Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

7 files changed, 1984 insertions, 0 deletions

diff --git a/drivers/staging/frontier/Kconfig b/drivers/staging/frontier/Kconfig
new file mode 100644
index 00000000..7121853b
--- /dev/null
+++ b/drivers/staging/frontier/Kconfig
@@ -0,0 +1,6 @@
+config TRANZPORT
+	tristate "Frontier Tranzport and Alphatrack support"
+	depends on USB
+	default N
+	---help---
+	  Enable support for the Frontier Tranzport and Alphatrack devices.
diff --git a/drivers/staging/frontier/Makefile b/drivers/staging/frontier/Makefile
new file mode 100644
index 00000000..2d2ac974
--- /dev/null
+++ b/drivers/staging/frontier/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_TRANZPORT)		+= tranzport.o
+obj-$(CONFIG_TRANZPORT)		+= alphatrack.o
diff --git a/drivers/staging/frontier/README b/drivers/staging/frontier/README
new file mode 100644
index 00000000..cd07af22
--- /dev/null
+++ b/drivers/staging/frontier/README
@@ -0,0 +1,47 @@
+This directory contains the Linux USB Tranzport and Alphatrack Kernel drivers.
+
+See http://www.frontierdesign.com for details on these devices.
+
+Userspace test code is available from
+
+git://toutatis.isc.org/home/d/src/git/frontier.git
+
+At present the tranzport does reads/writes of 8 byte cmds to
+/dev/tranzport0 to control the lights, screen, and wheel.
+
+At present the alphatrack accepts reads/writes of 12 byte cmds to
+/dev/tranzport0 to control the lights, screen, fader and touchpad.
+
+The tranzport driver provides a rudimentary sysfs interface for the status of
+the device and a writable parameter for turning wheel compression on and off.
+
+The API is nothing more than the USB commands issued to the device. Why?
+
+The control wheel/fader can generate events far too quickly for
+a typical userspace application to keep up with them via libusb. Input
+needs to be 100% accurate and fast in order for the alphatrack or tranzport
+to be useful.
+
+UIO would be useful except that usb disconnect events need
+to be handled correctly.
+
+A sysfs interface is perfect for simple userspace apps to do fun things with
+the lights and screen. But it's fairly lousy for handling input events and
+very lousy for watching the state of the shuttle wheel.
+
+A linux input events interface is great for the input events and shuttle wheel.
+* It's theoretically OK on LEDs.
+* A fader can be mapped to an absolute mouse device.
+* But there is no LCD support at all, or fader feedback support in that API
+
+So, thus, these stubby drivers exist.
+
+In the end this could be driven by a midi layer, which handles all those
+cases via a well defined API, but - among other things - is slow, doesn't do
+flow control, and is a LOT of extra work, none of which is required at
+the kernel level (probably). Frankly, I'd like to keep the
+core driver simple because the only realtime work really required is
+the bottom half interrupt handler and the output overlapping.
+
+Exposing some sort of clean api to userspace would be perfect. What that
+API looks like? Gah. beats me.
diff --git a/drivers/staging/frontier/TODO b/drivers/staging/frontier/TODO
new file mode 100644
index 00000000..3620ad2d
--- /dev/null
+++ b/drivers/staging/frontier/TODO
@@ -0,0 +1,9 @@
+TODO:
+	- checkpatch.pl clean
+	- sparse clean
+	- fix userspace interface to be sane
+	- possibly just port to userspace with libusb
+	- review by the USB developer community
+
+Please send any patches for this driver to Greg Kroah-Hartman <greg@kroah.com>
+and David Taht <d@teklibre.com>.
diff --git a/drivers/staging/frontier/alphatrack.c b/drivers/staging/frontier/alphatrack.c
new file mode 100644
index 00000000..3bf0f40e
--- /dev/null
+++ b/drivers/staging/frontier/alphatrack.c
@@ -0,0 +1,870 @@
+/*
+ * Frontier Designs Alphatrack driver
+ *
+ * Copyright (C) 2007 Michael Taht (m@taht.net)
+ *
+ * Based on the usbled driver and ldusb drivers by
+ *
+ * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
+ *
+ * The ldusb driver was, in turn, derived from Lego USB Tower driver
+ * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
+ *		 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License as
+ *	published by the Free Software Foundation, version 2.
+ *
+ */
+
+/**
+ * This driver uses a ring buffer for time critical reading of
+ * interrupt in reports and provides read and write methods for
+ * raw interrupt reports.
+ */
+
+/* Note: this currently uses a dumb ringbuffer for reads and writes.
+ * A more optimal driver would cache and kill off outstanding urbs that are
+ * now invalid, and ignore ones that already were in the queue but valid
+ * as we only have 30 commands for the alphatrack. In particular this is
+ * key for getting lights to flash in time as otherwise many commands
+ * can be buffered up before the light change makes it to the interface.
+*/
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include <linux/mutex.h>
+
+#include <linux/uaccess.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/poll.h>
+
+#include "alphatrack.h"
+
+#define VENDOR_ID	0x165b
+#define PRODUCT_ID	0xfad1
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+#define USB_ALPHATRACK_MINOR_BASE	0
+#else
+/* FIXME 176 - is another driver's minor - apply for that */
+#define USB_ALPHATRACK_MINOR_BASE	176
+#endif
+
+/* table of devices that work with this driver */
+static const struct usb_device_id usb_alphatrack_table[] = {
+	{USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
+	{}			/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
+MODULE_VERSION("0.41");
+MODULE_AUTHOR("Mike Taht <m@taht.net>");
+MODULE_DESCRIPTION("Alphatrack USB Driver");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
+
+/* These aren't done yet */
+
+#define SUPPRESS_EXTRA_ONLINE_EVENTS 0
+#define BUFFERED_WRITES 0
+#define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
+#define COMPRESS_FADER_EVENTS 0
+
+#define BUFFERED_READS 1
+#define RING_BUFFER_SIZE 512
+#define WRITE_BUFFER_SIZE 34
+#define ALPHATRACK_USB_TIMEOUT 10
+#define OUTPUT_CMD_SIZE 8
+#define INPUT_CMD_SIZE 12
+#define ALPHATRACK_DEBUG 0
+
+static int debug = ALPHATRACK_DEBUG;
+
+/* Use our own dbg macro */
+#define dbg_info(dev, format, arg...) do \
+	{ if (debug) dev_info(dev , format , ## arg); } while (0)
+
+#define alphatrack_ocmd_info(dev, cmd, format, arg...)
+
+#define alphatrack_icmd_info(dev, cmd, format, arg...)
+
+/* Module parameters */
+
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+
+/* All interrupt in transfers are collected in a ring buffer to
+ * avoid racing conditions and get better performance of the driver.
+ */
+
+static int ring_buffer_size = RING_BUFFER_SIZE;
+
+module_param(ring_buffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
+
+/* The write_buffer can one day contain more than one interrupt out transfer.
+ */
+
+static int write_buffer_size = WRITE_BUFFER_SIZE;
+module_param(write_buffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
+
+/*
+ * Increase the interval for debugging purposes.
+ * or set to 1 to use the standard interval from the endpoint descriptors.
