/** @file
  This code abstracts the CPU IO Protocol which installed by some platform or chipset-specific 
  PEIM that abstracts the processor-visible I/O operations.

  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:
  CPU IO Protocol is defined in Framework of EFI CPU IO Protocol Spec
  Version 0.9

**/

#ifndef _CPUIO_H_
#define _CPUIO_H_


#define EFI_CPU_IO_PROTOCOL_GUID \
  { \
    0xB0732526, 0x38C8, 0x4b40, {0x88, 0x77, 0x61, 0xC7, 0xB0, 0x6A, 0xAC, 0x45 } \
  }

typedef struct _EFI_CPU_IO_PROTOCOL EFI_CPU_IO_PROTOCOL;

///
/// Enumeration that defines the width of the I/O operation.
///
typedef enum {
  EfiCpuIoWidthUint8,
  EfiCpuIoWidthUint16,
  EfiCpuIoWidthUint32,
  EfiCpuIoWidthUint64,
  EfiCpuIoWidthFifoUint8,
  EfiCpuIoWidthFifoUint16,
  EfiCpuIoWidthFifoUint32,
  EfiCpuIoWidthFifoUint64,
  EfiCpuIoWidthFillUint8,
  EfiCpuIoWidthFillUint16,
  EfiCpuIoWidthFillUint32,
  EfiCpuIoWidthFillUint64,
  EfiCpuIoWidthMaximum
} EFI_CPU_IO_PROTOCOL_WIDTH;

/**
  Enables a driver to access memory-mapped registers in the EFI system memory space.
  Or, Enables a driver to access registers in the EFI CPU I/O space.

  @param[in]       This         A pointer to the EFI_CPU_IO_PROTOCOL instance.
  @param[in]       Width        Signifies the width of the I/O or Memory operation.
  @param[in]       Address      The base address of the I/O or Memoryoperation.
  @param[in]       Count        The number of I/O or Memory operations to perform.
                                The number of bytes moved is Width size * Count, starting at Address.
  @param[in, out]  Buffer       For read operations, the destination buffer to store the results.
                                For write operations, the source buffer from which to write data.

  @retval EFI_SUCCESS           The data was read from or written to the EFI system.
  @retval EFI_INVALID_PARAMETER Width is invalid for this EFI system.Or Buffer is NULL.
  @retval EFI_UNSUPPORTED       The Buffer is not aligned for the given Width.
                                Or,The address range specified by Address, Width, and Count is not valid for this EFI system.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_CPU_IO_PROTOCOL_IO_MEM)(
  IN     EFI_CPU_IO_PROTOCOL               *This,
  IN     EFI_CPU_IO_PROTOCOL_WIDTH         Width,
  IN     UINT64                            Address,
  IN     UINTN                             Count,
  IN OUT VOID                              *Buffer
  );

///
/// Servies for read and write accesses.
///
typedef struct {
  ///
  /// This service provides the various modalities of memory and I/O read.
  ///
  EFI_CPU_IO_PROTOCOL_IO_MEM  Read;
  ///
  /// This service provides the various modalities of memory and I/O write.
  ///
  EFI_CPU_IO_PROTOCOL_IO_MEM  Write;
} EFI_CPU_IO_PROTOCOL_ACCESS;

///
/// Provides the basic memory and I/O interfaces that are used to abstract
/// accesses to devices in a system.
///
struct _EFI_CPU_IO_PROTOCOL {
  ///
  /// Enables a driver to access memory-mapped registers in the EFI system memory space.
  ///
  EFI_CPU_IO_PROTOCOL_ACCESS  Mem;
  ///
  /// Enables a driver to access registers in the EFI CPU I/O space.
  ///
  EFI_CPU_IO_PROTOCOL_ACCESS  Io;
};

extern EFI_GUID gEfiCpuIoProtocolGuid;

#endif