/** @file
  This file declares EFI PCI Hot Plug Init Protocol.
  This protocol provides the necessary functionality to initialize the Hot Plug Controllers (HPCs) and
  the buses that they control. This protocol also provides information regarding resource padding.

  Copyright (c) 2007 - 2009, Intel Corporation
  All rights reserved. This program and the accompanying materials
  are licensed and made available under the terms and conditions of the BSD License
  which accompanies this distribution.  The full text of the license may be found at
  http://opensource.org/licenses/bsd-license.php

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

  @par Revision Reference:
  This protocol is defined in Framework of EFI Hot Plug Pci Initialization Protocol Spec
  Version 0.9

**/

#ifndef _EFI_PCI_HOT_PLUG_INIT_H_
#define _EFI_PCI_HOT_PLUG_INIT_H_

#include <PiDxe.h>

///
/// Global ID for the PCI Hot Plug Protocol
///
#define EFI_PCI_HOT_PLUG_INIT_PROTOCOL_GUID \
  { \
    0xaa0e8bc1, 0xdabc, 0x46b0, {0xa8, 0x44, 0x37, 0xb8, 0x16, 0x9b, 0x2b, 0xea } \
  }

typedef struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL EFI_PCI_HOT_PLUG_INIT_PROTOCOL;

///
/// Current state of an HPC
///
typedef UINT16 EFI_HPC_STATE;

///
/// The HPC initialization function was called and the HPC completed 
/// initialization, but it was not enabled for some reason. The HPC may be 
/// disabled in hardware, or it may be disabled due to user preferences, 
/// hardware failure, or other reasons. No resource padding is required.
///
#define  EFI_HPC_STATE_INITIALIZED    0x01

///
/// The HPC initialization function was called, the HPC completed 
/// initialization, and it was enabled. Resource padding is required.
///
#define  EFI_HPC_STATE_ENABLED        0x02

///
/// Location definition for PCI Hot Plug Controller
///
typedef struct{
  ///
  /// The device path to the Root HPC
  ///
  EFI_DEVICE_PATH_PROTOCOL  *HpcDevicePath;
  ///
  /// The device path to the Hot Plug Bus (HPB) that is controlled by 
  /// the root HPC.
  ///
  EFI_DEVICE_PATH_PROTOCOL  *HpbDevicePath;
} EFI_HPC_LOCATION;


///
/// Describes how resource padding should be applied
///
typedef enum{
  EfiPaddingPciBus,
  EfiPaddingPciRootBridge
} EFI_HPC_PADDING_ATTRIBUTES;

/**
  Returns a list of root Hot Plug Controllers (HPCs) that require initialization
  during the boot process.

  This procedure returns a list of root HPCs. The PCI bus driver must initialize these controllers 
  during the boot process. The PCI bus driver may or may not be able to detect these HPCs. If the 
  platform includes a PCI-to-CardBus bridge, it can be included in this list if it requires initialization. 
  The HpcList must be self consistent. An HPC cannot control any of its parent buses. Only one HPC 
  can control a PCI bus. Because this list includes only root HPCs, no HPC in the list can be a child of 
  another HPC. This policy must be enforced by the EFI_PCI_HOT_PLUG_INIT_PROTOCOL. 
  The PCI bus driver may not check for such invalid conditions. 
  The callee allocates the buffer HpcList

  @param  This                  Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
  @param  HpcCount              The number of root HPCs that were returned.
  @param  HpcList               The list of root HPCs. HpcCount defines the number of
                                elements in this list.

  @retval EFI_SUCCESS           HpcList was returned.
  @retval EFI_OUT_OF_RESOURCES  HpcList was not returned due to insufficient resources.
  @retval EFI_INVALID_PARAMETER HpcCount is NULL or HpcList is NULL.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_GET_ROOT_HPC_LIST)(
  IN  EFI_PCI_HOT_PLUG_INIT_PROTOCOL  *This,
  OUT UINTN                           *HpcCount,
  OUT EFI_HPC_LOCATION                **HpcList
);

/**
  Initializes one root Hot Plug Controller (HPC). This process may causes
  initialization of its subordinate buses.
  
  This function initializes the specified HPC. At the end of initialization, the hot-plug slots or sockets 
  (controlled by this HPC) are powered and are connected to the bus. All the necessary registers in the 
  HPC are set up. For a Standard (PCI) Hot Plug Controller (SHPC), the registers that must be set up 
  are defined in the PCI Standard Hot Plug Controller and Subsystem Specification.

