drivers/hid/hid-ntrig.c

   1 /*
   2  *  HID driver for N-Trig touchscreens
   3  *
   4  *  Copyright (c) 2008-2010 Rafi Rubin
   5  *  Copyright (c) 2009-2010 Stephane Chatty
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 2 of the License, or (at your option)
  13  * any later version.
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/hid.h>
  18 #include <linux/usb.h>
  19 #include "usbhid/usbhid.h"
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22
  23 #include "hid-ids.h"
  24
  25 #define NTRIG_DUPLICATE_USAGES  0x001
  26
  27 static unsigned int min_width;
  28 module_param(min_width, uint, 0644);
  29 MODULE_PARM_DESC(min_width, "Minimum touch contact width to accept.");
  30
  31 static unsigned int min_height;
  32 module_param(min_height, uint, 0644);
  33 MODULE_PARM_DESC(min_height, "Minimum touch contact height to accept.");
  34
  35 static unsigned int activate_slack = 1;
  36 module_param(activate_slack, uint, 0644);
  37 MODULE_PARM_DESC(activate_slack, "Number of touch frames to ignore at "
  38                  "the start of touch input.");
  39
  40 static unsigned int deactivate_slack = 4;
  41 module_param(deactivate_slack, uint, 0644);
  42 MODULE_PARM_DESC(deactivate_slack, "Number of empty frames to ignore before "
  43                  "deactivating touch.");
  44
  45 static unsigned int activation_width = 64;
  46 module_param(activation_width, uint, 0644);
  47 MODULE_PARM_DESC(activation_width, "Width threshold to immediately start "
  48                  "processing touch events.");
  49
  50 static unsigned int activation_height = 32;
  51 module_param(activation_height, uint, 0644);
  52 MODULE_PARM_DESC(activation_height, "Height threshold to immediately start "
  53                  "processing touch events.");
  54
  55 struct ntrig_data {
  56         /* Incoming raw values for a single contact */
  57         __u16 x, y, w, h;
  58         __u16 id;
  59
  60         bool tipswitch;
  61         bool confidence;
  62         bool first_contact_touch;
  63
  64         bool reading_mt;
  65
  66         __u8 mt_footer[4];
  67         __u8 mt_foot_count;
  68
  69         /* The current activation state. */
  70         __s8 act_state;
  71
  72         /* Empty frames to ignore before recognizing the end of activity */
  73         __s8 deactivate_slack;
  74
  75         /* Frames to ignore before acknowledging the start of activity */
  76         __s8 activate_slack;
  77
  78         /* Minimum size contact to accept */
  79         __u16 min_width;
  80         __u16 min_height;
  81
  82         /* Threshold to override activation slack */
  83         __u16 activation_width;
  84         __u16 activation_height;
  85
  86         __u16 sensor_logical_width;
  87         __u16 sensor_logical_height;
  88         __u16 sensor_physical_width;
  89         __u16 sensor_physical_height;
  90 };
  91
  92
  93 /*
  94  * This function converts the 4 byte raw firmware code into
  95  * a string containing 5 comma separated numbers.
  96  */
  97 static int ntrig_version_string(unsigned char *raw, char *buf)
  98 {
  99         __u8 a =  (raw[1] & 0x0e) >> 1;
 100         __u8 b =  (raw[0] & 0x3c) >> 2;
 101         __u8 c = ((raw[0] & 0x03) << 3) | ((raw[3] & 0xe0) >> 5);
 102         __u8 d = ((raw[3] & 0x07) << 3) | ((raw[2] & 0xe0) >> 5);
 103         __u8 e =   raw[2] & 0x07;
 104
 105         /*
 106          * As yet unmapped bits:
 107          * 0b11000000 0b11110001 0b00011000 0b00011000
 108          */
 109
 110         return sprintf(buf, "%u.%u.%u.%u.%u", a, b, c, d, e);
 111 }
 112
 113 static inline int ntrig_get_mode(struct hid_device *hdev)
 114 {
 115         struct hid_report *report = hdev->report_enum[HID_FEATURE_REPORT].
 116                                     report_id_hash[0x0d];
 117
 118         if (!report)
 119                 return -EINVAL;
 120
 121         usbhid_submit_report(hdev, report, USB_DIR_IN);
 122         usbhid_wait_io(hdev);
 123         return (int)report->field[0]->value[0];
 124 }
 125
 126 static inline void ntrig_set_mode(struct hid_device *hdev, const int mode)
 127 {
 128         struct hid_report *report;
 129         __u8 mode_commands[4] = { 0xe, 0xf, 0x1b, 0x10 };
 130
 131         if (mode < 0 || mode > 3)
 132                 return;
 133
 134         report = hdev->report_enum[HID_FEATURE_REPORT].
