MdeModulePkg/Universal/DebugPortDxe/DebugPort.h - third_party/edk2 - Git at Google

 /** @file
   Definitions and prototypes for DebugPort driver.

 Copyright (c) 2006 - 2014, 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 __DEBUGPORT_H__
 #define __DEBUGPORT_H__


 #include <Uefi.h>

 #include <Protocol/DevicePath.h>
 #include <Protocol/ComponentName.h>
 #include <Protocol/DriverBinding.h>
 #include <Protocol/SerialIo.h>
 #include <Protocol/DebugPort.h>

 #include <Library/DebugLib.h>
 #include <Library/UefiDriverEntryPoint.h>
 #include <Library/UefiLib.h>
 #include <Library/BaseMemoryLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/UefiRuntimeServicesTableLib.h>
 #include <Library/DevicePathLib.h>

 //
 // Driver Binding Externs
 //
 extern EFI_DRIVER_BINDING_PROTOCOL  gDebugPortDriverBinding;
 extern EFI_COMPONENT_NAME_PROTOCOL  gDebugPortComponentName;
 extern EFI_COMPONENT_NAME2_PROTOCOL gDebugPortComponentName2;

 //
 // local type definitions
 //
 #define DEBUGPORT_DEVICE_SIGNATURE  SIGNATURE_32 ('D', 'B', 'G', 'P')

 //
 // Device structure used by driver
 //
 typedef struct {
   UINT32                      Signature;
   EFI_HANDLE                  DriverBindingHandle;
   EFI_HANDLE                  DebugPortDeviceHandle;

   EFI_DEVICE_PATH_PROTOCOL    *DebugPortDevicePath;
   EFI_DEBUGPORT_PROTOCOL      DebugPortInterface;

   EFI_HANDLE                  SerialIoDeviceHandle;
   EFI_SERIAL_IO_PROTOCOL      *SerialIoBinding;
   UINT64                      BaudRate;
   UINT32                      ReceiveFifoDepth;
   UINT32                      Timeout;
   EFI_PARITY_TYPE             Parity;
   UINT8                       DataBits;
   EFI_STOP_BITS_TYPE          StopBits;
 } DEBUGPORT_DEVICE;

 #define DEBUGPORT_DEVICE_FROM_THIS(a)     CR (a, DEBUGPORT_DEVICE, DebugPortInterface, DEBUGPORT_DEVICE_SIGNATURE)

 #define EFI_ACPI_PC_COMPORT_HID           EISA_PNP_ID (0x0500)
 #define EFI_ACPI_16550UART_HID            EISA_PNP_ID (0x0501)

 #define DEBUGPORT_UART_DEFAULT_BAUDRATE   115200
 #define DEBUGPORT_UART_DEFAULT_PARITY     0
 #define DEBUGPORT_UART_DEFAULT_FIFO_DEPTH 16
 #define DEBUGPORT_UART_DEFAULT_TIMEOUT    50000 ///< 5 ms
 #define DEBUGPORT_UART_DEFAULT_DATA_BITS  8
 #define DEBUGPORT_UART_DEFAULT_STOP_BITS  1

 #define DEBUGPORT_DRIVER_VERSION          1

 #define IS_UART_DEVICEPATH(dp)           (DevicePathType (dp) == MESSAGING_DEVICE_PATH && DevicePathSubType (dp) == MSG_UART_DP)

 /**
   Debug Port Driver entry point.

   Reads DebugPort variable to determine what device and settings to use as the
   debug port.  Binds exclusively to SerialIo. Reverts to defaults if no variable
   is found.

   @param[in] ImageHandle       The firmware allocated handle for the EFI image.
   @param[in] SystemTable       A pointer to the EFI System Table.

   @retval EFI_SUCCESS          The entry point is executed successfully.
   @retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
   @retval other                Some error occurs when executing this entry point.

 **/
 EFI_STATUS
 EFIAPI
 InitializeDebugPortDriver (
   IN EFI_HANDLE                     ImageHandle,
   IN EFI_SYSTEM_TABLE               *SystemTable
   );

 /**
   Checks to see if there's not already a DebugPort interface somewhere.

   If there's a DEBUGPORT variable, the device path must match exactly.  If there's
   no DEBUGPORT variable, then device path is not checked and does not matter.
   Checks to see that there's a serial io interface on the controller handle
   that can be bound BY_DRIVER | EXCLUSIVE.
   If all these tests succeed, then we return EFI_SUCCESS, else, EFI_UNSUPPORTED
   or other error returned by OpenProtocol.

