path: root/MdeModulePkg/Bus/Pci/UhciDxe/Uhci.c

/** @file

  The UHCI driver model and HC protocol routines.

Copyright (c) 2004 - 2008, Intel Corporation
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 "Uhci.h"

/**
  Provides software reset for the USB host controller according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  Attributes             A bit mask of the reset operation to perform.  See
                                 below for a list of the supported bit mask values.

  @return EFI_SUCCESS            The reset operation succeeded.
  @return EFI_INVALID_PARAMETER  Attributes is not valid.
  @return EFI_UNSUPPORTED        This type of reset is not currently supported.
  @return EFI_DEVICE_ERROR       Other errors.

**/
EFI_STATUS
EFIAPI
Uhci2Reset (
  IN EFI_USB2_HC_PROTOCOL   *This,
  IN UINT16                 Attributes
  )
{
  USB_HC_DEV          *Uhc;
  EFI_TPL             OldTpl;

  if ((Attributes == EFI_USB_HC_RESET_GLOBAL_WITH_DEBUG) ||
      (Attributes == EFI_USB_HC_RESET_HOST_WITH_DEBUG)) {
    return EFI_UNSUPPORTED;
  }

  Uhc     = UHC_FROM_USB2_HC_PROTO (This);

  OldTpl  = gBS->RaiseTPL (UHCI_TPL);

  switch (Attributes) {
  case EFI_USB_HC_RESET_GLOBAL:
    //
    // Stop schedule and set the Global Reset bit in the command register
    //
    UhciStopHc (Uhc, UHC_GENERIC_TIMEOUT);
    UhciSetRegBit (Uhc->PciIo, USBCMD_OFFSET, USBCMD_GRESET);

    gBS->Stall (UHC_ROOT_PORT_RESET_STALL);

    //
    // Clear the Global Reset bit to zero.
    //
    UhciClearRegBit (Uhc->PciIo, USBCMD_OFFSET, USBCMD_GRESET);

    gBS->Stall (UHC_ROOT_PORT_RECOVERY_STALL);
    break;

  case EFI_USB_HC_RESET_HOST_CONTROLLER:
    //
    // Stop schedule and set Host Controller Reset bit to 1
    //
    UhciStopHc (Uhc, UHC_GENERIC_TIMEOUT);
    UhciSetRegBit (Uhc->PciIo, USBCMD_OFFSET, USBCMD_HCRESET);

    gBS->Stall (UHC_ROOT_PORT_RECOVERY_STALL);
    break;

  default:
    goto ON_INVAILD_PARAMETER;
  }

  //
  // Delete all old transactions on the USB bus, then
  // reinitialize the frame list
  //
  UhciFreeAllAsyncReq (Uhc);
  UhciDestoryFrameList (Uhc);
  UhciInitFrameList (Uhc);

  gBS->RestoreTPL (OldTpl);

  return EFI_SUCCESS;

ON_INVAILD_PARAMETER:

  gBS->RestoreTPL (OldTpl);

  return EFI_INVALID_PARAMETER;
}


/**
  Retrieves current state of the USB host controller according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  State                  Variable to receive current device state.

  @return EFI_SUCCESS            The state is returned.
  @return EFI_INVALID_PARAMETER  State is not valid.
  @return EFI_DEVICE_ERROR       Other errors.

**/
EFI_STATUS
EFIAPI
Uhci2GetState (
  IN CONST EFI_USB2_HC_PROTOCOL   *This,
  OUT      EFI_USB_HC_STATE       *State
  )
{
  USB_HC_DEV          *Uhc;
  UINT16              UsbSts;
  UINT16              UsbCmd;

  if (State == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  Uhc     = UHC_FROM_USB2_HC_PROTO (This);

  UsbCmd  = UhciReadReg (Uhc->PciIo, USBCMD_OFFSET);
  UsbSts  = UhciReadReg (Uhc->PciIo, USBSTS_OFFSET);

  if ((UsbCmd & USBCMD_EGSM) !=0 ) {
    *State = EfiUsbHcStateSuspend;

  } else if ((UsbSts & USBSTS_HCH) != 0) {
    *State = EfiUsbHcStateHalt;

  } else {
    *State = EfiUsbHcStateOperational;
  }

  return EFI_SUCCESS;
}


/**
  Sets the USB host controller to a specific state according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  State                  Indicates the state of the host controller that will
                                 be set.

  @return EFI_SUCCESS            Host controller was successfully placed in the state.
  @return EFI_INVALID_PARAMETER  State is invalid.
  @return EFI_DEVICE_ERROR       Failed to set the state.

**/
EFI_STATUS
EFIAPI
Uhci2SetState (
  IN EFI_USB2_HC_PROTOCOL    *This,
  IN EFI_USB_HC_STATE        State
  )
{
  EFI_USB_HC_STATE    CurState;
  USB_HC_DEV          *Uhc;
  EFI_TPL             OldTpl;
  EFI_STATUS          Status;
  UINT16              UsbCmd;

  Uhc     = UHC_FROM_USB2_HC_PROTO (This);
  Status  = Uhci2GetState (This, &CurState);

  if (EFI_ERROR (Status)) {
    return EFI_DEVICE_ERROR;
  }

  if (CurState == State) {
    return EFI_SUCCESS;
  }

  Status  = EFI_SUCCESS;
  OldTpl  = gBS->RaiseTPL (UHCI_TPL);

  switch (State) {
  case EfiUsbHcStateHalt:
    Status = UhciStopHc (Uhc, UHC_GENERIC_TIMEOUT);
    break;

  case EfiUsbHcStateOperational:
    UsbCmd = UhciReadReg (Uhc->PciIo, USBCMD_OFFSET);

    if (CurState == EfiUsbHcStateHalt) {
      //
      // Set Run/Stop bit to 1, also set the bandwidht reclamation
      // point to 64 bytes
      //
      UsbCmd |= USBCMD_RS | USBCMD_MAXP;
      UhciWriteReg (Uhc->PciIo, USBCMD_OFFSET, UsbCmd);

    } else if (CurState == EfiUsbHcStateSuspend) {
      //
      // If FGR(Force Global Resume) bit is 0, set it
      //
      if ((UsbCmd & USBCMD_FGR) == 0) {
        UsbCmd |= USBCMD_FGR;
        UhciWriteReg (Uhc->PciIo, USBCMD_OFFSET, UsbCmd);
      }

      //
      // wait 20ms to let resume complete (20ms is specified by UHCI spec)
      //
      gBS->Stall (UHC_FORCE_GLOBAL_RESUME_STALL);

      //
      // Write FGR bit to 0 and EGSM(Enter Global Suspend Mode) bit to 0
      //
      UsbCmd &= ~USBCMD_FGR;
      UsbCmd &= ~USBCMD_EGSM;
      UsbCmd |= USBCMD_RS;
      UhciWriteReg (Uhc->PciIo, USBCMD_OFFSET, UsbCmd);
    }

    break;

  case EfiUsbHcStateSuspend:
    Status = Uhci2SetState (This, EfiUsbHcStateHalt);

    if (EFI_ERROR (Status)) {
      Status = EFI_DEVICE_ERROR;
      goto ON_EXIT;
    }

    //
    // Set Enter Global Suspend Mode bit to 1.
    //
    UsbCmd = UhciReadReg (Uhc->PciIo, USBCMD_OFFSET);
    UsbCmd |= USBCMD_EGSM;
    UhciWriteReg (Uhc->PciIo, USBCMD_OFFSET, UsbCmd);
    break;

  default:
    Status = EFI_INVALID_PARAMETER;
    break;
  }

ON_EXIT:
  gBS->RestoreTPL (OldTpl);
  return Status;
}

/**
  Retrieves capabilities of USB host controller according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  MaxSpeed               A pointer to the max speed USB host controller
                                 supports.
  @param  PortNumber             A pointer to the number of root hub ports.
  @param  Is64BitCapable         A pointer to an integer to show whether USB host
                                 controller supports 64-bit memory addressing.

