USB: remove info() macro from usb/misc drivers
[linux-2.6.git] / 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 __func__
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 __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 <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 static DEFINE_MUTEX(open_disc_mutex);
202
203 #define LEGO_USB_TOWER_MINOR_BASE       160
204
205
206 /* Structure to hold all of our device specific stuff */
207 struct lego_usb_tower {
208         struct mutex            lock;           /* locks this structure */
209         struct usb_device*      udev;           /* save off the usb device pointer */
210         unsigned char           minor;          /* the starting minor number for this device */
211
212         int                     open_count;     /* number of times this port has been opened */
213
214         char*                   read_buffer;
215         size_t                  read_buffer_length; /* this much came in */
216         size_t                  read_packet_length; /* this much will be returned on read */
217         spinlock_t              read_buffer_lock;
218         int                     packet_timeout_jiffies;
219         unsigned long           read_last_arrival;
220
221         wait_queue_head_t       read_wait;
222         wait_queue_head_t       write_wait;
223
224         char*                   interrupt_in_buffer;
225         struct usb_endpoint_descriptor* interrupt_in_endpoint;
226         struct urb*             interrupt_in_urb;
227         int                     interrupt_in_interval;
228         int                     interrupt_in_running;
229         int                     interrupt_in_done;
230
231         char*                   interrupt_out_buffer;
232         struct usb_endpoint_descriptor* interrupt_out_endpoint;
233         struct urb*             interrupt_out_urb;
234         int                     interrupt_out_interval;
235         int                     interrupt_out_busy;
236
237 };
238
239
240 /* local function prototypes */
241 static ssize_t tower_read       (struct file *file, char __user *buffer, size_t count, loff_t *ppos);
242 static ssize_t tower_write      (struct file *file, const char __user *buffer, size_t count, loff_t *ppos);
243 static inline void tower_delete (struct lego_usb_tower *dev);
244 static int tower_open           (struct inode *inode, struct file *file);
245 static int tower_release        (struct inode *inode, struct file *file);
246 static unsigned int tower_poll  (struct file *file, poll_table *wait);
247 static loff_t tower_llseek      (struct file *file, loff_t off, int whence);
248
249 static void tower_abort_transfers (struct lego_usb_tower *dev);
250 static void tower_check_for_read_packet (struct lego_usb_tower *dev);
251 static void tower_interrupt_in_callback (struct urb *urb);
252 static void tower_interrupt_out_callback (struct urb *urb);
253
254 static int  tower_probe (struct usb_interface *interface, const struct usb_device_id *id);
255 static void tower_disconnect    (struct usb_interface *interface);
256
257
258 /* file operations needed when we register this driver */
259 static const struct file_operations tower_fops = {
260         .owner =        THIS_MODULE,
261         .read  =        tower_read,
262         .write =        tower_write,
263         .open =         tower_open,
264         .release =      tower_release,
265         .poll =         tower_poll,
266         .llseek =       tower_llseek,
267 };
268
269 /*
270  * usb class driver info in order to get a minor number from the usb core,
271  * and to have the device registered with the driver core
272  */
273 static struct usb_class_driver tower_class = {
274         .name =         "legousbtower%d",
275         .fops =         &tower_fops,
276         .minor_base =   LEGO_USB_TOWER_MINOR_BASE,
277 };
278
279
280 /* usb specific object needed to register this driver with the usb subsystem */
281 static struct usb_driver tower_driver = {
282         .name =         "legousbtower",
283         .probe =        tower_probe,
284         .disconnect =   tower_disconnect,
285         .id_table =     tower_table,
286 };
287
288
289 /**
290  *      lego_usb_tower_debug_data
291  */
292 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
293 {
294         int i;
295
296         if (debug < level)
297                 return;
298
299         printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size);
300         for (i = 0; i < size; ++i) {