 135                  report_id_hash[mode_commands[mode]];
 136
 137         if (!report)
 138                 return;
 139
 140         usbhid_submit_report(hdev, report, USB_DIR_IN);
 141 }
 142
 143 static void ntrig_report_version(struct hid_device *hdev)
 144 {
 145         int ret;
 146         char buf[20];
 147         struct usb_device *usb_dev = hid_to_usb_dev(hdev);
 148         unsigned char *data = kmalloc(8, GFP_KERNEL);
 149
 150         if (!data)
 151                 goto err_free;
 152
 153         ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 154                               USB_REQ_CLEAR_FEATURE,
 155                               USB_TYPE_CLASS | USB_RECIP_INTERFACE |
 156                               USB_DIR_IN,
 157                               0x30c, 1, data, 8,
 158                               USB_CTRL_SET_TIMEOUT);
 159
 160         if (ret == 8) {
 161                 ret = ntrig_version_string(&data[2], buf);
 162
 163                 hid_info(hdev, "Firmware version: %s (%02x%02x %02x%02x)\n",
 164                          buf, data[2], data[3], data[4], data[5]);
 165         }
 166
 167 err_free:
 168         kfree(data);
 169 }
 170
 171 static ssize_t show_phys_width(struct device *dev,
 172                                struct device_attribute *attr,
 173                                char *buf)
 174 {
 175         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 176         struct ntrig_data *nd = hid_get_drvdata(hdev);
 177
 178         return sprintf(buf, "%d\n", nd->sensor_physical_width);
 179 }
 180
 181 static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);
 182
 183 static ssize_t show_phys_height(struct device *dev,
 184                                 struct device_attribute *attr,
 185                                 char *buf)
 186 {
 187         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 188         struct ntrig_data *nd = hid_get_drvdata(hdev);
 189
 190         return sprintf(buf, "%d\n", nd->sensor_physical_height);
 191 }
 192
 193 static DEVICE_ATTR(sensor_physical_height, S_IRUGO, show_phys_height, NULL);
 194
 195 static ssize_t show_log_width(struct device *dev,
 196                               struct device_attribute *attr,
 197                               char *buf)
 198 {
 199         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 200         struct ntrig_data *nd = hid_get_drvdata(hdev);
 201
 202         return sprintf(buf, "%d\n", nd->sensor_logical_width);
 203 }
 204
 205 static DEVICE_ATTR(sensor_logical_width, S_IRUGO, show_log_width, NULL);
 206
 207 static ssize_t show_log_height(struct device *dev,
 208                                struct device_attribute *attr,
 209                                char *buf)
 210 {
 211         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 212         struct ntrig_data *nd = hid_get_drvdata(hdev);
 213
 214         return sprintf(buf, "%d\n", nd->sensor_logical_height);
 215 }
 216
 217 static DEVICE_ATTR(sensor_logical_height, S_IRUGO, show_log_height, NULL);
 218
 219 static ssize_t show_min_width(struct device *dev,
 220                               struct device_attribute *attr,
 221                               char *buf)
 222 {
 223         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 224         struct ntrig_data *nd = hid_get_drvdata(hdev);
 225
 226         return sprintf(buf, "%d\n", nd->min_width *
 227                                     nd->sensor_physical_width /
 228                                     nd->sensor_logical_width);
 229 }
 230
 231 static ssize_t set_min_width(struct device *dev,
 232                              struct device_attribute *attr,
 233                              const char *buf, size_t count)
 234 {
 235         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 236         struct ntrig_data *nd = hid_get_drvdata(hdev);
 237
 238         unsigned long val;
 239
 240         if (strict_strtoul(buf, 0, &val))
 241                 return -EINVAL;
 242
 243         if (val > nd->sensor_physical_width)
 244                 return -EINVAL;
 245
 246         nd->min_width = val * nd->sensor_logical_width /
 247                               nd->sensor_physical_width;
 248
 249         return count;
 250 }
 251
 252 static DEVICE_ATTR(min_width, S_IWUSR | S_IRUGO, show_min_width, set_min_width);
 253
 254 static ssize_t show_min_height(struct device *dev,
 255                                struct device_attribute *attr,
 256                                char *buf)
 257 {
 258         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 259         struct ntrig_data *nd = hid_get_drvdata(hdev);
 260
 261         return sprintf(buf, "%d\n", nd->min_height *
 262                                     nd->sensor_physical_height /
 263                                     nd->sensor_logical_height);
 264 }
 265
 266 static ssize_t set_min_height(struct device *dev,
 267                               struct device_attribute *attr,
 268                               const char *buf, size_t count)
 269 {
 270         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 271         struct ntrig_data *nd = hid_get_drvdata(hdev);
 272
 273         unsigned long val;
 274
 275         if (strict_strtoul(buf, 0, &val))
 276                 return -EINVAL;
 277
 278         if (val > nd->sensor_physical_height)
