Merge tag 'mailbox-v5.16' of git://git.linaro.org/landing-teams/working/fujitsu/integration

Pull mailbox updates from Jassi Brar:
 "qcom:
   - add support for qcm2290
   - consolidate msm8994 type apcs_data

  mtk:
   - fix clock id usage

  apple:
   - add driver for ASC/M3 controllers

  pcc:
   - reorganise PCC pcc_mbox_request_channel
   - add support for PCCT extended PCC subspaces

  misc:
   - make use of devm_platform_ioremap_resource()
   - change Altera, PCC and Apple mailbox maintainers"

* tag 'mailbox-v5.16' of git://git.linaro.org/landing-teams/working/fujitsu/integration: (38 commits)
  mailbox: imx: support i.MX8ULP S4 MU
  dt-bindings: mailbox: imx-mu: add i.MX8ULP S400 MU support
  ACPI/PCC: Add maintainer for PCC mailbox driver
  mailbox: pcc: Move bulk of PCCT parsing into pcc_mbox_probe
  mailbox: pcc: Add support for PCCT extended PCC subspaces(type 3/4)
  mailbox: pcc: Drop handling invalid bit-width in {read,write}_register
  mailbox: pcc: Avoid accessing PCCT table in pcc_send_data and pcc_mbox_irq
  mailbox: pcc: Add PCC register bundle and associated accessor functions
  mailbox: pcc: Rename doorbell ack to platform interrupt ack register
  mailbox: pcc: Use PCC mailbox channel pointer instead of standard
  mailbox: pcc: Add pcc_mbox_chan structure to hold shared memory region info
  mailbox: pcc: Consolidate subspace doorbell register parsing
  mailbox: pcc: Consolidate subspace interrupt information parsing
  mailbox: pcc: Refactor all PCC channel information into a structure
  mailbox: pcc: Fix kernel doc warnings
  mailbox: apple: Add driver for Apple mailboxes
  dt-bindings: mailbox: Add Apple mailbox bindings
  MAINTAINERS: Add Apple mailbox files
  mailbox: mtk-cmdq: Fix local clock ID usage
  mailbox: mtk-cmdq: Validate alias_id on probe
  ...

27 files changed, 1061 insertions, 417 deletions

diff --git a/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
new file mode 100644
index 000000000000..2c1704b34e7a
--- /dev/null
+++ b/Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0 OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/apple,mailbox.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Apple Mailbox Controller
+
+maintainers:
+  - Hector Martin <marcan@marcan.st>
+  - Sven Peter <sven@svenpeter.dev>
+
+description:
+  The Apple mailbox consists of two FIFOs used to exchange 64+32 bit
+  messages between the main CPU and a co-processor. Multiple instances
+  of this mailbox can be found on Apple SoCs.
+  One of the two FIFOs is used to send data to a co-processor while the other
+  FIFO is used for the other direction.
+  Various clients implement different IPC protocols based on these simple
+  messages and shared memory buffers.
+
+properties:
+  compatible:
+    oneOf:
+      - description:
+          ASC mailboxes are the most common variant found on the M1 used
+          for example for the display controller, the system management
+          controller and the NVMe coprocessor.
+        items:
+          - const: apple,t8103-asc-mailbox
+
+      - description:
+          M3 mailboxes are an older variant with a slightly different MMIO
+          interface still found on the M1. It is used for the Thunderbolt
+          co-processors.
+        items:
+          - const: apple,t8103-m3-mailbox
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    items:
+      - description: send fifo is empty interrupt
+      - description: send fifo is not empty interrupt
+      - description: receive fifo is empty interrupt
+      - description: receive fifo is not empty interrupt
+
+  interrupt-names:
+    items:
+      - const: send-empty
+      - const: send-not-empty
+      - const: recv-empty
+      - const: recv-not-empty
+
+  "#mbox-cells":
+    const: 0
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-names
+  - "#mbox-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+        mailbox@77408000 {
+                compatible = "apple,t8103-asc-mailbox";
+                reg = <0x77408000 0x4000>;
+                interrupts = <1 583 4>, <1 584 4>, <1 585 4>, <1 586 4>;
+                interrupt-names = "send-empty", "send-not-empty",
+                 "recv-empty", "recv-not-empty";
+                #mbox-cells = <0>;
+        };
diff --git a/Documentation/devicetree/bindings/mailbox/fsl,mu.yaml b/Documentation/devicetree/bindings/mailbox/fsl,mu.yaml
index 675ad9de15bb..a337bcd80c4a 100644
--- a/Documentation/devicetree/bindings/mailbox/fsl,mu.yaml
+++ b/Documentation/devicetree/bindings/mailbox/fsl,mu.yaml
@@ -28,6 +28,7 @@ properties:
       - const: fsl,imx7ulp-mu
       - const: fsl,imx8ulp-mu
       - const: fsl,imx8-mu-scu
+      - const: fsl,imx8ulp-mu-s4
       - items:
           - enum:
               - fsl,imx7s-mu
diff --git a/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.yaml b/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.yaml
index 6395281b0cec..01e9d9155c83 100644
--- a/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.yaml
+++ b/Documentation/devicetree/bindings/mailbox/qcom,apcs-kpss-global.yaml
@@ -11,7 +11,7 @@ description:
   platforms.
 
 maintainers:
-  - Sivaprakash Murugesan <sivaprak@codeaurora.org>
+  - Jassi Brar <jassisinghbrar@gmail.com>
 
 properties:
   compatible:
@@ -24,6 +24,7 @@ properties:
       - qcom,msm8994-apcs-kpss-global
       - qcom,msm8996-apcs-hmss-global
       - qcom,msm8998-apcs-hmss-global
+      - qcom,qcm2290-apcs-hmss-global
       - qcom,qcs404-apcs-apps-global
       - qcom,sc7180-apss-shared
       - qcom,sc8180x-apss-shared
diff --git a/MAINTAINERS b/MAINTAINERS
index de5d803f9b9f..62dd1f891cf7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -401,6 +401,12 @@ L:	platform-driver-x86@vger.kernel.org
 S:	Maintained
 F:	drivers/platform/x86/i2c-multi-instantiate.c
 
+ACPI PCC(Platform Communication Channel) MAILBOX DRIVER
+M:	Sudeep Holla <sudeep.holla@arm.com>
+L:	linux-acpi@vger.kernel.org
+S:	Supported
+F:	drivers/mailbox/pcc.c
+
 ACPI PMIC DRIVERS
 M:	"Rafael J. Wysocki" <rafael@kernel.org>
 M:	Len Brown <lenb@kernel.org>
@@ -798,7 +804,7 @@ F:	Documentation/devicetree/bindings/i2c/i2c-altera.txt
 F:	drivers/i2c/busses/i2c-altera.c
 
 ALTERA MAILBOX DRIVER
-M:	Joyce Ooi <joyce.ooi@intel.com>
+M:	Mun Yew Tham <mun.yew.tham@intel.com>
 S:	Maintained
 F:	drivers/mailbox/mailbox-altera.c
 
@@ -1723,11 +1729,14 @@ C:	irc://irc.oftc.net/asahi-dev
 T:	git https://github.com/AsahiLinux/linux.git
 F:	Documentation/devicetree/bindings/arm/apple.yaml
 F:	Documentation/devicetree/bindings/interrupt-controller/apple,aic.yaml
+F:	Documentation/devicetree/bindings/mailbox/apple,mailbox.yaml
 F:	Documentation/devicetree/bindings/pinctrl/apple,pinctrl.yaml
 F:	arch/arm64/boot/dts/apple/
 F:	drivers/irqchip/irq-apple-aic.c
+F:	drivers/mailbox/apple-mailbox.c
 F:	include/dt-bindings/interrupt-controller/apple-aic.h
 F:	include/dt-bindings/pinctrl/apple.h
+F:	include/linux/apple-mailbox.h
 
