Merge branch 'linus' into core/softlockup
[linux-2.6] / drivers / staging / frontier / alphatrack.c
1 /*
2  * Frontier Designs Alphatrack driver
3  *
4  * Copyright (C) 2007 Michael Taht (m@taht.net)
5  *
6  * Based on the usbled driver and ldusb drivers by
7  *
8  * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
9  * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
10  *
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>
14  *
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.
18  *
19  */
20
21 /**
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.
25  */
26
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.
33 */
34
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>
43
44 #include <linux/uaccess.h>
45 #include <linux/input.h>
46 #include <linux/usb.h>
47 #include <linux/poll.h>
48
49 #include "alphatrack.h"
50
51 #define VENDOR_ID       0x165b
52 #define PRODUCT_ID      0xfad1
53
54 #ifdef CONFIG_USB_DYNAMIC_MINORS
55 #define USB_ALPHATRACK_MINOR_BASE       0
56 #else
57 /* FIXME 176 - is another driver's minor - apply for that */
58 #define USB_ALPHATRACK_MINOR_BASE       176
59 #endif
60
61 /* table of devices that work with this driver */
62 static struct usb_device_id usb_alphatrack_table[] = {
63         {USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
64         {}                      /* Terminating entry */
65 };
66
67 MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
68 MODULE_VERSION("0.41");
69 MODULE_AUTHOR("Mike Taht <m@taht.net>");
70 MODULE_DESCRIPTION("Alphatrack USB Driver");
71 MODULE_LICENSE("GPL");
72 MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
73
74 /* These aren't done yet */
75
76 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
77 #define BUFFERED_WRITES 0
78 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
79 #define COMPRESS_FADER_EVENTS 0
80
81 #define BUFFERED_READS 1
82 #define RING_BUFFER_SIZE 512
83 #define WRITE_BUFFER_SIZE 34
84 #define ALPHATRACK_USB_TIMEOUT 10
85 #define OUTPUT_CMD_SIZE 8
86 #define INPUT_CMD_SIZE 12
87 #define ALPHATRACK_DEBUG 0
88
89 static int debug = ALPHATRACK_DEBUG;
90
91 /* Use our own dbg macro */
92 #define dbg_info(dev, format, arg...) do \
93     { if (debug) dev_info(dev , format , ## arg); } while (0)
94
95 #define alphatrack_ocmd_info(dev, cmd, format, arg...)
96
97 #define alphatrack_icmd_info(dev, cmd, format, arg...)
98
99 /* Module parameters */
100
101 module_param(debug, int, S_IRUGO | S_IWUSR);
102 MODULE_PARM_DESC(debug, "Debug enabled or not");
103
104 /* All interrupt in transfers are collected in a ring buffer to
105  * avoid racing conditions and get better performance of the driver.
106  */
107
108 static int ring_buffer_size = RING_BUFFER_SIZE;
109
110 module_param(ring_buffer_size, int, S_IRUGO);
111 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
112
113 /* The write_buffer can one day contain more than one interrupt out transfer.
114  */
115
116 static int write_buffer_size = WRITE_BUFFER_SIZE;
117 module_param(write_buffer_size, int, S_IRUGO);
118 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
119
120 /*
121  * Increase the interval for debugging purposes.
122  * or set to 1 to use the standard interval from the endpoint descriptors.
