/** @file
  Basic TIS (TPM Interface Specification) functions for Infineon I2C TPM.

  Copyright (c) 2013 - 2016, 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
  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 <PiPei.h>
#include <Library/Tpm12DeviceLib.h>
#include <Library/BaseLib.h>
#include <Library/TimerLib.h>
#include <Library/DebugLib.h>
#include <Library/I2cLib.h>

//
// Default TPM (Infineon SLB9645) I2C Slave Device Address on Crosshill board.
//
#define TPM_I2C_SLAVE_DEVICE_ADDRESS              0x20

//
// Default Infineon SLB9645 TPM I2C mapped registers (SLB9645 I2C Comm. Protocol Application Note).
//
#define INFINEON_TPM_ACCESS_0_ADDRESS_DEFAULT     0x0
#define INFINEON_TPM_STS_0_ADDRESS_DEFAULT        0x01
#define INFINEON_TPM_BURST0_COUNT_0_DEFAULT       0x02
#define INFINEON_TPM_BURST1_COUNT_0_DEFAULT       0x03
#define INFINEON_TPM_DATA_FIFO_0_ADDRESS_DEFAULT  0x05
#define INFINEON_TPM_DID_VID_0_DEFAULT            0x09

//
// Max. retry count for read transfers (as recommended by Infineon).
//
#define READ_RETRY  3

//
// Guard time of 250us between I2C read and next I2C write transfer (as recommended by Infineon).
//
#define GUARD_TIME  250

//
// Define bits of ACCESS and STATUS registers
//

///
/// This bit is a 1 to indicate that the other bits in this register are valid.
///
#define TIS_PC_VALID                BIT7
///
/// Indicate that this locality is active.
///
#define TIS_PC_ACC_ACTIVE           BIT5
///
/// Set to 1 to indicate that this locality had the TPM taken away while
/// this locality had the TIS_PC_ACC_ACTIVE bit set.
///
#define TIS_PC_ACC_SEIZED           BIT4
///
/// Set to 1 to indicate that TPM MUST reset the
/// TIS_PC_ACC_ACTIVE bit and remove ownership for localities less than the
/// locality that is writing this bit.
///
#define TIS_PC_ACC_SEIZE            BIT3
///
/// When this bit is 1, another locality is requesting usage of the TPM.
///
#define TIS_PC_ACC_PENDIND          BIT2
///
/// Set to 1 to indicate that this locality is requesting to use TPM.
///
#define TIS_PC_ACC_RQUUSE           BIT1
///
/// A value of 1 indicates that a T/OS has not been established on the platform
///
#define TIS_PC_ACC_ESTABLISH        BIT0

///
/// When this bit is 1, TPM is in the Ready state,
/// indicating it is ready to receive a new command.
///
#define TIS_PC_STS_READY            BIT6
///
/// Write a 1 to this bit to cause the TPM to execute that command.
///
#define TIS_PC_STS_GO               BIT5
///
/// This bit indicates that the TPM has data available as a response.
///
#define TIS_PC_STS_DATA             BIT4
///
/// The TPM sets this bit to a value of 1 when it expects another byte of data for a command.
///
#define TIS_PC_STS_EXPECT           BIT3
///
/// Writes a 1 to this bit to force the TPM to re-send the response.
///
#define TIS_PC_STS_RETRY            BIT1

//
// Default TimeOut values in microseconds
//
#define TIS_TIMEOUT_A               (750  * 1000)  // 750ms
#define TIS_TIMEOUT_B               (2000 * 1000)  // 2s
#define TIS_TIMEOUT_C               (750  * 1000)  // 750ms
#define TIS_TIMEOUT_D               (750  * 1000)  // 750ms

//
// Global variable to indicate if TPM I2C Read Transfer has previously occurred.
// NOTE: Given the GUARD_TIME requirement (TpmAccess.h), if this library loaded
// by PEI Drivers this global variable required to be resident in R/W memory
//
BOOLEAN mI2CPrevReadTransfer = FALSE;

/**
  Writes single byte data to TPM specified by I2C register address.

  @param[in]  TpmAddress  The register to write.
  @param[in]  Data        The data to write to the register.

