drivers/platform/x86/dell-wmi.c

   1 /*
   2  * Dell WMI hotkeys
   3  *
   4  * Copyright (C) 2008 Red Hat <mjg@redhat.com>
   5  * Copyright (C) 2014-2015 Pali Rohár <pali.rohar@gmail.com>
   6  *
   7  * Portions based on wistron_btns.c:
   8  * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
   9  * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
  10  * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2 of the License, or
  15  *  (at your option) any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; if not, write to the Free Software
  24  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  25  */
  26
  27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/types.h>
  34 #include <linux/input.h>
  35 #include <linux/input/sparse-keymap.h>
  36 #include <linux/acpi.h>
  37 #include <linux/string.h>
  38 #include <linux/dmi.h>
  39 #include <linux/wmi.h>
  40 #include <acpi/video.h>
  41 #include "dell-smbios.h"
  42
  43 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
  44 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
  45 MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
  46 MODULE_LICENSE("GPL");
  47
  48 #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
  49 #define DELL_DESCRIPTOR_GUID "8D9DDCBC-A997-11DA-B012-B622A1EF5492"
  50
  51 static u32 dell_wmi_interface_version;
  52 static bool wmi_requires_smbios_request;
  53
  54 MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
  55 MODULE_ALIAS("wmi:"DELL_DESCRIPTOR_GUID);
  56
  57 struct dell_wmi_priv {
  58         struct input_dev *input_dev;
  59 };
  60
  61 static int __init dmi_matched(const struct dmi_system_id *dmi)
  62 {
  63         wmi_requires_smbios_request = 1;
  64         return 1;
  65 }
  66
  67 static const struct dmi_system_id dell_wmi_smbios_list[] __initconst = {
  68         {
  69                 .callback = dmi_matched,
  70                 .ident = "Dell Inspiron M5110",
  71                 .matches = {
  72                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  73                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron M5110"),
  74                 },
  75         },
  76         {
  77                 .callback = dmi_matched,
  78                 .ident = "Dell Vostro V131",
  79                 .matches = {
  80                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
  81                         DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
  82                 },
  83         },
  84         { }
  85 };
  86
  87 /*
  88  * Keymap for WMI events of type 0x0000
  89  *
  90  * Certain keys are flagged as KE_IGNORE. All of these are either
  91  * notifications (rather than requests for change) or are also sent
  92  * via the keyboard controller so should not be sent again.
  93  */
  94 static const struct key_entry dell_wmi_keymap_type_0000[] = {
  95         { KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
  96
  97         /* Key code is followed by brightness level */
  98         { KE_KEY,    0xe005, { KEY_BRIGHTNESSDOWN } },
  99         { KE_KEY,    0xe006, { KEY_BRIGHTNESSUP } },
 100
 101         /* Battery health status button */
 102         { KE_KEY,    0xe007, { KEY_BATTERY } },
 103
 104         /* Radio devices state change, key code is followed by other values */
 105         { KE_IGNORE, 0xe008, { KEY_RFKILL } },
 106
 107         { KE_KEY,    0xe009, { KEY_EJECTCD } },
 108
 109         /* Key code is followed by: next, active and attached devices */
 110         { KE_KEY,    0xe00b, { KEY_SWITCHVIDEOMODE } },
 111
 112         /* Key code is followed by keyboard illumination level */
 113         { KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
 114
 115         /* BIOS error detected */
 116         { KE_IGNORE, 0xe00d, { KEY_RESERVED } },
 117
 118         /* Battery was removed or inserted */
 119         { KE_IGNORE, 0xe00e, { KEY_RESERVED } },
 120
 121         /* Wifi Catcher */
 122         { KE_KEY,    0xe011, { KEY_WLAN } },
 123
 124         /* Ambient light sensor toggle */
 125         { KE_IGNORE, 0xe013, { KEY_RESERVED } },
 126
 127         { KE_IGNORE, 0xe020, { KEY_MUTE } },
 128
 129         /* Unknown, defined in ACPI DSDT */
 130         /* { KE_IGNORE, 0xe023, { KEY_RESERVED } }, */
 131
 132         /* Untested, Dell Instant Launch key on Inspiron 7520 */
 133         /* { KE_IGNORE, 0xe024, { KEY_RESERVED } }, */
 134
 135         /* Dell Instant Launch key */
 136         { KE_KEY,    0xe025, { KEY_PROG4 } },
 137
 138         /* Audio panel key */
 139         { KE_IGNORE, 0xe026, { KEY_RESERVED } },
 140
