drivers/acpi/button.c

   1 /*
   2  *  button.c - ACPI Button Driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or (at
  12  *  your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful, but
  15  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  *  General Public License for more details.
  18  *
  19  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  20  */
  21
  22 #define pr_fmt(fmt) "ACPI : button: " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/seq_file.h>
  30 #include <linux/input.h>
  31 #include <linux/slab.h>
  32 #include <linux/acpi.h>
  33 #include <acpi/button.h>
  34
  35 #define PREFIX "ACPI: "
  36
  37 #define ACPI_BUTTON_CLASS               "button"
  38 #define ACPI_BUTTON_FILE_INFO           "info"
  39 #define ACPI_BUTTON_FILE_STATE          "state"
  40 #define ACPI_BUTTON_TYPE_UNKNOWN        0x00
  41 #define ACPI_BUTTON_NOTIFY_STATUS       0x80
  42
  43 #define ACPI_BUTTON_SUBCLASS_POWER      "power"
  44 #define ACPI_BUTTON_HID_POWER           "PNP0C0C"
  45 #define ACPI_BUTTON_DEVICE_NAME_POWER   "Power Button"
  46 #define ACPI_BUTTON_TYPE_POWER          0x01
  47
  48 #define ACPI_BUTTON_SUBCLASS_SLEEP      "sleep"
  49 #define ACPI_BUTTON_HID_SLEEP           "PNP0C0E"
  50 #define ACPI_BUTTON_DEVICE_NAME_SLEEP   "Sleep Button"
  51 #define ACPI_BUTTON_TYPE_SLEEP          0x03
  52
  53 #define ACPI_BUTTON_SUBCLASS_LID        "lid"
  54 #define ACPI_BUTTON_HID_LID             "PNP0C0D"
  55 #define ACPI_BUTTON_DEVICE_NAME_LID     "Lid Switch"
  56 #define ACPI_BUTTON_TYPE_LID            0x05
  57
  58 #define ACPI_BUTTON_LID_INIT_IGNORE     0x00
  59 #define ACPI_BUTTON_LID_INIT_OPEN       0x01
  60
  61 #define _COMPONENT              ACPI_BUTTON_COMPONENT
  62 ACPI_MODULE_NAME("button");
  63
  64 MODULE_AUTHOR("Paul Diefenbaugh");
  65 MODULE_DESCRIPTION("ACPI Button Driver");
  66 MODULE_LICENSE("GPL");
  67
  68 static const struct acpi_device_id button_device_ids[] = {
  69         {ACPI_BUTTON_HID_LID,    0},
  70         {ACPI_BUTTON_HID_SLEEP,  0},
  71         {ACPI_BUTTON_HID_SLEEPF, 0},
  72         {ACPI_BUTTON_HID_POWER,  0},
  73         {ACPI_BUTTON_HID_POWERF, 0},
  74         {"", 0},
  75 };
  76 MODULE_DEVICE_TABLE(acpi, button_device_ids);
  77
  78 static int acpi_button_add(struct acpi_device *device);
  79 static int acpi_button_remove(struct acpi_device *device);
  80 static void acpi_button_notify(struct acpi_device *device, u32 event);
  81
  82 #ifdef CONFIG_PM_SLEEP
  83 static int acpi_button_suspend(struct device *dev);
  84 static int acpi_button_resume(struct device *dev);
  85 #else
  86 #define acpi_button_suspend NULL
  87 #define acpi_button_resume NULL
  88 #endif
  89 static SIMPLE_DEV_PM_OPS(acpi_button_pm, acpi_button_suspend, acpi_button_resume);
  90
  91 static struct acpi_driver acpi_button_driver = {
  92         .name = "button",
  93         .class = ACPI_BUTTON_CLASS,
  94         .ids = button_device_ids,
  95         .ops = {
  96                 .add = acpi_button_add,
  97                 .remove = acpi_button_remove,
  98                 .notify = acpi_button_notify,
  99         },
 100         .drv.pm = &acpi_button_pm,
 101 };
 102
 103 struct acpi_button {
 104         unsigned int type;
 105         struct input_dev *input;
 106         char phys[32];                  /* for input device */
 107         unsigned long pushed;
 108         int last_state;
 109         ktime_t last_time;
 110         bool suspended;
 111 };
 112
 113 static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
 114 static struct acpi_device *lid_device;
 115 static u8 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
 116
 117 static unsigned long lid_report_interval __read_mostly = 500;
 118 module_param(lid_report_interval, ulong, 0644);
 119 MODULE_PARM_DESC(lid_report_interval, "Interval (ms) between lid key events");
 120
 121 /* --------------------------------------------------------------------------
 122                               FS Interface (/proc)
 123    -------------------------------------------------------------------------- */
 124
 125 static struct proc_dir_entry *acpi_button_dir;
 126 static struct proc_dir_entry *acpi_lid_dir;
 127
 128 static int acpi_lid_evaluate_state(struct acpi_device *device)
 129 {
 130         unsigned long long lid_state;
 131         acpi_status status;
 132
 133         status = acpi_evaluate_integer(device->handle, "_LID", NULL, &lid_state);
 134         if (ACPI_FAILURE(status))
 135                 return -ENODEV;
 136
 137         return lid_state ? 1 : 0;
 138 }
 139
