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/*
* Industrial Computer Source WDT500/501 driver for Linux 2.1.x
*
* (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 0.08.
*
* 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
* Tigran Aivazian : Restructured wdt_init() to handle failures
* Joel Becker : Added WDIOC_GET/SETTIMEOUT
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include "wd501p.h"
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
static int wdt_is_open;
/*
* You must set these - there is no sane way to probe for this board.
* You can use wdt=x,y to set these now.
*/
static int io=0x240;
static int irq=11;
/* Default margin */
#define WD_TIMO (100*60) /* 1 minute */
static int wd_margin = WD_TIMO;
#ifndef MODULE
/**
* wdt_setup:
* @str: command line string
*
* Setup options. The board isn't really probe-able so we have to
* get the user to tell us the configuration. Sane people build it
* modular but the others come here.
*/
static int __init wdt_setup(char *str)
{
int ints[4];
str = get_options (str, ARRAY_SIZE(ints), ints);
if (ints[0] > 0)
{
io = ints[1];
if(ints[0] > 1)
irq = ints[2];
}
return 1;
}
__setup("wdt=", wdt_setup);
#endif /* !MODULE */
MODULE_PARM(io, "i");
MODULE_PARM_DESC(io, "WDT io port (default=0x240)");
MODULE_PARM(irq, "i");
MODULE_PARM_DESC(irq, "WDT irq (default=11)");
/*
* Programming support
*/
static void wdt_ctr_mode(int ctr, int mode)
{
ctr<<=6;
ctr|=0x30;
ctr|=(mode<<1);
outb_p(ctr, WDT_CR);
}
static void wdt_ctr_load(int ctr, int val)
{
outb_p(val&0xFF, WDT_COUNT0+ctr);
outb_p(val>>8, WDT_COUNT0+ctr);
}
/*
* Kernel methods.
*/
/**
* wdt_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 wdt_status(void)
{
/*
* Status register to bit flags
*/
int flag=0;
unsigned char status=inb_p(WDT_SR);
status|=FEATUREMAP1;
status&=~FEATUREMAP2;
if(!(status&WDC_SR_TGOOD))
flag|=WDIOF_OVERHEAT;
if(!(status&WDC_SR_PSUOVER))
flag|=WDIOF_POWEROVER;
if(!(status&WDC_SR_PSUUNDR))
flag|=WDIOF_POWERUNDER;
if(!(status&WDC_SR_FANGOOD))
flag|=WDIOF_FANFAULT;
if(status&WDC_SR_ISOI0)
flag|=WDIOF_EXTERN1;
if(status&WDC_SR_ISII1)
flag|=WDIOF_EXTERN2;
return flag;
}
/**
* wdt_interrupt:
* @irq: Interrupt number
* @dev_id: Unused as we don't allow multiple devices.
* @regs: Unused.
*
* 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 occuring.
*/
void wdt_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
/*
* Read the status register see what is up and
* then printk it.
*/
unsigned char status=inb_p(WDT_SR);
status|=FEATUREMAP1;
status&=~FEATUREMAP2;
printk(KERN_CRIT "WDT status %d\n", status);
if(!(status&WDC_SR_TGOOD))
printk(KERN_CRIT "Overheat alarm.(%d)\n",inb_p(WDT_RT));
if(!(status&WDC_SR_PSUOVER))
printk(KERN_CRIT "PSU over voltage.\n");
if(!(status&WDC_SR_PSUUNDR))
printk(KERN_CRIT "PSU under voltage.\n");
if(!(status&WDC_SR_FANGOOD))
printk(KERN_CRIT "Possible fan fault.\n");
if(!(status&WDC_SR_WCCR))
#ifdef SOFTWARE_REBOOT
#ifdef ONLY_TESTING
printk(KERN_CRIT "Would Reboot.\n");
#else
printk(KERN_CRIT "Initiating system reboot.\n");
machine_restart(NULL);
#endif
#else
printk(KERN_CRIT "Reset in 5ms.\n");
#endif
}
/**
* wdt_ping:
*
* Reload counter one with the watchdog timeout. We don't bother reloading
* the cascade counter.
*/
static void wdt_ping(void)
{
/* Write a watchdog value */
inb_p(WDT_DC);
wdt_ctr_mode(1,2);
wdt_ctr_load(1,wd_margin); /* Timeout */
outb_p(0, WDT_DC);
}
/**
* wdt_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 wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
{
/* Can't seek (pwrite) on this device */
if (ppos != &file->f_pos)
return -ESPIPE;
if(count)
{
wdt_ping();
return 1;
}
return 0;
}
/**
* wdt_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
* farenheit. It was designed by an imperial measurement luddite.
