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