drivers/input/tablet/wacom_sys.c

   1 /*
   2  * drivers/input/tablet/wacom_sys.c
   3  *
   4  *  USB Wacom tablet support - system specific code
   5  */
   6
   7 /*
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include "wacom_wac.h"
  15 #include "wacom.h"
  16
  17 /* defines to get HID report descriptor */
  18 #define HID_DEVICET_HID         (USB_TYPE_CLASS | 0x01)
  19 #define HID_DEVICET_REPORT      (USB_TYPE_CLASS | 0x02)
  20 #define HID_USAGE_UNDEFINED             0x00
  21 #define HID_USAGE_PAGE                  0x05
  22 #define HID_USAGE_PAGE_DIGITIZER        0x0d
  23 #define HID_USAGE_PAGE_DESKTOP          0x01
  24 #define HID_USAGE                       0x09
  25 #define HID_USAGE_X                     0x30
  26 #define HID_USAGE_Y                     0x31
  27 #define HID_USAGE_X_TILT                0x3d
  28 #define HID_USAGE_Y_TILT                0x3e
  29 #define HID_USAGE_FINGER                0x22
  30 #define HID_USAGE_STYLUS                0x20
  31 #define HID_COLLECTION                  0xc0
  32
  33 enum {
  34         WCM_UNDEFINED = 0,
  35         WCM_DESKTOP,
  36         WCM_DIGITIZER,
  37 };
  38
  39 struct hid_descriptor {
  40         struct usb_descriptor_header header;
  41         __le16   bcdHID;
  42         u8       bCountryCode;
  43         u8       bNumDescriptors;
  44         u8       bDescriptorType;
  45         __le16   wDescriptorLength;
  46 } __attribute__ ((packed));
  47
  48 /* defines to get/set USB message */
  49 #define USB_REQ_GET_REPORT      0x01
  50 #define USB_REQ_SET_REPORT      0x09
  51 #define WAC_HID_FEATURE_REPORT  0x03
  52
  53 static int usb_get_report(struct usb_interface *intf, unsigned char type,
  54                                 unsigned char id, void *buf, int size)
  55 {
  56         return usb_control_msg(interface_to_usbdev(intf),
  57                 usb_rcvctrlpipe(interface_to_usbdev(intf), 0),
  58                 USB_REQ_GET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  59                 (type << 8) + id, intf->altsetting[0].desc.bInterfaceNumber,
  60                 buf, size, 100);
  61 }
  62
  63 static int usb_set_report(struct usb_interface *intf, unsigned char type,
  64                                 unsigned char id, void *buf, int size)
  65 {
  66         return usb_control_msg(interface_to_usbdev(intf),
  67                 usb_sndctrlpipe(interface_to_usbdev(intf), 0),
  68                 USB_REQ_SET_REPORT, USB_TYPE_CLASS | USB_RECIP_INTERFACE,
  69                 (type << 8) + id, intf->altsetting[0].desc.bInterfaceNumber,
  70                 buf, size, 1000);
  71 }
  72
  73 static void wacom_sys_irq(struct urb *urb)
  74 {
  75         struct wacom *wacom = urb->context;
  76         int retval;
  77
  78         switch (urb->status) {
  79         case 0:
  80                 /* success */
  81                 break;
  82         case -ECONNRESET:
  83         case -ENOENT:
  84         case -ESHUTDOWN:
  85                 /* this urb is terminated, clean up */
  86                 dbg("%s - urb shutting down with status: %d", __func__, urb->status);
  87                 return;
  88         default:
  89                 dbg("%s - nonzero urb status received: %d", __func__, urb->status);
  90                 goto exit;
  91         }
  92
  93         wacom_wac_irq(&wacom->wacom_wac, urb->actual_length);
  94
  95  exit:
  96         usb_mark_last_busy(wacom->usbdev);
  97         retval = usb_submit_urb(urb, GFP_ATOMIC);
  98         if (retval)
  99                 err ("%s - usb_submit_urb failed with result %d",
 100                      __func__, retval);
 101 }
 102
 103 static int wacom_open(struct input_dev *dev)
 104 {
 105         struct wacom *wacom = input_get_drvdata(dev);
 106
 107         mutex_lock(&wacom->lock);
 108
 109         wacom->irq->dev = wacom->usbdev;
 110
 111         if (usb_autopm_get_interface(wacom->intf) < 0) {
 112                 mutex_unlock(&wacom->lock);
 113                 return -EIO;
 114         }
 115
 116         if (usb_submit_urb(wacom->irq, GFP_KERNEL)) {
 117                 usb_autopm_put_interface(wacom->intf);
 118                 mutex_unlock(&wacom->lock);
 119                 return -EIO;
 120         }
 121
 122         wacom->open = true;
 123         wacom->intf->needs_remote_wakeup = 1;
 124
 125         mutex_unlock(&wacom->lock);
 126         return 0;
 127 }
 128
 129 static void wacom_close(struct input_dev *dev)
 130 {
 131         struct wacom *wacom = input_get_drvdata(dev);
 132
 133         mutex_lock(&wacom->lock);
 134         usb_kill_urb(wacom->irq);
 135         wacom->open = false;
 136         wacom->intf->needs_remote_wakeup = 0;
