Merge branch 'upstream-davem' of master.kernel.org:/pub/scm/linux/kernel/git/linville...
[linux-2.6] / drivers / usb / misc / legousbtower.c
1 /*
2  * LEGO USB Tower driver
3  *
4  * Copyright (C) 2003 David Glance <davidgsf@sourceforge.net>
5  *               2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
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 (greg@kroah.com)
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 (david@csse.uwa.edu.au)
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 __FUNCTION__
35  * 2003-01-12 - 0.53 david (david@csse.uwa.edu.au)
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 (david@csse.uwa.edu.au)
40  *   - initial import into LegoUSB project
41  *   - merge of existing LegoUSB.c driver
42  * 2003-07-18 - 0.56 davidgsf (david@csse.uwa.edu.au)
43  *   - port to 2.6 style driver
44  * 2004-02-29 - 0.6 Juergen Stuber <starblue@users.sourceforge.net>
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 __FUNCTION__
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 <starblue@users.sourceforge.net>
56  *   - timeout read now only after inactivity, shorten default accordingly
57  * 2004-03-11 - 0.8 Juergen Stuber <starblue@users.sourceforge.net>
58  *   - log major, minor instead of possibly confusing device filename
59  *   - whitespace cleanup
60  * 2004-03-12 - 0.9 Juergen Stuber <starblue@users.sourceforge.net>
61  *   - normalize whitespace in debug messages
62  *   - take care about endianness in control message responses
63  * 2004-03-13 - 0.91 Juergen Stuber <starblue@users.sourceforge.net>
64  *   - make default intervals longer to accommodate current EHCI driver
65  * 2004-03-19 - 0.92 Juergen Stuber <starblue@users.sourceforge.net>
66  *   - replaced atomic_t by memory barriers
67  * 2004-04-21 - 0.93 Juergen Stuber <starblue@users.sourceforge.net>
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 <starblue@users.sourceforge.net>
71  *   - make device locking interruptible
72  * 2004-04-30 - 0.95 Juergen Stuber <starblue@users.sourceforge.net>
73  *   - check for valid udev on resubmitting and unlinking urbs
74  * 2004-08-03 - 0.96 Juergen Stuber <starblue@users.sourceforge.net>
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...) do { if (debug >= lvl) printk(KERN_DEBUG  __FILE__ ": " format "\n", ## arg); } while (0)
99
100
101 /* Version Information */
102 #define DRIVER_VERSION "v0.96"
103 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
104 #define DRIVER_DESC "LEGO USB Tower Driver"
105
106 /* Module parameters */
107 module_param(debug, int, S_IRUGO | S_IWUSR);
108 MODULE_PARM_DESC(debug, "Debug enabled or not");
109
110 /* The defaults are chosen to work with the latest versions of leJOS and NQC.
111  */
112
113 /* Some legacy software likes to receive packets in one piece.
114  * In this case read_buffer_size should exceed the maximal packet length
115  * (417 for datalog uploads), and packet_timeout should be set.
116  */
117 static int read_buffer_size = 480;
118 module_param(read_buffer_size, int, 0);
119 MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
120
121 /* Some legacy software likes to send packets in one piece.
122  * In this case write_buffer_size should exceed the maximal packet length
123  * (417 for firmware and program downloads).
124  * A problem with long writes is that the following read may time out
125  * if the software is not prepared to wait long enough.
126  */
127 static int write_buffer_size = 480;
128 module_param(write_buffer_size, int, 0);
129 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
130
131 /* Some legacy software expects reads to contain whole LASM packets.
132  * To achieve this, characters which arrive before a packet timeout
133  * occurs will be returned in a single read operation.
134  * A problem with long reads is that the software may time out
135  * if it is not prepared to wait long enough.
136  * The packet timeout should be greater than the time between the
137  * reception of subsequent characters, which should arrive about
138  * every 5ms for the standard 2400 baud.
139  * Set it to 0 to disable.
140  */
141 static int packet_timeout = 50;
142 module_param(packet_timeout, int, 0);
143 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
144
145 /* Some legacy software expects blocking reads to time out.
146  * Timeout occurs after the specified time of read and write inactivity.
147  * Set it to 0 to disable.
148  */
149 static int read_timeout = 200;
150 module_param(read_timeout, int, 0);
151 MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
152
153 /* As of kernel version 2.6.4 ehci-hcd uses an
154  * "only one interrupt transfer per frame" shortcut
155  * to simplify the scheduling of periodic transfers.
