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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@cymru.net>, All Rights Reserved.
* http://www.cymru.net
*
* 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>
*
*/
#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/malloc.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 acq_is_open=0;
/*
* 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 -ENOIOCTLCMD;
}
return 0;
}
static int acq_open(struct inode *inode, struct file *file)
{
switch(MINOR(inode->i_rdev))
{
case WATCHDOG_MINOR:
if(acq_is_open)
return -EBUSY;
MOD_INC_USE_COUNT;
/*
* Activate
*/
acq_is_open=1;
inb_p(WDT_START);
return 0;
default:
return -ENODEV;
}
}
static int acq_close(struct inode *inode, struct file *file)
{
if(MINOR(inode->i_rdev)==WATCHDOG_MINOR)
{
#ifndef CONFIG_WATCHDOG_NOWAYOUT
inb_p(WDT_STOP);
#endif
acq_is_open=0;
}
MOD_DEC_USE_COUNT;
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 = {
NULL,
acq_read,
acq_write,
NULL, /* No Readdir */
NULL, /* No Select */
acq_ioctl,
NULL, /* No mmap */
acq_open,
NULL, /* flush */
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
};
#ifdef MODULE
#define acq_init init_module
void cleanup_module(void)
{
misc_deregister(&acq_miscdev);
unregister_reboot_notifier(&acq_notifier);
release_region(WDT_STOP,1);
release_region(WDT_START,1);
}
#endif
__initfunc(int acq_init(void))
{
printk("WDT driver for Acquire single board computer initialising.\n");
misc_register(&acq_miscdev);
request_region(WDT_STOP, 1, "Acquire WDT");
request_region(WDT_START, 1, "Acquire WDT");
unregister_reboot_notifier(&acq_notifier);
return 0;
}
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