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/drivers/usb/core/notify.c

https://bitbucket.org/cyanogenmod/android_kernel_asus_tf300t
C | 68 lines | 35 code | 10 blank | 23 comment | 0 complexity | 4d2bdcf623bf9904a267343bbeda78e6 MD5 | raw file
Possible License(s): LGPL-2.0, AGPL-1.0, GPL-2.0
 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/notifier.h>
14#include <linux/usb.h>
15#include <linux/mutex.h>
16#include "usb.h"
17
18static BLOCKING_NOTIFIER_HEAD(usb_notifier_list);
19
20/**
21 * usb_register_notify - register a notifier callback whenever a usb change happens
22 * @nb: pointer to the notifier block for the callback events.
23 *
24 * These changes are either USB devices or busses being added or removed.
25 */
26void usb_register_notify(struct notifier_block *nb)
27{
28	blocking_notifier_chain_register(&usb_notifier_list, nb);
29}
30EXPORT_SYMBOL_GPL(usb_register_notify);
31
32/**
33 * usb_unregister_notify - unregister a notifier callback
34 * @nb: pointer to the notifier block for the callback events.
35 *
36 * usb_register_notify() must have been previously called for this function
37 * to work properly.
38 */
39void usb_unregister_notify(struct notifier_block *nb)
40{
41	blocking_notifier_chain_unregister(&usb_notifier_list, nb);
42}
43EXPORT_SYMBOL_GPL(usb_unregister_notify);
44
45
46void usb_notify_add_device(struct usb_device *udev)
47{
48	blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
49}
50
51void usb_notify_remove_device(struct usb_device *udev)
52{
53	/* Protect against simultaneous usbfs open */
54	mutex_lock(&usbfs_mutex);
55	blocking_notifier_call_chain(&usb_notifier_list,
56			USB_DEVICE_REMOVE, udev);
57	mutex_unlock(&usbfs_mutex);
58}
59
60void usb_notify_add_bus(struct usb_bus *ubus)
61{
62	blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
63}
64
65void usb_notify_remove_bus(struct usb_bus *ubus)
66{
67	blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
68}