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 */ 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 */ 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 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 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 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 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