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legousbtower.c
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1 /*
2  * LEGO USB Tower driver
3  *
4  * Copyright (C) 2003 David Glance <[email protected]>
5  * 2001-2004 Juergen Stuber <[email protected]>
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License as
9  * published by the Free Software Foundation; either version 2 of
10  * the License, or (at your option) any later version.
11  *
12  * derived from USB Skeleton driver - 0.5
13  * Copyright (C) 2001 Greg Kroah-Hartman ([email protected])
14  *
15  * History:
16  *
17  * 2001-10-13 - 0.1 js
18  * - first version
19  * 2001-11-03 - 0.2 js
20  * - simplified buffering, one-shot URBs for writing
21  * 2001-11-10 - 0.3 js
22  * - removed IOCTL (setting power/mode is more complicated, postponed)
23  * 2001-11-28 - 0.4 js
24  * - added vendor commands for mode of operation and power level in open
25  * 2001-12-04 - 0.5 js
26  * - set IR mode by default (by oversight 0.4 set VLL mode)
27  * 2002-01-11 - 0.5? pcchan
28  * - make read buffer reusable and work around bytes_to_write issue between
29  * uhci and legusbtower
30  * 2002-09-23 - 0.52 david ([email protected])
31  * - imported into lejos project
32  * - changed wake_up to wake_up_interruptible
33  * - changed to use lego0 rather than tower0
34  * - changed dbg() to use __func__ rather than deprecated __func__
35  * 2003-01-12 - 0.53 david ([email protected])
36  * - changed read and write to write everything or
37  * timeout (from a patch by Chris Riesen and Brett Thaeler driver)
38  * - added ioctl functionality to set timeouts
39  * 2003-07-18 - 0.54 davidgsf ([email protected])
40  * - initial import into LegoUSB project
41  * - merge of existing LegoUSB.c driver
42  * 2003-07-18 - 0.56 davidgsf ([email protected])
43  * - port to 2.6 style driver
44  * 2004-02-29 - 0.6 Juergen Stuber <[email protected]>
45  * - fix locking
46  * - unlink read URBs which are no longer needed
47  * - allow increased buffer size, eliminates need for timeout on write
48  * - have read URB running continuously
49  * - added poll
50  * - forbid seeking
51  * - added nonblocking I/O
52  * - changed back __func__ to __func__
53  * - read and log tower firmware version
54  * - reset tower on probe, avoids failure of first write
55  * 2004-03-09 - 0.7 Juergen Stuber <[email protected]>
56  * - timeout read now only after inactivity, shorten default accordingly
57  * 2004-03-11 - 0.8 Juergen Stuber <[email protected]>
58  * - log major, minor instead of possibly confusing device filename
59  * - whitespace cleanup
60  * 2004-03-12 - 0.9 Juergen Stuber <[email protected]>
61  * - normalize whitespace in debug messages
62  * - take care about endianness in control message responses
63  * 2004-03-13 - 0.91 Juergen Stuber <[email protected]>
64  * - make default intervals longer to accommodate current EHCI driver
65  * 2004-03-19 - 0.92 Juergen Stuber <[email protected]>
66  * - replaced atomic_t by memory barriers
67  * 2004-04-21 - 0.93 Juergen Stuber <[email protected]>
68  * - wait for completion of write urb in release (needed for remotecontrol)
69  * - corrected poll for write direction (missing negation)
70  * 2004-04-22 - 0.94 Juergen Stuber <[email protected]>
71  * - make device locking interruptible
72  * 2004-04-30 - 0.95 Juergen Stuber <[email protected]>
73  * - check for valid udev on resubmitting and unlinking urbs
74  * 2004-08-03 - 0.96 Juergen Stuber <[email protected]>
75  * - move reset into open to clean out spurious data
76  */
77 
78 #include <linux/kernel.h>
79 #include <linux/errno.h>
80 #include <linux/init.h>
81 #include <linux/slab.h>
82 #include <linux/module.h>
83 #include <linux/completion.h>
84 #include <linux/mutex.h>
85 #include <asm/uaccess.h>
86 #include <linux/usb.h>
87 #include <linux/poll.h>
88 
89 
90 #ifdef CONFIG_USB_DEBUG
91  static int debug = 4;
92 #else
93  static int debug = 0;
94 #endif
95 
96 /* Use our own dbg macro */
97 #undef dbg
98 #define dbg(lvl, format, arg...) \
99 do { \
100  if (debug >= lvl) \
101  printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
102 } while (0)
103 
104 /* Version Information */
105 #define DRIVER_VERSION "v0.96"
106 #define DRIVER_AUTHOR "Juergen Stuber <[email protected]>"
107 #define DRIVER_DESC "LEGO USB Tower Driver"
108 
109 /* Module parameters */
111 MODULE_PARM_DESC(debug, "Debug enabled or not");
112 
113 /* The defaults are chosen to work with the latest versions of leJOS and NQC.
