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
  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 /*
  85  * The ACPI specification wants us to save NVS memory regions during hibernation
  86  * and to restore them during the subsequent resume.  Windows does that also for
  87  * suspend to RAM.  However, it is known that this mechanism does not work on
  88  * all machines, so we allow the user to disable it with the help of the
  89  * 'acpi_sleep=nonvs' kernel command line option.
  90  */
  91 static bool nvs_nosave;
  92
  93 void __init acpi_nvs_nosave(void)
  94 {
  95         nvs_nosave = true;
  96 }
  97
  98 /*
  99  * ACPI 1.0 wants us to execute _PTS before suspending devices, so we allow the
 100  * user to request that behavior by using the 'acpi_old_suspend_ordering'
 101  * kernel command line option that causes the following variable to be set.
 102  */
 103 static bool old_suspend_ordering;
 104
 105 void __init acpi_old_suspend_ordering(void)
 106 {
 107         old_suspend_ordering = true;
 108 }
 109
 110 /**
 111  * acpi_pm_freeze - Disable the GPEs and suspend EC transactions.
 112  */
 113 static int acpi_pm_freeze(void)
 114 {
 115         acpi_disable_all_gpes();
 116         acpi_os_wait_events_complete(NULL);
 117         acpi_ec_block_transactions();
 118         return 0;
 119 }
 120
 121 /**
 122  *      __acpi_pm_prepare - Prepare the platform to enter the target state.
 123  *
 124  *      If necessary, set the firmware waking vector and do arch-specific
 125  *      nastiness to get the wakeup code to the waking vector.
 126  */
 127 static int __acpi_pm_prepare(void)
 128 {
 129         int error = acpi_sleep_prepare(acpi_target_sleep_state);
 130
 131         suspend_nvs_save();
 132
 133         if (error)
 134                 acpi_target_sleep_state = ACPI_STATE_S0;
 135         return error;
 136 }
 137
 138 /**
 139  *      acpi_pm_prepare - Prepare the platform to enter the target sleep
 140  *              state and disable the GPEs.
 141  */
 142 static int acpi_pm_prepare(void)
 143 {
 144         int error = __acpi_pm_prepare();
 145
 146         if (!error)
 147                 acpi_pm_freeze();
 148
 149         return error;
 150 }
 151
 152 /**
 153  *      acpi_pm_finish - Instruct the platform to leave a sleep state.
 154  *
 155  *      This is called after we wake back up (or if entering the sleep state
 156  *      failed).
 157  */
 158 static void acpi_pm_finish(void)
 159 {
 160         u32 acpi_state = acpi_target_sleep_state;
 161
 162         suspend_nvs_free();
 163         acpi_ec_unblock_transactions();
 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         error = nvs_nosave ? 0 : suspend_nvs_alloc();
 215         if (error)
 216                 return error;
 217
 218         if (sleep_states[acpi_state]) {
 219                 acpi_target_sleep_state = acpi_state;
 220                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 221         } else {
 222                 printk(KERN_ERR "ACPI does not support this state: %d\n",
 223                         pm_state);
 224                 error = -ENOSYS;
 225         }
 226         return error;
 227 }
 228
 229 /**
 230  *      acpi_suspend_enter - Actually enter a sleep state.
 231  *      @pm_state: ignored
 232  *
 233  *      Flush caches and go to sleep. For STR we have to call arch-specific
 234  *      assembly, which in turn call acpi_enter_sleep_state().
 235  *      It's unfortunate, but it works. Please fix if you're feeling frisky.