 140 static int acpi_lid_notify_state(struct acpi_device *device, int state)
 141 {
 142         struct acpi_button *button = acpi_driver_data(device);
 143         int ret;
 144         ktime_t next_report;
 145         bool do_update;
 146
 147         /*
 148          * In lid_init_state=ignore mode, if user opens/closes lid
 149          * frequently with "open" missing, and "last_time" is also updated
 150          * frequently, "close" cannot be delivered to the userspace.
 151          * So "last_time" is only updated after a timeout or an actual
 152          * switch.
 153          */
 154         if (lid_init_state != ACPI_BUTTON_LID_INIT_IGNORE ||
 155             button->last_state != !!state)
 156                 do_update = true;
 157         else
 158                 do_update = false;
 159
 160         next_report = ktime_add(button->last_time,
 161                                 ms_to_ktime(lid_report_interval));
 162         if (button->last_state == !!state &&
 163             ktime_after(ktime_get(), next_report)) {
 164                 /* Complain the buggy firmware */
 165                 pr_warn_once("The lid device is not compliant to SW_LID.\n");
 166
 167                 /*
 168                  * Send the unreliable complement switch event:
 169                  *
 170                  * On most platforms, the lid device is reliable. However
 171                  * there are exceptions:
 172                  * 1. Platforms returning initial lid state as "close" by
 173                  *    default after booting/resuming:
 174                  *     https://bugzilla.kernel.org/show_bug.cgi?id=89211
 175                  *     https://bugzilla.kernel.org/show_bug.cgi?id=106151
 176                  * 2. Platforms never reporting "open" events:
 177                  *     https://bugzilla.kernel.org/show_bug.cgi?id=106941
 178                  * On these buggy platforms, the usage model of the ACPI
 179                  * lid device actually is:
 180                  * 1. The initial returning value of _LID may not be
 181                  *    reliable.
 182                  * 2. The open event may not be reliable.
 183                  * 3. The close event is reliable.
 184                  *
 185                  * But SW_LID is typed as input switch event, the input
 186                  * layer checks if the event is redundant. Hence if the
 187                  * state is not switched, the userspace cannot see this
 188                  * platform triggered reliable event. By inserting a
 189                  * complement switch event, it then is guaranteed that the
 190                  * platform triggered reliable one can always be seen by
 191                  * the userspace.
 192                  */
 193                 if (lid_init_state == ACPI_BUTTON_LID_INIT_IGNORE) {
 194                         do_update = true;
 195                         /*
 196                          * Do generate complement switch event for "close"
 197                          * as "close" is reliable and wrong "open" won't
 198                          * trigger unexpected behaviors.
 199                          * Do not generate complement switch event for
 200                          * "open" as "open" is not reliable and wrong
 201                          * "close" will trigger unexpected behaviors.
 202                          */
 203                         if (!state) {
 204                                 input_report_switch(button->input,
 205                                                     SW_LID, state);
 206                                 input_sync(button->input);
 207                         }
 208                 }
 209         }
 210         /* Send the platform triggered reliable event */
 211         if (do_update) {
 212                 input_report_switch(button->input, SW_LID, !state);
 213                 input_sync(button->input);
 214                 button->last_state = !!state;
 215                 button->last_time = ktime_get();
 216         }
 217
 218         if (state)
 219                 pm_wakeup_hard_event(&device->dev);
 220
 221         ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
 222         if (ret == NOTIFY_DONE)
 223                 ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
 224                                                    device);
 225         if (ret == NOTIFY_DONE || ret == NOTIFY_OK) {
 226                 /*
 227                  * It is also regarded as success if the notifier_chain
 228                  * returns NOTIFY_OK or NOTIFY_DONE.