114  */
115 
116 /* Some legacy software likes to receive packets in one piece.
117  * In this case read_buffer_size should exceed the maximal packet length
118  * (417 for datalog uploads), and packet_timeout should be set.
119  */
120 static int read_buffer_size = 480;
121 module_param(read_buffer_size, int, 0);
122 MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
123 
124 /* Some legacy software likes to send packets in one piece.
125  * In this case write_buffer_size should exceed the maximal packet length
126  * (417 for firmware and program downloads).
127  * A problem with long writes is that the following read may time out
128  * if the software is not prepared to wait long enough.
129  */
130 static int write_buffer_size = 480;
131 module_param(write_buffer_size, int, 0);
132 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
133 
134 /* Some legacy software expects reads to contain whole LASM packets.
135  * To achieve this, characters which arrive before a packet timeout
136  * occurs will be returned in a single read operation.
137  * A problem with long reads is that the software may time out
138  * if it is not prepared to wait long enough.
139  * The packet timeout should be greater than the time between the
140  * reception of subsequent characters, which should arrive about
141  * every 5ms for the standard 2400 baud.
142  * Set it to 0 to disable.
143  */
144 static int packet_timeout = 50;
145 module_param(packet_timeout, int, 0);
146 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
147 
148 /* Some legacy software expects blocking reads to time out.
149  * Timeout occurs after the specified time of read and write inactivity.
150  * Set it to 0 to disable.
151  */
152 static int read_timeout = 200;
153 module_param(read_timeout, int, 0);
154 MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
155 
156 /* As of kernel version 2.6.4 ehci-hcd uses an
157  * "only one interrupt transfer per frame" shortcut
158  * to simplify the scheduling of periodic transfers.
159  * This conflicts with our standard 1ms intervals for in and out URBs.
160  * We use default intervals of 2ms for in and 8ms for out transfers,
161  * which is fast enough for 2400 baud and allows a small additional load.
162  * Increase the interval to allow more devices that do interrupt transfers,
163  * or set to 0 to use the standard interval from the endpoint descriptors.
164  */
165 static int interrupt_in_interval = 2;
166 module_param(interrupt_in_interval, int, 0);
167 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
168 
169 static int interrupt_out_interval = 8;
170 module_param(interrupt_out_interval, int, 0);
171 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
172 
173 /* Define these values to match your device */
174 #define LEGO_USB_TOWER_VENDOR_ID 0x0694
175 #define LEGO_USB_TOWER_PRODUCT_ID 0x0001
176 
177 /* Vendor requests */
178 #define LEGO_USB_TOWER_REQUEST_RESET 0x04
179 #define LEGO_USB_TOWER_REQUEST_GET_VERSION 0xFD
180 
182  __le16 size; /* little-endian */
185 } __attribute__ ((packed));
188  __le16 size; /* little-endian */
193  __le16 build_no; /* little-endian */
194 } __attribute__ ((packed));
195 
196 
197 /* table of devices that work with this driver */
198 static const struct usb_device_id tower_table[] = {
200  { } /* Terminating entry */
201 };
202 
203 MODULE_DEVICE_TABLE (usb, tower_table);
204 static DEFINE_MUTEX(open_disc_mutex);
205 
206 #define LEGO_USB_TOWER_MINOR_BASE 160
207 
208 
209 /* Structure to hold all of our device specific stuff */
211  struct mutex lock; /* locks this structure */
212  struct usb_device* udev; /* save off the usb device pointer */
213  unsigned char minor; /* the starting minor number for this device */
214 
215  int open_count; /* number of times this port has been opened */
216 
217  char* read_buffer;
218  size_t read_buffer_length; /* this much came in */
219  size_t read_packet_length; /* this much will be returned on read */
