffer start address
+ * @resp_buf: local to remote response buffer start address
+ * @req_buf_size: request buffer size
+ * @resp_buf_size: response buffer size
+ * @rx_buf: receive buffer to pass received message to client
+ * @chan_type: channel type
+ */
+struct zynqmp_ipi_mchan {
+	int is_opened;
+	void __iomem *req_buf;
+	void __iomem *resp_buf;
+	void *rx_buf;
+	size_t req_buf_size;
+	size_t resp_buf_size;
+	unsigned int chan_type;
+};
+
+/**
+ * struct zynqmp_ipi_mbox - Description of a ZynqMP IPI mailbox
+ *                          platform data.
+ * @pdata:		  pointer to the IPI private data
+ * @dev:                  device pointer corresponding to the Xilinx ZynqMP
+ *                        IPI mailbox
+ * @remote_id:            remote IPI agent ID
+ * @mbox:                 mailbox Controller
+ * @mchans:               array for channels, tx channel and rx channel.
+ * @irq:                  IPI agent interrupt ID
+ */
+struct zynqmp_ipi_mbox {
+	struct zynqmp_ipi_pdata *pdata;
+	struct device dev;
+	u32 remote_id;
+	struct mbox_controller mbox;
+	struct zynqmp_ipi_mchan mchans[2];
+};
+
+/**
+ * struct zynqmp_ipi_pdata - Description of z ZynqMP IPI agent platform data.
+ *
+ * @dev:                  device pointer corresponding to the Xilinx ZynqMP
+ *                        IPI agent
+ * @irq:                  IPI agent interrupt ID
+ * @method:               IPI SMC or HVC is going to be used
+ * @local_id:             local IPI agent ID
+ * @num_mboxes:           number of mailboxes of this IPI agent
+ * @ipi_mboxes:           IPI mailboxes of this IPI agent
+ */
+struct zynqmp_ipi_pdata {
+	struct device *dev;
+	int irq;
+	unsigned int method;
+	u32 local_id;
+	int num_mboxes;
+	struct zynqmp_ipi_mbox ipi_mboxes[];
+};
+
+static struct device_driver zynqmp_ipi_mbox_driver = {
+	.owner = THIS_MODULE,
+	.name = "zynqmp-ipi-mbox",
+};
+
+static void zynqmp_ipi_fw_call(struct zynqmp_ipi_mbox *ipi_mbox,
+			       unsigned long a0, unsigned long a3,
+			       struct arm_smccc_res *res)
+{
+	struct zynqmp_ipi_pdata *pdata = ipi_mbox->pdata;
+	unsigned long a1, a2;
+
+	a1 = pdata->local_id;
+	a2 = ipi_mbox->remote_id;
+	if (pdata->method == USE_SMC)
+		arm_smccc_smc(a0, a1, a2, a3, 0, 0, 0, 0, res);
+	else
+		arm_smccc_hvc(a0, a1, a2, a3, 0, 0, 0, 0, res);
+}
+
+/**
+ * zynqmp_ipi_interrupt - Interrupt handler for IPI notification
+ *
+ * @irq:  Interrupt number
+ * @data: ZynqMP IPI mailbox platform data.
+ *
+ * Return: -EINVAL if there is no instance
+ * IRQ_NONE if the interrupt is not ours.
+ * IRQ_HANDLED if the rx interrupt was successfully handled.
