Pileus Git - ~andy/linux/blob - 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)
 181 {
 182         struct adu_device *dev = urb->context;
 183
 184         dbg(4," %s : enter, status %d", __FUNCTION__, urb->status);
 185         adu_debug_data(5, __FUNCTION__, urb->actual_length,
 186                        urb->transfer_buffer);
 187
 188         spin_lock(&dev->buflock);
 189
 190         if (urb->status != 0) {
 191                 if ((urb->status != -ENOENT) && (urb->status != -ECONNRESET)) {
 192                         dbg(1," %s : nonzero status received: %d",
 193                             __FUNCTION__, urb->status);
 194                 }
 195                 goto exit;
 196         }
 197
 198         if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
 199                 if (dev->read_buffer_length <
 200                     (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
 201                      (urb->actual_length)) {
 202                         memcpy (dev->read_buffer_primary +
 203                                 dev->read_buffer_length,
 204                                 dev->interrupt_in_buffer, urb->actual_length);
 205
 206                         dev->read_buffer_length += urb->actual_length;
 207                         dbg(2," %s reading  %d ", __FUNCTION__,
 208                             urb->actual_length);
 209                 } else {
 210                         dbg(1," %s : read_buffer overflow", __FUNCTION__);
 211                 }
 212         }
 213
 214 exit:
 215         dev->read_urb_finished = 1;
 216         spin_unlock(&dev->buflock);
 217         /* always wake up so we recover from errors */
 218         wake_up_interruptible(&dev->read_wait);
 219         adu_debug_data(5, __FUNCTION__, urb->actual_length,
 220                        urb->transfer_buffer);
 221         dbg(4," %s : leave, status %d", __FUNCTION__, urb->status);
 222 }
 223
 224 static void adu_interrupt_out_callback(struct urb *urb)
 225 {
 226         struct adu_device *dev = urb->context;
 227
 228         dbg(4," %s : enter, status %d", __FUNCTION__, urb->status);
 229         adu_debug_data(5,__FUNCTION__, urb->actual_length, urb->transfer_buffer);
 230
 231         if (urb->status != 0) {
 232                 if ((urb->status != -ENOENT) &&
 233                     (urb->status != -ECONNRESET)) {
 234                         dbg(1, " %s :nonzero status received: %d",
 235                             __FUNCTION__, urb->status);
 236                 }
 237                 goto exit;
 238         }
 239
 240         wake_up_interruptible(&dev->write_wait);
 241 exit:
 242
 243         adu_debug_data(5, __FUNCTION__, urb->actual_length,
 244                        urb->transfer_buffer);
 245         dbg(4," %s : leave, status %d", __FUNCTION__, urb->status);
 246 }
 247
 248 static int adu_open(struct inode *inode, struct file *file)
 249 {
 250         struct adu_device *dev = NULL;
 251         struct usb_interface *interface;
 252         int subminor;
 253         int retval = 0;
 254
 255         dbg(2,"%s : enter", __FUNCTION__);
 256
 257         subminor = iminor(inode);
 258
 259         mutex_lock(&disconnect_mutex);
 260
 261         interface = usb_find_interface(&adu_driver, subminor);
 262         if (!interface) {
 263                 err("%s - error, can't find device for minor %d",
 264                     __FUNCTION__, subminor);
 265                 retval = -ENODEV;
 266                 goto exit_no_device;
 267         }
 268
 269         dev = usb_get_intfdata(interface);
 270         if (!dev) {
 271                 retval = -ENODEV;
 272                 goto exit_no_device;
 273         }
 274
 275         /* lock this device */
 276         if ((retval = down_interruptible(&dev->sem))) {
 277                 dbg(2, "%s : sem down failed", __FUNCTION__);
 278                 goto exit_no_device;
 279         }
 280
 281         /* increment our usage count for the device */
 282         ++dev->open_count;
 283         dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count);
 284
 285         /* save device in the file's private structure */
 286         file->private_data = dev;
 287
 288         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         up(&dev->sem);
 307
 308 exit_no_device:
 309         mutex_unlock(&disconnect_mutex);
 310         dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval);
 311
 312         return retval;
 313 }
 314
 315 static int adu_release_internal(struct adu_device *dev)
 316 {
 317         int retval = 0;
 318
 319         dbg(2," %s : enter", __FUNCTION__);
 320
 321         if (dev->udev == NULL) {
 322                 /* the device was unplugged before the file was released */
 323                 adu_delete(dev);
 324                 goto exit;
 325         }
 326
 327         /* decrement our usage count for the device */
 328         --dev->open_count;
 329         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
 330         if (dev->open_count <= 0) {
 331                 adu_abort_transfers(dev);
 332                 dev->open_count = 0;
 333         }
 334
 335 exit:
 336         dbg(2," %s : leave", __FUNCTION__);
 337         return retval;
