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