+ */
+static irqreturn_t zynqmp_ipi_interrupt(int irq, void *data)
+{
+	struct zynqmp_ipi_pdata *pdata = data;
+	struct mbox_chan *chan;
+	struct zynqmp_ipi_mbox *ipi_mbox;
+	struct zynqmp_ipi_mchan *mchan;
+	struct zynqmp_ipi_message *msg;
+	u64 arg0, arg3;
+	struct arm_smccc_res res;
+	int ret, i, status = IRQ_NONE;
+
+	(void)irq;
+	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
+	arg3 = IPI_SMC_ENQUIRY_DIRQ_MASK;
+	for (i = 0; i < pdata->num_mboxes; i++) {
+		ipi_mbox = &pdata->ipi_mboxes[i];
+		mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
+		chan = &ipi_mbox->mbox.chans[IPI_MB_CHNL_RX];
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, arg3, &res);
+		ret = (int)(res.a0 & 0xFFFFFFFF);
+		if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
+			if (mchan->is_opened) {
+				msg = mchan->rx_buf;
+				msg->len = mchan->req_buf_size;
+				memcpy_fromio(msg->data, mchan->req_buf,
+					      msg->len);
+				mbox_chan_received_data(chan, (void *)msg);
+				status = IRQ_HANDLED;
+			}
+		}
+	}
+	return status;
+}
+
+/**
+ * zynqmp_ipi_peek_data - Peek to see if there are any rx messages.
+ *
+ * @chan: Channel Pointer
+ *
+ * Return: 'true' if there is pending rx data, 'false' if there is none.
+ */
+static bool zynqmp_ipi_peek_data(struct mbox_chan *chan)
+{
+	struct device *dev = chan->mbox->dev;
+	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
+	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
+	int ret;
+	u64 arg0;
+	struct arm_smccc_res res;
+
+	if (WARN_ON(!ipi_mbox)) {
+		dev_err(dev, "no platform drv data??\n");
+		return false;
+	}
+
+	arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
+	zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+	ret = (int)(res.a0 & 0xFFFFFFFF);
+
+	if (mchan->chan_type == IPI_MB_CHNL_TX) {
+		/* TX channel, check if the message has been acked
+		 * by the remote, if yes, response is available.
+		 */
+		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
+			return false;
+		else
+			return true;
+	} else if (ret > 0 && ret & IPI_MB_STATUS_RECV_PENDING) {
+		/* RX channel, check if there is message arrived. */
+		return true;
+	}
+	return false;
+}
+
+/**
+ * zynqmp_ipi_last_tx_done - See if the last tx message is sent
+ *
+ * @chan: Channel pointer
+ *
+ * Return: 'true' is no pending tx data, 'false' if there are any.
+ */
+static bool zynqmp_ipi_last_tx_done(struct mbox_chan *chan)
+{
+	struct device *dev = chan->mbox->dev;
+	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
+	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
+	int ret;
+	u64 arg0;
+	struct arm_smccc_res res;
+
+	if (WARN_ON(!ipi_mbox)) {
+		dev_err(dev, "no platform drv data??\n");
+		return false;
+	}
+
+	if (mchan->chan_type == IPI_MB_CHNL_TX) {
+		/* We only need to check if the message been taken
+		 * by the remote in the TX channel
+		 */
+		arg0 = SMC_IPI_MAILBOX_STATUS_ENQUIRY;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+		/* Check the SMC call status, a0 of the result */
+		ret = (int)(res.a0 & 0xFFFFFFFF);
+		if (ret < 0 || ret & IPI_MB_STATUS_SEND_PENDING)
+			return false;
+		return true;
+	}
+	/* Always true for the response message in RX channel */
+	return true;
+}
+
+/**
+ * zynqmp_ipi_send_data - Send data
+ *
+ * @chan: Channel Pointer
+ * @data: Message Pointer
+ *
+ * Return: 0 if all goes good, else appropriate error messages.