301                 printk ("%.2x ", data[i]);
302         }
303         printk ("\n");
304 }
305
306
307 /**
308  *      tower_delete
309  */
310 static inline void tower_delete (struct lego_usb_tower *dev)
311 {
312         dbg(2, "%s: enter", __func__);
313
314         tower_abort_transfers (dev);
315
316         /* free data structures */
317         usb_free_urb(dev->interrupt_in_urb);
318         usb_free_urb(dev->interrupt_out_urb);
319         kfree (dev->read_buffer);
320         kfree (dev->interrupt_in_buffer);
321         kfree (dev->interrupt_out_buffer);
322         kfree (dev);
323
324         dbg(2, "%s: leave", __func__);
325 }
326
327
328 /**
329  *      tower_open
330  */
331 static int tower_open (struct inode *inode, struct file *file)
332 {
333         struct lego_usb_tower *dev = NULL;
334         int subminor;
335         int retval = 0;
336         struct usb_interface *interface;
337         struct tower_reset_reply reset_reply;
338         int result;
339
340         dbg(2, "%s: enter", __func__);
341
342         nonseekable_open(inode, file);
343         subminor = iminor(inode);
344
345         interface = usb_find_interface (&tower_driver, subminor);
346
347         if (!interface) {
348                 err ("%s - error, can't find device for minor %d",
349                      __func__, subminor);
350                 retval = -ENODEV;
351                 goto exit;
352         }
353
354         mutex_lock(&open_disc_mutex);
355         dev = usb_get_intfdata(interface);
356
357         if (!dev) {
358                 mutex_unlock(&open_disc_mutex);
359                 retval = -ENODEV;
360                 goto exit;
361         }
362
363         /* lock this device */
364         if (mutex_lock_interruptible(&dev->lock)) {
365                 mutex_unlock(&open_disc_mutex);
366                 retval = -ERESTARTSYS;
367                 goto exit;
368         }
369
370
371         /* allow opening only once */
372         if (dev->open_count) {
373                 mutex_unlock(&open_disc_mutex);
374                 retval = -EBUSY;
375                 goto unlock_exit;
376         }
377         dev->open_count = 1;
378         mutex_unlock(&open_disc_mutex);
379
380         /* reset the tower */
381         result = usb_control_msg (dev->udev,
382                                   usb_rcvctrlpipe(dev->udev, 0),
383                                   LEGO_USB_TOWER_REQUEST_RESET,
384                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
385                                   0,
386                                   0,
387                                   &reset_reply,
388                                   sizeof(reset_reply),
389                                   1000);
390         if (result < 0) {
391                 err("LEGO USB Tower reset control request failed");
392                 retval = result;
393                 goto unlock_exit;
394         }
395
396         /* initialize in direction */
397         dev->read_buffer_length = 0;
398         dev->read_packet_length = 0;
399         usb_fill_int_urb (dev->interrupt_in_urb,
400                           dev->udev,
401                           usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
402                           dev->interrupt_in_buffer,
403                           le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
404                           tower_interrupt_in_callback,
405                           dev,
406                           dev->interrupt_in_interval);
407
408         dev->interrupt_in_running = 1;
409         dev->interrupt_in_done = 0;
410         mb();
411
412         retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
413         if (retval) {
414                 err("Couldn't submit interrupt_in_urb %d", retval);
415                 dev->interrupt_in_running = 0;
416                 dev->open_count = 0;
417                 goto unlock_exit;
418         }
419
420         /* save device in the file's private structure */
421         file->private_data = dev;
422
423 unlock_exit:
424         mutex_unlock(&dev->lock);
425
426 exit:
427         dbg(2, "%s: leave, return value %d ", __func__, retval);
428
429         return retval;
430 }
431
432 /**
433  *      tower_release
434  */
435 static int tower_release (struct inode *inode, struct file *file)
436 {
437         struct lego_usb_tower *dev;
438         int retval = 0;
439
440         dbg(2, "%s: enter", __func__);
441
