usbcore之usb_hub_init(1)

最新推荐文章于 2024-07-31 16:11:01 发布

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最新推荐文章于 2024-07-31 16:11:01 发布 · 755 阅读

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#kernel

本文详细解析了Linux内核中USB HUB驱动的初始化过程，包括`usb_hub_init`函数的执行流程，`usb_register_driver`的内部机制，以及如何在sysfs中创建相关属性文件。通过对`hub_driver`结构体的设置，驱动被成功注册到USB总线，随后启动守护线程`khubd`。

hub驱动定义如下

static struct usb_driver hub_driver = {
	.name =		"hub",
	.probe =	hub_probe,
	.disconnect =	hub_disconnect,
	.suspend =	hub_suspend,
	.resume =	hub_resume,
	.reset_resume =	hub_reset_resume,
	.pre_reset =	hub_pre_reset,
	.post_reset =	hub_post_reset,
	.unlocked_ioctl = hub_ioctl,
	.id_table =	hub_id_table,
	.supports_autosuspend =	1,
};


int usb_hub_init(void)
{
	if (usb_register(&hub_driver) < 0) {
		printk(KERN_ERR "%s: can't register hub driver\n",
			usbcore_name);
		return -1;
	}

	khubd_task = kthread_run(hub_thread, NULL, "khubd");
	if (!IS_ERR(khubd_task))
		return 0;

	/* Fall through if kernel_thread failed */
	usb_deregister(&hub_driver);
	printk(KERN_ERR "%s: can't start khubd\n", usbcore_name);

	return -1;
}




static inline int usb_register(struct usb_driver *driver)
{
	return usb_register_driver(driver, THIS_MODULE, KBUILD_MODNAME);
}




int usb_register_driver(struct usb_driver *new_driver, struct module *owner,
			const char *mod_name)
{
	int retval = 0;

	if (usb_disabled())
		return -ENODEV;

	new_driver->drvwrap.for_devices = 0;
	new_driver->drvwrap.driver.name = (char *) new_driver->name;
	new_driver->drvwrap.driver.bus = &usb_bus_type;
	new_driver->drvwrap.driver.probe = usb_probe_interface;
	new_driver->drvwrap.driver.remove = usb_unbind_int