   @param  This                 Protocol instance pointer.
   @param  ControllerHandle     Handle of device to test.
   @param  RemainingDevicePath  Optional parameter use to pick a specific child
                                device to start.

   @retval EFI_SUCCESS          This driver supports this device.
   @retval EFI_UNSUPPORTED      Debug Port device is not supported.
   @retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
   @retval others               Some error occurs.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortSupported (
   IN EFI_DRIVER_BINDING_PROTOCOL    *This,
   IN EFI_HANDLE                     Controller,
   IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
   );

 /**
   Binds exclusively to serial io on the controller handle, Produces DebugPort
   protocol and DevicePath on new handle.

   @param  This                 Protocol instance pointer.
   @param  ControllerHandle     Handle of device to bind driver to.
   @param  RemainingDevicePath  Optional parameter use to pick a specific child
                                device to start.

   @retval EFI_SUCCESS          This driver is added to ControllerHandle.
   @retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
   @retval others               Some error occurs.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortStart (
   IN EFI_DRIVER_BINDING_PROTOCOL    *This,
   IN EFI_HANDLE                     Controller,
   IN EFI_DEVICE_PATH_PROTOCOL       *RemainingDevicePath
   );

 /**
   Stop this driver on ControllerHandle by removing Serial IO protocol on
   the ControllerHandle.

   @param  This              Protocol instance pointer.
   @param  ControllerHandle  Handle of device to stop driver on
   @param  NumberOfChildren  Number of Handles in ChildHandleBuffer. If number of
                             children is zero stop the entire bus driver.
   @param  ChildHandleBuffer List of Child Handles to Stop.

   @retval EFI_SUCCESS       This driver is removed ControllerHandle.
   @retval other             This driver was not removed from this device.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortStop (
   IN  EFI_DRIVER_BINDING_PROTOCOL    *This,
   IN  EFI_HANDLE                     Controller,
   IN  UINTN                          NumberOfChildren,
   IN  EFI_HANDLE                     *ChildHandleBuffer
   );

 //
 // EFI Component Name Functions
 //
 /**
   Retrieves a Unicode string that is the user readable name of the driver.

   This function retrieves the user readable name of a driver in the form of a
   Unicode string. If the driver specified by This has a user readable name in
   the language specified by Language, then a pointer to the driver name is
   returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
   by This does not support the language specified by Language,
   then EFI_UNSUPPORTED is returned.

   @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
                                 EFI_COMPONENT_NAME_PROTOCOL instance.

   @param  Language[in]          A pointer to a Null-terminated ASCII string
                                 array indicating the language. This is the
                                 language of the driver name that the caller is
                                 requesting, and it must match one of the
                                 languages specified in SupportedLanguages. The
                                 number of languages supported by a driver is up
                                 to the driver writer. Language is specified
                                 in RFC 4646 or ISO 639-2 language code format.

   @param  DriverName[out]       A pointer to the Unicode string to return.
                                 This Unicode string is the name of the
                                 driver specified by This in the language
                                 specified by Language.

   @retval EFI_SUCCESS           The Unicode string for the Driver specified by
                                 This and the language specified by Language was
                                 returned in DriverName.

   @retval EFI_INVALID_PARAMETER Language is NULL.

   @retval EFI_INVALID_PARAMETER DriverName is NULL.

   @retval EFI_UNSUPPORTED       The driver specified by This does not support
                                 the language specified by Language.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortComponentNameGetDriverName (
   IN  EFI_COMPONENT_NAME_PROTOCOL  *This,
   IN  CHAR8                        *Language,
   OUT CHAR16                       **DriverName
   );


 /**
   Retrieves a Unicode string that is the user readable name of the controller
   that is being managed by a driver.

   This function retrieves the user readable name of the controller specified by
   ControllerHandle and ChildHandle in the form of a Unicode string. If the
   driver specified by This has a user readable name in the language specified by
   Language, then a pointer to the controller name is returned in ControllerName,
   and EFI_SUCCESS is returned.  If the driver specified by This is not currently
   managing the controller specified by ControllerHandle and ChildHandle,
   then EFI_UNSUPPORTED is returned.  If the driver specified by This does not
   support the language specified by Language, then EFI_UNSUPPORTED is returned.

   @param  This[in]              A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
                                 EFI_COMPONENT_NAME_PROTOCOL instance.

