1 files changed, 89 insertions, 2 deletions

diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index f86bf1454e21e..d12bc5e84a1a3 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -43,6 +43,7 @@
 #include <linux/module.h>
 #include <linux/usb.h>
 #include <linux/usbdevice_fs.h>
+#include <linux/cdev.h>
 #include <asm/uaccess.h>
 #include <asm/byteorder.h>
 #include <linux/moduleparam.h>
@@ -50,6 +51,10 @@
 #include "hcd.h"	/* for usbcore internals */
 #include "usb.h"
 
+#define USB_MAXBUS			64
+#define USB_DEVICE_MAX			USB_MAXBUS * 128
+static struct class *usb_device_class;
+
 struct async {
 	struct list_head asynclist;
 	struct dev_state *ps;
@@ -487,7 +492,7 @@ static int check_ctrlrecip(struct dev_state *ps, unsigned int requesttype, unsig
  */
 static int usbdev_open(struct inode *inode, struct file *file)
 {
-	struct usb_device *dev;
+	struct usb_device *dev = NULL;
 	struct dev_state *ps;
 	int ret;
 
@@ -501,11 +506,16 @@ static int usbdev_open(struct inode *inode, struct file *file)
 
 	lock_kernel();
 	ret = -ENOENT;
-	dev = usb_get_dev(inode->u.generic_ip);
+	/* check if we are called from a real node or usbfs */
+	if (imajor(inode) == USB_DEVICE_MAJOR)
+		dev = usbdev_lookup_minor(iminor(inode));
+	if (!dev)
+		dev = inode->u.generic_ip;
 	if (!dev) {
 		kfree(ps);
 		goto out;
 	}
+	usb_get_dev(dev);
 	ret = 0;
 	ps->dev = dev;
 	ps->file = file;
@@ -1477,3 +1487,80 @@ struct file_operations usbfs_device_file_operations = {
 	.open =		usbdev_open,
 	.release =	usbdev_release,
 };
+
+struct usb_device *usbdev_lookup_minor(int minor)
+{
+	struct class_device *class_dev;
+	struct usb_device *dev = NULL;
+
+	down(&usb_device_class->sem);
+	list_for_each_entry(class_dev, &usb_device_class->children, node) {
+		if (class_dev->devt == MKDEV(USB_DEVICE_MAJOR, minor)) {
+			dev = class_dev->class_data;
+			break;
+		}
+	}
+	up(&usb_device_class->sem);
+
+	return dev;
+};
+
+void usbdev_add(struct usb_device *dev)
+{
+	int minor = ((dev->bus->busnum-1) * 128) + (dev->devnum-1);
+
+	dev->class_dev = class_device_create(usb_device_class,
+				MKDEV(USB_DEVICE_MAJOR, minor), &dev->dev,
+				"usbdev%d.%d", dev->bus->busnum, dev->devnum);
+
+	dev->class_dev->class_data = dev;
+}
+
+void usbdev_remove(struct usb_device *dev)
+{
+	class_device_unregister(dev->class_dev);
+}
+
+static struct cdev usb_device_cdev = {
+	.kobj   = {.name = "usb_device", },
+	.owner  = THIS_MODULE,
+};
+
+int __init usbdev_init(void)
+{
+	int retval;
+
+	retval = register_chrdev_region(MKDEV(USB_DEVICE_MAJOR, 0),
+				        USB_DEVICE_MAX, "usb_device");
+	if (retval) {
+		err("unable to register minors for usb_device");
+		goto out;
+	}
+	cdev_init(&usb_device_cdev, &usbfs_device_file_operations);
+	retval = cdev_add(&usb_device_cdev,
+			  MKDEV(USB_DEVICE_MAJOR, 0), USB_DEVICE_MAX);
+	if (retval) {
+		err("unable to get usb_device major %d", USB_DEVICE_MAJOR);
+		unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX);
+		goto out;
+	}
+	usb_device_class = class_create(THIS_MODULE, "usb_device");
+	if (IS_ERR(usb_device_class)) {
+		err("unable to register usb_device class");
+		retval = PTR_ERR(usb_device_class);
+		usb_device_class = NULL;
+		cdev_del(&usb_device_cdev);
+		unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX);
+	}
+
+out:
+	return retval;
+}
+
+void usbdev_cleanup(void)
+{
+	class_destroy(usb_device_class);
+	cdev_del(&usb_device_cdev);
+	unregister_chrdev_region(USB_DEVICE_MAJOR, USB_DEVICE_MAX);
+}
+