[POWERPC] cell: add support for proper device-tree
[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/smp_lock.h>
84 #include <linux/completion.h>
85 #include <linux/mutex.h>
86 #include <asm/uaccess.h>
87 #include <linux/usb.h>
88 #include <linux/poll.h>
89
90
91 #ifdef CONFIG_USB_DEBUG
92         static int debug = 4;
93 #else
94         static int debug = 0;
95 #endif
96
97 /* Use our own dbg macro */
98 #undef dbg
99 #define dbg(lvl, format, arg...) do { if (debug >= lvl) printk(KERN_DEBUG  __FILE__ ": " format "\n", ## arg); } while (0)
100
101
102 /* Version Information */
103 #define DRIVER_VERSION "v0.96"
104 #define DRIVER_AUTHOR "Juergen Stuber <starblue@sourceforge.net>"
105 #define DRIVER_DESC "LEGO USB Tower Driver"
106
107 /* Module parameters */
108 module_param(debug, int, S_IRUGO | S_IWUSR);
109 MODULE_PARM_DESC(debug, "Debug enabled or not");
110
111 /* The defaults are chosen to work with the latest versions of leJOS and NQC.
112  */
113
114 /* Some legacy software likes to receive packets in one piece.
115  * In this case read_buffer_size should exceed the maximal packet length
116  * (417 for datalog uploads), and packet_timeout should be set.
117  */
118 static int read_buffer_size = 480;
119 module_param(read_buffer_size, int, 0);
120 MODULE_PARM_DESC(read_buffer_size, "Read buffer size");
121
122 /* Some legacy software likes to send packets in one piece.
123  * In this case write_buffer_size should exceed the maximal packet length
124  * (417 for firmware and program downloads).
125  * A problem with long writes is that the following read may time out
126  * if the software is not prepared to wait long enough.
127  */
128 static int write_buffer_size = 480;
129 module_param(write_buffer_size, int, 0);
130 MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
131
132 /* Some legacy software expects reads to contain whole LASM packets.
133  * To achieve this, characters which arrive before a packet timeout
134  * occurs will be returned in a single read operation.
135  * A problem with long reads is that the software may time out
136  * if it is not prepared to wait long enough.
137  * The packet timeout should be greater than the time between the
138  * reception of subsequent characters, which should arrive about
139  * every 5ms for the standard 2400 baud.
140  * Set it to 0 to disable.
141  */
142 static int packet_timeout = 50;
143 module_param(packet_timeout, int, 0);
144 MODULE_PARM_DESC(packet_timeout, "Packet timeout in ms");
145
146 /* Some legacy software expects blocking reads to time out.
147  * Timeout occurs after the specified time of read and write inactivity.
148  * Set it to 0 to disable.
149  */
150 static int read_timeout = 200;
151 module_param(read_timeout, int, 0);
152 MODULE_PARM_DESC(read_timeout, "Read timeout in ms");
153
154 /* As of kernel version 2.6.4 ehci-hcd uses an
155  * "only one interrupt transfer per frame" shortcut
156  * to simplify the scheduling of periodic transfers.
157  * This conflicts with our standard 1ms intervals for in and out URBs.
158  * We use default intervals of 2ms for in and 8ms for out transfers,
159  * which is fast enough for 2400 baud and allows a small additional load.
160  * Increase the interval to allow more devices that do interrupt transfers,
161  * or set to 0 to use the standard interval from the endpoint descriptors.