 279                 return -EINVAL;
 280
 281         nd->min_height = val * nd->sensor_logical_height /
 282                                nd->sensor_physical_height;
 283
 284         return count;
 285 }
 286
 287 static DEVICE_ATTR(min_height, S_IWUSR | S_IRUGO, show_min_height,
 288                    set_min_height);
 289
 290 static ssize_t show_activate_slack(struct device *dev,
 291                                    struct device_attribute *attr,
 292                                    char *buf)
 293 {
 294         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 295         struct ntrig_data *nd = hid_get_drvdata(hdev);
 296
 297         return sprintf(buf, "%d\n", nd->activate_slack);
 298 }
 299
 300 static ssize_t set_activate_slack(struct device *dev,
 301                                   struct device_attribute *attr,
 302                                   const char *buf, size_t count)
 303 {
 304         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 305         struct ntrig_data *nd = hid_get_drvdata(hdev);
 306
 307         unsigned long val;
 308
 309         if (strict_strtoul(buf, 0, &val))
 310                 return -EINVAL;
 311
 312         if (val > 0x7f)
 313                 return -EINVAL;
 314
 315         nd->activate_slack = val;
 316
 317         return count;
 318 }
 319
 320 static DEVICE_ATTR(activate_slack, S_IWUSR | S_IRUGO, show_activate_slack,
 321                    set_activate_slack);
 322
 323 static ssize_t show_activation_width(struct device *dev,
 324                                      struct device_attribute *attr,
 325                                      char *buf)
 326 {
 327         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 328         struct ntrig_data *nd = hid_get_drvdata(hdev);
 329
 330         return sprintf(buf, "%d\n", nd->activation_width *
 331                                     nd->sensor_physical_width /
 332                                     nd->sensor_logical_width);
 333 }
 334
 335 static ssize_t set_activation_width(struct device *dev,
 336                                     struct device_attribute *attr,
 337                                     const char *buf, size_t count)
 338 {
 339         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 340         struct ntrig_data *nd = hid_get_drvdata(hdev);
 341
 342         unsigned long val;
 343
 344         if (strict_strtoul(buf, 0, &val))
 345                 return -EINVAL;
 346
 347         if (val > nd->sensor_physical_width)
 348                 return -EINVAL;
 349
 350         nd->activation_width = val * nd->sensor_logical_width /
 351                                      nd->sensor_physical_width;
 352
 353         return count;
 354 }
 355
 356 static DEVICE_ATTR(activation_width, S_IWUSR | S_IRUGO, show_activation_width,
 357                    set_activation_width);
 358
 359 static ssize_t show_activation_height(struct device *dev,
 360                                       struct device_attribute *attr,
 361                                       char *buf)
 362 {
 363         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 364         struct ntrig_data *nd = hid_get_drvdata(hdev);
 365
 366         return sprintf(buf, "%d\n", nd->activation_height *
 367                                     nd->sensor_physical_height /
 368                                     nd->sensor_logical_height);
 369 }
 370
 371 static ssize_t set_activation_height(struct device *dev,
 372                                      struct device_attribute *attr,
 373                                      const char *buf, size_t count)
 374 {
 375         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 376         struct ntrig_data *nd = hid_get_drvdata(hdev);
 377
 378         unsigned long val;
 379
 380         if (strict_strtoul(buf, 0, &val))
 381                 return -EINVAL;
 382
 383         if (val > nd->sensor_physical_height)
 384                 return -EINVAL;
 385
 386         nd->activation_height = val * nd->sensor_logical_height /
 387                                       nd->sensor_physical_height;
 388
 389         return count;
 390 }
 391
 392 static DEVICE_ATTR(activation_height, S_IWUSR | S_IRUGO,
 393                    show_activation_height, set_activation_height);
 394
 395 static ssize_t show_deactivate_slack(struct device *dev,
 396                                      struct device_attribute *attr,
 397                                      char *buf)
 398 {
 399         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 400         struct ntrig_data *nd = hid_get_drvdata(hdev);
 401
 402         return sprintf(buf, "%d\n", -nd->deactivate_slack);
 403 }
 404
 405 static ssize_t set_deactivate_slack(struct device *dev,
 406                                     struct device_attribute *attr,
 407                                     const char *buf, size_t count)
 408 {
 409         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 410         struct ntrig_data *nd = hid_get_drvdata(hdev);
 411
 412         unsigned long val;
 413
 414         if (strict_strtoul(buf, 0, &val))
 415                 return -EINVAL;
 416
 417         /*
 418          * No more than 8 terminal frames have been observed so far
 419          * and higher slack is highly likely to leave the single
 420          * touch emulation stuck down.
