drivers/hid/hid-multitouch.c

   1 /*
   2  *  HID driver for multitouch panels
   3  *
   4  *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
   5  *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
   6  *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
   7  *
   8  *  This code is partly based on hid-egalax.c:
   9  *
  10  *  Copyright (c) 2010 Stephane Chatty <chatty@enac.fr>
  11  *  Copyright (c) 2010 Henrik Rydberg <rydberg@euromail.se>
  12  *  Copyright (c) 2010 Canonical, Ltd.
  13  *
  14  *  This code is partly based on hid-3m-pct.c:
  15  *
  16  *  Copyright (c) 2009-2010 Stephane Chatty <chatty@enac.fr>
  17  *  Copyright (c) 2010      Henrik Rydberg <rydberg@euromail.se>
  18  *  Copyright (c) 2010      Canonical, Ltd.
  19  *
  20  */
  21
  22 /*
  23  * This program is free software; you can redistribute it and/or modify it
  24  * under the terms of the GNU General Public License as published by the Free
  25  * Software Foundation; either version 2 of the License, or (at your option)
  26  * any later version.
  27  */
  28
  29 #include <linux/device.h>
  30 #include <linux/hid.h>
  31 #include <linux/module.h>
  32 #include <linux/slab.h>
  33 #include <linux/usb.h>
  34 #include <linux/input/mt.h>
  35 #include "usbhid/usbhid.h"
  36
  37
  38 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  39 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
  40 MODULE_DESCRIPTION("HID multitouch panels");
  41 MODULE_LICENSE("GPL");
  42
  43 #include "hid-ids.h"
  44
  45 /* quirks to control the device */
  46 #define MT_QUIRK_NOT_SEEN_MEANS_UP      (1 << 0)
  47 #define MT_QUIRK_SLOT_IS_CONTACTID      (1 << 1)
  48 #define MT_QUIRK_CYPRESS                (1 << 2)
  49 #define MT_QUIRK_SLOT_IS_CONTACTNUMBER  (1 << 3)
  50 #define MT_QUIRK_ALWAYS_VALID           (1 << 4)
  51 #define MT_QUIRK_VALID_IS_INRANGE       (1 << 5)
  52 #define MT_QUIRK_VALID_IS_CONFIDENCE    (1 << 6)
  53 #define MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE    (1 << 8)
  54
  55 struct mt_slot {
  56         __s32 x, y, p, w, h;
  57         __s32 contactid;        /* the device ContactID assigned to this slot */
  58         bool touch_state;       /* is the touch valid? */
  59         bool seen_in_this_frame;/* has this slot been updated */
  60 };
  61
  62 struct mt_class {
  63         __s32 name;     /* MT_CLS */
  64         __s32 quirks;
  65         __s32 sn_move;  /* Signal/noise ratio for move events */
  66         __s32 sn_width; /* Signal/noise ratio for width events */
  67         __s32 sn_height;        /* Signal/noise ratio for height events */
  68         __s32 sn_pressure;      /* Signal/noise ratio for pressure events */
  69         __u8 maxcontacts;
  70         bool is_indirect;       /* true for touchpads */
  71 };
  72
  73 struct mt_device {
  74         struct mt_slot curdata; /* placeholder of incoming data */
  75         struct mt_class mtclass;        /* our mt device class */
  76         unsigned last_field_index;      /* last field index of the report */
  77         unsigned last_slot_field;       /* the last field of a slot */
  78         int last_mt_collection; /* last known mt-related collection */
  79         __s8 inputmode;         /* InputMode HID feature, -1 if non-existent */
  80         __s8 maxcontact_report_id;      /* Maximum Contact Number HID feature,
  81                                    -1 if non-existent */
  82         __u8 num_received;      /* how many contacts we received */
  83         __u8 num_expected;      /* expected last contact index */
  84         __u8 maxcontacts;
  85         bool curvalid;          /* is the current contact valid? */
  86         struct mt_slot *slots;
  87 };
  88
  89 /* classes of device behavior */
  90 #define MT_CLS_DEFAULT                          0x0001
  91
  92 #define MT_CLS_SERIAL                           0x0002
  93 #define MT_CLS_CONFIDENCE                       0x0003
  94 #define MT_CLS_CONFIDENCE_CONTACT_ID            0x0004
  95 #define MT_CLS_CONFIDENCE_MINUS_ONE             0x0005
  96 #define MT_CLS_DUAL_INRANGE_CONTACTID           0x0006
  97 #define MT_CLS_DUAL_INRANGE_CONTACTNUMBER       0x0007
  98 #define MT_CLS_DUAL_NSMU_CONTACTID              0x0008
  99 #define MT_CLS_INRANGE_CONTACTNUMBER            0x0009
 100
 101 /* vendor specific classes */
 102 #define MT_CLS_3M                               0x0101
 103 #define MT_CLS_CYPRESS                          0x0102
 104 #define MT_CLS_EGALAX                           0x0103
 105 #define MT_CLS_EGALAX_SERIAL                    0x0104
 106 #define MT_CLS_TOPSEED                          0x0105
 107 #define MT_CLS_PANASONIC                        0x0106
 108
 109 #define MT_DEFAULT_MAXCONTACT   10
 110
 111 /*
 112  * these device-dependent functions determine what slot corresponds
 113  * to a valid contact that was just read.