123  */
124
125 static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
126 module_param(min_interrupt_in_interval, int, 0);
127 MODULE_PARM_DESC(min_interrupt_in_interval,
128                  "Minimum interrupt in interval in ms");
129
130 static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
131 module_param(min_interrupt_out_interval, int, 0);
132 MODULE_PARM_DESC(min_interrupt_out_interval,
133                  "Minimum interrupt out interval in ms");
134
135 /* Structure to hold all of our device specific stuff */
136
137 struct usb_alphatrack {
138         struct semaphore sem;   /* locks this structure */
139         struct usb_interface *intf;     /* save off the usb interface pointer */
140         int open_count;         /* number of times this port has been opened */
141
142         /* make gcc happy */
143         struct alphatrack_icmd (*ring_buffer)[RING_BUFFER_SIZE];
144         struct alphatrack_ocmd (*write_buffer)[WRITE_BUFFER_SIZE];
145         unsigned int ring_head;
146         unsigned int ring_tail;
147
148         wait_queue_head_t read_wait;
149         wait_queue_head_t write_wait;
150
151         unsigned char *interrupt_in_buffer;
152         unsigned char *oldi_buffer;
153         struct usb_endpoint_descriptor *interrupt_in_endpoint;
154         struct urb *interrupt_in_urb;
155         int interrupt_in_interval;
156         size_t interrupt_in_endpoint_size;
157         int interrupt_in_running;
158         int interrupt_in_done;
159
160         char *interrupt_out_buffer;
161         struct usb_endpoint_descriptor *interrupt_out_endpoint;
162         struct urb *interrupt_out_urb;
163         int interrupt_out_interval;
164         size_t interrupt_out_endpoint_size;
165         int interrupt_out_busy;
166
167         atomic_t writes_pending;
168         int event;              /* alternate interface to events */
169         int fader;              /* 10 bits */
170         int lights;             /* 23 bits */
171         unsigned char dump_state;       /* 0 if disabled 1 if enabled */
172         unsigned char enable;   /* 0 if disabled 1 if enabled */
173         unsigned char offline;  /* if the device is out of range or asleep */
174         unsigned char verbose;  /* be verbose in error reporting */
175         unsigned char last_cmd[OUTPUT_CMD_SIZE];
176         unsigned char screen[32];
177 };
178
179 /* prevent races between open() and disconnect() */
180 static DEFINE_MUTEX(disconnect_mutex);
181
182 /* forward declaration */
183
184 static struct usb_driver usb_alphatrack_driver;
185
186 /**
187  *      usb_alphatrack_abort_transfers
188  *      aborts transfers and frees associated data structures
189  */
190 static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
191 {
192         /* shutdown transfer */
193         if (dev->interrupt_in_running) {
194                 dev->interrupt_in_running = 0;
195                 if (dev->intf)
196                         usb_kill_urb(dev->interrupt_in_urb);
197         }
198         if (dev->interrupt_out_busy)
199                 if (dev->intf)
200                         usb_kill_urb(dev->interrupt_out_urb);
201 }
202
203 /**
204  *      usb_alphatrack_delete
205  */
206 static void usb_alphatrack_delete(struct usb_alphatrack *dev)
207 {
208         usb_alphatrack_abort_transfers(dev);
209         usb_free_urb(dev->interrupt_in_urb);
210         usb_free_urb(dev->interrupt_out_urb);
211         kfree(dev->ring_buffer);
212         kfree(dev->interrupt_in_buffer);
213         kfree(dev->interrupt_out_buffer);
214         kfree(dev);             /* fixme oldi_buffer */
215 }
216
217 /**
218  *      usb_alphatrack_interrupt_in_callback
219  */
220
221 static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
222 {
223         struct usb_alphatrack *dev = urb->context;
224         unsigned int next_ring_head;
225         int retval = -1;
226
227         if (urb->status) {
228                 if (urb->status == -ENOENT ||
229                     urb->status == -ECONNRESET || urb->status == -ESHUTDOWN) {
230                         goto exit;
231                 } else {
232                         dbg_info(&dev->intf->dev,
233                                  "%s: nonzero status received: %d\n", __func__,
234                                  urb->status);
235                         goto resubmit;  /* maybe we can recover */
236                 }
237         }
238
239         if (urb->actual_length != INPUT_CMD_SIZE) {
240                 dev_warn(&dev->intf->dev,
241                          "Urb length was %d bytes!!"
