// SPDX-License-Identifier: GPL-2.0+
/*
* Industrial Computer Source PCI-WDT500/501 driver
*
* (c) Copyright 1996-1997 Alan Cox <[email protected]>,
* All Rights Reserved.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <[email protected]>
*
* Release 0.10.
*
* Fixes
* Dave Gregorich : Modularisation and minor bugs
* Alan Cox : Added the watchdog ioctl() stuff
* Alan Cox : Fixed the reboot problem (as noted by
* Matt Crocker).
* Alan Cox : Added wdt= boot option
* Alan Cox : Cleaned up copy/user stuff
* Tim Hockin : Added insmod parameters, comment cleanup
* Parameterized timeout
* JP Nollmann : Added support for PCI wdt501p
* Alan Cox : Split ISA and PCI cards into two drivers
* Jeff Garzik : PCI cleanups
* Tigran Aivazian : Restructured wdtpci_init_one() to handle
* failures
* Joel Becker : Added WDIOC_GET/SETTIMEOUT
* Zwane Mwaikambo : Magic char closing, locking changes,
* cleanups
* Matt Domsch : nowayout module option
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/uaccess.h>
#define WDT_IS_PCI
#include "wd501p.h"
/* We can only use 1 card due to the /dev/watchdog restriction */
static int dev_count;
static unsigned long open_lock;
static DEFINE_SPINLOCK(wdtpci_lock);
static char expect_close;
static resource_size_t io;
static int irq;
/* Default timeout */
#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
static int heartbeat = WD_TIMO;
static int wd_heartbeat;
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat,
"Watchdog heartbeat in seconds. (0<heartbeat<65536, default="
__MODULE_STRING(WD_TIMO) ")");
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) ")");
/* Support for the Fan Tachometer on the PCI-WDT501 */
static int tachometer;
module_param(tachometer, int, 0);
MODULE_PARM_DESC(tachometer,
"PCI-WDT501 Fan Tachometer support (0=disable, default=0)");
static int type = 500;
module_param(type, int, 0);
MODULE_PARM_DESC(type,
"PCI-WDT501 Card type (500 or 501 , default=500)");
/*
* Programming support
*/
static void wdtpci_ctr_mode(int ctr, int mode)
{
ctr <<= 6;
ctr |= 0x30;
ctr |= (mode << 1);
outb(ctr, WDT_CR);
udelay(8);
}
static void wdtpci_ctr_load(int ctr, int val)
{
outb(val & 0xFF, WDT_COUNT0 + ctr);
udelay(8);
outb(val >> 8, WDT_COUNT0 + ctr);
udelay(8);
}
/**
* wdtpci_start:
*
* Start the watchdog driver.
*/
static int wdtpci_start(void)
{
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
/*
* "pet" the watchdog, as Access says.
* This resets the clock outputs.
*/
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_mode(2, 0); /* Program CTR2 for Mode 0:
Pulse on Terminal Count */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
inb(WDT_DC); /* Disable watchdog */
udelay(8);
outb(0, WDT_CLOCK); /* 2.0833MHz clock */
udelay(8);
inb(WDT_BUZZER); /* disable */
udelay(8);
inb(WDT_OPTONOTRST); /* disable */
udelay(8);
inb(WDT_OPTORST); /* disable */
udelay(8);
inb(WDT_PROGOUT); /* disable */
udelay(8);
wdtpci_ctr_mode(0, 3); /* Program CTR0 for Mode 3:
Square Wave Generator */
wdtpci_ctr_mode(1, 2); /* Program CTR1 for Mode 2:
Rate Generator */
wdtpci_ctr_mode(2, 1); /* Program CTR2 for Mode 1:
Retriggerable One-Shot */
wdtpci_ctr_load(0, 20833); /* count at 100Hz */
wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
/* DO NOT LOAD CTR2 on PCI card! -- JPN */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_stop:
*
* Stop the watchdog driver.
*/
static int wdtpci_stop(void)
{
unsigned long flags;
/* Turn the card off */
spin_lock_irqsave(&wdtpci_lock, flags);
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_load(2, 0); /* 0 length reset pulses now */
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_ping:
*
* Reload counter one with the watchdog heartbeat. We don't bother
* reloading the cascade counter.
