text: /** @file
    EFI_USB_HC_PROTOCOL as defined in EFI 1.10.
  
    The USB Host Controller Protocol is used by code, typically USB bus drivers, 
    running in the EFI boot services environment, to perform data transactions 
    over a USB bus. In addition, it provides an abstraction for the root hub of the USB bus.
  
    Copyright (c) 2006 - 2008, 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.             
  
  **/
  
  #ifndef _USB_HOSTCONTROLLER_H_
  #define _USB_HOSTCONTROLLER_H_
  
  #include <Protocol/Usb2HostController.h>
  
  #define EFI_USB_HC_PROTOCOL_GUID \
    { \
      0xf5089266, 0x1aa0, 0x4953, {0x97, 0xd8, 0x56, 0x2f, 0x8a, 0x73, 0xb5, 0x19 } \
    }
  
  ///
  /// Forward reference for pure ANSI compatability
  ///
  typedef struct _EFI_USB_HC_PROTOCOL EFI_USB_HC_PROTOCOL;
  
  //
  // Protocol definitions
  //
  
  /**                                                                 
    Provides software reset for the USB host controller.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  Attributes            A bit mask of the reset operation to perform.
                                  
    @retval EFI_SUCCESS           The reset operation succeeded.
    @retval EFI_UNSUPPORTED       The type of reset specified by Attributes is not currently supported
                                  by the host controller hardware.                                    
    @retval EFI_INVALID_PARAMETER Attributes is not valid.
    @retval EFI_DEVICE_ERROR      An error was encountered while attempting to perform the reset operation.
                                     
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_RESET)(
    IN EFI_USB_HC_PROTOCOL     *This,
    IN UINT16                  Attributes
    );
  
  /**                                                                 
    Retrieves current state of the USB host controller.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  State                 A pointer to the EFI_USB_HC_STATE data structure that
                                  indicates current state of the USB host controller.  
                                  
    @retval EFI_SUCCESS           The state information of the host controller was returned in State.
    @retval EFI_INVALID_PARAMETER State is NULL.
    @retval EFI_DEVICE_ERROR      An error was encountered while attempting to retrieve the host controller's
                                  current state.                                                                 
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_GET_STATE)(
    IN  EFI_USB_HC_PROTOCOL    *This,
    OUT EFI_USB_HC_STATE       *State
    );
  
  /**                                                                 
    Sets the USB host controller to a specific state.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  State                 Indicates the state of the host controller that will be set.                                
                                  
    @retval EFI_SUCCESS           The USB host controller was successfully placed in the state specified by
                                  State.                                                                   
    @retval EFI_INVALID_PARAMETER State is NULL.
    @retval EFI_DEVICE_ERROR      Failed to set the state specified by State due to device error.                                
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_SET_STATE)(
    IN EFI_USB_HC_PROTOCOL     *This,
    IN EFI_USB_HC_STATE        State
    );
  
  /**                                                                 
    Submits control transfer to a target USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  IsSlowDevice          Indicates whether the target device is slow device or full-speed
                                  device.                                                         
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving.     
    @param  Request               A pointer to the USB device request that will be sent to the USB
                                  device.
    @param  TransferDirection     Specifies the data direction for the transfer. There are three 
                                  values available, EfiUsbDataIn, EfiUsbDataOut and EfiUsbNoData.
    @param  Data                  A pointer to the buffer of data that will be transmitted to USB  
                                  device or received from USB device.                            
    @param  DataLength            On input, indicates the size, in bytes, of the data buffer specified
                                  by Data. On output, indicates the amount of data actually           
                                  transferred.                                                        
    @param  TimeOut               Indicates the maximum time, in milliseconds, which the transfer
                                  is allowed to complete.                                        
    @param  TransferResult        A pointer to the detailed result information generated by this  
                                  control transfer.
                                  