162  */
163 static int interrupt_in_interval = 2;
164 module_param(interrupt_in_interval, int, 0);
165 MODULE_PARM_DESC(interrupt_in_interval, "Interrupt in interval in ms");
166
167 static int interrupt_out_interval = 8;
168 module_param(interrupt_out_interval, int, 0);
169 MODULE_PARM_DESC(interrupt_out_interval, "Interrupt out interval in ms");
170
171 /* Define these values to match your device */
172 #define LEGO_USB_TOWER_VENDOR_ID        0x0694
173 #define LEGO_USB_TOWER_PRODUCT_ID       0x0001
174
175 /* Vendor requests */
176 #define LEGO_USB_TOWER_REQUEST_RESET            0x04
177 #define LEGO_USB_TOWER_REQUEST_GET_VERSION      0xFD
178
179 struct tower_reset_reply {
180         __le16 size;            /* little-endian */
181         __u8 err_code;
182         __u8 spare;
183 } __attribute__ ((packed));
184
185 struct tower_get_version_reply {
186         __le16 size;            /* little-endian */
187         __u8 err_code;
188         __u8 spare;
189         __u8 major;
190         __u8 minor;
191         __le16 build_no;                /* little-endian */
192 } __attribute__ ((packed));
193
194
195 /* table of devices that work with this driver */
196 static struct usb_device_id tower_table [] = {
197         { USB_DEVICE(LEGO_USB_TOWER_VENDOR_ID, LEGO_USB_TOWER_PRODUCT_ID) },
198         { }                                     /* Terminating entry */
199 };
200
201 MODULE_DEVICE_TABLE (usb, tower_table);
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 semaphore        sem;            /* 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 /* prevent races between open() and disconnect */
259 static DEFINE_MUTEX (disconnect_mutex);
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 /*
273  * usb class driver info in order to get a minor number from the usb core,
274  * and to have the device registered with the driver core
275  */
276 static struct usb_class_driver tower_class = {
277         .name =         "legousbtower%d",
278         .fops =         &tower_fops,
279         .minor_base =   LEGO_USB_TOWER_MINOR_BASE,
280 };
281
282
283 /* usb specific object needed to register this driver with the usb subsystem */
284 static struct usb_driver tower_driver = {
285         .name =         "legousbtower",
286         .probe =        tower_probe,
287         .disconnect =   tower_disconnect,
288         .id_table =     tower_table,
289 };
290
291
292 /**
293  *      lego_usb_tower_debug_data
294  */
295 static inline void lego_usb_tower_debug_data (int level, const char *function, int size, const unsigned char *data)
296 {
297         int i;
298
299         if (debug < level)
300                 return;
301
302         printk (KERN_DEBUG __FILE__": %s - length = %d, data = ", function, size);
303         for (i = 0; i < size; ++i) {
304                 printk ("%.2x ", data[i]);
305         }
306         printk ("\n");
307 }
308
309
310 /**
311  *      tower_delete
312  */
313 static inline void tower_delete (struct lego_usb_tower *dev)
314 {
315         dbg(2, "%s: enter", __FUNCTION__);
316
317         tower_abort_transfers (dev);
318
319         /* free data structures */
320         usb_free_urb(dev->interrupt_in_urb);
321         usb_free_urb(dev->interrupt_out_urb);
322         kfree (dev->read_buffer);
323         kfree (dev->interrupt_in_buffer);
324         kfree (dev->interrupt_out_buffer);
325         kfree (dev);
326
327         dbg(2, "%s: leave", __FUNCTION__);
328 }
329
330
331 /**
332  *      tower_open
333  */
334 static int tower_open (struct inode *inode, struct file *file)
335 {
336         struct lego_usb_tower *dev = NULL;
337         int subminor;
338         int retval = 0;
339         struct usb_interface *interface;
340         struct tower_reset_reply reset_reply;
341         int result;
342
343         dbg(2, "%s: enter", __FUNCTION__);
344
345         nonseekable_open(inode, file);
346         subminor = iminor(inode);
347
348         mutex_lock (&disconnect_mutex);
349
350         interface = usb_find_interface (&tower_driver, subminor);
351
352         if (!interface) {
353                 err ("%s - error, can't find device for minor %d",
354                      __FUNCTION__, subminor);
355                 retval = -ENODEV;
356                 goto unlock_disconnect_exit;
357         }
358
359         dev = usb_get_intfdata(interface);
360
361         if (!dev) {
362                 retval = -ENODEV;
363                 goto unlock_disconnect_exit;
364         }
365
366         /* lock this device */
367         if (down_interruptible (&dev->sem)) {
368                 retval = -ERESTARTSYS;
369                 goto unlock_disconnect_exit;
370         }
371
372         /* allow opening only once */
373         if (dev->open_count) {
374                 retval = -EBUSY;
375                 goto unlock_exit;
376         }
