drivers/acpi/acpica/hwsleep.c - maze/linux - Git at Google

 /******************************************************************************
  *
  * Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
  *                   original/legacy sleep/PM registers.
  *
  *****************************************************************************/

 /*
  * Copyright (C) 2000 - 2012, Intel Corp.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions, and the following disclaimer,
  *    without modification.
  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
  *    substantially similar to the "NO WARRANTY" disclaimer below
  *    ("Disclaimer") and any redistribution must be conditioned upon
  *    including a substantially similar Disclaimer requirement for further
  *    binary redistribution.
  * 3. Neither the names of the above-listed copyright holders nor the names
  *    of any contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * Alternatively, this software may be distributed under the terms of the
  * GNU General Public License ("GPL") version 2 as published by the Free
  * Software Foundation.
  *
  * NO WARRANTY
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGES.
  */

 #include <acpi/acpi.h>
 #include <linux/acpi.h>
 #include "accommon.h"
 #include <linux/module.h>

 #define _COMPONENT          ACPI_HARDWARE
 ACPI_MODULE_NAME("hwsleep")

 #if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
 /*******************************************************************************
  *
  * FUNCTION:    acpi_hw_legacy_sleep
  *
  * PARAMETERS:  sleep_state         - Which sleep state to enter
  *              Flags               - ACPI_EXECUTE_GTS to run optional method
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
  *              THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
  *
  ******************************************************************************/
 acpi_status acpi_hw_legacy_sleep(u8 sleep_state, u8 flags)
 {
 	struct acpi_bit_register_info *sleep_type_reg_info;
 	struct acpi_bit_register_info *sleep_enable_reg_info;
 	u32 pm1a_control;
 	u32 pm1b_control;
 	u32 in_value;
 	acpi_status status;

 	ACPI_FUNCTION_TRACE(hw_legacy_sleep);

 	sleep_type_reg_info =
 	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 	sleep_enable_reg_info =
 	    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

 	/* Clear wake status */

 	status =
 	    acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	/* Clear all fixed and general purpose status bits */

 	status = acpi_hw_clear_acpi_status();
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	/*
 	 * 1) Disable/Clear all GPEs
 	 * 2) Enable all wakeup GPEs
 	 */
 	status = acpi_hw_disable_all_gpes();
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}
 	acpi_gbl_system_awake_and_running = FALSE;

 	status = acpi_hw_enable_all_wakeup_gpes();
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	/* Optionally execute _GTS (Going To Sleep) */

 	if (flags & ACPI_EXECUTE_GTS) {
 		acpi_hw_execute_sleep_method(METHOD_PATHNAME__GTS, sleep_state);
 	}

 	/* Get current value of PM1A control */

 	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 				       &pm1a_control);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}
 	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
 			  "Entering sleep state [S%u]\n", sleep_state));

 	/* Clear the SLP_EN and SLP_TYP fields */

 	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
 			  sleep_enable_reg_info->access_bit_mask);
 	pm1b_control = pm1a_control;

 	/* Insert the SLP_TYP bits */

 	pm1a_control |=
 	    (acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
 	pm1b_control |=
 	    (acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);

 	/*
 	 * We split the writes of SLP_TYP and SLP_EN to workaround
 	 * poorly implemented hardware.
 	 */

 	/* Write #1: write the SLP_TYP data to the PM1 Control registers */

 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	/* Insert the sleep enable (SLP_EN) bit */

 	pm1a_control |= sleep_enable_reg_info->access_bit_mask;
 	pm1b_control |= sleep_enable_reg_info->access_bit_mask;

 	/* Flush caches, as per ACPI specification */

 	ACPI_FLUSH_CPU_CACHE();

 	status = acpi_os_prepare_sleep(sleep_state, pm1a_control,
 				       pm1b_control);
 	if (ACPI_SKIP(status))
 		return_ACPI_STATUS(AE_OK);
 	if (ACPI_FAILURE(status))
 		return_ACPI_STATUS(status);
 	/* Write #2: Write both SLP_TYP + SLP_EN */

