TisPc.c

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#include "CommonHeader.h"
 
BOOLEAN
TisPcPresenceCheck (
  IN      TIS_PC_REGISTERS_PTR  TisReg
  )
{
  UINT8  RegRead;
 
  RegRead = MmioRead8 ((UINTN)&TisReg->Access);
  return (BOOLEAN)(RegRead != (UINT8)-1);
}
 
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;
}
 
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;
}
 
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;
}
 
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);
  //
  // No locality set before, ACCESS_X.activeLocality MUST be valid within TIMEOUT_A
  //
  Status = TisPcWaitRegisterBits (
             &TisReg->Access,
             (UINT8)(TIS_PC_ACC_ACTIVE |TIS_PC_VALID),
             0,
             TIS_TIMEOUT_A
             );
  return Status;
}