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/*
* Acquire Single Board Computer Watchdog Timer driver for Linux 2.1.x
*
* Based on wdt.c. Original copyright messages:
*
* (c) Copyright 1996 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@redhat.com>
*
*/
#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/miscdevice.h>
#include <linux/watchdog.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>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
static int acq_is_open;
static spinlock_t acq_lock;
/*
* You must set these - there is no sane way to probe for this board.
*/
#define WDT_STOP 0x43
#define WDT_START 0x443
#define WD_TIMO (100*60) /* 1 minute */
/*
* Kernel methods.
*/
static void acq_ping(void)
{
/* Write a watchdog value */
inb_p(WDT_START);
}
static ssize_t acq_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)
{
acq_ping();
return 1;
}
return 0;
}
static ssize_t acq_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
return -EINVAL;
}
static int acq_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
static struct watchdog_info ident=
{
WDIOF_KEEPALIVEPING, 1, "Acquire WDT"
};
switch(cmd)
{
case WDIOC_GETSUPPORT:
if (copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
return -EFAULT;
break;
case WDIOC_GETSTATUS:
if (copy_to_user((int *)arg, &acq_is_open, sizeof(int)))
return -EFAULT;
break;
case WDIOC_KEEPALIVE:
acq_ping();
break;
default:
return -ENOTTY;
}
return 0;
}
static int acq_open(struct inode *inode, struct file *file)
{
switch(MINOR(inode->i_rdev))
{
case WATCHDOG_MINOR:
spin_lock(&acq_lock);
if(acq_is_open)
{
spin_unlock(&acq_lock);
return -EBUSY;
}
/*
* Activate
*/
acq_is_open=1;
inb_p(WDT_START);
spin_unlock(&acq_lock);
return 0;
default:
return -ENODEV;
}
}
static int acq_close(struct inode *inode, struct file *file)
{
lock_kernel();
if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
{
spin_lock(&acq_lock);
#ifndef CONFIG_WATCHDOG_NOWAYOUT
inb_p(WDT_STOP);
#endif
acq_is_open=0;
spin_unlock(&acq_lock);
}
unlock_kernel();
return 0;
}
/*
* Notifier for system down
*/
static int acq_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_STOP);
}
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static struct file_operations acq_fops = {
owner: THIS_MODULE,
read: acq_read,
write: acq_write,
ioctl: acq_ioctl,
open: acq_open,
release: acq_close,
};
static struct miscdevice acq_miscdev=
{
WATCHDOG_MINOR,
"watchdog",
&acq_fops
};
/*
* The WDT card needs to learn about soft shutdowns in order to
* turn the timebomb registers off.
*/
static struct notifier_block acq_notifier=
{
acq_notify_sys,
NULL,
0
};
static int __init acq_init(void)
{
printk("WDT driver for Acquire single board computer initialising.\n");
spin_lock_init(&acq_lock);
misc_register(&acq_miscdev);
request_region(WDT_STOP, 1, "Acquire WDT");
request_region(WDT_START, 1, "Acquire WDT");
register_reboot_notifier(&acq_notifier);
return 0;
}
static void __exit acq_exit(void)
{
misc_deregister(&acq_miscdev);
unregister_reboot_notifier(&acq_notifier);
release_region(WDT_STOP,1);
release_region(WDT_START,1);
}
module_init(acq_init);
module_exit(acq_exit);
MODULE_LICENSE("GPL");
EXPORT_NO_SYMBOLS;
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