+ */
+
+static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
+module_param(min_interrupt_in_interval, int, 0);
+MODULE_PARM_DESC(min_interrupt_in_interval,
+		 "Minimum interrupt in interval in ms");
+
+static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
+module_param(min_interrupt_out_interval, int, 0);
+MODULE_PARM_DESC(min_interrupt_out_interval,
+		 "Minimum interrupt out interval in ms");
+
+/* Structure to hold all of our device specific stuff */
+
+struct usb_alphatrack {
+	struct mutex mtx;	/* locks this structure */
+	struct usb_interface *intf;	/* save off the usb interface pointer */
+	int open_count;		/* number of times this port has been opened */
+
+	/* make gcc happy */
+	struct alphatrack_icmd (*ring_buffer)[RING_BUFFER_SIZE];
+	struct alphatrack_ocmd (*write_buffer)[WRITE_BUFFER_SIZE];
+	unsigned int ring_head;
+	unsigned int ring_tail;
+
+	wait_queue_head_t read_wait;
+	wait_queue_head_t write_wait;
+
+	unsigned char *interrupt_in_buffer;
+	unsigned char *oldi_buffer;
+	struct usb_endpoint_descriptor *interrupt_in_endpoint;
+	struct urb *interrupt_in_urb;
+	int interrupt_in_interval;
+	size_t interrupt_in_endpoint_size;
+	int interrupt_in_running;
+	int interrupt_in_done;
+
+	char *interrupt_out_buffer;
+	struct usb_endpoint_descriptor *interrupt_out_endpoint;
+	struct urb *interrupt_out_urb;
+	int interrupt_out_interval;
+	size_t interrupt_out_endpoint_size;
+	int interrupt_out_busy;
+
+	atomic_t writes_pending;
+	int event;		/* alternate interface to events */
+	int fader;		/* 10 bits */
+	int lights;		/* 23 bits */
+	unsigned char dump_state;	/* 0 if disabled 1 if enabled */
+	unsigned char enable;	/* 0 if disabled 1 if enabled */
+	unsigned char offline;	/* if the device is out of range or asleep */
+	unsigned char verbose;	/* be verbose in error reporting */
+	unsigned char last_cmd[OUTPUT_CMD_SIZE];
+	unsigned char screen[32];
+};
+
+/* prevent races between open() and disconnect() */
+static DEFINE_MUTEX(disconnect_mutex);
+
+/* forward declaration */
+
+static struct usb_driver usb_alphatrack_driver;
+
+/**
+ *	usb_alphatrack_abort_transfers
+ *      aborts transfers and frees associated data structures
+ */
+static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
+{
+	/* shutdown transfer */
+	if (dev->interrupt_in_running) {
+		dev->interrupt_in_running = 0;
+		if (dev->intf)
+			usb_kill_urb(dev->interrupt_in_urb);
+	}
+	if (dev->interrupt_out_busy)
+		if (dev->intf)
+			usb_kill_urb(dev->interrupt_out_urb);
+}
+
+/**
+ *	usb_alphatrack_delete
+ */
+static void usb_alphatrack_delete(struct usb_alphatrack *dev)
+{
+	usb_alphatrack_abort_transfers(dev);
+	usb_free_urb(dev->interrupt_in_urb);
+	usb_free_urb(dev->interrupt_out_urb);
+	kfree(dev->ring_buffer);
+	kfree(dev->interrupt_in_buffer);
+	kfree(dev->interrupt_out_buffer);
+	kfree(dev);		/* fixme oldi_buffer */
+}
+
+/**
+ *	usb_alphatrack_interrupt_in_callback
+ */
+
+static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
+{
+	struct usb_alphatrack *dev = urb->context;
+	unsigned int next_ring_head;
+	int retval = -1;
+
+	if (urb->status) {
+		if (urb->status == -ENOENT ||
+		    urb->status == -ECONNRESET || urb->status == -ESHUTDOWN) {
+			goto exit;
+		} else {
+			dbg_info(&dev->intf->dev,
+				 "%s: nonzero status received: %d\n", __func__,
+				 urb->status);
+			goto resubmit;	/* maybe we can recover */
+		}
+	}
+
+	if (urb->actual_length != INPUT_CMD_SIZE) {
+		dev_warn(&dev->intf->dev,
+			 "Urb length was %d bytes!!"
+			 "Do something intelligent\n", urb->actual_length);
+	} else {
+		alphatrack_ocmd_info(&dev->intf->dev,
+				     &(*dev->ring_buffer)[dev->ring_tail].cmd,
+				     "%s", "bla");
+		if (memcmp
+		    (dev->interrupt_in_buffer, dev->oldi_buffer,
+		     INPUT_CMD_SIZE) == 0) {
+			goto resubmit;
+		}
+		memcpy(dev->oldi_buffer, dev->interrupt_in_buffer,
+		       INPUT_CMD_SIZE);
+
+#if SUPPRESS_EXTRA_OFFLINE_EVENTS
+		if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
+			goto resubmit;
+		if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
+			dev->offline = 2;
+			goto resubmit;
+		}
+/* Always pass one offline event up the stack */
+		if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
+			dev->offline = 0;
+		if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
+			dev->offline = 1;
+#endif
+		dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
+			 __func__, dev->ring_head, dev->ring_tail);
+		next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
+
+		if (next_ring_head != dev->ring_tail) {
+			memcpy(&((*dev->ring_buffer)[dev->ring_head]),
+			       dev->interrupt_in_buffer, urb->actual_length);
+			dev->ring_head = next_ring_head;
+			retval = 0;
+			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
+		} else {
+			dev_warn(&dev->intf->dev,
+				 "Ring buffer overflow, %d bytes dropped\n",
+				 urb->actual_length);
+			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
+		}
+	}
+
+resubmit:
+	/* resubmit if we're still running */
+	if (dev->interrupt_in_running && dev->intf) {
+		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
+		if (retval)
+			dev_err(&dev->intf->dev,
+				"usb_submit_urb failed (%d)\n", retval);
+	}
+
+exit:
+	dev->interrupt_in_done = 1;
+	wake_up_interruptible(&dev->read_wait);
+}
+
+/**
+ *	usb_alphatrack_interrupt_out_callback
+ */
+static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
+{
+	struct usb_alphatrack *dev = urb->context;
+
+	/* sync/async unlink faults aren't errors */
+	if (urb->status && !(urb->status == -ENOENT ||
+			     urb->status == -ECONNRESET ||
+			     urb->status == -ESHUTDOWN))
+		dbg_info(&dev->intf->dev,
+			 "%s - nonzero write interrupt status received: %d\n",
+			 __func__, urb->status);
+	atomic_dec(&dev->writes_pending);
+	dev->interrupt_out_busy = 0;
+	wake_up_interruptible(&dev->write_wait);
+}
+
+/**
+ *	usb_alphatrack_open
+ */
+static int usb_alphatrack_open(struct inode *inode, struct file *file)
+{
+	struct usb_alphatrack *dev;
+	int subminor;
+	int retval = 0;
+	struct usb_interface *interface;
+
+	nonseekable_open(inode, file);
+	subminor = iminor(inode);
+
+	mutex_lock(&disconnect_mutex);
+
+	interface = usb_find_interface(&usb_alphatrack_driver, subminor);
+
+	if (!interface) {
+		err("%s - error, can't find device for minor %d\n",
+		    __func__, subminor);
+		retval = -ENODEV;
+		goto unlock_disconnect_exit;
+	}
+
+	dev = usb_get_intfdata(interface);
+
+	if (!dev) {
+		retval = -ENODEV;
+		goto unlock_disconnect_exit;
+	}
+
+	/* lock this device */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto unlock_disconnect_exit;
+	}
+
+	/* allow opening only once */
+	if (dev->open_count) {
+		retval = -EBUSY;
+		goto unlock_exit;
+	}
+	dev->open_count = 1;
+
+	/* initialize in direction */
+	dev->ring_head = 0;
+	dev->ring_tail = 0;
+	usb_fill_int_urb(dev->interrupt_in_urb,
+			 interface_to_usbdev(interface),
+			 usb_rcvintpipe(interface_to_usbdev(interface),
+					dev->interrupt_in_endpoint->
+					bEndpointAddress),
+			 dev->interrupt_in_buffer,
+			 dev->interrupt_in_endpoint_size,
+			 usb_alphatrack_interrupt_in_callback, dev,
+			 dev->interrupt_in_interval);
+
+	dev->interrupt_in_running = 1;
+	dev->interrupt_in_done = 0;
+	dev->enable = 1;
+	dev->offline = 0;
+
+	retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+	if (retval) {
+		dev_err(&interface->dev,
+			"Couldn't submit interrupt_in_urb %d\n", retval);
+		dev->interrupt_in_running = 0;
+		dev->open_count = 0;
+		goto unlock_exit;
+	}
+
+	/* save device in the file's private structure */
+	file->private_data = dev;
+
+unlock_exit:
+	mutex_unlock(&dev->mtx);
+
+unlock_disconnect_exit:
+	mutex_unlock(&disconnect_mutex);
