2022-01-08

struct ap3216c_dev {
    dev_t devid;            /* 设备号   */
    struct cdev cdev;       /* cdev     */
    struct class *class;    /* 类        */
    struct device *device;  /* 设备    */
    struct device_node  *nd; /* 设备节点 */
    int major;          /* 主设备号 */
    void *private_data; /* 私有数据 */
    unsigned short ir, als, ps;     /* 三个光传感器数据 */
};

static struct ap3216c_dev ap3216cdev;

static int ap3216c_open(struct inode *inode, struct file *filp)
{
    filp->private_data = &ap3216cdev;
}
static ssize_t ap3216c_read(struct file *filp, char __user *buf, size_t cnt, loff_t *off)
static int ap3216c_release(struct inode *inode, struct file *filp)

static const struct file_operations ap3216c_ops = {
    .owner = THIS_MODULE,
    .open = ap3216c_open,
    .read = ap3216c_read,
    .release = ap3216c_release,
};
static int ap3216c_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
    /* 1、构建设备号 */
    if (ap3216cdev.major) {
        ap3216cdev.devid = MKDEV(ap3216cdev.major, 0);
        register_chrdev_region(ap3216cdev.devid, AP3216C_CNT, AP3216C_NAME);
    } else {
        alloc_chrdev_region(&ap3216cdev.devid, 0, AP3216C_CNT, AP3216C_NAME);
        ap3216cdev.major = MAJOR(ap3216cdev.devid);
    }

    /* 2、注册设备 */
    cdev_init(&ap3216cdev.cdev, &ap3216c_ops);
    cdev_add(&ap3216cdev.cdev, ap3216cdev.devid, AP3216C_CNT);

    /* 3、创建类 */
    ap3216cdev.class = class_create(THIS_MODULE, AP3216C_NAME);
    if (IS_ERR(ap3216cdev.class)) {
        return PTR_ERR(ap3216cdev.class);
    }

    /* 4、创建设备 */
    ap3216cdev.device = device_create(ap3216cdev.class, NULL, ap3216cdev.devid, NULL, AP3216C_NAME);
    if (IS_ERR(ap3216cdev.device)) {
        return PTR_ERR(ap3216cdev.device);
    }

    ap3216cdev.private_data = client;

    return 0;
}

static int ap3216c_remove(struct i2c_client *client)
{
    /* 删除设备 */
    cdev_del(&ap3216cdev.cdev);
    unregister_chrdev_region(ap3216cdev.devid, AP3216C_CNT);

    /* 注销掉类和设备 */
    device_destroy(ap3216cdev.class, ap3216cdev.devid);
    class_destroy(ap3216cdev.class);
    return 0;
}


/* i2c驱动结构体 */  
static struct i2c_driver ap3216c_driver = {
    .probe = ap3216c_probe,
    .remove = ap3216c_remove,
    .driver = {
            .owner = THIS_MODULE,
            .name = "ap3216c",
            .of_match_table = ap3216c_of_match, 
           },
    .id_table = ap3216c_id,
};
           
static int __init ap3216c_init(void)
{
    int ret = 0;

    ret = i2c_add_driver(&ap3216c_driver);
    return ret;
}

static void __exit ap3216c_exit(void)
{
    i2c_del_driver(&ap3216c_driver);
}

module_init(ap3216c_init);
module_exit(ap3216c_exit);
MODULE_LICENSE("GPL");