drivers/hid/hid-ntrig.c

   1 /*
   2  *  HID driver for N-Trig touchscreens
   3  *
   4  *  Copyright (c) 2008 Rafi Rubin
   5  *  Copyright (c) 2009 Stephane Chatty
   6  *
   7  */
   8
   9 /*
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the Free
  12  * Software Foundation; either version 2 of the License, or (at your option)
  13  * any later version.
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/hid.h>
  18 #include <linux/module.h>
  19
  20 #include "hid-ids.h"
  21
  22 #define NTRIG_DUPLICATE_USAGES  0x001
  23
  24 #define nt_map_key_clear(c)     hid_map_usage_clear(hi, usage, bit, max, \
  25                                         EV_KEY, (c))
  26
  27 struct ntrig_data {
  28         /* Incoming raw values for a single contact */
  29         __u16 x, y, w, h;
  30         __u16 id;
  31         __u8 confidence;
  32
  33         bool reading_mt;
  34         __u8 first_contact_confidence;
  35
  36         __u8 mt_footer[4];
  37         __u8 mt_foot_count;
  38 };
  39
  40 /*
  41  * this driver is aimed at two firmware versions in circulation:
  42  *  - dual pen/finger single touch
  43  *  - finger multitouch, pen not working
  44  */
  45
  46 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  47                 struct hid_field *field, struct hid_usage *usage,
  48                 unsigned long **bit, int *max)
  49 {
  50         /* No special mappings needed for the pen and single touch */
  51         if (field->physical)
  52                 return 0;
  53
  54         switch (usage->hid & HID_USAGE_PAGE) {
  55         case HID_UP_GENDESK:
  56                 switch (usage->hid) {
  57                 case HID_GD_X:
  58                         hid_map_usage(hi, usage, bit, max,
  59                                         EV_ABS, ABS_MT_POSITION_X);
  60                         input_set_abs_params(hi->input, ABS_X,
  61                                         field->logical_minimum,
  62                                         field->logical_maximum, 0, 0);
  63                         return 1;
  64                 case HID_GD_Y:
  65                         hid_map_usage(hi, usage, bit, max,
  66                                         EV_ABS, ABS_MT_POSITION_Y);
  67                         input_set_abs_params(hi->input, ABS_Y,
  68                                         field->logical_minimum,
  69                                         field->logical_maximum, 0, 0);
  70                         return 1;
  71                 }
  72                 return 0;
  73
  74         case HID_UP_DIGITIZER:
  75                 switch (usage->hid) {
  76                 /* we do not want to map these for now */
  77                 case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
  78                 case HID_DG_INPUTMODE:
  79                 case HID_DG_DEVICEINDEX:
  80                 case HID_DG_CONTACTMAX:
  81                         return -1;
  82
  83                 /* width/height mapped on TouchMajor/TouchMinor/Orientation */
  84                 case HID_DG_WIDTH:
  85                         hid_map_usage(hi, usage, bit, max,
  86                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
  87                         return 1;
  88                 case HID_DG_HEIGHT:
  89                         hid_map_usage(hi, usage, bit, max,
  90                                         EV_ABS, ABS_MT_TOUCH_MINOR);
  91                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
  92                                         0, 1, 0, 0);
  93                         return 1;
  94                 }
  95                 return 0;
  96
  97         case 0xff000000:
  98                 /* we do not want to map these: no input-oriented meaning */
  99                 return -1;
 100         }
 101
 102         return 0;
 103 }
 104
 105 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 106                 struct hid_field *field, struct hid_usage *usage,
 107                 unsigned long **bit, int *max)
 108 {
 109         /* No special mappings needed for the pen and single touch */
 110         if (field->physical)
 111                 return 0;
 112
 113         if (usage->type == EV_KEY || usage->type == EV_REL
 114                         || usage->type == EV_ABS)
 115                 clear_bit(usage->code, *bit);
 116
 117         return 0;
 118 }
 119
 120 /*
 121  * this function is called upon all reports
 122  * so that we can filter contact point information,
 123  * decide whether we are in multi or single touch mode
 124  * and call input_mt_sync after each point if necessary
 125  */
 126 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
 127                                         struct hid_usage *usage, __s32 value)
 128 {
 129         struct input_dev *input = field->hidinput->input;
 130         struct ntrig_data *nd = hid_get_drvdata(hid);
 131
 132         /* No special handling needed for the pen */
 133         if (field->application == HID_DG_PEN)
 134                 return 0;
 135
 136         if (hid->claimed & HID_CLAIMED_INPUT) {
 137                 switch (usage->hid) {
 138                 case 0xff000001:
 139                         /* Tag indicating the start of a multitouch group */
 140                         nd->reading_mt = 1;
 141                         nd->first_contact_confidence = 0;
 142                         break;
 143                 case HID_DG_TIPSWITCH:
 144                         /* Prevent emission of touch until validated */
 145                         return 1;
 146                 case HID_DG_CONFIDENCE:
 147                         nd->confidence = value;
 148                         break;
 149                 case HID_GD_X:
 150                         nd->x = value;
 151                         /* Clear the contact footer */
 152                         nd->mt_foot_count = 0;
 153                         break;
 154                 case HID_GD_Y:
 155                         nd->y = value;
 156                         break;
 157                 case HID_DG_CONTACTID:
 158                         nd->id = value;
 159                         break;
 160                 case HID_DG_WIDTH:
 161                         nd->w = value;
 162                         break;
 163                 case HID_DG_HEIGHT:
 164                         nd->h = value;
 165                         /*
 166                          * when in single touch mode, this is the last
 167                          * report received in a finger event. We want
 168                          * to emit a normal (X, Y) position
 169                          */
 170                         if (!nd->reading_mt) {
 171                                 input_report_key(input, BTN_TOOL_DOUBLETAP,
 172                                                  (nd->confidence != 0));
 173                                 input_event(input, EV_ABS, ABS_X, nd->x);
 174                                 input_event(input, EV_ABS, ABS_Y, nd->y);
 175                         }
 176                         break;
 177                 case 0xff000002:
 178                         /*
 179                          * we receive this when the device is in multitouch
 180                          * mode. The first of the three values tagged with
 181                          * this usage tells if the contact point is real
 182                          * or a placeholder
 183                          */
 184
 185                         /* Shouldn't get more than 4 footer packets, so skip */
 186                         if (nd->mt_foot_count >= 4)
 187                                 break;
 188
 189                         nd->mt_footer[nd->mt_foot_count++] = value;
 190
 191                         /* if the footer isn't complete break */
 192                         if (nd->mt_foot_count != 4)
 193                                 break;
 194
 195                         /* Pen activity signal, trigger end of touch. */
 196                         if (nd->mt_footer[2]) {
 197                                 nd->confidence = 0;
 198                                 break;
 199                         }
 200
 201                         /* If the contact was invalid */
 202                         if (!(nd->confidence && nd->mt_footer[0])
 203                                         || nd->w <= 250
 204                                         || nd->h <= 190) {
 205                                 nd->confidence = 0;
 206                                 break;
 207                         }
 208
 209                         /* emit a normal (X, Y) for the first point only */
 210                         if (nd->id == 0) {
 211                                 nd->first_contact_confidence = nd->confidence;
 212                                 input_event(input, EV_ABS, ABS_X, nd->x);
 213                                 input_event(input, EV_ABS, ABS_Y, nd->y);
 214                         }
 215                         input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
 216                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
 217                         if (nd->w > nd->h) {
 218                                 input_event(input, EV_ABS,
 219                                                 ABS_MT_ORIENTATION, 1);
 220                                 input_event(input, EV_ABS,
 221                                                 ABS_MT_TOUCH_MAJOR, nd->w);
 222                                 input_event(input, EV_ABS,
 223                                                 ABS_MT_TOUCH_MINOR, nd->h);
 224                         } else {
 225                                 input_event(input, EV_ABS,
 226                                                 ABS_MT_ORIENTATION, 0);
 227                                 input_event(input, EV_ABS,
 228                                                 ABS_MT_TOUCH_MAJOR, nd->h);
 229                                 input_event(input, EV_ABS,
 230                                                 ABS_MT_TOUCH_MINOR, nd->w);
 231                         }
 232                         input_mt_sync(field->hidinput->input);
 233                         break;
 234
 235                 case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
 236                         if (!nd->reading_mt)
 237                                 break;
 238
 239                         nd->reading_mt = 0;
 240
 241                         if (nd->first_contact_confidence) {
 242                                 switch (value) {
 243                                 case 0: /* for single touch devices */
 244                                 case 1:
 245                                         input_report_key(input,
 246                                                         BTN_TOOL_DOUBLETAP, 1);
 247                                         break;
 248                                 case 2:
 249                                         input_report_key(input,
 250                                                         BTN_TOOL_TRIPLETAP, 1);
 251                                         break;
 252                                 case 3:
 253                                 default:
 254                                         input_report_key(input,
 255                                                         BTN_TOOL_QUADTAP, 1);
 256                                 }
 257                                 input_report_key(input, BTN_TOUCH, 1);
 258                         } else {
 259                                 input_report_key(input,
 260                                                 BTN_TOOL_DOUBLETAP, 0);
 261                                 input_report_key(input,
 262                                                 BTN_TOOL_TRIPLETAP, 0);
 263                                 input_report_key(input,
 264                                                 BTN_TOOL_QUADTAP, 0);
 265                                 input_report_key(input, BTN_TOUCH, 0);
 266                         }
 267                         break;
 268
 269                 default:
 270                         /* fallback to the generic hidinput handling */
 271                         return 0;
 272                 }
 273         }
 274
 275         /* we have handled the hidinput part, now remains hiddev */
 276         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
 277                 hid->hiddev_hid_event(hid, field, usage, value);
 278
 279         return 1;
 280 }
 281
 282 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 283 {
 284         int ret;
 285         struct ntrig_data *nd;
 286         struct hid_input *hidinput;
 287         struct input_dev *input;
 288
 289         if (id->driver_data)
 290                 hdev->quirks |= HID_QUIRK_MULTI_INPUT;
 291
 292         nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
 293         if (!nd) {
 294                 dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
 295                 return -ENOMEM;
 296         }
 297
 298         nd->reading_mt = 0;
 299         hid_set_drvdata(hdev, nd);
 300
 301         ret = hid_parse(hdev);
 302         if (ret) {
 303                 dev_err(&hdev->dev, "parse failed\n");
 304                 goto err_free;
 305         }
 306
 307         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 308         if (ret) {
 309                 dev_err(&hdev->dev, "hw start failed\n");
 310                 goto err_free;
 311         }
 312
 313
 314         list_for_each_entry(hidinput, &hdev->inputs, list) {
 315                 if (hidinput->report->maxfield < 1)
 316                         continue;
 317
 318                 input = hidinput->input;
 319                 switch (hidinput->report->field[0]->application) {
 320                 case HID_DG_PEN:
 321                         input->name = "N-Trig Pen";
 322                         break;
 323                 case HID_DG_TOUCHSCREEN:
 324                         /* These keys are redundant for fingers, clear them
 325                          * to prevent incorrect identification */
 326                         __clear_bit(BTN_TOOL_PEN, input->keybit);
 327                         __clear_bit(BTN_TOOL_FINGER, input->keybit);
 328                         __clear_bit(BTN_0, input->keybit);
 329                         /*
 330                          * A little something special to enable
 331                          * two and three finger taps.
 332                          */
 333                         __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 334                         __set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
 335                         __set_bit(BTN_TOOL_QUADTAP, input->keybit);
 336                         /*
 337                          * The physical touchscreen (single touch)
 338                          * input has a value for physical, whereas
 339                          * the multitouch only has logical input
 340                          * fields.
 341                          */
 342                         input->name =
 343                                 (hidinput->report->field[0]
 344                                  ->physical) ?
 345                                 "N-Trig Touchscreen" :
 346                                 "N-Trig MultiTouch";
 347                         break;
 348                 }
 349         }
 350
 351         return 0;
 352 err_free:
 353         kfree(nd);
 354         return ret;
 355 }
 356
 357 static void ntrig_remove(struct hid_device *hdev)
 358 {
 359         hid_hw_stop(hdev);
 360         kfree(hid_get_drvdata(hdev));
 361 }
 362
 363 static const struct hid_device_id ntrig_devices[] = {
 364         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
 365                 .driver_data = NTRIG_DUPLICATE_USAGES },
 366         { }
 367 };
 368 MODULE_DEVICE_TABLE(hid, ntrig_devices);
 369
 370 static const struct hid_usage_id ntrig_grabbed_usages[] = {
 371         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 372         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
 373 };
 374
 375 static struct hid_driver ntrig_driver = {
 376         .name = "ntrig",
 377         .id_table = ntrig_devices,
 378         .probe = ntrig_probe,
 379         .remove = ntrig_remove,
 380         .input_mapping = ntrig_input_mapping,
 381         .input_mapped = ntrig_input_mapped,
 382         .usage_table = ntrig_grabbed_usages,
 383         .event = ntrig_event,
 384 };
 385
 386 static int __init ntrig_init(void)
 387 {
 388         return hid_register_driver(&ntrig_driver);
 389 }
 390
 391 static void __exit ntrig_exit(void)
 392 {
 393         hid_unregister_driver(&ntrig_driver);
 394 }
 395
 396 module_init(ntrig_init);
 397 module_exit(ntrig_exit);
 398 MODULE_LICENSE("GPL");