drivers/acpi/button.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  button.c - ACPI Button Driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  */
   8
   9 #define pr_fmt(fmt) "ACPI: button: " fmt
  10
  11 #include <linux/compiler.h>
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/proc_fs.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/input.h>
  19 #include <linux/slab.h>
  20 #include <linux/acpi.h>
  21 #include <linux/dmi.h>
  22 #include <acpi/button.h>
  23
  24 #define ACPI_BUTTON_CLASS               "button"
  25 #define ACPI_BUTTON_FILE_STATE          "state"
  26 #define ACPI_BUTTON_TYPE_UNKNOWN        0x00
  27 #define ACPI_BUTTON_NOTIFY_STATUS       0x80
  28
  29 #define ACPI_BUTTON_SUBCLASS_POWER      "power"
  30 #define ACPI_BUTTON_DEVICE_NAME_POWER   "Power Button"
  31 #define ACPI_BUTTON_TYPE_POWER          0x01
  32
  33 #define ACPI_BUTTON_SUBCLASS_SLEEP      "sleep"
  34 #define ACPI_BUTTON_DEVICE_NAME_SLEEP   "Sleep Button"
  35 #define ACPI_BUTTON_TYPE_SLEEP          0x03
  36
  37 #define ACPI_BUTTON_SUBCLASS_LID        "lid"
  38 #define ACPI_BUTTON_DEVICE_NAME_LID     "Lid Switch"
  39 #define ACPI_BUTTON_TYPE_LID            0x05
  40
  41 enum {
  42         ACPI_BUTTON_LID_INIT_IGNORE,
  43         ACPI_BUTTON_LID_INIT_OPEN,
  44         ACPI_BUTTON_LID_INIT_METHOD,
  45         ACPI_BUTTON_LID_INIT_DISABLED,
  46 };
  47
  48 static const char * const lid_init_state_str[] = {
  49         [ACPI_BUTTON_LID_INIT_IGNORE]           = "ignore",
  50         [ACPI_BUTTON_LID_INIT_OPEN]             = "open",
  51         [ACPI_BUTTON_LID_INIT_METHOD]           = "method",
  52         [ACPI_BUTTON_LID_INIT_DISABLED]         = "disabled",
  53 };
  54
  55 MODULE_AUTHOR("Paul Diefenbaugh");
  56 MODULE_DESCRIPTION("ACPI Button Driver");
  57 MODULE_LICENSE("GPL");
  58
  59 static const struct acpi_device_id button_device_ids[] = {
  60         {ACPI_BUTTON_HID_LID,    0},
  61         {ACPI_BUTTON_HID_SLEEP,  0},
  62         {ACPI_BUTTON_HID_SLEEPF, 0},
  63         {ACPI_BUTTON_HID_POWER,  0},
  64         {ACPI_BUTTON_HID_POWERF, 0},
  65         {"", 0},
  66 };
  67 MODULE_DEVICE_TABLE(acpi, button_device_ids);
  68
  69 /* Please keep this list sorted alphabetically by vendor and model */
  70 static const struct dmi_system_id dmi_lid_quirks[] = {
  71         {
  72                 /* GP-electronic T701, _LID method points to a floating GPIO */
  73                 .matches = {
  74                         DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),
  75                         DMI_MATCH(DMI_PRODUCT_NAME, "T701"),
  76                         DMI_MATCH(DMI_BIOS_VERSION, "BYT70A.YNCHENG.WIN.007"),
  77                 },
  78                 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,
  79         },
  80         {
  81                 /*
  82                  * Medion Akoya E2215T, notification of the LID device only
  83                  * happens on close, not on open and _LID always returns closed.
  84                  */
  85                 .matches = {
  86                         DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
  87                         DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),
  88                 },
  89                 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
  90         },
  91         {
  92                 /*
  93                  * Medion Akoya E2228T, notification of the LID device only
  94                  * happens on close, not on open and _LID always returns closed.
  95                  */
  96                 .matches = {
  97                         DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),
  98                         DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),
  99                 },
 100                 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
 101         },
 102         {
 103                 /*
 104                  * Razer Blade Stealth 13 late 2019, notification of the LID device
 105                  * only happens on close, not on open and _LID always returns closed.