  @return EFI_SUCCESS            capabilities were retrieved successfully.
  @return EFI_INVALID_PARAMETER  MaxSpeed or PortNumber or Is64BitCapable is NULL.
  @return EFI_DEVICE_ERROR       An error was encountered.

**/
EFI_STATUS
EFIAPI
Uhci2GetCapability (
  IN  EFI_USB2_HC_PROTOCOL  *This,
  OUT UINT8                 *MaxSpeed,
  OUT UINT8                 *PortNumber,
  OUT UINT8                 *Is64BitCapable
  )
{
  USB_HC_DEV          *Uhc;
  UINT32              Offset;
  UINT16              PortSC;
  UINT32              Index;

  Uhc = UHC_FROM_USB2_HC_PROTO (This);

  if ((NULL == MaxSpeed) || (NULL == PortNumber) || (NULL == Is64BitCapable)) {
    return EFI_INVALID_PARAMETER;
  }

  *MaxSpeed       = EFI_USB_SPEED_FULL;
  *Is64BitCapable = (UINT8) FALSE;

  *PortNumber = 0;

  for (Index = 0; Index < USB_MAX_ROOTHUB_PORT; Index++) {
    Offset  = USBPORTSC_OFFSET + Index * 2;
    PortSC  = UhciReadReg (Uhc->PciIo, Offset);

    //
    // Port status's bit 7 is reserved and always returns 1 if
    // the port number is valid. Intel's UHCI (in EHCI controller)
    // returns 0 in this bit if port number is invalid. Also, if
    // PciIo IoRead returns error, 0xFFFF is returned to caller.
    //
    if (((PortSC & 0x80) == 0) || (PortSC == 0xFFFF)) {
      break;
    }
    (*PortNumber)++;
  }

  Uhc->RootPorts = *PortNumber;

  DEBUG ((EFI_D_INFO, "Uhci2GetCapability: %d ports\n", Uhc->RootPorts));
  return EFI_SUCCESS;
}


/**
  Retrieves the current status of a USB root hub port according to UEFI 2.0 spec.

  @param  This                    A pointer to the EFI_USB2_HC_PROTOCOL.
  @param  PortNumber              The port to get status.
  @param  PortStatus              A pointer to the current port status bits and  port
                                  status change bits.

  @return EFI_SUCCESS             status of the USB root hub port was returned in PortStatus.
  @return EFI_INVALID_PARAMETER   PortNumber is invalid.
  @return EFI_DEVICE_ERROR        Can't read register.

**/
EFI_STATUS
EFIAPI
Uhci2GetRootHubPortStatus (
  IN  CONST EFI_USB2_HC_PROTOCOL   *This,
  IN  CONST UINT8                  PortNumber,
  OUT       EFI_USB_PORT_STATUS    *PortStatus
  )
{
  USB_HC_DEV          *Uhc;
  UINT32              Offset;
  UINT16              PortSC;

  Uhc = UHC_FROM_USB2_HC_PROTO (This);

  if (PortStatus == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (PortNumber >= Uhc->RootPorts) {
    return EFI_INVALID_PARAMETER;
  }

  Offset                        = USBPORTSC_OFFSET + PortNumber * 2;
  PortStatus->PortStatus        = 0;
  PortStatus->PortChangeStatus  = 0;

  PortSC                        = UhciReadReg (Uhc->PciIo, Offset);

  if ((PortSC & USBPORTSC_CCS) != 0) {
    PortStatus->PortStatus |= USB_PORT_STAT_CONNECTION;
  }

  if ((PortSC & USBPORTSC_PED) != 0) {
    PortStatus->PortStatus |= USB_PORT_STAT_ENABLE;
  }

  if ((PortSC & USBPORTSC_SUSP) != 0) {
    DEBUG ((EFI_D_INFO, "Uhci2GetRootHubPortStatus: port %d is suspended\n", PortNumber));
    PortStatus->PortStatus |= USB_PORT_STAT_SUSPEND;
  }

  if ((PortSC & USBPORTSC_PR) != 0) {
    PortStatus->PortStatus |= USB_PORT_STAT_RESET;
  }

  if ((PortSC & USBPORTSC_LSDA) != 0) {
    PortStatus->PortStatus |= USB_PORT_STAT_LOW_SPEED;
  }

  //
  // CHC will always return one in port owner bit
  //
  PortStatus->PortStatus |= USB_PORT_STAT_OWNER;

  if ((PortSC & USBPORTSC_CSC) != 0) {
    PortStatus->PortChangeStatus |= USB_PORT_STAT_C_CONNECTION;
  }

  if ((PortSC & USBPORTSC_PEDC) != 0) {
    PortStatus->PortChangeStatus |= USB_PORT_STAT_C_ENABLE;
  }

  return EFI_SUCCESS;
}


/**
  Sets a feature for the specified root hub port according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL.
  @param  PortNumber             Specifies the root hub port whose feature  is
                                 requested to be set.
  @param  PortFeature            Indicates the feature selector associated  with the
                                 feature set request.

  @return EFI_SUCCESS            PortFeature was set for the root port.
  @return EFI_INVALID_PARAMETER  PortNumber is invalid or PortFeature is invalid.
  @return EFI_DEVICE_ERROR       Can't read register.

