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 #define MT_QUIRK_VALID_IS_INRANGE       (1 << 4)
  38 #define MT_QUIRK_VALID_IS_CONFIDENCE    (1 << 5)
  39
  40 struct mt_slot {
  41         __s32 x, y, p, w, h;
  42         __s32 contactid;        /* the device ContactID assigned to this slot */
  43         bool touch_state;       /* is the touch valid? */
  44         bool seen_in_this_frame;/* has this slot been updated */
  45 };
  46
  47 struct mt_device {
  48         struct mt_slot curdata; /* placeholder of incoming data */
  49         struct mt_class *mtclass;       /* our mt device class */
  50         unsigned last_field_index;      /* last field index of the report */
  51         unsigned last_slot_field;       /* the last field of a slot */
  52         __s8 inputmode;         /* InputMode HID feature, -1 if non-existent */
  53         __u8 num_received;      /* how many contacts we received */
  54         __u8 num_expected;      /* expected last contact index */
  55         bool curvalid;          /* is the current contact valid? */
  56         struct mt_slot slots[0];        /* first slot */
  57 };
  58
  59 struct mt_class {
  60         __s32 name;     /* MT_CLS */
  61         __s32 quirks;
  62         __s32 sn_move;  /* Signal/noise ratio for move events */
  63         __s32 sn_pressure;      /* Signal/noise ratio for pressure events */
  64         __u8 maxcontacts;
  65 };
  66
  67 /* classes of device behavior */
  68 #define MT_CLS_DEFAULT  1
  69 #define MT_CLS_DUAL1    2
  70 #define MT_CLS_DUAL2    3
  71 #define MT_CLS_CYPRESS  4
  72
  73 /*
  74  * these device-dependent functions determine what slot corresponds
  75  * to a valid contact that was just read.
  76  */
  77
  78 static int cypress_compute_slot(struct mt_device *td)
  79 {
  80         if (td->curdata.contactid != 0 || td->num_received == 0)
  81                 return td->curdata.contactid;
  82         else
  83                 return -1;
  84 }
  85
  86 static int find_slot_from_contactid(struct mt_device *td)
  87 {
  88         int i;
  89         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
  90                 if (td->slots[i].contactid == td->curdata.contactid &&
  91                         td->slots[i].touch_state)
  92                         return i;
  93         }
  94         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
  95                 if (!td->slots[i].seen_in_this_frame &&
  96                         !td->slots[i].touch_state)
  97                         return i;
  98         }
  99         /* should not occurs. If this happens that means
 100          * that the device sent more touches that it says
 101          * in the report descriptor. It is ignored then. */
 102         return -1;
 103 }
 104
 105 struct mt_class mt_classes[] = {
 106         { .name = MT_CLS_DEFAULT,
 107                 .quirks = MT_QUIRK_VALID_IS_INRANGE,
 108                 .maxcontacts = 10 },
 109         { .name = MT_CLS_DUAL1,
 110                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 111                         MT_QUIRK_SLOT_IS_CONTACTID,
 112                 .maxcontacts = 2 },
 113         { .name = MT_CLS_DUAL2,
 114                 .quirks = MT_QUIRK_VALID_IS_INRANGE |
 115                         MT_QUIRK_SLOT_IS_CONTACTNUMBER,
 116                 .maxcontacts = 2 },
 117         { .name = MT_CLS_CYPRESS,
 118                 .quirks = MT_QUIRK_NOT_SEEN_MEANS_UP |
 119                         MT_QUIRK_CYPRESS,
 120                 .maxcontacts = 10 },
 121
 122         { }
 123 };
 124
 125 static void mt_feature_mapping(struct hid_device *hdev, struct hid_input *hi,
 126                 struct hid_field *field, struct hid_usage *usage)
 127 {
 128         if (usage->hid == HID_DG_INPUTMODE) {
 129                 struct mt_device *td = hid_get_drvdata(hdev);
 130                 td->inputmode = field->report->id;
 131         }
 132 }
 133
 134 static void set_abs(struct input_dev *input, unsigned int code,
 135                 struct hid_field *field, int snratio)
 136 {
 137         int fmin = field->logical_minimum;
 138         int fmax = field->logical_maximum;
 139         int fuzz = snratio ? (fmax - fmin) / snratio : 0;
 140         input_set_abs_params(input, code, fmin, fmax, fuzz, 0);
 141 }
 142
 143 static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 144                 struct hid_field *field, struct hid_usage *usage,
 145                 unsigned long **bit, int *max)
 146 {
 147         struct mt_device *td = hid_get_drvdata(hdev);
 148         struct mt_class *cls = td->mtclass;
 149         switch (usage->hid & HID_USAGE_PAGE) {
 150
 151         case HID_UP_GENDESK:
 152                 switch (usage->hid) {
 153                 case HID_GD_X:
 154                         hid_map_usage(hi, usage, bit, max,
 155                                         EV_ABS, ABS_MT_POSITION_X);
 156                         set_abs(hi->input, ABS_MT_POSITION_X, field,
 157                                 cls->sn_move);
 158                         /* touchscreen emulation */
 159                         set_abs(hi->input, ABS_X, field, cls->sn_move);
 160                         td->last_slot_field = usage->hid;
