diff --git a/Documentation/arch/x86/amd_hsmp.rst b/Documentation/arch/x86/amd_hsmp.rst
index 1e499ecf5f4e..2e5802783da4 100644
--- a/Documentation/arch/x86/amd_hsmp.rst
+++ b/Documentation/arch/x86/amd_hsmp.rst
@@ -4,8 +4,8 @@
 AMD HSMP interface
 ============================================
 
-Newer Fam19h EPYC server line of processors from AMD support system
-management functionality via HSMP (Host System Management Port).
+Newer Fam19h(model 0x00-0x1f, 0x30-0x3f, 0x90-0x9f, 0xa0-0xaf), Fam1Ah(model 0x00-0x1f) EPYC server line of processors
+from AMD support system management functionality via HSMP (Host System Management Port).
 
 The Host System Management Port (HSMP) is an interface to provide
 OS-level software with access to system management functions via a
@@ -16,14 +16,21 @@ More details on the interface can be found in chapter
 Eg: https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/programmer-references/55898_B1_pub_0_50.zip
 
 
-HSMP interface is supported on EPYC server CPU models only.
+HSMP interface is supported on EPYC line of server CPUs and MI300A (APU).
 
 
 HSMP device
 ============================================
 
-amd_hsmp driver under the drivers/platforms/x86/ creates miscdevice
-/dev/hsmp to let user space programs run hsmp mailbox commands.
+amd_hsmp driver under the drivers/platforms/x86/amd/hsmp/ is now split into separate driver files
+with mutually exclusive compile time Kconfig options to choose between ACPI object based probing
+or as a platform device which continues to create the miscdevice /dev/hsmp to let user
+space programs run hsmp mailbox commands.
+
+The ACPI object format supported by the driver is defined below.
+
+Kconfig option CONFIG_AMD_HSMP compiles plat.c + hsmp.c for platform probing.
+Kconfig option CONFIG_AMD_HSMP_ACPI compiles acpi.c + hsmp.c for ACPI probing.
 
 $ ls -al /dev/hsmp
 crw-r--r-- 1 root root 10, 123 Jan 21 21:41 /dev/hsmp
@@ -59,6 +66,51 @@ Note: lseek() is not supported as entire metrics table is read.
 Metrics table definitions will be documented as part of Public PPR.
 The same is defined in the amd_hsmp.h header.
 
+ACPI device object format
+=========================
+The ACPI object format expected from the amd_hsmp driver
+for socket with ID00 is given below.
+
+Device(HSMP)
+		{
+			Name(_HID, "AMDI0097")
+			Name(_UID, "ID00")
+			Name(HSE0, 0x00000001)
+			Name(RBF0, ResourceTemplate()
+			{
+				Memory32Fixed(ReadWrite, 0xxxxxxx, 0x00100000)
+			})
+			Method(_CRS, 0, NotSerialized)
+			{
+				Return(RBF0)
+			}
+			Method(_STA, 0, NotSerialized)
+			{
+				If(LEqual(HSE0, One))
+				{
+					Return(0x0F)
+				}
+				Else
+				{
+					Return(Zero)
+				}
+			}
+			Name(_DSD, Package(2)
+			{
+				Buffer(0x10)
+				{
+					0x9D, 0x61, 0x4D, 0xB7, 0x07, 0x57, 0xBD, 0x48,
+					0xA6, 0x9F, 0x4E, 0xA2, 0x87, 0x1F, 0xC2, 0xF6
+				},
+				Package(3)
+				{
+					Package(2) {"MsgIdOffset", 0x00010934},
+					Package(2) {"MsgRspOffset", 0x00010980},
+					Package(2) {"MsgArgOffset", 0x000109E0}
+				}
+			})
+		}
+
 
 An example
 ==========
diff --git a/arch/x86/include/asm/amd_hsmp.h b/arch/x86/include/asm/amd_hsmp.h
index 03c2ce3edaf5..ada14e55f9f4 100644
--- a/arch/x86/include/asm/amd_hsmp.h
+++ b/arch/x86/include/asm/amd_hsmp.h
@@ -5,7 +5,7 @@
 
