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/module.h>
  20 #include <linux/slab.h>
  21 #include <linux/usb.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 || strict_strtoul(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_touches = true;
  52 module_param(report_touches, bool, 0644);
  53 MODULE_PARM_DESC(report_touches, "Emit touch records (otherwise, only use them for emulation)");
  54
  55 static bool report_undeciphered;
  56 module_param(report_undeciphered, bool, 0644);
  57 MODULE_PARM_DESC(report_undeciphered, "Report undeciphered multi-touch state field using a MSC_RAW event");
  58
  59 #define TRACKPAD_REPORT_ID 0x28
  60 #define MOUSE_REPORT_ID    0x29
  61 #define DOUBLE_REPORT_ID   0xf7
  62 /* These definitions are not precise, but they're close enough.  (Bits
  63  * 0x03 seem to indicate the aspect ratio of the touch, bits 0x70 seem
  64  * to be some kind of bit mask -- 0x20 may be a near-field reading,
  65  * and 0x40 is actual contact, and 0x10 may be a start/stop or change
  66  * indication.)
  67  */
  68 #define TOUCH_STATE_MASK  0xf0
  69 #define TOUCH_STATE_NONE  0x00
  70 #define TOUCH_STATE_START 0x30
  71 #define TOUCH_STATE_DRAG  0x40
  72
  73 #define SCROLL_ACCEL_DEFAULT 7
  74
  75 /* Single touch emulation should only begin when no touches are currently down.
  76  * This is true when single_touch_id is equal to NO_TOUCHES. If multiple touches
  77  * are down and the touch providing for single touch emulation is lifted,
  78  * single_touch_id is equal to SINGLE_TOUCH_UP. While single touch emulation is
  79  * occurring, single_touch_id corresponds with the tracking id of the touch used.
  80  */
  81 #define NO_TOUCHES -1
  82 #define SINGLE_TOUCH_UP -2
  83
  84 /* Touch surface information. Dimension is in hundredths of a mm, min and max
  85  * are in units. */
  86 #define MOUSE_DIMENSION_X (float)9056
  87 #define MOUSE_MIN_X -1100
  88 #define MOUSE_MAX_X 1258
  89 #define MOUSE_RES_X ((MOUSE_MAX_X - MOUSE_MIN_X) / (MOUSE_DIMENSION_X / 100))
  90 #define MOUSE_DIMENSION_Y (float)5152
  91 #define MOUSE_MIN_Y -1589
  92 #define MOUSE_MAX_Y 2047
  93 #define MOUSE_RES_Y ((MOUSE_MAX_Y - MOUSE_MIN_Y) / (MOUSE_DIMENSION_Y / 100))
  94
  95 #define TRACKPAD_DIMENSION_X (float)13000
  96 #define TRACKPAD_MIN_X -2909
  97 #define TRACKPAD_MAX_X 3167
  98 #define TRACKPAD_RES_X \
  99         ((TRACKPAD_MAX_X - TRACKPAD_MIN_X) / (TRACKPAD_DIMENSION_X / 100))
 100 #define TRACKPAD_DIMENSION_Y (float)11000
 101 #define TRACKPAD_MIN_Y -2456
 102 #define TRACKPAD_MAX_Y 2565
 103 #define TRACKPAD_RES_Y \
 104         ((TRACKPAD_MAX_Y - TRACKPAD_MIN_Y) / (TRACKPAD_DIMENSION_Y / 100))
 105
 106 /**
 107  * struct magicmouse_sc - Tracks Magic Mouse-specific data.
 108  * @input: Input device through which we report events.
 109  * @quirks: Currently unused.
 110  * @ntouches: Number of touches in most recent touch report.
 111  * @scroll_accel: Number of consecutive scroll motions.
 112  * @scroll_jiffies: Time of last scroll motion.
 113  * @touches: Most recent data for a touch, indexed by tracking ID.
 114  * @tracking_ids: Mapping of current touch input data to @touches.
