1/*
2 * All the USB notify logic
3 *
4 * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
5 *
6 * notifier functions originally based on those in kernel/sys.c
7 * but fixed up to not be so broken.
8 *
9 */
10
11
12#include <linux/kernel.h>
13#include <linux/export.h>
14#include <linux/notifier.h>
15#include <linux/usb.h>
16#include <linux/mutex.h>
17#include "usb.h"
18
19static BLOCKING_NOTIFIER_HEAD(usb_notifier_list);
20
21/**
22 * usb_register_notify - register a notifier callback whenever a usb change happens
23 * @nb: pointer to the notifier block for the callback events.
24 *
25 * These changes are either USB devices or busses being added or removed.
26 */
27void usb_register_notify(struct notifier_block *nb)
28{
29	blocking_notifier_chain_register(&usb_notifier_list, nb);
30}
31EXPORT_SYMBOL_GPL(usb_register_notify);
32
33/**
34 * usb_unregister_notify - unregister a notifier callback
35 * @nb: pointer to the notifier block for the callback events.
36 *
37 * usb_register_notify() must have been previously called for this function
38 * to work properly.
39 */
40void usb_unregister_notify(struct notifier_block *nb)
41{
42	blocking_notifier_chain_unregister(&usb_notifier_list, nb);
43}
44EXPORT_SYMBOL_GPL(usb_unregister_notify);
45
46
47void usb_notify_add_device(struct usb_device *udev)
48{
49	blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
50}
51
52void usb_notify_remove_device(struct usb_device *udev)
53{
54	/* Protect against simultaneous usbfs open */
55	mutex_lock(&usbfs_mutex);
56	blocking_notifier_call_chain(&usb_notifier_list,
57			USB_DEVICE_REMOVE, udev);
58	mutex_unlock(&usbfs_mutex);
59}
60
61void usb_notify_add_bus(struct usb_bus *ubus)
62{
63	blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
64}
65
66void usb_notify_remove_bus(struct usb_bus *ubus)
67{
68	blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
69}
70