// SPDX-License-Identifier: GPL-2.0-or-later
/*
* sp5100_tco : TCO timer driver for sp5100 chipsets
*
* (c) Copyright 2009 Google Inc., All Rights Reserved.
*
* Based on i8xx_tco.c:
* (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights
* Reserved.
* http://www.kernelconcepts.de
*
* See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide",
* AMD Publication 45482 "AMD SB800-Series Southbridges Register
* Reference Guide"
* AMD Publication 48751 "BIOS and Kernel Developer’s Guide (BKDG)
* for AMD Family 16h Models 00h-0Fh Processors"
* AMD Publication 51192 "AMD Bolton FCH Register Reference Guide"
* AMD Publication 52740 "BIOS and Kernel Developer’s Guide (BKDG)
* for AMD Family 16h Models 30h-3Fh Processors"
*/
/*
* Includes, defines, variables, module parameters, ...
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/init.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/watchdog.h>
#include "sp5100_tco.h"
#define TCO_DRIVER_NAME "sp5100-tco"
/* internal variables */
enum tco_reg_layout {
sp5100, sb800, efch
};
struct sp5100_tco {
struct watchdog_device wdd;
void __iomem *tcobase;
enum tco_reg_layout tco_reg_layout;
};
/* the watchdog platform device */
static struct platform_device *sp5100_tco_platform_device;
/* the associated PCI device */
static struct pci_dev *sp5100_tco_pci;
/* module parameters */
#define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */
static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default="
__MODULE_STRING(WATCHDOG_HEARTBEAT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started."
" (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
/*
* Some TCO specific functions
*/
static enum tco_reg_layout tco_reg_layout(struct pci_dev *dev)
{
if (dev->vendor == PCI_VENDOR_ID_ATI &&
dev->device == PCI_DEVICE_ID_ATI_SBX00_SMBUS &&
dev->revision < 0x40) {
return sp5100;
} else if (dev->vendor == PCI_VENDOR_ID_AMD &&
((dev->device == PCI_DEVICE_ID_AMD_HUDSON2_SMBUS &&
dev->revision >= 0x41) ||
(dev->device == PCI_DEVICE_ID_AMD_KERNCZ_SMBUS &&
dev->revision >= 0x49))) {
return efch;
}
return sb800;
}
static int tco_timer_start(struct watchdog_device *wdd)
{
struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
u32 val;
val = readl(SP5100_WDT_CONTROL(tco->tcobase));
val |= SP5100_WDT_START_STOP_BIT;
writel(val, SP5100_WDT_CONTROL(tco->tcobase));
return 0;
}
static int tco_timer_stop(struct watchdog_device *wdd)
{
struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
u32 val;
val = readl(SP5100_WDT_CONTROL(tco->tcobase));
val &= ~SP5100_WDT_START_STOP_BIT;
writel(val, SP5100_WDT_CONTROL(tco->tcobase));
return 0;
}
static int tco_timer_ping(struct watchdog_device *wdd)
{
struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
u32 val;
val = readl(SP5100_WDT_CONTROL(tco->tcobase));
val |= SP5100_WDT_TRIGGER_BIT;
writel(val, SP5100_WDT_CONTROL(tco->tcobase));
return 0;
}
static int tco_timer_set_timeout(struct watchdog_device *wdd,
unsigned int t)
{
struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
/* Write new heartbeat to watchdog */
writel(t, SP5100_WDT_COUNT(tco->tcobase));
wdd->timeout = t;
return 0;
}
static u8 sp5100_tco_read_pm_reg8(u8 index)
{
outb(index, SP5100_IO_PM_INDEX_REG);
return inb(SP5100_IO_PM_DATA_REG);
}
static void sp5100_tco_update_pm_reg8(u8 index, u8 reset, u8 set)
{
u8 val;
outb(index, SP5100_IO_PM_INDEX_REG);
val = inb(SP5100_IO_PM_DATA_REG);
val &= reset;
val |= set;
outb(val, SP5100_IO_PM_DATA_REG);
}
static void tco_timer_enable(struct sp5100_tco *tco)
{
u32 val;
switch (tco->tco_reg_layout) {
case sb800:
/* For SB800 or later */
/* Set the Watchdog timer resolution to 1 sec */
sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONFIG,
0xff, SB800_PM_WATCHDOG_SECOND_RES);
/* Enable watchdog decode bit and watchdog timer */
sp5100_tco_update_pm_reg8(SB800_PM_WATCHDOG_CONTROL,