 #include <uapi/asm/amd_hsmp.h>
 
-#if IS_ENABLED(CONFIG_AMD_HSMP)
+#if IS_ENABLED(CONFIG_AMD_HSMP) || IS_ENABLED(CONFIG_AMD_HSMP_ACPI)
 int hsmp_send_message(struct hsmp_message *msg);
 #else
 static inline int hsmp_send_message(struct hsmp_message *msg)
diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile
index 96ec24c8701b..f0b2fe81c685 100644
--- a/drivers/platform/x86/amd/Makefile
+++ b/drivers/platform/x86/amd/Makefile
@@ -5,6 +5,6 @@
 #
 
 obj-$(CONFIG_AMD_PMC)		+= pmc/
-obj-y				+= hsmp/
+obj-$(CONFIG_AMD_HSMP)		+= hsmp/
 obj-$(CONFIG_AMD_PMF)		+= pmf/
 obj-$(CONFIG_AMD_WBRF)		+= wbrf.o
diff --git a/drivers/platform/x86/amd/hsmp/Kconfig b/drivers/platform/x86/amd/hsmp/Kconfig
index b55d4ed9bceb..6740f68243d7 100644
--- a/drivers/platform/x86/amd/hsmp/Kconfig
+++ b/drivers/platform/x86/amd/hsmp/Kconfig
@@ -4,14 +4,45 @@
 #
 
 config AMD_HSMP
-	tristate "AMD HSMP Driver"
-	depends on AMD_NB && X86_64 && ACPI
+	tristate
+
+menu "AMD HSMP Driver"
+	depends on AMD_NB || COMPILE_TEST
+
+config AMD_HSMP_ACPI
+	tristate "AMD HSMP ACPI device driver"
+	depends on ACPI
+	select AMD_HSMP
 	help
+	  Host System Management Port (HSMP) interface is a mailbox interface
+	  between the x86 core and the System Management Unit (SMU) firmware.
 	  The driver provides a way for user space tools to monitor and manage
-	  system management functionality on EPYC server CPUs from AMD.
+	  system management functionality on EPYC and MI300A server CPUs
+	  from AMD.
+
+	  This option supports ACPI based probing.
+	  You may enable this, if your platform BIOS provides an ACPI object
+	  as described in the documentation.
+
+	  If you choose to compile this driver as a module the module will be
+	  called amd_hsmp.
 
+config AMD_HSMP_PLAT
+	tristate "AMD HSMP platform device driver"
+	depends on AMD_HSMP_ACPI=n
+	select AMD_HSMP
+	help
 	  Host System Management Port (HSMP) interface is a mailbox interface
 	  between the x86 core and the System Management Unit (SMU) firmware.
+	  The driver provides a way for user space tools to monitor and manage
+	  system management functionality on EPYC and MI300A server CPUs
+	  from AMD.
+
+	  This option supports platform device based probing.
+	  You may enable this, if your platform BIOS does not provide
+	  HSMP ACPI object.
 
 	  If you choose to compile this driver as a module the module will be
 	  called amd_hsmp.
+
+endmenu
diff --git a/drivers/platform/x86/amd/hsmp/Makefile b/drivers/platform/x86/amd/hsmp/Makefile
index 0cc92865c0a2..18d9a0d1e8c5 100644
--- a/drivers/platform/x86/amd/hsmp/Makefile
+++ b/drivers/platform/x86/amd/hsmp/Makefile
@@ -4,5 +4,7 @@
 # AMD HSMP Driver
 #
 
-obj-$(CONFIG_AMD_HSMP)		+= amd_hsmp.o
-amd_hsmp-objs			:= hsmp.o plat.o acpi.o
+obj-$(CONFIG_AMD_HSMP)			+= amd_hsmp.o
+amd_hsmp-objs				:= hsmp.o
+amd_hsmp-$(CONFIG_AMD_HSMP_PLAT)	+= plat.o
+amd_hsmp-$(CONFIG_AMD_HSMP_ACPI)	+= acpi.o
diff --git a/drivers/platform/x86/amd/hsmp/acpi.c b/drivers/platform/x86/amd/hsmp/acpi.c
index 6f8e7962266a..6aa7810ebc71 100644
--- a/drivers/platform/x86/amd/hsmp/acpi.c
+++ b/drivers/platform/x86/amd/hsmp/acpi.c
@@ -9,11 +9,15 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <asm/amd_nb.h>
+
 #include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/dev_printk.h>
 #include <linux/ioport.h>
 #include <linux/kstrtox.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
 #include <linux/sysfs.h>
 #include <linux/uuid.h>
 
