uefi/linaro-edk2/MdePkg/Include/Protocol/DriverBinding.h

/** @file
  UEFI DriverBinding Protocol is defined in UEFI specification.
  
  This protocol is produced by every driver that follows the UEFI Driver Model, 
  and it is the central component that allows drivers and controllers to be managed.

Copyright (c) 2006 - 2010, 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 that 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 __EFI_DRIVER_BINDING_H__
#define __EFI_DRIVER_BINDING_H__

///
/// The global ID for the ControllerHandle Driver Protocol.
///
#define EFI_DRIVER_BINDING_PROTOCOL_GUID \
  { \
    0x18a031ab, 0xb443, 0x4d1a, {0xa5, 0xc0, 0xc, 0x9, 0x26, 0x1e, 0x9f, 0x71 } \
  }

typedef struct _EFI_DRIVER_BINDING_PROTOCOL  EFI_DRIVER_BINDING_PROTOCOL;

/**
  Tests to see if this driver supports a given controller. If a child device is provided, 
  it further tests to see if this driver supports creating a handle for the specified child device.

  This function checks to see if the driver specified by This supports the device specified by 
  ControllerHandle. Drivers will typically use the device path attached to 
  ControllerHandle and/or the services from the bus I/O abstraction attached to 
  ControllerHandle to determine if the driver supports ControllerHandle. This function 
  may be called many times during platform initialization. In order to reduce boot times, the tests 
  performed by this function must be very small, and take as little time as possible to execute. This 
  function must not change the state of any hardware devices, and this function must be aware that the 
  device specified by ControllerHandle may already be managed by the same driver or a 
  different driver. This function must match its calls to AllocatePages() with FreePages(), 
  AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().  
  Because ControllerHandle may have been previously started by the same driver, if a protocol is 
  already in the opened state, then it must not be closed with CloseProtocol(). This is required 
  to guarantee the state of ControllerHandle is not modified by this function.

  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle     The handle of the controller to test. This handle 
                                   must support a protocol interface that supplies 
                                   an I/O abstraction to the driver.
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This 
                                   parameter is ignored by device drivers, and is optional for bus 
                                   drivers. For bus drivers, if this parameter is not NULL, then 
                                   the bus driver must determine if the bus controller specified 
                                   by ControllerHandle and the child controller specified 
                                   by RemainingDevicePath are both supported by this 
                                   bus driver.

  @retval EFI_SUCCESS              The device specified by ControllerHandle and
                                   RemainingDevicePath is supported by the driver specified by This.
  @retval EFI_ALREADY_STARTED      The device specified by ControllerHandle and
                                   RemainingDevicePath is already being managed by the driver
                                   specified by This.
  @retval EFI_ACCESS_DENIED        The device specified by ControllerHandle and
                                   RemainingDevicePath is already being managed by a different
                                   driver or an application that requires exclusive access.
                                   Currently not implemented.
  @retval EFI_UNSUPPORTED          The device specified by ControllerHandle and
                                   RemainingDevicePath is not supported by the driver specified by This.
**/
typedef
EFI_STATUS
(EFIAPI *EFI_DRIVER_BINDING_SUPPORTED)(
  IN EFI_DRIVER_BINDING_PROTOCOL            *This,
  IN EFI_HANDLE                             ControllerHandle,
  IN EFI_DEVICE_PATH_PROTOCOL               *RemainingDevicePath OPTIONAL
  );

/**
  Starts a device controller or a bus controller.

  The Start() function is designed to be invoked from the EFI boot service ConnectController().
  As a result, much of the error checking on the parameters to Start() has been moved into this 
  common boot service. It is legal to call Start() from other locations, 
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.
  1. ControllerHandle must be a valid EFI_HANDLE.
  2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
     EFI_DEVICE_PATH_PROTOCOL.
  3. Prior to calling Start(), the Supported() function for the driver specified by This must
     have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.  