+ */
+static int zynqmp_ipi_send_data(struct mbox_chan *chan, void *data)
+{
+	struct device *dev = chan->mbox->dev;
+	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
+	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
+	struct zynqmp_ipi_message *msg = data;
+	u64 arg0;
+	struct arm_smccc_res res;
+
+	if (WARN_ON(!ipi_mbox)) {
+		dev_err(dev, "no platform drv data??\n");
+		return -EINVAL;
+	}
+
+	if (mchan->chan_type == IPI_MB_CHNL_TX) {
+		/* Send request message */
+		if (msg && msg->len > mchan->req_buf_size) {
+			dev_err(dev, "channel %d message length %u > max %lu\n",
+				mchan->chan_type, (unsigned int)msg->len,
+				mchan->req_buf_size);
+			return -EINVAL;
+		}
+		if (msg && msg->len)
+			memcpy_toio(mchan->req_buf, msg->data, msg->len);
+		/* Kick IPI mailbox to send message */
+		arg0 = SMC_IPI_MAILBOX_NOTIFY;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+	} else {
+		/* Send response message */
+		if (msg && msg->len > mchan->resp_buf_size) {
+			dev_err(dev, "channel %d message length %u > max %lu\n",
+				mchan->chan_type, (unsigned int)msg->len,
+				mchan->resp_buf_size);
+			return -EINVAL;
+		}
+		if (msg && msg->len)
+			memcpy_toio(mchan->resp_buf, msg->data, msg->len);
+		arg0 = SMC_IPI_MAILBOX_ACK;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, IPI_SMC_ACK_EIRQ_MASK,
+				   &res);
+	}
+	return 0;
+}
+
+/**
+ * zynqmp_ipi_startup - Startup the IPI channel
+ *
+ * @chan: Channel pointer
+ *
+ * Return: 0 if all goes good, else return corresponding error message
+ */
+static int zynqmp_ipi_startup(struct mbox_chan *chan)
+{
+	struct device *dev = chan->mbox->dev;
+	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
+	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
+	u64 arg0;
+	struct arm_smccc_res res;
+	int ret = 0;
+	unsigned int nchan_type;
+
+	if (mchan->is_opened)
+		return 0;
+
+	/* If no channel has been opened, open the IPI mailbox */
+	nchan_type = (mchan->chan_type + 1) % 2;
+	if (!ipi_mbox->mchans[nchan_type].is_opened) {
+		arg0 = SMC_IPI_MAILBOX_OPEN;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+		/* Check the SMC call status, a0 of the result */
+		ret = (int)(res.a0 & 0xFFFFFFFF);
+		if (ret < 0) {
+			dev_err(dev, "SMC to open the IPI channel failed.\n");
+			return ret;
+		}
+		ret = 0;
+	}
+
+	/* If it is RX channel, enable the IPI notification interrupt */
+	if (mchan->chan_type == IPI_MB_CHNL_RX) {
+		arg0 = SMC_IPI_MAILBOX_ENABLE_IRQ;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+	}
+	mchan->is_opened = 1;
+
+	return ret;
+}
+
+/**
+ * zynqmp_ipi_shutdown - Shutdown the IPI channel
+ *
+ * @chan: Channel pointer
+ */
+static void zynqmp_ipi_shutdown(struct mbox_chan *chan)
+{
+	struct device *dev = chan->mbox->dev;
+	struct zynqmp_ipi_mbox *ipi_mbox = dev_get_drvdata(dev);
+	struct zynqmp_ipi_mchan *mchan = chan->con_priv;
+	u64 arg0;
+	struct arm_smccc_res res;
+	unsigned int chan_type;
+
+	if (!mchan->is_opened)
+		return;
+
+	/* If it is RX channel, disable notification interrupt */
+	chan_type = mchan->chan_type;
+	if (chan_type == IPI_MB_CHNL_RX) {
+		arg0 = SMC_IPI_MAILBOX_DISABLE_IRQ;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+	}
+	/* Release IPI mailbox if no other channel is opened */
+	chan_type = (chan_type + 1) % 2;
+	if (!ipi_mbox->mchans[chan_type].is_opened) {
+		arg0 = SMC_IPI_MAILBOX_RELEASE;
+		zynqmp_ipi_fw_call(ipi_mbox, arg0, 0, &res);
+	}
+
+	mchan->is_opened = 0;
+}
+
+/* ZynqMP IPI mailbox operations */
+static const struct mbox_chan_ops zynqmp_ipi_chan_ops = {
+	.startup = zynqmp_ipi_startup,
+	.shutdown = zynqmp_ipi_shutdown,
+	.peek_data = zynqmp_ipi_peek_data,
+	.last_tx_done = zynqmp_ipi_last_tx_done,
+	.send_data = zynqmp_ipi_send_data,
+};
+
+/**
+ * zynqmp_ipi_of_xlate - Translate of phandle to IPI mailbox channel
+ *
+ * @mbox: mailbox controller pointer
+ * @p:    phandle pointer
+ *
+ * Return: Mailbox channel, else return error pointer.
