drivers/hid/hid-elan.c

   1 /*
   2  * HID Driver for ELAN Touchpad
   3  *
   4  * Currently only supports touchpad found on HP Pavilion X2 10
   5  *
   6  * Copyright (c) 2016 Alexandrov Stanislav <neko@nya.ai>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 2 of the License, or (at your option)
  11  * any later version.
  12  */
  13
  14 #include <linux/hid.h>
  15 #include <linux/input/mt.h>
  16 #include <linux/leds.h>
  17 #include <linux/module.h>
  18 #include <linux/usb.h>
  19
  20 #include "hid-ids.h"
  21
  22 #define ELAN_MT_I2C             0x5d
  23 #define ELAN_SINGLE_FINGER      0x81
  24 #define ELAN_MT_FIRST_FINGER    0x82
  25 #define ELAN_MT_SECOND_FINGER   0x83
  26 #define ELAN_INPUT_REPORT_SIZE  8
  27 #define ELAN_I2C_REPORT_SIZE    32
  28 #define ELAN_FINGER_DATA_LEN    5
  29 #define ELAN_MAX_FINGERS        5
  30 #define ELAN_MAX_PRESSURE       255
  31 #define ELAN_TP_USB_INTF        1
  32
  33 #define ELAN_FEATURE_REPORT     0x0d
  34 #define ELAN_FEATURE_SIZE       5
  35 #define ELAN_PARAM_MAX_X        6
  36 #define ELAN_PARAM_MAX_Y        7
  37 #define ELAN_PARAM_RES          8
  38
  39 #define ELAN_MUTE_LED_REPORT    0xBC
  40 #define ELAN_LED_REPORT_SIZE    8
  41
  42 #define ELAN_HAS_LED            BIT(0)
  43
  44 struct elan_drvdata {
  45         struct input_dev *input;
  46         u8 prev_report[ELAN_INPUT_REPORT_SIZE];
  47         struct led_classdev mute_led;
  48         u8 mute_led_state;
  49         u16 max_x;
  50         u16 max_y;
  51         u16 res_x;
  52         u16 res_y;
  53 };
  54
  55 static int is_not_elan_touchpad(struct hid_device *hdev)
  56 {
  57         if (hid_is_usb(hdev)) {
  58                 struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
  59
  60                 return (intf->altsetting->desc.bInterfaceNumber !=
  61                         ELAN_TP_USB_INTF);
  62         }
  63
  64         return 0;
  65 }
  66
  67 static int elan_input_mapping(struct hid_device *hdev, struct hid_input *hi,
  68                               struct hid_field *field, struct hid_usage *usage,
  69                               unsigned long **bit, int *max)
  70 {
  71         if (is_not_elan_touchpad(hdev))
  72                 return 0;
  73
  74         if (field->report->id == ELAN_SINGLE_FINGER ||
  75             field->report->id == ELAN_MT_FIRST_FINGER ||
  76             field->report->id == ELAN_MT_SECOND_FINGER ||
  77             field->report->id == ELAN_MT_I2C)
  78                 return -1;
  79
  80         return 0;
  81 }
  82
  83 static int elan_get_device_param(struct hid_device *hdev,
  84                                  unsigned char *dmabuf, unsigned char param)
  85 {
  86         int ret;
  87
  88         dmabuf[0] = ELAN_FEATURE_REPORT;
  89         dmabuf[1] = 0x05;
  90         dmabuf[2] = 0x03;
  91         dmabuf[3] = param;
  92         dmabuf[4] = 0x01;
  93
  94         ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
  95                                  ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
  96                                  HID_REQ_SET_REPORT);
  97         if (ret != ELAN_FEATURE_SIZE) {
  98                 hid_err(hdev, "Set report error for parm %d: %d\n", param, ret);
  99                 return ret;
 100         }
 101
 102         ret = hid_hw_raw_request(hdev, ELAN_FEATURE_REPORT, dmabuf,
 103                                  ELAN_FEATURE_SIZE, HID_FEATURE_REPORT,
 104                                  HID_REQ_GET_REPORT);
 105         if (ret != ELAN_FEATURE_SIZE) {
 106                 hid_err(hdev, "Get report error for parm %d: %d\n", param, ret);
 107                 return ret;
 108         }
 109
 110         return 0;
 111 }
 112
 113 static unsigned int elan_convert_res(char val)
 114 {
 115         /*
 116          * (value from firmware) * 10 + 790 = dpi
 117          * dpi * 10 / 254 = dots/mm
 118          */
 119         return (val * 10 + 790) * 10 / 254;
 120 }
 121
 122 static int elan_get_device_params(struct hid_device *hdev)
 123 {
 124         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 125         unsigned char *dmabuf;
 126         int ret;
 127
 128         dmabuf = kmalloc(ELAN_FEATURE_SIZE, GFP_KERNEL);
 129         if (!dmabuf)
 130                 return -ENOMEM;
 131
 132         ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_X);
 133         if (ret)
 134                 goto err;
 135
 136         drvdata->max_x = (dmabuf[4] << 8) | dmabuf[3];
 137
 138         ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_MAX_Y);
 139         if (ret)
 140                 goto err;
 141
 142         drvdata->max_y = (dmabuf[4] << 8) | dmabuf[3];
 143
 144         ret = elan_get_device_param(hdev, dmabuf, ELAN_PARAM_RES);
 145         if (ret)
 146                 goto err;
 147
 148         drvdata->res_x = elan_convert_res(dmabuf[3]);
 149         drvdata->res_y = elan_convert_res(dmabuf[4]);
 150
 151 err:
 152         kfree(dmabuf);
 153         return ret;
 154 }
 155
 156 static int elan_input_configured(struct hid_device *hdev, struct hid_input *hi)
 157 {
 158         int ret;
 159         struct input_dev *input;
 160         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 161
 162         if (is_not_elan_touchpad(hdev))
 163                 return 0;
 164
 165         ret = elan_get_device_params(hdev);
 166         if (ret)
 167                 return ret;
 168
 169         input = devm_input_allocate_device(&hdev->dev);
 170         if (!input)
 171                 return -ENOMEM;
 172
 173         input->name = "Elan Touchpad";
 174         input->phys = hdev->phys;
 175         input->uniq = hdev->uniq;
 176         input->id.bustype = hdev->bus;
 177         input->id.vendor  = hdev->vendor;
 178         input->id.product = hdev->product;
 179         input->id.version = hdev->version;
 180         input->dev.parent = &hdev->dev;
 181
 182         input_set_abs_params(input, ABS_MT_POSITION_X, 0, drvdata->max_x,
 183                              0, 0);
 184         input_set_abs_params(input, ABS_MT_POSITION_Y, 0, drvdata->max_y,
 185                              0, 0);
 186         input_set_abs_params(input, ABS_MT_PRESSURE, 0, ELAN_MAX_PRESSURE,
 187                              0, 0);
 188
 189         __set_bit(BTN_LEFT, input->keybit);
 190         __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
 191
 192         ret = input_mt_init_slots(input, ELAN_MAX_FINGERS, INPUT_MT_POINTER);
 193         if (ret) {
 194                 hid_err(hdev, "Failed to init elan MT slots: %d\n", ret);
 195                 return ret;
 196         }
 197
 198         input_abs_set_res(input, ABS_X, drvdata->res_x);
 199         input_abs_set_res(input, ABS_Y, drvdata->res_y);
 200
 201         ret = input_register_device(input);
 202         if (ret) {
 203                 hid_err(hdev, "Failed to register elan input device: %d\n",
 204                         ret);
 205                 input_mt_destroy_slots(input);
 206                 return ret;
 207         }
 208
 209         drvdata->input = input;
 210
 211         return 0;
 212 }
 213
 214 static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
 215                                 unsigned int slot_num)
 216 {
 217         struct input_dev *input = drvdata->input;
 218         int x, y, p;
 219
 220         bool active = !!data;
 221
 222         input_mt_slot(input, slot_num);
 223         input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
 224         if (active) {
 225                 x = ((data[0] & 0xF0) << 4) | data[1];
 226                 y = drvdata->max_y -
 227                     (((data[0] & 0x07) << 8) | data[2]);
 228                 p = data[4];
 229
 230                 input_report_abs(input, ABS_MT_POSITION_X, x);
 231                 input_report_abs(input, ABS_MT_POSITION_Y, y);
 232                 input_report_abs(input, ABS_MT_PRESSURE, p);
 233         }
 234 }
 235
 236 static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data)
 237 {
 238         int i;
 239         struct input_dev *input = drvdata->input;
 240
 241         /*
 242          * There is 3 types of reports: for single touch,
 243          * for multitouch - first finger and for multitouch - second finger
 244          *
 245          * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
 246          *
 247          * byte 1: 1   0   0   0   0   0   0   1  // 0x81 or 0x82
 248          * byte 2: 0   0   0   0   0   0   0   0  // looks like unused
 249          * byte 3: f5  f4  f3  f2  f1  0   0   L
 250          * byte 4: x12 x11 x10 x9  0?  y11 y10 y9
 251          * byte 5: x8  x7  x6  x5  x4  x3  x2  x1
 252          * byte 6: y8  y7  y6  y5  y4  y3  y2  y1
 253          * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 254          * byte 8: p8  p7  p6  p5  p4  p3  p2  p1
 255          *
 256          * packet structure for ELAN_MT_SECOND_FINGER:
 257          *
 258          * byte 1: 1   0   0   0   0   0   1   1  // 0x83
 259          * byte 2: x12 x11 x10 x9  0   y11 y10 y9
 260          * byte 3: x8  x7  x6  x5  x4  x3  x2  x1
 261          * byte 4: y8  y7  y6  y5  y4  y3  y2  y1
 262          * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 263          * byte 6: p8  p7  p6  p5  p4  p3  p2  p1
 264          * byte 7: 0   0   0   0   0   0   0   0
 265          * byte 8: 0   0   0   0   0   0   0   0
 266          *
 267          * f5-f1: finger touch bits
 268          * L: clickpad button
 269          * sy / sx: finger width / height expressed in traces, the total number
 270          *          of traces can be queried by doing a HID_REQ_SET_REPORT
 271          *          { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
 272          *          returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
 273          * p: pressure
 274          */
 275
 276         if (data[0] == ELAN_SINGLE_FINGER) {