 421          */
 422         if (val > 7)
 423                 return -EINVAL;
 424
 425         nd->deactivate_slack = -val;
 426
 427         return count;
 428 }
 429
 430 static DEVICE_ATTR(deactivate_slack, S_IWUSR | S_IRUGO, show_deactivate_slack,
 431                    set_deactivate_slack);
 432
 433 static struct attribute *sysfs_attrs[] = {
 434         &dev_attr_sensor_physical_width.attr,
 435         &dev_attr_sensor_physical_height.attr,
 436         &dev_attr_sensor_logical_width.attr,
 437         &dev_attr_sensor_logical_height.attr,
 438         &dev_attr_min_height.attr,
 439         &dev_attr_min_width.attr,
 440         &dev_attr_activate_slack.attr,
 441         &dev_attr_activation_width.attr,
 442         &dev_attr_activation_height.attr,
 443         &dev_attr_deactivate_slack.attr,
 444         NULL
 445 };
 446
 447 static struct attribute_group ntrig_attribute_group = {
 448         .attrs = sysfs_attrs
 449 };
 450
 451 /*
 452  * this driver is aimed at two firmware versions in circulation:
 453  *  - dual pen/finger single touch
 454  *  - finger multitouch, pen not working
 455  */
 456
 457 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 458                                struct hid_field *field, struct hid_usage *usage,
 459                                unsigned long **bit, int *max)
 460 {
 461         struct ntrig_data *nd = hid_get_drvdata(hdev);
 462
 463         /* No special mappings needed for the pen and single touch */
 464         if (field->physical)
 465                 return 0;
 466
 467         switch (usage->hid & HID_USAGE_PAGE) {
 468         case HID_UP_GENDESK:
 469                 switch (usage->hid) {
 470                 case HID_GD_X:
 471                         hid_map_usage(hi, usage, bit, max,
 472                                         EV_ABS, ABS_MT_POSITION_X);
 473                         input_set_abs_params(hi->input, ABS_X,
 474                                         field->logical_minimum,
 475                                         field->logical_maximum, 0, 0);
 476
 477                         if (!nd->sensor_logical_width) {
 478                                 nd->sensor_logical_width =
 479                                         field->logical_maximum -
 480                                         field->logical_minimum;
 481                                 nd->sensor_physical_width =
 482                                         field->physical_maximum -
 483                                         field->physical_minimum;
 484                                 nd->activation_width = activation_width *
 485                                         nd->sensor_logical_width /
 486                                         nd->sensor_physical_width;
 487                                 nd->min_width = min_width *
 488                                         nd->sensor_logical_width /
 489                                         nd->sensor_physical_width;
 490                         }
 491                         return 1;
 492                 case HID_GD_Y:
 493                         hid_map_usage(hi, usage, bit, max,
 494                                         EV_ABS, ABS_MT_POSITION_Y);
 495                         input_set_abs_params(hi->input, ABS_Y,
 496                                         field->logical_minimum,
 497                                         field->logical_maximum, 0, 0);
 498
 499                         if (!nd->sensor_logical_height) {
 500                                 nd->sensor_logical_height =
 501                                         field->logical_maximum -
 502                                         field->logical_minimum;
 503                                 nd->sensor_physical_height =
 504                                         field->physical_maximum -
 505                                         field->physical_minimum;
 506                                 nd->activation_height = activation_height *
 507                                         nd->sensor_logical_height /
 508                                         nd->sensor_physical_height;
 509                                 nd->min_height = min_height *
 510                                         nd->sensor_logical_height /
 511                                         nd->sensor_physical_height;
 512                         }
 513                         return 1;
 514                 }
 515                 return 0;
 516
 517         case HID_UP_DIGITIZER:
 518                 switch (usage->hid) {
 519                 /* we do not want to map these for now */
 520                 case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
 521                 case HID_DG_INPUTMODE:
 522                 case HID_DG_DEVICEINDEX:
 523                 case HID_DG_CONTACTMAX:
 524                         return -1;
 525
 526                 /* width/height mapped on TouchMajor/TouchMinor/Orientation */
 527                 case HID_DG_WIDTH:
 528                         hid_map_usage(hi, usage, bit, max,
 529                                       EV_ABS, ABS_MT_TOUCH_MAJOR);
 530                         return 1;
 531                 case HID_DG_HEIGHT:
 532                         hid_map_usage(hi, usage, bit, max,
 533                                       EV_ABS, ABS_MT_TOUCH_MINOR);
 534                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
 535                                              0, 1, 0, 0);
 536                         return 1;
 537                 }
 538                 return 0;
 539
 540         case 0xff000000:
 541                 /* we do not want to map these: no input-oriented meaning */
 542                 return -1;
 543         }
 544
 545         return 0;
 546 }
 547
 548 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 549                               struct hid_field *field, struct hid_usage *usage,
 550                               unsigned long **bit, int *max)
 551 {
 552         /* No special mappings needed for the pen and single touch */
 553         if (field->physical)
 554                 return 0;
 555
 556         if (usage->type == EV_KEY || usage->type == EV_REL
 557                         || usage->type == EV_ABS)
 558                 clear_bit(usage->code, *bit);
 559
 560         return 0;
 561 }
 562
 563 /*
 564  * this function is called upon all reports
 565  * so that we can filter contact point information,
 566  * decide whether we are in multi or single touch mode
 567  * and call input_mt_sync after each point if necessary
 568  */
 569 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
 570                         struct hid_usage *usage, __s32 value)
 571 {
 572         struct ntrig_data *nd = hid_get_drvdata(hid);
 573         struct input_dev *input;
 574
 575         /* Skip processing if not a claimed input */
 576         if (!(hid->claimed & HID_CLAIMED_INPUT))
 577                 goto not_claimed_input;
 578
 579         /* This function is being called before the structures are fully
 580          * initialized */
 581         if(!(field->hidinput && field->hidinput->input))
 582                 return -EINVAL;
 583
 584         input = field->hidinput->input;
 585
 586         /* No special handling needed for the pen */
 587         if (field->application == HID_DG_PEN)
 588                 return 0;
 589
 590         switch (usage->hid) {
 591         case 0xff000001:
 592                 /* Tag indicating the start of a multitouch group */
 593                 nd->reading_mt = 1;
 594                 nd->first_contact_touch = 0;
 595                 break;
 596         case HID_DG_TIPSWITCH:
 597                 nd->tipswitch = value;
 598                 /* Prevent emission of touch until validated */
 599                 return 1;
 600         case HID_DG_CONFIDENCE:
 601                 nd->confidence = value;
 602                 break;
 603         case HID_GD_X:
 604                 nd->x = value;
 605                 /* Clear the contact footer */
 606                 nd->mt_foot_count = 0;
 607                 break;
 608         case HID_GD_Y:
 609                 nd->y = value;
 610                 break;
 611         case HID_DG_CONTACTID:
 612                 nd->id = value;
 613                 break;
 614         case HID_DG_WIDTH:
 615                 nd->w = value;
 616                 break;
 617         case HID_DG_HEIGHT:
 618                 nd->h = value;
 619                 /*
 620                  * when in single touch mode, this is the last
 621                  * report received in a finger event. We want
 622                  * to emit a normal (X, Y) position
 623                  */
 624                 if (!nd->reading_mt) {
 625                         /*
 626                          * TipSwitch indicates the presence of a
 627                          * finger in single touch mode.
 628                          */
 629                         input_report_key(input, BTN_TOUCH,
 630                                          nd->tipswitch);
 631                         input_report_key(input, BTN_TOOL_DOUBLETAP,
 632                                          nd->tipswitch);
 633                         input_event(input, EV_ABS, ABS_X, nd->x);
 634                         input_event(input, EV_ABS, ABS_Y, nd->y);
 635                 }
 636                 break;
 637         case 0xff000002:
 638                 /*
 639                  * we receive this when the device is in multitouch
 640                  * mode. The first of the three values tagged with
 641                  * this usage tells if the contact point is real
 642                  * or a placeholder
 643                  */
 644
 645                 /* Shouldn't get more than 4 footer packets, so skip */
 646                 if (nd->mt_foot_count >= 4)
 647                         break;
 648
 649                 nd->mt_footer[nd->mt_foot_count++] = value;
 650
 651                 /* if the footer isn't complete break */
 652                 if (nd->mt_foot_count != 4)
 653                         break;
 654
 655                 /* Pen activity signal. */
 656                 if (nd->mt_footer[2]) {
 657                         /*
 658                          * When the pen deactivates touch, we see a
 659                          * bogus frame with ContactCount > 0.