222  unsigned long read_last_arrival;
223 
226 
233 
239 
240 };
241 
242 
243 /* local function prototypes */
244 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
245 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
246 static inline void tower_delete (struct lego_usb_tower *dev);
247 static int tower_open (struct inode *inode, struct file *file);
248 static int tower_release (struct inode *inode, struct file *file);
249 static unsigned int tower_poll (struct file *file, poll_table *wait);
250 static loff_t tower_llseek (struct file *file, loff_t off, int whence);
251 
252 static void tower_abort_transfers (struct lego_usb_tower *dev);
253 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
254 static void tower_interrupt_in_callback (struct urb *urb);
255 static void tower_interrupt_out_callback (struct urb *urb);
256 
257 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
258 static void tower_disconnect (struct usb_interface *interface);
259 
260 
261 /* file operations needed when we register this driver */
262 static const struct file_operations tower_fops = {
263  .owner = THIS_MODULE,
264  .read = tower_read,
265  .write = tower_write,
266  .open = tower_open,
267  .release = tower_release,
268  .poll = tower_poll,
269  .llseek = tower_llseek,
270 };
271 
272 static char *legousbtower_devnode(struct device *dev, umode_t *mode)
273 {
274  return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
275 }
276 
277 /*
278  * usb class driver info in order to get a minor number from the usb core,
279  * and to have the device registered with the driver core
280  */
281 static struct usb_class_driver tower_class = {
282  .name = "legousbtower%d",
283  .devnode = legousbtower_devnode,
284  .fops = &tower_fops,
285  .minor_base = LEGO_USB_TOWER_MINOR_BASE,
286 };
287 
288 
289 /* usb specific object needed to register this driver with the usb subsystem */
290 static struct usb_driver tower_driver = {
291  .name = "legousbtower",
292  .probe = tower_probe,
293  .disconnect = tower_disconnect,
294  .id_table = tower_table,
295 };
296 
297 
301 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
302 {
303  int i;
304 
305  if (debug < level)
306  return;
307 
308  printk (KERN_DEBUG "%s: %s - length = %d, data = ", __FILE__, function, size);
309  for (i = 0; i < size; ++i) {
310  printk ("%.2x ", data[i]);
311  }
312  printk ("\n");
313 }
314 
315 
319 static inline void tower_delete (struct lego_usb_tower *dev)
320 {
321  dbg(2, "%s: enter", __func__);
322 
323  tower_abort_transfers (dev);
324 
325  /* free data structures */
328  kfree (dev->read_buffer);
329  kfree (dev->interrupt_in_buffer);
331  kfree (dev);
332 
333  dbg(2, "%s: leave", __func__);
334 }
335 
336 
340 static int tower_open (struct inode *inode, struct file *file)
341 {
342  struct lego_usb_tower *dev = NULL;
343  int subminor;
344  int retval = 0;
345  struct usb_interface *interface;
346  struct tower_reset_reply reset_reply;
347  int result;
348 
349  dbg(2, "%s: enter", __func__);
350 
351  nonseekable_open(inode, file);
352  subminor = iminor(inode);
353 
354  interface = usb_find_interface (&tower_driver, subminor);
355 
356  if (!interface) {
357  printk(KERN_ERR "%s - error, can't find device for minor %d\n",
358  __func__, subminor);
359  retval = -ENODEV;
360  goto exit;
361  }
362 
363  mutex_lock(&open_disc_mutex);
364  dev = usb_get_intfdata(interface);
365 
366  if (!dev) {
367  mutex_unlock(&open_disc_mutex);
368  retval = -ENODEV;
369  goto exit;
370  }
371 
372  /* lock this device */
373  if (mutex_lock_interruptible(&dev->lock)) {
374  mutex_unlock(&open_disc_mutex);
375  retval = -ERESTARTSYS;
376  goto exit;
377  }
378 
379 
380  /* allow opening only once */
381  if (dev->open_count) {
382  mutex_unlock(&open_disc_mutex);
383  retval = -EBUSY;
384  goto unlock_exit;
385  }
386  dev->open_count = 1;
387  mutex_unlock(&open_disc_mutex);
388 
389  /* reset the tower */
