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 || report->maxfield < 1 ||
 119             report->field[0]->report_count < 1)
 120                 return -EINVAL;
 121
 122         hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
 123         hid_hw_wait(hdev);
 124         return (int)report->field[0]->value[0];
 125 }
 126
 127 static inline void ntrig_set_mode(struct hid_device *hdev, const int mode)
 128 {
 129         struct hid_report *report;
 130         __u8 mode_commands[4] = { 0xe, 0xf, 0x1b, 0x10 };
 131
 132         if (mode < 0 || mode > 3)
 133                 return;
 134
 135         report = hdev->report_enum[HID_FEATURE_REPORT].
 136                  report_id_hash[mode_commands[mode]];
 137
 138         if (!report)
 139                 return;
 140
 141         hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
 142 }
 143
 144 static void ntrig_report_version(struct hid_device *hdev)
 145 {
 146         int ret;
 147         char buf[20];
 148         struct usb_device *usb_dev = hid_to_usb_dev(hdev);
 149         unsigned char *data = kmalloc(8, GFP_KERNEL);
 150
 151         if (!data)
 152                 goto err_free;
 153
 154         ret = usb_control_msg(usb_dev, usb_rcvctrlpipe(usb_dev, 0),
 155                               USB_REQ_CLEAR_FEATURE,
 156                               USB_TYPE_CLASS | USB_RECIP_INTERFACE |
 157                               USB_DIR_IN,
 158                               0x30c, 1, data, 8,
 159                               USB_CTRL_SET_TIMEOUT);
 160
 161         if (ret == 8) {
 162                 ret = ntrig_version_string(&data[2], buf);
 163
 164                 hid_info(hdev, "Firmware version: %s (%02x%02x %02x%02x)\n",
 165                          buf, data[2], data[3], data[4], data[5]);
 166         }
 167
 168 err_free:
 169         kfree(data);
 170 }
 171
 172 static ssize_t show_phys_width(struct device *dev,
 173                                struct device_attribute *attr,
 174                                char *buf)
 175 {
 176         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 177         struct ntrig_data *nd = hid_get_drvdata(hdev);
 178
 179         return sprintf(buf, "%d\n", nd->sensor_physical_width);
 180 }
 181
 182 static DEVICE_ATTR(sensor_physical_width, S_IRUGO, show_phys_width, NULL);
 183
 184 static ssize_t show_phys_height(struct device *dev,
 185                                 struct device_attribute *attr,
 186                                 char *buf)
 187 {
 188         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 189         struct ntrig_data *nd = hid_get_drvdata(hdev);
 190
 191         return sprintf(buf, "%d\n", nd->sensor_physical_height);
 192 }
 193
 194 static DEVICE_ATTR(sensor_physical_height, S_IRUGO, show_phys_height, NULL);
 195
 196 static ssize_t show_log_width(struct device *dev,
 197                               struct device_attribute *attr,
 198                               char *buf)
 199 {
 200         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 201         struct ntrig_data *nd = hid_get_drvdata(hdev);
 202
 203         return sprintf(buf, "%d\n", nd->sensor_logical_width);
 204 }
 205
 206 static DEVICE_ATTR(sensor_logical_width, S_IRUGO, show_log_width, NULL);
 207
 208 static ssize_t show_log_height(struct device *dev,
 209                                struct device_attribute *attr,
 210                                char *buf)
 211 {
 212         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 213         struct ntrig_data *nd = hid_get_drvdata(hdev);
 214
 215         return sprintf(buf, "%d\n", nd->sensor_logical_height);
 216 }
 217
 218 static DEVICE_ATTR(sensor_logical_height, S_IRUGO, show_log_height, NULL);
 219
 220 static ssize_t show_min_width(struct device *dev,
 221                               struct device_attribute *attr,
 222                               char *buf)
 223 {
 224         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 225         struct ntrig_data *nd = hid_get_drvdata(hdev);
 226
 227         return sprintf(buf, "%d\n", nd->min_width *
 228                                     nd->sensor_physical_width /
 229                                     nd->sensor_logical_width);
 230 }
 231
 232 static ssize_t set_min_width(struct device *dev,
 233                              struct device_attribute *attr,
 234                              const char *buf, size_t count)
 235 {
 236         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 237         struct ntrig_data *nd = hid_get_drvdata(hdev);
 238
 239         unsigned long val;
 240
 241         if (strict_strtoul(buf, 0, &val))
 242                 return -EINVAL;
 243
 244         if (val > nd->sensor_physical_width)
 245                 return -EINVAL;
 246
 247         nd->min_width = val * nd->sensor_logical_width /