377         dev->open_count = 1;
378
379         /* reset the tower */
380         result = usb_control_msg (dev->udev,
381                                   usb_rcvctrlpipe(dev->udev, 0),
382                                   LEGO_USB_TOWER_REQUEST_RESET,
383                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
384                                   0,
385                                   0,
386                                   &reset_reply,
387                                   sizeof(reset_reply),
388                                   1000);
389         if (result < 0) {
390                 err("LEGO USB Tower reset control request failed");
391                 retval = result;
392                 goto unlock_exit;
393         }
394
395         /* initialize in direction */
396         dev->read_buffer_length = 0;
397         dev->read_packet_length = 0;
398         usb_fill_int_urb (dev->interrupt_in_urb,
399                           dev->udev,
400                           usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
401                           dev->interrupt_in_buffer,
402                           le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
403                           tower_interrupt_in_callback,
404                           dev,
405                           dev->interrupt_in_interval);
406
407         dev->interrupt_in_running = 1;
408         dev->interrupt_in_done = 0;
409         mb();
410
411         retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
412         if (retval) {
413                 err("Couldn't submit interrupt_in_urb %d", retval);
414                 dev->interrupt_in_running = 0;
415                 dev->open_count = 0;
416                 goto unlock_exit;
417         }
418
419         /* save device in the file's private structure */
420         file->private_data = dev;
421
422 unlock_exit:
423         up (&dev->sem);
424
425 unlock_disconnect_exit:
426         mutex_unlock (&disconnect_mutex);
427
428         dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval);
429
430         return retval;
431 }
432
433 /**
434  *      tower_release
435  */
436 static int tower_release (struct inode *inode, struct file *file)
437 {
438         struct lego_usb_tower *dev;
439         int retval = 0;
440
441         dbg(2, "%s: enter", __FUNCTION__);
442
443         dev = (struct lego_usb_tower *)file->private_data;
444
445         if (dev == NULL) {
446                 dbg(1, "%s: object is NULL", __FUNCTION__);
447                 retval = -ENODEV;
448                 goto exit;
449         }
450
451         if (down_interruptible (&dev->sem)) {
452                 retval = -ERESTARTSYS;
453                 goto exit;
454         }
455
456         if (dev->open_count != 1) {
457                 dbg(1, "%s: device not opened exactly once", __FUNCTION__);
458                 retval = -ENODEV;
459                 goto unlock_exit;
460         }
461         if (dev->udev == NULL) {
462                 /* the device was unplugged before the file was released */
463                 up (&dev->sem); /* unlock here as tower_delete frees dev */
464                 tower_delete (dev);
465                 goto exit;
466         }
467
468         /* wait until write transfer is finished */
469         if (dev->interrupt_out_busy) {
470                 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
471         }
472         tower_abort_transfers (dev);
473         dev->open_count = 0;
474
475 unlock_exit:
476         up (&dev->sem);
477
478 exit:
479         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
480         return retval;
481 }
482
483
484 /**
485  *      tower_abort_transfers
486  *      aborts transfers and frees associated data structures
487  */
488 static void tower_abort_transfers (struct lego_usb_tower *dev)
489 {
490         dbg(2, "%s: enter", __FUNCTION__);
491
492         if (dev == NULL) {
493                 dbg(1, "%s: dev is null", __FUNCTION__);
494                 goto exit;
495         }
496
497         /* shutdown transfer */
498         if (dev->interrupt_in_running) {
499                 dev->interrupt_in_running = 0;
500                 mb();
501                 if (dev->udev)
502                         usb_kill_urb (dev->interrupt_in_urb);
503         }
504         if (dev->interrupt_out_busy && dev->udev)
505                 usb_kill_urb(dev->interrupt_out_urb);
506
507 exit:
508         dbg(2, "%s: leave", __FUNCTION__);
509 }
510
511
512 /**
513  *      tower_check_for_read_packet
514  *
515  *      To get correct semantics for signals and non-blocking I/O
516  *      with packetizing we pretend not to see any data in the read buffer
517  *      until it has been there unchanged for at least
518  *      dev->packet_timeout_jiffies, or until the buffer is full.
