diff --git a/MAINTAINERS b/MAINTAINERS
index da0429b1426b4d70265b8e4a7ac46c9c240c5177..0e54a5841b98fed64ec5dec125dde66720d7deb0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -929,6 +929,12 @@ L: linux-i2c@vger.kernel.org
S: Maintained
F: drivers/i2c/busses/i2c-amd-mp2*
+AMD PMC DRIVER
+M: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+L: platform-driver-x86@vger.kernel.org
+S: Maintained
+F: drivers/platform/x86/amd-pmc.*
+
AMD POWERPLAY
M: Evan Quan <evan.quan@amd.com>
L: amd-gfx@lists.freedesktop.org
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 8045303223166e40cd5d4113b936ac35db75e6fa..a8ea8ab093b996e58d6abd6eebb3b40a69a1c055 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -180,6 +180,20 @@ config ACER_WMI
If you have an ACPI-WMI compatible Acer/ Wistron laptop, say Y or M
here.
+config AMD_PMC
+ tristate "AMD SoC PMC driver"
+ depends on ACPI && PCI
+ help
+ The driver provides support for AMD Power Management Controller
+ primarily responsible for S2Idle transactions that are driven from
+ a platform firmware running on SMU. This driver also provides a debug
+ mechanism to investigate the S2Idle transactions and failures.
+
+ Say Y or M here if you have a notebook powered by AMD RYZEN CPU/APU.
+
+ If you choose to compile this driver as a module the module will be
+ called amd-pmc.
+
config APPLE_GMUX
tristate "Apple Gmux Driver"
depends on ACPI && PCI
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 3415c675535b4c29f02ce790122694fdd809c8f3..8a47c7627c0a1546fae213a0aa910178a7bbb0b0 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -22,6 +22,9 @@ obj-$(CONFIG_ACERHDF) += acerhdf.o
obj-$(CONFIG_ACER_WIRELESS) += acer-wireless.o
obj-$(CONFIG_ACER_WMI) += acer-wmi.o
+# AMD
+obj-$(CONFIG_AMD_PMC) += amd-pmc.o
+
# Apple
obj-$(CONFIG_APPLE_GMUX) += apple-gmux.o
diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c
new file mode 100644
index 0000000000000000000000000000000000000000..0102bf1c7916028b0b785c19e1f42e1fa211872f
--- /dev/null
+++ b/drivers/platform/x86/amd-pmc.c
@@ -0,0 +1,286 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * AMD SoC Power Management Controller Driver
+ *
+ * Copyright (c) 2020, Advanced Micro Devices, Inc.
+ * All Rights Reserved.
+ *
+ * Author: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/platform_device.h>
+#include <linux/suspend.h>
+#include <linux/seq_file.h>
+#include <linux/uaccess.h>
+
+/* SMU communication registers */
+#define AMD_PMC_REGISTER_MESSAGE 0x538
+#define AMD_PMC_REGISTER_RESPONSE 0x980
+#define AMD_PMC_REGISTER_ARGUMENT 0x9BC
+
+/* Base address of SMU for mapping physical address to virtual address */
+#define AMD_PMC_SMU_INDEX_ADDRESS 0xB8
+#define AMD_PMC_SMU_INDEX_DATA 0xBC
+#define AMD_PMC_MAPPING_SIZE 0x01000
+#define AMD_PMC_BASE_ADDR_OFFSET 0x10000
+#define AMD_PMC_BASE_ADDR_LO 0x13B102E8
+#define AMD_PMC_BASE_ADDR_HI 0x13B102EC
+#define AMD_PMC_BASE_ADDR_LO_MASK GENMASK(15, 0)
+#define AMD_PMC_BASE_ADDR_HI_MASK GENMASK(31, 20)
+
+/* SMU Response Codes */
+#define AMD_PMC_RESULT_OK 0x01
+#define AMD_PMC_RESULT_CMD_REJECT_BUSY 0xFC
+#define AMD_PMC_RESULT_CMD_REJECT_PREREQ 0xFD