 229                  */
 230                 ret = 0;
 231         }
 232         return ret;
 233 }
 234
 235 static int acpi_button_state_seq_show(struct seq_file *seq, void *offset)
 236 {
 237         struct acpi_device *device = seq->private;
 238         int state;
 239
 240         state = acpi_lid_evaluate_state(device);
 241         seq_printf(seq, "state:      %s\n",
 242                    state < 0 ? "unsupported" : (state ? "open" : "closed"));
 243         return 0;
 244 }
 245
 246 static int acpi_button_state_open_fs(struct inode *inode, struct file *file)
 247 {
 248         return single_open(file, acpi_button_state_seq_show, PDE_DATA(inode));
 249 }
 250
 251 static const struct file_operations acpi_button_state_fops = {
 252         .owner = THIS_MODULE,
 253         .open = acpi_button_state_open_fs,
 254         .read = seq_read,
 255         .llseek = seq_lseek,
 256         .release = single_release,
 257 };
 258
 259 static int acpi_button_add_fs(struct acpi_device *device)
 260 {
 261         struct acpi_button *button = acpi_driver_data(device);
 262         struct proc_dir_entry *entry = NULL;
 263         int ret = 0;
 264
 265         /* procfs I/F for ACPI lid device only */
 266         if (button->type != ACPI_BUTTON_TYPE_LID)
 267                 return 0;
 268
 269         if (acpi_button_dir || acpi_lid_dir) {
 270                 printk(KERN_ERR PREFIX "More than one Lid device found!\n");
 271                 return -EEXIST;
 272         }
 273
 274         /* create /proc/acpi/button */
 275         acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
 276         if (!acpi_button_dir)
 277                 return -ENODEV;
 278
 279         /* create /proc/acpi/button/lid */
 280         acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 281         if (!acpi_lid_dir) {
 282                 ret = -ENODEV;
 283                 goto remove_button_dir;
 284         }
 285
 286         /* create /proc/acpi/button/lid/LID/ */
 287         acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
 288         if (!acpi_device_dir(device)) {
 289                 ret = -ENODEV;
 290                 goto remove_lid_dir;
 291         }
 292
 293         /* create /proc/acpi/button/lid/LID/state */
 294         entry = proc_create_data(ACPI_BUTTON_FILE_STATE,
 295                                  S_IRUGO, acpi_device_dir(device),
 296                                  &acpi_button_state_fops, device);
 297         if (!entry) {
 298                 ret = -ENODEV;
 299                 goto remove_dev_dir;
 300         }
 301
 302 done:
 303         return ret;
 304
 305 remove_dev_dir:
 306         remove_proc_entry(acpi_device_bid(device),
 307                           acpi_lid_dir);
 308         acpi_device_dir(device) = NULL;
 309 remove_lid_dir:
 310         remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 311         acpi_lid_dir = NULL;
 312 remove_button_dir:
 313         remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
 314         acpi_button_dir = NULL;
 315         goto done;
 316 }
 317
 318 static int acpi_button_remove_fs(struct acpi_device *device)
 319 {
 320         struct acpi_button *button = acpi_driver_data(device);
 321
 322         if (button->type != ACPI_BUTTON_TYPE_LID)
 323                 return 0;
 324
 325         remove_proc_entry(ACPI_BUTTON_FILE_STATE,
 326                           acpi_device_dir(device));
 327         remove_proc_entry(acpi_device_bid(device),
 328                           acpi_lid_dir);
 329         acpi_device_dir(device) = NULL;
 330         remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
 331         acpi_lid_dir = NULL;
 332         remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
 333         acpi_button_dir = NULL;
 334
 335         return 0;
 336 }
 337
 338 /* --------------------------------------------------------------------------
 339                                 Driver Interface
 340    -------------------------------------------------------------------------- */
 341 int acpi_lid_notifier_register(struct notifier_block *nb)
 342 {
 343         return blocking_notifier_chain_register(&acpi_lid_notifier, nb);
 344 }
 345 EXPORT_SYMBOL(acpi_lid_notifier_register);
 346
 347 int acpi_lid_notifier_unregister(struct notifier_block *nb)
 348 {
 349         return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);
 350 }
 351 EXPORT_SYMBOL(acpi_lid_notifier_unregister);
 352