 115  */
 116 struct magicmouse_sc {
 117         struct input_dev *input;
 118         unsigned long quirks;
 119
 120         int ntouches;
 121         int scroll_accel;
 122         unsigned long scroll_jiffies;
 123
 124         struct {
 125                 short x;
 126                 short y;
 127                 short scroll_x;
 128                 short scroll_y;
 129                 u8 size;
 130         } touches[16];
 131         int tracking_ids[16];
 132         int single_touch_id;
 133 };
 134
 135 static int magicmouse_firm_touch(struct magicmouse_sc *msc)
 136 {
 137         int touch = -1;
 138         int ii;
 139
 140         /* If there is only one "firm" touch, set touch to its
 141          * tracking ID.
 142          */
 143         for (ii = 0; ii < msc->ntouches; ii++) {
 144                 int idx = msc->tracking_ids[ii];
 145                 if (msc->touches[idx].size < 8) {
 146                         /* Ignore this touch. */
 147                 } else if (touch >= 0) {
 148                         touch = -1;
 149                         break;
 150                 } else {
 151                         touch = idx;
 152                 }
 153         }
 154
 155         return touch;
 156 }
 157
 158 static void magicmouse_emit_buttons(struct magicmouse_sc *msc, int state)
 159 {
 160         int last_state = test_bit(BTN_LEFT, msc->input->key) << 0 |
 161                 test_bit(BTN_RIGHT, msc->input->key) << 1 |
 162                 test_bit(BTN_MIDDLE, msc->input->key) << 2;
 163
 164         if (emulate_3button) {
 165                 int id;
 166
 167                 /* If some button was pressed before, keep it held
 168                  * down.  Otherwise, if there's exactly one firm
 169                  * touch, use that to override the mouse's guess.
 170                  */
 171                 if (state == 0) {
 172                         /* The button was released. */
 173                 } else if (last_state != 0) {
 174                         state = last_state;
 175                 } else if ((id = magicmouse_firm_touch(msc)) >= 0) {
 176                         int x = msc->touches[id].x;
 177                         if (x < middle_button_start)
 178                                 state = 1;
 179                         else if (x > middle_button_stop)
 180                                 state = 2;
 181                         else
 182                                 state = 4;
 183                 } /* else: we keep the mouse's guess */
 184
 185                 input_report_key(msc->input, BTN_MIDDLE, state & 4);
 186         }
 187
 188         input_report_key(msc->input, BTN_LEFT, state & 1);
 189         input_report_key(msc->input, BTN_RIGHT, state & 2);
 190
 191         if (state != last_state)
 192                 msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 193 }
 194
 195 static void magicmouse_emit_touch(struct magicmouse_sc *msc, int raw_id, u8 *tdata)
 196 {
 197         struct input_dev *input = msc->input;
 198         int id, x, y, size, orientation, touch_major, touch_minor, state, down;
 199
 200         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 201                 id = (tdata[6] << 2 | tdata[5] >> 6) & 0xf;
 202                 x = (tdata[1] << 28 | tdata[0] << 20) >> 20;
 203                 y = -((tdata[2] << 24 | tdata[1] << 16) >> 20);
 204                 size = tdata[5] & 0x3f;
 205                 orientation = (tdata[6] >> 2) - 32;
 206                 touch_major = tdata[3];
 207                 touch_minor = tdata[4];
 208                 state = tdata[7] & TOUCH_STATE_MASK;
 209                 down = state != TOUCH_STATE_NONE;
 210         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 211                 id = (tdata[7] << 2 | tdata[6] >> 6) & 0xf;
 212                 x = (tdata[1] << 27 | tdata[0] << 19) >> 19;
 213                 y = -((tdata[3] << 30 | tdata[2] << 22 | tdata[1] << 14) >> 19);
 214                 size = tdata[6] & 0x3f;
 215                 orientation = (tdata[7] >> 2) - 32;
 216                 touch_major = tdata[4];
 217                 touch_minor = tdata[5];
 218                 state = tdata[8] & TOUCH_STATE_MASK;
 219                 down = state != TOUCH_STATE_NONE;
 220         }
 221
 222         /* Store tracking ID and other fields. */
 223         msc->tracking_ids[raw_id] = id;
 224         msc->touches[id].x = x;
 225         msc->touches[id].y = y;
 226         msc->touches[id].size = size;
 227
 228         /* If requested, emulate a scroll wheel by detecting small
 229          * vertical touch motions.