+
+	return retval;
+}
+
+/**
+ *	usb_alphatrack_release
+ */
+static int usb_alphatrack_release(struct inode *inode, struct file *file)
+{
+	struct usb_alphatrack *dev;
+	int retval = 0;
+
+	dev = file->private_data;
+
+	if (dev == NULL) {
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+
+	if (dev->open_count != 1) {
+		retval = -ENODEV;
+		goto unlock_exit;
+	}
+
+	if (dev->intf == NULL) {
+		/* the device was unplugged before the file was released */
+		mutex_unlock(&dev->mtx);
+		/* unlock here as usb_alphatrack_delete frees dev */
+		usb_alphatrack_delete(dev);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	/* wait until write transfer is finished */
+	if (dev->interrupt_out_busy)
+		wait_event_interruptible_timeout(dev->write_wait,
+						 !dev->interrupt_out_busy,
+						 2 * HZ);
+	usb_alphatrack_abort_transfers(dev);
+	dev->open_count = 0;
+
+unlock_exit:
+	mutex_unlock(&dev->mtx);
+
+exit:
+	return retval;
+}
+
+/**
+ *	usb_alphatrack_poll
+ */
+static unsigned int usb_alphatrack_poll(struct file *file, poll_table *wait)
+{
+	struct usb_alphatrack *dev;
+	unsigned int mask = 0;
+
+	dev = file->private_data;
+
+	poll_wait(file, &dev->read_wait, wait);
+	poll_wait(file, &dev->write_wait, wait);
+
+	if (dev->ring_head != dev->ring_tail)
+		mask |= POLLIN | POLLRDNORM;
+	if (!dev->interrupt_out_busy)
+		mask |= POLLOUT | POLLWRNORM;
+
+	return mask;
+}
+
+/**
+ *	usb_alphatrack_read
+ */
+static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer,
+				   size_t count, loff_t *ppos)
+{
+	struct usb_alphatrack *dev;
+	int retval = 0;
+
+	int c = 0;
+
+	dev = file->private_data;
+
+	/* verify that we actually have some data to read */
+	if (count == 0)
+		goto exit;
+
+	/* lock this object */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+
+	/* verify that the device wasn't unplugged */
+	if (dev->intf == NULL) {
+		retval = -ENODEV;
+		err("No device or device unplugged %d\n", retval);
+		goto unlock_exit;
+	}
+
+	while (dev->ring_head == dev->ring_tail) {
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto unlock_exit;
+		}
+		dev->interrupt_in_done = 0;
+		retval =
+		    wait_event_interruptible(dev->read_wait,
+					     dev->interrupt_in_done);
+		if (retval < 0)
+			goto unlock_exit;
+	}
+
+	alphatrack_ocmd_info(&dev->intf->dev,
+			     &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s",
+			     ": copying to userspace");
+
+	c = 0;
+	while ((c < count) && (dev->ring_tail != dev->ring_head)) {
+		if (copy_to_user
+		    (&buffer[c], &(*dev->ring_buffer)[dev->ring_tail],
+		     INPUT_CMD_SIZE)) {
+			retval = -EFAULT;
+			goto unlock_exit;
+		}
+		dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
+		c += INPUT_CMD_SIZE;
+		dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
+			 __func__, dev->ring_head, dev->ring_tail);
+	}
+	retval = c;
+
+unlock_exit:
+	/* unlock the device */
+	mutex_unlock(&dev->mtx);
+
+exit:
+	return retval;
+}
+
+/**
+ *	usb_alphatrack_write
+ */
+static ssize_t usb_alphatrack_write(struct file *file,
+				    const char __user *buffer, size_t count,
+				    loff_t *ppos)
+{
+	struct usb_alphatrack *dev;
+	size_t bytes_to_write;
+	int retval = 0;
+
+	dev = file->private_data;
+
+	/* verify that we actually have some data to write */
+	if (count == 0)
+		goto exit;
+
+	/* lock this object */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+
+	/* verify that the device wasn't unplugged */
+	if (dev->intf == NULL) {
+		retval = -ENODEV;
+		err("No device or device unplugged %d\n", retval);
+		goto unlock_exit;
+	}
+
+	/* wait until previous transfer is finished */
+	if (dev->interrupt_out_busy) {
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto unlock_exit;
+		}
+		retval =
+		    wait_event_interruptible(dev->write_wait,
+					     !dev->interrupt_out_busy);
+		if (retval < 0)
+			goto unlock_exit;
+	}
+
+	/* write the data into interrupt_out_buffer from userspace */
+	/* FIXME - if you write more than 12 bytes this breaks */
+	bytes_to_write =
+	    min(count, write_buffer_size * dev->interrupt_out_endpoint_size);
+	if (bytes_to_write < count)
+		dev_warn(&dev->intf->dev,
+			 "Write buffer overflow, %zd bytes dropped\n",
+			 count - bytes_to_write);
+
+	dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
+		 __func__, count, bytes_to_write);
+
+	if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
+		retval = -EFAULT;
+		goto unlock_exit;
+	}
+
+	if (dev->interrupt_out_endpoint == NULL) {
+		err("Endpoint should not be be null!\n");
+		goto unlock_exit;
+	}
+
+	/* send off the urb */
+	usb_fill_int_urb(dev->interrupt_out_urb,
+			 interface_to_usbdev(dev->intf),
+			 usb_sndintpipe(interface_to_usbdev(dev->intf),
+					dev->interrupt_out_endpoint->
+					bEndpointAddress),
+			 dev->interrupt_out_buffer, bytes_to_write,
+			 usb_alphatrack_interrupt_out_callback, dev,
+			 dev->interrupt_out_interval);
+	dev->interrupt_out_busy = 1;
+	atomic_inc(&dev->writes_pending);
+	wmb();
+
+	retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
+	if (retval) {
+		dev->interrupt_out_busy = 0;
+		err("Couldn't submit interrupt_out_urb %d\n", retval);
+		atomic_dec(&dev->writes_pending);
+		goto unlock_exit;
+	}
+	retval = bytes_to_write;
+
+unlock_exit:
+	/* unlock the device */
+	mutex_unlock(&dev->mtx);
+
+exit:
+	return retval;
+}
+
+/* file operations needed when we register this driver */
+static const struct file_operations usb_alphatrack_fops = {
+	.owner = THIS_MODULE,
+	.read = usb_alphatrack_read,
+	.write = usb_alphatrack_write,
+	.open = usb_alphatrack_open,
+	.release = usb_alphatrack_release,
+	.poll = usb_alphatrack_poll,
+	.llseek = no_llseek,
+};
+
+/*
+ * usb class driver info in order to get a minor number from the usb core,
+ * and to have the device registered with the driver core
+ */
+
+static struct usb_class_driver usb_alphatrack_class = {
+	.name = "alphatrack%d",
+	.fops = &usb_alphatrack_fops,
+	.minor_base = USB_ALPHATRACK_MINOR_BASE,
+};
+
+/**
+ *	usb_alphatrack_probe
+ *
+ *	Called by the usb core when a new device is connected that it thinks
+ *	this driver might be interested in.
+ */
+static int usb_alphatrack_probe(struct usb_interface *intf,
+				const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_alphatrack *dev = NULL;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	int i;
+	int true_size;
+	int retval = -ENOMEM;
+
+	/* allocate memory for our device state and initialize it */
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL) {
+		dev_err(&intf->dev, "Out of memory\n");
+		goto exit;
+	}
+	mutex_init(&dev->mtx);
+	dev->intf = intf;
+	init_waitqueue_head(&dev->read_wait);
+	init_waitqueue_head(&dev->write_wait);
+
+	iface_desc = intf->cur_altsetting;
+
+	/* set up the endpoint information */
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (usb_endpoint_is_int_in(endpoint))
+			dev->interrupt_in_endpoint = endpoint;
+
+		if (usb_endpoint_is_int_out(endpoint))
+			dev->interrupt_out_endpoint = endpoint;
+	}
+	if (dev->interrupt_in_endpoint == NULL) {
+		dev_err(&intf->dev, "Interrupt in endpoint not found\n");
+		goto error;
+	}
+	if (dev->interrupt_out_endpoint == NULL)
+		dev_warn(&intf->dev,
+			 "Interrupt out endpoint not found"
+			 "(using control endpoint instead)\n");
+
+	dev->interrupt_in_endpoint_size =
+	    le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
+
+	if (dev->interrupt_in_endpoint_size != 64)
+		dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
+
+	if (ring_buffer_size == 0)
+		ring_buffer_size = RING_BUFFER_SIZE;
+
+	true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
+
+	/* FIXME - there are more usb_alloc routines for dma correctness.
