[PATCH] USB: remove .owner field from struct usb_driver
[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 __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/config.h>
79 #include <linux/kernel.h>
80 #include <linux/errno.h>
81 #include <linux/init.h>
82 #include <linux/slab.h>
83 #include <linux/module.h>
84 #include <linux/smp_lock.h>
85 #include <linux/completion.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, struct pt_regs *regs);
252 static void tower_interrupt_out_callback (struct urb *urb, struct pt_regs *regs);
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 DECLARE_MUTEX (disconnect_sem);
260
261 /* file operations needed when we register this driver */
262 static 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         if (dev->interrupt_in_urb != NULL) {
321                 usb_free_urb (dev->interrupt_in_urb);
322         }
323         if (dev->interrupt_out_urb != NULL) {
324                 usb_free_urb (dev->interrupt_out_urb);
325         }
326         kfree (dev->read_buffer);
327         kfree (dev->interrupt_in_buffer);
328         kfree (dev->interrupt_out_buffer);
329         kfree (dev);
330
331         dbg(2, "%s: leave", __FUNCTION__);
332 }
333
334
335 /**
336  *      tower_open
337  */
338 static int tower_open (struct inode *inode, struct file *file)
339 {
340         struct lego_usb_tower *dev = NULL;
341         int subminor;
342         int retval = 0;
343         struct usb_interface *interface;
344         struct tower_reset_reply reset_reply;
345         int result;
346
347         dbg(2, "%s: enter", __FUNCTION__);
348
349         nonseekable_open(inode, file);
350         subminor = iminor(inode);
351
352         down (&disconnect_sem);
353
354         interface = usb_find_interface (&tower_driver, subminor);
355
356         if (!interface) {
357                 err ("%s - error, can't find device for minor %d",
358                      __FUNCTION__, subminor);
359                 retval = -ENODEV;
360                 goto unlock_disconnect_exit;
361         }
362
363         dev = usb_get_intfdata(interface);
364
365         if (!dev) {
366                 retval = -ENODEV;
367                 goto unlock_disconnect_exit;
368         }
369
370         /* lock this device */
371         if (down_interruptible (&dev->sem)) {
372                 retval = -ERESTARTSYS;
373                 goto unlock_disconnect_exit;
374         }
375
376         /* allow opening only once */
377         if (dev->open_count) {
378                 retval = -EBUSY;
379                 goto unlock_exit;
380         }
381         dev->open_count = 1;
382
383         /* reset the tower */
384         result = usb_control_msg (dev->udev,
385                                   usb_rcvctrlpipe(dev->udev, 0),
386                                   LEGO_USB_TOWER_REQUEST_RESET,
387                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
388                                   0,
389                                   0,
390                                   &reset_reply,
391                                   sizeof(reset_reply),
392                                   1000);
393         if (result < 0) {
394                 err("LEGO USB Tower reset control request failed");
395                 retval = result;
396                 goto unlock_exit;
397         }
398
399         /* initialize in direction */
400         dev->read_buffer_length = 0;
401         dev->read_packet_length = 0;
402         usb_fill_int_urb (dev->interrupt_in_urb,
403                           dev->udev,
404                           usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress),
405                           dev->interrupt_in_buffer,
406                           le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
407                           tower_interrupt_in_callback,
408                           dev,
409                           dev->interrupt_in_interval);
410
411         dev->interrupt_in_running = 1;
412         dev->interrupt_in_done = 0;
413         mb();
414
415         retval = usb_submit_urb (dev->interrupt_in_urb, GFP_KERNEL);
416         if (retval) {
417                 err("Couldn't submit interrupt_in_urb %d", retval);
418                 dev->interrupt_in_running = 0;
419                 dev->open_count = 0;
420                 goto unlock_exit;
421         }
422
423         /* save device in the file's private structure */
424         file->private_data = dev;
425
426 unlock_exit:
427         up (&dev->sem);
428
429 unlock_disconnect_exit:
430         up (&disconnect_sem);
431
