Linux字符设备驱动模板

以下是一个简单的Linux字符设备驱动程序模板，供参考：

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/uaccess.h>

#define DEVICE_NAME "mychardev"
#define CLASS_NAME "mycharclass"

static int major_num = 0;
static struct class* mycharclass = NULL;
static struct device* mychardev = NULL;
static struct cdev mycdev;

static int mychardev_open(struct inode*, struct file*);
static int mychardev_release(struct inode*, struct file*);
static ssize_t mychardev_read(struct file*, char*, size_t, loff_t*);
static ssize_t mychardev_write(struct file*, const char*, size_t, loff_t*);

static struct file_operations mychardev_fops = {
    .owner = THIS_MODULE,
    .open = mychardev_open,
    .release = mychardev_release,
    .read = mychardev_read,
    .write = mychardev_write,
};

static int __init mychardev_init(void) {
    // allocate major number dynamically
    if (alloc_chrdev_region(&major_num, 0, 1, DEVICE_NAME) < 0) {
        return -1;
    }

    // create device class
    if ((mycharclass = class_create(THIS_MODULE, CLASS_NAME)) == NULL) {
        unregister_chrdev_region(major_num, 1);
        return -1;
    }

    // create device
    if ((mychardev = device_create(mycharclass, NULL, major_num, NULL, DEVICE_NAME)) == NULL) {
        class_destroy(mycharclass);
        unregister_chrdev_region(major_num, 1);
        return -1;
    }

    // initialize cdev
    cdev_init(&mycdev, &mychardev_fops);
    mycdev.owner = THIS_MODULE;

    // add cdev to kernel
    if (cdev_add(&mycdev, major_num, 1) < 0) {
        device_destroy(mycharclass, major_num);
        class_destroy(mycharclass);
        unregister_chrdev_region(major_num, 1);
        return -1;
    }

    printk(KERN_INFO "mychardev: registered\n");

    return 0;
}

static void __exit mychardev_exit(void) {
    cdev_del(&mycdev);
    device_destroy(mycharclass, major_num);
    class_destroy(mycharclass);
    unregister_chrdev_region(major_num, 1);

    printk(KERN_INFO "mychardev: unregistered\n");
}

static int mychardev_open(struct inode* inodep, struct file* filep) {
    printk(KERN_INFO "mychardev: opened\n");
    return 0;
}

static int mychardev_release(struct inode* inodep, struct file* filep) {
    printk(KERN_INFO "mychardev: closed\n");
    return 0;
}

static ssize_t mychardev_read(struct file* filep, char* buffer, size_t len, loff_t* offset) {
    printk(KERN_INFO "mychardev: read from device\n");
    return 0;
}

static ssize_t mychardev_write(struct file* filep, const char* buffer, size_t len, loff_t* offset) {
    printk(KERN_INFO "mychardev: wrote to device\n");
    return len;
}

module_init(mychardev_init);
module_exit(mychardev_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("A simple character device driver");

需要注意的是，该模板仅提供了一个最基本的字符设备驱动程序框架，需要根据实际需求进行修改。此外，还需要在Makefile中添加相应的编译规则，将驱动程序编译成内核模块。