+	   Needed? */
+	dev->ring_buffer =
+	    kmalloc((true_size * sizeof(struct alphatrack_icmd)), GFP_KERNEL);
+
+	if (!dev->ring_buffer) {
+		dev_err(&intf->dev,
+			"Couldn't allocate input ring_buffer of size %d\n",
+			true_size);
+		goto error;
+	}
+
+	dev->interrupt_in_buffer =
+	    kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
+
+	if (!dev->interrupt_in_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
+		goto error;
+	}
+	dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
+	if (!dev->oldi_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate old buffer\n");
+		goto error;
+	}
+	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!dev->interrupt_in_urb) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
+		goto error;
+	}
+
+	dev->interrupt_out_endpoint_size =
+	    dev->interrupt_out_endpoint ? le16_to_cpu(dev->
+						      interrupt_out_endpoint->
+						      wMaxPacketSize) : udev->
+	    descriptor.bMaxPacketSize0;
+
+	if (dev->interrupt_out_endpoint_size != 64)
+		dev_warn(&intf->dev,
+			 "Interrupt out endpoint size is not 64!)\n");
+
+	if (write_buffer_size == 0)
+		write_buffer_size = WRITE_BUFFER_SIZE;
+	true_size = min(write_buffer_size, WRITE_BUFFER_SIZE);
+
+	dev->interrupt_out_buffer =
+	    kmalloc(true_size * dev->interrupt_out_endpoint_size, GFP_KERNEL);
+
+	if (!dev->interrupt_out_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
+		goto error;
+	}
+
+	dev->write_buffer =
+	    kmalloc(true_size * sizeof(struct alphatrack_ocmd), GFP_KERNEL);
+
+	if (!dev->write_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate write_buffer\n");
+		goto error;
+	}
+
+	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!dev->interrupt_out_urb) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
+		goto error;
+	}
+	dev->interrupt_in_interval =
+	    min_interrupt_in_interval >
+	    dev->interrupt_in_endpoint->
+	    bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->
+	    bInterval;
+	if (dev->interrupt_out_endpoint)
+		dev->interrupt_out_interval =
+		    min_interrupt_out_interval >
+		    dev->interrupt_out_endpoint->
+		    bInterval ? min_interrupt_out_interval : dev->
+		    interrupt_out_endpoint->bInterval;
+
+	/* we can register the device now, as it is ready */
+	usb_set_intfdata(intf, dev);
+
+	atomic_set(&dev->writes_pending, 0);
+	retval = usb_register_dev(intf, &usb_alphatrack_class);
+	if (retval) {
+		/* something prevented us from registering this driver */
+		dev_err(&intf->dev,
+			"Not able to get a minor for this device.\n");
+		usb_set_intfdata(intf, NULL);
+		goto error;
+	}
+
+	/* let the user know what node this device is now attached to */
+	dev_info(&intf->dev,
+		 "Alphatrack Device #%d now attached to major %d minor %d\n",
+		 (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR,
+		 intf->minor);
+
+exit:
+	return retval;
+
+error:
+	usb_alphatrack_delete(dev);
+
+	return retval;
+}
+
+/**
+ *	usb_alphatrack_disconnect
+ *
+ *	Called by the usb core when the device is removed from the system.
+ */
+static void usb_alphatrack_disconnect(struct usb_interface *intf)
+{
+	struct usb_alphatrack *dev;
+	int minor;
+
+	mutex_lock(&disconnect_mutex);
+
+	dev = usb_get_intfdata(intf);
+	usb_set_intfdata(intf, NULL);
+
+	mutex_lock(&dev->mtx);
+
+	minor = intf->minor;
+
+	/* give back our minor */
+	usb_deregister_dev(intf, &usb_alphatrack_class);
+
+	/* if the device is not opened, then we clean up right now */
+	if (!dev->open_count) {
+		mutex_unlock(&dev->mtx);
+		usb_alphatrack_delete(dev);
+	} else {
+		dev->intf = NULL;
+		mutex_unlock(&dev->mtx);
+	}
+
+	atomic_set(&dev->writes_pending, 0);
+	mutex_unlock(&disconnect_mutex);
+
+	dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
+		 (minor - USB_ALPHATRACK_MINOR_BASE));
+}
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver usb_alphatrack_driver = {
+	.name = "alphatrack",
+	.probe = usb_alphatrack_probe,
+	.disconnect = usb_alphatrack_disconnect,
+	.id_table = usb_alphatrack_table,
+};
+
+module_usb_driver(usb_alphatrack_driver);
diff --git a/drivers/staging/frontier/alphatrack.h b/drivers/staging/frontier/alphatrack.h
new file mode 100644
index 00000000..10a79726
--- /dev/null
+++ b/drivers/staging/frontier/alphatrack.h
@@ -0,0 +1,76 @@
+struct alphatrack_icmd {
+	unsigned char cmd[12];
+};
+
+struct alphatrack_ocmd {
+	unsigned char cmd[8];
+};
+
+/* These are unused by the present driver but provide documentation for the
+ * userspace API.
+ */
+enum LightID {
+	LIGHT_EQ = 0,
+	LIGHT_OUT,
+	LIGHT_F2,
+	LIGHT_SEND,
+	LIGHT_IN,
+	LIGHT_F1,
+	LIGHT_PAN,
+	LIGHT_UNDEF1,
+	LIGHT_UNDEF2,
+	LIGHT_SHIFT,
+	LIGHT_TRACKMUTE,
+	LIGHT_TRACKSOLO,
+	LIGHT_TRACKREC,
+	LIGHT_READ,
+	LIGHT_WRITE,
+	LIGHT_ANYSOLO,
+	LIGHT_AUTO,
+	LIGHT_F4,
+	LIGHT_RECORD,
+	LIGHT_WINDOW,
+	LIGHT_PLUGIN,
+	LIGHT_F3,
+	LIGHT_LOOP
+};
+
+#define BUTTONMASK_BATTERY     0x00004000
+#define BUTTONMASK_BACKLIGHT   0x00008000
+#define BUTTONMASK_FASTFORWARD 0x04000000
+#define BUTTONMASK_TRACKMUTE   0x00040000
+#define BUTTONMASK_TRACKSOLO   0x00800000
+#define BUTTONMASK_TRACKLEFT   0x80000000
+#define BUTTONMASK_RECORD      0x02000000
+#define BUTTONMASK_SHIFT       0x20000000
+#define BUTTONMASK_PUNCH       0x00800000
+#define BUTTONMASK_TRACKRIGHT  0x00020000
+#define BUTTONMASK_REWIND      0x01000000
+#define BUTTONMASK_STOP        0x10000000
+#define BUTTONMASK_LOOP        0x00010000
+#define BUTTONMASK_TRACKREC    0x00001000
+#define BUTTONMASK_PLAY        0x08000000
+#define BUTTONMASK_TOUCH1      0x00000008
+#define BUTTONMASK_TOUCH2      0x00000010
+#define BUTTONMASK_TOUCH3      0x00000020
+
+#define BUTTONMASK_PRESS1      0x00000009
+#define BUTTONMASK_PRESS2      0x00008010
+#define BUTTONMASK_PRESS3      0x00002020
+
+/* last 3 bytes are the slider position
+ * 40 is the actual slider moving, the most sig bits, and 3 lsb
+ */
+
+#define BUTTONMASK_FLIP         0x40000000
+#define BUTTONMASK_F1           0x00100000
+#define BUTTONMASK_F2           0x00400000
+#define BUTTONMASK_F3           0x00200000
+#define BUTTONMASK_F4           0x00080000
+#define BUTTONMASK_PAN          0x00000200
+#define BUTTONMASK_SEND         0x00000800
+#define BUTTONMASK_EQ           0x00004000
+#define BUTTONMASK_PLUGIN       0x00000400
+#define BUTTONMASK_AUTO         0x00000100
+
+/* #define BUTTONMASK_FOOTSWITCH FIXME */
diff --git a/drivers/staging/frontier/tranzport.c b/drivers/staging/frontier/tranzport.c
new file mode 100644
index 00000000..29e99bbc
--- /dev/null
+++ b/drivers/staging/frontier/tranzport.c
@@ -0,0 +1,974 @@
+/*
+ * Frontier Designs Tranzport driver
+ *
+ * Copyright (C) 2007 Michael Taht (m@taht.net)
+ *
+ * Based on the usbled driver and ldusb drivers by
+ *
+ * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
+ * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
+ *
+ * The ldusb driver was, in turn, derived from Lego USB Tower driver
+ * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
+ *		 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License as
+ *	published by the Free Software Foundation, version 2.