 161                         return 1;
 162                 case HID_GD_Y:
 163                         hid_map_usage(hi, usage, bit, max,
 164                                         EV_ABS, ABS_MT_POSITION_Y);
 165                         set_abs(hi->input, ABS_MT_POSITION_Y, field,
 166                                 cls->sn_move);
 167                         /* touchscreen emulation */
 168                         set_abs(hi->input, ABS_Y, field, cls->sn_move);
 169                         td->last_slot_field = usage->hid;
 170                         return 1;
 171                 }
 172                 return 0;
 173
 174         case HID_UP_DIGITIZER:
 175                 switch (usage->hid) {
 176                 case HID_DG_INRANGE:
 177                         td->last_slot_field = usage->hid;
 178                         return 1;
 179                 case HID_DG_CONFIDENCE:
 180                         td->last_slot_field = usage->hid;
 181                         return 1;
 182                 case HID_DG_TIPSWITCH:
 183                         hid_map_usage(hi, usage, bit, max, EV_KEY, BTN_TOUCH);
 184                         input_set_capability(hi->input, EV_KEY, BTN_TOUCH);
 185                         td->last_slot_field = usage->hid;
 186                         return 1;
 187                 case HID_DG_CONTACTID:
 188                         input_mt_init_slots(hi->input,
 189                                         td->mtclass->maxcontacts);
 190                         td->last_slot_field = usage->hid;
 191                         return 1;
 192                 case HID_DG_WIDTH:
 193                         hid_map_usage(hi, usage, bit, max,
 194                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
 195                         td->last_slot_field = usage->hid;
 196                         return 1;
 197                 case HID_DG_HEIGHT:
 198                         hid_map_usage(hi, usage, bit, max,
 199                                         EV_ABS, ABS_MT_TOUCH_MINOR);
 200                         field->logical_maximum = 1;
 201                         field->logical_minimum = 0;
 202                         set_abs(hi->input, ABS_MT_ORIENTATION, field, 0);
 203                         td->last_slot_field = usage->hid;
 204                         return 1;
 205                 case HID_DG_TIPPRESSURE:
 206                         hid_map_usage(hi, usage, bit, max,
 207                                         EV_ABS, ABS_MT_PRESSURE);
 208                         set_abs(hi->input, ABS_MT_PRESSURE, field,
 209                                 cls->sn_pressure);
 210                         /* touchscreen emulation */
 211                         set_abs(hi->input, ABS_PRESSURE, field,
 212                                 cls->sn_pressure);
 213                         td->last_slot_field = usage->hid;
 214                         return 1;
 215                 case HID_DG_CONTACTCOUNT:
 216                         td->last_field_index = field->report->maxfield - 1;
 217                         return 1;
 218                 case HID_DG_CONTACTMAX:
 219                         /* we don't set td->last_slot_field as contactcount and
 220                          * contact max are global to the report */
 221                         return -1;
 222                 }
 223                 /* let hid-input decide for the others */
 224                 return 0;
 225
 226         case 0xff000000:
 227                 /* we do not want to map these: no input-oriented meaning */
 228                 return -1;
 229         }
 230
 231         return 0;
 232 }
 233
 234 static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 235                 struct hid_field *field, struct hid_usage *usage,
 236                 unsigned long **bit, int *max)
 237 {
 238         if (usage->type == EV_KEY || usage->type == EV_ABS)
 239                 set_bit(usage->type, hi->input->evbit);
 240
 241         return -1;
 242 }
 243
 244 static int mt_compute_slot(struct mt_device *td)
 245 {
 246         __s32 quirks = td->mtclass->quirks;
 247
 248         if (quirks & MT_QUIRK_SLOT_IS_CONTACTID)
 249                 return td->curdata.contactid;
 250
 251         if (quirks & MT_QUIRK_CYPRESS)
 252                 return cypress_compute_slot(td);
 253
 254         if (quirks & MT_QUIRK_SLOT_IS_CONTACTNUMBER)
 255                 return td->num_received;
 256
 257         return find_slot_from_contactid(td);
 258 }
 259
 260 /*
 261  * this function is called when a whole contact has been processed,
 262  * so that it can assign it to a slot and store the data there
 263  */
 264 static void mt_complete_slot(struct mt_device *td)
 265 {
 266         td->curdata.seen_in_this_frame = true;
 267         if (td->curvalid) {
 268                 int slotnum = mt_compute_slot(td);
 269
 270                 if (slotnum >= 0 && slotnum < td->mtclass->maxcontacts)
 271                         td->slots[slotnum] = td->curdata;
 272         }
 273         td->num_received++;
 274 }
 275
 276
 277 /*
 278  * this function is called when a whole packet has been received and processed,
 279  * so that it can decide what to send to the input layer.
