drivers/hid/hid-magicmouse.c

   1 /*
   2  *   Apple "Magic" Wireless Mouse driver
   3  *
   4  *   Copyright (c) 2010 Michael Poole <mdpoole@troilus.org>
   5  *   Copyright (c) 2010 Chase Douglas <chase.douglas@canonical.com>
   6  */
   7
   8 /*
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the Free
  11  * Software Foundation; either version 2 of the License, or (at your option)
  12  * any later version.
  13  */
  14
  15 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  16
  17 #include <linux/device.h>
  18 #include <linux/hid.h>
  19 #include <linux/input/mt.h>
  20 #include <linux/module.h>
  21 #include <linux/slab.h>
  22
  23 #include "hid-ids.h"
  24
  25 static bool emulate_3button = true;
  26 module_param(emulate_3button, bool, 0644);
  27 MODULE_PARM_DESC(emulate_3button, "Emulate a middle button");
  28
  29 static int middle_button_start = -350;
  30 static int middle_button_stop = +350;
  31
  32 static bool emulate_scroll_wheel = true;
  33 module_param(emulate_scroll_wheel, bool, 0644);
  34 MODULE_PARM_DESC(emulate_scroll_wheel, "Emulate a scroll wheel");
  35
  36 static unsigned int scroll_speed = 32;
  37 static int param_set_scroll_speed(const char *val, struct kernel_param *kp) {
  38         unsigned long speed;
  39         if (!val || kstrtoul(val, 0, &speed) || speed > 63)
  40                 return -EINVAL;
  41         scroll_speed = speed;
  42         return 0;
  43 }
  44 module_param_call(scroll_speed, param_set_scroll_speed, param_get_uint, &scroll_speed, 0644);
  45 MODULE_PARM_DESC(scroll_speed, "Scroll speed, value from 0 (slow) to 63 (fast)");
  46
  47 static bool scroll_acceleration = false;
  48 module_param(scroll_acceleration, bool, 0644);
  49 MODULE_PARM_DESC(scroll_acceleration, "Accelerate sequential scroll events");
  50
  51 static bool report_undeciphered;
  52 module_param(report_undeciphered, bool, 0644);
  53 MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state field using a MSC_RAW event");
  54
  55 #define TRACKPAD_REPORT_ID 0x28
  56 #define MOUSE_REPORT_ID    0x29
  57 #define DOUBLE_REPORT_ID   0xf7
  58 /* These definitions are not precise, but they're close enough.  (Bits
  59  * 0x03 seem to indicate the aspect ratio of the touch, bits 0x70 seem
  60  * to be some kind of bit mask -- 0x20 may be a near-field reading,
  61  * and 0x40 is actual contact, and 0x10 may be a start/stop or change
  62  * indication.)
  63  */
  64 #define TOUCH_STATE_MASK  0xf0
  65 #define TOUCH_STATE_NONE  0x00
  66 #define TOUCH_STATE_START 0x30
  67 #define TOUCH_STATE_DRAG  0x40
  68
  69 #define SCROLL_ACCEL_DEFAULT 7
  70
  71 /* Touch surface information. Dimension is in hundredths of a mm, min and max
  72  * are in units. */
  73 #define MOUSE_DIMENSION_X (float)9056
  74 #define MOUSE_MIN_X -1100
  75 #define MOUSE_MAX_X 1258
  76 #define MOUSE_RES_X ((MOUSE_MAX_X - MOUSE_MIN_X) / (MOUSE_DIMENSION_X / 100))
  77 #define MOUSE_DIMENSION_Y (float)5152
  78 #define MOUSE_MIN_Y -1589
  79 #define MOUSE_MAX_Y 2047
  80 #define MOUSE_RES_Y ((MOUSE_MAX_Y - MOUSE_MIN_Y) / (MOUSE_DIMENSION_Y / 100))
  81
  82 #define TRACKPAD_DIMENSION_X (float)13000
  83 #define TRACKPAD_MIN_X -2909
  84 #define TRACKPAD_MAX_X 3167
  85 #define TRACKPAD_RES_X \
  86         ((TRACKPAD_MAX_X - TRACKPAD_MIN_X) / (TRACKPAD_DIMENSION_X / 100))
  87 #define TRACKPAD_DIMENSION_Y (float)11000
  88 #define TRACKPAD_MIN_Y -2456
  89 #define TRACKPAD_MAX_Y 2565
  90 #define TRACKPAD_RES_Y \
  91         ((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))
  92
  93 /**
  94  * struct magicmouse_sc - Tracks Magic Mouse-specific data.
