Merge commit 'v2.6.29-rc1' into tracing/urgent
[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 <asm/uaccess.h>
45 #include <linux/input.h>
46 #include <linux/usb.h>
47 #include <linux/poll.h>
48
49 #include "surface_sysfs.h"
50
51 /* make this work on older kernel versions */
52
53 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 19)
54 #include "frontier_compat.h"
55 #endif /* older kernel versions */
56
57 #include "alphatrack.h"
58
59 #define VENDOR_ID       0x165b
60 #define PRODUCT_ID      0xfad1
61
62 #ifdef CONFIG_USB_DYNAMIC_MINORS
63 #define USB_ALPHATRACK_MINOR_BASE       0
64 #else
65 // FIXME 176 - is another driver's minor - apply for that
66 // #define USB_ALPHATRACK_MINOR_BASE    177
67 #define USB_ALPHATRACK_MINOR_BASE       176
68 #endif
69
70 /* table of devices that work with this driver */
71 static struct usb_device_id usb_alphatrack_table [] = {
72         { USB_DEVICE(VENDOR_ID, PRODUCT_ID) },
73         { }                                     /* Terminating entry */
74 };
75
76 MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
77 MODULE_VERSION("0.40");
78 MODULE_AUTHOR("Mike Taht <m@taht.net>");
79 MODULE_DESCRIPTION("Alphatrack USB Driver");
80 MODULE_LICENSE("GPL");
81 MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
82
83 /* These aren't done yet */
84
85 #define SUPPRESS_EXTRA_ONLINE_EVENTS 0
86 #define BUFFERED_WRITES 0
87 #define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
88 #define COMPRESS_FADER_EVENTS 0
89
90 #define BUFFERED_READS 1
91 #define RING_BUFFER_SIZE 512
92 #define WRITE_BUFFER_SIZE 34
93 #define ALPHATRACK_USB_TIMEOUT 10
94 #define OUTPUT_CMD_SIZE 8
95 #define INPUT_CMD_SIZE 12
96
97
98 static int debug = 0;
99
100 /* Use our own dbg macro */
101 #define dbg_info(dev, format, arg...) do { if (debug) dev_info(dev , format , ## arg); } while (0)
102
103 #define alphatrack_ocmd_info(dev, cmd, format, arg...)
104
105 #define alphatrack_icmd_info(dev, cmd, format, arg...)
106
107
108 /* Module parameters */
109
110 module_param(debug, int, S_IRUGO | S_IWUSR);
111 MODULE_PARM_DESC(debug, "Debug enabled or not");
112
113 /* All interrupt in transfers are collected in a ring buffer to
114  * avoid racing conditions and get better performance of the driver.
115  */
116
117 static int ring_buffer_size = RING_BUFFER_SIZE;
118
119 module_param(ring_buffer_size, int,  S_IRUGO);
120 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
121
122 /* The write_buffer can one day contain more than one interrupt out transfer.
123  */
124
125 static int write_buffer_size = WRITE_BUFFER_SIZE;
126 module_param(write_buffer_size, int,  S_IRUGO);
127 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
128
129 /*
130  * Increase the interval for debugging purposes.
131  * or set to 1 to use the standard interval from the endpoint descriptors.