   @param  ControllerHandle[in]  The handle of a controller that the driver
                                 specified by This is managing.  This handle
                                 specifies the controller whose name is to be
                                 returned.

   @param  ChildHandle[in]       The handle of the child controller to retrieve
                                 the name of.  This is an optional parameter that
                                 may be NULL.  It will be NULL for device
                                 drivers.  It will also be NULL for a bus drivers
                                 that wish to retrieve the name of the bus
                                 controller.  It will not be NULL for a bus
                                 driver that wishes to retrieve the name of a
                                 child controller.

   @param  Language[in]          A pointer to a Null-terminated ASCII string
                                 array indicating the language.  This is the
                                 language of the driver name that the caller is
                                 requesting, and it must match one of the
                                 languages specified in SupportedLanguages. The
                                 number of languages supported by a driver is up
                                 to the driver writer. Language is specified in
                                 RFC 4646 or ISO 639-2 language code format.

   @param  ControllerName[out]   A pointer to the Unicode string to return.
                                 This Unicode string is the name of the
                                 controller specified by ControllerHandle and
                                 ChildHandle in the language specified by
                                 Language from the point of view of the driver
                                 specified by This.

   @retval EFI_SUCCESS           The Unicode string for the user readable name in
                                 the language specified by Language for the
                                 driver specified by This was returned in
                                 DriverName.

   @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.

   @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
                                 EFI_HANDLE.

   @retval EFI_INVALID_PARAMETER Language is NULL.

   @retval EFI_INVALID_PARAMETER ControllerName is NULL.

   @retval EFI_UNSUPPORTED       The driver specified by This is not currently
                                 managing the controller specified by
                                 ControllerHandle and ChildHandle.

   @retval EFI_UNSUPPORTED       The driver specified by This does not support
                                 the language specified by Language.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortComponentNameGetControllerName (
   IN  EFI_COMPONENT_NAME_PROTOCOL                     *This,
   IN  EFI_HANDLE                                      ControllerHandle,
   IN  EFI_HANDLE                                      ChildHandle        OPTIONAL,
   IN  CHAR8                                           *Language,
   OUT CHAR16                                          **ControllerName
   );


 /**
   DebugPort protocol member function.  Calls SerialIo:GetControl to flush buffer.
   We cannot call SerialIo:SetAttributes because it uses pool services, which use
   locks, which affect TPL, so it's not interrupt context safe or re-entrant.
   SerialIo:Reset() calls SetAttributes, so it can't be used either.

   The port itself should be fine since it was set up during initialization.

   @param  This              Protocol instance pointer.

   @return EFI_SUCCESS       Always.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortReset (
   IN EFI_DEBUGPORT_PROTOCOL         *This
   );

 /**
   DebugPort protocol member function.  Calls SerialIo:Read() after setting
   if it's different than the last SerialIo access.

   @param  This                Pointer to DebugPort protocol.
   @param  Timeout             Timeout value.
   @param  BufferSize          On input, the size of Buffer.
                               On output, the amount of data actually written.
   @param  Buffer              Pointer to buffer to read.

   @retval EFI_SUCCESS
   @retval others

 **/
 EFI_STATUS
 EFIAPI
 DebugPortRead (
   IN EFI_DEBUGPORT_PROTOCOL         *This,
   IN UINT32                         Timeout,
   IN OUT UINTN                      *BufferSize,
   IN VOID                           *Buffer
   );

 /**
   DebugPort protocol member function.  Calls SerialIo:Write() Writes 8 bytes at
   a time and does a GetControl between 8 byte writes to help insure reads are
   interspersed This is poor-man's flow control.

   @param  This                Pointer to DebugPort protocol.
   @param  Timeout             Timeout value.
   @param  BufferSize          On input, the size of Buffer.
                               On output, the amount of data actually written.
   @param  Buffer              Pointer to buffer to read.

   @retval EFI_SUCCESS         The data was written.
   @retval others              Fails when writting datas to debug port device.

 **/
 EFI_STATUS
 EFIAPI
 DebugPortWrite (
   IN EFI_DEBUGPORT_PROTOCOL         *This,
   IN UINT32                         Timeout,
   IN OUT UINTN                      *BufferSize,
   OUT VOID                          *Buffer
   );

 /**
   DebugPort protocol member function.  Calls SerialIo:Write() after setting
   if it's different than the last SerialIo access.

   @param  This                Pointer to DebugPort protocol.

