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