 114  */
 115
 116 static int cypress_compute_slot(struct mt_device *td)
 117 {
 118         if (td->curdata.contactid != 0 || td->num_received == 0)
 119                 return td->curdata.contactid;
 120         else
 121                 return -1;
 122 }
 123
 124 static int find_slot_from_contactid(struct mt_device *td)
 125 {
 126         int i;
 127         for (i = 0; i < td->maxcontacts; ++i) {
 128                 if (td->slots[i].contactid == td->curdata.contactid &&
 129                         td->slots[i].touch_state)
 130                         return i;
 131         }
 132         for (i = 0; i < td->maxcontacts; ++i) {
 133                 if (!td->slots[i].seen_in_this_frame &&
 134                         !td->slots[i].touch_state)
 135                         return i;
 136         }
 137         /* should not occurs. If this happens that means
 138          * that the device sent more touches that it says
 139          * in the report descriptor. It is ignored then. */
 140         return -1;
 141 }
 142
 143 static struct mt_class mt_classes[] = {
 144         { .name = MT_CLS_DEFAULT,
 145                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP },
 146         { .name = MT_CLS_SERIAL,
 147                 .quirks = MT_QUIRK_ALWAYS_VALID},
 148         { .name = MT_CLS_CONFIDENCE,
 149                 .quirks = MT_QUIRK_VALID_IS_CONFIDENCE },
 150         { .name = MT_CLS_CONFIDENCE_CONTACT_ID,
 151                 .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
 152                         MT_QUIRK_SLOT_IS_CONTACTID },
 153         { .name = MT_CLS_CONFIDENCE_MINUS_ONE,
 154                 .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
 155                         MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE },
 156         { .name = MT_CLS_DUAL_INRANGE_CONTACTID,
 157                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 158                         MT_QUIRK_SLOT_IS_CONTACTID,
 159                 .maxcontacts = 2 },
 160         { .name = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 161                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 162                         MT_QUIRK_SLOT_IS_CONTACTNUMBER,
 163                 .maxcontacts = 2 },
 164         { .name = MT_CLS_DUAL_NSMU_CONTACTID,
 165                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
 166                         MT_QUIRK_SLOT_IS_CONTACTID,
 167                 .maxcontacts = 2 },
 168         { .name = MT_CLS_INRANGE_CONTACTNUMBER,
 169                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 170                         MT_QUIRK_SLOT_IS_CONTACTNUMBER },
 171
 172         /*
 173          * vendor specific classes
 174          */
 175         { .name = MT_CLS_3M,
 176                 .quirks = MT_QUIRK_VALID_IS_CONFIDENCE |
 177                         MT_QUIRK_SLOT_IS_CONTACTID,
 178                 .sn_move = 2048,
 179                 .sn_width = 128,
 180                 .sn_height = 128 },
 181         { .name = MT_CLS_CYPRESS,
 182                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
 183                         MT_QUIRK_CYPRESS,
 184                 .maxcontacts = 10 },
 185         { .name = MT_CLS_EGALAX,
 186                 .quirks =  MT_QUIRK_SLOT_IS_CONTACTID |
 187                         MT_QUIRK_VALID_IS_INRANGE,
 188                 .sn_move = 4096,
 189                 .sn_pressure = 32,
 190         },
 191         { .name = MT_CLS_EGALAX_SERIAL,
 192                 .quirks =  MT_QUIRK_SLOT_IS_CONTACTID |
 193                         MT_QUIRK_ALWAYS_VALID,
 194                 .sn_move = 4096,
 195                 .sn_pressure = 32,
 196         },
 197         { .name = MT_CLS_TOPSEED,
 198                 .quirks = MT_QUIRK_ALWAYS_VALID,
 199                 .is_indirect = true,
 200                 .maxcontacts = 2,
 201         },
 202         { .name = MT_CLS_PANASONIC,
 203                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP,
 204                 .maxcontacts = 4 },
 205
 206         { }
 207 };
 208
 209 static ssize_t mt_show_quirks(struct device *dev,
 210                            struct device_attribute *attr,
 211                            char *buf)
 212 {
 213         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 214         struct mt_device *td = hid_get_drvdata(hdev);
 215
 216         return sprintf(buf, "%u\n", td->mtclass.quirks);
 217 }
 218
 219 static ssize_t mt_set_quirks(struct device *dev,
 220                           struct device_attribute *attr,
 221                           const char *buf, size_t count)
 222 {
 223         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 224         struct mt_device *td = hid_get_drvdata(hdev);
 225
 226         unsigned long val;
 227
 228         if (kstrtoul(buf, 0, &val))
 229                 return -EINVAL;
 230
 231         td->mtclass.quirks = val;
 232
 233         return count;
 234 }
 235
 236 static DEVICE_ATTR(quirks, S_IWUSR | S_IRUGO, mt_show_quirks, mt_set_quirks);
 237
 238 static struct attribute *sysfs_attrs[] = {
 239         &dev_attr_quirks.attr,
 240         NULL
 241 };
 242
 243 static struct attribute_group mt_attribute_group = {
 244         .attrs = sysfs_attrs
 245 };
 246
 247 static void mt_feature_mapping(struct hid_device *hdev,
 248                 struct hid_field *field, struct hid_usage *usage)
 249 {
 250         struct mt_device *td = hid_get_drvdata(hdev);
 251
 252         switch (usage->hid) {
 253         case HID_DG_INPUTMODE:
 254                 td->inputmode = field->report->id;
 255                 break;
 256         case HID_DG_CONTACTMAX:
 257                 td->maxcontact_report_id = field->report->id;
 258                 td->maxcontacts = field->value[0];
 259                 if (td->mtclass.maxcontacts)
 260                         /* check if the maxcontacts is given by the class */
 261                         td->maxcontacts = td->mtclass.maxcontacts;
 262
 263                 break;
 264         }
 265 }
 266
 267 static void set_abs(struct input_dev *input, unsigned int code,
 268                 struct hid_field *field, int snratio)
 269 {
 270         int fmin = field->logical_minimum;
 271         int fmax = field->logical_maximum;
 272         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
 273         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
 274 }
 275
 276 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 277                 struct hid_field *field, struct hid_usage *usage,
 278                 unsigned long **bit, int *max)
 279 {
 280         struct mt_device *td = hid_get_drvdata(hdev);
 281         struct mt_class *cls = &td->mtclass;
 282         int code;
 283
 284         /* Only map fields from TouchScreen or TouchPad collections.