  @param[in]  This                 A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle     The handle of the controller to start. This handle 
                                   must support a protocol interface that supplies 
                                   an I/O abstraction to the driver.
  @param[in]  RemainingDevicePath  A pointer to the remaining portion of a device path.  This 
                                   parameter is ignored by device drivers, and is optional for bus 
                                   drivers. For a bus driver, if this parameter is NULL, then handles 
                                   for all the children of Controller are created by this driver.  
                                   If this parameter is not NULL and the first Device Path Node is 
                                   not the End of Device Path Node, then only the handle for the 
                                   child device specified by the first Device Path Node of 
                                   RemainingDevicePath is created by this driver.
                                   If the first Device Path Node of RemainingDevicePath is 
                                   the End of Device Path Node, no child handle is created by this
                                   driver.

  @retval EFI_SUCCESS              The device was started.
  @retval EFI_DEVICE_ERROR         The device could not be started due to a device error.Currently not implemented.
  @retval EFI_OUT_OF_RESOURCES     The request could not be completed due to a lack of resources.
  @retval Others                   The driver failded to start the device.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_DRIVER_BINDING_START)(
  IN EFI_DRIVER_BINDING_PROTOCOL            *This,
  IN EFI_HANDLE                             ControllerHandle,
  IN EFI_DEVICE_PATH_PROTOCOL               *RemainingDevicePath OPTIONAL
  );

/**
  Stops a device controller or a bus controller.
  
  The Stop() function is designed to be invoked from the EFI boot service DisconnectController(). 
  As a result, much of the error checking on the parameters to Stop() has been moved 
  into this common boot service. It is legal to call Stop() from other locations, 
  but the following calling restrictions must be followed, or the system behavior will not be deterministic.
  1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
     same driver's Start() function.
  2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
     EFI_HANDLE. In addition, all of these handles must have been created in this driver's
     Start() function, and the Start() function must have called OpenProtocol() on
     ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
  
  @param[in]  This              A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
  @param[in]  ControllerHandle  A handle to the device being stopped. The handle must 
                                support a bus specific I/O protocol for the driver 
                                to use to stop the device.
  @param[in]  NumberOfChildren  The number of child device handles in ChildHandleBuffer.
  @param[in]  ChildHandleBuffer An array of child handles to be freed. May be NULL 
                                if NumberOfChildren is 0.

  @retval EFI_SUCCESS           The device was stopped.
  @retval EFI_DEVICE_ERROR      The device could not be stopped due to a device error.

**/
typedef
EFI_STATUS
(EFIAPI *EFI_DRIVER_BINDING_STOP)(
  IN EFI_DRIVER_BINDING_PROTOCOL            *This,
  IN  EFI_HANDLE                            ControllerHandle,
  IN  UINTN                                 NumberOfChildren,
  IN  EFI_HANDLE                            *ChildHandleBuffer OPTIONAL
  );

///
/// This protocol provides the services required to determine if a driver supports a given controller. 
/// If a controller is supported, then it also provides routines to start and stop the controller.
///
struct _EFI_DRIVER_BINDING_PROTOCOL {
  EFI_DRIVER_BINDING_SUPPORTED  Supported;
  EFI_DRIVER_BINDING_START      Start;
  EFI_DRIVER_BINDING_STOP       Stop;
  
  ///
  /// The version number of the UEFI driver that produced the
  /// EFI_DRIVER_BINDING_PROTOCOL. This field is used by
  /// the EFI boot service ConnectController() to determine
  /// the order that driver's Supported() service will be used when
  /// a controller needs to be started. EFI Driver Binding Protocol
  /// instances with higher Version values will be used before ones
  /// with lower Version values. The Version values of 0x0-
  /// 0x0f and 0xfffffff0-0xffffffff are reserved for
  /// platform/OEM specific drivers. The Version values of 0x10-
  /// 0xffffffef are reserved for IHV-developed drivers.
  ///
  UINT32                        Version;
  
  ///
  /// The image handle of the UEFI driver that produced this instance
  /// of the EFI_DRIVER_BINDING_PROTOCOL.
  ///
  EFI_HANDLE                    ImageHandle;
  
  ///
  /// The handle on which this instance of the
  /// EFI_DRIVER_BINDING_PROTOCOL is installed. In most
  /// cases, this is the same handle as ImageHandle. However, for
  /// UEFI drivers that produce more than one instance of the
  /// EFI_DRIVER_BINDING_PROTOCOL, this value may not be
  /// the same as ImageHandle.  
  ///
  EFI_HANDLE                    DriverBindingHandle;
};

extern EFI_GUID gEfiDriverBindingProtocolGuid;

#endif