suspend: switch the Asus Pundit P1-AH2 to old ACPI sleep ordering
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / acpi / sleep.c
blob3ca98686f28b837dbbcb461f77f59009c3ae1644
1 /*
2 * sleep.c - ACPI sleep support.
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
9 * This file is released under the GPLv2.
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>
20 #include <asm/io.h>
22 #include <acpi/acpi_bus.h>
23 #include <acpi/acpi_drivers.h>
24 #include "sleep.h"
26 u8 sleep_states[ACPI_S_STATE_COUNT];
28 static void acpi_sleep_tts_switch(u32 acpi_state)
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;
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) {
38 * OS can't evaluate the _TTS object correctly. Some warning
39 * message will be printed. But it won't break anything.
41 printk(KERN_NOTICE "Failure in evaluating _TTS object\n");
45 static int tts_notify_reboot(struct notifier_block *this,
46 unsigned long code, void *x)
48 acpi_sleep_tts_switch(ACPI_STATE_S5);
49 return NOTIFY_DONE;
52 static struct notifier_block tts_notifier = {
53 .notifier_call = tts_notify_reboot,
54 .next = NULL,
55 .priority = 0,
58 static int acpi_sleep_prepare(u32 acpi_state)
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;
66 acpi_set_firmware_waking_vector(
67 (acpi_physical_address)acpi_wakeup_address);
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;
79 #ifdef CONFIG_ACPI_SLEEP
80 static u32 acpi_target_sleep_state = ACPI_STATE_S0;
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.
86 static bool old_suspend_ordering;
88 void __init acpi_old_suspend_ordering(void)
90 old_suspend_ordering = true;
93 /**
94 * acpi_pm_disable_gpes - Disable the GPEs.
96 static int acpi_pm_disable_gpes(void)
98 acpi_disable_all_gpes();
99 return 0;
103 * __acpi_pm_prepare - Prepare the platform to enter the target state.
105 * If necessary, set the firmware waking vector and do arch-specific
106 * nastiness to get the wakeup code to the waking vector.
108 static int __acpi_pm_prepare(void)
110 int error = acpi_sleep_prepare(acpi_target_sleep_state);
112 if (error)
113 acpi_target_sleep_state = ACPI_STATE_S0;
114 return error;
118 * acpi_pm_prepare - Prepare the platform to enter the target sleep
119 * state and disable the GPEs.
121 static int acpi_pm_prepare(void)
123 int error = __acpi_pm_prepare();
125 if (!error)
126 acpi_disable_all_gpes();
127 return error;
131 * acpi_pm_finish - Instruct the platform to leave a sleep state.
133 * This is called after we wake back up (or if entering the sleep state
134 * failed).
136 static void acpi_pm_finish(void)
138 u32 acpi_state = acpi_target_sleep_state;
140 if (acpi_state == ACPI_STATE_S0)
141 return;
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);
148 /* reset firmware waking vector */
149 acpi_set_firmware_waking_vector((acpi_physical_address) 0);
151 acpi_target_sleep_state = ACPI_STATE_S0;
155 * acpi_pm_end - Finish up suspend sequence.
157 static void acpi_pm_end(void)
160 * This is necessary in case acpi_pm_finish() is not called during a
161 * failing transition to a sleep state.
163 acpi_target_sleep_state = ACPI_STATE_S0;
164 acpi_sleep_tts_switch(acpi_target_sleep_state);
166 #else /* !CONFIG_ACPI_SLEEP */
167 #define acpi_target_sleep_state ACPI_STATE_S0
168 #endif /* CONFIG_ACPI_SLEEP */
170 #ifdef CONFIG_SUSPEND
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.
181 static bool set_sci_en_on_resume;
183 extern void do_suspend_lowlevel(void);
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
193 * acpi_suspend_begin - Set the target system sleep state to the state
194 * associated with given @pm_state, if supported.
196 static int acpi_suspend_begin(suspend_state_t pm_state)
198 u32 acpi_state = acpi_suspend_states[pm_state];
199 int error = 0;
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;
209 return error;
213 * acpi_suspend_enter - Actually enter a sleep state.
214 * @pm_state: ignored
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.
