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 (hdev->bus == BUS_USB) {
  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                 input_free_device(input);
 196                 return ret;
 197         }
 198
 199         input_abs_set_res(input, ABS_X, drvdata->res_x);
 200         input_abs_set_res(input, ABS_Y, drvdata->res_y);
 201
 202         ret = input_register_device(input);
 203         if (ret) {
 204                 hid_err(hdev, "Failed to register elan input device: %d\n",
 205                         ret);
 206                 input_mt_destroy_slots(input);
 207                 input_free_device(input);
 208                 return ret;
 209         }
 210
 211         drvdata->input = input;
 212
 213         return 0;
 214 }
 215
 216 static void elan_report_mt_slot(struct elan_drvdata *drvdata, u8 *data,
 217                                 unsigned int slot_num)
 218 {
 219         struct input_dev *input = drvdata->input;
 220         int x, y, p;
 221
 222         bool active = !!data;
 223
 224         input_mt_slot(input, slot_num);
 225         input_mt_report_slot_state(input, MT_TOOL_FINGER, active);
 226         if (active) {
 227                 x = ((data[0] & 0xF0) << 4) | data[1];
 228                 y = drvdata->max_y -
 229                     (((data[0] & 0x07) << 8) | data[2]);
 230                 p = data[4];
 231
 232                 input_report_abs(input, ABS_MT_POSITION_X, x);
 233                 input_report_abs(input, ABS_MT_POSITION_Y, y);
 234                 input_report_abs(input, ABS_MT_PRESSURE, p);
 235         }
 236 }
 237
 238 static void elan_usb_report_input(struct elan_drvdata *drvdata, u8 *data)
 239 {
 240         int i;
 241         struct input_dev *input = drvdata->input;
 242
 243         /*
 244          * There is 3 types of reports: for single touch,
 245          * for multitouch - first finger and for multitouch - second finger
 246          *
 247          * packet structure for ELAN_SINGLE_FINGER and ELAN_MT_FIRST_FINGER:
 248          *
 249          * byte 1: 1   0   0   0   0   0   0   1  // 0x81 or 0x82
 250          * byte 2: 0   0   0   0   0   0   0   0  // looks like unused
 251          * byte 3: f5  f4  f3  f2  f1  0   0   L
 252          * byte 4: x12 x11 x10 x9  0?  y11 y10 y9
 253          * byte 5: x8  x7  x6  x5  x4  x3  x2  x1
 254          * byte 6: y8  y7  y6  y5  y4  y3  y2  y1
 255          * byte 7: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 256          * byte 8: p8  p7  p6  p5  p4  p3  p2  p1
 257          *
 258          * packet structure for ELAN_MT_SECOND_FINGER:
 259          *
 260          * byte 1: 1   0   0   0   0   0   1   1  // 0x83
 261          * byte 2: x12 x11 x10 x9  0   y11 y10 y9
 262          * byte 3: x8  x7  x6  x5  x4  x3  x2  x1
 263          * byte 4: y8  y7  y6  y5  y4  y3  y2  y1
 264          * byte 5: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 265          * byte 6: p8  p7  p6  p5  p4  p3  p2  p1
 266          * byte 7: 0   0   0   0   0   0   0   0
 267          * byte 8: 0   0   0   0   0   0   0   0
 268          *
 269          * f5-f1: finger touch bits
 270          * L: clickpad button
 271          * sy / sx: finger width / height expressed in traces, the total number
 272          *          of traces can be queried by doing a HID_REQ_SET_REPORT
 273          *          { 0x0d, 0x05, 0x03, 0x05, 0x01 } followed by a GET, in the
 274          *          returned buf, buf[3]=no-x-traces, buf[4]=no-y-traces.
