2 * Frontier Designs Alphatrack driver
4 * Copyright (C) 2007 Michael Taht (m@taht.net)
6 * Based on the usbled driver and ldusb drivers by
8 * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
9 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
11 * The ldusb driver was, in turn, derived from Lego USB Tower driver
12 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
13 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation, version 2.
22 * This driver uses a ring buffer for time critical reading of
23 * interrupt in reports and provides read and write methods for
24 * raw interrupt reports.
27 /* Note: this currently uses a dumb ringbuffer for reads and writes.
28 * A more optimal driver would cache and kill off outstanding urbs that are
29 * now invalid, and ignore ones that already were in the queue but valid
30 * as we only have 30 commands for the alphatrack. In particular this is
31 * key for getting lights to flash in time as otherwise many commands
32 * can be buffered up before the light change makes it to the interface.
35 #include <linux/kernel.h>
36 #include <linux/errno.h>
37 #include <linux/init.h>
38 #include <linux/slab.h>
39 #include <linux/module.h>
40 #include <linux/kobject.h>
41 #include <linux/mutex.h>
42 #include <linux/version.h>
44 #include <linux/uaccess.h>
45 #include <linux/input.h>
46 #include <linux/usb.h>
47 #include <linux/poll.h>
49 #include "surface_sysfs.h"
51 #include "alphatrack.h"
53 #define VENDOR_ID 0x165b
54 #define PRODUCT_ID 0xfad1
56 #ifdef CONFIG_USB_DYNAMIC_MINORS
57 #define USB_ALPHATRACK_MINOR_BASE 0
59 /* FIXME 176 - is another driver's minor - apply for that */
60 #define USB_ALPHATRACK_MINOR_BASE 176
63 /* table of devices that work with this driver */
64 static struct usb_device_id usb_alphatrack_table[] = {
65 {USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
66 {} /* Terminating entry */
69 MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
70 MODULE_VERSION("0.41");
71 MODULE_AUTHOR("Mike Taht <m@taht.net>");
72 MODULE_DESCRIPTION("Alphatrack USB Driver");
73 MODULE_LICENSE("GPL");
74 MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
76 /* These aren't done yet */
78 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
79 #define BUFFERED_WRITES 0
80 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
81 #define COMPRESS_FADER_EVENTS 0
83 #define BUFFERED_READS 1
84 #define RING_BUFFER_SIZE 512
85 #define WRITE_BUFFER_SIZE 34
86 #define ALPHATRACK_USB_TIMEOUT 10
87 #define OUTPUT_CMD_SIZE 8
88 #define INPUT_CMD_SIZE 12
89 #define ALPHATRACK_DEBUG 0
91 static int debug = ALPHATRACK_DEBUG;
93 /* Use our own dbg macro */
94 #define dbg_info(dev, format, arg...) do \
95 { if (debug) dev_info(dev , format , ## arg); } while (0)
97 #define alphatrack_ocmd_info(dev, cmd, format, arg...)
99 #define alphatrack_icmd_info(dev, cmd, format, arg...)
101 /* Module parameters */
103 module_param(debug, int, S_IRUGO | S_IWUSR);
104 MODULE_PARM_DESC(debug, "Debug enabled or not");
106 /* All interrupt in transfers are collected in a ring buffer to
107 * avoid racing conditions and get better performance of the driver.
110 static int ring_buffer_size = RING_BUFFER_SIZE;
112 module_param(ring_buffer_size, int, S_IRUGO);
113 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
115 /* The write_buffer can one day contain more than one interrupt out transfer.
118 static int write_buffer_size = WRITE_BUFFER_SIZE;
119 module_param(write_buffer_size, int, S_IRUGO);
120 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
123 * Increase the interval for debugging purposes.
124 * or set to 1 to use the standard interval from the endpoint descriptors.