 660                          * We can
 661                          * save a bit of work by ensuring act_state < 0
 662                          * even if deactivation slack is turned off.
 663                          */
 664                         nd->act_state = deactivate_slack - 1;
 665                         nd->confidence = 0;
 666                         break;
 667                 }
 668
 669                 /*
 670                  * The first footer value indicates the presence of a
 671                  * finger.
 672                  */
 673                 if (nd->mt_footer[0]) {
 674                         /*
 675                          * We do not want to process contacts under
 676                          * the size threshold, but do not want to
 677                          * ignore them for activation state
 678                          */
 679                         if (nd->w < nd->min_width ||
 680                             nd->h < nd->min_height)
 681                                 nd->confidence = 0;
 682                 } else
 683                         break;
 684
 685                 if (nd->act_state > 0) {
 686                         /*
 687                          * Contact meets the activation size threshold
 688                          */
 689                         if (nd->w >= nd->activation_width &&
 690                             nd->h >= nd->activation_height) {
 691                                 if (nd->id)
 692                                         /*
 693                                          * first contact, activate now
 694                                          */
 695                                         nd->act_state = 0;
 696                                 else {
 697                                         /*
 698                                          * avoid corrupting this frame
 699                                          * but ensure next frame will
 700                                          * be active
 701                                          */
 702                                         nd->act_state = 1;
 703                                         break;
 704                                 }
 705                         } else
 706                                 /*
 707                                  * Defer adjusting the activation state
 708                                  * until the end of the frame.
 709                                  */
 710                                 break;
 711                 }
 712
 713                 /* Discarding this contact */
 714                 if (!nd->confidence)
 715                         break;
 716
 717                 /* emit a normal (X, Y) for the first point only */
 718                 if (nd->id == 0) {
 719                         /*
 720                          * TipSwitch is superfluous in multitouch
 721                          * mode.  The footer events tell us
 722                          * if there is a finger on the screen or
 723                          * not.
 724                          */
 725                         nd->first_contact_touch = nd->confidence;
 726                         input_event(input, EV_ABS, ABS_X, nd->x);
 727                         input_event(input, EV_ABS, ABS_Y, nd->y);
 728                 }
 729
 730                 /* Emit MT events */
 731                 input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
 732                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
 733
 734                 /*
 735                  * Translate from height and width to size
 736                  * and orientation.
 737                  */
 738                 if (nd->w > nd->h) {
 739                         input_event(input, EV_ABS,
 740                                         ABS_MT_ORIENTATION, 1);
 741                         input_event(input, EV_ABS,
 742                                         ABS_MT_TOUCH_MAJOR, nd->w);
 743                         input_event(input, EV_ABS,
 744                                         ABS_MT_TOUCH_MINOR, nd->h);
 745                 } else {
 746                         input_event(input, EV_ABS,
 747                                         ABS_MT_ORIENTATION, 0);
 748                         input_event(input, EV_ABS,
 749                                         ABS_MT_TOUCH_MAJOR, nd->h);
 750                         input_event(input, EV_ABS,
 751                                         ABS_MT_TOUCH_MINOR, nd->w);
 752                 }
 753                 input_mt_sync(field->hidinput->input);
 754                 break;
 755
 756         case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
 757                 if (!nd->reading_mt) /* Just to be sure */
 758                         break;
 759
 760                 nd->reading_mt = 0;
 761
 762
 763                 /*
 764                  * Activation state machine logic:
 765                  *
 766                  * Fundamental states:
 767                  *      state >  0: Inactive
 768                  *      state <= 0: Active
 769                  *      state <  -deactivate_slack:
 770                  *               Pen termination of touch
 771                  *
 772                  * Specific values of interest
 773                  *      state == activate_slack
 774                  *               no valid input since the last reset
 775                  *
 776                  *      state == 0
 777                  *               general operational state
 778                  *
 779                  *      state == -deactivate_slack
 780                  *               read sufficient empty frames to accept
 781                  *               the end of input and reset
 782                  */
 783
 784                 if (nd->act_state > 0) { /* Currently inactive */
 785                         if (value)
 786                                 /*
 787                                  * Consider each live contact as
 788                                  * evidence of intentional activity.
