字符杂项设备（miscdevice）

misc杂项设备是主设备号为10的驱动设备

在linux内核源码miscdevice.h里杂项设备描述结构体定义：

struct miscdevice  {

int minor;

const char *name;

const struct file_operations *fops;

struct list_head list;

struct device *parent;

struct device *this_device;

const char *nodename;

mode_t mode;

};

extern int misc_register(struct miscdevice * misc); 

extern int misc_deregister(struct miscdevice *misc);

misc咋想设备框架：

static ssize_t mydev_read(struct file *filp, char __user * buf, size_t count, loff_t *f_pos)

{

}

static int mydev_ioctl( struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)

{

return 0;

}

static struct file_operations mydev_fops = {     //虚拟文件系统

.owner = THIS_MODULE,

.ioctl = mydev_ioctl,

.read = mydev_read,

};

static struct miscdevice misc = {

.minor = MISC_DYNAMIC_MINOR,

.name = DEVICE_NAME,

.fops = &mydev_fops,

};

static int mydev_init(void)

{

    int ret;

    ret = misc_register(&misc);

    return ret;

}

static void mydev_exit(void)

{

    misc_deregister(&misc);

}

module_init(mydev_init);   //模块加载函数

module_exit(mydev_exit);   //模块卸载函数

MODULE_LICENSE("Dual BSD/GPL");  //模块声明