 230          */
 231         if (emulate_scroll_wheel) {
 232                 unsigned long now = jiffies;
 233                 int step_x = msc->touches[id].scroll_x - x;
 234                 int step_y = msc->touches[id].scroll_y - y;
 235
 236                 /* Calculate and apply the scroll motion. */
 237                 switch (state) {
 238                 case TOUCH_STATE_START:
 239                         msc->touches[id].scroll_x = x;
 240                         msc->touches[id].scroll_y = y;
 241
 242                         /* Reset acceleration after half a second. */
 243                         if (scroll_acceleration && time_before(now,
 244                                                 msc->scroll_jiffies + HZ / 2))
 245                                 msc->scroll_accel = max_t(int,
 246                                                 msc->scroll_accel - 1, 1);
 247                         else
 248                                 msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 249
 250                         break;
 251                 case TOUCH_STATE_DRAG:
 252                         step_x /= (64 - (int)scroll_speed) * msc->scroll_accel;
 253                         if (step_x != 0) {
 254                                 msc->touches[id].scroll_x -= step_x *
 255                                         (64 - scroll_speed) * msc->scroll_accel;
 256                                 msc->scroll_jiffies = now;
 257                                 input_report_rel(input, REL_HWHEEL, -step_x);
 258                         }
 259
 260                         step_y /= (64 - (int)scroll_speed) * msc->scroll_accel;
 261                         if (step_y != 0) {
 262                                 msc->touches[id].scroll_y -= step_y *
 263                                         (64 - scroll_speed) * msc->scroll_accel;
 264                                 msc->scroll_jiffies = now;
 265                                 input_report_rel(input, REL_WHEEL, step_y);
 266                         }
 267                         break;
 268                 }
 269         }
 270
 271         if (down) {
 272                 msc->ntouches++;
 273                 if (msc->single_touch_id == NO_TOUCHES)
 274                         msc->single_touch_id = id;
 275         } else if (msc->single_touch_id == id)
 276                 msc->single_touch_id = SINGLE_TOUCH_UP;
 277
 278         /* Generate the input events for this touch. */
 279         if (report_touches && down) {
 280                 input_report_abs(input, ABS_MT_TRACKING_ID, id);
 281                 input_report_abs(input, ABS_MT_TOUCH_MAJOR, touch_major << 2);
 282                 input_report_abs(input, ABS_MT_TOUCH_MINOR, touch_minor << 2);
 283                 input_report_abs(input, ABS_MT_ORIENTATION, -orientation);
 284                 input_report_abs(input, ABS_MT_POSITION_X, x);
 285                 input_report_abs(input, ABS_MT_POSITION_Y, y);
 286
 287                 if (report_undeciphered) {
 288                         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 289                                 input_event(input, EV_MSC, MSC_RAW, tdata[7]);
 290                         else /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 291                                 input_event(input, EV_MSC, MSC_RAW, tdata[8]);
 292                 }
 293
 294                 input_mt_sync(input);
 295         }
 296 }
 297
 298 static int magicmouse_raw_event(struct hid_device *hdev,
 299                 struct hid_report *report, u8 *data, int size)
 300 {
 301         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 302         struct input_dev *input = msc->input;
 303         int x = 0, y = 0, ii, clicks = 0, npoints;
 304
 305         switch (data[0]) {
 306         case TRACKPAD_REPORT_ID:
 307                 /* Expect four bytes of prefix, and N*9 bytes of touch data. */
 308                 if (size < 4 || ((size - 4) % 9) != 0)
 309                         return 0;
 310                 npoints = (size - 4) / 9;
 311                 msc->ntouches = 0;
 312                 for (ii = 0; ii < npoints; ii++)
 313                         magicmouse_emit_touch(msc, ii, data + ii * 9 + 4);
 314
 315                 /* We don't need an MT sync here because trackpad emits a
 316                  * BTN_TOUCH event in a new frame when all touches are released.
 317                  */
 318                 if (msc->ntouches == 0)
 319                         msc->single_touch_id = NO_TOUCHES;
 320
 321                 clicks = data[1];
 322
 323                 /* The following bits provide a device specific timestamp. They
 324                  * are unused here.