432         dbg(2, "%s: leave, return value %d ", __FUNCTION__, retval);
433
434         return retval;
435 }
436
437 /**
438  *      tower_release
439  */
440 static int tower_release (struct inode *inode, struct file *file)
441 {
442         struct lego_usb_tower *dev;
443         int retval = 0;
444
445         dbg(2, "%s: enter", __FUNCTION__);
446
447         dev = (struct lego_usb_tower *)file->private_data;
448
449         if (dev == NULL) {
450                 dbg(1, "%s: object is NULL", __FUNCTION__);
451                 retval = -ENODEV;
452                 goto exit;
453         }
454
455         if (down_interruptible (&dev->sem)) {
456                 retval = -ERESTARTSYS;
457                 goto exit;
458         }
459
460         if (dev->open_count != 1) {
461                 dbg(1, "%s: device not opened exactly once", __FUNCTION__);
462                 retval = -ENODEV;
463                 goto unlock_exit;
464         }
465         if (dev->udev == NULL) {
466                 /* the device was unplugged before the file was released */
467                 up (&dev->sem); /* unlock here as tower_delete frees dev */
468                 tower_delete (dev);
469                 goto exit;
470         }
471
472         /* wait until write transfer is finished */
473         if (dev->interrupt_out_busy) {
474                 wait_event_interruptible_timeout (dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
475         }
476         tower_abort_transfers (dev);
477         dev->open_count = 0;
478
479 unlock_exit:
480         up (&dev->sem);
481
482 exit:
483         dbg(2, "%s: leave, return value %d", __FUNCTION__, 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", __FUNCTION__);
495
496         if (dev == NULL) {
497                 dbg(1, "%s: dev is null", __FUNCTION__);
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->interrupt_in_urb != NULL && dev->udev) {
506                         usb_kill_urb (dev->interrupt_in_urb);
507                 }
508         }
509         if (dev->interrupt_out_busy) {
510                 if (dev->interrupt_out_urb != NULL && dev->udev) {
511                         usb_kill_urb (dev->interrupt_out_urb);
512                 }
513         }
514
515 exit:
516         dbg(2, "%s: leave", __FUNCTION__);
517 }
518
519
520 /**
521  *      tower_check_for_read_packet
522  *
523  *      To get correct semantics for signals and non-blocking I/O
524  *      with packetizing we pretend not to see any data in the read buffer
525  *      until it has been there unchanged for at least
526  *      dev->packet_timeout_jiffies, or until the buffer is full.
527  */
528 static void tower_check_for_read_packet (struct lego_usb_tower *dev)
529 {
530         spin_lock_irq (&dev->read_buffer_lock);
531         if (!packet_timeout
532             || time_after(jiffies, dev->read_last_arrival + dev->packet_timeout_jiffies)
533             || dev->read_buffer_length == read_buffer_size) {
534                 dev->read_packet_length = dev->read_buffer_length;
535         }
536         dev->interrupt_in_done = 0;
537         spin_unlock_irq (&dev->read_buffer_lock);
538 }
539
540
541 /**
542  *      tower_poll
543  */
544 static unsigned int tower_poll (struct file *file, poll_table *wait)
545 {
546         struct lego_usb_tower *dev;
547         unsigned int mask = 0;
548
549         dbg(2, "%s: enter", __FUNCTION__);
550
551         dev = file->private_data;
552
553         poll_wait(file, &dev->read_wait, wait);
554         poll_wait(file, &dev->write_wait, wait);
555
556         tower_check_for_read_packet(dev);
557         if (dev->read_packet_length > 0) {
558                 mask |= POLLIN | POLLRDNORM;
559         }
560         if (!dev->interrupt_out_busy) {
561                 mask |= POLLOUT | POLLWRNORM;
562         }
563
564         dbg(2, "%s: leave, mask = %d", __FUNCTION__, mask);
565
566         return mask;
567 }
568
569
570 /**
571  *      tower_llseek
572  */
573 static loff_t tower_llseek (struct file *file, loff_t off, int whence)
574 {
575         return -ESPIPE;         /* unseekable */
576 }
577
578
579 /**
580  *      tower_read
581  */
582 static ssize_t tower_read (struct file *file, char __user *buffer, size_t count, loff_t *ppos)
583 {
584         struct lego_usb_tower *dev;
585         size_t bytes_to_read;
586         int i;
587         int retval = 0;
588         unsigned long timeout = 0;
589
590         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
591
592         dev = (struct lego_usb_tower *)file->private_data;
593
594         /* lock this object */
595         if (down_interruptible (&dev->sem)) {