**/
EFI_STATUS
EFIAPI
Uhci2SetRootHubPortFeature (
  IN EFI_USB2_HC_PROTOCOL    *This,
  IN UINT8                   PortNumber,
  IN EFI_USB_PORT_FEATURE    PortFeature
  )
{
  USB_HC_DEV          *Uhc;
  EFI_TPL             OldTpl;
  UINT32              Offset;
  UINT16              PortSC;
  UINT16              Command;

  Uhc = UHC_FROM_USB2_HC_PROTO (This);

  if (PortNumber >= Uhc->RootPorts) {
    return EFI_INVALID_PARAMETER;
  }

  Offset  = USBPORTSC_OFFSET + PortNumber * 2;

  OldTpl  = gBS->RaiseTPL (UHCI_TPL);
  PortSC  = UhciReadReg (Uhc->PciIo, Offset);

  switch (PortFeature) {
  case EfiUsbPortSuspend:
    Command = UhciReadReg (Uhc->PciIo, USBCMD_OFFSET);
    if ((Command & USBCMD_EGSM) == 0) {
      //
      // if global suspend is not active, can set port suspend
      //
      PortSC &= 0xfff5;
      PortSC |= USBPORTSC_SUSP;
    }
    break;

  case EfiUsbPortReset:
    PortSC &= 0xfff5;
    PortSC |= USBPORTSC_PR;
    break;

  case EfiUsbPortPower:
    //
    // No action
    //
    break;

  case EfiUsbPortEnable:
    PortSC &= 0xfff5;
    PortSC |= USBPORTSC_PED;
    break;

  default:
    gBS->RestoreTPL (OldTpl);
    return EFI_INVALID_PARAMETER;
  }

  UhciWriteReg (Uhc->PciIo, Offset, PortSC);
  gBS->RestoreTPL (OldTpl);

  return EFI_SUCCESS;
}


/**
  Clears a feature for the specified root hub port according to Uefi 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  PortNumber             Specifies the root hub port whose feature  is
                                 requested to be cleared.
  @param  PortFeature            Indicates the feature selector associated with the
                                 feature clear request.

  @return EFI_SUCCESS            PortFeature was cleared for the USB root hub port.
  @return EFI_INVALID_PARAMETER  PortNumber is invalid or PortFeature is invalid.
  @return EFI_DEVICE_ERROR       Can't read register.

**/
EFI_STATUS
EFIAPI
Uhci2ClearRootHubPortFeature (
  IN EFI_USB2_HC_PROTOCOL    *This,
  IN UINT8                   PortNumber,
  IN EFI_USB_PORT_FEATURE    PortFeature
  )
{
  USB_HC_DEV          *Uhc;
  EFI_TPL             OldTpl;
  UINT32              Offset;
  UINT16              PortSC;

  Uhc = UHC_FROM_USB2_HC_PROTO (This);

  if (PortNumber >= Uhc->RootPorts) {
    return EFI_INVALID_PARAMETER;
  }

  Offset  = USBPORTSC_OFFSET + PortNumber * 2;

  OldTpl  = gBS->RaiseTPL (UHCI_TPL);
  PortSC  = UhciReadReg (Uhc->PciIo, Offset);

  switch (PortFeature) {
  case EfiUsbPortEnable:
    PortSC &= 0xfff5;
    PortSC &= ~USBPORTSC_PED;
    break;

  case EfiUsbPortSuspend:
    //
    // Cause a resume on the specified port if in suspend mode.
    //
    PortSC &= 0xfff5;
    PortSC &= ~USBPORTSC_SUSP;
    break;

  case EfiUsbPortPower:
    //
    // No action
    //
    break;

  case EfiUsbPortReset:
    PortSC &= 0xfff5;
    PortSC &= ~USBPORTSC_PR;
    break;

  case EfiUsbPortConnectChange:
    PortSC &= 0xfff5;
    PortSC |= USBPORTSC_CSC;
    break;

  case EfiUsbPortEnableChange:
    PortSC &= 0xfff5;
    PortSC |= USBPORTSC_PEDC;
    break;

  case EfiUsbPortSuspendChange:
    //
    // Root hub does not support this
    //
    break;

  case EfiUsbPortOverCurrentChange:
    //
    // Root hub does not support this
    //
    break;

  case EfiUsbPortResetChange:
    //
    // Root hub does not support this
    //
    break;

  default:
    gBS->RestoreTPL (OldTpl);
    return EFI_INVALID_PARAMETER;
  }

  UhciWriteReg (Uhc->PciIo, Offset, PortSC);
  gBS->RestoreTPL (OldTpl);

  return EFI_SUCCESS;
}


/**
  Submits control transfer to a target USB device accroding to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress          Target device address.
  @param  DeviceSpeed            Device speed.
  @param  MaximumPacketLength    Maximum packet size of the target endpoint.
  @param  Request                USB device request to send.
  @param  TransferDirection      Data direction of the Data stage in control transfer.
  @param  Data                   Data to transmit/receive in data stage.
  @param  DataLength             Length of the data.
  @param  TimeOut                Maximum time, in microseconds, for transfer to complete.
  @param  Translator             Transaction translator to be used by this device.
  @param  TransferResult         Variable to receive the transfer result.

  @return EFI_SUCCESS            The control transfer was completed successfully.
  @return EFI_OUT_OF_RESOURCES   Failed due to lack of resource.
  @return EFI_INVALID_PARAMETER  Some parameters are invalid.
  @return EFI_TIMEOUT            Failed due to timeout.
  @return EFI_DEVICE_ERROR       Failed due to host controller or device error.

**/
EFI_STATUS
EFIAPI
Uhci2ControlTransfer (
  IN     EFI_USB2_HC_PROTOCOL                 *This,
  IN     UINT8                                DeviceAddress,
  IN     UINT8                                DeviceSpeed,
  IN     UINTN                                MaximumPacketLength,
  IN     EFI_USB_DEVICE_REQUEST               *Request,
  IN     EFI_USB_DATA_DIRECTION               TransferDirection,
  IN OUT VOID                                 *Data,
  IN OUT UINTN                                *DataLength,
  IN     UINTN                                TimeOut,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR   *Translator,
  OUT    UINT32                               *TransferResult
  )
{
  USB_HC_DEV              *Uhc;
  UHCI_TD_SW              *TDs;
  EFI_TPL                 OldTpl;
  EFI_STATUS              Status;
  UHCI_QH_RESULT          QhResult;
  UINT8                   PktId;
  UINT8                   *RequestPhy;
  VOID                    *RequestMap;
  UINT8                   *DataPhy;
  VOID                    *DataMap;
  BOOLEAN                 IsSlowDevice;

  Uhc         = UHC_FROM_USB2_HC_PROTO (This);
  TDs         = NULL;
  DataPhy     = NULL;
  DataMap     = NULL;
  RequestPhy  = NULL;
  RequestMap  = NULL;

  IsSlowDevice  = (BOOLEAN) ((EFI_USB_SPEED_LOW == DeviceSpeed) ? TRUE : FALSE);

  //
  // Parameters Checking
  //
  if (Request == NULL || TransferResult == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  if (IsSlowDevice && (MaximumPacketLength != 8)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((MaximumPacketLength != 8) &&  (MaximumPacketLength != 16) &&
      (MaximumPacketLength != 32) && (MaximumPacketLength != 64)) {

    return EFI_INVALID_PARAMETER;
  }

  if ((TransferDirection != EfiUsbNoData) && (DataLength == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  *TransferResult = EFI_USB_ERR_SYSTEM;
  Status          = EFI_DEVICE_ERROR;

  //
  // If errors exist that cause host controller halt,
  // clear status then return EFI_DEVICE_ERROR.
  //
  UhciAckAllInterrupt (Uhc);

  if (!UhciIsHcWorking (Uhc->PciIo)) {
    return EFI_DEVICE_ERROR;
  }

  OldTpl = gBS->RaiseTPL (UHCI_TPL);