  95  * @input: Input device through which we report events.
  96  * @quirks: Currently unused.
  97  * @ntouches: Number of touches in most recent touch report.
  98  * @scroll_accel: Number of consecutive scroll motions.
  99  * @scroll_jiffies: Time of last scroll motion.
 100  * @touches: Most recent data for a touch, indexed by tracking ID.
 101  * @tracking_ids: Mapping of current touch input data to @touches.
 102  */
 103 struct magicmouse_sc {
 104         struct input_dev *input;
 105         unsigned long quirks;
 106
 107         int ntouches;
 108         int scroll_accel;
 109         unsigned long scroll_jiffies;
 110
 111         struct {
 112                 short x;
 113                 short y;
 114                 short scroll_x;
 115                 short scroll_y;
 116                 u8 size;
 117         } touches[16];
 118         int tracking_ids[16];
 119 };
 120
 121 static int magicmouse_firm_touch(struct magicmouse_sc *msc)
 122 {
 123         int touch = -1;
 124         int ii;
 125
 126         /* If there is only one "firm" touch, set touch to its
 127          * tracking ID.
 128          */
 129         for (ii = 0; ii < msc->ntouches; ii++) {
 130                 int idx = msc->tracking_ids[ii];
 131                 if (msc->touches[idx].size < 8) {
 132                         /* Ignore this touch. */
 133                 } else if (touch >= 0) {
 134                         touch = -1;
 135                         break;
 136                 } else {
 137                         touch = idx;
 138                 }
 139         }
 140
 141         return touch;
 142 }
 143
 144 static void magicmouse_emit_buttons(struct magicmouse_sc *msc, int state)
 145 {
 146         int last_state = test_bit(BTN_LEFT, msc->input->key) << 0 |
 147                 test_bit(BTN_RIGHT, msc->input->key) << 1 |
 148                 test_bit(BTN_MIDDLE, msc->input->key) << 2;
 149
 150         if (emulate_3button) {
 151                 int id;
 152
 153                 /* If some button was pressed before, keep it held
 154                  * down.  Otherwise, if there's exactly one firm
 155                  * touch, use that to override the mouse's guess.
 156                  */
 157                 if (state == 0) {
 158                         /* The button was released. */
 159                 } else if (last_state != 0) {
 160                         state = last_state;
 161                 } else if ((id = magicmouse_firm_touch(msc)) >= 0) {
 162                         int x = msc->touches[id].x;
 163                         if (x < middle_button_start)
 164                                 state = 1;
 165                         else if (x > middle_button_stop)
 166                                 state = 2;
 167                         else
 168                                 state = 4;
 169                 } /* else: we keep the mouse's guess */
 170
 171                 input_report_key(msc->input, BTN_MIDDLE, state & 4);
 172         }
 173
 174         input_report_key(msc->input, BTN_LEFT, state & 1);
 175         input_report_key(msc->input, BTN_RIGHT, state & 2);
 176
 177         if (state != last_state)
 178                 msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 179 }
 180
 181 static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tdata)
 182 {
 183         struct input_dev *input = msc->input;
 184         int id, x, y, size, orientation, touch_major, touch_minor, state, down;
 185
 186         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 187                 id = (tdata[6] << 2 | tdata[5] >> 6) & 0xf;
 188                 x = (tdata[1] << 28 | tdata[0] << 20) >> 20;
 189                 y = -((tdata[2] << 24 | tdata[1] << 16) >> 20);
 190                 size = tdata[5] & 0x3f;
 191                 orientation = (tdata[6] >> 2) - 32;
 192                 touch_major = tdata[3];
 193                 touch_minor = tdata[4];
 194                 state = tdata[7] & TOUCH_STATE_MASK;
 195                 down = state != TOUCH_STATE_NONE;
 196         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 197                 id = (tdata[7] << 2 | tdata[6] >> 6) & 0xf;
 198                 x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
 199                 y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
 200                 size = tdata[6] & 0x3f;
 201                 orientation = (tdata[7] >> 2) - 32;
 202                 touch_major = tdata[4];
 203                 touch_minor = tdata[5];
 204                 state = tdata[8] & TOUCH_STATE_MASK;
 205                 down = state != TOUCH_STATE_NONE;
 206         }
 207
 208         /* Store tracking ID and other fields. */
