driverb-a.c

这是一个基于S3C2410的8位按键的驱动程序源代码

/*This is a keybd char device driver.
* author:Aaron
*date:2007-1-16
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/iobuf.h>
#include <linux/major.h>
#include <linux/blkdev.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm/arch/cpu_s3c2410.h>
#include <asm/io.h>
#include <linux/vmalloc.h>
#include<linux/delay.h>

/*#define INPUT_MAJOR 200
*/
unsigned int input_major=231;
int result=0;
#define NOKEY   0

/*static char *key="";
*/
int key=0;

#define key_rGPCCON (*(volatile unsigned long *)key_r_GPCCON)
#define key_rGPCUP  (*(volatile unsigned long *)key_r_GPCUP)    
#define key_rGPCDAT (*(volatile unsigned long *)key_r_GPCDAT)

#define key_rGPDCON (*(volatile unsigned long *)key_r_GPDCON)
#define key_rGPDUP (*(volatile unsigned long *)key_r_GPDUP)
#define key_rGPDDAT (*(volatile unsigned long *)key_r_GPDDAT)

volatile unsigned long *key_r_GPCCON;
volatile unsigned long *key_r_GPCUP;
volatile unsigned long *key_r_GPCDAT;
volatile unsigned long *key_r_GPDCON;
volatile unsigned long *key_r_GPDUP;
volatile unsigned long *key_r_GPDDAT;
                                                                                

devfs_handle_t devfs_keybd;

int keybd_open(struct inode *, struct file *);
int keybd_release(struct inode *, struct file *);
ssize_t keybd_read(struct file *file, char *buf , size_t size,loff_t *inode );

/*
* Open/close code for raw IO.
*/

int keybd_open(struct inode *inode, struct file *file)
{

printk("open ok\n");
return 0;

}


ssize_t keybd_read(struct file *file, char * buf,size_t size,loff_t *inode)
{
/*int left;*/
      
     key_rGPCCON &= 0xffc0ffff;
     key_rGPDCON &= 0xfff0fff0;        //input

   mdelay(20);                                                                
 if ((key_rGPCDAT & 0x100) == 0)           key=1;   //F1
 else if ((key_rGPCDAT & 0x200) == 0)      key=3;   //F3
 else if ((key_rGPCDAT & 0x400) == 0)      key=6  ;   //F6
 else if ((key_rGPDDAT & 0x1) == 0)      key=4;   //F4
 else if ((key_rGPDDAT & 0x2) == 0)      key=5;   //F5
 else if ((key_rGPDDAT & 0x100) == 0)      key =7;   //F7
 else if ((key_rGPDDAT & 0x200) == 0)      key=8;   //F8
 else key=0;

copy_to_user(buf,&key,size);
 

   return 1;
}

int keybd_release(struct inode *inode, struct file *filp)
{
printk("release ok\n");
return 0;
}

static struct file_operations keybd_fops={
open:keybd_open,
read:keybd_read,
release:keybd_release,
};

int __init keybd_init(void)
{
printk("*********************keybd_init**************\n");
//address map
       key_r_GPCCON=ioremap(0x56000020,4);
       key_r_GPCDAT=ioremap(0x56000024,4);
       key_r_GPCUP=ioremap(0x56000028,4);
      
      key_r_GPDCON=ioremap(0x56000030,4);
      key_r_GPDDAT=ioremap(0x56000034,4);
      key_r_GPDUP=ioremap(0x56000038,4);

         key_rGPCUP &= 0xf8ff;
         key_rGPDUP &= 0xfcfc;
    
     //  key_rGPFUP &= 0xef;    

     //key_rGPFCON &= 0x8002;        //input
/*       devfs_keybd = devfs_register(NULL, "buttons", DEVFS_FL_DEFAULT,
            INPUT_MAJOR, 0,
              S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP,
              &keybd_fops, NULL);
*/
    result=register_chrdev(200,"buttons",&keybd_fops);
 if(result<0)
  {
   printk("buttons:can't get major number\n");
 }
  if(input_major==200)
 {
   input_major=result;
 return 0;
}

printk("*********************keybd_init**************\n");
      return 0;
}

static void __exit keybd_exit(void)
{
/*  devfs_unregister(devfs_keybd);
*/
   unregister_chrdev(input_major,"buttons");
       printk("rmmod ok!\n");
}

module_init(keybd_init);
module_exit(keybd_exit);