390  result = usb_control_msg (dev->udev,
391  usb_rcvctrlpipe(dev->udev, 0),
394  0,
395  0,
396  &reset_reply,
397  sizeof(reset_reply),
398  1000);
399  if (result < 0) {
400  dev_err(&dev->udev->dev,
401  "LEGO USB Tower reset control request failed\n");
402  retval = result;
403  goto unlock_exit;
404  }
405 
406  /* initialize in direction */
407  dev->read_buffer_length = 0;
408  dev->read_packet_length = 0;
409  usb_fill_int_urb (dev->interrupt_in_urb,
410  dev->udev,
411  usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
412  dev->interrupt_in_buffer,
413  usb_endpoint_maxp(dev->interrupt_in_endpoint),
414  tower_interrupt_in_callback,
415  dev,
416  dev->interrupt_in_interval);
417 
418  dev->interrupt_in_running = 1;
419  dev->interrupt_in_done = 0;
420  mb();
421 
422  retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
423  if (retval) {
424  dev_err(&dev->udev->dev,
425  "Couldn't submit interrupt_in_urb %d\n", retval);
426  dev->interrupt_in_running = 0;
427  dev->open_count = 0;
428  goto unlock_exit;
429  }
430 
431  /* save device in the file's private structure */
432  file->private_data = dev;
433 
434 unlock_exit:
435  mutex_unlock(&dev->lock);
436 
437 exit:
438  dbg(2, "%s: leave, return value %d ", __func__, retval);
439 
440  return retval;
441 }
442 
446 static int tower_release (struct inode *inode, struct file *file)
447 {
448  struct lego_usb_tower *dev;
449  int retval = 0;
450 
451  dbg(2, "%s: enter", __func__);
452 
453  dev = file->private_data;
454 
455  if (dev == NULL) {
456  dbg(1, "%s: object is NULL", __func__);
457  retval = -ENODEV;
458  goto exit_nolock;
459  }
460 
461  mutex_lock(&open_disc_mutex);
462  if (mutex_lock_interruptible(&dev->lock)) {
463  retval = -ERESTARTSYS;
464  goto exit;
465  }
466 
467  if (dev->open_count != 1) {
468  dbg(1, "%s: device not opened exactly once", __func__);
469  retval = -ENODEV;
470  goto unlock_exit;
471  }
472  if (dev->udev == NULL) {
473  /* the device was unplugged before the file was released */
474 
475  /* unlock here as tower_delete frees dev */
476  mutex_unlock(&dev->lock);
477  tower_delete (dev);
478  goto exit;
479  }
480 
481  /* wait until write transfer is finished */
482  if (dev->interrupt_out_busy) {
484  }
485  tower_abort_transfers (dev);
486  dev->open_count = 0;
487 
488 unlock_exit:
489  mutex_unlock(&dev->lock);
490 
491 exit:
492  mutex_unlock(&open_disc_mutex);
493 exit_nolock:
494  dbg(2, "%s: leave, return value %d", __func__, retval);
495  return retval;
496 }
497 
498 
503 static void tower_abort_transfers (struct lego_usb_tower *dev)
504 {
505  dbg(2, "%s: enter", __func__);
506 
507  if (dev == NULL) {
508  dbg(1, "%s: dev is null", __func__);
509  goto exit;
510  }
511 
512  /* shutdown transfer */
513  if (dev->interrupt_in_running) {
514  dev->interrupt_in_running = 0;
515  mb();
516  if (dev->udev)
518  }
519  if (dev->interrupt_out_busy && dev->udev)
521 
522 exit:
523  dbg(2, "%s: leave", __func__);
524 }
525 
526 
535 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
536 {
537  spin_lock_irq (&dev->read_buffer_lock);
538  if (!packet_timeout
539  || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
540  || dev->read_buffer_length == read_buffer_size) {
542  }
543  dev->interrupt_in_done = 0;
544  spin_unlock_irq (&dev->read_buffer_lock);
545 }
546 
547 
551 static unsigned int tower_poll (struct file *file, poll_table *wait)
552 {
553  struct lego_usb_tower *dev;
554  unsigned int mask = 0;
555 
556  dbg(2, "%s: enter", __func__);
557 
558  dev = file->private_data;
559 
560  if (!dev->udev)
561  return POLLERR | POLLHUP;
562 
563  poll_wait(file, &dev->read_wait, wait);
564  poll_wait(file, &dev->write_wait, wait);
565 
566  tower_check_for_read_packet(dev);
567  if (dev->read_packet_length > 0) {
568  mask |= POLLIN | POLLRDNORM;
569  }
570  if (!dev->interrupt_out_busy) {
571  mask |= POLLOUT | POLLWRNORM;
572  }
573 
574  dbg(2, "%s: leave, mask = %d", __func__, mask);