  //
  // Map the Request and data for bus master access,
  // then create a list of TD for this transfer
  //
  Status = UhciMapUserRequest (Uhc, Request, &RequestPhy, &RequestMap);

  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Status = UhciMapUserData (Uhc, TransferDirection, Data, DataLength, &PktId, &DataPhy, &DataMap);

  if (EFI_ERROR (Status)) {
    Uhc->PciIo->Unmap (Uhc->PciIo, RequestMap);
    goto ON_EXIT;
  }

  TDs = UhciCreateCtrlTds (
          Uhc,
          DeviceAddress,
          PktId,
          RequestPhy,
          DataPhy,
          *DataLength,
          (UINT8) MaximumPacketLength,
          IsSlowDevice
          );

  if (TDs == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto UNMAP_DATA;
  }

  //
  // According to the speed of the end point, link
  // the TD to corrosponding queue head, then check
  // the execution result
  //
  UhciLinkTdToQh (Uhc->CtrlQh, TDs);
  Status = UhciExecuteTransfer (Uhc, Uhc->CtrlQh, TDs, TimeOut, IsSlowDevice, &QhResult);
  UhciUnlinkTdFromQh (Uhc->CtrlQh, TDs);

  Uhc->PciIo->Flush (Uhc->PciIo);

  *TransferResult = QhResult.Result;

  if (DataLength != NULL) {
    *DataLength = QhResult.Complete;
  }

  UhciDestoryTds (Uhc, TDs);

UNMAP_DATA:
  Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);
  Uhc->PciIo->Unmap (Uhc->PciIo, RequestMap);

ON_EXIT:
  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Submits bulk transfer to a bulk endpoint of a USB device.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress          Target device address.
  @param  EndPointAddress        Endpoint number and direction.
  @param  DeviceSpeed            Device speed.
  @param  MaximumPacketLength    Maximum packet size of the target endpoint.
  @param  DataBuffersNumber      Number of data buffers prepared for the transfer.
  @param  Data                   Array of pointers to the buffers of data.
  @param  DataLength             On input, size of the data buffer, On output,
                                 actually transferred data size.
  @param  DataToggle             On input, data toggle to use; On output, next data toggle.
  @param  TimeOut                Maximum time out, in microseconds.
  @param  Translator             A pointr to the transaction translator data.
  @param  TransferResult         Variable to receive transfer result.

  @return EFI_SUCCESS            The bulk transfer was completed successfully.
  @return EFI_OUT_OF_RESOURCES   Failed due to lack of resource.
  @return EFI_INVALID_PARAMETER  Some parameters are invalid.
  @return EFI_TIMEOUT            Failed due to timeout.
  @return EFI_DEVICE_ERROR       Failed due to host controller or device error.

**/
EFI_STATUS
EFIAPI
Uhci2BulkTransfer (
  IN     EFI_USB2_HC_PROTOCOL               *This,
  IN     UINT8                              DeviceAddress,
  IN     UINT8                              EndPointAddress,
  IN     UINT8                              DeviceSpeed,
  IN     UINTN                              MaximumPacketLength,
  IN     UINT8                              DataBuffersNumber,
  IN OUT VOID                               *Data[EFI_USB_MAX_BULK_BUFFER_NUM],
  IN OUT UINTN                              *DataLength,
  IN OUT UINT8                              *DataToggle,
  IN     UINTN                              TimeOut,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR *Translator,
  OUT    UINT32                             *TransferResult
  )
{
  EFI_USB_DATA_DIRECTION  Direction;
  EFI_TPL                 OldTpl;
  USB_HC_DEV              *Uhc;
  UHCI_TD_SW              *TDs;
  UHCI_QH_SW              *BulkQh;
  UHCI_QH_RESULT          QhResult;
  EFI_STATUS              Status;
  UINT8                   PktId;
  UINT8                   *DataPhy;
  VOID                    *DataMap;

  Uhc     = UHC_FROM_USB2_HC_PROTO (This);
  DataPhy = NULL;
  DataMap = NULL;

  if (DeviceSpeed == EFI_USB_SPEED_LOW) {
    return EFI_INVALID_PARAMETER;
  }

  if ((DataLength == NULL) || (*DataLength == 0) || (Data == NULL) || (TransferResult == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((*DataToggle != 1) && (*DataToggle != 0)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((MaximumPacketLength != 8) && (MaximumPacketLength != 16) &&
      (MaximumPacketLength != 32) && (MaximumPacketLength != 64)) {
    return EFI_INVALID_PARAMETER;
  }

  *TransferResult = EFI_USB_ERR_SYSTEM;
  Status          = EFI_OUT_OF_RESOURCES;

  //
  // If has errors that cause host controller halt,
  // then return EFI_DEVICE_ERROR directly.
  //
  UhciAckAllInterrupt (Uhc);

  if (!UhciIsHcWorking (Uhc->PciIo)) {
    return EFI_DEVICE_ERROR;
  }

  OldTpl = gBS->RaiseTPL (UHCI_TPL);

  //
  // Map the source data buffer for bus master access,
  // then create a list of TDs
  //
  if ((EndPointAddress & 0x80) != 0) {
    Direction = EfiUsbDataIn;
  } else {
    Direction = EfiUsbDataOut;
  }

  Status = UhciMapUserData (Uhc, Direction, *Data, DataLength, &PktId, &DataPhy, &DataMap);

  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  Status = EFI_OUT_OF_RESOURCES;
  TDs    = UhciCreateBulkOrIntTds (
             Uhc,
             DeviceAddress,
             EndPointAddress,
             PktId,
             DataPhy,
             *DataLength,
             DataToggle,
             (UINT8) MaximumPacketLength,
             FALSE
             );

  if (TDs == NULL) {
    Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);
    goto ON_EXIT;
  }


  //
  // Link the TDs to bulk queue head. According to the platfore
  // defintion of UHCI_NO_BW_RECLAMATION, BulkQh is either configured
  // to do full speed bandwidth reclamation or not.
  //
  BulkQh = Uhc->BulkQh;

  UhciLinkTdToQh (BulkQh, TDs);
  Status = UhciExecuteTransfer (Uhc, BulkQh, TDs, TimeOut, FALSE, &QhResult);
  UhciUnlinkTdFromQh (BulkQh, TDs);

  Uhc->PciIo->Flush (Uhc->PciIo);

  *TransferResult = QhResult.Result;
  *DataToggle     = QhResult.NextToggle;
  *DataLength     = QhResult.Complete;

  UhciDestoryTds (Uhc, TDs);
  Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);

ON_EXIT:
  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Submits an asynchronous interrupt transfer to an
  interrupt endpoint of a USB device according to UEFI 2.0 spec.