 248                               nd->sensor_physical_width;
 249
 250         return count;
 251 }
 252
 253 static DEVICE_ATTR(min_width, S_IWUSR | S_IRUGO, show_min_width, set_min_width);
 254
 255 static ssize_t show_min_height(struct device *dev,
 256                                struct device_attribute *attr,
 257                                char *buf)
 258 {
 259         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 260         struct ntrig_data *nd = hid_get_drvdata(hdev);
 261
 262         return sprintf(buf, "%d\n", nd->min_height *
 263                                     nd->sensor_physical_height /
 264                                     nd->sensor_logical_height);
 265 }
 266
 267 static ssize_t set_min_height(struct device *dev,
 268                               struct device_attribute *attr,
 269                               const char *buf, size_t count)
 270 {
 271         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 272         struct ntrig_data *nd = hid_get_drvdata(hdev);
 273
 274         unsigned long val;
 275
 276         if (strict_strtoul(buf, 0, &val))
 277                 return -EINVAL;
 278
 279         if (val > nd->sensor_physical_height)
 280                 return -EINVAL;
 281
 282         nd->min_height = val * nd->sensor_logical_height /
 283                                nd->sensor_physical_height;
 284
 285         return count;
 286 }
 287
 288 static DEVICE_ATTR(min_height, S_IWUSR | S_IRUGO, show_min_height,
 289                    set_min_height);
 290
 291 static ssize_t show_activate_slack(struct device *dev,
 292                                    struct device_attribute *attr,
 293                                    char *buf)
 294 {
 295         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 296         struct ntrig_data *nd = hid_get_drvdata(hdev);
 297
 298         return sprintf(buf, "%d\n", nd->activate_slack);
 299 }
 300
 301 static ssize_t set_activate_slack(struct device *dev,
 302                                   struct device_attribute *attr,
 303                                   const char *buf, size_t count)
 304 {
 305         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 306         struct ntrig_data *nd = hid_get_drvdata(hdev);
 307
 308         unsigned long val;
 309
 310         if (strict_strtoul(buf, 0, &val))
 311                 return -EINVAL;
 312
 313         if (val > 0x7f)
 314                 return -EINVAL;
 315
 316         nd->activate_slack = val;
 317
 318         return count;
 319 }
 320
 321 static DEVICE_ATTR(activate_slack, S_IWUSR | S_IRUGO, show_activate_slack,
 322                    set_activate_slack);
 323
 324 static ssize_t show_activation_width(struct device *dev,
 325                                      struct device_attribute *attr,
 326                                      char *buf)
 327 {
 328         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 329         struct ntrig_data *nd = hid_get_drvdata(hdev);
 330
 331         return sprintf(buf, "%d\n", nd->activation_width *
 332                                     nd->sensor_physical_width /
 333                                     nd->sensor_logical_width);
 334 }
 335
 336 static ssize_t set_activation_width(struct device *dev,
 337                                     struct device_attribute *attr,
 338                                     const char *buf, size_t count)
 339 {
 340         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 341         struct ntrig_data *nd = hid_get_drvdata(hdev);
 342
 343         unsigned long val;
 344
 345         if (strict_strtoul(buf, 0, &val))
 346                 return -EINVAL;
 347
 348         if (val > nd->sensor_physical_width)
 349                 return -EINVAL;
 350
 351         nd->activation_width = val * nd->sensor_logical_width /
 352                                      nd->sensor_physical_width;
 353
 354         return count;
 355 }
 356
 357 static DEVICE_ATTR(activation_width, S_IWUSR | S_IRUGO, show_activation_width,
 358                    set_activation_width);
 359
 360 static ssize_t show_activation_height(struct device *dev,
 361                                       struct device_attribute *attr,
 362                                       char *buf)
 363 {
 364         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 365         struct ntrig_data *nd = hid_get_drvdata(hdev);
 366
 367         return sprintf(buf, "%d\n", nd->activation_height *
 368                                     nd->sensor_physical_height /
 369                                     nd->sensor_logical_height);
 370 }
 371
 372 static ssize_t set_activation_height(struct device *dev,
 373                                      struct device_attribute *attr,
 374                                      const char *buf, size_t count)
 375 {