575 
576  return mask;
577 }
578 
579 
583 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
584 {
585  return -ESPIPE; /* unseekable */
586 }
587 
588 
592 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
593 {
594  struct lego_usb_tower *dev;
595  size_t bytes_to_read;
596  int i;
597  int retval = 0;
598  unsigned long timeout = 0;
599 
600  dbg(2, "%s: enter, count = %Zd", __func__, count);
601 
602  dev = file->private_data;
603 
604  /* lock this object */
605  if (mutex_lock_interruptible(&dev->lock)) {
606  retval = -ERESTARTSYS;
607  goto exit;
608  }
609 
610  /* verify that the device wasn't unplugged */
611  if (dev->udev == NULL) {
612  retval = -ENODEV;
613  printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval);
614  goto unlock_exit;
615  }
616 
617  /* verify that we actually have some data to read */
618  if (count == 0) {
619  dbg(1, "%s: read request of 0 bytes", __func__);
620  goto unlock_exit;
621  }
622 
623  if (read_timeout) {
624  timeout = jiffies + read_timeout * HZ / 1000;
625  }
626 
627  /* wait for data */
628  tower_check_for_read_packet (dev);
629  while (dev->read_packet_length == 0) {
630  if (file->f_flags & O_NONBLOCK) {
631  retval = -EAGAIN;
632  goto unlock_exit;
633  }
635  if (retval < 0) {
636  goto unlock_exit;
637  }
638 
639  /* reset read timeout during read or write activity */
640  if (read_timeout
641  && (dev->read_buffer_length || dev->interrupt_out_busy)) {
642  timeout = jiffies + read_timeout * HZ / 1000;
643  }
644  /* check for read timeout */
645  if (read_timeout && time_after (jiffies, timeout)) {
646  retval = -ETIMEDOUT;
647  goto unlock_exit;
648  }
649  tower_check_for_read_packet (dev);
650  }
651 
652  /* copy the data from read_buffer into userspace */
653  bytes_to_read = min(count, dev->read_packet_length);
654 
655  if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
656  retval = -EFAULT;
657  goto unlock_exit;
658  }
659 
660  spin_lock_irq (&dev->read_buffer_lock);
661  dev->read_buffer_length -= bytes_to_read;
662  dev->read_packet_length -= bytes_to_read;
663  for (i=0; i<dev->read_buffer_length; i++) {
664  dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
665  }
666  spin_unlock_irq (&dev->read_buffer_lock);
667 
668  retval = bytes_to_read;
669 
670 unlock_exit:
671  /* unlock the device */
672  mutex_unlock(&dev->lock);
673 
674 exit:
675  dbg(2, "%s: leave, return value %d", __func__, retval);
676  return retval;
677 }
678 
679 
683 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
684 {
685  struct lego_usb_tower *dev;
686  size_t bytes_to_write;
687  int retval = 0;
688 
689  dbg(2, "%s: enter, count = %Zd", __func__, count);
690 
691  dev = file->private_data;
692 
693  /* lock this object */
694  if (mutex_lock_interruptible(&dev->lock)) {
695  retval = -ERESTARTSYS;
696  goto exit;
697  }
698 
699  /* verify that the device wasn't unplugged */
700  if (dev->udev == NULL) {
701  retval = -ENODEV;
702  printk(KERN_ERR "legousbtower: No device or device unplugged %d\n", retval);
703  goto unlock_exit;
704  }
705 
706  /* verify that we actually have some data to write */
707  if (count == 0) {
708  dbg(1, "%s: write request of 0 bytes", __func__);
709  goto unlock_exit;
710  }
711 
712  /* wait until previous transfer is finished */
713  while (dev->interrupt_out_busy) {
714  if (file->f_flags & O_NONBLOCK) {
715  retval = -EAGAIN;
716  goto unlock_exit;
717  }
719  if (retval) {
720  goto unlock_exit;
721  }
722  }
723 
724  /* write the data into interrupt_out_buffer from userspace */
725  bytes_to_write = min_t(int, count, write_buffer_size);
726  dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write);
727 
728  if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
729  retval = -EFAULT;
730  goto unlock_exit;
731  }
732 
733  /* send off the urb */
734  usb_fill_int_urb(dev->interrupt_out_urb,
735  dev->udev,
736  usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