~SB800_PM_WATCHDOG_DISABLE,
SB800_PCI_WATCHDOG_DECODE_EN);
break;
case sp5100:
/* For SP5100 or SB7x0 */
/* Enable watchdog decode bit */
pci_read_config_dword(sp5100_tco_pci,
SP5100_PCI_WATCHDOG_MISC_REG,
&val);
val |= SP5100_PCI_WATCHDOG_DECODE_EN;
pci_write_config_dword(sp5100_tco_pci,
SP5100_PCI_WATCHDOG_MISC_REG,
val);
/* Enable Watchdog timer and set the resolution to 1 sec */
sp5100_tco_update_pm_reg8(SP5100_PM_WATCHDOG_CONTROL,
~SP5100_PM_WATCHDOG_DISABLE,
SP5100_PM_WATCHDOG_SECOND_RES);
break;
case efch:
/* Set the Watchdog timer resolution to 1 sec and enable */
sp5100_tco_update_pm_reg8(EFCH_PM_DECODEEN3,
~EFCH_PM_WATCHDOG_DISABLE,
EFCH_PM_DECODEEN_SECOND_RES);
break;
}
}
static u32 sp5100_tco_read_pm_reg32(u8 index)
{
u32 val = 0;
int i;
for (i = 3; i >= 0; i--)
val = (val << 8) + sp5100_tco_read_pm_reg8(index + i);
return val;
}
static int sp5100_tco_setupdevice(struct device *dev,
struct watchdog_device *wdd)
{
struct sp5100_tco *tco = watchdog_get_drvdata(wdd);
const char *dev_name;
u32 mmio_addr = 0, val;
int ret;
/* Request the IO ports used by this driver */
if (!request_muxed_region(SP5100_IO_PM_INDEX_REG,
SP5100_PM_IOPORTS_SIZE, "sp5100_tco")) {
dev_err(dev, "I/O address 0x%04x already in use\n",
SP5100_IO_PM_INDEX_REG);
return -EBUSY;
}
/*
* Determine type of southbridge chipset.
*/
switch (tco->tco_reg_layout) {
case sp5100:
dev_name = SP5100_DEVNAME;
mmio_addr = sp5100_tco_read_pm_reg32(SP5100_PM_WATCHDOG_BASE) &
0xfffffff8;
break;
case sb800:
dev_name = SB800_DEVNAME;
mmio_addr = sp5100_tco_read_pm_reg32(SB800_PM_WATCHDOG_BASE) &
0xfffffff8;
break;
case efch:
dev_name = SB800_DEVNAME;
val = sp5100_tco_read_pm_reg8(EFCH_PM_DECODEEN);
if (val & EFCH_PM_DECODEEN_WDT_TMREN)
mmio_addr = EFCH_PM_WDT_ADDR;
break;
default:
return -ENODEV;
}
/* Check MMIO address conflict */
if (!mmio_addr ||
!devm_request_mem_region(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE,
dev_name)) {
if (mmio_addr)
dev_dbg(dev, "MMIO address 0x%08x already in use\n",
mmio_addr);
switch (tco->tco_reg_layout) {
case sp5100:
/*
* Secondly, Find the watchdog timer MMIO address
* from SBResource_MMIO register.
*/
/* Read SBResource_MMIO from PCI config(PCI_Reg: 9Ch) */
pci_read_config_dword(sp5100_tco_pci,
SP5100_SB_RESOURCE_MMIO_BASE,
&mmio_addr);
if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
SB800_ACPI_MMIO_SEL)) !=
SB800_ACPI_MMIO_DECODE_EN) {
ret = -ENODEV;
goto unreg_region;
}
mmio_addr &= ~0xFFF;
mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
break;
case sb800:
/* Read SBResource_MMIO from AcpiMmioEn(PM_Reg: 24h) */
mmio_addr =
sp5100_tco_read_pm_reg32(SB800_PM_ACPI_MMIO_EN);
if ((mmio_addr & (SB800_ACPI_MMIO_DECODE_EN |
SB800_ACPI_MMIO_SEL)) !=
SB800_ACPI_MMIO_DECODE_EN) {
ret = -ENODEV;
goto unreg_region;
}
mmio_addr &= ~0xFFF;
mmio_addr += SB800_PM_WDT_MMIO_OFFSET;
break;
case efch:
val = sp5100_tco_read_pm_reg8(EFCH_PM_ISACONTROL);
if (!(val & EFCH_PM_ISACONTROL_MMIOEN)) {
ret = -ENODEV;
goto unreg_region;
}
mmio_addr = EFCH_PM_ACPI_MMIO_ADDR +
EFCH_PM_ACPI_MMIO_WDT_OFFSET;
break;
}
dev_dbg(dev, "Got 0x%08x from SBResource_MMIO register\n",
mmio_addr);
if (!devm_request_mem_region(dev, mmio_addr,
SP5100_WDT_MEM_MAP_SIZE,
dev_name)) {
dev_dbg(dev, "MMIO address 0x%08x already in use\n",
mmio_addr);
ret = -EBUSY;
goto unreg_region;
}
}
tco->tcobase = devm_ioremap(dev, mmio_addr, SP5100_WDT_MEM_MAP_SIZE);
if (!tco->tcobase) {
dev_err(dev, "failed to get tcobase address\n");
ret = -ENOMEM;
goto unreg_region;
}
dev_info(dev, "Using 0x%08x for watchdog MMIO address\n", mmio_addr);
/* Setup the watchdog timer */
tco_timer_enable(tco);
val = readl(SP5100_WDT_CONTROL(tco->tcobase));
if (val & SP5100_WDT_DISABLED) {
dev_err(dev, "Watchdog hardware is disabled\n");
ret = -ENODEV;
goto unreg_region;
}
/*
* Save WatchDogFired status, because WatchDogFired flag is
* cleared here.