@@ -21,6 +25,10 @@
 
 #include "hsmp.h"
 
+#define DRIVER_NAME		"amd_hsmp"
+#define DRIVER_VERSION		"2.3"
+#define ACPI_HSMP_DEVICE_HID	"AMDI0097"
+
 /* These are the strings specified in ACPI table */
 #define MSG_IDOFF_STR		"MsgIdOffset"
 #define MSG_ARGOFF_STR		"MsgArgOffset"
@@ -37,6 +45,12 @@ static int amd_hsmp_acpi_rdwr(struct hsmp_socket *sock, u32 offset,
 	return 0;
 }
 
+static const struct file_operations hsmp_fops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= hsmp_ioctl,
+	.compat_ioctl	= hsmp_ioctl,
+};
+
 /* This is the UUID used for HSMP */
 static const guid_t acpi_hsmp_uuid = GUID_INIT(0xb74d619d, 0x5707, 0x48bd,
 						0xa6, 0x9f, 0x4e, 0xa2,
@@ -200,7 +214,6 @@ static int hsmp_parse_acpi_table(struct device *dev, u16 sock_ind)
 	sock->sock_ind		= sock_ind;
 	sock->dev		= dev;
 	sock->amd_hsmp_rdwr	= amd_hsmp_acpi_rdwr;
-	hsmp_pdev.is_acpi_device	= true;
 
 	sema_init(&sock->hsmp_sem, 1);
 
@@ -213,7 +226,7 @@ static int hsmp_parse_acpi_table(struct device *dev, u16 sock_ind)
 	return hsmp_read_acpi_dsd(sock);
 }
 
-int hsmp_create_acpi_sysfs_if(struct device *dev)
+static int hsmp_create_acpi_sysfs_if(struct device *dev)
 {
 	struct attribute_group *attr_grp;
 	u16 sock_ind;
@@ -236,7 +249,7 @@ int hsmp_create_acpi_sysfs_if(struct device *dev)
 	return devm_device_add_group(dev, attr_grp);
 }
 
-int init_acpi(struct device *dev)
+static int init_acpi(struct device *dev)
 {
 	u16 sock_ind;
 	int ret;
@@ -270,3 +283,94 @@ int init_acpi(struct device *dev)
 
 	return ret;
 }
+
+static const struct acpi_device_id amd_hsmp_acpi_ids[] = {
+	{ACPI_HSMP_DEVICE_HID, 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, amd_hsmp_acpi_ids);
+
+static bool check_acpi_support(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+
+	if (adev && !acpi_match_device_ids(adev, amd_hsmp_acpi_ids))
+		return true;
+
+	return false;
+}
+
+static int hsmp_acpi_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	if (!hsmp_pdev.is_probed) {
+		hsmp_pdev.num_sockets = amd_nb_num();
+		if (hsmp_pdev.num_sockets == 0 || hsmp_pdev.num_sockets > MAX_AMD_SOCKETS)
+			return -ENODEV;
+
+		hsmp_pdev.sock = devm_kcalloc(&pdev->dev, hsmp_pdev.num_sockets,
+					      sizeof(*hsmp_pdev.sock),
+					      GFP_KERNEL);
+		if (!hsmp_pdev.sock)
+			return -ENOMEM;
+	}
+
+	if (!check_acpi_support(&pdev->dev)) {
+		dev_err(&pdev->dev, "Not ACPI device?\n");
+		return -ENODEV;
+	}
+
+	ret = init_acpi(&pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to initialize HSMP interface.\n");
+		return ret;
+	}
+
+	ret = hsmp_create_acpi_sysfs_if(&pdev->dev);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to create HSMP sysfs interface\n");
+
+	if (!hsmp_pdev.is_probed) {
+		hsmp_pdev.mdev.name	= HSMP_CDEV_NAME;
+		hsmp_pdev.mdev.minor	= MISC_DYNAMIC_MINOR;
+		hsmp_pdev.mdev.fops	= &hsmp_fops;
+		hsmp_pdev.mdev.parent	= &pdev->dev;
+		hsmp_pdev.mdev.nodename	= HSMP_DEVNODE_NAME;
+		hsmp_pdev.mdev.mode	= 0644;
+
+		ret = misc_register(&hsmp_pdev.mdev);
+		if (ret)
+			return ret;
+		hsmp_pdev.is_probed = true;
+	}
+
+	return 0;
+}
+
+static void hsmp_acpi_remove(struct platform_device *pdev)
+{
+	/*
+	 * We register only one misc_device even on multi-socket system.
+	 * So, deregister should happen only once.
+	 */
+	if (hsmp_pdev.is_probed) {
+		misc_deregister(&hsmp_pdev.mdev);
+		hsmp_pdev.is_probed = false;
+	}
+}
+
+static struct platform_driver amd_hsmp_driver = {
+	.probe		= hsmp_acpi_probe,
+	.remove_new	= hsmp_acpi_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.acpi_match_table = amd_hsmp_acpi_ids,
+	},
+};
+
+module_platform_driver(amd_hsmp_driver);
+
+MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.c b/drivers/platform/x86/amd/hsmp/hsmp.c
index 78945750d590..bbe4d9aa8963 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.c
+++ b/drivers/platform/x86/amd/hsmp/hsmp.c
@@ -15,17 +15,11 @@
 #include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/device.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
 #include <linux/semaphore.h>
 #include <linux/sysfs.h>
 
