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   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/suspend.h>
  18 #include <linux/reboot.h>
  19
  20 #include <asm/io.h>
  21
  22 #include <acpi/acpi_bus.h>
  23 #include <acpi/acpi_drivers.h>
  24 #include "sleep.h"
  25
  26 u8 sleep_states[ACPI_S_STATE_COUNT];
  27
  28 static void acpi_sleep_tts_switch(u32 acpi_state)
  29 {
  30         union acpi_object in_arg = { ACPI_TYPE_INTEGER };
  31         struct acpi_object_list arg_list = { 1, &in_arg };
  32         acpi_status status = AE_OK;
  33
  34         in_arg.integer.value = acpi_state;
  35         status = acpi_evaluate_object(NULL, "\\_TTS", &arg_list, NULL);
  36         if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
  37                 /*
  38                  * OS can't evaluate the _TTS object correctly. Some warning
  39                  * message will be printed. But it won't break anything.
  40                  */
  41                 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
  42         }
  43 }
  44
  45 static int tts_notify_reboot(struct notifier_block *this,
  46                         unsigned long code, void *x)
  47 {
  48         acpi_sleep_tts_switch(ACPI_STATE_S5);
  49         return NOTIFY_DONE;
  50 }
  51
  52 static struct notifier_block tts_notifier = {
  53         .notifier_call  = tts_notify_reboot,
  54         .next           = NULL,
  55         .priority       = 0,
  56 };
  57
  58 static int acpi_sleep_prepare(u32 acpi_state)
  59 {
  60 #ifdef CONFIG_ACPI_SLEEP
  61         /* do we have a wakeup address for S2 and S3? */
  62         if (acpi_state == ACPI_STATE_S3) {
  63                 if (!acpi_wakeup_address) {
  64                         return -EFAULT;
  65                 }
  66                 acpi_set_firmware_waking_vector(
  67                                 (acpi_physical_address)acpi_wakeup_address);
  68
  69         }
  70         ACPI_FLUSH_CPU_CACHE();
  71         acpi_enable_wakeup_device_prep(acpi_state);
  72 #endif
  73         printk(KERN_INFO PREFIX "Preparing to enter system sleep state S%d\n",
  74                 acpi_state);
  75         acpi_enter_sleep_state_prep(acpi_state);
  76         return 0;
  77 }
  78
  79 #ifdef CONFIG_ACPI_SLEEP
  80 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
  81 /*
  82  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
  83  * user to request that behavior by using the 'acpi_old_suspend_ordering'
  84  * kernel command line option that causes the following variable to be set.
  85  */
  86 static bool old_suspend_ordering;
  87
  88 void __init acpi_old_suspend_ordering(void)
  89 {
  90         old_suspend_ordering = true;
  91 }
  92
  93 /**
  94  *      acpi_pm_disable_gpes - Disable the GPEs.
  95  */
  96 static int acpi_pm_disable_gpes(void)
  97 {
  98         acpi_disable_all_gpes();
  99         return 0;
 100 }
 101
 102 /**
 103  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
 104  *
 105  *      If necessary, set the firmware waking vector and do arch-specific
 106  *      nastiness to get the wakeup code to the waking vector.
 107  */
 108 static int __acpi_pm_prepare(void)
 109 {
 110         int error = acpi_sleep_prepare(acpi_target_sleep_state);
 111
 112         if (error)
 113                 acpi_target_sleep_state = ACPI_STATE_S0;
 114         return error;
 115 }
 116
 117 /**
 118  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
 119  *              state and disable the GPEs.
 120  */
 121 static int acpi_pm_prepare(void)
 122 {
 123         int error = __acpi_pm_prepare();
 124
 125         if (!error)
 126                 acpi_disable_all_gpes();
 127         return error;
 128 }
 129
 130 /**
 131  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
 132  *
 133  *      This is called after we wake back up (or if entering the sleep state
 134  *      failed).
 135  */
 136 static void acpi_pm_finish(void)
 137 {
 138         u32 acpi_state = acpi_target_sleep_state;
 139
 140         if (acpi_state == ACPI_STATE_S0)
 141                 return;
 142
 143         printk(KERN_INFO PREFIX "Waking up from system sleep state S%d\n",
 144                 acpi_state);
 145         acpi_disable_wakeup_device(acpi_state);
 146         acpi_leave_sleep_state(acpi_state);
 147
 148         /* reset firmware waking vector */
 149         acpi_set_firmware_waking_vector((acpi_physical_address) 0);
 150
 151         acpi_target_sleep_state = ACPI_STATE_S0;
 152 }
 153
 154 /**
 155  *      acpi_pm_end - Finish up suspend sequence.
