drivers/acpi/sleep.c

   1 /*
   2  * sleep.c - ACPI sleep support.
   3  *
   4  * Copyright (c) 2005 Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
   5  * Copyright (c) 2004 David Shaohua Li <shaohua.li@intel.com>
   6  * Copyright (c) 2000-2003 Patrick Mochel
   7  * Copyright (c) 2003 Open Source Development Lab
   8  *
   9  * This file is released under the GPLv2.
  10  *
  11  */
  12
  13 #include <linux/delay.h>
  14 #include <linux/irq.h>
  15 #include <linux/dmi.h>
  16 #include <linux/device.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/suspend.h>
  19 #include <linux/reboot.h>
  20 #include <linux/acpi.h>
  21 #include <linux/module.h>
  22 #include <linux/syscore_ops.h>
  23 #include <asm/io.h>
  24 #include <trace/events/power.h>
  25
  26 #include "internal.h"
  27 #include "sleep.h"
  28
  29 /*
  30  * Some HW-full platforms do not have _S5, so they may need
  31  * to leverage efi power off for a shutdown.
  32  */
  33 bool acpi_no_s5;
  34 static u8 sleep_states[ACPI_S_STATE_COUNT];
  35
  36 static void acpi_sleep_tts_switch(u32 acpi_state)
  37 {
  38         acpi_status status;
  39
  40         status = acpi_execute_simple_method(NULL, "\\_TTS", acpi_state);
  41         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  42                 /*
  43                  * OS can't evaluate the _TTS object correctly. Some warning
  44                  * message will be printed. But it won't break anything.
  45                  */
  46                 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
  47         }
  48 }
  49
  50 static int tts_notify_reboot(struct notifier_block *this,
  51                         unsigned long code, void *x)
  52 {
  53         acpi_sleep_tts_switch(ACPI_STATE_S5);
  54         return NOTIFY_DONE;
  55 }
  56
  57 static struct notifier_block tts_notifier = {
  58         .notifier_call  = tts_notify_reboot,
  59         .next           = NULL,
  60         .priority       = 0,
  61 };
  62
  63 static int acpi_sleep_prepare(u32 acpi_state)
  64 {
  65 #ifdef CONFIG_ACPI_SLEEP
  66         /* do we have a wakeup address for S2 and S3? */
  67         if (acpi_state == ACPI_STATE_S3) {
  68                 if (!acpi_wakeup_address)
  69                         return -EFAULT;
  70                 acpi_set_waking_vector(acpi_wakeup_address);
  71
  72         }
  73         ACPI_FLUSH_CPU_CACHE();
  74 #endif
  75         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
  76                 acpi_state);
  77         acpi_enable_wakeup_devices(acpi_state);
  78         acpi_enter_sleep_state_prep(acpi_state);
  79         return 0;
  80 }
  81
  82 static bool acpi_sleep_state_supported(u8 sleep_state)
  83 {
  84         acpi_status status;
  85         u8 type_a, type_b;
  86
  87         status = acpi_get_sleep_type_data(sleep_state, &type_a, &type_b);
  88         return ACPI_SUCCESS(status) && (!acpi_gbl_reduced_hardware
  89                 || (acpi_gbl_FADT.sleep_control.address
  90                         && acpi_gbl_FADT.sleep_status.address));
  91 }
  92
  93 #ifdef CONFIG_ACPI_SLEEP
  94 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
  95
  96 u32 acpi_target_system_state(void)
  97 {
  98         return acpi_target_sleep_state;
  99 }
 100 EXPORT_SYMBOL_GPL(acpi_target_system_state);
 101
 102 static bool pwr_btn_event_pending;
 103
 104 /*
 105  * The ACPI specification wants us to save NVS memory regions during hibernation
 106  * and to restore them during the subsequent resume.  Windows does that also for
 107  * suspend to RAM.  However, it is known that this mechanism does not work on
 108  * all machines, so we allow the user to disable it with the help of the
 109  * 'acpi_sleep=nonvs' kernel command line option.
 110  */
 111 static bool nvs_nosave;
 112
 113 void __init acpi_nvs_nosave(void)
 114 {
 115         nvs_nosave = true;
 116 }
 117
 118 /*
 119  * The ACPI specification wants us to save NVS memory regions during hibernation
 120  * but says nothing about saving NVS during S3.  Not all versions of Windows
 121  * save NVS on S3 suspend either, and it is clear that not all systems need
 122  * NVS to be saved at S3 time.  To improve suspend/resume time, allow the
 123  * user to disable saving NVS on S3 if their system does not require it, but
 124  * continue to save/restore NVS for S4 as specified.
 125  */
 126 static bool nvs_nosave_s3;
 127
 128 void __init acpi_nvs_nosave_s3(void)
 129 {
 130         nvs_nosave_s3 = true;
 131 }
 132
 133 static int __init init_nvs_save_s3(const struct dmi_system_id *d)
 134 {
 135         nvs_nosave_s3 = false;
 136         return 0;
 137 }
 138
 139 /*
 140  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 141  * user to request that behavior by using the 'acpi_old_suspend_ordering'
 142  * kernel command line option that causes the following variable to be set.
