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
19 static 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 */
usb_register_notify(struct notifier_block * nb)27 void usb_register_notify(struct notifier_block *nb)
28 {
29 blocking_notifier_chain_register(&usb_notifier_list, nb);
30 }
31 EXPORT_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 */
usb_unregister_notify(struct notifier_block * nb)40 void usb_unregister_notify(struct notifier_block *nb)
41 {
42 blocking_notifier_chain_unregister(&usb_notifier_list, nb);
43 }
44 EXPORT_SYMBOL_GPL(usb_unregister_notify);
45
46
usb_notify_add_device(struct usb_device * udev)47 void usb_notify_add_device(struct usb_device *udev)
48 {
49 blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
50 }
51
usb_notify_remove_device(struct usb_device * udev)52 void 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
usb_notify_add_bus(struct usb_bus * ubus)61 void usb_notify_add_bus(struct usb_bus *ubus)
62 {
63 blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
64 }
65
usb_notify_remove_bus(struct usb_bus * ubus)66 void usb_notify_remove_bus(struct usb_bus *ubus)
67 {
68 blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
69 }
70