 	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	if (sleep_state > ACPI_STATE_S3) {
 		/*
 		 * We wanted to sleep > S3, but it didn't happen (by virtue of the
 		 * fact that we are still executing!)
 		 *
 		 * Wait ten seconds, then try again. This is to get S4/S5 to work on
 		 * all machines.
 		 *
 		 * We wait so long to allow chipsets that poll this reg very slowly
 		 * to still read the right value. Ideally, this block would go
 		 * away entirely.
 		 */
 		acpi_os_stall(10000000);

 		status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
 						sleep_enable_reg_info->
 						access_bit_mask);
 		if (ACPI_FAILURE(status)) {
 			return_ACPI_STATUS(status);
 		}
 	}

 	/* Wait for transition back to Working State */

 	do {
 		status =
 		    acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
 		if (ACPI_FAILURE(status)) {
 			return_ACPI_STATUS(status);
 		}

 	} while (!in_value);

 	return_ACPI_STATUS(AE_OK);
 }

 /*******************************************************************************
  *
  * FUNCTION:    acpi_hw_legacy_wake_prep
  *
  * PARAMETERS:  sleep_state         - Which sleep state we just exited
  *              Flags               - ACPI_EXECUTE_BFS to run optional method
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
  *              sleep.
  *              Called with interrupts ENABLED.
  *
  ******************************************************************************/

 acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state, u8 flags)
 {
 	acpi_status status;
 	struct acpi_bit_register_info *sleep_type_reg_info;
 	struct acpi_bit_register_info *sleep_enable_reg_info;
 	u32 pm1a_control;
 	u32 pm1b_control;

 	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);

 	/*
 	 * Set SLP_TYPE and SLP_EN to state S0.
 	 * This is unclear from the ACPI Spec, but it is required
 	 * by some machines.
 	 */
 	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
 					  &acpi_gbl_sleep_type_a,
 					  &acpi_gbl_sleep_type_b);
 	if (ACPI_SUCCESS(status)) {
 		sleep_type_reg_info =
 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 		sleep_enable_reg_info =
 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

 		/* Get current value of PM1A control */

 		status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
 					       &pm1a_control);
 		if (ACPI_SUCCESS(status)) {

 			/* Clear the SLP_EN and SLP_TYP fields */

 			pm1a_control &= ~(sleep_type_reg_info->access_bit_mask |
 					  sleep_enable_reg_info->
 					  access_bit_mask);
 			pm1b_control = pm1a_control;

 			/* Insert the SLP_TYP bits */

 			pm1a_control |= (acpi_gbl_sleep_type_a <<
 					 sleep_type_reg_info->bit_position);
 			pm1b_control |= (acpi_gbl_sleep_type_b <<
 					 sleep_type_reg_info->bit_position);

 			/* Write the control registers and ignore any errors */

 			(void)acpi_hw_write_pm1_control(pm1a_control,
 							pm1b_control);
 		}
 	}

 	/* Optionally execute _BFS (Back From Sleep) */

 	if (flags & ACPI_EXECUTE_BFS) {
 		acpi_hw_execute_sleep_method(METHOD_PATHNAME__BFS, sleep_state);
 	}
 	return_ACPI_STATUS(status);
 }

 /*******************************************************************************
  *
  * FUNCTION:    acpi_hw_legacy_wake
  *
  * PARAMETERS:  sleep_state         - Which sleep state we just exited
  *              Flags               - Reserved, set to zero
  *
  * RETURN:      Status
  *
  * DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
  *              Called with interrupts ENABLED.
  *
  ******************************************************************************/

 acpi_status acpi_hw_legacy_wake(u8 sleep_state, u8 flags)
 {
 	acpi_status status;

 	ACPI_FUNCTION_TRACE(hw_legacy_wake);

 	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */

 	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);