 143  */
 144 static bool old_suspend_ordering;
 145
 146 void __init acpi_old_suspend_ordering(void)
 147 {
 148         old_suspend_ordering = true;
 149 }
 150
 151 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
 152 {
 153         acpi_old_suspend_ordering();
 154         return 0;
 155 }
 156
 157 static int __init init_nvs_nosave(const struct dmi_system_id *d)
 158 {
 159         acpi_nvs_nosave();
 160         return 0;
 161 }
 162
 163 static bool acpi_sleep_no_lps0;
 164
 165 static int __init init_no_lps0(const struct dmi_system_id *d)
 166 {
 167         acpi_sleep_no_lps0 = true;
 168         return 0;
 169 }
 170
 171 static const struct dmi_system_id acpisleep_dmi_table[] __initconst = {
 172         {
 173         .callback = init_old_suspend_ordering,
 174         .ident = "Abit KN9 (nForce4 variant)",
 175         .matches = {
 176                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
 177                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
 178                 },
 179         },
 180         {
 181         .callback = init_old_suspend_ordering,
 182         .ident = "HP xw4600 Workstation",
 183         .matches = {
 184                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 185                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 186                 },
 187         },
 188         {
 189         .callback = init_old_suspend_ordering,
 190         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
 191         .matches = {
 192                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
 193                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
 194                 },
 195         },
 196         {
 197         .callback = init_old_suspend_ordering,
 198         .ident = "Panasonic CF51-2L",
 199         .matches = {
 200                 DMI_MATCH(DMI_BOARD_VENDOR,
 201                                 "Matsushita Electric Industrial Co.,Ltd."),
 202                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
 203                 },
 204         },
 205         {
 206         .callback = init_nvs_nosave,
 207         .ident = "Sony Vaio VGN-FW41E_H",
 208         .matches = {
 209                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 210                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW41E_H"),
 211                 },
 212         },
 213         {
 214         .callback = init_nvs_nosave,
 215         .ident = "Sony Vaio VGN-FW21E",
 216         .matches = {
 217                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 218                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21E"),
 219                 },
 220         },
 221         {
 222         .callback = init_nvs_nosave,
 223         .ident = "Sony Vaio VGN-FW21M",
 224         .matches = {
 225                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 226                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW21M"),
 227                 },
 228         },
 229         {
 230         .callback = init_nvs_nosave,
 231         .ident = "Sony Vaio VPCEB17FX",
 232         .matches = {
 233                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 234                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB17FX"),
 235                 },
 236         },
 237         {
 238         .callback = init_nvs_nosave,
 239         .ident = "Sony Vaio VGN-SR11M",
 240         .matches = {
 241                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 242                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR11M"),
 243                 },
 244         },
 245         {
 246         .callback = init_nvs_nosave,
 247         .ident = "Everex StepNote Series",
 248         .matches = {
 249                 DMI_MATCH(DMI_SYS_VENDOR, "Everex Systems, Inc."),
 250                 DMI_MATCH(DMI_PRODUCT_NAME, "Everex StepNote Series"),
 251                 },
 252         },
 253         {
 254         .callback = init_nvs_nosave,
 255         .ident = "Sony Vaio VPCEB1Z1E",
 256         .matches = {
 257                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 258                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1Z1E"),
 259                 },
 260         },
 261         {
 262         .callback = init_nvs_nosave,
 263         .ident = "Sony Vaio VGN-NW130D",
 264         .matches = {
 265                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 266                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-NW130D"),
 267                 },
 268         },
 269         {
 270         .callback = init_nvs_nosave,
 271         .ident = "Sony Vaio VPCCW29FX",
 272         .matches = {
 273                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 274                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCCW29FX"),
 275                 },
 276         },
 277         {
 278         .callback = init_nvs_nosave,
 279         .ident = "Averatec AV1020-ED2",
 280         .matches = {
 281                 DMI_MATCH(DMI_SYS_VENDOR, "AVERATEC"),
 282                 DMI_MATCH(DMI_PRODUCT_NAME, "1000 Series"),
 283                 },
 284         },
 285         {
 286         .callback = init_old_suspend_ordering,
 287         .ident = "Asus A8N-SLI DELUXE",
 288         .matches = {
 289                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 290                 DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI DELUXE"),
 291                 },
 292         },
 293         {
 294         .callback = init_old_suspend_ordering,
 295         .ident = "Asus A8N-SLI Premium",
 296         .matches = {
 297                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
 298                 DMI_MATCH(DMI_BOARD_NAME, "A8N-SLI Premium"),
 299                 },
 300         },
 301         {
 302         .callback = init_nvs_nosave,
 303         .ident = "Sony Vaio VGN-SR26GN_P",
 304         .matches = {
 305                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 306                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-SR26GN_P"),
 307                 },
 308         },
 309         {
 310         .callback = init_nvs_nosave,
 311         .ident = "Sony Vaio VPCEB1S1E",
 312         .matches = {
 313                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 314                 DMI_MATCH(DMI_PRODUCT_NAME, "VPCEB1S1E"),
 315                 },
 316         },
 317         {
 318         .callback = init_nvs_nosave,
 319         .ident = "Sony Vaio VGN-FW520F",
 320         .matches = {
 321                 DMI_MATCH(DMI_SYS_VENDOR, "Sony Corporation"),
 322                 DMI_MATCH(DMI_PRODUCT_NAME, "VGN-FW520F"),
 323                 },
 324         },
 325         {
 326         .callback = init_nvs_nosave,
 327         .ident = "Asus K54C",
 328         .matches = {
 329                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 330                 DMI_MATCH(DMI_PRODUCT_NAME, "K54C"),
 331                 },
 332         },
 333         {
 334         .callback = init_nvs_nosave,
 335         .ident = "Asus K54HR",
 336         .matches = {
 337                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 338                 DMI_MATCH(DMI_PRODUCT_NAME, "K54HR"),
 339                 },
 340         },
 341         {
 342         .callback = init_nvs_save_s3,
 343         .ident = "Asus 1025C",
 344         .matches = {
 345                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
 346                 DMI_MATCH(DMI_PRODUCT_NAME, "1025C"),
 347                 },
 348         },
 349         /*
 350          * https://bugzilla.kernel.org/show_bug.cgi?id=189431
 351          * Lenovo G50-45 is a platform later than 2012, but needs nvs memory
 352          * saving during S3.
