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 /* 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, struct pt_regs *regs)
 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, struct pt_regs *regs)
 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         up(&dev->sem);
 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 (down_interruptible(&dev->sem))
 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_KERNEL);
 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         up(&dev->sem);
 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 = 0;
 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         down_interruptible(&dev->sem);
 550
 551         /* verify that the device wasn't unplugged */
 552         if (dev->udev == NULL || dev->minor == 0) {
 553                 retval = -ENODEV;
 554                 err("No device or device unplugged %d", retval);
 555                 goto exit;
 556         }
 557
 558         /* verify that we actually have some data to write */
 559         if (count == 0) {
 560                 dbg(1," %s : write request of 0 bytes", __FUNCTION__);
 561                 goto exit;
 562         }
 563
 564
 565         while (count > 0) {
 566                 if (dev->interrupt_out_urb->status == -EINPROGRESS) {
 567                         timeout = COMMAND_TIMEOUT;
 568
 569                         while (timeout > 0) {
 570                                 if (signal_pending(current)) {
 571                                 dbg(1," %s : interrupted", __FUNCTION__);
 572                                 retval = -EINTR;
 573                                 goto exit;
 574                         }
 575                         up(&dev->sem);
 576                         timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
 577                         down_interruptible(&dev->sem);
 578                         if (timeout > 0) {
 579                                 break;
 580                         }
 581                         dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout);
 582                 }
 583
 584
 585                 dbg(1," %s : final timeout: %d", __FUNCTION__, timeout);
 586
 587                 if (timeout == 0) {
 588                         dbg(1, "%s - command timed out.", __FUNCTION__);
 589                         retval = -ETIMEDOUT;
 590                         goto exit;
 591                 }
 592
 593                 dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
 594
 595                 } else {
 596                         dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
 597
 598                         /* write the data into interrupt_out_buffer from userspace */
 599                         buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 600                         bytes_to_write = count > buffer_size ? buffer_size : count;
 601                         dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
 602                             __FUNCTION__, buffer_size, count, bytes_to_write);
 603
 604                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
 605                                 retval = -EFAULT;
 606                                 goto exit;
 607                         }
 608
 609                         /* send off the urb */
 610                         usb_fill_int_urb(
 611                                 dev->interrupt_out_urb,
 612                                 dev->udev,
 613                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
 614                                 dev->interrupt_out_buffer,
 615                                 bytes_to_write,
 616                                 adu_interrupt_out_callback,
 617                                 dev,
 618                                 dev->interrupt_in_endpoint->bInterval);
 619                         /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 620                         dev->interrupt_out_urb->actual_length = bytes_to_write;
 621                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 622                         if (retval < 0) {
 623                                 err("Couldn't submit interrupt_out_urb %d", retval);
 624                                 goto exit;
 625                         }
 626
 627                         buffer += bytes_to_write;
 628                         count -= bytes_to_write;
 629
 630                         bytes_written += bytes_to_write;
 631                 }
 632         }
 633
 634         retval = bytes_written;
 635
 636 exit:
 637         /* unlock the device */
 638         up(&dev->sem);
 639
 640         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 641
 642         return retval;
 643 }
 644
 645 /* file operations needed when we register this driver */
 646 static struct file_operations adu_fops = {
 647         .owner = THIS_MODULE,
 648         .read  = adu_read,
 649         .write = adu_write,
 650         .open = adu_open,
 651         .release = adu_release,
 652 };
 653
 654 /*
 655  * usb class driver info in order to get a minor number from the usb core,
 656  * and to have the device registered with devfs and the driver core
 657  */
 658 static struct usb_class_driver adu_class = {
 659         .name = "usb/adutux%d",
 660         .fops = &adu_fops,
 661         .minor_base = ADU_MINOR_BASE,
 662 };
 663
 664 /**
 665  * adu_probe
 666  *
 667  * Called by the usb core when a new device is connected that it thinks
 668  * this driver might be interested in.
