USB: testing driver: convert dev->sem to mutex
[linux-2.6] / drivers / usb / misc / adutux.c
1 /*
2  * adutux - driver for ADU devices from Ontrak Control Systems
3  * This is an experimental driver. Use at your own risk.
4  * This driver is not supported by Ontrak Control Systems.
5  *
6  * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of
11  * the License, or (at your option) any later version.
12  *
13  * derived from the Lego USB Tower driver 0.56:
14  * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
15  *               2001 Juergen Stuber <stuber@loria.fr>
16  * that was derived from USB Skeleton driver - 0.5
17  * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
18  *
19  */
20
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/module.h>
26 #include <linux/usb.h>
27 #include <linux/mutex.h>
28 #include <asm/uaccess.h>
29
30 #ifdef CONFIG_USB_DEBUG
31 static int debug = 5;
32 #else
33 static int debug = 1;
34 #endif
35
36 /* Use our own dbg macro */
37 #undef dbg
38 #define dbg(lvl, format, arg...)                                        \
39 do {                                                                    \
40         if (debug >= lvl)                                               \
41                 printk(KERN_DEBUG __FILE__ " : " format " \n", ## arg); \
42 } while (0)
43
44
45 /* Version Information */
46 #define DRIVER_VERSION "v0.0.13"
47 #define DRIVER_AUTHOR "John Homppi"
48 #define DRIVER_DESC "adutux (see www.ontrak.net)"
49
50 /* Module parameters */
51 module_param(debug, int, S_IRUGO | S_IWUSR);
52 MODULE_PARM_DESC(debug, "Debug enabled or not");
53
54 /* Define these values to match your device */
55 #define ADU_VENDOR_ID 0x0a07
56 #define ADU_PRODUCT_ID 0x0064
57
58 /* table of devices that work with this driver */
59 static struct usb_device_id device_table [] = {
60         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },          /* ADU100 */
61         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) },       /* ADU120 */
62         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) },       /* ADU130 */
63         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },      /* ADU200 */
64         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },      /* ADU208 */
65         { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },      /* ADU218 */
66         { }/* Terminating entry */
67 };
68
69 MODULE_DEVICE_TABLE(usb, device_table);
70
71 #ifdef CONFIG_USB_DYNAMIC_MINORS
72 #define ADU_MINOR_BASE  0
73 #else
74 #define ADU_MINOR_BASE  67
75 #endif
76
77 /* we can have up to this number of device plugged in at once */
78 #define MAX_DEVICES     16
79
80 #define COMMAND_TIMEOUT (2*HZ)  /* 60 second timeout for a command */
81
82 /*
83  * The locking scheme is a vanilla 3-lock:
84  *   adu_device.buflock: A spinlock, covers what IRQs touch.
85  *   adutux_mutex:       A Static lock to cover open_count. It would also cover
86  *                       any globals, but we don't have them in 2.6.
87  *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
88  *                       It covers all of adu_device, except the open_count
89  *                       and what .buflock covers.
90  */
91
92 /* Structure to hold all of our device specific stuff */
93 struct adu_device {
94         struct mutex            mtx;
95         struct usb_device*      udev; /* save off the usb device pointer */
96         struct usb_interface*   interface;
97         unsigned int            minor; /* the starting minor number for this device */
98         char                    serial_number[8];
99
100         int                     open_count; /* number of times this port has been opened */
101
102         char*                   read_buffer_primary;
103         int                     read_buffer_length;
104         char*                   read_buffer_secondary;
105         int                     secondary_head;
106         int                     secondary_tail;
107         spinlock_t              buflock;
108
109         wait_queue_head_t       read_wait;
110         wait_queue_head_t       write_wait;
111
112         char*                   interrupt_in_buffer;
113         struct usb_endpoint_descriptor* interrupt_in_endpoint;
114         struct urb*             interrupt_in_urb;
115         int                     read_urb_finished;
116
117         char*                   interrupt_out_buffer;
118         struct usb_endpoint_descriptor* interrupt_out_endpoint;
119         struct urb*             interrupt_out_urb;
120         int                     out_urb_finished;
121 };
122
123 static DEFINE_MUTEX(adutux_mutex);
124
125 static struct usb_driver adu_driver;
126
127 static void adu_debug_data(int level, const char *function, int size,
128                            const unsigned char *data)
129 {
130         int i;
131
132         if (debug < level)
133                 return;
134
135         printk(KERN_DEBUG __FILE__": %s - length = %d, data = ",
136                function, size);
137         for (i = 0; i < size; ++i)
138                 printk("%.2x ", data[i]);
139         printk("\n");
140 }
141
142 /**
143  * adu_abort_transfers
144  *      aborts transfers and frees associated data structures
145  */
146 static void adu_abort_transfers(struct adu_device *dev)