220 static int acpi_suspend_enter(suspend_state_t pm_state)
222 acpi_status status = AE_OK;
223 unsigned long flags = 0;
224 u32 acpi_state = acpi_target_sleep_state;
226 ACPI_FLUSH_CPU_CACHE();
228 /* Do arch specific saving of state. */
229 if (acpi_state == ACPI_STATE_S3) {
230 int error = acpi_save_state_mem();
232 if (error)
233 return error;
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;
244 case ACPI_STATE_S3:
245 do_suspend_lowlevel();
246 break;
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();
255 /* Reprogram control registers and execute _BFS */
256 acpi_leave_sleep_state_prep(acpi_state);
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 ]
262 if (ACPI_SUCCESS(status) && (acpi_state == ACPI_STATE_S3))
263 acpi_clear_event(ACPI_EVENT_POWER_BUTTON);
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
270 acpi_disable_all_gpes();
272 local_irq_restore(flags);
273 printk(KERN_DEBUG "Back to C!\n");
275 /* restore processor state */
276 if (acpi_state == ACPI_STATE_S3)
277 acpi_restore_state_mem();
279 return ACPI_SUCCESS(status) ? 0 : -EFAULT;
282 static int acpi_suspend_state_valid(suspend_state_t pm_state)
284 u32 acpi_state;
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];
292 return sleep_states[acpi_state];
293 default:
294 return 0;
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,
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.
313 static int acpi_suspend_begin_old(suspend_state_t pm_state)
315 int error = acpi_suspend_begin(pm_state);
317 if (!error)
318 error = __acpi_pm_prepare();
319 return error;
323 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
324 * been requested.
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,
336 static int __init init_old_suspend_ordering(const struct dmi_system_id *d)
338 old_suspend_ordering = true;
339 return 0;
342 static int __init init_set_sci_en_on_resume(const struct dmi_system_id *d)
344 set_sci_en_on_resume = true;
345 return 0;
348 static struct dmi_system_id __initdata acpisleep_dmi_table[] = {
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)"),
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"),
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"),
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"),
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"),
391 #endif /* CONFIG_SUSPEND */
393 #ifdef CONFIG_HIBERNATION
395 * The ACPI specification wants us to save NVS memory regions during hibernation
396 * and to restore them during the subsequent resume. However, it is not certain
397 * if this mechanism is going to work on all machines, so we allow the user to
398 * disable this mechanism using the 'acpi_sleep=s4_nonvs' kernel command line
399 * option.
401 static bool s4_no_nvs;
403 void __init acpi_s4_no_nvs(void)
405 s4_no_nvs = true;
408 static unsigned long s4_hardware_signature;
409 static struct acpi_table_facs *facs;
410 static bool nosigcheck;
412 void __init acpi_no_s4_hw_signature(void)
414 nosigcheck = true;
417 static int acpi_hibernation_begin(void)
419 int error;
421 error = s4_no_nvs ? 0 : hibernate_nvs_alloc();
422 if (!error) {
423 acpi_target_sleep_state = ACPI_STATE_S4;
424 acpi_sleep_tts_switch(acpi_target_sleep_state);
427 return error;
430 static int acpi_hibernation_pre_snapshot(void)
432 int error = acpi_pm_prepare();
434 if (!error)
435 hibernate_nvs_save();
437 return error;
440 static int acpi_hibernation_enter(void)
442 acpi_status status = AE_OK;
443 unsigned long flags = 0;
445 ACPI_FLUSH_CPU_CACHE();
447 local_irq_save(flags);
448 acpi_enable_wakeup_device(ACPI_STATE_S4);
449 /* This shouldn't return. If it returns, we have a problem */
450 status = acpi_enter_sleep_state(ACPI_STATE_S4);
451 /* Reprogram control registers and execute _BFS */
452 acpi_leave_sleep_state_prep(ACPI_STATE_S4);
453 local_irq_restore(flags);
455 return ACPI_SUCCESS(status) ? 0 : -EFAULT;
458 static void acpi_hibernation_finish(void)
460 hibernate_nvs_free();
461 acpi_pm_finish();
464 static void acpi_hibernation_leave(void)
467 * If ACPI is not enabled by the BIOS and the boot kernel, we need to
468 * enable it here.
470 acpi_enable();
471 /* Reprogram control registers and execute _BFS */
472 acpi_leave_sleep_state_prep(ACPI_STATE_S4);
473 /* Check the hardware signature */
474 if (facs && s4_hardware_signature != facs->hardware_signature) {
475 printk(KERN_EMERG "ACPI: Hardware changed while hibernated, "
476 "cannot resume!\n");
477 panic("ACPI S4 hardware signature mismatch");
479 /* Restore the NVS memory area */
480 hibernate_nvs_restore();
483 static void acpi_pm_enable_gpes(void)
485 acpi_enable_all_runtime_gpes();
488 static struct platform_hibernation_ops acpi_hibernation_ops = {
489 .begin = acpi_hibernation_begin,
490 .end = acpi_pm_end,
491 .pre_snapshot = acpi_hibernation_pre_snapshot,
492 .finish = acpi_hibernation_finish,
493 .prepare = acpi_pm_prepare,
494 .enter = acpi_hibernation_enter,
495 .leave = acpi_hibernation_leave,
496 .pre_restore = acpi_pm_disable_gpes,
497 .restore_cleanup = acpi_pm_enable_gpes,
501 * acpi_hibernation_begin_old - Set the target system sleep state to
502 * ACPI_STATE_S4 and execute the _PTS control method. This
503 * function is used if the pre-ACPI 2.0 suspend ordering has been
504 * requested.