 353          */
 354         {
 355         .callback = init_nvs_save_s3,
 356         .ident = "Lenovo G50-45",
 357         .matches = {
 358                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 359                 DMI_MATCH(DMI_PRODUCT_NAME, "80E3"),
 360                 },
 361         },
 362         /*
 363          * https://bugzilla.kernel.org/show_bug.cgi?id=196907
 364          * Some Dell XPS13 9360 cannot do suspend-to-idle using the Low Power
 365          * S0 Idle firmware interface.
 366          */
 367         {
 368         .callback = init_no_lps0,
 369         .ident = "Dell XPS13 9360",
 370         .matches = {
 371                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 372                 DMI_MATCH(DMI_PRODUCT_NAME, "XPS 13 9360"),
 373                 },
 374         },
 375         /*
 376          * ThinkPad X1 Tablet(2016) cannot do suspend-to-idle using
 377          * the Low Power S0 Idle firmware interface (see
 378          * https://bugzilla.kernel.org/show_bug.cgi?id=199057).
 379          */
 380         {
 381         .callback = init_no_lps0,
 382         .ident = "ThinkPad X1 Tablet(2016)",
 383         .matches = {
 384                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 385                 DMI_MATCH(DMI_PRODUCT_NAME, "20GGA00L00"),
 386                 },
 387         },
 388         {},
 389 };
 390
 391 static bool ignore_blacklist;
 392
 393 void __init acpi_sleep_no_blacklist(void)
 394 {
 395         ignore_blacklist = true;
 396 }
 397
 398 static void __init acpi_sleep_dmi_check(void)
 399 {
 400         if (ignore_blacklist)
 401                 return;
 402
 403         if (dmi_get_bios_year() >= 2012)
 404                 acpi_nvs_nosave_s3();
 405
 406         dmi_check_system(acpisleep_dmi_table);
 407 }
 408
 409 /**
 410  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
 411  */
 412 static int acpi_pm_freeze(void)
 413 {
 414         acpi_disable_all_gpes();
 415         acpi_os_wait_events_complete();
 416         acpi_ec_block_transactions();
 417         return 0;
 418 }
 419
 420 /**
 421  * acpi_pre_suspend - Enable wakeup devices, "freeze" EC and save NVS.
 422  */
 423 static int acpi_pm_pre_suspend(void)
 424 {
 425         acpi_pm_freeze();
 426         return suspend_nvs_save();
 427 }
 428
 429 /**
 430  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
 431  *
 432  *      If necessary, set the firmware waking vector and do arch-specific
 433  *      nastiness to get the wakeup code to the waking vector.
 434  */
 435 static int __acpi_pm_prepare(void)
 436 {
 437         int error = acpi_sleep_prepare(acpi_target_sleep_state);
 438         if (error)
 439                 acpi_target_sleep_state = ACPI_STATE_S0;
 440
 441         return error;
 442 }
 443
 444 /**
 445  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
 446  *              state and disable the GPEs.
 447  */
 448 static int acpi_pm_prepare(void)
 449 {
 450         int error = __acpi_pm_prepare();
 451         if (!error)
 452                 error = acpi_pm_pre_suspend();
 453
 454         return error;
 455 }
 456
 457 static int find_powerf_dev(struct device *dev, void *data)
 458 {
 459         struct acpi_device *device = to_acpi_device(dev);
 460         const char *hid = acpi_device_hid(device);
 461
 462         return !strcmp(hid, ACPI_BUTTON_HID_POWERF);
 463 }
 464
 465 /**
 466  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
 467  *
 468  *      This is called after we wake back up (or if entering the sleep state
 469  *      failed).
 470  */
 471 static void acpi_pm_finish(void)
 472 {
 473         struct device *pwr_btn_dev;
 474         u32 acpi_state = acpi_target_sleep_state;
 475
 476         acpi_ec_unblock_transactions();
 477         suspend_nvs_free();
 478
 479         if (acpi_state == ACPI_STATE_S0)
 480                 return;
 481
 482         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
 483                 acpi_state);
 484         acpi_disable_wakeup_devices(acpi_state);
 485         acpi_leave_sleep_state(acpi_state);
 486
 487         /* reset firmware waking vector */
 488         acpi_set_waking_vector(0);
 489
 490         acpi_target_sleep_state = ACPI_STATE_S0;
 491
 492         acpi_resume_power_resources();
 493
 494         /* If we were woken with the fixed power button, provide a small
 495          * hint to userspace in the form of a wakeup event on the fixed power
 496          * button device (if it can be found).
 497          *
 498          * We delay the event generation til now, as the PM layer requires
 499          * timekeeping to be running before we generate events. */
 500         if (!pwr_btn_event_pending)
 501                 return;
 502
 503         pwr_btn_event_pending = false;
 504         pwr_btn_dev = bus_find_device(&acpi_bus_type, NULL, NULL,
 505                                       find_powerf_dev);
 506         if (pwr_btn_dev) {
 507                 pm_wakeup_event(pwr_btn_dev, 0);
 508                 put_device(pwr_btn_dev);
 509         }
 510 }
 511
 512 /**
 513  * acpi_pm_start - Start system PM transition.
 514  */
 515 static void acpi_pm_start(u32 acpi_state)
 516 {
 517         acpi_target_sleep_state = acpi_state;
 518         acpi_sleep_tts_switch(acpi_target_sleep_state);
 519         acpi_scan_lock_acquire();
 520 }
 521
 522 /**
 523  * acpi_pm_end - Finish up system PM transition.
 524  */
 525 static void acpi_pm_end(void)
 526 {
 527         acpi_turn_off_unused_power_resources();
 528         acpi_scan_lock_release();
 529         /*
 530          * This is necessary in case acpi_pm_finish() is not called during a
 531          * failing transition to a sleep state.