+ */
+static struct mbox_chan *zynqmp_ipi_of_xlate(struct mbox_controller *mbox,
+					     const struct of_phandle_args *p)
+{
+	struct mbox_chan *chan;
+	struct device *dev = mbox->dev;
+	unsigned int chan_type;
+
+	/* Only supports TX and RX channels */
+	chan_type = p->args[0];
+	if (chan_type != IPI_MB_CHNL_TX && chan_type != IPI_MB_CHNL_RX) {
+		dev_err(dev, "req chnl failure: invalid chnl type %u.\n",
+			chan_type);
+		return ERR_PTR(-EINVAL);
+	}
+	chan = &mbox->chans[chan_type];
+	return chan;
+}
+
+static const struct of_device_id zynqmp_ipi_of_match[] = {
+	{ .compatible = "xlnx,zynqmp-ipi-mailbox" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, zynqmp_ipi_of_match);
+
+/**
+ * zynqmp_ipi_mbox_get_buf_res - Get buffer resource from the IPI dev node
+ *
+ * @node: IPI mbox device child node
+ * @name: name of the IPI buffer
+ * @res: pointer to where the resource information will be stored.
+ *
+ * Return: 0 for success, negative value for failure
+ */
+static int zynqmp_ipi_mbox_get_buf_res(struct device_node *node,
+				       const char *name,
+				       struct resource *res)
+{
+	int ret, index;
+
+	index = of_property_match_string(node, "reg-names", name);
+	if (index >= 0) {
+		ret = of_address_to_resource(node, index, res);
+		if (ret < 0)
+			return -EINVAL;
+		return 0;
+	}
+	return -ENODEV;
+}
+
+/**
+ * zynqmp_ipi_mbox_dev_release() - release the existence of a ipi mbox dev
+ *
+ * @dev: the ipi mailbox device
+ *
+ * This is to avoid the no device release() function kernel warning.
+ *
+ */
+static void zynqmp_ipi_mbox_dev_release(struct device *dev)
+{
+	(void)dev;
+}
+
+/**
+ * zynqmp_ipi_mbox_probe - probe IPI mailbox resource from device node
+ *
+ * @ipi_mbox: pointer to IPI mailbox private data structure
+ * @node: IPI mailbox device node
+ *
+ * Return: 0 for success, negative value for failure
+ */
+static int zynqmp_ipi_mbox_probe(struct zynqmp_ipi_mbox *ipi_mbox,
+				 struct device_node *node)
+{
+	struct zynqmp_ipi_mchan *mchan;
+	struct mbox_chan *chans;
+	struct mbox_controller *mbox;
+	struct resource res;
+	struct device *dev, *mdev;
+	const char *name;
+	int ret;
+
+	dev = ipi_mbox->pdata->dev;
+	/* Initialize dev for IPI mailbox */
+	ipi_mbox->dev.parent = dev;
+	ipi_mbox->dev.release = NULL;
+	ipi_mbox->dev.of_node = node;
+	dev_set_name(&ipi_mbox->dev, "%s", of_node_full_name(node));
+	dev_set_drvdata(&ipi_mbox->dev, ipi_mbox);
+	ipi_mbox->dev.release = zynqmp_ipi_mbox_dev_release;
+	ipi_mbox->dev.driver = &zynqmp_ipi_mbox_driver;
+	ret = device_register(&ipi_mbox->dev);
+	if (ret) {
+		dev_err(dev, "Failed to register ipi mbox dev.\n");
+		put_device(&ipi_mbox->dev);
+		return ret;
+	}
+	mdev = &ipi_mbox->dev;
+
+	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
+	name = "local_request_region";
+	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
+	if (!ret) {
+		mchan->req_buf_size = resource_size(&res);