 141         /* LCD Display On/Off Control key */
 142         { KE_KEY,    0xe027, { KEY_DISPLAYTOGGLE } },
 143
 144         /* Untested, Multimedia key on Dell Vostro 3560 */
 145         /* { KE_IGNORE, 0xe028, { KEY_RESERVED } }, */
 146
 147         /* Dell Instant Launch key */
 148         { KE_KEY,    0xe029, { KEY_PROG4 } },
 149
 150         /* Untested, Windows Mobility Center button on Inspiron 7520 */
 151         /* { KE_IGNORE, 0xe02a, { KEY_RESERVED } }, */
 152
 153         /* Unknown, defined in ACPI DSDT */
 154         /* { KE_IGNORE, 0xe02b, { KEY_RESERVED } }, */
 155
 156         /* Untested, Dell Audio With Preset Switch button on Inspiron 7520 */
 157         /* { KE_IGNORE, 0xe02c, { KEY_RESERVED } }, */
 158
 159         { KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
 160         { KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
 161         { KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
 162         { KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
 163         { KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
 164
 165         /* NIC Link is Up */
 166         { KE_IGNORE, 0xe043, { KEY_RESERVED } },
 167
 168         /* NIC Link is Down */
 169         { KE_IGNORE, 0xe044, { KEY_RESERVED } },
 170
 171         /*
 172          * This entry is very suspicious!
 173          * Originally Matthew Garrett created this dell-wmi driver specially for
 174          * "button with a picture of a battery" which has event code 0xe045.
 175          * Later Mario Limonciello from Dell told us that event code 0xe045 is
 176          * reported by Num Lock and should be ignored because key is send also
 177          * by keyboard controller.
 178          * So for now we will ignore this event to prevent potential double
 179          * Num Lock key press.
 180          */
 181         { KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
 182
 183         /* Scroll lock and also going to tablet mode on portable devices */
 184         { KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
 185
 186         /* Untested, going from tablet mode on portable devices */
 187         /* { KE_IGNORE, 0xe047, { KEY_RESERVED } }, */
 188
 189         /* Dell Support Center key */
 190         { KE_IGNORE, 0xe06e, { KEY_RESERVED } },
 191
 192         { KE_IGNORE, 0xe0f7, { KEY_MUTE } },
 193         { KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
 194         { KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
 195 };
 196
 197 struct dell_bios_keymap_entry {
 198         u16 scancode;
 199         u16 keycode;
 200 };
 201
 202 struct dell_bios_hotkey_table {
 203         struct dmi_header header;
 204         struct dell_bios_keymap_entry keymap[];
 205
 206 };
 207
 208 struct dell_dmi_results {
 209         int err;
 210         int keymap_size;
 211         struct key_entry *keymap;
 212 };
 213
 214 /* Uninitialized entries here are KEY_RESERVED == 0. */
 215 static const u16 bios_to_linux_keycode[256] = {
 216         [0]     = KEY_MEDIA,
 217         [1]     = KEY_NEXTSONG,
 218         [2]     = KEY_PLAYPAUSE,
 219         [3]     = KEY_PREVIOUSSONG,
 220         [4]     = KEY_STOPCD,
 221         [5]     = KEY_UNKNOWN,
 222         [6]     = KEY_UNKNOWN,
 223         [7]     = KEY_UNKNOWN,
 224         [8]     = KEY_WWW,
 225         [9]     = KEY_UNKNOWN,
 226         [10]    = KEY_VOLUMEDOWN,
 227         [11]    = KEY_MUTE,
 228         [12]    = KEY_VOLUMEUP,
 229         [13]    = KEY_UNKNOWN,
 230         [14]    = KEY_BATTERY,
 231         [15]    = KEY_EJECTCD,
 232         [16]    = KEY_UNKNOWN,
 233         [17]    = KEY_SLEEP,
 234         [18]    = KEY_PROG1,
 235         [19]    = KEY_BRIGHTNESSDOWN,
 236         [20]    = KEY_BRIGHTNESSUP,
 237         [21]    = KEY_UNKNOWN,
 238         [22]    = KEY_KBDILLUMTOGGLE,
 239         [23]    = KEY_UNKNOWN,
 240         [24]    = KEY_SWITCHVIDEOMODE,
 241         [25]    = KEY_UNKNOWN,
 242         [26]    = KEY_UNKNOWN,
 243         [27]    = KEY_SWITCHVIDEOMODE,
 244         [28]    = KEY_UNKNOWN,
 245         [29]    = KEY_UNKNOWN,
 246         [30]    = KEY_PROG2,
 247         [31]    = KEY_UNKNOWN,
 248         [32]    = KEY_UNKNOWN,
 249         [33]    = KEY_UNKNOWN,
 250         [34]    = KEY_UNKNOWN,
 251         [35]    = KEY_UNKNOWN,
 252         [36]    = KEY_UNKNOWN,
 253         [37]    = KEY_UNKNOWN,
 254         [38]    = KEY_MICMUTE,
 255         [255]   = KEY_PROG3,
 256 };
 257
 258 /*
 259  * Keymap for WMI events of type 0x0010
 260  *
 261  * These are applied if the 0xB2 DMI hotkey table is present and doesn't
 262  * override them.