519  */
520 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
521 {
522         spin_lock_irq (&dev->read_buffer_lock);
523         if (!packet_timeout
524             || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
525             || dev->read_buffer_length == read_buffer_size) {
526                 dev->read_packet_length = dev->read_buffer_length;
527         }
528         dev->interrupt_in_done = 0;
529         spin_unlock_irq (&dev->read_buffer_lock);
530 }
531
532
533 /**
534  *      tower_poll
535  */
536 static unsigned int tower_poll (struct file *file, poll_table *wait)
537 {
538         struct lego_usb_tower *dev;
539         unsigned int mask = 0;
540
541         dbg(2, "%s: enter", __FUNCTION__);
542
543         dev = file->private_data;
544
545         poll_wait(file, &dev->read_wait, wait);
546         poll_wait(file, &dev->write_wait, wait);
547
548         tower_check_for_read_packet(dev);
549         if (dev->read_packet_length > 0) {
550                 mask |= POLLIN | POLLRDNORM;
551         }
552         if (!dev->interrupt_out_busy) {
553                 mask |= POLLOUT | POLLWRNORM;
554         }
555
556         dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask);
557
558         return mask;
559 }
560
561
562 /**
563  *      tower_llseek
564  */
565 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
566 {
567         return -ESPIPE;         /* unseekable */
568 }
569
570
571 /**
572  *      tower_read
573  */
574 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
575 {
576         struct lego_usb_tower *dev;
577         size_t bytes_to_read;
578         int i;
579         int retval = 0;
580         unsigned long timeout = 0;
581
582         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
583
584         dev = (struct lego_usb_tower *)file->private_data;
585
586         /* lock this object */
587         if (down_interruptible (&dev->sem)) {
588                 retval = -ERESTARTSYS;
589                 goto exit;
590         }
591
592         /* verify that the device wasn't unplugged */
593         if (dev->udev == NULL) {
594                 retval = -ENODEV;
595                 err("No device or device unplugged %d", retval);
596                 goto unlock_exit;
597         }
598
599         /* verify that we actually have some data to read */
600         if (count == 0) {
601                 dbg(1, "%s: read request of 0 bytes", __FUNCTION__);
602                 goto unlock_exit;
603         }
604
605         if (read_timeout) {
606                 timeout = jiffies + read_timeout * HZ / 1000;
607         }
608
609         /* wait for data */
610         tower_check_for_read_packet (dev);
611         while (dev->read_packet_length == 0) {
612                 if (file->f_flags & O_NONBLOCK) {
613                         retval = -EAGAIN;
614                         goto unlock_exit;
615                 }
616                 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
617                 if (retval < 0) {
618                         goto unlock_exit;
619                 }
620
621                 /* reset read timeout during read or write activity */
622                 if (read_timeout
623                     && (dev->read_buffer_length || dev->interrupt_out_busy)) {
624                         timeout = jiffies + read_timeout * HZ / 1000;
625                 }
626                 /* check for read timeout */
627                 if (read_timeout && time_after (jiffies, timeout)) {
628                         retval = -ETIMEDOUT;
629                         goto unlock_exit;
630                 }
631                 tower_check_for_read_packet (dev);
632         }
633
634         /* copy the data from read_buffer into userspace */
635         bytes_to_read = min(count, dev->read_packet_length);
636
637         if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
638                 retval = -EFAULT;
639                 goto unlock_exit;
640         }
641
642         spin_lock_irq (&dev->read_buffer_lock);
643         dev->read_buffer_length -= bytes_to_read;
644         dev->read_packet_length -= bytes_to_read;
645         for (i=0; i<dev->read_buffer_length; i++) {
646                 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
647         }
648         spin_unlock_irq (&dev->read_buffer_lock);
649
650         retval = bytes_to_read;
651
652 unlock_exit:
653         /* unlock the device */
654         up (&dev->sem);
655
656 exit:
657         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
658         return retval;
659 }
660
661
662 /**
663  *      tower_write
664  */
665 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
666 {
667         struct lego_usb_tower *dev;
668         size_t bytes_to_write;
669         int retval = 0;
670
671         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
672
673         dev = (struct lego_usb_tower *)file->private_data;
674
675         /* lock this object */
676         if (down_interruptible (&dev->sem)) {
677                 retval = -ERESTARTSYS;
678                 goto exit;
679         }
680
681         /* verify that the device wasn't unplugged */
682         if (dev->udev == NULL) {
683                 retval = -ENODEV;
684                 err("No device or device unplugged %d", retval);
685                 goto unlock_exit;
686         }
687
688         /* verify that we actually have some data to write */