242                          "Do something intelligent \n", urb->actual_length);
243         } else {
244                 alphatrack_ocmd_info(&dev->intf->dev,
245                                      &(*dev->ring_buffer)[dev->ring_tail].cmd,
246                                      "%s", "bla");
247                 if (memcmp
248                     (dev->interrupt_in_buffer, dev->oldi_buffer,
249                      INPUT_CMD_SIZE) == 0) {
250                         goto resubmit;
251                 }
252                 memcpy(dev->oldi_buffer, dev->interrupt_in_buffer,
253                        INPUT_CMD_SIZE);
254
255 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
256                 if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
257                         goto resubmit;
258                 if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
259                         dev->offline = 2;
260                         goto resubmit;
261                 }
262 /* Always pass one offline event up the stack */
263                 if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
264                         dev->offline = 0;
265                 if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
266                         dev->offline = 1;
267 #endif
268                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
269                          __func__, dev->ring_head, dev->ring_tail);
270                 next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
271
272                 if (next_ring_head != dev->ring_tail) {
273                         memcpy(&((*dev->ring_buffer)[dev->ring_head]),
274                                dev->interrupt_in_buffer, urb->actual_length);
275                         dev->ring_head = next_ring_head;
276                         retval = 0;
277                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
278                 } else {
279                         dev_warn(&dev->intf->dev,
280                                  "Ring buffer overflow, %d bytes dropped\n",
281                                  urb->actual_length);
282                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
283                 }
284         }
285
286 resubmit:
287         /* resubmit if we're still running */
288         if (dev->interrupt_in_running && dev->intf) {
289                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
290                 if (retval)
291                         dev_err(&dev->intf->dev,
292                                 "usb_submit_urb failed (%d)\n", retval);
293         }
294
295 exit:
296         dev->interrupt_in_done = 1;
297         wake_up_interruptible(&dev->read_wait);
298 }
299
300 /**
301  *      usb_alphatrack_interrupt_out_callback
302  */
303 static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
304 {
305         struct usb_alphatrack *dev = urb->context;
306
307         /* sync/async unlink faults aren't errors */
308         if (urb->status && !(urb->status == -ENOENT ||
309                              urb->status == -ECONNRESET ||
310                              urb->status == -ESHUTDOWN))
311                 dbg_info(&dev->intf->dev,
312                          "%s - nonzero write interrupt status received: %d\n",
313                          __func__, urb->status);
314         atomic_dec(&dev->writes_pending);
315         dev->interrupt_out_busy = 0;
316         wake_up_interruptible(&dev->write_wait);
317 }
318
319 /**
320  *      usb_alphatrack_open
321  */
322 static int usb_alphatrack_open(struct inode *inode, struct file *file)
323 {
324         struct usb_alphatrack *dev;
325         int subminor;
326         int retval = 0;
327         struct usb_interface *interface;
328
329         nonseekable_open(inode, file);
330         subminor = iminor(inode);
331
332         mutex_lock(&disconnect_mutex);
333
334         interface = usb_find_interface(&usb_alphatrack_driver, subminor);
335
336         if (!interface) {
337                 err("%s - error, can't find device for minor %d\n",
338                     __func__, subminor);
339                 retval = -ENODEV;
340                 goto unlock_disconnect_exit;
341         }
342
343         dev = usb_get_intfdata(interface);
344
345         if (!dev) {
346                 retval = -ENODEV;
347                 goto unlock_disconnect_exit;
348         }
349
350         /* lock this device */
351         if (down_interruptible(&dev->sem)) {
352                 retval = -ERESTARTSYS;
353                 goto unlock_disconnect_exit;
354         }
355
356         /* allow opening only once */
357         if (dev->open_count) {
358                 retval = -EBUSY;
359                 goto unlock_exit;
360         }
361         dev->open_count = 1;
362
363         /* initialize in direction */
364         dev->ring_head = 0;
365         dev->ring_tail = 0;
366         usb_fill_int_urb(dev->interrupt_in_urb,
367                          interface_to_usbdev(interface),
368                          usb_rcvintpipe(interface_to_usbdev(interface),
