drivers/hid/hid-ntrig.c

   1 /*
   2  *  HID driver for N-Trig touchscreens
   3  *
   4  *  Copyright (c) 2008-2010 Rafi Rubin
   5  *  Copyright (c) 2009-2010 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/usb.h>
  19 #include "usbhid/usbhid.h"
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22
  23 #include "hid-ids.h"
  24
  25 #define NTRIG_DUPLICATE_USAGES  0x001
  26
  27 #define nt_map_key_clear(c)     hid_map_usage_clear(hi, usage, bit, max, \
  28                                         EV_KEY, (c))
  29
  30 struct ntrig_data {
  31         /* Incoming raw values for a single contact */
  32         __u16 x, y, w, h;
  33         __u16 id;
  34         __u8 confidence;
  35
  36         bool reading_mt;
  37         __u8 first_contact_confidence;
  38
  39         __u8 mt_footer[4];
  40         __u8 mt_foot_count;
  41 };
  42
  43 /*
  44  * this driver is aimed at two firmware versions in circulation:
  45  *  - dual pen/finger single touch
  46  *  - finger multitouch, pen not working
  47  */
  48
  49 static int ntrig_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  50                 struct hid_field *field, struct hid_usage *usage,
  51                 unsigned long **bit, int *max)
  52 {
  53         /* No special mappings needed for the pen and single touch */
  54         if (field->physical)
  55                 return 0;
  56
  57         switch (usage->hid & HID_USAGE_PAGE) {
  58         case HID_UP_GENDESK:
  59                 switch (usage->hid) {
  60                 case HID_GD_X:
  61                         hid_map_usage(hi, usage, bit, max,
  62                                         EV_ABS, ABS_MT_POSITION_X);
  63                         input_set_abs_params(hi->input, ABS_X,
  64                                         field->logical_minimum,
  65                                         field->logical_maximum, 0, 0);
  66                         return 1;
  67                 case HID_GD_Y:
  68                         hid_map_usage(hi, usage, bit, max,
  69                                         EV_ABS, ABS_MT_POSITION_Y);
  70                         input_set_abs_params(hi->input, ABS_Y,
  71                                         field->logical_minimum,
  72                                         field->logical_maximum, 0, 0);
  73                         return 1;
  74                 }
  75                 return 0;
  76
  77         case HID_UP_DIGITIZER:
  78                 switch (usage->hid) {
  79                 /* we do not want to map these for now */
  80                 case HID_DG_CONTACTID: /* Not trustworthy, squelch for now */
  81                 case HID_DG_INPUTMODE:
  82                 case HID_DG_DEVICEINDEX:
  83                 case HID_DG_CONTACTMAX:
  84                         return -1;
  85
  86                 /* width/height mapped on TouchMajor/TouchMinor/Orientation */
  87                 case HID_DG_WIDTH:
  88                         hid_map_usage(hi, usage, bit, max,
  89                                         EV_ABS, ABS_MT_TOUCH_MAJOR);
  90                         return 1;
  91                 case HID_DG_HEIGHT:
  92                         hid_map_usage(hi, usage, bit, max,
  93                                         EV_ABS, ABS_MT_TOUCH_MINOR);
  94                         input_set_abs_params(hi->input, ABS_MT_ORIENTATION,
  95                                         0, 1, 0, 0);
  96                         return 1;
  97                 }
  98                 return 0;
  99
 100         case 0xff000000:
 101                 /* we do not want to map these: no input-oriented meaning */
 102                 return -1;
 103         }
 104
 105         return 0;
 106 }
 107
 108 static int ntrig_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 109                 struct hid_field *field, struct hid_usage *usage,
 110                 unsigned long **bit, int *max)
 111 {
 112         /* No special mappings needed for the pen and single touch */
 113         if (field->physical)
 114                 return 0;
 115
 116         if (usage->type == EV_KEY || usage->type == EV_REL
 117                         || usage->type == EV_ABS)
 118                 clear_bit(usage->code, *bit);
 119
 120         return 0;
 121 }
 122
 123 /*
 124  * this function is called upon all reports
 125  * so that we can filter contact point information,
 126  * decide whether we are in multi or single touch mode
 127  * and call input_mt_sync after each point if necessary
 128  */
 129 static int ntrig_event (struct hid_device *hid, struct hid_field *field,
 130                                         struct hid_usage *usage, __s32 value)
 131 {
 132         struct input_dev *input = field->hidinput->input;
 133         struct ntrig_data *nd = hid_get_drvdata(hid);
 134
 135         /* No special handling needed for the pen */
 136         if (field->application == HID_DG_PEN)
 137                 return 0;
 138
 139         if (hid->claimed & HID_CLAIMED_INPUT) {
 140                 switch (usage->hid) {
 141                 case 0xff000001:
 142                         /* Tag indicating the start of a multitouch group */
 143                         nd->reading_mt = 1;
 144                         nd->first_contact_confidence = 0;
 145                         break;
 146                 case HID_DG_TIPSWITCH:
 147                         /* Prevent emission of touch until validated */
 148                         return 1;
 149                 case HID_DG_CONFIDENCE:
 150                         nd->confidence = value;
 151                         break;
 152                 case HID_GD_X:
 153                         nd->x = value;