442         dev = (struct lego_usb_tower *)file->private_data;
443
444         if (dev == NULL) {
445                 dbg(1, "%s: object is NULL", __func__);
446                 retval = -ENODEV;
447                 goto exit_nolock;
448         }
449
450         mutex_lock(&open_disc_mutex);
451         if (mutex_lock_interruptible(&dev->lock)) {
452                 retval = -ERESTARTSYS;
453                 goto exit;
454         }
455
456         if (dev->open_count != 1) {
457                 dbg(1, "%s: device not opened exactly once", __func__);
458                 retval = -ENODEV;
459                 goto unlock_exit;
460         }
461         if (dev->udev == NULL) {
462                 /* the device was unplugged before the file was released */
463
464                 /* unlock here as tower_delete frees dev */
465                 mutex_unlock(&dev->lock);
466                 tower_delete (dev);
467                 goto exit;
468         }
469
470         /* wait until write transfer is finished */
471         if (dev->interrupt_out_busy) {
472                 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
473         }
474         tower_abort_transfers (dev);
475         dev->open_count = 0;
476
477 unlock_exit:
478         mutex_unlock(&dev->lock);
479
480 exit:
481         mutex_unlock(&open_disc_mutex);
482 exit_nolock:
483         dbg(2, "%s: leave, return value %d", __func__, retval);
484         return retval;
485 }
486
487
488 /**
489  *      tower_abort_transfers
490  *      aborts transfers and frees associated data structures
491  */
492 static void tower_abort_transfers (struct lego_usb_tower *dev)
493 {
494         dbg(2, "%s: enter", __func__);
495
496         if (dev == NULL) {
497                 dbg(1, "%s: dev is null", __func__);
498                 goto exit;
499         }
500
501         /* shutdown transfer */
502         if (dev->interrupt_in_running) {
503                 dev->interrupt_in_running = 0;
504                 mb();
505                 if (dev->udev)
506                         usb_kill_urb (dev->interrupt_in_urb);
507         }
508         if (dev->interrupt_out_busy && dev->udev)
509                 usb_kill_urb(dev->interrupt_out_urb);
510
511 exit:
512         dbg(2, "%s: leave", __func__);
513 }
514
515
516 /**
517  *      tower_check_for_read_packet
518  *
519  *      To get correct semantics for signals and non-blocking I/O
520  *      with packetizing we pretend not to see any data in the read buffer
521  *      until it has been there unchanged for at least
522  *      dev->packet_timeout_jiffies, or until the buffer is full.
523  */
524 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
525 {
526         spin_lock_irq (&dev->read_buffer_lock);
527         if (!packet_timeout
528             || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
529             || dev->read_buffer_length == read_buffer_size) {
530                 dev->read_packet_length = dev->read_buffer_length;
531         }
532         dev->interrupt_in_done = 0;
533         spin_unlock_irq (&dev->read_buffer_lock);
534 }
535
536
537 /**
538  *      tower_poll
539  */
540 static unsigned int tower_poll (struct file *file, poll_table *wait)
541 {
542         struct lego_usb_tower *dev;
543         unsigned int mask = 0;
544
545         dbg(2, "%s: enter", __func__);
546
547         dev = file->private_data;
548
549         poll_wait(file, &dev->read_wait, wait);
550         poll_wait(file, &dev->write_wait, wait);
551
552         tower_check_for_read_packet(dev);
553         if (dev->read_packet_length > 0) {
554                 mask |= POLLIN | POLLRDNORM;
555         }
556         if (!dev->interrupt_out_busy) {
557                 mask |= POLLOUT | POLLWRNORM;
558         }
559
560         dbg(2, "%s: leave, mask = %d", __func__, mask);
561
562         return mask;
563 }
564
565
566 /**
567  *      tower_llseek
568  */
569 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
570 {
571         return -ESPIPE;         /* unseekable */
572 }
573
574
575 /**
576  *      tower_read
577  */
578 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
579 {
580         struct lego_usb_tower *dev;
581         size_t bytes_to_read;
582         int i;
583         int retval = 0;
584         unsigned long timeout = 0;
585
586         dbg(2, "%s: enter, count = %Zd", __func__, count);
587
588         dev = (struct lego_usb_tower *)file->private_data;
589
590         /* lock this object */
591         if (mutex_lock_interruptible(&dev->lock)) {