+		mchan->req_buf = devm_ioremap(mdev, res.start,
+					      mchan->req_buf_size);
+		if (!mchan->req_buf) {
+			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+			return -ENOMEM;
+		}
+	} else if (ret != -ENODEV) {
+		dev_err(mdev, "Unmatched resource %s, %d.\n", name, ret);
+		return ret;
+	}
+
+	name = "remote_response_region";
+	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
+	if (!ret) {
+		mchan->resp_buf_size = resource_size(&res);
+		mchan->resp_buf = devm_ioremap(mdev, res.start,
+					       mchan->resp_buf_size);
+		if (!mchan->resp_buf) {
+			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+			return -ENOMEM;
+		}
+	} else if (ret != -ENODEV) {
+		dev_err(mdev, "Unmatched resource %s.\n", name);
+		return ret;
+	}
+	mchan->rx_buf = devm_kzalloc(mdev,
+				     mchan->resp_buf_size +
+				     sizeof(struct zynqmp_ipi_message),
+				     GFP_KERNEL);
+	if (!mchan->rx_buf)
+		return -ENOMEM;
+
+	mchan = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
+	name = "remote_request_region";
+	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
+	if (!ret) {
+		mchan->req_buf_size = resource_size(&res);
+		mchan->req_buf = devm_ioremap(mdev, res.start,
+					      mchan->req_buf_size);
+		if (!mchan->req_buf) {
+			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+			return -ENOMEM;
+		}
+	} else if (ret != -ENODEV) {
+		dev_err(mdev, "Unmatched resource %s.\n", name);
+		return ret;
+	}
+
+	name = "local_response_region";
+	ret = zynqmp_ipi_mbox_get_buf_res(node, name, &res);
+	if (!ret) {
+		mchan->resp_buf_size = resource_size(&res);
+		mchan->resp_buf = devm_ioremap(mdev, res.start,
+					       mchan->resp_buf_size);
+		if (!mchan->resp_buf) {
+			dev_err(mdev, "Unable to map IPI buffer I/O memory\n");
+			return -ENOMEM;
+		}
+	} else if (ret != -ENODEV) {
+		dev_err(mdev, "Unmatched resource %s.\n", name);
+		return ret;
+	}
+	mchan->rx_buf = devm_kzalloc(mdev,
+				     mchan->resp_buf_size +
+				     sizeof(struct zynqmp_ipi_message),
+				     GFP_KERNEL);
+	if (!mchan->rx_buf)
+		return -ENOMEM;
+
+	/* Get the IPI remote agent ID */
+	ret = of_property_read_u32(node, "xlnx,ipi-id", &ipi_mbox->remote_id);
+	if (ret < 0) {
+		dev_err(dev, "No IPI remote ID is specified.\n");
+		return ret;
+	}
+
+	mbox = &ipi_mbox->mbox;
+	mbox->dev = mdev;
+	mbox->ops = &zynqmp_ipi_chan_ops;
+	mbox->num_chans = 2;
+	mbox->txdone_irq = false;
+	mbox->txdone_poll = true;
+	mbox->txpoll_period = 5;
+	mbox->of_xlate = zynqmp_ipi_of_xlate;
+	chans = devm_kzalloc(mdev, 2 * sizeof(*chans), GFP_KERNEL);
+	if (!chans)
+		return -ENOMEM;
+	mbox->chans = chans;
+	chans[IPI_MB_CHNL_TX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_TX];
+	chans[IPI_MB_CHNL_RX].con_priv = &ipi_mbox->mchans[IPI_MB_CHNL_RX];
+	ipi_mbox->mchans[IPI_MB_CHNL_TX].chan_type = IPI_MB_CHNL_TX;
+	ipi_mbox->mchans[IPI_MB_CHNL_RX].chan_type = IPI_MB_CHNL_RX;
+	ret = devm_mbox_controller_register(mdev, mbox);
+	if (ret)
