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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * button.c - ACPI Button Driver4 *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: " fmt10 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 0x0027#define ACPI_BUTTON_NOTIFY_STATUS 0x8028 29#define ACPI_BUTTON_SUBCLASS_POWER "power"30#define ACPI_BUTTON_DEVICE_NAME_POWER "Power Button"31#define ACPI_BUTTON_TYPE_POWER 0x0132 33#define ACPI_BUTTON_SUBCLASS_SLEEP "sleep"34#define ACPI_BUTTON_DEVICE_NAME_SLEEP "Sleep Button"35#define ACPI_BUTTON_TYPE_SLEEP 0x0336 37#define ACPI_BUTTON_SUBCLASS_LID "lid"38#define ACPI_BUTTON_DEVICE_NAME_LID "Lid Switch"39#define ACPI_BUTTON_TYPE_LID 0x0540 41enum {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 48static 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 55MODULE_AUTHOR("Paul Diefenbaugh");56MODULE_DESCRIPTION("ACPI Button Driver");57MODULE_LICENSE("GPL");58 59static 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};67MODULE_DEVICE_TABLE(acpi, button_device_ids);68 69/* Please keep this list sorted alphabetically by vendor and model */70static 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 /* Nextbook Ares 8A tablet, _LID device always reports lid closed */82 .matches = {83 DMI_MATCH(DMI_SYS_VENDOR, "Insyde"),84 DMI_MATCH(DMI_PRODUCT_NAME, "CherryTrail"),85 DMI_MATCH(DMI_BIOS_VERSION, "M882"),86 },87 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_DISABLED,88 },89 {90 /*91 * Lenovo Yoga 9 14ITL5, initial notification of the LID device92 * never happens.93 */94 .matches = {95 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),96 DMI_MATCH(DMI_PRODUCT_NAME, "82BG"),97 },98 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,99 },100 {101 /*102 * Medion Akoya E2215T, notification of the LID device only103 * happens on close, not on open and _LID always returns closed.104 */105 .matches = {106 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),107 DMI_MATCH(DMI_PRODUCT_NAME, "E2215T"),108 },109 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,110 },111 {112 /*113 * Medion Akoya E2228T, notification of the LID device only114 * happens on close, not on open and _LID always returns closed.115 */116 .matches = {117 DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),118 DMI_MATCH(DMI_PRODUCT_NAME, "E2228T"),119 },120 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,121 },122 {123 /*124 * Razer Blade Stealth 13 late 2019, notification of the LID device125 * only happens on close, not on open and _LID always returns closed.126 */127 .matches = {128 DMI_MATCH(DMI_SYS_VENDOR, "Razer"),129 DMI_MATCH(DMI_PRODUCT_NAME, "Razer Blade Stealth 13 Late 2019"),130 },131 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,132 },133 {134 /*135 * Samsung galaxybook2 ,initial _LID device notification returns136 * lid closed.137 */138 .matches = {139 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),140 DMI_MATCH(DMI_PRODUCT_NAME, "750XED"),141 },142 .driver_data = (void *)(long)ACPI_BUTTON_LID_INIT_OPEN,143 },144 {}145};146 147static int acpi_button_add(struct acpi_device *device);148static void acpi_button_remove(struct acpi_device *device);149 150#ifdef CONFIG_PM_SLEEP151static int acpi_button_suspend(struct device *dev);152static int acpi_button_resume(struct device *dev);153#else154#define acpi_button_suspend NULL155#define acpi_button_resume NULL156#endif157static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);158 159static struct acpi_driver acpi_button_driver = {160 .name = "button",161 .class = ACPI_BUTTON_CLASS,162 .ids = button_device_ids,163 .ops = {164 .add = acpi_button_add,165 .remove = acpi_button_remove,166 },167 .drv.pm = &acpi_button_pm,168};169 170struct acpi_button {171 unsigned int type;172 struct input_dev *input;173 char phys[32]; /* for input device */174 unsigned long pushed;175 int last_state;176 ktime_t last_time;177 bool suspended;178 bool lid_state_initialized;179};180 181static struct acpi_device *lid_device;182static long lid_init_state = -1;183 184static unsigned long lid_report_interval __read_mostly = 500;185module_param(lid_report_interval, ulong, 0644);186MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");187 188/* FS Interface (/proc) */189static struct proc_dir_entry *acpi_button_dir;190static struct proc_dir_entry *acpi_lid_dir;191 192static int acpi_lid_evaluate_state(struct acpi_device *device)193{194 unsigned long long lid_state;195 acpi_status status;196 197 status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);198 if (ACPI_FAILURE(status))199 return -ENODEV;200 201 return lid_state ? 1 : 0;202}203 204static int acpi_lid_notify_state(struct acpi_device *device, int state)205{206 struct acpi_button *button = acpi_driver_data(device);207 ktime_t next_report;208 bool do_update;209 210 /*211 * In lid_init_state=ignore mode, if user opens/closes lid212 * frequently with "open" missing, and "last_time" is also updated213 * frequently, "close" cannot be delivered to the userspace.214 * So "last_time" is only updated after a timeout or an actual215 * switch.216 */217 if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||218 button->last_state != !!state)219 do_update = true;220 else221 do_update = false;222 223 next_report = ktime_add(button->last_time,224 ms_to_ktime(lid_report_interval));225 if (button->last_state == !!state &&226 ktime_after(ktime_get(), next_report)) {227 /* Complain the buggy firmware */228 pr_warn_once("The lid device is not compliant to SW_LID.\n");229 230 /*231 * Send the unreliable complement switch event:232 *233 * On most platforms, the lid device is reliable. However234 * there are exceptions:235 * 1. Platforms returning initial lid state as "close" by236 * default after booting/resuming:237 * https://bugzilla.kernel.org/show_bug.cgi?id=89211238 * https://bugzilla.kernel.org/show_bug.cgi?id=106151239 * 2. Platforms never reporting "open" events:240 * https://bugzilla.kernel.org/show_bug.cgi?id=106941241 * On these buggy platforms, the usage model of the ACPI242 * lid device actually is:243 * 1. The initial returning value of _LID may not be244 * reliable.245 * 2. The open event may not be reliable.246 * 3. The close event is reliable.247 *248 * But SW_LID is typed as input switch event, the input249 * layer checks if the event is redundant. Hence if the250 * state is not switched, the userspace cannot see this251 * platform triggered reliable event. By inserting a252 * complement switch event, it then is guaranteed that the253 * platform triggered reliable one can always be seen by254 * the userspace.255 */256 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {257 do_update = true;258 /*259 * Do generate complement switch event for "close"260 * as "close" is reliable and wrong "open" won't261 * trigger unexpected behaviors.262 * Do not generate complement switch event for263 * "open" as "open" is not reliable and wrong264 * "close" will trigger unexpected behaviors.265 */266 if (!state) {267 input_report_switch(button->input,268 SW_LID, state);269 input_sync(button->input);270 }271 }272 }273 /* Send the platform triggered reliable event */274 if (do_update) {275 acpi_handle_debug(device->handle, "ACPI LID %s\n",276 state ? "open" : "closed");277 input_report_switch(button->input, SW_LID, !state);278 input_sync(button->input);279 button->last_state = !!state;280 button->last_time = ktime_get();281 }282 283 return 0;284}285 286static int __maybe_unused acpi_button_state_seq_show(struct seq_file *seq,287 void *offset)288{289 struct acpi_device *device = seq->private;290 int state;291 292 state = acpi_lid_evaluate_state(device);293 seq_printf(seq, "state: %s\n",294 state < 0 ? "unsupported" : (state ? "open" : "closed"));295 return 0;296}297 298static int acpi_button_add_fs(struct acpi_device *device)299{300 struct acpi_button *button = acpi_driver_data(device);301 struct proc_dir_entry *entry = NULL;302 int ret = 0;303 304 /* procfs I/F for ACPI lid device only */305 if (button->type != ACPI_BUTTON_TYPE_LID)306 return 0;307 308 if (acpi_button_dir || acpi_lid_dir) {309 pr_info("More than one Lid device found!