 137         mutex_unlock(&wacom->lock);
 138 }
 139
 140 static int wacom_parse_hid(struct usb_interface *intf, struct hid_descriptor *hid_desc,
 141                            struct wacom_features *features)
 142 {
 143         struct usb_device *dev = interface_to_usbdev(intf);
 144         char limit = 0;
 145         /* result has to be defined as int for some devices */
 146         int result = 0;
 147         int i = 0, usage = WCM_UNDEFINED, finger = 0, pen = 0;
 148         unsigned char *report;
 149
 150         report = kzalloc(hid_desc->wDescriptorLength, GFP_KERNEL);
 151         if (!report)
 152                 return -ENOMEM;
 153
 154         /* retrive report descriptors */
 155         do {
 156                 result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
 157                         USB_REQ_GET_DESCRIPTOR,
 158                         USB_RECIP_INTERFACE | USB_DIR_IN,
 159                         HID_DEVICET_REPORT << 8,
 160                         intf->altsetting[0].desc.bInterfaceNumber, /* interface */
 161                         report,
 162                         hid_desc->wDescriptorLength,
 163                         5000); /* 5 secs */
 164         } while (result < 0 && limit++ < 5);
 165
 166         /* No need to parse the Descriptor. It isn't an error though */
 167         if (result < 0)
 168                 goto out;
 169
 170         for (i = 0; i < hid_desc->wDescriptorLength; i++) {
 171
 172                 switch (report[i]) {
 173                 case HID_USAGE_PAGE:
 174                         switch (report[i + 1]) {
 175                         case HID_USAGE_PAGE_DIGITIZER:
 176                                 usage = WCM_DIGITIZER;
 177                                 i++;
 178                                 break;
 179
 180                         case HID_USAGE_PAGE_DESKTOP:
 181                                 usage = WCM_DESKTOP;
 182                                 i++;
 183                                 break;
 184                         }
 185                         break;
 186
 187                 case HID_USAGE:
 188                         switch (report[i + 1]) {
 189                         case HID_USAGE_X:
 190                                 if (usage == WCM_DESKTOP) {
 191                                         if (finger) {
 192                                                 features->device_type = BTN_TOOL_DOUBLETAP;
 193                                                 if (features->type == TABLETPC2FG) {
 194                                                         /* need to reset back */
 195                                                         features->pktlen = WACOM_PKGLEN_TPC2FG;
 196                                                         features->device_type = BTN_TOOL_TRIPLETAP;
 197                                                 }
 198                                                 if (features->type == BAMBOO_PT) {
 199                                                         /* need to reset back */
 200                                                         features->pktlen = WACOM_PKGLEN_BBTOUCH;
 201                                                         features->device_type = BTN_TOOL_TRIPLETAP;
 202                                                         features->x_phy =
 203                                                                 get_unaligned_le16(&report[i + 5]);
 204                                                         features->x_max =
 205                                                                 get_unaligned_le16(&report[i + 8]);
 206                                                         i += 15;
 207                                                 } else {
 208                                                         features->x_max =
 209                                                                 get_unaligned_le16(&report[i + 3]);
 210                                                         features->x_phy =
 211                                                                 get_unaligned_le16(&report[i + 6]);
 212                                                         features->unit = report[i + 9];
 213                                                         features->unitExpo = report[i + 11];
 214                                                         i += 12;
 215                                                 }
 216                                         } else if (pen) {
 217                                                 /* penabled only accepts exact bytes of data */
 218                                                 if (features->type == TABLETPC2FG)