 236  */
 237 static int acpi_suspend_enter(suspend_state_t pm_state)
 238 {
 239         acpi_status status = AE_OK;
 240         unsigned long flags = 0;
 241         u32 acpi_state = acpi_target_sleep_state;
 242
 243         ACPI_FLUSH_CPU_CACHE();
 244
 245         /* Do arch specific saving of state. */
 246         if (acpi_state == ACPI_STATE_S3) {
 247                 int error = acpi_save_state_mem();
 248
 249                 if (error)
 250                         return error;
 251         }
 252
 253         local_irq_save(flags);
 254         acpi_enable_wakeup_device(acpi_state);
 255         switch (acpi_state) {
 256         case ACPI_STATE_S1:
 257                 barrier();
 258                 status = acpi_enter_sleep_state(acpi_state);
 259                 break;
 260
 261         case ACPI_STATE_S3:
 262                 do_suspend_lowlevel();
 263                 break;
 264         }
 265
 266         /* This violates the spec but is required for bug compatibility. */
 267         acpi_write_bit_register(ACPI_BITREG_SCI_ENABLE, 1);
 268
 269         /* Reprogram control registers and execute _BFS */
 270         acpi_leave_sleep_state_prep(acpi_state);
 271
 272         /* ACPI 3.0 specs (P62) says that it's the responsibility
 273          * of the OSPM to clear the status bit [ implying that the
 274          * POWER_BUTTON event should not reach userspace ]
 275          */
 276         if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
 277                 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
 278
 279         /*
 280          * Disable and clear GPE status before interrupt is enabled. Some GPEs
 281          * (like wakeup GPE) haven't handler, this can avoid such GPE misfire.
 282          * acpi_leave_sleep_state will reenable specific GPEs later
 283          */
 284         acpi_disable_all_gpes();
 285         /* Allow EC transactions to happen. */
 286         acpi_ec_unblock_transactions_early();
 287
 288         local_irq_restore(flags);
 289         printk(KERN_DEBUG "Back to C!\n");
 290
 291         /* restore processor state */
 292         if (acpi_state == ACPI_STATE_S3)
 293                 acpi_restore_state_mem();
 294
 295         suspend_nvs_restore();
 296
 297         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 298 }
 299
 300 static void acpi_suspend_finish(void)
 301 {
 302         acpi_pm_finish();
 303 }
 304
 305 static int acpi_suspend_state_valid(suspend_state_t pm_state)
 306 {
 307         u32 acpi_state;
 308
 309         switch (pm_state) {
 310         case PM_SUSPEND_ON:
 311         case PM_SUSPEND_STANDBY:
 312         case PM_SUSPEND_MEM:
 313                 acpi_state = acpi_suspend_states[pm_state];
 314
 315                 return sleep_states[acpi_state];
 316         default:
 317                 return 0;
 318         }
 319 }
 320
 321 static struct platform_suspend_ops acpi_suspend_ops = {
 322         .valid = acpi_suspend_state_valid,
 323         .begin = acpi_suspend_begin,
 324         .prepare_late = acpi_pm_prepare,
 325         .enter = acpi_suspend_enter,
 326         .wake = acpi_suspend_finish,
 327         .end = acpi_pm_end,
 328 };
 329
 330 /**
 331  *      acpi_suspend_begin_old - Set the target system sleep state to the
 332  *              state associated with given @pm_state, if supported, and
 333  *              execute the _PTS control method.  This function is used if the
 334  *              pre-ACPI 2.0 suspend ordering has been requested.
 335  */
 336 static int acpi_suspend_begin_old(suspend_state_t pm_state)
 337 {
 338         int error = acpi_suspend_begin(pm_state);
 339
 340         if (!error)
 341                 error = __acpi_pm_prepare();
 342         return error;
 343 }
 344
 345 /*
 346  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 347  * been requested.