\n");310 return -EEXIST;311 }312 313 /* create /proc/acpi/button */314 acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);315 if (!acpi_button_dir)316 return -ENODEV;317 318 /* create /proc/acpi/button/lid */319 acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);320 if (!acpi_lid_dir) {321 ret = -ENODEV;322 goto remove_button_dir;323 }324 325 /* create /proc/acpi/button/lid/LID/ */326 acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);327 if (!acpi_device_dir(device)) {328 ret = -ENODEV;329 goto remove_lid_dir;330 }331 332 /* create /proc/acpi/button/lid/LID/state */333 entry = proc_create_single_data(ACPI_BUTTON_FILE_STATE, S_IRUGO,334 acpi_device_dir(device), acpi_button_state_seq_show,335 device);336 if (!entry) {337 ret = -ENODEV;338 goto remove_dev_dir;339 }340 341done:342 return ret;343 344remove_dev_dir:345 remove_proc_entry(acpi_device_bid(device),346 acpi_lid_dir);347 acpi_device_dir(device) = NULL;348remove_lid_dir:349 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);350 acpi_lid_dir = NULL;351remove_button_dir:352 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);353 acpi_button_dir = NULL;354 goto done;355}356 357static int acpi_button_remove_fs(struct acpi_device *device)358{359 struct acpi_button *button = acpi_driver_data(device);360 361 if (button->type != ACPI_BUTTON_TYPE_LID)362 return 0;363 364 remove_proc_entry(ACPI_BUTTON_FILE_STATE,365 acpi_device_dir(device));366 remove_proc_entry(acpi_device_bid(device),367 acpi_lid_dir);368 acpi_device_dir(device) = NULL;369 remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);370 acpi_lid_dir = NULL;371 remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);372 acpi_button_dir = NULL;373 374 return 0;375}376 377/* Driver Interface */378int acpi_lid_open(void)379{380 if (!lid_device)381 return -ENODEV;382 383 return acpi_lid_evaluate_state(lid_device);384}385EXPORT_SYMBOL(acpi_lid_open);386 387static int acpi_lid_update_state(struct acpi_device *device,388 bool signal_wakeup)389{390 int state;391 392 state = acpi_lid_evaluate_state(device);393 if (state < 0)394 return state;395 396 if (state && signal_wakeup)397 acpi_pm_wakeup_event(&device->dev);398 399 return acpi_lid_notify_state(device, state);400}401 402static void acpi_lid_initialize_state(struct acpi_device *device)403{404 struct acpi_button *button = acpi_driver_data(device);405 406 switch (lid_init_state) {407 case ACPI_BUTTON_LID_INIT_OPEN:408 (void)acpi_lid_notify_state(device, 1);409 break;410 case ACPI_BUTTON_LID_INIT_METHOD:411 (void)acpi_lid_update_state(device, false);412 break;413 case ACPI_BUTTON_LID_INIT_IGNORE:414 default:415 break;416 }417 418 button->lid_state_initialized = true;419}420 421static void acpi_lid_notify(acpi_handle handle, u32 event, void *data)422{423 struct acpi_device *device = data;424 struct acpi_button *button;425 426 if (event != ACPI_BUTTON_NOTIFY_STATUS) {427 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",428 event);429 return;430 }431 432 button = acpi_driver_data(device);433 if (!button->lid_state_initialized)434 return;435 436 acpi_lid_update_state(device, true);437}438 439static void acpi_button_notify(acpi_handle handle, u32 event, void *data)440{441 struct acpi_device *device = data;442 struct acpi_button *button;443 struct input_dev *input;444 int keycode;445 446 if (event != ACPI_BUTTON_NOTIFY_STATUS) {447 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",448 event);449 return;450 }451 452 acpi_pm_wakeup_event(&device->dev);453 454 button = acpi_driver_data(device);455 if (button->suspended)456 return;457 458 input = button->input;459 keycode = test_bit(KEY_SLEEP, input->keybit) ? KEY_SLEEP : KEY_POWER;460 461 input_report_key(input, keycode, 1);462 input_sync(input);463 input_report_key(input, keycode, 0);464 input_sync(input);465 466 acpi_bus_generate_netlink_event(device->pnp.device_class,467 