*/
if (val & SP5100_WDT_FIRED)
wdd->bootstatus = WDIOF_CARDRESET;
/* Set watchdog action to reset the system */
val &= ~SP5100_WDT_ACTION_RESET;
writel(val, SP5100_WDT_CONTROL(tco->tcobase));
/* Set a reasonable heartbeat before we stop the timer */
tco_timer_set_timeout(wdd, wdd->timeout);
/*
* Stop the TCO before we change anything so we don't race with
* a zeroed timer.
*/
tco_timer_stop(wdd);
release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
return 0;
unreg_region:
release_region(SP5100_IO_PM_INDEX_REG, SP5100_PM_IOPORTS_SIZE);
return ret;
}
static struct watchdog_info sp5100_tco_wdt_info = {
.identity = "SP5100 TCO timer",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops sp5100_tco_wdt_ops = {
.owner = THIS_MODULE,
.start = tco_timer_start,
.stop = tco_timer_stop,
.ping = tco_timer_ping,
.set_timeout = tco_timer_set_timeout,
};
static int sp5100_tco_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
struct sp5100_tco *tco;
int ret;
tco = devm_kzalloc(dev, sizeof(*tco), GFP_KERNEL);
if (!tco)
return -ENOMEM;
tco->tco_reg_layout = tco_reg_layout(sp5100_tco_pci);
wdd = &tco->wdd;
wdd->parent = dev;
wdd->info = &sp5100_tco_wdt_info;
wdd->ops = &sp5100_tco_wdt_ops;
wdd->timeout = WATCHDOG_HEARTBEAT;
wdd->min_timeout = 1;
wdd->max_timeout = 0xffff;
watchdog_init_timeout(wdd, heartbeat, NULL);
watchdog_set_nowayout(wdd, nowayout);
watchdog_stop_on_reboot(wdd);
watchdog_stop_on_unregister(wdd);
watchdog_set_drvdata(wdd, tco);
ret = sp5100_tco_setupdevice(dev, wdd);
if (ret)
return ret;
ret = devm_watchdog_register_device(dev, wdd);
if (ret) {
dev_err(dev, "cannot register watchdog device (err=%d)\n", ret);
return ret;
}
/* Show module parameters */
dev_info(dev, "initialized. heartbeat=%d sec (nowayout=%d)\n",
wdd->timeout, nowayout);
return 0;
}
static struct platform_driver sp5100_tco_driver = {
.probe = sp5100_tco_probe,
.driver = {
.name = TCO_DRIVER_NAME,
},
};
/*
* Data for PCI driver interface
*
* This data only exists for exporting the supported
* PCI ids via MODULE_DEVICE_TABLE. We do not actually
* register a pci_driver, because someone else might
* want to register another driver on the same PCI id.
*/
static const struct pci_device_id sp5100_tco_pci_tbl[] = {
{ PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID,
PCI_ANY_ID, },
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, PCI_ANY_ID,
PCI_ANY_ID, },
{ PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_KERNCZ_SMBUS, PCI_ANY_ID,
PCI_ANY_ID, },
{ 0, }, /* End of list */
};
MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl);
static int __init sp5100_tco_init(void)
{
struct pci_dev *dev = NULL;
int err;
/* Match the PCI device */
for_each_pci_dev(dev) {
if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) {
sp5100_tco_pci = dev;
break;
}
}
if (!sp5100_tco_pci)
return -ENODEV;
pr_info("SP5100/SB800 TCO WatchDog Timer Driver\n");
err = platform_driver_register(&sp5100_tco_driver);
if (err)
return err;
sp5100_tco_platform_device =
platform_device_register_simple(TCO_DRIVER_NAME, -1, NULL, 0);
if (IS_ERR(sp5100_tco_platform_device)) {
err = PTR_ERR(sp5100_tco_platform_device);
goto unreg_platform_driver;
}
return 0;
unreg_platform_driver:
platform_driver_unregister(&sp5100_tco_driver);
return err;
}
static void __exit sp5100_tco_exit(void)
{
platform_device_unregister(sp5100_tco_platform_device);
platform_driver_unregister(&sp5100_tco_driver);
}
module_init(sp5100_tco_init);
module_exit(sp5100_tco_exit);
MODULE_AUTHOR("Priyanka Gupta");
MODULE_DESCRIPTION("TCO timer driver for SP5100/SB800 chipset");
MODULE_LICENSE("GPL");
