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adc.c#include
   
    #include
    
     #include
     
      #include
      
       #include
       
        #include
        
         #include
         
          #include
          
           #include
           
            #include
            
             #include
             
              #define ADCCON 0x126c0000#define ADCDAT 0x126c000c#define ADCMUX 0x126c001c#define ADCCLEAR 0x126c0018struct cdev adccdev;static wait_queue_head_t wq;dev_t devid;static int have_data;static int adc;unsigned int *adccon;unsigned int *adcdat;unsigned int *adcmux;unsigned int *adcclear;static irqreturn_t adc_interrupt(int irqno,void *dev)//中断处理函数{ have_data=1;//转换完成标志位， writel(0x12,adcclear);//清除中断标志位 wake_up_interruptible(&wq);//唤醒等待队列 return IRQ_HANDLED;}static int adcinit(){ request_irq(IRQ_ADC,adc_interrupt,IRQF_DISABLED,"adc1",NULL);//申请中断 adccon=ioremap(ADCCON,4);//物理地址到虚拟地址映射 adcdat=ioremap(ADCDAT,4); adcmux=ioremap(ADCMUX,4); adcclear=ioremap(ADCCLEAR,4); init_waitqueue_head(&wq);初始化等待队列 return 0;}static ssize_t adc_read(struct file *filep,char __user *buf,size_t len, loff_t *pos){ writel(0x3,ADCMUX);//选择转换通道 writel(1<<0|0x1<<16|0xff<<6,ADCCON);//启动12位AD转换 wait_event_interruptible(wq,have_data==1);//进入等待队列 adc=readl(adcdat)&0xfff; if(copy_to_user(buf,&adc,sizeof(int))) { return -EFAULT; } have_data=0; return len;}static int adc_release(struct inode *inode,struct file *file){ return 0;}static int adc_open(struct inode *inde,struct file *file){ return 0;}struct file_operations adcops={.owner=THIS_MODULE,.open=adc_open,.read=adc_read,.release=adc_release,};static void adc_init(){ cdev_init(&adccdev,&adcops); alloc_chrdev_region(&devid, 0 , 1 , "adc12"); cdev_add(&adccdev,devid,1); adcinit();}static void adc_exit(){ unregister_chrdev_region(&devid,1); cdev_del(&adccdev);}MODULE_LICENSE("GPL");module_init(adc_init);module_exit(adc_exit);
             
            
           
          
         
        
       
      
     
    
   

insmod ADC.ko

APP_ADC.c#include
   
    #include
    
     #include
     
      #include
      
       int main(int argc char **argv){    int fd,len;    int adc;    fd=open("dev/adc",O_RDWR);    if(fd<0)    {        perror("open fail\n");        return;    }    while(1){        read(fd,&adc,4);        printf("adc%0.2f V\n",(1.8*adc)/4096);    }    close(fd);}
      
     
    
   

./APP_ADC