 156  */
 157 static void acpi_pm_end(void)
 158 {
 159         /*
 160          * This is necessary in case acpi_pm_finish() is not called during a
 161          * failing transition to a sleep state.
 162          */
 163         acpi_target_sleep_state = ACPI_STATE_S0;
 164         acpi_sleep_tts_switch(acpi_target_sleep_state);
 165 }
 166 #else /* !CONFIG_ACPI_SLEEP */
 167 #define acpi_target_sleep_state ACPI_STATE_S0
 168 #endif /* CONFIG_ACPI_SLEEP */
 169
 170 #ifdef CONFIG_SUSPEND
 171 /*
 172  * According to the ACPI specification the BIOS should make sure that ACPI is
 173  * enabled and SCI_EN bit is set on wake-up from S1 - S3 sleep states.  Still,
 174  * some BIOSes don't do that and therefore we use acpi_enable() to enable ACPI
 175  * on such systems during resume.  Unfortunately that doesn't help in
 176  * particularly pathological cases in which SCI_EN has to be set directly on
 177  * resume, although the specification states very clearly that this flag is
 178  * owned by the hardware.  The set_sci_en_on_resume variable will be set in such
 179  * cases.
 180  */
 181 static bool set_sci_en_on_resume;
 182
 183 extern void do_suspend_lowlevel(void);
 184
 185 static u32 acpi_suspend_states[] = {
 186         [PM_SUSPEND_ON] = ACPI_STATE_S0,
 187         [PM_SUSPEND_STANDBY] = ACPI_STATE_S1,
 188         [PM_SUSPEND_MEM] = ACPI_STATE_S3,
 189         [PM_SUSPEND_MAX] = ACPI_STATE_S5
 190 };
 191
 192 /**
 193  *      acpi_suspend_begin - Set the target system sleep state to the state
 194  *              associated with given @pm_state, if supported.
 195  */
 196 static int acpi_suspend_begin(suspend_state_t pm_state)
 197 {
 198         u32 acpi_state = acpi_suspend_states[pm_state];
 199         int error = 0;
 200
 201         if (sleep_states[acpi_state]) {
 202                 acpi_target_sleep_state = acpi_state;
 203                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 204         } else {
 205                 printk(KERN_ERR "ACPI does not support this state: %d\n",
 206                         pm_state);
 207                 error = -ENOSYS;
 208         }
 209         return error;
 210 }
 211
 212 /**
 213  *      acpi_suspend_enter - Actually enter a sleep state.
 214  *      @pm_state: ignored
 215  *
 216  *      Flush caches and go to sleep. For STR we have to call arch-specific
 217  *      assembly, which in turn call acpi_enter_sleep_state().
