10device-create.rar

#include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/fs.h> #include <linux/cdev.h> static struct class *cls; static struct device *device; static dev_t dev_num; static struct cdev cdev = { .owner = THIS_MODULE, }; int my_open(struct inode *inode, struct file *fp) { printk("open......\n"); return 0; } ssize_t my_read(struct file *fp, char __user *puser, size_t size, loff_t *off) { printk("read......\n"); return 0; } ssize_t my_write(struct file *fp, const char __user *puser, size_t size, loff_t *off) { printk("write......\n"); return 0; } int my_close(struct inode *inode, struct file *fp) { printk("close......\n"); return 0; } static struct file_operations fops = { .owner = THIS_MODULE, .open = my_open, .read = my_read, .write = my_write, .release = my_close, }; static int __init test_init(void) { int ret = 0; printk("test_init.....\n"); //动态分配设备号 ret = alloc_chrdev_region(&dev_num, 0, 1, "ddev"); if (ret < 0) { printk("alloc_chrdev_region failed.....\n"); return 1; } printk("major = %d minor: %d\n", MAJOR(dev_num), MINOR(dev_num)); printk("alloc_chrdev_region OK.....\n"); //初始化cdev cdev_init(&cdev, &fops); //字符设备添加到内核 cdev_add(&cdev, dev_num, 1); //创建设备类 cls = class_create(THIS_MODULE, "chardev_class"); //创建设备 device = device_create(cls, NULL, dev_num, NULL, "char_device"); return 0; } static void __exit test_exit(void) { unregister_chrdev_region(dev_num, 1); cdev_del(&cdev); //销毁设备 device_destroy(cls, dev_num); //设备类销毁 class_destroy(cls); printk("test_exit......\n"); } module_init(test_init); module_exit(test_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Jin.Deng"); MODULE_INFO(intree, "Y");