*/
static ssize_t wdt_read(struct file *file, char *buf, size_t count, loff_t *ptr)
{
unsigned short c=inb_p(WDT_RT);
unsigned char cp;
/* Can't seek (pread) on this device */
if (ptr != &file->f_pos)
return -ESPIPE;
switch(MINOR(file->f_dentry->d_inode->i_rdev))
{
case TEMP_MINOR:
c*=11;
c/=15;
cp=c+7;
if(copy_to_user(buf,&cp,1))
return -EFAULT;
return 1;
default:
return -EINVAL;
}
}
/**
* wdt_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 wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_margin;
static struct watchdog_info ident=
{
WDIOF_OVERHEAT|WDIOF_POWERUNDER|WDIOF_POWEROVER
|WDIOF_EXTERN1|WDIOF_EXTERN2|WDIOF_FANFAULT
|WDIOF_SETTIMEOUT,
1,
"WDT500/501"
};
ident.options&=WDT_OPTION_MASK; /* Mask down to the card we have */
switch(cmd)
{
default:
return -ENOTTY;
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))?-EFAULT:0;
case WDIOC_GETSTATUS:
return put_user(wdt_status(),(int *)arg);
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int *)arg);
case WDIOC_KEEPALIVE:
wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int *)arg))
return -EFAULT;
/* Arbitrary, can't find the card's limits */
if ((new_margin < 0) || (new_margin > 60))
return -EINVAL;
wd_margin = new_margin * 100;
wdt_ping();
/* Fall */
case WDIOC_GETTIMEOUT:
return put_user(wd_margin / 100, (int *)arg);
}
}
/**
* wdt_open:
* @inode: inode of device
* @file: file handle to device
*
* One of our two misc devices 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 wdt_open(struct inode *inode, struct file *file)
{
switch(MINOR(inode->i_rdev))
{
case WATCHDOG_MINOR:
if(wdt_is_open)
return -EBUSY;
/*
* Activate
*/
wdt_is_open=1;
inb_p(WDT_DC); /* Disable */
wdt_ctr_mode(0,3);
wdt_ctr_mode(1,2);
wdt_ctr_mode(2,0);
wdt_ctr_load(0, 8948); /* count at 100Hz */
wdt_ctr_load(1,wd_margin); /* Timeout 120 seconds */
wdt_ctr_load(2,65535);
outb_p(0, WDT_DC); /* Enable */
return 0;
case TEMP_MINOR:
return 0;
default:
return -ENODEV;
}
}
/**
* wdt_close:
* @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 wdt_release(struct inode *inode, struct file *file)
{
lock_kernel();
if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
{
#ifndef CONFIG_WATCHDOG_NOWAYOUT
inb_p(WDT_DC); /* Disable counters */
wdt_ctr_load(2,0); /* 0 length reset pulses now */
#endif
wdt_is_open=0;
}
unlock_kernel();
return 0;
}
/**
* 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 wdt_notify_sys(struct notifier_block *this, unsigned long code,
void *unused)
{
if(code==SYS_DOWN || code==SYS_HALT)
{
/* Turn the card off */
inb_p(WDT_DC);
wdt_ctr_load(2,0);
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static struct file_operations wdt_fops = {
owner: THIS_MODULE,
llseek: no_llseek,
read: wdt_read,
write: wdt_write,
ioctl: wdt_ioctl,
open: wdt_open,
release: wdt_release,
};
static struct miscdevice wdt_miscdev=
{
WATCHDOG_MINOR,
"watchdog",
&wdt_fops
};
#ifdef CONFIG_WDT_501
static struct miscdevice temp_miscdev=
{
TEMP_MINOR,
"temperature",
&wdt_fops
};
#endif
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block wdt_notifier=
{
wdt_notify_sys,
NULL,
0
};
/**
* cleanup_module:
*
* 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 60 seconds or reboot.
*/
static void __exit wdt_exit(void)
{
misc_deregister(&wdt_miscdev);
#ifdef CONFIG_WDT_501
misc_deregister(&temp_miscdev);
#endif
unregister_reboot_notifier(&wdt_notifier);
release_region(io,8);
free_irq(irq, NULL);
}
/**
* wdt_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 wdt_init(void)
{
int ret;
ret = misc_register(&wdt_miscdev);
if (ret) {
printk(KERN_ERR "wdt: can't misc_register on minor=%d\n", WATCHDOG_MINOR);
goto out;
}
ret = request_irq(irq, wdt_interrupt, SA_INTERRUPT, "wdt501p", NULL);
if(ret) {
printk(KERN_ERR "wdt: IRQ %d is not free.\n", irq);
goto outmisc;
}
if (!request_region(io, 8, "wdt501p")) {
printk(KERN_ERR "wdt: IO %X is not free.\n", io);
ret = -EBUSY;
goto outirq;
}
ret = register_reboot_notifier(&wdt_notifier);
if(ret) {
printk(KERN_ERR "wdt: can't register reboot notifier (err=%d)\n", ret);
goto outreg;
}
#ifdef CONFIG_WDT_501
ret = misc_register(&temp_miscdev);
if (ret) {
printk(KERN_ERR "wdt: can't misc_register (temp) on minor=%d\n", TEMP_MINOR);
goto outrbt;
}
#endif
ret = 0;
printk(KERN_INFO "WDT500/501-P driver 0.07 at %X (Interrupt %d)\n", io, irq);
out:
return ret;
#ifdef CONFIG_WDT_501
outrbt:
unregister_reboot_notifier(&wdt_notifier);
#endif
outreg:
release_region(io,8);
outirq:
free_irq(irq, NULL);
outmisc:
misc_deregister(&wdt_miscdev);
goto out;
}
module_init(wdt_init);
module_exit(wdt_exit);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("Driver for ISA ICS watchdog cards (WDT500/501)");
MODULE_LICENSE("GPL");
EXPORT_NO_SYMBOLS;
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