 263  */
 264 static const struct key_entry dell_wmi_keymap_type_0010[] = {
 265         /* Fn-lock */
 266         { KE_IGNORE, 0x151, { KEY_RESERVED } },
 267
 268         /* Change keyboard illumination */
 269         { KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
 270
 271         /*
 272          * Radio disable (notify only -- there is no model for which the
 273          * WMI event is supposed to trigger an action).
 274          */
 275         { KE_IGNORE, 0x153, { KEY_RFKILL } },
 276
 277         /* RGB keyboard backlight control */
 278         { KE_IGNORE, 0x154, { KEY_RESERVED } },
 279
 280         /*
 281          * Stealth mode toggle. This will "disable all lights and sounds".
 282          * The action is performed by the BIOS and EC; the WMI event is just
 283          * a notification. On the XPS 13 9350, this is Fn+F7, and there's
 284          * a BIOS setting to enable and disable the hotkey.
 285          */
 286         { KE_IGNORE, 0x155, { KEY_RESERVED } },
 287
 288         /* Rugged magnetic dock attach/detach events */
 289         { KE_IGNORE, 0x156, { KEY_RESERVED } },
 290         { KE_IGNORE, 0x157, { KEY_RESERVED } },
 291
 292         /* Rugged programmable (P1/P2/P3 keys) */
 293         { KE_KEY,    0x850, { KEY_PROG1 } },
 294         { KE_KEY,    0x851, { KEY_PROG2 } },
 295         { KE_KEY,    0x852, { KEY_PROG3 } },
 296
 297 };
 298
 299 /*
 300  * Keymap for WMI events of type 0x0011
 301  */
 302 static const struct key_entry dell_wmi_keymap_type_0011[] = {
 303         /* Battery unplugged */
 304         { KE_IGNORE, 0xfff0, { KEY_RESERVED } },
 305
 306         /* Battery inserted */
 307         { KE_IGNORE, 0xfff1, { KEY_RESERVED } },
 308
 309         /* Keyboard backlight level changed */
 310         { KE_IGNORE, 0x01e1, { KEY_RESERVED } },
 311         { KE_IGNORE, 0x02ea, { KEY_RESERVED } },
 312         { KE_IGNORE, 0x02eb, { KEY_RESERVED } },
 313         { KE_IGNORE, 0x02ec, { KEY_RESERVED } },
 314         { KE_IGNORE, 0x02f6, { KEY_RESERVED } },
 315 };
 316
 317 static void dell_wmi_process_key(struct wmi_device *wdev, int type, int code)
 318 {
 319         struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
 320         const struct key_entry *key;
 321
 322         key = sparse_keymap_entry_from_scancode(priv->input_dev,
 323                                                 (type << 16) | code);
 324         if (!key) {
 325                 pr_info("Unknown key with type 0x%04x and code 0x%04x pressed\n",
 326                         type, code);
 327                 return;
 328         }
 329
 330         pr_debug("Key with type 0x%04x and code 0x%04x pressed\n", type, code);
 331
 332         /* Don't report brightness notifications that will also come via ACPI */
 333         if ((key->keycode == KEY_BRIGHTNESSUP ||
 334              key->keycode == KEY_BRIGHTNESSDOWN) &&
 335             acpi_video_handles_brightness_key_presses())
 336                 return;
 337
 338         if (type == 0x0000 && code == 0xe025 && !wmi_requires_smbios_request)
 339                 return;
 340
 341         if (key->keycode == KEY_KBDILLUMTOGGLE)
 342                 dell_laptop_call_notifier(
 343                         DELL_LAPTOP_KBD_BACKLIGHT_BRIGHTNESS_CHANGED, NULL);
 344
 345         sparse_keymap_report_entry(priv->input_dev, key, 1, true);
 346 }
 347
 348 static void dell_wmi_notify(struct wmi_device *wdev,
 349                             union acpi_object *obj)
 350 {
 351         u16 *buffer_entry, *buffer_end;
 352         acpi_size buffer_size;
 353         int len, i;
 354
 355         if (obj->type != ACPI_TYPE_BUFFER) {
 356                 pr_warn("bad response type %x\n", obj->type);
 357                 return;
 358         }
 359
 360         pr_debug("Received WMI event (%*ph)\n",
 361                 obj->buffer.length, obj->buffer.pointer);
 362
 363         buffer_entry = (u16 *)obj->buffer.pointer;
 364         buffer_size = obj->buffer.length/2;
 365         buffer_end = buffer_entry + buffer_size;