 106                  */
 107                 .matches = {
 108                         DMI_MATCH(DMI_SYS_VENDOR, "Razer"),
 109                         DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),
 110                 },
 111                 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,
 112         },
 113         {}
 114 };
 115
 116 static int acpi_button_add(struct acpi_device *device);
 117 static int acpi_button_remove(struct acpi_device *device);
 118 static void acpi_button_notify(struct acpi_device *device, u32 event);
 119
 120 #ifdef CONFIG_PM_SLEEP
 121 static int acpi_button_suspend(struct device *dev);
 122 static int acpi_button_resume(struct device *dev);
 123 #else
 124 #define acpi_button_suspend NULL
 125 #define acpi_button_resume NULL
 126 #endif
 127 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
 128
 129 static struct acpi_driver acpi_button_driver = {
 130         .name = "button",
 131         .class = ACPI_BUTTON_CLASS,
 132         .ids = button_device_ids,
 133         .ops = {
 134                 .add = acpi_button_add,
 135                 .remove = acpi_button_remove,
 136                 .notify = acpi_button_notify,
 137         },
 138         .drv.pm = &acpi_button_pm,
 139 };
 140
 141 struct acpi_button {
 142         unsigned int type;
 143         struct input_dev *input;
 144         char phys[32];                  /* for input device */
 145         unsigned long pushed;
 146         int last_state;
 147         ktime_t last_time;
 148         bool suspended;
 149         bool lid_state_initialized;
 150 };
 151
 152 static struct acpi_device *lid_device;
 153 static long lid_init_state = -1;
 154
 155 static unsigned long lid_report_interval __read_mostly = 500;
 156 module_param(lid_report_interval, ulong, 0644);
 157 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
 158
 159 /* --------------------------------------------------------------------------
 160                               FS Interface (/proc)
 161    -------------------------------------------------------------------------- */
 162
 163 static struct proc_dir_entry *acpi_button_dir;
 164 static struct proc_dir_entry *acpi_lid_dir;
 165
 166 static int acpi_lid_evaluate_state(struct acpi_device *device)
 167 {
 168         unsigned long long lid_state;
 169         acpi_status status;
 170
 171         status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
 172         if (ACPI_FAILURE(status))
 173                 return -ENODEV;
 174
 175         return lid_state ? 1 : 0;
 176 }
 177
 178 static int acpi_lid_notify_state(struct acpi_device *device, int state)
 179 {
 180         struct acpi_button *button = acpi_driver_data(device);
 181         ktime_t next_report;
 182         bool do_update;
 183
 184         /*
 185          * In lid_init_state=ignore mode, if user opens/closes lid
 186          * frequently with "open" missing, and "last_time" is also updated
 187          * frequently, "close" cannot be delivered to the userspace.
 188          * So "last_time" is only updated after a timeout or an actual
 189          * switch.
 190          */
 191         if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
 192             button->last_state != !!state)
 193                 do_update = true;
 194         else
 195                 do_update = false;
 196
 197         next_report = ktime_add(button->last_time,
 198                                 ms_to_ktime(lid_report_interval));
 199         if (button->last_state == !!state &&
 200             ktime_after(ktime_get(), next_report)) {
 201                 /* Complain the buggy firmware */
 202                 pr_warn_once("The lid device is not compliant to SW_LID.\n");
 203
 204                 /*
 205                  * Send the unreliable complement switch event:
 206                  *
 207                  * On most platforms, the lid device is reliable. However
 208                  * there are exceptions:
 209                  * 1. Platforms returning initial lid state as "close" by
 210                  *    default after booting/resuming:
 211                  *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
 212                  *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
 213                  * 2. Platforms never reporting "open" events:
 214                  *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
 215                  * On these buggy platforms, the usage model of the ACPI
 216                  * lid device actually is:
 217                  * 1. The initial returning value of _LID may not be
 218                  *    reliable.
 219                  * 2. The open event may not be reliable.
 220                  * 3. The close event is reliable.
 221                  *
 222                  * But SW_LID is typed as input switch event, the input
 223                  * layer checks if the event is redundant. Hence if the
 224                  * state is not switched, the userspace cannot see this
 225                  * platform triggered reliable event. By inserting a
 226                  * complement switch event, it then is guaranteed that the
 227                  * platform triggered reliable one can always be seen by
 228                  * the userspace.
 229                  */
 230                 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
 231                         do_update = true;
 232                         /*
 233                          * Do generate complement switch event for "close"
 234                          * as "close" is reliable and wrong "open" won't
 235                          * trigger unexpected behaviors.
 236                          * Do not generate complement switch event for
 237                          * "open" as "open" is not reliable and wrong
 238                          * "close" will trigger unexpected behaviors.