 338 }
 339
 340 static int adu_release(struct inode *inode, struct file *file)
 341 {
 342         struct adu_device *dev = NULL;
 343         int retval = 0;
 344
 345         dbg(2," %s : enter", __FUNCTION__);
 346
 347         if (file == NULL) {
 348                 dbg(1," %s : file is NULL", __FUNCTION__);
 349                 retval = -ENODEV;
 350                 goto exit;
 351         }
 352
 353         dev = file->private_data;
 354
 355         if (dev == NULL) {
 356                 dbg(1," %s : object is NULL", __FUNCTION__);
 357                 retval = -ENODEV;
 358                 goto exit;
 359         }
 360
 361         /* lock our device */
 362         down(&dev->sem); /* not interruptible */
 363
 364         if (dev->open_count <= 0) {
 365                 dbg(1," %s : device not opened", __FUNCTION__);
 366                 retval = -ENODEV;
 367                 goto exit;
 368         }
 369
 370         /* do the work */
 371         retval = adu_release_internal(dev);
 372
 373 exit:
 374         if (dev)
 375                 up(&dev->sem);
 376         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 377         return retval;
 378 }
 379
 380 static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
 381                         loff_t *ppos)
 382 {
 383         struct adu_device *dev;
 384         size_t bytes_read = 0;
 385         size_t bytes_to_read = count;
 386         int i;
 387         int retval = 0;
 388         int timeout = 0;
 389         int should_submit = 0;
 390         unsigned long flags;
 391         DECLARE_WAITQUEUE(wait, current);
 392
 393         dbg(2," %s : enter, count = %Zd, file=%p", __FUNCTION__, count, file);
 394
 395         dev = file->private_data;
 396         dbg(2," %s : dev=%p", __FUNCTION__, dev);
 397         /* lock this object */
 398         if (down_interruptible(&dev->sem))
 399                 return -ERESTARTSYS;
 400
 401         /* verify that the device wasn't unplugged */
 402         if (dev->udev == NULL || dev->minor == 0) {
 403                 retval = -ENODEV;
 404                 err("No device or device unplugged %d", retval);
 405                 goto exit;
 406         }
 407
 408         /* verify that some data was requested */
 409         if (count == 0) {
 410                 dbg(1," %s : read request of 0 bytes", __FUNCTION__);
 411                 goto exit;
 412         }
 413
 414         timeout = COMMAND_TIMEOUT;
 415         dbg(2," %s : about to start looping", __FUNCTION__);
 416         while (bytes_to_read) {
 417                 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
 418                 dbg(2," %s : while, data_in_secondary=%d, status=%d",
 419                     __FUNCTION__, data_in_secondary,
 420                     dev->interrupt_in_urb->status);
 421
 422                 if (data_in_secondary) {
 423                         /* drain secondary buffer */
 424                         int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
 425                         i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
 426                         if (i < 0) {
 427                                 retval = -EFAULT;
 428                                 goto exit;
 429                         }
 430                         dev->secondary_head += (amount - i);
 431                         bytes_read += (amount - i);
 432                         bytes_to_read -= (amount - i);
 433                         if (i) {
 434                                 retval = bytes_read ? bytes_read : -EFAULT;
 435                                 goto exit;
 436                         }
 437                 } else {
 438                         /* we check the primary buffer */
 439                         spin_lock_irqsave (&dev->buflock, flags);
 440                         if (dev->read_buffer_length) {
 441                                 /* we secure access to the primary */
 442                                 char *tmp;
 443                                 dbg(2," %s : swap, read_buffer_length = %d",
 444                                     __FUNCTION__, dev->read_buffer_length);
 445                                 tmp = dev->read_buffer_secondary;
 446                                 dev->read_buffer_secondary = dev->read_buffer_primary;
 447                                 dev->read_buffer_primary = tmp;
 448                                 dev->secondary_head = 0;
 449                                 dev->secondary_tail = dev->read_buffer_length;
 450                                 dev->read_buffer_length = 0;
 451                                 spin_unlock_irqrestore(&dev->buflock, flags);
 452                                 /* we have a free buffer so use it */
 453                                 should_submit = 1;
 454                         } else {
 455                                 /* even the primary was empty - we may need to do IO */
 456                                 if (dev->interrupt_in_urb->status == -EINPROGRESS) {
 457                                         /* somebody is doing IO */
 458                                         spin_unlock_irqrestore(&dev->buflock, flags);
 459                                         dbg(2," %s : submitted already", __FUNCTION__);