 218  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
 219  */
 220 static int acpi_suspend_enter(suspend_state_t pm_state)
 221 {
 222         acpi_status status = AE_OK;
 223         unsigned long flags = 0;
 224         u32 acpi_state = acpi_target_sleep_state;
 225
 226         ACPI_FLUSH_CPU_CACHE();
 227
 228         /* Do arch specific saving of state. */
 229         if (acpi_state == ACPI_STATE_S3) {
 230                 int error = acpi_save_state_mem();
 231
 232                 if (error)
 233                         return error;
 234         }
 235
 236         local_irq_save(flags);
 237         acpi_enable_wakeup_device(acpi_state);
 238         switch (acpi_state) {
 239         case ACPI_STATE_S1:
 240                 barrier();
 241                 status = acpi_enter_sleep_state(acpi_state);
 242                 break;
 243
 244         case ACPI_STATE_S3:
 245                 do_suspend_lowlevel();
 246                 break;
 247         }
 248
 249         /* If ACPI is not enabled by the BIOS, we need to enable it here. */
 250         if (set_sci_en_on_resume)
 251                 acpi_set_register(ACPI_BITREG_SCI_ENABLE, 1);
 252         else
 253                 acpi_enable();
 254
 255         /* Reprogram control registers and execute _BFS */
 256         acpi_leave_sleep_state_prep(acpi_state);
 257
 258         /* ACPI 3.0 specs (P62) says that it's the responsibility
 259          * of the OSPM to clear the status bit [ implying that the
 260          * POWER_BUTTON event should not reach userspace ]
 261          */
 262         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
 263                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
 264
 265         /*
 266          * Disable and clear GPE status before interrupt is enabled. Some GPEs
 267          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
 268          * acpi_leave_sleep_state will reenable specific GPEs later
 269          */
 270         acpi_disable_all_gpes();
 271
 272         local_irq_restore(flags);
 273         printk(KERN_DEBUG "Back to C!\n");
 274
 275         /* restore processor state */
 276         if (acpi_state == ACPI_STATE_S3)
 277                 acpi_restore_state_mem();
 278
 279         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 280 }
 281
 282 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 283 {
 284         u32 acpi_state;
 285
 286         switch (pm_state) {
 287         case PM_SUSPEND_ON:
 288         case PM_SUSPEND_STANDBY:
 289         case PM_SUSPEND_MEM:
 290                 acpi_state = acpi_suspend_states[pm_state];
 291
 292                 return sleep_states[acpi_state];
 293         default:
 294                 return 0;
 295         }
 296 }
 297
 298 static struct platform_suspend_ops acpi_suspend_ops = {
 299         .valid = acpi_suspend_state_valid,
 300         .begin = acpi_suspend_begin,
 301         .prepare = acpi_pm_prepare,
 302         .enter = acpi_suspend_enter,
 303         .finish = acpi_pm_finish,
 304         .end = acpi_pm_end,
 305 };
 306
 307 /**
 308  *      acpi_suspend_begin_old - Set the target system sleep state to the
 309  *              state associated with given @pm_state, if supported, and
 310  *              execute the _PTS control method.  This function is used if the
 311  *              pre-ACPI 2.0 suspend ordering has been requested.
 312  */
 313 static int acpi_suspend_begin_old(suspend_state_t pm_state)
 314 {
 315         int error = acpi_suspend_begin(pm_state);
 316
 317         if (!error)
 318                 error = __acpi_pm_prepare();
 319         return error;
 320 }
 321
 322 /*
 323  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 324  * been requested.
 325  */
 326 static struct platform_suspend_ops acpi_suspend_ops_old = {
 327         .valid = acpi_suspend_state_valid,
 328         .begin = acpi_suspend_begin_old,
 329         .prepare = acpi_pm_disable_gpes,
 330         .enter = acpi_suspend_enter,
 331         .finish = acpi_pm_finish,
 332         .end = acpi_pm_end,
 333         .recover = acpi_pm_finish,
 334 };
 335
 336 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
 337 {
 338         old_suspend_ordering = true;
 339         return 0;
 340 }
 341
 342 static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
 343 {
 344         set_sci_en_on_resume = true;
 345         return 0;
 346 }
 347
 348 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 349         {
 350         .callback = init_old_suspend_ordering,
 351         .ident = "Abit KN9 (nForce4 variant)",
 352         .matches = {
 353                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
 354                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
 355                 },
 356         },
 357         {
 358         .callback = init_old_suspend_ordering,
 359         .ident = "HP xw4600 Workstation",
 360         .matches = {
 361                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 362                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 363                 },
 364         },
 365         {
 366         .callback = init_set_sci_en_on_resume,
 367         .ident = "Apple MacBook 1,1",
 368         .matches = {
 369                 DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
 370                 DMI_MATCH(DMI_PRODUCT_NAME, "MacBook1,1"),
 371                 },
 372         },
 373         {
 374         .callback = init_set_sci_en_on_resume,
 375         .ident = "Apple MacMini 1,1",
 376         .matches = {
 377                 DMI_MATCH(DMI_SYS_VENDOR, "Apple Computer, Inc."),
 378                 DMI_MATCH(DMI_PRODUCT_NAME, "Macmini1,1"),
 379                 },
 380         },
 381         {
 382         .callback = init_old_suspend_ordering,
 383         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
 384         .matches = {
 385                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
 386                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
 387                 },
 388         },
 389         {
 390         .callback = init_set_sci_en_on_resume,
 391         .ident = "Toshiba Satellite L300",
 392         .matches = {
 393                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 394                 DMI_MATCH(DMI_PRODUCT_NAME, "Satellite L300"),
 395                 },
 396         },
 397         {
 398         .callback = init_old_suspend_ordering,
 399         .ident = "Panasonic CF51-2L",
 400         .matches = {
 401                 DMI_MATCH(DMI_BOARD_VENDOR,
 402                                 "Matsushita Electric Industrial Co.,Ltd."),
 403                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
 404                 },
 405         },
 406         {},
 407 };
 408 #endif /* CONFIG_SUSPEND */
 409
 410 #ifdef CONFIG_HIBERNATION
 411 /*
 412  * The ACPI specification wants us to save NVS memory regions during hibernation
 413  * and to restore them during the subsequent resume.  However, it is not certain
 414  * if this mechanism is going to work on all machines, so we allow the user to
 415  * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
 416  * option.