369                                         dev->interrupt_in_endpoint->
370                                         bEndpointAddress),
371                          dev->interrupt_in_buffer,
372                          dev->interrupt_in_endpoint_size,
373                          usb_alphatrack_interrupt_in_callback, dev,
374                          dev->interrupt_in_interval);
375
376         dev->interrupt_in_running = 1;
377         dev->interrupt_in_done = 0;
378         dev->enable = 1;
379         dev->offline = 0;
380
381         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
382         if (retval) {
383                 dev_err(&interface->dev,
384                         "Couldn't submit interrupt_in_urb %d\n", retval);
385                 dev->interrupt_in_running = 0;
386                 dev->open_count = 0;
387                 goto unlock_exit;
388         }
389
390         /* save device in the file's private structure */
391         file->private_data = dev;
392
393 unlock_exit:
394         up(&dev->sem);
395
396 unlock_disconnect_exit:
397         mutex_unlock(&disconnect_mutex);
398
399         return retval;
400 }
401
402 /**
403  *      usb_alphatrack_release
404  */
405 static int usb_alphatrack_release(struct inode *inode, struct file *file)
406 {
407         struct usb_alphatrack *dev;
408         int retval = 0;
409
410         dev = file->private_data;
411
412         if (dev == NULL) {
413                 retval = -ENODEV;
414                 goto exit;
415         }
416
417         if (down_interruptible(&dev->sem)) {
418                 retval = -ERESTARTSYS;
419                 goto exit;
420         }
421
422         if (dev->open_count != 1) {
423                 retval = -ENODEV;
424                 goto unlock_exit;
425         }
426
427         if (dev->intf == NULL) {
428                 /* the device was unplugged before the file was released */
429                 up(&dev->sem);
430                 /* unlock here as usb_alphatrack_delete frees dev */
431                 usb_alphatrack_delete(dev);
432                 retval = -ENODEV;
433                 goto exit;
434         }
435
436         /* wait until write transfer is finished */
437         if (dev->interrupt_out_busy)
438                 wait_event_interruptible_timeout(dev->write_wait,
439                                                  !dev->interrupt_out_busy,
440                                                  2 * HZ);
441         usb_alphatrack_abort_transfers(dev);
442         dev->open_count = 0;
443
444 unlock_exit:
445         up(&dev->sem);
446
447 exit:
448         return retval;
449 }
450
451 /**
452  *      usb_alphatrack_poll
453  */
454 static unsigned int usb_alphatrack_poll(struct file *file, poll_table * wait)
455 {
456         struct usb_alphatrack *dev;
457         unsigned int mask = 0;
458
459         dev = file->private_data;
460
461         poll_wait(file, &dev->read_wait, wait);
462         poll_wait(file, &dev->write_wait, wait);
463
464         if (dev->ring_head != dev->ring_tail)
465                 mask |= POLLIN | POLLRDNORM;
466         if (!dev->interrupt_out_busy)
467                 mask |= POLLOUT | POLLWRNORM;
468
469         return mask;
470 }
471
472 /**
473  *      usb_alphatrack_read
474  */
475 static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer,
476                                    size_t count, loff_t *ppos)
477 {
478         struct usb_alphatrack *dev;
479         int retval = 0;
480
481         int c = 0;
482
483         dev = file->private_data;
484
485         /* verify that we actually have some data to read */
486         if (count == 0)
487                 goto exit;
488
489         /* lock this object */
490         if (down_interruptible(&dev->sem)) {
491                 retval = -ERESTARTSYS;
492                 goto exit;
493         }
494
495         /* verify that the device wasn't unplugged */
496         if (dev->intf == NULL) {
497                 retval = -ENODEV;
498                 err("No device or device unplugged %d\n", retval);
499                 goto unlock_exit;
500         }
501
502         while (dev->ring_head == dev->ring_tail) {
503                 if (file->f_flags & O_NONBLOCK) {
504                         retval = -EAGAIN;
505                         goto unlock_exit;
506                 }
507                 dev->interrupt_in_done = 0;
508                 retval =
509                     wait_event_interruptible(dev->read_wait,
510                                              dev->interrupt_in_done);
511                 if (retval < 0)
512                         goto unlock_exit;
513         }
514
515         alphatrack_ocmd_info(&dev->intf->dev,
516                              &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s",
517                              ": copying to userspace");
518
519         c = 0;
520         while ((c < count) && (dev->ring_tail != dev->ring_head)) {
521                 if (copy_to_user
522                     (&buffer[c], &(*dev->ring_buffer)[dev->ring_tail],