**/
VOID
TpmWriteByte (
  IN UINTN  TpmAddress,
  IN UINT8  Data
  )
{
  EFI_STATUS              Status;
  UINTN                   WriteLength;
  UINT8                   WriteData[2];
  EFI_I2C_DEVICE_ADDRESS  I2CDeviceAddr;

  //
  // Setup I2C Slave device address and address mode (7-bit).
  //
  I2CDeviceAddr.I2CDeviceAddress = TPM_I2C_SLAVE_DEVICE_ADDRESS;

  //
  // As recommended by Infineon (SLB9645 I2C Communication protocol application
  // note revision 1.0) wait 250 microseconds between a read and a write transfer.
  //
  if (mI2CPrevReadTransfer) {
    MicroSecondDelay (GUARD_TIME);
  }

  //
  // Write to TPM register.
  //
  WriteLength = 2;
  WriteData[0] = (UINT8)TpmAddress;
  WriteData[1] = Data;

  Status = I2cWriteMultipleByte (
             I2CDeviceAddr,
             EfiI2CSevenBitAddrMode,
             &WriteLength,
             &WriteData
             );
  if (EFI_ERROR(Status)) {
    DEBUG ((EFI_D_ERROR, "TpmWriteByte(): I2C Write to TPM address %0x failed (%r)\n", TpmAddress, Status));
    ASSERT (FALSE);  // Writes to TPM should always succeed.
  }

  mI2CPrevReadTransfer = FALSE;
}

/**
  Reads single byte data from TPM specified by I2C register address.

  Due to stability issues when using I2C combined write/read transfers (with
  RESTART) to TPM (specifically read from status register), a single write is
  performed followed by single read (with STOP condition in between).

  @param[in] TpmAddress  Address of register  to read.

  @return  The value register read.

**/
UINT8
TpmReadByte (
  IN UINTN  TpmAddress
  )
{
  UINT8                   Data[1];
  UINT8                   ReadData;
  UINT8                   ReadCount;

  EFI_I2C_DEVICE_ADDRESS  I2CDeviceAddr;
  EFI_I2C_ADDR_MODE       I2CAddrMode;

  EFI_STATUS              Status;

  Status = EFI_SUCCESS;
  ReadData  = 0xFF;
  ReadCount = 0;

  //
  // Locate I2C protocol for TPM I2C access.
  //
  I2CDeviceAddr.I2CDeviceAddress = TPM_I2C_SLAVE_DEVICE_ADDRESS;
  I2CAddrMode = EfiI2CSevenBitAddrMode;

  //
  // As recommended by Infineon (SLB9645 I2C Communication protocol application
  // note revision 1.0) retry up to 3 times if TPM status, access or burst count
  // registers return 0xFF.
  //
  while ((ReadData == 0xFF) && (ReadCount < READ_RETRY)) {
    //
    // As recommended by Infineon (SLB9645 I2C Communication protocol application
    // note revision 1.0) wait 250 microseconds between a read and a write transfer.
    //
    if (mI2CPrevReadTransfer) {
      MicroSecondDelay (GUARD_TIME);
    }

    //
    // Write address to TPM.
    //
    Data[0] = (UINT8)TpmAddress;
    Status = I2cWriteByte (
               I2CDeviceAddr,
               I2CAddrMode,
               &Data
               );

    if (EFI_ERROR(Status)) {
      DEBUG ((EFI_D_INFO, "TpmReadByte(): write to TPM address %0x failed (%r)\n", TpmAddress, Status));
    }

    mI2CPrevReadTransfer = FALSE;

    //
    // Read data from TPM.
    //
    Data[0] = (UINT8)TpmAddress;
    Status = I2cReadByte (
               I2CDeviceAddr,
               I2CAddrMode,
               &Data
               );

    if (EFI_ERROR(Status)) {
      DEBUG ((EFI_D_INFO, "TpmReadByte(): read from TPM address %0x failed (%r)\n", TpmAddress, Status));
      ReadData = 0xFF;
    } else {
      ReadData = Data[0];
    }

