115 lines
2.5 KiB
C
115 lines
2.5 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.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
|
||
|
|
#include <linux/config.h>
|
||
|
|
#include <linux/kernel.h>
|
||
|
|
#include <linux/notifier.h>
|
||
|
|
#include <linux/usb.h>
|
||
|
|
#include "usb.h"
|
||
|
|
|
||
|
|
|
||
|
|
static struct notifier_block *usb_notifier_list;
|
||
|
|
static DECLARE_MUTEX(usb_notifier_lock);
|
||
|
|
|
||
|
|
static void usb_notifier_chain_register(struct notifier_block **list,
|
||
|
|
struct notifier_block *n)
|
||
|
|
{
|
||
|
|
down(&usb_notifier_lock);
|
||
|
|
while (*list) {
|
||
|
|
if (n->priority > (*list)->priority)
|
||
|
|
break;
|
||
|
|
list = &((*list)->next);
|
||
|
|
}
|
||
|
|
n->next = *list;
|
||
|
|
*list = n;
|
||
|
|
up(&usb_notifier_lock);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void usb_notifier_chain_unregister(struct notifier_block **nl,
|
||
|
|
struct notifier_block *n)
|
||
|
|
{
|
||
|
|
down(&usb_notifier_lock);
|
||
|
|
while ((*nl)!=NULL) {
|
||
|
|
if ((*nl)==n) {
|
||
|
|
*nl = n->next;
|
||
|
|
goto exit;
|
||
|
|
}
|
||
|
|
nl=&((*nl)->next);
|
||
|
|
}
|
||
|
|
exit:
|
||
|
|
up(&usb_notifier_lock);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int usb_notifier_call_chain(struct notifier_block **n,
|
||
|
|
unsigned long val, void *v)
|
||
|
|
{
|
||
|
|
int ret=NOTIFY_DONE;
|
||
|
|
struct notifier_block *nb = *n;
|
||
|
|
|
||
|
|
down(&usb_notifier_lock);
|
||
|
|
while (nb) {
|
||
|
|
ret = nb->notifier_call(nb,val,v);
|
||
|
|
if (ret&NOTIFY_STOP_MASK) {
|
||
|
|
goto exit;
|
||
|
|
}
|
||
|
|
nb = nb->next;
|
||
|
|
}
|
||
|
|
exit:
|
||
|
|
up(&usb_notifier_lock);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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)
|
||
|
|
{
|
||
|
|
usb_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_notifier() must have been previously called for this function
|
||
|
|
* to work properly.
|
||
|
|
*/
|
||
|
|
void usb_unregister_notify(struct notifier_block *nb)
|
||
|
|
{
|
||
|
|
usb_notifier_chain_unregister(&usb_notifier_list, nb);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL_GPL(usb_unregister_notify);
|
||
|
|
|
||
|
|
|
||
|
|
void usb_notify_add_device(struct usb_device *udev)
|
||
|
|
{
|
||
|
|
usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev);
|
||
|
|
}
|
||
|
|
|
||
|
|
void usb_notify_remove_device(struct usb_device *udev)
|
||
|
|
{
|
||
|
|
usb_notifier_call_chain(&usb_notifier_list, USB_DEVICE_REMOVE, udev);
|
||
|
|
}
|
||
|
|
|
||
|
|
void usb_notify_add_bus(struct usb_bus *ubus)
|
||
|
|
{
|
||
|
|
usb_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus);
|
||
|
|
}
|
||
|
|
|
||
|
|
void usb_notify_remove_bus(struct usb_bus *ubus)
|
||
|
|
{
|
||
|
|
usb_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus);
|
||
|
|
}
|