dev_name(&device->dev),468 event, ++button->pushed);469}470 471static void acpi_button_notify_run(void *data)472{473 acpi_button_notify(NULL, ACPI_BUTTON_NOTIFY_STATUS, data);474}475 476static u32 acpi_button_event(void *data)477{478 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_button_notify_run, data);479 return ACPI_INTERRUPT_HANDLED;480}481 482#ifdef CONFIG_PM_SLEEP483static int acpi_button_suspend(struct device *dev)484{485 struct acpi_device *device = to_acpi_device(dev);486 struct acpi_button *button = acpi_driver_data(device);487 488 button->suspended = true;489 return 0;490}491 492static int acpi_button_resume(struct device *dev)493{494 struct input_dev *input;495 struct acpi_device *device = to_acpi_device(dev);496 struct acpi_button *button = acpi_driver_data(device);497 498 button->suspended = false;499 if (button->type == ACPI_BUTTON_TYPE_LID) {500 button->last_state = !!acpi_lid_evaluate_state(device);501 button->last_time = ktime_get();502 acpi_lid_initialize_state(device);503 }504 505 if (button->type == ACPI_BUTTON_TYPE_POWER) {506 input = button->input;507 input_report_key(input, KEY_WAKEUP, 1);508 input_sync(input);509 input_report_key(input, KEY_WAKEUP, 0);510 input_sync(input);511 }512 return 0;513}514#endif515 516static int acpi_lid_input_open(struct input_dev *input)517{518 struct acpi_device *device = input_get_drvdata(input);519 struct acpi_button *button = acpi_driver_data(device);520 521 button->last_state = !!acpi_lid_evaluate_state(device);522 button->last_time = ktime_get();523 acpi_lid_initialize_state(device);524 525 return 0;526}527 528static int acpi_button_add(struct acpi_device *device)529{530 acpi_notify_handler handler;531 struct acpi_button *button;532 struct input_dev *input;533 const char *hid = acpi_device_hid(device);534 acpi_status status;535 char *name, *class;536 int error = 0;537 538 if (!strcmp(hid, ACPI_BUTTON_HID_LID) &&539 lid_init_state == ACPI_BUTTON_LID_INIT_DISABLED)540 return -ENODEV;541 542 button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);543 if (!button)544 return -ENOMEM;545 546 device->driver_data = button;547 548 button->input = input = input_allocate_device();549 if (!input) {550 error = -ENOMEM;551 goto err_free_button;552 }553 554 name = acpi_device_name(device);555 class = acpi_device_class(device);556 557 if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||558 !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {559 button->type = ACPI_BUTTON_TYPE_POWER;560 handler = acpi_button_notify;561 strscpy(name, ACPI_BUTTON_DEVICE_NAME_POWER, MAX_ACPI_DEVICE_NAME_LEN);562 sprintf(class, "%s/%s",563 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);564 } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||565 !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {566 button->type = ACPI_BUTTON_TYPE_SLEEP;567 handler = acpi_button_notify;568 strscpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP, MAX_ACPI_DEVICE_NAME_LEN);569 sprintf(class, "%s/%s",570 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);571 } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {572 button->type = ACPI_BUTTON_TYPE_LID;573 handler = acpi_lid_notify;574 strscpy(name, ACPI_BUTTON_DEVICE_NAME_LID, MAX_ACPI_DEVICE_NAME_LEN);575 sprintf(class, "%s/%s",576 ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);577 input->open = acpi_lid_input_open;578 } else {579 pr_info("Unsupported hid [%s]\n", hid);580 error = -ENODEV;581 }582 583 if (!error)584 error = acpi_button_add_fs(device);585 586 if (error) {587 input_free_device(input);588 goto err_free_button;589 }590 591 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);592 593 input->name = name;594 input->phys = button->phys;595 input->id.bustype = BUS_HOST;596 input->id.product = button->type;597 input->dev.parent = &device->dev;598 599 switch (button->type) {600 case ACPI_BUTTON_TYPE_POWER:601 input_set_capability(input, EV_KEY, KEY_POWER);602 input_set_capability(input, EV_KEY, KEY_WAKEUP);603 