   @retval EFI_SUCCESS         At least 1 character is ready to be read from
                               the DebugPort interface.
   @retval EFI_NOT_READY       There are no characters ready to read from the
                               DebugPort interface
   @retval EFI_DEVICE_ERROR    A hardware failure occured... (from SerialIo)

 **/
 EFI_STATUS
 EFIAPI
 DebugPortPoll (
   IN EFI_DEBUGPORT_PROTOCOL         *This
   );

 #endif
	/** @file
	Definitions and prototypes for DebugPort driver.

	Copyright (c) 2006 - 2014, 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 __DEBUGPORT_H__
	#define __DEBUGPORT_H__


	#include <Uefi.h>

	#include <Protocol/DevicePath.h>
	#include <Protocol/ComponentName.h>
	#include <Protocol/DriverBinding.h>
	#include <Protocol/SerialIo.h>
	#include <Protocol/DebugPort.h>

	#include <Library/DebugLib.h>
	#include <Library/UefiDriverEntryPoint.h>
	#include <Library/UefiLib.h>
	#include <Library/BaseMemoryLib.h>
	#include <Library/MemoryAllocationLib.h>
	#include <Library/UefiBootServicesTableLib.h>
	#include <Library/UefiRuntimeServicesTableLib.h>
	#include <Library/DevicePathLib.h>

	//
	// Driver Binding Externs
	//
	extern EFI_DRIVER_BINDING_PROTOCOL gDebugPortDriverBinding;
	extern EFI_COMPONENT_NAME_PROTOCOL gDebugPortComponentName;
	extern EFI_COMPONENT_NAME2_PROTOCOL gDebugPortComponentName2;

	//
	// local type definitions
	//
	#define DEBUGPORT_DEVICE_SIGNATURE SIGNATURE_32 ('D', 'B', 'G', 'P')

	//
	// Device structure used by driver
	//
	typedef struct {
	UINT32 Signature;
	EFI_HANDLE DriverBindingHandle;
	EFI_HANDLE DebugPortDeviceHandle;

	EFI_DEVICE_PATH_PROTOCOL *DebugPortDevicePath;
	EFI_DEBUGPORT_PROTOCOL DebugPortInterface;

	EFI_HANDLE SerialIoDeviceHandle;
	EFI_SERIAL_IO_PROTOCOL *SerialIoBinding;
	UINT64 BaudRate;
	UINT32 ReceiveFifoDepth;
	UINT32 Timeout;
	EFI_PARITY_TYPE Parity;
	UINT8 DataBits;
	EFI_STOP_BITS_TYPE StopBits;
	} DEBUGPORT_DEVICE;

	#define DEBUGPORT_DEVICE_FROM_THIS(a) CR (a, DEBUGPORT_DEVICE, DebugPortInterface, DEBUGPORT_DEVICE_SIGNATURE)

	#define EFI_ACPI_PC_COMPORT_HID EISA_PNP_ID (0x0500)
	#define EFI_ACPI_16550UART_HID EISA_PNP_ID (0x0501)

	#define DEBUGPORT_UART_DEFAULT_BAUDRATE 115200
	#define DEBUGPORT_UART_DEFAULT_PARITY 0
	#define DEBUGPORT_UART_DEFAULT_FIFO_DEPTH 16
	#define DEBUGPORT_UART_DEFAULT_TIMEOUT 50000 ///< 5 ms
	#define DEBUGPORT_UART_DEFAULT_DATA_BITS 8
	#define DEBUGPORT_UART_DEFAULT_STOP_BITS 1

	#define DEBUGPORT_DRIVER_VERSION 1

	#define IS_UART_DEVICEPATH(dp) (DevicePathType (dp) == MESSAGING_DEVICE_PATH && DevicePathSubType (dp) == MSG_UART_DP)

	/**
	Debug Port Driver entry point.

	Reads DebugPort variable to determine what device and settings to use as the
	debug port. Binds exclusively to SerialIo. Reverts to defaults if no variable
	is found.

	@param[in] ImageHandle The firmware allocated handle for the EFI image.
	@param[in] SystemTable A pointer to the EFI System Table.

	@retval EFI_SUCCESS The entry point is executed successfully.
	@retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
	@retval other Some error occurs when executing this entry point.

	**/
	EFI_STATUS
	EFIAPI
	InitializeDebugPortDriver (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	);

	/**
	Checks to see if there's not already a DebugPort interface somewhere.