+ *
+ */
+
+/*
+ * This driver uses a ring buffer for time critical reading of
+ * interrupt in reports and provides read and write methods for
+ * raw interrupt reports.
+ */
+
+/* Note: this currently uses a dumb ringbuffer for reads and writes.
+ * A more optimal driver would cache and kill off outstanding urbs that are
+ * now invalid, and ignore ones that already were in the queue but valid
+ * as we only have 17 commands for the tranzport. In particular this is
+ * key for getting lights to flash in time as otherwise many commands
+ * can be buffered up before the light change makes it to the interface.
+ */
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+
+#include <linux/uaccess.h>
+#include <linux/input.h>
+#include <linux/usb.h>
+#include <linux/poll.h>
+
+/* Define these values to match your devices */
+#define VENDOR_ID   0x165b
+#define PRODUCT_ID  0x8101
+
+#ifdef CONFIG_USB_DYNAMIC_MINORS
+#define USB_TRANZPORT_MINOR_BASE	0
+#else  /* FIXME 177- is the another driver's minor - apply for a minor soon */
+#define USB_TRANZPORT_MINOR_BASE	177
+#endif
+
+/* table of devices that work with this driver */
+static const struct usb_device_id usb_tranzport_table[] = {
+	{USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
+	{}			/* Terminating entry */
+};
+
+MODULE_DEVICE_TABLE(usb, usb_tranzport_table);
+MODULE_VERSION("0.35");
+MODULE_AUTHOR("Mike Taht <m@taht.net>");
+MODULE_DESCRIPTION("Tranzport USB Driver");
+MODULE_LICENSE("GPL");
+MODULE_SUPPORTED_DEVICE("Frontier Designs Tranzport Control Surface");
+
+#define SUPPRESS_EXTRA_OFFLINE_EVENTS 1
+#define COMPRESS_WHEEL_EVENTS 1
+#define BUFFERED_READS 1
+#define RING_BUFFER_SIZE 1000
+#define WRITE_BUFFER_SIZE 34
+#define TRANZPORT_USB_TIMEOUT 10
+#define TRANZPORT_DEBUG 0
+
+static int debug = TRANZPORT_DEBUG;
+
+/* Use our own dbg macro */
+#define dbg_info(dev, format, arg...) do			\
+	{ if (debug) dev_info(dev , format , ## arg); } while (0)
+
+/* Module parameters */
+
+module_param(debug, int, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Debug enabled or not");
+
+/* All interrupt in transfers are collected in a ring buffer to
+ * avoid racing conditions and get better performance of the driver.
+ */
+
+static int ring_buffer_size = RING_BUFFER_SIZE;
+
+module_param(ring_buffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
+
+/* The write_buffer can one day contain more than one interrupt out transfer.
+ */
+static int write_buffer_size = WRITE_BUFFER_SIZE;
+module_param(write_buffer_size, int, S_IRUGO);
+MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
+
+/*
+ * Increase the interval for debugging purposes.
+ * or set to 1 to use the standard interval from the endpoint descriptors.
+ */
+
+static int min_interrupt_in_interval = TRANZPORT_USB_TIMEOUT;
+module_param(min_interrupt_in_interval, int, 0);
+MODULE_PARM_DESC(min_interrupt_in_interval,
+		"Minimum interrupt in interval in ms");
+
+static int min_interrupt_out_interval = TRANZPORT_USB_TIMEOUT;
+module_param(min_interrupt_out_interval, int, 0);
+MODULE_PARM_DESC(min_interrupt_out_interval,
+		"Minimum interrupt out interval in ms");
+
+struct tranzport_cmd {
+	unsigned char cmd[8];
+};
+
+/* Structure to hold all of our device specific stuff */
+
+struct usb_tranzport {
+	struct mutex mtx;	/* locks this structure */
+	struct usb_interface *intf;	/* save off the usb interface pointer */
+	int open_count;		/* number of times this port opened */
+	struct tranzport_cmd (*ring_buffer)[RING_BUFFER_SIZE];
+	unsigned int ring_head;
+	unsigned int ring_tail;
+	wait_queue_head_t read_wait;
+	wait_queue_head_t write_wait;
+	unsigned char *interrupt_in_buffer;
+	struct usb_endpoint_descriptor *interrupt_in_endpoint;
+	struct urb *interrupt_in_urb;
+	int interrupt_in_interval;
+	size_t interrupt_in_endpoint_size;
+	int interrupt_in_running;
+	int interrupt_in_done;
+	char *interrupt_out_buffer;
+	struct usb_endpoint_descriptor *interrupt_out_endpoint;
+	struct urb *interrupt_out_urb;
+	int interrupt_out_interval;
+	size_t interrupt_out_endpoint_size;
+	int interrupt_out_busy;
+
+	/* Sysfs support */
+
+	unsigned char enable;	/* 0 if disabled 1 if enabled */
+	unsigned char offline;	/* if the device is out of range or asleep */
+	unsigned char compress_wheel;	/* flag to compress wheel events */
+};
+
+/* prevent races between open() and disconnect() */
+static DEFINE_MUTEX(disconnect_mutex);
+
+static struct usb_driver usb_tranzport_driver;
+
+/**
+ *	usb_tranzport_abort_transfers
+ *      aborts transfers and frees associated data structures
+ */
+static void usb_tranzport_abort_transfers(struct usb_tranzport *dev)
+{
+	/* shutdown transfer */
+	if (dev->interrupt_in_running) {
+		dev->interrupt_in_running = 0;
+		if (dev->intf)
+			usb_kill_urb(dev->interrupt_in_urb);
+	}
+	if (dev->interrupt_out_busy)
+		if (dev->intf)
+			usb_kill_urb(dev->interrupt_out_urb);
+}
+
+#define show_int(value)	\
+	static ssize_t show_##value(struct device *dev,	\
+			      struct device_attribute *attr, char *buf)	\
+	{	\
+		struct usb_interface *intf = to_usb_interface(dev);	\
+		struct usb_tranzport *t = usb_get_intfdata(intf);	\
+		return sprintf(buf, "%d\n", t->value);	\
+	}	\
+	static DEVICE_ATTR(value, S_IRUGO, show_##value, NULL);
+
+#define show_set_int(value)	\
+	static ssize_t show_##value(struct device *dev,	\
+			      struct device_attribute *attr, char *buf)	\
+	{	\
+		struct usb_interface *intf = to_usb_interface(dev);	\
+		struct usb_tranzport *t = usb_get_intfdata(intf);	\
+		return sprintf(buf, "%d\n", t->value);	\
+	}	\
+	static ssize_t set_##value(struct device *dev,	\
+			     struct device_attribute *attr,		\
+			     const char *buf, size_t count)		\
+	{	\
+		struct usb_interface *intf = to_usb_interface(dev);	\
+		struct usb_tranzport *t = usb_get_intfdata(intf);	\
+		unsigned long temp;	\
+		if (kstrtoul(buf, 10, &temp))	\
+			return -EINVAL;	\
+		t->value = temp;	\
+		return count;	\
+	}	\
+	static DEVICE_ATTR(value, S_IWUSR | S_IRUGO, show_##value, set_##value);
+
+show_int(enable);
+show_int(offline);
+show_set_int(compress_wheel);
+
+/**
+ *	usb_tranzport_delete
+ */
+static void usb_tranzport_delete(struct usb_tranzport *dev)
+{
+	usb_tranzport_abort_transfers(dev);
+	if (dev->intf != NULL) {
+		device_remove_file(&dev->intf->dev, &dev_attr_enable);
+		device_remove_file(&dev->intf->dev, &dev_attr_offline);
+		device_remove_file(&dev->intf->dev, &dev_attr_compress_wheel);
+	}
+
+	/* free data structures */
+	usb_free_urb(dev->interrupt_in_urb);
+	usb_free_urb(dev->interrupt_out_urb);
+	kfree(dev->ring_buffer);
+	kfree(dev->interrupt_in_buffer);
+	kfree(dev->interrupt_out_buffer);
+	kfree(dev);
+}
+
+/**
+ *	usb_tranzport_interrupt_in_callback
+ */
+
+static void usb_tranzport_interrupt_in_callback(struct urb *urb)
+{
+	struct usb_tranzport *dev = urb->context;
+	unsigned int next_ring_head;
+	int retval = -1;
+
+	if (urb->status) {
+		if (urb->status == -ENOENT ||
+			urb->status == -ECONNRESET ||
+			urb->status == -ESHUTDOWN) {
+			goto exit;
+		} else {
+			dbg_info(&dev->intf->dev,
+				 "%s: nonzero status received: %d\n",
+				 __func__, urb->status);
+			goto resubmit;	/* maybe we can recover */
+		}
+	}
+
+	if (urb->actual_length != 8) {
+		dev_warn(&dev->intf->dev,
+			"Urb length was %d bytes!!"