147 {
148         unsigned long flags;
149
150         dbg(2," %s : enter", __FUNCTION__);
151
152         if (dev->udev == NULL) {
153                 dbg(1," %s : udev is null", __FUNCTION__);
154                 goto exit;
155         }
156
157         /* shutdown transfer */
158
159         /* XXX Anchor these instead */
160         spin_lock_irqsave(&dev->buflock, flags);
161         if (!dev->read_urb_finished) {
162                 spin_unlock_irqrestore(&dev->buflock, flags);
163                 usb_kill_urb(dev->interrupt_in_urb);
164         } else
165                 spin_unlock_irqrestore(&dev->buflock, flags);
166
167         spin_lock_irqsave(&dev->buflock, flags);
168         if (!dev->out_urb_finished) {
169                 spin_unlock_irqrestore(&dev->buflock, flags);
170                 usb_kill_urb(dev->interrupt_out_urb);
171         } else
172                 spin_unlock_irqrestore(&dev->buflock, flags);
173
174 exit:
175         dbg(2," %s : leave", __FUNCTION__);
176 }
177
178 static void adu_delete(struct adu_device *dev)
179 {
180         dbg(2, "%s enter", __FUNCTION__);
181
182         /* free data structures */
183         usb_free_urb(dev->interrupt_in_urb);
184         usb_free_urb(dev->interrupt_out_urb);
185         kfree(dev->read_buffer_primary);
186         kfree(dev->read_buffer_secondary);
187         kfree(dev->interrupt_in_buffer);
188         kfree(dev->interrupt_out_buffer);
189         kfree(dev);
190
191         dbg(2, "%s : leave", __FUNCTION__);
192 }
193
194 static void adu_interrupt_in_callback(struct urb *urb)
195 {
196         struct adu_device *dev = urb->context;
197         int status = urb->status;
198
199         dbg(4," %s : enter, status %d", __FUNCTION__, status);
200         adu_debug_data(5, __FUNCTION__, urb->actual_length,
201                        urb->transfer_buffer);
202
203         spin_lock(&dev->buflock);
204
205         if (status != 0) {
206                 if ((status != -ENOENT) && (status != -ECONNRESET) &&
207                         (status != -ESHUTDOWN)) {
208                         dbg(1," %s : nonzero status received: %d",
209                             __FUNCTION__, status);
210                 }
211                 goto exit;
212         }
213
214         if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
215                 if (dev->read_buffer_length <
216                     (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
217                      (urb->actual_length)) {
218                         memcpy (dev->read_buffer_primary +
219                                 dev->read_buffer_length,
220                                 dev->interrupt_in_buffer, urb->actual_length);
221
222                         dev->read_buffer_length += urb->actual_length;
223                         dbg(2," %s reading  %d ", __FUNCTION__,
224                             urb->actual_length);
225                 } else {
226                         dbg(1," %s : read_buffer overflow", __FUNCTION__);
227                 }
228         }
229
230 exit:
231         dev->read_urb_finished = 1;
232         spin_unlock(&dev->buflock);
233         /* always wake up so we recover from errors */
234         wake_up_interruptible(&dev->read_wait);
235         adu_debug_data(5, __FUNCTION__, urb->actual_length,
236                        urb->transfer_buffer);
237         dbg(4," %s : leave, status %d", __FUNCTION__, status);
238 }
239
240 static void adu_interrupt_out_callback(struct urb *urb)
241 {
242         struct adu_device *dev = urb->context;
243         int status = urb->status;
244
245         dbg(4," %s : enter, status %d", __FUNCTION__, status);
246         adu_debug_data(5,__FUNCTION__, urb->actual_length, urb->transfer_buffer);
247
248         if (status != 0) {
249                 if ((status != -ENOENT) &&
250                     (status != -ECONNRESET)) {
251                         dbg(1, " %s :nonzero status received: %d",
252                             __FUNCTION__, status);
253                 }
254                 goto exit;
255         }
256
257         spin_lock(&dev->buflock);
258         dev->out_urb_finished = 1;
259         wake_up(&dev->write_wait);
260         spin_unlock(&dev->buflock);
261 exit:
262
263         adu_debug_data(5, __FUNCTION__, urb->actual_length,
264                        urb->transfer_buffer);
265         dbg(4," %s : leave, status %d", __FUNCTION__, status);
266 }
267
268 static int adu_open(struct inode *inode, struct file *file)
269 {
270         struct adu_device *dev = NULL;
271         struct usb_interface *interface;
272         int subminor;
273         int retval;
274
275         dbg(2,"%s : enter", __FUNCTION__);
276
277         subminor = iminor(inode);
278
279         if ((retval = mutex_lock_interruptible(&adutux_mutex))) {
280                 dbg(2, "%s : mutex lock failed", __FUNCTION__);
281                 goto exit_no_lock;
282         }
283
284         interface = usb_find_interface(&adu_driver, subminor);
285         if (!interface) {
286                 err("%s - error, can't find device for minor %d",
287                     __FUNCTION__, subminor);
288                 retval = -ENODEV;
289                 goto exit_no_device;
290         }
291
