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_notifier() 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} 69