 669  */
 670 static int adu_probe(struct usb_interface *interface,
 671                      const struct usb_device_id *id)
 672 {
 673         struct usb_device *udev = interface_to_usbdev(interface);
 674         struct adu_device *dev = NULL;
 675         struct usb_host_interface *iface_desc;
 676         struct usb_endpoint_descriptor *endpoint;
 677         int retval = -ENODEV;
 678         int in_end_size;
 679         int out_end_size;
 680         int i;
 681
 682         dbg(2," %s : enter", __FUNCTION__);
 683
 684         if (udev == NULL) {
 685                 dev_err(&interface->dev, "udev is NULL.\n");
 686                 goto exit;
 687         }
 688
 689         /* allocate memory for our device state and intialize it */
 690         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
 691         if (dev == NULL) {
 692                 dev_err(&interface->dev, "Out of memory\n");
 693                 retval = -ENOMEM;
 694                 goto exit;
 695         }
 696
 697         init_MUTEX(&dev->sem);
 698         spin_lock_init(&dev->buflock);
 699         dev->udev = udev;
 700         init_waitqueue_head(&dev->read_wait);
 701         init_waitqueue_head(&dev->write_wait);
 702
 703         iface_desc = &interface->altsetting[0];
 704
 705         /* set up the endpoint information */
 706         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 707                 endpoint = &iface_desc->endpoint[i].desc;
 708
 709                 if (usb_endpoint_is_int_in(endpoint))
 710                         dev->interrupt_in_endpoint = endpoint;
 711
 712                 if (usb_endpoint_is_int_out(endpoint))
 713                         dev->interrupt_out_endpoint = endpoint;
 714         }
 715         if (dev->interrupt_in_endpoint == NULL) {
 716                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
 717                 goto error;
 718         }
 719         if (dev->interrupt_out_endpoint == NULL) {
 720                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
 721                 goto error;
 722         }
 723
 724         in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 725         out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 726
 727         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
 728         if (!dev->read_buffer_primary) {
 729                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
 730                 retval = -ENOMEM;
 731                 goto error;
 732         }
 733
 734         /* debug code prime the buffer */
 735         memset(dev->read_buffer_primary, 'a', in_end_size);
 736         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
 737         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
 738         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
 739
 740         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
 741         if (!dev->read_buffer_secondary) {
 742                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
 743                 retval = -ENOMEM;
 744                 goto error;
 745         }
 746
 747         /* debug code prime the buffer */
 748         memset(dev->read_buffer_secondary, 'e', in_end_size);
 749         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
 750         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
 751         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
 752
 753         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
 754         if (!dev->interrupt_in_buffer) {
 755                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
 756                 goto error;
 757         }
 758
 759         /* debug code prime the buffer */
 760         memset(dev->interrupt_in_buffer, 'i', in_end_size);
 761
 762         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 763         if (!dev->interrupt_in_urb) {
 764                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 765                 goto error;
 766         }
 767         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
 768         if (!dev->interrupt_out_buffer) {
 769                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
 770                 goto error;
 771         }
 772         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 773         if (!dev->interrupt_out_urb) {
 774                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
 775                 goto error;
 776         }
 777
 778         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
 779                         sizeof(dev->serial_number))) {
 780                 dev_err(&interface->dev, "Could not retrieve serial number\n");
 781                 goto error;
 782         }
 783         dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
 784
 785         /* we can register the device now, as it is ready */
 786         usb_set_intfdata(interface, dev);
 787
 788         retval = usb_register_dev(interface, &adu_class);
 789
 790         if (retval) {
 791                 /* something prevented us from registering this driver */
 792                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 793                 usb_set_intfdata(interface, NULL);
 794                 goto error;
 795         }
 796
 797         dev->minor = interface->minor;
 798
 799         /* let the user know what node this device is now attached to */
 800         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d",
 801                  udev->descriptor.idProduct, dev->serial_number,
 802                  (dev->minor - ADU_MINOR_BASE));
 803 exit:
 804         dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
 805
 806         return retval;
 807
 808 error:
 809         adu_delete(dev);
 810         return retval;
 811 }
 812
 813 /**
 814  * adu_disconnect
 815  *
 816  * Called by the usb core when the device is removed from the system.
 817  */
 818 static void adu_disconnect(struct usb_interface *interface)
 819 {
 820         struct adu_device *dev;
 821         int minor;
 822
 823         dbg(2," %s : enter", __FUNCTION__);
 824
 825         mutex_lock(&disconnect_mutex); /* not interruptible */
 826
 827         dev = usb_get_intfdata(interface);
 828         usb_set_intfdata(interface, NULL);
 829
 830         down(&dev->sem); /* not interruptible */
 831
 832         minor = dev->minor;
 833
 834         /* give back our minor */
 835         usb_deregister_dev(interface, &adu_class);
 836         dev->minor = 0;
 837
 838         /* if the device is not opened, then we clean up right now */
 839         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
 840         if (!dev->open_count) {
 841                 up(&dev->sem);
 842                 adu_delete(dev);
 843         } else {
 844                 dev->udev = NULL;
 845                 up(&dev->sem);
 846         }
 847
 848         mutex_unlock(&disconnect_mutex);
 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");