 325                  *
 326                  * ts = data[1] >> 6 | data[2] << 2 | data[3] << 10;
 327                  */
 328                 break;
 329         case MOUSE_REPORT_ID:
 330                 /* Expect six bytes of prefix, and N*8 bytes of touch data. */
 331                 if (size < 6 || ((size - 6) % 8) != 0)
 332                         return 0;
 333                 npoints = (size - 6) / 8;
 334                 msc->ntouches = 0;
 335                 for (ii = 0; ii < npoints; ii++)
 336                         magicmouse_emit_touch(msc, ii, data + ii * 8 + 6);
 337
 338                 if (report_touches && msc->ntouches == 0)
 339                         input_mt_sync(input);
 340
 341                 /* When emulating three-button mode, it is important
 342                  * to have the current touch information before
 343                  * generating a click event.
 344                  */
 345                 x = (int)(((data[3] & 0x0c) << 28) | (data[1] << 22)) >> 22;
 346                 y = (int)(((data[3] & 0x30) << 26) | (data[2] << 22)) >> 22;
 347                 clicks = data[3];
 348
 349                 /* The following bits provide a device specific timestamp. They
 350                  * are unused here.
 351                  *
 352                  * ts = data[3] >> 6 | data[4] << 2 | data[5] << 10;
 353                  */
 354                 break;
 355         case DOUBLE_REPORT_ID:
 356                 /* Sometimes the trackpad sends two touch reports in one
 357                  * packet.
 358                  */
 359                 magicmouse_raw_event(hdev, report, data + 2, data[1]);
 360                 magicmouse_raw_event(hdev, report, data + 2 + data[1],
 361                         size - 2 - data[1]);
 362                 break;
 363         default:
 364                 return 0;
 365         }
 366
 367         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 368                 magicmouse_emit_buttons(msc, clicks & 3);
 369                 input_report_rel(input, REL_X, x);
 370                 input_report_rel(input, REL_Y, y);
 371         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 372                 input_report_key(input, BTN_MOUSE, clicks & 1);
 373                 input_report_key(input, BTN_TOUCH, msc->ntouches > 0);
 374                 input_report_key(input, BTN_TOOL_FINGER, msc->ntouches == 1);
 375                 input_report_key(input, BTN_TOOL_DOUBLETAP, msc->ntouches == 2);
 376                 input_report_key(input, BTN_TOOL_TRIPLETAP, msc->ntouches == 3);
 377                 input_report_key(input, BTN_TOOL_QUADTAP, msc->ntouches == 4);
 378                 if (msc->single_touch_id >= 0) {
 379                         input_report_abs(input, ABS_X,
 380                                 msc->touches[msc->single_touch_id].x);
 381                         input_report_abs(input, ABS_Y,
 382                                 msc->touches[msc->single_touch_id].y);
 383                 }
 384         }
 385
 386         input_sync(input);
 387         return 1;
 388 }
 389
 390 static void magicmouse_setup_input(struct input_dev *input, struct hid_device *hdev)
 391 {
 392         __set_bit(EV_KEY, input->evbit);
 393
 394         if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 395                 __set_bit(BTN_LEFT, input->keybit);
 396                 __set_bit(BTN_RIGHT, input->keybit);
 397                 if (emulate_3button)
 398                         __set_bit(BTN_MIDDLE, input->keybit);
 399
 400                 __set_bit(EV_REL, input->evbit);
 401                 __set_bit(REL_X, input->relbit);
 402                 __set_bit(REL_Y, input->relbit);
 403                 if (emulate_scroll_wheel) {
 404                         __set_bit(REL_WHEEL, input->relbit);
 405                         __set_bit(REL_HWHEEL, input->relbit);
 406                 }
 407         } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 408                 __set_bit(BTN_MOUSE, input->keybit);
 409                 __set_bit(BTN_TOOL_FINGER, input->keybit);
 410                 __set_bit(BTN_TOOL_DOUBLETAP, input->keybit);
 411                 __set_bit(BTN_TOOL_TRIPLETAP, input->keybit);
 412                 __set_bit(BTN_TOOL_QUADTAP, input->keybit);
 413                 __set_bit(BTN_TOUCH, input->keybit);
 414         }
 415
 416         if (report_touches) {
 417                 __set_bit(EV_ABS, input->evbit);
 418
 419                 input_set_abs_params(input, ABS_MT_TRACKING_ID, 0, 15, 0, 0);
 420                 input_set_abs_params(input, ABS_MT_TOUCH_MAJOR, 0, 255, 4, 0);
 421                 input_set_abs_params(input, ABS_MT_TOUCH_MINOR, 0, 255, 4, 0);
 422                 input_set_abs_params(input, ABS_MT_ORIENTATION, -31, 32, 1, 0);
 423
 424                 /* Note: Touch Y position from the device is inverted relative
 425                  * to how pointer motion is reported (and relative to how USB
 426                  * HID recommends the coordinates work).  This driver keeps
 427                  * the origin at the same position, and just uses the additive
 428                  * inverse of the reported Y.
