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_DESCRIPTION("HID multitouch panels");
  28 MODULE_LICENSE("GPL");
  29
  30 #include "hid-ids.h"
  31
  32 /* quirks to control the device */
  33 #define MT_QUIRK_NOT_SEEN_MEANS_UP      (1 << 0)
  34 #define MT_QUIRK_SLOT_IS_CONTACTID      (1 << 1)
  35 #define MT_QUIRK_CYPRESS        (1 << 2)
  36 #define MT_QUIRK_SLOT_IS_CONTACTNUMBER  (1 << 3)
  37
  38 struct mt_slot {
  39         __s32 x, y, p, w, h;
  40         __s32 contactid;        /* the device ContactID assigned to this slot */
  41         bool touch_state;       /* is the touch valid? */
  42         bool seen_in_this_frame;/* has this slot been updated */
  43 };
  44
  45 struct mt_device {
  46         struct mt_slot curdata; /* placeholder of incoming data */
  47         struct mt_class *mtclass;       /* our mt device class */
  48         unsigned last_field_index;      /* last field index of the report */
  49         unsigned last_slot_field;       /* the last field of a slot */
  50         __s8 inputmode;         /* InputMode HID feature, -1 if non-existent */
  51         __u8 num_received;      /* how many contacts we received */
  52         __u8 num_expected;      /* expected last contact index */
  53         bool curvalid;          /* is the current contact valid? */
  54         struct mt_slot slots[0];        /* first slot */
  55 };
  56
  57 struct mt_class {
  58         __s32 quirks;
  59         __s32 sn_move;  /* Signal/noise ratio for move events */
  60         __s32 sn_pressure;      /* Signal/noise ratio for pressure events */
  61         __u8 maxcontacts;
  62 };
  63
  64 /* classes of device behavior */
  65 #define MT_CLS_DEFAULT 0
  66 #define MT_CLS_DUAL1 1
  67 #define MT_CLS_DUAL2 2
  68 #define MT_CLS_CYPRESS 3
  69
  70 /*
  71  * these device-dependent functions determine what slot corresponds
  72  * to a valid contact that was just read.
  73  */
  74
  75 static int slot_is_contactid(struct mt_device *td)
  76 {
  77         return td->curdata.contactid;
  78 }
  79
  80 static int slot_is_contactnumber(struct mt_device *td)
  81 {
  82         return td->num_received;
  83 }
  84
  85 static int cypress_compute_slot(struct mt_device *td)
  86 {
  87         if (td->curdata.contactid != 0 || td->num_received == 0)
  88                 return td->curdata.contactid;
  89         else
  90                 return -1;
  91 }
  92
  93 static int find_slot_from_contactid(struct mt_device *td)
  94 {
  95         int i;
  96         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
  97                 if (td->slots[i].contactid == td->curdata.contactid &&
  98                         td->slots[i].touch_state)
  99                         return i;
 100         }
 101         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
 102                 if (!td->slots[i].seen_in_this_frame &&
 103                         !td->slots[i].touch_state)
 104                         return i;
 105         }
 106         return -1;
 107         /* should not occurs. If this happens that means
 108          * that the device sent more touches that it says
 109          * in the report descriptor. It is ignored then. */
 110 }
 111
 112 struct mt_class mt_classes[] = {
 113         { 0, 0, 0, 10 },                             /* MT_CLS_DEFAULT */
 114         { MT_QUIRK_SLOT_IS_CONTACTID, 0, 0, 2 },     /* MT_CLS_DUAL1 */
 115         { MT_QUIRK_SLOT_IS_CONTACTNUMBER, 0, 0, 10 },    /* MT_CLS_DUAL2 */
 116         { MT_QUIRK_CYPRESS | MT_QUIRK_NOT_SEEN_MEANS_UP, 0, 0, 10 }, /* MT_CLS_CYPRESS */
 117 };
 118
 119 static void mt_feature_mapping(struct hid_device *hdev, struct hid_input *hi,
 120                 struct hid_field *field, struct hid_usage *usage)
 121 {
 122         if (usage->hid == HID_DG_INPUTMODE) {
 123                 struct mt_device *td = hid_get_drvdata(hdev);
 124                 td->inputmode = field->report->id;
 125         }
 126 }
 127
 128 static void set_abs(struct input_dev *input, unsigned int code,
 129                 struct hid_field *field, int snratio)
 130 {
 131         int fmin = field->logical_minimum;
 132         int fmax = field->logical_maximum;
 133         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
 134         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
 135 }
 136
 137 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 138                 struct hid_field *field, struct hid_usage *usage,
 139                 unsigned long **bit, int *max)
 140 {
 141         struct mt_device *td = hid_get_drvdata(hdev);
 142         struct mt_class *cls = td->mtclass;
 143         switch (usage->hid & HID_USAGE_PAGE) {
 144
 145         case HID_UP_GENDESK:
 146                 switch (usage->hid) {
 147                 case HID_GD_X:
 148                         hid_map_usage(hi, usage, bit, max,
 149                                         EV_ABS, ABS_MT_POSITION_X);
 150                         set_abs(hi->input, ABS_MT_POSITION_X, field,
 151                                 cls->sn_move);
