linux 模块ioctl

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>

#define DEVICE_PATH "/dev/mydevice"
#define IOCTL_CMD_SET_VALUE _IOW('m', 1, int) // 假设的设备特定ioctl命令

int main() {
    int fd = open(DEVICE_PATH, O_RDWR);
    if (fd < 0) {
        perror("Failed to open device");
        return -1;
    }

    int value = 42;
    if (ioctl(fd, IOCTL_CMD_SET_VALUE, &value) < 0) {
        perror("ioctl failed");
        close(fd);
        return -1;
    }

    printf("ioctl command executed successfully\n");
    close(fd);
    return 0;
}

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/fs.h>

#define DEVICE_NAME "mydevice"
#define IOCTL_CMD_SET_VALUE _IOW('m', 1, int)

static long my_ioctl(struct file *file, unsigned int cmd, unsigned long arg) {
    switch (cmd) {
        case IOCTL_CMD_SET_VALUE:
            // 处理设置值的逻辑
            break;
        default:
            return -EINVAL;
    }
    return 0;
}

static struct file_operations fops = {
    .unlocked_ioctl = my_ioctl,
};

static int __init my_module_init(void) {
    register_chrdev(240, DEVICE_NAME, &fops);
    printk(KERN_INFO "My device driver loaded.\n");
    return 0;
}

static void __exit my_module_exit(void) {
    unregister_chrdev(240, DEVICE_NAME);
    printk(KERN_INFO "My device driver unloaded.\n");
}

module_init(my_module_init);
module_exit(my_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("A simple device driver with ioctl support.");