132  */
133
134 static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
135 module_param(min_interrupt_in_interval, int, 0);
136 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
137
138 static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
139 module_param(min_interrupt_out_interval, int, 0);
140 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
141
142
143
144 /* Structure to hold all of our device specific stuff */
145
146 struct usb_alphatrack {
147         struct semaphore        sem;            /* locks this structure */
148         struct usb_interface*   intf;           /* save off the usb interface pointer */
149         int                     open_count;     /* number of times this port has been opened */
150
151         struct alphatrack_icmd  (*ring_buffer)[RING_BUFFER_SIZE]; /* just make c happy */
152         struct alphatrack_ocmd  (*write_buffer)[WRITE_BUFFER_SIZE]; /* just make c happy */
153         unsigned int            ring_head;
154         unsigned int            ring_tail;
155
156         wait_queue_head_t       read_wait;
157         wait_queue_head_t       write_wait;
158
159         unsigned char*          interrupt_in_buffer;
160         unsigned char*          oldi_buffer;
161         struct usb_endpoint_descriptor* interrupt_in_endpoint;
162         struct urb*             interrupt_in_urb;
163         int                     interrupt_in_interval;
164         size_t                  interrupt_in_endpoint_size;
165         int                     interrupt_in_running;
166         int                     interrupt_in_done;
167
168         char*                   interrupt_out_buffer;
169         struct usb_endpoint_descriptor* interrupt_out_endpoint;
170         struct urb*             interrupt_out_urb;
171         int                     interrupt_out_interval;
172         size_t                  interrupt_out_endpoint_size;
173         int                     interrupt_out_busy;
174
175         atomic_t writes_pending;
176         int event; /* alternate interface to events */
177         int fader; /* 10 bits */
178         int lights; /* 23 bits */
179         unsigned char dump_state; /* 0 if disabled 1 if enabled */
180         unsigned char enable; /* 0 if disabled 1 if enabled */
181         unsigned char offline; /* if the device is out of range or asleep */
182         unsigned char verbose; /* be verbose in error reporting */
183         unsigned char  last_cmd[OUTPUT_CMD_SIZE];
184         unsigned char  screen[32];
185 };
186
187 /* prevent races between open() and disconnect() */
188 static DEFINE_MUTEX(disconnect_mutex);
189
190 /* forward declaration */
191
192 static struct usb_driver usb_alphatrack_driver;
193
194 /**
195  *      usb_alphatrack_abort_transfers
196  *      aborts transfers and frees associated data structures
197  */
198 static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
199 {
200         /* shutdown transfer */
201         if (dev->interrupt_in_running) {
202                 dev->interrupt_in_running = 0;
203                 if (dev->intf)
204                         usb_kill_urb(dev->interrupt_in_urb);
205         }
206         if (dev->interrupt_out_busy)
207                 if (dev->intf)
208                         usb_kill_urb(dev->interrupt_out_urb);
209 }
210
211 /**
212  *      usb_alphatrack_delete
213  */
214 static void usb_alphatrack_delete(struct usb_alphatrack *dev)
215 {
216         usb_alphatrack_abort_transfers(dev);
217         usb_free_urb(dev->interrupt_in_urb);
218         usb_free_urb(dev->interrupt_out_urb);
219         kfree(dev->ring_buffer);
220         kfree(dev->interrupt_in_buffer);
221         kfree(dev->interrupt_out_buffer);
222         kfree(dev); // fixme oldi_buffer
223 }
224
225 /**
226  *      usb_alphatrack_interrupt_in_callback
227  */
228
229 static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
230 {
231         struct usb_alphatrack *dev = urb->context;
232         unsigned int next_ring_head;
233         int retval = -1;
234
235         if (urb->status) {
236                 if (urb->status == -ENOENT ||
237                     urb->status == -ECONNRESET ||
238                     urb->status == -ESHUTDOWN) {
239                         goto exit;
240                 } else {
241                         dbg_info(&dev->intf->dev, "%s: nonzero status received: %d\n",
242                                  __func__, urb->status);
243                         goto resubmit; /* maybe we can recover */
244                 }
245         }
246
247         if (urb->actual_length != INPUT_CMD_SIZE) {
248                 dev_warn(&dev->intf->dev,
249                          "Urb length was %d bytes!! Do something intelligent \n", urb->actual_length);
250         } else {
251                  alphatrack_ocmd_info(&dev->intf->dev,&(*dev->ring_buffer)[dev->ring_tail].cmd,"%s", "bla");
252                  if(memcmp(dev->interrupt_in_buffer,dev->oldi_buffer,INPUT_CMD_SIZE)==0) {
253                                                 goto resubmit;
254                 }
255                 memcpy(dev->oldi_buffer,dev->interrupt_in_buffer,INPUT_CMD_SIZE);
256
257 #if SUPPRESS_EXTRA_OFFLINE_EVENTS
258         if(dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff) { goto resubmit; }
259                 if(dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 2; goto resubmit; }
260 /* Always pass one offline event up the stack */