 285         * We need to ignore fields that belong to other collections
 286         * such as Mouse that might have the same GenericDesktop usages. */
 287         if (field->application == HID_DG_TOUCHSCREEN)
 288                 set_bit(INPUT_PROP_DIRECT, hi->input->propbit);
 289         else if (field->application != HID_DG_TOUCHPAD)
 290                 return 0;
 291
 292         /* In case of an indirect device (touchpad), we need to add
 293          * specific BTN_TOOL_* to be handled by the synaptics xorg
 294          * driver.
 295          * We also consider that touchscreens providing buttons are touchpads.
 296          */
 297         if (field->application == HID_DG_TOUCHPAD ||
 298             (usage->hid & HID_USAGE_PAGE) == HID_UP_BUTTON ||
 299             cls->is_indirect) {
 300                 set_bit(INPUT_PROP_POINTER, hi->input->propbit);
 301                 set_bit(BTN_TOOL_FINGER, hi->input->keybit);
 302                 set_bit(BTN_TOOL_DOUBLETAP, hi->input->keybit);
 303                 set_bit(BTN_TOOL_TRIPLETAP, hi->input->keybit);
 304                 set_bit(BTN_TOOL_QUADTAP, hi->input->keybit);
 305         }
 306
 307         /* eGalax devices provide a Digitizer.Stylus input which overrides
 308          * the correct Digitizers.Finger X/Y ranges.
 309          * Let's just ignore this input. */
 310         if (field->physical == HID_DG_STYLUS)
 311                 return -1;
 312
 313         switch (usage->hid & HID_USAGE_PAGE) {
 314
 315         case HID_UP_GENDESK:
 316                 switch (usage->hid) {
 317                 case HID_GD_X:
 318                         hid_map_usage(hi, usage, bit, max,
 319                                         EV_ABS, ABS_MT_POSITION_X);
 320                         set_abs(hi->input, ABS_MT_POSITION_X, field,
 321                                 cls->sn_move);
 322                         /* touchscreen emulation */
 323                         set_abs(hi->input, ABS_X, field, cls->sn_move);
 324                         if (td->last_mt_collection == usage->collection_index) {
 325                                 td->last_slot_field = usage->hid;
 326                                 td->last_field_index = field->index;
 327                         }
 328                         return 1;
 329                 case HID_GD_Y:
 330                         hid_map_usage(hi, usage, bit, max,
 331                                         EV_ABS, ABS_MT_POSITION_Y);
 332                         set_abs(hi->input, ABS_MT_POSITION_Y, field,
 333                                 cls->sn_move);
 334                         /* touchscreen emulation */
 335                         set_abs(hi->input, ABS_Y, field, cls->sn_move);
 336                         if (td->last_mt_collection == usage->collection_index) {
 337                                 td->last_slot_field = usage->hid;
 338                                 td->last_field_index = field->index;
 339                         }
 340                         return 1;
 341                 }
 342                 return 0;
 343
 344         case HID_UP_DIGITIZER:
 345                 switch (usage->hid) {
 346                 case HID_DG_INRANGE:
 347                         if (td->last_mt_collection == usage->collection_index) {
 348                                 td->last_slot_field = usage->hid;
 349                                 td->last_field_index = field->index;
 350                         }
 351                         return 1;
 352                 case HID_DG_CONFIDENCE:
 353                         if (td->last_mt_collection == usage->collection_index) {
 354                                 td->last_slot_field = usage->hid;
 355                                 td->last_field_index = field->index;
 356                         }
 357                         return 1;
 358                 case HID_DG_TIPSWITCH:
 359                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 360                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
 361                         if (td->last_mt_collection == usage->collection_index) {
 362                                 td->last_slot_field = usage->hid;
 363                                 td->last_field_index = field->index;
 364                         }
 365                         return 1;
 366                 case HID_DG_CONTACTID:
 367                         if (!td->maxcontacts)
 368                                 td->maxcontacts = MT_DEFAULT_MAXCONTACT;
 369                         input_mt_init_slots(hi->input, td->maxcontacts);
 370                         td->last_slot_field = usage->hid;
 371                         td->last_field_index = field->index;
 372                         td->last_mt_collection = usage->collection_index;
 373                         return 1;
 374                 case HID_DG_WIDTH:
 375                         hid_map_usage(hi, usage, bit, max,
 376                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
 377                         set_abs(hi->input, ABS_MT_TOUCH_MAJOR, field,