 154                         /* Clear the contact footer */
 155                         nd->mt_foot_count = 0;
 156                         break;
 157                 case HID_GD_Y:
 158                         nd->y = value;
 159                         break;
 160                 case HID_DG_CONTACTID:
 161                         nd->id = value;
 162                         break;
 163                 case HID_DG_WIDTH:
 164                         nd->w = value;
 165                         break;
 166                 case HID_DG_HEIGHT:
 167                         nd->h = value;
 168                         /*
 169                          * when in single touch mode, this is the last
 170                          * report received in a finger event. We want
 171                          * to emit a normal (X, Y) position
 172                          */
 173                         if (!nd->reading_mt) {
 174                                 input_report_key(input, BTN_TOOL_DOUBLETAP,
 175                                                  (nd->confidence != 0));
 176                                 input_event(input, EV_ABS, ABS_X, nd->x);
 177                                 input_event(input, EV_ABS, ABS_Y, nd->y);
 178                         }
 179                         break;
 180                 case 0xff000002:
 181                         /*
 182                          * we receive this when the device is in multitouch
 183                          * mode. The first of the three values tagged with
 184                          * this usage tells if the contact point is real
 185                          * or a placeholder
 186                          */
 187
 188                         /* Shouldn't get more than 4 footer packets, so skip */
 189                         if (nd->mt_foot_count >= 4)
 190                                 break;
 191
 192                         nd->mt_footer[nd->mt_foot_count++] = value;
 193
 194                         /* if the footer isn't complete break */
 195                         if (nd->mt_foot_count != 4)
 196                                 break;
 197
 198                         /* Pen activity signal, trigger end of touch. */
 199                         if (nd->mt_footer[2]) {
 200                                 nd->confidence = 0;
 201                                 break;
 202                         }
 203
 204                         /* If the contact was invalid */
 205                         if (!(nd->confidence && nd->mt_footer[0])
 206                                         || nd->w <= 250
 207                                         || nd->h <= 190) {
 208                                 nd->confidence = 0;
 209                                 break;
 210                         }
 211
 212                         /* emit a normal (X, Y) for the first point only */
 213                         if (nd->id == 0) {
 214                                 nd->first_contact_confidence = nd->confidence;
 215                                 input_event(input, EV_ABS, ABS_X, nd->x);
 216                                 input_event(input, EV_ABS, ABS_Y, nd->y);
 217                         }
 218                         input_event(input, EV_ABS, ABS_MT_POSITION_X, nd->x);
 219                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, nd->y);
 220                         if (nd->w > nd->h) {
 221                                 input_event(input, EV_ABS,
 222                                                 ABS_MT_ORIENTATION, 1);
 223                                 input_event(input, EV_ABS,
 224                                                 ABS_MT_TOUCH_MAJOR, nd->w);
 225                                 input_event(input, EV_ABS,
 226                                                 ABS_MT_TOUCH_MINOR, nd->h);
 227                         } else {
 228                                 input_event(input, EV_ABS,
 229                                                 ABS_MT_ORIENTATION, 0);
 230                                 input_event(input, EV_ABS,
 231                                                 ABS_MT_TOUCH_MAJOR, nd->h);
 232                                 input_event(input, EV_ABS,
 233                                                 ABS_MT_TOUCH_MINOR, nd->w);
 234                         }
 235                         input_mt_sync(field->hidinput->input);
 236                         break;
 237
 238                 case HID_DG_CONTACTCOUNT: /* End of a multitouch group */
 239                         if (!nd->reading_mt)
 240                                 break;
 241
 242                         nd->reading_mt = 0;
 243
 244                         if (nd->first_contact_confidence) {
 245                                 switch (value) {
 246                                 case 0: /* for single touch devices */
 247                                 case 1:
 248                                         input_report_key(input,
 249                                                         BTN_TOOL_DOUBLETAP, 1);
 250                                         break;
 251                                 case 2:
 252                                         input_report_key(input,
 253                                                         BTN_TOOL_TRIPLETAP, 1);
 254                                         break;
 255                                 case 3:
 256                                 default:
 257                                         input_report_key(input,
 258                                                         BTN_TOOL_QUADTAP, 1);
 259                                 }
 260                                 input_report_key(input, BTN_TOUCH, 1);