  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress          Target device address.
  @param  EndPointAddress        Endpoint number and direction.
  @param  DeviceSpeed            Device speed.
  @param  MaximumPacketLength    Maximum packet size of the target endpoint.
  @param  IsNewTransfer          If TRUE, submit a new transfer, if FALSE cancel old transfer.
  @param  DataToggle             On input, data toggle to use; On output, next data toggle.
  @param  PollingInterval        Interrupt poll rate in milliseconds.
  @param  DataLength             On input, size of the data buffer, On output,
                                 actually transferred data size.
  @param  Translator             A pointr to the transaction translator data.
  @param  CallBackFunction       Function to call periodically.
  @param  Context                User context.

  @return EFI_SUCCESS            Transfer was submitted.
  @return EFI_INVALID_PARAMETER  Some parameters are invalid.
  @return EFI_OUT_OF_RESOURCES   Failed due to a lack of resources.
  @return EFI_DEVICE_ERROR       Can't read register.

**/
EFI_STATUS
EFIAPI
Uhci2AsyncInterruptTransfer (
  IN     EFI_USB2_HC_PROTOCOL               *This,
  IN     UINT8                              DeviceAddress,
  IN     UINT8                              EndPointAddress,
  IN     UINT8                              DeviceSpeed,
  IN     UINTN                              MaximumPacketLength,
  IN     BOOLEAN                            IsNewTransfer,
  IN OUT UINT8                              *DataToggle,
  IN     UINTN                              PollingInterval,
  IN     UINTN                              DataLength,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR *Translator,
  IN     EFI_ASYNC_USB_TRANSFER_CALLBACK    CallBackFunction,
  IN     VOID                               *Context
  )
{
  USB_HC_DEV          *Uhc;
  BOOLEAN             IsSlowDevice;
  UHCI_QH_SW          *Qh;
  UHCI_TD_SW          *IntTds;
  EFI_TPL             OldTpl;
  EFI_STATUS          Status;
  UINT8               *DataPtr;
  UINT8               *DataPhy;
  VOID                *DataMap;
  UINT8               PktId;

  Uhc       = UHC_FROM_USB2_HC_PROTO (This);
  Qh        = NULL;
  IntTds    = NULL;
  DataPtr   = NULL;
  DataPhy   = NULL;
  DataMap   = NULL;

  IsSlowDevice  = (BOOLEAN) ((EFI_USB_SPEED_LOW == DeviceSpeed) ? TRUE : FALSE);

  if ((EndPointAddress & 0x80) == 0) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Delete Async interrupt transfer request
  //
  if (!IsNewTransfer) {
    OldTpl = gBS->RaiseTPL (UHCI_TPL);
    Status = UhciRemoveAsyncReq (Uhc, DeviceAddress, EndPointAddress, DataToggle);

    gBS->RestoreTPL (OldTpl);
    return Status;
  }

  if (PollingInterval < 1 || PollingInterval > 255) {
    return EFI_INVALID_PARAMETER;
  }

  if (DataLength == 0) {
    return EFI_INVALID_PARAMETER;
  }

  if ((*DataToggle != 1) && (*DataToggle != 0)) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // If has errors that cause host controller halt,
  // then return EFI_DEVICE_ERROR directly.
  //
  UhciAckAllInterrupt (Uhc);

  if (!UhciIsHcWorking (Uhc->PciIo)) {
    return EFI_DEVICE_ERROR;
  }

  //
  // Allocate and map source data buffer for bus master access.
  //
  DataPtr = AllocatePool (DataLength);

  if (DataPtr == NULL) {
    return EFI_OUT_OF_RESOURCES;
  }

  OldTpl = gBS->RaiseTPL (UHCI_TPL);

  //
  // Map the user data then create a queue head and
  // list of TD for it.
  //
  Status = UhciMapUserData (
             Uhc,
             EfiUsbDataIn,
             DataPtr,
             &DataLength,
             &PktId,
             &DataPhy,
             &DataMap
             );

  if (EFI_ERROR (Status)) {
    goto FREE_DATA;
  }

  Qh = UhciCreateQh (Uhc, PollingInterval);

  if (Qh == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto UNMAP_DATA;
  }

  IntTds = UhciCreateBulkOrIntTds (
             Uhc,
             DeviceAddress,
             EndPointAddress,
             PktId,
             DataPhy,
             DataLength,
             DataToggle,
             (UINT8) MaximumPacketLength,
             IsSlowDevice
             );

  if (IntTds == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto DESTORY_QH;
  }

  UhciLinkTdToQh (Qh, IntTds);

  //
  // Save QH-TD structures to async Interrupt transfer list,
  // for monitor interrupt transfer execution routine use.
  //
  Status = UhciCreateAsyncReq (
             Uhc,
             Qh,
             IntTds,
             DeviceAddress,
             EndPointAddress,
             DataLength,
             PollingInterval,
             DataMap,
             DataPtr,
             CallBackFunction,
             Context,
             IsSlowDevice
             );

  if (EFI_ERROR (Status)) {
    goto DESTORY_QH;
  }

  UhciLinkQhToFrameList (Uhc->FrameBase, Qh);

  gBS->RestoreTPL (OldTpl);
  return EFI_SUCCESS;

DESTORY_QH:
  UsbHcFreeMem (Uhc->MemPool, Qh, sizeof (UHCI_QH_SW));

UNMAP_DATA:
  Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);

FREE_DATA:
  gBS->FreePool (DataPtr);
  Uhc->PciIo->Flush (Uhc->PciIo);

  gBS->RestoreTPL (OldTpl);
  return Status;
}

/**
  Submits synchronous interrupt transfer to an interrupt endpoint
  of a USB device according to UEFI 2.0 spec.


  @param  This                   A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress          Target device address.
  @param  EndPointAddress        Endpoint number and direction.
  @param  DeviceSpeed            Device speed.
  @param  MaximumPacketLength    Maximum packet size of the target endpoint.
  @param  Data                   Array of pointers to the buffers of data.
  @param  DataLength             On input, size of the data buffer, On output,
                                 actually transferred data size.
  @param  DataToggle             On input, data toggle to use; On output, next data toggle.
  @param  TimeOut                Maximum time out, in microseconds.
  @param  Translator             A pointr to the transaction translator data.
  @param  TransferResult         Variable to receive transfer result.

  @return EFI_SUCCESS            The transfer was completed successfully.
  @return EFI_OUT_OF_RESOURCES   Failed due to lack of resource.
  @return EFI_INVALID_PARAMETER  Some parameters are invalid.
  @return EFI_TIMEOUT            Failed due to timeout.
  @return EFI_DEVICE_ERROR       Failed due to host controller or device error.

