linux/drivers/usb/core/notify.c
Greg Kroah-Hartman b65fba3d87 USB: core: add missing license information to some files
Some of the USB core files were missing explicit license information.
As all files in the kernel tree are implicitly licensed under the
GPLv2-only, be explicit in case someone get confused looking at
individual files by using the SPDX nomenclature.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-29 12:51:56 -04:00

72 lines
1.8 KiB
C

/*
* All the USB notify logic
*
* (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
*
* notifier functions originally based on those in kernel/sys.c
* but fixed up to not be so broken.
*
* Released under the GPLv2 only.
* SPDX-License-Identifier: GPL-2.0
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/notifier.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include "usb.h"
static BLOCKING_NOTIFIER_HEAD(usb_notifier_list);
/**
* usb_register_notify - register a notifier callback whenever a usb change happens
* @nb: pointer to the notifier block for the callback events.
*
* These changes are either USB devices or busses being added or removed.
*/
void usb_register_notify(struct notifier_block *nb)
{
blocking_notifier_chain_register(&usb_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(usb_register_notify);
/**
* usb_unregister_notify - unregister a notifier callback
* @nb: pointer to the notifier block for the callback events.
*
* usb_register_notify() must have been previously called for this function
* to work properly.
*/
void usb_unregister_notify(struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&usb_notifier_list, nb);
}
EXPORT_SYMBOL_GPL(usb_unregister_notify);
void usb_notify_add_device(struct usb_device *udev)
{
blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
}
void usb_notify_remove_device(struct usb_device *udev)
{
/* Protect against simultaneous usbfs open */
mutex_lock(&usbfs_mutex);
blocking_notifier_call_chain(&usb_notifier_list,
USB_DEVICE_REMOVE, udev);
mutex_unlock(&usbfs_mutex);
}
void usb_notify_add_bus(struct usb_bus *ubus)
{
blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
}
void usb_notify_remove_bus(struct usb_bus *ubus)
{
blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
}