 532          */
 533         acpi_target_sleep_state = ACPI_STATE_S0;
 534         acpi_sleep_tts_switch(acpi_target_sleep_state);
 535 }
 536 #else /* !CONFIG_ACPI_SLEEP */
 537 #define acpi_target_sleep_state ACPI_STATE_S0
 538 #define acpi_sleep_no_lps0      (false)
 539 static inline void acpi_sleep_dmi_check(void) {}
 540 #endif /* CONFIG_ACPI_SLEEP */
 541
 542 #ifdef CONFIG_SUSPEND
 543 static u32 acpi_suspend_states[] = {
 544         [PM_SUSPEND_ON] = ACPI_STATE_S0,
 545         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
 546         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
 547         [PM_SUSPEND_MAX] = ACPI_STATE_S5
 548 };
 549
 550 /**
 551  *      acpi_suspend_begin - Set the target system sleep state to the state
 552  *              associated with given @pm_state, if supported.
 553  */
 554 static int acpi_suspend_begin(suspend_state_t pm_state)
 555 {
 556         u32 acpi_state = acpi_suspend_states[pm_state];
 557         int error;
 558
 559         error = (nvs_nosave || nvs_nosave_s3) ? 0 : suspend_nvs_alloc();
 560         if (error)
 561                 return error;
 562
 563         if (!sleep_states[acpi_state]) {
 564                 pr_err("ACPI does not support sleep state S%u\n", acpi_state);
 565                 return -ENOSYS;
 566         }
 567         if (acpi_state > ACPI_STATE_S1)
 568                 pm_set_suspend_via_firmware();
 569
 570         acpi_pm_start(acpi_state);
 571         return 0;
 572 }
 573
 574 /**
 575  *      acpi_suspend_enter - Actually enter a sleep state.
 576  *      @pm_state: ignored
 577  *
 578  *      Flush caches and go to sleep. For STR we have to call arch-specific
 579  *      assembly, which in turn call acpi_enter_sleep_state().
 580  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
 581  */
 582 static int acpi_suspend_enter(suspend_state_t pm_state)
 583 {
 584         acpi_status status = AE_OK;
 585         u32 acpi_state = acpi_target_sleep_state;
 586         int error;
 587
 588         ACPI_FLUSH_CPU_CACHE();
 589
 590         trace_suspend_resume(TPS("acpi_suspend"), acpi_state, true);
 591         switch (acpi_state) {
 592         case ACPI_STATE_S1:
 593                 barrier();
 594                 status = acpi_enter_sleep_state(acpi_state);
 595                 break;
 596
 597         case ACPI_STATE_S3:
 598                 if (!acpi_suspend_lowlevel)
 599                         return -ENOSYS;
 600                 error = acpi_suspend_lowlevel();
 601                 if (error)
 602                         return error;
 603                 pr_info(PREFIX "Low-level resume complete\n");
 604                 pm_set_resume_via_firmware();
 605                 break;
 606         }
 607         trace_suspend_resume(TPS("acpi_suspend"), acpi_state, false);
 608
 609         /* This violates the spec but is required for bug compatibility. */
 610         acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
 611
 612         /* Reprogram control registers */
 613         acpi_leave_sleep_state_prep(acpi_state);
 614
 615         /* ACPI 3.0 specs (P62) says that it's the responsibility
 616          * of the OSPM to clear the status bit [ implying that the
 617          * POWER_BUTTON event should not reach userspace ]
 618          *
 619          * However, we do generate a small hint for userspace in the form of
 620          * a wakeup event. We flag this condition for now and generate the
 621          * event later, as we're currently too early in resume to be able to
 622          * generate wakeup events.
 623          */
 624         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3)) {
 625                 acpi_event_status pwr_btn_status = ACPI_EVENT_FLAG_DISABLED;
 626
 627                 acpi_get_event_status(ACPI_EVENT_POWER_BUTTON, &pwr_btn_status);
 628
 629                 if (pwr_btn_status & ACPI_EVENT_FLAG_STATUS_SET) {
 630                         acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
 631                         /* Flag for later */
 632                         pwr_btn_event_pending = true;
 633                 }
 634         }
 635
 636         /*
 637          * Disable and clear GPE status before interrupt is enabled. Some GPEs
 638          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
 639          * acpi_leave_sleep_state will reenable specific GPEs later
 640          */
 641         acpi_disable_all_gpes();
 642         /* Allow EC transactions to happen. */
 643         acpi_ec_unblock_transactions();
 644
 645         suspend_nvs_restore();
 646
 647         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 648 }
 649
 650 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 651 {
 652         u32 acpi_state;
 653
 654         switch (pm_state) {
 655         case PM_SUSPEND_ON:
 656         case PM_SUSPEND_STANDBY:
 657         case PM_SUSPEND_MEM:
 658                 acpi_state = acpi_suspend_states[pm_state];
 659
 660                 return sleep_states[acpi_state];
 661         default:
 662                 return 0;
 663         }
 664 }
 665
 666 static const struct platform_suspend_ops acpi_suspend_ops = {
 667         .valid = acpi_suspend_state_valid,
 668         .begin = acpi_suspend_begin,
 669         .prepare_late = acpi_pm_prepare,
 670         .enter = acpi_suspend_enter,
 671         .wake = acpi_pm_finish,
 672         .end = acpi_pm_end,
 673 };
 674
 675 /**
 676  *      acpi_suspend_begin_old - Set the target system sleep state to the
 677  *              state associated with given @pm_state, if supported, and
 678  *              execute the _PTS control method.  This function is used if the
 679  *              pre-ACPI 2.0 suspend ordering has been requested.