    @retval EFI_SUCCESS           The control transfer was completed successfully.
    @retval EFI_OUT_OF_RESOURCES  The control transfer could not be completed due to a lack of resources.                                
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
    @retval EFI_TIMEOUT           The control transfer failed due to timeout.
    @retval EFI_DEVICE_ERROR      The control transfer failed due to host controller or device error.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_CONTROL_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL       *This,
    IN     UINT8                     DeviceAddress,
    IN     BOOLEAN                   IsSlowDevice,
    IN     UINT8                     MaximumPacketLength,
    IN     EFI_USB_DEVICE_REQUEST    *Request,
    IN     EFI_USB_DATA_DIRECTION    TransferDirection,
    IN OUT VOID                      *Data       OPTIONAL,
    IN OUT UINTN                     *DataLength OPTIONAL,
    IN     UINTN                     TimeOut,
    OUT    UINT32                    *TransferResult
    );
  
  /**                                                                 
    Submits bulk transfer to a bulk endpoint of a USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  EndPointAddress       The combination of an endpoint number and an endpoint 
                                  direction of the target USB device. Each endpoint address 
                                  supports data transfer in one direction except the control 
                                  endpoint (whose default endpoint address is 0). It is the 
                                  caller's responsibility to make sure that the EndPointAddress 
                                  represents a bulk endpoint.                 
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving.     
    @param  Data                  A pointer to the buffer of data that will be transmitted to USB  
                                  device or received from USB device.                            
    @param  DataLength            On input, indicates the size, in bytes, of the data buffer specified
                                  by Data. On output, indicates the amount of data actually           
                                  transferred.             
    @param  DataToggle            A pointer to the data toggle value.                                                                           
    @param  TimeOut               Indicates the maximum time, in milliseconds, which the transfer
                                  is allowed to complete.                                        
    @param  TransferResult        A pointer to the detailed result information of the bulk transfer.
                                  
    @retval EFI_SUCCESS           The bulk transfer was completed successfully.
    @retval EFI_OUT_OF_RESOURCES  The bulk transfer could not be completed due to a lack of resources.                                
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
    @retval EFI_TIMEOUT           The bulk transfer failed due to timeout.
    @retval EFI_DEVICE_ERROR      The bulk transfer failed due to host controller or device error.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_BULK_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL    *This,
    IN     UINT8                  DeviceAddress,
    IN     UINT8                  EndPointAddress,
    IN     UINT8                  MaximumPacketLength,
    IN OUT VOID                   *Data,
    IN OUT UINTN                  *DataLength,
    IN OUT UINT8                  *DataToggle,
    IN     UINTN                  TimeOut,
    OUT    UINT32                 *TransferResult
    );
  
  /**                                                                 
    Submits an asynchronous interrupt transfer to an interrupt endpoint of a USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  EndPointAddress       The combination of an endpoint number and an endpoint
                                  direction of the target USB device. Each endpoint address
                                  supports data transfer in one direction except the control
                                  endpoint (whose default endpoint address is zero). It is the
                                  caller's responsibility to make sure that the
                                  EndPointAddress represents an interrupt endpoint.     
    @param  IsSlowDevice          Indicates whether the target device is slow device or full-speed
                                  device.                                                                          
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving.     
    @param  IsNewTransfer         If TRUE, an asynchronous interrupt pipe is built between the host                       
                                  and the target interrupt endpoint. If FALSE, the specified asynchronous 
                                  interrupt pipe is canceled. If TRUE, and an interrupt transfer exists 
                                  for the target end point, then EFI_INVALID_PARAMETER is returned.      
    @param  DataToggle            A pointer to the data toggle value. On input, it is valid when 
                                  IsNewTransfer is TRUE, and it indicates the initial data toggle 
                                  value the asynchronous interrupt transfer should adopt. On output, 
                                  it is valid when IsNewTransfer is FALSE, and it is updated to indicate 
                                  the data toggle value of the subsequent asynchronous interrupt transfer.     
    @param  PollingInterval       Indicates the interval, in milliseconds, that the asynchronous
                                  interrupt transfer is polled. 
    @param  DataLength            Indicates the length of data to be received at the rate specified by
                                  PollingInterval from the target asynchronous interrupt              
                                  endpoint. This parameter is only required when IsNewTransfer is TRUE.                                                            
    @param  CallBackFunction      The Callback function. This function is called at the rate specified by 
                                  PollingInterval. This parameter is only required when IsNewTransfer is TRUE.                               
    @param  Context               The context that is passed to the CallBackFunction.
                                  