 	/*
 	 * GPEs must be enabled before _WAK is called as GPEs
 	 * might get fired there
 	 *
 	 * Restore the GPEs:
 	 * 1) Disable/Clear all GPEs
 	 * 2) Enable all runtime GPEs
 	 */
 	status = acpi_hw_disable_all_gpes();
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	status = acpi_hw_enable_all_runtime_gpes();
 	if (ACPI_FAILURE(status)) {
 		return_ACPI_STATUS(status);
 	}

 	/*
 	 * Now we can execute _WAK, etc. Some machines require that the GPEs
 	 * are enabled before the wake methods are executed.
 	 */
 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);

 	/*
 	 * Some BIOS code assumes that WAK_STS will be cleared on resume
 	 * and use it to determine whether the system is rebooting or
 	 * resuming. Clear WAK_STS for compatibility.
 	 */
 	acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);
 	acpi_gbl_system_awake_and_running = TRUE;

 	/* Enable power button */

 	(void)
 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
 				    [ACPI_EVENT_POWER_BUTTON].
 				    enable_register_id, ACPI_ENABLE_EVENT);

 	(void)
 	    acpi_write_bit_register(acpi_gbl_fixed_event_info
 				    [ACPI_EVENT_POWER_BUTTON].
 				    status_register_id, ACPI_CLEAR_STATUS);

 	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
 	return_ACPI_STATUS(status);
 }

 #endif				/* !ACPI_REDUCED_HARDWARE */
	/******************************************************************************
	*
	* Name: hwsleep.c - ACPI Hardware Sleep/Wake Support functions for the
	* original/legacy sleep/PM registers.
	*
	*****************************************************************************/

	/*
	* Copyright (C) 2000 - 2012, Intel Corp.
	* All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	* 1. Redistributions of source code must retain the above copyright
	* notice, this list of conditions, and the following disclaimer,
	* without modification.
	* 2. Redistributions in binary form must reproduce at minimum a disclaimer
	* substantially similar to the "NO WARRANTY" disclaimer below
	* ("Disclaimer") and any redistribution must be conditioned upon
	* including a substantially similar Disclaimer requirement for further
	* binary redistribution.
	* 3. Neither the names of the above-listed copyright holders nor the names
	* of any contributors may be used to endorse or promote products derived
	* from this software without specific prior written permission.
	*
	* Alternatively, this software may be distributed under the terms of the
	* GNU General Public License ("GPL") version 2 as published by the Free
	* Software Foundation.
	*
	* NO WARRANTY
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
	* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	* POSSIBILITY OF SUCH DAMAGES.
	*/

	#include <acpi/acpi.h>
	#include <linux/acpi.h>
	#include "accommon.h"
	#include <linux/module.h>

	#define _COMPONENT ACPI_HARDWARE
	ACPI_MODULE_NAME("hwsleep")

	#if (!ACPI_REDUCED_HARDWARE) /* Entire module */
	/*******************************************************************************
	*
	* FUNCTION: acpi_hw_legacy_sleep
	*
	* PARAMETERS: sleep_state - Which sleep state to enter
	* Flags - ACPI_EXECUTE_GTS to run optional method
	*
	* RETURN: Status
	*
	* DESCRIPTION: Enter a system sleep state via the legacy FADT PM registers
	* THIS FUNCTION MUST BE CALLED WITH INTERRUPTS DISABLED
	*
	******************************************************************************/
	acpi_status acpi_hw_legacy_sleep(u8 sleep_state, u8 flags)
	{
	struct acpi_bit_register_info *sleep_type_reg_info;
	struct acpi_bit_register_info *sleep_enable_reg_info;
	u32 pm1a_control;
	u32 pm1b_control;
	u32 in_value;
	acpi_status status;

	ACPI_FUNCTION_TRACE(hw_legacy_sleep);

	sleep_type_reg_info =
	acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
	sleep_enable_reg_info =
	acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

