drivers/hid/hid-multitouch.c

   1 /*
   2  *  HID driver for multitouch panels
   3  *
   4  *  Copyright (c) 2010-2011 Stephane Chatty <chatty@enac.fr>
   5  *  Copyright (c) 2010-2011 Benjamin Tissoires <benjamin.tissoires@gmail.com>
   6  *  Copyright (c) 2010-2011 Ecole Nationale de l'Aviation Civile, France
   7  *
   8  */
   9
  10 /*
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by the Free
  13  * Software Foundation; either version 2 of the License, or (at your option)
  14  * any later version.
  15  */
  16
  17 #include <linux/device.h>
  18 #include <linux/hid.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/usb.h>
  22 #include <linux/input/mt.h>
  23 #include "usbhid/usbhid.h"
  24
  25
  26 MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  27 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
  28 MODULE_DESCRIPTION("HID multitouch panels");
  29 MODULE_LICENSE("GPL");
  30
  31 #include "hid-ids.h"
  32
  33 /* quirks to control the device */
  34 #define MT_QUIRK_NOT_SEEN_MEANS_UP      (1 << 0)
  35 #define MT_QUIRK_SLOT_IS_CONTACTID      (1 << 1)
  36 #define MT_QUIRK_CYPRESS                (1 << 2)
  37 #define MT_QUIRK_SLOT_IS_CONTACTNUMBER  (1 << 3)
  38 #define MT_QUIRK_VALID_IS_INRANGE       (1 << 4)
  39 #define MT_QUIRK_VALID_IS_CONFIDENCE    (1 << 5)
  40
  41 struct mt_slot {
  42         __s32 x, y, p, w, h;
  43         __s32 contactid;        /* the device ContactID assigned to this slot */
  44         bool touch_state;       /* is the touch valid? */
  45         bool seen_in_this_frame;/* has this slot been updated */
  46 };
  47
  48 struct mt_device {
  49         struct mt_slot curdata; /* placeholder of incoming data */
  50         struct mt_class *mtclass;       /* our mt device class */
  51         unsigned last_field_index;      /* last field index of the report */
  52         unsigned last_slot_field;       /* the last field of a slot */
  53         __s8 inputmode;         /* InputMode HID feature, -1 if non-existent */
  54         __u8 num_received;      /* how many contacts we received */
  55         __u8 num_expected;      /* expected last contact index */
  56         bool curvalid;          /* is the current contact valid? */
  57         struct mt_slot slots[0];        /* first slot */
  58 };
  59
  60 struct mt_class {
  61         __s32 name;     /* MT_CLS */
  62         __s32 quirks;
  63         __s32 sn_move;  /* Signal/noise ratio for move events */
  64         __s32 sn_pressure;      /* Signal/noise ratio for pressure events */
  65         __u8 maxcontacts;
  66 };
  67
  68 /* classes of device behavior */
  69 #define MT_CLS_DEFAULT                          1
  70 #define MT_CLS_DUAL_INRANGE_CONTACTID           2
  71 #define MT_CLS_DUAL_INRANGE_CONTACTNUMBER       3
  72 #define MT_CLS_CYPRESS                          4
  73
  74 /*
  75  * these device-dependent functions determine what slot corresponds
  76  * to a valid contact that was just read.