 378                                 cls->sn_width);
 379                         if (td->last_mt_collection == usage->collection_index) {
 380                                 td->last_slot_field = usage->hid;
 381                                 td->last_field_index = field->index;
 382                         }
 383                         return 1;
 384                 case HID_DG_HEIGHT:
 385                         hid_map_usage(hi, usage, bit, max,
 386                                         EV_ABS, ABS_MT_TOUCH_MINOR);
 387                         set_abs(hi->input, ABS_MT_TOUCH_MINOR, field,
 388                                 cls->sn_height);
 389                         input_set_abs_params(hi->input,
 390                                         ABS_MT_ORIENTATION, 0, 1, 0, 0);
 391                         if (td->last_mt_collection == usage->collection_index) {
 392                                 td->last_slot_field = usage->hid;
 393                                 td->last_field_index = field->index;
 394                         }
 395                         return 1;
 396                 case HID_DG_TIPPRESSURE:
 397                         hid_map_usage(hi, usage, bit, max,
 398                                         EV_ABS, ABS_MT_PRESSURE);
 399                         set_abs(hi->input, ABS_MT_PRESSURE, field,
 400                                 cls->sn_pressure);
 401                         /* touchscreen emulation */
 402                         set_abs(hi->input, ABS_PRESSURE, field,
 403                                 cls->sn_pressure);
 404                         if (td->last_mt_collection == usage->collection_index) {
 405                                 td->last_slot_field = usage->hid;
 406                                 td->last_field_index = field->index;
 407                         }
 408                         return 1;
 409                 case HID_DG_CONTACTCOUNT:
 410                         if (td->last_mt_collection == usage->collection_index)
 411                                 td->last_field_index = field->index;
 412                         return 1;
 413                 case HID_DG_CONTACTMAX:
 414                         /* we don't set td->last_slot_field as contactcount and
 415                          * contact max are global to the report */
 416                         if (td->last_mt_collection == usage->collection_index)
 417                                 td->last_field_index = field->index;
 418                         return -1;
 419                 }
 420                 case HID_DG_TOUCH:
 421                         /* Legacy devices use TIPSWITCH and not TOUCH.
 422                          * Let's just ignore this field. */
 423                         return -1;
 424                 /* let hid-input decide for the others */
 425                 return 0;
 426
 427         case HID_UP_BUTTON:
 428                 code = BTN_MOUSE + ((usage->hid - 1) & HID_USAGE);
 429                 hid_map_usage(hi, usage, bit, max, EV_KEY, code);
 430                 input_set_capability(hi->input, EV_KEY, code);
 431                 return 1;
 432
 433         case 0xff000000:
 434                 /* we do not want to map these: no input-oriented meaning */
 435                 return -1;
 436         }
 437
 438         return 0;
 439 }
 440
 441 static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 442                 struct hid_field *field, struct hid_usage *usage,
 443                 unsigned long **bit, int *max)
 444 {
 445         if (usage->type == EV_KEY || usage->type == EV_ABS)
 446                 set_bit(usage->type, hi->input->evbit);
 447
 448         return -1;
 449 }
 450
 451 static int mt_compute_slot(struct mt_device *td)
 452 {
 453         __s32 quirks = td->mtclass.quirks;
 454
 455         if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
 456                 return td->curdata.contactid;
 457
 458         if (quirks & MT_QUIRK_CYPRESS)
 459                 return cypress_compute_slot(td);
 460
 461         if (quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
 462                 return td->num_received;
 463
 464         if (quirks & MT_QUIRK_SLOT_IS_CONTACTID_MINUS_ONE)
 465                 return td->curdata.contactid - 1;
 466
 467         return find_slot_from_contactid(td);
 468 }
 469
 470 /*
 471  * this function is called when a whole contact has been processed,
 472  * so that it can assign it to a slot and store the data there
 473  */
 474 static void mt_complete_slot(struct mt_device *td)
 475 {
 476         td->curdata.seen_in_this_frame = true;
 477         if (td->curvalid) {
 478                 int slotnum = mt_compute_slot(td);
 479
 480                 if (slotnum >= 0 && slotnum < td->maxcontacts)
 481                         td->slots[slotnum] = td->curdata;
 482         }
 483         td->num_received++;
 484 }
 485
 486
 487 /*
 488  * this function is called when a whole packet has been received and processed,
 489  * so that it can decide what to send to the input layer.
