/******************************************************************************
   *
   * Module Name: evxfgpe - External Interfaces for General Purpose Events (GPEs)
   *
   *****************************************************************************/
  
  /*
   * Copyright (C) 2000 - 2013, 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.
   */
  
  #define EXPORT_ACPI_INTERFACES
  
  #include <acpi/acpi.h>
  #include "accommon.h"
  #include "acevents.h"
  #include "acnamesp.h"
  
  #define _COMPONENT          ACPI_EVENTS
  ACPI_MODULE_NAME("evxfgpe")
  
  #if (!ACPI_REDUCED_HARDWARE)	/* Entire module */
  /*******************************************************************************
   *
   * FUNCTION:    acpi_update_all_gpes
   *
   * PARAMETERS:  None
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Complete GPE initialization and enable all GPEs that have
   *              associated _Lxx or _Exx methods and are not pointed to by any
   *              device _PRW methods (this indicates that these GPEs are
   *              generally intended for system or device wakeup. Such GPEs
   *              have to be enabled directly when the devices whose _PRW
   *              methods point to them are set up for wakeup signaling.)
   *
   * NOTE: Should be called after any GPEs are added to the system. Primarily,
   * after the system _PRW methods have been run, but also after a GPE Block
   * Device has been added or if any new GPE methods have been added via a
   * dynamic table load.
   *
   ******************************************************************************/
  
  acpi_status acpi_update_all_gpes(void)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(acpi_update_all_gpes);
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	if (acpi_gbl_all_gpes_initialized) {
  		goto unlock_and_exit;
  	}
  
  	status = acpi_ev_walk_gpe_list(acpi_ev_initialize_gpe_block, NULL);
  	if (ACPI_SUCCESS(status)) {
  		acpi_gbl_all_gpes_initialized = TRUE;
  	}
  
  unlock_and_exit:
  	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
  
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_update_all_gpes)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_enable_gpe
   *
   * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number      - GPE level within the GPE block
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Add a reference to a GPE. On the first reference, the GPE is
   *              hardware-enabled.
   *
   ******************************************************************************/
  
  acpi_status acpi_enable_gpe(acpi_handle gpe_device, u32 gpe_number)
  {
  	acpi_status status = AE_BAD_PARAMETER;
  	struct acpi_gpe_event_info *gpe_event_info;
  	acpi_cpu_flags flags;
  
  	ACPI_FUNCTION_TRACE(acpi_enable_gpe);
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/* Ensure that we have a valid GPE number */
  
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (gpe_event_info) {
  		status = acpi_ev_add_gpe_reference(gpe_event_info);
  	}
  
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  	return_ACPI_STATUS(status);
  }
  ACPI_EXPORT_SYMBOL(acpi_enable_gpe)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_disable_gpe
   *
   * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number      - GPE level within the GPE block
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Remove a reference to a GPE. When the last reference is
   *              removed, only then is the GPE disabled (for runtime GPEs), or
   *              the GPE mask bit disabled (for wake GPEs)
   *
   ******************************************************************************/
  
  acpi_status acpi_disable_gpe(acpi_handle gpe_device, u32 gpe_number)
  {
  	acpi_status status = AE_BAD_PARAMETER;
  	struct acpi_gpe_event_info *gpe_event_info;
  	acpi_cpu_flags flags;
  
  	ACPI_FUNCTION_TRACE(acpi_disable_gpe);
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/* Ensure that we have a valid GPE number */
  
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (gpe_event_info) {
  		status = acpi_ev_remove_gpe_reference(gpe_event_info) ;
  	}
  
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_disable_gpe)
  
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_setup_gpe_for_wake
   *
   * PARAMETERS:  wake_device         - Device associated with the GPE (via _PRW)
   *              gpe_device          - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number          - GPE level within the GPE block
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Mark a GPE as having the ability to wake the system. This
   *              interface is intended to be used as the host executes the
   *              _PRW methods (Power Resources for Wake) in the system tables.
   *              Each _PRW appears under a Device Object (The wake_device), and
   *              contains the info for the wake GPE associated with the
   *              wake_device.
   *
   ******************************************************************************/
  acpi_status
  acpi_setup_gpe_for_wake(acpi_handle wake_device,
  			acpi_handle gpe_device, u32 gpe_number)
  {
  	acpi_status status;
  	struct acpi_gpe_event_info *gpe_event_info;
  	struct acpi_namespace_node *device_node;
  	struct acpi_gpe_notify_info *notify;
  	struct acpi_gpe_notify_info *new_notify;
  	acpi_cpu_flags flags;
  
  	ACPI_FUNCTION_TRACE(acpi_setup_gpe_for_wake);
  