506 static int acpi_hibernation_begin_old(void)
508 int error;
510 * The _TTS object should always be evaluated before the _PTS object.
511 * When the old_suspended_ordering is true, the _PTS object is
512 * evaluated in the acpi_sleep_prepare.
514 acpi_sleep_tts_switch(ACPI_STATE_S4);
516 error = acpi_sleep_prepare(ACPI_STATE_S4);
518 if (!error) {
519 if (!s4_no_nvs)
520 error = hibernate_nvs_alloc();
521 if (!error)
522 acpi_target_sleep_state = ACPI_STATE_S4;
524 return error;
527 static int acpi_hibernation_pre_snapshot_old(void)
529 int error = acpi_pm_disable_gpes();
531 if (!error)
532 hibernate_nvs_save();
534 return error;
538 * The following callbacks are used if the pre-ACPI 2.0 suspend ordering has
539 * been requested.
541 static struct platform_hibernation_ops acpi_hibernation_ops_old = {
542 .begin = acpi_hibernation_begin_old,
543 .end = acpi_pm_end,
544 .pre_snapshot = acpi_hibernation_pre_snapshot_old,
545 .finish = acpi_hibernation_finish,
546 .prepare = acpi_pm_disable_gpes,
547 .enter = acpi_hibernation_enter,
548 .leave = acpi_hibernation_leave,
549 .pre_restore = acpi_pm_disable_gpes,
550 .restore_cleanup = acpi_pm_enable_gpes,
551 .recover = acpi_pm_finish,
553 #endif /* CONFIG_HIBERNATION */
555 int acpi_suspend(u32 acpi_state)
557 suspend_state_t states[] = {
558 [1] = PM_SUSPEND_STANDBY,
559 [3] = PM_SUSPEND_MEM,
560 [5] = PM_SUSPEND_MAX
563 if (acpi_state < 6 && states[acpi_state])
564 return pm_suspend(states[acpi_state]);
565 if (acpi_state == 4)
566 return hibernate();
567 return -EINVAL;
570 #ifdef CONFIG_PM_SLEEP
572 * acpi_pm_device_sleep_state - return preferred power state of ACPI device
573 * in the system sleep state given by %acpi_target_sleep_state
574 * @dev: device to examine; its driver model wakeup flags control
575 * whether it should be able to wake up the system
576 * @d_min_p: used to store the upper limit of allowed states range
577 * Return value: preferred power state of the device on success, -ENODEV on
578 * failure (ie. if there's no 'struct acpi_device' for @dev)
580 * Find the lowest power (highest number) ACPI device power state that
581 * device @dev can be in while the system is in the sleep state represented
582 * by %acpi_target_sleep_state. If @wake is nonzero, the device should be
583 * able to wake up the system from this sleep state. If @d_min_p is set,
584 * the highest power (lowest number) device power state of @dev allowed
585 * in this system sleep state is stored at the location pointed to by it.
587 * The caller must ensure that @dev is valid before using this function.
588 * The caller is also responsible for figuring out if the device is
589 * supposed to be able to wake up the system and passing this information
590 * via @wake.
593 int acpi_pm_device_sleep_state(struct device *dev, int *d_min_p)
595 acpi_handle handle = DEVICE_ACPI_HANDLE(dev);
596 struct acpi_device *adev;
597 char acpi_method[] = "_SxD";
598 unsigned long long d_min, d_max;
600 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
601 printk(KERN_DEBUG "ACPI handle has no context!\n");
602 return -ENODEV;
605 acpi_method[2] = '0' + acpi_target_sleep_state;
607 * If the sleep state is S0, we will return D3, but if the device has
608 * _S0W, we will use the value from _S0W
610 d_min = ACPI_STATE_D0;
611 d_max = ACPI_STATE_D3;
614 * If present, _SxD methods return the minimum D-state (highest power
615 * state) we can use for the corresponding S-states. Otherwise, the
616 * minimum D-state is D0 (ACPI 3.x).
618 * NOTE: We rely on acpi_evaluate_integer() not clobbering the integer
619 * provided -- that's our fault recovery, we ignore retval.