    @retval EFI_SUCCESS           The asynchronous interrupt transfer request has been successfully
                                  submitted or canceled.    
    @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.                                
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
    @retval EFI_TIMEOUT           The bulk transfer failed due to timeout.
    @retval EFI_DEVICE_ERROR      The bulk transfer failed due to host controller or device error.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_ASYNC_INTERRUPT_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL                                 *This,
    IN     UINT8                                               DeviceAddress,
    IN     UINT8                                               EndPointAddress,
    IN     BOOLEAN                                             IsSlowDevice,
    IN     UINT8                                               MaxiumPacketLength,
    IN     BOOLEAN                                             IsNewTransfer,
    IN OUT UINT8                                               *DataToggle,
    IN     UINTN                                               PollingInterval  OPTIONAL,
    IN     UINTN                                               DataLength       OPTIONAL,
    IN     EFI_ASYNC_USB_TRANSFER_CALLBACK                     CallBackFunction OPTIONAL,
    IN     VOID                                                *Context         OPTIONAL
    );
  
  /**                                                                 
    Submits synchronous interrupt transfer to an interrupt endpoint of a USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  EndPointAddress       The combination of an endpoint number and an endpoint
                                  direction of the target USB device. Each endpoint address
                                  supports data transfer in one direction except the control
                                  endpoint (whose default endpoint address is zero). It is the
                                  caller's responsibility to make sure that the
                                  EndPointAddress represents an interrupt endpoint.  
    @param  IsSlowDevice          Indicates whether the target device is slow device or full-speed
                                  device.                                                                          
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving.       
    @param  Data                  A pointer to the buffer of data that will be transmitted to USB
                                  device or received from USB device.                                                                                            asynchronous interrupt pipe is canceled.                         
    @param  DataLength            On input, the size, in bytes, of the data buffer specified by Data.
                                  On output, the number of bytes transferred.                          
    @param  DataToggle            A pointer to the data toggle value. On input, it indicates the initial 
                                  data toggle value the synchronous interrupt transfer should adopt; 
                                  on output, it is updated to indicate the data toggle value of the 
                                  subsequent synchronous interrupt transfer.                               
    @param  TimeOut               Indicates the maximum time, in milliseconds, which the transfer    
                                  is allowed to complete.                                            
    @param  TransferResult        A pointer to the detailed result information from the synchronous
                                  interrupt transfer.
                                  
    @retval EFI_SUCCESS           The synchronous interrupt transfer was completed successfully.
    @retval EFI_OUT_OF_RESOURCES  The request could not be completed due to a lack of resources.                                  
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
    @retval EFI_TIMEOUT           The synchronous interrupt transfer failed due to timeout.
    @retval EFI_DEVICE_ERROR      The synchronous interrupt transfer failed due to host controller or device error.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_SYNC_INTERRUPT_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL    *This,
    IN     UINT8                  DeviceAddress,
    IN     UINT8                  EndPointAddress,
    IN     BOOLEAN                IsSlowDevice,
    IN     UINT8                  MaximumPacketLength,
    IN OUT VOID                   *Data,
    IN OUT UINTN                  *DataLength,
    IN OUT UINT8                  *DataToggle,
    IN     UINTN                  TimeOut,
    OUT    UINT32                 *TransferResult
    );
  
  /**                                                                 
    Submits isochronous transfer to an isochronous endpoint of a USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  EndPointAddress       The combination of an endpoint number and an endpoint
                                  direction of the target USB device. Each endpoint address
                                  supports data transfer in one direction except the control
                                  endpoint (whose default endpoint address is 0). It is the caller's
                                  responsibility to make sure that the EndPointAddress
                                  represents an isochronous endpoint.                  
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving.       
    @param  Data                  A pointer to the buffer of data that will be transmitted to USB
                                  device or received from USB device.                                                                                            asynchronous interrupt pipe is canceled.                         
    @param  DataLength            Specifies the length, in bytes, of the data to be sent to or received
                                  from the USB device.                                                 
    @param  TransferResult        A pointer to the detailed result information from the isochronous
                                  transfer.
                                  