 #include "hsmp.h"
 
-#define DRIVER_NAME		"amd_hsmp"
-#define DRIVER_VERSION		"2.2"
-#define ACPI_HSMP_DEVICE_HID	"AMDI0097"
-
 /* HSMP Status / Error codes */
 #define HSMP_STATUS_NOT_READY	0x00
 #define HSMP_STATUS_OK		0x01
@@ -228,7 +222,7 @@ int hsmp_test(u16 sock_ind, u32 value)
 	return ret;
 }
 
-static long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
+long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 {
 	int __user *arguser = (int  __user *)arg;
 	struct hsmp_message msg = { 0 };
@@ -284,12 +278,6 @@ static long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
 	return 0;
 }
 
-static const struct file_operations hsmp_fops = {
-	.owner		= THIS_MODULE,
-	.unlocked_ioctl	= hsmp_ioctl,
-	.compat_ioctl	= hsmp_ioctl,
-};
-
 ssize_t hsmp_metric_tbl_read(struct file *filp, struct kobject *kobj,
 			     struct bin_attribute *bin_attr, char *buf,
 			     loff_t off, size_t count)
@@ -413,194 +401,3 @@ int hsmp_cache_proto_ver(u16 sock_ind)
 
 	return ret;
 }
-
-static const struct acpi_device_id amd_hsmp_acpi_ids[] = {
-	{ACPI_HSMP_DEVICE_HID, 0},
-	{}
-};
-MODULE_DEVICE_TABLE(acpi, amd_hsmp_acpi_ids);
-
-static bool check_acpi_support(struct device *dev)
-{
-	struct acpi_device *adev = ACPI_COMPANION(dev);
-
-	if (adev && !acpi_match_device_ids(adev, amd_hsmp_acpi_ids))
-		return true;
-
-	return false;
-}
-
-static int hsmp_pltdrv_probe(struct platform_device *pdev)
-{
-	int ret;
-
-	/*
-	 * On ACPI supported BIOS, there is an ACPI HSMP device added for
-	 * each socket, so the per socket probing, but the memory allocated for
-	 * sockets should be contiguous to access it as an array,
-	 * Hence allocate memory for all the sockets at once instead of allocating
-	 * on each probe.
-	 */
-	if (!hsmp_pdev.is_probed) {
-		hsmp_pdev.sock = devm_kcalloc(&pdev->dev, hsmp_pdev.num_sockets,
-					      sizeof(*hsmp_pdev.sock),
-					      GFP_KERNEL);
-		if (!hsmp_pdev.sock)
-			return -ENOMEM;
-	}
-	if (check_acpi_support(&pdev->dev)) {
-		ret = init_acpi(&pdev->dev);
-		if (ret) {
-			dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
-			return ret;
-		}
-		ret = hsmp_create_acpi_sysfs_if(&pdev->dev);
-		if (ret)
-			dev_err(&pdev->dev, "Failed to create HSMP sysfs interface\n");
-	} else {
-		ret = init_platform_device(&pdev->dev);
-		if (ret) {
-			dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
-			return ret;
-		}
-		ret = hsmp_create_non_acpi_sysfs_if(&pdev->dev);
-		if (ret)
-			dev_err(&pdev->dev, "Failed to create HSMP sysfs interface\n");
-	}
-
-	if (!hsmp_pdev.is_probed) {
-		hsmp_pdev.mdev.name	= HSMP_CDEV_NAME;
-		hsmp_pdev.mdev.minor	= MISC_DYNAMIC_MINOR;
-		hsmp_pdev.mdev.fops	= &hsmp_fops;
-		hsmp_pdev.mdev.parent	= &pdev->dev;
-		hsmp_pdev.mdev.nodename	= HSMP_DEVNODE_NAME;
-		hsmp_pdev.mdev.mode	= 0644;
-
-		ret = misc_register(&hsmp_pdev.mdev);
-		if (ret)
-			return ret;
-
-		hsmp_pdev.is_probed = true;
-	}
-
-	return 0;
-
-}
-
-static void hsmp_pltdrv_remove(struct platform_device *pdev)
-{
-	/*