127 static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
128 module_param(min_interrupt_in_interval, int, 0);
129 MODULE_PARM_DESC(min_interrupt_in_interval,
130 "Minimum interrupt in interval in ms");
132 static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
133 module_param(min_interrupt_out_interval, int, 0);
134 MODULE_PARM_DESC(min_interrupt_out_interval,
135 "Minimum interrupt out interval in ms");
137 /* Structure to hold all of our device specific stuff */
139 struct usb_alphatrack {
140 struct semaphore sem; /* locks this structure */
141 struct usb_interface *intf; /* save off the usb interface pointer */
142 int open_count; /* number of times this port has been opened */
145 struct alphatrack_icmd (*ring_buffer)[RING_BUFFER_SIZE];
146 struct alphatrack_ocmd (*write_buffer)[WRITE_BUFFER_SIZE];
147 unsigned int ring_head;
148 unsigned int ring_tail;
150 wait_queue_head_t read_wait;
151 wait_queue_head_t write_wait;
153 unsigned char *interrupt_in_buffer;
154 unsigned char *oldi_buffer;
155 struct usb_endpoint_descriptor *interrupt_in_endpoint;
156 struct urb *interrupt_in_urb;
157 int interrupt_in_interval;
158 size_t interrupt_in_endpoint_size;
159 int interrupt_in_running;
160 int interrupt_in_done;
162 char *interrupt_out_buffer;
163 struct usb_endpoint_descriptor *interrupt_out_endpoint;
164 struct urb *interrupt_out_urb;
165 int interrupt_out_interval;
166 size_t interrupt_out_endpoint_size;
167 int interrupt_out_busy;
169 atomic_t writes_pending;
170 int event; /* alternate interface to events */
171 int fader; /* 10 bits */
172 int lights; /* 23 bits */
173 unsigned char dump_state; /* 0 if disabled 1 if enabled */
174 unsigned char enable; /* 0 if disabled 1 if enabled */
175 unsigned char offline; /* if the device is out of range or asleep */
176 unsigned char verbose; /* be verbose in error reporting */
177 unsigned char last_cmd[OUTPUT_CMD_SIZE];
178 unsigned char screen[32];
181 /* prevent races between open() and disconnect() */
182 static DEFINE_MUTEX(disconnect_mutex);
184 /* forward declaration */
186 static struct usb_driver usb_alphatrack_driver;
189 * usb_alphatrack_abort_transfers
190 * aborts transfers and frees associated data structures
192 static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
194 /* shutdown transfer */
195 if (dev->interrupt_in_running) {
196 dev->interrupt_in_running = 0;
198 usb_kill_urb(dev->interrupt_in_urb);
200 if (dev->interrupt_out_busy)
202 usb_kill_urb(dev->interrupt_out_urb);
206 * usb_alphatrack_delete
208 static void usb_alphatrack_delete(struct usb_alphatrack *dev)
210 usb_alphatrack_abort_transfers(dev);
211 usb_free_urb(dev->interrupt_in_urb);
212 usb_free_urb(dev->interrupt_out_urb);
213 kfree(dev->ring_buffer);
214 kfree(dev->interrupt_in_buffer);
215 kfree(dev->interrupt_out_buffer);
216 kfree(dev); /* fixme oldi_buffer */
220 * usb_alphatrack_interrupt_in_callback
223 static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
225 struct usb_alphatrack *dev = urb->context;
226 unsigned int next_ring_head;
230 if (urb->status == -ENOENT ||
231 urb->status == -ECONNRESET || urb->status == -ESHUTDOWN) {
234 dbg_info(&dev->intf->dev,
235 "%s: nonzero status received: %d\n", __func__,
237 goto resubmit; /* maybe we can recover */
241 if (urb->actual_length != INPUT_CMD_SIZE) {
242 dev_warn(&dev->intf->dev,
243 "Urb length was %d bytes!!"
244 "Do something intelligent \n", urb->actual_length);
246 alphatrack_ocmd_info(&dev->intf->dev,
247 &(*dev->ring_buffer)[dev->ring_tail].cmd,
250 (dev->interrupt_in_buffer, dev->oldi_buffer,
251 INPUT_CMD_SIZE) == 0) {
254 memcpy(dev->oldi_buffer, dev->interrupt_in_buffer,
257 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
258 if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
260 if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
264 /* Always pass one offline event up the stack */
265 if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
267 if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
270 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
271 __func__, dev->ring_head, dev->ring_tail);
272 next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
274 if (next_ring_head != dev->ring_tail) {
275 memcpy(&((*dev->ring_buffer)[dev->ring_head]),
276 dev->interrupt_in_buffer, urb->actual_length);
277 dev->ring_head = next_ring_head;
279 memset(dev->interrupt_in_buffer, 0, urb->actual_length);
281 dev_warn(&dev->intf->dev,