 ARM/ARTPEC MACHINE SUPPORT
 M:	Jesper Nilsson <jesper.nilsson@axis.com>
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index bd482108310c..a85c351589be 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -43,7 +43,7 @@
 #include <acpi/cppc_acpi.h>
 
 struct cppc_pcc_data {
-	struct mbox_chan *pcc_channel;
+	struct pcc_mbox_chan *pcc_channel;
 	void __iomem *pcc_comm_addr;
 	bool pcc_channel_acquired;
 	unsigned int deadline_us;
@@ -295,7 +295,7 @@ static int send_pcc_cmd(int pcc_ss_id, u16 cmd)
 	pcc_ss_data->platform_owns_pcc = true;
 
 	/* Ring doorbell */
-	ret = mbox_send_message(pcc_ss_data->pcc_channel, &cmd);
+	ret = mbox_send_message(pcc_ss_data->pcc_channel->mchan, &cmd);
 	if (ret < 0) {
 		pr_err("Err sending PCC mbox message. ss: %d cmd:%d, ret:%d\n",
 		       pcc_ss_id, cmd, ret);
@@ -308,10 +308,10 @@ static int send_pcc_cmd(int pcc_ss_id, u16 cmd)
 	if (pcc_ss_data->pcc_mrtt)
 		pcc_ss_data->last_cmd_cmpl_time = ktime_get();
 
-	if (pcc_ss_data->pcc_channel->mbox->txdone_irq)
-		mbox_chan_txdone(pcc_ss_data->pcc_channel, ret);
+	if (pcc_ss_data->pcc_channel->mchan->mbox->txdone_irq)
+		mbox_chan_txdone(pcc_ss_data->pcc_channel->mchan, ret);
 	else
-		mbox_client_txdone(pcc_ss_data->pcc_channel, ret);
+		mbox_client_txdone(pcc_ss_data->pcc_channel->mchan, ret);
 
 end:
 	if (cmd == CMD_WRITE) {
@@ -493,46 +493,33 @@ EXPORT_SYMBOL_GPL(acpi_get_psd_map);
 
 static int register_pcc_channel(int pcc_ss_idx)
 {
-	struct acpi_pcct_hw_reduced *cppc_ss;
+	struct pcc_mbox_chan *pcc_chan;
 	u64 usecs_lat;
 
 	if (pcc_ss_idx >= 0) {
-		pcc_data[pcc_ss_idx]->pcc_channel =
-			pcc_mbox_request_channel(&cppc_mbox_cl,	pcc_ss_idx);
+		pcc_chan = pcc_mbox_request_channel(&cppc_mbox_cl, pcc_ss_idx);
 
-		if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
+		if (IS_ERR(pcc_chan)) {
 			pr_err("Failed to find PCC channel for subspace %d\n",
 			       pcc_ss_idx);
 			return -ENODEV;
 		}
 
-		/*
-		 * The PCC mailbox controller driver should
-		 * have parsed the PCCT (global table of all
-		 * PCC channels) and stored pointers to the
-		 * subspace communication region in con_priv.
-		 */
-		cppc_ss = (pcc_data[pcc_ss_idx]->pcc_channel)->con_priv;
-
-		if (!cppc_ss) {
-			pr_err("No PCC subspace found for %d CPPC\n",
-			       pcc_ss_idx);
-			return -ENODEV;
-		}
-
+		pcc_data[pcc_ss_idx]->pcc_channel = pcc_chan;
 		/*
 		 * cppc_ss->latency is just a Nominal value. In reality
 		 * the remote processor could be much slower to reply.
 		 * So add an arbitrary amount of wait on top of Nominal.
 		 */
-		usecs_lat = NUM_RETRIES * cppc_ss->latency;
+		usecs_lat = NUM_RETRIES * pcc_chan->latency;
 		pcc_data[pcc_ss_idx]->deadline_us = usecs_lat;
-		pcc_data[pcc_ss_idx]->pcc_mrtt = cppc_ss->min_turnaround_time;
-		pcc_data[pcc_ss_idx]->pcc_mpar = cppc_ss->max_access_rate;
-		pcc_data[pcc_ss_idx]->pcc_nominal = cppc_ss->latency;
+		pcc_data[pcc_ss_idx]->pcc_mrtt = pcc_chan->min_turnaround_time;
+		pcc_data[pcc_ss_idx]->pcc_mpar = pcc_chan->max_access_rate;
+		pcc_data[pcc_ss_idx]->pcc_nominal = pcc_chan->latency;
 
 		pcc_data[pcc_ss_idx]->pcc_comm_addr =
-			acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
+			acpi_os_ioremap(pcc_chan->shmem_base_addr,
+					pcc_chan->shmem_size);
 		if (!pcc_data[pcc_ss_idx]->pcc_comm_addr) {
 			pr_err("Failed to ioremap PCC comm region mem for %d\n",
 			       pcc_ss_idx);
diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c
index 382ef0395d8e..30aae8642069 100644
--- a/drivers/hwmon/xgene-hwmon.c
+++ b/drivers/hwmon/xgene-hwmon.c
@@ -93,6 +93,7 @@ struct slimpro_resp_msg {
 struct xgene_hwmon_dev {
 	struct device		*dev;
 	struct mbox_chan	*mbox_chan;
+	struct pcc_mbox_chan	*pcc_chan;
 	struct mbox_client	mbox_client;
 	int			mbox_idx;
 
@@ -652,7 +653,7 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 			goto out_mbox_free;
 		}
 	} else {
-		struct acpi_pcct_hw_reduced *cppc_ss;
+		struct pcc_mbox_chan *pcc_chan;
 		const struct acpi_device_id *acpi_id;
 		int version;
 
@@ -671,26 +672,16 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 		}
 
 		cl->rx_callback = xgene_hwmon_pcc_rx_cb;
-		ctx->mbox_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
-		if (IS_ERR(ctx->mbox_chan)) {
+		pcc_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
+		if (IS_ERR(pcc_chan)) {
 			dev_err(&pdev->dev,
 				"PPC channel request failed\n");
 			rc = -ENODEV;
 			goto out_mbox_free;
 		}
 
-		/*
-		 * The PCC mailbox controller driver should
-		 * have parsed the PCCT (global table of all
-		 * PCC channels) and stored pointers to the
-		 * subspace communication region in con_priv.
-		 */
-		cppc_ss = ctx->mbox_chan->con_priv;
-		if (!cppc_ss) {
-			dev_err(&pdev->dev, "PPC subspace not found\n");
-			rc = -ENODEV;
-			goto out;
-		}
+		ctx->pcc_chan = pcc_chan;
+		ctx->mbox_chan = pcc_chan->mchan;
 
 		if (!ctx->mbox_chan->mbox->txdone_irq) {
 			dev_err(&pdev->dev, "PCC IRQ not supported\n");
@@ -702,16 +693,16 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 		 * This is the shared communication region
 		 * for the OS and Platform to communicate over.
 		 */
-		ctx->comm_base_addr = cppc_ss->base_address;
+		ctx->comm_base_addr = pcc_chan->shmem_base_addr;
 		if (ctx->comm_base_addr) {
 			if (version == XGENE_HWMON_V2)
 				ctx->pcc_comm_addr = (void __force *)ioremap(
 							ctx->comm_base_addr,
-							cppc_ss->length);
+							pcc_chan->shmem_size);
 			else
 				ctx->pcc_comm_addr = memremap(
 							ctx->comm_base_addr,
-							cppc_ss->length,
+							pcc_chan->shmem_size,
 							MEMREMAP_WB);
 		} else {
 			dev_err(&pdev->dev, "Failed to get PCC comm region\n");
@@ -727,11 +718,11 @@ static int xgene_hwmon_probe(struct platform_device *pdev)
 		}
 