523                      INPUT_CMD_SIZE)) {
524                         retval = -EFAULT;
525                         goto unlock_exit;
526                 }
527                 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
528                 c += INPUT_CMD_SIZE;
529                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
530                          __func__, dev->ring_head, dev->ring_tail);
531         }
532         retval = c;
533
534 unlock_exit:
535         /* unlock the device */
536         up(&dev->sem);
537
538 exit:
539         return retval;
540 }
541
542 /**
543  *      usb_alphatrack_write
544  */
545 static ssize_t usb_alphatrack_write(struct file *file,
546                                     const char __user *buffer, size_t count,
547                                     loff_t *ppos)
548 {
549         struct usb_alphatrack *dev;
550         size_t bytes_to_write;
551         int retval = 0;
552
553         dev = file->private_data;
554
555         /* verify that we actually have some data to write */
556         if (count == 0)
557                 goto exit;
558
559         /* lock this object */
560         if (down_interruptible(&dev->sem)) {
561                 retval = -ERESTARTSYS;
562                 goto exit;
563         }
564
565         /* verify that the device wasn't unplugged */
566         if (dev->intf == NULL) {
567                 retval = -ENODEV;
568                 err("No device or device unplugged %d\n", retval);
569                 goto unlock_exit;
570         }
571
572         /* wait until previous transfer is finished */
573         if (dev->interrupt_out_busy) {
574                 if (file->f_flags & O_NONBLOCK) {
575                         retval = -EAGAIN;
576                         goto unlock_exit;
577                 }
578                 retval =
579                     wait_event_interruptible(dev->write_wait,
580                                              !dev->interrupt_out_busy);
581                 if (retval < 0)
582                         goto unlock_exit;
583         }
584
585         /* write the data into interrupt_out_buffer from userspace */
586         /* FIXME - if you write more than 12 bytes this breaks */
587         bytes_to_write =
588             min(count, write_buffer_size * dev->interrupt_out_endpoint_size);
589         if (bytes_to_write < count)
590                 dev_warn(&dev->intf->dev,
591                          "Write buffer overflow, %zd bytes dropped\n",
592                          count - bytes_to_write);
593
594         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
595                  __func__, count, bytes_to_write);
596
597         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
598                 retval = -EFAULT;
599                 goto unlock_exit;
600         }
601
602         if (dev->interrupt_out_endpoint == NULL) {
603                 err("Endpoint should not be be null! \n");
604                 goto unlock_exit;
605         }
606
607         /* send off the urb */
608         usb_fill_int_urb(dev->interrupt_out_urb,
609                          interface_to_usbdev(dev->intf),
610                          usb_sndintpipe(interface_to_usbdev(dev->intf),
611                                         dev->interrupt_out_endpoint->
612                                         bEndpointAddress),
613                          dev->interrupt_out_buffer, bytes_to_write,
614                          usb_alphatrack_interrupt_out_callback, dev,
615                          dev->interrupt_out_interval);
616         dev->interrupt_out_busy = 1;
617         atomic_inc(&dev->writes_pending);
618         wmb();
619
620         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
621         if (retval) {
622                 dev->interrupt_out_busy = 0;
623                 err("Couldn't submit interrupt_out_urb %d\n", retval);
624                 atomic_dec(&dev->writes_pending);
625                 goto unlock_exit;
626         }
627         retval = bytes_to_write;
628
629 unlock_exit:
630         /* unlock the device */
631         up(&dev->sem);
632
633 exit:
634         return retval;
635 }
636
637 /* file operations needed when we register this driver */
638 static const struct file_operations usb_alphatrack_fops = {
639         .owner = THIS_MODULE,
640         .read = usb_alphatrack_read,
641         .write = usb_alphatrack_write,
642         .open = usb_alphatrack_open,
643         .release = usb_alphatrack_release,
644         .poll = usb_alphatrack_poll,
645 };
646
647 /*
648  * usb class driver info in order to get a minor number from the usb core,
649  * and to have the device registered with the driver core
650  */
651
652 static struct usb_class_driver usb_alphatrack_class = {
653         .name = "alphatrack%d",
654         .fops = &usb_alphatrack_fops,
655         .minor_base = USB_ALPHATRACK_MINOR_BASE,
656 };
657
658 /**
659  *      usb_alphatrack_probe
660  *
661  *      Called by the usb core when a new device is connected that it thinks
662  *      this driver might be interested in.
