watdog.c

arm linux 平台下的watchdog程序,C语言代码

/*
 *
 *watchdog.c
 *
 *  Copyright (C) 2006  ccb
 *
 *author: lichao
 *email:[e-mail]
 *  May be freely distributed as part of Linux.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/version.h>
#include <asm-arm/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/poll.h>
#include <asm-arm/delay.h>

#include <asm/hardware.h>
#include <asm-arm/arch-s3c2410/S3C2410.h>
//#include "weida_printer.h"
#if CONFIG_MODVERSIONS==1
#define MODVERSIONS
#include <linux/modversions.h>
#endif

#define DEVICE_NAME	"watchdog"
#define WATCHDOG_MAJOR 234
//#define rWTCNT (*(volatile unsigned long*)0x53000008)
//#define rWTCON (*(volatile unsigned long*)0x53000000)


int WATCHDOG_DEV=0;

static int watchdog_write(struct file * file, const char * buffer, size_t count, loff_t *ppos)
{
	WTCNT=8448*2;
	
}

static int watchdog_open(struct inode *inode,struct file *file)
{
	printk("the watchdog device will be opened");
	if(WATCHDOG_DEV) 
		return -EBUSY;
	WATCHDOG_DEV++;
	//D_INC_USE_COUNT;
	WTCNT=8448*2;  /*setup the initial value of the watchdog*/
	WTCON=0xff39;
	return 0;
}

static struct file_operations watchdog_fops = {
	open:	watchdog_open,
	write: 	watchdog_write,
};

static int __init watchdog_init(void)
{
	int ret;  	
	ret = register_chrdev(WATCHDOG_MAJOR, DEVICE_NAME, &watchdog_fops);
	if (ret < 0) {
	  printk(DEVICE_NAME " Can't initial the watchdog device\n");
	  return ret;
	}	
	return 0;
}

static void __exit watchdog_exit(void)
{
	unregister_chrdev(WATCHDOG_MAJOR, DEVICE_NAME);
}

module_init(watchdog_init);
module_exit(watchdog_exit);
MODULE_LICENSE("GPL");