  77  */
  78
  79 static int cypress_compute_slot(struct mt_device *td)
  80 {
  81         if (td->curdata.contactid != 0 || td->num_received == 0)
  82                 return td->curdata.contactid;
  83         else
  84                 return -1;
  85 }
  86
  87 static int find_slot_from_contactid(struct mt_device *td)
  88 {
  89         int i;
  90         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
  91                 if (td->slots[i].contactid == td->curdata.contactid &&
  92                         td->slots[i].touch_state)
  93                         return i;
  94         }
  95         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
  96                 if (!td->slots[i].seen_in_this_frame &&
  97                         !td->slots[i].touch_state)
  98                         return i;
  99         }
 100         /* should not occurs. If this happens that means
 101          * that the device sent more touches that it says
 102          * in the report descriptor. It is ignored then. */
 103         return -1;
 104 }
 105
 106 struct mt_class mt_classes[] = {
 107         { .name = MT_CLS_DEFAULT,
 108                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP,
 109                 .maxcontacts = 10 },
 110         { .name = MT_CLS_DUAL_INRANGE_CONTACTID,
 111                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 112                         MT_QUIRK_SLOT_IS_CONTACTID,
 113                 .maxcontacts = 2 },
 114         { .name = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 115                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 116                         MT_QUIRK_SLOT_IS_CONTACTNUMBER,
 117                 .maxcontacts = 2 },
 118         { .name = MT_CLS_CYPRESS,
 119                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
 120                         MT_QUIRK_CYPRESS,
 121                 .maxcontacts = 10 },
 122
 123         { }
 124 };
 125
 126 static void mt_feature_mapping(struct hid_device *hdev, struct hid_input *hi,
 127                 struct hid_field *field, struct hid_usage *usage)
 128 {
 129         if (usage->hid == HID_DG_INPUTMODE) {
 130                 struct mt_device *td = hid_get_drvdata(hdev);
 131                 td->inputmode = field->report->id;
 132         }
 133 }
 134
 135 static void set_abs(struct input_dev *input, unsigned int code,
 136                 struct hid_field *field, int snratio)
 137 {
 138         int fmin = field->logical_minimum;
 139         int fmax = field->logical_maximum;
 140         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
 141         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
 142 }
 143
 144 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 145                 struct hid_field *field, struct hid_usage *usage,
 146                 unsigned long **bit, int *max)
 147 {
 148         struct mt_device *td = hid_get_drvdata(hdev);
 149         struct mt_class *cls = td->mtclass;
 150         switch (usage->hid & HID_USAGE_PAGE) {
 151
 152         case HID_UP_GENDESK:
 153                 switch (usage->hid) {
 154                 case HID_GD_X:
 155                         hid_map_usage(hi, usage, bit, max,
 156                                         EV_ABS, ABS_MT_POSITION_X);
 157                         set_abs(hi->input, ABS_MT_POSITION_X, field,
 158                                 cls->sn_move);
 159                         /* touchscreen emulation */
 160                         set_abs(hi->input, ABS_X, field, cls->sn_move);
 161                         td->last_slot_field = usage->hid;
 162                         return 1;
 163                 case HID_GD_Y:
 164                         hid_map_usage(hi, usage, bit, max,
 165                                         EV_ABS, ABS_MT_POSITION_Y);
 166                         set_abs(hi->input, ABS_MT_POSITION_Y, field,
 167                                 cls->sn_move);
 168                         /* touchscreen emulation */
 169                         set_abs(hi->input, ABS_Y, field, cls->sn_move);
 170                         td->last_slot_field = usage->hid;
 171                         return 1;
 172                 }
 173                 return 0;
 174
 175         case HID_UP_DIGITIZER:
 176                 switch (usage->hid) {
 177                 case HID_DG_INRANGE:
 178                         td->last_slot_field = usage->hid;
 179                         return 1;
 180                 case HID_DG_CONFIDENCE:
 181                         td->last_slot_field = usage->hid;
 182                         return 1;
 183                 case HID_DG_TIPSWITCH:
 184                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 185                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
 186                         td->last_slot_field = usage->hid;
 187                         return 1;
 188                 case HID_DG_CONTACTID:
 189                         input_mt_init_slots(hi->input,
 190                                         td->mtclass->maxcontacts);
 191                         td->last_slot_field = usage->hid;
 192                         return 1;
 193                 case HID_DG_WIDTH:
 194                         hid_map_usage(hi, usage, bit, max,
 195                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
 196                         td->last_slot_field = usage->hid;
 197                         return 1;
 198                 case HID_DG_HEIGHT:
 199                         hid_map_usage(hi, usage, bit, max,
 200                                         EV_ABS, ABS_MT_TOUCH_MINOR);
 201                         field->logical_maximum = 1;
 202                         field->logical_minimum = 0;
 203                         set_abs(hi->input, ABS_MT_ORIENTATION, field, 0);
 204                         td->last_slot_field = usage->hid;
 205                         return 1;
 206                 case HID_DG_TIPPRESSURE:
 207                         hid_map_usage(hi, usage, bit, max,
 208                                         EV_ABS, ABS_MT_PRESSURE);
