linux/drivers/hid/hid-multitouch.c
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   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
  26MODULE_AUTHOR("Stephane Chatty <chatty@enac.fr>");
  27MODULE_DESCRIPTION("HID multitouch panels");
  28MODULE_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
  40struct 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
  47struct 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
  59struct 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
  78static 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
  86static 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
 105struct 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
 125static void mt_feature_mapping(struct hid_device *hdev,
 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
 134static 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
 143static 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
 234static 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
 244static 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 */
 264static 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 */
 281static 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
 313static 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
 382static 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
 399static 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
 440fail:
 441        kfree(td);
 442        return ret;
 443}
 444
 445#ifdef CONFIG_PM
 446static int mt_reset_resume(struct hid_device *hdev)
 447{
 448        mt_set_input_mode(hdev);
 449        return 0;
 450}
 451#endif
 452
 453static 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
 461static 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};
 483MODULE_DEVICE_TABLE(hid, mt_devices);
 484
 485static 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
 490static 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
 505static int __init mt_init(void)
 506{
 507        return hid_register_driver(&mt_driver);
 508}
 509
 510static void __exit mt_exit(void)
 511{
 512        hid_unregister_driver(&mt_driver);
 513}
 514
 515module_init(mt_init);
 516module_exit(mt_exit);
 517