 209         msc->tracking_ids[raw_id] = id;
 210         msc->touches[id].x = x;
 211         msc->touches[id].y = y;
 212         msc->touches[id].size = size;
 213
 214         /* If requested, emulate a scroll wheel by detecting small
 215          * vertical touch motions.
 216          */
 217         if (emulate_scroll_wheel) {
 218                 unsigned long now = jiffies;
 219                 int step_x = msc->touches[id].scroll_x - x;
 220                 int step_y = msc->touches[id].scroll_y - y;
 221
 222                 /* Calculate and apply the scroll motion. */
 223                 switch (state) {
 224                 case TOUCH_STATE_START:
 225                         msc->touches[id].scroll_x = x;
 226                         msc->touches[id].scroll_y = y;
 227
 228                         /* Reset acceleration after half a second. */
 229                         if (scroll_acceleration && time_before(now,
 230                                                 msc->scroll_jiffies + HZ / 2))
 231                                 msc->scroll_accel = max_t(int,
 232                                                 msc->scroll_accel - 1, 1);
 233                         else
 234                                 msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 235
 236                         break;
 237                 case TOUCH_STATE_DRAG:
 238                         step_x /= (64 - (int)scroll_speed) * msc->scroll_accel;
 239                         if (step_x != 0) {
 240                                 msc->touches[id].scroll_x -= step_x *
 241                                         (64 - scroll_speed) * msc->scroll_accel;
 242                                 msc->scroll_jiffies = now;
 243                                 input_report_rel(input, REL_HWHEEL, -step_x);
 244                         }
 245
 246                         step_y /= (64 - (int)scroll_speed) * msc->scroll_accel;
 247                         if (step_y != 0) {
 248                                 msc->touches[id].scroll_y -= step_y *
 249                                         (64 - scroll_speed) * msc->scroll_accel;
 250                                 msc->scroll_jiffies = now;
 251                                 input_report_rel(input, REL_WHEEL, step_y);
 252                         }
 253                         break;
 254                 }
 255         }
 256
 257         if (down)
 258                 msc->ntouches++;
 259
 260         input_mt_slot(input, id);
 261         input_mt_report_slot_state(input, MT_TOOL_FINGER, down);
 262
 263         /* Generate the input events for this touch. */
 264         if (down) {
 265                 input_report_abs(input, ABS_MT_TOUCH_MAJOR, touch_major << 2);
 266                 input_report_abs(input, ABS_MT_TOUCH_MINOR, touch_minor << 2);
 267                 input_report_abs(input, ABS_MT_ORIENTATION, -orientation);
 268                 input_report_abs(input, ABS_MT_POSITION_X, x);
 269                 input_report_abs(input, ABS_MT_POSITION_Y, y);
 270
 271                 if (report_undeciphered) {
 272                         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 273                                 input_event(input, EV_MSC, MSC_RAW, tdata[7]);
 274                         else /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 275                                 input_event(input, EV_MSC, MSC_RAW, tdata[8]);
 276                 }
 277         }
 278 }
 279
 280 static int magicmouse_raw_event(struct hid_device *hdev,
 281                 struct hid_report *report, u8 *data, int size)
 282 {
 283         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 284         struct input_dev *input = msc->input;
 285         int x = 0, y = 0, ii, clicks = 0, npoints;
 286
 287         switch (data[0]) {
 288         case TRACKPAD_REPORT_ID:
 289                 /* Expect four bytes of prefix, and N*9 bytes of touch data. */
 290                 if (size < 4 || ((size - 4) % 9) != 0)
 291                         return 0;
 292                 npoints = (size - 4) / 9;
 293                 if (npoints > 15) {
 294                         hid_warn(hdev, "invalid size value (%d) for TRACKPAD_REPORT_ID\n",
 295                                         size);
 296                         return 0;
 297                 }
 298                 msc->ntouches = 0;
 299                 for (ii = 0; ii < npoints; ii++)
 300                         magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);
 301
 302                 clicks = data[1];
 303
 304                 /* The following bits provide a device specific timestamp. They
 305                  * are unused here.