156  * This conflicts with our standard 1ms intervals for in and out URBs.
157  * We use default intervals of 2ms for in and 8ms for out transfers,
158  * which is fast enough for 2400 baud and allows a small additional load.
159  * Increase the interval to allow more devices that do interrupt transfers,
160  * or set to 0 to use the standard interval from the endpoint descriptors.
161  */
162 static int interrupt_in_interval = 2;
163 module_param(interrupt_in_interval, int, 0);
164 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
165
166 static int interrupt_out_interval = 8;
167 module_param(interrupt_out_interval, int, 0);
168 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
169
170 /* Define these values to match your device */
171 #define LEGO_USB_TOWER_VENDOR_ID        0x0694
172 #define LEGO_USB_TOWER_PRODUCT_ID       0x0001
173
174 /* Vendor requests */
175 #define LEGO_USB_TOWER_REQUEST_RESET            0x04
176 #define LEGO_USB_TOWER_REQUEST_GET_VERSION      0xFD
177
178 struct tower_reset_reply {
179         __le16 size;            /* little-endian */
180         __u8 err_code;
181         __u8 spare;
182 } __attribute__ ((packed));
183
184 struct tower_get_version_reply {
185         __le16 size;            /* little-endian */
186         __u8 err_code;
187         __u8 spare;
188         __u8 major;
189         __u8 minor;
190         __le16 build_no;                /* little-endian */
191 } __attribute__ ((packed));
192
193
194 /* table of devices that work with this driver */
195 static struct usb_device_id tower_table [] = {
196         { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
197         { }                                     /* Terminating entry */
198 };
199
200 MODULE_DEVICE_TABLE (usb, tower_table);
201
202 #define LEGO_USB_TOWER_MINOR_BASE       160
203
204
205 /* Structure to hold all of our device specific stuff */
206 struct lego_usb_tower {
207         struct semaphore        sem;            /* locks this structure */
208         struct usb_device*      udev;           /* save off the usb device pointer */
209         unsigned char           minor;          /* the starting minor number for this device */
210
211         int                     open_count;     /* number of times this port has been opened */
212
213         char*                   read_buffer;
214         size_t                  read_buffer_length; /* this much came in */
215         size_t                  read_packet_length; /* this much will be returned on read */
216         spinlock_t              read_buffer_lock;
217         int                     packet_timeout_jiffies;
218         unsigned long           read_last_arrival;
219
220         wait_queue_head_t       read_wait;
221         wait_queue_head_t       write_wait;
222
223         char*                   interrupt_in_buffer;
224         struct usb_endpoint_descriptor* interrupt_in_endpoint;
225         struct urb*             interrupt_in_urb;
226         int                     interrupt_in_interval;
227         int                     interrupt_in_running;
228         int                     interrupt_in_done;
229
230         char*                   interrupt_out_buffer;
231         struct usb_endpoint_descriptor* interrupt_out_endpoint;
232         struct urb*             interrupt_out_urb;
233         int                     interrupt_out_interval;
234         int                     interrupt_out_busy;
235
236 };
237
238
239 /* local function prototypes */
240 static ssize_t tower_read       (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
241 static ssize_t tower_write      (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
242 static inline void tower_delete (struct lego_usb_tower *dev);
243 static int tower_open           (struct inode *inode, struct file *file);
244 static int tower_release        (struct inode *inode, struct file *file);
245 static unsigned int tower_poll  (struct file *file, poll_table *wait);
246 static loff_t tower_llseek      (struct file *file, loff_t off, int whence);
247
248 static void tower_abort_transfers (struct lego_usb_tower *dev);
249 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
250 static void tower_interrupt_in_callback (struct urb *urb);
251 static void tower_interrupt_out_callback (struct urb *urb);
252
253 static int  tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
254 static void tower_disconnect    (struct usb_interface *interface);
255
256
257 /* file operations needed when we register this driver */
258 static const struct file_operations tower_fops = {
259         .owner =        THIS_MODULE,
260         .read  =        tower_read,
261         .write =        tower_write,
262         .open =         tower_open,
263         .release =      tower_release,
264         .poll =         tower_poll,
265         .llseek =       tower_llseek,
266 };
267
268 /*
269  * usb class driver info in order to get a minor number from the usb core,
270  * and to have the device registered with the driver core
271  */
272 static struct usb_class_driver tower_class = {
273         .name =         "legousbtower%d",
274         .fops =         &tower_fops,
275         .minor_base =   LEGO_USB_TOWER_MINOR_BASE,
276 };
277
278