596                 retval = -ERESTARTSYS;
597                 goto exit;
598         }
599
600         /* verify that the device wasn't unplugged */
601         if (dev->udev == NULL) {
602                 retval = -ENODEV;
603                 err("No device or device unplugged %d", retval);
604                 goto unlock_exit;
605         }
606
607         /* verify that we actually have some data to read */
608         if (count == 0) {
609                 dbg(1, "%s: read request of 0 bytes", __FUNCTION__);
610                 goto unlock_exit;
611         }
612
613         if (read_timeout) {
614                 timeout = jiffies + read_timeout * HZ / 1000;
615         }
616
617         /* wait for data */
618         tower_check_for_read_packet (dev);
619         while (dev->read_packet_length == 0) {
620                 if (file->f_flags & O_NONBLOCK) {
621                         retval = -EAGAIN;
622                         goto unlock_exit;
623                 }
624                 retval = wait_event_interruptible_timeout(dev->read_wait, dev->interrupt_in_done, dev->packet_timeout_jiffies);
625                 if (retval < 0) {
626                         goto unlock_exit;
627                 }
628
629                 /* reset read timeout during read or write activity */
630                 if (read_timeout
631                     && (dev->read_buffer_length || dev->interrupt_out_busy)) {
632                         timeout = jiffies + read_timeout * HZ / 1000;
633                 }
634                 /* check for read timeout */
635                 if (read_timeout && time_after (jiffies, timeout)) {
636                         retval = -ETIMEDOUT;
637                         goto unlock_exit;
638                 }
639                 tower_check_for_read_packet (dev);
640         }
641
642         /* copy the data from read_buffer into userspace */
643         bytes_to_read = min(count, dev->read_packet_length);
644
645         if (copy_to_user (buffer, dev->read_buffer, bytes_to_read)) {
646                 retval = -EFAULT;
647                 goto unlock_exit;
648         }
649
650         spin_lock_irq (&dev->read_buffer_lock);
651         dev->read_buffer_length -= bytes_to_read;
652         dev->read_packet_length -= bytes_to_read;
653         for (i=0; i<dev->read_buffer_length; i++) {
654                 dev->read_buffer[i] = dev->read_buffer[i+bytes_to_read];
655         }
656         spin_unlock_irq (&dev->read_buffer_lock);
657
658         retval = bytes_to_read;
659
660 unlock_exit:
661         /* unlock the device */
662         up (&dev->sem);
663
664 exit:
665         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
666         return retval;
667 }
668
669
670 /**
671  *      tower_write
672  */
673 static ssize_t tower_write (struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
674 {
675         struct lego_usb_tower *dev;
676         size_t bytes_to_write;
677         int retval = 0;
678
679         dbg(2, "%s: enter, count = %Zd", __FUNCTION__, count);
680
681         dev = (struct lego_usb_tower *)file->private_data;
682
683         /* lock this object */
684         if (down_interruptible (&dev->sem)) {
685                 retval = -ERESTARTSYS;
686                 goto exit;
687         }
688
689         /* verify that the device wasn't unplugged */
690         if (dev->udev == NULL) {
691                 retval = -ENODEV;
692                 err("No device or device unplugged %d", retval);
693                 goto unlock_exit;
694         }
695
696         /* verify that we actually have some data to write */
697         if (count == 0) {
698                 dbg(1, "%s: write request of 0 bytes", __FUNCTION__);
699                 goto unlock_exit;
700         }
701
702         /* wait until previous transfer is finished */
703         while (dev->interrupt_out_busy) {
704                 if (file->f_flags & O_NONBLOCK) {
705                         retval = -EAGAIN;
706                         goto unlock_exit;
707                 }
708                 retval = wait_event_interruptible (dev->write_wait, !dev->interrupt_out_busy);
709                 if (retval) {
710                         goto unlock_exit;
711                 }
712         }
713
714         /* write the data into interrupt_out_buffer from userspace */
715         bytes_to_write = min_t(int, count, write_buffer_size);
716         dbg(4, "%s: count = %Zd, bytes_to_write = %Zd", __FUNCTION__, count, bytes_to_write);
717
718         if (copy_from_user (dev->interrupt_out_buffer, buffer, bytes_to_write)) {
719                 retval = -EFAULT;