 417  */
 418 static bool s4_no_nvs;
 419
 420 void __init acpi_s4_no_nvs(void)
 421 {
 422         s4_no_nvs = true;
 423 }
 424
 425 static unsigned long s4_hardware_signature;
 426 static struct acpi_table_facs *facs;
 427 static bool nosigcheck;
 428
 429 void __init acpi_no_s4_hw_signature(void)
 430 {
 431         nosigcheck = true;
 432 }
 433
 434 static int acpi_hibernation_begin(void)
 435 {
 436         int error;
 437
 438         error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
 439         if (!error) {
 440                 acpi_target_sleep_state = ACPI_STATE_S4;
 441                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 442         }
 443
 444         return error;
 445 }
 446
 447 static int acpi_hibernation_pre_snapshot(void)
 448 {
 449         int error = acpi_pm_prepare();
 450
 451         if (!error)
 452                 hibernate_nvs_save();
 453
 454         return error;
 455 }
 456
 457 static int acpi_hibernation_enter(void)
 458 {
 459         acpi_status status = AE_OK;
 460         unsigned long flags = 0;
 461
 462         ACPI_FLUSH_CPU_CACHE();
 463
 464         local_irq_save(flags);
 465         acpi_enable_wakeup_device(ACPI_STATE_S4);
 466         /* This shouldn't return.  If it returns, we have a problem */
 467         status = acpi_enter_sleep_state(ACPI_STATE_S4);
 468         /* Reprogram control registers and execute _BFS */
 469         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 470         local_irq_restore(flags);
 471
 472         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 473 }
 474
 475 static void acpi_hibernation_finish(void)
 476 {
 477         hibernate_nvs_free();
 478         acpi_pm_finish();
 479 }
 480
 481 static void acpi_hibernation_leave(void)
 482 {
 483         /*
 484          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
 485          * enable it here.
 486          */
 487         acpi_enable();
 488         /* Reprogram control registers and execute _BFS */
 489         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 490         /* Check the hardware signature */
 491         if (facs && s4_hardware_signature != facs->hardware_signature) {
 492                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
 493                         "cannot resume!\n");
 494                 panic("ACPI S4 hardware signature mismatch");
 495         }
 496         /* Restore the NVS memory area */
 497         hibernate_nvs_restore();
 498 }
 499
 500 static void acpi_pm_enable_gpes(void)
 501 {
 502         acpi_enable_all_runtime_gpes();
 503 }
 504
 505 static struct platform_hibernation_ops acpi_hibernation_ops = {
 506         .begin = acpi_hibernation_begin,
 507         .end = acpi_pm_end,
 508         .pre_snapshot = acpi_hibernation_pre_snapshot,
 509         .finish = acpi_hibernation_finish,
 510         .prepare = acpi_pm_prepare,
 511         .enter = acpi_hibernation_enter,
 512         .leave = acpi_hibernation_leave,
 513         .pre_restore = acpi_pm_disable_gpes,
 514         .restore_cleanup = acpi_pm_enable_gpes,
 515 };
 516
 517 /**
 518  *      acpi_hibernation_begin_old - Set the target system sleep state to
 519  *              ACPI_STATE_S4 and execute the _PTS control method.  This
 520  *              function is used if the pre-ACPI 2.0 suspend ordering has been
 521  *              requested.