 680  */
 681 static int acpi_suspend_begin_old(suspend_state_t pm_state)
 682 {
 683         int error = acpi_suspend_begin(pm_state);
 684         if (!error)
 685                 error = __acpi_pm_prepare();
 686
 687         return error;
 688 }
 689
 690 /*
 691  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 692  * been requested.
 693  */
 694 static const struct platform_suspend_ops acpi_suspend_ops_old = {
 695         .valid = acpi_suspend_state_valid,
 696         .begin = acpi_suspend_begin_old,
 697         .prepare_late = acpi_pm_pre_suspend,
 698         .enter = acpi_suspend_enter,
 699         .wake = acpi_pm_finish,
 700         .end = acpi_pm_end,
 701         .recover = acpi_pm_finish,
 702 };
 703
 704 static bool s2idle_in_progress;
 705 static bool s2idle_wakeup;
 706
 707 /*
 708  * On platforms supporting the Low Power S0 Idle interface there is an ACPI
 709  * device object with the PNP0D80 compatible device ID (System Power Management
 710  * Controller) and a specific _DSM method under it.  That method, if present,
 711  * can be used to indicate to the platform that the OS is transitioning into a
 712  * low-power state in which certain types of activity are not desirable or that
 713  * it is leaving such a state, which allows the platform to adjust its operation
 714  * mode accordingly.
 715  */
 716 static const struct acpi_device_id lps0_device_ids[] = {
 717         {"PNP0D80", },
 718         {"", },
 719 };
 720
 721 #define ACPI_LPS0_DSM_UUID      "c4eb40a0-6cd2-11e2-bcfd-0800200c9a66"
 722
 723 #define ACPI_LPS0_GET_DEVICE_CONSTRAINTS        1
 724 #define ACPI_LPS0_SCREEN_OFF    3
 725 #define ACPI_LPS0_SCREEN_ON     4
 726 #define ACPI_LPS0_ENTRY         5
 727 #define ACPI_LPS0_EXIT          6
 728
 729 static acpi_handle lps0_device_handle;
 730 static guid_t lps0_dsm_guid;
 731 static char lps0_dsm_func_mask;
 732
 733 /* Device constraint entry structure */
 734 struct lpi_device_info {
 735         char *name;
 736         int enabled;
 737         union acpi_object *package;
 738 };
 739
 740 /* Constraint package structure */
 741 struct lpi_device_constraint {
 742         int uid;
 743         int min_dstate;
 744         int function_states;
 745 };
 746
 747 struct lpi_constraints {
 748         acpi_handle handle;
 749         int min_dstate;
 750 };
 751
 752 static struct lpi_constraints *lpi_constraints_table;
 753 static int lpi_constraints_table_size;
 754
 755 static void lpi_device_get_constraints(void)
 756 {
 757         union acpi_object *out_obj;
 758         int i;
 759
 760         out_obj = acpi_evaluate_dsm_typed(lps0_device_handle, &lps0_dsm_guid,
 761                                           1, ACPI_LPS0_GET_DEVICE_CONSTRAINTS,
 762                                           NULL, ACPI_TYPE_PACKAGE);
 763
 764         acpi_handle_debug(lps0_device_handle, "_DSM function 1 eval %s\n",
 765                           out_obj ? "successful" : "failed");
 766
 767         if (!out_obj)
 768                 return;
 769
 770         lpi_constraints_table = kcalloc(out_obj->package.count,
 771                                         sizeof(*lpi_constraints_table),
 772                                         GFP_KERNEL);
 773         if (!lpi_constraints_table)
 774                 goto free_acpi_buffer;
 775
 776         acpi_handle_debug(lps0_device_handle, "LPI: constraints list begin:\n");
 777
 778         for (i = 0; i < out_obj->package.count; i++) {
 779                 struct lpi_constraints *constraint;
 780                 acpi_status status;
 781                 union acpi_object *package = &out_obj->package.elements[i];
 782                 struct lpi_device_info info = { };
 783                 int package_count = 0, j;
 784
 785                 if (!package)
 786                         continue;
 787
 788                 for (j = 0; j < package->package.count; ++j) {
 789                         union acpi_object *element =
 790                                         &(package->package.elements[j]);
 791
 792                         switch (element->type) {
 793                         case ACPI_TYPE_INTEGER:
 794                                 info.enabled = element->integer.value;
 795                                 break;
 796                         case ACPI_TYPE_STRING:
 797                                 info.name = element->string.pointer;
 798                                 break;
 799                         case ACPI_TYPE_PACKAGE:
 800                                 package_count = element->package.count;
 801                                 info.package = element->package.elements;
 802                                 break;
 803                         }
 804                 }
 805
 806                 if (!info.enabled || !info.package || !info.name)
 807                         continue;
 808
 809                 constraint = &lpi_constraints_table[lpi_constraints_table_size];
 810
 811                 status = acpi_get_handle(NULL, info.name, &constraint->handle);
 812                 if (ACPI_FAILURE(status))
 813                         continue;
 814
 815                 acpi_handle_debug(lps0_device_handle,
 816                                   "index:%d Name:%s\n", i, info.name);
 817
 818                 constraint->min_dstate = -1;
 819
 820                 for (j = 0; j < package_count; ++j) {
 821                         union acpi_object *info_obj = &info.package[j];
 822                         union acpi_object *cnstr_pkg;
 823                         union acpi_object *obj;
 824                         struct lpi_device_constraint dev_info;
 825
 826                         switch (info_obj->type) {
 827                         case ACPI_TYPE_INTEGER:
 828                                 /* version */
 829                                 break;
 830                         case ACPI_TYPE_PACKAGE:
 831                                 if (info_obj->package.count < 2)
 832                                         break;
 833
 834                                 cnstr_pkg = info_obj->package.elements;
 835                                 obj = &cnstr_pkg[0];
 836                                 dev_info.uid = obj->integer.value;
 837                                 obj = &cnstr_pkg[1];