 219                                                         features->pktlen = WACOM_PKGLEN_GRAPHIRE;
 220                                                 if (features->type == BAMBOO_PT)
 221                                                         features->pktlen = WACOM_PKGLEN_BBFUN;
 222                                                 features->device_type = BTN_TOOL_PEN;
 223                                                 features->x_max =
 224                                                         get_unaligned_le16(&report[i + 3]);
 225                                                 i += 4;
 226                                         }
 227                                 } else if (usage == WCM_DIGITIZER) {
 228                                         /* max pressure isn't reported
 229                                         features->pressure_max = (unsigned short)
 230                                                         (report[i+4] << 8  | report[i + 3]);
 231                                         */
 232                                         features->pressure_max = 255;
 233                                         i += 4;
 234                                 }
 235                                 break;
 236
 237                         case HID_USAGE_Y:
 238                                 if (usage == WCM_DESKTOP) {
 239                                         if (finger) {
 240                                                 features->device_type = BTN_TOOL_DOUBLETAP;
 241                                                 if (features->type == TABLETPC2FG) {
 242                                                         /* need to reset back */
 243                                                         features->pktlen = WACOM_PKGLEN_TPC2FG;
 244                                                         features->device_type = BTN_TOOL_TRIPLETAP;
 245                                                         features->y_max =
 246                                                                 get_unaligned_le16(&report[i + 3]);
 247                                                         features->y_phy =
 248                                                                 get_unaligned_le16(&report[i + 6]);
 249                                                         i += 7;
 250                                                 } else if (features->type == BAMBOO_PT) {
 251                                                         /* need to reset back */
 252                                                         features->pktlen = WACOM_PKGLEN_BBTOUCH;
 253                                                         features->device_type = BTN_TOOL_TRIPLETAP;
 254                                                         features->y_phy =
 255                                                                 get_unaligned_le16(&report[i + 3]);
 256                                                         features->y_max =
 257                                                                 get_unaligned_le16(&report[i + 6]);
 258                                                         i += 12;
 259                                                 } else {
 260                                                         features->y_max =
 261                                                                 features->x_max;
 262                                                         features->y_phy =
 263                                                                 get_unaligned_le16(&report[i + 3]);
 264                                                         i += 4;
 265                                                 }
 266                                         } else if (pen) {
 267                                                 /* penabled only accepts exact bytes of data */
 268                                                 if (features->type == TABLETPC2FG)
 269                                                         features->pktlen = WACOM_PKGLEN_GRAPHIRE;
 270                                                 if (features->type == BAMBOO_PT)
 271                                                         features->pktlen = WACOM_PKGLEN_BBFUN;
 272                                                 features->device_type = BTN_TOOL_PEN;
 273                                                 features->y_max =
 274                                                         get_unaligned_le16(&report[i + 3]);
 275                                                 i += 4;
 276                                         }
 277                                 }
 278                                 break;
 279
 280                         case HID_USAGE_FINGER:
