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                         (status != -ESHUTDOWN)) {
 193                         dbg(1," %s : nonzero status received: %d",
 194                             __FUNCTION__, status);
 195                 }
 196                 goto exit;
 197         }
 198
 199         if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
 200                 if (dev->read_buffer_length <
 201                     (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
 202                      (urb->actual_length)) {
 203                         memcpy (dev->read_buffer_primary +
 204                                 dev->read_buffer_length,
 205                                 dev->interrupt_in_buffer, urb->actual_length);
 206
 207                         dev->read_buffer_length += urb->actual_length;
 208                         dbg(2," %s reading  %d ", __FUNCTION__,
 209                             urb->actual_length);
 210                 } else {
 211                         dbg(1," %s : read_buffer overflow", __FUNCTION__);
 212                 }
 213         }
 214
 215 exit:
 216         dev->read_urb_finished = 1;
 217         spin_unlock(&dev->buflock);
 218         /* always wake up so we recover from errors */
 219         wake_up_interruptible(&dev->read_wait);
 220         adu_debug_data(5, __FUNCTION__, urb->actual_length,
 221                        urb->transfer_buffer);
 222         dbg(4," %s : leave, status %d", __FUNCTION__, status);
 223 }
 224
 225 static void adu_interrupt_out_callback(struct urb *urb)
 226 {
 227         struct adu_device *dev = urb->context;
 228         int status = urb->status;
 229
 230         dbg(4," %s : enter, status %d", __FUNCTION__, status);
 231         adu_debug_data(5,__FUNCTION__, urb->actual_length, urb->transfer_buffer);
 232
 233         if (status != 0) {
 234                 if ((status != -ENOENT) &&
 235                     (status != -ECONNRESET)) {
 236                         dbg(1, " %s :nonzero status received: %d",
 237                             __FUNCTION__, status);
 238                 }
 239                 goto exit;
 240         }
 241
 242         wake_up_interruptible(&dev->write_wait);
 243 exit:
 244
 245         adu_debug_data(5, __FUNCTION__, urb->actual_length,
 246                        urb->transfer_buffer);
 247         dbg(4," %s : leave, status %d", __FUNCTION__, status);
 248 }
 249
 250 static int adu_open(struct inode *inode, struct file *file)
 251 {
 252         struct adu_device *dev = NULL;
 253         struct usb_interface *interface;
 254         int subminor;
 255         int retval = 0;
 256
 257         dbg(2,"%s : enter", __FUNCTION__);
 258
 259         subminor = iminor(inode);
 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 = mutex_lock_interruptible(&dev->mtx))) {
 277                 dbg(2, "%s : mutex lock 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         if (dev->open_count == 1) {
 289                 /* initialize in direction */
 290                 dev->read_buffer_length = 0;
 291
 292                 /* fixup first read by having urb waiting for it */
 293                 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
 294                                  usb_rcvintpipe(dev->udev,
 295                                                 dev->interrupt_in_endpoint->bEndpointAddress),
 296                                  dev->interrupt_in_buffer,
 297                                  le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
 298                                  adu_interrupt_in_callback, dev,
 299                                  dev->interrupt_in_endpoint->bInterval);
 300                 /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 301                 dev->read_urb_finished = 0;
 302                 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 303                 if (retval)
 304                         --dev->open_count;
 305         }
 306         mutex_unlock(&dev->mtx);
 307
 308 exit_no_device:
 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         /* decrement our usage count for the device */
 321         --dev->open_count;
 322         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
 323         if (dev->open_count <= 0) {
 324                 adu_abort_transfers(dev);
 325                 dev->open_count = 0;
 326         }
 327
 328         dbg(2," %s : leave", __FUNCTION__);
 329         return retval;
 330 }
 331
 332 static int adu_release(struct inode *inode, struct file *file)
 333 {
 334         struct adu_device *dev = NULL;
 335         int retval = 0;
 336
 337         dbg(2," %s : enter", __FUNCTION__);
 338
 339         if (file == NULL) {
 340                 dbg(1," %s : file is NULL", __FUNCTION__);
 341                 retval = -ENODEV;
 342                 goto exit;
 343         }
 344
 345         dev = file->private_data;
 346
 347         if (dev == NULL) {
 348                 dbg(1," %s : object is NULL", __FUNCTION__);
 349                 retval = -ENODEV;
 350                 goto exit;
 351         }
 352
 353         /* lock our device */
 354         mutex_lock(&dev->mtx); /* not interruptible */
 355
 356         if (dev->open_count <= 0) {
 357                 dbg(1," %s : device not opened", __FUNCTION__);
 358                 retval = -ENODEV;
 359                 goto exit;
 360         }
 361
 362         if (dev->udev == NULL) {
 363                 /* the device was unplugged before the file was released */
 364                 mutex_unlock(&dev->mtx);
 365                 adu_delete(dev);
 366                 dev = NULL;
 367         } else {
 368                 /* do the work */
 369                 retval = adu_release_internal(dev);
 370         }
 371
