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