282 "Ring buffer overflow, %d bytes dropped\n",
284 memset(dev->interrupt_in_buffer, 0, urb->actual_length);
289 /* resubmit if we're still running */
290 if (dev->interrupt_in_running && dev->intf) {
291 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
293 dev_err(&dev->intf->dev,
294 "usb_submit_urb failed (%d)\n", retval);
298 dev->interrupt_in_done = 1;
299 wake_up_interruptible(&dev->read_wait);
303 * usb_alphatrack_interrupt_out_callback
305 static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
307 struct usb_alphatrack *dev = urb->context;
309 /* sync/async unlink faults aren't errors */
310 if (urb->status && !(urb->status == -ENOENT ||
311 urb->status == -ECONNRESET ||
312 urb->status == -ESHUTDOWN))
313 dbg_info(&dev->intf->dev,
314 "%s - nonzero write interrupt status received: %d\n",
315 __func__, urb->status);
316 atomic_dec(&dev->writes_pending);
317 dev->interrupt_out_busy = 0;
318 wake_up_interruptible(&dev->write_wait);
322 * usb_alphatrack_open
324 static int usb_alphatrack_open(struct inode *inode, struct file *file)
326 struct usb_alphatrack *dev;
329 struct usb_interface *interface;
331 nonseekable_open(inode, file);
332 subminor = iminor(inode);
334 mutex_lock(&disconnect_mutex);
336 interface = usb_find_interface(&usb_alphatrack_driver, subminor);
339 err("%s - error, can't find device for minor %d\n",
342 goto unlock_disconnect_exit;
345 dev = usb_get_intfdata(interface);
349 goto unlock_disconnect_exit;
352 /* lock this device */
353 if (down_interruptible(&dev->sem)) {
354 retval = -ERESTARTSYS;
355 goto unlock_disconnect_exit;
358 /* allow opening only once */
359 if (dev->open_count) {
365 /* initialize in direction */
368 usb_fill_int_urb(dev->interrupt_in_urb,
369 interface_to_usbdev(interface),
370 usb_rcvintpipe(interface_to_usbdev(interface),
371 dev->interrupt_in_endpoint->
373 dev->interrupt_in_buffer,
374 dev->interrupt_in_endpoint_size,
375 usb_alphatrack_interrupt_in_callback, dev,
376 dev->interrupt_in_interval);
378 dev->interrupt_in_running = 1;
379 dev->interrupt_in_done = 0;
383 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
385 dev_err(&interface->dev,
386 "Couldn't submit interrupt_in_urb %d\n", retval);
387 dev->interrupt_in_running = 0;
392 /* save device in the file's private structure */
393 file->private_data = dev;
398 unlock_disconnect_exit:
399 mutex_unlock(&disconnect_mutex);
405 * usb_alphatrack_release
407 static int usb_alphatrack_release(struct inode *inode, struct file *file)
409 struct usb_alphatrack *dev;
412 dev = file->private_data;
419 if (down_interruptible(&dev->sem)) {
420 retval = -ERESTARTSYS;
424 if (dev->open_count != 1) {
429 if (dev->intf == NULL) {
430 /* the device was unplugged before the file was released */
432 /* unlock here as usb_alphatrack_delete frees dev */
433 usb_alphatrack_delete(dev);
438 /* wait until write transfer is finished */
439 if (dev->interrupt_out_busy)
440 wait_event_interruptible_timeout(dev->write_wait,
441 !dev->interrupt_out_busy,
443 usb_alphatrack_abort_transfers(dev);
454 * usb_alphatrack_poll
456 static unsigned int usb_alphatrack_poll(struct file *file, poll_table * wait)
458 struct usb_alphatrack *dev;
459 unsigned int mask = 0;
461 dev = file->private_data;
463 poll_wait(file, &dev->read_wait, wait);
464 poll_wait(file, &dev->write_wait, wait);
466 if (dev->ring_head != dev->ring_tail)
467 mask |= POLLIN | POLLRDNORM;
468 if (!dev->interrupt_out_busy)
469 mask |= POLLOUT | POLLWRNORM;
475 * usb_alphatrack_read
477 static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer,
478 size_t count, loff_t *ppos)
480 struct usb_alphatrack *dev;
485 dev = file->private_data;
487 /* verify that we actually have some data to read */
491 /* lock this object */
492 if (down_interruptible(&dev->sem)) {
493 retval = -ERESTARTSYS;
497 /* verify that the device wasn't unplugged */
498 if (dev->intf == NULL) {
500 err("No device or device unplugged %d\n", retval);
504 while (dev->ring_head == dev->ring_tail) {
505 if (file->f_flags & O_NONBLOCK) {
509 dev->interrupt_in_done = 0;
511 wait_event_interruptible(dev->read_wait,
512 dev->interrupt_in_done);
517 alphatrack_ocmd_info(&dev->intf->dev,
518 &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s",
519 ": copying to userspace");
522 while ((c < count) && (dev->ring_tail != dev->ring_head)) {
524 (&buffer[c], &(*dev->ring_buffer)[dev->ring_tail],
529 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