 275          * p: pressure
 276          */
 277
 278         if (data[0] == ELAN_SINGLE_FINGER) {
 279                 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 280                         if (data[2] & BIT(i + 3))
 281                                 elan_report_mt_slot(drvdata, data + 3, i);
 282                         else
 283                                 elan_report_mt_slot(drvdata, NULL, i);
 284                 }
 285                 input_report_key(input, BTN_LEFT, data[2] & 0x01);
 286         }
 287         /*
 288          * When touched with two fingers Elan touchpad will emit two HID reports
 289          * first is ELAN_MT_FIRST_FINGER and second is ELAN_MT_SECOND_FINGER
 290          * we will save ELAN_MT_FIRST_FINGER report and wait for
 291          * ELAN_MT_SECOND_FINGER to finish multitouch
 292          */
 293         if (data[0] == ELAN_MT_FIRST_FINGER) {
 294                 memcpy(drvdata->prev_report, data,
 295                        sizeof(drvdata->prev_report));
 296                 return;
 297         }
 298
 299         if (data[0] == ELAN_MT_SECOND_FINGER) {
 300                 int first = 0;
 301                 u8 *prev_report = drvdata->prev_report;
 302
 303                 if (prev_report[0] != ELAN_MT_FIRST_FINGER)
 304                         return;
 305
 306                 for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 307                         if (prev_report[2] & BIT(i + 3)) {
 308                                 if (!first) {
 309                                         first = 1;
 310                                         elan_report_mt_slot(drvdata, prev_report + 3, i);
 311                                 } else {
 312                                         elan_report_mt_slot(drvdata, data + 1, i);
 313                                 }
 314                         } else {
 315                                 elan_report_mt_slot(drvdata, NULL, i);
 316                         }
 317                 }
 318                 input_report_key(input, BTN_LEFT, prev_report[2] & 0x01);
 319         }
 320
 321         input_mt_sync_frame(input);
 322         input_sync(input);
 323 }
 324
 325 static void elan_i2c_report_input(struct elan_drvdata *drvdata, u8 *data)
 326 {
 327         struct input_dev *input = drvdata->input;
 328         u8 *finger_data;
 329         int i;
 330
 331         /*
 332          * Elan MT touchpads in i2c mode send finger data in the same format
 333          * as in USB mode, but then with all fingers in a single packet.
 334          *
 335          * packet structure for ELAN_MT_I2C:
 336          *
 337          * byte     1: 1   0   0   1   1   1   0   1   // 0x5d
 338          * byte     2: f5  f4  f3  f2  f1  0   0   L
 339          * byte     3: x12 x11 x10 x9  0?  y11 y10 y9
 340          * byte     4: x8  x7  x6  x5  x4  x3  x2  x1
 341          * byte     5: y8  y7  y6  y5  y4  y3  y2  y1
 342          * byte     6: sy4 sy3 sy2 sy1 sx4 sx3 sx2 sx1
 343          * byte     7: p8  p7  p6  p5  p4  p3  p2  p1
 344          * byte  8-12: Same as byte 3-7 for second finger down
 345          * byte 13-17: Same as byte 3-7 for third finger down
 346          * byte 18-22: Same as byte 3-7 for fourth finger down
 347          * byte 23-27: Same as byte 3-7 for fifth finger down
 348          */
 349
 350         finger_data = data + 2;
 351         for (i = 0; i < ELAN_MAX_FINGERS; i++) {
 352                 if (data[1] & BIT(i + 3)) {
 353                         elan_report_mt_slot(drvdata, finger_data, i);
 354                         finger_data += ELAN_FINGER_DATA_LEN;
 355                 } else {
 356                         elan_report_mt_slot(drvdata, NULL, i);
 357                 }
 358         }
 359
 360         input_report_key(input, BTN_LEFT, data[1] & 0x01);
 361         input_mt_sync_frame(input);
 362         input_sync(input);
 363 }
 364
 365 static int elan_raw_event(struct hid_device *hdev,
 366                           struct hid_report *report, u8 *data, int size)
 367 {
 368         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 369
 370         if (is_not_elan_touchpad(hdev))
 371                 return 0;
 372
 373         if (data[0] == ELAN_SINGLE_FINGER ||
 374             data[0] == ELAN_MT_FIRST_FINGER ||
 375             data[0] == ELAN_MT_SECOND_FINGER) {
 376                 if (size == ELAN_INPUT_REPORT_SIZE) {
 377                         elan_usb_report_input(drvdata, data);
 378                         return 1;
 379                 }
 380         }
 381
 382         if (data[0] == ELAN_MT_I2C && size == ELAN_I2C_REPORT_SIZE) {
 383                 elan_i2c_report_input(drvdata, data);
 384                 return 1;
 385         }
 386
 387         return 0;
 388 }
 389
 390 static int elan_start_multitouch(struct hid_device *hdev)
 391 {
 392         int ret;
 393
 394         /*
 395          * This byte sequence will enable multitouch mode and disable
 396          * mouse emulation
 397          */
 398         const unsigned char buf[] = { 0x0D, 0x00, 0x03, 0x21, 0x00 };