*/
static int wdtpci_ping(void)
{
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
/* Write a watchdog value */
inb(WDT_DC); /* Disable watchdog */
udelay(8);
wdtpci_ctr_mode(1, 2); /* Re-Program CTR1 for Mode 2:
Rate Generator */
wdtpci_ctr_load(1, wd_heartbeat);/* Heartbeat */
outb(0, WDT_DC); /* Enable watchdog */
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
return 0;
}
/**
* wdtpci_set_heartbeat:
* @t: the new heartbeat value that needs to be set.
*
* Set a new heartbeat value for the watchdog device. If the heartbeat
* value is incorrect we keep the old value and return -EINVAL.
* If successful we return 0.
*/
static int wdtpci_set_heartbeat(int t)
{
/* Arbitrary, can't find the card's limits */
if (t < 1 || t > 65535)
return -EINVAL;
heartbeat = t;
wd_heartbeat = t * 100;
return 0;
}
/**
* wdtpci_get_status:
* @status: the new status.
*
* Extract the status information from a WDT watchdog device. There are
* several board variants so we have to know which bits are valid. Some
* bits default to one and some to zero in order to be maximally painful.
*
* we then map the bits onto the status ioctl flags.
*/
static int wdtpci_get_status(int *status)
{
unsigned char new_status;
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
new_status = inb(WDT_SR);
spin_unlock_irqrestore(&wdtpci_lock, flags);
*status = 0;
if (new_status & WDC_SR_ISOI0)
*status |= WDIOF_EXTERN1;
if (new_status & WDC_SR_ISII1)
*status |= WDIOF_EXTERN2;
if (type == 501) {
if (!(new_status & WDC_SR_TGOOD))
*status |= WDIOF_OVERHEAT;
if (!(new_status & WDC_SR_PSUOVER))
*status |= WDIOF_POWEROVER;
if (!(new_status & WDC_SR_PSUUNDR))
*status |= WDIOF_POWERUNDER;
if (tachometer) {
if (!(new_status & WDC_SR_FANGOOD))
*status |= WDIOF_FANFAULT;
}
}
return 0;
}
/**
* wdtpci_get_temperature:
*
* Reports the temperature in degrees Fahrenheit. The API is in
* farenheit. It was designed by an imperial measurement luddite.
*/
static int wdtpci_get_temperature(int *temperature)
{
unsigned short c;
unsigned long flags;
spin_lock_irqsave(&wdtpci_lock, flags);
c = inb(WDT_RT);
udelay(8);
spin_unlock_irqrestore(&wdtpci_lock, flags);
*temperature = (c * 11 / 15) + 7;
return 0;
}
/**
* wdtpci_interrupt:
* @irq: Interrupt number
* @dev_id: Unused as we don't allow multiple devices.
*
* Handle an interrupt from the board. These are raised when the status
* map changes in what the board considers an interesting way. That means
* a failure condition occurring.
*/
static irqreturn_t wdtpci_interrupt(int irq, void *dev_id)
{
/*
* Read the status register see what is up and
* then printk it.
*/
unsigned char status;
spin_lock(&wdtpci_lock);
status = inb(WDT_SR);
udelay(8);
pr_crit("status %d\n", status);
if (type == 501) {
if (!(status & WDC_SR_TGOOD)) {
pr_crit("Overheat alarm (%d)\n", inb(WDT_RT));
udelay(8);
}
if (!(status & WDC_SR_PSUOVER))
pr_crit("PSU over voltage\n");
if (!(status & WDC_SR_PSUUNDR))
pr_crit("PSU under voltage\n");
if (tachometer) {
if (!(status & WDC_SR_FANGOOD))
pr_crit("Possible fan fault\n");
}
}
if (!(status & WDC_SR_WCCR)) {
#ifdef SOFTWARE_REBOOT
#ifdef ONLY_TESTING
pr_crit("Would Reboot\n");
#else
pr_crit("Initiating system reboot\n");
emergency_restart();
#endif
#else
pr_crit("Reset in 5ms\n");
#endif
}
spin_unlock(&wdtpci_lock);
return IRQ_HANDLED;
}
/**
* wdtpci_write:
* @file: file handle to the watchdog
* @buf: buffer to write (unused as data does not matter here
* @count: count of bytes
* @ppos: pointer to the position to write. No seeks allowed
*
* A write to a watchdog device is defined as a keepalive signal. Any
* write of data will do, as we we don't define content meaning.
