kernel-ark/drivers/watchdog/wdt_pci.c
Alexey Dobriyan c7dfd0cca3 [WATCHDOG] spin_lock_init() fixes
Some watchdog drivers initialize global spinlocks in module's init function
which is tolerable, but some do it in PCI probe function.  So, switch to
static initialization to fix theoretical bugs and, more importantly, stop
giving people bad examples.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2007-11-02 19:09:07 +00:00

757 lines
18 KiB
C

/*
* Industrial Computer Source PCI-WDT500/501 driver
*
* (c) Copyright 1996-1997 Alan Cox <alan@redhat.com>, All Rights Reserved.
* http://www.redhat.com
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* 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 <alan@lxorguk.ukuu.org.uk>
*
* 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
*/
#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/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/pci.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define WDT_IS_PCI
#include "wd501p.h"
#define PFX "wdt_pci: "
/*
* Until Access I/O gets their application for a PCI vendor ID approved,
* I don't think that it's appropriate to move these constants into the
* regular pci_ids.h file. -- JPN 2000/01/18
*/
#ifndef PCI_VENDOR_ID_ACCESSIO
#define PCI_VENDOR_ID_ACCESSIO 0x494f
#endif
#ifndef PCI_DEVICE_ID_WDG_CSM
#define PCI_DEVICE_ID_WDG_CSM 0x22c0
#endif
/* We can only use 1 card due to the /dev/watchdog restriction */
static int dev_count;
static struct semaphore open_sem;
static DEFINE_SPINLOCK(wdtpci_lock);
static char expect_close;
static int 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 int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
#ifdef CONFIG_WDT_501_PCI
/* 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)");
#endif /* CONFIG_WDT_501_PCI */
/*
* Programming support
*/
static void wdtpci_ctr_mode(int ctr, int mode)
{
ctr<<=6;
ctr|=0x30;
ctr|=(mode<<1);
outb_p(ctr, WDT_CR);
}
static void wdtpci_ctr_load(int ctr, int val)
{
outb_p(val&0xFF, WDT_COUNT0+ctr);
outb_p(val>>8, WDT_COUNT0+ctr);
}
/**
* 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_p(WDT_DC); /* Disable watchdog */
wdtpci_ctr_mode(2,0); /* Program CTR2 for Mode 0: Pulse on Terminal Count */
outb_p(0, WDT_DC); /* Enable watchdog */
inb_p(WDT_DC); /* Disable watchdog */
outb_p(0, WDT_CLOCK); /* 2.0833MHz clock */
inb_p(WDT_BUZZER); /* disable */
inb_p(WDT_OPTONOTRST); /* disable */
inb_p(WDT_OPTORST); /* disable */
inb_p(WDT_PROGOUT); /* disable */
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_p(0, WDT_DC); /* Enable watchdog */
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_p(WDT_DC); /* Disable watchdog */
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;
/* Write a watchdog value */
spin_lock_irqsave(&wdtpci_lock, flags);
inb_p(WDT_DC); /* Disable watchdog */
wdtpci_ctr_mode(1,2); /* Re-Program CTR1 for Mode 2: Rate Generator */
wdtpci_ctr_load(1,wd_heartbeat);/* Heartbeat */
outb_p(0, WDT_DC); /* Enable watchdog */
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 successfull 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=inb_p(WDT_SR);
*status=0;
if (new_status & WDC_SR_ISOI0)
*status |= WDIOF_EXTERN1;
if (new_status & WDC_SR_ISII1)
*status |= WDIOF_EXTERN2;
#ifdef CONFIG_WDT_501_PCI
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;
}
#endif /* CONFIG_WDT_501_PCI */
return 0;
}
#ifdef CONFIG_WDT_501_PCI
/**
* 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=inb_p(WDT_RT);
*temperature = (c * 11 / 15) + 7;
return 0;
}
#endif /* CONFIG_WDT_501_PCI */
/**
* 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=inb_p(WDT_SR);
printk(KERN_CRIT PFX "status %d\n", status);
#ifdef CONFIG_WDT_501_PCI
if (!(status & WDC_SR_TGOOD))
printk(KERN_CRIT PFX "Overheat alarm.(%d)\n",inb_p(WDT_RT));
if (!(status & WDC_SR_PSUOVER))
printk(KERN_CRIT PFX "PSU over voltage.\n");
if (!(status & WDC_SR_PSUUNDR))
printk(KERN_CRIT PFX "PSU under voltage.\n");
if (tachometer) {
if (!(status & WDC_SR_FANGOOD))
printk(KERN_CRIT PFX "Possible fan fault.\n");
}
#endif /* CONFIG_WDT_501_PCI */
if (!(status&WDC_SR_WCCR)) {
#ifdef SOFTWARE_REBOOT
#ifdef ONLY_TESTING
printk(KERN_CRIT PFX "Would Reboot.\n");
#else
printk(KERN_CRIT PFX "Initiating system reboot.\n");
emergency_restart(NULL);
#endif
#else
printk(KERN_CRIT PFX "Reset in 5ms.\n");
#endif
}
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;
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:
* @inode: inode of the device
* @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 int wdtpci_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_heartbeat;
int status;
void __user *argp = (void __user *)arg;
int __user *p = argp;
static 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);
#ifdef CONFIG_WDT_501_PCI
ident.options |= (WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER);
if (tachometer)
ident.options |= WDIOF_FANFAULT;
#endif /* CONFIG_WDT_501_PCI */
switch(cmd)
{
default:
return -ENOTTY;