 490  */
 491 static void mt_emit_event(struct mt_device *td, struct input_dev *input)
 492 {
 493         int i;
 494
 495         for (i = 0; i < td->maxcontacts; ++i) {
 496                 struct mt_slot *s = &(td->slots[i]);
 497                 if ((td->mtclass.quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
 498                         !s->seen_in_this_frame) {
 499                         s->touch_state = false;
 500                 }
 501
 502                 input_mt_slot(input, i);
 503                 input_mt_report_slot_state(input, MT_TOOL_FINGER,
 504                         s->touch_state);
 505                 if (s->touch_state) {
 506                         /* this finger is on the screen */
 507                         int wide = (s->w > s->h);
 508                         /* divided by two to match visual scale of touch */
 509                         int major = max(s->w, s->h) >> 1;
 510                         int minor = min(s->w, s->h) >> 1;
 511
 512                         input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
 513                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
 514                         input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
 515                         input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
 516                         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
 517                         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
 518                 }
 519                 s->seen_in_this_frame = false;
 520
 521         }
 522
 523         input_mt_report_pointer_emulation(input, true);
 524         input_sync(input);
 525         td->num_received = 0;
 526 }
 527
 528
 529
 530 static int mt_event(struct hid_device *hid, struct hid_field *field,
 531                                 struct hid_usage *usage, __s32 value)
 532 {
 533         struct mt_device *td = hid_get_drvdata(hid);
 534         __s32 quirks = td->mtclass.quirks;
 535
 536         if (hid->claimed & HID_CLAIMED_INPUT && td->slots) {
 537                 switch (usage->hid) {
 538                 case HID_DG_INRANGE:
 539                         if (quirks & MT_QUIRK_ALWAYS_VALID)
 540                                 td->curvalid = true;
 541                         else if (quirks & MT_QUIRK_VALID_IS_INRANGE)
 542                                 td->curvalid = value;
 543                         break;
 544                 case HID_DG_TIPSWITCH:
 545                         if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
 546                                 td->curvalid = value;
 547                         td->curdata.touch_state = value;
 548                         break;
 549                 case HID_DG_CONFIDENCE:
 550                         if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
 551                                 td->curvalid = value;
 552                         break;
 553                 case HID_DG_CONTACTID:
 554                         td->curdata.contactid = value;
 555                         break;
 556                 case HID_DG_TIPPRESSURE:
 557                         td->curdata.p = value;
 558                         break;
 559                 case HID_GD_X:
 560                         td->curdata.x = value;
 561                         break;
 562                 case HID_GD_Y:
 563                         td->curdata.y = value;
 564                         break;
 565                 case HID_DG_WIDTH:
 566                         td->curdata.w = value;
 567                         break;
 568                 case HID_DG_HEIGHT:
 569                         td->curdata.h = value;
 570                         break;
 571                 case HID_DG_CONTACTCOUNT:
 572                         /*
 573                          * Includes multi-packet support where subsequent
 574                          * packets are sent with zero contactcount.
 575                          */
 576                         if (value)
 577                                 td->num_expected = value;
 578                         break;
 579                 case HID_DG_TOUCH:
 580                         /* do nothing */
 581                         break;
 582
 583                 default:
 584                         /* fallback to the generic hidinput handling */
 585                         return 0;
 586                 }
 587
 588                 if (usage->hid == td->last_slot_field)
 589                         mt_complete_slot(td);
 590
 591                 if (field->index == td->last_field_index
 592                         && td->num_received >= td->num_expected)
 593                         mt_emit_event(td, field->hidinput->input);
 594
 595         }
 596
 597         /* we have handled the hidinput part, now remains hiddev */
 598         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 599                 hid->hiddev_hid_event(hid, field, usage, value);
 600
 601         return 1;
 602 }
 603
 604 static void mt_set_input_mode(struct hid_device *hdev)
 605 {
 606         struct mt_device *td = hid_get_drvdata(hdev);
 607         struct hid_report *r;
 608         struct hid_report_enum *re;
 609
 610         if (td->inputmode < 0)
 611                 return;
 612
 613         re = &(hdev->report_enum[HID_FEATURE_REPORT]);
 614         r = re->report_id_hash[td->inputmode];
 615         if (r) {
 616                 r->field[0]->value[0] = 0x02;
 617                 usbhid_submit_report(hdev, r, USB_DIR_OUT);
 618         }
 619 }
 620
 621 static void mt_set_maxcontacts(struct hid_device *hdev)
 622 {
 623         struct mt_device *td = hid_get_drvdata(hdev);
 624         struct hid_report *r;
 625         struct hid_report_enum *re;
 626         int fieldmax, max;
 627
 628         if (td->maxcontact_report_id < 0)
 629                 return;
 630
 631         if (!td->mtclass.maxcontacts)
 632                 return;
 633
 634         re = &hdev->report_enum[HID_FEATURE_REPORT];
 635         r = re->report_id_hash[td->maxcontact_report_id];
 636         if (r) {
 637                 max = td->mtclass.maxcontacts;
 638                 fieldmax = r->field[0]->logical_maximum;
 639                 max = min(fieldmax, max);
 640                 if (r->field[0]->value[0] != max) {
 641                         r->field[0]->value[0] = max;
 642                         usbhid_submit_report(hdev, r, USB_DIR_OUT);
 643                 }
 644         }
 645 }
 646
 647 static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 648 {
 649         int ret, i;
 650         struct mt_device *td;
 651         struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
 652
 653         for (i = 0; mt_classes[i].name ; i++) {
 654                 if (id->driver_data == mt_classes[i].name) {
 655                         mtclass = &(mt_classes[i]);
 656                         break;
 657                 }
 658         }
 659
 660         /* This allows the driver to correctly support devices
 661          * that emit events over several HID messages.
