/** @file
  The EFI_FORM_CALLBACK_PROTOCOL is the defined interface for access to custom
  NV storage devices and for communication of user selections in a more
  interactive environment.  This protocol should be published by hardware
  specific drivers that want to export access to custom hardware storage or
  publish IFR that need to call back the original driver.

Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available under 
the terms and conditions of the BSD License that 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 HII spec 0.92.

**/

#ifndef __FRAMEWORK_FORM_CALLBACK_H__
#define __FRAMEWORK_FORM_CALLBACK_H__

#include <Protocol/FrameworkHii.h>
#include <Protocol/FrameworkFormBrowser.h>

#define EFI_FORM_CALLBACK_PROTOCOL_GUID \
  { \
    0xf3e4543d, 0xcf35, 0x6cef, {0x35, 0xc4, 0x4f, 0xe6, 0x34, 0x4d, 0xfc, 0x54 } \
  }

//
// Forward reference for pure ANSI compatability
//
typedef struct _EFI_FORM_CALLBACK_PROTOCOL  EFI_FORM_CALLBACK_PROTOCOL;

///
///  Inconsistent with specification here: 
///  RESET_REQUIRED, EXIT_REQUIRED, SAVE_REQUIRED, NV_CHANGED and NV_NOT_CHANGED are not 
///  defined in HII specification. These Flags of EFI_IFR_DATA_ENTRY should be defined
///  to describe the standard behavior of the browser after the callback.
///
/// If this flag is set, the browser will exit and reset after processing callback results.
///
#define RESET_REQUIRED  1 
///
/// If this flag is set, the browser will exit after processing callback results.
///
#define EXIT_REQUIRED   2
///
/// If this flag is set, the browser will save the NV data after processing callback results.
///
#define SAVE_REQUIRED   4
///
/// If this flag is set, the browser will turn the NV flag on after processing callback results.
///
#define NV_CHANGED      8
///
/// If this flag is set, the browser will turn the NV flag off after processing callback results.
///
#define NV_NOT_CHANGED  16

#pragma pack(1)
typedef struct {
  UINT8   OpCode;           ///< Likely a string, numeric, or one-of
  UINT8   Length;           ///< Length of the EFI_IFR_DATA_ENTRY packet.
  UINT16  Flags;            ///< Flags settings to determine what behavior is desired from the browser after the callback.
  VOID    *Data;            ///< The data in the form based on the op-code type. This is not a pointer to the data; the data follows immediately.
  ///
  /// If the OpCode is a OneOf or Numeric type - Data is a UINT16 value.
  /// If the OpCode is a String type - Data is a CHAR16[x] type.
  /// If the OpCode is a Checkbox type - Data is a UINT8 value.
  /// If the OpCode is a NV Access type - Data is a EFI_IFR_NV_DATA structure.
  ///
} EFI_IFR_DATA_ENTRY;

typedef struct {
  VOID                *NvRamMap;  ///< If the flag of the op-code specified retrieval of a copy of the NVRAM map.
  //
  // this is a pointer to a buffer copy
  //
  UINT32              EntryCount; ///< Number of EFI_IFR_DATA_ENTRY entries.
  //
  // EFI_IFR_DATA_ENTRY  Data[1];    // The in-line Data entries.
  //
} EFI_IFR_DATA_ARRAY;


typedef union {
  EFI_IFR_DATA_ARRAY  DataArray;  ///< Primarily used by those that call back to their drivers and use HII as a repository.
  EFI_IFR_PACKET      DataPacket; ///< Primarily used by those that do not use HII as a repository.
  CHAR16              String[1];  ///< If returning an error - fill the string with null-terminated contents.
} EFI_HII_CALLBACK_PACKET;

typedef struct {
  FRAMEWORK_EFI_IFR_OP_HEADER Header;
  UINT16            QuestionId;   ///< Offset into the map.
  UINT8             StorageWidth; ///< Width of the value.
  //
  // CHAR8             Data[1];      // The Data itself
  //
} EFI_IFR_NV_DATA;

#pragma pack()
//
// The following types are currently defined:
//
/**
  Returns the value of a variable.

  @param  This                  A pointer to the EFI_FORM_CALLBACK_PROTOCOL instance.
  @param  VariableName          A NULL-terminated Unicode string that is the
                                name of the vendor's variable.
  @param  VendorGuid            A unique identifier for the vendor.
  @param  Attributes            If not NULL, a pointer to the memory location to
                                return the attribute's bit-mask for the variable.
  @param  DataSize              The size in bytes of the Buffer. A size of zero causes
                                the variable to be deleted.
  @param  Buffer                The buffer to return the contents of the variable.