  @param  This                  Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
  @param  HpcDevicePath         The device path to the HPC that is being initialized.
  @param  HpcPciAddress         The address of the HPC function on the PCI bus.
  @param  Event                 The event that should be signaled when the HPC initialization
                                is complete.
  @param  HpcState              The state of the HPC hardware. The state is EFI_HPC_STATE_INITIALIZED
                                or EFI_HPC_STATE_ENABLED.

  @retval EFI_SUCCESS           If Event is NULL, the specific HPC was successfully
                                initialized. If Event is not NULL, Event will be signaled at a later time
                                when initialization is complete.
  @retval EFI_UNSUPPORTED       This instance of EFI_PCI_HOT_PLUG_INIT_PROTOCOL
                                does not support the specified HPC.
  @retval EFI_OUT_OF_RESOURCES  Initialization failed due to insufficient
                                resources.
  @retval EFI_INVALID_PARAMETER HpcState is NULL.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_INITIALIZE_ROOT_HPC)(
  IN  EFI_PCI_HOT_PLUG_INIT_PROTOCOL    *This,
  IN  EFI_DEVICE_PATH_PROTOCOL          *HpcDevicePath,
  IN  UINT64                            HpcPciAddress,
  IN  EFI_EVENT                         Event, OPTIONAL
  OUT EFI_HPC_STATE                     *HpcState
);

/**
  Returns the resource padding that is required by the PCI bus that is controlled
  by the specified Hot Plug Controller (HPC).

  This function returns the resource padding that is required by the PCI bus that is controlled by the 
  specified HPC. This member function is called for all the root HPCs and nonroot HPCs that are 
  detected by the PCI bus enumerator. This function will be called before PCI resource allocation is 
  completed. This function must be called after all the root HPCs, with the possible exception of a 
  PCI-to-CardBus bridge, have completed initialization.

  @param  This                  Pointer to the EFI_PCI_HOT_PLUG_INIT_PROTOCOL instance.
  @param  HpcDevicePath         The device path to the HPC.
  @param  HpcPciAddress         The address of the HPC function on the PCI bus.
  @param  HpcState              The state of the HPC hardware.
  @param  Padding               The amount of resource padding that is required by the
                                PCI bus under the control of the specified HPC.
  @param  Attributes            Describes how padding is accounted for. The padding
                                is returned in the form of ACPI 2.0 resource descriptors.

  @retval EFI_SUCCESS           The resource padding was successfully returned.
  @retval EFI_UNSUPPORTED       This instance of the EFI_PCI_HOT_PLUG_INIT_PROTOCOL
                                does not support the specified HPC.
  @retval EFI_NOT_READY         This function was called before HPC initialization is complete.
  @retval EFI_INVALID_PARAMETER HpcState or Padding or Attributes is NULL.
  @retval EFI_OUT_OF_RESOURCES  ACPI 2.0 resource descriptors for Padding
                                cannot be allocated due to insufficient resources.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_GET_HOT_PLUG_PADDING)(
  IN  EFI_PCI_HOT_PLUG_INIT_PROTOCOL    *This,
  IN  EFI_DEVICE_PATH_PROTOCOL          *HpcDevicePath,
  IN  UINT64                            HpcPciAddress,
  OUT EFI_HPC_STATE                     *HpcState,
  OUT VOID                              **Padding,
  OUT EFI_HPC_PADDING_ATTRIBUTES        *Attributes
);


//
// Prototypes for the PCI Hot Plug Init Protocol
//

///
/// This protocol provides the necessary functionality to initialize the
/// Hot Plug Controllers (HPCs) and the buses that they control. This protocol
/// also provides information regarding resource padding.
///
struct _EFI_PCI_HOT_PLUG_INIT_PROTOCOL {
  ///
  /// Returns a list of root HPCs and the buses that they control.
  ///
  EFI_GET_ROOT_HPC_LIST                                  GetRootHpcList;
  
  ///
  /// Initializes the specified root HPC.
  ///
  EFI_INITIALIZE_ROOT_HPC                                InitializeRootHpc;
  
  ///
  /// Returns the resource padding that is required by the HPC.
  ///
  EFI_GET_HOT_PLUG_PADDING                               GetResourcePadding;
};

extern EFI_GUID gEfiPciHotPlugInitProtocolGuid;

#endif