689         if (count == 0) {
690                 dbg(1, "%s: write request of 0 bytes", __FUNCTION__);
691                 goto unlock_exit;
692         }
693
694         /* wait until previous transfer is finished */
695         while (dev->interrupt_out_busy) {
696                 if (file->f_flags & O_NONBLOCK) {
697                         retval = -EAGAIN;
698                         goto unlock_exit;
699                 }
700                 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
701                 if (retval) {
702                         goto unlock_exit;
703                 }
704         }
705
706         /* write the data into interrupt_out_buffer from userspace */
707         bytes_to_write = min_t(int, count, write_buffer_size);
708         dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write);
709
710         if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
711                 retval = -EFAULT;
712                 goto unlock_exit;
713         }
714
715         /* send off the urb */
716         usb_fill_int_urb(dev->interrupt_out_urb,
717                          dev->udev,
718                          usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
719                          dev->interrupt_out_buffer,
720                          bytes_to_write,
721                          tower_interrupt_out_callback,
722                          dev,
723                          dev->interrupt_out_interval);
724
725         dev->interrupt_out_busy = 1;
726         wmb();
727
728         retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
729         if (retval) {
730                 dev->interrupt_out_busy = 0;
731                 err("Couldn't submit interrupt_out_urb %d", retval);
732                 goto unlock_exit;
733         }
734         retval = bytes_to_write;
735
736 unlock_exit:
737         /* unlock the device */
738         up (&dev->sem);
739
740 exit:
741         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
742
743         return retval;
744 }
745
746
747 /**
748  *      tower_interrupt_in_callback
749  */
750 static void tower_interrupt_in_callback (struct urb *urb)
751 {
752         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
753         int retval;
754
755         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
756
757         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
758
759         if (urb->status) {
760                 if (urb->status == -ENOENT ||
761                     urb->status == -ECONNRESET ||
762                     urb->status == -ESHUTDOWN) {
763                         goto exit;
764                 } else {
765                         dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status);
766                         goto resubmit; /* maybe we can recover */
767                 }
768         }
769
770         if (urb->actual_length > 0) {
771                 spin_lock (&dev->read_buffer_lock);
772                 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
773                         memcpy (dev->read_buffer + dev->read_buffer_length,
774                                 dev->interrupt_in_buffer,
775                                 urb->actual_length);
776                         dev->read_buffer_length += urb->actual_length;
777                         dev->read_last_arrival = jiffies;
778                         dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length);
779                 } else {
780                         printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length);
781                 }
782                 spin_unlock (&dev->read_buffer_lock);
783         }
784
785 resubmit:
786         /* resubmit if we're still running */
787         if (dev->interrupt_in_running && dev->udev) {
788                 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
789                 if (retval) {
790                         err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval);
791                 }
792         }
793
794 exit:
795         dev->interrupt_in_done = 1;
796         wake_up_interruptible (&dev->read_wait);
797
798         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
799         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
800 }
801
802
803 /**
804  *      tower_interrupt_out_callback
805  */
806 static void tower_interrupt_out_callback (struct urb *urb)
807 {
808         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
809
810         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
811         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
812
813         /* sync/async unlink faults aren't errors */
814         if (urb->status && !(urb->status == -ENOENT ||
815                              urb->status == -ECONNRESET ||
816                              urb->status == -ESHUTDOWN)) {
817                 dbg(1, "%s - nonzero write bulk status received: %d",
818                     __FUNCTION__, urb->status);
819         }
820
821         dev->interrupt_out_busy = 0;
822         wake_up_interruptible(&dev->write_wait);
823
824         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
825         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
826 }
827
828
829 /**
830  *      tower_probe
831  *
832  *      Called by the usb core when a new device is connected that it thinks
833  *      this driver might be interested in.