 348  */
 349 static struct platform_suspend_ops acpi_suspend_ops_old = {
 350         .valid = acpi_suspend_state_valid,
 351         .begin = acpi_suspend_begin_old,
 352         .prepare_late = acpi_pm_freeze,
 353         .enter = acpi_suspend_enter,
 354         .wake = acpi_suspend_finish,
 355         .end = acpi_pm_end,
 356         .recover = acpi_pm_finish,
 357 };
 358
 359 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
 360 {
 361         old_suspend_ordering = true;
 362         return 0;
 363 }
 364
 365 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
 366         {
 367         .callback = init_old_suspend_ordering,
 368         .ident = "Abit KN9 (nForce4 variant)",
 369         .matches = {
 370                 DMI_MATCH(DMI_BOARD_VENDOR, "http://www.abit.com.tw/"),
 371                 DMI_MATCH(DMI_BOARD_NAME, "KN9 Series(NF-CK804)"),
 372                 },
 373         },
 374         {
 375         .callback = init_old_suspend_ordering,
 376         .ident = "HP xw4600 Workstation",
 377         .matches = {
 378                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 379                 DMI_MATCH(DMI_PRODUCT_NAME, "HP xw4600 Workstation"),
 380                 },
 381         },
 382         {
 383         .callback = init_old_suspend_ordering,
 384         .ident = "Asus Pundit P1-AH2 (M2N8L motherboard)",
 385         .matches = {
 386                 DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTek Computer INC."),
 387                 DMI_MATCH(DMI_BOARD_NAME, "M2N8L"),
 388                 },
 389         },
 390         {
 391         .callback = init_old_suspend_ordering,
 392         .ident = "Panasonic CF51-2L",
 393         .matches = {
 394                 DMI_MATCH(DMI_BOARD_VENDOR,
 395                                 "Matsushita Electric Industrial Co.,Ltd."),
 396                 DMI_MATCH(DMI_BOARD_NAME, "CF51-2L"),
 397                 },
 398         },
 399         {},
 400 };
 401 #endif /* CONFIG_SUSPEND */
 402
 403 #ifdef CONFIG_HIBERNATION
 404 static unsigned long s4_hardware_signature;
 405 static struct acpi_table_facs *facs;
 406 static bool nosigcheck;
 407
 408 void __init acpi_no_s4_hw_signature(void)
 409 {
 410         nosigcheck = true;
 411 }
 412
 413 static int acpi_hibernation_begin(void)
 414 {
 415         int error;
 416
 417         error = nvs_nosave ? 0 : suspend_nvs_alloc();
 418         if (!error) {
 419                 acpi_target_sleep_state = ACPI_STATE_S4;
 420                 acpi_sleep_tts_switch(acpi_target_sleep_state);
 421         }
 422
 423         return error;
 424 }
 425
 426 static int acpi_hibernation_pre_snapshot(void)
 427 {
 428         int error = acpi_pm_prepare();
 429
 430         if (!error)
 431                 suspend_nvs_save();
 432
 433         return error;
 434 }
 435
 436 static int acpi_hibernation_enter(void)
 437 {
 438         acpi_status status = AE_OK;
 439         unsigned long flags = 0;
 440
 441         ACPI_FLUSH_CPU_CACHE();
 442
 443         local_irq_save(flags);
 444         acpi_enable_wakeup_device(ACPI_STATE_S4);
 445         /* This shouldn't return.  If it returns, we have a problem */
 446         status = acpi_enter_sleep_state(ACPI_STATE_S4);
 447         /* Reprogram control registers and execute _BFS */
 448         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 449         local_irq_restore(flags);
 450
 451         return ACPI_SUCCESS(status) ? 0 : -EFAULT;
 452 }
 453
 454 static void acpi_hibernation_leave(void)
 455 {
 456         /*
 457          * If ACPI is not enabled by the BIOS and the boot kernel, we need to
 458          * enable it here.