592                 retval = -ERESTARTSYS;
593                 goto exit;
594         }
595
596         /* verify that the device wasn't unplugged */
597         if (dev->udev == NULL) {
598                 retval = -ENODEV;
599                 err("No device or device unplugged %d", retval);
600                 goto unlock_exit;
601         }
602
603         /* verify that we actually have some data to read */
604         if (count == 0) {
605                 dbg(1, "%s: read request of 0 bytes", __func__);
606                 goto unlock_exit;
607         }
608
609         if (read_timeout) {
610                 timeout = jiffies + read_timeout * HZ / 1000;
611         }
612
613         /* wait for data */
614         tower_check_for_read_packet (dev);
615         while (dev->read_packet_length == 0) {
616                 if (file->f_flags & O_NONBLOCK) {
617                         retval = -EAGAIN;
618                         goto unlock_exit;
619                 }
620                 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
621                 if (retval < 0) {
622                         goto unlock_exit;
623                 }
624
625                 /* reset read timeout during read or write activity */
626                 if (read_timeout
627                     && (dev->read_buffer_length || dev->interrupt_out_busy)) {
628                         timeout = jiffies + read_timeout * HZ / 1000;
629                 }
630                 /* check for read timeout */
631                 if (read_timeout && time_after (jiffies, timeout)) {
632                         retval = -ETIMEDOUT;
633                         goto unlock_exit;
634                 }
635                 tower_check_for_read_packet (dev);
636         }
637
638         /* copy the data from read_buffer into userspace */
639         bytes_to_read = min(count, dev->read_packet_length);
640
641         if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
642                 retval = -EFAULT;
643                 goto unlock_exit;
644         }
645
646         spin_lock_irq (&dev->read_buffer_lock);
647         dev->read_buffer_length -= bytes_to_read;
648         dev->read_packet_length -= bytes_to_read;
649         for (i=0; i<dev->read_buffer_length; i++) {
650                 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
651         }
652         spin_unlock_irq (&dev->read_buffer_lock);
653
654         retval = bytes_to_read;
655
656 unlock_exit:
657         /* unlock the device */
658         mutex_unlock(&dev->lock);
659
660 exit:
661         dbg(2, "%s: leave, return value %d", __func__, retval);
662         return retval;
663 }
664
665
666 /**
667  *      tower_write
668  */
669 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
670 {
671         struct lego_usb_tower *dev;
672         size_t bytes_to_write;
673         int retval = 0;
674
675         dbg(2, "%s: enter, count = %Zd", __func__, count);
676
677         dev = (struct lego_usb_tower *)file->private_data;
678
679         /* lock this object */
680         if (mutex_lock_interruptible(&dev->lock)) {
681                 retval = -ERESTARTSYS;
682                 goto exit;
683         }
684
685         /* verify that the device wasn't unplugged */
686         if (dev->udev == NULL) {
687                 retval = -ENODEV;
688                 err("No device or device unplugged %d", retval);
689                 goto unlock_exit;
690         }
691
692         /* verify that we actually have some data to write */
693         if (count == 0) {
694                 dbg(1, "%s: write request of 0 bytes", __func__);
695                 goto unlock_exit;
696         }
697
698         /* wait until previous transfer is finished */
699         while (dev->interrupt_out_busy) {
700                 if (file->f_flags & O_NONBLOCK) {
701                         retval = -EAGAIN;
702                         goto unlock_exit;
703                 }
704                 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
705                 if (retval) {
706                         goto unlock_exit;
707                 }
708         }
709
710         /* write the data into interrupt_out_buffer from userspace */
711         bytes_to_write = min_t(int, count, write_buffer_size);
712         dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __func__, count, bytes_to_write);
713
714         if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
715                 retval = -EFAULT;