 838                                 dev_info.min_dstate = obj->integer.value;
 839
 840                                 acpi_handle_debug(lps0_device_handle,
 841                                         "uid:%d min_dstate:%s\n",
 842                                         dev_info.uid,
 843                                         acpi_power_state_string(dev_info.min_dstate));
 844
 845                                 constraint->min_dstate = dev_info.min_dstate;
 846                                 break;
 847                         }
 848                 }
 849
 850                 if (constraint->min_dstate < 0) {
 851                         acpi_handle_debug(lps0_device_handle,
 852                                           "Incomplete constraint defined\n");
 853                         continue;
 854                 }
 855
 856                 lpi_constraints_table_size++;
 857         }
 858
 859         acpi_handle_debug(lps0_device_handle, "LPI: constraints list end\n");
 860
 861 free_acpi_buffer:
 862         ACPI_FREE(out_obj);
 863 }
 864
 865 static void lpi_check_constraints(void)
 866 {
 867         int i;
 868
 869         for (i = 0; i < lpi_constraints_table_size; ++i) {
 870                 acpi_handle handle = lpi_constraints_table[i].handle;
 871                 struct acpi_device *adev;
 872
 873                 if (!handle || acpi_bus_get_device(handle, &adev))
 874                         continue;
 875
 876                 acpi_handle_debug(handle,
 877                         "LPI: required min power state:%s current power state:%s\n",
 878                         acpi_power_state_string(lpi_constraints_table[i].min_dstate),
 879                         acpi_power_state_string(adev->power.state));
 880
 881                 if (!adev->flags.power_manageable) {
 882                         acpi_handle_info(handle, "LPI: Device not power manageable\n");
 883                         lpi_constraints_table[i].handle = NULL;
 884                         continue;
 885                 }
 886
 887                 if (adev->power.state < lpi_constraints_table[i].min_dstate)
 888                         acpi_handle_info(handle,
 889                                 "LPI: Constraint not met; min power state:%s current power state:%s\n",
 890                                 acpi_power_state_string(lpi_constraints_table[i].min_dstate),
 891                                 acpi_power_state_string(adev->power.state));
 892         }
 893 }
 894
 895 static void acpi_sleep_run_lps0_dsm(unsigned int func)
 896 {
 897         union acpi_object *out_obj;
 898
 899         if (!(lps0_dsm_func_mask & (1 << func)))
 900                 return;
 901
 902         out_obj = acpi_evaluate_dsm(lps0_device_handle, &lps0_dsm_guid, 1, func, NULL);
 903         ACPI_FREE(out_obj);
 904
 905         acpi_handle_debug(lps0_device_handle, "_DSM function %u evaluation %s\n",
 906                           func, out_obj ? "successful" : "failed");
 907 }
 908
 909 static int lps0_device_attach(struct acpi_device *adev,
 910                               const struct acpi_device_id *not_used)
 911 {
 912         union acpi_object *out_obj;
 913
 914         if (lps0_device_handle)
 915                 return 0;
 916
 917         if (acpi_sleep_no_lps0) {
 918                 acpi_handle_info(adev->handle,
 919                                  "Low Power S0 Idle interface disabled\n");
 920                 return 0;
 921         }
 922
 923         if (!(acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0))
 924                 return 0;
 925
 926         guid_parse(ACPI_LPS0_DSM_UUID, &lps0_dsm_guid);
 927         /* Check if the _DSM is present and as expected. */
 928         out_obj = acpi_evaluate_dsm(adev->handle, &lps0_dsm_guid, 1, 0, NULL);
 929         if (out_obj && out_obj->type == ACPI_TYPE_BUFFER) {
 930                 char bitmask = *(char *)out_obj->buffer.pointer;
 931
 932                 lps0_dsm_func_mask = bitmask;
 933                 lps0_device_handle = adev->handle;
 934                 /*
 935                  * Use suspend-to-idle by default if the default
 936                  * suspend mode was not set from the command line.
 937                  */
 938                 if (mem_sleep_default > PM_SUSPEND_MEM)
 939                         mem_sleep_current = PM_SUSPEND_TO_IDLE;
 940
 941                 acpi_handle_debug(adev->handle, "_DSM function mask: 0x%x\n",
 942                                   bitmask);
 943
 944                 acpi_ec_mark_gpe_for_wake();
 945         } else {
 946                 acpi_handle_debug(adev->handle,
 947                                   "_DSM function 0 evaluation failed\n");
 948         }
 949         ACPI_FREE(out_obj);
 950
 951         lpi_device_get_constraints();
 952
 953         return 0;
 954 }
 955
 956 static struct acpi_scan_handler lps0_handler = {
 957         .ids = lps0_device_ids,
 958         .attach = lps0_device_attach,
 959 };
 960
 961 static int acpi_s2idle_begin(void)
 962 {
 963         acpi_scan_lock_acquire();
 964         s2idle_in_progress = true;
 965         return 0;
 966 }
 967
 968 static int acpi_s2idle_prepare(void)
 969 {
 970         if (lps0_device_handle) {
 971                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_OFF);
 972                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_ENTRY);
 973
 974                 acpi_ec_set_gpe_wake_mask(ACPI_GPE_ENABLE);
 975         }
 976
 977         if (acpi_sci_irq_valid())
 978                 enable_irq_wake(acpi_sci_irq);
 979
 980         /* Change the configuration of GPEs to avoid spurious wakeup. */
 981         acpi_enable_all_wakeup_gpes();
 982         acpi_os_wait_events_complete();
 983         return 0;
 984 }
 985
 986 static void acpi_s2idle_wake(void)
 987 {
 988         if (!lps0_device_handle)
 989                 return;
 990
 991         if (pm_debug_messages_on)
 992                 lpi_check_constraints();
 993
 994         /*
 995          * If IRQD_WAKEUP_ARMED is not set for the SCI at this point, it means
 996          * that the SCI has triggered while suspended, so cancel the wakeup in
 997          * case it has not been a wakeup event (the GPEs will be checked later).