 280  */
 281 static void mt_emit_event(struct mt_device *td, struct input_dev *input)
 282 {
 283         int i;
 284
 285         for (i = 0; i < td->mtclass->maxcontacts; ++i) {
 286                 struct mt_slot *s = &(td->slots[i]);
 287                 if ((td->mtclass->quirks & MT_QUIRK_NOT_SEEN_MEANS_UP) &&
 288                         !s->seen_in_this_frame) {
 289                         s->touch_state = false;
 290                 }
 291
 292                 input_mt_slot(input, i);
 293                 input_mt_report_slot_state(input, MT_TOOL_FINGER,
 294                         s->touch_state);
 295                 if (s->touch_state) {
 296                         input_event(input, EV_ABS, ABS_MT_POSITION_X, s->x);
 297                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, s->y);
 298                         input_event(input, EV_ABS, ABS_MT_PRESSURE, s->p);
 299                         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, s->w);
 300                         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, s->h);
 301                 }
 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         __s32 quirks = td->mtclass->quirks;
 318
 319         if (hid->claimed & HID_CLAIMED_INPUT) {
 320                 switch (usage->hid) {
 321                 case HID_DG_INRANGE:
 322                         if (quirks & MT_QUIRK_VALID_IS_INRANGE)
 323                                 td->curvalid = value;
 324                         break;
 325                 case HID_DG_TIPSWITCH:
 326                         if (quirks & MT_QUIRK_NOT_SEEN_MEANS_UP)
 327                                 td->curvalid = value;
 328                         td->curdata.touch_state = value;
 329                         break;
 330                 case HID_DG_CONFIDENCE:
 331                         if (quirks & MT_QUIRK_VALID_IS_CONFIDENCE)
 332                                 td->curvalid = value;
 333                         break;
 334                 case HID_DG_CONTACTID:
 335                         td->curdata.contactid = value;
 336                         break;
 337                 case HID_DG_TIPPRESSURE:
 338                         td->curdata.p = value;
 339                         break;
 340                 case HID_GD_X:
 341                         td->curdata.x = value;
 342                         break;
 343                 case HID_GD_Y:
 344                         td->curdata.y = value;
 345                         break;
 346                 case HID_DG_WIDTH:
 347                         td->curdata.w = value;
 348                         break;
 349                 case HID_DG_HEIGHT:
 350                         td->curdata.h = value;
 351                         break;
 352                 case HID_DG_CONTACTCOUNT:
 353                         /*
 354                          * Includes multi-packet support where subsequent
 355                          * packets are sent with zero contactcount.
 356                          */
 357                         if (value)
 358                                 td->num_expected = value;
 359                         break;
 360
 361                 default:
 362                         /* fallback to the generic hidinput handling */
 363                         return 0;
 364                 }
 365
 366                 if (usage->hid == td->last_slot_field)
 367                         mt_complete_slot(td);
 368
 369                 if (field->index == td->last_field_index
 370                         && td->num_received >= td->num_expected)
 371                         mt_emit_event(td, field->hidinput->input);
 372
 373         }
 374
 375         /* we have handled the hidinput part, now remains hiddev */
 376         if (hid->claimed & HID_CLAIMED_HIDDEV && hid->hiddev_hid_event)
 377                 hid->hiddev_hid_event(hid, field, usage, value);
 378
 379         return 1;
 380 }
 381
 382 static void mt_set_input_mode(struct hid_device *hdev)
 383 {
 384         struct mt_device *td = hid_get_drvdata(hdev);
 385         struct hid_report *r;
 386         struct hid_report_enum *re;
 387
 388         if (td->inputmode < 0)
 389                 return;
 390
 391         re = &(hdev->report_enum[HID_FEATURE_REPORT]);
 392         r = re->report_id_hash[td->inputmode];
 393         if (r) {
 394                 r->field[0]->value[0] = 0x02;
 395                 usbhid_submit_report(hdev, r, USB_DIR_OUT);
 396         }
 397 }
 398
 399 static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 400 {
 401         int ret, i;
 402         struct mt_device *td;
 403         struct mt_class *mtclass = mt_classes; /* MT_CLS_DEFAULT */
 404
 405         for (i = 0; mt_classes[i].name ; i++) {
 406                 if (id->driver_data == mt_classes[i].name) {
 407                         mtclass = &(mt_classes[i]);
 408                         break;
 409                 }
 410         }
 411
 412         /* This allows the driver to correctly support devices
 413          * that emit events over several HID messages.