 277                 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 278                         if (data[2] & BIT(i + 3))
 279                                 elan_report_mt_slot(drvdata, data + 3, i);
 280                         else
 281                                 elan_report_mt_slot(drvdata, NULL, i);
 282                 }
 283                 input_report_key(input, BTN_LEFT, data[2] & 0x01);
 284         }
 285         /*
 286          * When touched with two fingers Elan touchpad will emit two HID reports
 287          * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
 288          * we will save ELAN_MT_FIRST_FINGER report and wait for
 289          * ELAN_MT_SECOND_FINGER to finish multitouch
 290          */
 291         if (data[0] == ELAN_MT_FIRST_FINGER) {
 292                 memcpy(drvdata->prev_report, data,
 293                        sizeof(drvdata->prev_report));
 294                 return;
 295         }
 296
 297         if (data[0] == ELAN_MT_SECOND_FINGER) {
 298                 int first = 0;
 299                 u8 *prev_report = drvdata->prev_report;
 300
 301                 if (prev_report[0] != ELAN_MT_FIRST_FINGER)
 302                         return;
 303
 304                 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 305                         if (prev_report[2] & BIT(i + 3)) {
 306                                 if (!first) {
 307                                         first = 1;
 308                                         elan_report_mt_slot(drvdata, prev_report + 3, i);
 309                                 } else {
 310                                         elan_report_mt_slot(drvdata, data + 1, i);
 311                                 }
 312                         } else {
 313                                 elan_report_mt_slot(drvdata, NULL, i);
 314                         }
 315                 }
 316                 input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
 317         }
 318
 319         input_mt_sync_frame(input);
 320         input_sync(input);
 321 }
 322
 323 static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data)
 324 {
 325         struct input_dev *input = drvdata->input;
 326         u8 *finger_data;
 327         int i;
 328
 329         /*
 330          * Elan MT touchpads in i2c mode send finger data in the same format
 331          * as in USB mode, but then with all fingers in a single packet.
 332          *
 333          * packet structure for ELAN_MT_I2C:
 334          *
 335          * byte     1: 1   0   0   1   1   1   0   1   // 0x5d
 336          * byte     2: f5  f4  f3  f2  f1  0   0   L
 337          * byte     3: x12 x11 x10 x9  0?  y11 y10 y9
 338          * byte     4: x8  x7  x6  x5  x4  x3  x2  x1
 339          * byte     5: y8  y7  y6  y5  y4  y3  y2  y1
 340          * byte     6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 341          * byte     7: p8  p7  p6  p5  p4  p3  p2  p1
 342          * byte  8-12: Same as byte 3-7 for second finger down
 343          * byte 13-17: Same as byte 3-7 for third finger down
 344          * byte 18-22: Same as byte 3-7 for fourth finger down
 345          * byte 23-27: Same as byte 3-7 for fifth finger down
 346          */
 347
 348         finger_data = data + 2;
 349         for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 350                 if (data[1] & BIT(i + 3)) {
 351                         elan_report_mt_slot(drvdata, finger_data, i);
 352                         finger_data += ELAN_FINGER_DATA_LEN;
 353                 } else {
 354                         elan_report_mt_slot(drvdata, NULL, i);
 355                 }
 356         }
 357
 358         input_report_key(input, BTN_LEFT, data[1] & 0x01);
 359         input_mt_sync_frame(input);
 360         input_sync(input);
 361 }
 362
 363 static int elan_raw_event(struct hid_device *hdev,
 364                           struct hid_report *report, u8 *data, int size)
 365 {
 366         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 367
 368         if (is_not_elan_touchpad(hdev))
 369                 return 0;
 370
 371         if (data[0] == ELAN_SINGLE_FINGER ||
 372             data[0] == ELAN_MT_FIRST_FINGER ||
 373             data[0] == ELAN_MT_SECOND_FINGER) {
 374                 if (size == ELAN_INPUT_REPORT_SIZE) {
 375                         elan_usb_report_input(drvdata, data);
 376                         return 1;
 377                 }
 378         }
 379
 380         if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
 381                 elan_i2c_report_input(drvdata, data);
 382                 return 1;
 383         }
 384
 385         return 0;
 386 }
 387
 388 static int elan_start_multitouch(struct hid_device *hdev)
 389 {
 390         int ret;
 391
 392         /*
 393          * This byte sequence will enable multitouch mode and disable
 394          * mouse emulation
 395          */