 239                          */
 240                         if (!state) {
 241                                 input_report_switch(button->input,
 242                                                     SW_LID, state);
 243                                 input_sync(button->input);
 244                         }
 245                 }
 246         }
 247         /* Send the platform triggered reliable event */
 248         if (do_update) {
 249                 acpi_handle_debug(device->handle, "ACPI LID %s\n",
 250                                   state ? "open" : "closed");
 251                 input_report_switch(button->input, SW_LID, !state);
 252                 input_sync(button->input);
 253                 button->last_state = !!state;
 254                 button->last_time = ktime_get();
 255         }
 256
 257         return 0;
 258 }
 259
 260 static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,
 261                                                      void *offset)
 262 {
 263         struct acpi_device *device = seq->private;
 264         int state;
 265
 266         state = acpi_lid_evaluate_state(device);
 267         seq_printf(seq, "state:      %s\n",
 268                    state < 0 ? "unsupported" : (state ? "open" : "closed"));
 269         return 0;
 270 }
 271
 272 static int acpi_button_add_fs(struct acpi_device *device)
 273 {
 274         struct acpi_button *button = acpi_driver_data(device);
 275         struct proc_dir_entry *entry = NULL;
 276         int ret = 0;
 277
 278         /* procfs I/F for ACPI lid device only */
 279         if (button->type != ACPI_BUTTON_TYPE_LID)
 280                 return 0;
 281
 282         if (acpi_button_dir || acpi_lid_dir) {
 283                 pr_info("More than one Lid device found!\n");
 284                 return -EEXIST;
 285         }
 286
 287         /* create /proc/acpi/button */
 288         acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
 289         if (!acpi_button_dir)
 290                 return -ENODEV;
 291
 292         /* create /proc/acpi/button/lid */
 293         acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 294         if (!acpi_lid_dir) {
 295                 ret = -ENODEV;
 296                 goto remove_button_dir;
 297         }
 298
 299         /* create /proc/acpi/button/lid/LID/ */
 300         acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
 301         if (!acpi_device_dir(device)) {
 302                 ret = -ENODEV;
 303                 goto remove_lid_dir;
 304         }
 305
 306         /* create /proc/acpi/button/lid/LID/state */
 307         entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,
 308                         acpi_device_dir(device), acpi_button_state_seq_show,
 309                         device);
 310         if (!entry) {
 311                 ret = -ENODEV;
 312                 goto remove_dev_dir;
 313         }
 314
 315 done:
 316         return ret;
 317
 318 remove_dev_dir:
 319         remove_proc_entry(acpi_device_bid(device),
 320                           acpi_lid_dir);
 321         acpi_device_dir(device) = NULL;
 322 remove_lid_dir:
 323         remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 324         acpi_lid_dir = NULL;
 325 remove_button_dir:
 326         remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
 327         acpi_button_dir = NULL;
 328         goto done;
 329 }
 330
 331 static int acpi_button_remove_fs(struct acpi_device *device)
 332 {
 333         struct acpi_button *button = acpi_driver_data(device);
 334
 335         if (button->type != ACPI_BUTTON_TYPE_LID)
 336                 return 0;
 337
 338         remove_proc_entry(ACPI_BUTTON_FILE_STATE,
 339                           acpi_device_dir(device));
 340         remove_proc_entry(acpi_device_bid(device),
 341                           acpi_lid_dir);
 342         acpi_device_dir(device) = NULL;
 343         remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 344         acpi_lid_dir = NULL;
 345         remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
 346         acpi_button_dir = NULL;
 347
 348         return 0;
 349 }
 350
 351 /* --------------------------------------------------------------------------
 352                                 Driver Interface
 353    -------------------------------------------------------------------------- */
 354 int acpi_lid_open(void)
 355 {
 356         if (!lid_device)
 357                 return -ENODEV;
 358
 359         return acpi_lid_evaluate_state(lid_device);
 360 }
 361 EXPORT_SYMBOL(acpi_lid_open);
 362
 363 static int acpi_lid_update_state(struct acpi_device *device,
 364                                  bool signal_wakeup)
 365 {
 366         int state;
 367
 368         state = acpi_lid_evaluate_state(device);
 369         if (state < 0)
 370                 return state;
 371
 372         if (state && signal_wakeup)
 373                 acpi_pm_wakeup_event(&device->dev);
 374
 375         return acpi_lid_notify_state(device, state);
 376 }
 377
 378 static void acpi_lid_initialize_state(struct acpi_device *device)
 379 {
 380         struct acpi_button *button = acpi_driver_data(device);