  @retval EFI_SUCCESS           The function completed successfully.
  @retval EFI_NOT_FOUND         The variable was not found.
  @retval EFI_BUFFER_TOO_SMALL  The DataSize is too small for the result.
                                DataSize has been updated with the size needed to complete the request.
  @retval EFI_INVALID_PARAMETER One of the parameters has an invalid value.
  @retval EFI_DEVICE_ERROR      The variable could not be saved due to a hardware failure.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_NV_READ)(
  IN     EFI_FORM_CALLBACK_PROTOCOL    *This,
  IN     CHAR16                        *VariableName,
  IN     EFI_GUID                      *VendorGuid,
  OUT    UINT32                        *Attributes OPTIONAL,
  IN OUT UINTN                         *DataSize,
  OUT    VOID                          *Buffer
  );

/**
  Sets the value of a variable.

  @param  This                  A pointer to the EFI_FORM_CALLBACK_PROTOCOL instance.
  @param  VariableName          A NULL-terminated Unicode string that is the
                                name of the vendor's variable. Each VariableName 
                                is unique for each VendorGuid.  
  @param  VendorGuid            A unique identifier for the vendor.
  @param  Attributes            Attributes bit-mask to set for the variable.
                                Inconsistent with specification here: 
                                Attributes data type has been changed from 
                                UINT32 * to UINT32, because the input parameter is
                                not necessary to use a pointer date type.
  @param  DataSize              The size in bytes of the Buffer. A size of zero causes
                                the variable to be deleted.
  @param  Buffer                The buffer containing the contents of the variable.
  @param  ResetRequired         Returns a value from the driver that abstracts this
                                information and will enable a system to know if a
                                system reset is required to achieve the configuration
                                changes being enabled through this function.

  @retval EFI_SUCCESS           The firmware has successfully stored the variable and
                                its data as defined by the Attributes.
  @retval EFI_OUT_OF_RESOURCES  Not enough storage is available to hold
                                the variable and its data.
  @retval EFI_INVALID_PARAMETER An invalid combination of Attributes bits
                                was supplied, or the DataSize exceeds the maximum allowed.
  @retval EFI_DEVICE_ERROR      The variable could not be saved due to a hardware failure.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_NV_WRITE)(
  IN     EFI_FORM_CALLBACK_PROTOCOL    *This,
  IN     CHAR16                        *VariableName,
  IN     EFI_GUID                      *VendorGuid,
  IN     UINT32                        Attributes,
  IN     UINTN                         DataSize,
  IN     VOID                          *Buffer,
  OUT    BOOLEAN                       *ResetRequired
  );

/**
  This function is called to provide results data to the driver.

  @param  This                  A pointer to the EFI_FORM_CALLBACK_PROTOCOL instance.
  @param  KeyValue              A unique value which is sent to the original exporting
                                driver so that it can identify the type of data 
                                to expect. The format of the data tends to vary based 
                                on the opcode that generated the callback.
  @param  Data                  A pointer to the data being sent to the original exporting driver.
  @param  Packet                A pointer to a packet of information that a driver passes
                                back to the browser.

  @return Status Code

**/
typedef
EFI_STATUS
(EFIAPI *EFI_FORM_CALLBACK)(
  IN     EFI_FORM_CALLBACK_PROTOCOL    *This,
  IN     UINT16                        KeyValue,
  IN     EFI_IFR_DATA_ARRAY  *Data,
  OUT    EFI_HII_CALLBACK_PACKET       **Packet
  );

/**
  The EFI_FORM_CALLBACK_PROTOCOL is the defined interface for access to
  custom NVS devices as well as communication of user selections in a more
  interactive environment. This protocol should be published by platform-specific
  drivers that want to export access to custom hardware storage or publish IFR
  that has a requirement to call back the original driver.
**/
struct _EFI_FORM_CALLBACK_PROTOCOL {
  EFI_NV_READ       NvRead;     ///< The read operation to access the NV data serviced by a hardware-specific driver.
  EFI_NV_WRITE      NvWrite;    ///< The write operation to access the NV data serviced by a hardware-specific driver.
  EFI_FORM_CALLBACK Callback;   ///< The function that is called from the configuration browser to communicate key value pairs.
};

extern EFI_GUID gEfiFormCallbackProtocolGuid;

#endif