 399         unsigned char *dmabuf = kmemdup(buf, sizeof(buf), GFP_KERNEL);
 400
 401         if (!dmabuf)
 402                 return -ENOMEM;
 403
 404         ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, sizeof(buf),
 405                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 406
 407         kfree(dmabuf);
 408
 409         if (ret != sizeof(buf)) {
 410                 hid_err(hdev, "Failed to start multitouch: %d\n", ret);
 411                 return ret;
 412         }
 413
 414         return 0;
 415 }
 416
 417 static enum led_brightness elan_mute_led_get_brigtness(struct led_classdev *led_cdev)
 418 {
 419         struct device *dev = led_cdev->dev->parent;
 420         struct hid_device *hdev = to_hid_device(dev);
 421         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 422
 423         return drvdata->mute_led_state;
 424 }
 425
 426 static int elan_mute_led_set_brigtness(struct led_classdev *led_cdev,
 427                                        enum led_brightness value)
 428 {
 429         int ret;
 430         u8 led_state;
 431         struct device *dev = led_cdev->dev->parent;
 432         struct hid_device *hdev = to_hid_device(dev);
 433         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 434
 435         unsigned char *dmabuf = kzalloc(ELAN_LED_REPORT_SIZE, GFP_KERNEL);
 436
 437         if (!dmabuf)
 438                 return -ENOMEM;
 439
 440         led_state = !!value;
 441
 442         dmabuf[0] = ELAN_MUTE_LED_REPORT;
 443         dmabuf[1] = 0x02;
 444         dmabuf[2] = led_state;
 445
 446         ret = hid_hw_raw_request(hdev, dmabuf[0], dmabuf, ELAN_LED_REPORT_SIZE,
 447                                  HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 448
 449         kfree(dmabuf);
 450
 451         if (ret != ELAN_LED_REPORT_SIZE) {
 452                 hid_err(hdev, "Failed to set mute led brightness: %d\n", ret);
 453                 return ret;
 454         }
 455
 456         drvdata->mute_led_state = led_state;
 457         return 0;
 458 }
 459
 460 static int elan_init_mute_led(struct hid_device *hdev)
 461 {
 462         struct elan_drvdata *drvdata = hid_get_drvdata(hdev);
 463         struct led_classdev *mute_led = &drvdata->mute_led;
 464
 465         mute_led->name = "elan:red:mute";
 466         mute_led->brightness_get = elan_mute_led_get_brigtness;
 467         mute_led->brightness_set_blocking = elan_mute_led_set_brigtness;
 468         mute_led->max_brightness = LED_ON;
 469         mute_led->dev = &hdev->dev;
 470
 471         return devm_led_classdev_register(&hdev->dev, mute_led);
 472 }
 473
 474 static int elan_probe(struct hid_device *hdev, const struct hid_device_id *id)
 475 {
 476         int ret;
 477         struct elan_drvdata *drvdata;
 478
 479         drvdata = devm_kzalloc(&hdev->dev, sizeof(*drvdata), GFP_KERNEL);
 480
 481         if (!drvdata)
 482                 return -ENOMEM;
 483
 484         hid_set_drvdata(hdev, drvdata);
 485
 486         ret = hid_parse(hdev);
 487         if (ret) {
 488                 hid_err(hdev, "Hid Parse failed\n");
 489                 return ret;
 490         }
 491
 492         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 493         if (ret) {
 494                 hid_err(hdev, "Hid hw start failed\n");
 495                 return ret;
 496         }
 497
 498         if (is_not_elan_touchpad(hdev))
 499                 return 0;
 500
 501         if (!drvdata->input) {
 502                 hid_err(hdev, "Input device is not registred\n");
 503                 ret = -ENAVAIL;
 504                 goto err;
 505         }
 506
 507         ret = elan_start_multitouch(hdev);
 508         if (ret)
 509                 goto err;
 510
 511         if (id->driver_data & ELAN_HAS_LED) {
 512                 ret = elan_init_mute_led(hdev);
 513                 if (ret)
 514                         goto err;
 515         }
 516
 517         return 0;
 518 err:
 519         hid_hw_stop(hdev);
 520         return ret;
 521 }
 522
 523 static void elan_remove(struct hid_device *hdev)
 524 {
 525         hid_hw_stop(hdev);
 526 }
 527
 528 static const struct hid_device_id elan_devices[] = {
 529         { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2),
 530           .driver_data = ELAN_HAS_LED },
 531         { HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
 532           .driver_data = ELAN_HAS_LED },
 533         { HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
 534         { }
 535 };
 536 MODULE_DEVICE_TABLE(hid, elan_devices);
 537
 538 static struct hid_driver elan_driver = {
 539         .name = "elan",
 540         .id_table = elan_devices,
 541         .input_mapping = elan_input_mapping,
 542         .input_configured = elan_input_configured,
 543         .raw_event = elan_raw_event,
 544         .probe = elan_probe,
 545         .remove = elan_remove,
 546 };
 547
 548 module_hid_driver(elan_driver);
 549
 550 MODULE_LICENSE("GPL");
 551 MODULE_AUTHOR("Alexandrov Stanislav");
 552 MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");