 		/*
-		 * cppc_ss->latency is just a Nominal value. In reality
+		 * pcc_chan->latency is just a Nominal value. In reality
 		 * the remote processor could be much slower to reply.
 		 * So add an arbitrary amount of wait on top of Nominal.
 		 */
-		ctx->usecs_lat = PCC_NUM_RETRIES * cppc_ss->latency;
+		ctx->usecs_lat = PCC_NUM_RETRIES * pcc_chan->latency;
 	}
 
 	ctx->hwmon_dev = hwmon_device_register_with_groups(ctx->dev,
@@ -757,7 +748,7 @@ out:
 	if (acpi_disabled)
 		mbox_free_channel(ctx->mbox_chan);
 	else
-		pcc_mbox_free_channel(ctx->mbox_chan);
+		pcc_mbox_free_channel(ctx->pcc_chan);
 out_mbox_free:
 	kfifo_free(&ctx->async_msg_fifo);
 
@@ -773,7 +764,7 @@ static int xgene_hwmon_remove(struct platform_device *pdev)
 	if (acpi_disabled)
 		mbox_free_channel(ctx->mbox_chan);
 	else
-		pcc_mbox_free_channel(ctx->mbox_chan);
+		pcc_mbox_free_channel(ctx->pcc_chan);
 
 	return 0;
 }
diff --git a/drivers/i2c/busses/i2c-xgene-slimpro.c b/drivers/i2c/busses/i2c-xgene-slimpro.c
index bba08cbce6e1..1a19ebad60ad 100644
--- a/drivers/i2c/busses/i2c-xgene-slimpro.c
+++ b/drivers/i2c/busses/i2c-xgene-slimpro.c
@@ -103,6 +103,7 @@ struct slimpro_i2c_dev {
 	struct i2c_adapter adapter;
 	struct device *dev;
 	struct mbox_chan *mbox_chan;
+	struct pcc_mbox_chan *pcc_chan;
 	struct mbox_client mbox_client;
 	int mbox_idx;
 	struct completion rd_complete;
@@ -466,7 +467,7 @@ static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
 			return PTR_ERR(ctx->mbox_chan);
 		}
 	} else {
-		struct acpi_pcct_hw_reduced *cppc_ss;
+		struct pcc_mbox_chan *pcc_chan;
 		const struct acpi_device_id *acpi_id;
 		int version = XGENE_SLIMPRO_I2C_V1;
 
@@ -483,24 +484,14 @@ static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
 
 		cl->tx_block = false;
 		cl->rx_callback = slimpro_i2c_pcc_rx_cb;
-		ctx->mbox_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
-		if (IS_ERR(ctx->mbox_chan)) {
+		pcc_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
+		if (IS_ERR(pcc_chan)) {
 			dev_err(&pdev->dev, "PCC mailbox channel request failed\n");
-			return PTR_ERR(ctx->mbox_chan);
+			return PTR_ERR(ctx->pcc_chan);
 		}
 
-		/*
-		 * The PCC mailbox controller driver should
-		 * have parsed the PCCT (global table of all
-		 * PCC channels) and stored pointers to the
-		 * subspace communication region in con_priv.
-		 */
-		cppc_ss = ctx->mbox_chan->con_priv;
-		if (!cppc_ss) {
-			dev_err(&pdev->dev, "PPC subspace not found\n");
-			rc = -ENOENT;
-			goto mbox_err;
-		}
+		ctx->pcc_chan = pcc_chan;
+		ctx->mbox_chan = pcc_chan->mchan;
 
 		if (!ctx->mbox_chan->mbox->txdone_irq) {
 			dev_err(&pdev->dev, "PCC IRQ not supported\n");
@@ -512,17 +503,17 @@ static int xgene_slimpro_i2c_probe(struct platform_device *pdev)
 		 * This is the shared communication region
 		 * for the OS and Platform to communicate over.
 		 */
-		ctx->comm_base_addr = cppc_ss->base_address;
+		ctx->comm_base_addr = pcc_chan->shmem_base_addr;
 		if (ctx->comm_base_addr) {
 			if (version == XGENE_SLIMPRO_I2C_V2)
 				ctx->pcc_comm_addr = memremap(
 							ctx->comm_base_addr,
-							cppc_ss->length,
+							pcc_chan->shmem_size,
 							MEMREMAP_WT);
 			else
 				ctx->pcc_comm_addr = memremap(
 							ctx->comm_base_addr,
-							cppc_ss->length,
+							pcc_chan->shmem_size,
 							MEMREMAP_WB);
 		} else {
 			dev_err(&pdev->dev, "Failed to get PCC comm region\n");
@@ -561,7 +552,7 @@ mbox_err:
 	if (acpi_disabled)
 		mbox_free_channel(ctx->mbox_chan);
 	else
-		pcc_mbox_free_channel(ctx->mbox_chan);
+		pcc_mbox_free_channel(ctx->pcc_chan);
 
 	return rc;
 }
@@ -575,7 +566,7 @@ static int xgene_slimpro_i2c_remove(struct platform_device *pdev)
 	if (acpi_disabled)
 		mbox_free_channel(ctx->mbox_chan);
 	else
-		pcc_mbox_free_channel(ctx->mbox_chan);
+		pcc_mbox_free_channel(ctx->pcc_chan);
 
 	return 0;
 }
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
index c9fc06c7e685..d9cd3606040e 100644
--- a/drivers/mailbox/Kconfig
+++ b/drivers/mailbox/Kconfig
@@ -8,6 +8,18 @@ menuconfig MAILBOX
 
 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
diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
index c2089f04887e..338cc05e5431 100644
--- a/drivers/mailbox/Makefile
+++ b/drivers/mailbox/Makefile
@@ -58,3 +58,5 @@ 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 000000000000..72942002a54a
--- /dev/null
+++ b/drivers/mailbox/apple-mailbox.c
@@ -0,0 +1,384 @@
+// 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/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/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;
+};
+
+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 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 irqreturn_t apple_mbox_recv_irq(int irq, void *data)
+{
+	struct apple_mbox *apple_mbox = data;
+	struct apple_mbox_msg msg;
+
+	while (apple_mbox_hw_recv(apple_mbox, &msg) == 0)
+		mbox_chan_received_data(&apple_mbox->chan, (void *)&msg);
+
+	/*
+	 * 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 IRQ_HANDLED;
+}
+
+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,
+	.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;
+
+	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,t8103-asc-mailbox", .data = &apple_mbox_asc_hw },
+	{ .compatible = "apple,t8103-m3-mailbox", .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/bcm2835-mailbox.c b/drivers/mailbox/bcm2835-mailbox.c
index 86b7ce3549c5..fbfd0202047c 100644
--- a/drivers/mailbox/bcm2835-mailbox.c
+++ b/drivers/mailbox/bcm2835-mailbox.c
@@ -137,7 +137,6 @@ static int bcm2835_mbox_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	int ret = 0;
-	struct resource *iomem;
 	struct bcm2835_mbox *mbox;
 
 	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
@@ -153,8 +152,7 @@ static int bcm2835_mbox_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
-	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mbox->regs = devm_ioremap_resource(&pdev->dev, iomem);
+	mbox->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mbox->regs)) {
 		ret = PTR_ERR(mbox->regs);
 		return ret;
diff --git a/drivers/mailbox/hi3660-mailbox.c b/drivers/mailbox/hi3660-mailbox.c
index 395ddc250828..e41bd2f5ea46 100644
--- a/drivers/mailbox/hi3660-mailbox.c
+++ b/drivers/mailbox/hi3660-mailbox.c
@@ -240,7 +240,6 @@ static int hi3660_mbox_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct hi3660_mbox *mbox;
 	struct mbox_chan *chan;
-	struct resource *res;
 	unsigned long ch;
 	int err;
 