 209                         set_abs(hi->input, ABS_MT_PRESSURE, field,
 210                                 cls->sn_pressure);
 211                         /* touchscreen emulation */
 212                         set_abs(hi->input, ABS_PRESSURE, field,
 213                                 cls->sn_pressure);
 214                         td->last_slot_field = usage->hid;
 215                         return 1;
 216                 case HID_DG_CONTACTCOUNT:
 217                         td->last_field_index = field->report->maxfield - 1;
 218                         return 1;
 219                 case HID_DG_CONTACTMAX:
 220                         /* we don't set td->last_slot_field as contactcount and
 221                          * contact max are global to the report */
 222                         return -1;
 223                 }
 224                 /* let hid-input decide for the others */
 225                 return 0;
 226
 227         case 0xff000000:
 228                 /* we do not want to map these: no input-oriented meaning */
 229                 return -1;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 236                 struct hid_field *field, struct hid_usage *usage,
 237                 unsigned long **bit, int *max)
 238 {
 239         if (usage->type == EV_KEY || usage->type == EV_ABS)
 240                 set_bit(usage->type, hi->input->evbit);
 241
 242         return -1;
 243 }
 244
 245 static int mt_compute_slot(struct mt_device *td)
 246 {
 247         __s32 quirks = td->mtclass->quirks;
 248
 249         if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
 250                 return td->curdata.contactid;
 251
 252         if (quirks & MT_QUIRK_CYPRESS)
 253                 return cypress_compute_slot(td);
 254
 255         if (quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
 256                 return td->num_received;
 257
 258         return find_slot_from_contactid(td);
 259 }
 260
 261 /*
 262  * this function is called when a whole contact has been processed,
 263  * so that it can assign it to a slot and store the data there
 264  */
 265 static void mt_complete_slot(struct mt_device *td)
 266 {
 267         td->curdata.seen_in_this_frame = true;
 268         if (td->curvalid) {
 269                 int slotnum = mt_compute_slot(td);
 270
 271                 if (slotnum >= 0 && slotnum < td->mtclass->maxcontacts)
 272                         td->slots[slotnum] = td->curdata;
 273         }
 274         td->num_received++;
 275 }
 276
 277
 278 /*
 279  * this function is called when a whole packet has been received and processed,
 280  * so that it can decide what to send to the input layer.
 281  */
 282 static void mt_emit_event(struct mt_device *td, struct input_dev *input)
 283 {
 284         int i;
 285
 286         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
 287                 struct mt_slot *s = &(td->slots[i]);
 288                 if ((td->mtclass->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
 289                         !s->seen_in_this_frame) {
 290                         s->touch_state = false;
 291                 }
 292
 293                 input_mt_slot(input, i);
 294                 input_mt_report_slot_state(input, MT_TOOL_FINGER,
 295                         s->touch_state);
 296                 if (s->touch_state) {
 297                         input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
 298                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
 299                         input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
 300                         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
 301                         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
 302                 }
 303                 s->seen_in_this_frame = false;
 304
 305         }
 306
 307         input_mt_report_pointer_emulation(input, true);
 308         input_sync(input);
 309         td->num_received = 0;
 310 }
 311
 312
 313
 314 static int mt_event(struct hid_device *hid, struct hid_field *field,
 315                                 struct hid_usage *usage, __s32 value)
 316 {
 317         struct mt_device *td = hid_get_drvdata(hid);
 318         __s32 quirks = td->mtclass->quirks;
 319
 320         if (hid->claimed & HID_CLAIMED_INPUT) {
 321                 switch (usage->hid) {
 322                 case HID_DG_INRANGE:
 323                         if (quirks & MT_QUIRK_VALID_IS_INRANGE)
 324                                 td->curvalid = value;
 325                         break;
 326                 case HID_DG_TIPSWITCH:
 327                         if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
 328                                 td->curvalid = value;
 329                         td->curdata.touch_state = value;
 330                         break;
 331                 case HID_DG_CONFIDENCE:
 332                         if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
 333                                 td->curvalid = value;
 334                         break;
 335                 case HID_DG_CONTACTID:
 336                         td->curdata.contactid = value;
 337                         break;
 338                 case HID_DG_TIPPRESSURE:
 339                         td->curdata.p = value;
 340                         break;
 341                 case HID_GD_X:
 342                         td->curdata.x = value;
 343                         break;
 344                 case HID_GD_Y:
 345                         td->curdata.y = value;
 346                         break;
 347                 case HID_DG_WIDTH:
 348                         td->curdata.w = value;
 349                         break;
 350                 case HID_DG_HEIGHT:
 351                         td->curdata.h = value;
 352                         break;
 353                 case HID_DG_CONTACTCOUNT:
 354                         /*
 355                          * Includes multi-packet support where subsequent
 356                          * packets are sent with zero contactcount.
