USB: Fix a bug on appledisplay.c regarding signedness
[linux-2.6.git] / 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", __func__);
151
152         if (dev->udev == NULL) {
153                 dbg(1," %s : udev is null", __func__);
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", __func__);
176 }
177
178 static void adu_delete(struct adu_device *dev)
179 {
180         dbg(2, "%s enter", __func__);
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", __func__);
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", __func__, status);
200         adu_debug_data(5, __func__, 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                             __func__, 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 ", __func__,
224                             urb->actual_length);
225                 } else {
226                         dbg(1," %s : read_buffer overflow", __func__);
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, __func__, urb->actual_length,
236                        urb->transfer_buffer);
237         dbg(4," %s : leave, status %d", __func__, 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", __func__, status);
246         adu_debug_data(5,__func__, 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                             __func__, 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, __func__, urb->actual_length,
264                        urb->transfer_buffer);
265         dbg(4," %s : leave, status %d", __func__, 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", __func__);
276
277         subminor = iminor(inode);
278
279         if ((retval = mutex_lock_interruptible(&adutux_mutex))) {
280                 dbg(2, "%s : mutex lock failed", __func__);
281                 goto exit_no_lock;
282         }
283
284         interface = usb_find_interface(&adu_driver, subminor);
285         if (!interface) {
286                 printk(KERN_ERR "adutux: %s - error, can't find device for "
287                        "minor %d\n", __func__, 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", __func__, 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 ", __func__, retval);
336         return retval;
337 }
338
339 static void adu_release_internal(struct adu_device *dev)
340 {
341         dbg(2," %s : enter", __func__);
342
343         /* decrement our usage count for the device */
344         --dev->open_count;
345         dbg(2," %s : open count %d", __func__, 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", __func__);
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", __func__);
360
361         if (file == NULL) {
362                 dbg(1," %s : file is NULL", __func__);
363                 retval = -ENODEV;
364                 goto exit;
365         }
366
367         dev = file->private_data;
368         if (dev == NULL) {
369                 dbg(1," %s : object is NULL", __func__);
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", __func__);
378                 retval = -ENODEV;
379                 goto unlock;
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 unlock:
389         mutex_unlock(&adutux_mutex);
390 exit:
391         dbg(2," %s : leave, return value %d", __func__, 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", __func__, count, file);
409
410         dev = file->private_data;
411         dbg(2," %s : dev=%p", __func__, 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                 printk(KERN_ERR "adutux: No device or device unplugged %d\n",
420                        retval);
421                 goto exit;
422         }
423
424         /* verify that some data was requested */
425         if (count == 0) {
426                 dbg(1," %s : read request of 0 bytes", __func__);
427                 goto exit;
428         }
429
430         timeout = COMMAND_TIMEOUT;
431         dbg(2," %s : about to start looping", __func__);
432         while (bytes_to_read) {
433                 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
434                 dbg(2," %s : while, data_in_secondary=%d, status=%d",
435                     __func__, data_in_secondary,
436                     dev->interrupt_in_urb->status);
437
438                 if (data_in_secondary) {
439                         /* drain secondary buffer */
440                         int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
441                         i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
442                         if (i < 0) {
443                                 retval = -EFAULT;
444                                 goto exit;
445                         }
446                         dev->secondary_head += (amount - i);
447                         bytes_read += (amount - i);
448                         bytes_to_read -= (amount - i);
449                         if (i) {
450                                 retval = bytes_read ? bytes_read : -EFAULT;
451                                 goto exit;
452                         }
453                 } else {
454                         /* we check the primary buffer */
455                         spin_lock_irqsave (&dev->buflock, flags);
456                         if (dev->read_buffer_length) {
457                                 /* we secure access to the primary */
458                                 char *tmp;
459                                 dbg(2," %s : swap, read_buffer_length = %d",
460                                     __func__, dev->read_buffer_length);
461                                 tmp = dev->read_buffer_secondary;
462                                 dev->read_buffer_secondary = dev->read_buffer_primary;
463                                 dev->read_buffer_primary = tmp;
464                                 dev->secondary_head = 0;
465                                 dev->secondary_tail = dev->read_buffer_length;
466                                 dev->read_buffer_length = 0;
467                                 spin_unlock_irqrestore(&dev->buflock, flags);
468                                 /* we have a free buffer so use it */
469                                 should_submit = 1;
470                         } else {
471                                 /* even the primary was empty - we may need to do IO */
472                                 if (!dev->read_urb_finished) {
473                                         /* somebody is doing IO */