716                 goto unlock_exit;
717         }
718
719         /* send off the urb */
720         usb_fill_int_urb(dev->interrupt_out_urb,
721                          dev->udev,
722                          usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
723                          dev->interrupt_out_buffer,
724                          bytes_to_write,
725                          tower_interrupt_out_callback,
726                          dev,
727                          dev->interrupt_out_interval);
728
729         dev->interrupt_out_busy = 1;
730         wmb();
731
732         retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
733         if (retval) {
734                 dev->interrupt_out_busy = 0;
735                 err("Couldn't submit interrupt_out_urb %d", retval);
736                 goto unlock_exit;
737         }
738         retval = bytes_to_write;
739
740 unlock_exit:
741         /* unlock the device */
742         mutex_unlock(&dev->lock);
743
744 exit:
745         dbg(2, "%s: leave, return value %d", __func__, retval);
746
747         return retval;
748 }
749
750
751 /**
752  *      tower_interrupt_in_callback
753  */
754 static void tower_interrupt_in_callback (struct urb *urb)
755 {
756         struct lego_usb_tower *dev = urb->context;
757         int status = urb->status;
758         int retval;
759
760         dbg(4, "%s: enter, status %d", __func__, status);
761
762         lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
763
764         if (status) {
765                 if (status == -ENOENT ||
766                     status == -ECONNRESET ||
767                     status == -ESHUTDOWN) {
768                         goto exit;
769                 } else {
770                         dbg(1, "%s: nonzero status received: %d", __func__, status);
771                         goto resubmit; /* maybe we can recover */
772                 }
773         }
774
775         if (urb->actual_length > 0) {
776                 spin_lock (&dev->read_buffer_lock);
777                 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
778                         memcpy (dev->read_buffer + dev->read_buffer_length,
779                                 dev->interrupt_in_buffer,
780                                 urb->actual_length);
781                         dev->read_buffer_length += urb->actual_length;
782                         dev->read_last_arrival = jiffies;
783                         dbg(3, "%s: received %d bytes", __func__, urb->actual_length);
784                 } else {
785                         printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __func__, urb->actual_length);
786                 }
787                 spin_unlock (&dev->read_buffer_lock);
788         }
789
790 resubmit:
791         /* resubmit if we're still running */
792         if (dev->interrupt_in_running && dev->udev) {
793                 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
794                 if (retval) {
795                         err("%s: usb_submit_urb failed (%d)", __func__, retval);
796                 }
797         }
798
799 exit:
800         dev->interrupt_in_done = 1;
801         wake_up_interruptible (&dev->read_wait);
802
803         lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
804         dbg(4, "%s: leave, status %d", __func__, status);
805 }
806
807
808 /**
809  *      tower_interrupt_out_callback
810  */
811 static void tower_interrupt_out_callback (struct urb *urb)
812 {
813         struct lego_usb_tower *dev = urb->context;
814         int status = urb->status;
815
816         dbg(4, "%s: enter, status %d", __func__, status);
817         lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
818
819         /* sync/async unlink faults aren't errors */
820         if (status && !(status == -ENOENT ||
821                         status == -ECONNRESET ||
822                         status == -ESHUTDOWN)) {
823                 dbg(1, "%s - nonzero write bulk status received: %d",
824                     __func__, status);
825         }
826
827         dev->interrupt_out_busy = 0;
828         wake_up_interruptible(&dev->write_wait);
829
830         lego_usb_tower_debug_data(5, __func__, urb->actual_length, urb->transfer_buffer);
831         dbg(4, "%s: leave, status %d", __func__, status);
832 }
833
834
835 /**
836  *      tower_probe
837  *
838  *      Called by the usb core when a new device is connected that it thinks
839  *      this driver might be interested in.