 306                  *
 307                  * ts = data[1] >> 6 | data[2] << 2 | data[3] << 10;
 308                  */
 309                 break;
 310         case MOUSE_REPORT_ID:
 311                 /* Expect six bytes of prefix, and N*8 bytes of touch data. */
 312                 if (size < 6 || ((size - 6) % 8) != 0)
 313                         return 0;
 314                 npoints = (size - 6) / 8;
 315                 if (npoints > 15) {
 316                         hid_warn(hdev, "invalid size value (%d) for MOUSE_REPORT_ID\n",
 317                                         size);
 318                         return 0;
 319                 }
 320                 msc->ntouches = 0;
 321                 for (ii = 0; ii < npoints; ii++)
 322                         magicmouse_emit_touch(msc, ii, data + ii * 8 + 6);
 323
 324                 /* When emulating three-button mode, it is important
 325                  * to have the current touch information before
 326                  * generating a click event.
 327                  */
 328                 x = (int)(((data[3] & 0x0c) << 28) | (data[1] << 22)) >> 22;
 329                 y = (int)(((data[3] & 0x30) << 26) | (data[2] << 22)) >> 22;
 330                 clicks = data[3];
 331
 332                 /* The following bits provide a device specific timestamp. They
 333                  * are unused here.
 334                  *
 335                  * ts = data[3] >> 6 | data[4] << 2 | data[5] << 10;
 336                  */
 337                 break;
 338         case DOUBLE_REPORT_ID:
 339                 /* Sometimes the trackpad sends two touch reports in one
 340                  * packet.
 341                  */
 342                 magicmouse_raw_event(hdev, report, data + 2, data[1]);
 343                 magicmouse_raw_event(hdev, report, data + 2 + data[1],
 344                         size - 2 - data[1]);
 345                 break;
 346         default:
 347                 return 0;
 348         }
 349
 350         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 351                 magicmouse_emit_buttons(msc, clicks & 3);
 352                 input_report_rel(input, REL_X, x);
 353                 input_report_rel(input, REL_Y, y);
 354         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 355                 input_report_key(input, BTN_MOUSE, clicks & 1);
 356                 input_mt_report_pointer_emulation(input, true);
 357         }
 358
 359         input_sync(input);
 360         return 1;
 361 }
 362
 363 static int magicmouse_setup_input(struct input_dev *input, struct hid_device *hdev)
 364 {
 365         int error;
 366
 367         __set_bit(EV_KEY, input->evbit);
 368
 369         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 370                 __set_bit(BTN_LEFT, input->keybit);
 371                 __set_bit(BTN_RIGHT, input->keybit);
 372                 if (emulate_3button)
 373                         __set_bit(BTN_MIDDLE, input->keybit);
 374
 375                 __set_bit(EV_REL, input->evbit);
 376                 __set_bit(REL_X, input->relbit);
 377                 __set_bit(REL_Y, input->relbit);
 378                 if (emulate_scroll_wheel) {
 379                         __set_bit(REL_WHEEL, input->relbit);
 380                         __set_bit(REL_HWHEEL, input->relbit);
 381                 }
 382         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 383                 /* input->keybit is initialized with incorrect button info
 384                  * for Magic Trackpad. There really is only one physical
 385                  * button (BTN_LEFT == BTN_MOUSE). Make sure we don't
 386                  * advertise buttons that don't exist...
