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authorPaul Mackerras <paulus@samba.org>2005-10-30 21:37:12 -0500
committerPaul Mackerras <paulus@samba.org>2005-10-30 21:37:12 -0500
commit23fd07750a789a66fe88cf173d52a18f1a387da4 (patch)
tree06fdd6df35fdb835abdaa9b754d62f6b84b97250 /drivers/usb/core/notify.c
parentbd787d438a59266af3c9f6351644c85ef1dd21fe (diff)
parented28f96ac1960f30f818374d65be71d2fdf811b0 (diff)
Merge ../linux-2.6 by hand
Diffstat (limited to 'drivers/usb/core/notify.c')
-rw-r--r--drivers/usb/core/notify.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/usb/core/notify.c b/drivers/usb/core/notify.c
new file mode 100644
index 000000000000..37da059eced7
--- /dev/null
+++ b/drivers/usb/core/notify.c
@@ -0,0 +1,120 @@
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/config.h>
13#include <linux/kernel.h>
14#include <linux/notifier.h>
15#ifdef CONFIG_USB_DEBUG
16 #define DEBUG
17#else
18 #undef DEBUG
19#endif
20#include <linux/usb.h>
21
22#include "usb.h"
23
24
25static struct notifier_block *usb_notifier_list;
26static DECLARE_MUTEX(usb_notifier_lock);
27
28static void usb_notifier_chain_register(struct notifier_block **list,
29 struct notifier_block *n)
30{
31 down(&usb_notifier_lock);
32 while (*list) {
33 if (n->priority > (*list)->priority)
34 break;
35 list = &((*list)->next);
36 }
37 n->next = *list;
38 *list = n;
39 up(&usb_notifier_lock);
40}
41
42static void usb_notifier_chain_unregister(struct notifier_block **nl,
43 struct notifier_block *n)
44{
45 down(&usb_notifier_lock);
46 while ((*nl)!=NULL) {
47 if ((*nl)==n) {
48 *nl = n->next;
49 goto exit;
50 }
51 nl=&((*nl)->next);
52 }
53exit:
54 up(&usb_notifier_lock);
55}
56
57static int usb_notifier_call_chain(struct notifier_block **n,
58 unsigned long val, void *v)
59{
60 int ret=NOTIFY_DONE;
61 struct notifier_block *nb = *n;
62
63 down(&usb_notifier_lock);
64 while (nb) {
65 ret = nb->notifier_call(nb,val,v);
66 if (ret&NOTIFY_STOP_MASK) {
67 goto exit;
68 }
69 nb = nb->next;
70 }
71exit:
72 up(&usb_notifier_lock);
73 return ret;
74}
75
76/**
77 * usb_register_notify - register a notifier callback whenever a usb change happens
78 * @nb: pointer to the notifier block for the callback events.
79 *
80 * These changes are either USB devices or busses being added or removed.
81 */
82void usb_register_notify(struct notifier_block *nb)
83{
84 usb_notifier_chain_register(&usb_notifier_list, nb);
85}
86EXPORT_SYMBOL_GPL(usb_register_notify);
87
88/**
89 * usb_unregister_notify - unregister a notifier callback
90 * @nb: pointer to the notifier block for the callback events.
91 *
92 * usb_register_notifier() must have been previously called for this function
93 * to work properly.
94 */
95void usb_unregister_notify(struct notifier_block *nb)
96{
97 usb_notifier_chain_unregister(&usb_notifier_list, nb);
98}
99EXPORT_SYMBOL_GPL(usb_unregister_notify);
100
101
102void usb_notify_add_device(struct usb_device *udev)
103{
104 usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
105}
106
107void usb_notify_remove_device(struct usb_device *udev)
108{
109 usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_REMOVE, udev);
110}
111
112void usb_notify_add_bus(struct usb_bus *ubus)
113{
114 usb_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
115}
116
117void usb_notify_remove_bus(struct usb_bus *ubus)
118{
119 usb_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
120}