279 /* usb specific object needed to register this driver with the usb subsystem */
280 static struct usb_driver tower_driver = {
281         .name =         "legousbtower",
282         .probe =        tower_probe,
283         .disconnect =   tower_disconnect,
284         .id_table =     tower_table,
285 };
286
287
288 /**
289  *      lego_usb_tower_debug_data
290  */
291 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
292 {
293         int i;
294
295         if (debug < level)
296                 return;
297
298         printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size);
299         for (i = 0; i < size; ++i) {
300                 printk ("%.2x ", data[i]);
301         }
302         printk ("\n");
303 }
304
305
306 /**
307  *      tower_delete
308  */
309 static inline void tower_delete (struct lego_usb_tower *dev)
310 {
311         dbg(2, "%s: enter", __FUNCTION__);
312
313         tower_abort_transfers (dev);
314
315         /* free data structures */
316         usb_free_urb(dev->interrupt_in_urb);
317         usb_free_urb(dev->interrupt_out_urb);
318         kfree (dev->read_buffer);
319         kfree (dev->interrupt_in_buffer);
320         kfree (dev->interrupt_out_buffer);
321         kfree (dev);
322
323         dbg(2, "%s: leave", __FUNCTION__);
324 }
325
326
327 /**
328  *      tower_open
329  */
330 static int tower_open (struct inode *inode, struct file *file)
331 {
332         struct lego_usb_tower *dev = NULL;
333         int subminor;
334         int retval = 0;
335         struct usb_interface *interface;
336         struct tower_reset_reply reset_reply;
337         int result;
338
339         dbg(2, "%s: enter", __FUNCTION__);
340
341         nonseekable_open(inode, file);
342         subminor = iminor(inode);
343
344         interface = usb_find_interface (&tower_driver, subminor);
345
346         if (!interface) {
347                 err ("%s - error, can't find device for minor %d",
348                      __FUNCTION__, subminor);
349                 retval = -ENODEV;
350                 goto exit;
351         }
352
353         dev = usb_get_intfdata(interface);
354
355         if (!dev) {
356                 retval = -ENODEV;
357                 goto exit;
358         }
359
360         /* lock this device */
361         if (down_interruptible (&dev->sem)) {
362                 retval = -ERESTARTSYS;
363                 goto exit;
364         }
365
366         /* allow opening only once */
367         if (dev->open_count) {
368                 retval = -EBUSY;
369                 goto unlock_exit;
370         }
371         dev->open_count = 1;
372
373         /* reset the tower */
374         result = usb_control_msg (dev->udev,
375                                   usb_rcvctrlpipe(dev->udev, 0),
376                                   LEGO_USB_TOWER_REQUEST_RESET,
377                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
378                                   0,
379                                   0,
380                                   &reset_reply,
381                                   sizeof(reset_reply),
382                                   1000);
383         if (result < 0) {
384                 err("LEGO USB Tower reset control request failed");
385                 retval = result;
386                 goto unlock_exit;
387         }
388
389         /* initialize in direction */
390         dev->read_buffer_length = 0;
391         dev->read_packet_length = 0;
392         usb_fill_int_urb (dev->interrupt_in_urb,
393                           dev->udev,
394                           usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
395                           dev->interrupt_in_buffer,
396                           le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
397                           tower_interrupt_in_callback,
398                           dev,
399                           dev->interrupt_in_interval);
400
401         dev->interrupt_in_running = 1;
402         dev->interrupt_in_done = 0;
403         mb();
404
405         retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
406         if (retval) {
407                 err("Couldn't submit interrupt_in_urb %d", retval);
408                 dev->interrupt_in_running = 0;
409                 dev->open_count = 0;
410                 goto unlock_exit;
411         }
412
413         /* save device in the file's private structure */
414         file->private_data = dev;
415
416 unlock_exit:
417         up (&dev->sem);
418
419 exit:
420         dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval);
421
422         return retval;
423 }
424
425 /**
426  *      tower_release
427  */
428 static int tower_release (struct inode *inode, struct file *file)
429 {
430         struct lego_usb_tower *dev;
431         int retval = 0;
432
433         dbg(2, "%s: enter", __FUNCTION__);
434
435         dev = (struct lego_usb_tower *)file->private_data;
436
437         if (dev == NULL) {
438                 dbg(1, "%s: object is NULL", __FUNCTION__);
439                 retval = -ENODEV;
440                 goto exit;
441         }
442
443         if (down_interruptible (&dev->sem)) {
444                 retval = -ERESTARTSYS;
445                 goto exit;
446         }
