内核驱动之内核定时器示例

最新推荐文章于 2024-01-07 18:59:04 发布

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最新推荐文章于 2024-01-07 18:59:04 发布

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分类专栏：代码编程文章标签： timer module io list c

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#include<linux/module.h>
#include<linux/timer.h>
#include<linux/jiffies.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/err.h> 
#include <asm/io.h> 
#define	IBX_GPIO12_OUT   ( 1 << 12 )
#define	IBX_GPIO44_OUT   ( 1 << 12)
#define	IBEX_GPIOBASE  (0x500)
#define GP_LVL   (IBEX_GPIOBASE + 0x0c)
#define GP_LVL2   (IBEX_GPIOBASE+0x38)
#define GPIO_USE_SEL   (IBEX_GPIOBASE + 0x00)
#define GP_IO_SEL   (IBEX_GPIOBASE+0x04)
#define GPIO_USE_SEL2   (IBEX_GPIOBASE + 0x30)
#define GP_IO_SEL2   (IBEX_GPIOBASE+0x34)
#define TRUE 1
#define FALSE 0
typedef unsigned int        uint32;
typedef unsigned char       BOOL;
struct timer_list watchdogtimer;
BOOL Enablewatchdog( BOOL b)
{    
    uint32 value;
    if(b){
        value=inl(GP_LVL2)&(~IBX_GPIO44_OUT);
        outl(value,GP_LVL2);
        if(inl(GP_LVL2)&(IBX_GPIO44_OUT))
           return FALSE;
        else 
            return TRUE;
    }else{
       value=inl(GP_LVL2)|(IBX_GPIO44_OUT);
       outl(value,GP_LVL2);
       if(inl(GP_LVL2)&(IBX_GPIO44_OUT))
          return TRUE;
       else 
          return FALSE;
    }
}
static void feed_dog(unsigned long data)
{
	uint32 forword;
    forword=inl(GP_LVL)|IBX_GPIO12_OUT;
    outl(forword,GP_LVL);
    if((forword=inl(GP_LVL))&(IBX_GPIO12_OUT)){
        msleep(8000);
        forword&=(~IBX_GPIO12_OUT);
        outl(forword,GP_LVL);
    }else{
        printk(KERN_ALERT"feed dog fault !\n");
        mod_timer(&watchdogtimer,jiffies+1*HZ);
        return;
    }
    mod_timer(&watchdogtimer,jiffies+10*HZ);
}
static int __init watchdogtimer_init(void)
{
	uint32 value;
    value=inl(GPIO_USE_SEL2)|IBX_GPIO44_OUT;
        outl(value,GPIO_USE_SEL2);
    value=inl(GP_IO_SEL2)&(~IBX_GPIO44_OUT);
        outl(value,GP_IO_SEL2);
    value=inl(GPIO_USE_SEL)|IBX_GPIO12_OUT;
        outl(value,GPIO_USE_SEL);
    value=inl(GP_IO_SEL)&(~IBX_GPIO12_OUT);
        outl(value,GP_IO_SEL);
   setup_timer(&watchdogtimer,feed_dog,0);
   watchdogtimer.expires=jiffies+2*HZ;
   if(Enablewatchdog(TRUE))
   {
		printk(KERN_ALERT"Watchdog is start succeed !\n");
		add_timer(&watchdogtimer);
   }else{
     printk(KERN_ALERT"Watchdog is start fail !\n");
   }
	return 0;
}
static void __exit watchdogtimer_exit(void)
{
   if(Enablewatchdog(FALSE))
   {
		printk(KERN_ALERT"Watchdog is stop succeed !\n");
		del_timer(&watchdogtimer);
   }else{
		printk(KERN_ALERT"Watchdog is stop fault !\n");
   }   
}
module_init(watchdogtimer_init);
module_exit(watchdogtimer_exit);
MODULE_LICENSE("GPL");