TaiShanPai/驱动文件/2024-11-6/ledByMySelf.c

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>  // for copy_to_user() and copy_from_user()
const char *TAG = "MYNEWNODE";\

static int major_number = 0;  // 默认自动分配主设备号
static struct cdev my_cdev;
static struct class *my_class;


// 打开字符设备
static int gpio_led_open(struct inode *inode, struct file *file)
{
    printk("%s:open!\n", TAG);
    return 0;
}

// 关闭字符设备
static int gpio_led_release(struct inode *inode, struct file *file)
{
    printk("%s:release!\n", TAG);
    return 0;
}

// 读取数据（此示例没有实际硬件操作）
static ssize_t gpio_led_read(struct file *file, char __user *buf, size_t len, loff_t *offset)
{
    printk("%s:read!\n", TAG);
    // 这里可以填充实际的读取逻辑，如果需要从硬件读取数据
    return 0;
}

// 写入数据（此示例没有实际硬件操作）
static ssize_t gpio_led_write(struct file *file, const char __user *buf, size_t len, loff_t *offset)
{
    printk("%s:write!\n", TAG);
    // 这里可以填充实际的写入逻辑，如果需要控制硬件
    return len;  // 返回实际写入的字节数
}

// 字符设备操作结构体
static const struct file_operations gpio_led_fops = {
    .owner = THIS_MODULE,
    .open = gpio_led_open,
    .release = gpio_led_release,
    .read = gpio_led_read,
    .write = gpio_led_write,
};

static int gpio_led_probe(struct platform_device *pdev)
{   int ret;
    // 这里可以添加初始化代码
    printk("%s:probe!\n",TAG);

    ret = alloc_chrdev_region(&major_number,0,1,"gpio_led");
    if(ret < 0){
        printk("%s:alloc_chrdev_region failed!\n", TAG);
        return ret;
    }

    // 注册字符设备
    cdev_init(&my_cdev, &gpio_led_fops);
    my_cdev.owner = THIS_MODULE;
    ret = cdev_add(&my_cdev, major_number, 1);
    if (ret) {
        printk("%s:cdev_add failed!\n", TAG);
        unregister_chrdev_region(major_number, 1);
        return ret;
    }

    // 创建设备文件
    my_class = class_create(THIS_MODULE, "gpio_led_class");
    if (IS_ERR(my_class)) {
        ret = PTR_ERR(my_class);
        printk("%s:class_create failed!\n", TAG);
        cdev_del(&my_cdev);
        unregister_chrdev_region(major_number, 1);
        return ret;
    }

    if (IS_ERR(device_create(my_class, NULL, major_number, NULL, "gpio_led"))) {
        printk("%s:device_create failed!\n", TAG);
        class_destroy(my_class);
        cdev_del(&my_cdev);
        unregister_chrdev_region(major_number, 1);
        return -ENOMEM;
    }

    return 0; // 返回 0 表示成功
}

// 设备remove函数
static int gpio_led_remove(struct platform_device *pdev)
{
    printk("%s:remove!\n", TAG);

    // 注销字符设备
    device_destroy(my_class, major_number);
    class_destroy(my_class);
    cdev_del(&my_cdev);
    unregister_chrdev_region(major_number, 1);

    return 0;
}

static void gpio_led_shutdown(struct platform_device *pdev)
{
    printk("%s:shutdown!\n", TAG);
}

static const struct of_device_id of_gpio_leds_match[] = {
    { .compatible = "led-user", },
    {}
};

MODULE_DEVICE_TABLE(of, of_gpio_leds_match);

static struct platform_driver gpio_led_driver = {
    .probe      = gpio_led_probe,
    .remove     = gpio_led_remove,
    .shutdown   = gpio_led_shutdown,
    .driver     = {
        .name   = "led-user",
        .of_match_table = of_gpio_leds_match,
    },
};

module_platform_driver(gpio_led_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Your Name");
MODULE_DESCRIPTION("Simple GPIO LEDs driver");