eatpcpld.c

UCLINUX字符驱动程序,用ARM7多功能口实现跑马灯.

#ifndef __KERNEL__
        #define __KERNEL__
#endif
#ifndef MODULE
        #define MODULE
#endif
#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/kernel.h>     // printk()
#include <linux/slab.h>     // kmalloc()
#include <linux/errno.h>   // error codes
#include <linux/types.h>   // size_t
#include <linux/interrupt.h>   // mark_bh
#include <linux/i2c.h>       
#include <linux/skbuff.h>
#include <asm/segment.h>
#include <asm/uaccess.h>
#include <asm/irq.h>
#include <linux/wait.h>
#include <asm/arch/hardware.h>

#include "eatpcpld.h"

static int       eatpcpld_open(struct inode * inode, struct file * flip);
static int       eatpcpld_release(struct inode * inode, struct file * flip);
static int       eatpcpld_ioctl(struct inode * inode, struct file * flip, unsigned int cmd, unsigned long param);

int eatpcpld_init(void);
void eatpcpld_cleanup(void);

#define MAJOR_NR 240
#define DEVICE_NAME "eatpcpld"

module_init(eatpcpld_init);
module_exit(eatpcpld_cleanup);

static struct file_operations eatpcpld_fops = 
{
	owner:		THIS_MODULE,
	ioctl:		eatpcpld_ioctl,
	open:		  eatpcpld_open,
	release:	eatpcpld_release,
};


static int eatpcpld_open(struct inode * inode,struct file * flip)
{
	MOD_INC_USE_COUNT;
	printk(KERN_ERR "Hello from eatpcpld_open()..\n");
	return 0;
}

static int eatpcpld_release(struct inode * inode,struct file * flip)
{
	MOD_DEC_USE_COUNT;
	printk(KERN_ERR "Hello form eatpcpld_release()\n");
	return 0;
}

static int eatpcpld_ioctl(struct inode * inode,struct file * flip,unsigned int cmd,unsigned long arg)
{
	
long int *REGCON;
long int *REGDATA;

if(_IOC_TYPE(cmd)!=EATPCPLD_IOC_MAGIC)
	{
		return -ENOTTY;
	}

if(_IOC_NR(cmd)>=EATPCPLD_MAXNR)
	{
		return -ENOTTY;
	}
	
REGCON=0x01d20040;
REGDATA=0x01d20044;

switch(cmd)
{
case EATPCPLD_SET_PIN_OUT:
		 {
			*REGCON|=(0x0001<<(arg*2));
			*REGCON&=~(0x0002<<(arg*2));
	   }
	  break;
case EATPCPLD_SET_DATA:
		{
			*REGDATA|=(0x0001<<arg);
	  }
	  break;

case EATPCPLD_CLR_DATA:
		{
			*REGDATA&=~(0x0001<<arg);
	  }
	  break;
default:
	return -ENOTTY;
	break;
	
}
	
	return 0;
}

int eatpcpld_init(void)
{
	int result;
	
	result = register_chrdev(MAJOR_NR, DEVICE_NAME, &eatpcpld_fops);

	if(result < 0)
	{
		printk(KERN_ERR DEVICE_NAME ": Unable to get major %d\n",MAJOR_NR);
		return result;
	}

	printk(KERN_ERR DEVICE_NAME ": init OK\n");
	return 0;
}

void eatpcpld_cleanup(void)
{
	unregister_chrdev(MAJOR_NR, DEVICE_NAME);
	printk("bye!\n");
}