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