    //
    // Only need to retry 3 times for TPM status, access, and burst count registers.
    // If read transfer is to TPM Data FIFO, do not retry, exit loop.
    //
    if (TpmAddress == INFINEON_TPM_DATA_FIFO_0_ADDRESS_DEFAULT) {
      ReadCount = READ_RETRY;
    } else {
      ReadCount++;
    }

    mI2CPrevReadTransfer = TRUE;
  }

  if (EFI_ERROR(Status)) {
    //
    //  Only reads to access register allowed to fail.
    //
    if (TpmAddress != INFINEON_TPM_ACCESS_0_ADDRESS_DEFAULT) {
      DEBUG ((EFI_D_ERROR, "TpmReadByte(): read from TPM address %0x failed\n", TpmAddress));
      ASSERT_EFI_ERROR (Status);
    }
  }
  return ReadData;
}

/**
  Check whether the value of a TPM chip register satisfies the input BIT setting.

  @param[in] Register  TPM register to be checked.
  @param[in] BitSet    Check these data bits are set.
  @param[in] BitClear  Check these data bits are clear.
  @param[in] TimeOut   The max wait time (unit MicroSecond) when checking register.

  @retval EFI_SUCCESS  The register satisfies the check bit.
  @retval EFI_TIMEOUT  The register can't run into the expected status in time.
**/
EFI_STATUS
TisPcWaitRegisterBits (
  IN UINTN   Register,
  IN UINT8   BitSet,
  IN UINT8   BitClear,
  IN UINT32  TimeOut
  )
{
  UINT8   RegRead;
  UINT32  WaitTime;

  for (WaitTime = 0; WaitTime < TimeOut; WaitTime += 30){
    RegRead = TpmReadByte (Register);
    if ((RegRead & BitSet) == BitSet && (RegRead & BitClear) == 0)
      return EFI_SUCCESS;
    MicroSecondDelay (30);
  }
  return EFI_TIMEOUT;
}

/**
  Get BurstCount by reading the burstCount field of a TIS register
  in the time of default TIS_TIMEOUT_D.

  @param[out] BurstCount  Pointer to a buffer to store the got BurstConut.

  @retval EFI_SUCCESS            Get BurstCount.
  @retval EFI_INVALID_PARAMETER  BurstCount is NULL.
  @retval EFI_TIMEOUT            BurstCount can't be got in time.
**/
EFI_STATUS
TisPcReadBurstCount (
  OUT UINT16  *BurstCount
  )
{
  UINT32  WaitTime;
  UINT8   DataByte0;
  UINT8   DataByte1;

  if (BurstCount == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  WaitTime = 0;
  do {
    //
    // BurstCount is UINT16, but it is not 2bytes aligned,
    // so it needs to use TpmReadByte to read two times
    //
    DataByte0   = TpmReadByte (INFINEON_TPM_BURST0_COUNT_0_DEFAULT);
    DataByte1   = TpmReadByte (INFINEON_TPM_BURST1_COUNT_0_DEFAULT);
    *BurstCount = (UINT16)((DataByte1 << 8) + DataByte0);
    if (*BurstCount != 0) {
      return EFI_SUCCESS;
    }
    MicroSecondDelay (30);
    WaitTime += 30;
  } while (WaitTime < TIS_TIMEOUT_D);

  return EFI_TIMEOUT;
}

/**
  Set TPM chip to ready state by sending ready command TIS_PC_STS_READY
  to Status Register in time.

  @retval EFI_SUCCESS  TPM chip enters into ready state.
  @retval EFI_TIMEOUT  TPM chip can't be set to ready state in time.
**/
EFI_STATUS
TisPcPrepareCommand (
  VOID
  )
{
  EFI_STATUS  Status;

  TpmWriteByte (INFINEON_TPM_STS_0_ADDRESS_DEFAULT, TIS_PC_STS_READY);
  Status = TisPcWaitRegisterBits (
             INFINEON_TPM_STS_0_ADDRESS_DEFAULT,
             TIS_PC_STS_READY,
             0,
             TIS_TIMEOUT_B
             );
  return Status;
}

/**
  This service requests use TPM12.