 459          */
 460         acpi_enable();
 461         /* Reprogram control registers and execute _BFS */
 462         acpi_leave_sleep_state_prep(ACPI_STATE_S4);
 463         /* Check the hardware signature */
 464         if (facs && s4_hardware_signature != facs->hardware_signature) {
 465                 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
 466                         "cannot resume!\n");
 467                 panic("ACPI S4 hardware signature mismatch");
 468         }
 469         /* Restore the NVS memory area */
 470         suspend_nvs_restore();
 471         /* Allow EC transactions to happen. */
 472         acpi_ec_unblock_transactions_early();
 473 }
 474
 475 static void acpi_pm_thaw(void)
 476 {
 477         acpi_ec_unblock_transactions();
 478         acpi_enable_all_runtime_gpes();
 479 }
 480
 481 static struct platform_hibernation_ops acpi_hibernation_ops = {
 482         .begin = acpi_hibernation_begin,
 483         .end = acpi_pm_end,
 484         .pre_snapshot = acpi_hibernation_pre_snapshot,
 485         .finish = acpi_pm_finish,
 486         .prepare = acpi_pm_prepare,
 487         .enter = acpi_hibernation_enter,
 488         .leave = acpi_hibernation_leave,
 489         .pre_restore = acpi_pm_freeze,
 490         .restore_cleanup = acpi_pm_thaw,
 491 };
 492
 493 /**
 494  *      acpi_hibernation_begin_old - Set the target system sleep state to
 495  *              ACPI_STATE_S4 and execute the _PTS control method.  This
 496  *              function is used if the pre-ACPI 2.0 suspend ordering has been
 497  *              requested.
 498  */
 499 static int acpi_hibernation_begin_old(void)
 500 {
 501         int error;
 502         /*
 503          * The _TTS object should always be evaluated before the _PTS object.
 504          * When the old_suspended_ordering is true, the _PTS object is
 505          * evaluated in the acpi_sleep_prepare.
 506          */
 507         acpi_sleep_tts_switch(ACPI_STATE_S4);
 508
 509         error = acpi_sleep_prepare(ACPI_STATE_S4);
 510
 511         if (!error) {
 512                 if (!nvs_nosave)
 513                         error = suspend_nvs_alloc();
 514                 if (!error)
 515                         acpi_target_sleep_state = ACPI_STATE_S4;
 516         }
 517         return error;
 518 }
 519
 520 static int acpi_hibernation_pre_snapshot_old(void)
 521 {
 522         acpi_pm_freeze();
 523         suspend_nvs_save();
 524         return 0;
 525 }
 526
 527 /*
 528  * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
 529  * been requested.
 530  */
 531 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
 532         .begin = acpi_hibernation_begin_old,
 533         .end = acpi_pm_end,
 534         .pre_snapshot = acpi_hibernation_pre_snapshot_old,
 535         .prepare = acpi_pm_freeze,
 536         .finish = acpi_pm_finish,
 537         .enter = acpi_hibernation_enter,
 538         .leave = acpi_hibernation_leave,
 539         .pre_restore = acpi_pm_freeze,
 540         .restore_cleanup = acpi_pm_thaw,
 541         .recover = acpi_pm_finish,
 542 };
 543 #endif /* CONFIG_HIBERNATION */
 544
 545 int acpi_suspend(u32 acpi_state)
 546 {
 547         suspend_state_t states[] = {
 548                 [1] = PM_SUSPEND_STANDBY,
 549                 [3] = PM_SUSPEND_MEM,
 550                 [5] = PM_SUSPEND_MAX
 551         };
 552
 553         if (acpi_state < 6 && states[acpi_state])
 554                 return pm_suspend(states[acpi_state]);
 555         if (acpi_state == 4)
 556                 return hibernate();
 557         return -EINVAL;
 558 }
 559
 560 #ifdef CONFIG_PM_SLEEP
 561 /**
 562  *      acpi_pm_device_sleep_state - return preferred power state of ACPI device
 563  *              in the system sleep state given by %acpi_target_sleep_state
 564  *      @dev: device to examine; its driver model wakeup flags control
 565  *              whether it should be able to wake up the system
 566  *      @d_min_p: used to store the upper limit of allowed states range
 567  *      Return value: preferred power state of the device on success, -ENODEV on
 568  *              failure (ie. if there's no 'struct acpi_device' for @dev)
 569  *
 570  *      Find the lowest power (highest number) ACPI device power state that
 571  *      device @dev can be in while the system is in the sleep state represented
 572  *      by %acpi_target_sleep_state.  If @wake is nonzero, the device should be
 573  *      able to wake up the system from this sleep state.  If @d_min_p is set,
 574  *      the highest power (lowest number) device power state of @dev allowed
 575  *      in this system sleep state is stored at the location pointed to by it.