738  bytes_to_write,
739  tower_interrupt_out_callback,
740  dev,
742 
743  dev->interrupt_out_busy = 1;
744  wmb();
745 
747  if (retval) {
748  dev->interrupt_out_busy = 0;
749  dev_err(&dev->udev->dev,
750  "Couldn't submit interrupt_out_urb %d\n", retval);
751  goto unlock_exit;
752  }
753  retval = bytes_to_write;
754 
755 unlock_exit:
756  /* unlock the device */
757  mutex_unlock(&dev->lock);
758 
759 exit:
760  dbg(2, "%s: leave, return value %d", __func__, retval);
761 
762  return retval;
763 }
764 
765 
769 static void tower_interrupt_in_callback (struct urb *urb)
770 {
771  struct lego_usb_tower *dev = urb->context;
772  int status = urb->status;
773  int retval;
774 
775  dbg(4, "%s: enter, status %d", __func__, status);
776 
777  lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
778 
779  if (status) {
780  if (status == -ENOENT ||
781  status == -ECONNRESET ||
782  status == -ESHUTDOWN) {
783  goto exit;
784  } else {
785  dbg(1, "%s: nonzero status received: %d", __func__, status);
786  goto resubmit; /* maybe we can recover */
787  }
788  }
789 
790  if (urb->actual_length > 0) {
791  spin_lock (&dev->read_buffer_lock);
792  if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
794  dev->interrupt_in_buffer,
795  urb->actual_length);
796  dev->read_buffer_length += urb->actual_length;
797  dev->read_last_arrival = jiffies;
798  dbg(3, "%s: received %d bytes", __func__, urb->actual_length);
799  } else {
800  printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length);
801  }
802  spin_unlock (&dev->read_buffer_lock);
803  }
804 
805 resubmit:
806  /* resubmit if we're still running */
807  if (dev->interrupt_in_running && dev->udev) {
808  retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
809  if (retval)
810  dev_err(&dev->udev->dev,
811  "%s: usb_submit_urb failed (%d)\n",
812  __func__, retval);
813  }
814 
815 exit:
816  dev->interrupt_in_done = 1;
818 
819  lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
820  dbg(4, "%s: leave, status %d", __func__, status);
821 }
822 
823 
827 static void tower_interrupt_out_callback (struct urb *urb)
828 {
829  struct lego_usb_tower *dev = urb->context;
830  int status = urb->status;
831 
832  dbg(4, "%s: enter, status %d", __func__, status);
833  lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
834 
835  /* sync/async unlink faults aren't errors */
836  if (status && !(status == -ENOENT ||
837  status == -ECONNRESET ||
838  status == -ESHUTDOWN)) {
839  dbg(1, "%s - nonzero write bulk status received: %d",
840  __func__, status);
841  }
842 
843  dev->interrupt_out_busy = 0;
845 
846  lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
847  dbg(4, "%s: leave, status %d", __func__, status);
848 }
849 
850 
857 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
858 {
859  struct device *idev = &interface->dev;
860  struct usb_device *udev = interface_to_usbdev(interface);
861  struct lego_usb_tower *dev = NULL;
862  struct usb_host_interface *iface_desc;
864  struct tower_get_version_reply get_version_reply;
865  int i;
866  int retval = -ENOMEM;
867  int result;
868 
869  dbg(2, "%s: enter", __func__);
870 
871  /* allocate memory for our device state and initialize it */
872 
873  dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
874 
875  if (dev == NULL) {
876  dev_err(idev, "Out of memory\n");
877  goto exit;
878  }
879 
880  mutex_init(&dev->lock);
881 
882  dev->udev = udev;
883  dev->open_count = 0;
884 
885  dev->read_buffer = NULL;
886  dev->read_buffer_length = 0;
887  dev->read_packet_length = 0;
889  dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
890  dev->read_last_arrival = jiffies;
891 
894 
895  dev->interrupt_in_buffer = NULL;
897  dev->interrupt_in_urb = NULL;
898  dev->interrupt_in_running = 0;
899  dev->interrupt_in_done = 0;
900 
901  dev->interrupt_out_buffer = NULL;
903  dev->interrupt_out_urb = NULL;
904  dev->interrupt_out_busy = 0;
905 
906  iface_desc = interface->cur_altsetting;