  @retval EFI_SUCCESS      Get the control of TPM12 chip.
  @retval EFI_NOT_FOUND    TPM12 not found.
  @retval EFI_DEVICE_ERROR Unexpected device behavior.
**/
EFI_STATUS
EFIAPI
Tpm12RequestUseTpm (
  VOID
  )
{
  EFI_STATUS  Status;

  //
  // Check to see if TPM exists
  //
  if (TpmReadByte (INFINEON_TPM_ACCESS_0_ADDRESS_DEFAULT) == 0xFF) {
    return EFI_NOT_FOUND;
  }

  TpmWriteByte (INFINEON_TPM_ACCESS_0_ADDRESS_DEFAULT, TIS_PC_ACC_RQUUSE);

  //
  // No locality set before, ACCESS_X.activeLocality MUST be valid within TIMEOUT_A
  //
  Status = TisPcWaitRegisterBits (
             INFINEON_TPM_ACCESS_0_ADDRESS_DEFAULT,
             (UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
             0,
             TIS_TIMEOUT_A
             );
  return Status;
}

/**
  Send command to TPM for execution.

  @param[in] TpmBuffer   Buffer for TPM command data.
  @param[in] DataLength  TPM command data length.

  @retval EFI_SUCCESS  Operation completed successfully.
  @retval EFI_TIMEOUT  The register can't run into the expected status in time.

**/
EFI_STATUS
TisPcSend (
  IN UINT8   *TpmBuffer,
  IN UINT32  DataLength
  )
{
  UINT16      BurstCount;
  UINT32      Index;
  EFI_STATUS  Status;

  Status = TisPcPrepareCommand ();
  if (EFI_ERROR (Status)){
    DEBUG ((DEBUG_ERROR, "The TPM is not ready!\n"));
    goto Done;
  }
  Index = 0;
  while (Index < DataLength) {
    Status = TisPcReadBurstCount (&BurstCount);
    if (EFI_ERROR (Status)) {
      Status = EFI_TIMEOUT;
      goto Done;
    }
    for (; BurstCount > 0 && Index < DataLength; BurstCount--) {
      TpmWriteByte (INFINEON_TPM_DATA_FIFO_0_ADDRESS_DEFAULT, *(TpmBuffer + Index));
      Index++;
    }
  }
  //
  // Ensure the TPM status STS_EXPECT change from 1 to 0
  //
  Status = TisPcWaitRegisterBits (
             INFINEON_TPM_STS_0_ADDRESS_DEFAULT,
             (UINT8) TIS_PC_VALID,
             TIS_PC_STS_EXPECT,
             TIS_TIMEOUT_C
             );
  if (EFI_ERROR (Status)) {
    goto Done;
  }

  //
  // Start the command
  //
  TpmWriteByte (INFINEON_TPM_STS_0_ADDRESS_DEFAULT, TIS_PC_STS_GO);

Done:
  if (EFI_ERROR (Status))  {
    //
    // Ensure the TPM state change from "Reception" to "Idle/Ready"
    //
    TpmWriteByte (INFINEON_TPM_STS_0_ADDRESS_DEFAULT, TIS_PC_STS_READY);
  }

  return Status;
}

/**
  Receive response data of last command from TPM.

  @param[out] TpmBuffer  Buffer for response data.
  @param[out] RespSize   Response data length.

  @retval EFI_SUCCESS           Operation completed successfully.
  @retval EFI_TIMEOUT           The register can't run into the expected status in time.
  @retval EFI_DEVICE_ERROR      Unexpected device status.
  @retval EFI_BUFFER_TOO_SMALL  Response data is too long.