 576  *
 577  *      The caller must ensure that @dev is valid before using this function.
 578  *      The caller is also responsible for figuring out if the device is
 579  *      supposed to be able to wake up the system and passing this information
 580  *      via @wake.
 581  */
 582
 583 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
 584 {
 585         acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
 586         struct acpi_device *adev;
 587         char acpi_method[] = "_SxD";
 588         unsigned long long d_min, d_max;
 589
 590         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 591                 printk(KERN_DEBUG "ACPI handle has no context!\n");
 592                 return -ENODEV;
 593         }
 594
 595         acpi_method[2] = '0' + acpi_target_sleep_state;
 596         /*
 597          * If the sleep state is S0, we will return D3, but if the device has
 598          * _S0W, we will use the value from _S0W
 599          */
 600         d_min = ACPI_STATE_D0;
 601         d_max = ACPI_STATE_D3;
 602
 603         /*
 604          * If present, _SxD methods return the minimum D-state (highest power
 605          * state) we can use for the corresponding S-states.  Otherwise, the
 606          * minimum D-state is D0 (ACPI 3.x).
 607          *
 608          * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
 609          * provided -- that's our fault recovery, we ignore retval.
 610          */
 611         if (acpi_target_sleep_state > ACPI_STATE_S0)
 612                 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
 613
 614         /*
 615          * If _PRW says we can wake up the system from the target sleep state,
 616          * the D-state returned by _SxD is sufficient for that (we assume a
 617          * wakeup-aware driver if wake is set).  Still, if _SxW exists
 618          * (ACPI 3.x), it should return the maximum (lowest power) D-state that
 619          * can wake the system.  _S0W may be valid, too.
 620          */
 621         if (acpi_target_sleep_state == ACPI_STATE_S0 ||
 622             (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
 623              adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
 624                 acpi_status status;
 625
 626                 acpi_method[3] = 'W';
 627                 status = acpi_evaluate_integer(handle, acpi_method, NULL,
 628                                                 &d_max);
 629                 if (ACPI_FAILURE(status)) {
 630                         d_max = d_min;
 631                 } else if (d_max < d_min) {
 632                         /* Warn the user of the broken DSDT */
 633                         printk(KERN_WARNING "ACPI: Wrong value from %s\n",
 634                                 acpi_method);
 635                         /* Sanitize it */
 636                         d_min = d_max;
 637                 }
 638         }
 639
 640         if (d_min_p)
 641                 *d_min_p = d_min;
 642         return d_max;
 643 }
 644
 645 /**
 646  *      acpi_pm_device_sleep_wake - enable or disable the system wake-up
 647  *                                  capability of given device
 648  *      @dev: device to handle
 649  *      @enable: 'true' - enable, 'false' - disable the wake-up capability
 650  */
 651 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
 652 {
 653         acpi_handle handle;
 654         struct acpi_device *adev;
 655         int error;
 656
 657         if (!device_can_wakeup(dev))
 658                 return -EINVAL;
 659
 660         handle = DEVICE_ACPI_HANDLE(dev);
 661         if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
 662                 dev_dbg(dev, "ACPI handle has no context in %s!\n", __func__);
 663                 return -ENODEV;
 664         }
 665
 666         error = enable ?