+		dev_err(mdev,
+			"Failed to register mbox_controller(%d)\n", ret);
+	else
+		dev_info(mdev,
+			 "Registered ZynqMP IPI mbox with TX/RX channels.\n");
+	return ret;
+}
+
+/**
+ * zynqmp_ipi_free_mboxes - Free IPI mailboxes devices
+ *
+ * @pdata: IPI private data
+ */
+static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
+{
+	struct zynqmp_ipi_mbox *ipi_mbox;
+	int i;
+
+	i = pdata->num_mboxes;
+	for (; i >= 0; i--) {
+		ipi_mbox = &pdata->ipi_mboxes[i];
+		if (ipi_mbox->dev.parent) {
+			mbox_controller_unregister(&ipi_mbox->mbox);
+			if (device_is_registered(&ipi_mbox->dev))
+				device_unregister(&ipi_mbox->dev);
+		}
+	}
+}
+
+static int zynqmp_ipi_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *nc, *np = pdev->dev.of_node;
+	struct zynqmp_ipi_pdata *pdata;
+	struct zynqmp_ipi_mbox *mbox;
+	int num_mboxes, ret = -EINVAL;
+
+	num_mboxes = of_get_available_child_count(np);
+	if (num_mboxes == 0) {
+		dev_err(dev, "mailbox nodes not available\n");
+		return -EINVAL;
+	}
+
+	pdata = devm_kzalloc(dev, struct_size(pdata, ipi_mboxes, num_mboxes),
+			     GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
+	pdata->dev = dev;
+
+	/* Get the IPI local agents ID */
+	ret = of_property_read_u32(np, "xlnx,ipi-id", &pdata->local_id);
+	if (ret < 0) {
+		dev_err(dev, "No IPI local ID is specified.\n");
+		return ret;
+	}
+
+	pdata->num_mboxes = num_mboxes;
+
+	mbox = pdata->ipi_mboxes;
+	for_each_available_child_of_node(np, nc) {
+		mbox->pdata = pdata;
+		ret = zynqmp_ipi_mbox_probe(mbox, nc);
+		if (ret) {
+			of_node_put(nc);
+			dev_err(dev, "failed to probe subdev.\n");
+			ret = -EINVAL;
+			goto free_mbox_dev;
+		}
+		mbox++;
+	}
+
+	/* IPI IRQ */
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0)
+		goto free_mbox_dev;
+
+	pdata->irq = ret;
+	ret = devm_request_irq(dev, pdata->irq, zynqmp_ipi_interrupt,
+			       IRQF_SHARED, dev_name(dev), pdata);
+	if (ret) {
+		dev_err(dev, "IRQ %d is not requested successfully.\n",
+			pdata->irq);
+		goto free_mbox_dev;
+	}
+
+	platform_set_drvdata(pdev, pdata);
+	return ret;
+
+free_mbox_dev:
+	zynqmp_ipi_free_mboxes(pdata);
+	return ret;
+}
+
+static int zynqmp_ipi_remove(struct platform_device *pdev)
+{
+	struct zynqmp_ipi_pdata *pdata;
+
+	pdata = platform_get_drvdata(pdev);
+	zynqmp_ipi_free_mboxes(pdata);
+
+	return 0;
+}
+
+static struct platform_driver zynqmp_ipi_driver = {
+	.probe = zynqmp_ipi_probe,
+	.remove = zynqmp_ipi_remove,
+	.driver = {
+		   .name = "zynqmp-ipi",
+		   .of_match_table = of_match_ptr(zynqmp_ipi_of_match),
+	},
+};
+
+static int __init zynqmp_ipi_init(void)
+{
+	return platform_driver_register(&zynqmp_ipi_driver);
+}
+subsys_initcall(zynqmp_ipi_init);
+
+static void __exit zynqmp_ipi_exit(void)
+{
+	platform_driver_unregister(&zynqmp_ipi_driver);
+}
+module_exit(zynqmp_ipi_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Xilinx ZynqMP IPI Mailbox driver");
+MODULE_AUTHOR("Xilinx Inc.");