834  */
835 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
836 {
837         struct usb_device *udev = interface_to_usbdev(interface);
838         struct lego_usb_tower *dev = NULL;
839         struct usb_host_interface *iface_desc;
840         struct usb_endpoint_descriptor* endpoint;
841         struct tower_get_version_reply get_version_reply;
842         int i;
843         int retval = -ENOMEM;
844         int result;
845
846         dbg(2, "%s: enter", __FUNCTION__);
847
848         if (udev == NULL) {
849                 info ("udev is NULL.");
850         }
851
852         /* allocate memory for our device state and initialize it */
853
854         dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
855
856         if (dev == NULL) {
857                 err ("Out of memory");
858                 goto exit;
859         }
860
861         init_MUTEX (&dev->sem);
862
863         dev->udev = udev;
864         dev->open_count = 0;
865
866         dev->read_buffer = NULL;
867         dev->read_buffer_length = 0;
868         dev->read_packet_length = 0;
869         spin_lock_init (&dev->read_buffer_lock);
870         dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
871         dev->read_last_arrival = jiffies;
872
873         init_waitqueue_head (&dev->read_wait);
874         init_waitqueue_head (&dev->write_wait);
875
876         dev->interrupt_in_buffer = NULL;
877         dev->interrupt_in_endpoint = NULL;
878         dev->interrupt_in_urb = NULL;
879         dev->interrupt_in_running = 0;
880         dev->interrupt_in_done = 0;
881
882         dev->interrupt_out_buffer = NULL;
883         dev->interrupt_out_endpoint = NULL;
884         dev->interrupt_out_urb = NULL;
885         dev->interrupt_out_busy = 0;
886
887         iface_desc = interface->cur_altsetting;
888
889         /* set up the endpoint information */
890         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
891                 endpoint = &iface_desc->endpoint[i].desc;
892
893                 if (usb_endpoint_xfer_int(endpoint)) {
894                         if (usb_endpoint_dir_in(endpoint))
895                                 dev->interrupt_in_endpoint = endpoint;
896                         else
897                                 dev->interrupt_out_endpoint = endpoint;
898                 }
899         }
900         if(dev->interrupt_in_endpoint == NULL) {
901                 err("interrupt in endpoint not found");
902                 goto error;
903         }
904         if (dev->interrupt_out_endpoint == NULL) {
905                 err("interrupt out endpoint not found");
906                 goto error;
907         }
908
909         dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
910         if (!dev->read_buffer) {
911                 err("Couldn't allocate read_buffer");
912                 goto error;
913         }
914         dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL);
915         if (!dev->interrupt_in_buffer) {
916                 err("Couldn't allocate interrupt_in_buffer");
917                 goto error;
918         }
919         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
920         if (!dev->interrupt_in_urb) {
921                 err("Couldn't allocate interrupt_in_urb");
922                 goto error;
923         }
924         dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
925         if (!dev->interrupt_out_buffer) {
926                 err("Couldn't allocate interrupt_out_buffer");
927                 goto error;
928         }
929         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
930         if (!dev->interrupt_out_urb) {
931                 err("Couldn't allocate interrupt_out_urb");
932                 goto error;
933         }
934         dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
935         dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
936
937         /* we can register the device now, as it is ready */
938         usb_set_intfdata (interface, dev);
939
940         retval = usb_register_dev (interface, &tower_class);
941
