s3c44b0-seg7.c

来自「linux操作系统的七段数码管的驱动程序」· C语言 代码 · 共 102 行

#include	<linux/config.h>
#include	<linux/module.h>
#include	<linux/kernel.h>
#include	<linux/init.h>
#include	<asm/delay.h>
#include	<asm/uaccess.h>
#include	<linux/fs.h>
#include	<linux/devfs_fs_kernel.h>

//#undef	DEBUG
#define		DEBUG
#ifdef		DEBUG
#define		DPRINTK(x... )	printk("s3c44b0_seg7:"##x)
#else	
#define		DPRINTK(x...)
#endif

#define		SEG7	*((volatile unsigned char *)0x08000000)
#define		SEG7MUM	8

#define		DEVICE_NAME	"s3c44b0_seg7"
#define		DEVICESEG7_MINOR	1
const 	char    nameseg7[]="seg7";
const	char	snameseg7[]="0";
static 	int	SEG7Major = 0;
static	char	seg7status= 0xff;

static	void	Updateseg7(void)
{
	SEG7=0xff&seg7status;
}
static	ssize_t s3c44b0_Seg7_write(struct file *file,const char *buffer,size_t count, loff_t *ppos)
{
	copy_from_user(&seg7status,buffer,sizeof(seg7status));
	Updateseg7();
	
	DPRINTK("write:	seg7=0x%x, count=%d\n",seg7status,count);
	return sizeof(seg7status);
}

static	int	s3c44b0_Seg7_open(struct inode *inode,struct file *filp)
{
	MOD_INC_USE_COUNT;
	DPRINTK("open\n");
	return 0;
}
static	int	s3c44b0_Seg7_release(struct inode *inode, struct file *filp)
{
	MOD_DEC_USE_COUNT;
	DPRINTK("release\n");
	return 0;
}
static	struct	file_operations s3c44b0_fops = {
	owner:	THIS_MODULE,
	open:	s3c44b0_Seg7_open,
	write:  s3c44b0_Seg7_write,
	release:s3c44b0_Seg7_release,
};

#ifdef CONFIG_DEVFS_FS
static	devfs_handle_t	devfs_s3c44b0_dir,devfs_s3c44b0raw;
#endif

static	int	__init	s3c44b0_Seg7_init(void)
{
	int ret;
	seg7status=0x00;
	Updateseg7();
		
	ret = register_chrdev(SEG7Major,DEVICE_NAME,&s3c44b0_fops);
	if(ret<0)
	{
		printk(DEVICE_NAME "can't get major number\n");
		return ret;
	}
	SEG7Major = ret;
#ifdef	CONFIG_DEVFS_FS
        devfs_s3c44b0_dir=devfs_mk_dir(NULL,nameseg7,NULL);
	devfs_s3c44b0raw=devfs_register(devfs_s3c44b0_dir,snameseg7,DEVFS_FL_DEFAULT,SEG7Major,\
					DEVICESEG7_MINOR,S_IFCHR|S_IRUSR|S_IWUSR,&s3c44b0_fops,NULL);
#endif

	printk(DEVICE_NAME "initialized\n");
	return 0;
}

static	void	__exit	s3c44b0_Seg7_exit(void)
{
#ifdef	CONFIG_DEVFS_FS
	devfs_unregister(devfs_s3c44b0raw);
	devfs_unregister(devfs_s3c44b0_dir);
#endif
	unregister_chrdev(SEG7Major, DEVICE_NAME);
}

module_init(s3c44b0_Seg7_init);
module_exit(s3c44b0_Seg7_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("ZCY");
MODULE_DESCRIPTION("SEG7 driver fo EB44b0");