 152                         /* touchscreen emulation */
 153                         set_abs(hi->input, ABS_X, field, cls->sn_move);
 154                         td->last_slot_field = usage->hid;
 155                         return 1;
 156                 case HID_GD_Y:
 157                         hid_map_usage(hi, usage, bit, max,
 158                                         EV_ABS, ABS_MT_POSITION_Y);
 159                         set_abs(hi->input, ABS_MT_POSITION_Y, field,
 160                                 cls->sn_move);
 161                         /* touchscreen emulation */
 162                         set_abs(hi->input, ABS_Y, field, cls->sn_move);
 163                         td->last_slot_field = usage->hid;
 164                         return 1;
 165                 }
 166                 return 0;
 167
 168         case HID_UP_DIGITIZER:
 169                 switch (usage->hid) {
 170                 case HID_DG_INRANGE:
 171                         td->last_slot_field = usage->hid;
 172                         return 1;
 173                 case HID_DG_CONFIDENCE:
 174                         td->last_slot_field = usage->hid;
 175                         return 1;
 176                 case HID_DG_TIPSWITCH:
 177                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 178                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
 179                         td->last_slot_field = usage->hid;
 180                         return 1;
 181                 case HID_DG_CONTACTID:
 182                         input_mt_init_slots(hi->input,
 183                                         td->mtclass->maxcontacts);
 184                         td->last_slot_field = usage->hid;
 185                         return 1;
 186                 case HID_DG_WIDTH:
 187                         hid_map_usage(hi, usage, bit, max,
 188                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
 189                         td->last_slot_field = usage->hid;
 190                         return 1;
 191                 case HID_DG_HEIGHT:
 192                         hid_map_usage(hi, usage, bit, max,
 193                                         EV_ABS, ABS_MT_TOUCH_MINOR);
 194                         field->logical_maximum = 1;
 195                         field->logical_minimum = 1;
 196                         set_abs(hi->input, ABS_MT_ORIENTATION, field, 0);
 197                         td->last_slot_field = usage->hid;
 198                         return 1;
 199                 case HID_DG_TIPPRESSURE:
 200                         hid_map_usage(hi, usage, bit, max,
 201                                         EV_ABS, ABS_MT_PRESSURE);
 202                         set_abs(hi->input, ABS_MT_PRESSURE, field,
 203                                 cls->sn_pressure);
 204                         /* touchscreen emulation */
 205                         set_abs(hi->input, ABS_PRESSURE, field,
 206                                 cls->sn_pressure);
 207                         td->last_slot_field = usage->hid;
 208                         return 1;
 209                 case HID_DG_CONTACTCOUNT:
 210                         td->last_field_index = field->report->maxfield - 1;
 211                         return 1;
 212                 case HID_DG_CONTACTMAX:
 213                         /* we don't set td->last_slot_field as contactcount and
 214                          * contact max are global to the report */
 215                         return -1;
 216                 }
 217                 /* let hid-input decide for the others */
 218                 return 0;
 219
 220         case 0xff000000:
 221                 /* we do not want to map these: no input-oriented meaning */
 222                 return -1;
 223         }
 224
 225         return 0;
 226 }
 227
 228 static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 229                 struct hid_field *field, struct hid_usage *usage,
 230                 unsigned long **bit, int *max)
 231 {
 232         if (usage->type == EV_KEY || usage->type == EV_ABS)
 233                 set_bit(usage->type, hi->input->evbit);
 234
 235         return -1;
 236 }
 237
 238 static int mt_compute_slot(struct mt_device *td)
 239 {
 240         struct mt_class *cls = td->mtclass;
 241
 242         if (cls->quirks & MT_QUIRK_SLOT_IS_CONTACTID)
 243                 return slot_is_contactid(td);
 244
 245         if (cls->quirks & MT_QUIRK_CYPRESS)
 246                 return cypress_compute_slot(td);
 247
 248         if (cls->quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
 249                 return slot_is_contactnumber(td);
 250
 251         return find_slot_from_contactid(td);
 252 }
 253
 254 /*
 255  * this function is called when a whole contact has been processed,
 256  * so that it can assign it to a slot and store the data there
 257  */
 258 static void mt_complete_slot(struct mt_device *td)
 259 {
 260         if (td->curvalid) {
 261                 struct mt_slot *slot;
 262                 int slotnum = mt_compute_slot(td);
 263