663  */
664 static int usb_alphatrack_probe(struct usb_interface *intf,
665                                 const struct usb_device_id *id)
666 {
667         struct usb_device *udev = interface_to_usbdev(intf);
668         struct usb_alphatrack *dev = NULL;
669         struct usb_host_interface *iface_desc;
670         struct usb_endpoint_descriptor *endpoint;
671         int i;
672         int true_size;
673         int retval = -ENOMEM;
674
675         /* allocate memory for our device state and intialize it */
676
677         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
678         if (dev == NULL) {
679                 dev_err(&intf->dev, "Out of memory\n");
680                 goto exit;
681         }
682         init_MUTEX(&dev->sem);
683         dev->intf = intf;
684         init_waitqueue_head(&dev->read_wait);
685         init_waitqueue_head(&dev->write_wait);
686
687         iface_desc = intf->cur_altsetting;
688
689         /* set up the endpoint information */
690         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
691                 endpoint = &iface_desc->endpoint[i].desc;
692
693                 if (usb_endpoint_is_int_in(endpoint))
694                         dev->interrupt_in_endpoint = endpoint;
695
696                 if (usb_endpoint_is_int_out(endpoint))
697                         dev->interrupt_out_endpoint = endpoint;
698         }
699         if (dev->interrupt_in_endpoint == NULL) {
700                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
701                 goto error;
702         }
703         if (dev->interrupt_out_endpoint == NULL)
704                 dev_warn(&intf->dev,
705                          "Interrupt out endpoint not found"
706                          "(using control endpoint instead)\n");
707
708         dev->interrupt_in_endpoint_size =
709             le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
710
711         if (dev->interrupt_in_endpoint_size != 64)
712                 dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
713
714         if (ring_buffer_size == 0)
715                 ring_buffer_size = RING_BUFFER_SIZE;
716
717         true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
718
719         /* FIXME - there are more usb_alloc routines for dma correctness.
720            Needed? */
721         dev->ring_buffer =
722             kmalloc((true_size * sizeof(struct alphatrack_icmd)), GFP_KERNEL);
723
724         if (!dev->ring_buffer) {
725                 dev_err(&intf->dev,
726                         "Couldn't allocate input ring_buffer of size %d\n",
727                         true_size);
728                 goto error;
729         }
730
731         dev->interrupt_in_buffer =
732             kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
733
734         if (!dev->interrupt_in_buffer) {
735                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
736                 goto error;
737         }
738         dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
739         if (!dev->oldi_buffer) {
740                 dev_err(&intf->dev, "Couldn't allocate old buffer\n");
741                 goto error;
742         }
743         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
744         if (!dev->interrupt_in_urb) {
745                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
746                 goto error;
747         }
748
749         dev->interrupt_out_endpoint_size =
750             dev->interrupt_out_endpoint ? le16_to_cpu(dev->
751                                                       interrupt_out_endpoint->
752                                                       wMaxPacketSize) : udev->
753             descriptor.bMaxPacketSize0;
754
755         if (dev->interrupt_out_endpoint_size != 64)
756                 dev_warn(&intf->dev,
757                          "Interrupt out endpoint size is not 64!)\n");
758
759         if (write_buffer_size == 0)
760                 write_buffer_size = WRITE_BUFFER_SIZE;
761         true_size = min(write_buffer_size, WRITE_BUFFER_SIZE);
762
763         dev->interrupt_out_buffer =
764             kmalloc(true_size * dev->interrupt_out_endpoint_size, GFP_KERNEL);
765
766         if (!dev->interrupt_out_buffer) {
767                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
