1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
new file mode 100644
index 000000000000..80ce9644d0ee
--- /dev/null
+++ b/drivers/usb/core/file.c
@@ -0,0 +1,227 @@
+/*
+ * drivers/usb/file.c
+ *
+ * (C) Copyright Linus Torvalds 1999
+ * (C) Copyright Johannes Erdfelt 1999-2001
+ * (C) Copyright Andreas Gal 1999
+ * (C) Copyright Gregory P. Smith 1999
+ * (C) Copyright Deti Fliegl 1999 (new USB architecture)
+ * (C) Copyright Randy Dunlap 2000
+ * (C) Copyright David Brownell 2000-2001 (kernel hotplug, usb_device_id,
+ 	more docs, etc)
+ * (C) Copyright Yggdrasil Computing, Inc. 2000
+ *     (usb_device_id matching changes by Adam J. Richter)
+ * (C) Copyright Greg Kroah-Hartman 2002-2003
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/devfs_fs_kernel.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+
+#ifdef CONFIG_USB_DEBUG
+	#define DEBUG
+#else
+	#undef DEBUG
+#endif
+#include <linux/usb.h>
+
+#define MAX_USB_MINORS	256
+static struct file_operations *usb_minors[MAX_USB_MINORS];
+static DEFINE_SPINLOCK(minor_lock);
+
+static int usb_open(struct inode * inode, struct file * file)
+{
+	int minor = iminor(inode);
+	struct file_operations *c;
+	int err = -ENODEV;
+	struct file_operations *old_fops, *new_fops = NULL;
+
+	spin_lock (&minor_lock);
+	c = usb_minors[minor];
+
+	if (!c || !(new_fops = fops_get(c))) {
+		spin_unlock(&minor_lock);
+		return err;
+	}
+	spin_unlock(&minor_lock);
+
+	old_fops = file->f_op;
+	file->f_op = new_fops;
+	/* Curiouser and curiouser... NULL ->open() as "no device" ? */
+	if (file->f_op->open)
+		err = file->f_op->open(inode,file);
+	if (err) {
+		fops_put(file->f_op);
+		file->f_op = fops_get(old_fops);
+	}
+	fops_put(old_fops);
+	return err;
+}
+
+static struct file_operations usb_fops = {
+	.owner =	THIS_MODULE,
+	.open =		usb_open,
+};
+
+static struct class_simple *usb_class;
+
+int usb_major_init(void)
+{
+	int error;
+
+	error = register_chrdev(USB_MAJOR, "usb", &usb_fops);
+	if (error) {
+		err("unable to get major %d for usb devices", USB_MAJOR);
+		goto out;
+	}
+
+	usb_class = class_simple_create(THIS_MODULE, "usb");
+	if (IS_ERR(usb_class)) {
+		err("class_simple_create failed for usb devices");
+		unregister_chrdev(USB_MAJOR, "usb");
+		goto out;
+	}
+
+	devfs_mk_dir("usb");
+
+out:
+	return error;
+}
+
+void usb_major_cleanup(void)
+{
+	class_simple_destroy(usb_class);
+	devfs_remove("usb");
+	unregister_chrdev(USB_MAJOR, "usb");
+}
+
+/**
+ * usb_register_dev - register a USB device, and ask for a minor number
+ * @intf: pointer to the usb_interface that is being registered
+ * @class_driver: pointer to the usb_class_driver for this device
+ *
+ * This should be called by all USB drivers that use the USB major number.
+ * If CONFIG_USB_DYNAMIC_MINORS is enabled, the minor number will be
+ * dynamically allocated out of the list of available ones.  If it is not
+ * enabled, the minor number will be based on the next available free minor,
+ * starting at the class_driver->minor_base.
+ *
+ * This function also creates the devfs file for the usb device, if devfs
+ * is enabled, and creates a usb class device in the sysfs tree.
+ *
+ * usb_deregister_dev() must be called when the driver is done with
+ * the minor numbers given out by this function.
+ *
+ * Returns -EINVAL if something bad happens with trying to register a
+ * device, and 0 on success.
+ */
+int usb_register_dev(struct usb_interface *intf,
+		     struct usb_class_driver *class_driver)
+{
+	int retval = -EINVAL;
+	int minor_base = class_driver->minor_base;
+	int minor = 0;
+	char name[BUS_ID_SIZE];
+	char *temp;
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+	/* 
+	 * We don't care what the device tries to start at, we want to start
+	 * at zero to pack the devices into the smallest available space with
+	 * no holes in the minor range.
+	 */
+	minor_base = 0;
+#endif
+	intf->minor = -1;
+
+	dbg ("looking for a minor, starting at %d", minor_base);
+
+	if (class_driver->fops == NULL)
+		goto exit;
+
+	spin_lock (&minor_lock);
+	for (minor = minor_base; minor < MAX_USB_MINORS; ++minor) {
+		if (usb_minors[minor])
+			continue;
+
+		usb_minors[minor] = class_driver->fops;
+
+		retval = 0;
+		break;
+	}
+	spin_unlock (&minor_lock);
+
+	if (retval)
+		goto exit;
+
+	intf->minor = minor;
+
+	/* handle the devfs registration */
+	snprintf(name, BUS_ID_SIZE, class_driver->name, minor - minor_base);
+	devfs_mk_cdev(MKDEV(USB_MAJOR, minor), class_driver->mode, name);
+
+	/* create a usb class device for this usb interface */
+	temp = strrchr(name, '/');
+	if (temp && (temp[1] != 0x00))
+		++temp;
+	else
+		temp = name;
+	intf->class_dev = class_simple_device_add(usb_class, MKDEV(USB_MAJOR, minor), &intf->dev, "%s", temp);
+	if (IS_ERR(intf->class_dev)) {
+		spin_lock (&minor_lock);
+		usb_minors[intf->minor] = NULL;
+		spin_unlock (&minor_lock);
+		devfs_remove (name);
+		retval = PTR_ERR(intf->class_dev);
+	}
+exit:
+	return retval;
+}
+EXPORT_SYMBOL(usb_register_dev);
+
+/**
+ * usb_deregister_dev - deregister a USB device's dynamic minor.
+ * @intf: pointer to the usb_interface that is being deregistered
+ * @class_driver: pointer to the usb_class_driver for this device
+ *
+ * Used in conjunction with usb_register_dev().  This function is called
+ * when the USB driver is finished with the minor numbers gotten from a
+ * call to usb_register_dev() (usually when the device is disconnected
+ * from the system.)
+ *
+ * This function also cleans up the devfs file for the usb device, if devfs
+ * is enabled, and removes the usb class device from the sysfs tree.
+ * 
+ * This should be called by all drivers that use the USB major number.
+ */
+void usb_deregister_dev(struct usb_interface *intf,
+			struct usb_class_driver *class_driver)
+{
+	int minor_base = class_driver->minor_base;
+	char name[BUS_ID_SIZE];
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+	minor_base = 0;
+#endif
+
+	if (intf->minor == -1)
+		return;
+
+	dbg ("removing %d minor", intf->minor);
+
+	spin_lock (&minor_lock);
+	usb_minors[intf->minor] = NULL;
+	spin_unlock (&minor_lock);
+
+	snprintf(name, BUS_ID_SIZE, class_driver->name, intf->minor - minor_base);
+	devfs_remove (name);
+	class_simple_device_remove(MKDEV(USB_MAJOR, intf->minor));
+	intf->class_dev = NULL;
+	intf->minor = -1;
+}
+EXPORT_SYMBOL(usb_deregister_dev);
+
+