 460                                 } else {
 461                                         /* we must initiate input */
 462                                         dbg(2," %s : initiate input", __FUNCTION__);
 463                                         dev->read_urb_finished = 0;
 464
 465                                         usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
 466                                                          usb_rcvintpipe(dev->udev,
 467                                                                         dev->interrupt_in_endpoint->bEndpointAddress),
 468                                                          dev->interrupt_in_buffer,
 469                                                          le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
 470                                                          adu_interrupt_in_callback,
 471                                                          dev,
 472                                                          dev->interrupt_in_endpoint->bInterval);
 473                                         retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
 474                                         if (!retval) {
 475                                                 spin_unlock_irqrestore(&dev->buflock, flags);
 476                                                 dbg(2," %s : submitted OK", __FUNCTION__);
 477                                         } else {
 478                                                 if (retval == -ENOMEM) {
 479                                                         retval = bytes_read ? bytes_read : -ENOMEM;
 480                                                 }
 481                                                 spin_unlock_irqrestore(&dev->buflock, flags);
 482                                                 dbg(2," %s : submit failed", __FUNCTION__);
 483                                                 goto exit;
 484                                         }
 485                                 }
 486
 487                                 /* we wait for I/O to complete */
 488                                 set_current_state(TASK_INTERRUPTIBLE);
 489                                 add_wait_queue(&dev->read_wait, &wait);
 490                                 if (!dev->read_urb_finished)
 491                                         timeout = schedule_timeout(COMMAND_TIMEOUT);
 492                                 else
 493                                         set_current_state(TASK_RUNNING);
 494                                 remove_wait_queue(&dev->read_wait, &wait);
 495
 496                                 if (timeout <= 0) {
 497                                         dbg(2," %s : timeout", __FUNCTION__);
 498                                         retval = bytes_read ? bytes_read : -ETIMEDOUT;
 499                                         goto exit;
 500                                 }
 501
 502                                 if (signal_pending(current)) {
 503                                         dbg(2," %s : signal pending", __FUNCTION__);
 504                                         retval = bytes_read ? bytes_read : -EINTR;
 505                                         goto exit;
 506                                 }
 507                         }
 508                 }
 509         }
 510
 511         retval = bytes_read;
 512         /* if the primary buffer is empty then use it */
 513         if (should_submit && !dev->interrupt_in_urb->status==-EINPROGRESS) {
 514                 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
 515                                  usb_rcvintpipe(dev->udev,
 516                                                 dev->interrupt_in_endpoint->bEndpointAddress),
 517                                                 dev->interrupt_in_buffer,
 518                                                 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
 519                                                 adu_interrupt_in_callback,
 520                                                 dev,
 521                                                 dev->interrupt_in_endpoint->bInterval);
 522                 /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 523                 dev->read_urb_finished = 0;
 524                 usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
 525                 /* we ignore failure */
 526         }
 527
 528 exit:
 529         /* unlock the device */
 530         up(&dev->sem);
 531
 532         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 533         return retval;
 534 }
 535
 536 static ssize_t adu_write(struct file *file, const __user char *buffer,
 537                          size_t count, loff_t *ppos)
 538 {
 539         struct adu_device *dev;
 540         size_t bytes_written = 0;
 541         size_t bytes_to_write;
 542         size_t buffer_size;
 543         int retval;
 544         int timeout = 0;
 545
 546         dbg(2," %s : enter, count = %Zd", __FUNCTION__, count);
 547
 548         dev = file->private_data;
 549
 550         /* lock this object */
 551         retval = down_interruptible(&dev->sem);