 281                                 finger = 1;
 282                                 i++;
 283                                 break;
 284
 285                         case HID_USAGE_STYLUS:
 286                                 pen = 1;
 287                                 i++;
 288                                 break;
 289
 290                         case HID_USAGE_UNDEFINED:
 291                                 if (usage == WCM_DESKTOP && finger) /* capacity */
 292                                         features->pressure_max =
 293                                                 get_unaligned_le16(&report[i + 3]);
 294                                 i += 4;
 295                                 break;
 296                         }
 297                         break;
 298
 299                 case HID_COLLECTION:
 300                         /* reset UsagePage and Finger */
 301                         finger = usage = 0;
 302                         break;
 303                 }
 304         }
 305
 306  out:
 307         result = 0;
 308         kfree(report);
 309         return result;
 310 }
 311
 312 static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_features *features)
 313 {
 314         unsigned char *rep_data;
 315         int limit = 0, report_id = 2;
 316         int error = -ENOMEM;
 317
 318         rep_data = kmalloc(2, GFP_KERNEL);
 319         if (!rep_data)
 320                 return error;
 321
 322         /* ask to report tablet data if it is 2FGT or not a Tablet PC */
 323         if (features->device_type == BTN_TOOL_TRIPLETAP) {
 324                 do {
 325                         rep_data[0] = 3;
 326                         rep_data[1] = 4;
 327                         report_id = 3;
 328                         error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
 329                                 report_id, rep_data, 2);
 330                         if (error >= 0)
 331                                 error = usb_get_report(intf,
 332                                         WAC_HID_FEATURE_REPORT, report_id,
 333                                         rep_data, 3);
 334                 } while ((error < 0 || rep_data[1] != 4) && limit++ < 5);
 335         } else if (features->type != TABLETPC && features->type != TABLETPC2FG) {
 336                 do {
 337                         rep_data[0] = 2;
 338                         rep_data[1] = 2;
 339                         error = usb_set_report(intf, WAC_HID_FEATURE_REPORT,
 340                                 report_id, rep_data, 2);
 341                         if (error >= 0)
 342                                 error = usb_get_report(intf,
 343                                         WAC_HID_FEATURE_REPORT, report_id,
 344                                         rep_data, 2);
 345                 } while ((error < 0 || rep_data[1] != 2) && limit++ < 5);
 346         }
 347
 348         kfree(rep_data);
 349
 350         return error < 0 ? error : 0;
 351 }
 352
 353 static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
 354                 struct wacom_features *features)
 355 {
 356         int error = 0;
 357         struct usb_host_interface *interface = intf->cur_altsetting;
 358         struct hid_descriptor *hid_desc;
 359
 360         /* default features */
 361         features->device_type = BTN_TOOL_PEN;
 362         features->x_fuzz = 4;
 363         features->y_fuzz = 4;
 364         features->pressure_fuzz = 0;
 365         features->distance_fuzz = 0;
 366
 367         /* only Tablet PCs need to retrieve the info */
 368         if ((features->type != TABLETPC) && (features->type != TABLETPC2FG) &&
 369             (features->type != BAMBOO_PT))
 370                 goto out;
 371
 372         if (usb_get_extra_descriptor(interface, HID_DEVICET_HID, &hid_desc)) {
 373                 if (usb_get_extra_descriptor(&interface->endpoint[0],
 374                                 HID_DEVICET_REPORT, &hid_desc)) {
 375                         printk("wacom: can not retrieve extra class descriptor\n");
 376                         error = 1;
 377                         goto out;
 378                 }
 379         }
 380         error = wacom_parse_hid(intf, hid_desc, features);
 381         if (error)
 382                 goto out;
 383
 384         /* touch device found but size is not defined. use default */
 385         if (features->device_type == BTN_TOOL_DOUBLETAP && !features->x_max) {
 386                 features->x_max = 1023;
 387                 features->y_max = 1023;
 388         }
 389
 390  out:
 391         return error;
 392 }
 393
 394 struct wacom_usbdev_data {
 395         struct list_head list;