	If there's a DEBUGPORT variable, the device path must match exactly. If there's
	no DEBUGPORT variable, then device path is not checked and does not matter.
	Checks to see that there's a serial io interface on the controller handle
	that can be bound BY_DRIVER \| EXCLUSIVE.
	If all these tests succeed, then we return EFI_SUCCESS, else, EFI_UNSUPPORTED
	or other error returned by OpenProtocol.

	@param This Protocol instance pointer.
	@param ControllerHandle Handle of device to test.
	@param RemainingDevicePath Optional parameter use to pick a specific child
	device to start.

	@retval EFI_SUCCESS This driver supports this device.
	@retval EFI_UNSUPPORTED Debug Port device is not supported.
	@retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
	@retval others Some error occurs.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortSupported (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	);

	/**
	Binds exclusively to serial io on the controller handle, Produces DebugPort
	protocol and DevicePath on new handle.

	@param This Protocol instance pointer.
	@param ControllerHandle Handle of device to bind driver to.
	@param RemainingDevicePath Optional parameter use to pick a specific child
	device to start.

	@retval EFI_SUCCESS This driver is added to ControllerHandle.
	@retval EFI_OUT_OF_RESOURCES Fails to allocate memory for device.
	@retval others Some error occurs.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortStart (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
	);

	/**
	Stop this driver on ControllerHandle by removing Serial IO protocol on
	the ControllerHandle.

	@param This Protocol instance pointer.
	@param ControllerHandle Handle of device to stop driver on
	@param NumberOfChildren Number of Handles in ChildHandleBuffer. If number of
	children is zero stop the entire bus driver.
	@param ChildHandleBuffer List of Child Handles to Stop.

	@retval EFI_SUCCESS This driver is removed ControllerHandle.
	@retval other This driver was not removed from this device.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortStop (
	IN EFI_DRIVER_BINDING_PROTOCOL *This,
	IN EFI_HANDLE Controller,
	IN UINTN NumberOfChildren,
	IN EFI_HANDLE *ChildHandleBuffer
	);

	//
	// EFI Component Name Functions
	//
	/**
	Retrieves a Unicode string that is the user readable name of the driver.

	This function retrieves the user readable name of a driver in the form of a
	Unicode string. If the driver specified by This has a user readable name in
	the language specified by Language, then a pointer to the driver name is
	returned in DriverName, and EFI_SUCCESS is returned. If the driver specified
	by This does not support the language specified by Language,
	then EFI_UNSUPPORTED is returned.

	@param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
	EFI_COMPONENT_NAME_PROTOCOL instance.

	@param Language[in] A pointer to a Null-terminated ASCII string
	array indicating the language. This is the
	language of the driver name that the caller is
	requesting, and it must match one of the
	languages specified in SupportedLanguages. The
	number of languages supported by a driver is up
	to the driver writer. Language is specified
	in RFC 4646 or ISO 639-2 language code format.

	@param DriverName[out] A pointer to the Unicode string to return.
	This Unicode string is the name of the
	driver specified by This in the language
	specified by Language.

	@retval EFI_SUCCESS The Unicode string for the Driver specified by
	This and the language specified by Language was
	returned in DriverName.

	@retval EFI_INVALID_PARAMETER Language is NULL.

	@retval EFI_INVALID_PARAMETER DriverName is NULL.

	@retval EFI_UNSUPPORTED The driver specified by This does not support
	the language specified by Language.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortComponentNameGetDriverName (
	IN EFI_COMPONENT_NAME_PROTOCOL *This,
	IN CHAR8 *Language,
	OUT CHAR16 **DriverName
	);


	/**
	Retrieves a Unicode string that is the user readable name of the controller
	that is being managed by a driver.

	This function retrieves the user readable name of the controller specified by
	ControllerHandle and ChildHandle in the form of a Unicode string. If the
	driver specified by This has a user readable name in the language specified by
	Language, then a pointer to the controller name is returned in ControllerName,
	and EFI_SUCCESS is returned. If the driver specified by This is not currently
	managing the controller specified by ControllerHandle and ChildHandle,
	then EFI_UNSUPPORTED is returned. If the driver specified by This does not
	support the language specified by Language, then EFI_UNSUPPORTED is returned.

	@param This[in] A pointer to the EFI_COMPONENT_NAME2_PROTOCOL or
	EFI_COMPONENT_NAME_PROTOCOL instance.

	@param ControllerHandle[in] The handle of a controller that the driver
	specified by This is managing. This handle
	specifies the controller whose name is to be
	returned.