292         dev = usb_get_intfdata(interface);
293         if (!dev || !dev->udev) {
294                 retval = -ENODEV;
295                 goto exit_no_device;
296         }
297
298         /* check that nobody else is using the device */
299         if (dev->open_count) {
300                 retval = -EBUSY;
301                 goto exit_no_device;
302         }
303
304         ++dev->open_count;
305         dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count);
306
307         /* save device in the file's private structure */
308         file->private_data = dev;
309
310         /* initialize in direction */
311         dev->read_buffer_length = 0;
312
313         /* fixup first read by having urb waiting for it */
314         usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
315                          usb_rcvintpipe(dev->udev,
316                                         dev->interrupt_in_endpoint->bEndpointAddress),
317                          dev->interrupt_in_buffer,
318                          le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
319                          adu_interrupt_in_callback, dev,
320                          dev->interrupt_in_endpoint->bInterval);
321         dev->read_urb_finished = 0;
322         if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
323                 dev->read_urb_finished = 1;
324         /* we ignore failure */
325         /* end of fixup for first read */
326
327         /* initialize out direction */
328         dev->out_urb_finished = 1;
329
330         retval = 0;
331
332 exit_no_device:
333         mutex_unlock(&adutux_mutex);
334 exit_no_lock:
335         dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval);
336         return retval;
337 }
338
339 static void adu_release_internal(struct adu_device *dev)
340 {
341         dbg(2," %s : enter", __FUNCTION__);
342
343         /* decrement our usage count for the device */
344         --dev->open_count;
345         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
346         if (dev->open_count <= 0) {
347                 adu_abort_transfers(dev);
348                 dev->open_count = 0;
349         }
350
351         dbg(2," %s : leave", __FUNCTION__);
352 }
353
354 static int adu_release(struct inode *inode, struct file *file)
355 {
356         struct adu_device *dev;
357         int retval = 0;
358
359         dbg(2," %s : enter", __FUNCTION__);
360
361         if (file == NULL) {
362                 dbg(1," %s : file is NULL", __FUNCTION__);
363                 retval = -ENODEV;
364                 goto exit;
365         }
366
367         dev = file->private_data;
368         if (dev == NULL) {
369                 dbg(1," %s : object is NULL", __FUNCTION__);
370                 retval = -ENODEV;
371                 goto exit;
372         }
373
374         mutex_lock(&adutux_mutex); /* not interruptible */
375
376         if (dev->open_count <= 0) {
377                 dbg(1," %s : device not opened", __FUNCTION__);
378                 retval = -ENODEV;
379                 goto exit;
380         }
381
382         adu_release_internal(dev);
383         if (dev->udev == NULL) {
384                 /* the device was unplugged before the file was released */
385                 if (!dev->open_count)   /* ... and we're the last user */
386                         adu_delete(dev);
387         }
388
389 exit:
390         mutex_unlock(&adutux_mutex);
391         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
392         return retval;
393 }
394
395 static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
396                         loff_t *ppos)
397 {
398         struct adu_device *dev;
399         size_t bytes_read = 0;
400         size_t bytes_to_read = count;
401         int i;
402         int retval = 0;
403         int timeout = 0;
404         int should_submit = 0;
405         unsigned long flags;
406         DECLARE_WAITQUEUE(wait, current);
407
408         dbg(2," %s : enter, count = %Zd, file=%p", __FUNCTION__, count, file);
409
410         dev = file->private_data;
411         dbg(2," %s : dev=%p", __FUNCTION__, dev);
412
413         if (mutex_lock_interruptible(&dev->mtx))
414                 return -ERESTARTSYS;
415
416         /* verify that the device wasn't unplugged */
417         if (dev->udev == NULL) {
418                 retval = -ENODEV;
419                 err("No device or device unplugged %d", retval);
420                 goto exit;
421         }
422
423         /* verify that some data was requested */
424         if (count == 0) {
425                 dbg(1," %s : read request of 0 bytes", __FUNCTION__);
426                 goto exit;
427         }
428
429         timeout = COMMAND_TIMEOUT;
430         dbg(2," %s : about to start looping", __FUNCTION__);
431         while (bytes_to_read) {
432                 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
433                 dbg(2," %s : while, data_in_secondary=%d, status=%d",
434                     __FUNCTION__, data_in_secondary,
435                     dev->interrupt_in_urb->status);
436
437                 if (data_in_secondary) {
438                         /* drain secondary buffer */
439                         int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