 261                         } else {
 262                                 input_report_key(input,
 263                                                 BTN_TOOL_DOUBLETAP, 0);
 264                                 input_report_key(input,
 265                                                 BTN_TOOL_TRIPLETAP, 0);
 266                                 input_report_key(input,
 267                                                 BTN_TOOL_QUADTAP, 0);
 268                                 input_report_key(input, BTN_TOUCH, 0);
 269                         }
 270                         break;
 271
 272                 default:
 273                         /* fallback to the generic hidinput handling */
 274                         return 0;
 275                 }
 276         }
 277
 278         /* we have handled the hidinput part, now remains hiddev */
 279         if ((hid->claimed & HID_CLAIMED_HIDDEV) && hid->hiddev_hid_event)
 280                 hid->hiddev_hid_event(hid, field, usage, value);
 281
 282         return 1;
 283 }
 284
 285 static int ntrig_probe(struct hid_device *hdev, const struct hid_device_id *id)
 286 {
 287         int ret;
 288         struct ntrig_data *nd;
 289         struct hid_input *hidinput;
 290         struct input_dev *input;
 291         struct hid_report *report;
 292
 293         if (id->driver_data)
 294                 hdev->quirks |= HID_QUIRK_MULTI_INPUT;
 295
 296         nd = kmalloc(sizeof(struct ntrig_data), GFP_KERNEL);
 297         if (!nd) {
 298                 dev_err(&hdev->dev, "cannot allocate N-Trig data\n");
 299                 return -ENOMEM;
 300         }
 301
 302         nd->reading_mt = 0;
 303         hid_set_drvdata(hdev, nd);
 304
 305         ret = hid_parse(hdev);
 306         if (ret) {
 307                 dev_err(&hdev->dev, "parse failed\n");
 308                 goto err_free;
 309         }
 310
 311         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT & ~HID_CONNECT_FF);
 312         if (ret) {
 313                 dev_err(&hdev->dev, "hw start failed\n");
 314                 goto err_free;
 315         }
 316
 317
 318         list_for_each_entry(hidinput, &hdev->inputs, list) {
 319                 if (hidinput->report->maxfield < 1)
 320                         continue;
 321
 322                 input = hidinput->input;
 323                 switch (hidinput->report->field[0]->application) {
 324                 case HID_DG_PEN:
 325                         input->name = "N-Trig Pen";
 326                         break;
 327                 case HID_DG_TOUCHSCREEN:
 328                         /* These keys are redundant for fingers, clear them
 329                          * to prevent incorrect identification */
 330                         __clear_bit(BTN_TOOL_PEN, input->keybit);
 331                         __clear_bit(BTN_TOOL_FINGER, input->keybit);
 332                         __clear_bit(BTN_0, input->keybit);
 333                         /*
 334                          * A little something special to enable
 335                          * two and three finger taps.
 336                          */
 337                         __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 338                         __set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
 339                         __set_bit(BTN_TOOL_QUADTAP, input->keybit);
 340                         /*
 341                          * The physical touchscreen (single touch)
 342                          * input has a value for physical, whereas
 343                          * the multitouch only has logical input
 344                          * fields.
 345                          */
 346                         input->name =
 347                                 (hidinput->report->field[0]
 348                                  ->physical) ?
 349                                 "N-Trig Touchscreen" :
 350                                 "N-Trig MultiTouch";
 351                         break;
 352                 }
 353         }
 354
 355         /* This is needed for devices with more recent firmware versions */
 356         report = hdev->report_enum[HID_FEATURE_REPORT].report_id_hash[0x0a];
 357         if (report)
 358                 usbhid_submit_report(hdev, report, USB_DIR_OUT);
 359
 360
 361         return 0;
 362 err_free:
 363         kfree(nd);
 364         return ret;
 365 }
 366
 367 static void ntrig_remove(struct hid_device *hdev)
 368 {
 369         hid_hw_stop(hdev);
 370         kfree(hid_get_drvdata(hdev));
 371 }
 372
 373 static const struct hid_device_id ntrig_devices[] = {
 374         { HID_USB_DEVICE(USB_VENDOR_ID_NTRIG, USB_DEVICE_ID_NTRIG_TOUCH_SCREEN),
 375                 .driver_data = NTRIG_DUPLICATE_USAGES },
 376         { }
 377 };
 378 MODULE_DEVICE_TABLE(hid, ntrig_devices);
 379
 380 static const struct hid_usage_id ntrig_grabbed_usages[] = {
 381         { HID_ANY_ID, HID_ANY_ID, HID_ANY_ID },
 382         { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1 }
 383 };
 384
 385 static struct hid_driver ntrig_driver = {
 386         .name = "ntrig",
 387         .id_table = ntrig_devices,
 388         .probe = ntrig_probe,
 389         .remove = ntrig_remove,
 390         .input_mapping = ntrig_input_mapping,
 391         .input_mapped = ntrig_input_mapped,
 392         .usage_table = ntrig_grabbed_usages,
 393         .event = ntrig_event,
 394 };
 395
 396 static int __init ntrig_init(void)
 397 {
 398         return hid_register_driver(&ntrig_driver);
 399 }
 400
 401 static void __exit ntrig_exit(void)
 402 {
 403         hid_unregister_driver(&ntrig_driver);
 404 }
 405
 406 module_init(ntrig_init);
 407 module_exit(ntrig_exit);
 408 MODULE_LICENSE("GPL");