 366
 367         /*
 368          * BIOS/ACPI on devices with WMI interface version 0 does not clear
 369          * buffer before filling it. So next time when BIOS/ACPI send WMI event
 370          * which is smaller as previous then it contains garbage in buffer from
 371          * previous event.
 372          *
 373          * BIOS/ACPI on devices with WMI interface version 1 clears buffer and
 374          * sometimes send more events in buffer at one call.
 375          *
 376          * So to prevent reading garbage from buffer we will process only first
 377          * one event on devices with WMI interface version 0.
 378          */
 379         if (dell_wmi_interface_version == 0 && buffer_entry < buffer_end)
 380                 if (buffer_end > buffer_entry + buffer_entry[0] + 1)
 381                         buffer_end = buffer_entry + buffer_entry[0] + 1;
 382
 383         while (buffer_entry < buffer_end) {
 384
 385                 len = buffer_entry[0];
 386                 if (len == 0)
 387                         break;
 388
 389                 len++;
 390
 391                 if (buffer_entry + len > buffer_end) {
 392                         pr_warn("Invalid length of WMI event\n");
 393                         break;
 394                 }
 395
 396                 pr_debug("Process buffer (%*ph)\n", len*2, buffer_entry);
 397
 398                 switch (buffer_entry[1]) {
 399                 case 0x0000: /* One key pressed or event occurred */
 400                         if (len > 2)
 401                                 dell_wmi_process_key(wdev, 0x0000,
 402                                                      buffer_entry[2]);
 403                         /* Other entries could contain additional information */
 404                         break;
 405                 case 0x0010: /* Sequence of keys pressed */
 406                 case 0x0011: /* Sequence of events occurred */
 407                         for (i = 2; i < len; ++i)
 408                                 dell_wmi_process_key(wdev, buffer_entry[1],
 409                                                      buffer_entry[i]);
 410                         break;
 411                 default: /* Unknown event */
 412                         pr_info("Unknown WMI event type 0x%x\n",
 413                                 (int)buffer_entry[1]);
 414                         break;
 415                 }
 416
 417                 buffer_entry += len;
 418
 419         }
 420
 421 }
 422
 423 static bool have_scancode(u32 scancode, const struct key_entry *keymap, int len)
 424 {
 425         int i;
 426
 427         for (i = 0; i < len; i++)
 428                 if (keymap[i].code == scancode)
 429                         return true;
 430
 431         return false;
 432 }
 433
 434 static void handle_dmi_entry(const struct dmi_header *dm, void *opaque)
 435 {
 436         struct dell_dmi_results *results = opaque;
 437         struct dell_bios_hotkey_table *table;
 438         int hotkey_num, i, pos = 0;
 439         struct key_entry *keymap;
 440
 441         if (results->err || results->keymap)
 442                 return;         /* We already found the hotkey table. */
 443
 444         /* The Dell hotkey table is type 0xB2.  Scan until we find it. */
 445         if (dm->type != 0xb2)
 446                 return;
 447
 448         table = container_of(dm, struct dell_bios_hotkey_table, header);
 449
 450         hotkey_num = (table->header.length -
 451                       sizeof(struct dell_bios_hotkey_table)) /
 452                                 sizeof(struct dell_bios_keymap_entry);
 453         if (hotkey_num < 1) {
 454                 /*
 455                  * Historically, dell-wmi would ignore a DMI entry of
 456                  * fewer than 7 bytes.  Sizes between 4 and 8 bytes are
 457                  * nonsensical (both the header and all entries are 4
 458                  * bytes), so we approximate the old behavior by
 459                  * ignoring tables with fewer than one entry.
