参照元

説明

引数

返り値

参考

実装

/**
 * __register_chrdev() - create and register a cdev occupying a range of minors
 * @major: major device number or 0 for dynamic allocation
 * @baseminor: first of the requested range of minor numbers
 * @count: the number of minor numbers required
 * @name: name of this range of devices
 * @fops: file operations associated with this devices
 *
 * If @major == 0 this functions will dynamically allocate a major and return
 * its number.
 *
 * If @major > 0 this function will attempt to reserve a device with the given
 * major number and will return zero on success.
 *
 * Returns a -ve errno on failure.
 *
 * The name of this device has nothing to do with the name of the device in
 * /dev. It only helps to keep track of the different owners of devices. If
 * your module name has only one type of devices it's ok to use e.g. the name
 * of the module here.
 */
int __register_chrdev(unsigned int major, unsigned int baseminor,
                      unsigned int count, const char *name,
                      const struct file_operations *fops)
{
        struct char_device_struct *cd;
        struct cdev *cdev;
        int err = -ENOMEM;
        cd = __register_chrdev_region(major, baseminor, count, name);
        if (IS_ERR(cd))
                return PTR_ERR(cd);
        cdev = cdev_alloc();
        if (!cdev)
                goto out2;
        cdev->owner = fops->owner;
        cdev->ops = fops;
        kobject_set_name(&cdev->kobj, "%s", name);
        err = cdev_add(cdev, MKDEV(cd->major, baseminor), count);
        if (err)
                goto out;
        cd->cdev = cdev;

        return major ? 0 : cd->major;
out:
        kobject_put(&cdev->kobj);
out2:
        kfree(__unregister_chrdev_region(cd->major, baseminor, count));
        return err;
}

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Last-modified: 2016-02-16 (火) 18:32:56