@@ -248,8 +247,7 @@ static int hi3660_mbox_probe(struct platform_device *pdev)
 	if (!mbox)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mbox->base = devm_ioremap_resource(dev, res);
+	mbox->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mbox->base))
 		return PTR_ERR(mbox->base);
 
diff --git a/drivers/mailbox/hi6220-mailbox.c b/drivers/mailbox/hi6220-mailbox.c
index 560cd09538b1..fca61f5312d9 100644
--- a/drivers/mailbox/hi6220-mailbox.c
+++ b/drivers/mailbox/hi6220-mailbox.c
@@ -264,7 +264,6 @@ 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;
-	struct resource *res;
 	int i, err;
 
 	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
@@ -287,15 +286,13 @@ static int hi6220_mbox_probe(struct platform_device *pdev)
 	if (mbox->irq < 0)
 		return mbox->irq;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mbox->ipc = devm_ioremap_resource(dev, res);
+	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);
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-	mbox->base = devm_ioremap_resource(dev, res);
+	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);
diff --git a/drivers/mailbox/imx-mailbox.c b/drivers/mailbox/imx-mailbox.c
index 0ce75c6b36b6..ffe36a6bef9e 100644
--- a/drivers/mailbox/imx-mailbox.c
+++ b/drivers/mailbox/imx-mailbox.c
@@ -5,6 +5,7 @@
 
 #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>
@@ -18,6 +19,8 @@
 #define IMX_MU_CHANS		16
 /* 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
 
 enum imx_mu_chan_type {
@@ -47,6 +50,11 @@ struct imx_sc_rpc_msg_max {
 	u32 data[7];
 };
 
+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];
@@ -58,6 +66,7 @@ struct imx_mu_con_priv {
 struct imx_mu_priv {
 	struct device		*dev;
 	void __iomem		*base;
+	void			*msg;
 	spinlock_t		xcr_lock; /* control register lock */
 
 	struct mbox_controller	mbox;
@@ -75,7 +84,8 @@ struct imx_mu_priv {
 
 enum imx_mu_type {
 	IMX_MU_V1,
-	IMX_MU_V2,
+	IMX_MU_V2 = BIT(1),
+	IMX_MU_V2_S4 = BIT(15),
 };
 
 struct imx_mu_dcfg {
@@ -89,18 +99,18 @@ struct imx_mu_dcfg {
 	u32	xCR[4];		/* 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))))
+#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))))
+#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))))
+#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))))
+#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))))
+#define IMX_MU_xCR_GIRn(type, x) (type & IMX_MU_V2 ? BIT(x) : BIT(16 + (3 - (x))))
 
 
 static struct imx_mu_priv *to_imx_mu_priv(struct mbox_controller *mbox)
@@ -167,14 +177,22 @@ static int imx_mu_generic_rx(struct imx_mu_priv *priv,
 	return 0;
 }
 
-static int imx_mu_scu_tx(struct imx_mu_priv *priv,
-			 struct imx_mu_con_priv *cp,
-			 void *data)
+static int imx_mu_specific_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;
 	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:
@@ -183,27 +201,27 @@ static int imx_mu_scu_tx(struct imx_mu_priv *priv,
 		 * sizeof yields bytes.
 		 */
 
-		if (msg->hdr.size > sizeof(*msg) / 4) {
+		if (size > max_size / 4) {
 			/*
 			 * The real message size can be different to
-			 * struct imx_sc_rpc_msg_max size
+			 * struct imx_sc_rpc_msg_max/imx_s4_rpc_msg_max size
 			 */
-			dev_err(priv->dev, "Maximal message size (%zu bytes) exceeded on TX; got: %i bytes\n", sizeof(*msg), msg->hdr.size << 2);
+			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 < 4 && i < msg->hdr.size; i++)
-			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % 4) * 4);
-		for (; i < msg->hdr.size; i++) {
+		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 % 4),
+						 xsr & IMX_MU_xSR_TEn(priv->dcfg->type, i % num_tr),
 						 0, 100);
 			if (ret) {
 				dev_err(priv->dev, "Send data index: %d timeout\n", i);
 				return ret;
 			}
-			imx_mu_write(priv, *arg++, priv->dcfg->xTR + (i % 4) * 4);
+			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);
@@ -216,23 +234,32 @@ static int imx_mu_scu_tx(struct imx_mu_priv *priv,
 	return 0;
 }
 
-static int imx_mu_scu_rx(struct imx_mu_priv *priv,
-			 struct imx_mu_con_priv *cp)
+static int imx_mu_specific_rx(struct imx_mu_priv *priv, struct imx_mu_con_priv *cp)
 {
-	struct imx_sc_rpc_msg_max msg;
-	u32 *data = (u32 *)&msg;
+	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 (msg.hdr.size > sizeof(msg) / 4) {
-		dev_err(priv->dev, "Maximal message size (%zu bytes) exceeded on RX; got: %i bytes\n", sizeof(msg), msg.hdr.size << 2);
+	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 < msg.hdr.size; i++) {
+	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, 100);
 		if (ret) {
@@ -243,7 +270,7 @@ static int imx_mu_scu_rx(struct imx_mu_priv *priv,
 	}
 
 	imx_mu_xcr_rmw(priv, IMX_MU_RCR, IMX_MU_xCR_RIEn(priv->dcfg->type, 0), 0);
-	mbox_chan_received_data(cp->chan, (void *)&msg);
+	mbox_chan_received_data(cp->chan, (void *)priv->msg);
 
 	return 0;
 }
@@ -394,8 +421,8 @@ static const struct mbox_chan_ops imx_mu_ops = {
 	.shutdown = imx_mu_shutdown,
 };
 
-static struct mbox_chan *imx_mu_scu_xlate(struct mbox_controller *mbox,
-					  const struct of_phandle_args *sp)
+static struct mbox_chan *imx_mu_specific_xlate(struct mbox_controller *mbox,
+					       const struct of_phandle_args *sp)
 {
 	u32 type, idx, chan;
 
@@ -478,11 +505,12 @@ static void imx_mu_init_generic(struct imx_mu_priv *priv)
 		imx_mu_write(priv, 0, priv->dcfg->xCR[i]);
 }
 
-static void imx_mu_init_scu(struct imx_mu_priv *priv)
+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 < IMX_MU_SCU_CHANS; i++) {
+	for (i = 0; i < num_chans; i++) {
 		struct imx_mu_con_priv *cp = &priv->con_priv[i];
 
 		cp->idx = i < 2 ? 0 : i - 2;
@@ -493,8 +521,8 @@ static void imx_mu_init_scu(struct imx_mu_priv *priv)
 			 "imx_mu_chan[%i-%i]", cp->type, cp->idx);
 	}
 
-	priv->mbox.num_chans = IMX_MU_SCU_CHANS;
-	priv->mbox.of_xlate = imx_mu_scu_xlate;
+	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++)
@@ -508,6 +536,7 @@ static int imx_mu_probe(struct platform_device *pdev)
 	struct imx_mu_priv *priv;
 	const struct imx_mu_dcfg *dcfg;
 	int ret;
+	u32 size;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -528,6 +557,15 @@ static int imx_mu_probe(struct platform_device *pdev)
 		return -EINVAL;
 	priv->dcfg = dcfg;
 