 662          */
 663         hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 664
 665         td = kzalloc(sizeof(struct mt_device), GFP_KERNEL);
 666         if (!td) {
 667                 dev_err(&hdev->dev, "cannot allocate multitouch data\n");
 668                 return -ENOMEM;
 669         }
 670         td->mtclass = *mtclass;
 671         td->inputmode = -1;
 672         td->maxcontact_report_id = -1;
 673         td->last_mt_collection = -1;
 674         hid_set_drvdata(hdev, td);
 675
 676         ret = hid_parse(hdev);
 677         if (ret != 0)
 678                 goto fail;
 679
 680         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 681         if (ret)
 682                 goto fail;
 683
 684         td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),
 685                                 GFP_KERNEL);
 686         if (!td->slots) {
 687                 dev_err(&hdev->dev, "cannot allocate multitouch slots\n");
 688                 hid_hw_stop(hdev);
 689                 ret = -ENOMEM;
 690                 goto fail;
 691         }
 692
 693         ret = sysfs_create_group(&hdev->dev.kobj, &mt_attribute_group);
 694
 695         mt_set_maxcontacts(hdev);
 696         mt_set_input_mode(hdev);
 697
 698         return 0;
 699
 700 fail:
 701         kfree(td);
 702         return ret;
 703 }
 704
 705 #ifdef CONFIG_PM
 706 static int mt_reset_resume(struct hid_device *hdev)
 707 {
 708         mt_set_maxcontacts(hdev);
 709         mt_set_input_mode(hdev);
 710         return 0;
 711 }
 712 #endif
 713
 714 static void mt_remove(struct hid_device *hdev)
 715 {
 716         struct mt_device *td = hid_get_drvdata(hdev);
 717         sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);
 718         hid_hw_stop(hdev);
 719         kfree(td->slots);
 720         kfree(td);
 721         hid_set_drvdata(hdev, NULL);
 722 }
 723
 724 static const struct hid_device_id mt_devices[] = {
 725
 726         /* 3M panels */
 727         { .driver_data = MT_CLS_3M,
 728                 HID_USB_DEVICE(USB_VENDOR_ID_3M,
 729                         USB_DEVICE_ID_3M1968) },
 730         { .driver_data = MT_CLS_3M,
 731                 HID_USB_DEVICE(USB_VENDOR_ID_3M,
 732                         USB_DEVICE_ID_3M2256) },
 733         { .driver_data = MT_CLS_3M,
 734                 HID_USB_DEVICE(USB_VENDOR_ID_3M,
 735                         USB_DEVICE_ID_3M3266) },
 736
 737         /* ActionStar panels */
 738         { .driver_data = MT_CLS_DEFAULT,
 739                 HID_USB_DEVICE(USB_VENDOR_ID_ACTIONSTAR,
 740                         USB_DEVICE_ID_ACTIONSTAR_1011) },
 741
 742         /* Atmel panels */
 743         { .driver_data = MT_CLS_SERIAL,
 744                 HID_USB_DEVICE(USB_VENDOR_ID_ATMEL,
 745                         USB_DEVICE_ID_ATMEL_MULTITOUCH) },
 746         { .driver_data = MT_CLS_SERIAL,
 747                 HID_USB_DEVICE(USB_VENDOR_ID_ATMEL,
 748                         USB_DEVICE_ID_ATMEL_MXT_DIGITIZER) },
 749
 750         /* Cando panels */
 751         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 752                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 753                         USB_DEVICE_ID_CANDO_MULTI_TOUCH) },
 754         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 755                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 756                         USB_DEVICE_ID_CANDO_MULTI_TOUCH_10_1) },
 757         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 758                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 759                         USB_DEVICE_ID_CANDO_MULTI_TOUCH_11_6) },
 760         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 761                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 762                         USB_DEVICE_ID_CANDO_MULTI_TOUCH_15_6) },
 763
 764         /* Chunghwa Telecom touch panels */
 765         {  .driver_data = MT_CLS_DEFAULT,
 766                 HID_USB_DEVICE(USB_VENDOR_ID_CHUNGHWAT,
 767                         USB_DEVICE_ID_CHUNGHWAT_MULTITOUCH) },
 768
 769         /* CVTouch panels */
 770         { .driver_data = MT_CLS_DEFAULT,
 771                 HID_USB_DEVICE(USB_VENDOR_ID_CVTOUCH,
 772                         USB_DEVICE_ID_CVTOUCH_SCREEN) },
 773
 774         /* Cypress panel */
 775         { .driver_data = MT_CLS_CYPRESS,
 776                 HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS,
 777                         USB_DEVICE_ID_CYPRESS_TRUETOUCH) },
 778
 779         /* eGalax devices (resistive) */
 780         { .driver_data = MT_CLS_EGALAX,
 781                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 782                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_480D) },
 783         { .driver_data = MT_CLS_EGALAX,
 784                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 785                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_480E) },
 786
 787         /* eGalax devices (capacitive) */
 788         { .driver_data = MT_CLS_EGALAX,
 789                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 790                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_720C) },
 791         { .driver_data = MT_CLS_EGALAX_SERIAL,
 792                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 793                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7207) },
 794         { .driver_data = MT_CLS_EGALAX_SERIAL,
 795                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 796                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_725E) },
 797         { .driver_data = MT_CLS_EGALAX_SERIAL,