621 if (acpi_target_sleep_state > ACPI_STATE_S0)
622 acpi_evaluate_integer(handle, acpi_method, NULL, &d_min);
625 * If _PRW says we can wake up the system from the target sleep state,
626 * the D-state returned by _SxD is sufficient for that (we assume a
627 * wakeup-aware driver if wake is set). Still, if _SxW exists
628 * (ACPI 3.x), it should return the maximum (lowest power) D-state that
629 * can wake the system. _S0W may be valid, too.
631 if (acpi_target_sleep_state == ACPI_STATE_S0 ||
632 (device_may_wakeup(dev) && adev->wakeup.state.enabled &&
633 adev->wakeup.sleep_state <= acpi_target_sleep_state)) {
634 acpi_status status;
636 acpi_method[3] = 'W';
637 status = acpi_evaluate_integer(handle, acpi_method, NULL,
638 &d_max);
639 if (ACPI_FAILURE(status)) {
640 d_max = d_min;
641 } else if (d_max < d_min) {
642 /* Warn the user of the broken DSDT */
643 printk(KERN_WARNING "ACPI: Wrong value from %s\n",
644 acpi_method);
645 /* Sanitize it */
646 d_min = d_max;
650 if (d_min_p)
651 *d_min_p = d_min;
652 return d_max;
656 * acpi_pm_device_sleep_wake - enable or disable the system wake-up
657 * capability of given device
658 * @dev: device to handle
659 * @enable: 'true' - enable, 'false' - disable the wake-up capability
661 int acpi_pm_device_sleep_wake(struct device *dev, bool enable)
663 acpi_handle handle;
664 struct acpi_device *adev;
666 if (!device_may_wakeup(dev))
667 return -EINVAL;
669 handle = DEVICE_ACPI_HANDLE(dev);
670 if (!handle || ACPI_FAILURE(acpi_bus_get_device(handle, &adev))) {
671 printk(KERN_DEBUG "ACPI handle has no context!\n");
672 return -ENODEV;
675 return enable ?
676 acpi_enable_wakeup_device_power(adev, acpi_target_sleep_state) :
677 acpi_disable_wakeup_device_power(adev);
679 #endif
681 static void acpi_power_off_prepare(void)
683 /* Prepare to power off the system */
684 acpi_sleep_prepare(ACPI_STATE_S5);
685 acpi_disable_all_gpes();
688 static void acpi_power_off(void)
690 /* acpi_sleep_prepare(ACPI_STATE_S5) should have already been called */
691 printk(KERN_DEBUG "%s called\n", __func__);
692 local_irq_disable();
693 acpi_enable_wakeup_device(ACPI_STATE_S5);
694 acpi_enter_sleep_state(ACPI_STATE_S5);
697 int __init acpi_sleep_init(void)
699 acpi_status status;
700 u8 type_a, type_b;
701 #ifdef CONFIG_SUSPEND
702 int i = 0;
704 dmi_check_system(acpisleep_dmi_table);
705 #endif
707 if (acpi_disabled)
708 return 0;
710 sleep_states[ACPI_STATE_S0] = 1;
711 printk(KERN_INFO PREFIX "(supports S0");
713 #ifdef CONFIG_SUSPEND
714 for (i = ACPI_STATE_S1; i < ACPI_STATE_S4; i++) {
715 status = acpi_get_sleep_type_data(i, &type_a, &type_b);
716 if (ACPI_SUCCESS(status)) {
717 sleep_states[i] = 1;
718 printk(" S%d", i);
722 suspend_set_ops(old_suspend_ordering ?
723 &acpi_suspend_ops_old : &acpi_suspend_ops);
724 #endif
726 #ifdef CONFIG_HIBERNATION
727 status = acpi_get_sleep_type_data(ACPI_STATE_S4, &type_a, &type_b);
728 if (ACPI_SUCCESS(status)) {
729 hibernation_set_ops(old_suspend_ordering ?
730 &acpi_hibernation_ops_old : &acpi_hibernation_ops);
731 sleep_states[ACPI_STATE_S4] = 1;
732 printk(" S4");
733 if (!nosigcheck) {
734 acpi_get_table(ACPI_SIG_FACS, 1,
735 (struct acpi_table_header **)&facs);
736 if (facs)
737 s4_hardware_signature =
738 facs->hardware_signature;
741 #endif
742 status = acpi_get_sleep_type_data(ACPI_STATE_S5, &type_a, &type_b);
743 if (ACPI_SUCCESS(status)) {
744 sleep_states[ACPI_STATE_S5] = 1;
745 printk(" S5");
746 pm_power_off_prepare = acpi_power_off_prepare;
747 pm_power_off = acpi_power_off;
749 printk(")\n");
751 * Register the tts_notifier to reboot notifier list so that the _TTS
752 * object can also be evaluated when the system enters S5.
754 register_reboot_notifier(&tts_notifier);
755 return 0;