// 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);
}
#ifdef 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)) {
pci_dev_put(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);
pci_dev_put(rdev);
return pcibios_err_to_errno(err);
}
err = pci_read_config_dword(rdev, AMD_PMC_SMU_INDEX_DATA, &val);
if (err) {
pci_dev_put(rdev);
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);
pci_dev_put(rdev);
return pcibios_err_to_errno(err);
}
err = pci_read_config_dword(rdev, AMD_PMC_SMU_INDEX_DATA, &val);
if (err) {
pci_dev_put(rdev);
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");