 798                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 799                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7224) },
 800         { .driver_data = MT_CLS_EGALAX_SERIAL,
 801                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 802                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_722A) },
 803         { .driver_data = MT_CLS_EGALAX,
 804                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 805                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_726B) },
 806         { .driver_data = MT_CLS_EGALAX_SERIAL,
 807                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 808                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7262) },
 809         { .driver_data = MT_CLS_EGALAX,
 810                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 811                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72A1) },
 812         { .driver_data = MT_CLS_EGALAX_SERIAL,
 813                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 814                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72AA) },
 815         { .driver_data = MT_CLS_EGALAX,
 816                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 817                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_72FA) },
 818         { .driver_data = MT_CLS_EGALAX,
 819                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 820                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7302) },
 821         { .driver_data = MT_CLS_EGALAX_SERIAL,
 822                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 823                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_7349) },
 824         { .driver_data = MT_CLS_EGALAX_SERIAL,
 825                 HID_USB_DEVICE(USB_VENDOR_ID_DWAV,
 826                         USB_DEVICE_ID_DWAV_EGALAX_MULTITOUCH_A001) },
 827
 828         /* Elo TouchSystems IntelliTouch Plus panel */
 829         { .driver_data = MT_CLS_DUAL_NSMU_CONTACTID,
 830                 HID_USB_DEVICE(USB_VENDOR_ID_ELO,
 831                         USB_DEVICE_ID_ELO_TS2515) },
 832
 833         /* GeneralTouch panel */
 834         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 835                 HID_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
 836                         USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },
 837
 838         /* GoodTouch panels */
 839         { .driver_data = MT_CLS_DEFAULT,
 840                 HID_USB_DEVICE(USB_VENDOR_ID_GOODTOUCH,
 841                         USB_DEVICE_ID_GOODTOUCH_000f) },
 842
 843         /* Hanvon panels */
 844         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 845                 HID_USB_DEVICE(USB_VENDOR_ID_HANVON_ALT,
 846                         USB_DEVICE_ID_HANVON_ALT_MULTITOUCH) },
 847
 848         /* Ideacom panel */
 849         { .driver_data = MT_CLS_SERIAL,
 850                 HID_USB_DEVICE(USB_VENDOR_ID_IDEACOM,
 851                         USB_DEVICE_ID_IDEACOM_IDC6650) },
 852         { .driver_data = MT_CLS_SERIAL,
 853                 HID_USB_DEVICE(USB_VENDOR_ID_IDEACOM,
 854                         USB_DEVICE_ID_IDEACOM_IDC6651) },
 855
 856         /* Ilitek dual touch panel */
 857         {  .driver_data = MT_CLS_DEFAULT,
 858                 HID_USB_DEVICE(USB_VENDOR_ID_ILITEK,
 859                         USB_DEVICE_ID_ILITEK_MULTITOUCH) },
 860
 861         /* IRTOUCH panels */
 862         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 863                 HID_USB_DEVICE(USB_VENDOR_ID_IRTOUCHSYSTEMS,
 864                         USB_DEVICE_ID_IRTOUCH_INFRARED_USB) },
 865
 866         /* LG Display panels */
 867         { .driver_data = MT_CLS_DEFAULT,
 868                 HID_USB_DEVICE(USB_VENDOR_ID_LG,
 869                         USB_DEVICE_ID_LG_MULTITOUCH) },
 870
 871         /* Lumio panels */
 872         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
 873                 HID_USB_DEVICE(USB_VENDOR_ID_LUMIO,
 874                         USB_DEVICE_ID_CRYSTALTOUCH) },
 875         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
 876                 HID_USB_DEVICE(USB_VENDOR_ID_LUMIO,
 877                         USB_DEVICE_ID_CRYSTALTOUCH_DUAL) },
 878
 879         /* MosArt panels */
 880         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
 881                 HID_USB_DEVICE(USB_VENDOR_ID_ASUS,
 882                         USB_DEVICE_ID_ASUS_T91MT)},
 883         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
 884                 HID_USB_DEVICE(USB_VENDOR_ID_ASUS,
 885                         USB_DEVICE_ID_ASUSTEK_MULTITOUCH_YFO) },
 886         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
 887                 HID_USB_DEVICE(USB_VENDOR_ID_TURBOX,
 888                         USB_DEVICE_ID_TURBOX_TOUCHSCREEN_MOSART) },
 889
 890         /* Panasonic panels */
 891         { .driver_data = MT_CLS_PANASONIC,
 892                 HID_USB_DEVICE(USB_VENDOR_ID_PANASONIC,
 893                         USB_DEVICE_ID_PANABOARD_UBT780) },
 894         { .driver_data = MT_CLS_PANASONIC,
 895                 HID_USB_DEVICE(USB_VENDOR_ID_PANASONIC,
 896                         USB_DEVICE_ID_PANABOARD_UBT880) },
 897
 898         /* PenMount panels */
 899         { .driver_data = MT_CLS_CONFIDENCE,
 900                 HID_USB_DEVICE(USB_VENDOR_ID_PENMOUNT,
 901                         USB_DEVICE_ID_PENMOUNT_PCI) },
 902
 903         /* PixArt optical touch screen */
 904         { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
 905                 HID_USB_DEVICE(USB_VENDOR_ID_PIXART,
 906                         USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN) },