 998          */
 999         if (acpi_sci_irq_valid() &&
1000             !irqd_is_wakeup_armed(irq_get_irq_data(acpi_sci_irq))) {
1001                 pm_system_cancel_wakeup();
1002                 s2idle_wakeup = true;
1003                 /*
1004                  * On some platforms with the LPS0 _DSM device noirq resume
1005                  * takes too much time for EC wakeup events to survive, so look
1006                  * for them now.
1007                  */
1008                 acpi_ec_dispatch_gpe();
1009         }
1010 }
1011
1012 static void acpi_s2idle_sync(void)
1013 {
1014         /*
1015          * Process all pending events in case there are any wakeup ones.
1016          *
1017          * The EC driver uses the system workqueue and an additional special
1018          * one, so those need to be flushed too.
1019          */
1020         acpi_os_wait_events_complete(); /* synchronize SCI IRQ handling */
1021         acpi_ec_flush_work();
1022         acpi_os_wait_events_complete(); /* synchronize Notify handling */
1023         s2idle_wakeup = false;
1024 }
1025
1026 static void acpi_s2idle_restore(void)
1027 {
1028         acpi_enable_all_runtime_gpes();
1029
1030         if (acpi_sci_irq_valid())
1031                 disable_irq_wake(acpi_sci_irq);
1032
1033         if (lps0_device_handle) {
1034                 acpi_ec_set_gpe_wake_mask(ACPI_GPE_DISABLE);
1035
1036                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_EXIT);
1037                 acpi_sleep_run_lps0_dsm(ACPI_LPS0_SCREEN_ON);
1038         }
1039 }
1040
1041 static void acpi_s2idle_end(void)
1042 {
1043         s2idle_in_progress = false;
1044         acpi_scan_lock_release();
1045 }
1046
1047 static const struct platform_s2idle_ops acpi_s2idle_ops = {
1048         .begin = acpi_s2idle_begin,
1049         .prepare = acpi_s2idle_prepare,
1050         .wake = acpi_s2idle_wake,
1051         .sync = acpi_s2idle_sync,
1052         .restore = acpi_s2idle_restore,
1053         .end = acpi_s2idle_end,
1054 };
1055
1056 static void acpi_sleep_suspend_setup(void)
1057 {
1058         int i;
1059
1060         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++)
1061                 if (acpi_sleep_state_supported(i))
1062                         sleep_states[i] = 1;
1063
1064         suspend_set_ops(old_suspend_ordering ?
1065                 &acpi_suspend_ops_old : &acpi_suspend_ops);
1066
1067         acpi_scan_add_handler(&lps0_handler);
1068         s2idle_set_ops(&acpi_s2idle_ops);
1069 }
1070
1071 #else /* !CONFIG_SUSPEND */
1072 #define s2idle_in_progress      (false)
1073 #define s2idle_wakeup           (false)
1074 #define lps0_device_handle      (NULL)
1075 static inline void acpi_sleep_suspend_setup(void) {}
1076 #endif /* !CONFIG_SUSPEND */
1077
1078 bool acpi_s2idle_wakeup(void)
1079 {
1080         return s2idle_wakeup;
1081 }
1082
1083 bool acpi_sleep_no_ec_events(void)
1084 {
1085         return !s2idle_in_progress || !lps0_device_handle;
1086 }
1087
1088 #ifdef CONFIG_PM_SLEEP
1089 static u32 saved_bm_rld;
1090
1091 static int  acpi_save_bm_rld(void)
1092 {
1093         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
1094         return 0;
1095 }
1096
1097 static void  acpi_restore_bm_rld(void)
1098 {
1099         u32 resumed_bm_rld = 0;
1100
1101         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
1102         if (resumed_bm_rld == saved_bm_rld)
1103                 return;
1104
1105         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
1106 }
1107
1108 static struct syscore_ops acpi_sleep_syscore_ops = {
1109         .suspend = acpi_save_bm_rld,
1110         .resume = acpi_restore_bm_rld,
1111 };
1112
1113 static void acpi_sleep_syscore_init(void)
1114 {
1115         register_syscore_ops(&acpi_sleep_syscore_ops);
1116 }
1117 #else
1118 static inline void acpi_sleep_syscore_init(void) {}
1119 #endif /* CONFIG_PM_SLEEP */
1120
1121 #ifdef CONFIG_HIBERNATION
1122 static unsigned long s4_hardware_signature;
1123 static struct acpi_table_facs *facs;
1124 static bool nosigcheck;
1125
1126 void __init acpi_no_s4_hw_signature(void)
1127 {
1128         nosigcheck = true;
1129 }
1130
1131 static int acpi_hibernation_begin(void)
1132 {
1133         int error;
1134
1135         error = nvs_nosave ? 0 : suspend_nvs_alloc();
1136         if (!error)
1137                 acpi_pm_start(ACPI_STATE_S4);
1138
1139         return error;
1140 }
1141
1142 static int acpi_hibernation_enter(void)
1143 {
1144         acpi_status status = AE_OK;
1145
1146         ACPI_FLUSH_CPU_CACHE();
1147
1148         /* This shouldn't return.  If it returns, we have a problem */
1149         status = acpi_enter_sleep_state(ACPI_STATE_S4);
1150         /* Reprogram control registers */
1151         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
1152
1153         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
1154 }
1155
1156 static void acpi_hibernation_leave(void)
1157 {
1158         pm_set_resume_via_firmware();
1159         /*
1160          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
1161          * enable it here.