	/* Clear wake status */

	status =
	acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, ACPI_CLEAR_STATUS);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	/* Clear all fixed and general purpose status bits */

	status = acpi_hw_clear_acpi_status();
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	/*
	* 1) Disable/Clear all GPEs
	* 2) Enable all wakeup GPEs
	*/
	status = acpi_hw_disable_all_gpes();
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	acpi_gbl_system_awake_and_running = FALSE;

	status = acpi_hw_enable_all_wakeup_gpes();
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	/* Optionally execute _GTS (Going To Sleep) */

	if (flags & ACPI_EXECUTE_GTS) {
	acpi_hw_execute_sleep_method(METHOD_PATHNAME__GTS, sleep_state);
	}

	/* Get current value of PM1A control */

	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
	&pm1a_control);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	ACPI_DEBUG_PRINT((ACPI_DB_INIT,
	"Entering sleep state [S%u]\n", sleep_state));

	/* Clear the SLP_EN and SLP_TYP fields */

	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask \|
	sleep_enable_reg_info->access_bit_mask);
	pm1b_control = pm1a_control;

	/* Insert the SLP_TYP bits */

	pm1a_control \|=
	(acpi_gbl_sleep_type_a << sleep_type_reg_info->bit_position);
	pm1b_control \|=
	(acpi_gbl_sleep_type_b << sleep_type_reg_info->bit_position);

	/*
	* We split the writes of SLP_TYP and SLP_EN to workaround
	* poorly implemented hardware.
	*/

	/* Write #1: write the SLP_TYP data to the PM1 Control registers */

	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	/* Insert the sleep enable (SLP_EN) bit */

	pm1a_control \|= sleep_enable_reg_info->access_bit_mask;
	pm1b_control \|= sleep_enable_reg_info->access_bit_mask;

	/* Flush caches, as per ACPI specification */

	ACPI_FLUSH_CPU_CACHE();

	status = acpi_os_prepare_sleep(sleep_state, pm1a_control,
	pm1b_control);
	if (ACPI_SKIP(status))
	return_ACPI_STATUS(AE_OK);
	if (ACPI_FAILURE(status))
	return_ACPI_STATUS(status);
	/* Write #2: Write both SLP_TYP + SLP_EN */

	status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	if (sleep_state > ACPI_STATE_S3) {
	/*
	* We wanted to sleep > S3, but it didn't happen (by virtue of the
	* fact that we are still executing!)
	*
	* Wait ten seconds, then try again. This is to get S4/S5 to work on
	* all machines.
	*
	* We wait so long to allow chipsets that poll this reg very slowly
	* to still read the right value. Ideally, this block would go
	* away entirely.
	*/
	acpi_os_stall(10000000);

	status = acpi_hw_register_write(ACPI_REGISTER_PM1_CONTROL,
	sleep_enable_reg_info->
	access_bit_mask);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}
	}

	/* Wait for transition back to Working State */

	do {
	status =
	acpi_read_bit_register(ACPI_BITREG_WAKE_STATUS, &in_value);
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	} while (!in_value);

	return_ACPI_STATUS(AE_OK);
	}

	/*******************************************************************************
	*
	* FUNCTION: acpi_hw_legacy_wake_prep
	*
	* PARAMETERS: sleep_state - Which sleep state we just exited
	* Flags - ACPI_EXECUTE_BFS to run optional method
	*
	* RETURN: Status
	*
	* DESCRIPTION: Perform the first state of OS-independent ACPI cleanup after a
	* sleep.
	* Called with interrupts ENABLED.
	*
	******************************************************************************/

	acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state, u8 flags)
	{
	acpi_status status;
	struct acpi_bit_register_info *sleep_type_reg_info;
	struct acpi_bit_register_info *sleep_enable_reg_info;
	u32 pm1a_control;
	u32 pm1b_control;

	ACPI_FUNCTION_TRACE(hw_legacy_wake_prep);