**/
EFI_STATUS
TisPcReceive (
  OUT UINT8   *TpmBuffer,
  OUT UINT32  *RespSize
  )
{
  EFI_STATUS           Status;
  UINT16               BurstCount;
  UINT32               Index;
  UINT32               ResponseSize;
  TPM_RSP_COMMAND_HDR  *ResponseHeader;

  //
  // Wait for the command completion
  //
  Status = TisPcWaitRegisterBits (
             INFINEON_TPM_STS_0_ADDRESS_DEFAULT,
             (UINT8) (TIS_PC_VALID | TIS_PC_STS_DATA),
             0,
             TIS_TIMEOUT_B
             );
  if (EFI_ERROR (Status)) {
    Status = EFI_TIMEOUT;
    goto Done;
  }
  //
  // Read the response data header and check it
  //
  Index = 0;
  BurstCount = 0;
  while (Index < sizeof (TPM_RSP_COMMAND_HDR)) {
    Status = TisPcReadBurstCount (&BurstCount);
    if (EFI_ERROR (Status)) {
      Status = EFI_TIMEOUT;
      goto Done;
    }
    for (; BurstCount > 0 ; BurstCount--) {
      *(TpmBuffer + Index) = TpmReadByte (INFINEON_TPM_DATA_FIFO_0_ADDRESS_DEFAULT);
      Index++;
      if (Index == sizeof (TPM_RSP_COMMAND_HDR))
        break;
    }
  }

  //
  // Check the response data header (tag, parasize and returncode)
  //
  ResponseHeader = (TPM_RSP_COMMAND_HDR *)TpmBuffer;
  if (SwapBytes16 (ReadUnaligned16 (&ResponseHeader->tag)) != TPM_TAG_RSP_COMMAND) {
    Status = EFI_DEVICE_ERROR;
    goto Done;
  }

  ResponseSize = SwapBytes32 (ReadUnaligned32 (&ResponseHeader->paramSize));
  if (ResponseSize == sizeof (TPM_RSP_COMMAND_HDR)) {
    Status = EFI_SUCCESS;
    goto Done;
  }
  if (ResponseSize < sizeof (TPM_RSP_COMMAND_HDR)) {
    Status = EFI_DEVICE_ERROR;
    goto Done;
  }
  if (*RespSize < ResponseSize) {
    Status = EFI_BUFFER_TOO_SMALL;
    goto Done;
  }
  *RespSize = ResponseSize;

  //
  // Continue reading the remaining data
  //
  while (Index < ResponseSize) {
    for (; BurstCount > 0 ; BurstCount--) {
      *(TpmBuffer + Index) = TpmReadByte (INFINEON_TPM_DATA_FIFO_0_ADDRESS_DEFAULT);
      Index++;
      if (Index == ResponseSize) {
        Status = EFI_SUCCESS;
        goto Done;
      }
    }
    Status = TisPcReadBurstCount (&BurstCount);
    if (EFI_ERROR (Status) && (Index < ResponseSize)) {
      Status = EFI_DEVICE_ERROR;
      goto Done;
    }
  }

Done:
  //
  // Ensure the TPM state change from "Execution" or "Completion" to "Idle/Ready"
  //
  TpmWriteByte (INFINEON_TPM_STS_0_ADDRESS_DEFAULT, TIS_PC_STS_READY);

  return Status;
}

/**
  This service enables the sending of commands to the TPM12.

  @param[in]     InputParameterBlockSize   Size of the TPM12 input parameter block.
  @param[in]     InputParameterBlock       Pointer to the TPM12 input parameter block.
  @param[in,out] OutputParameterBlockSize  Size of the TPM12 output parameter block.
  @param[in]     OutputParameterBlock      Pointer to the TPM12 output parameter block.

  @retval EFI_SUCCESS           The command byte stream was successfully sent to
                                the device and a response was successfully received.
  @retval EFI_DEVICE_ERROR      The command was not successfully sent to the
                                device or a response was not successfully received
                                from the device.
  @retval EFI_BUFFER_TOO_SMALL  The output parameter block is too small.
**/
EFI_STATUS
EFIAPI
Tpm12SubmitCommand (
  IN UINT32      InputParameterBlockSize,
  IN UINT8       *InputParameterBlock,
  IN OUT UINT32  *OutputParameterBlockSize,
  IN UINT8       *OutputParameterBlock
  )
{
  EFI_STATUS  Status;

  Status = TisPcSend (InputParameterBlock, InputParameterBlockSize);
  if (!EFI_ERROR (Status)) {
    Status = TisPcReceive (OutputParameterBlock, OutputParameterBlockSize);
  }
  return Status;
}