 387                  */
 388                 __clear_bit(BTN_RIGHT, input->keybit);
 389                 __clear_bit(BTN_MIDDLE, input->keybit);
 390                 __set_bit(BTN_MOUSE, input->keybit);
 391                 __set_bit(BTN_TOOL_FINGER, input->keybit);
 392                 __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 393                 __set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
 394                 __set_bit(BTN_TOOL_QUADTAP, input->keybit);
 395                 __set_bit(BTN_TOOL_QUINTTAP, input->keybit);
 396                 __set_bit(BTN_TOUCH, input->keybit);
 397                 __set_bit(INPUT_PROP_POINTER, input->propbit);
 398                 __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
 399         }
 400
 401
 402         __set_bit(EV_ABS, input->evbit);
 403
 404         error = input_mt_init_slots(input, 16, 0);
 405         if (error)
 406                 return error;
 407         input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255 << 2,
 408                              4, 0);
 409         input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 255 << 2,
 410                              4, 0);
 411         input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
 412
 413         /* Note: Touch Y position from the device is inverted relative
 414          * to how pointer motion is reported (and relative to how USB
 415          * HID recommends the coordinates work).  This driver keeps
 416          * the origin at the same position, and just uses the additive
 417          * inverse of the reported Y.
 418          */
 419         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 420                 input_set_abs_params(input, ABS_MT_POSITION_X,
 421                                      MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
 422                 input_set_abs_params(input, ABS_MT_POSITION_Y,
 423                                      MOUSE_MIN_Y, MOUSE_MAX_Y, 4, 0);
 424
 425                 input_abs_set_res(input, ABS_MT_POSITION_X,
 426                                   MOUSE_RES_X);
 427                 input_abs_set_res(input, ABS_MT_POSITION_Y,
 428                                   MOUSE_RES_Y);
 429         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 430                 input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
 431                                      TRACKPAD_MAX_X, 4, 0);
 432                 input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
 433                                      TRACKPAD_MAX_Y, 4, 0);
 434                 input_set_abs_params(input, ABS_MT_POSITION_X,
 435                                      TRACKPAD_MIN_X, TRACKPAD_MAX_X, 4, 0);
 436                 input_set_abs_params(input, ABS_MT_POSITION_Y,
 437                                      TRACKPAD_MIN_Y, TRACKPAD_MAX_Y, 4, 0);
 438
 439                 input_abs_set_res(input, ABS_X, TRACKPAD_RES_X);
 440                 input_abs_set_res(input, ABS_Y, TRACKPAD_RES_Y);
 441                 input_abs_set_res(input, ABS_MT_POSITION_X,
 442                                   TRACKPAD_RES_X);
 443                 input_abs_set_res(input, ABS_MT_POSITION_Y,
 444                                   TRACKPAD_RES_Y);
 445         }
 446
 447         input_set_events_per_packet(input, 60);
 448
 449         if (report_undeciphered) {
 450                 __set_bit(EV_MSC, input->evbit);
 451                 __set_bit(MSC_RAW, input->mscbit);
 452         }
 453
 454         return 0;
 455 }
 456
 457 static int magicmouse_input_mapping(struct hid_device *hdev,
 458                 struct hid_input *hi, struct hid_field *field,
 459                 struct hid_usage *usage, unsigned long **bit, int *max)
 460 {
 461         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 462
 463         if (!msc->input)
 464                 msc->input = hi->input;
 465
 466         /* Magic Trackpad does not give relative data after switching to MT */
 467         if (hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD &&
 468             field->flags & HID_MAIN_ITEM_RELATIVE)
 469                 return -1;
 470
 471         return 0;
 472 }
 473
 474 static int magicmouse_input_configured(struct hid_device *hdev,
 475                 struct hid_input *hi)
 476
 477 {
 478         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 479         int ret;