**/
EFI_STATUS
EFIAPI
Uhci2SyncInterruptTransfer (
  IN     EFI_USB2_HC_PROTOCOL                      *This,
  IN     UINT8                                     DeviceAddress,
  IN     UINT8                                     EndPointAddress,
  IN     UINT8                                     DeviceSpeed,
  IN     UINTN                                     MaximumPacketLength,
  IN OUT VOID                                      *Data,
  IN OUT UINTN                                     *DataLength,
  IN OUT UINT8                                     *DataToggle,
  IN     UINTN                                     TimeOut,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR        *Translator,
  OUT    UINT32                                    *TransferResult
  )
{
  EFI_STATUS          Status;
  USB_HC_DEV          *Uhc;
  UHCI_TD_SW          *TDs;
  UHCI_QH_RESULT      QhResult;
  EFI_TPL             OldTpl;
  UINT8               *DataPhy;
  VOID                *DataMap;
  UINT8               PktId;
  BOOLEAN             IsSlowDevice;

  Uhc     = UHC_FROM_USB2_HC_PROTO (This);
  DataPhy = NULL;
  DataMap = NULL;
  TDs     = NULL;

  if (DeviceSpeed == EFI_USB_SPEED_HIGH) {
    return EFI_INVALID_PARAMETER;
  }

  IsSlowDevice  = (BOOLEAN) ((EFI_USB_SPEED_LOW == DeviceSpeed) ? TRUE : FALSE);

  if ((DataLength == NULL) || (Data == NULL) || (TransferResult == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((EndPointAddress & 0x80) == 0) {
    return EFI_INVALID_PARAMETER;
  }

  if ((*DataToggle != 1) && (*DataToggle != 0)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((*DataLength == 0) || (MaximumPacketLength > 64)) {
    return EFI_INVALID_PARAMETER;
  }

  if (IsSlowDevice && (MaximumPacketLength > 8)) {
    return EFI_INVALID_PARAMETER;
  }

  *TransferResult = EFI_USB_ERR_SYSTEM;
  Status          = EFI_DEVICE_ERROR;


  UhciAckAllInterrupt (Uhc);

  if (!UhciIsHcWorking (Uhc->PciIo)) {
    return Status;
  }

  OldTpl = gBS->RaiseTPL (UHCI_TPL);

  //
  // Map the source data buffer for bus master access.
  // Create Tds list, then link it to the UHC's interrupt list
  //
  Status = UhciMapUserData (
             Uhc,
             EfiUsbDataIn,
             Data,
             DataLength,
             &PktId,
             &DataPhy,
             &DataMap
             );

  if (EFI_ERROR (Status)) {
    goto ON_EXIT;
  }

  TDs = UhciCreateBulkOrIntTds (
          Uhc,
          DeviceAddress,
          EndPointAddress,
          PktId,
          DataPhy,
          *DataLength,
          DataToggle,
          (UINT8) MaximumPacketLength,
          IsSlowDevice
          );

  if (TDs == NULL) {
    Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);

    Status = EFI_OUT_OF_RESOURCES;
    goto ON_EXIT;
  }


  UhciLinkTdToQh (Uhc->SyncIntQh, TDs);

  Status = UhciExecuteTransfer (Uhc, Uhc->SyncIntQh, TDs, TimeOut, IsSlowDevice, &QhResult);

  UhciUnlinkTdFromQh (Uhc->SyncIntQh, TDs);
  Uhc->PciIo->Flush (Uhc->PciIo);

  *TransferResult = QhResult.Result;
  *DataToggle     = QhResult.NextToggle;
  *DataLength     = QhResult.Complete;

  UhciDestoryTds (Uhc, TDs);
  Uhc->PciIo->Unmap (Uhc->PciIo, DataMap);

ON_EXIT:
  gBS->RestoreTPL (OldTpl);
  return Status;
}


/**
  Submits isochronous transfer to a target USB device according to UEFI 2.0 spec.

  @param  This                  A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress         Target device address.
  @param  EndPointAddress       Endpoint number and direction.
  @param  DeviceSpeed           Device speed.
  @param  MaximumPacketLength   Maximum packet size of the target endpoint.
  @param  DataBuffersNumber     Number of data buffers prepared for the transfer.
  @param  Data                  Array of pointers to the buffers of data.
  @param  DataLength            On input, size of the data buffer, On output,
                                actually transferred data size.
  @param  Translator            A pointr to the transaction translator data.
  @param  TransferResult        Variable to receive transfer result.

  @return EFI_UNSUPPORTED

**/
EFI_STATUS
EFIAPI
Uhci2IsochronousTransfer (
  IN     EFI_USB2_HC_PROTOCOL               *This,
  IN     UINT8                              DeviceAddress,
  IN     UINT8                              EndPointAddress,
  IN     UINT8                              DeviceSpeed,
  IN     UINTN                              MaximumPacketLength,
  IN     UINT8                              DataBuffersNumber,
  IN OUT VOID                               *Data[EFI_USB_MAX_ISO_BUFFER_NUM],
  IN     UINTN                              DataLength,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR *Translator,
  OUT    UINT32                             *TransferResult
  )
{
  return EFI_UNSUPPORTED;
}


/**
  Submits Async isochronous transfer to a target USB device according to UEFI 2.0 spec.

  @param  This                  A pointer to the EFI_USB2_HC_PROTOCOL instance.
  @param  DeviceAddress         Target device address.
  @param  EndPointAddress       Endpoint number and direction.
  @param  DeviceSpeed           Device speed.
  @param  MaximumPacketLength   Maximum packet size of the target endpoint.
  @param  DataBuffersNumber     Number of data buffers prepared for the transfer.
  @param  Data                  Array of pointers to the buffers of data.
  @param  DataLength            On input, size of the data buffer, On output,
                                actually transferred data size.
  @param  Translator            A pointr to the transaction translator data.
  @param  IsochronousCallBack   Function to call when the transfer complete.
  @param  Context               Pass to the call back function as parameter.

  @return EFI_UNSUPPORTED

**/
EFI_STATUS
EFIAPI
Uhci2AsyncIsochronousTransfer (
  IN     EFI_USB2_HC_PROTOCOL                *This,
  IN     UINT8                               DeviceAddress,
  IN     UINT8                               EndPointAddress,
  IN     UINT8                               DeviceSpeed,
  IN     UINTN                               MaximumPacketLength,
  IN     UINT8                               DataBuffersNumber,
  IN OUT VOID                                *Data[EFI_USB_MAX_ISO_BUFFER_NUM],
  IN     UINTN                               DataLength,
  IN     EFI_USB2_HC_TRANSACTION_TRANSLATOR  *Translator,
  IN     EFI_ASYNC_USB_TRANSFER_CALLBACK     IsochronousCallBack,
  IN     VOID                                *Context
  )
{
  return EFI_UNSUPPORTED;
}

/**
  Entry point for EFI drivers.

  @param  ImageHandle      EFI_HANDLE.
  @param  SystemTable      EFI_SYSTEM_TABLE.

  @retval EFI_SUCCESS      Driver is successfully loaded.
  @return Others           Failed.

**/
EFI_STATUS
EFIAPI
UhciDriverEntryPoint (
  IN EFI_HANDLE           ImageHandle,
  IN EFI_SYSTEM_TABLE     *SystemTable
  )
{
  return EfiLibInstallDriverBindingComponentName2 (
           ImageHandle,
           SystemTable,
           &gUhciDriverBinding,
           ImageHandle,
           &gUhciComponentName,
           &gUhciComponentName2
           );
}


/**
  Test to see if this driver supports ControllerHandle. Any
  ControllerHandle that has UsbHcProtocol installed will be supported.