447
448         if (dev->open_count != 1) {
449                 dbg(1, "%s: device not opened exactly once", __FUNCTION__);
450                 retval = -ENODEV;
451                 goto unlock_exit;
452         }
453         if (dev->udev == NULL) {
454                 /* the device was unplugged before the file was released */
455                 up (&dev->sem); /* unlock here as tower_delete frees dev */
456                 tower_delete (dev);
457                 goto exit;
458         }
459
460         /* wait until write transfer is finished */
461         if (dev->interrupt_out_busy) {
462                 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
463         }
464         tower_abort_transfers (dev);
465         dev->open_count = 0;
466
467 unlock_exit:
468         up (&dev->sem);
469
470 exit:
471         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
472         return retval;
473 }
474
475
476 /**
477  *      tower_abort_transfers
478  *      aborts transfers and frees associated data structures
479  */
480 static void tower_abort_transfers (struct lego_usb_tower *dev)
481 {
482         dbg(2, "%s: enter", __FUNCTION__);
483
484         if (dev == NULL) {
485                 dbg(1, "%s: dev is null", __FUNCTION__);
486                 goto exit;
487         }
488
489         /* shutdown transfer */
490         if (dev->interrupt_in_running) {
491                 dev->interrupt_in_running = 0;
492                 mb();
493                 if (dev->udev)
494                         usb_kill_urb (dev->interrupt_in_urb);
495         }
496         if (dev->interrupt_out_busy && dev->udev)
497                 usb_kill_urb(dev->interrupt_out_urb);
498
499 exit:
500         dbg(2, "%s: leave", __FUNCTION__);
501 }
502
503
504 /**
505  *      tower_check_for_read_packet
506  *
507  *      To get correct semantics for signals and non-blocking I/O
508  *      with packetizing we pretend not to see any data in the read buffer
509  *      until it has been there unchanged for at least
510  *      dev->packet_timeout_jiffies, or until the buffer is full.
511  */
512 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
513 {
514         spin_lock_irq (&dev->read_buffer_lock);
515         if (!packet_timeout
516             || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
517             || dev->read_buffer_length == read_buffer_size) {
518                 dev->read_packet_length = dev->read_buffer_length;
519         }
520         dev->interrupt_in_done = 0;
521         spin_unlock_irq (&dev->read_buffer_lock);
522 }
523
524
525 /**
526  *      tower_poll
527  */
528 static unsigned int tower_poll (struct file *file, poll_table *wait)
529 {
530         struct lego_usb_tower *dev;
531         unsigned int mask = 0;
532
533         dbg(2, "%s: enter", __FUNCTION__);
534
535         dev = file->private_data;
536
537         poll_wait(file, &dev->read_wait, wait);
538         poll_wait(file, &dev->write_wait, wait);
539
540         tower_check_for_read_packet(dev);
541         if (dev->read_packet_length > 0) {
542                 mask |= POLLIN | POLLRDNORM;
543         }
544         if (!dev->interrupt_out_busy) {
545                 mask |= POLLOUT | POLLWRNORM;
546         }
547
548         dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask);
549
550         return mask;
551 }
552
553
554 /**
555  *      tower_llseek
556  */
557 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
558 {
559         return -ESPIPE;         /* unseekable */
560 }
561
562
563 /**
564  *      tower_read
565  */
566 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
567 {
568         struct lego_usb_tower *dev;
569         size_t bytes_to_read;
570         int i;
571         int retval = 0;
572         unsigned long timeout = 0;
573
574         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
575
576         dev = (struct lego_usb_tower *)file->private_data;
577
578         /* lock this object */
579         if (down_interruptible (&dev->sem)) {
580                 retval = -ERESTARTSYS;
581                 goto exit;
582         }
583
584         /* verify that the device wasn't unplugged */
585         if (dev->udev == NULL) {
586                 retval = -ENODEV;
587                 err("No device or device unplugged %d", retval);
588                 goto unlock_exit;
589         }
590
591         /* verify that we actually have some data to read */
592         if (count == 0) {
593                 dbg(1, "%s: read request of 0 bytes", __FUNCTION__);
594                 goto unlock_exit;
595         }
596
597         if (read_timeout) {
598                 timeout = jiffies + read_timeout * HZ / 1000;
599         }
600
601         /* wait for data */
602         tower_check_for_read_packet (dev);
603         while (dev->read_packet_length == 0) {
604                 if (file->f_flags & O_NONBLOCK) {
605                         retval = -EAGAIN;
606                         goto unlock_exit;
607                 }
608                 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
609                 if (retval < 0) {
610                         goto unlock_exit;
611                 }
612
613                 /* reset read timeout during read or write activity */