261                 if(dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff) { dev->offline = 0; }
262                 if(dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff) { dev->offline = 1; }
263 #endif
264                 dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __func__,dev->ring_head,dev->ring_tail);
265                 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
266
267                 if (next_ring_head != dev->ring_tail) {
268                         memcpy(&((*dev->ring_buffer)[dev->ring_head]),
269                                                  dev->interrupt_in_buffer, urb->actual_length);
270                         dev->ring_head = next_ring_head;
271                         retval = 0;
272                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
273                 } else {
274                         dev_warn(&dev->intf->dev,
275                                  "Ring buffer overflow, %d bytes dropped\n",
276                                  urb->actual_length);
277                         memset(dev->interrupt_in_buffer, 0, urb->actual_length);
278                 }
279         }
280
281 resubmit:
282         /* resubmit if we're still running */
283         if (dev->interrupt_in_running && dev->intf) {
284                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
285                 if (retval)
286                         dev_err(&dev->intf->dev,
287                                 "usb_submit_urb failed (%d)\n", retval);
288         }
289
290 exit:
291         dev->interrupt_in_done = 1;
292         wake_up_interruptible(&dev->read_wait);
293 }
294
295 /**
296  *      usb_alphatrack_interrupt_out_callback
297  */
298 static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
299 {
300         struct usb_alphatrack *dev = urb->context;
301
302         /* sync/async unlink faults aren't errors */
303         if (urb->status && !(urb->status == -ENOENT ||
304                              urb->status == -ECONNRESET ||
305                              urb->status == -ESHUTDOWN))
306                 dbg_info(&dev->intf->dev,
307                          "%s - nonzero write interrupt status received: %d\n",
308                          __func__, urb->status);
309         atomic_dec(&dev->writes_pending);
310         dev->interrupt_out_busy = 0;
311         wake_up_interruptible(&dev->write_wait);
312 }
313
314 /**
315  *      usb_alphatrack_open
316  */
317 static int usb_alphatrack_open(struct inode *inode, struct file *file)
318 {
319         struct usb_alphatrack *dev;
320         int subminor;
321         int retval = 0;
322         struct usb_interface *interface;
323
324         nonseekable_open(inode, file);
325         subminor = iminor(inode);
326
327         mutex_lock(&disconnect_mutex);
328
329         interface = usb_find_interface(&usb_alphatrack_driver, subminor);
330
331         if (!interface) {
332                 err("%s - error, can't find device for minor %d\n",
333                      __func__, subminor);
334                 retval = -ENODEV;
335                 goto unlock_disconnect_exit;
336         }
337
338         dev = usb_get_intfdata(interface);
339
340         if (!dev) {
341                 retval = -ENODEV;
342                 goto unlock_disconnect_exit;
343         }
344
345         /* lock this device */
346         if (down_interruptible(&dev->sem)) {
347                 retval = -ERESTARTSYS;
348                 goto unlock_disconnect_exit;
349         }
350
351         /* allow opening only once */
352         if (dev->open_count) {
353                 retval = -EBUSY;
354                 goto unlock_exit;
355         }
356         dev->open_count = 1;
357
358         /* initialize in direction */
359         dev->ring_head = 0;
360         dev->ring_tail = 0;
361         usb_fill_int_urb(dev->interrupt_in_urb,
362                          interface_to_usbdev(interface),
363                          usb_rcvintpipe(interface_to_usbdev(interface),
364                                         dev->interrupt_in_endpoint->bEndpointAddress),
365                          dev->interrupt_in_buffer,
366                          dev->interrupt_in_endpoint_size,
367                          usb_alphatrack_interrupt_in_callback,
368                          dev,
369                          dev->interrupt_in_interval);
370
371         dev->interrupt_in_running = 1;
372         dev->interrupt_in_done = 0;
373         dev->enable = 1;
374         dev->offline = 0;
375
376         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
377         if (retval) {
378                 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
379                 dev->interrupt_in_running = 0;
380                 dev->open_count = 0;
381                 goto unlock_exit;
382         }
383
384         /* save device in the file's private structure */
385         file->private_data = dev;
386
387
388 unlock_exit:
389         up(&dev->sem);
390
391 unlock_disconnect_exit:
392         mutex_unlock(&disconnect_mutex);
393
394         return retval;
395 }
396
397 /**
398  *      usb_alphatrack_release
399  */
400 static int usb_alphatrack_release(struct inode *inode, struct file *file)
401 {
402         struct usb_alphatrack *dev;
403         int retval = 0;
404
405         dev = file->private_data;
406
407         if (dev == NULL) {
408                 retval = -ENODEV;
409                 goto exit;
410         }
411