+	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 (IS_ERR(priv->msg))
+		return PTR_ERR(priv->msg);
+
 	priv->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(priv->clk)) {
 		if (PTR_ERR(priv->clk) != -ENOENT)
@@ -623,10 +661,21 @@ static const struct imx_mu_dcfg imx_mu_cfg_imx8ulp = {
 	.xCR	= {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	= {0x110, 0x114, 0x120, 0x128},
+};
+
 static const struct imx_mu_dcfg imx_mu_cfg_imx8_scu = {
-	.tx	= imx_mu_scu_tx,
-	.rx	= imx_mu_scu_rx,
-	.init	= imx_mu_init_scu,
+	.tx	= imx_mu_specific_tx,
+	.rx	= imx_mu_specific_rx,
+	.init	= imx_mu_init_specific,
 	.xTR	= 0x0,
 	.xRR	= 0x10,
 	.xSR	= {0x20, 0x20, 0x20, 0x20},
@@ -637,6 +686,7 @@ 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,imx8-mu-scu", .data = &imx_mu_cfg_imx8_scu },
 	{ },
 };
diff --git a/drivers/mailbox/mailbox-altera.c b/drivers/mailbox/mailbox-altera.c
index 75282666fb06..afb320e9d69c 100644
--- a/drivers/mailbox/mailbox-altera.c
+++ b/drivers/mailbox/mailbox-altera.c
@@ -285,7 +285,6 @@ static const struct mbox_chan_ops altera_mbox_ops = {
 static int altera_mbox_probe(struct platform_device *pdev)
 {
 	struct altera_mbox *mbox;
-	struct resource	*regs;
 	struct mbox_chan *chans;
 	int ret;
 
@@ -299,9 +298,7 @@ static int altera_mbox_probe(struct platform_device *pdev)
 	if (!chans)
 		return -ENOMEM;
 
-	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-
-	mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
+	mbox->mbox_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mbox->mbox_base))
 		return PTR_ERR(mbox->mbox_base);
 
diff --git a/drivers/mailbox/mailbox-sti.c b/drivers/mailbox/mailbox-sti.c
index ab3a6ab762d3..823061dd8c8e 100644
--- a/drivers/mailbox/mailbox-sti.c
+++ b/drivers/mailbox/mailbox-sti.c
@@ -408,7 +408,6 @@ static int sti_mbox_probe(struct platform_device *pdev)
 	struct sti_mbox_device *mdev;
 	struct device_node *np = pdev->dev.of_node;
 	struct mbox_chan *chans;
-	struct resource *res;
 	int irq;
 	int ret;
 
@@ -425,8 +424,7 @@ static int sti_mbox_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, mdev);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mdev->base = devm_ioremap_resource(&pdev->dev, res);
+	mdev->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mdev->base))
 		return PTR_ERR(mdev->base);
 
diff --git a/drivers/mailbox/mailbox-xgene-slimpro.c b/drivers/mailbox/mailbox-xgene-slimpro.c
index 5b3a2dcd5955..946ea773ec33 100644
--- a/drivers/mailbox/mailbox-xgene-slimpro.c
+++ b/drivers/mailbox/mailbox-xgene-slimpro.c
@@ -170,7 +170,6 @@ static const struct mbox_chan_ops slimpro_mbox_ops = {
 static int slimpro_mbox_probe(struct platform_device *pdev)
 {
 	struct slimpro_mbox *ctx;
-	struct resource *regs;
 	void __iomem *mb_base;
 	int rc;
 	int i;
@@ -181,8 +180,7 @@ static int slimpro_mbox_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, ctx);
 
-	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mb_base = devm_ioremap_resource(&pdev->dev, regs);
+	mb_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mb_base))
 		return PTR_ERR(mb_base);
 
diff --git a/drivers/mailbox/mtk-cmdq-mailbox.c b/drivers/mailbox/mtk-cmdq-mailbox.c
index 64175a893312..a8845b162dbf 100644
--- a/drivers/mailbox/mtk-cmdq-mailbox.c
+++ b/drivers/mailbox/mtk-cmdq-mailbox.c
@@ -195,7 +195,6 @@ static void cmdq_task_exec_done(struct cmdq_task *task, int sta)
 	struct cmdq_task_cb *cb = &task->pkt->async_cb;
 	struct cmdq_cb_data data;
 
-	WARN_ON(cb->cb == (cmdq_async_flush_cb)NULL);
 	data.sta = sta;
 	data.data = cb->data;
 	data.pkt = task->pkt;
@@ -525,21 +524,20 @@ static struct mbox_chan *cmdq_xlate(struct mbox_controller *mbox,
 static int cmdq_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
-	struct resource *res;
 	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;
-	char clk_name[4] = "gce";
+	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;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	cmdq->base = devm_ioremap_resource(dev, res);
+	cmdq->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(cmdq->base))
 		return PTR_ERR(cmdq->base);
 
@@ -570,12 +568,9 @@ static int cmdq_probe(struct platform_device *pdev)
 
 	if (cmdq->gce_num > 1) {
 		for_each_child_of_node(phandle->parent, node) {
-			char clk_id[8];
-
 			alias_id = of_alias_get_id(node, clk_name);
-			if (alias_id < cmdq->gce_num) {
-				snprintf(clk_id, sizeof(clk_id), "%s%d", clk_name, alias_id);
-				cmdq->clocks[alias_id].id = clk_id;
+			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)) {
 					dev_err(dev, "failed to get gce clk: %d\n", alias_id);
diff --git a/drivers/mailbox/omap-mailbox.c b/drivers/mailbox/omap-mailbox.c
index 7295e3835e30..58f3d569f095 100644
--- a/drivers/mailbox/omap-mailbox.c
+++ b/drivers/mailbox/omap-mailbox.c
@@ -699,7 +699,6 @@ static struct mbox_chan *omap_mbox_of_xlate(struct mbox_controller *controller,
 
 static int omap_mbox_probe(struct platform_device *pdev)
 {
-	struct resource *mem;
 	int ret;
 	struct mbox_chan *chnls;
 	struct omap_mbox **list, *mbox, *mboxblk;
@@ -776,8 +775,7 @@ static int omap_mbox_probe(struct platform_device *pdev)
 	if (!mdev)
 		return -ENOMEM;
 
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
+	mdev->mbox_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mdev->mbox_base))
 		return PTR_ERR(mdev->mbox_base);
 
diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 0296558f9e22..887a3704c12e 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -52,6 +52,7 @@
 #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>
@@ -62,31 +63,48 @@
 
 #define MBOX_IRQ_NAME		"pcc-mbox"
 
-static struct mbox_chan *pcc_mbox_channels;
-
-/* Array of cached virtual address for doorbell registers */
-static void __iomem **pcc_doorbell_vaddr;
-/* Array of cached virtual address for doorbell ack registers */
-static void __iomem **pcc_doorbell_ack_vaddr;
-/* Array of doorbell interrupts */
-static int *pcc_doorbell_irq;
+/**
+ * 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;
+};
 
-static struct mbox_controller pcc_mbox_ctrl = {};
 /**
- * get_pcc_channel - Given a PCC subspace idx, get
- *	the respective mbox_channel.
- * @id: PCC subspace index.
+ * struct pcc_chan_info - PCC channel specific information
  *
- * Return: ERR_PTR(errno) if error, else pointer
- *	to mbox channel.
+ * @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
  */
-static struct mbox_chan *get_pcc_channel(int id)
-{
-	if (id < 0 || id >= pcc_mbox_ctrl.num_chans)
-		return ERR_PTR(-ENOENT);
+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;
+};
 