 460                  */
 461                 return;
 462         }
 463
 464         keymap = kcalloc(hotkey_num, sizeof(struct key_entry), GFP_KERNEL);
 465         if (!keymap) {
 466                 results->err = -ENOMEM;
 467                 return;
 468         }
 469
 470         for (i = 0; i < hotkey_num; i++) {
 471                 const struct dell_bios_keymap_entry *bios_entry =
 472                                         &table->keymap[i];
 473
 474                 /* Uninitialized entries are 0 aka KEY_RESERVED. */
 475                 u16 keycode = (bios_entry->keycode <
 476                                ARRAY_SIZE(bios_to_linux_keycode)) ?
 477                         bios_to_linux_keycode[bios_entry->keycode] :
 478                         KEY_RESERVED;
 479
 480                 /*
 481                  * Log if we find an entry in the DMI table that we don't
 482                  * understand.  If this happens, we should figure out what
 483                  * the entry means and add it to bios_to_linux_keycode.
 484                  */
 485                 if (keycode == KEY_RESERVED) {
 486                         pr_info("firmware scancode 0x%x maps to unrecognized keycode 0x%x\n",
 487                                 bios_entry->scancode, bios_entry->keycode);
 488                         continue;
 489                 }
 490
 491                 if (keycode == KEY_KBDILLUMTOGGLE)
 492                         keymap[pos].type = KE_IGNORE;
 493                 else
 494                         keymap[pos].type = KE_KEY;
 495                 keymap[pos].code = bios_entry->scancode;
 496                 keymap[pos].keycode = keycode;
 497
 498                 pos++;
 499         }
 500
 501         results->keymap = keymap;
 502         results->keymap_size = pos;
 503 }
 504
 505 static int dell_wmi_input_setup(struct wmi_device *wdev)
 506 {
 507         struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
 508         struct dell_dmi_results dmi_results = {};
 509         struct key_entry *keymap;
 510         int err, i, pos = 0;
 511
 512         priv->input_dev = input_allocate_device();
 513         if (!priv->input_dev)
 514                 return -ENOMEM;
 515
 516         priv->input_dev->name = "Dell WMI hotkeys";
 517         priv->input_dev->id.bustype = BUS_HOST;
 518         priv->input_dev->dev.parent = &wdev->dev;
 519
 520         if (dmi_walk(handle_dmi_entry, &dmi_results)) {
 521                 /*
 522                  * Historically, dell-wmi ignored dmi_walk errors.  A failure
 523                  * is certainly surprising, but it probably just indicates
 524                  * a very old laptop.
 525                  */
 526                 pr_warn("no DMI; using the old-style hotkey interface\n");
 527         }
 528
 529         if (dmi_results.err) {
 530                 err = dmi_results.err;
 531                 goto err_free_dev;
 532         }
 533
 534         keymap = kcalloc(dmi_results.keymap_size +
 535                          ARRAY_SIZE(dell_wmi_keymap_type_0000) +
 536                          ARRAY_SIZE(dell_wmi_keymap_type_0010) +
 537                          ARRAY_SIZE(dell_wmi_keymap_type_0011) +
 538                          1,
 539                          sizeof(struct key_entry), GFP_KERNEL);
 540         if (!keymap) {
 541                 kfree(dmi_results.keymap);
 542                 err = -ENOMEM;
 543                 goto err_free_dev;
 544         }
 545
 546         /* Append table with events of type 0x0010 which comes from DMI */
 547         for (i = 0; i < dmi_results.keymap_size; i++) {
 548                 keymap[pos] = dmi_results.keymap[i];
 549                 keymap[pos].code |= (0x0010 << 16);
 550                 pos++;
 551         }
 552
 553         kfree(dmi_results.keymap);
 554
 555         /* Append table with extra events of type 0x0010 which are not in DMI */
 556         for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0010); i++) {
 557                 const struct key_entry *entry = &dell_wmi_keymap_type_0010[i];
 558
 559                 /*
 560                  * Check if we've already found this scancode.  This takes
 561                  * quadratic time, but it doesn't matter unless the list
 562                  * of extra keys gets very long.
