/** @file
 	Implementation of reading and writing operations on the NVRAM device
 	attached to a network interface.
 
Copyright (c) 2004 - 2009, Intel Corporation. <BR> 
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.

**/

#include "Snp.h"


/**
  This routine calls Undi to read the desired number of eeprom bytes.

  @param  Snp          pointer to the snp driver structure
  @param  Offset       eeprom register value relative to the base address
  @param  BufferSize   number of bytes to read
  @param  Buffer       pointer where to read into

  @retval EFI_SUCCESS           The NVRAM access was performed.
  @retval EFI_INVALID_PARAMETER Invalid UNDI command.
  @retval EFI_UNSUPPORTED       Command is not supported by UNDI.
  @retval EFI_DEVICE_ERROR      Fail to execute UNDI command.

**/
EFI_STATUS
PxeNvDataRead (
  IN SNP_DRIVER *Snp,
  IN UINTN      Offset,
  IN UINTN      BufferSize,
  IN OUT VOID   *Buffer
  )
{
  PXE_DB_NVDATA *Db;

  Db                  = Snp->Db;
  Snp->Cdb.OpCode     = PXE_OPCODE_NVDATA;

  Snp->Cdb.OpFlags    = PXE_OPFLAGS_NVDATA_READ;

  Snp->Cdb.CPBsize    = PXE_CPBSIZE_NOT_USED;
  Snp->Cdb.CPBaddr    = PXE_CPBADDR_NOT_USED;

  Snp->Cdb.DBsize     = sizeof (PXE_DB_NVDATA);
  Snp->Cdb.DBaddr     = (UINT64)(UINTN) Db;

  Snp->Cdb.StatCode   = PXE_STATCODE_INITIALIZE;
  Snp->Cdb.StatFlags  = PXE_STATFLAGS_INITIALIZE;
  Snp->Cdb.IFnum      = Snp->IfNum;
  Snp->Cdb.Control    = PXE_CONTROL_LAST_CDB_IN_LIST;

  //
  // Issue UNDI command and check result.
  //
  DEBUG ((EFI_D_NET, "\nsnp->undi.nvdata ()  "));

  (*Snp->IssueUndi32Command) ((UINT64)(UINTN) &Snp->Cdb);

  switch (Snp->Cdb.StatCode) {
  case PXE_STATCODE_SUCCESS:
    break;

  case PXE_STATCODE_UNSUPPORTED:
    DEBUG (
      (EFI_D_NET,
      "\nsnp->undi.nvdata()  %xh:%xh\n",
      Snp->Cdb.StatFlags,
      Snp->Cdb.StatCode)
      );

    return EFI_UNSUPPORTED;

  default:
    DEBUG (
      (EFI_D_NET,
      "\nsnp->undi.nvdata()  %xh:%xh\n",
      Snp->Cdb.StatFlags,
      Snp->Cdb.StatCode)
      );

    return EFI_DEVICE_ERROR;
  }

  ASSERT (Offset < sizeof (Db->Data));

  CopyMem (Buffer, &Db->Data.Byte[Offset], BufferSize);

  return EFI_SUCCESS;
}


/**
  Performs read and write operations on the NVRAM device attached to a network 
  interface.
  
  This function performs read and write operations on the NVRAM device attached 
  to a network interface. If ReadWrite is TRUE, a read operation is performed.
  If ReadWrite is FALSE, a write operation is performed. Offset specifies the 
  byte offset at which to start either operation. Offset must be a multiple of 
  NvRamAccessSize , and it must have a value between zero and NvRamSize. 
  BufferSize specifies the length of the read or write operation. BufferSize must
  also be a multiple of NvRamAccessSize, and Offset + BufferSize must not exceed
  NvRamSize. 
  If any of the above conditions is not met, then EFI_INVALID_PARAMETER will be 
  returned. 
  If all the conditions are met and the operation is "read," the NVRAM device 
  attached to the network interface will be read into Buffer and EFI_SUCCESS 
  will be returned. If this is a write operation, the contents of Buffer will be
  used to update the contents of the NVRAM device attached to the network 
  interface and EFI_SUCCESS will be returned.
  