 357                          */
 358                         if (value)
 359                                 td->num_expected = value;
 360                         break;
 361
 362                 default:
 363                         /* fallback to the generic hidinput handling */
 364                         return 0;
 365                 }
 366
 367                 if (usage->hid == td->last_slot_field)
 368                         mt_complete_slot(td);
 369
 370                 if (field->index == td->last_field_index
 371                         && td->num_received >= td->num_expected)
 372                         mt_emit_event(td, field->hidinput->input);
 373
 374         }
 375
 376         /* we have handled the hidinput part, now remains hiddev */
 377         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 378                 hid->hiddev_hid_event(hid, field, usage, value);
 379
 380         return 1;
 381 }
 382
 383 static void mt_set_input_mode(struct hid_device *hdev)
 384 {
 385         struct mt_device *td = hid_get_drvdata(hdev);
 386         struct hid_report *r;
 387         struct hid_report_enum *re;
 388
 389         if (td->inputmode < 0)
 390                 return;
 391
 392         re = &(hdev->report_enum[HID_FEATURE_REPORT]);
 393         r = re->report_id_hash[td->inputmode];
 394         if (r) {
 395                 r->field[0]->value[0] = 0x02;
 396                 usbhid_submit_report(hdev, r, USB_DIR_OUT);
 397         }
 398 }
 399
 400 static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 401 {
 402         int ret, i;
 403         struct mt_device *td;
 404         struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
 405
 406         for (i = 0; mt_classes[i].name ; i++) {
 407                 if (id->driver_data == mt_classes[i].name) {
 408                         mtclass = &(mt_classes[i]);
 409                         break;
 410                 }
 411         }
 412
 413         /* This allows the driver to correctly support devices
 414          * that emit events over several HID messages.
 415          */
 416         hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 417
 418         td = kzalloc(sizeof(struct mt_device) +
 419                                 mtclass->maxcontacts * sizeof(struct mt_slot),
 420                                 GFP_KERNEL);
 421         if (!td) {
 422                 dev_err(&hdev->dev, "cannot allocate multitouch data\n");
 423                 return -ENOMEM;
 424         }
 425         td->mtclass = mtclass;
 426         td->inputmode = -1;
 427         hid_set_drvdata(hdev, td);
 428
 429         ret = hid_parse(hdev);
 430         if (ret != 0)
 431                 goto fail;
 432
 433         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 434         if (ret)
 435                 goto fail;
 436
 437         mt_set_input_mode(hdev);
 438
 439         return 0;
 440
 441 fail:
 442         kfree(td);
 443         return ret;
 444 }
 445
 446 #ifdef CONFIG_PM
 447 static int mt_reset_resume(struct hid_device *hdev)
 448 {
 449         mt_set_input_mode(hdev);
 450         return 0;
 451 }
 452 #endif
 453
 454 static void mt_remove(struct hid_device *hdev)
 455 {
 456         struct mt_device *td = hid_get_drvdata(hdev);
 457         hid_hw_stop(hdev);
 458         kfree(td);
 459         hid_set_drvdata(hdev, NULL);
 460 }
 461
 462 static const struct hid_device_id mt_devices[] = {
 463
 464         /* Cypress panel */
 465         { .driver_data = MT_CLS_CYPRESS,
 466                 HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS,
 467                         USB_DEVICE_ID_CYPRESS_TRUETOUCH) },
 468
 469         /* GeneralTouch panel */
 470         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTNUMBER,
 471                 HID_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
 472                         USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },
 473
 474         /* PixCir-based panels */
 475         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 476                 HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
 477                         USB_DEVICE_ID_HANVON_MULTITOUCH) },
 478         { .driver_data = MT_CLS_DUAL_INRANGE_CONTACTID,
 479                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 480                         USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
 481
 482         { }
 483 };
 484 MODULE_DEVICE_TABLE(hid, mt_devices);
 485
 486 static const struct hid_usage_id mt_grabbed_usages[] = {
 487         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 488         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 489 };
 490
 491 static struct hid_driver mt_driver = {
 492         .name = "hid-multitouch",
 493         .id_table = mt_devices,
 494         .probe = mt_probe,
 495         .remove = mt_remove,
 496         .input_mapping = mt_input_mapping,
 497         .input_mapped = mt_input_mapped,
 498         .feature_mapping = mt_feature_mapping,
 499         .usage_table = mt_grabbed_usages,
 500         .event = mt_event,
 501 #ifdef CONFIG_PM
 502         .reset_resume = mt_reset_resume,
 503 #endif
 504 };
 505
 506 static int __init mt_init(void)
 507 {
 508         return hid_register_driver(&mt_driver);
 509 }
 510
 511 static void __exit mt_exit(void)
 512 {
 513         hid_unregister_driver(&mt_driver);
 514 }
 515
 516 module_init(mt_init);
 517 module_exit(mt_exit);