*/
static ssize_t wdtpci_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
if (count) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
expect_close = 0;
for (i = 0; i != count; i++) {
char c;
if (get_user(c, buf + i))
return -EFAULT;
if (c == 'V')
expect_close = 42;
}
}
wdtpci_ping();
}
return count;
}
/**
* wdtpci_ioctl:
* @file: file handle to the device
* @cmd: watchdog command
* @arg: argument pointer
*
* The watchdog API defines a common set of functions for all watchdogs
* according to their available features. We only actually usefully support
* querying capabilities and current status.
*/
static long wdtpci_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_heartbeat;
int status;
struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT|
WDIOF_MAGICCLOSE|
WDIOF_KEEPALIVEPING,
.firmware_version = 1,
.identity = "PCI-WDT500/501",
};
/* Add options according to the card we have */
ident.options |= (WDIOF_EXTERN1|WDIOF_EXTERN2);
if (type == 501) {
ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|
WDIOF_POWEROVER);
if (tachometer)
ident.options |= WDIOF_FANFAULT;
}
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
wdtpci_get_status(&status);
return put_user(status, p);
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
wdtpci_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_heartbeat, p))
return -EFAULT;
if (wdtpci_set_heartbeat(new_heartbeat))
return -EINVAL;
wdtpci_ping();
fallthrough;
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
default:
return -ENOTTY;
}
}
/**
* wdtpci_open:
* @inode: inode of device
* @file: file handle to device
*
* The watchdog device has been opened. The watchdog device is single
* open and on opening we load the counters. Counter zero is a 100Hz
* cascade, into counter 1 which downcounts to reboot. When the counter
* triggers counter 2 downcounts the length of the reset pulse which
* set set to be as long as possible.
*/
static int wdtpci_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(0, &open_lock))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
/*
* Activate
*/
wdtpci_start();
return stream_open(inode, file);
}
/**
* wdtpci_release:
* @inode: inode to board
* @file: file handle to board
*
* The watchdog has a configurable API. There is a religious dispute
* between people who want their watchdog to be able to shut down and
* those who want to be sure if the watchdog manager dies the machine
* reboots. In the former case we disable the counters, in the latter
* case you have to open it again very soon.
*/
static int wdtpci_release(struct inode *inode, struct file *file)
{
if (expect_close == 42) {
wdtpci_stop();
} else {
pr_crit("Unexpected close, not stopping timer!\n");
wdtpci_ping();
}
expect_close = 0;
clear_bit(0, &open_lock);
return 0;
}
/**
* wdtpci_temp_read:
* @file: file handle to the watchdog board
* @buf: buffer to write 1 byte into
* @count: length of buffer
* @ptr: offset (no seek allowed)
*
* Read reports the temperature in degrees Fahrenheit. The API is in
* fahrenheit. It was designed by an imperial measurement luddite.
*/
static ssize_t wdtpci_temp_read(struct file *file, char __user *buf,
size_t count, loff_t *ptr)
{
int temperature;
if (wdtpci_get_temperature(&temperature))
return -EFAULT;
if (copy_to_user(buf, &temperature, 1))
return -EFAULT;
return 1;
}
/**
* wdtpci_temp_open:
* @inode: inode of device
* @file: file handle to device
*
* The temperature device has been opened.
*/
static int wdtpci_temp_open(struct inode *inode, struct file *file)
{
return stream_open(inode, file);
}
/**
* wdtpci_temp_release:
* @inode: inode to board
* @file: file handle to board
*
* The temperature device has been closed.
*/
static int wdtpci_temp_release(struct inode *inode, struct file *file)
{
return 0;
}
/**
* wdtpci_notify_sys:
* @this: our notifier block
* @code: the event being reported
* @unused: unused
*
* Our notifier is called on system shutdowns. We want to turn the card
* off at reboot otherwise the machine will reboot again during memory
* test or worse yet during the following fsck. This would suck, in fact
* trust me - if it happens it does suck.