 552         if (retval)
 553                 goto exit_nolock;
 554
 555         /* verify that the device wasn't unplugged */
 556         if (dev->udev == NULL || dev->minor == 0) {
 557                 retval = -ENODEV;
 558                 err("No device or device unplugged %d", retval);
 559                 goto exit;
 560         }
 561
 562         /* verify that we actually have some data to write */
 563         if (count == 0) {
 564                 dbg(1," %s : write request of 0 bytes", __FUNCTION__);
 565                 goto exit;
 566         }
 567
 568
 569         while (count > 0) {
 570                 if (dev->interrupt_out_urb->status == -EINPROGRESS) {
 571                         timeout = COMMAND_TIMEOUT;
 572
 573                         while (timeout > 0) {
 574                                 if (signal_pending(current)) {
 575                                 dbg(1," %s : interrupted", __FUNCTION__);
 576                                 retval = -EINTR;
 577                                 goto exit;
 578                         }
 579                         up(&dev->sem);
 580                         timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
 581                         retval = down_interruptible(&dev->sem);
 582                         if (retval) {
 583                                 retval = bytes_written ? bytes_written : retval;
 584                                 goto exit_nolock;
 585                         }
 586                         if (timeout > 0) {
 587                                 break;
 588                         }
 589                         dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout);
 590                 }
 591
 592
 593                 dbg(1," %s : final timeout: %d", __FUNCTION__, timeout);
 594
 595                 if (timeout == 0) {
 596                         dbg(1, "%s - command timed out.", __FUNCTION__);
 597                         retval = -ETIMEDOUT;
 598                         goto exit;
 599                 }
 600
 601                 dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
 602
 603                 } else {
 604                         dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
 605
 606                         /* write the data into interrupt_out_buffer from userspace */
 607                         buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 608                         bytes_to_write = count > buffer_size ? buffer_size : count;
 609                         dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
 610                             __FUNCTION__, buffer_size, count, bytes_to_write);
 611
 612                         if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
 613                                 retval = -EFAULT;
 614                                 goto exit;
 615                         }
 616
 617                         /* send off the urb */
 618                         usb_fill_int_urb(
 619                                 dev->interrupt_out_urb,
 620                                 dev->udev,
 621                                 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
 622                                 dev->interrupt_out_buffer,
 623                                 bytes_to_write,
 624                                 adu_interrupt_out_callback,
 625                                 dev,
 626                                 dev->interrupt_in_endpoint->bInterval);
 627                         /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
 628                         dev->interrupt_out_urb->actual_length = bytes_to_write;
 629                         retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
 630                         if (retval < 0) {
 631                                 err("Couldn't submit interrupt_out_urb %d", retval);
 632                                 goto exit;
 633                         }
 634
 635                         buffer += bytes_to_write;
 636                         count -= bytes_to_write;
 637
 638                         bytes_written += bytes_to_write;
 639                 }
 640         }
 641
 642         retval = bytes_written;
 643
 644 exit:
 645         /* unlock the device */
 646         up(&dev->sem);
 647 exit_nolock:
 648
 649         dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
 650
 651         return retval;
 652 }
 653
 654 /* file operations needed when we register this driver */
 655 static const struct file_operations adu_fops = {
 656         .owner = THIS_MODULE,
 657         .read  = adu_read,
 658         .write = adu_write,
 659         .open = adu_open,
 660         .release = adu_release,
 661 };
 662
 663 /*
 664  * usb class driver info in order to get a minor number from the usb core,
 665  * and to have the device registered with devfs and the driver core
 666  */
 667 static struct usb_class_driver adu_class = {
 668         .name = "usb/adutux%d",
 669         .fops = &adu_fops,
 670         .minor_base = ADU_MINOR_BASE,
 671 };
 672
 673 /**
 674  * adu_probe
 675  *
 676  * Called by the usb core when a new device is connected that it thinks
 677  * this driver might be interested in.