 789                                  */
 790                                 nd->act_state = (nd->act_state > value)
 791                                                 ? nd->act_state - value
 792                                                 : 0;
 793                         else
 794                                 /*
 795                                  * Empty frame before we hit the
 796                                  * activity threshold, reset.
 797                                  */
 798                                 nd->act_state = nd->activate_slack;
 799
 800                         /*
 801                          * Entered this block inactive and no
 802                          * coordinates sent this frame, so hold off
 803                          * on button state.
 804                          */
 805                         break;
 806                 } else { /* Currently active */
 807                         if (value && nd->act_state >=
 808                                      nd->deactivate_slack)
 809                                 /*
 810                                  * Live point: clear accumulated
 811                                  * deactivation count.
 812                                  */
 813                                 nd->act_state = 0;
 814                         else if (nd->act_state <= nd->deactivate_slack)
 815                                 /*
 816                                  * We've consumed the deactivation
 817                                  * slack, time to deactivate and reset.
 818                                  */
 819                                 nd->act_state =
 820                                         nd->activate_slack;
 821                         else { /* Move towards deactivation */
 822                                 nd->act_state--;
 823                                 break;
 824                         }
 825                 }
 826
 827                 if (nd->first_contact_touch && nd->act_state <= 0) {
 828                         /*
 829                          * Check to see if we're ready to start
 830                          * emitting touch events.
 831                          *
 832                          * Note: activation slack will decrease over
 833                          * the course of the frame, and it will be
 834                          * inconsistent from the start to the end of
 835                          * the frame.  However if the frame starts
 836                          * with slack, first_contact_touch will still
 837                          * be 0 and we will not get to this point.
 838                          */
 839                         input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
 840                         input_report_key(input, BTN_TOUCH, 1);
 841                 } else {
 842                         input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
 843                         input_report_key(input, BTN_TOUCH, 0);
 844                 }
 845                 break;
 846
 847         default:
 848                 /* fall-back to the generic hidinput handling */
 849                 return 0;
 850         }
 851
 852 not_claimed_input:
 853
 854         /* we have handled the hidinput part, now remains hiddev */
 855         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
 856                 hid->hiddev_hid_event(hid, field, usage, value);
 857
 858         return 1;
 859 }
 860
 861 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 862 {
 863         int ret;
 864         struct ntrig_data *nd;
 865         struct hid_input *hidinput;
 866         struct input_dev *input;
 867         struct hid_report *report;
 868
 869         if (id->driver_data)
 870                 hdev->quirks |= HID_QUIRK_MULTI_INPUT
 871                                 | HID_QUIRK_NO_INIT_REPORTS;
 872
 873         nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
 874         if (!nd) {
 875                 hid_err(hdev, "cannot allocate N-Trig data\n");
 876                 return -ENOMEM;
 877         }
 878
 879         nd->reading_mt = 0;
 880         nd->min_width = 0;
 881         nd->min_height = 0;
 882         nd->activate_slack = activate_slack;
 883         nd->act_state = activate_slack;
 884         nd->deactivate_slack = -deactivate_slack;
 885         nd->sensor_logical_width = 0;
 886         nd->sensor_logical_height = 0;
 887         nd->sensor_physical_width = 0;
 888         nd->sensor_physical_height = 0;
 889
 890         hid_set_drvdata(hdev, nd);
 891
 892         ret = hid_parse(hdev);
 893         if (ret) {
 894                 hid_err(hdev, "parse failed\n");
 895                 goto err_free;
 896         }
 897
 898         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 899         if (ret) {
 900                 hid_err(hdev, "hw start failed\n");
 901                 goto err_free;
 902         }
 903
 904
 905         list_for_each_entry(hidinput, &hdev->inputs, list) {
 906                 if (hidinput->report->maxfield < 1)
 907                         continue;
 908
 909                 input = hidinput->input;
 910                 switch (hidinput->report->field[0]->application) {
 911                 case HID_DG_PEN:
 912                         input->name = "N-Trig Pen";
 913                         break;
 914                 case HID_DG_TOUCHSCREEN:
 915                         /* These keys are redundant for fingers, clear them
 916                          * to prevent incorrect identification */
 917                         __clear_bit(BTN_TOOL_PEN, input->keybit);
 918                         __clear_bit(BTN_TOOL_FINGER, input->keybit);
 919                         __clear_bit(BTN_0, input->keybit);
 920                         __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 921                         /*
 922                          * The physical touchscreen (single touch)
 923                          * input has a value for physical, whereas
 924                          * the multitouch only has logical input
 925                          * fields.