*/
static int wdtpci_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
wdtpci_stop();
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations wdtpci_fops = {
.owner = THIS_MODULE,
.write = wdtpci_write,
.unlocked_ioctl = wdtpci_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = wdtpci_open,
.release = wdtpci_release,
};
static struct miscdevice wdtpci_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdtpci_fops,
};
static const struct file_operations wdtpci_temp_fops = {
.owner = THIS_MODULE,
.read = wdtpci_temp_read,
.open = wdtpci_temp_open,
.release = wdtpci_temp_release,
};
static struct miscdevice temp_miscdev = {
.minor = TEMP_MINOR,
.name = "temperature",
.fops = &wdtpci_temp_fops,
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdtpci_notifier = {
.notifier_call = wdtpci_notify_sys,
};
static int wdtpci_init_one(struct pci_dev *dev,
const struct pci_device_id *ent)
{
int ret = -EIO;
dev_count++;
if (dev_count > 1) {
pr_err("This driver only supports one device\n");
return -ENODEV;
}
if (type != 500 && type != 501) {
pr_err("unknown card type '%d'\n", type);
return -ENODEV;
}
if (pci_enable_device(dev)) {
pr_err("Not possible to enable PCI Device\n");
return -ENODEV;
}
if (pci_resource_start(dev, 2) == 0x0000) {
pr_err("No I/O-Address for card detected\n");
ret = -ENODEV;
goto out_pci;
}
if (pci_request_region(dev, 2, "wdt_pci")) {
pr_err("I/O address 0x%llx already in use\n",
(unsigned long long)pci_resource_start(dev, 2));
goto out_pci;
}
irq = dev->irq;
io = pci_resource_start(dev, 2);
if (request_irq(irq, wdtpci_interrupt, IRQF_SHARED,
"wdt_pci", &wdtpci_miscdev)) {
pr_err("IRQ %d is not free\n", irq);
goto out_reg;
}
pr_info("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%llx (Interrupt %d)\n",
(unsigned long long)io, irq);
/* Check that the heartbeat value is within its range;
if not reset to the default */
if (wdtpci_set_heartbeat(heartbeat)) {
wdtpci_set_heartbeat(WD_TIMO);
pr_info("heartbeat value must be 0 < heartbeat < 65536, using %d\n",
WD_TIMO);
}
ret = register_reboot_notifier(&wdtpci_notifier);
if (ret) {
pr_err("cannot register reboot notifier (err=%d)\n", ret);
goto out_irq;
}
if (type == 501) {
ret = misc_register(&temp_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
TEMP_MINOR, ret);
goto out_rbt;
}
}
ret = misc_register(&wdtpci_miscdev);
if (ret) {
pr_err("cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto out_misc;
}
pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);
if (type == 501)
pr_info("Fan Tachometer is %s\n",
tachometer ? "Enabled" : "Disabled");
ret = 0;
out:
return ret;
out_misc:
if (type == 501)
misc_deregister(&temp_miscdev);
out_rbt:
unregister_reboot_notifier(&wdtpci_notifier);
out_irq:
free_irq(irq, &wdtpci_miscdev);
out_reg:
pci_release_region(dev, 2);
out_pci:
pci_disable_device(dev);
goto out;
}
static void wdtpci_remove_one(struct pci_dev *pdev)
{
/* here we assume only one device will ever have
* been picked up and registered by probe function */
misc_deregister(&wdtpci_miscdev);
if (type == 501)
misc_deregister(&temp_miscdev);
unregister_reboot_notifier(&wdtpci_notifier);
free_irq(irq, &wdtpci_miscdev);
pci_release_region(pdev, 2);
pci_disable_device(pdev);
dev_count--;
}
static const struct pci_device_id wdtpci_pci_tbl[] = {
{
.vendor = PCI_VENDOR_ID_ACCESSIO,
.device = PCI_DEVICE_ID_ACCESSIO_WDG_CSM,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
},
{ 0, }, /* terminate list */
};
MODULE_DEVICE_TABLE(pci, wdtpci_pci_tbl);
static struct pci_driver wdtpci_driver = {
.name = "wdt_pci",
.id_table = wdtpci_pci_tbl,
.probe = wdtpci_init_one,
.remove = wdtpci_remove_one,
};
module_pci_driver(wdtpci_driver);
MODULE_AUTHOR("JP Nollmann, Alan Cox");
MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
MODULE_LICENSE("GPL");
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