474                                         spin_unlock_irqrestore(&dev->buflock, flags);
475                                         dbg(2," %s : submitted already", __func__);
476                                 } else {
477                                         /* we must initiate input */
478                                         dbg(2," %s : initiate input", __func__);
479                                         dev->read_urb_finished = 0;
480                                         spin_unlock_irqrestore(&dev->buflock, flags);
481
482                                         usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
483                                                          usb_rcvintpipe(dev->udev,
484                                                                         dev->interrupt_in_endpoint->bEndpointAddress),
485                                                          dev->interrupt_in_buffer,
486                                                          le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
487                                                          adu_interrupt_in_callback,
488                                                          dev,
489                                                          dev->interrupt_in_endpoint->bInterval);
490                                         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
491                                         if (retval) {
492                                                 dev->read_urb_finished = 1;
493                                                 if (retval == -ENOMEM) {
494                                                         retval = bytes_read ? bytes_read : -ENOMEM;
495                                                 }
496                                                 dbg(2," %s : submit failed", __func__);
497                                                 goto exit;
498                                         }
499                                 }
500
501                                 /* we wait for I/O to complete */
502                                 set_current_state(TASK_INTERRUPTIBLE);
503                                 add_wait_queue(&dev->read_wait, &wait);
504                                 spin_lock_irqsave(&dev->buflock, flags);
505                                 if (!dev->read_urb_finished) {
506                                         spin_unlock_irqrestore(&dev->buflock, flags);
507                                         timeout = schedule_timeout(COMMAND_TIMEOUT);
508                                 } else {
509                                         spin_unlock_irqrestore(&dev->buflock, flags);
510                                         set_current_state(TASK_RUNNING);
511                                 }
512                                 remove_wait_queue(&dev->read_wait, &wait);
513
514                                 if (timeout <= 0) {
515                                         dbg(2," %s : timeout", __func__);
516                                         retval = bytes_read ? bytes_read : -ETIMEDOUT;
517                                         goto exit;
518                                 }
519
520                                 if (signal_pending(current)) {
521                                         dbg(2," %s : signal pending", __func__);
522                                         retval = bytes_read ? bytes_read : -EINTR;
523                                         goto exit;
524                                 }
525                         }
526                 }
527         }
528
529         retval = bytes_read;
530         /* if the primary buffer is empty then use it */
531         spin_lock_irqsave(&dev->buflock, flags);
532         if (should_submit && dev->read_urb_finished) {
533                 dev->read_urb_finished = 0;
534                 spin_unlock_irqrestore(&dev->buflock, flags);
535                 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
536                                  usb_rcvintpipe(dev->udev,
537                                                 dev->interrupt_in_endpoint->bEndpointAddress),
538                                 dev->interrupt_in_buffer,
539                                 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
540                                 adu_interrupt_in_callback,
541                                 dev,
542                                 dev->interrupt_in_endpoint->bInterval);
543                 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
544                         dev->read_urb_finished = 1;
545                 /* we ignore failure */
546         } else {
547                 spin_unlock_irqrestore(&dev->buflock, flags);
548         }
549
550 exit:
551         /* unlock the device */
552         mutex_unlock(&dev->mtx);
553
554         dbg(2," %s : leave, return value %d", __func__, retval);
555         return retval;
556 }
557
558 static ssize_t adu_write(struct file *file, const __user char *buffer,
559                          size_t count, loff_t *ppos)
560 {
561         DECLARE_WAITQUEUE(waita, current);
562         struct adu_device *dev;
563         size_t bytes_written = 0;
564         size_t bytes_to_write;
565         size_t buffer_size;
566         unsigned long flags;
567         int retval;
568
569         dbg(2," %s : enter, count = %Zd", __func__, count);
570
571         dev = file->private_data;
572
573         retval = mutex_lock_interruptible(&dev->mtx);
574         if (retval)
575                 goto exit_nolock;
576
577         /* verify that the device wasn't unplugged */
578         if (dev->udev == NULL) {
579                 retval = -ENODEV;
580                 printk(KERN_ERR "adutux: No device or device unplugged %d\n",
581                        retval);
582                 goto exit;
583         }
584
585         /* verify that we actually have some data to write */
586         if (count == 0) {
587                 dbg(1," %s : write request of 0 bytes", __func__);
588                 goto exit;
589         }
590
591         while (count > 0) {
592                 add_wait_queue(&dev->write_wait, &waita);
593                 set_current_state(TASK_INTERRUPTIBLE);
594                 spin_lock_irqsave(&dev->buflock, flags);
595                 if (!dev->out_urb_finished) {
596                         spin_unlock_irqrestore(&dev->buflock, flags);
