USB: make usbdevices export their device nodes instead of using a separate class

o The "real" usb-devices export now a device node which can
  populate /dev/bus/usb.

o The usb_device class is optional now and can be disabled in the
  kernel config. Major/minor of the "real" devices and class devices
  are the same.

o The environment of the usb-device event contains DEVNUM and BUSNUM to
  help udev and get rid of the ugly udev rule we need for the class
  devices.

o The usb-devices and usb-interfaces share the same bus, so I used
  the new "struct device_type" to let these devices identify
  themselves. This also removes the current logic of using a magic
  platform-pointer.
  The name of the device_type is also added to the environment
  which makes it easier to distinguish the different kinds of devices
  on the same subsystem.

  It looks like this:
    add@/devices/pci0000:00/0000:00:1d.1/usb2/2-1
    ACTION=add
    DEVPATH=/devices/pci0000:00/0000:00:1d.1/usb2/2-1
    SUBSYSTEM=usb
    SEQNUM=1533
    MAJOR=189
    MINOR=131
    DEVTYPE=usb_device
    PRODUCT=46d/c03e/2000
    TYPE=0/0/0
    BUSNUM=002
    DEVNUM=004

This udev rule works as a replacement for usb_device class devices:
  SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \
    NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644"

Updated patch, which needs the device_type patches in Greg's tree.

I also got a bugzilla assigned for this. :)
  https://bugzilla.novell.com/show_bug.cgi?id=250659


Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index fc3545d..e023f3d 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -57,7 +57,6 @@
 
 #define USB_MAXBUS			64
 #define USB_DEVICE_MAX			USB_MAXBUS * 128
-static struct class *usb_device_class;
 
 /* Mutual exclusion for removal, open, and release */
 DEFINE_MUTEX(usbfs_mutex);
@@ -514,22 +513,25 @@
 	return ret;
 }
 
-static struct usb_device *usbdev_lookup_minor(int minor)
+static int __match_minor(struct device *dev, void *data)
 {
-	struct device *device;
-	struct usb_device *udev = NULL;
+	int minor = *((int *)data);
 
-	down(&usb_device_class->sem);
-	list_for_each_entry(device, &usb_device_class->devices, node) {
-		if (device->devt == MKDEV(USB_DEVICE_MAJOR, minor)) {
-			udev = device->platform_data;
-			break;
-		}
-	}
-	up(&usb_device_class->sem);
+	if (dev->devt == MKDEV(USB_DEVICE_MAJOR, minor))
+		return 1;
+	return 0;
+}
 
-	return udev;
-};
+static struct usb_device *usbdev_lookup_by_minor(int minor)
+{
+	struct device *dev;
+
+	dev = bus_find_device(&usb_bus_type, NULL, &minor, __match_minor);
+	if (!dev)
+		return NULL;
+	put_device(dev);
+	return container_of(dev, struct usb_device, dev);
+}
 
 /*
  * file operations
@@ -548,11 +550,14 @@
 		goto out;
 
 	ret = -ENOENT;
-	/* check if we are called from a real node or usbfs */
+	/* usbdev device-node */
 	if (imajor(inode) == USB_DEVICE_MAJOR)
-		dev = usbdev_lookup_minor(iminor(inode));
+		dev = usbdev_lookup_by_minor(iminor(inode));
+#ifdef CONFIG_USB_DEVICEFS
+	/* procfs file */
 	if (!dev)
 		dev = inode->i_private;
+#endif
 	if (!dev)
 		goto out;
 	ret = usb_autoresume_device(dev);
@@ -1570,7 +1575,7 @@
 	return mask;
 }
 
-const struct file_operations usbfs_device_file_operations = {
+const struct file_operations usbdev_file_operations = {
 	.llseek =	usbdev_lseek,
 	.read =		usbdev_read,
 	.poll =		usbdev_poll,
@@ -1579,50 +1584,53 @@
 	.release =	usbdev_release,
 };
 