 678  */
 679 static int adu_probe(struct usb_interface *interface,
 680                      const struct usb_device_id *id)
 681 {
 682         struct usb_device *udev = interface_to_usbdev(interface);
 683         struct adu_device *dev = NULL;
 684         struct usb_host_interface *iface_desc;
 685         struct usb_endpoint_descriptor *endpoint;
 686         int retval = -ENODEV;
 687         int in_end_size;
 688         int out_end_size;
 689         int i;
 690
 691         dbg(2," %s : enter", __FUNCTION__);
 692
 693         if (udev == NULL) {
 694                 dev_err(&interface->dev, "udev is NULL.\n");
 695                 goto exit;
 696         }
 697
 698         /* allocate memory for our device state and intialize it */
 699         dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
 700         if (dev == NULL) {
 701                 dev_err(&interface->dev, "Out of memory\n");
 702                 retval = -ENOMEM;
 703                 goto exit;
 704         }
 705
 706         init_MUTEX(&dev->sem);
 707         spin_lock_init(&dev->buflock);
 708         dev->udev = udev;
 709         init_waitqueue_head(&dev->read_wait);
 710         init_waitqueue_head(&dev->write_wait);
 711
 712         iface_desc = &interface->altsetting[0];
 713
 714         /* set up the endpoint information */
 715         for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
 716                 endpoint = &iface_desc->endpoint[i].desc;
 717
 718                 if (usb_endpoint_is_int_in(endpoint))
 719                         dev->interrupt_in_endpoint = endpoint;
 720
 721                 if (usb_endpoint_is_int_out(endpoint))
 722                         dev->interrupt_out_endpoint = endpoint;
 723         }
 724         if (dev->interrupt_in_endpoint == NULL) {
 725                 dev_err(&interface->dev, "interrupt in endpoint not found\n");
 726                 goto error;
 727         }
 728         if (dev->interrupt_out_endpoint == NULL) {
 729                 dev_err(&interface->dev, "interrupt out endpoint not found\n");
 730                 goto error;
 731         }
 732
 733         in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
 734         out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
 735
 736         dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
 737         if (!dev->read_buffer_primary) {
 738                 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
 739                 retval = -ENOMEM;
 740                 goto error;
 741         }
 742
 743         /* debug code prime the buffer */
 744         memset(dev->read_buffer_primary, 'a', in_end_size);
 745         memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
 746         memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
 747         memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
 748
 749         dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
 750         if (!dev->read_buffer_secondary) {
 751                 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
 752                 retval = -ENOMEM;
 753                 goto error;
 754         }
 755
 756         /* debug code prime the buffer */
 757         memset(dev->read_buffer_secondary, 'e', in_end_size);
 758         memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
 759         memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
 760         memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
 761
 762         dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
 763         if (!dev->interrupt_in_buffer) {
 764                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
 765                 goto error;
 766         }
 767
 768         /* debug code prime the buffer */
 769         memset(dev->interrupt_in_buffer, 'i', in_end_size);
 770
 771         dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
 772         if (!dev->interrupt_in_urb) {
 773                 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
 774                 goto error;
 775         }
 776         dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
 777         if (!dev->interrupt_out_buffer) {
 778                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
 779                 goto error;
 780         }