 667                 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
 668                 acpi_disable_wakeup_device_power(adev);
 669         if (!error)
 670                 dev_info(dev, "wake-up capability %s by ACPI\n",
 671                                 enable ? "enabled" : "disabled");
 672
 673         return error;
 674 }
 675 #endif
 676
 677 static void acpi_power_off_prepare(void)
 678 {
 679         /* Prepare to power off the system */
 680         acpi_sleep_prepare(ACPI_STATE_S5);
 681         acpi_disable_all_gpes();
 682 }
 683
 684 static void acpi_power_off(void)
 685 {
 686         /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
 687         printk(KERN_DEBUG "%s called\n", __func__);
 688         local_irq_disable();
 689         acpi_enable_wakeup_device(ACPI_STATE_S5);
 690         acpi_enter_sleep_state(ACPI_STATE_S5);
 691 }
 692
 693 /*
 694  * ACPI 2.0 created the optional _GTS and _BFS,
 695  * but industry adoption has been neither rapid nor broad.
 696  *
 697  * Linux gets into trouble when it executes poorly validated
 698  * paths through the BIOS, so disable _GTS and _BFS by default,
 699  * but do speak up and offer the option to enable them.
 700  */
 701 void __init acpi_gts_bfs_check(void)
 702 {
 703         acpi_handle dummy;
 704
 705         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__GTS, &dummy)))
 706         {
 707                 printk(KERN_NOTICE PREFIX "BIOS offers _GTS\n");
 708                 printk(KERN_NOTICE PREFIX "If \"acpi.gts=1\" improves suspend, "
 709                         "please notify linux-acpi@vger.kernel.org\n");
 710         }
 711         if (ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT, METHOD_NAME__BFS, &dummy)))
 712         {
 713                 printk(KERN_NOTICE PREFIX "BIOS offers _BFS\n");
 714                 printk(KERN_NOTICE PREFIX "If \"acpi.bfs=1\" improves resume, "
 715                         "please notify linux-acpi@vger.kernel.org\n");
 716         }
 717 }
 718
 719 int __init acpi_sleep_init(void)
 720 {
 721         acpi_status status;
 722         u8 type_a, type_b;
 723 #ifdef CONFIG_SUSPEND
 724         int i = 0;
 725
 726         dmi_check_system(acpisleep_dmi_table);
 727 #endif
 728
 729         if (acpi_disabled)
 730                 return 0;
 731
 732         sleep_states[ACPI_STATE_S0] = 1;
 733         printk(KERN_INFO PREFIX "(supports S0");
 734
 735 #ifdef CONFIG_SUSPEND
 736         for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
 737                 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
 738                 if (ACPI_SUCCESS(status)) {
 739                         sleep_states[i] = 1;
 740                         printk(" S%d", i);
 741                 }
 742         }
 743
 744         suspend_set_ops(old_suspend_ordering ?
 745                 &acpi_suspend_ops_old : &acpi_suspend_ops);
 746 #endif
 747
 748 #ifdef CONFIG_HIBERNATION
 749         status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
 750         if (ACPI_SUCCESS(status)) {
 751                 hibernation_set_ops(old_suspend_ordering ?
 752                         &acpi_hibernation_ops_old : &acpi_hibernation_ops);
 753                 sleep_states[ACPI_STATE_S4] = 1;
 754                 printk(" S4");
 755                 if (!nosigcheck) {
 756                         acpi_get_table(ACPI_SIG_FACS, 1,
 757                                 (struct acpi_table_header **)&facs);
 758                         if (facs)
 759                                 s4_hardware_signature =
 760                                         facs->hardware_signature;
 761                 }
 762         }
 763 #endif
 764         status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
 765         if (ACPI_SUCCESS(status)) {
 766                 sleep_states[ACPI_STATE_S5] = 1;
 767                 printk(" S5");
 768                 pm_power_off_prepare = acpi_power_off_prepare;
 769                 pm_power_off = acpi_power_off;
 770         }
 771         printk(")\n");
 772         /*
 773          * Register the tts_notifier to reboot notifier list so that the _TTS
 774          * object can also be evaluated when the system enters S5.
 775          */
 776         register_reboot_notifier(&tts_notifier);
 777         acpi_gts_bfs_check();
 778         return 0;
 779 }