keypad.c

键盘驱动实验 基于TEB-44B0实验平台的键盘驱动 包括键盘驱动程序与测试程序

// keypad driver
// Vencent 
 
#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 <linux/delay.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/segment.h>
#include <asm/arch/s3c44b0x.h>

#define KEYPAD_DEBUG

int keypad_major=40;              /* Select 0 for Dynamic adressing */

#define NOKEY   0

//keypad_arr is an keyboard_map array.
unsigned char keypad_arr[5][5] = {{0,0,0,0,0},{0,'0','1','2','3'},{0,'4','5','6','7'},{0,'8','9','A','B'},{0,'C','D','E','F'}};

static char key=NOKEY;
static int x;
                                
static ssize_t keypad_read(struct file *file, char *buffer, size_t len, loff_t *offset)
{
	int row,line;
	row=0;
	line=0;

	outl(inl(S3C44B0X_PCONG)&(0xc03f), S3C44B0X_PCONG);   
       	outl(inl(S3C44B0X_PCONG)|(0x1540), S3C44B0X_PCONG);   // PG3~6 as output 
       	outl(inl(S3C44B0X_PDATG)&(0x87), S3C44B0X_PDATG);      // PG3~6 ->0
       
	outl(inl(S3C44B0X_PCONE)&(0x3303f), S3C44B0X_PCONE);  // PE3~5,7 as input
	mdelay(10);
	x = inl(S3C44B0X_PDATE) & 0xb8;
       	switch(x)
	{
	case 0xb0:
		row = 1;
		break;
	case 0xa8:
		row = 2;
		break;
	case 0x98:
		row = 3;
		break;
	case 0x38:
		row = 4;
		break;
	}

	outl(inl(S3C44B0X_PCONE)&(0x3303f), S3C44B0X_PCONE);   
       	outl(inl(S3C44B0X_PCONE)|(0x4540), S3C44B0X_PCONE);   // PE3~5,7 as output 
       	outl(inl(S3C44B0X_PDATE)&(0x147), S3C44B0X_PDATE);      // PE3~5,7 ->0
       
	outl(inl(S3C44B0X_PCONG)&(0xc03f), S3C44B0X_PCONG);     // PG3~6 as input
	mdelay(10);
	x = inl(S3C44B0X_PDATG) & 0x78;
       	switch(x)
	{
	case 0x70:
		line = 1;
		break;
	case 0x68:
		line = 2;
		break;
	case 0x58:
		line = 3;
		break;
	case 0x38:
		line = 4;
		break;
	}
	
	key = keypad_arr[row][line];
 	copy_to_user(buffer,&key,1);
	key=NOKEY;

	return 1;
}

/* Open-Funktion des Devices */
static int keypad_open(struct inode *inode, struct file *file)
{
#ifdef KEYPAD_DEBUG
	printk("the keypad is open\n");
#endif
	return 0;
}

/* Close-Funktion des Devices */
static void keypad_close(struct inode *inode, struct file *file)
{
#ifdef KEYPAD_DEBUG 
  	printk("the keypad is closed\n");
#endif
}

struct file_operations keypad_fops=
{
        read: keypad_read,
        open: keypad_open,
        release: keypad_close,
};
                               
int insert_keypad(void)
{
	int rc;

	rc=register_chrdev(keypad_major, "keypad", &keypad_fops);
	if(rc<0)
	{
#ifdef KEYPAD_DEBUG
		printk("Panic! Could not register KEYPAD-Driver\n");
#endif
		return -ENODEV;
	}
	
	return 0;
}


int keypad_init(void)
{
	int rc;
        
	rc=insert_keypad();
	if(rc)
	{
#ifdef KEYPAD_DEBUG
		printk("Panic! KEYPAD-driver could not be loaded!\n");
#endif
	}
	
#ifdef KEYPAD_DEBUG
	printk("KEYPAD-driver init OK\n");
#endif
	
	outl(inl(S3C44B0X_PCONE)&(0x3cfff), S3C44B0X_PCONE); 
  	outl(inl(S3C44B0X_PCONE)|(0x1000), S3C44B0X_PCONE);    //PE6 as output  
  	outl(inl(S3C44B0X_PDATE)|(0x40), S3C44B0X_PDATE);      /* PE6->1, disable CPLD I/O expand */

	outl(inl(S3C44B0X_PUPE)&(0x147), S3C44B0X_PUPE);    
        outl(inl(S3C44B0X_PUPG)&(0x87), S3C44B0X_PUPG);        // Pull up for row and line

	return rc;
}