-	 * We register only one misc_device even on multi socket system.
-	 * So, deregister should happen only once.
-	 */
-	if (hsmp_pdev.is_probed) {
-		misc_deregister(&hsmp_pdev.mdev);
-		hsmp_pdev.is_probed = false;
-	}
-}
-
-static struct platform_driver amd_hsmp_driver = {
-	.probe		= hsmp_pltdrv_probe,
-	.remove_new	= hsmp_pltdrv_remove,
-	.driver		= {
-		.name	= DRIVER_NAME,
-		.acpi_match_table = amd_hsmp_acpi_ids,
-	},
-};
-
-static struct platform_device *amd_hsmp_platdev;
-
-static int hsmp_plat_dev_register(void)
-{
-	int ret;
-
-	amd_hsmp_platdev = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE);
-	if (!amd_hsmp_platdev)
-		return -ENOMEM;
-
-	ret = platform_device_add(amd_hsmp_platdev);
-	if (ret)
-		platform_device_put(amd_hsmp_platdev);
-
-	return ret;
-}
-
-/*
- * This check is only needed for backward compatibility of previous platforms.
- * All new platforms are expected to support ACPI based probing.
- */
-static bool legacy_hsmp_support(void)
-{
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
-		return false;
-
-	switch (boot_cpu_data.x86) {
-	case 0x19:
-		switch (boot_cpu_data.x86_model) {
-		case 0x00 ... 0x1F:
-		case 0x30 ... 0x3F:
-		case 0x90 ... 0x9F:
-		case 0xA0 ... 0xAF:
-			return true;
-		default:
-			return false;
-		}
-	case 0x1A:
-		switch (boot_cpu_data.x86_model) {
-		case 0x00 ... 0x1F:
-			return true;
-		default:
-			return false;
-		}
-	default:
-		return false;
-	}
-
-	return false;
-}
-
-static int __init hsmp_plt_init(void)
-{
-	int ret = -ENODEV;
-
-	/*
-	 * amd_nb_num() returns number of SMN/DF interfaces present in the system
-	 * if we have N SMN/DF interfaces that ideally means N sockets
-	 */
-	hsmp_pdev.num_sockets = amd_nb_num();
-	if (hsmp_pdev.num_sockets == 0 || hsmp_pdev.num_sockets > MAX_AMD_SOCKETS)
-		return ret;
-
-	ret = platform_driver_register(&amd_hsmp_driver);
-	if (ret)
-		return ret;
-
-	if (!hsmp_pdev.is_acpi_device) {
-		if (legacy_hsmp_support()) {
-			/* Not ACPI device, but supports HSMP, register a plat_dev */
-			ret = hsmp_plat_dev_register();
-		} else {
-			/* Not ACPI, Does not support HSMP */
-			pr_info("HSMP is not supported on Family:%x model:%x\n",
-				boot_cpu_data.x86, boot_cpu_data.x86_model);
-			ret = -ENODEV;
-		}
-		if (ret)
-			platform_driver_unregister(&amd_hsmp_driver);
-	}
-
-	return ret;
-}
-
-static void __exit hsmp_plt_exit(void)
-{
-	platform_device_unregister(amd_hsmp_platdev);
-	platform_driver_unregister(&amd_hsmp_driver);
-}
-
-device_initcall(hsmp_plt_init);
-module_exit(hsmp_plt_exit);
-
-MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
-MODULE_VERSION(DRIVER_VERSION);
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/platform/x86/amd/hsmp/hsmp.h b/drivers/platform/x86/amd/hsmp/hsmp.h
index 9c5b9c263fc1..90d76070c93a 100644
--- a/drivers/platform/x86/amd/hsmp/hsmp.h
+++ b/drivers/platform/x86/amd/hsmp/hsmp.h
@@ -52,7 +52,6 @@ struct hsmp_plat_device {
 	struct hsmp_socket *sock;
 	u32 proto_ver;
 	u16 num_sockets;
-	bool is_acpi_device;
 	bool is_probed;
 };
 