 376         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 377         struct ntrig_data *nd = hid_get_drvdata(hdev);
 378
 379         unsigned long val;
 380
 381         if (strict_strtoul(buf, 0, &val))
 382                 return -EINVAL;
 383
 384         if (val > nd->sensor_physical_height)
 385                 return -EINVAL;
 386
 387         nd->activation_height = val * nd->sensor_logical_height /
 388                                       nd->sensor_physical_height;
 389
 390         return count;
 391 }
 392
 393 static DEVICE_ATTR(activation_height, S_IWUSR | S_IRUGO,
 394                    show_activation_height, set_activation_height);
 395
 396 static ssize_t show_deactivate_slack(struct device *dev,
 397                                      struct device_attribute *attr,
 398                                      char *buf)
 399 {
 400         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 401         struct ntrig_data *nd = hid_get_drvdata(hdev);
 402
 403         return sprintf(buf, "%d\n", -nd->deactivate_slack);
 404 }
 405
 406 static ssize_t set_deactivate_slack(struct device *dev,
 407                                     struct device_attribute *attr,
 408                                     const char *buf, size_t count)
 409 {
 410         struct hid_device *hdev = container_of(dev, struct hid_device, dev);
 411         struct ntrig_data *nd = hid_get_drvdata(hdev);
 412
 413         unsigned long val;
 414
 415         if (strict_strtoul(buf, 0, &val))
 416                 return -EINVAL;
 417
 418         /*
 419          * No more than 8 terminal frames have been observed so far
 420          * and higher slack is highly likely to leave the single
 421          * touch emulation stuck down.
 422          */
 423         if (val > 7)
 424                 return -EINVAL;
 425
 426         nd->deactivate_slack = -val;
 427
 428         return count;
 429 }
 430
 431 static DEVICE_ATTR(deactivate_slack, S_IWUSR | S_IRUGO, show_deactivate_slack,
 432                    set_deactivate_slack);
 433
 434 static struct attribute *sysfs_attrs[] = {
 435         &dev_attr_sensor_physical_width.attr,
 436         &dev_attr_sensor_physical_height.attr,
 437         &dev_attr_sensor_logical_width.attr,
 438         &dev_attr_sensor_logical_height.attr,
 439         &dev_attr_min_height.attr,
 440         &dev_attr_min_width.attr,
 441         &dev_attr_activate_slack.attr,
 442         &dev_attr_activation_width.attr,
 443         &dev_attr_activation_height.attr,
 444         &dev_attr_deactivate_slack.attr,
 445         NULL
 446 };
 447
 448 static struct attribute_group ntrig_attribute_group = {
 449         .attrs = sysfs_attrs
 450 };
 451
 452 /*
 453  * this driver is aimed at two firmware versions in circulation:
 454  *  - dual pen/finger single touch
 455  *  - finger multitouch, pen not working
 456  */
 457
 458 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 459                                struct hid_field *field, struct hid_usage *usage,
 460                                unsigned long **bit, int *max)
 461 {
 462         struct ntrig_data *nd = hid_get_drvdata(hdev);
 463
 464         /* No special mappings needed for the pen and single touch */
 465         if (field->physical)
 466                 return 0;
 467
 468         switch (usage->hid & HID_USAGE_PAGE) {
 469         case HID_UP_GENDESK:
 470                 switch (usage->hid) {
 471                 case HID_GD_X:
 472                         hid_map_usage(hi, usage, bit, max,
 473                                         EV_ABS, ABS_MT_POSITION_X);
 474                         input_set_abs_params(hi->input, ABS_X,
 475                                         field->logical_minimum,
 476                                         field->logical_maximum, 0, 0);
 477
 478                         if (!nd->sensor_logical_width) {
 479                                 nd->sensor_logical_width =
 480                                         field->logical_maximum -
 481                                         field->logical_minimum;
 482                                 nd->sensor_physical_width =
 483                                         field->physical_maximum -
 484                                         field->physical_minimum;
 485                                 nd->activation_width = activation_width *
 486                                         nd->sensor_logical_width /
 487                                         nd->sensor_physical_width;
 488                                 nd->min_width = min_width *
 489                                         nd->sensor_logical_width /
 490                                         nd->sensor_physical_width;
 491                         }
 492                         return 1;
 493                 case HID_GD_Y:
 494                         hid_map_usage(hi, usage, bit, max,
