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