 353 int acpi_lid_open(void)
 354 {
 355         if (!lid_device)
 356                 return -ENODEV;
 357
 358         return acpi_lid_evaluate_state(lid_device);
 359 }
 360 EXPORT_SYMBOL(acpi_lid_open);
 361
 362 static int acpi_lid_update_state(struct acpi_device *device)
 363 {
 364         int state;
 365
 366         state = acpi_lid_evaluate_state(device);
 367         if (state < 0)
 368                 return state;
 369
 370         return acpi_lid_notify_state(device, state);
 371 }
 372
 373 static void acpi_lid_initialize_state(struct acpi_device *device)
 374 {
 375         switch (lid_init_state) {
 376         case ACPI_BUTTON_LID_INIT_OPEN:
 377                 (void)acpi_lid_notify_state(device, 1);
 378                 break;
 379         case ACPI_BUTTON_LID_INIT_IGNORE:
 380         default:
 381                 break;
 382         }
 383 }
 384
 385 static void acpi_button_notify(struct acpi_device *device, u32 event)
 386 {
 387         struct acpi_button *button = acpi_driver_data(device);
 388         struct input_dev *input;
 389
 390         switch (event) {
 391         case ACPI_FIXED_HARDWARE_EVENT:
 392                 event = ACPI_BUTTON_NOTIFY_STATUS;
 393                 /* fall through */
 394         case ACPI_BUTTON_NOTIFY_STATUS:
 395                 input = button->input;
 396                 if (button->type == ACPI_BUTTON_TYPE_LID) {
 397                         acpi_lid_update_state(device);
 398                 } else {
 399                         int keycode;
 400
 401                         pm_wakeup_hard_event(&device->dev);
 402                         if (button->suspended)
 403                                 break;
 404
 405                         keycode = test_bit(KEY_SLEEP, input->keybit) ?
 406                                                 KEY_SLEEP : KEY_POWER;
 407                         input_report_key(input, keycode, 1);
 408                         input_sync(input);
 409                         input_report_key(input, keycode, 0);
 410                         input_sync(input);
 411
 412                         acpi_bus_generate_netlink_event(
 413                                         device->pnp.device_class,
 414                                         dev_name(&device->dev),
 415                                         event, ++button->pushed);
 416                 }
 417                 break;
 418         default:
 419                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 420                                   "Unsupported event [0x%x]\n", event));
 421                 break;
 422         }
 423 }
 424
 425 #ifdef CONFIG_PM_SLEEP
 426 static int acpi_button_suspend(struct device *dev)
 427 {
 428         struct acpi_device *device = to_acpi_device(dev);
 429         struct acpi_button *button = acpi_driver_data(device);
 430
 431         button->suspended = true;
 432         return 0;
 433 }
 434
 435 static int acpi_button_resume(struct device *dev)
 436 {
 437         struct acpi_device *device = to_acpi_device(dev);
 438         struct acpi_button *button = acpi_driver_data(device);
 439
 440         button->suspended = false;
 441         if (button->type == ACPI_BUTTON_TYPE_LID)
 442                 acpi_lid_initialize_state(device);
 443         return 0;
 444 }
 445 #endif
 446
 447 static int acpi_button_add(struct acpi_device *device)
 448 {
 449         struct acpi_button *button;
 450         struct input_dev *input;
 451         const char *hid = acpi_device_hid(device);
 452         char *name, *class;
 453         int error;
 454
 455         button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);
 456         if (!button)
 457                 return -ENOMEM;
 458
 459         device->driver_data = button;
 460
 461         button->input = input = input_allocate_device();
 462         if (!input) {
 463                 error = -ENOMEM;
 464                 goto err_free_button;
 465         }
 466
 467         name = acpi_device_name(device);
 468         class = acpi_device_class(device);
 469
 470         if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
 471             !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {
 472                 button->type = ACPI_BUTTON_TYPE_POWER;
 473                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
 474                 sprintf(class, "%s/%s",
 475                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);
