/** @file
Basic TIS (TPM Interface Specification) functions.
Copyright (c) 2005 - 2011, 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 "CommonHeader.h"
/**
Check whether TPM chip exist.
@param[in] TisReg Pointer to TIS register.
@retval TRUE TPM chip exists.
@retval FALSE TPM chip is not found.
**/
BOOLEAN
TisPcPresenceCheck (
IN TIS_PC_REGISTERS_PTR TisReg
)
{
UINT8 RegRead;
RegRead = MmioRead8 ((UINTN)&TisReg->Access);
return (BOOLEAN)(RegRead != (UINT8)-1);
}
/**
Check whether the value of a TPM chip register satisfies the input BIT setting.
@param[in] Register Address port of 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
EFIAPI
TisPcWaitRegisterBits (
IN UINT8 *Register,
IN UINT8 BitSet,
IN UINT8 BitClear,
IN UINT32 TimeOut
)
{
UINT8 RegRead;
UINT32 WaitTime;
for (WaitTime = 0; WaitTime < TimeOut; WaitTime += 30){
RegRead = MmioRead8 ((UINTN)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 regiger
in the time of default TIS_TIMEOUT_D.
@param[in] TisReg Pointer to TIS register.
@param[out] BurstCount Pointer to a buffer to store the got BurstConut.
@retval EFI_SUCCESS Get BurstCount.
@retval EFI_INVALID_PARAMETER TisReg is NULL or BurstCount is NULL.
@retval EFI_TIMEOUT BurstCount can't be got in time.
**/
EFI_STATUS
EFIAPI
TisPcReadBurstCount (
IN TIS_PC_REGISTERS_PTR TisReg,
OUT UINT16 *BurstCount
)
{
UINT32 WaitTime;
UINT8 DataByte0;
UINT8 DataByte1;
if (BurstCount == NULL || TisReg == NULL) {
return EFI_INVALID_PARAMETER;
}
WaitTime = 0;
do {
//
// TIS_PC_REGISTERS_PTR->burstCount is UINT16, but it is not 2bytes aligned,
// so it needs to use MmioRead8 to read two times
//
DataByte0 = MmioRead8 ((UINTN)&TisReg->BurstCount);
DataByte1 = MmioRead8 ((UINTN)&TisReg->BurstCount + 1);
*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.
@param[in] TisReg Pointer to TIS register.
@retval EFI_SUCCESS TPM chip enters into ready state.
@retval EFI_INVALID_PARAMETER TisReg is NULL.
@retval EFI_TIMEOUT TPM chip can't be set to ready state in time.
**/
EFI_STATUS
EFIAPI
TisPcPrepareCommand (
IN TIS_PC_REGISTERS_PTR TisReg
)
{
EFI_STATUS Status;
if (TisReg == NULL) {
return EFI_INVALID_PARAMETER;
}
MmioWrite8((UINTN)&TisReg->Status, TIS_PC_STS_READY);
Status = TisPcWaitRegisterBits (
&TisReg->Status,
TIS_PC_STS_READY,
0,
TIS_TIMEOUT_B
);
return Status;
}
/**
Get the control of TPM chip by sending requestUse command TIS_PC_ACC_RQUUSE
to ACCESS Register in the time of default TIS_TIMEOUT_D.
@param[in] TisReg Pointer to TIS register.
@retval EFI_SUCCESS Get the control of TPM chip.
@retval EFI_INVALID_PARAMETER TisReg is NULL.
@retval EFI_NOT_FOUND TPM chip doesn't exit.
@retval EFI_TIMEOUT Can't get the TPM control in time.
**/
EFI_STATUS
EFIAPI
TisPcRequestUseTpm (
IN TIS_PC_REGISTERS_PTR TisReg
)
{
EFI_STATUS Status;
if (TisReg == NULL) {
return EFI_INVALID_PARAMETER;
}
if (!TisPcPresenceCheck (TisReg)) {
return EFI_NOT_FOUND;
}
MmioWrite8((UINTN)&TisReg->Access, TIS_PC_ACC_RQUUSE);
Status = TisPcWaitRegisterBits (
&TisReg->Access,
(UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
0,
TIS_TIMEOUT_D
);
return Status;
}