 522  */
 523 static int acpi_hibernation_begin_old(void)
 524 {
 525         int error;
 526         /*
 527          * The _TTS object should always be evaluated before the _PTS object.
 528          * When the old_suspended_ordering is true, the _PTS object is
 529          * evaluated in the acpi_sleep_prepare.
 530          */
 531         acpi_sleep_tts_switch(ACPI_STATE_S4);
 532
 533         error = acpi_sleep_prepare(ACPI_STATE_S4);
 534
 535         if (!error) {
 536                 if (!s4_no_nvs)
 537                         error = hibernate_nvs_alloc();
 538                 if (!error)
 539                         acpi_target_sleep_state = ACPI_STATE_S4;
 540         }
 541         return error;
 542 }
 543
 544 static int acpi_hibernation_pre_snapshot_old(void)
 545 {
 546         int error = acpi_pm_disable_gpes();
 547
 548         if (!error)
 549                 hibernate_nvs_save();
 550
 551         return error;
 552 }
 553
 554 /*
 555  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 556  * been requested.
 557  */
 558 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
 559         .begin = acpi_hibernation_begin_old,
 560         .end = acpi_pm_end,
 561         .pre_snapshot = acpi_hibernation_pre_snapshot_old,
 562         .finish = acpi_hibernation_finish,
 563         .prepare = acpi_pm_disable_gpes,
 564         .enter = acpi_hibernation_enter,
 565         .leave = acpi_hibernation_leave,
 566         .pre_restore = acpi_pm_disable_gpes,
 567         .restore_cleanup = acpi_pm_enable_gpes,
 568         .recover = acpi_pm_finish,
 569 };
 570 #endif /* CONFIG_HIBERNATION */
 571
 572 int acpi_suspend(u32 acpi_state)
 573 {
 574         suspend_state_t states[] = {
 575                 [1] = PM_SUSPEND_STANDBY,
 576                 [3] = PM_SUSPEND_MEM,
 577                 [5] = PM_SUSPEND_MAX
 578         };
 579
 580         if (acpi_state < 6 && states[acpi_state])
 581                 return pm_suspend(states[acpi_state]);
 582         if (acpi_state == 4)
 583                 return hibernate();
 584         return -EINVAL;
 585 }
 586
 587 #ifdef CONFIG_PM_SLEEP
 588 /**
 589  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
 590  *              in the system sleep state given by %acpi_target_sleep_state
 591  *      @dev: device to examine; its driver model wakeup flags control
 592  *              whether it should be able to wake up the system
 593  *      @d_min_p: used to store the upper limit of allowed states range
 594  *      Return value: preferred power state of the device on success, -ENODEV on
 595  *              failure (ie. if there's no 'struct acpi_device' for @dev)
 596  *
 597  *      Find the lowest power (highest number) ACPI device power state that
 598  *      device @dev can be in while the system is in the sleep state represented
 599  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
 600  *      able to wake up the system from this sleep state.  If @d_min_p is set,
 601  *      the highest power (lowest number) device power state of @dev allowed
 602  *      in this system sleep state is stored at the location pointed to by it.
 603  *
 604  *      The caller must ensure that @dev is valid before using this function.
 605  *      The caller is also responsible for figuring out if the device is
 606  *      supposed to be able to wake up the system and passing this information
 607  *      via @wake.
 608  */
 609
 610 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
 611 {
 612         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 613         struct acpi_device *adev;
 614         char acpi_method[] = "_SxD";
 615         unsigned long long d_min, d_max;
 616
 617         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 618                 printk(KERN_DEBUG "ACPI handle has no context!\n");
 619                 return -ENODEV;
 620         }
 621
 622         acpi_method[2] = '0' + acpi_target_sleep_state;
 623         /*
 624          * If the sleep state is S0, we will return D3, but if the device has
 625          * _S0W, we will use the value from _S0W
 626          */
 627         d_min = ACPI_STATE_D0;
 628         d_max = ACPI_STATE_D3;
 629
 630         /*
 631          * If present, _SxD methods return the minimum D-state (highest power
 632          * state) we can use for the corresponding S-states.  Otherwise, the
 633          * minimum D-state is D0 (ACPI 3.x).
 634          *
 635          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 636          * provided -- that's our fault recovery, we ignore retval.