412         if (down_interruptible(&dev->sem)) {
413                 retval = -ERESTARTSYS;
414                 goto exit;
415         }
416
417         if (dev->open_count != 1) {
418                 retval = -ENODEV;
419                 goto unlock_exit;
420         }
421
422         if (dev->intf == NULL) {
423                 /* the device was unplugged before the file was released */
424                 up(&dev->sem);
425                 /* unlock here as usb_alphatrack_delete frees dev */
426                 usb_alphatrack_delete(dev);
427                 retval = -ENODEV;
428                 goto exit;
429         }
430
431         /* wait until write transfer is finished */
432         if (dev->interrupt_out_busy)
433                 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
434         usb_alphatrack_abort_transfers(dev);
435         dev->open_count = 0;
436
437 unlock_exit:
438         up(&dev->sem);
439
440 exit:
441         return retval;
442 }
443
444 /**
445  *      usb_alphatrack_poll
446  */
447 static unsigned int usb_alphatrack_poll(struct file *file, poll_table *wait)
448 {
449         struct usb_alphatrack *dev;
450         unsigned int mask = 0;
451
452         dev = file->private_data;
453
454         poll_wait(file, &dev->read_wait, wait);
455         poll_wait(file, &dev->write_wait, wait);
456
457         if (dev->ring_head != dev->ring_tail)
458                 mask |= POLLIN | POLLRDNORM;
459         if (!dev->interrupt_out_busy)
460                 mask |= POLLOUT | POLLWRNORM;
461
462         return mask;
463 }
464
465 /**
466  *      usb_alphatrack_read
467  */
468 static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer, size_t count,
469                            loff_t *ppos)
470 {
471         struct usb_alphatrack *dev;
472         int retval = 0;
473
474         int c = 0;
475
476         dev = file->private_data;
477
478         /* verify that we actually have some data to read */
479         if (count == 0)
480                 goto exit;
481
482         /* lock this object */
483         if (down_interruptible(&dev->sem)) {
484                 retval = -ERESTARTSYS;
485                 goto exit;
486         }
487
488         /* verify that the device wasn't unplugged */
489         if (dev->intf == NULL) {
490                 retval = -ENODEV;
491                 err("No device or device unplugged %d\n", retval);
492                 goto unlock_exit;
493         }
494
495         while (dev->ring_head == dev->ring_tail) {
496                                         if (file->f_flags & O_NONBLOCK) {
497                                                                         retval = -EAGAIN;
498                                                                         goto unlock_exit;
499                                         }
500                                         dev->interrupt_in_done = 0 ;
501                                         retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
502                                         if (retval < 0) {
503                                                                         goto unlock_exit;
504                                         }
505         }
506
507         alphatrack_ocmd_info(&dev->intf->dev, &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s", ": copying to userspace");
508
509            c = 0;
510            while((c < count) && (dev->ring_tail != dev->ring_head)) {
511                                                  if (copy_to_user(&buffer[c], &(*dev->ring_buffer)[dev->ring_tail], INPUT_CMD_SIZE)) {
512                                                                                  retval = -EFAULT;
513                                                                                  goto unlock_exit;
514                                                  }
515                                                  dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
516                                                  c+=INPUT_CMD_SIZE;
517                                                  dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n", __func__,dev->ring_head,dev->ring_tail);
518            }
519            retval = c;
520
521 unlock_exit:
522         /* unlock the device */
523         up(&dev->sem);
524
525 exit:
526         return retval;
527 }
528
529 /**
530  *      usb_alphatrack_write
531  */
532 static ssize_t usb_alphatrack_write(struct file *file, const char __user *buffer,
533                             size_t count, loff_t *ppos)
534 {
535         struct usb_alphatrack *dev;
536         size_t bytes_to_write;
537         int retval = 0;
538
539         dev = file->private_data;
540
541         /* verify that we actually have some data to write */
542         if (count == 0)
543                 goto exit;
544
545         /* lock this object */
546         if (down_interruptible(&dev->sem)) {
547                 retval = -ERESTARTSYS;
548                 goto exit;
549         }
550
551         /* verify that the device wasn't unplugged */
552         if (dev->intf == NULL) {
553                 retval = -ENODEV;
554                 err("No device or device unplugged %d\n", retval);
555                 goto unlock_exit;
556         }
557
558         /* wait until previous transfer is finished */
559         if (dev->interrupt_out_busy) {
560                 if (file->f_flags & O_NONBLOCK) {
561                         retval = -EAGAIN;