 429                  */
 430                 if (input->id.product == USB_DEVICE_ID_APPLE_MAGICMOUSE) {
 431                         input_set_abs_params(input, ABS_MT_POSITION_X,
 432                                 MOUSE_MIN_X, MOUSE_MAX_X, 4, 0);
 433                         input_set_abs_params(input, ABS_MT_POSITION_Y,
 434                                 MOUSE_MIN_Y, MOUSE_MAX_Y, 4, 0);
 435
 436                         input_abs_set_res(input, ABS_MT_POSITION_X,
 437                                 MOUSE_RES_X);
 438                         input_abs_set_res(input, ABS_MT_POSITION_Y,
 439                                 MOUSE_RES_Y);
 440                 } else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 441                         input_set_abs_params(input, ABS_X, TRACKPAD_MIN_X,
 442                                 TRACKPAD_MAX_X, 4, 0);
 443                         input_set_abs_params(input, ABS_Y, TRACKPAD_MIN_Y,
 444                                 TRACKPAD_MAX_Y, 4, 0);
 445                         input_set_abs_params(input, ABS_MT_POSITION_X,
 446                                 TRACKPAD_MIN_X, TRACKPAD_MAX_X, 4, 0);
 447                         input_set_abs_params(input, ABS_MT_POSITION_Y,
 448                                 TRACKPAD_MIN_Y, TRACKPAD_MAX_Y, 4, 0);
 449
 450                         input_abs_set_res(input, ABS_X, TRACKPAD_RES_X);
 451                         input_abs_set_res(input, ABS_Y, TRACKPAD_RES_Y);
 452                         input_abs_set_res(input, ABS_MT_POSITION_X,
 453                                 TRACKPAD_RES_X);
 454                         input_abs_set_res(input, ABS_MT_POSITION_Y,
 455                                 TRACKPAD_RES_Y);
 456                 }
 457
 458                 input_set_events_per_packet(input, 60);
 459         }
 460
 461         if (report_undeciphered) {
 462                 __set_bit(EV_MSC, input->evbit);
 463                 __set_bit(MSC_RAW, input->mscbit);
 464         }
 465 }
 466
 467 static int magicmouse_input_mapping(struct hid_device *hdev,
 468                 struct hid_input *hi, struct hid_field *field,
 469                 struct hid_usage *usage, unsigned long **bit, int *max)
 470 {
 471         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 472
 473         if (!msc->input)
 474                 msc->input = hi->input;
 475
 476         /* Magic Trackpad does not give relative data after switching to MT */
 477         if (hi->input->id.product == USB_DEVICE_ID_APPLE_MAGICTRACKPAD &&
 478             field->flags & HID_MAIN_ITEM_RELATIVE)
 479                 return -1;
 480
 481         return 0;
 482 }
 483
 484 static int magicmouse_probe(struct hid_device *hdev,
 485         const struct hid_device_id *id)
 486 {
 487         __u8 feature[] = { 0xd7, 0x01 };
 488         struct magicmouse_sc *msc;
 489         struct hid_report *report;
 490         int ret;
 491
 492         msc = kzalloc(sizeof(*msc), GFP_KERNEL);
 493         if (msc == NULL) {
 494                 hid_err(hdev, "can't alloc magicmouse descriptor\n");
 495                 return -ENOMEM;
 496         }
 497
 498         msc->scroll_accel = SCROLL_ACCEL_DEFAULT;
 499
 500         msc->quirks = id->driver_data;
 501         hid_set_drvdata(hdev, msc);
 502
 503         msc->single_touch_id = NO_TOUCHES;
 504
 505         ret = hid_parse(hdev);
 506         if (ret) {
 507                 hid_err(hdev, "magicmouse hid parse failed\n");
 508                 goto err_free;
 509         }
 510
 511         ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
 512         if (ret) {
 513                 hid_err(hdev, "magicmouse hw start failed\n");
 514                 goto err_free;
 515         }
 516
 517         /* We do this after hid-input is done parsing reports so that
 518          * hid-input uses the most natural button and axis IDs.