440                         i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
441                         if (i < 0) {
442                                 retval = -EFAULT;
443                                 goto exit;
444                         }
445                         dev->secondary_head += (amount - i);
446                         bytes_read += (amount - i);
447                         bytes_to_read -= (amount - i);
448                         if (i) {
449                                 retval = bytes_read ? bytes_read : -EFAULT;
450                                 goto exit;
451                         }
452                 } else {
453                         /* we check the primary buffer */
454                         spin_lock_irqsave (&dev->buflock, flags);
455                         if (dev->read_buffer_length) {
456                                 /* we secure access to the primary */
457                                 char *tmp;
458                                 dbg(2," %s : swap, read_buffer_length = %d",
459                                     __FUNCTION__, dev->read_buffer_length);
460                                 tmp = dev->read_buffer_secondary;
461                                 dev->read_buffer_secondary = dev->read_buffer_primary;
462                                 dev->read_buffer_primary = tmp;
463                                 dev->secondary_head = 0;
464                                 dev->secondary_tail = dev->read_buffer_length;
465                                 dev->read_buffer_length = 0;
466                                 spin_unlock_irqrestore(&dev->buflock, flags);
467                                 /* we have a free buffer so use it */
468                                 should_submit = 1;
469                         } else {
470                                 /* even the primary was empty - we may need to do IO */
471                                 if (!dev->read_urb_finished) {
472                                         /* somebody is doing IO */
473                                         spin_unlock_irqrestore(&dev->buflock, flags);
474                                         dbg(2," %s : submitted already", __FUNCTION__);
475                                 } else {
476                                         /* we must initiate input */
477                                         dbg(2," %s : initiate input", __FUNCTION__);
478                                         dev->read_urb_finished = 0;
479                                         spin_unlock_irqrestore(&dev->buflock, flags);
480
481                                         usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
482                                                          usb_rcvintpipe(dev->udev,
483                                                                         dev->interrupt_in_endpoint->bEndpointAddress),
484                                                          dev->interrupt_in_buffer,
485                                                          le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
486                                                          adu_interrupt_in_callback,
487                                                          dev,
488                                                          dev->interrupt_in_endpoint->bInterval);
489                                         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
490                                         if (retval) {
491                                                 dev->read_urb_finished = 1;
492                                                 if (retval == -ENOMEM) {
493                                                         retval = bytes_read ? bytes_read : -ENOMEM;
494                                                 }
495                                                 dbg(2," %s : submit failed", __FUNCTION__);
496                                                 goto exit;
497                                         }
498                                 }
499
500                                 /* we wait for I/O to complete */
501                                 set_current_state(TASK_INTERRUPTIBLE);
502                                 add_wait_queue(&dev->read_wait, &wait);
503                                 spin_lock_irqsave(&dev->buflock, flags);
504                                 if (!dev->read_urb_finished) {
505                                         spin_unlock_irqrestore(&dev->buflock, flags);
506                                         timeout = schedule_timeout(COMMAND_TIMEOUT);
507                                 } else {
508                                         spin_unlock_irqrestore(&dev->buflock, flags);
509                                         set_current_state(TASK_RUNNING);
510                                 }
511                                 remove_wait_queue(&dev->read_wait, &wait);
512
513                                 if (timeout <= 0) {
514                                         dbg(2," %s : timeout", __FUNCTION__);
515                                         retval = bytes_read ? bytes_read : -ETIMEDOUT;
516                                         goto exit;
517                                 }
518