    @retval EFI_SUCCESS           The isochronous transfer was completed successfully.
    @retval EFI_OUT_OF_RESOURCES  The isochronous could not be completed due to a lack of resources.                                  
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
    @retval EFI_TIMEOUT           The isochronous transfer failed due to timeout.
    @retval EFI_DEVICE_ERROR      The isochronous transfer failed due to host controller or device error.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_ISOCHRONOUS_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL    *This,
    IN     UINT8                  DeviceAddress,
    IN     UINT8                  EndPointAddress,
    IN     UINT8                  MaximumPacketLength,
    IN OUT VOID                   *Data,
    IN     UINTN                  DataLength,
    OUT    UINT32                 *TransferResult
    );
  
  /**                                                                 
    Submits nonblocking isochronous transfer to an isochronous endpoint of a USB device.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  DeviceAddress         Represents the address of the target device on the USB, which is
                                  assigned during USB enumeration.                                
    @param  EndPointAddress       The combination of an endpoint number and an endpoint
                                  direction of the target USB device. Each endpoint address
                                  supports data transfer in one direction except the control
                                  endpoint (whose default endpoint address is zero). It is the
                                  caller's responsibility to make sure that the
                                  EndPointAddress represents an isochronous endpoint.             
    @param  MaximumPacketLength   Indicates the maximum packet size that the default control 
                                  transfer endpoint is capable of sending or receiving. For isochronous 
                                  endpoints, this value is used to reserve the bus time in the schedule, 
                                  required for the perframe data payloads. The pipe may, on an ongoing basis,
                                  actually use less bandwidth than that reserved.      
    @param  Data                  A pointer to the buffer of data that will be transmitted to USB
                                  device or received from USB device.                                                                                            asynchronous interrupt pipe is canceled.                         
    @param  DataLength            Specifies the length, in bytes, of the data to be sent to or received
                                  from the USB device.                                                 
    @param  IsochronousCallback   The Callback function.This function is called if the requested
                                  isochronous transfer is completed.
    @param  Context               Data passed to the IsochronousCallback function. This is
                                  an optional parameter and may be NULL.
                                  
    @retval EFI_SUCCESS           The asynchronous isochronous transfer was completed successfully.
    @retval EFI_OUT_OF_RESOURCES  The asynchronous isochronous could not be completed due to a lack of resources.                                  
    @retval EFI_INVALID_PARAMETER Some parameters are invalid.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_ASYNC_ISOCHRONOUS_TRANSFER)(
    IN     EFI_USB_HC_PROTOCOL                *This,
    IN     UINT8                              DeviceAddress,
    IN     UINT8                              EndPointAddress,
    IN     UINT8                              MaximumPacketLength,
    IN OUT VOID                               *Data,
    IN     UINTN                              DataLength,
    IN     EFI_ASYNC_USB_TRANSFER_CALLBACK    IsochronousCallBack,
    IN     VOID                               *Context OPTIONAL
    );
  
  /**                                                                 
    Retrieves the number of root hub ports.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  PortNumber            A pointer to the number of the root hub ports.                                
                                  
    @retval EFI_SUCCESS           The port number was retrieved successfully.
    @retval EFI_DEVICE_ERROR      An error was encountered while attempting to retrieve the port number.
    @retval EFI_INVALID_PARAMETER PortNumber is NULL.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_GET_ROOTHUB_PORT_NUMBER)(
    IN EFI_USB_HC_PROTOCOL    *This,
    OUT UINT8                 *PortNumber
    );
  
  /**                                                                 
    Retrieves the current status of a USB root hub port.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  PortNumber            Specifies the root hub port from which the status is to be retrieved.
                                  This value is zero based. For example, if a root hub has two ports,
                                  then the first port is numbered 0, and the second port is
                                  numbered 1.
    @param  PortStatus            A pointer to the current port status bits and port status change bits.                                
                                  
    @retval EFI_SUCCESS           The status of the USB root hub port specified by PortNumber
                                  was returned in PortStatus.                                
    @retval EFI_INVALID_PARAMETER PortNumber is invalid.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_GET_ROOTHUB_PORT_STATUS)(
    IN EFI_USB_HC_PROTOCOL     *This,
    IN  UINT8                  PortNumber,
    OUT EFI_USB_PORT_STATUS    *PortStatus
    );
  
  /**                                                                 
    Sets a feature for the specified root hub port.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  PortNumber            Specifies the root hub port from which the status is to be retrieved.
                                  This value is zero based. For example, if a root hub has two ports,
                                  then the first port is numbered 0, and the second port is
                                  numbered 1.
    @param  PortFeature           Indicates the feature selector associated with the feature set
                                  request.
                                  