942         if (retval) {
943                 /* something prevented us from registering this driver */
944                 err ("Not able to get a minor for this device.");
945                 usb_set_intfdata (interface, NULL);
946                 goto error;
947         }
948         dev->minor = interface->minor;
949
950         /* let the user know what node this device is now attached to */
951         info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor);
952
953         /* get the firmware version and log it */
954         result = usb_control_msg (udev,
955                                   usb_rcvctrlpipe(udev, 0),
956                                   LEGO_USB_TOWER_REQUEST_GET_VERSION,
957                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
958                                   0,
959                                   0,
960                                   &get_version_reply,
961                                   sizeof(get_version_reply),
962                                   1000);
963         if (result < 0) {
964                 err("LEGO USB Tower get version control request failed");
965                 retval = result;
966                 goto error;
967         }
968         info("LEGO USB Tower firmware version is %d.%d build %d",
969              get_version_reply.major,
970              get_version_reply.minor,
971              le16_to_cpu(get_version_reply.build_no));
972
973
974 exit:
975         dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev);
976
977         return retval;
978
979 error:
980         tower_delete(dev);
981         return retval;
982 }
983
984
985 /**
986  *      tower_disconnect
987  *
988  *      Called by the usb core when the device is removed from the system.
989  */
990 static void tower_disconnect (struct usb_interface *interface)
991 {
992         struct lego_usb_tower *dev;
993         int minor;
994
995         dbg(2, "%s: enter", __FUNCTION__);
996
997         mutex_lock (&disconnect_mutex);
998
999         dev = usb_get_intfdata (interface);
1000         usb_set_intfdata (interface, NULL);
1001
1002
1003         down (&dev->sem);
1004
1005         minor = dev->minor;
1006
1007         /* give back our minor */
1008         usb_deregister_dev (interface, &tower_class);
1009
1010         /* if the device is not opened, then we clean up right now */
1011         if (!dev->open_count) {
1012                 up (&dev->sem);
1013                 tower_delete (dev);
1014         } else {
1015                 dev->udev = NULL;
1016                 up (&dev->sem);
1017         }
1018
1019         mutex_unlock (&disconnect_mutex);
1020
1021         info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE));
1022
1023         dbg(2, "%s: leave", __FUNCTION__);
1024 }
1025
1026
1027
1028 /**
1029  *      lego_usb_tower_init
1030  */
1031 static int __init lego_usb_tower_init(void)
1032 {
1033         int result;
1034         int retval = 0;
1035
1036         dbg(2, "%s: enter", __FUNCTION__);
1037
1038         /* register this driver with the USB subsystem */
1039         result = usb_register(&tower_driver);
1040         if (result < 0) {
1041                 err("usb_register failed for the "__FILE__" driver. Error number %d", result);
1042                 retval = -1;
1043                 goto exit;
1044         }
1045
1046         info(DRIVER_DESC " " DRIVER_VERSION);
1047
1048 exit:
1049         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
1050
1051         return retval;
1052 }
1053
1054
1055 /**
1056  *      lego_usb_tower_exit
1057  */
1058 static void __exit lego_usb_tower_exit(void)
1059 {
1060         dbg(2, "%s: enter", __FUNCTION__);
1061
1062         /* deregister this driver with the USB subsystem */
1063         usb_deregister (&tower_driver);
1064
1065         dbg(2, "%s: leave", __FUNCTION__);
1066 }
1067
1068 module_init (lego_usb_tower_init);
1069 module_exit (lego_usb_tower_exit);
1070
1071 MODULE_AUTHOR(DRIVER_AUTHOR);
1072 MODULE_DESCRIPTION(DRIVER_DESC);
1073 #ifdef MODULE_LICENSE
1074 MODULE_LICENSE("GPL");
1075 #endif