  @param  This                 Protocol instance pointer.
  @param  Controller           Handle of device to test.
  @param  RemainingDevicePath  Not used.

  @return EFI_SUCCESS          This driver supports this device.
  @return EFI_UNSUPPORTED      This driver does not support this device.

**/
EFI_STATUS
EFIAPI
UhciDriverBindingSupported (
  IN EFI_DRIVER_BINDING_PROTOCOL     *This,
  IN EFI_HANDLE                      Controller,
  IN EFI_DEVICE_PATH_PROTOCOL        *RemainingDevicePath
  )
{
  EFI_STATUS            OpenStatus;
  EFI_STATUS            Status;
  EFI_PCI_IO_PROTOCOL   *PciIo;
  USB_CLASSC            UsbClassCReg;

  //
  // Test whether there is PCI IO Protocol attached on the controller handle.
  //
  OpenStatus = gBS->OpenProtocol (
                      Controller,
                      &gEfiPciIoProtocolGuid,
                      (VOID **) &PciIo,
                      This->DriverBindingHandle,
                      Controller,
                      EFI_OPEN_PROTOCOL_BY_DRIVER
                      );

  if (EFI_ERROR (OpenStatus)) {
    return OpenStatus;
  }

  Status = PciIo->Pci.Read (
                        PciIo,
                        EfiPciIoWidthUint8,
                        CLASSC_OFFSET,
                        sizeof (USB_CLASSC) / sizeof (UINT8),
                        &UsbClassCReg
                        );

  if (EFI_ERROR (Status)) {
    Status = EFI_UNSUPPORTED;
    goto ON_EXIT;
  }

  //
  // Test whether the controller belongs to UHCI type
  //
  if ((UsbClassCReg.BaseCode != PCI_CLASS_SERIAL) ||
      (UsbClassCReg.SubClassCode != PCI_CLASS_SERIAL_USB) ||
      (UsbClassCReg.PI != PCI_CLASSC_PI_UHCI)
      ) {

    Status = EFI_UNSUPPORTED;
  }

ON_EXIT:
  gBS->CloseProtocol (
         Controller,
         &gEfiPciIoProtocolGuid,
         This->DriverBindingHandle,
         Controller
         );

  return Status;

}


/**
  Allocate and initialize the empty UHCI device.

  @param  PciIo                  The PCIIO to use.
  @param  OriginalPciAttributes  The original PCI attributes.

  @return Allocated UHCI device. If err, return NULL.

**/
USB_HC_DEV *
UhciAllocateDev (
  IN EFI_PCI_IO_PROTOCOL    *PciIo,
  IN UINT64                 OriginalPciAttributes
  )
{
  USB_HC_DEV  *Uhc;
  EFI_STATUS  Status;

  Uhc = AllocateZeroPool (sizeof (USB_HC_DEV));

  if (Uhc == NULL) {
    return NULL;
  }

  //
  // This driver supports both USB_HC_PROTOCOL and USB2_HC_PROTOCOL.
  // USB_HC_PROTOCOL is for EFI 1.1 backward compability.
  //
  Uhc->Signature                        = USB_HC_DEV_SIGNATURE;
  Uhc->Usb2Hc.GetCapability             = Uhci2GetCapability;
  Uhc->Usb2Hc.Reset                     = Uhci2Reset;
  Uhc->Usb2Hc.GetState                  = Uhci2GetState;
  Uhc->Usb2Hc.SetState                  = Uhci2SetState;
  Uhc->Usb2Hc.ControlTransfer           = Uhci2ControlTransfer;
  Uhc->Usb2Hc.BulkTransfer              = Uhci2BulkTransfer;
  Uhc->Usb2Hc.AsyncInterruptTransfer    = Uhci2AsyncInterruptTransfer;
  Uhc->Usb2Hc.SyncInterruptTransfer     = Uhci2SyncInterruptTransfer;
  Uhc->Usb2Hc.IsochronousTransfer       = Uhci2IsochronousTransfer;
  Uhc->Usb2Hc.AsyncIsochronousTransfer  = Uhci2AsyncIsochronousTransfer;
  Uhc->Usb2Hc.GetRootHubPortStatus      = Uhci2GetRootHubPortStatus;
  Uhc->Usb2Hc.SetRootHubPortFeature     = Uhci2SetRootHubPortFeature;
  Uhc->Usb2Hc.ClearRootHubPortFeature   = Uhci2ClearRootHubPortFeature;
  Uhc->Usb2Hc.MajorRevision             = 0x1;
  Uhc->Usb2Hc.MinorRevision             = 0x1;

  Uhc->PciIo                 = PciIo;
  Uhc->OriginalPciAttributes = OriginalPciAttributes;
  Uhc->MemPool               = UsbHcInitMemPool (PciIo, TRUE, 0);

  if (Uhc->MemPool == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto ON_ERROR;
  }

  InitializeListHead (&Uhc->AsyncIntList);

  Status = gBS->CreateEvent (
                  EVT_TIMER | EVT_NOTIFY_SIGNAL,
                  TPL_CALLBACK,
                  UhciMonitorAsyncReqList,
                  Uhc,
                  &Uhc->AsyncIntMonitor
                  );

  if (EFI_ERROR (Status)) {
    UsbHcFreeMemPool (Uhc->MemPool);
    goto ON_ERROR;
  }

  return Uhc;

ON_ERROR:
  gBS->FreePool (Uhc);
  return NULL;
}


/**
  Free the UHCI device and release its associated resources.

  @param  Uhc     The UHCI device to release.

  @return None.

**/
VOID
UhciFreeDev (
  IN USB_HC_DEV           *Uhc
  )
{
  if (Uhc->AsyncIntMonitor != NULL) {
    gBS->CloseEvent (Uhc->AsyncIntMonitor);
  }

  if (Uhc->MemPool != NULL) {
    UsbHcFreeMemPool (Uhc->MemPool);
  }

  if (Uhc->CtrlNameTable != NULL) {
    FreeUnicodeStringTable (Uhc->CtrlNameTable);
  }

  gBS->FreePool (Uhc);
}


/**
  Uninstall all Uhci Interface.

  @param  Controller           Controller handle.
  @param  This                 Protocol instance pointer.

  @return None.

**/
VOID
UhciCleanDevUp (
  IN  EFI_HANDLE           Controller,
  IN  EFI_USB2_HC_PROTOCOL *This
  )
{
  USB_HC_DEV          *Uhc;

  //
  // Uninstall the USB_HC and USB_HC2 protocol, then disable the controller
  //
  Uhc = UHC_FROM_USB2_HC_PROTO (This);
  UhciStopHc (Uhc, UHC_GENERIC_TIMEOUT);

  gBS->UninstallProtocolInterface (
        Controller,
        &gEfiUsb2HcProtocolGuid,
        &Uhc->Usb2Hc
        );

  UhciFreeAllAsyncReq (Uhc);
  UhciDestoryFrameList (Uhc);

  //
  // Restore original PCI attributes
  //
  Uhc->PciIo->Attributes (
                  Uhc->PciIo,
                  EfiPciIoAttributeOperationSet,
                  Uhc->OriginalPciAttributes,
                  NULL
                  );

  UhciFreeDev (Uhc);
}


/**
  Starting the Usb UHCI Driver.