768                 goto error;
769         }
770
771         dev->write_buffer =
772             kmalloc(sizeof(struct alphatrack_ocmd) * true_size, GFP_KERNEL);
773
774         if (!dev->write_buffer) {
775                 dev_err(&intf->dev, "Couldn't allocate write_buffer \n");
776                 goto error;
777         }
778
779         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
780         if (!dev->interrupt_out_urb) {
781                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
782                 goto error;
783         }
784         dev->interrupt_in_interval =
785             min_interrupt_in_interval >
786             dev->interrupt_in_endpoint->
787             bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->
788             bInterval;
789         if (dev->interrupt_out_endpoint)
790                 dev->interrupt_out_interval =
791                     min_interrupt_out_interval >
792                     dev->interrupt_out_endpoint->
793                     bInterval ? min_interrupt_out_interval : dev->
794                     interrupt_out_endpoint->bInterval;
795
796         /* we can register the device now, as it is ready */
797         usb_set_intfdata(intf, dev);
798
799         atomic_set(&dev->writes_pending, 0);
800         retval = usb_register_dev(intf, &usb_alphatrack_class);
801         if (retval) {
802                 /* something prevented us from registering this driver */
803                 dev_err(&intf->dev,
804                         "Not able to get a minor for this device.\n");
805                 usb_set_intfdata(intf, NULL);
806                 goto error;
807         }
808
809         /* let the user know what node this device is now attached to */
810         dev_info(&intf->dev,
811                  "Alphatrack Device #%d now attached to major %d minor %d\n",
812                  (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR,
813                  intf->minor);
814
815 exit:
816         return retval;
817
818 error:
819         usb_alphatrack_delete(dev);
820
821         return retval;
822 }
823
824 /**
825  *      usb_alphatrack_disconnect
826  *
827  *      Called by the usb core when the device is removed from the system.
828  */
829 static void usb_alphatrack_disconnect(struct usb_interface *intf)
830 {
831         struct usb_alphatrack *dev;
832         int minor;
833
834         mutex_lock(&disconnect_mutex);
835
836         dev = usb_get_intfdata(intf);
837         usb_set_intfdata(intf, NULL);
838
839         down(&dev->sem);
840
841         minor = intf->minor;
842
843         /* give back our minor */
844         usb_deregister_dev(intf, &usb_alphatrack_class);
845
846         /* if the device is not opened, then we clean up right now */
847         if (!dev->open_count) {
848                 up(&dev->sem);
849                 usb_alphatrack_delete(dev);
850         } else {
851                 dev->intf = NULL;
852                 up(&dev->sem);
853         }
854
855         atomic_set(&dev->writes_pending, 0);
856         mutex_unlock(&disconnect_mutex);
857
858         dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
859                  (minor - USB_ALPHATRACK_MINOR_BASE));
860 }
861
862 /* usb specific object needed to register this driver with the usb subsystem */
863 static struct usb_driver usb_alphatrack_driver = {
864         .name = "alphatrack",
865         .probe = usb_alphatrack_probe,
866         .disconnect = usb_alphatrack_disconnect,
867         .id_table = usb_alphatrack_table,
868 };
869
870 /**
871  *      usb_alphatrack_init
872  */
873 static int __init usb_alphatrack_init(void)
874 {
875         int retval;
876
877         /* register this driver with the USB subsystem */
878         retval = usb_register(&usb_alphatrack_driver);
879         if (retval)
880                 err("usb_register failed for the " __FILE__
881                     " driver. Error number %d\n", retval);
882
883         return retval;
884 }
885
886 /**
887  *      usb_alphatrack_exit
888  */
889 static void __exit usb_alphatrack_exit(void)
890 {
891         /* deregister this driver with the USB subsystem */
892         usb_deregister(&usb_alphatrack_driver);
893 }
894
895 module_init(usb_alphatrack_init);
896 module_exit(usb_alphatrack_exit);