  	/* Parameter Validation */
  
  	if (!wake_device) {
  		/*
  		 * By forcing wake_device to be valid, we automatically enable the
  		 * implicit notify feature on all hosts.
  		 */
  		return_ACPI_STATUS(AE_BAD_PARAMETER);
  	}
  
  	/* Handle root object case */
  
  	if (wake_device == ACPI_ROOT_OBJECT) {
  		device_node = acpi_gbl_root_node;
  	} else {
  		device_node =
  		    ACPI_CAST_PTR(struct acpi_namespace_node, wake_device);
  	}
  
  	/* Validate wake_device is of type Device */
  
  	if (device_node->type != ACPI_TYPE_DEVICE) {
  		return_ACPI_STATUS (AE_BAD_PARAMETER);
  	}
  
  	/*
  	 * Allocate a new notify object up front, in case it is needed.
  	 * Memory allocation while holding a spinlock is a big no-no
  	 * on some hosts.
  	 */
  	new_notify = ACPI_ALLOCATE_ZEROED(sizeof(struct acpi_gpe_notify_info));
  	if (!new_notify) {
  		return_ACPI_STATUS(AE_NO_MEMORY);
  	}
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/* Ensure that we have a valid GPE number */
  
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (!gpe_event_info) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	/*
  	 * If there is no method or handler for this GPE, then the
  	 * wake_device will be notified whenever this GPE fires. This is
  	 * known as an "implicit notify". Note: The GPE is assumed to be
  	 * level-triggered (for windows compatibility).
  	 */
  	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
  	    ACPI_GPE_DISPATCH_NONE) {
  		/*
  		 * This is the first device for implicit notify on this GPE.
  		 * Just set the flags here, and enter the NOTIFY block below.
  		 */
  		gpe_event_info->flags =
  		    (ACPI_GPE_DISPATCH_NOTIFY | ACPI_GPE_LEVEL_TRIGGERED);
  	}
  
  	/*
  	 * If we already have an implicit notify on this GPE, add
  	 * this device to the notify list.
  	 */
  	if ((gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK) ==
  	    ACPI_GPE_DISPATCH_NOTIFY) {
  
  		/* Ensure that the device is not already in the list */
  
  		notify = gpe_event_info->dispatch.notify_list;
  		while (notify) {
  			if (notify->device_node == device_node) {
  				status = AE_ALREADY_EXISTS;
  				goto unlock_and_exit;
  			}
  			notify = notify->next;
  		}
  
  		/* Add this device to the notify list for this GPE */
  
  		new_notify->device_node = device_node;
  		new_notify->next = gpe_event_info->dispatch.notify_list;
  		gpe_event_info->dispatch.notify_list = new_notify;
  		new_notify = NULL;
  	}
  
  	/* Mark the GPE as a possible wake event */
  
  	gpe_event_info->flags |= ACPI_GPE_CAN_WAKE;
  	status = AE_OK;
  
  unlock_and_exit:
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  
  	/* Delete the notify object if it was not used above */
  
  	if (new_notify) {
  		ACPI_FREE(new_notify);
  	}
  	return_ACPI_STATUS(status);
  }
  ACPI_EXPORT_SYMBOL(acpi_setup_gpe_for_wake)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_set_gpe_wake_mask
   *
   * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number      - GPE level within the GPE block
   *              action              - Enable or Disable
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Set or clear the GPE's wakeup enable mask bit. The GPE must
   *              already be marked as a WAKE GPE.
   *
   ******************************************************************************/
  
  acpi_status
  acpi_set_gpe_wake_mask(acpi_handle gpe_device, u32 gpe_number, u8 action)
  {
  	acpi_status status = AE_OK;
  	struct acpi_gpe_event_info *gpe_event_info;
  	struct acpi_gpe_register_info *gpe_register_info;
  	acpi_cpu_flags flags;
  	u32 register_bit;
  
  	ACPI_FUNCTION_TRACE(acpi_set_gpe_wake_mask);
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/*
  	 * Ensure that we have a valid GPE number and that this GPE is in
  	 * fact a wake GPE
  	 */
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (!gpe_event_info) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	if (!(gpe_event_info->flags & ACPI_GPE_CAN_WAKE)) {
  		status = AE_TYPE;
  		goto unlock_and_exit;
  	}
  
  	gpe_register_info = gpe_event_info->register_info;
  	if (!gpe_register_info) {
  		status = AE_NOT_EXIST;
  		goto unlock_and_exit;
  	}
  
  	register_bit = acpi_hw_get_gpe_register_bit(gpe_event_info);
  
  	/* Perform the action */
  
  	switch (action) {
  	case ACPI_GPE_ENABLE:
  
  		ACPI_SET_BIT(gpe_register_info->enable_for_wake,
  			     (u8)register_bit);
  		break;
  
  	case ACPI_GPE_DISABLE:
  