 372 exit:
 373         if (dev)
 374                 mutex_unlock(&dev->mtx);
 375         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 376         return retval;
 377 }
 378
 379 static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 380                         loff_t *ppos)
 381 {
 382         struct adu_device *dev;
 383         size_t bytes_read = 0;
 384         size_t bytes_to_read = count;
 385         int i;
 386         int retval = 0;
 387         int timeout = 0;
 388         int should_submit = 0;
 389         unsigned long flags;
 390         DECLARE_WAITQUEUE(wait, current);
 391
 392         dbg(2," %s : enter, count = %Zd, file=%p", __FUNCTION__, count, file);
 393
 394         dev = file->private_data;
 395         dbg(2," %s : dev=%p", __FUNCTION__, dev);
 396         /* lock this object */
 397         if (mutex_lock_interruptible(&dev->mtx))
 398                 return -ERESTARTSYS;
 399
 400         /* verify that the device wasn't unplugged */
 401         if (dev->udev == NULL || dev->minor == 0) {
 402                 retval = -ENODEV;
 403                 err("No device or device unplugged %d", retval);
 404                 goto exit;
 405         }
 406
 407         /* verify that some data was requested */
 408         if (count == 0) {
 409                 dbg(1," %s : read request of 0 bytes", __FUNCTION__);
 410                 goto exit;
 411         }
 412
 413         timeout = COMMAND_TIMEOUT;
 414         dbg(2," %s : about to start looping", __FUNCTION__);
 415         while (bytes_to_read) {
 416                 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
 417                 dbg(2," %s : while, data_in_secondary=%d, status=%d",
 418                     __FUNCTION__, data_in_secondary,
 419                     dev->interrupt_in_urb->status);
 420
 421                 if (data_in_secondary) {
 422                         /* drain secondary buffer */
 423                         int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
 424                         i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
 425                         if (i < 0) {
 426                                 retval = -EFAULT;
 427                                 goto exit;
 428                         }
 429                         dev->secondary_head += (amount - i);
 430                         bytes_read += (amount - i);
 431                         bytes_to_read -= (amount - i);
 432                         if (i) {
 433                                 retval = bytes_read ? bytes_read : -EFAULT;
 434                                 goto exit;
 435                         }
 436                 } else {
 437                         /* we check the primary buffer */
 438                         spin_lock_irqsave (&dev->buflock, flags);
 439                         if (dev->read_buffer_length) {
 440                                 /* we secure access to the primary */
 441                                 char *tmp;
 442                                 dbg(2," %s : swap, read_buffer_length = %d",
 443                                     __FUNCTION__, dev->read_buffer_length);
 444                                 tmp = dev->read_buffer_secondary;
 445                                 dev->read_buffer_secondary = dev->read_buffer_primary;
 446                                 dev->read_buffer_primary = tmp;
 447                                 dev->secondary_head = 0;
 448                                 dev->secondary_tail = dev->read_buffer_length;
 449                                 dev->read_buffer_length = 0;
 450                                 spin_unlock_irqrestore(&dev->buflock, flags);
 451                                 /* we have a free buffer so use it */
 452                                 should_submit = 1;
 453                         } else {
 454                                 /* even the primary was empty - we may need to do IO */
 455                                 if (dev->interrupt_in_urb->status == -EINPROGRESS) {
 456                                         /* somebody is doing IO */
 457                                         spin_unlock_irqrestore(&dev->buflock, flags);
 458                                         dbg(2," %s : submitted already", __FUNCTION__);
 459                                 } else {
 460                                         /* we must initiate input */
 461                                         dbg(2," %s : initiate input", __FUNCTION__);
 462                                         dev->read_urb_finished = 0;
 463
 464                                         usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
 465                                                          usb_rcvintpipe(dev->udev,
 466                                                                         dev->interrupt_in_endpoint->bEndpointAddress),
 467                                                          dev->interrupt_in_buffer,
 468                                                          le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
 469                                                          adu_interrupt_in_callback,
 470                                                          dev,
 471                                                          dev->interrupt_in_endpoint->bInterval);
 472                                         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 473                                         if (!retval) {
 474                                                 spin_unlock_irqrestore(&dev->buflock, flags);
 475                                                 dbg(2," %s : submitted OK", __FUNCTION__);
 476                                         } else {
 477                                                 if (retval == -ENOMEM) {