614                 if (read_timeout
615                     && (dev->read_buffer_length || dev->interrupt_out_busy)) {
616                         timeout = jiffies + read_timeout * HZ / 1000;
617                 }
618                 /* check for read timeout */
619                 if (read_timeout && time_after (jiffies, timeout)) {
620                         retval = -ETIMEDOUT;
621                         goto unlock_exit;
622                 }
623                 tower_check_for_read_packet (dev);
624         }
625
626         /* copy the data from read_buffer into userspace */
627         bytes_to_read = min(count, dev->read_packet_length);
628
629         if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
630                 retval = -EFAULT;
631                 goto unlock_exit;
632         }
633
634         spin_lock_irq (&dev->read_buffer_lock);
635         dev->read_buffer_length -= bytes_to_read;
636         dev->read_packet_length -= bytes_to_read;
637         for (i=0; i<dev->read_buffer_length; i++) {
638                 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
639         }
640         spin_unlock_irq (&dev->read_buffer_lock);
641
642         retval = bytes_to_read;
643
644 unlock_exit:
645         /* unlock the device */
646         up (&dev->sem);
647
648 exit:
649         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
650         return retval;
651 }
652
653
654 /**
655  *      tower_write
656  */
657 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
658 {
659         struct lego_usb_tower *dev;
660         size_t bytes_to_write;
661         int retval = 0;
662
663         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
664
665         dev = (struct lego_usb_tower *)file->private_data;
666
667         /* lock this object */
668         if (down_interruptible (&dev->sem)) {
669                 retval = -ERESTARTSYS;
670                 goto exit;
671         }
672
673         /* verify that the device wasn't unplugged */
674         if (dev->udev == NULL) {
675                 retval = -ENODEV;
676                 err("No device or device unplugged %d", retval);
677                 goto unlock_exit;
678         }
679
680         /* verify that we actually have some data to write */
681         if (count == 0) {
682                 dbg(1, "%s: write request of 0 bytes", __FUNCTION__);
683                 goto unlock_exit;
684         }
685
686         /* wait until previous transfer is finished */
687         while (dev->interrupt_out_busy) {
688                 if (file->f_flags & O_NONBLOCK) {
689                         retval = -EAGAIN;
690                         goto unlock_exit;
691                 }
692                 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
693                 if (retval) {
694                         goto unlock_exit;
695                 }
696         }
697
698         /* write the data into interrupt_out_buffer from userspace */
699         bytes_to_write = min_t(int, count, write_buffer_size);
700         dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write);
701
702         if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
703                 retval = -EFAULT;
704                 goto unlock_exit;
705         }
706
707         /* send off the urb */
708         usb_fill_int_urb(dev->interrupt_out_urb,
709                          dev->udev,
710                          usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
711                          dev->interrupt_out_buffer,
712                          bytes_to_write,
713                          tower_interrupt_out_callback,
714                          dev,
715                          dev->interrupt_out_interval);
716
717         dev->interrupt_out_busy = 1;
718         wmb();
719
720         retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
721         if (retval) {
722                 dev->interrupt_out_busy = 0;
723                 err("Couldn't submit interrupt_out_urb %d", retval);
724                 goto unlock_exit;
725         }
726         retval = bytes_to_write;
727
728 unlock_exit:
729         /* unlock the device */
730         up (&dev->sem);
731
732 exit:
733         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
734
735         return retval;
736 }
737
738
739 /**
740  *      tower_interrupt_in_callback
741  */
742 static void tower_interrupt_in_callback (struct urb *urb)
743 {
744         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
745         int retval;
746
747         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
748
749         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
750
751         if (urb->status) {
752                 if (urb->status == -ENOENT ||
753                     urb->status == -ECONNRESET ||
754                     urb->status == -ESHUTDOWN) {
755                         goto exit;
756                 } else {
757                         dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status);
758                         goto resubmit; /* maybe we can recover */
759                 }
760         }
761
762         if (urb->actual_length > 0) {
763                 spin_lock (&dev->read_buffer_lock);