 637          */
 638         if (acpi_target_sleep_state > ACPI_STATE_S0)
 639                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
 640
 641         /*
 642          * If _PRW says we can wake up the system from the target sleep state,
 643          * the D-state returned by _SxD is sufficient for that (we assume a
 644          * wakeup-aware driver if wake is set).  Still, if _SxW exists
 645          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 646          * can wake the system.  _S0W may be valid, too.
 647          */
 648         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
 649             (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
 650              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
 651                 acpi_status status;
 652
 653                 acpi_method[3] = 'W';
 654                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
 655                                                 &d_max);
 656                 if (ACPI_FAILURE(status)) {
 657                         d_max = d_min;
 658                 } else if (d_max < d_min) {
 659                         /* Warn the user of the broken DSDT */
 660                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
 661                                 acpi_method);
 662                         /* Sanitize it */
 663                         d_min = d_max;
 664                 }
 665         }
 666
 667         if (d_min_p)
 668                 *d_min_p = d_min;
 669         return d_max;
 670 }
 671
 672 /**
 673  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
 674  *                                  capability of given device
 675  *      @dev: device to handle
 676  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
 677  */
 678 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 679 {
 680         acpi_handle handle;
 681         struct acpi_device *adev;
 682
 683         if (!device_may_wakeup(dev))
 684                 return -EINVAL;
 685
 686         handle = DEVICE_ACPI_HANDLE(dev);
 687         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 688                 printk(KERN_DEBUG "ACPI handle has no context!\n");
 689                 return -ENODEV;
 690         }
 691
 692         return enable ?
 693                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
 694                 acpi_disable_wakeup_device_power(adev);
 695 }
 696 #endif
 697
 698 static void acpi_power_off_prepare(void)
 699 {
 700         /* Prepare to power off the system */
 701         acpi_sleep_prepare(ACPI_STATE_S5);
 702         acpi_disable_all_gpes();
 703 }
 704
 705 static void acpi_power_off(void)
 706 {
 707         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
 708         printk(KERN_DEBUG "%s called\n", __func__);
 709         local_irq_disable();
 710         acpi_enable_wakeup_device(ACPI_STATE_S5);
 711         acpi_enter_sleep_state(ACPI_STATE_S5);
 712 }
 713
 714 int __init acpi_sleep_init(void)
 715 {
 716         acpi_status status;
 717         u8 type_a, type_b;
 718 #ifdef CONFIG_SUSPEND
 719         int i = 0;
 720
 721         dmi_check_system(acpisleep_dmi_table);
 722 #endif
 723
 724         if (acpi_disabled)
 725                 return 0;
 726
 727         sleep_states[ACPI_STATE_S0] = 1;
 728         printk(KERN_INFO PREFIX "(supports S0");
 729
 730 #ifdef CONFIG_SUSPEND
 731         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
 732                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
 733                 if (ACPI_SUCCESS(status)) {
 734                         sleep_states[i] = 1;
 735                         printk(" S%d", i);
 736                 }
 737         }
 738
 739         suspend_set_ops(old_suspend_ordering ?
 740                 &acpi_suspend_ops_old : &acpi_suspend_ops);
 741 #endif
 742
 743 #ifdef CONFIG_HIBERNATION
 744         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
 745         if (ACPI_SUCCESS(status)) {
 746                 hibernation_set_ops(old_suspend_ordering ?
 747                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
 748                 sleep_states[ACPI_STATE_S4] = 1;
 749                 printk(" S4");
 750                 if (!nosigcheck) {
 751                         acpi_get_table(ACPI_SIG_FACS, 1,
 752                                 (struct acpi_table_header **)&facs);
 753                         if (facs)
 754                                 s4_hardware_signature =
 755                                         facs->hardware_signature;
 756                 }
 757         }
 758 #endif
 759         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
 760         if (ACPI_SUCCESS(status)) {
 761                 sleep_states[ACPI_STATE_S5] = 1;
 762                 printk(" S5");
 763                 pm_power_off_prepare = acpi_power_off_prepare;
 764                 pm_power_off = acpi_power_off;
 765         }
 766         printk(")\n");
 767         /*
 768          * Register the tts_notifier to reboot notifier list so that the _TTS
 769          * object can also be evaluated when the system enters S5.
 770          */
 771         register_reboot_notifier(&tts_notifier);
 772         return 0;
 773 }