+#define AMD_PMC_RESULT_CMD_UNKNOWN 0xFE
+#define AMD_PMC_RESULT_FAILED 0xFF
+
+/* List of supported CPU ids */
+#define AMD_CPU_ID_RV 0x15D0
+#define AMD_CPU_ID_RN 0x1630
+#define AMD_CPU_ID_PCO AMD_CPU_ID_RV
+#define AMD_CPU_ID_CZN AMD_CPU_ID_RN
+
+#define AMD_SMU_FW_VERSION 0x0
+#define PMC_MSG_DELAY_MIN_US 100
+#define RESPONSE_REGISTER_LOOP_MAX 200
+
+enum amd_pmc_def {
+ MSG_TEST = 0x01,
+ MSG_OS_HINT_PCO,
+ MSG_OS_HINT_RN,
+};
+
+struct amd_pmc_dev {
+ void __iomem *regbase;
+ void __iomem *smu_base;
+ u32 base_addr;
+ u32 cpu_id;
+ struct device *dev;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+ struct dentry *dbgfs_dir;
+#endif /* CONFIG_DEBUG_FS */
+};
+
+static struct amd_pmc_dev pmc;
+
+static inline u32 amd_pmc_reg_read(struct amd_pmc_dev *dev, int reg_offset)
+{
+ return ioread32(dev->regbase + reg_offset);
+}
+
+static inline void amd_pmc_reg_write(struct amd_pmc_dev *dev, int reg_offset, u32 val)
+{
+ iowrite32(val, dev->regbase + reg_offset);
+}
+
+#if CONFIG_DEBUG_FS
+static int smu_fw_info_show(struct seq_file *s, void *unused)
+{
+ struct amd_pmc_dev *dev = s->private;
+ u32 value;
+
+ value = ioread32(dev->smu_base + AMD_SMU_FW_VERSION);
+ seq_printf(s, "SMU FW Info: %x\n", value);
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(smu_fw_info);
+
+static void amd_pmc_dbgfs_unregister(struct amd_pmc_dev *dev)
+{
+ debugfs_remove_recursive(dev->dbgfs_dir);
+}
+
+static void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
+{
+ dev->dbgfs_dir = debugfs_create_dir("amd_pmc", NULL);
+ debugfs_create_file("smu_fw_info", 0644, dev->dbgfs_dir, dev,
+ &smu_fw_info_fops);
+}
+#else
+static inline void amd_pmc_dbgfs_register(struct amd_pmc_dev *dev)
+{
+}
+
+static inline void amd_pmc_dbgfs_unregister(struct amd_pmc_dev *dev)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
+static void amd_pmc_dump_registers(struct amd_pmc_dev *dev)
+{
+ u32 value;
+
+ value = amd_pmc_reg_read(dev, AMD_PMC_REGISTER_RESPONSE);
+ dev_dbg(dev->dev, "AMD_PMC_REGISTER_RESPONSE:%x\n", value);
+
+ value = amd_pmc_reg_read(dev, AMD_PMC_REGISTER_ARGUMENT);
+ dev_dbg(dev->dev, "AMD_PMC_REGISTER_ARGUMENT:%x\n", value);
+
+ value = amd_pmc_reg_read(dev, AMD_PMC_REGISTER_MESSAGE);
+ dev_dbg(dev->dev, "AMD_PMC_REGISTER_MESSAGE:%x\n", value);
+}
+
+static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set)
+{
+ int rc;
+ u8 msg;
+ u32 val;
+
+ /* Wait until we get a valid response */
+ rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMC_REGISTER_RESPONSE,
+ val, val > 0, PMC_MSG_DELAY_MIN_US,
+ PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX);
+ if (rc) {
+ dev_err(dev->dev, "failed to talk to SMU\n");
+ return rc;
+ }
+
+ /* Write zero to response register */
+ amd_pmc_reg_write(dev, AMD_PMC_REGISTER_RESPONSE, 0);
+
+ /* Write argument into response register */
+ amd_pmc_reg_write(dev, AMD_PMC_REGISTER_ARGUMENT, set);
+
+ /* Write message ID to message ID register */
+ msg = (dev->cpu_id == AMD_CPU_ID_RN) ? MSG_OS_HINT_RN : MSG_OS_HINT_PCO;
+ amd_pmc_reg_write(dev, AMD_PMC_REGISTER_MESSAGE, msg);
+ return 0;
+}
+
+static int __maybe_unused amd_pmc_suspend(struct device *dev)
+{
+ struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+ int rc;
+
+ rc = amd_pmc_send_cmd(pdev, 1);
+ if (rc)
+ dev_err(pdev->dev, "suspend failed\n");
+
+ amd_pmc_dump_registers(pdev);
+ return 0;
+}
+
+static int __maybe_unused amd_pmc_resume(struct device *dev)
+{
+ struct amd_pmc_dev *pdev = dev_get_drvdata(dev);
+ int rc;
+
+ rc = amd_pmc_send_cmd(pdev, 0);
+ if (rc)
+ dev_err(pdev->dev, "resume failed\n");
+
+ amd_pmc_dump_registers(pdev);
+ return 0;
+}
+
+static const struct dev_pm_ops amd_pmc_pm_ops = {
+ SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(amd_pmc_suspend, amd_pmc_resume)
+};
+
+static const struct pci_device_id pmc_pci_ids[] = {
+ { PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_CZN) },
+ { PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_RN) },
+ { PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_PCO) },
+ { PCI_DEVICE(PCI_VENDOR_ID_AMD, AMD_CPU_ID_RV) },
+ { }
+};
+
+static int amd_pmc_probe(struct platform_device *pdev)
+{
+ struct amd_pmc_dev *dev = &pmc;
+ struct pci_dev *rdev;
+ u32 base_addr_lo;
+ u32 base_addr_hi;
+ u64 base_addr;
+ int err;
+ u32 val;
+
+ dev->dev = &pdev->dev;
+
+ rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
+ if (!rdev || !pci_match_id(pmc_pci_ids, rdev))
+ return -ENODEV;
+
+ dev->cpu_id = rdev->device;
+ err = pci_write_config_dword(rdev, AMD_PMC_SMU_INDEX_ADDRESS, AMD_PMC_BASE_ADDR_LO);
+ if (err) {
+ dev_err(dev->dev, "error writing to 0x%x\n", AMD_PMC_SMU_INDEX_ADDRESS);
+ return pcibios_err_to_errno(err);
+ }
+
+ err = pci_read_config_dword(rdev, AMD_PMC_SMU_INDEX_DATA, &val);
+ if (err)
+ return pcibios_err_to_errno(err);
+
+ base_addr_lo = val & AMD_PMC_BASE_ADDR_HI_MASK;
+
+ err = pci_write_config_dword(rdev, AMD_PMC_SMU_INDEX_ADDRESS, AMD_PMC_BASE_ADDR_HI);
+ if (err) {
+ dev_err(dev->dev, "error writing to 0x%x\n", AMD_PMC_SMU_INDEX_ADDRESS);
+ return pcibios_err_to_errno(err);
+ }
+
+ err = pci_read_config_dword(rdev, AMD_PMC_SMU_INDEX_DATA, &val);
+ if (err)
+ return pcibios_err_to_errno(err);
+
+ base_addr_hi = val & AMD_PMC_BASE_ADDR_LO_MASK;
+ pci_dev_put(rdev);
+ base_addr = ((u64)base_addr_hi << 32 | base_addr_lo);
+
+ dev->smu_base = devm_ioremap(dev->dev, base_addr, AMD_PMC_MAPPING_SIZE);
+ if (!dev->smu_base)
+ return -ENOMEM;
+
+ dev->regbase = devm_ioremap(dev->dev, base_addr + AMD_PMC_BASE_ADDR_OFFSET,
+ AMD_PMC_MAPPING_SIZE);
+ if (!dev->regbase)
+ return -ENOMEM;
+
+ amd_pmc_dump_registers(dev);
+
+ platform_set_drvdata(pdev, dev);
+ amd_pmc_dbgfs_register(dev);
+ return 0;
+}
+
+static int amd_pmc_remove(struct platform_device *pdev)
+{
+ struct amd_pmc_dev *dev = platform_get_drvdata(pdev);
+
+ amd_pmc_dbgfs_unregister(dev);
+ return 0;
+}
+
+static const struct acpi_device_id amd_pmc_acpi_ids[] = {
+ {"AMDI0005", 0},
+ {"AMD0004", 0},
+ { }
+};
+MODULE_DEVICE_TABLE(acpi, amd_pmc_acpi_ids);
+
+static struct platform_driver amd_pmc_driver = {
+ .driver = {
+ .name = "amd_pmc",
+ .acpi_match_table = amd_pmc_acpi_ids,
+ .pm = &amd_pmc_pm_ops,
+ },
+ .probe = amd_pmc_probe,
+ .remove = amd_pmc_remove,
+};
+module_platform_driver(amd_pmc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("AMD PMC Driver");