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