 381
 382         switch (lid_init_state) {
 383         case ACPI_BUTTON_LID_INIT_OPEN:
 384                 (void)acpi_lid_notify_state(device, 1);
 385                 break;
 386         case ACPI_BUTTON_LID_INIT_METHOD:
 387                 (void)acpi_lid_update_state(device, false);
 388                 break;
 389         case ACPI_BUTTON_LID_INIT_IGNORE:
 390         default:
 391                 break;
 392         }
 393
 394         button->lid_state_initialized = true;
 395 }
 396
 397 static void acpi_button_notify(struct acpi_device *device, u32 event)
 398 {
 399         struct acpi_button *button = acpi_driver_data(device);
 400         struct input_dev *input;
 401
 402         switch (event) {
 403         case ACPI_FIXED_HARDWARE_EVENT:
 404                 event = ACPI_BUTTON_NOTIFY_STATUS;
 405                 fallthrough;
 406         case ACPI_BUTTON_NOTIFY_STATUS:
 407                 input = button->input;
 408                 if (button->type == ACPI_BUTTON_TYPE_LID) {
 409                         if (button->lid_state_initialized)
 410                                 acpi_lid_update_state(device, true);
 411                 } else {
 412                         int keycode;
 413
 414                         acpi_pm_wakeup_event(&device->dev);
 415                         if (button->suspended)
 416                                 break;
 417
 418                         keycode = test_bit(KEY_SLEEP, input->keybit) ?
 419                                                 KEY_SLEEP : KEY_POWER;
 420                         input_report_key(input, keycode, 1);
 421                         input_sync(input);
 422                         input_report_key(input, keycode, 0);
 423                         input_sync(input);
 424
 425                         acpi_bus_generate_netlink_event(
 426                                         device->pnp.device_class,
 427                                         dev_name(&device->dev),
 428                                         event, ++button->pushed);
 429                 }
 430                 break;
 431         default:
 432                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
 433                                   event);
 434                 break;
 435         }
 436 }
 437
 438 #ifdef CONFIG_PM_SLEEP
 439 static int acpi_button_suspend(struct device *dev)
 440 {
 441         struct acpi_device *device = to_acpi_device(dev);
 442         struct acpi_button *button = acpi_driver_data(device);
 443
 444         button->suspended = true;
 445         return 0;
 446 }
 447
 448 static int acpi_button_resume(struct device *dev)
 449 {
 450         struct acpi_device *device = to_acpi_device(dev);
 451         struct acpi_button *button = acpi_driver_data(device);
 452
 453         button->suspended = false;
 454         if (button->type == ACPI_BUTTON_TYPE_LID) {
 455                 button->last_state = !!acpi_lid_evaluate_state(device);
 456                 button->last_time = ktime_get();
 457                 acpi_lid_initialize_state(device);
 458         }
 459         return 0;
 460 }
 461 #endif
 462
 463 static int acpi_lid_input_open(struct input_dev *input)
 464 {
 465         struct acpi_device *device = input_get_drvdata(input);
 466         struct acpi_button *button = acpi_driver_data(device);
 467
 468         button->last_state = !!acpi_lid_evaluate_state(device);
 469         button->last_time = ktime_get();
 470         acpi_lid_initialize_state(device);
 471
 472         return 0;
 473 }
 474
 475 static int acpi_button_add(struct acpi_device *device)
 476 {
 477         struct acpi_button *button;
 478         struct input_dev *input;
 479         const char *hid = acpi_device_hid(device);
 480         char *name, *class;
 481         int error;
 482
 483         if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&
 484              lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)
 485                 return -ENODEV;
 486
 487         button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
 488         if (!button)
 489                 return -ENOMEM;
 490
 491         device->driver_data = button;
 492
 493         button->input = input = input_allocate_device();
 494         if (!input) {
 495                 error = -ENOMEM;
 496                 goto err_free_button;
 497         }
 498
 499         name = acpi_device_name(device);
 500         class = acpi_device_class(device);
 501
 502         if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
 503             !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
 504                 button->type = ACPI_BUTTON_TYPE_POWER;
 505                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
 506                 sprintf(class, "%s/%s",
 507                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
 508         } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
 509                    !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
 510                 button->type = ACPI_BUTTON_TYPE_SLEEP;
 511                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