+			"Do something intelligent\n",
+			 urb->actual_length);
+	} else {
+		dbg_info(&dev->intf->dev,
+			 "%s: received: %02x%02x%02x%02x%02x%02x%02x%02x\n",
+			 __func__, dev->interrupt_in_buffer[0],
+			 dev->interrupt_in_buffer[1],
+			 dev->interrupt_in_buffer[2],
+			 dev->interrupt_in_buffer[3],
+			 dev->interrupt_in_buffer[4],
+			 dev->interrupt_in_buffer[5],
+			 dev->interrupt_in_buffer[6],
+			 dev->interrupt_in_buffer[7]);
+#if SUPPRESS_EXTRA_OFFLINE_EVENTS
+	if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
+		goto resubmit;
+		if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
+			dev->offline = 2;
+			goto resubmit;
+		}
+
+		/* Always pass one offline event up the stack */
+		if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
+			dev->offline = 0;
+		if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
+			dev->offline = 1;
+
+#endif	/* SUPPRESS_EXTRA_OFFLINE_EVENTS */
+	   dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
+		__func__, dev->ring_head, dev->ring_tail);
+
+		next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
+
+		if (next_ring_head != dev->ring_tail) {
+			memcpy(&((*dev->ring_buffer)[dev->ring_head]),
+			       dev->interrupt_in_buffer, urb->actual_length);
+			dev->ring_head = next_ring_head;
+			retval = 0;
+			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
+		} else {
+			dev_warn(&dev->intf->dev,
+				 "Ring buffer overflow, %d bytes dropped\n",
+				 urb->actual_length);
+			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
+		}
+	}
+
+resubmit:
+/* resubmit if we're still running */
+	if (dev->interrupt_in_running && dev->intf) {
+		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
+		if (retval)
+			dev_err(&dev->intf->dev,
+				"usb_submit_urb failed (%d)\n", retval);
+	}
+
+exit:
+	dev->interrupt_in_done = 1;
+	wake_up_interruptible(&dev->read_wait);
+}
+
+/**
+ *	usb_tranzport_interrupt_out_callback
+ */
+static void usb_tranzport_interrupt_out_callback(struct urb *urb)
+{
+	struct usb_tranzport *dev = urb->context;
+	/* sync/async unlink faults aren't errors */
+	if (urb->status && !(urb->status == -ENOENT ||
+				urb->status == -ECONNRESET ||
+				urb->status == -ESHUTDOWN))
+		dbg_info(&dev->intf->dev,
+			"%s - nonzero write interrupt status received: %d\n",
+			__func__, urb->status);
+
+	dev->interrupt_out_busy = 0;
+	wake_up_interruptible(&dev->write_wait);
+}
+/**
+ *	usb_tranzport_open
+ */
+static int usb_tranzport_open(struct inode *inode, struct file *file)
+{
+	struct usb_tranzport *dev;
+	int subminor;
+	int retval = 0;
+	struct usb_interface *interface;
+
+	nonseekable_open(inode, file);
+	subminor = iminor(inode);
+
+	mutex_lock(&disconnect_mutex);
+
+	interface = usb_find_interface(&usb_tranzport_driver, subminor);
+
+	if (!interface) {
+		err("%s - error, can't find device for minor %d\n",
+			__func__, subminor);
+		retval = -ENODEV;
+		goto unlock_disconnect_exit;
+	}
+
+	dev = usb_get_intfdata(interface);
+
+	if (!dev) {
+		retval = -ENODEV;
+		goto unlock_disconnect_exit;
+	}
+
+	/* lock this device */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto unlock_disconnect_exit;
+	}
+
+	/* allow opening only once */
+	if (dev->open_count) {
+		retval = -EBUSY;
+		goto unlock_exit;
+	}
+	dev->open_count = 1;
+
+	/* initialize in direction */
+	dev->ring_head = 0;
+	dev->ring_tail = 0;
+	usb_fill_int_urb(dev->interrupt_in_urb,
+			interface_to_usbdev(interface),
+			usb_rcvintpipe(interface_to_usbdev(interface),
+				dev->interrupt_in_endpoint->
+				bEndpointAddress),
+			dev->interrupt_in_buffer,
+			dev->interrupt_in_endpoint_size,
+			usb_tranzport_interrupt_in_callback, dev,
+			dev->interrupt_in_interval);
+
+	dev->interrupt_in_running = 1;
+	dev->interrupt_in_done = 0;
+	dev->enable = 1;
+	dev->offline = 0;
+	dev->compress_wheel = 1;
+
+	retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
+	if (retval) {
+		dev_err(&interface->dev,
+			"Couldn't submit interrupt_in_urb %d\n", retval);
+		dev->interrupt_in_running = 0;
+		dev->open_count = 0;
+		goto unlock_exit;
+	}
+
+	/* save device in the file's private structure */
+	file->private_data = dev;
+
+unlock_exit:
+	mutex_unlock(&dev->mtx);
+
+unlock_disconnect_exit:
+	mutex_unlock(&disconnect_mutex);
+
+	return retval;
+}
+
+/**
+ *	usb_tranzport_release
+ */
+static int usb_tranzport_release(struct inode *inode, struct file *file)
+{
+	struct usb_tranzport *dev;
+	int retval = 0;
+
+	dev = file->private_data;
+
+	if (dev == NULL) {
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+
+	if (dev->open_count != 1) {
+		retval = -ENODEV;
+		goto unlock_exit;
+	}
+
+	if (dev->intf == NULL) {
+		/* the device was unplugged before the file was released */
+		mutex_unlock(&dev->mtx);
+		/* unlock here as usb_tranzport_delete frees dev */
+		usb_tranzport_delete(dev);
+		retval = -ENODEV;
+		goto exit;
+	}
+
+	/* wait until write transfer is finished */
+	if (dev->interrupt_out_busy)
+		wait_event_interruptible_timeout(dev->write_wait,
+						!dev->interrupt_out_busy,
+						2 * HZ);
+	usb_tranzport_abort_transfers(dev);
+	dev->open_count = 0;
+
+unlock_exit:
+	mutex_unlock(&dev->mtx);
+
+exit:
+	return retval;
+}
+
+/**
+ *	usb_tranzport_poll
+ */
+static unsigned int usb_tranzport_poll(struct file *file, poll_table *wait)
+{
+	struct usb_tranzport *dev;
+	unsigned int mask = 0;
+	dev = file->private_data;
+	poll_wait(file, &dev->read_wait, wait);
+	poll_wait(file, &dev->write_wait, wait);
+	if (dev->ring_head != dev->ring_tail)
+		mask |= POLLIN | POLLRDNORM;
+	if (!dev->interrupt_out_busy)
+		mask |= POLLOUT | POLLWRNORM;
+	return mask;
+}
+/**
+ *	usb_tranzport_read
+ */
+
+static ssize_t usb_tranzport_read(struct file *file, char __user *buffer,
+				size_t count, loff_t *ppos)
+{
+	struct usb_tranzport *dev;
+	int retval = 0;
+#if BUFFERED_READS
+	int c = 0;
+#endif
+#if COMPRESS_WHEEL_EVENTS
+	signed char oldwheel;
+	signed char newwheel;
+	int cancompress = 1;
+	int next_tail;
+#endif
+
+	/* do I have such a thing as a null event? */
+
+	dev = file->private_data;
+
+	/* verify that we actually have some data to read */
+	if (count == 0)
+		goto exit;
+
+	/* lock this object */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+
+	/* verify that the device wasn't unplugged */ if (dev->intf == NULL) {
+		retval = -ENODEV;
+		err("No device or device unplugged %d\n", retval);
+		goto unlock_exit;
+	}
+
+	while (dev->ring_head == dev->ring_tail) {
+
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto unlock_exit;
+		}
+		/* tiny race - FIXME: make atomic? */
+		/* atomic_cmp_exchange(&dev->interrupt_in_done,0,0); */
+		dev->interrupt_in_done = 0;
+		retval = wait_event_interruptible(dev->read_wait,
+						  dev->interrupt_in_done);
+		if (retval < 0)
+			goto unlock_exit;
+	}
+
+	dbg_info(&dev->intf->dev,
+		"%s: copying to userspace: "
+		"%02x%02x%02x%02x%02x%02x%02x%02x\n",
+		 __func__,
