[질문] 리눅스 디바이스 드라이버 (유영창 저), 12장 인터럽트 예제

// int_dev.c
 
 
#include <linux/init.h> 
#include <linux/module.h> 
#include <linux/kernel.h> 
 
#include <linux/fs.h>            
#include <linux/errno.h>         
#include <linux/types.h>         
#include <linux/fcntl.h>         
 
#include <asm/uaccess.h>  
#include <asm/io.h>  
 
#include <linux/time.h> 
#include <linux/timer.h> 
 
#include <linux/interrupt.h>  
 
#define   INT_DEV_NAME            "intdev"  
#define   INT_DEV_MAJOR            240        
 
#define   INT_WRITE_ADDR        0x0378        
#define   INT_READ_ADDR         0x0379        
#define   INT_CTRL_ADDR         0x037A     
 
#define   PRINT_IRQ                  7  
#define   PRINT_IRQ_ENABLE_MASK   0x10     
 
#define   INT_BUFF_MAX              64  
 
typedef struct   
{  
  unsigned long time;  
} __attribute__ ((packed)) R_INT_INFO;  
 
R_INT_INFO intbuffer[INT_BUFF_MAX];  
int        intcount = 0;  
 
void int_clear( void )  
{  
  int lp;  
 
  for(lp = 0; lp < INT_BUFF_MAX; lp++)  
  { 
    intbuffer[lp].time  = 0;  
  } 
 
    intcount = 0;  
}  
 
irqreturn_t int_interrupt(int irq, void *dev_id, struct pt_regs *regs)  
{  
  //printk();   
 
 
  printk(KERN_EMERG "int_interrupt\n");
 
 
 
  if( intcount < INT_BUFF_MAX )  
    {  
        intbuffer[intcount].time  = get_jiffies_64();  
        intcount++;  
    }  
    return IRQ_HANDLED;   
}  
 
int int_open (struct inode *inode, struct file *filp)  
{  
  printk(KERN_EMERG "int_open\n");   
 
 
 
  int a = request_irq( PRINT_IRQ , int_interrupt, IRQF_DISABLED, INT_DEV_NAME, NULL);
  printk(KERN_EMERG "request_irq() : %d\n", a);
 
 
  if(!a)  
  {  
 
	//printk(KERN_EMERG "111\n");
     outb( PRINT_IRQ_ENABLE_MASK, INT_CTRL_ADDR );  
  }  
 
    int_clear();  
 
    return 0;  
}  
 
ssize_t int_read(struct file *filp, char *buf, size_t count, loff_t *f_pos)  
{  
    int   readcount;  
    char *ptrdata;   
    int   loop;  
  //printk(KERN_EMERG "int_read - %d\n", intcount);
    readcount = count / sizeof( R_INT_INFO );  
    if( readcount > intcount ) readcount = intcount;  
 
    ptrdata = (char * ) &intbuffer[0];  
 
    for( loop = 0; loop < readcount * sizeof(R_INT_INFO); loop++ )  
    {  
        put_user( ptrdata[loop], (char *) &buf[loop] );   
    }  
 
    return readcount * sizeof( R_INT_INFO );  
}  
 
ssize_t int_write (struct file *filp, const char *buf, size_t count, loff_t *f_pos)  
{  
    unsigned char status;  
    int           loop;  
 
    int_clear();  
 
    for( loop = 0; loop < count; loop++ )  
    {  
        get_user( status, (char *) buf );   
        outb( status , INT_WRITE_ADDR );     
    }      
 
    return count;  
}  
 
int int_release (struct inode *inode, struct file *filp)  
{  
    outb( 0x00, INT_CTRL_ADDR );   
    free_irq( PRINT_IRQ , NULL );  
    return 0;  
}  
 
struct file_operations int_fops =  
{  
    .owner    = THIS_MODULE,  
    .read     = int_read,  
    .write    = int_write,  
    .open     = int_open,  
    .release  = int_release,    
};  
 
int int_init(void)  
{  
    int result;  
 
    result = register_chrdev( INT_DEV_MAJOR, INT_DEV_NAME, &int_fops);  
    if (result < 0) return result;  
 
    return 0;  
}  
 
void int_exit(void)  
{  
    unregister_chrdev( INT_DEV_MAJOR, INT_DEV_NAME );  
}  
 
module_init(int_init);  
module_exit(int_exit);  
 
MODULE_LICENSE("Dual BSD/GPL");  

// int_app.c 
 
 
#include stdio.h>
#include sys/types.h>
#include sys/stat.h>
#include sys/ioctl.h>
#include fcntl.h>
#include unistd.h>
 
#define DEVICE_FILENAME  "/dev/intdev"
 
typedef struct 
{
    unsigned long time;
} __attribute__ ((packed)) R_INT_INFO;
 
#define   INT_BUFF_MAX              64
 
int main()
{
    int        dev;
    R_INT_INFO intbuffer[INT_BUFF_MAX];
    int        intcount;
    char       buff[128];
    int        loop;
 
    dev = open( DEVICE_FILENAME, O_RDWR|O_NDELAY );
    if( dev >= 0 )
    {
 
        printf( "start...\n" );
        buff[0] = 0xFF; 
        write(dev,buff,1 );
 
        printf( "wait... input\n" );
        while(1)
        {
            memset( intbuffer, 0, sizeof( intbuffer ) );    
            intcount = read(dev,(char *) &intbuffer[0],sizeof(R_INT_INFO) ) / sizeof(R_INT_INFO) ;    
            if( intcount ) break;
 
 
//sleep(1);
      }
 
        printf( "input ok...\n");
        sleep(1);
        memset( intbuffer, 0, sizeof( intbuffer ) );    
 
        printf( "read interrupt times\n" );
        intcount = read(dev,(char *) intbuffer,sizeof(intbuffer) ) / sizeof(R_INT_INFO) ;    
        for( loop =0; loop < intcount; loop++ )
        {
           printf( "index = %d time = %ld\n", loop, intbuffer[loop].time );
        }   
 
        printf( "led flashing...\n");
        for( loop=0; loop<5; loop++ )
        {
            buff[0] = 0xFF; 
            write(dev,buff,1 );
            sleep(1);
            buff[0] = 0x00; 
            write(dev,buff,1 );
            sleep(1);
        }
        close(dev);
    }
 
    return 0;
}