907 
908  /* set up the endpoint information */
909  for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
910  endpoint = &iface_desc->endpoint[i].desc;
911 
912  if (usb_endpoint_xfer_int(endpoint)) {
913  if (usb_endpoint_dir_in(endpoint))
914  dev->interrupt_in_endpoint = endpoint;
915  else
916  dev->interrupt_out_endpoint = endpoint;
917  }
918  }
919  if(dev->interrupt_in_endpoint == NULL) {
920  dev_err(idev, "interrupt in endpoint not found\n");
921  goto error;
922  }
923  if (dev->interrupt_out_endpoint == NULL) {
924  dev_err(idev, "interrupt out endpoint not found\n");
925  goto error;
926  }
927 
928  dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
929  if (!dev->read_buffer) {
930  dev_err(idev, "Couldn't allocate read_buffer\n");
931  goto error;
932  }
933  dev->interrupt_in_buffer = kmalloc (usb_endpoint_maxp(dev->interrupt_in_endpoint), GFP_KERNEL);
934  if (!dev->interrupt_in_buffer) {
935  dev_err(idev, "Couldn't allocate interrupt_in_buffer\n");
936  goto error;
937  }
939  if (!dev->interrupt_in_urb) {
940  dev_err(idev, "Couldn't allocate interrupt_in_urb\n");
941  goto error;
942  }
943  dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
944  if (!dev->interrupt_out_buffer) {
945  dev_err(idev, "Couldn't allocate interrupt_out_buffer\n");
946  goto error;
947  }
949  if (!dev->interrupt_out_urb) {
950  dev_err(idev, "Couldn't allocate interrupt_out_urb\n");
951  goto error;
952  }
953  dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
954  dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
955 
956  /* we can register the device now, as it is ready */
957  usb_set_intfdata (interface, dev);
958 
959  retval = usb_register_dev (interface, &tower_class);
960 
961  if (retval) {
962  /* something prevented us from registering this driver */
963  dev_err(idev, "Not able to get a minor for this device.\n");
964  usb_set_intfdata (interface, NULL);
965  goto error;
966  }
967  dev->minor = interface->minor;
968 
969  /* let the user know what node this device is now attached to */
970  dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
971  "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
972  USB_MAJOR, dev->minor);
973 
974  /* get the firmware version and log it */
975  result = usb_control_msg (udev,
976  usb_rcvctrlpipe(udev, 0),
979  0,
980  0,
981  &get_version_reply,
982  sizeof(get_version_reply),
983  1000);
984  if (result < 0) {
985  dev_err(idev, "LEGO USB Tower get version control request failed\n");
986  retval = result;
987  goto error;
988  }
989  dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
990  "build %d\n", get_version_reply.major,
991  get_version_reply.minor,
992  le16_to_cpu(get_version_reply.build_no));
993 
994 
995 exit:
996  dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev);
997 
998  return retval;
999 
1000 error:
1001  tower_delete(dev);
1002  return retval;
1003 }
1004 
1005 
1011 static void tower_disconnect (struct usb_interface *interface)
1012 {
1013  struct lego_usb_tower *dev;
1014  int minor;
1015 
1016  dbg(2, "%s: enter", __func__);
1017 
1018  dev = usb_get_intfdata (interface);
1019  mutex_lock(&open_disc_mutex);
1020  usb_set_intfdata (interface, NULL);
1021 
1022  minor = dev->minor;
1023 
1024  /* give back our minor */
1025  usb_deregister_dev (interface, &tower_class);
1026 
1027  mutex_lock(&dev->lock);
1028  mutex_unlock(&open_disc_mutex);
1029 
1030  /* if the device is not opened, then we clean up right now */
1031  if (!dev->open_count) {
1032  mutex_unlock(&dev->lock);
1033  tower_delete (dev);
1034  } else {
1035  dev->udev = NULL;
1036  /* wake up pollers */
1039  mutex_unlock(&dev->lock);
1040  }
1041 
1042  dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
1043  (minor - LEGO_USB_TOWER_MINOR_BASE));
1044 
1045  dbg(2, "%s: leave", __func__);
1046 }
1047 
1048 module_usb_driver(tower_driver);
1049 
1052 #ifdef MODULE_LICENSE
1053 MODULE_LICENSE("GPL");
1054 #endif