 478                                                         retval = bytes_read ? bytes_read : -ENOMEM;
 479                                                 }
 480                                                 spin_unlock_irqrestore(&dev->buflock, flags);
 481                                                 dbg(2," %s : submit failed", __FUNCTION__);
 482                                                 goto exit;
 483                                         }
 484                                 }
 485
 486                                 /* we wait for I/O to complete */
 487                                 set_current_state(TASK_INTERRUPTIBLE);
 488                                 add_wait_queue(&dev->read_wait, &wait);
 489                                 if (!dev->read_urb_finished)
 490                                         timeout = schedule_timeout(COMMAND_TIMEOUT);
 491                                 else
 492                                         set_current_state(TASK_RUNNING);
 493                                 remove_wait_queue(&dev->read_wait, &wait);
 494
 495                                 if (timeout <= 0) {
 496                                         dbg(2," %s : timeout", __FUNCTION__);
 497                                         retval = bytes_read ? bytes_read : -ETIMEDOUT;
 498                                         goto exit;
 499                                 }
 500
 501                                 if (signal_pending(current)) {
 502                                         dbg(2," %s : signal pending", __FUNCTION__);
 503                                         retval = bytes_read ? bytes_read : -EINTR;
 504                                         goto exit;
 505                                 }
 506                         }
 507                 }
 508         }
 509
 510         retval = bytes_read;
 511         /* if the primary buffer is empty then use it */
 512         if (should_submit && !dev->interrupt_in_urb->status==-EINPROGRESS) {
 513                 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
 514                                  usb_rcvintpipe(dev->udev,
 515                                                 dev->interrupt_in_endpoint->bEndpointAddress),
 516                                                 dev->interrupt_in_buffer,
 517                                                 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
 518                                                 adu_interrupt_in_callback,
 519                                                 dev,
 520                                                 dev->interrupt_in_endpoint->bInterval);
 521                 /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 522                 dev->read_urb_finished = 0;
 523                 usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 524                 /* we ignore failure */
 525         }
 526
 527 exit:
 528         /* unlock the device */
 529         mutex_unlock(&dev->mtx);
 530
 531         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 532         return retval;
 533 }
 534
 535 static ssize_t adu_write(struct file *file, const __user char *buffer,
 536                          size_t count, loff_t *ppos)
 537 {
 538         struct adu_device *dev;
 539         size_t bytes_written = 0;
 540         size_t bytes_to_write;
 541         size_t buffer_size;
 542         int retval;
 543         int timeout = 0;
 544
 545         dbg(2," %s : enter, count = %Zd", __FUNCTION__, count);
 546
 547         dev = file->private_data;
 548
 549         /* lock this object */
 550         retval = mutex_lock_interruptible(&dev->mtx);
 551         if (retval)
 552                 goto exit_nolock;
 553
 554         /* verify that the device wasn't unplugged */
 555         if (dev->udev == NULL || dev->minor == 0) {
 556                 retval = -ENODEV;
 557                 err("No device or device unplugged %d", retval);
 558                 goto exit;
 559         }
 560
 561         /* verify that we actually have some data to write */
 562         if (count == 0) {
 563                 dbg(1," %s : write request of 0 bytes", __FUNCTION__);
 564                 goto exit;
 565         }
 566
 567
 568         while (count > 0) {
 569                 if (dev->interrupt_out_urb->status == -EINPROGRESS) {
 570                         timeout = COMMAND_TIMEOUT;
 571
 572                         while (timeout > 0) {
 573                                 if (signal_pending(current)) {
 574                                 dbg(1," %s : interrupted", __FUNCTION__);
 575                                 retval = -EINTR;
 576                                 goto exit;
 577                         }
 578                         mutex_unlock(&dev->mtx);
 579                         timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
 580                         retval = mutex_lock_interruptible(&dev->mtx);
 581                         if (retval) {
 582                                 retval = bytes_written ? bytes_written : retval;
 583                                 goto exit_nolock;
 584                         }
 585                         if (timeout > 0) {
 586                                 break;
 587                         }
 588                         dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout);
 589                 }
 590
 591
 592                 dbg(1," %s : final timeout: %d", __FUNCTION__, timeout);
 593
 594                 if (timeout == 0) {
 595                         dbg(1, "%s - command timed out.", __FUNCTION__);
 596                         retval = -ETIMEDOUT;
 597                         goto exit;
 598                 }
 599