720                 goto unlock_exit;
721         }
722
723         /* send off the urb */
724         usb_fill_int_urb(dev->interrupt_out_urb,
725                          dev->udev,
726                          usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
727                          dev->interrupt_out_buffer,
728                          bytes_to_write,
729                          tower_interrupt_out_callback,
730                          dev,
731                          dev->interrupt_out_interval);
732
733         dev->interrupt_out_busy = 1;
734         wmb();
735
736         retval = usb_submit_urb (dev->interrupt_out_urb, GFP_KERNEL);
737         if (retval) {
738                 dev->interrupt_out_busy = 0;
739                 err("Couldn't submit interrupt_out_urb %d", retval);
740                 goto unlock_exit;
741         }
742         retval = bytes_to_write;
743
744 unlock_exit:
745         /* unlock the device */
746         up (&dev->sem);
747
748 exit:
749         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
750
751         return retval;
752 }
753
754
755 /**
756  *      tower_interrupt_in_callback
757  */
758 static void tower_interrupt_in_callback (struct urb *urb, struct pt_regs *regs)
759 {
760         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
761         int retval;
762
763         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
764
765         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
766
767         if (urb->status) {
768                 if (urb->status == -ENOENT ||
769                     urb->status == -ECONNRESET ||
770                     urb->status == -ESHUTDOWN) {
771                         goto exit;
772                 } else {
773                         dbg(1, "%s: nonzero status received: %d", __FUNCTION__, urb->status);
774                         goto resubmit; /* maybe we can recover */
775                 }
776         }
777
778         if (urb->actual_length > 0) {
779                 spin_lock (&dev->read_buffer_lock);
780                 if (dev->read_buffer_length + urb->actual_length < read_buffer_size) {
781                         memcpy (dev->read_buffer + dev->read_buffer_length,
782                                 dev->interrupt_in_buffer,
783                                 urb->actual_length);
784                         dev->read_buffer_length += urb->actual_length;
785                         dev->read_last_arrival = jiffies;
786                         dbg(3, "%s: received %d bytes", __FUNCTION__, urb->actual_length);
787                 } else {
788                         printk(KERN_WARNING "%s: read_buffer overflow, %d bytes dropped", __FUNCTION__, urb->actual_length);
789                 }
790                 spin_unlock (&dev->read_buffer_lock);
791         }
792
793 resubmit:
794         /* resubmit if we're still running */
795         if (dev->interrupt_in_running && dev->udev) {
796                 retval = usb_submit_urb (dev->interrupt_in_urb, GFP_ATOMIC);
797                 if (retval) {
798                         err("%s: usb_submit_urb failed (%d)", __FUNCTION__, retval);
799                 }
800         }
801
802 exit:
803         dev->interrupt_in_done = 1;
804         wake_up_interruptible (&dev->read_wait);
805
806         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
807         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
808 }
809
810
811 /**
812  *      tower_interrupt_out_callback
813  */
814 static void tower_interrupt_out_callback (struct urb *urb, struct pt_regs *regs)
815 {
816         struct lego_usb_tower *dev = (struct lego_usb_tower *)urb->context;
817
818         dbg(4, "%s: enter, status %d", __FUNCTION__, urb->status);
819         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
820
821         /* sync/async unlink faults aren't errors */
822         if (urb->status && !(urb->status == -ENOENT ||
823                              urb->status == -ECONNRESET ||
824                              urb->status == -ESHUTDOWN)) {
825                 dbg(1, "%s - nonzero write bulk status received: %d",
826                     __FUNCTION__, urb->status);
827         }
828
829         dev->interrupt_out_busy = 0;
830         wake_up_interruptible(&dev->write_wait);
831
832         lego_usb_tower_debug_data(5, __FUNCTION__, urb->actual_length, urb->transfer_buffer);
833         dbg(4, "%s: leave, status %d", __FUNCTION__, urb->status);
834 }
835
836
837 /**
838  *      tower_probe
839  *
840  *      Called by the usb core when a new device is connected that it thinks
841  *      this driver might be interested in.