 926                          */
 927                         input->name =
 928                                 (hidinput->report->field[0]
 929                                  ->physical) ?
 930                                 "N-Trig Touchscreen" :
 931                                 "N-Trig MultiTouch";
 932                         break;
 933                 }
 934         }
 935
 936         /* This is needed for devices with more recent firmware versions */
 937         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
 938         if (report) {
 939                 /* Let the device settle to ensure the wakeup message gets
 940                  * through */
 941                 usbhid_wait_io(hdev);
 942                 usbhid_submit_report(hdev, report, USB_DIR_IN);
 943
 944                 /*
 945                  * Sanity check: if the current mode is invalid reset it to
 946                  * something reasonable.
 947                  */
 948                 if (ntrig_get_mode(hdev) >= 4)
 949                         ntrig_set_mode(hdev, 3);
 950         }
 951
 952         ntrig_report_version(hdev);
 953
 954         ret = sysfs_create_group(&hdev->dev.kobj,
 955                         &ntrig_attribute_group);
 956
 957         return 0;
 958 err_free:
 959         kfree(nd);
 960         return ret;
 961 }
 962
 963 static void ntrig_remove(struct hid_device *hdev)
 964 {
 965         sysfs_remove_group(&hdev->dev.kobj,
 966                            &ntrig_attribute_group);
 967         hid_hw_stop(hdev);
 968         kfree(hid_get_drvdata(hdev));
 969 }
 970
 971 static const struct hid_device_id ntrig_devices[] = {
 972         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
 973                 .driver_data = NTRIG_DUPLICATE_USAGES },
 974         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_1),
 975                 .driver_data = NTRIG_DUPLICATE_USAGES },
 976         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_2),
 977                 .driver_data = NTRIG_DUPLICATE_USAGES },
 978         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_3),
 979                 .driver_data = NTRIG_DUPLICATE_USAGES },
 980         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_4),
 981                 .driver_data = NTRIG_DUPLICATE_USAGES },
 982         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_5),
 983                 .driver_data = NTRIG_DUPLICATE_USAGES },
 984         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_6),
 985                 .driver_data = NTRIG_DUPLICATE_USAGES },
 986         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_7),
 987                 .driver_data = NTRIG_DUPLICATE_USAGES },
 988         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_8),
 989                 .driver_data = NTRIG_DUPLICATE_USAGES },
 990         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_9),
 991                 .driver_data = NTRIG_DUPLICATE_USAGES },
 992         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_10),
 993                 .driver_data = NTRIG_DUPLICATE_USAGES },
 994         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_11),
 995                 .driver_data = NTRIG_DUPLICATE_USAGES },
 996         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_12),
 997                 .driver_data = NTRIG_DUPLICATE_USAGES },
 998         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_13),
 999                 .driver_data = NTRIG_DUPLICATE_USAGES },
1000         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_14),
1001                 .driver_data = NTRIG_DUPLICATE_USAGES },
1002         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_15),
1003                 .driver_data = NTRIG_DUPLICATE_USAGES },
1004         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_16),
1005                 .driver_data = NTRIG_DUPLICATE_USAGES },
1006         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_17),
1007                 .driver_data = NTRIG_DUPLICATE_USAGES },
1008         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN_18),
1009                 .driver_data = NTRIG_DUPLICATE_USAGES },
1010         { }
1011 };
1012 MODULE_DEVICE_TABLE(hid, ntrig_devices);
1013
1014 static const struct hid_usage_id ntrig_grabbed_usages[] = {
1015         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
1016         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
1017 };
1018
1019 static struct hid_driver ntrig_driver = {
1020         .name = "ntrig",
1021         .id_table = ntrig_devices,
1022         .probe = ntrig_probe,
1023         .remove = ntrig_remove,
1024         .input_mapping = ntrig_input_mapping,
1025         .input_mapped = ntrig_input_mapped,
1026         .usage_table = ntrig_grabbed_usages,
1027         .event = ntrig_event,
1028 };
1029
1030 static int __init ntrig_init(void)
1031 {
1032         return hid_register_driver(&ntrig_driver);
1033 }
1034
1035 static void __exit ntrig_exit(void)
1036 {
1037         hid_unregister_driver(&ntrig_driver);
1038 }
1039
1040 module_init(ntrig_init);
1041 module_exit(ntrig_exit);
1042 MODULE_LICENSE("GPL");