 563                  */
 564                 if (dmi_results.keymap_size &&
 565                     have_scancode(entry->code | (0x0010 << 16),
 566                                   keymap, dmi_results.keymap_size)
 567                    )
 568                         continue;
 569
 570                 keymap[pos] = *entry;
 571                 keymap[pos].code |= (0x0010 << 16);
 572                 pos++;
 573         }
 574
 575         /* Append table with events of type 0x0011 */
 576         for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0011); i++) {
 577                 keymap[pos] = dell_wmi_keymap_type_0011[i];
 578                 keymap[pos].code |= (0x0011 << 16);
 579                 pos++;
 580         }
 581
 582         /*
 583          * Now append also table with "legacy" events of type 0x0000. Some of
 584          * them are reported also on laptops which have scancodes in DMI.
 585          */
 586         for (i = 0; i < ARRAY_SIZE(dell_wmi_keymap_type_0000); i++) {
 587                 keymap[pos] = dell_wmi_keymap_type_0000[i];
 588                 pos++;
 589         }
 590
 591         keymap[pos].type = KE_END;
 592
 593         err = sparse_keymap_setup(priv->input_dev, keymap, NULL);
 594         /*
 595          * Sparse keymap library makes a copy of keymap so we don't need the
 596          * original one that was allocated.
 597          */
 598         kfree(keymap);
 599         if (err)
 600                 goto err_free_dev;
 601
 602         err = input_register_device(priv->input_dev);
 603         if (err)
 604                 goto err_free_dev;
 605
 606         return 0;
 607
 608  err_free_dev:
 609         input_free_device(priv->input_dev);
 610         return err;
 611 }
 612
 613 static void dell_wmi_input_destroy(struct wmi_device *wdev)
 614 {
 615         struct dell_wmi_priv *priv = dev_get_drvdata(&wdev->dev);
 616
 617         input_unregister_device(priv->input_dev);
 618 }
 619
 620 /*
 621  * Descriptor buffer is 128 byte long and contains:
 622  *
 623  *       Name             Offset  Length  Value
 624  * Vendor Signature          0       4    "DELL"
 625  * Object Signature          4       4    " WMI"
 626  * WMI Interface Version     8       4    <version>
 627  * WMI buffer length        12       4    4096
 628  */
 629 static int __init dell_wmi_check_descriptor_buffer(void)
 630 {
 631         struct acpi_buffer out = { ACPI_ALLOCATE_BUFFER, NULL };
 632         union acpi_object *obj;
 633         acpi_status status;
 634         u32 *buffer;
 635
 636         status = wmi_query_block(DELL_DESCRIPTOR_GUID, 0, &out);
 637         if (ACPI_FAILURE(status)) {
 638                 pr_err("Cannot read Dell descriptor buffer - %d\n", status);
 639                 return status;
 640         }
 641
 642         obj = (union acpi_object *)out.pointer;
 643         if (!obj) {
 644                 pr_err("Dell descriptor buffer is empty\n");
 645                 return -EINVAL;
 646         }
 647
 648         if (obj->type != ACPI_TYPE_BUFFER) {
 649                 pr_err("Cannot read Dell descriptor buffer\n");
 650                 kfree(obj);
 651                 return -EINVAL;
 652         }
 653
 654         if (obj->buffer.length != 128) {
 655                 pr_err("Dell descriptor buffer has invalid length (%d)\n",
 656                         obj->buffer.length);
 657                 if (obj->buffer.length < 16) {
 658                         kfree(obj);
 659                         return -EINVAL;
 660                 }
 661         }
 662
 663         buffer = (u32 *)obj->buffer.pointer;
 664