842  */
843 static int tower_probe (struct usb_interface *interface, const struct usb_device_id *id)
844 {
845         struct usb_device *udev = interface_to_usbdev(interface);
846         struct lego_usb_tower *dev = NULL;
847         struct usb_host_interface *iface_desc;
848         struct usb_endpoint_descriptor* endpoint;
849         struct tower_get_version_reply get_version_reply;
850         int i;
851         int retval = -ENOMEM;
852         int result;
853
854         dbg(2, "%s: enter", __FUNCTION__);
855
856         if (udev == NULL) {
857                 info ("udev is NULL.");
858         }
859
860         /* allocate memory for our device state and initialize it */
861
862         dev = kmalloc (sizeof(struct lego_usb_tower), GFP_KERNEL);
863
864         if (dev == NULL) {
865                 err ("Out of memory");
866                 goto exit;
867         }
868
869         init_MUTEX (&dev->sem);
870
871         dev->udev = udev;
872         dev->open_count = 0;
873
874         dev->read_buffer = NULL;
875         dev->read_buffer_length = 0;
876         dev->read_packet_length = 0;
877         spin_lock_init (&dev->read_buffer_lock);
878         dev->packet_timeout_jiffies = packet_timeout * HZ / 1000;
879         dev->read_last_arrival = jiffies;
880
881         init_waitqueue_head (&dev->read_wait);
882         init_waitqueue_head (&dev->write_wait);
883
884         dev->interrupt_in_buffer = NULL;
885         dev->interrupt_in_endpoint = NULL;
886         dev->interrupt_in_urb = NULL;
887         dev->interrupt_in_running = 0;
888         dev->interrupt_in_done = 0;
889
890         dev->interrupt_out_buffer = NULL;
891         dev->interrupt_out_endpoint = NULL;
892         dev->interrupt_out_urb = NULL;
893         dev->interrupt_out_busy = 0;
894
895         iface_desc = interface->cur_altsetting;
896
897         /* set up the endpoint information */
898         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
899                 endpoint = &iface_desc->endpoint[i].desc;
900
901                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN) &&
902                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
903                         dev->interrupt_in_endpoint = endpoint;
904                 }
905
906                 if (((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) &&
907                     ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) {
908                         dev->interrupt_out_endpoint = endpoint;
909                 }
910         }
911         if(dev->interrupt_in_endpoint == NULL) {
912                 err("interrupt in endpoint not found");
913                 goto error;
914         }
915         if (dev->interrupt_out_endpoint == NULL) {
916                 err("interrupt out endpoint not found");
917                 goto error;
918         }
919
920         dev->read_buffer = kmalloc (read_buffer_size, GFP_KERNEL);
921         if (!dev->read_buffer) {
922                 err("Couldn't allocate read_buffer");
923                 goto error;
924         }
925         dev->interrupt_in_buffer = kmalloc (le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), GFP_KERNEL);
926         if (!dev->interrupt_in_buffer) {
927                 err("Couldn't allocate interrupt_in_buffer");
928                 goto error;
929         }
930         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
931         if (!dev->interrupt_in_urb) {
932                 err("Couldn't allocate interrupt_in_urb");
933                 goto error;
934         }
935         dev->interrupt_out_buffer = kmalloc (write_buffer_size, GFP_KERNEL);
936         if (!dev->interrupt_out_buffer) {
937                 err("Couldn't allocate interrupt_out_buffer");
938                 goto error;
939         }
940         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
941         if (!dev->interrupt_out_urb) {
942                 err("Couldn't allocate interrupt_out_urb");
943                 goto error;
944         }
945         dev->interrupt_in_interval = interrupt_in_interval ? interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
946         dev->interrupt_out_interval = interrupt_out_interval ? interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
947
948         /* we can register the device now, as it is ready */