 495                                         EV_ABS, ABS_MT_POSITION_Y);
 496                         input_set_abs_params(hi->input, ABS_Y,
 497                                         field->logical_minimum,
 498                                         field->logical_maximum, 0, 0);
 499
 500                         if (!nd->sensor_logical_height) {
 501                                 nd->sensor_logical_height =
 502                                         field->logical_maximum -
 503                                         field->logical_minimum;
 504                                 nd->sensor_physical_height =
 505                                         field->physical_maximum -
 506                                         field->physical_minimum;
 507                                 nd->activation_height = activation_height *
 508                                         nd->sensor_logical_height /
 509                                         nd->sensor_physical_height;
 510                                 nd->min_height = min_height *
 511                                         nd->sensor_logical_height /
 512                                         nd->sensor_physical_height;
 513                         }
 514                         return 1;
 515                 }
 516                 return 0;
 517
 518         case HID_UP_DIGITIZER:
 519                 switch (usage->hid) {
 520                 /* we do not want to map these for now */
 521                 case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
 522                 case HID_DG_INPUTMODE:
 523                 case HID_DG_DEVICEINDEX:
 524                 case HID_DG_CONTACTMAX:
 525                         return -1;
 526
 527                 /* width/height mapped on TouchMajor/TouchMinor/Orientation */
 528                 case HID_DG_WIDTH:
 529                         hid_map_usage(hi, usage, bit, max,
 530                                       EV_ABS, ABS_MT_TOUCH_MAJOR);
 531                         return 1;
 532                 case HID_DG_HEIGHT:
 533                         hid_map_usage(hi, usage, bit, max,
 534                                       EV_ABS, ABS_MT_TOUCH_MINOR);
 535                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
 536                                              0, 1, 0, 0);
 537                         return 1;
 538                 }
 539                 return 0;
 540
 541         case 0xff000000:
 542                 /* we do not want to map these: no input-oriented meaning */
 543                 return -1;
 544         }
 545
 546         return 0;
 547 }
 548
 549 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 550                               struct hid_field *field, struct hid_usage *usage,
 551                               unsigned long **bit, int *max)
 552 {
 553         /* No special mappings needed for the pen and single touch */
 554         if (field->physical)
 555                 return 0;
 556
 557         if (usage->type == EV_KEY || usage->type == EV_REL
 558                         || usage->type == EV_ABS)
 559                 clear_bit(usage->code, *bit);
 560
 561         return 0;
 562 }
 563
 564 /*
 565  * this function is called upon all reports
 566  * so that we can filter contact point information,
 567  * decide whether we are in multi or single touch mode
 568  * and call input_mt_sync after each point if necessary
 569  */
 570 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
 571                         struct hid_usage *usage, __s32 value)
 572 {
 573         struct ntrig_data *nd = hid_get_drvdata(hid);
 574         struct input_dev *input;
 575
 576         /* Skip processing if not a claimed input */
 577         if (!(hid->claimed & HID_CLAIMED_INPUT))
 578                 goto not_claimed_input;
 579
 580         /* This function is being called before the structures are fully
 581          * initialized */
 582         if(!(field->hidinput && field->hidinput->input))
 583                 return -EINVAL;
 584
 585         input = field->hidinput->input;
 586
 587         /* No special handling needed for the pen */
 588         if (field->application == HID_DG_PEN)
 589                 return 0;
 590
 591         switch (usage->hid) {
 592         case 0xff000001:
 593                 /* Tag indicating the start of a multitouch group */
 594                 nd->reading_mt = 1;
 595                 nd->first_contact_touch = 0;
 596                 break;
 597         case HID_DG_TIPSWITCH:
 598                 nd->tipswitch = value;
 599                 /* Prevent emission of touch until validated */
 600                 return 1;
 601         case HID_DG_CONFIDENCE:
 602                 nd->confidence = value;
 603                 break;
 604         case HID_GD_X:
 605                 nd->x = value;
 606                 /* Clear the contact footer */
 607                 nd->mt_foot_count = 0;
 608                 break;
 609         case HID_GD_Y:
 610                 nd->y = value;
 611                 break;
 612         case HID_DG_CONTACTID:
 613                 nd->id = value;
 614                 break;
 615         case HID_DG_WIDTH:
 616                 nd->w = value;
 617                 break;
 618         case HID_DG_HEIGHT:
 619                 nd->h = value;
 620                 /*
 621                  * when in single touch mode, this is the last
 622                  * report received in a finger event. We want
 623                  * to emit a normal (X, Y) position
 624                  */
 625                 if (!nd->reading_mt) {
 626                         /*
 627                          * TipSwitch indicates the presence of a
 628                          * finger in single touch mode.
 629                          */
 630                         input_report_key(input, BTN_TOUCH,
 631                                          nd->tipswitch);
 632                         input_report_key(input, BTN_TOOL_DOUBLETAP,
 633                                          nd->tipswitch);
 634                         input_event(input, EV_ABS, ABS_X, nd->x);
 635                         input_event(input, EV_ABS, ABS_Y, nd->y);
 636                 }
 637                 break;
 638         case 0xff000002:
 639                 /*
 640                  * we receive this when the device is in multitouch
 641                  * mode. The first of the three values tagged with
 642                  * this usage tells if the contact point is real
 643                  * or a placeholder
 644                  */
 645
 646                 /* Shouldn't get more than 4 footer packets, so skip */
 647                 if (nd->mt_foot_count >= 4)
 648                         break;
 649
 650                 nd->mt_footer[nd->mt_foot_count++] = value;
 651
 652                 /* if the footer isn't complete break */
 653                 if (nd->mt_foot_count != 4)
 654                         break;
 655
 656                 /* Pen activity signal. */
 657                 if (nd->mt_footer[2]) {
 658                         /*
 659                          * When the pen deactivates touch, we see a
 660                          * bogus frame with ContactCount > 0.
 661                          * We can
 662                          * save a bit of work by ensuring act_state < 0
 663                          * even if deactivation slack is turned off.
 664                          */
 665                         nd->act_state = deactivate_slack - 1;
 666                         nd->confidence = 0;
 667                         break;
 668                 }
 669
 670                 /*
 671                  * The first footer value indicates the presence of a
 672                  * finger.
 673                  */
 674                 if (nd->mt_footer[0]) {
 675                         /*
 676                          * We do not want to process contacts under
 677                          * the size threshold, but do not want to
 678                          * ignore them for activation state
 679                          */
 680                         if (nd->w < nd->min_width ||
 681                             nd->h < nd->min_height)
 682                                 nd->confidence = 0;
 683                 } else
 684                         break;
 685
 686                 if (nd->act_state > 0) {
 687                         /*
 688                          * Contact meets the activation size threshold
 689                          */
 690                         if (nd->w >= nd->activation_width &&
 691                             nd->h >= nd->activation_height) {
 692                                 if (nd->id)
 693                                         /*
 694                                          * first contact, activate now
 695                                          */
 696                                         nd->act_state = 0;
 697                                 else {
 698                                         /*
 699                                          * avoid corrupting this frame
 700                                          * but ensure next frame will
 701                                          * be active
 702                                          */
 703                                         nd->act_state = 1;
 704                                         break;
 705                                 }
 706                         } else
 707                                 /*
 708                                  * Defer adjusting the activation state
 709                                  * until the end of the frame.