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[0],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[1],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[2],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[3],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[4],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[5],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[6],
+		 (*dev->ring_buffer)[dev->ring_tail].cmd[7]);
+
+#if BUFFERED_READS
+	c = 0;
+	while ((c < count) && (dev->ring_tail != dev->ring_head)) {
+
+#if COMPRESS_WHEEL_EVENTS
+		next_tail = (dev->ring_tail+1) % ring_buffer_size;
+		if (dev->compress_wheel)
+			cancompress = 1;
+		while (dev->ring_head != next_tail && cancompress == 1) {
+			newwheel = (*dev->ring_buffer)[next_tail].cmd[6];
+			oldwheel = (*dev->ring_buffer)[dev->ring_tail].cmd[6];
+			/* if both are wheel events, and
+			   no buttons have changes (FIXME, do I have to check?),
+			   and we are the same sign, we can compress +- 7F
+			*/
+			dbg_info(&dev->intf->dev,
+				"%s: trying to compress: "
+				"%02x%02x%02x%02x%02x%02x%02x%02x\n",
+				__func__,
+				(*dev->ring_buffer)[dev->ring_tail].cmd[0],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[1],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[2],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[3],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[4],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[5],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[6],
+				(*dev->ring_buffer)[dev->ring_tail].cmd[7]);
+
+			if (((*dev->ring_buffer)[dev->ring_tail].cmd[6] != 0 &&
+				(*dev->ring_buffer)[next_tail].cmd[6] != 0) &&
+				((newwheel > 0 && oldwheel > 0) ||
+					(newwheel < 0 && oldwheel < 0)) &&
+				((*dev->ring_buffer)[dev->ring_tail].cmd[2] ==
+				(*dev->ring_buffer)[next_tail].cmd[2]) &&
+				((*dev->ring_buffer)[dev->ring_tail].cmd[3] ==
+				(*dev->ring_buffer)[next_tail].cmd[3]) &&
+				((*dev->ring_buffer)[dev->ring_tail].cmd[4] ==
+				(*dev->ring_buffer)[next_tail].cmd[4]) &&
+				((*dev->ring_buffer)[dev->ring_tail].cmd[5] ==
+				(*dev->ring_buffer)[next_tail].cmd[5])) {
+				dbg_info(&dev->intf->dev,
+					"%s: should compress: "
+					"%02x%02x%02x%02x%02x%02x%02x%02x\n",
+					__func__,
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[0],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[1],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[2],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[3],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[4],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[5],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[6],
+					(*dev->ring_buffer)[dev->ring_tail].
+					cmd[7]);
+				newwheel += oldwheel;
+				if (oldwheel > 0 && !(newwheel > 0)) {
+					newwheel = 0x7f;
+					cancompress = 0;
+				}
+				if (oldwheel < 0 && !(newwheel < 0)) {
+					newwheel = 0x80;
+					cancompress = 0;
+				}
+
+				(*dev->ring_buffer)[next_tail].cmd[6] =
+					newwheel;
+				dev->ring_tail = next_tail;
+				next_tail =
+					(dev->ring_tail + 1) % ring_buffer_size;
+			} else {
+				cancompress = 0;
+			}
+		}
+#endif /* COMPRESS_WHEEL_EVENTS */
+		if (copy_to_user(
+				&buffer[c],
+				&(*dev->ring_buffer)[dev->ring_tail], 8)) {
+			retval = -EFAULT;
+			goto unlock_exit;
+		}
+		dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
+		c += 8;
+		dbg_info(&dev->intf->dev,
+			 "%s: head, tail are %x, %x\n",
+			 __func__, dev->ring_head, dev->ring_tail);
+	}
+	retval = c;
+
+#else
+/*  if (copy_to_user(buffer, &(*dev->ring_buffer)[dev->ring_tail], 8)) { */
+	retval = -EFAULT;
+	goto unlock_exit;
+}
+
+dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
+dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
+	 __func__, dev->ring_head, dev->ring_tail);
+
+retval = 8;
+#endif /* BUFFERED_READS */
+
+unlock_exit:
+/* unlock the device */
+mutex_unlock(&dev->mtx);
+
+exit:
+return retval;
+}
+
+/**
+ *	usb_tranzport_write
+ */
+static ssize_t usb_tranzport_write(struct file *file,
+				const char __user *buffer, size_t count,
+				loff_t *ppos)
+{
+	struct usb_tranzport *dev;
+	size_t bytes_to_write;
+	int retval = 0;
+
+	dev = file->private_data;
+
+	/* verify that we actually have some data to write */
+	if (count == 0)
+		goto exit;
+
+	/* lock this object */
+	if (mutex_lock_interruptible(&dev->mtx)) {
+		retval = -ERESTARTSYS;
+		goto exit;
+	}
+	/* verify that the device wasn't unplugged */
+	if (dev->intf == NULL) {
+		retval = -ENODEV;
+		err("No device or device unplugged %d\n", retval);
+		goto unlock_exit;
+	}
+
+	/* wait until previous transfer is finished */
+	if (dev->interrupt_out_busy) {
+		if (file->f_flags & O_NONBLOCK) {
+			retval = -EAGAIN;
+			goto unlock_exit;
+		}
+		retval = wait_event_interruptible(dev->write_wait,
+						!dev->interrupt_out_busy);
+		if (retval < 0)
+			goto unlock_exit;
+	}
+
+	/* write the data into interrupt_out_buffer from userspace */
+	bytes_to_write = min(count,
+			write_buffer_size *
+			dev->interrupt_out_endpoint_size);
+	if (bytes_to_write < count)
+		dev_warn(&dev->intf->dev,
+			"Write buffer overflow, %zd bytes dropped\n",
+			count - bytes_to_write);
+
+	dbg_info(&dev->intf->dev,
+		"%s: count = %zd, bytes_to_write = %zd\n", __func__,
+		count, bytes_to_write);
+
+	if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
+		retval = -EFAULT;
+		goto unlock_exit;
+	}
+
+	if (dev->interrupt_out_endpoint == NULL) {
+		err("Endpoint should not be be null!\n");
+		goto unlock_exit;
+	}
+
+	/* send off the urb */
+	usb_fill_int_urb(dev->interrupt_out_urb,
+			interface_to_usbdev(dev->intf),
+			usb_sndintpipe(interface_to_usbdev(dev->intf),
+				dev->interrupt_out_endpoint->
+				bEndpointAddress),
+			dev->interrupt_out_buffer, bytes_to_write,
+			usb_tranzport_interrupt_out_callback, dev,
+			dev->interrupt_out_interval);
+
+	dev->interrupt_out_busy = 1;
+	wmb();
+
+	retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
+	if (retval) {
+		dev->interrupt_out_busy = 0;
+		err("Couldn't submit interrupt_out_urb %d\n", retval);
+		goto unlock_exit;
+	}
+	retval = bytes_to_write;
+
+unlock_exit:
+	/* unlock the device */
+	mutex_unlock(&dev->mtx);
+
+exit:
+	return retval;
+}
+
+/* file operations needed when we register this driver */
+static const struct file_operations usb_tranzport_fops = {
+	.owner = THIS_MODULE,
+	.read = usb_tranzport_read,
+	.write = usb_tranzport_write,
+	.open = usb_tranzport_open,
+	.release = usb_tranzport_release,
+	.poll = usb_tranzport_poll,
+	.llseek = no_llseek,
+};
+
+/*
+ * usb class driver info in order to get a minor number from the usb core,
+ * and to have the device registered with the driver core
+ */
+static struct usb_class_driver usb_tranzport_class = {
+	.name = "tranzport%d",
+	.fops = &usb_tranzport_fops,
+	.minor_base = USB_TRANZPORT_MINOR_BASE,
+};
+
+/**
+ *	usb_tranzport_probe
+ *
+ *	Called by the usb core when a new device is connected that it thinks
+ *	this driver might be interested in.