 264                 if (slotnum >= 0 && slotnum < td->mtclass->maxcontacts) {
 265                         slot = td->slots + slotnum;
 266
 267                         memcpy(slot, &(td->curdata), sizeof(struct mt_slot));
 268                         slot->seen_in_this_frame = true;
 269                 }
 270         }
 271         td->num_received++;
 272 }
 273
 274
 275 /*
 276  * this function is called when a whole packet has been received and processed,
 277  * so that it can decide what to send to the input layer.
 278  */
 279 static void mt_emit_event(struct mt_device *td, struct input_dev *input)
 280 {
 281         int i;
 282
 283         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
 284                 struct mt_slot *s = &(td->slots[i]);
 285                 if ((td->mtclass->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
 286                         !s->seen_in_this_frame) {
 287                         /*
 288                          * this slot does not contain useful data,
 289                          * notify its closure
 290                          */
 291                         s->touch_state = false;
 292                 }
 293
 294                 input_mt_slot(input, i);
 295                 input_mt_report_slot_state(input, MT_TOOL_FINGER,
 296                         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                 s->seen_in_this_frame = false;
 303
 304         }
 305
 306         input_mt_report_pointer_emulation(input, true);
 307         input_sync(input);
 308         td->num_received = 0;
 309 }
 310
 311
 312
 313 static int mt_event(struct hid_device *hid, struct hid_field *field,
 314                                 struct hid_usage *usage, __s32 value)
 315 {
 316         struct mt_device *td = hid_get_drvdata(hid);
 317
 318         if (hid->claimed & HID_CLAIMED_INPUT) {
 319                 switch (usage->hid) {
 320                 case HID_DG_INRANGE:
 321                         break;
 322                 case HID_DG_TIPSWITCH:
 323                         td->curvalid = value;
 324                         td->curdata.touch_state = value;
 325                         break;
 326                 case HID_DG_CONFIDENCE:
 327                         break;
 328                 case HID_DG_CONTACTID:
 329                         td->curdata.contactid = value;
 330                         break;
 331                 case HID_DG_TIPPRESSURE:
 332                         td->curdata.p = value;
 333                         break;
 334                 case HID_GD_X:
 335                         td->curdata.x = value;
 336                         break;
 337                 case HID_GD_Y:
 338                         td->curdata.y = value;
 339                         break;
 340                 case HID_DG_WIDTH:
 341                         td->curdata.w = value;
 342                         break;
 343                 case HID_DG_HEIGHT:
 344                         td->curdata.h = value;
 345                         break;
 346                 case HID_DG_CONTACTCOUNT:
 347                         /*
 348                          * We must not overwrite the previous value (some
 349                          * devices send one sequence splitted over several
 350                          * messages)
 351                          */
 352                         if (value)
 353                                 td->num_expected = value - 1;
 354                         break;
 355
 356                 default:
 357                         /* fallback to the generic hidinput handling */
 358                         return 0;
 359                 }
 360         }
 361
 362         if (usage->hid == td->last_slot_field)
 363                 mt_complete_slot(td);
 364
 365         if (field->index == td->last_field_index
 366                 && td->num_received > td->num_expected)
 367                 mt_emit_event(td, field->hidinput->input);
 368
 369         /* we have handled the hidinput part, now remains hiddev */
 370         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 371                 hid->hiddev_hid_event(hid, field, usage, value);
 372
 373         return 1;
 374 }
 375
 376 static void mt_set_input_mode(struct hid_device *hdev)
 377 {
 378         struct mt_device *td = hid_get_drvdata(hdev);
 379         struct hid_report *r;
 380         struct hid_report_enum *re;
 381
 382         if (td->inputmode < 0)
 383                 return;
 384
 385         re = &(hdev->report_enum[HID_FEATURE_REPORT]);
 386         r = re->report_id_hash[td->inputmode];
 387         if (r) {
 388                 r->field[0]->value[0] = 0x02;
 389                 usbhid_submit_report(hdev, r, USB_DIR_OUT);
 390         }
 391 }
 392
 393 static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 394 {
 395         int ret;
 396         struct mt_device *td;
 397         struct mt_class *mtclass = mt_classes + id->driver_data;
 398
 399         /* This allows the driver to correctly support devices
 400          * that emit events over several HID messages.
