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