949         usb_set_intfdata (interface, dev);
950
951         retval = usb_register_dev (interface, &tower_class);
952
953         if (retval) {
954                 /* something prevented us from registering this driver */
955                 err ("Not able to get a minor for this device.");
956                 usb_set_intfdata (interface, NULL);
957                 goto error;
958         }
959         dev->minor = interface->minor;
960
961         /* let the user know what node this device is now attached to */
962         info ("LEGO USB Tower #%d now attached to major %d minor %d", (dev->minor - LEGO_USB_TOWER_MINOR_BASE), USB_MAJOR, dev->minor);
963
964         /* get the firmware version and log it */
965         result = usb_control_msg (udev,
966                                   usb_rcvctrlpipe(udev, 0),
967                                   LEGO_USB_TOWER_REQUEST_GET_VERSION,
968                                   USB_TYPE_VENDOR | USB_DIR_IN | USB_RECIP_DEVICE,
969                                   0,
970                                   0,
971                                   &get_version_reply,
972                                   sizeof(get_version_reply),
973                                   1000);
974         if (result < 0) {
975                 err("LEGO USB Tower get version control request failed");
976                 retval = result;
977                 goto error;
978         }
979         info("LEGO USB Tower firmware version is %d.%d build %d",
980              get_version_reply.major,
981              get_version_reply.minor,
982              le16_to_cpu(get_version_reply.build_no));
983
984
985 exit:
986         dbg(2, "%s: leave, return value 0x%.8lx (dev)", __FUNCTION__, (long) dev);
987
988         return retval;
989
990 error:
991         tower_delete(dev);
992         return retval;
993 }
994
995
996 /**
997  *      tower_disconnect
998  *
999  *      Called by the usb core when the device is removed from the system.
1000  */
1001 static void tower_disconnect (struct usb_interface *interface)
1002 {
1003         struct lego_usb_tower *dev;
1004         int minor;
1005
1006         dbg(2, "%s: enter", __FUNCTION__);
1007
1008         down (&disconnect_sem);
1009
1010         dev = usb_get_intfdata (interface);
1011         usb_set_intfdata (interface, NULL);
1012
1013
1014         down (&dev->sem);
1015
1016         minor = dev->minor;
1017
1018         /* give back our minor */
1019         usb_deregister_dev (interface, &tower_class);
1020
1021         /* if the device is not opened, then we clean up right now */
1022         if (!dev->open_count) {
1023                 up (&dev->sem);
1024                 tower_delete (dev);
1025         } else {
1026                 dev->udev = NULL;
1027                 up (&dev->sem);
1028         }
1029
1030         up (&disconnect_sem);
1031
1032         info("LEGO USB Tower #%d now disconnected", (minor - LEGO_USB_TOWER_MINOR_BASE));
1033
1034         dbg(2, "%s: leave", __FUNCTION__);
1035 }
1036
1037
1038
1039 /**
1040  *      lego_usb_tower_init
1041  */
1042 static int __init lego_usb_tower_init(void)
1043 {
1044         int result;
1045         int retval = 0;
1046
1047         dbg(2, "%s: enter", __FUNCTION__);
1048
1049         /* register this driver with the USB subsystem */
1050         result = usb_register(&tower_driver);
1051         if (result < 0) {
1052                 err("usb_register failed for the "__FILE__" driver. Error number %d", result);
1053                 retval = -1;
1054                 goto exit;
1055         }
1056
1057         info(DRIVER_DESC " " DRIVER_VERSION);
1058
1059 exit:
1060         dbg(2, "%s: leave, return value %d", __FUNCTION__, retval);
1061
1062         return retval;
1063 }
1064
1065
1066 /**
1067  *      lego_usb_tower_exit
1068  */
1069 static void __exit lego_usb_tower_exit(void)
1070 {
1071         dbg(2, "%s: enter", __FUNCTION__);
1072
1073         /* deregister this driver with the USB subsystem */
1074         usb_deregister (&tower_driver);
1075
1076         dbg(2, "%s: leave", __FUNCTION__);
1077 }
1078
1079 module_init (lego_usb_tower_init);
1080 module_exit (lego_usb_tower_exit);
1081
1082 MODULE_AUTHOR(DRIVER_AUTHOR);
1083 MODULE_DESCRIPTION(DRIVER_DESC);
1084 #ifdef MODULE_LICENSE
1085 MODULE_LICENSE("GPL");
1086 #endif