764                 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
765                         memcpy (dev->read_buffer + dev->read_buffer_length,
766                                 dev->interrupt_in_buffer,
767                                 urb->actual_length);
768                         dev->read_buffer_length += urb->actual_length;
769                         dev->read_last_arrival = jiffies;
770                         dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length);
771                 } else {
772                         printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length);
773                 }
774                 spin_unlock (&dev->read_buffer_lock);
775         }
776
777 resubmit:
778         /* resubmit if we're still running */
779         if (dev->interrupt_in_running && dev->udev) {
780                 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
781                 if (retval) {
782                         err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval);
783                 }
784         }
785
786 exit:
787         dev->interrupt_in_done = 1;
788         wake_up_interruptible (&dev->read_wait);
789
790         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
791         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
792 }
793
794
795 /**
796  *      tower_interrupt_out_callback
797  */
798 static void tower_interrupt_out_callback (struct urb *urb)
799 {
800         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
801
802         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
803         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
804
805         /* sync/async unlink faults aren't errors */
806         if (urb->status && !(urb->status == -ENOENT ||
807                              urb->status == -ECONNRESET ||
808                              urb->status == -ESHUTDOWN)) {
809                 dbg(1, "%s - nonzero write bulk status received: %d",
810                     __FUNCTION__, urb->status);
811         }
812
813         dev->interrupt_out_busy = 0;
814         wake_up_interruptible(&dev->write_wait);
815
816         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
817         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
818 }
819
820
821 /**
822  *      tower_probe
823  *
824  *      Called by the usb core when a new device is connected that it thinks
825  *      this driver might be interested in.
826  */
827 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
828 {
829         struct usb_device *udev = interface_to_usbdev(interface);
830         struct lego_usb_tower *dev = NULL;
831         struct usb_host_interface *iface_desc;
832         struct usb_endpoint_descriptor* endpoint;
833         struct tower_get_version_reply get_version_reply;
834         int i;
835         int retval = -ENOMEM;
836         int result;
837
838         dbg(2, "%s: enter", __FUNCTION__);
839
840         if (udev == NULL) {
841                 info ("udev is NULL.");
842         }
843
844         /* allocate memory for our device state and initialize it */
845
846         dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
847
848         if (dev == NULL) {
849                 err ("Out of memory");
850                 goto exit;
851         }
852
853         init_MUTEX (&dev->sem);
854
855         dev->udev = udev;
856         dev->open_count = 0;
857
858         dev->read_buffer = NULL;
859         dev->read_buffer_length = 0;
860         dev->read_packet_length = 0;
861         spin_lock_init (&dev->read_buffer_lock);
862         dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
863         dev->read_last_arrival = jiffies;
864
865         init_waitqueue_head (&dev->read_wait);
866         init_waitqueue_head (&dev->write_wait);
867
868         dev->interrupt_in_buffer = NULL;
869         dev->interrupt_in_endpoint = NULL;
870         dev->interrupt_in_urb = NULL;
871         dev->interrupt_in_running = 0;
872         dev->interrupt_in_done = 0;
873
874         dev->interrupt_out_buffer = NULL;
875         dev->interrupt_out_endpoint = NULL;
876         dev->interrupt_out_urb = NULL;
877         dev->interrupt_out_busy = 0;
878
879         iface_desc = interface->cur_altsetting;
880
881         /* set up the endpoint information */
882         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
883                 endpoint = &iface_desc->endpoint[i].desc;
884
885                 if (usb_endpoint_xfer_int(endpoint)) {
886                         if (usb_endpoint_dir_in(endpoint))
887                                 dev->interrupt_in_endpoint = endpoint;
888                         else
889                                 dev->interrupt_out_endpoint = endpoint;
890                 }
891         }
892         if(dev->interrupt_in_endpoint == NULL) {
893                 err("interrupt in endpoint not found");
894                 goto error;
895         }
896         if (dev->interrupt_out_endpoint == NULL) {
897                 err("interrupt out endpoint not found");
898                 goto error;
899         }
900
901         dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
902         if (!dev->read_buffer) {
903                 err("Couldn't allocate read_buffer");