 600                 dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
 601
 602                 } else {
 603                         dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
 604
 605                         /* write the data into interrupt_out_buffer from userspace */
 606                         buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 607                         bytes_to_write = count > buffer_size ? buffer_size : count;
 608                         dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
 609                             __FUNCTION__, buffer_size, count, bytes_to_write);
 610
 611                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
 612                                 retval = -EFAULT;
 613                                 goto exit;
 614                         }
 615
 616                         /* send off the urb */
 617                         usb_fill_int_urb(
 618                                 dev->interrupt_out_urb,
 619                                 dev->udev,
 620                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
 621                                 dev->interrupt_out_buffer,
 622                                 bytes_to_write,
 623                                 adu_interrupt_out_callback,
 624                                 dev,
 625                                 dev->interrupt_in_endpoint->bInterval);
 626                         /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 627                         dev->interrupt_out_urb->actual_length = bytes_to_write;
 628                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 629                         if (retval < 0) {
 630                                 err("Couldn't submit interrupt_out_urb %d", retval);
 631                                 goto exit;
 632                         }
 633
 634                         buffer += bytes_to_write;
 635                         count -= bytes_to_write;
 636
 637                         bytes_written += bytes_to_write;
 638                 }
 639         }
 640
 641         retval = bytes_written;
 642
 643 exit:
 644         /* unlock the device */
 645         mutex_unlock(&dev->mtx);
 646 exit_nolock:
 647
 648         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 649
 650         return retval;
 651 }
 652
 653 /* file operations needed when we register this driver */
 654 static const struct file_operations adu_fops = {
 655         .owner = THIS_MODULE,
 656         .read  = adu_read,
 657         .write = adu_write,
 658         .open = adu_open,
 659         .release = adu_release,
 660 };
 661
 662 /*
 663  * usb class driver info in order to get a minor number from the usb core,
 664  * and to have the device registered with devfs and the driver core
 665  */
 666 static struct usb_class_driver adu_class = {
 667         .name = "usb/adutux%d",
 668         .fops = &adu_fops,
 669         .minor_base = ADU_MINOR_BASE,
 670 };
 671
 672 /**
 673  * adu_probe
 674  *
 675  * Called by the usb core when a new device is connected that it thinks
 676  * this driver might be interested in.
 677  */
 678 static int adu_probe(struct usb_interface *interface,
 679                      const struct usb_device_id *id)
 680 {
 681         struct usb_device *udev = interface_to_usbdev(interface);
 682         struct adu_device *dev = NULL;
 683         struct usb_host_interface *iface_desc;
 684         struct usb_endpoint_descriptor *endpoint;
 685         int retval = -ENODEV;
 686         int in_end_size;
 687         int out_end_size;
 688         int i;
 689
 690         dbg(2," %s : enter", __FUNCTION__);
 691
 692         if (udev == NULL) {
 693                 dev_err(&interface->dev, "udev is NULL.\n");
 694                 goto exit;
 695         }
 696
 697         /* allocate memory for our device state and intialize it */
 698         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
 699         if (dev == NULL) {
 700                 dev_err(&interface->dev, "Out of memory\n");
 701                 retval = -ENOMEM;
 702                 goto exit;
 703         }
 704
 705         mutex_init(&dev->mtx);
 706         spin_lock_init(&dev->buflock);
 707         dev->udev = udev;
 708         init_waitqueue_head(&dev->read_wait);
 709         init_waitqueue_head(&dev->write_wait);
 710
 711         iface_desc = &interface->altsetting[0];
 712
 713         /* set up the endpoint information */
 714         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 715                 endpoint = &iface_desc->endpoint[i].desc;
 716
 717                 if (usb_endpoint_is_int_in(endpoint))
 718                         dev->interrupt_in_endpoint = endpoint;
 719
 720                 if (usb_endpoint_is_int_out(endpoint))
 721                         dev->interrupt_out_endpoint = endpoint;
 722         }
 723         if (dev->interrupt_in_endpoint == NULL) {
 724                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
 725                 goto error;
 726         }
 727         if (dev->interrupt_out_endpoint == NULL) {
 728                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
 729                 goto error;
 730         }
 731
 732         in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 733         out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 734
 735         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
 736         if (!dev->read_buffer_primary) {
 737                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
 738                 retval = -ENOMEM;
 739                 goto error;
 740         }
 741
 742         /* debug code prime the buffer */
 743         memset(dev->read_buffer_primary, 'a', in_end_size);
 744         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
