复件 led.c

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/**************************************************************/
/* name       : /linux/drivers/led/led.c                     */
/* description: board-EDUKIT-II/III                          */
/* copyright  : version 1.0                                  */
/* cpu        : S3C44B0X                                     */

/* author     : HaiTao Guo                                   */
/* company    : South China University                       */
/* date       : Sunday,Octorber 05,2008                      */
/**************************************************************/

#include<linux/module.h>
#include<linux/init.h>
#include<linux/sched.h>
#include<linux/kernel.h>
#include<linux/fs.h>
#include<linux/errno.h>
#include<linux/types.h>
#include<linux/types.h>
#include<asm-arm/uaccess.h>
#include<asm-arm/s3c44b0x.h>


#undef DEBUG
#ifdef DEBUG
#define TRACE(str,args...) printk("led: ",str,##args)
#else
#define TRACE(str,args...)
#endif


#define LED_MAJOR 60 
#define LED_DEVNAME "led0"

#define GPB_MASK (3<<4)
#define GPF_MASK (3<<3)
#define GET_DATA(b,f) ((u8)( ((~b&0x20)>>5) | ((~b&0x10)>>2) | ((~b&0x08)>>2) | ((~b&0x10)>>1) )
#define SET_DATA(t,b,f) (b=( ((~t&0x01)<<5) | ((~t&0x04)<<2)), f=(((~t&0x02)<<2) | ((~t&0x08)<<1)) )

#define LED_LOCK(u) down(&u->lock)
#define LED_UNLOCK(u) up(&u->lock)


/*led control unit*/
struct unit{
	struct semaphore lock;
	u32 *PCONB;
 	u32 *PDATB;
	u32 *PCONF;
	u32 *PDATF;
	u32 *PUPF;
	u32 b;
	u32 f;
};

static char *version="Embest EDUKIT-II led driver version 1.0(2008-10-05)<www.edmbedinfo.com>\n";

static struct unit led_unit={
	.PCONB=(u32 *)S3C44B0X_PCONB,
	.PDATB=(u32 *)S3C44B0X_PDATB,
	.PCONF=(u32 *)S3C44B0X_PCONF,
	.PDATF=(u32 *)S3C44B0X_PDATF,
	.PUPF =(u32 *)S3C44B0X_PUPF,
};

static void led_set_value(struct unit *unit,u8 val)
{
	u32 temp;
	SET_DATA(val,unit->b,unit->f);
	temp=*unit->PDATB;
	temp&=~GPB_MASK;
	temp|=unit->b;
	*unit->PDATB=temp;

	temp=*unit->PDATF;
	temp&=~GPF_MASK;
	temp|=unit->f;
	*unit->PDATF=temp;
}

static u8 led_get_value(struct unit *unit)
{
	u8 temp=GET_DATA(unit->b,unit->f);
	return temp;
}

static int led_open(struct inode *inode, struct file *file)
{
	TRACE("open\n");
	file->private_data=&led_unit;
	MOD_INC_USE_COUNT;
	return 0;
}

static int led_release(struct inode *inode,struct file *file)
{
	TRACE("release\n");
	MOD_DEC_USE_COUNT;
	return 0;
}

static ssize_t led_read(struct file *file,char *buf,size_t count,loff_t *offset)
{
	u8 temp;
	int ret;
	struct unit *unit=(struct unit *)file->private_data;
      	TRACE("read\n");
	if(count>1)
		count=1;
	LED_LOCK(unit);
	ret=copy_to_user(buf,&temp,count)?-EFAULT:count;
	LED_UNLOCK(unit);
	return ret;
}

static ssize_t led_write(struct file *file,const char *buf,size_t count,loff_t *offset)
{
	u8 temp;
	int ret;
	struct unit *unit=(struct unit *)file->private_data;
	TRACE("write\n");
	if(count>1)
		count=1;
	LED_LOCK(unit);	
	ret=copy_from_user(&temp,buf,count)?-EFAULT:count;
	if(ret)
		led_set_value(unit,temp);
	LED_UNLOCK(unit);
	return ret;
}

static struct file_operations led_file_operations={
	owner:THIS_MODULE,
	open :led_open,
	release:led_release,
	read:led_read,
	write:led_write,
};

static void __init led_init(struct unit *unit)
{
	u32 temp;
	/*init device lock*/
	init_MUTEX(&unit->lock);

	/*init io port*/
	temp=*unit->PCONB;
	temp&=~(3<<4);
	*unit->PCONB=temp;

	temp=*unit->PCONF;
	temp&=~((3<<8)~(3<<6));
	temp|=((1<<8)|(1<<6));
	*unit->PCONF=temp;

	temp=*unit->PUPF;
	temp|=(3<<3);
	*unit->PUPF=temp;

	/*init data and turn on led*/
	led_set_value(unit,0x0f);
	mdelay(100);
	led_set_value(unit,0x00);
}

/*module init functions */
int __init led_init_module(void)
{
	int res;
	TRACE("init_module\n");
	/*print version information*/
	printk(KERN_INFO "%s",version);
	/*register device*/
	res=register_chrdev(LED_MAJOR,LED_DEVNAME,&led_file_operations);
	if(res<0){
		printk("ekii-led.o:unable to get major %d for led device.       \n",LED_MAJOR);
		return res;
	}
	/*then call led_init()*/
	led_init(&led_unit);
	return 0;
}

/*module exit functions*/
void __exit led_cleanup(void)
{
	int res;
	TRACE("cleanup\n");
	res=unregister_chrdev(LED_MAJOR,LED_DEVNAME);
	if(res<0)
		printk("ekii-led.o:unable to release major %d for led device.\n",LED_MAJOR);
}

module_init(led_init_module);
module_exit(led_cleanup);

MODULE_DESCRIPTION("EDUKIT-II led driver");
MODULE_AUTHOR("Embest tech&info Co.,Ltd.<www.embedinfo.com>");
MODULE_LICENSE("GPL");