@@ -61,14 +60,11 @@ extern struct hsmp_plat_device hsmp_pdev;
 ssize_t hsmp_metric_tbl_read(struct file *filp, struct kobject *kobj,
 			     struct bin_attribute *bin_attr, char *buf,
 			     loff_t off, size_t count);
-int hsmp_create_non_acpi_sysfs_if(struct device *dev);
-int hsmp_create_acpi_sysfs_if(struct device *dev);
 int hsmp_cache_proto_ver(u16 sock_ind);
 umode_t hsmp_is_sock_attr_visible(struct kobject *kobj,
 				  struct bin_attribute *battr, int id);
 int hsmp_create_attr_list(struct attribute_group *attr_grp,
 			  struct device *dev, u16 sock_ind);
 int hsmp_test(u16 sock_ind, u32 value);
-int init_platform_device(struct device *dev);
-int init_acpi(struct device *dev);
+long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg);
 #endif /* HSMP_H */
diff --git a/drivers/platform/x86/amd/hsmp/plat.c b/drivers/platform/x86/amd/hsmp/plat.c
index e18cf82478a0..bc1f2693c04e 100644
--- a/drivers/platform/x86/amd/hsmp/plat.c
+++ b/drivers/platform/x86/amd/hsmp/plat.c
@@ -12,11 +12,16 @@
 #include <asm/amd_nb.h>
 
 #include <linux/device.h>
+#include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/platform_device.h>
 #include <linux/sysfs.h>
 
 #include "hsmp.h"
 
+#define DRIVER_NAME		"amd_hsmp"
+#define DRIVER_VERSION		"2.3"
+
 /*
  * To access specific HSMP mailbox register, s/w writes the SMN address of HSMP mailbox
  * register into the SMN_INDEX register, and reads/writes the SMN_DATA reg.
@@ -50,7 +55,13 @@ static int amd_hsmp_pci_rdwr(struct hsmp_socket *sock, u32 offset,
 	return ret;
 }
 
-int hsmp_create_non_acpi_sysfs_if(struct device *dev)
+static const struct file_operations hsmp_fops = {
+	.owner		= THIS_MODULE,
+	.unlocked_ioctl	= hsmp_ioctl,
+	.compat_ioctl	= hsmp_ioctl,
+};
+
+static int hsmp_create_non_acpi_sysfs_if(struct device *dev)
 {
 	const struct attribute_group **hsmp_attr_grps;
 	struct attribute_group *attr_grp;
@@ -88,7 +99,7 @@ static inline bool is_f1a_m0h(void)
 	return false;
 }
 