 396         struct kref kref;
 397         struct usb_device *dev;
 398         struct wacom_shared shared;
 399 };
 400
 401 static LIST_HEAD(wacom_udev_list);
 402 static DEFINE_MUTEX(wacom_udev_list_lock);
 403
 404 static struct wacom_usbdev_data *wacom_get_usbdev_data(struct usb_device *dev)
 405 {
 406         struct wacom_usbdev_data *data;
 407
 408         list_for_each_entry(data, &wacom_udev_list, list) {
 409                 if (data->dev == dev) {
 410                         kref_get(&data->kref);
 411                         return data;
 412                 }
 413         }
 414
 415         return NULL;
 416 }
 417
 418 static int wacom_add_shared_data(struct wacom_wac *wacom,
 419                                  struct usb_device *dev)
 420 {
 421         struct wacom_usbdev_data *data;
 422         int retval = 0;
 423
 424         mutex_lock(&wacom_udev_list_lock);
 425
 426         data = wacom_get_usbdev_data(dev);
 427         if (!data) {
 428                 data = kzalloc(sizeof(struct wacom_usbdev_data), GFP_KERNEL);
 429                 if (!data) {
 430                         retval = -ENOMEM;
 431                         goto out;
 432                 }
 433
 434                 kref_init(&data->kref);
 435                 data->dev = dev;
 436                 list_add_tail(&data->list, &wacom_udev_list);
 437         }
 438
 439         wacom->shared = &data->shared;
 440
 441 out:
 442         mutex_unlock(&wacom_udev_list_lock);
 443         return retval;
 444 }
 445
 446 static void wacom_release_shared_data(struct kref *kref)
 447 {
 448         struct wacom_usbdev_data *data =
 449                 container_of(kref, struct wacom_usbdev_data, kref);
 450
 451         mutex_lock(&wacom_udev_list_lock);
 452         list_del(&data->list);
 453         mutex_unlock(&wacom_udev_list_lock);
 454
 455         kfree(data);
 456 }
 457
 458 static void wacom_remove_shared_data(struct wacom_wac *wacom)
 459 {
 460         struct wacom_usbdev_data *data;
 461
 462         if (wacom->shared) {
 463                 data = container_of(wacom->shared, struct wacom_usbdev_data, shared);
 464                 kref_put(&data->kref, wacom_release_shared_data);
 465                 wacom->shared = NULL;
 466         }
 467 }
 468
 469 static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *id)
 470 {
 471         struct usb_device *dev = interface_to_usbdev(intf);
 472         struct usb_endpoint_descriptor *endpoint;
 473         struct wacom *wacom;
 474         struct wacom_wac *wacom_wac;
 475         struct wacom_features *features;
 476         struct input_dev *input_dev;
 477         int error;
 478
 479         if (!id->driver_info)
 480                 return -EINVAL;
 481
 482         wacom = kzalloc(sizeof(struct wacom), GFP_KERNEL);
 483         input_dev = input_allocate_device();
 484         if (!wacom || !input_dev) {
 485                 error = -ENOMEM;
 486                 goto fail1;
 487         }
 488
 489         wacom_wac = &wacom->wacom_wac;
 490         wacom_wac->features = *((struct wacom_features *)id->driver_info);
 491         features = &wacom_wac->features;
 492         if (features->pktlen > WACOM_PKGLEN_MAX) {
 493                 error = -EINVAL;
 494                 goto fail1;
 495         }
 496
 497         wacom_wac->data = usb_alloc_coherent(dev, WACOM_PKGLEN_MAX,
 498                                              GFP_KERNEL, &wacom->data_dma);
 499         if (!wacom_wac->data) {
 500                 error = -ENOMEM;
 501                 goto fail1;
 502         }
 503
 504         wacom->irq = usb_alloc_urb(0, GFP_KERNEL);
 505         if (!wacom->irq) {
 506                 error = -ENOMEM;
 507                 goto fail2;
 508         }
 509
 510         wacom->usbdev = dev;
 511         wacom->intf = intf;
 512         mutex_init(&wacom->lock);
 513         usb_make_path(dev, wacom->phys, sizeof(wacom->phys));
 514         strlcat(wacom->phys, "/input0", sizeof(wacom->phys));
 515
 516         wacom_wac->input = input_dev;
 517
 518         endpoint = &intf->cur_altsetting->endpoint[0].desc;
 519
 520         /* Retrieve the physical and logical size for OEM devices */
 521         error = wacom_retrieve_hid_descriptor(intf, features);
 522         if (error)
 523                 goto fail2;
 524
 525         strlcpy(wacom_wac->name, features->name, sizeof(wacom_wac->name));
 526
 527         if (features->type == TABLETPC || features->type == TABLETPC2FG ||
 528             features->type == BAMBOO_PT) {
 529                 /* Append the device type to the name */
 530                 strlcat(wacom_wac->name,
 531                         features->device_type == BTN_TOOL_PEN ?
