demo.h

linux 简单字符设备驱动......

#ifndef _DEMO_H_
#define _DEMO_H_

#include <linux/ioctl.h> /* needed for the _IOW etc stuff used later */

/********************************************************
* Macros to help debugging
********************************************************/
#undef PDEBUG             /* undef it, just in case */
#ifdef DEMO_DEBUG
#ifdef __KERNEL__
#    define PDEBUG(fmt, args...) printk( KERN_DEBUG "DEMO: " fmt, ## args)
#else//usr space
#    define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args)
#endif
#else
# define PDEBUG(fmt, args...) /* not debugging: nothing */
#endif

#undef PDEBUGG
#define PDEBUGG(fmt, args...) /* nothing: it's a placeholder */

//设备号
#define DEMO_MAJOR 50
#define DEMO_MINOR 0
#define COMMAND1 1
#define COMMAND2 2

//自己定义的设备结构
struct DEMO_dev
{
    struct cdev cdev;    /* Char device structure        */
};

//函数申明 原来Linux驱动程序设计这么简单 只需要实现这么几个函数就可以了
ssize_t DEMO_read(struct file *filp, char __user *buf, size_t count,
                   loff_t *f_pos);
ssize_t DEMO_write(struct file *filp, const char __user *buf, size_t count,
                    loff_t *f_pos);
loff_t DEMO_llseek(struct file *filp, loff_t off, int whence);
int     DEMO_ioctl(struct inode *inode, struct file *filp,
                    unsigned int cmd, unsigned long arg);


#endif /* _DEMO_H_ */