 480
 481         ret = magicmouse_setup_input(msc->input, hdev);
 482         if (ret) {
 483                 hid_err(hdev, "magicmouse setup input failed (%d)\n", ret);
 484                 /* clean msc->input to notify probe() of the failure */
 485                 msc->input = NULL;
 486                 return ret;
 487         }
 488
 489         return 0;
 490 }
 491
 492
 493 static int magicmouse_probe(struct hid_device *hdev,
 494         const struct hid_device_id *id)
 495 {
 496         const u8 feature[] = { 0xd7, 0x01 };
 497         u8 *buf;
 498         struct magicmouse_sc *msc;
 499         struct hid_report *report;
 500         int ret;
 501
 502         msc = devm_kzalloc(&hdev->dev, sizeof(*msc), GFP_KERNEL);
 503         if (msc == NULL) {
 504                 hid_err(hdev, "can't alloc magicmouse descriptor\n");
 505                 return -ENOMEM;
 506         }
 507
 508         msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 509
 510         msc->quirks = id->driver_data;
 511         hid_set_drvdata(hdev, msc);
 512
 513         ret = hid_parse(hdev);
 514         if (ret) {
 515                 hid_err(hdev, "magicmouse hid parse failed\n");
 516                 return ret;
 517         }
 518
 519         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 520         if (ret) {
 521                 hid_err(hdev, "magicmouse hw start failed\n");
 522                 return ret;
 523         }
 524
 525         if (!msc->input) {
 526                 hid_err(hdev, "magicmouse input not registered\n");
 527                 ret = -ENOMEM;
 528                 goto err_stop_hw;
 529         }
 530
 531         if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 532                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 533                         MOUSE_REPORT_ID);
 534         else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 535                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 536                         TRACKPAD_REPORT_ID);
 537                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 538                         DOUBLE_REPORT_ID);
 539         }
 540
 541         if (!report) {
 542                 hid_err(hdev, "unable to register touch report\n");
 543                 ret = -ENOMEM;
 544                 goto err_stop_hw;
 545         }
 546         report->size = 6;
 547
 548         buf = kmemdup(feature, sizeof(feature), GFP_KERNEL);
 549         if (!buf) {
 550                 ret = -ENOMEM;
 551                 goto err_stop_hw;
 552         }
 553
 554         /*
 555          * Some devices repond with 'invalid report id' when feature
 556          * report switching it into multitouch mode is sent to it.
 557          *
 558          * This results in -EIO from the _raw low-level transport callback,
 559          * but there seems to be no other way of switching the mode.
 560          * Thus the super-ugly hacky success check below.
 561          */
 562         ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(feature),
 563                                 HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
 564         kfree(buf);
 565         if (ret != -EIO && ret != sizeof(feature)) {
 566                 hid_err(hdev, "unable to request touch data (%d)\n", ret);
 567                 goto err_stop_hw;
 568         }
 569
 570         return 0;
 571 err_stop_hw:
 572         hid_hw_stop(hdev);
 573         return ret;
 574 }
 575
 576 static const struct hid_device_id magic_mice[] = {
 577         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 578                 USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
 579         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 580                 USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .driver_data = 0 },
 581         { }
 582 };
 583 MODULE_DEVICE_TABLE(hid, magic_mice);
 584
 585 static struct hid_driver magicmouse_driver = {
 586         .name = "magicmouse",
 587         .id_table = magic_mice,
 588         .probe = magicmouse_probe,
 589         .raw_event = magicmouse_raw_event,
 590         .input_mapping = magicmouse_input_mapping,
 591         .input_configured = magicmouse_input_configured,
 592 };
 593 module_hid_driver(magicmouse_driver);
 594
 595 MODULE_LICENSE("GPL");