 519          */
 520         if (msc->input)
 521                 magicmouse_setup_input(msc->input, hdev);
 522
 523         if (id->product == USB_DEVICE_ID_APPLE_MAGICMOUSE)
 524                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 525                         MOUSE_REPORT_ID);
 526         else { /* USB_DEVICE_ID_APPLE_MAGICTRACKPAD */
 527                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 528                         TRACKPAD_REPORT_ID);
 529                 report = hid_register_report(hdev, HID_INPUT_REPORT,
 530                         DOUBLE_REPORT_ID);
 531         }
 532
 533         if (!report) {
 534                 hid_err(hdev, "unable to register touch report\n");
 535                 ret = -ENOMEM;
 536                 goto err_stop_hw;
 537         }
 538         report->size = 6;
 539
 540         /*
 541          * Some devices repond with 'invalid report id' when feature
 542          * report switching it into multitouch mode is sent to it.
 543          *
 544          * This results in -EIO from the _raw low-level transport callback,
 545          * but there seems to be no other way of switching the mode.
 546          * Thus the super-ugly hacky success check below.
 547          */
 548         ret = hdev->hid_output_raw_report(hdev, feature, sizeof(feature),
 549                         HID_FEATURE_REPORT);
 550         if (ret != -EIO && ret != sizeof(feature)) {
 551                 hid_err(hdev, "unable to request touch data (%d)\n", ret);
 552                 goto err_stop_hw;
 553         }
 554
 555         return 0;
 556 err_stop_hw:
 557         hid_hw_stop(hdev);
 558 err_free:
 559         kfree(msc);
 560         return ret;
 561 }
 562
 563 static void magicmouse_remove(struct hid_device *hdev)
 564 {
 565         struct magicmouse_sc *msc = hid_get_drvdata(hdev);
 566
 567         hid_hw_stop(hdev);
 568         kfree(msc);
 569 }
 570
 571 static const struct hid_device_id magic_mice[] = {
 572         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 573                 USB_DEVICE_ID_APPLE_MAGICMOUSE), .driver_data = 0 },
 574         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_APPLE,
 575                 USB_DEVICE_ID_APPLE_MAGICTRACKPAD), .driver_data = 0 },
 576         { }
 577 };
 578 MODULE_DEVICE_TABLE(hid, magic_mice);
 579
 580 static struct hid_driver magicmouse_driver = {
 581         .name = "magicmouse",
 582         .id_table = magic_mice,
 583         .probe = magicmouse_probe,
 584         .remove = magicmouse_remove,
 585         .raw_event = magicmouse_raw_event,
 586         .input_mapping = magicmouse_input_mapping,
 587 };
 588
 589 static int __init magicmouse_init(void)
 590 {
 591         int ret;
 592
 593         ret = hid_register_driver(&magicmouse_driver);
 594         if (ret)
 595                 pr_err("can't register magicmouse driver\n");
 596
 597         return ret;
 598 }
 599
 600 static void __exit magicmouse_exit(void)
 601 {
 602         hid_unregister_driver(&magicmouse_driver);
 603 }
 604
 605 module_init(magicmouse_init);
 606 module_exit(magicmouse_exit);
 607 MODULE_LICENSE("GPL");