    @retval EFI_SUCCESS           The feature specified by PortFeature was set for the USB
                                  root hub port specified by PortNumber.                  
    @retval EFI_INVALID_PARAMETER PortNumber is invalid or PortFeature is invalid for this function.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_SET_ROOTHUB_PORT_FEATURE)(
    IN EFI_USB_HC_PROTOCOL     *This,
    IN UINT8                   PortNumber,
    IN EFI_USB_PORT_FEATURE    PortFeature
    );
  
  /**                                                                 
    Clears a feature for the specified root hub port.
      
    @param  This                  A pointer to the EFI_USB_HC_PROTOCOL instance.
    @param  PortNumber            Specifies the root hub port from which the status is to be retrieved.
                                  This value is zero based. For example, if a root hub has two ports,
                                  then the first port is numbered 0, and the second port is
                                  numbered 1.
    @param  PortFeature           Indicates the feature selector associated with the feature clear
                                  request.
                                  
    @retval EFI_SUCCESS           The feature specified by PortFeature was cleared for the USB
                                  root hub port specified by PortNumber.                  
    @retval EFI_INVALID_PARAMETER PortNumber is invalid or PortFeature is invalid for this function.
                                  
  **/
  typedef
  EFI_STATUS
  (EFIAPI *EFI_USB_HC_PROTOCOL_CLEAR_ROOTHUB_PORT_FEATURE)(
    IN EFI_USB_HC_PROTOCOL     *This,
    IN UINT8                   PortNumber,
    IN EFI_USB_PORT_FEATURE    PortFeature
    );
  
  
  ///
  /// The EFI_USB_HC_PROTOCOL provides USB host controller management, basic data transactions
  /// over a USB bus, and USB root hub access. A device driver that wishes to manage a USB bus in a
  /// system retrieves the EFI_USB_HC_PROTOCOL instance that is associated with the USB bus to be
  /// managed. A device handle for a USB host controller will minimally contain an
  /// EFI_DEVICE_PATH_PROTOCOL instance, and an EFI_USB_HC_PROTOCOL instance. 
  ///
  struct _EFI_USB_HC_PROTOCOL {
    EFI_USB_HC_PROTOCOL_RESET                       Reset;
    EFI_USB_HC_PROTOCOL_GET_STATE                   GetState;
    EFI_USB_HC_PROTOCOL_SET_STATE                   SetState;
    EFI_USB_HC_PROTOCOL_CONTROL_TRANSFER            ControlTransfer;
    EFI_USB_HC_PROTOCOL_BULK_TRANSFER               BulkTransfer;
    EFI_USB_HC_PROTOCOL_ASYNC_INTERRUPT_TRANSFER    AsyncInterruptTransfer;
    EFI_USB_HC_PROTOCOL_SYNC_INTERRUPT_TRANSFER     SyncInterruptTransfer;
    EFI_USB_HC_PROTOCOL_ISOCHRONOUS_TRANSFER        IsochronousTransfer;
    EFI_USB_HC_PROTOCOL_ASYNC_ISOCHRONOUS_TRANSFER  AsyncIsochronousTransfer;
    EFI_USB_HC_PROTOCOL_GET_ROOTHUB_PORT_NUMBER     GetRootHubPortNumber;
    EFI_USB_HC_PROTOCOL_GET_ROOTHUB_PORT_STATUS     GetRootHubPortStatus;
    EFI_USB_HC_PROTOCOL_SET_ROOTHUB_PORT_FEATURE    SetRootHubPortFeature;
    EFI_USB_HC_PROTOCOL_CLEAR_ROOTHUB_PORT_FEATURE  ClearRootHubPortFeature;
    ///
    /// The major revision number of the USB host controller. The revision information 
    /// indicates the release of the Universal Serial Bus Specification with which the 
    /// host controller is compliant.
    ///  
    UINT16                                          MajorRevision;
    ///
    /// The minor revision number of the USB host controller. The revision information 
    /// indicates the release of the Universal Serial Bus Specification with which the 
    /// host controller is compliant.  
    ///  
    UINT16                                          MinorRevision;
  };
  
  extern EFI_GUID gEfiUsbHcProtocolGuid;
  
  #endif
  