  It does the basic checking on the input parameters and retrieves snp structure
  and then calls the read_nvdata() call which does the actual reading

  @param This       A pointer to the EFI_SIMPLE_NETWORK_PROTOCOL instance.
  @param ReadWrite  TRUE for read operations, FALSE for write operations.
  @param Offset     Byte offset in the NVRAM device at which to start the read or 
                    write operation. This must be a multiple of NvRamAccessSize 
                    and less than NvRamSize. (See EFI_SIMPLE_NETWORK_MODE)  
  @param BufferSize The number of bytes to read or write from the NVRAM device. 
                    This must also be a multiple of NvramAccessSize.
  @param Buffer     A pointer to the data buffer.

  @retval EFI_SUCCESS           The NVRAM access was performed.
  @retval EFI_NOT_STARTED       The network interface has not been started.
  @retval EFI_INVALID_PARAMETER One or more of the following conditions is TRUE:
                                * The This parameter is NULL 
                                * The This parameter does not point to a valid 
                                  EFI_SIMPLE_NETWORK_PROTOCOL  structure
                                * The Offset parameter is not a multiple of 
                                  EFI_SIMPLE_NETWORK_MODE.NvRamAccessSize
                                * The Offset parameter is not less than 
                                  EFI_SIMPLE_NETWORK_MODE.NvRamSize
                                * The BufferSize parameter is not a multiple of 
                                  EFI_SIMPLE_NETWORK_MODE.NvRamAccessSize
                                * The Buffer parameter is NULL
  @retval EFI_DEVICE_ERROR      The command could not be sent to the network 
                                interface.
  @retval EFI_UNSUPPORTED       This function is not supported by the network
                                interface.

**/
EFI_STATUS
EFIAPI
SnpUndi32NvData (
  IN EFI_SIMPLE_NETWORK_PROTOCOL *This,
  IN BOOLEAN                     ReadWrite,
  IN UINTN                       Offset,
  IN UINTN                       BufferSize,
  IN OUT VOID                    *Buffer
  )
{
  SNP_DRIVER  *Snp;
  EFI_TPL     OldTpl;
  EFI_STATUS  Status;

  //
  // Get pointer to SNP driver instance for *this.
  //
  if (This == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Snp = EFI_SIMPLE_NETWORK_DEV_FROM_THIS (This);

  OldTpl = gBS->RaiseTPL (TPL_CALLBACK);

  //
  // Return error if the SNP is not initialized.
  //
  switch (Snp->Mode.State) {
  case EfiSimpleNetworkInitialized:
    break;

  case EfiSimpleNetworkStopped:
    Status = EFI_NOT_STARTED;
    goto ON_EXIT;

  default:
    Status = EFI_DEVICE_ERROR;
    goto ON_EXIT;
  }
  //
  // Return error if non-volatile memory variables are not valid.
  //
  if (Snp->Mode.NvRamSize == 0 || Snp->Mode.NvRamAccessSize == 0) {
    Status = EFI_UNSUPPORTED;
    goto ON_EXIT;
  }
  //
  // Check for invalid parameter combinations.
  //
  if ((BufferSize == 0) ||
      (Buffer == NULL) ||
      (Offset >= Snp->Mode.NvRamSize) ||
      (Offset + BufferSize > Snp->Mode.NvRamSize) ||
      (BufferSize % Snp->Mode.NvRamAccessSize != 0) ||
      (Offset % Snp->Mode.NvRamAccessSize != 0)
      ) {
    Status = EFI_INVALID_PARAMETER;
    goto ON_EXIT;
  }
  //
  // check the implementation flags of undi if we can write the nvdata!
  //
  if (!ReadWrite) {
    Status = EFI_UNSUPPORTED;
  } else {
    Status = PxeNvDataRead (Snp, Offset, BufferSize, Buffer);
  }

ON_EXIT:
  gBS->RestoreTPL (OldTpl);

  return Status;
}