 781         dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
 782         if (!dev->interrupt_out_urb) {
 783                 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
 784                 goto error;
 785         }
 786
 787         if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
 788                         sizeof(dev->serial_number))) {
 789                 dev_err(&interface->dev, "Could not retrieve serial number\n");
 790                 goto error;
 791         }
 792         dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
 793
 794         /* we can register the device now, as it is ready */
 795         usb_set_intfdata(interface, dev);
 796
 797         retval = usb_register_dev(interface, &adu_class);
 798
 799         if (retval) {
 800                 /* something prevented us from registering this driver */
 801                 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
 802                 usb_set_intfdata(interface, NULL);
 803                 goto error;
 804         }
 805
 806         dev->minor = interface->minor;
 807
 808         /* let the user know what node this device is now attached to */
 809         dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d",
 810                  udev->descriptor.idProduct, dev->serial_number,
 811                  (dev->minor - ADU_MINOR_BASE));
 812 exit:
 813         dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
 814
 815         return retval;
 816
 817 error:
 818         adu_delete(dev);
 819         return retval;
 820 }
 821
 822 /**
 823  * adu_disconnect
 824  *
 825  * Called by the usb core when the device is removed from the system.
 826  */
 827 static void adu_disconnect(struct usb_interface *interface)
 828 {
 829         struct adu_device *dev;
 830         int minor;
 831
 832         dbg(2," %s : enter", __FUNCTION__);
 833
 834         mutex_lock(&disconnect_mutex); /* not interruptible */
 835
 836         dev = usb_get_intfdata(interface);
 837         usb_set_intfdata(interface, NULL);
 838
 839         down(&dev->sem); /* not interruptible */
 840
 841         minor = dev->minor;
 842
 843         /* give back our minor */
 844         usb_deregister_dev(interface, &adu_class);
 845         dev->minor = 0;
 846
 847         /* if the device is not opened, then we clean up right now */
 848         dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
 849         if (!dev->open_count) {
 850                 up(&dev->sem);
 851                 adu_delete(dev);
 852         } else {
 853                 dev->udev = NULL;
 854                 up(&dev->sem);
 855         }
 856
 857         mutex_unlock(&disconnect_mutex);
 858
 859         dev_info(&interface->dev, "ADU device adutux%d now disconnected",
 860                  (minor - ADU_MINOR_BASE));
 861
 862         dbg(2," %s : leave", __FUNCTION__);
 863 }
 864
 865 /* usb specific object needed to register this driver with the usb subsystem */
 866 static struct usb_driver adu_driver = {
 867         .name = "adutux",
 868         .probe = adu_probe,
 869         .disconnect = adu_disconnect,
 870         .id_table = device_table,
 871 };
 872
 873 static int __init adu_init(void)
 874 {
 875         int result;
 876
 877         dbg(2," %s : enter", __FUNCTION__);
 878
 879         /* register this driver with the USB subsystem */
 880         result = usb_register(&adu_driver);
 881         if (result < 0) {
 882                 err("usb_register failed for the "__FILE__" driver. "
 883                     "Error number %d", result);
 884                 goto exit;
 885         }
 886
 887         info("adutux " DRIVER_DESC " " DRIVER_VERSION);
 888         info("adutux is an experimental driver. Use at your own risk");
 889
 890 exit:
 891         dbg(2," %s : leave, return value %d", __FUNCTION__, result);
 892
 893         return result;
 894 }
 895
 896 static void __exit adu_exit(void)
 897 {
 898         dbg(2," %s : enter", __FUNCTION__);
 899         /* deregister this driver with the USB subsystem */
 900         usb_deregister(&adu_driver);
 901         dbg(2," %s : leave", __FUNCTION__);
 902 }
 903
 904 module_init(adu_init);
 905 module_exit(adu_exit);
 906
 907 MODULE_AUTHOR(DRIVER_AUTHOR);
 908 MODULE_DESCRIPTION(DRIVER_DESC);
 909 MODULE_LICENSE("GPL");