 401          */
 402         hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 403
 404         td = kzalloc(sizeof(struct mt_device) +
 405                                 mtclass->maxcontacts * sizeof(struct mt_slot),
 406                                 GFP_KERNEL);
 407         if (!td) {
 408                 dev_err(&hdev->dev, "cannot allocate multitouch data\n");
 409                 return -ENOMEM;
 410         }
 411         td->mtclass = mtclass;
 412         td->inputmode = -1;
 413         hid_set_drvdata(hdev, td);
 414
 415         ret = hid_parse(hdev);
 416         if (ret != 0)
 417                 goto fail;
 418
 419         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 420         if (ret != 0)
 421                 goto fail;
 422
 423         mt_set_input_mode(hdev);
 424
 425         return 0;
 426
 427 fail:
 428         kfree(td);
 429         return ret;
 430 }
 431
 432 #ifdef CONFIG_PM
 433 static int mt_reset_resume(struct hid_device *hdev)
 434 {
 435         mt_set_input_mode(hdev);
 436         return 0;
 437 }
 438 #endif
 439
 440 static void mt_remove(struct hid_device *hdev)
 441 {
 442         struct mt_device *td = hid_get_drvdata(hdev);
 443         hid_hw_stop(hdev);
 444         kfree(td);
 445         hid_set_drvdata(hdev, NULL);
 446 }
 447
 448 static const struct hid_device_id mt_devices[] = {
 449
 450         /* Cypress panel */
 451         { .driver_data = MT_CLS_CYPRESS,
 452                 HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS,
 453                         USB_DEVICE_ID_CYPRESS_TRUETOUCH) },
 454
 455         /* GeneralTouch panel */
 456         { .driver_data = MT_CLS_DUAL2,
 457                 HID_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
 458                         USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },
 459
 460         /* PixCir-based panels */
 461         { .driver_data = MT_CLS_DUAL1,
 462                 HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
 463                         USB_DEVICE_ID_HANVON_MULTITOUCH) },
 464         { .driver_data = MT_CLS_DUAL1,
 465                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 466                         USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
 467
 468         { }
 469 };
 470 MODULE_DEVICE_TABLE(hid, mt_devices);
 471
 472 static const struct hid_usage_id mt_grabbed_usages[] = {
 473         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 474         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 475 };
 476
 477 static struct hid_driver mt_driver = {
 478         .name = "hid-multitouch",
 479         .id_table = mt_devices,
 480         .probe = mt_probe,
 481         .remove = mt_remove,
 482         .input_mapping = mt_input_mapping,
 483         .input_mapped = mt_input_mapped,
 484         .feature_mapping = mt_feature_mapping,
 485         .usage_table = mt_grabbed_usages,
 486         .event = mt_event,
 487 #ifdef CONFIG_PM
 488         .reset_resume = mt_reset_resume,
 489 #endif
 490 };
 491
 492 static int __init mt_init(void)
 493 {
 494         return hid_register_driver(&mt_driver);
 495 }
 496
 497 static void __exit mt_exit(void)
 498 {
 499         hid_unregister_driver(&mt_driver);
 500 }
 501
 502 module_init(mt_init);
 503 module_exit(mt_exit);