  @param  This                 Protocol instance pointer.
  @param  Controller           Handle of device to test.
  @param  RemainingDevicePath  Not used.

  @retval EFI_SUCCESS          This driver supports this device.
  @retval EFI_UNSUPPORTED      This driver does not support this device.
  @retval EFI_DEVICE_ERROR     This driver cannot be started due to device Error.
                               EFI_OUT_OF_RESOURCES- Failed due to resource shortage.

**/
EFI_STATUS
EFIAPI
UhciDriverBindingStart (
  IN EFI_DRIVER_BINDING_PROTOCOL     *This,
  IN EFI_HANDLE                      Controller,
  IN EFI_DEVICE_PATH_PROTOCOL        *RemainingDevicePath
  )
{
  EFI_STATUS          Status;
  EFI_PCI_IO_PROTOCOL *PciIo;
  USB_HC_DEV          *Uhc;
  UINT64              Supports;
  UINT64              OriginalPciAttributes;
  BOOLEAN             PciAttributesSaved;

  //
  // Open PCIIO, then enable the EHC device and turn off emulation
  //
  Uhc = NULL;
  Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiPciIoProtocolGuid,
                  (VOID **) &PciIo,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_BY_DRIVER
                  );

  if (EFI_ERROR (Status)) {
    return Status;
  }

  PciAttributesSaved = FALSE;
  //
  // Save original PCI attributes
  //
  Status = PciIo->Attributes (
                    PciIo,
                    EfiPciIoAttributeOperationGet,
                    0,
                    &OriginalPciAttributes
                    );

  if (EFI_ERROR (Status)) {
    goto CLOSE_PCIIO;
  }
  PciAttributesSaved = TRUE;

  //
  // Robustnesss improvement such as for UoL
  // Default is not required.
  //
  if (FeaturePcdGet (PcdTurnOffUsbLegacySupport)) {
    UhciTurnOffUsbEmulation (PciIo);
  }

  Status = PciIo->Attributes (
                    PciIo,
                    EfiPciIoAttributeOperationSupported,
                    0,
                    &Supports
                    );
  if (!EFI_ERROR (Status)) {
    Supports &= EFI_PCI_DEVICE_ENABLE;
    Status = PciIo->Attributes (
                      PciIo,
                      EfiPciIoAttributeOperationEnable,
                      Supports,
                      NULL
                      );
  }

  if (EFI_ERROR (Status)) {
    goto CLOSE_PCIIO;
  }

  Uhc = UhciAllocateDev (PciIo, OriginalPciAttributes);

  if (Uhc == NULL) {
    Status = EFI_OUT_OF_RESOURCES;
    goto CLOSE_PCIIO;
  }

  //
  // Allocate and Init Host Controller's Frame List Entry
  //
  Status = UhciInitFrameList (Uhc);

  if (EFI_ERROR (Status)) {
    Status = EFI_OUT_OF_RESOURCES;
    goto FREE_UHC;
  }

  Status = gBS->SetTimer (
                  Uhc->AsyncIntMonitor,
                  TimerPeriodic,
                  UHC_ASYNC_POLL_INTERVAL
                  );

  if (EFI_ERROR (Status)) {
    goto FREE_UHC;
  }

  //
  // Install USB2_HC_PROTOCOL
  //
  Status = gBS->InstallMultipleProtocolInterfaces (
                  &Controller,
                  &gEfiUsb2HcProtocolGuid,
                  &Uhc->Usb2Hc,
                  NULL
                  );

  if (EFI_ERROR (Status)) {
    goto FREE_UHC;
  }

  //
  // Install the component name protocol
  //
  Uhc->CtrlNameTable = NULL;

  AddUnicodeString2 (
    "eng",
    gUhciComponentName.SupportedLanguages,
    &Uhc->CtrlNameTable,
    L"Usb Universal Host Controller",
    TRUE
    );
  AddUnicodeString2 (
    "en",
    gUhciComponentName2.SupportedLanguages,
    &Uhc->CtrlNameTable,
    L"Usb Universal Host Controller",
    FALSE
    );


  //
  // Start the UHCI hardware, also set its reclamation point to 64 bytes
  //
  UhciWriteReg (Uhc->PciIo, USBCMD_OFFSET, USBCMD_RS | USBCMD_MAXP);

  return EFI_SUCCESS;

FREE_UHC:
  UhciFreeDev (Uhc);

CLOSE_PCIIO:
  if (PciAttributesSaved) {
    //
    // Restore original PCI attributes
    //
    PciIo->Attributes (
                    PciIo,
                    EfiPciIoAttributeOperationSet,
                    OriginalPciAttributes,
                    NULL
                    );
  }

  gBS->CloseProtocol (
        Controller,
        &gEfiPciIoProtocolGuid,
        This->DriverBindingHandle,
        Controller
        );

  return Status;
}


/**
  Stop this driver on ControllerHandle. Support stoping any child handles
  created by this driver.

  @param  This                 Protocol instance pointer.
  @param  Controller           Handle of device to stop driver on.
  @param  NumberOfChildren     Number of Children in the ChildHandleBuffer.
  @param  ChildHandleBuffer    List of handles for the children we need to stop.

  @return EFI_SUCCESS
  @return others

**/
EFI_STATUS
EFIAPI
UhciDriverBindingStop (
  IN EFI_DRIVER_BINDING_PROTOCOL     *This,
  IN EFI_HANDLE                      Controller,
  IN UINTN                           NumberOfChildren,
  IN EFI_HANDLE                      *ChildHandleBuffer
  )
{
  EFI_USB2_HC_PROTOCOL  *Usb2Hc;
  EFI_STATUS            Status;

   Status = gBS->OpenProtocol (
                  Controller,
                  &gEfiUsb2HcProtocolGuid,
                  (VOID **) &Usb2Hc,
                  This->DriverBindingHandle,
                  Controller,
                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
                  );

  //
  // Test whether the Controller handler passed in is a valid
  // Usb controller handle that should be supported, if not,
  // return the error status directly
  //
  if (EFI_ERROR (Status)) {
    return Status;
  }

  UhciCleanDevUp (Controller, Usb2Hc);

  gBS->CloseProtocol (
        Controller,
        &gEfiPciIoProtocolGuid,
        This->DriverBindingHandle,
        Controller
        );

  return EFI_SUCCESS;
}

EFI_DRIVER_BINDING_PROTOCOL gUhciDriverBinding = {
  UhciDriverBindingSupported,
  UhciDriverBindingStart,
  UhciDriverBindingStop,
  0x20,
  NULL,
  NULL
};