 396         const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
 397         unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);
 398
 399         if (!dmabuf)
 400                 return -ENOMEM;
 401
 402         ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
 403                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 404
 405         kfree(dmabuf);
 406
 407         if (ret != sizeof(buf)) {
 408                 hid_err(hdev, "Failed to start multitouch: %d\n", ret);
 409                 return ret;
 410         }
 411
 412         return 0;
 413 }
 414
 415 static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
 416 {
 417         struct device *dev = led_cdev->dev->parent;
 418         struct hid_device *hdev = to_hid_device(dev);
 419         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 420
 421         return drvdata->mute_led_state;
 422 }
 423
 424 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 425                                        enum led_brightness value)
 426 {
 427         int ret;
 428         u8 led_state;
 429         struct device *dev = led_cdev->dev->parent;
 430         struct hid_device *hdev = to_hid_device(dev);
 431         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 432
 433         unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);
 434
 435         if (!dmabuf)
 436                 return -ENOMEM;
 437
 438         led_state = !!value;
 439
 440         dmabuf[0] = ELAN_MUTE_LED_REPORT;
 441         dmabuf[1] = 0x02;
 442         dmabuf[2] = led_state;
 443
 444         ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
 445                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 446
 447         kfree(dmabuf);
 448
 449         if (ret != ELAN_LED_REPORT_SIZE) {
 450                 hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
 451                 return ret;
 452         }
 453
 454         drvdata->mute_led_state = led_state;
 455         return 0;
 456 }
 457
 458 static int elan_init_mute_led(struct hid_device *hdev)
 459 {
 460         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 461         struct led_classdev *mute_led = &drvdata->mute_led;
 462
 463         mute_led->name = "elan:red:mute";
 464         mute_led->brightness_get = elan_mute_led_get_brigtness;
 465         mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 466         mute_led->max_brightness = LED_ON;
 467         mute_led->dev = &hdev->dev;
 468
 469         return devm_led_classdev_register(&hdev->dev, mute_led);
 470 }
 471
 472 static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
 473 {
 474         int ret;
 475         struct elan_drvdata *drvdata;
 476
 477         drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
 478
 479         if (!drvdata)
 480                 return -ENOMEM;
 481
 482         hid_set_drvdata(hdev, drvdata);
 483
 484         ret = hid_parse(hdev);
 485         if (ret) {
 486                 hid_err(hdev, "Hid Parse failed\n");
 487                 return ret;
 488         }
 489
 490         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 491         if (ret) {
 492                 hid_err(hdev, "Hid hw start failed\n");
 493                 return ret;
 494         }
 495
 496         if (is_not_elan_touchpad(hdev))
 497                 return 0;
 498
 499         if (!drvdata->input) {
 500                 hid_err(hdev, "Input device is not registred\n");
 501                 ret = -ENAVAIL;
 502                 goto err;
 503         }
 504
 505         ret = elan_start_multitouch(hdev);
 506         if (ret)
 507                 goto err;
 508
 509         if (id->driver_data & ELAN_HAS_LED) {
 510                 ret = elan_init_mute_led(hdev);
 511                 if (ret)
 512                         goto err;
 513         }
 514
 515         return 0;
 516 err:
 517         hid_hw_stop(hdev);
 518         return ret;
 519 }
 520
 521 static void elan_remove(struct hid_device *hdev)
 522 {
 523         hid_hw_stop(hdev);
 524 }
 525
 526 static const struct hid_device_id elan_devices[] = {
 527         { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
 528           .driver_data = ELAN_HAS_LED },
 529         { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
 530           .driver_data = ELAN_HAS_LED },
 531         { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
 532         { }
 533 };
 534 MODULE_DEVICE_TABLE(hid, elan_devices);
 535
 536 static struct hid_driver elan_driver = {
 537         .name = "elan",
 538         .id_table = elan_devices,
 539         .input_mapping = elan_input_mapping,
 540         .input_configured = elan_input_configured,
 541         .raw_event = elan_raw_event,
 542         .probe = elan_probe,
 543         .remove = elan_remove,
 544 };
 545
 546 module_hid_driver(elan_driver);
 547
 548 MODULE_LICENSE("GPL");
 549 MODULE_AUTHOR("Alexandrov Stanislav");
 550 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");