text: /** @file
  
    Copyright (c) 2008 - 2009, Apple Inc. 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.
  
  **/
  
  #include <Uefi.h>
  
  #include <TPS65950.h>
  
  #include <Library/BaseMemoryLib.h>
  #include <Library/DebugLib.h>
  #include <Library/MemoryAllocationLib.h>
  #include <Library/UefiBootServicesTableLib.h>
  
  #include <Protocol/EmbeddedExternalDevice.h>
  #include <Protocol/SmbusHc.h>
  
  EFI_SMBUS_HC_PROTOCOL *Smbus;
  
  EFI_STATUS
  Read (
    IN  EMBEDDED_EXTERNAL_DEVICE    *This,
    IN  UINTN                       Register,
    IN  UINTN                       Length,
    OUT VOID                        *Buffer
    )
  {
    EFI_STATUS               Status;
    EFI_SMBUS_DEVICE_ADDRESS SlaveAddress;
    UINT8                    DeviceRegister;
    UINTN                    DeviceRegisterLength = 1;
  
    SlaveAddress.SmbusDeviceAddress = EXTERNAL_DEVICE_REGISTER_TO_SLAVE_ADDRESS(Register);
    DeviceRegister = (UINT8)EXTERNAL_DEVICE_REGISTER_TO_REGISTER(Register);
  
    //Write DeviceRegister.
    Status = Smbus->Execute(Smbus, SlaveAddress, 0, EfiSmbusWriteBlock, FALSE, &DeviceRegisterLength, &DeviceRegister);
    if (EFI_ERROR(Status)) {
      return Status;
    }
  
    //Read Data
    Status = Smbus->Execute(Smbus, SlaveAddress, 0, EfiSmbusReadBlock, FALSE, &Length, Buffer);
    return Status;
  }
  
  EFI_STATUS
  Write (
    IN EMBEDDED_EXTERNAL_DEVICE   *This,
    IN UINTN                      Register,
    IN UINTN                      Length,
    IN VOID                       *Buffer
    )
  {
    EFI_STATUS               Status;
    EFI_SMBUS_DEVICE_ADDRESS SlaveAddress;
    UINT8                    DeviceRegister;
    UINTN                    DeviceBufferLength = Length + 1;
    UINT8                    *DeviceBuffer;
  
    SlaveAddress.SmbusDeviceAddress = EXTERNAL_DEVICE_REGISTER_TO_SLAVE_ADDRESS(Register);
    DeviceRegister = (UINT8)EXTERNAL_DEVICE_REGISTER_TO_REGISTER(Register);
  
    //Prepare buffer for writing
    DeviceBuffer = (UINT8 *)AllocatePool(DeviceBufferLength);
    if (DeviceBuffer == NULL) {
      Status = EFI_OUT_OF_RESOURCES;
      goto exit;
    }
  
    //Set Device register followed by data to write.
    DeviceBuffer[0] = DeviceRegister;
    CopyMem(&DeviceBuffer[1], Buffer, Length);
  
    //Write Data
    Status = Smbus->Execute(Smbus, SlaveAddress, 0, EfiSmbusWriteBlock, FALSE, &DeviceBufferLength, DeviceBuffer);
    if (EFI_ERROR(Status)) {
      goto exit;
    }
  
  exit:
    if (DeviceBuffer) {
      FreePool(DeviceBuffer);
    }
  
    return Status;
  }
  
  EMBEDDED_EXTERNAL_DEVICE ExternalDevice = {
    Read,
    Write
  };
  
  EFI_STATUS
  TPS65950Initialize (
    IN EFI_HANDLE         ImageHandle,
    IN EFI_SYSTEM_TABLE   *SystemTable
    )
  {
    EFI_STATUS  Status;
  
    Status = gBS->LocateProtocol(&gEfiSmbusHcProtocolGuid, NULL, (VOID **)&Smbus);
    ASSERT_EFI_ERROR(Status);
  
    Status = gBS->InstallMultipleProtocolInterfaces(&ImageHandle, &gEmbeddedExternalDeviceProtocolGuid, &ExternalDevice, NULL);
    return Status;
  }
  