+ */
+static int usb_tranzport_probe(struct usb_interface *intf,
+			       const struct usb_device_id *id) {
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_tranzport *dev = NULL;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	int i;
+	int true_size;
+	int retval = -ENOMEM;
+
+	/* allocate memory for our device state and initialize it */
+
+	 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (dev == NULL) {
+		dev_err(&intf->dev, "Out of memory\n");
+		goto exit;
+	}
+	mutex_init(&dev->mtx);
+	dev->intf = intf;
+	init_waitqueue_head(&dev->read_wait);
+	init_waitqueue_head(&dev->write_wait);
+
+	iface_desc = intf->cur_altsetting;
+
+	/* set up the endpoint information */
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (usb_endpoint_is_int_in(endpoint))
+			dev->interrupt_in_endpoint = endpoint;
+
+		if (usb_endpoint_is_int_out(endpoint))
+			dev->interrupt_out_endpoint = endpoint;
+	}
+	if (dev->interrupt_in_endpoint == NULL) {
+		dev_err(&intf->dev, "Interrupt in endpoint not found\n");
+		goto error;
+	}
+	if (dev->interrupt_out_endpoint == NULL)
+		dev_warn(&intf->dev,
+			"Interrupt out endpoint not found"
+			"(using control endpoint instead)\n");
+
+	dev->interrupt_in_endpoint_size =
+	    le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
+
+	if (dev->interrupt_in_endpoint_size != 8)
+		dev_warn(&intf->dev, "Interrupt in endpoint size is not 8!\n");
+
+	if (ring_buffer_size == 0)
+		ring_buffer_size = RING_BUFFER_SIZE;
+	true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
+
+	/* FIXME - there are more usb_alloc routines for dma correctness.
+	   Needed? */
+
+	dev->ring_buffer =
+	    kmalloc((true_size * sizeof(struct tranzport_cmd)) + 8, GFP_KERNEL);
+
+	if (!dev->ring_buffer) {
+		dev_err(&intf->dev,
+			"Couldn't allocate ring_buffer size %d\n", true_size);
+		goto error;
+	}
+	dev->interrupt_in_buffer =
+	    kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
+	if (!dev->interrupt_in_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
+		goto error;
+	}
+	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!dev->interrupt_in_urb) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
+		goto error;
+	}
+	dev->interrupt_out_endpoint_size =
+	    dev->interrupt_out_endpoint ?
+	    le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
+	    udev->descriptor.bMaxPacketSize0;
+
+	if (dev->interrupt_out_endpoint_size != 8)
+		dev_warn(&intf->dev,
+			 "Interrupt out endpoint size is not 8!)\n");
+
+	dev->interrupt_out_buffer =
+	    kmalloc(write_buffer_size * dev->interrupt_out_endpoint_size,
+		    GFP_KERNEL);
+	if (!dev->interrupt_out_buffer) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
+		goto error;
+	}
+	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!dev->interrupt_out_urb) {
+		dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
+		goto error;
+	}
+	dev->interrupt_in_interval =
+	    min_interrupt_in_interval >
+	    dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval
+	    : dev->interrupt_in_endpoint->bInterval;
+
+	if (dev->interrupt_out_endpoint) {
+		dev->interrupt_out_interval =
+		    min_interrupt_out_interval >
+		    dev->interrupt_out_endpoint->bInterval ?
+		    min_interrupt_out_interval :
+		    dev->interrupt_out_endpoint->bInterval;
+	}
+
+	/* we can register the device now, as it is ready */
+	usb_set_intfdata(intf, dev);
+
+	retval = usb_register_dev(intf, &usb_tranzport_class);
+	if (retval) {
+		/* something prevented us from registering this driver */
+		dev_err(&intf->dev,
+			"Not able to get a minor for this device.\n");
+		usb_set_intfdata(intf, NULL);
+		goto error;
+	}
+
+	retval = device_create_file(&intf->dev, &dev_attr_compress_wheel);
+	if (retval)
+		goto error;
+	retval = device_create_file(&intf->dev, &dev_attr_enable);
+	if (retval)
+		goto error;
+	retval = device_create_file(&intf->dev, &dev_attr_offline);
+	if (retval)
+		goto error;
+
+	/* let the user know what node this device is now attached to */
+	dev_info(&intf->dev,
+		"Tranzport Device #%d now attached to major %d minor %d\n",
+		(intf->minor - USB_TRANZPORT_MINOR_BASE), USB_MAJOR,
+		intf->minor);
+
+exit:
+	return retval;
+
+error:
+	usb_tranzport_delete(dev);
+	return retval;
+}
+
+/**
+ *	usb_tranzport_disconnect
+ *
+ *	Called by the usb core when the device is removed from the system.
+ */
+static void usb_tranzport_disconnect(struct usb_interface *intf)
+{
+	struct usb_tranzport *dev;
+	int minor;
+	mutex_lock(&disconnect_mutex);
+	dev = usb_get_intfdata(intf);
+	usb_set_intfdata(intf, NULL);
+	mutex_lock(&dev->mtx);
+	minor = intf->minor;
+	/* give back our minor */
+	usb_deregister_dev(intf, &usb_tranzport_class);
+
+	/* if the device is not opened, then we clean up right now */
+	if (!dev->open_count) {
+		mutex_unlock(&dev->mtx);
+		usb_tranzport_delete(dev);
+	} else {
+		dev->intf = NULL;
+		mutex_unlock(&dev->mtx);
+	}
+
+	mutex_unlock(&disconnect_mutex);
+
+	dev_info(&intf->dev, "Tranzport Surface #%d now disconnected\n",
+		(minor - USB_TRANZPORT_MINOR_BASE));
+}
+
+/* usb specific object needed to register this driver with the usb subsystem */
+static struct usb_driver usb_tranzport_driver = {
+	.name = "tranzport",
+	.probe = usb_tranzport_probe,
+	.disconnect = usb_tranzport_disconnect,
+	.id_table = usb_tranzport_table,
+};
+
+module_usb_driver(usb_tranzport_driver);