 665         if (buffer[0] != 0x4C4C4544 && buffer[1] != 0x494D5720)
 666                 pr_warn("Dell descriptor buffer has invalid signature (%*ph)\n",
 667                         8, buffer);
 668
 669         if (buffer[2] != 0 && buffer[2] != 1)
 670                 pr_warn("Dell descriptor buffer has unknown version (%d)\n",
 671                         buffer[2]);
 672
 673         if (buffer[3] != 4096)
 674                 pr_warn("Dell descriptor buffer has invalid buffer length (%d)\n",
 675                         buffer[3]);
 676
 677         dell_wmi_interface_version = buffer[2];
 678
 679         pr_info("Detected Dell WMI interface version %u\n",
 680                 dell_wmi_interface_version);
 681
 682         kfree(obj);
 683         return 0;
 684 }
 685
 686 /*
 687  * According to Dell SMBIOS documentation:
 688  *
 689  * 17  3  Application Program Registration
 690  *
 691  *     cbArg1 Application ID 1 = 0x00010000
 692  *     cbArg2 Application ID 2
 693  *            QUICKSET/DCP = 0x51534554 "QSET"
 694  *            ALS Driver   = 0x416c7353 "AlsS"
 695  *            Latitude ON  = 0x4c6f6e52 "LonR"
 696  *     cbArg3 Application version or revision number
 697  *     cbArg4 0 = Unregister application
 698  *            1 = Register application
 699  *     cbRes1 Standard return codes (0, -1, -2)
 700  */
 701
 702 static int dell_wmi_events_set_enabled(bool enable)
 703 {
 704         struct calling_interface_buffer *buffer;
 705         int ret;
 706
 707         buffer = dell_smbios_get_buffer();
 708         buffer->input[0] = 0x10000;
 709         buffer->input[1] = 0x51534554;
 710         buffer->input[3] = enable;
 711         dell_smbios_send_request(17, 3);
 712         ret = buffer->output[0];
 713         dell_smbios_release_buffer();
 714
 715         return dell_smbios_error(ret);
 716 }
 717
 718 static int dell_wmi_probe(struct wmi_device *wdev)
 719 {
 720         struct dell_wmi_priv *priv = devm_kzalloc(
 721                 &wdev->dev, sizeof(struct dell_wmi_priv), GFP_KERNEL);
 722
 723         dev_set_drvdata(&wdev->dev, priv);
 724
 725         return dell_wmi_input_setup(wdev);
 726 }
 727
 728 static int dell_wmi_remove(struct wmi_device *wdev)
 729 {
 730         dell_wmi_input_destroy(wdev);
 731         return 0;
 732 }
 733 static const struct wmi_device_id dell_wmi_id_table[] = {
 734         { .guid_string = DELL_EVENT_GUID },
 735         { },
 736 };
 737
 738 static struct wmi_driver dell_wmi_driver = {
 739         .driver = {
 740                 .name = "dell-wmi",
 741         },
 742         .id_table = dell_wmi_id_table,
 743         .probe = dell_wmi_probe,
 744         .remove = dell_wmi_remove,
 745         .notify = dell_wmi_notify,
 746 };
 747
 748 static int __init dell_wmi_init(void)
 749 {
 750         int err;
 751
 752         err = dell_wmi_check_descriptor_buffer();
 753         if (err)
 754                 return err;
 755
 756         dmi_check_system(dell_wmi_smbios_list);
 757
 758         if (wmi_requires_smbios_request) {
 759                 err = dell_wmi_events_set_enabled(true);
 760                 if (err) {
 761                         pr_err("Failed to enable WMI events\n");
 762                         return err;
 763                 }
 764         }
 765
 766         return wmi_driver_register(&dell_wmi_driver);
 767 }
 768 module_init(dell_wmi_init);
 769
 770 static void __exit dell_wmi_exit(void)
 771 {
 772         if (wmi_requires_smbios_request)
 773                 dell_wmi_events_set_enabled(false);
 774
 775         wmi_driver_unregister(&dell_wmi_driver);
 776 }
 777 module_exit(dell_wmi_exit);