904                 goto error;
905         }
906         dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL);
907         if (!dev->interrupt_in_buffer) {
908                 err("Couldn't allocate interrupt_in_buffer");
909                 goto error;
910         }
911         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
912         if (!dev->interrupt_in_urb) {
913                 err("Couldn't allocate interrupt_in_urb");
914                 goto error;
915         }
916         dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
917         if (!dev->interrupt_out_buffer) {
918                 err("Couldn't allocate interrupt_out_buffer");
919                 goto error;
920         }
921         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
922         if (!dev->interrupt_out_urb) {
923                 err("Couldn't allocate interrupt_out_urb");
924                 goto error;
925         }
926         dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
927         dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
928
929         /* we can register the device now, as it is ready */
930         usb_set_intfdata (interface, dev);
931
932         retval = usb_register_dev (interface, &tower_class);
933
934         if (retval) {
935                 /* something prevented us from registering this driver */
936                 err ("Not able to get a minor for this device.");
937                 usb_set_intfdata (interface, NULL);
938                 goto error;
939         }
940         dev->minor = interface->minor;
941
942         /* let the user know what node this device is now attached to */
943         info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor);
944
945         /* get the firmware version and log it */
946         result = usb_control_msg (udev,
947                                   usb_rcvctrlpipe(udev, 0),
948                                   LEGO_USB_TOWER_REQUEST_GET_VERSION,
949                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
950                                   0,
951                                   0,
952                                   &get_version_reply,
953                                   sizeof(get_version_reply),
954                                   1000);
955         if (result < 0) {
956                 err("LEGO USB Tower get version control request failed");
957                 retval = result;
958                 goto error;
959         }
960         info("LEGO USB Tower firmware version is %d.%d build %d",
961              get_version_reply.major,
962              get_version_reply.minor,
963              le16_to_cpu(get_version_reply.build_no));
964
965
966 exit:
967         dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev);
968
969         return retval;
970
971 error:
972         tower_delete(dev);
973         return retval;
974 }
975
976
977 /**
978  *      tower_disconnect
979  *
980  *      Called by the usb core when the device is removed from the system.
981  */
982 static void tower_disconnect (struct usb_interface *interface)
983 {
984         struct lego_usb_tower *dev;
985         int minor;
986
987         dbg(2, "%s: enter", __FUNCTION__);
988
989         dev = usb_get_intfdata (interface);
990         usb_set_intfdata (interface, NULL);
991
992         minor = dev->minor;
993
994         /* give back our minor */
995         usb_deregister_dev (interface, &tower_class);
996
997         down (&dev->sem);
998
999         /* if the device is not opened, then we clean up right now */
1000         if (!dev->open_count) {
1001                 up (&dev->sem);
1002                 tower_delete (dev);
1003         } else {
1004                 dev->udev = NULL;
1005                 up (&dev->sem);
1006         }
1007
1008         info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE));
1009
1010         dbg(2, "%s: leave", __FUNCTION__);
1011 }
1012
1013
1014
1015 /**
1016  *      lego_usb_tower_init
1017  */
1018 static int __init lego_usb_tower_init(void)
1019 {
1020         int result;
1021         int retval = 0;
1022
1023         dbg(2, "%s: enter", __FUNCTION__);
1024
1025         /* register this driver with the USB subsystem */
1026         result = usb_register(&tower_driver);
1027         if (result < 0) {
1028                 err("usb_register failed for the "__FILE__" driver. Error number %d", result);
1029                 retval = -1;
1030                 goto exit;
1031         }
1032
1033         info(DRIVER_DESC " " DRIVER_VERSION);
1034
1035 exit:
1036         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
1037
1038         return retval;
1039 }
1040
1041
1042 /**
1043  *      lego_usb_tower_exit
1044  */
1045 static void __exit lego_usb_tower_exit(void)
1046 {
1047         dbg(2, "%s: enter", __FUNCTION__);
1048
1049         /* deregister this driver with the USB subsystem */
1050         usb_deregister (&tower_driver);
1051
1052         dbg(2, "%s: leave", __FUNCTION__);
1053 }
1054
1055 module_init (lego_usb_tower_init);
1056 module_exit (lego_usb_tower_exit);
1057
1058 MODULE_AUTHOR(DRIVER_AUTHOR);
1059 MODULE_DESCRIPTION(DRIVER_DESC);
1060 #ifdef MODULE_LICENSE
1061 MODULE_LICENSE("GPL");
1062 #endif