 476         } else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
 477                    !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {
 478                 button->type = ACPI_BUTTON_TYPE_SLEEP;
 479                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
 480                 sprintf(class, "%s/%s",
 481                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);
 482         } else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {
 483                 button->type = ACPI_BUTTON_TYPE_LID;
 484                 strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
 485                 sprintf(class, "%s/%s",
 486                         ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);
 487                 button->last_state = !!acpi_lid_evaluate_state(device);
 488                 button->last_time = ktime_get();
 489         } else {
 490                 printk(KERN_ERR PREFIX "Unsupported hid [%s]\n", hid);
 491                 error = -ENODEV;
 492                 goto err_free_input;
 493         }
 494
 495         error = acpi_button_add_fs(device);
 496         if (error)
 497                 goto err_free_input;
 498
 499         snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);
 500
 501         input->name = name;
 502         input->phys = button->phys;
 503         input->id.bustype = BUS_HOST;
 504         input->id.product = button->type;
 505         input->dev.parent = &device->dev;
 506
 507         switch (button->type) {
 508         case ACPI_BUTTON_TYPE_POWER:
 509                 input_set_capability(input, EV_KEY, KEY_POWER);
 510                 break;
 511
 512         case ACPI_BUTTON_TYPE_SLEEP:
 513                 input_set_capability(input, EV_KEY, KEY_SLEEP);
 514                 break;
 515
 516         case ACPI_BUTTON_TYPE_LID:
 517                 input_set_capability(input, EV_SW, SW_LID);
 518                 break;
 519         }
 520
 521         error = input_register_device(input);
 522         if (error)
 523                 goto err_remove_fs;
 524         if (button->type == ACPI_BUTTON_TYPE_LID) {
 525                 acpi_lid_initialize_state(device);
 526                 /*
 527                  * This assumes there's only one lid device, or if there are
 528                  * more we only care about the last one...
 529                  */
 530                 lid_device = device;
 531         }
 532
 533         device_init_wakeup(&device->dev, true);
 534         printk(KERN_INFO PREFIX "%s [%s]\n", name, acpi_device_bid(device));
 535         return 0;
 536
 537  err_remove_fs:
 538         acpi_button_remove_fs(device);
 539  err_free_input:
 540         input_free_device(input);
 541  err_free_button:
 542         kfree(button);
 543         return error;
 544 }
 545
 546 static int acpi_button_remove(struct acpi_device *device)
 547 {
 548         struct acpi_button *button = acpi_driver_data(device);
 549
 550         acpi_button_remove_fs(device);
 551         input_unregister_device(button->input);
 552         kfree(button);
 553         return 0;
 554 }
 555
 556 static int param_set_lid_init_state(const char *val, struct kernel_param *kp)
 557 {
 558         int result = 0;
 559
 560         if (!strncmp(val, "open", sizeof("open") - 1)) {
 561                 lid_init_state = ACPI_BUTTON_LID_INIT_OPEN;
 562                 pr_info("Notify initial lid state as open\n");
 563         } else if (!strncmp(val, "ignore", sizeof("ignore") - 1)) {
 564                 lid_init_state = ACPI_BUTTON_LID_INIT_IGNORE;
 565                 pr_info("Do not notify initial lid state\n");
 566         } else
 567                 result = -EINVAL;
 568         return result;
 569 }
 570
 571 static int param_get_lid_init_state(char *buffer, struct kernel_param *kp)
 572 {
 573         switch (lid_init_state) {
 574         case ACPI_BUTTON_LID_INIT_OPEN:
 575                 return sprintf(buffer, "open");
 576         case ACPI_BUTTON_LID_INIT_IGNORE:
 577                 return sprintf(buffer, "ignore");
 578         default:
 579                 return sprintf(buffer, "invalid");
 580         }
 581         return 0;
 582 }
 583
 584 module_param_call(lid_init_state,
 585                   param_set_lid_init_state, param_get_lid_init_state,
 586                   NULL, 0644);
 587 MODULE_PARM_DESC(lid_init_state, "Behavior for reporting LID initial state");
 588
 589 module_acpi_driver(acpi_button_driver);