led.c

本程序为嵌入式linux驱动

#include <linux/config.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/iobuf.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <asm/uaccess.h>
#include <asm/hardware.h>
#include <asm-arm/arch-s3c2410/cpu_s3c2410.h>
#include <asm/io.h>
#include <linux/vmalloc.h>


#define IOPORT_MAJOR 220 



int gpio_open(struct inode*,struct file*);
int gpio_release(struct inode*,struct file*);
int gpio_ctl_ioctl(struct inode*,struct file*,unsigned int,unsigned long);


static struct file_operations gpio_ctl_fops={
ioctl:		gpio_ctl_ioctl, 
open :		gpio_open, 
release:	gpio_release,
};
	

#define LED1_ON()	(GPFDAT	&= ~0x10)
#define LED2_ON()	(GPFDAT	&= ~0x20)
#define LED3_ON()	(GPFDAT	&= ~0x40)
#define LED4_ON()	(GPFDAT	&= ~0x80)
#define LED1_OFF()	(GPFDAT	|= 0x10)
#define LED2_OFF()	(GPFDAT	|= 0x20)
#define LED3_OFF()	(GPFDAT	|= 0x40)
#define LED4_OFF()	(GPFDAT	|= 0x80)

static int LedStatus;

void LedSet(int led)
{
LedStatus = led;
if(LedStatus&1) LED1_ON();
else
LED1_OFF();
if(LedStatus&2) LED2_ON();
else
LED2_OFF();
if(LedStatus&4) LED3_ON();
else
LED3_OFF();
if(LedStatus&8) LED4_ON();
else
LED4_OFF();
} 

void udelay(unsigned int time)
{
unsigned int a,b;
for(a=0;a<time;a++)
 for(b=0;b<a;b++);
}


void LedDisp(void)
{
LedSet(0x08);
udelay(0x500000);
LedSet(0x04);
udelay(0x500000);
LedSet(0x02);
udelay(0x500000);
LedSet(0x01);
udelay(0x500000);
LedSet(0x02);
udelay(0x500000);
LedSet(0x04);
udelay(0x500000);
LedSet(0x08);
udelay(0x500000);
}



static int __init gpio_init(void)
{
int err=0;
printk("gpio_init\n"); 
err=register_chrdev(IOPORT_MAJOR,"gpio",&gpio_ctl_fops); 
if(err)
{	
printk("fail to register\n");
return -1;
}	
printk("success to register\n");
return 0;
}


int gpio_open(struct inode *inode,struct file *fllp)
{
GPFCON=0x5500;
GPFUP=0xff;
printk("open gpio devices\n");
return 0;
}


int gpio_release(struct inode *inode,struct file *filp)
{
printk("release this device\n");
return 0;
}


int gpio_ctl_ioctl(struct inode *inode,struct file *flip,unsigned int command, unsigned long arg)
{
int err=0;
if(command==1){
while(arg--)
{	
LedDisp();	
printk("....");	
}	 
printk("\n"); 
return 0;
}	
return err;
}


module_init(gpio_init);
module_exit(gpio_release);