break;604 605 case ACPI_BUTTON_TYPE_SLEEP:606 input_set_capability(input, EV_KEY, KEY_SLEEP);607 break;608 609 case ACPI_BUTTON_TYPE_LID:610 input_set_capability(input, EV_SW, SW_LID);611 break;612 }613 614 input_set_drvdata(input, device);615 error = input_register_device(input);616 if (error)617 goto err_remove_fs;618 619 switch (device->device_type) {620 case ACPI_BUS_TYPE_POWER_BUTTON:621 status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,622 acpi_button_event,623 device);624 break;625 case ACPI_BUS_TYPE_SLEEP_BUTTON:626 status = acpi_install_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,627 acpi_button_event,628 device);629 break;630 default:631 status = acpi_install_notify_handler(device->handle,632 ACPI_DEVICE_NOTIFY, handler,633 device);634 break;635 }636 if (ACPI_FAILURE(status)) {637 error = -ENODEV;638 goto err_input_unregister;639 }640 641 if (button->type == ACPI_BUTTON_TYPE_LID) {642 /*643 * This assumes there's only one lid device, or if there are644 * more we only care about the last one...645 */646 lid_device = device;647 }648 649 device_init_wakeup(&device->dev, true);650 pr_info("%s [%s]\n", name, acpi_device_bid(device));651 return 0;652 653err_input_unregister:654 input_unregister_device(input);655err_remove_fs:656 acpi_button_remove_fs(device);657err_free_button:658 kfree(button);659 return error;660}661 662static void acpi_button_remove(struct acpi_device *device)663{664 struct acpi_button *button = acpi_driver_data(device);665 666 switch (device->device_type) {667 case ACPI_BUS_TYPE_POWER_BUTTON:668 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,669 acpi_button_event);670 break;671 case ACPI_BUS_TYPE_SLEEP_BUTTON:672 acpi_remove_fixed_event_handler(ACPI_EVENT_SLEEP_BUTTON,673 acpi_button_event);674 break;675 default:676 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,677 button->type == ACPI_BUTTON_TYPE_LID ?678 acpi_lid_notify :679 acpi_button_notify);680 break;681 }682 acpi_os_wait_events_complete();683 684 acpi_button_remove_fs(device);685 input_unregister_device(button->input);686 kfree(button);687}688 689static int param_set_lid_init_state(const char *val,690 const struct kernel_param *kp)691{692 int i;693 694 i = sysfs_match_string(lid_init_state_str, val);695 if (i < 0)696 return i;697 698 lid_init_state = i;699 pr_info("Initial lid state set to '%s'\n", lid_init_state_str[i]);700 return 0;701}702 703static int param_get_lid_init_state(char *buf, const struct kernel_param *kp)704{705 int i, c = 0;706 707 for (i = 0; i < ARRAY_SIZE(lid_init_state_str); i++)708 if (i == lid_init_state)709 c += sprintf(buf + c, "[%s] ", lid_init_state_str[i]);710 else711 c += sprintf(buf + c, "%s ", lid_init_state_str[i]);712 713 buf[c - 1] = '\n'; /* Replace the final space with a newline */714 715 return c;716}717 718module_param_call(lid_init_state,719 param_set_lid_init_state, param_get_lid_init_state,720 NULL, 0644);721MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");722 723static int acpi_button_register_driver(struct acpi_driver *driver)724{725 const struct dmi_system_id *dmi_id;726 727 if (lid_init_state == -1) {728 dmi_id = dmi_first_match(dmi_lid_quirks);729 if (dmi_id)730 lid_init_state = (long)dmi_id->driver_data;731 else732 lid_init_state = ACPI_BUTTON_LID_INIT_METHOD;733 }734 735 /*736 * Modules such as nouveau.ko and i915.ko have a link time dependency737 * on acpi_lid_open(), and would therefore not be loadable on ACPI738 * capable kernels booted in non-ACPI mode if the return value of739 * acpi_bus_register_driver() is returned from here with ACPI disabled740 * when this driver is built as a module.741 */742 if (acpi_disabled)743 return 0;744 745 return acpi_bus_register_driver(driver);746}747 748static void acpi_button_unregister_driver(struct acpi_driver *driver)749{750 if (!acpi_disabled)751 acpi_bus_unregister_driver(driver);752}753 754module_driver(acpi_button_driver, acpi_button_register_driver,755 acpi_button_unregister_driver);756