531 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
532 __func__, dev->ring_head, dev->ring_tail);
537 /* unlock the device */
545 * usb_alphatrack_write
547 static ssize_t usb_alphatrack_write(struct file *file,
548 const char __user *buffer, size_t count,
551 struct usb_alphatrack *dev;
552 size_t bytes_to_write;
555 dev = file->private_data;
557 /* verify that we actually have some data to write */
561 /* lock this object */
562 if (down_interruptible(&dev->sem)) {
563 retval = -ERESTARTSYS;
567 /* verify that the device wasn't unplugged */
568 if (dev->intf == NULL) {
570 err("No device or device unplugged %d\n", retval);
574 /* wait until previous transfer is finished */
575 if (dev->interrupt_out_busy) {
576 if (file->f_flags & O_NONBLOCK) {
581 wait_event_interruptible(dev->write_wait,
582 !dev->interrupt_out_busy);
587 /* write the data into interrupt_out_buffer from userspace */
588 /* FIXME - if you write more than 12 bytes this breaks */
590 min(count, write_buffer_size * dev->interrupt_out_endpoint_size);
591 if (bytes_to_write < count)
592 dev_warn(&dev->intf->dev,
593 "Write buffer overflow, %zd bytes dropped\n",
594 count - bytes_to_write);
596 dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
597 __func__, count, bytes_to_write);
599 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
604 if (dev->interrupt_out_endpoint == NULL) {
605 err("Endpoint should not be be null! \n");
609 /* send off the urb */
610 usb_fill_int_urb(dev->interrupt_out_urb,
611 interface_to_usbdev(dev->intf),
612 usb_sndintpipe(interface_to_usbdev(dev->intf),
613 dev->interrupt_out_endpoint->
615 dev->interrupt_out_buffer, bytes_to_write,
616 usb_alphatrack_interrupt_out_callback, dev,
617 dev->interrupt_out_interval);
618 dev->interrupt_out_busy = 1;
619 atomic_inc(&dev->writes_pending);
622 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
624 dev->interrupt_out_busy = 0;
625 err("Couldn't submit interrupt_out_urb %d\n", retval);
626 atomic_dec(&dev->writes_pending);
629 retval = bytes_to_write;
632 /* unlock the device */
639 /* file operations needed when we register this driver */
640 static const struct file_operations usb_alphatrack_fops = {
641 .owner = THIS_MODULE,
642 .read = usb_alphatrack_read,
643 .write = usb_alphatrack_write,
644 .open = usb_alphatrack_open,
645 .release = usb_alphatrack_release,
646 .poll = usb_alphatrack_poll,
650 * usb class driver info in order to get a minor number from the usb core,
651 * and to have the device registered with the driver core
654 static struct usb_class_driver usb_alphatrack_class = {
655 .name = "alphatrack%d",
656 .fops = &usb_alphatrack_fops,
657 .minor_base = USB_ALPHATRACK_MINOR_BASE,
661 * usb_alphatrack_probe
663 * Called by the usb core when a new device is connected that it thinks
664 * this driver might be interested in.
666 static int usb_alphatrack_probe(struct usb_interface *intf,
667 const struct usb_device_id *id)
669 struct usb_device *udev = interface_to_usbdev(intf);
670 struct usb_alphatrack *dev = NULL;
671 struct usb_host_interface *iface_desc;
672 struct usb_endpoint_descriptor *endpoint;
675 int retval = -ENOMEM;
677 /* allocate memory for our device state and intialize it */
679 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
681 dev_err(&intf->dev, "Out of memory\n");
684 init_MUTEX(&dev->sem);
686 init_waitqueue_head(&dev->read_wait);
687 init_waitqueue_head(&dev->write_wait);
689 iface_desc = intf->cur_altsetting;
691 /* set up the endpoint information */
692 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
693 endpoint = &iface_desc->endpoint[i].desc;
695 if (usb_endpoint_is_int_in(endpoint))
696 dev->interrupt_in_endpoint = endpoint;
698 if (usb_endpoint_is_int_out(endpoint))
699 dev->interrupt_out_endpoint = endpoint;
701 if (dev->interrupt_in_endpoint == NULL) {
702 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
705 if (dev->interrupt_out_endpoint == NULL)
707 "Interrupt out endpoint not found"
708 "(using control endpoint instead)\n");
710 dev->interrupt_in_endpoint_size =
711 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
713 if (dev->interrupt_in_endpoint_size != 64)
714 dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
716 if (ring_buffer_size == 0)
717 ring_buffer_size = RING_BUFFER_SIZE;
719 true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
721 /* FIXME - there are more usb_alloc routines for dma correctness.