597
598                         mutex_unlock(&dev->mtx);
599                         if (signal_pending(current)) {
600                                 dbg(1," %s : interrupted", __func__);
601                                 set_current_state(TASK_RUNNING);
602                                 retval = -EINTR;
603                                 goto exit_onqueue;
604                         }
605                         if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
606                                 dbg(1, "%s - command timed out.", __func__);
607                                 retval = -ETIMEDOUT;
608                                 goto exit_onqueue;
609                         }
610                         remove_wait_queue(&dev->write_wait, &waita);
611                         retval = mutex_lock_interruptible(&dev->mtx);
612                         if (retval) {
613                                 retval = bytes_written ? bytes_written : retval;
614                                 goto exit_nolock;
615                         }
616
617                         dbg(4," %s : in progress, count = %Zd", __func__, count);
618                 } else {
619                         spin_unlock_irqrestore(&dev->buflock, flags);
620                         set_current_state(TASK_RUNNING);
621                         remove_wait_queue(&dev->write_wait, &waita);
622                         dbg(4," %s : sending, count = %Zd", __func__, count);
623
624                         /* write the data into interrupt_out_buffer from userspace */
625                         buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
626                         bytes_to_write = count > buffer_size ? buffer_size : count;
627                         dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
628                             __func__, buffer_size, count, bytes_to_write);
629
630                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
631                                 retval = -EFAULT;
632                                 goto exit;
633                         }
634
635                         /* send off the urb */
636                         usb_fill_int_urb(
637                                 dev->interrupt_out_urb,
638                                 dev->udev,
639                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
640                                 dev->interrupt_out_buffer,
641                                 bytes_to_write,
642                                 adu_interrupt_out_callback,
643                                 dev,
644                                 dev->interrupt_out_endpoint->bInterval);
645                         dev->interrupt_out_urb->actual_length = bytes_to_write;
646                         dev->out_urb_finished = 0;
647                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
648                         if (retval < 0) {
649                                 dev->out_urb_finished = 1;
650                                 dev_err(&dev->udev->dev, "Couldn't submit "
651                                         "interrupt_out_urb %d\n", retval);
652                                 goto exit;
653                         }
654
655                         buffer += bytes_to_write;
656                         count -= bytes_to_write;
657
658                         bytes_written += bytes_to_write;
659                 }
660         }
661         mutex_unlock(&dev->mtx);
662         return bytes_written;
663
664 exit:
665         mutex_unlock(&dev->mtx);
666 exit_nolock:
667         dbg(2," %s : leave, return value %d", __func__, retval);
668         return retval;
669
670 exit_onqueue:
671         remove_wait_queue(&dev->write_wait, &waita);
672         return retval;
673 }
674
675 /* file operations needed when we register this driver */
676 static const struct file_operations adu_fops = {
677         .owner = THIS_MODULE,
678         .read  = adu_read,
679         .write = adu_write,
680         .open = adu_open,
681         .release = adu_release,
682 };
683
684 /*
685  * usb class driver info in order to get a minor number from the usb core,
686  * and to have the device registered with devfs and the driver core
687  */
688 static struct usb_class_driver adu_class = {
689         .name = "usb/adutux%d",
690         .fops = &adu_fops,
691         .minor_base = ADU_MINOR_BASE,
692 };
693
694 /**
695  * adu_probe
696  *
697  * Called by the usb core when a new device is connected that it thinks
698  * this driver might be interested in.
699  */
700 static int adu_probe(struct usb_interface *interface,
701                      const struct usb_device_id *id)
702 {
703         struct usb_device *udev = interface_to_usbdev(interface);
704         struct adu_device *dev = NULL;
705         struct usb_host_interface *iface_desc;
706         struct usb_endpoint_descriptor *endpoint;
707         int retval = -ENODEV;
708         int in_end_size;
709         int out_end_size;
710         int i;
711
712         dbg(2," %s : enter", __func__);
713
714         if (udev == NULL) {
715                 dev_err(&interface->dev, "udev is NULL.\n");
716                 goto exit;
717         }
718
719         /* allocate memory for our device state and intialize it */
720         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
721         if (dev == NULL) {
722                 dev_err(&interface->dev, "Out of memory\n");
723                 retval = -ENOMEM;
724                 goto exit;
725         }
726
727         mutex_init(&dev->mtx);
728         spin_lock_init(&dev->buflock);
729         dev->udev = udev;
730         init_waitqueue_head(&dev->read_wait);
731         init_waitqueue_head(&dev->write_wait);
732
733         iface_desc = &interface->altsetting[0];
734
735         /* set up the endpoint information */
736         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
737                 endpoint = &iface_desc->endpoint[i].desc;
738
739                 if (usb_endpoint_is_int_in(endpoint))
740                         dev->interrupt_in_endpoint = endpoint;
741
742                 if (usb_endpoint_is_int_out(endpoint))
743                         dev->interrupt_out_endpoint = endpoint;
744         }
745         if (dev->interrupt_in_endpoint == NULL) {
746                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