  		ACPI_CLEAR_BIT(gpe_register_info->enable_for_wake,
  			       (u8)register_bit);
  		break;
  
  	default:
  
  		ACPI_ERROR((AE_INFO, "%u, Invalid action", action));
  		status = AE_BAD_PARAMETER;
  		break;
  	}
  
  unlock_and_exit:
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_set_gpe_wake_mask)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_clear_gpe
   *
   * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number      - GPE level within the GPE block
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Clear an ACPI event (general purpose)
   *
   ******************************************************************************/
  acpi_status acpi_clear_gpe(acpi_handle gpe_device, u32 gpe_number)
  {
  	acpi_status status = AE_OK;
  	struct acpi_gpe_event_info *gpe_event_info;
  	acpi_cpu_flags flags;
  
  	ACPI_FUNCTION_TRACE(acpi_clear_gpe);
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/* Ensure that we have a valid GPE number */
  
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (!gpe_event_info) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	status = acpi_hw_clear_gpe(gpe_event_info);
  
        unlock_and_exit:
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_clear_gpe)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_get_gpe_status
   *
   * PARAMETERS:  gpe_device      - Parent GPE Device. NULL for GPE0/GPE1
   *              gpe_number      - GPE level within the GPE block
   *              event_status        - Where the current status of the event
   *                                    will be returned
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Get the current status of a GPE (signalled/not_signalled)
   *
   ******************************************************************************/
  acpi_status
  acpi_get_gpe_status(acpi_handle gpe_device,
  		    u32 gpe_number, acpi_event_status *event_status)
  {
  	acpi_status status = AE_OK;
  	struct acpi_gpe_event_info *gpe_event_info;
  	acpi_cpu_flags flags;
  
  	ACPI_FUNCTION_TRACE(acpi_get_gpe_status);
  
  	flags = acpi_os_acquire_lock(acpi_gbl_gpe_lock);
  
  	/* Ensure that we have a valid GPE number */
  
  	gpe_event_info = acpi_ev_get_gpe_event_info(gpe_device, gpe_number);
  	if (!gpe_event_info) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	/* Obtain status on the requested GPE number */
  
  	status = acpi_hw_get_gpe_status(gpe_event_info, event_status);
  
  	if (gpe_event_info->flags & ACPI_GPE_DISPATCH_MASK)
  		*event_status |= ACPI_EVENT_FLAG_HANDLE;
  
  unlock_and_exit:
  	acpi_os_release_lock(acpi_gbl_gpe_lock, flags);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_get_gpe_status)
  
  /******************************************************************************
   *
   * FUNCTION:    acpi_disable_all_gpes
   *
   * PARAMETERS:  None
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Disable and clear all GPEs in all GPE blocks
   *
   ******************************************************************************/
  
  acpi_status acpi_disable_all_gpes(void)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(acpi_disable_all_gpes);
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	status = acpi_hw_disable_all_gpes();
  	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
  
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_disable_all_gpes)
  
  /******************************************************************************
   *
   * FUNCTION:    acpi_enable_all_runtime_gpes
   *
   * PARAMETERS:  None
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Enable all "runtime" GPEs, in all GPE blocks
   *
   ******************************************************************************/
  
  acpi_status acpi_enable_all_runtime_gpes(void)
  {
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(acpi_enable_all_runtime_gpes);
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_EVENTS);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	status = acpi_hw_enable_all_runtime_gpes();
  	(void)acpi_ut_release_mutex(ACPI_MTX_EVENTS);
  
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_enable_all_runtime_gpes)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_install_gpe_block
   *
   * PARAMETERS:  gpe_device          - Handle to the parent GPE Block Device
   *              gpe_block_address   - Address and space_ID
   *              register_count      - Number of GPE register pairs in the block
   *              interrupt_number    - H/W interrupt for the block
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Create and Install a block of GPE registers. The GPEs are not
   *              enabled here.
   *
   ******************************************************************************/
  acpi_status
  acpi_install_gpe_block(acpi_handle gpe_device,
  		       struct acpi_generic_address *gpe_block_address,
  		       u32 register_count, u32 interrupt_number)
  {
  	acpi_status status;
  	union acpi_operand_object *obj_desc;
  	struct acpi_namespace_node *node;
  	struct acpi_gpe_block_info *gpe_block;
  