-	return &pcc_mbox_channels[id];
-}
+#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
@@ -96,10 +114,8 @@ static struct mbox_chan *get_pcc_channel(int id)
  * The below read_register and write_registers are used to read and
  * write from perf critical registers such as PCC doorbell register
  */
-static int read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
+static void read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
 {
-	int ret_val = 0;
-
 	switch (bit_width) {
 	case 8:
 		*val = readb(vaddr);
@@ -113,19 +129,11 @@ static int read_register(void __iomem *vaddr, u64 *val, unsigned int bit_width)
 	case 64:
 		*val = readq(vaddr);
 		break;
-	default:
-		pr_debug("Error: Cannot read register of %u bit width",
-			bit_width);
-		ret_val = -EFAULT;
-		break;
 	}
-	return ret_val;
 }
 
-static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
+static void write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
 {
-	int ret_val = 0;
-
 	switch (bit_width) {
 	case 8:
 		writeb(val, vaddr);
@@ -139,13 +147,54 @@ static int write_register(void __iomem *vaddr, u64 val, unsigned int bit_width)
 	case 64:
 		writeq(val, vaddr);
 		break;
-	default:
-		pr_debug("Error: Cannot write register of %u bit width",
-			bit_width);
-		ret_val = -EFAULT;
-		break;
 	}
-	return ret_val;
+}
+
+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);
 }
 
 /**
@@ -174,42 +223,42 @@ static int pcc_map_interrupt(u32 interrupt, u32 flags)
 
 /**
  * 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 acpi_generic_address *doorbell_ack;
-	struct acpi_pcct_hw_reduced *pcct_ss;
+	struct pcc_chan_info *pchan;
 	struct mbox_chan *chan = p;
-	u64 doorbell_ack_preserve;
-	u64 doorbell_ack_write;
-	u64 doorbell_ack_val;
+	u64 val;
 	int ret;
 
-	pcct_ss = chan->con_priv;
+	pchan = chan->con_priv;
 
-	mbox_chan_received_data(chan, NULL);
+	ret = pcc_chan_reg_read(&pchan->cmd_complete, &val);
+	if (ret)
+		return IRQ_NONE;
 
-	if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
-		struct acpi_pcct_hw_reduced_type2 *pcct2_ss = chan->con_priv;
-		u32 id = chan - pcc_mbox_channels;
+	val &= pchan->cmd_complete.status_mask;
+	if (!val)
+		return IRQ_NONE;
 
-		doorbell_ack = &pcct2_ss->platform_ack_register;
-		doorbell_ack_preserve = pcct2_ss->ack_preserve_mask;
-		doorbell_ack_write = pcct2_ss->ack_write_mask;
+	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;
+	}
 
-		ret = read_register(pcc_doorbell_ack_vaddr[id],
-				    &doorbell_ack_val,
-				    doorbell_ack->bit_width);
-		if (ret)
-			return IRQ_NONE;
+	if (pcc_chan_reg_read_modify_write(&pchan->plat_irq_ack))
+		return IRQ_NONE;
 
-		ret = write_register(pcc_doorbell_ack_vaddr[id],
-				     (doorbell_ack_val & doorbell_ack_preserve)
-					| doorbell_ack_write,
-				     doorbell_ack->bit_width);
-		if (ret)
-			return IRQ_NONE;
-	}
+	mbox_chan_received_data(chan, NULL);
 
 	return IRQ_HANDLED;
 }
@@ -224,29 +273,26 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
  *		ACPI package. This is used to lookup the array of PCC
  *		subspaces as parsed by the PCC Mailbox controller.
  *
- * Return: Pointer to the Mailbox Channel if successful or
- *		ERR_PTR.
+ * Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
  */
-struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
-		int subspace_id)
+struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
 {
-	struct device *dev = pcc_mbox_ctrl.dev;
+	struct pcc_chan_info *pchan;
 	struct mbox_chan *chan;
+	struct device *dev;
 	unsigned long flags;
 
-	/*
-	 * Each PCC Subspace is a Mailbox Channel.
-	 * The PCC Clients get their PCC Subspace ID
-	 * from their own tables and pass it here.
-	 * This returns a pointer to the PCC subspace
-	 * for the Client to operate on.
-	 */
-	chan = get_pcc_channel(subspace_id);
+	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) {
 		dev_err(dev, "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;
@@ -260,44 +306,40 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
 
 	spin_unlock_irqrestore(&chan->lock, flags);
 
-	if (pcc_doorbell_irq[subspace_id] > 0) {
+	if (pchan->plat_irq > 0) {
 		int rc;
 
-		rc = devm_request_irq(dev, pcc_doorbell_irq[subspace_id],
-				      pcc_mbox_irq, 0, MBOX_IRQ_NAME, chan);
+		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",
-				pcc_doorbell_irq[subspace_id]);
-			pcc_mbox_free_channel(chan);
-			chan = ERR_PTR(rc);
+				pchan->plat_irq);
+			pcc_mbox_free_channel(&pchan->chan);
+			return ERR_PTR(rc);
 		}
 	}
 
-	return chan;
+	return &pchan->chan;
 }
 EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
 
 /**
  * pcc_mbox_free_channel - Clients call this to free their Channel.
  *
- * @chan: Pointer to the mailbox channel as returned by
- *		pcc_mbox_request_channel()
+ * @pchan: Pointer to the PCC mailbox channel as returned by
+ *	   pcc_mbox_request_channel()
  */
-void pcc_mbox_free_channel(struct mbox_chan *chan)
+void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
 {
-	u32 id = chan - pcc_mbox_channels;
+	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 (id >= pcc_mbox_ctrl.num_chans) {
-		pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
-		return;
-	}
-
-	if (pcc_doorbell_irq[id] > 0)
-		devm_free_irq(chan->mbox->dev, pcc_doorbell_irq[id], chan);
+	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;
@@ -323,40 +365,14 @@ EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);
  */
 static int pcc_send_data(struct mbox_chan *chan, void *data)
 {
-	struct acpi_pcct_hw_reduced *pcct_ss = chan->con_priv;
-	struct acpi_generic_address *doorbell;
-	u64 doorbell_preserve;
-	u64 doorbell_val;
-	u64 doorbell_write;
-	u32 id = chan - pcc_mbox_channels;
-	int ret = 0;
-
-	if (id >= pcc_mbox_ctrl.num_chans) {
-		pr_debug("pcc_send_data: Invalid mbox_chan passed\n");
-		return -ENOENT;
-	}
+	int ret;
+	struct pcc_chan_info *pchan = chan->con_priv;
 
-	doorbell = &pcct_ss->doorbell_register;
-	doorbell_preserve = pcct_ss->preserve_mask;
-	doorbell_write = pcct_ss->write_mask;
+	ret = pcc_chan_reg_read_modify_write(&pchan->cmd_update);
+	if (ret)
+		return ret;
 
-	/* Sync notification from OS to Platform. */
-	if (pcc_doorbell_vaddr[id]) {
-		ret = read_register(pcc_doorbell_vaddr[id], &doorbell_val,
-			doorbell->bit_width);
-		if (ret)
-			return ret;
-		ret = write_register(pcc_doorbell_vaddr[id],
-			(doorbell_val & doorbell_preserve) | doorbell_write,
-			doorbell->bit_width);
-	} else {
-		ret = acpi_read(&doorbell_val, doorbell);
-		if (ret)
-			return ret;
-		ret = acpi_write((doorbell_val & doorbell_preserve) | doorbell_write,
-			doorbell);
-	}
-	return ret;
+	return pcc_chan_reg_read_modify_write(&pchan->db);
 }
 
 static const struct mbox_chan_ops pcc_chan_ops = {
@@ -364,7 +380,7 @@ static const struct mbox_chan_ops pcc_chan_ops = {
 };
 