1162          */
1163         acpi_enable();
1164         /* Reprogram control registers */
1165         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
1166         /* Check the hardware signature */
1167         if (facs && s4_hardware_signature != facs->hardware_signature)
1168                 pr_crit("ACPI: Hardware changed while hibernated, success doubtful!\n");
1169         /* Restore the NVS memory area */
1170         suspend_nvs_restore();
1171         /* Allow EC transactions to happen. */
1172         acpi_ec_unblock_transactions();
1173 }
1174
1175 static void acpi_pm_thaw(void)
1176 {
1177         acpi_ec_unblock_transactions();
1178         acpi_enable_all_runtime_gpes();
1179 }
1180
1181 static const struct platform_hibernation_ops acpi_hibernation_ops = {
1182         .begin = acpi_hibernation_begin,
1183         .end = acpi_pm_end,
1184         .pre_snapshot = acpi_pm_prepare,
1185         .finish = acpi_pm_finish,
1186         .prepare = acpi_pm_prepare,
1187         .enter = acpi_hibernation_enter,
1188         .leave = acpi_hibernation_leave,
1189         .pre_restore = acpi_pm_freeze,
1190         .restore_cleanup = acpi_pm_thaw,
1191 };
1192
1193 /**
1194  *      acpi_hibernation_begin_old - Set the target system sleep state to
1195  *              ACPI_STATE_S4 and execute the _PTS control method.  This
1196  *              function is used if the pre-ACPI 2.0 suspend ordering has been
1197  *              requested.
1198  */
1199 static int acpi_hibernation_begin_old(void)
1200 {
1201         int error;
1202         /*
1203          * The _TTS object should always be evaluated before the _PTS object.
1204          * When the old_suspended_ordering is true, the _PTS object is
1205          * evaluated in the acpi_sleep_prepare.
1206          */
1207         acpi_sleep_tts_switch(ACPI_STATE_S4);
1208
1209         error = acpi_sleep_prepare(ACPI_STATE_S4);
1210
1211         if (!error) {
1212                 if (!nvs_nosave)
1213                         error = suspend_nvs_alloc();
1214                 if (!error) {
1215                         acpi_target_sleep_state = ACPI_STATE_S4;
1216                         acpi_scan_lock_acquire();
1217                 }
1218         }
1219         return error;
1220 }
1221
1222 /*
1223  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
1224  * been requested.
1225  */
1226 static const struct platform_hibernation_ops acpi_hibernation_ops_old = {
1227         .begin = acpi_hibernation_begin_old,
1228         .end = acpi_pm_end,
1229         .pre_snapshot = acpi_pm_pre_suspend,
1230         .prepare = acpi_pm_freeze,
1231         .finish = acpi_pm_finish,
1232         .enter = acpi_hibernation_enter,
1233         .leave = acpi_hibernation_leave,
1234         .pre_restore = acpi_pm_freeze,
1235         .restore_cleanup = acpi_pm_thaw,
1236         .recover = acpi_pm_finish,
1237 };
1238
1239 static void acpi_sleep_hibernate_setup(void)
1240 {
1241         if (!acpi_sleep_state_supported(ACPI_STATE_S4))
1242                 return;
1243
1244         hibernation_set_ops(old_suspend_ordering ?
1245                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
1246         sleep_states[ACPI_STATE_S4] = 1;
1247         if (nosigcheck)
1248                 return;
1249
1250         acpi_get_table(ACPI_SIG_FACS, 1, (struct acpi_table_header **)&facs);
1251         if (facs)
1252                 s4_hardware_signature = facs->hardware_signature;
1253 }
1254 #else /* !CONFIG_HIBERNATION */
1255 static inline void acpi_sleep_hibernate_setup(void) {}
1256 #endif /* !CONFIG_HIBERNATION */
1257
1258 static void acpi_power_off_prepare(void)
1259 {
1260         /* Prepare to power off the system */
1261         acpi_sleep_prepare(ACPI_STATE_S5);
1262         acpi_disable_all_gpes();
1263         acpi_os_wait_events_complete();
1264 }
1265
1266 static void acpi_power_off(void)
1267 {
1268         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
1269         printk(KERN_DEBUG "%s called\n", __func__);
1270         local_irq_disable();
1271         acpi_enter_sleep_state(ACPI_STATE_S5);
1272 }
1273
1274 int __init acpi_sleep_init(void)
1275 {
1276         char supported[ACPI_S_STATE_COUNT * 3 + 1];
1277         char *pos = supported;
1278         int i;
1279
1280         acpi_sleep_dmi_check();
1281
1282         sleep_states[ACPI_STATE_S0] = 1;
1283
1284         acpi_sleep_syscore_init();
1285         acpi_sleep_suspend_setup();
1286         acpi_sleep_hibernate_setup();
1287
1288         if (acpi_sleep_state_supported(ACPI_STATE_S5)) {
1289                 sleep_states[ACPI_STATE_S5] = 1;
1290                 pm_power_off_prepare = acpi_power_off_prepare;
1291                 pm_power_off = acpi_power_off;
1292         } else {
1293                 acpi_no_s5 = true;
1294         }
1295
1296         supported[0] = 0;
1297         for (i = 0; i < ACPI_S_STATE_COUNT; i++) {
1298                 if (sleep_states[i])
1299                         pos += sprintf(pos, " S%d", i);
1300         }
1301         pr_info(PREFIX "(supports%s)\n", supported);
1302
1303         /*
1304          * Register the tts_notifier to reboot notifier list so that the _TTS
1305          * object can also be evaluated when the system enters S5.
1306          */
1307         register_reboot_notifier(&tts_notifier);
1308         return 0;
1309 }