watchdog.c

基于s3c44b0的rtc,watchdog,adc,ads的驱动程序

#include <linux/config.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/string.h>
#include <linux/fcntl.h>
#include <linux/timer.h>
#include <linux/sched.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/spinlock.h>

#include <asm/mach/irq.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>

#include <linux/poll.h>
#include <asm/arch/io.h>

#include "44b.h"

#define DEVICE_NAME	"watchdog"
#define MCLK 64000000

void Test_WDTimer(void);
void Feed_WDTimer(void);
void Stop_WDTimer(void);

void Stop_WDTimer(void)
{
    rWTCON = ((MCLK/1000000-1)<<8) | (3<<3) | (0);
}
void Feed_WDTimer(void)
{
    rWTCNT = 8448*2;
}
static void Watchdog_ISR(int irq,void* dev_id,struct pt_regs * regs)
{ 
    rI_ISPC = BIT_WDT;
}
void Test_WDTimer(void)
{
    //rINTMSK = ~(BIT_GLOBAL | BIT_WDT);

    //rWTCON = ((MCLK/1000000-1)<<8) | (3<<3) | (1<<2);  
    rWTCON = ((MCLK/1000000-1)<<8) | (3<<3) | (1);
    rWTDAT = 8448*3;
    rWTCNT = 8448*3;
    rWTCON = rWTCON | (1<<5);  
}
static int s3c44b0_wdg_open(struct inode *inode, struct file *filp)
{
	//printk("Open successful\n");
	return 0;
}
static int s3c44b0_wdg_release(struct inode *inode, struct file *filp)
{
	//printk("Close successful\n");
  	return 0;
}
static int s3c44b0_wdg_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	switch(cmd) 
	{
		case 0:
			Test_WDTimer();	
			return 0;	
		case 1:
			Feed_WDTimer();	
			return 0;	
		case 2:
			Stop_WDTimer();	
			return 0;		
        	default:
                        printk("ERROR\n");
    	}
    	return 0;
}
static struct file_operations s3c44b0_fops = {
  	open:	s3c44b0_wdg_open,
	ioctl:	s3c44b0_wdg_ioctl,
  	release:	s3c44b0_wdg_release,
};
int s3c44b0_wdg_init(void)
{
	int ret;

	ret = register_chrdev(251, DEVICE_NAME, &s3c44b0_fops);
	if (ret < 0) {
		printk(DEVICE_NAME " can't get major number\n");
		return ret;
	}
	else 
		printk("OK\n");	

	if (request_irq(15,Watchdog_ISR,0,"watchdog",NULL))
	{
   		printk(KERN_INFO"[FALLED: Cannot register Watchdog_Interrupt!]\n");
		return -EBUSY;
	}
	else
		printk("[OK]\n");

	return 0;
}