840  */
841 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
842 {
843         struct usb_device *udev = interface_to_usbdev(interface);
844         struct lego_usb_tower *dev = NULL;
845         struct usb_host_interface *iface_desc;
846         struct usb_endpoint_descriptor* endpoint;
847         struct tower_get_version_reply get_version_reply;
848         int i;
849         int retval = -ENOMEM;
850         int result;
851
852         dbg(2, "%s: enter", __func__);
853
854         if (udev == NULL)
855                 dev_info(&interface->dev, "udev is NULL.\n");
856
857         /* allocate memory for our device state and initialize it */
858
859         dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
860
861         if (dev == NULL) {
862                 err ("Out of memory");
863                 goto exit;
864         }
865
866         mutex_init(&dev->lock);
867
868         dev->udev = udev;
869         dev->open_count = 0;
870
871         dev->read_buffer = NULL;
872         dev->read_buffer_length = 0;
873         dev->read_packet_length = 0;
874         spin_lock_init (&dev->read_buffer_lock);
875         dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
876         dev->read_last_arrival = jiffies;
877
878         init_waitqueue_head (&dev->read_wait);
879         init_waitqueue_head (&dev->write_wait);
880
881         dev->interrupt_in_buffer = NULL;
882         dev->interrupt_in_endpoint = NULL;
883         dev->interrupt_in_urb = NULL;
884         dev->interrupt_in_running = 0;
885         dev->interrupt_in_done = 0;
886
887         dev->interrupt_out_buffer = NULL;
888         dev->interrupt_out_endpoint = NULL;
889         dev->interrupt_out_urb = NULL;
890         dev->interrupt_out_busy = 0;
891
892         iface_desc = interface->cur_altsetting;
893
894         /* set up the endpoint information */
895         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
896                 endpoint = &iface_desc->endpoint[i].desc;
897
898                 if (usb_endpoint_xfer_int(endpoint)) {
899                         if (usb_endpoint_dir_in(endpoint))
900                                 dev->interrupt_in_endpoint = endpoint;
901                         else
902                                 dev->interrupt_out_endpoint = endpoint;
903                 }
904         }
905         if(dev->interrupt_in_endpoint == NULL) {
906                 err("interrupt in endpoint not found");
907                 goto error;
908         }
909         if (dev->interrupt_out_endpoint == NULL) {
910                 err("interrupt out endpoint not found");
911                 goto error;
912         }
913
914         dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
915         if (!dev->read_buffer) {
916                 err("Couldn't allocate read_buffer");
917                 goto error;
918         }
919         dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL);
920         if (!dev->interrupt_in_buffer) {
921                 err("Couldn't allocate interrupt_in_buffer");
922                 goto error;
923         }
924         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
925         if (!dev->interrupt_in_urb) {
926                 err("Couldn't allocate interrupt_in_urb");
927                 goto error;
928         }
929         dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
930         if (!dev->interrupt_out_buffer) {
931                 err("Couldn't allocate interrupt_out_buffer");
932                 goto error;
933         }
934         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
935         if (!dev->interrupt_out_urb) {
936                 err("Couldn't allocate interrupt_out_urb");
937                 goto error;
938         }
939         dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
940         dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
941
942         /* we can register the device now, as it is ready */
943         usb_set_intfdata (interface, dev);
944
945         retval = usb_register_dev (interface, &tower_class);
946
947         if (retval) {
948                 /* something prevented us from registering this driver */
949                 err ("Not able to get a minor for this device.");