  	ACPI_FUNCTION_TRACE(acpi_install_gpe_block);
  
  	if ((!gpe_device) || (!gpe_block_address) || (!register_count)) {
  		return_ACPI_STATUS(AE_BAD_PARAMETER);
  	}
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	node = acpi_ns_validate_handle(gpe_device);
  	if (!node) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	/*
  	 * For user-installed GPE Block Devices, the gpe_block_base_number
  	 * is always zero
  	 */
  	status =
  	    acpi_ev_create_gpe_block(node, gpe_block_address, register_count, 0,
  				     interrupt_number, &gpe_block);
  	if (ACPI_FAILURE(status)) {
  		goto unlock_and_exit;
  	}
  
  	/* Install block in the device_object attached to the node */
  
  	obj_desc = acpi_ns_get_attached_object(node);
  	if (!obj_desc) {
  
  		/*
  		 * No object, create a new one (Device nodes do not always have
  		 * an attached object)
  		 */
  		obj_desc = acpi_ut_create_internal_object(ACPI_TYPE_DEVICE);
  		if (!obj_desc) {
  			status = AE_NO_MEMORY;
  			goto unlock_and_exit;
  		}
  
  		status =
  		    acpi_ns_attach_object(node, obj_desc, ACPI_TYPE_DEVICE);
  
  		/* Remove local reference to the object */
  
  		acpi_ut_remove_reference(obj_desc);
  
  		if (ACPI_FAILURE(status)) {
  			goto unlock_and_exit;
  		}
  	}
  
  	/* Now install the GPE block in the device_object */
  
  	obj_desc->device.gpe_block = gpe_block;
  
  unlock_and_exit:
  	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_install_gpe_block)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_remove_gpe_block
   *
   * PARAMETERS:  gpe_device          - Handle to the parent GPE Block Device
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Remove a previously installed block of GPE registers
   *
   ******************************************************************************/
  acpi_status acpi_remove_gpe_block(acpi_handle gpe_device)
  {
  	union acpi_operand_object *obj_desc;
  	acpi_status status;
  	struct acpi_namespace_node *node;
  
  	ACPI_FUNCTION_TRACE(acpi_remove_gpe_block);
  
  	if (!gpe_device) {
  		return_ACPI_STATUS(AE_BAD_PARAMETER);
  	}
  
  	status = acpi_ut_acquire_mutex(ACPI_MTX_NAMESPACE);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	node = acpi_ns_validate_handle(gpe_device);
  	if (!node) {
  		status = AE_BAD_PARAMETER;
  		goto unlock_and_exit;
  	}
  
  	/* Get the device_object attached to the node */
  
  	obj_desc = acpi_ns_get_attached_object(node);
  	if (!obj_desc || !obj_desc->device.gpe_block) {
  		return_ACPI_STATUS(AE_NULL_OBJECT);
  	}
  
  	/* Delete the GPE block (but not the device_object) */
  
  	status = acpi_ev_delete_gpe_block(obj_desc->device.gpe_block);
  	if (ACPI_SUCCESS(status)) {
  		obj_desc->device.gpe_block = NULL;
  	}
  
  unlock_and_exit:
  	(void)acpi_ut_release_mutex(ACPI_MTX_NAMESPACE);
  	return_ACPI_STATUS(status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_remove_gpe_block)
  
  /*******************************************************************************
   *
   * FUNCTION:    acpi_get_gpe_device
   *
   * PARAMETERS:  index               - System GPE index (0-current_gpe_count)
   *              gpe_device          - Where the parent GPE Device is returned
   *
   * RETURN:      Status
   *
   * DESCRIPTION: Obtain the GPE device associated with the input index. A NULL
   *              gpe device indicates that the gpe number is contained in one of
   *              the FADT-defined gpe blocks. Otherwise, the GPE block device.
   *
   ******************************************************************************/
  acpi_status acpi_get_gpe_device(u32 index, acpi_handle * gpe_device)
  {
  	struct acpi_gpe_device_info info;
  	acpi_status status;
  
  	ACPI_FUNCTION_TRACE(acpi_get_gpe_device);
  
  	if (!gpe_device) {
  		return_ACPI_STATUS(AE_BAD_PARAMETER);
  	}
  
  	if (index >= acpi_current_gpe_count) {
  		return_ACPI_STATUS(AE_NOT_EXIST);
  	}
  
  	/* Setup and walk the GPE list */
  
  	info.index = index;
  	info.status = AE_NOT_EXIST;
  	info.gpe_device = NULL;
  	info.next_block_base_index = 0;
  
  	status = acpi_ev_walk_gpe_list(acpi_ev_get_gpe_device, &info);
  	if (ACPI_FAILURE(status)) {
  		return_ACPI_STATUS(status);
  	}
  
  	*gpe_device = ACPI_CAST_PTR(acpi_handle, info.gpe_device);
  	return_ACPI_STATUS(info.status);
  }
  
  ACPI_EXPORT_SYMBOL(acpi_get_gpe_device)
  #endif				/* !ACPI_REDUCED_HARDWARE */