 414          */
 415         hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 416
 417         td = kzalloc(sizeof(struct mt_device) +
 418                                 mtclass->maxcontacts * sizeof(struct mt_slot),
 419                                 GFP_KERNEL);
 420         if (!td) {
 421                 dev_err(&hdev->dev, "cannot allocate multitouch data\n");
 422                 return -ENOMEM;
 423         }
 424         td->mtclass = mtclass;
 425         td->inputmode = -1;
 426         hid_set_drvdata(hdev, td);
 427
 428         ret = hid_parse(hdev);
 429         if (ret != 0)
 430                 goto fail;
 431
 432         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 433         if (ret)
 434                 goto fail;
 435
 436         mt_set_input_mode(hdev);
 437
 438         return 0;
 439
 440 fail:
 441         kfree(td);
 442         return ret;
 443 }
 444
 445 #ifdef CONFIG_PM
 446 static int mt_reset_resume(struct hid_device *hdev)
 447 {
 448         mt_set_input_mode(hdev);
 449         return 0;
 450 }
 451 #endif
 452
 453 static void mt_remove(struct hid_device *hdev)
 454 {
 455         struct mt_device *td = hid_get_drvdata(hdev);
 456         hid_hw_stop(hdev);
 457         kfree(td);
 458         hid_set_drvdata(hdev, NULL);
 459 }
 460
 461 static const struct hid_device_id mt_devices[] = {
 462
 463         /* Cypress panel */
 464         { .driver_data = MT_CLS_CYPRESS,
 465                 HID_USB_DEVICE(USB_VENDOR_ID_CYPRESS,
 466                         USB_DEVICE_ID_CYPRESS_TRUETOUCH) },
 467
 468         /* GeneralTouch panel */
 469         { .driver_data = MT_CLS_DUAL2,
 470                 HID_USB_DEVICE(USB_VENDOR_ID_GENERAL_TOUCH,
 471                         USB_DEVICE_ID_GENERAL_TOUCH_WIN7_TWOFINGERS) },
 472
 473         /* PixCir-based panels */
 474         { .driver_data = MT_CLS_DUAL1,
 475                 HID_USB_DEVICE(USB_VENDOR_ID_HANVON,
 476                         USB_DEVICE_ID_HANVON_MULTITOUCH) },
 477         { .driver_data = MT_CLS_DUAL1,
 478                 HID_USB_DEVICE(USB_VENDOR_ID_CANDO,
 479                         USB_DEVICE_ID_CANDO_PIXCIR_MULTI_TOUCH) },
 480
 481         { }
 482 };
 483 MODULE_DEVICE_TABLE(hid, mt_devices);
 484
 485 static const struct hid_usage_id mt_grabbed_usages[] = {
 486         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 487         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1}
 488 };
 489
 490 static struct hid_driver mt_driver = {
 491         .name = "hid-multitouch",
 492         .id_table = mt_devices,
 493         .probe = mt_probe,
 494         .remove = mt_remove,
 495         .input_mapping = mt_input_mapping,
 496         .input_mapped = mt_input_mapped,
 497         .feature_mapping = mt_feature_mapping,
 498         .usage_table = mt_grabbed_usages,
 499         .event = mt_event,
 500 #ifdef CONFIG_PM
 501         .reset_resume = mt_reset_resume,
 502 #endif
 503 };
 504
 505 static int __init mt_init(void)
 506 {
 507         return hid_register_driver(&mt_driver);
 508 }
 509
 510 static void __exit mt_exit(void)
 511 {
 512         hid_unregister_driver(&mt_driver);
 513 }
 514
 515 module_init(mt_init);
 516 module_exit(mt_exit);