 512                 sprintf(class, "%s/%s",
 513                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
 514         } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
 515                 button->type = ACPI_BUTTON_TYPE_LID;
 516                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
 517                 sprintf(class, "%s/%s",
 518                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
 519                 input->open = acpi_lid_input_open;
 520         } else {
 521                 pr_info("Unsupported hid [%s]\n", hid);
 522                 error = -ENODEV;
 523                 goto err_free_input;
 524         }
 525
 526         error = acpi_button_add_fs(device);
 527         if (error)
 528                 goto err_free_input;
 529
 530         snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 531
 532         input->name = name;
 533         input->phys = button->phys;
 534         input->id.bustype = BUS_HOST;
 535         input->id.product = button->type;
 536         input->dev.parent = &device->dev;
 537
 538         switch (button->type) {
 539         case ACPI_BUTTON_TYPE_POWER:
 540                 input_set_capability(input, EV_KEY, KEY_POWER);
 541                 break;
 542
 543         case ACPI_BUTTON_TYPE_SLEEP:
 544                 input_set_capability(input, EV_KEY, KEY_SLEEP);
 545                 break;
 546
 547         case ACPI_BUTTON_TYPE_LID:
 548                 input_set_capability(input, EV_SW, SW_LID);
 549                 break;
 550         }
 551
 552         input_set_drvdata(input, device);
 553         error = input_register_device(input);
 554         if (error)
 555                 goto err_remove_fs;
 556         if (button->type == ACPI_BUTTON_TYPE_LID) {
 557                 /*
 558                  * This assumes there's only one lid device, or if there are
 559                  * more we only care about the last one...
 560                  */
 561                 lid_device = device;
 562         }
 563
 564         device_init_wakeup(&device->dev, true);
 565         pr_info("%s [%s]\n", name, acpi_device_bid(device));
 566         return 0;
 567
 568  err_remove_fs:
 569         acpi_button_remove_fs(device);
 570  err_free_input:
 571         input_free_device(input);
 572  err_free_button:
 573         kfree(button);
 574         return error;
 575 }
 576
 577 static int acpi_button_remove(struct acpi_device *device)
 578 {
 579         struct acpi_button *button = acpi_driver_data(device);
 580
 581         acpi_button_remove_fs(device);
 582         input_unregister_device(button->input);
 583         kfree(button);
 584         return 0;
 585 }
 586
 587 static int param_set_lid_init_state(const char *val,
 588                                     const struct kernel_param *kp)
 589 {
 590         int i;
 591
 592         i = sysfs_match_string(lid_init_state_str, val);
 593         if (i < 0)
 594                 return i;
 595
 596         lid_init_state = i;
 597         pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);
 598         return 0;
 599 }
 600
 601 static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)
 602 {
 603         int i, c = 0;
 604
 605         for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)
 606                 if (i == lid_init_state)
 607                         c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);
 608                 else
 609                         c += sprintf(buf + c, "%s ", lid_init_state_str[i]);
 610
 611         buf[c - 1] = '\n'; /* Replace the final space with a newline */
 612
 613         return c;
 614 }
 615
 616 module_param_call(lid_init_state,
 617                   param_set_lid_init_state, param_get_lid_init_state,
 618                   NULL, 0644);
 619 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
 620
 621 static int acpi_button_register_driver(struct acpi_driver *driver)
 622 {
 623         const struct dmi_system_id *dmi_id;
 624
 625         if (lid_init_state == -1) {
 626                 dmi_id = dmi_first_match(dmi_lid_quirks);
 627                 if (dmi_id)
 628                         lid_init_state = (long)dmi_id->driver_data;
 629                 else
 630                         lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;
 631         }
 632
 633         /*
 634          * Modules such as nouveau.ko and i915.ko have a link time dependency
 635          * on acpi_lid_open(), and would therefore not be loadable on ACPI
 636          * capable kernels booted in non-ACPI mode if the return value of
 637          * acpi_bus_register_driver() is returned from here with ACPI disabled
 638          * when this driver is built as a module.
 639          */
 640         if (acpi_disabled)
 641                 return 0;
 642
 643         return acpi_bus_register_driver(driver);
 644 }
 645
 646 static void acpi_button_unregister_driver(struct acpi_driver *driver)
 647 {
 648         if (!acpi_disabled)
 649                 acpi_bus_unregister_driver(driver);
 650 }
 651
 652 module_driver(acpi_button_driver, acpi_button_register_driver,
 653                acpi_button_unregister_driver);