519                                 if (signal_pending(current)) {
520                                         dbg(2," %s : signal pending", __FUNCTION__);
521                                         retval = bytes_read ? bytes_read : -EINTR;
522                                         goto exit;
523                                 }
524                         }
525                 }
526         }
527
528         retval = bytes_read;
529         /* if the primary buffer is empty then use it */
530         spin_lock_irqsave(&dev->buflock, flags);
531         if (should_submit && dev->read_urb_finished) {
532                 dev->read_urb_finished = 0;
533                 spin_unlock_irqrestore(&dev->buflock, flags);
534                 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
535                                  usb_rcvintpipe(dev->udev,
536                                                 dev->interrupt_in_endpoint->bEndpointAddress),
537                                 dev->interrupt_in_buffer,
538                                 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
539                                 adu_interrupt_in_callback,
540                                 dev,
541                                 dev->interrupt_in_endpoint->bInterval);
542                 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
543                         dev->read_urb_finished = 1;
544                 /* we ignore failure */
545         } else {
546                 spin_unlock_irqrestore(&dev->buflock, flags);
547         }
548
549 exit:
550         /* unlock the device */
551         mutex_unlock(&dev->mtx);
552
553         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
554         return retval;
555 }
556
557 static ssize_t adu_write(struct file *file, const __user char *buffer,
558                          size_t count, loff_t *ppos)
559 {
560         DECLARE_WAITQUEUE(waita, current);
561         struct adu_device *dev;
562         size_t bytes_written = 0;
563         size_t bytes_to_write;
564         size_t buffer_size;
565         unsigned long flags;
566         int retval;
567
568         dbg(2," %s : enter, count = %Zd", __FUNCTION__, count);
569
570         dev = file->private_data;
571
572         retval = mutex_lock_interruptible(&dev->mtx);
573         if (retval)
574                 goto exit_nolock;
575
576         /* verify that the device wasn't unplugged */
577         if (dev->udev == NULL) {
578                 retval = -ENODEV;
579                 err("No device or device unplugged %d", retval);
580                 goto exit;
581         }
582
583         /* verify that we actually have some data to write */
584         if (count == 0) {
585                 dbg(1," %s : write request of 0 bytes", __FUNCTION__);
586                 goto exit;
587         }
588
589         while (count > 0) {
590                 add_wait_queue(&dev->write_wait, &waita);
591                 set_current_state(TASK_INTERRUPTIBLE);
592                 spin_lock_irqsave(&dev->buflock, flags);
593                 if (!dev->out_urb_finished) {
594                         spin_unlock_irqrestore(&dev->buflock, flags);
595
596                         mutex_unlock(&dev->mtx);
597                         if (signal_pending(current)) {
598                                 dbg(1," %s : interrupted", __FUNCTION__);
599                                 set_current_state(TASK_RUNNING);
600                                 retval = -EINTR;
601                                 goto exit_onqueue;
602                         }
603                         if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
604                                 dbg(1, "%s - command timed out.", __FUNCTION__);
605                                 retval = -ETIMEDOUT;
606                                 goto exit_onqueue;
607                         }
608                         remove_wait_queue(&dev->write_wait, &waita);
609                         retval = mutex_lock_interruptible(&dev->mtx);
610                         if (retval) {
611                                 retval = bytes_written ? bytes_written : retval;
612                                 goto exit_nolock;
613                         }
614
615                         dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
616                 } else {
617                         spin_unlock_irqrestore(&dev->buflock, flags);
618                         set_current_state(TASK_RUNNING);
619                         remove_wait_queue(&dev->write_wait, &waita);
620                         dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
621
622                         /* write the data into interrupt_out_buffer from userspace */
623                         buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
624                         bytes_to_write = count > buffer_size ? buffer_size : count;
625                         dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
626                             __FUNCTION__, buffer_size, count, bytes_to_write);
627
628                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
629                                 retval = -EFAULT;
630                                 goto exit;
631                         }
