【嵌入式】字符驱动开发框架

来源：互联网发布：淘宝助理怎么拆分订单编辑：程序博客网时间：2024/06/05 06:41

开发字符驱动时，应该有如下框架：

1.构建file_operation，

static struct file_operations second_drv_fops = {    .owner  =   THIS_MODULE,       .open   =   second_drv_open,     .read=second_drv_write,   };

2.在结构体之前加入操作函数

static int first_drv_open(struct inode *inode, struct file *file){return 0;}ssize_t second_drv_read(struct file *file, char __user *buf, size_t size, loff_t *ppos){return 0;}

3.写入入口和出口函数，入口函数的主要功能是注册结构体，出口函数反之。在这里，我们为了使系统自动注册，加入一些代码。

static struct class *seconddrv_class;static struct class_device*seconddrv_class_dev;

static int second_drv_init(void){major = register_chrdev(0, "key_drv", &second_drv_fops);seconddrv_class = class_create(THIS_MODULE, "seconddrv");seconddrv_class_dev = class_device_create(seconddrv_class, NULL, MKDEV(major, 0), NULL, "xyz1"); /* /dev/xyz */printk("register a char device: key_drv !\n");return 0;}static int second_drv_exit(void){unregister_chrdev(major, "key_drv");class_device_unregister(seconddrv_class_dev);class_destroy(seconddrv_class);printk("unregister a char device: key_drv !\n");return 0;}module_init(second_drv_init);module_exit(second_drv_exit);MODULE_LICENSE("GPL");

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