562                         goto unlock_exit;
563                 }
564                 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
565                 if (retval < 0) {
566                         goto unlock_exit;
567                 }
568         }
569
570         /* write the data into interrupt_out_buffer from userspace */
571   /* FIXME - if you write more than 12 bytes this breaks */
572         bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
573         if (bytes_to_write < count)
574                 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n",count-bytes_to_write);
575
576         dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n", __func__, count, bytes_to_write);
577
578         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
579                 retval = -EFAULT;
580                 goto unlock_exit;
581         }
582
583         if (dev->interrupt_out_endpoint == NULL) {
584                 err("Endpoint should not be be null! \n");
585                 goto unlock_exit;
586         }
587
588         /* send off the urb */
589         usb_fill_int_urb(dev->interrupt_out_urb,
590                          interface_to_usbdev(dev->intf),
591                          usb_sndintpipe(interface_to_usbdev(dev->intf),
592                                         dev->interrupt_out_endpoint->bEndpointAddress),
593                          dev->interrupt_out_buffer,
594                          bytes_to_write,
595                          usb_alphatrack_interrupt_out_callback,
596                          dev,
597                          dev->interrupt_out_interval);
598         dev->interrupt_out_busy = 1;
599         atomic_inc(&dev->writes_pending);
600         wmb();
601
602         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
603         if (retval) {
604                 dev->interrupt_out_busy = 0;
605                 err("Couldn't submit interrupt_out_urb %d\n", retval);
606                 atomic_dec(&dev->writes_pending);
607                 goto unlock_exit;
608         }
609         retval = bytes_to_write;
610
611 unlock_exit:
612         /* unlock the device */
613         up(&dev->sem);
614
615 exit:
616         return retval;
617 }
618
619 /* file operations needed when we register this driver */
620 static const struct file_operations usb_alphatrack_fops = {
621         .owner =        THIS_MODULE,
622         .read  =        usb_alphatrack_read,
623         .write =        usb_alphatrack_write,
624         .open =         usb_alphatrack_open,
625         .release =      usb_alphatrack_release,
626         .poll =         usb_alphatrack_poll,
627 };
628
629 /*
630  * usb class driver info in order to get a minor number from the usb core,
631  * and to have the device registered with the driver core
632  */
633
634 static struct usb_class_driver usb_alphatrack_class = {
635         .name =         "alphatrack%d",
636         .fops =         &usb_alphatrack_fops,
637         .minor_base =   USB_ALPHATRACK_MINOR_BASE,
638 };
639
640
641 /**
642  *      usb_alphatrack_probe
643  *
644  *      Called by the usb core when a new device is connected that it thinks
645  *      this driver might be interested in.
646  */
647 static int usb_alphatrack_probe(struct usb_interface *intf, const struct usb_device_id *id)
648 {
649         struct usb_device *udev = interface_to_usbdev(intf);
650         struct usb_alphatrack *dev = NULL;
651         struct usb_host_interface *iface_desc;
652         struct usb_endpoint_descriptor *endpoint;
653         int i;
654         int true_size;
655         int retval = -ENOMEM;
656
657         /* allocate memory for our device state and intialize it */
658
659         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
660         if (dev == NULL) {
661                 dev_err(&intf->dev, "Out of memory\n");
662                 goto exit;
663         }
664         init_MUTEX(&dev->sem);
665         dev->intf = intf;
666         init_waitqueue_head(&dev->read_wait);
667         init_waitqueue_head(&dev->write_wait);
668
669         iface_desc = intf->cur_altsetting;
670
671         /* set up the endpoint information */
672         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
673                 endpoint = &iface_desc->endpoint[i].desc;
674
675                 if (usb_endpoint_is_int_in(endpoint))
676                         dev->interrupt_in_endpoint = endpoint;
677
678                 if (usb_endpoint_is_int_out(endpoint))
679                         dev->interrupt_out_endpoint = endpoint;
680         }
681         if (dev->interrupt_in_endpoint == NULL) {
682                 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
683                 goto error;
684         }
685         if (dev->interrupt_out_endpoint == NULL)
686                 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
687
688         dev->interrupt_in_endpoint_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
689
690         if (dev->interrupt_in_endpoint_size != 64)
691             dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
692
693         if(ring_buffer_size == 0) { ring_buffer_size = RING_BUFFER_SIZE; }
694
695         true_size = min(ring_buffer_size,RING_BUFFER_SIZE);
696
697         /* FIXME - there are more usb_alloc routines for dma correctness. Needed? */
698
699 //      dev->ring_buffer = kmalloc((true_size*sizeof(struct alphatrack_icmd))+12, GFP_KERNEL);
700         dev->ring_buffer = kmalloc((true_size*sizeof(struct alphatrack_icmd)), GFP_KERNEL);