	/*
	* Set SLP_TYPE and SLP_EN to state S0.
	* This is unclear from the ACPI Spec, but it is required
	* by some machines.
	*/
	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
	&acpi_gbl_sleep_type_a,
	&acpi_gbl_sleep_type_b);
	if (ACPI_SUCCESS(status)) {
	sleep_type_reg_info =
	acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
	sleep_enable_reg_info =
	acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_ENABLE);

	/* Get current value of PM1A control */

	status = acpi_hw_register_read(ACPI_REGISTER_PM1_CONTROL,
	&pm1a_control);
	if (ACPI_SUCCESS(status)) {

	/* Clear the SLP_EN and SLP_TYP fields */

	pm1a_control &= ~(sleep_type_reg_info->access_bit_mask \|
	sleep_enable_reg_info->
	access_bit_mask);
	pm1b_control = pm1a_control;

	/* Insert the SLP_TYP bits */

	pm1a_control \|= (acpi_gbl_sleep_type_a <<
	sleep_type_reg_info->bit_position);
	pm1b_control \|= (acpi_gbl_sleep_type_b <<
	sleep_type_reg_info->bit_position);

	/* Write the control registers and ignore any errors */

	(void)acpi_hw_write_pm1_control(pm1a_control,
	pm1b_control);
	}
	}

	/* Optionally execute _BFS (Back From Sleep) */

	if (flags & ACPI_EXECUTE_BFS) {
	acpi_hw_execute_sleep_method(METHOD_PATHNAME__BFS, sleep_state);
	}
	return_ACPI_STATUS(status);
	}

	/*******************************************************************************
	*
	* FUNCTION: acpi_hw_legacy_wake
	*
	* PARAMETERS: sleep_state - Which sleep state we just exited
	* Flags - Reserved, set to zero
	*
	* RETURN: Status
	*
	* DESCRIPTION: Perform OS-independent ACPI cleanup after a sleep
	* Called with interrupts ENABLED.
	*
	******************************************************************************/

	acpi_status acpi_hw_legacy_wake(u8 sleep_state, u8 flags)
	{
	acpi_status status;

	ACPI_FUNCTION_TRACE(hw_legacy_wake);

	/* Ensure enter_sleep_state_prep -> enter_sleep_state ordering */

	acpi_gbl_sleep_type_a = ACPI_SLEEP_TYPE_INVALID;
	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WAKING);

	/*
	* GPEs must be enabled before _WAK is called as GPEs
	* might get fired there
	*
	* Restore the GPEs:
	* 1) Disable/Clear all GPEs
	* 2) Enable all runtime GPEs
	*/
	status = acpi_hw_disable_all_gpes();
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	status = acpi_hw_enable_all_runtime_gpes();
	if (ACPI_FAILURE(status)) {
	return_ACPI_STATUS(status);
	}

	/*
	* Now we can execute _WAK, etc. Some machines require that the GPEs
	* are enabled before the wake methods are executed.
	*/
	acpi_hw_execute_sleep_method(METHOD_PATHNAME__WAK, sleep_state);

	/*
	* Some BIOS code assumes that WAK_STS will be cleared on resume
	* and use it to determine whether the system is rebooting or
	* resuming. Clear WAK_STS for compatibility.
	*/
	acpi_write_bit_register(ACPI_BITREG_WAKE_STATUS, 1);
	acpi_gbl_system_awake_and_running = TRUE;

	/* Enable power button */

	(void)
	acpi_write_bit_register(acpi_gbl_fixed_event_info
	[ACPI_EVENT_POWER_BUTTON].
	enable_register_id, ACPI_ENABLE_EVENT);

	(void)
	acpi_write_bit_register(acpi_gbl_fixed_event_info
	[ACPI_EVENT_POWER_BUTTON].
	status_register_id, ACPI_CLEAR_STATUS);

	acpi_hw_execute_sleep_method(METHOD_PATHNAME__SST, ACPI_SST_WORKING);
	return_ACPI_STATUS(status);
	}

	#endif /* !ACPI_REDUCED_HARDWARE */