632
633                         /* send off the urb */
634                         usb_fill_int_urb(
635                                 dev->interrupt_out_urb,
636                                 dev->udev,
637                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
638                                 dev->interrupt_out_buffer,
639                                 bytes_to_write,
640                                 adu_interrupt_out_callback,
641                                 dev,
642                                 dev->interrupt_out_endpoint->bInterval);
643                         dev->interrupt_out_urb->actual_length = bytes_to_write;
644                         dev->out_urb_finished = 0;
645                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
646                         if (retval < 0) {
647                                 dev->out_urb_finished = 1;
648                                 err("Couldn't submit interrupt_out_urb %d", retval);
649                                 goto exit;
650                         }
651
652                         buffer += bytes_to_write;
653                         count -= bytes_to_write;
654
655                         bytes_written += bytes_to_write;
656                 }
657         }
658         mutex_unlock(&dev->mtx);
659         return bytes_written;
660
661 exit:
662         mutex_unlock(&dev->mtx);
663 exit_nolock:
664         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
665         return retval;
666
667 exit_onqueue:
668         remove_wait_queue(&dev->write_wait, &waita);
669         return retval;
670 }
671
672 /* file operations needed when we register this driver */
673 static const struct file_operations adu_fops = {
674         .owner = THIS_MODULE,
675         .read  = adu_read,
676         .write = adu_write,
677         .open = adu_open,
678         .release = adu_release,
679 };
680
681 /*
682  * usb class driver info in order to get a minor number from the usb core,
683  * and to have the device registered with devfs and the driver core
684  */
685 static struct usb_class_driver adu_class = {
686         .name = "usb/adutux%d",
687         .fops = &adu_fops,
688         .minor_base = ADU_MINOR_BASE,
689 };
690
691 /**
692  * adu_probe
693  *
694  * Called by the usb core when a new device is connected that it thinks
695  * this driver might be interested in.
696  */
697 static int adu_probe(struct usb_interface *interface,
698                      const struct usb_device_id *id)
699 {
700         struct usb_device *udev = interface_to_usbdev(interface);
701         struct adu_device *dev = NULL;
702         struct usb_host_interface *iface_desc;
703         struct usb_endpoint_descriptor *endpoint;
704         int retval = -ENODEV;
705         int in_end_size;
706         int out_end_size;
707         int i;
708
709         dbg(2," %s : enter", __FUNCTION__);
710
711         if (udev == NULL) {
712                 dev_err(&interface->dev, "udev is NULL.\n");
713                 goto exit;
714         }
715
716         /* allocate memory for our device state and intialize it */
717         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
718         if (dev == NULL) {
719                 dev_err(&interface->dev, "Out of memory\n");
720                 retval = -ENOMEM;
721                 goto exit;
722         }
723
724         mutex_init(&dev->mtx);
725         spin_lock_init(&dev->buflock);
726         dev->udev = udev;
727         init_waitqueue_head(&dev->read_wait);
728         init_waitqueue_head(&dev->write_wait);
729
730         iface_desc = &interface->altsetting[0];
731
732         /* set up the endpoint information */
733         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
734                 endpoint = &iface_desc->endpoint[i].desc;
735
736                 if (usb_endpoint_is_int_in(endpoint))
737                         dev->interrupt_in_endpoint = endpoint;
738
739                 if (usb_endpoint_is_int_out(endpoint))
740                         dev->interrupt_out_endpoint = endpoint;
741         }
742         if (dev->interrupt_in_endpoint == NULL) {
743                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
744                 goto error;
745         }
746         if (dev->interrupt_out_endpoint == NULL) {
747                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
748                 goto error;
749         }
750
751         in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
752         out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
753
754         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
755         if (!dev->read_buffer_primary) {
756                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
757                 retval = -ENOMEM;
758                 goto error;
759         }
760
761         /* debug code prime the buffer */
762         memset(dev->read_buffer_primary, 'a', in_end_size);
763         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
764         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
765         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
766
767         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
768         if (!dev->read_buffer_secondary) {