-static int usbdev_add(struct usb_device *dev)
+#ifdef CONFIG_USB_DEVICE_CLASS
+static struct class *usb_classdev_class;
+
+static int usb_classdev_add(struct usb_device *dev)
 {
 	int minor = ((dev->bus->busnum-1) * 128) + (dev->devnum-1);
 
-	dev->usbfs_dev = device_create(usb_device_class, &dev->dev,
+	dev->usb_classdev = device_create(usb_classdev_class, &dev->dev,
 				MKDEV(USB_DEVICE_MAJOR, minor),
 				"usbdev%d.%d", dev->bus->busnum, dev->devnum);
-	if (IS_ERR(dev->usbfs_dev))
-		return PTR_ERR(dev->usbfs_dev);
+	if (IS_ERR(dev->usb_classdev))
+		return PTR_ERR(dev->usb_classdev);
 
-	dev->usbfs_dev->platform_data = dev;
 	return 0;
 }
 
-static void usbdev_remove(struct usb_device *dev)
+static void usb_classdev_remove(struct usb_device *dev)
 {
-	device_unregister(dev->usbfs_dev);
+	device_unregister(dev->usb_classdev);
 }
 
-static int usbdev_notify(struct notifier_block *self, unsigned long action,
-			 void *dev)
+static int usb_classdev_notify(struct notifier_block *self,
+			       unsigned long action, void *dev)
 {
 	switch (action) {
 	case USB_DEVICE_ADD:
-		if (usbdev_add(dev))
+		if (usb_classdev_add(dev))
 			return NOTIFY_BAD;
 		break;
 	case USB_DEVICE_REMOVE:
-		usbdev_remove(dev);
+		usb_classdev_remove(dev);
 		break;
 	}
 	return NOTIFY_OK;
 }
 
 static struct notifier_block usbdev_nb = {
-	.notifier_call = 	usbdev_notify,
+	.notifier_call = 	usb_classdev_notify,
 };
+#endif
 
 static struct cdev usb_device_cdev = {
 	.kobj   = {.name = "usb_device", },
 	.owner  = THIS_MODULE,
 };
 
-int __init usbdev_init(void)
+int __init usb_devio_init(void)
 {
 	int retval;
 
@@ -1632,38 +1640,38 @@
 		err("unable to register minors for usb_device");
 		goto out;
 	}
-	cdev_init(&usb_device_cdev, &usbfs_device_file_operations);
+	cdev_init(&usb_device_cdev, &usbdev_file_operations);
 	retval = cdev_add(&usb_device_cdev, USB_DEVICE_DEV, USB_DEVICE_MAX);
 	if (retval) {
 		err("unable to get usb_device major %d", USB_DEVICE_MAJOR);
 		goto error_cdev;
 	}
-	usb_device_class = class_create(THIS_MODULE, "usb_device");
-	if (IS_ERR(usb_device_class)) {
+#ifdef CONFIG_USB_DEVICE_CLASS
+	usb_classdev_class = class_create(THIS_MODULE, "usb_device");
+	if (IS_ERR(usb_classdev_class)) {
 		err("unable to register usb_device class");
-		retval = PTR_ERR(usb_device_class);
-		goto error_class;
+		retval = PTR_ERR(usb_classdev_class);
+		cdev_del(&usb_device_cdev);
+		usb_classdev_class = NULL;
+		goto out;
 	}
 
 	usb_register_notify(&usbdev_nb);
-
+#endif
 out:
 	return retval;
 
-error_class:
-	usb_device_class = NULL;
-	cdev_del(&usb_device_cdev);
-
 error_cdev:
 	unregister_chrdev_region(USB_DEVICE_DEV, USB_DEVICE_MAX);
 	goto out;
 }
 
-void usbdev_cleanup(void)
+void usb_devio_cleanup(void)
 {
+#ifdef CONFIG_USB_DEVICE_CLASS
 	usb_unregister_notify(&usbdev_nb);
-	class_destroy(usb_device_class);
+	class_destroy(usb_classdev_class);
+#endif
 	cdev_del(&usb_device_cdev);
 	unregister_chrdev_region(USB_DEVICE_DEV, USB_DEVICE_MAX);
 }
-