701
702         if (!dev->ring_buffer) {
703                 dev_err(&intf->dev, "Couldn't allocate input ring_buffer of size %d\n",true_size);
704                 goto error;
705         }
706
707         dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
708
709         if (!dev->interrupt_in_buffer) {
710                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
711                 goto error;
712         }
713         dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
714         if (!dev->oldi_buffer) {
715                 dev_err(&intf->dev, "Couldn't allocate old buffer\n");
716                 goto error;
717         }
718         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
719         if (!dev->interrupt_in_urb) {
720                 dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
721                 goto error;
722         }
723
724         dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize) :
725                                                                          udev->descriptor.bMaxPacketSize0;
726
727         if (dev->interrupt_out_endpoint_size !=64)
728                 dev_warn(&intf->dev, "Interrupt out endpoint size is not 64!)\n");
729
730         if(write_buffer_size == 0) { write_buffer_size = WRITE_BUFFER_SIZE; }
731         true_size = min(write_buffer_size,WRITE_BUFFER_SIZE);
732
733         dev->interrupt_out_buffer = kmalloc(true_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
734
735         if (!dev->interrupt_out_buffer) {
736                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
737                 goto error;
738         }
739
740         dev->write_buffer = kmalloc(sizeof(struct alphatrack_ocmd)*true_size, GFP_KERNEL);
741
742         if (!dev->write_buffer) {
743                 dev_err(&intf->dev, "Couldn't allocate write_buffer \n");
744                 goto error;
745         }
746
747         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
748         if (!dev->interrupt_out_urb) {
749                 dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
750                 goto error;
751         }
752         dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
753         if (dev->interrupt_out_endpoint)
754                 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
755
756         /* we can register the device now, as it is ready */
757         usb_set_intfdata(intf, dev);
758
759         atomic_set(&dev->writes_pending,0);
760         retval = usb_register_dev(intf, &usb_alphatrack_class);
761         if (retval) {
762                 /* something prevented us from registering this driver */
763                 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
764                 usb_set_intfdata(intf, NULL);
765                 goto error;
766         }
767
768         /* let the user know what node this device is now attached to */
769         dev_info(&intf->dev, "Alphatrack Device #%d now attached to major %d minor %d\n",
770                 (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR, intf->minor);
771
772 exit:
773         return retval;
774
775 error:
776         usb_alphatrack_delete(dev);
777
778         return retval;
779 }
780
781 /**
782  *      usb_alphatrack_disconnect
783  *
784  *      Called by the usb core when the device is removed from the system.
785  */
786 static void usb_alphatrack_disconnect(struct usb_interface *intf)
787 {
788         struct usb_alphatrack *dev;
789         int minor;
790
791         mutex_lock(&disconnect_mutex);
792
793         dev = usb_get_intfdata(intf);
794         usb_set_intfdata(intf, NULL);
795
796         down(&dev->sem);
797
798         minor = intf->minor;
799
800         /* give back our minor */
801         usb_deregister_dev(intf, &usb_alphatrack_class);
802
803         /* if the device is not opened, then we clean up right now */
804         if (!dev->open_count) {
805                 up(&dev->sem);
806                 usb_alphatrack_delete(dev);
807         } else {
808                 dev->intf = NULL;
809                 up(&dev->sem);
810         }
811
812         atomic_set(&dev->writes_pending,0);
813         mutex_unlock(&disconnect_mutex);
814
815         dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
816                  (minor - USB_ALPHATRACK_MINOR_BASE));
817 }
818
819 /* usb specific object needed to register this driver with the usb subsystem */
820 static struct usb_driver usb_alphatrack_driver = {
821         .name =         "alphatrack",
822         .probe =        usb_alphatrack_probe,
823         .disconnect =   usb_alphatrack_disconnect,
824         .id_table =     usb_alphatrack_table,
825 };
826
827 /**
828  *      usb_alphatrack_init
829  */
830 static int __init usb_alphatrack_init(void)
831 {
832         int retval;
833
834         /* register this driver with the USB subsystem */
835         retval = usb_register(&usb_alphatrack_driver);
836         if (retval)
837                 err("usb_register failed for the "__FILE__" driver. Error number %d\n", retval);
838
839         return retval;
840 }
841
842 /**
843  *      usb_alphatrack_exit
844  */
845 static void __exit usb_alphatrack_exit(void)
846 {
847         /* deregister this driver with the USB subsystem */
848         usb_deregister(&usb_alphatrack_driver);
849 }
850
851 module_init(usb_alphatrack_init);
852 module_exit(usb_alphatrack_exit);
853