769                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
770                 retval = -ENOMEM;
771                 goto error;
772         }
773
774         /* debug code prime the buffer */
775         memset(dev->read_buffer_secondary, 'e', in_end_size);
776         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
777         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
778         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
779
780         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
781         if (!dev->interrupt_in_buffer) {
782                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
783                 goto error;
784         }
785
786         /* debug code prime the buffer */
787         memset(dev->interrupt_in_buffer, 'i', in_end_size);
788
789         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
790         if (!dev->interrupt_in_urb) {
791                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
792                 goto error;
793         }
794         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
795         if (!dev->interrupt_out_buffer) {
796                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
797                 goto error;
798         }
799         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
800         if (!dev->interrupt_out_urb) {
801                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
802                 goto error;
803         }
804
805         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
806                         sizeof(dev->serial_number))) {
807                 dev_err(&interface->dev, "Could not retrieve serial number\n");
808                 goto error;
809         }
810         dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
811
812         /* we can register the device now, as it is ready */
813         usb_set_intfdata(interface, dev);
814
815         retval = usb_register_dev(interface, &adu_class);
816
817         if (retval) {
818                 /* something prevented us from registering this driver */
819                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
820                 usb_set_intfdata(interface, NULL);
821                 goto error;
822         }
823
824         dev->minor = interface->minor;
825
826         /* let the user know what node this device is now attached to */
827         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
828                  udev->descriptor.idProduct, dev->serial_number,
829                  (dev->minor - ADU_MINOR_BASE));
830 exit:
831         dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
832
833         return retval;
834
835 error:
836         adu_delete(dev);
837         return retval;
838 }
839
840 /**
841  * adu_disconnect
842  *
843  * Called by the usb core when the device is removed from the system.
844  */
845 static void adu_disconnect(struct usb_interface *interface)
846 {
847         struct adu_device *dev;
848         int minor;
849
850         dbg(2," %s : enter", __FUNCTION__);
851
852         dev = usb_get_intfdata(interface);
853
854         mutex_lock(&dev->mtx);  /* not interruptible */
855         dev->udev = NULL;       /* poison */
856         minor = dev->minor;
857         usb_deregister_dev(interface, &adu_class);
858         mutex_unlock(&dev->mtx);
859
860         mutex_lock(&adutux_mutex);
861         usb_set_intfdata(interface, NULL);
862
863         /* if the device is not opened, then we clean up right now */
864         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
865         if (!dev->open_count)
866                 adu_delete(dev);
867
868         mutex_unlock(&adutux_mutex);
869
870         dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
871                  (minor - ADU_MINOR_BASE));
872
873         dbg(2," %s : leave", __FUNCTION__);
874 }
875
876 /* usb specific object needed to register this driver with the usb subsystem */
877 static struct usb_driver adu_driver = {
878         .name = "adutux",
879         .probe = adu_probe,
880         .disconnect = adu_disconnect,
881         .id_table = device_table,
882 };
883
884 static int __init adu_init(void)
885 {
886         int result;
887
888         dbg(2," %s : enter", __FUNCTION__);
889
890         /* register this driver with the USB subsystem */
891         result = usb_register(&adu_driver);
892         if (result < 0) {
893                 err("usb_register failed for the "__FILE__" driver. "
894                     "Error number %d", result);
895                 goto exit;
896         }
897
898         info("adutux " DRIVER_DESC " " DRIVER_VERSION);
899         info("adutux is an experimental driver. Use at your own risk");
900
901 exit:
902         dbg(2," %s : leave, return value %d", __FUNCTION__, result);
903
904         return result;
905 }
906
907 static void __exit adu_exit(void)
908 {
909         dbg(2," %s : enter", __FUNCTION__);
910         /* deregister this driver with the USB subsystem */
911         usb_deregister(&adu_driver);
912         dbg(2," %s : leave", __FUNCTION__);
913 }
914
915 module_init(adu_init);
916 module_exit(adu_exit);
917
918 MODULE_AUTHOR(DRIVER_AUTHOR);
919 MODULE_DESCRIPTION(DRIVER_DESC);
920 MODULE_LICENSE("GPL");