 710                                  */
 711                                 break;
 712                 }
 713
 714                 /* Discarding this contact */
 715                 if (!nd->confidence)
 716                         break;
 717
 718                 /* emit a normal (X, Y) for the first point only */
 719                 if (nd->id == 0) {
 720                         /*
 721                          * TipSwitch is superfluous in multitouch
 722                          * mode.  The footer events tell us
 723                          * if there is a finger on the screen or
 724                          * not.
 725                          */
 726                         nd->first_contact_touch = nd->confidence;
 727                         input_event(input, EV_ABS, ABS_X, nd->x);
 728                         input_event(input, EV_ABS, ABS_Y, nd->y);
 729                 }
 730
 731                 /* Emit MT events */
 732                 input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
 733                 input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
 734
 735                 /*
 736                  * Translate from height and width to size
 737                  * and orientation.
 738                  */
 739                 if (nd->w > nd->h) {
 740                         input_event(input, EV_ABS,
 741                                         ABS_MT_ORIENTATION, 1);
 742                         input_event(input, EV_ABS,
 743                                         ABS_MT_TOUCH_MAJOR, nd->w);
 744                         input_event(input, EV_ABS,
 745                                         ABS_MT_TOUCH_MINOR, nd->h);
 746                 } else {
 747                         input_event(input, EV_ABS,
 748                                         ABS_MT_ORIENTATION, 0);
 749                         input_event(input, EV_ABS,
 750                                         ABS_MT_TOUCH_MAJOR, nd->h);
 751                         input_event(input, EV_ABS,
 752                                         ABS_MT_TOUCH_MINOR, nd->w);
 753                 }
 754                 input_mt_sync(field->hidinput->input);
 755                 break;
 756
 757         case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
 758                 if (!nd->reading_mt) /* Just to be sure */
 759                         break;
 760
 761                 nd->reading_mt = 0;
 762
 763
 764                 /*
 765                  * Activation state machine logic:
 766                  *
 767                  * Fundamental states:
 768                  *      state >  0: Inactive
 769                  *      state <= 0: Active
 770                  *      state <  -deactivate_slack:
 771                  *               Pen termination of touch
 772                  *
 773                  * Specific values of interest
 774                  *      state == activate_slack
 775                  *               no valid input since the last reset
 776                  *
 777                  *      state == 0
 778                  *               general operational state
 779                  *
 780                  *      state == -deactivate_slack
 781                  *               read sufficient empty frames to accept
 782                  *               the end of input and reset
 783                  */
 784
 785                 if (nd->act_state > 0) { /* Currently inactive */
 786                         if (value)
 787                                 /*
 788                                  * Consider each live contact as
 789                                  * evidence of intentional activity.
 790                                  */
 791                                 nd->act_state = (nd->act_state > value)
 792                                                 ? nd->act_state - value
 793                                                 : 0;
 794                         else
 795                                 /*
 796                                  * Empty frame before we hit the
 797                                  * activity threshold, reset.
 798                                  */
 799                                 nd->act_state = nd->activate_slack;
 800
 801                         /*
 802                          * Entered this block inactive and no
 803                          * coordinates sent this frame, so hold off
 804                          * on button state.
 805                          */
 806                         break;
 807                 } else { /* Currently active */
 808                         if (value && nd->act_state >=
 809                                      nd->deactivate_slack)
 810                                 /*
 811                                  * Live point: clear accumulated
 812                                  * deactivation count.
 813                                  */
 814                                 nd->act_state = 0;
 815                         else if (nd->act_state <= nd->deactivate_slack)
 816                                 /*
 817                                  * We've consumed the deactivation
 818                                  * slack, time to deactivate and reset.
 819                                  */
 820                                 nd->act_state =
 821                                         nd->activate_slack;
 822                         else { /* Move towards deactivation */
 823                                 nd->act_state--;
 824                                 break;
 825                         }
 826                 }
 827
 828                 if (nd->first_contact_touch && nd->act_state <= 0) {
 829                         /*
 830                          * Check to see if we're ready to start
 831                          * emitting touch events.
