keypad.c

实现了一个简单的web服务器

/***********************************************************************
 * Filename     : xhyper250-keypad.c                                    *
 * Program      : xhyper250 led&key test driver                         *
 * Copyright    : Copyright (C) 2001, newboder                         *
 * Author       : newboder <[e-mail]>                        *
 * Description  : StrongArm externd base boad interface test           *
 * Created at   : 2002.05.06                                           *
 * Based on     :                                                      *
 * Modified by  :                                                      *
 * Modified at  :                                                      *
 ***********************************************************************/

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/rtc.h>
#include <linux/delay.h>

#include <asm/hardware.h>
#include <asm/delay.h>


#define LEDnKEY_MAJOR 	251
#define KEYPAD_NAME     "Keypad"
#define KEYPAD_VERSION  "Version 0.1"

#define EXT_KEY_CS  EXT_PORT2
#define EXT_LED_CS  EXT_PORT3
#define LED_SHOW    10


void led_off_on()
{
	int i;
	EXT_LED_CS = 0xff;
	
	for(i =0 ; i<8;++i)
	{
		EXT_LED_CS = ~((1 << i) & 0xff);		
		udelay(30000);
	}
	EXT_LED_CS = 0xff;
}

int lednkey_open(struct inode *inode, struct file *filp)
{
	MOD_INC_USE_COUNT;
	return (0);          /* success */		 
}

int lednkey_release(struct inode *inode, struct file *filp)
{
//	led_off_on();
	MOD_DEC_USE_COUNT;
	return (0);
}

ssize_t lednkey_read(struct file *filp, char *Putbuf, size_t length, loff_t *f_pos)
{
	unsigned short BottonStatus;
   	unsigned char Bottontmp = 0;
	int i;

	BottonStatus = ( EXT_KEY_CS & 0xff );

	for(i = 0 ; i < 8; ++i)
	{
		if( ((BottonStatus >> i) & 1) == 0 ) 
			Bottontmp = (i+1);
	}

	copy_to_user( Putbuf, &Bottontmp, length);
	
	return length;
}

ssize_t lednkey_write(struct file *filp, const char *Getbuf, size_t length, loff_t *f_pos)
{
	int num;
	unsigned char UsrWantLed;
	  
  	copy_from_user( &UsrWantLed, Getbuf, length);	
	
	num =  ( (UsrWantLed) & 0xff );

	
	EXT_LED_CS = ~(1 << (num-1)); 
	printk("the %d statues is %x\n",num,EXT_LED_CS);

	return (0);	
}

int lednkey_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,unsigned long arg)
{

	printk ( "\n Enter the keypad driver code - lednkey_ioctl\n" );
	switch(cmd)
	{
		case LED_SHOW:
			{
				if(arg)
					led_off_on();
				break;
			}
	}
	return 0;
}

struct file_operations lednkey_fops = {
	open:       lednkey_open,
	read:       lednkey_read,
	write:      lednkey_write,
	ioctl:      lednkey_ioctl,
	release:    lednkey_release,
};


static int __init xhyper250_keypad_init(void)
{
	int result;
	result = register_chrdev(LEDnKEY_MAJOR, "lednkey", &lednkey_fops);

	printk("%s %s initialized.\n",KEYPAD_NAME, KEYPAD_VERSION);
	led_off_on();

	return 0;
}

static void __exit xhyper250_keypad_exit(void)
{  
	unregister_chrdev( LEDnKEY_MAJOR, "lednkey" );       	
//	led_off_on();
}

module_init(xhyper250_keypad_init);
module_exit(xhyper250_keypad_exit);