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