 832                          *
 833                          * Note: activation slack will decrease over
 834                          * the course of the frame, and it will be
 835                          * inconsistent from the start to the end of
 836                          * the frame.  However if the frame starts
 837                          * with slack, first_contact_touch will still
 838                          * be 0 and we will not get to this point.
 839                          */
 840                         input_report_key(input, BTN_TOOL_DOUBLETAP, 1);
 841                         input_report_key(input, BTN_TOUCH, 1);
 842                 } else {
 843                         input_report_key(input, BTN_TOOL_DOUBLETAP, 0);
 844                         input_report_key(input, BTN_TOUCH, 0);
 845                 }
 846                 break;
 847
 848         default:
 849                 /* fall-back to the generic hidinput handling */
 850                 return 0;
 851         }
 852
 853 not_claimed_input:
 854
 855         /* we have handled the hidinput part, now remains hiddev */
 856         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
 857                 hid->hiddev_hid_event(hid, field, usage, value);
 858
 859         return 1;
 860 }
 861
 862 static void ntrig_input_configured(struct hid_device *hid,
 863                 struct hid_input *hidinput)
 864
 865 {
 866         struct input_dev *input = hidinput->input;
 867
 868         if (hidinput->report->maxfield < 1)
 869                 return;
 870
 871         switch (hidinput->report->field[0]->application) {
 872         case HID_DG_PEN:
 873                 input->name = "N-Trig Pen";
 874                 break;
 875         case HID_DG_TOUCHSCREEN:
 876                 /* These keys are redundant for fingers, clear them
 877                  * to prevent incorrect identification */
 878                 __clear_bit(BTN_TOOL_PEN, input->keybit);
 879                 __clear_bit(BTN_TOOL_FINGER, input->keybit);
 880                 __clear_bit(BTN_0, input->keybit);
 881                 __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 882                 /*
 883                  * The physical touchscreen (single touch)
 884                  * input has a value for physical, whereas
 885                  * the multitouch only has logical input
 886                  * fields.
 887                  */
 888                 input->name = (hidinput->report->field[0]->physical) ?
 889                                                         "N-Trig Touchscreen" :
 890                                                         "N-Trig MultiTouch";
 891                 break;
 892         }
 893 }
 894
 895 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 896 {
 897         int ret;
 898         struct ntrig_data *nd;
 899         struct hid_report *report;
 900
 901         if (id->driver_data)
 902                 hdev->quirks |= HID_QUIRK_MULTI_INPUT
 903                                 | HID_QUIRK_NO_INIT_REPORTS;
 904
 905         nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
 906         if (!nd) {
 907                 hid_err(hdev, "cannot allocate N-Trig data\n");
 908                 return -ENOMEM;
 909         }
 910
 911         nd->reading_mt = 0;
 912         nd->min_width = 0;
 913         nd->min_height = 0;
 914         nd->activate_slack = activate_slack;
 915         nd->act_state = activate_slack;
 916         nd->deactivate_slack = -deactivate_slack;
 917         nd->sensor_logical_width = 1;
 918         nd->sensor_logical_height = 1;
 919         nd->sensor_physical_width = 1;
 920         nd->sensor_physical_height = 1;
 921
 922         hid_set_drvdata(hdev, nd);
 923
 924         ret = hid_parse(hdev);
 925         if (ret) {
 926                 hid_err(hdev, "parse failed\n");
 927                 goto err_free;
 928         }
 929
 930         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 931         if (ret) {
 932                 hid_err(hdev, "hw start failed\n");
 933                 goto err_free;
 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                 hid_hw_wait(hdev);
 942                 hid_hw_request(hdev, report, HID_REQ_GET_REPORT);
 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         .input_configured = ntrig_input_configured,
1027         .usage_table = ntrig_grabbed_usages,
1028         .event = ntrig_event,
1029 };
1030 module_hid_driver(ntrig_driver);
1031
1032 MODULE_LICENSE("GPL");