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();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
}
}
/**
* 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 (down_trylock(&open_sem))
return -EBUSY;
if (nowayout) {
__module_get(THIS_MODULE);
}
/*
* Activate
*/
wdtpci_start();
return nonseekable_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 {
printk(KERN_CRIT PFX "Unexpected close, not stopping timer!");
wdtpci_ping();
}
expect_close = 0;
up(&open_sem);
return 0;
}
#ifdef CONFIG_WDT_501_PCI
/**
* 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 nonseekable_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;
}
#endif /* CONFIG_WDT_501_PCI */
/**
* 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) {
/* Turn the card off */
wdtpci_stop();
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations wdtpci_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = wdtpci_write,
.ioctl = wdtpci_ioctl,
.open = wdtpci_open,
.release = wdtpci_release,
};
static struct miscdevice wdtpci_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &wdtpci_fops,
};
#ifdef CONFIG_WDT_501_PCI
static const struct file_operations wdtpci_temp_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.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,
};
#endif /* CONFIG_WDT_501_PCI */
/*
* 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 __devinit wdtpci_init_one (struct pci_dev *dev,
const struct pci_device_id *ent)
{
int ret = -EIO;
dev_count++;
if (dev_count > 1) {
printk (KERN_ERR PFX "this driver only supports 1 device\n");
return -ENODEV;
}
if (pci_enable_device (dev)) {
printk (KERN_ERR PFX "Not possible to enable PCI Device\n");
return -ENODEV;
}
if (pci_resource_start (dev, 2) == 0x0000) {
printk (KERN_ERR PFX "No I/O-Address for card detected\n");
ret = -ENODEV;
goto out_pci;
}
sema_init(&open_sem, 1);
irq = dev->irq;
io = pci_resource_start (dev, 2);
if (request_region (io, 16, "wdt_pci") == NULL) {
printk (KERN_ERR PFX "I/O address 0x%04x already in use\n", io);
goto out_pci;
}
if (request_irq (irq, wdtpci_interrupt, IRQF_DISABLED | IRQF_SHARED,
"wdt_pci", &wdtpci_miscdev)) {
printk (KERN_ERR PFX "IRQ %d is not free\n", irq);
goto out_reg;
}
printk ("PCI-WDT500/501 (PCI-WDG-CSM) driver 0.10 at 0x%04x (Interrupt %d)\n",
io, irq);
/* Check that the heartbeat value is within it's range ; if not reset to the default */
if (wdtpci_set_heartbeat(heartbeat)) {
wdtpci_set_heartbeat(WD_TIMO);
printk(KERN_INFO PFX "heartbeat value must be 0<heartbeat<65536, using %d\n",
WD_TIMO);
}
ret = register_reboot_notifier (&wdtpci_notifier);
if (ret) {
printk (KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", ret);
goto out_irq;
}
#ifdef CONFIG_WDT_501_PCI
ret = misc_register (&temp_miscdev);
if (ret) {
printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
TEMP_MINOR, ret);
goto out_rbt;
}
#endif /* CONFIG_WDT_501_PCI */
ret = misc_register (&wdtpci_miscdev);
if (ret) {
printk (KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto out_misc;
}
printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n",
heartbeat, nowayout);
#ifdef CONFIG_WDT_501_PCI
printk(KERN_INFO "wdt: Fan Tachometer is %s\n", (tachometer ? "Enabled" : "Disabled"));
#endif /* CONFIG_WDT_501_PCI */
ret = 0;
out:
return ret;
out_misc:
#ifdef CONFIG_WDT_501_PCI
misc_deregister(&temp_miscdev);
out_rbt:
#endif /* CONFIG_WDT_501_PCI */
unregister_reboot_notifier(&wdtpci_notifier);
out_irq:
free_irq(irq, &wdtpci_miscdev);
out_reg:
release_region (io, 16);
out_pci:
pci_disable_device(dev);
goto out;
}
static void __devexit 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);
#ifdef CONFIG_WDT_501_PCI
misc_deregister(&temp_miscdev);
#endif /* CONFIG_WDT_501_PCI */
unregister_reboot_notifier(&wdtpci_notifier);
free_irq(irq, &wdtpci_miscdev);
release_region(io, 16);
pci_disable_device(pdev);
dev_count--;
}
static struct pci_device_id wdtpci_pci_tbl[] = {
{
.vendor = PCI_VENDOR_ID_ACCESSIO,
.device = PCI_DEVICE_ID_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 = __devexit_p(wdtpci_remove_one),
};
/**
* wdtpci_cleanup:
*
* Unload the watchdog. You cannot do this with any file handles open.
* If your watchdog is set to continue ticking on close and you unload
* it, well it keeps ticking. We won't get the interrupt but the board
* will not touch PC memory so all is fine. You just have to load a new
* module in xx seconds or reboot.
*/
static void __exit wdtpci_cleanup(void)
{
pci_unregister_driver (&wdtpci_driver);
}
/**
* wdtpci_init:
*
* Set up the WDT watchdog board. All we have to do is grab the
* resources we require and bitch if anyone beat us to them.
* The open() function will actually kick the board off.
*/
static int __init wdtpci_init(void)
{
return pci_register_driver (&wdtpci_driver);
}
module_init(wdtpci_init);
module_exit(wdtpci_cleanup);
MODULE_AUTHOR("JP Nollmann, Alan Cox");
MODULE_DESCRIPTION("Driver for the ICS PCI-WDT500/501 watchdog cards");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS_MISCDEV(TEMP_MINOR);