 532                                 " Pen" : " Finger",
 533                         sizeof(wacom_wac->name));
 534
 535                 error = wacom_add_shared_data(wacom_wac, dev);
 536                 if (error)
 537                         goto fail3;
 538         }
 539
 540         input_dev->name = wacom_wac->name;
 541         input_dev->dev.parent = &intf->dev;
 542         input_dev->open = wacom_open;
 543         input_dev->close = wacom_close;
 544         usb_to_input_id(dev, &input_dev->id);
 545         input_set_drvdata(input_dev, wacom);
 546
 547         wacom_setup_input_capabilities(input_dev, wacom_wac);
 548
 549         usb_fill_int_urb(wacom->irq, dev,
 550                          usb_rcvintpipe(dev, endpoint->bEndpointAddress),
 551                          wacom_wac->data, features->pktlen,
 552                          wacom_sys_irq, wacom, endpoint->bInterval);
 553         wacom->irq->transfer_dma = wacom->data_dma;
 554         wacom->irq->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 555
 556         error = input_register_device(input_dev);
 557         if (error)
 558                 goto fail4;
 559
 560         /* Note that if query fails it is not a hard failure */
 561         wacom_query_tablet_data(intf, features);
 562
 563         usb_set_intfdata(intf, wacom);
 564         return 0;
 565
 566  fail4: wacom_remove_shared_data(wacom_wac);
 567  fail3: usb_free_urb(wacom->irq);
 568  fail2: usb_free_coherent(dev, WACOM_PKGLEN_MAX, wacom_wac->data, wacom->data_dma);
 569  fail1: input_free_device(input_dev);
 570         kfree(wacom);
 571         return error;
 572 }
 573
 574 static void wacom_disconnect(struct usb_interface *intf)
 575 {
 576         struct wacom *wacom = usb_get_intfdata(intf);
 577
 578         usb_set_intfdata(intf, NULL);
 579
 580         usb_kill_urb(wacom->irq);
 581         input_unregister_device(wacom->wacom_wac.input);
 582         usb_free_urb(wacom->irq);
 583         usb_free_coherent(interface_to_usbdev(intf), WACOM_PKGLEN_MAX,
 584                         wacom->wacom_wac.data, wacom->data_dma);
 585         wacom_remove_shared_data(&wacom->wacom_wac);
 586         kfree(wacom);
 587 }
 588
 589 static int wacom_suspend(struct usb_interface *intf, pm_message_t message)
 590 {
 591         struct wacom *wacom = usb_get_intfdata(intf);
 592
 593         mutex_lock(&wacom->lock);
 594         usb_kill_urb(wacom->irq);
 595         mutex_unlock(&wacom->lock);
 596
 597         return 0;
 598 }
 599
 600 static int wacom_resume(struct usb_interface *intf)
 601 {
 602         struct wacom *wacom = usb_get_intfdata(intf);
 603         struct wacom_features *features = &wacom->wacom_wac.features;
 604         int rv;
 605
 606         mutex_lock(&wacom->lock);
 607
 608         /* switch to wacom mode first */
 609         wacom_query_tablet_data(intf, features);
 610
 611         if (wacom->open)
 612                 rv = usb_submit_urb(wacom->irq, GFP_NOIO);
 613         else
 614                 rv = 0;
 615
 616         mutex_unlock(&wacom->lock);
 617
 618         return rv;
 619 }
 620
 621 static int wacom_reset_resume(struct usb_interface *intf)
 622 {
 623         return wacom_resume(intf);
 624 }
 625
 626 static struct usb_driver wacom_driver = {
 627         .name =         "wacom",
 628         .id_table =     wacom_ids,
 629         .probe =        wacom_probe,
 630         .disconnect =   wacom_disconnect,
 631         .suspend =      wacom_suspend,
 632         .resume =       wacom_resume,
 633         .reset_resume = wacom_reset_resume,
 634         .supports_autosuspend = 1,
 635 };
 636
 637 static int __init wacom_init(void)
 638 {
 639         int result;
 640
 641         result = usb_register(&wacom_driver);
 642         if (result == 0)
 643                 printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
 644                        DRIVER_DESC "\n");
 645         return result;
 646 }
 647
 648 static void __exit wacom_exit(void)
 649 {
 650         usb_deregister(&wacom_driver);
 651 }
 652
 653 module_init(wacom_init);
 654 module_exit(wacom_exit);