 /**
- * parse_pcc_subspaces -- Count PCC subspaces defined
+ * parse_pcc_subspace - Count PCC subspaces defined
  * @header: Pointer to the ACPI subtable header under the PCCT.
  * @end: End of subtable entry.
  *
@@ -384,41 +400,172 @@ static int parse_pcc_subspace(union acpi_subtable_headers *header,
 	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
- *		There should be one entry per PCC client.
- * @id: PCC subspace index.
- * @pcct_ss: Pointer to the ACPI subtable header under the PCCT.
+ *
+ * @pchan: Pointer to the PCC channel info structure.
+ * @pcct_entry: Pointer to the ACPI subtable header.
  *
  * Return: 0 for Success, else errno.
  *
- * This gets called for each entry in the PCC table.
+ * 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(int id,
-				  struct acpi_pcct_hw_reduced *pcct_ss)
+static int pcc_parse_subspace_irq(struct pcc_chan_info *pchan,
+				  struct acpi_subtable_header *pcct_entry)
 {
-	pcc_doorbell_irq[id] = pcc_map_interrupt(pcct_ss->platform_interrupt,
-						 (u32)pcct_ss->flags);
-	if (pcc_doorbell_irq[id] <= 0) {
+	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) {
+	if (pcct_ss->header.type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
 		struct acpi_pcct_hw_reduced_type2 *pcct2_ss = (void *)pcct_ss;
 
-		pcc_doorbell_ack_vaddr[id] = acpi_os_ioremap(
-				pcct2_ss->platform_ack_register.address,
-				pcct2_ss->platform_ack_register.bit_width / 8);
-		if (!pcc_doorbell_ack_vaddr[id]) {
-			pr_err("Failed to ioremap PCC ACK register\n");
-			return -ENOMEM;
-		}
+		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 0;
+	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;
+	}
 }
 
 /**
@@ -428,16 +575,12 @@ static int pcc_parse_subspace_irq(int id,
  */
 static int __init acpi_pcc_probe(void)
 {
+	int count, i, rc = 0;
+	acpi_status status;
 	struct acpi_table_header *pcct_tbl;
-	struct acpi_subtable_header *pcct_entry;
-	struct acpi_table_pcct *acpi_pcct_tbl;
 	struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
-	int count, i, rc;
-	acpi_status status = AE_OK;
 
-	/* Search for PCCT */
 	status = acpi_get_table(ACPI_SIG_PCCT, 0, &pcct_tbl);
-
 	if (ACPI_FAILURE(status) || !pcct_tbl)
 		return -ENODEV;
 
@@ -459,33 +602,60 @@ static int __init acpi_pcc_probe(void)
 			pr_warn("Invalid PCCT: %d PCC subspaces\n", count);
 
 		rc = -EINVAL;
-		goto err_put_pcct;
+	} else {
+		pcc_chan_count = count;
 	}
 
-	pcc_mbox_channels = kcalloc(count, sizeof(struct mbox_chan),
-				    GFP_KERNEL);
-	if (!pcc_mbox_channels) {
-		pr_err("Could not allocate space for PCC mbox channels\n");
-		rc = -ENOMEM;
-		goto err_put_pcct;
-	}
+	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_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
-	if (!pcc_doorbell_vaddr) {
+	pcc_mbox_channels = devm_kcalloc(dev, count, sizeof(*pcc_mbox_channels),
+					 GFP_KERNEL);
+	if (!pcc_mbox_channels) {
 		rc = -ENOMEM;
-		goto err_free_mbox;
+		goto err;
 	}
 
-	pcc_doorbell_ack_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
-	if (!pcc_doorbell_ack_vaddr) {
+	chan_info = devm_kcalloc(dev, count, sizeof(*chan_info), GFP_KERNEL);
+	if (!chan_info) {
 		rc = -ENOMEM;
-		goto err_free_db_vaddr;
+		goto err;
 	}
 
-	pcc_doorbell_irq = kcalloc(count, sizeof(int), GFP_KERNEL);
-	if (!pcc_doorbell_irq) {
+	pcc_mbox_ctrl = devm_kmalloc(dev, sizeof(*pcc_mbox_ctrl), GFP_KERNEL);
+	if (!pcc_mbox_ctrl) {
 		rc = -ENOMEM;
-		goto err_free_db_ack_vaddr;
+		goto err;
 	}
 
 	/* Point to the first PCC subspace entry */
@@ -494,85 +664,55 @@ static int __init acpi_pcc_probe(void)
 
 	acpi_pcct_tbl = (struct acpi_table_pcct *) pcct_tbl;
 	if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
-		pcc_mbox_ctrl.txdone_irq = true;
+		pcc_mbox_ctrl->txdone_irq = true;
 
 	for (i = 0; i < count; i++) {
-		struct acpi_generic_address *db_reg;
-		struct acpi_pcct_subspace *pcct_ss;
-		pcc_mbox_channels[i].con_priv = pcct_entry;
+		struct pcc_chan_info *pchan = chan_info + i;
 
-		if (pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
-		    pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
-			struct acpi_pcct_hw_reduced *pcct_hrss;
+		pcc_mbox_channels[i].con_priv = pchan;
+		pchan->chan.mchan = &pcc_mbox_channels[i];
 
-			pcct_hrss = (struct acpi_pcct_hw_reduced *) pcct_entry;
+		if (pcct_entry->type == ACPI_PCCT_TYPE_EXT_PCC_SLAVE_SUBSPACE &&
+		    !pcc_mbox_ctrl->txdone_irq) {
+			pr_err("Plaform Interrupt flag must be set to 1");
+			rc = -EINVAL;
+			goto err;
+		}
 
-			if (pcc_mbox_ctrl.txdone_irq) {
-				rc = pcc_parse_subspace_irq(i, pcct_hrss);
-				if (rc < 0)
-					goto err;
-			}
+		if (pcc_mbox_ctrl->txdone_irq) {
+			rc = pcc_parse_subspace_irq(pchan, pcct_entry);
+			if (rc < 0)
+				goto err;
 		}
-		pcct_ss = (struct acpi_pcct_subspace *) pcct_entry;
+		rc = pcc_parse_subspace_db_reg(pchan, pcct_entry);
+		if (rc < 0)
+			goto err;
+
+		pcc_parse_subspace_shmem(pchan, pcct_entry);
 
-		/* If doorbell is in system memory cache the virt address */
-		db_reg = &pcct_ss->doorbell_register;
-		if (db_reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
-			pcc_doorbell_vaddr[i] = acpi_os_ioremap(db_reg->address,
-							db_reg->bit_width/8);
 		pcct_entry = (struct acpi_subtable_header *)
 			((unsigned long) pcct_entry + pcct_entry->length);
 	}
 
-	pcc_mbox_ctrl.num_chans = count;
+	pcc_mbox_ctrl->num_chans = count;
 
-	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
+	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl->num_chans);
 
