嵌入式linux培训课程

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

#define DEVICE_NAME "led_blink"
#define GPIO_PIN 17

static int major_number;

static int device_open(struct inode *inode, struct file *file) {
    gpio_set_value(GPIO_PIN, 1); // Turn on LED
    return 0;
}

static int device_release(struct inode *inode, struct file *file) {
    gpio_set_value(GPIO_PIN, 0); // Turn off LED
    return 0;
}

static struct file_operations fops = {
    .open = device_open,
    .release = device_release,
};

static int __init led_init(void) {
    major_number = register_chrdev(0, DEVICE_NAME, &fops);
    if (major_number < 0) {
        printk(KERN_ALERT "Failed to register device\n");
        return major_number;
    }
    gpio_request(GPIO_PIN, "led_blink");
    gpio_direction_output(GPIO_PIN, 0);
    printk(KERN_INFO "LED Blink Device Registered\n");
    return 0;
}

static void __exit led_exit(void) {
    unregister_chrdev(major_number, DEVICE_NAME);
    gpio_free(GPIO_PIN);
    printk(KERN_INFO "LED Blink Device Unregistered\n");
}

module_init(led_init);
module_exit(led_exit);

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