key_led.c

按键+LED驱动实验 基于TEB-44B0实验平台 包括按键+LED驱动程序与测按键试程序

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/miscdevice.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/segment.h>
//#include <asm/MC68VZ328.h>
#include <asm/arch/s3c44b0x.h>

//#define KEY&LED_DEBUG

int key_led_major=30;              /* Select 0 for Dynamic adressing */

DECLARE_WAIT_QUEUE_HEAD(wq);
static char message;
int count=2000;
int x;

void delay(int time)
{
	while (time--);
}

static char scans()
{
 	int x;
	
       outl(inl(S3C44B0X_PCONE)&(0x3cfff), S3C44B0X_PCONE); 
  	outl(inl(S3C44B0X_PCONE)|(0x1000), S3C44B0X_PCONE);    //PE6 as output
  	
 	outl(inl(S3C44B0X_PUPE)&(0x1bf), S3C44B0X_PUPE);
  
       outl(inl(S3C44B0X_PDATE)&(0x1bf), S3C44B0X_PDATE);      //PE6->0
  
  	outl(inl(S3C44B0X_PCONF)&(~((0x03)<<4)), S3C44B0X_PCONF); 
 	outl(inl(S3C44B0X_PCONF)|((0x01)<<4), S3C44B0X_PCONF);    //PF2 as output
  
       outl(inl(S3C44B0X_PUPF)&(0x1fb), S3C44B0X_PUPF);
  
       outl(inl(S3C44B0X_PDATF)|(0x04), S3C44B0X_PDATF);      //PF2->1

	outl(inl(S3C44B0X_PCONG)&(0x0000), S3C44B0X_PCONG);    //PG7 ~ PG0 as input
  	x = inl(S3C44B0X_PDATG);

	if(x != 0x00)                       /* if key play */
      {     
       
       outl(inl(S3C44B0X_PDATF)&(0xfb), S3C44B0X_PDATF);      //PF2->0
       outl(inl(S3C44B0X_PCONG)|(0x5555), S3C44B0X_PCONG);    //PG7 ~ PG0 as output
       outl(x, S3C44B0X_PDATG);                               //PG7 ~ PG0 ->x

	switch (x)
	{
	 case 0x01:
		message = '1';
		break;
	 case 0x02:
		message = '2';
              break;
        case 0x04:
              message = '3';
              break;
	 case 0x08:
		message = '4';
		break;
	 case 0x10:
		message = '5';
		break;
	 case 0x20:
		message = '6';
		break;
	 case 0x40:
		message = '7';
		break;
	 case 0x80:
		message = '8';
		break;        
        }
     delay(10*count);
   }
   
   return message;
      
}
                                
static ssize_t key_led_read(struct file *file, char *buffer, size_t len, loff_t *offset)
{
	scans();
 	copy_to_user(&buffer[0],&message,1);
	return 1;
}

/* Open-Funktion des Devices */
static int key_led_open(struct inode *inode, struct file *file)
{

	 return 0;
}

/* Close-Funktion des Devices */
static void key_led_close(struct inode *inode, struct file *file)
{

        //free_irq(IRQ_KEY&LED,NULL);

#ifdef KEY&LED_DEBUG
   	printk("the device is closed\n");
#endif
 
}

struct file_operations key_led_fops=
{
        read: key_led_read,
//	 write: key_led_write,
        open: key_led_open,
        release: key_led_close,
};
                               
int insert_key_led(void)
{
	int rc;

	rc=register_chrdev(key_led_major, "key_led", &key_led_fops);
	if(rc<0)
	{
#ifdef KEY&LED_DEBUG
		printk("Panic! Could not register KEY_LED-Driver\n");
#endif
		return rc;
	};
	return 0;
}


int key_led_init(void)
{
	int rc;

	rc=insert_key_led();
	if(rc<0)
	{
#ifdef KEY&LED_DEBUG
		printk("Panic! KEY_LED-driver could not be loaded!\n");
#endif
		return -ENODEV;
	}
	else 
	{
#ifdef KEY&LED_DEBUG
		printk("KEY_LED-driver init OK\n");
#endif
	}
	return 0;
}