724 kmalloc((true_size * sizeof(struct alphatrack_icmd)), GFP_KERNEL);
726 if (!dev->ring_buffer) {
728 "Couldn't allocate input ring_buffer of size %d\n",
733 dev->interrupt_in_buffer =
734 kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
736 if (!dev->interrupt_in_buffer) {
737 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
740 dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
741 if (!dev->oldi_buffer) {
742 dev_err(&intf->dev, "Couldn't allocate old buffer\n");
745 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
746 if (!dev->interrupt_in_urb) {
747 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
751 dev->interrupt_out_endpoint_size =
752 dev->interrupt_out_endpoint ? le16_to_cpu(dev->
753 interrupt_out_endpoint->
754 wMaxPacketSize) : udev->
755 descriptor.bMaxPacketSize0;
757 if (dev->interrupt_out_endpoint_size != 64)
759 "Interrupt out endpoint size is not 64!)\n");
761 if (write_buffer_size == 0)
762 write_buffer_size = WRITE_BUFFER_SIZE;
763 true_size = min(write_buffer_size, WRITE_BUFFER_SIZE);
765 dev->interrupt_out_buffer =
766 kmalloc(true_size * dev->interrupt_out_endpoint_size, GFP_KERNEL);
768 if (!dev->interrupt_out_buffer) {
769 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
774 kmalloc(sizeof(struct alphatrack_ocmd) * true_size, GFP_KERNEL);
776 if (!dev->write_buffer) {
777 dev_err(&intf->dev, "Couldn't allocate write_buffer \n");
781 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
782 if (!dev->interrupt_out_urb) {
783 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
786 dev->interrupt_in_interval =
787 min_interrupt_in_interval >
788 dev->interrupt_in_endpoint->
789 bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->
791 if (dev->interrupt_out_endpoint)
792 dev->interrupt_out_interval =
793 min_interrupt_out_interval >
794 dev->interrupt_out_endpoint->
795 bInterval ? min_interrupt_out_interval : dev->
796 interrupt_out_endpoint->bInterval;
798 /* we can register the device now, as it is ready */
799 usb_set_intfdata(intf, dev);
801 atomic_set(&dev->writes_pending, 0);
802 retval = usb_register_dev(intf, &usb_alphatrack_class);
804 /* something prevented us from registering this driver */
806 "Not able to get a minor for this device.\n");
807 usb_set_intfdata(intf, NULL);
811 /* let the user know what node this device is now attached to */
813 "Alphatrack Device #%d now attached to major %d minor %d\n",
814 (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR,
821 usb_alphatrack_delete(dev);
827 * usb_alphatrack_disconnect
829 * Called by the usb core when the device is removed from the system.
831 static void usb_alphatrack_disconnect(struct usb_interface *intf)
833 struct usb_alphatrack *dev;
836 mutex_lock(&disconnect_mutex);
838 dev = usb_get_intfdata(intf);
839 usb_set_intfdata(intf, NULL);
845 /* give back our minor */
846 usb_deregister_dev(intf, &usb_alphatrack_class);
848 /* if the device is not opened, then we clean up right now */
849 if (!dev->open_count) {
851 usb_alphatrack_delete(dev);
857 atomic_set(&dev->writes_pending, 0);
858 mutex_unlock(&disconnect_mutex);
860 dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
861 (minor - USB_ALPHATRACK_MINOR_BASE));
864 /* usb specific object needed to register this driver with the usb subsystem */
865 static struct usb_driver usb_alphatrack_driver = {
866 .name = "alphatrack",
867 .probe = usb_alphatrack_probe,
868 .disconnect = usb_alphatrack_disconnect,
869 .id_table = usb_alphatrack_table,
873 * usb_alphatrack_init
875 static int __init usb_alphatrack_init(void)
879 /* register this driver with the USB subsystem */
880 retval = usb_register(&usb_alphatrack_driver);
882 err("usb_register failed for the " __FILE__
883 " driver. Error number %d\n", retval);
889 * usb_alphatrack_exit
891 static void __exit usb_alphatrack_exit(void)
893 /* deregister this driver with the USB subsystem */
894 usb_deregister(&usb_alphatrack_driver);
897 module_init(usb_alphatrack_init);
898 module_exit(usb_alphatrack_exit);