-	return 0;
+	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:
-	kfree(pcc_doorbell_irq);
-err_free_db_ack_vaddr:
-	kfree(pcc_doorbell_ack_vaddr);
-err_free_db_vaddr:
-	kfree(pcc_doorbell_vaddr);
-err_free_mbox:
-	kfree(pcc_mbox_channels);
-err_put_pcct:
 	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)
-{
-	int ret = 0;
-
-	pcc_mbox_ctrl.chans = pcc_mbox_channels;
-	pcc_mbox_ctrl.ops = &pcc_chan_ops;
-	pcc_mbox_ctrl.dev = &pdev->dev;
-
-	pr_info("Registering PCC driver as Mailbox controller\n");
-	ret = mbox_controller_register(&pcc_mbox_ctrl);
-
-	if (ret) {
-		pr_err("Err registering PCC as Mailbox controller: %d\n", ret);
-		ret = -ENODEV;
-	}
-
-	return ret;
-}
-
 static struct platform_driver pcc_mbox_driver = {
 	.probe = pcc_mbox_probe,
 	.driver = {
diff --git a/drivers/mailbox/platform_mhu.c b/drivers/mailbox/platform_mhu.c
index b6e34952246b..a5922ac0b0bf 100644
--- a/drivers/mailbox/platform_mhu.c
+++ b/drivers/mailbox/platform_mhu.c
@@ -117,7 +117,6 @@ static int platform_mhu_probe(struct platform_device *pdev)
 	int i, err;
 	struct platform_mhu *mhu;
 	struct device *dev = &pdev->dev;
-	struct resource *res;
 	int platform_mhu_reg[MHU_CHANS] = {
 		MHU_SEC_OFFSET, MHU_LP_OFFSET, MHU_HP_OFFSET
 	};
@@ -127,8 +126,7 @@ static int platform_mhu_probe(struct platform_device *pdev)
 	if (!mhu)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mhu->base = devm_ioremap_resource(dev, res);
+	mhu->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(mhu->base)) {
 		dev_err(dev, "ioremap failed\n");
 		return PTR_ERR(mhu->base);
diff --git a/drivers/mailbox/qcom-apcs-ipc-mailbox.c b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
index 82ccfaf14b24..9325d2abc745 100644
--- a/drivers/mailbox/qcom-apcs-ipc-mailbox.c
+++ b/drivers/mailbox/qcom-apcs-ipc-mailbox.c
@@ -33,10 +33,6 @@ 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 ipq8074_apcs_data = {
-	.offset = 8, .clk_name = NULL
-};
-
 static const struct qcom_apcs_ipc_data msm8916_apcs_data = {
 	.offset = 8, .clk_name = "qcom-apcs-msm8916-clk"
 };
@@ -49,18 +45,6 @@ static const struct qcom_apcs_ipc_data msm8996_apcs_data = {
 	.offset = 16, .clk_name = NULL
 };
 
-static const struct qcom_apcs_ipc_data msm8998_apcs_data = {
-	.offset = 8, .clk_name = NULL
-};
-
-static const struct qcom_apcs_ipc_data sdm660_apcs_data = {
-	.offset = 8, .clk_name = NULL
-};
-
-static const struct qcom_apcs_ipc_data sm6125_apcs_data = {
-	.offset = 8, .clk_name = NULL
-};
-
 static const struct qcom_apcs_ipc_data apps_shared_apcs_data = {
 	.offset = 12, .clk_name = NULL
 };
@@ -95,7 +79,6 @@ 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;
-	struct resource *res;
 	void __iomem *base;
 	unsigned long i;
 	int ret;
@@ -104,8 +87,7 @@ static int qcom_apcs_ipc_probe(struct platform_device *pdev)
 	if (!apcs)
 		return -ENOMEM;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	base = devm_ioremap_resource(&pdev->dev, res);
+	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
@@ -160,21 +142,22 @@ static int qcom_apcs_ipc_remove(struct platform_device *pdev)
 /* .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 = &ipq8074_apcs_data },
+	{ .compatible = "qcom,ipq8074-apcs-apps-global", .data = &msm8994_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,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 = &msm8998_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 = &sdm660_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 = &sm6125_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 = &sdm660_apcs_data },
+	{ .compatible = "qcom,sm6115-apcs-hmss-global", .data = &msm8994_apcs_data },
 	{ .compatible = "qcom,sdx55-apcs-gcc", .data = &sdx55_apcs_data },
 	{}
 };
diff --git a/drivers/mailbox/stm32-ipcc.c b/drivers/mailbox/stm32-ipcc.c
index b84e0587937c..15d538fe2113 100644
--- a/drivers/mailbox/stm32-ipcc.c
+++ b/drivers/mailbox/stm32-ipcc.c
@@ -205,7 +205,6 @@ 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;
-	struct resource *res;
 	unsigned long i;
 	int ret;
 	u32 ip_ver;
@@ -235,8 +234,7 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 	}
 
 	/* regs */
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	ipcc->reg_base = devm_ioremap_resource(dev, res);
+	ipcc->reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ipcc->reg_base))
 		return PTR_ERR(ipcc->reg_base);
 
diff --git a/drivers/mailbox/sun6i-msgbox.c b/drivers/mailbox/sun6i-msgbox.c
index ccecf2e5941d..7f8d931042d3 100644
--- a/drivers/mailbox/sun6i-msgbox.c
+++ b/drivers/mailbox/sun6i-msgbox.c
@@ -197,7 +197,6 @@ static int sun6i_msgbox_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct mbox_chan *chans;
 	struct reset_control *reset;
-	struct resource *res;
 	struct sun6i_msgbox *mbox;
 	int i, ret;
 
@@ -246,13 +245,7 @@ static int sun6i_msgbox_probe(struct platform_device *pdev)
 		goto err_disable_unprepare;
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		ret = -ENODEV;
-		goto err_disable_unprepare;
-	}
-
-	mbox->regs = devm_ioremap_resource(&pdev->dev, res);
+	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);
diff --git a/include/acpi/pcc.h b/include/acpi/pcc.h
index 4dec4ed138cd..73e806fe7ce7 100644
--- a/include/acpi/pcc.h
+++ b/include/acpi/pcc.h
@@ -9,18 +9,27 @@
 #include <linux/mailbox_controller.h>
 #include <linux/mailbox_client.h>
 
+struct pcc_mbox_chan {
+	struct mbox_chan *mchan;
+	u64 shmem_base_addr;
+	u64 shmem_size;
+	u32 latency;
+	u32 max_access_rate;
+	u16 min_turnaround_time;
+};
+
 #define MAX_PCC_SUBSPACES	256
 #ifdef CONFIG_PCC
-extern struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
-						  int subspace_id);
-extern void pcc_mbox_free_channel(struct mbox_chan *chan);
+extern struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id);
+extern void pcc_mbox_free_channel(struct pcc_mbox_chan *chan);
 #else
-static inline struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
-							 int subspace_id)
+static inline struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
 {
 	return ERR_PTR(-ENODEV);
 }
-static inline void pcc_mbox_free_channel(struct mbox_chan *chan) { }
+static inline void pcc_mbox_free_channel(struct pcc_mbox_chan *chan) { }
 #endif
 
 #endif /* _PCC_H */
diff --git a/include/linux/apple-mailbox.h b/include/linux/apple-mailbox.h
new file mode 100644
index 000000000000..720fbb70294a
--- /dev/null
+++ b/include/linux/apple-mailbox.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only OR MIT */
+/*
+ * Apple mailbox message format
+ *
+ * Copyright (C) 2021 The Asahi Linux Contributors
+ */
+
+#ifndef _LINUX_APPLE_MAILBOX_H_
+#define _LINUX_APPLE_MAILBOX_H_
+
+#include <linux/types.h>
+
+/* encodes a single 96bit message sent over the single channel */
+struct apple_mbox_msg {
+	u64 msg0;
+	u32 msg1;
+};
+
+#endif
diff --git a/include/linux/firmware/imx/s4.h b/include/linux/firmware/imx/s4.h
new file mode 100644
index 000000000000..9e34923ae1d6
--- /dev/null
+++ b/include/linux/firmware/imx/s4.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021 NXP
+ *
+ * Header file for the IPC implementation.
+ */
+
+#ifndef _S4_IPC_H
+#define _S4_IPC_H
+
+struct imx_s4_ipc;
+
+struct imx_s4_rpc_msg {
+	uint8_t ver;
+	uint8_t size;
+	uint8_t cmd;
+	uint8_t tag;
+} __packed;
+
+#endif /* _S4_IPC_H */