	@param ChildHandle[in] The handle of the child controller to retrieve
	the name of. This is an optional parameter that
	may be NULL. It will be NULL for device
	drivers. It will also be NULL for a bus drivers
	that wish to retrieve the name of the bus
	controller. It will not be NULL for a bus
	driver that wishes to retrieve the name of a
	child controller.

	@param Language[in] A pointer to a Null-terminated ASCII string
	array indicating the language. This is the
	language of the driver name that the caller is
	requesting, and it must match one of the
	languages specified in SupportedLanguages. The
	number of languages supported by a driver is up
	to the driver writer. Language is specified in
	RFC 4646 or ISO 639-2 language code format.

	@param ControllerName[out] A pointer to the Unicode string to return.
	This Unicode string is the name of the
	controller specified by ControllerHandle and
	ChildHandle in the language specified by
	Language from the point of view of the driver
	specified by This.

	@retval EFI_SUCCESS The Unicode string for the user readable name in
	the language specified by Language for the
	driver specified by This was returned in
	DriverName.

	@retval EFI_INVALID_PARAMETER ControllerHandle is NULL.

	@retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid
	EFI_HANDLE.

	@retval EFI_INVALID_PARAMETER Language is NULL.

	@retval EFI_INVALID_PARAMETER ControllerName is NULL.

	@retval EFI_UNSUPPORTED The driver specified by This is not currently
	managing the controller specified by
	ControllerHandle and ChildHandle.

	@retval EFI_UNSUPPORTED The driver specified by This does not support
	the language specified by Language.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortComponentNameGetControllerName (
	IN EFI_COMPONENT_NAME_PROTOCOL *This,
	IN EFI_HANDLE ControllerHandle,
	IN EFI_HANDLE ChildHandle OPTIONAL,
	IN CHAR8 *Language,
	OUT CHAR16 **ControllerName
	);


	/**
	DebugPort protocol member function. Calls SerialIo:GetControl to flush buffer.
	We cannot call SerialIo:SetAttributes because it uses pool services, which use
	locks, which affect TPL, so it's not interrupt context safe or re-entrant.
	SerialIo:Reset() calls SetAttributes, so it can't be used either.

	The port itself should be fine since it was set up during initialization.

	@param This Protocol instance pointer.

	@return EFI_SUCCESS Always.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortReset (
	IN EFI_DEBUGPORT_PROTOCOL *This
	);

	/**
	DebugPort protocol member function. Calls SerialIo:Read() after setting
	if it's different than the last SerialIo access.

	@param This Pointer to DebugPort protocol.
	@param Timeout Timeout value.
	@param BufferSize On input, the size of Buffer.
	On output, the amount of data actually written.
	@param Buffer Pointer to buffer to read.

	@retval EFI_SUCCESS
	@retval others

	**/
	EFI_STATUS
	EFIAPI
	DebugPortRead (
	IN EFI_DEBUGPORT_PROTOCOL *This,
	IN UINT32 Timeout,
	IN OUT UINTN *BufferSize,
	IN VOID *Buffer
	);

	/**
	DebugPort protocol member function. Calls SerialIo:Write() Writes 8 bytes at
	a time and does a GetControl between 8 byte writes to help insure reads are
	interspersed This is poor-man's flow control.

	@param This Pointer to DebugPort protocol.
	@param Timeout Timeout value.
	@param BufferSize On input, the size of Buffer.
	On output, the amount of data actually written.
	@param Buffer Pointer to buffer to read.

	@retval EFI_SUCCESS The data was written.
	@retval others Fails when writting datas to debug port device.

	**/
	EFI_STATUS
	EFIAPI
	DebugPortWrite (
	IN EFI_DEBUGPORT_PROTOCOL *This,
	IN UINT32 Timeout,
	IN OUT UINTN *BufferSize,
	OUT VOID *Buffer
	);

	/**
	DebugPort protocol member function. Calls SerialIo:Write() after setting
	if it's different than the last SerialIo access.

	@param This Pointer to DebugPort protocol.

	@retval EFI_SUCCESS At least 1 character is ready to be read from
	the DebugPort interface.
	@retval EFI_NOT_READY There are no characters ready to read from the
	DebugPort interface
	@retval EFI_DEVICE_ERROR A hardware failure occured... (from SerialIo)

	**/
	EFI_STATUS
	EFIAPI
	DebugPortPoll (
	IN EFI_DEBUGPORT_PROTOCOL *This
	);

	#endif