 745         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
 746         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
 747
 748         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
 749         if (!dev->read_buffer_secondary) {
 750                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
 751                 retval = -ENOMEM;
 752                 goto error;
 753         }
 754
 755         /* debug code prime the buffer */
 756         memset(dev->read_buffer_secondary, 'e', in_end_size);
 757         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
 758         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
 759         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
 760
 761         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
 762         if (!dev->interrupt_in_buffer) {
 763                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
 764                 goto error;
 765         }
 766
 767         /* debug code prime the buffer */
 768         memset(dev->interrupt_in_buffer, 'i', in_end_size);
 769
 770         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 771         if (!dev->interrupt_in_urb) {
 772                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 773                 goto error;
 774         }
 775         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
 776         if (!dev->interrupt_out_buffer) {
 777                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
 778                 goto error;
 779         }
 780         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 781         if (!dev->interrupt_out_urb) {
 782                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
 783                 goto error;
 784         }
 785
 786         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
 787                         sizeof(dev->serial_number))) {
 788                 dev_err(&interface->dev, "Could not retrieve serial number\n");
 789                 goto error;
 790         }
 791         dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
 792
 793         /* we can register the device now, as it is ready */
 794         usb_set_intfdata(interface, dev);
 795
 796         retval = usb_register_dev(interface, &adu_class);
 797
 798         if (retval) {
 799                 /* something prevented us from registering this driver */
 800                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 801                 usb_set_intfdata(interface, NULL);
 802                 goto error;
 803         }
 804
 805         dev->minor = interface->minor;
 806
 807         /* let the user know what node this device is now attached to */
 808         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d",
 809                  udev->descriptor.idProduct, dev->serial_number,
 810                  (dev->minor - ADU_MINOR_BASE));
 811 exit:
 812         dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
 813
 814         return retval;
 815
 816 error:
 817         adu_delete(dev);
 818         return retval;
 819 }
 820
 821 /**
 822  * adu_disconnect
 823  *
 824  * Called by the usb core when the device is removed from the system.
 825  */
 826 static void adu_disconnect(struct usb_interface *interface)
 827 {
 828         struct adu_device *dev;
 829         int minor;
 830
 831         dbg(2," %s : enter", __FUNCTION__);
 832
 833         dev = usb_get_intfdata(interface);
 834         usb_set_intfdata(interface, NULL);
 835
 836         minor = dev->minor;
 837
 838         /* give back our minor */
 839         usb_deregister_dev(interface, &adu_class);
 840         dev->minor = 0;
 841
 842         mutex_lock(&dev->mtx); /* not interruptible */
 843
 844         /* if the device is not opened, then we clean up right now */
 845         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
 846         if (!dev->open_count) {
 847                 mutex_unlock(&dev->mtx);
 848                 adu_delete(dev);
 849         } else {
 850                 dev->udev = NULL;
 851                 mutex_unlock(&dev->mtx);
 852         }
 853
 854         dev_info(&interface->dev, "ADU device adutux%d now disconnected",
 855                  (minor - ADU_MINOR_BASE));
 856
 857         dbg(2," %s : leave", __FUNCTION__);
 858 }
 859
 860 /* usb specific object needed to register this driver with the usb subsystem */
 861 static struct usb_driver adu_driver = {
 862         .name = "adutux",
 863         .probe = adu_probe,
 864         .disconnect = adu_disconnect,
 865         .id_table = device_table,
 866 };
 867
 868 static int __init adu_init(void)
 869 {
 870         int result;
 871
 872         dbg(2," %s : enter", __FUNCTION__);
 873
 874         /* register this driver with the USB subsystem */
 875         result = usb_register(&adu_driver);
 876         if (result < 0) {
 877                 err("usb_register failed for the "__FILE__" driver. "
 878                     "Error number %d", result);
 879                 goto exit;
 880         }
 881
 882         info("adutux " DRIVER_DESC " " DRIVER_VERSION);
 883         info("adutux is an experimental driver. Use at your own risk");
 884
 885 exit:
 886         dbg(2," %s : leave, return value %d", __FUNCTION__, result);
 887
 888         return result;
 889 }
 890
 891 static void __exit adu_exit(void)
 892 {
 893         dbg(2," %s : enter", __FUNCTION__);
 894         /* deregister this driver with the USB subsystem */
 895         usb_deregister(&adu_driver);
 896         dbg(2," %s : leave", __FUNCTION__);
 897 }
 898
 899 module_init(adu_init);
 900 module_exit(adu_exit);
 901
 902 MODULE_AUTHOR(DRIVER_AUTHOR);
 903 MODULE_DESCRIPTION(DRIVER_DESC);
 904 MODULE_LICENSE("GPL");