linux/drivers/hid/hid-elan.c
<<
>>
Prefs
   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
  44struct 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
  55static 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
  67static 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
  83static 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
 113static 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
 122static 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
 151err:
 152        kfree(dmabuf);
 153        return ret;
 154}
 155
 156static 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_free_device(input);
 206                return ret;
 207        }
 208
 209        drvdata->input = input;
 210
 211        return 0;
 212}
 213
 214static 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
 236static 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
 323static 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
 363static 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
 388static 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        static 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
 415static 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
 424static 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
 458static 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
 472static 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 registered\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;
 516err:
 517        hid_hw_stop(hdev);
 518        return ret;
 519}
 520
 521static void elan_remove(struct hid_device *hdev)
 522{
 523        hid_hw_stop(hdev);
 524}
 525
 526static 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};
 534MODULE_DEVICE_TABLE(hid, elan_devices);
 535
 536static 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
 546module_hid_driver(elan_driver);
 547
 548MODULE_LICENSE("GPL");
 549MODULE_AUTHOR("Alexandrov Stanislav");
 550MODULE_DESCRIPTION("Driver for HID ELAN Touchpads");
 551