747                 goto error;
748         }
749         if (dev->interrupt_out_endpoint == NULL) {
750                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
751                 goto error;
752         }
753
754         in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
755         out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
756
757         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
758         if (!dev->read_buffer_primary) {
759                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
760                 retval = -ENOMEM;
761                 goto error;
762         }
763
764         /* debug code prime the buffer */
765         memset(dev->read_buffer_primary, 'a', in_end_size);
766         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
767         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
768         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
769
770         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
771         if (!dev->read_buffer_secondary) {
772                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
773                 retval = -ENOMEM;
774                 goto error;
775         }
776
777         /* debug code prime the buffer */
778         memset(dev->read_buffer_secondary, 'e', in_end_size);
779         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
780         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
781         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
782
783         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
784         if (!dev->interrupt_in_buffer) {
785                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
786                 goto error;
787         }
788
789         /* debug code prime the buffer */
790         memset(dev->interrupt_in_buffer, 'i', in_end_size);
791
792         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
793         if (!dev->interrupt_in_urb) {
794                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
795                 goto error;
796         }
797         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
798         if (!dev->interrupt_out_buffer) {
799                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
800                 goto error;
801         }
802         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
803         if (!dev->interrupt_out_urb) {
804                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
805                 goto error;
806         }
807
808         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
809                         sizeof(dev->serial_number))) {
810                 dev_err(&interface->dev, "Could not retrieve serial number\n");
811                 goto error;
812         }
813         dbg(2," %s : serial_number=%s", __func__, dev->serial_number);
814
815         /* we can register the device now, as it is ready */
816         usb_set_intfdata(interface, dev);
817
818         retval = usb_register_dev(interface, &adu_class);
819
820         if (retval) {
821                 /* something prevented us from registering this driver */
822                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
823                 usb_set_intfdata(interface, NULL);
824                 goto error;
825         }
826
827         dev->minor = interface->minor;
828
829         /* let the user know what node this device is now attached to */
830         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
831                  udev->descriptor.idProduct, dev->serial_number,
832                  (dev->minor - ADU_MINOR_BASE));
833 exit:
834         dbg(2," %s : leave, return value %p (dev)", __func__, dev);
835
836         return retval;
837
838 error:
839         adu_delete(dev);
840         return retval;
841 }
842
843 /**
844  * adu_disconnect
845  *
846  * Called by the usb core when the device is removed from the system.
847  */
848 static void adu_disconnect(struct usb_interface *interface)
849 {
850         struct adu_device *dev;
851         int minor;
852
853         dbg(2," %s : enter", __func__);
854
855         dev = usb_get_intfdata(interface);
856
857         mutex_lock(&dev->mtx);  /* not interruptible */
858         dev->udev = NULL;       /* poison */
859         minor = dev->minor;
860         usb_deregister_dev(interface, &adu_class);
861         mutex_unlock(&dev->mtx);
862
863         mutex_lock(&adutux_mutex);
864         usb_set_intfdata(interface, NULL);
865
866         /* if the device is not opened, then we clean up right now */
867         dbg(2," %s : open count %d", __func__, dev->open_count);
868         if (!dev->open_count)
869                 adu_delete(dev);
870
871         mutex_unlock(&adutux_mutex);
872
873         dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
874                  (minor - ADU_MINOR_BASE));
875
876         dbg(2," %s : leave", __func__);
877 }
878
879 /* usb specific object needed to register this driver with the usb subsystem */
880 static struct usb_driver adu_driver = {
881         .name = "adutux",
882         .probe = adu_probe,
883         .disconnect = adu_disconnect,
884         .id_table = device_table,
885 };
886
887 static int __init adu_init(void)
888 {
889         int result;
890
891         dbg(2," %s : enter", __func__);
892
893         /* register this driver with the USB subsystem */
894         result = usb_register(&adu_driver);
895         if (result < 0) {
896                 printk(KERN_ERR "usb_register failed for the "__FILE__
897                        " driver. Error number %d\n", result);
898                 goto exit;
899         }
900
901         printk(KERN_INFO "adutux " DRIVER_DESC " " DRIVER_VERSION "\n");
902         printk(KERN_INFO "adutux is an experimental driver. "
903                "Use at your own risk\n");
904
905 exit:
906         dbg(2," %s : leave, return value %d", __func__, result);
907
908         return result;
909 }
910
911 static void __exit adu_exit(void)
912 {
913         dbg(2," %s : enter", __func__);
914         /* deregister this driver with the USB subsystem */
915         usb_deregister(&adu_driver);
916         dbg(2," %s : leave", __func__);
917 }
918
919 module_init(adu_init);
920 module_exit(adu_exit);
921
922 MODULE_AUTHOR(DRIVER_AUTHOR);
923 MODULE_DESCRIPTION(DRIVER_DESC);
924 MODULE_LICENSE("GPL");