 907         { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
 908                 HID_USB_DEVICE(USB_VENDOR_ID_PIXART,
 909                         USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN1) },
 910         { .driver_data = MT_CLS_INRANGE_CONTACTNUMBER,
 911                 HID_USB_DEVICE(USB_VENDOR_ID_PIXART,
 912                         USB_DEVICE_ID_PIXART_OPTICAL_TOUCH_SCREEN2) },
 913
 914         /* PixCir-based panels */
 915         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 916                 HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
 917                         USB_DEVICE_ID_HANVON_MULTITOUCH) },
 918         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 919                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 920                         USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
 921
 922         /* Quanta-based panels */
 923         { .driver_data = MT_CLS_CONFIDENCE_CONTACT_ID,
 924                 HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
 925                         USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH) },
 926         { .driver_data = MT_CLS_CONFIDENCE_CONTACT_ID,
 927                 HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
 928                         USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3001) },
 929         { .driver_data = MT_CLS_CONFIDENCE_CONTACT_ID,
 930                 HID_USB_DEVICE(USB_VENDOR_ID_QUANTA,
 931                         USB_DEVICE_ID_QUANTA_OPTICAL_TOUCH_3008) },
 932
 933         /* Stantum panels */
 934         { .driver_data = MT_CLS_CONFIDENCE,
 935                 HID_USB_DEVICE(USB_VENDOR_ID_STANTUM,
 936                         USB_DEVICE_ID_MTP)},
 937         { .driver_data = MT_CLS_CONFIDENCE,
 938                 HID_USB_DEVICE(USB_VENDOR_ID_STANTUM_STM,
 939                         USB_DEVICE_ID_MTP_STM)},
 940         { .driver_data = MT_CLS_CONFIDENCE,
 941                 HID_USB_DEVICE(USB_VENDOR_ID_STANTUM_SITRONIX,
 942                         USB_DEVICE_ID_MTP_SITRONIX)},
 943
 944         /* TopSeed panels */
 945         { .driver_data = MT_CLS_TOPSEED,
 946                 HID_USB_DEVICE(USB_VENDOR_ID_TOPSEED2,
 947                         USB_DEVICE_ID_TOPSEED2_PERIPAD_701) },
 948
 949         /* Touch International panels */
 950         { .driver_data = MT_CLS_DEFAULT,
 951                 HID_USB_DEVICE(USB_VENDOR_ID_TOUCH_INTL,
 952                         USB_DEVICE_ID_TOUCH_INTL_MULTI_TOUCH) },
 953
 954         /* Unitec panels */
 955         { .driver_data = MT_CLS_DEFAULT,
 956                 HID_USB_DEVICE(USB_VENDOR_ID_UNITEC,
 957                         USB_DEVICE_ID_UNITEC_USB_TOUCH_0709) },
 958         { .driver_data = MT_CLS_DEFAULT,
 959                 HID_USB_DEVICE(USB_VENDOR_ID_UNITEC,
 960                         USB_DEVICE_ID_UNITEC_USB_TOUCH_0A19) },
 961         /* XAT */
 962         { .driver_data = MT_CLS_DEFAULT,
 963                 HID_USB_DEVICE(USB_VENDOR_ID_XAT,
 964                         USB_DEVICE_ID_XAT_CSR) },
 965
 966         /* Xiroku */
 967         { .driver_data = MT_CLS_DEFAULT,
 968                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 969                         USB_DEVICE_ID_XIROKU_SPX) },
 970         { .driver_data = MT_CLS_DEFAULT,
 971                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 972                         USB_DEVICE_ID_XIROKU_MPX) },
 973         { .driver_data = MT_CLS_DEFAULT,
 974                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 975                         USB_DEVICE_ID_XIROKU_CSR) },
 976         { .driver_data = MT_CLS_DEFAULT,
 977                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 978                         USB_DEVICE_ID_XIROKU_SPX1) },
 979         { .driver_data = MT_CLS_DEFAULT,
 980                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 981                         USB_DEVICE_ID_XIROKU_MPX1) },
 982         { .driver_data = MT_CLS_DEFAULT,
 983                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 984                         USB_DEVICE_ID_XIROKU_CSR1) },
 985         { .driver_data = MT_CLS_DEFAULT,
 986                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 987                         USB_DEVICE_ID_XIROKU_SPX2) },
 988         { .driver_data = MT_CLS_DEFAULT,
 989                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 990                         USB_DEVICE_ID_XIROKU_MPX2) },
 991         { .driver_data = MT_CLS_DEFAULT,
 992                 HID_USB_DEVICE(USB_VENDOR_ID_XIROKU,
 993                         USB_DEVICE_ID_XIROKU_CSR2) },
 994
 995         { }
 996 };
 997 MODULE_DEVICE_TABLE(hid, mt_devices);
 998
 999 static const struct hid_usage_id mt_grabbed_usages[] = {
1000         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
1001         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
1002 };
1003
1004 static struct hid_driver mt_driver = {
1005         .name = "hid-multitouch",
1006         .id_table = mt_devices,
1007         .probe = mt_probe,
1008         .remove = mt_remove,
1009         .input_mapping = mt_input_mapping,
1010         .input_mapped = mt_input_mapped,
1011         .feature_mapping = mt_feature_mapping,
1012         .usage_table = mt_grabbed_usages,
1013         .event = mt_event,
1014 #ifdef CONFIG_PM
1015         .reset_resume = mt_reset_resume,
1016 #endif
1017 };
1018
1019 static int __init mt_init(void)
1020 {
1021         return hid_register_driver(&mt_driver);
1022 }
1023
1024 static void __exit mt_exit(void)
1025 {
1026         hid_unregister_driver(&mt_driver);
1027 }
1028
1029 module_init(mt_init);
1030 module_exit(mt_exit);