-int init_platform_device(struct device *dev)
+static int init_platform_device(struct device *dev)
 {
 	struct hsmp_socket *sock;
 	int ret, i;
@@ -134,3 +145,139 @@ int init_platform_device(struct device *dev)
 
 	return 0;
 }
+
+static int hsmp_pltdrv_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	hsmp_pdev.sock = devm_kcalloc(&pdev->dev, hsmp_pdev.num_sockets,
+				      sizeof(*hsmp_pdev.sock),
+				      GFP_KERNEL);
+	if (!hsmp_pdev.sock)
+		return -ENOMEM;
+
+	ret = init_platform_device(&pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to init HSMP mailbox\n");
+		return ret;
+	}
+
+	ret = hsmp_create_non_acpi_sysfs_if(&pdev->dev);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to create HSMP sysfs interface\n");
+
+	hsmp_pdev.mdev.name	= HSMP_CDEV_NAME;
+	hsmp_pdev.mdev.minor	= MISC_DYNAMIC_MINOR;
+	hsmp_pdev.mdev.fops	= &hsmp_fops;
+	hsmp_pdev.mdev.parent	= &pdev->dev;
+	hsmp_pdev.mdev.nodename	= HSMP_DEVNODE_NAME;
+	hsmp_pdev.mdev.mode	= 0644;
+
+	return misc_register(&hsmp_pdev.mdev);
+}
+
+static void hsmp_pltdrv_remove(struct platform_device *pdev)
+{
+	misc_deregister(&hsmp_pdev.mdev);
+}
+
+static struct platform_driver amd_hsmp_driver = {
+	.probe		= hsmp_pltdrv_probe,
+	.remove_new	= hsmp_pltdrv_remove,
+	.driver		= {
+		.name	= DRIVER_NAME,
+	},
+};
+
+static struct platform_device *amd_hsmp_platdev;
+
+static int hsmp_plat_dev_register(void)
+{
+	int ret;
+
+	amd_hsmp_platdev = platform_device_alloc(DRIVER_NAME, PLATFORM_DEVID_NONE);
+	if (!amd_hsmp_platdev)
+		return -ENOMEM;
+
+	ret = platform_device_add(amd_hsmp_platdev);
+	if (ret)
+		platform_device_put(amd_hsmp_platdev);
+
+	return ret;
+}
+
+/*
+ * This check is only needed for backward compatibility of previous platforms.
+ * All new platforms are expected to support ACPI based probing.
+ */
+static bool legacy_hsmp_support(void)
+{
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+		return false;
+
+	switch (boot_cpu_data.x86) {
+	case 0x19:
+		switch (boot_cpu_data.x86_model) {
+		case 0x00 ... 0x1F:
+		case 0x30 ... 0x3F:
+		case 0x90 ... 0x9F:
+		case 0xA0 ... 0xAF:
+			return true;
+		default:
+			return false;
+		}
+	case 0x1A:
+		switch (boot_cpu_data.x86_model) {
+		case 0x00 ... 0x1F:
+			return true;
+		default:
+			return false;
+		}
+	default:
+		return false;
+	}
+
+	return false;
+}
+
+static int __init hsmp_plt_init(void)
+{
+	int ret = -ENODEV;
+
+	if (!legacy_hsmp_support()) {
+		pr_info("HSMP is not supported on Family:%x model:%x\n",
+			boot_cpu_data.x86, boot_cpu_data.x86_model);
+		return ret;
+	}
+
+	/*
+	 * amd_nb_num() returns number of SMN/DF interfaces present in the system
+	 * if we have N SMN/DF interfaces that ideally means N sockets
+	 */
+	hsmp_pdev.num_sockets = amd_nb_num();
+	if (hsmp_pdev.num_sockets == 0 || hsmp_pdev.num_sockets > MAX_AMD_SOCKETS)
+		return ret;
+
+	ret = platform_driver_register(&amd_hsmp_driver);
+	if (ret)
+		return ret;
+
+	ret = hsmp_plat_dev_register();
+	if (ret)
+		platform_driver_unregister(&amd_hsmp_driver);
+
+	return ret;
+}
+
+static void __exit hsmp_plt_exit(void)
+{
+	platform_device_unregister(amd_hsmp_platdev);
+	platform_driver_unregister(&amd_hsmp_driver);
+}
+
+device_initcall(hsmp_plt_init);
+module_exit(hsmp_plt_exit);
+
+MODULE_DESCRIPTION("AMD HSMP Platform Interface Driver");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL v2");