950                 usb_set_intfdata (interface, NULL);
951                 goto error;
952         }
953         dev->minor = interface->minor;
954
955         /* let the user know what node this device is now attached to */
956         dev_info(&interface->dev, "LEGO USB Tower #%d now attached to major "
957                  "%d minor %d\n", (dev->minor - LEGO_USB_TOWER_MINOR_BASE),
958                  USB_MAJOR, dev->minor);
959
960         /* get the firmware version and log it */
961         result = usb_control_msg (udev,
962                                   usb_rcvctrlpipe(udev, 0),
963                                   LEGO_USB_TOWER_REQUEST_GET_VERSION,
964                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
965                                   0,
966                                   0,
967                                   &get_version_reply,
968                                   sizeof(get_version_reply),
969                                   1000);
970         if (result < 0) {
971                 err("LEGO USB Tower get version control request failed");
972                 retval = result;
973                 goto error;
974         }
975         dev_info(&interface->dev, "LEGO USB Tower firmware version is %d.%d "
976                  "build %d\n", get_version_reply.major,
977                  get_version_reply.minor,
978                  le16_to_cpu(get_version_reply.build_no));
979
980
981 exit:
982         dbg(2, "%s: leave, return value 0x%.8lx (dev)", __func__, (long) dev);
983
984         return retval;
985
986 error:
987         tower_delete(dev);
988         return retval;
989 }
990
991
992 /**
993  *      tower_disconnect
994  *
995  *      Called by the usb core when the device is removed from the system.
996  */
997 static void tower_disconnect (struct usb_interface *interface)
998 {
999         struct lego_usb_tower *dev;
1000         int minor;
1001
1002         dbg(2, "%s: enter", __func__);
1003
1004         dev = usb_get_intfdata (interface);
1005         mutex_lock(&open_disc_mutex);
1006         usb_set_intfdata (interface, NULL);
1007
1008         minor = dev->minor;
1009
1010         /* give back our minor */
1011         usb_deregister_dev (interface, &tower_class);
1012
1013         mutex_lock(&dev->lock);
1014         mutex_unlock(&open_disc_mutex);
1015
1016         /* if the device is not opened, then we clean up right now */
1017         if (!dev->open_count) {
1018                 mutex_unlock(&dev->lock);
1019                 tower_delete (dev);
1020         } else {
1021                 dev->udev = NULL;
1022                 mutex_unlock(&dev->lock);
1023         }
1024
1025         dev_info(&interface->dev, "LEGO USB Tower #%d now disconnected\n",
1026                  (minor - LEGO_USB_TOWER_MINOR_BASE));
1027
1028         dbg(2, "%s: leave", __func__);
1029 }
1030
1031
1032
1033 /**
1034  *      lego_usb_tower_init
1035  */
1036 static int __init lego_usb_tower_init(void)
1037 {
1038         int result;
1039         int retval = 0;
1040
1041         dbg(2, "%s: enter", __func__);
1042
1043         /* register this driver with the USB subsystem */
1044         result = usb_register(&tower_driver);
1045         if (result < 0) {
1046                 err("usb_register failed for the "__FILE__" driver. Error number %d", result);
1047                 retval = -1;
1048                 goto exit;
1049         }
1050
1051         printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
1052                DRIVER_DESC "\n");
1053
1054 exit:
1055         dbg(2, "%s: leave, return value %d", __func__, retval);
1056
1057         return retval;
1058 }
1059
1060
1061 /**
1062  *      lego_usb_tower_exit
1063  */
1064 static void __exit lego_usb_tower_exit(void)
1065 {
1066         dbg(2, "%s: enter", __func__);
1067
1068         /* deregister this driver with the USB subsystem */
1069         usb_deregister (&tower_driver);
1070
1071         dbg(2, "%s: leave", __func__);
1072 }
1073
1074 module_init (lego_usb_tower_init);
1075 module_exit (lego_usb_tower_exit);
1076
1077 MODULE_AUTHOR(DRIVER_AUTHOR);
1078 MODULE_DESCRIPTION(DRIVER_DESC);
1079 #ifdef MODULE_LICENSE
1080 MODULE_LICENSE("GPL");
1081 #endif