/** @file
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Device driver for the Atmel ATSHA204A random number generator.
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Copyright (c) 2018, Linaro Ltd. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#include <Library/UefiDriverEntryPoint.h>
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#include "AtSha204aDriver.h"
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/**
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Tests to see if this driver supports a given controller.
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@param This[in] A pointer to the EFI_DRIVER_BINDING_PROTOCOL
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instance.
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@param ControllerHandle[in] The handle of the controller to test.
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@param RemainingDevicePath[in] The remaining device path.
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(Ignored - this is not a bus driver.)
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@retval EFI_SUCCESS The driver supports this controller.
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@retval EFI_ALREADY_STARTED The device specified by ControllerHandle is
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already being managed by the driver specified
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by This.
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@retval EFI_UNSUPPORTED The device specified by ControllerHandle is
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not supported by the driver specified by This.
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**/
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EFI_STATUS
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EFIAPI
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I2cHwrngDriverBindingSupported (
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IN EFI_DRIVER_BINDING_PROTOCOL *This,
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IN EFI_HANDLE ControllerHandle,
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IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath
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)
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{
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EFI_I2C_IO_PROTOCOL *I2cIo;
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EFI_STATUS Status;
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//
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// Connect to the I2C stack
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//
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Status = gBS->OpenProtocol (ControllerHandle,
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&gEfiI2cIoProtocolGuid,
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(VOID **) &I2cIo,
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This->DriverBindingHandle,
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ControllerHandle,
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EFI_OPEN_PROTOCOL_BY_DRIVER);
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if (EFI_ERROR (Status)) {
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return Status;
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}
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if (CompareGuid (I2cIo->DeviceGuid, &gAtSha204aI2cDeviceGuid)) {
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DEBUG ((DEBUG_INIT | DEBUG_INFO, "Detected AtSha204a RNG device\n"));
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Status = EFI_SUCCESS;
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} else {
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Status = EFI_UNSUPPORTED;
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}
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//
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// Clean up.
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//
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gBS->CloseProtocol (ControllerHandle,
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&gEfiI2cIoProtocolGuid,
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This->DriverBindingHandle,
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ControllerHandle);
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return Status;
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}
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/**
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Starts a device controller or a bus controller.
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@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL
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instance.
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@param[in] ControllerHandle The handle of the device to start. This
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handle must support a protocol interface that
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supplies an I/O abstraction to the driver.
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@param[in] RemainingDevicePath The remaining portion of the device path.
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(Ignored - this is not a bus driver.)
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@retval EFI_SUCCESS The device was started.
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@retval EFI_DEVICE_ERROR The device could not be started due to a
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device error.
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@retval EFI_OUT_OF_RESOURCES The request could not be completed due to a
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lack of resources.
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**/
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EFI_STATUS
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EFIAPI
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I2cHwrngDriverBindingStart (
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IN EFI_DRIVER_BINDING_PROTOCOL *This,
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IN EFI_HANDLE ControllerHandle,
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IN EFI_DEVICE_PATH_PROTOCOL *RemainingDevicePath OPTIONAL
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)
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{
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return AtSha204aInit (This->DriverBindingHandle, ControllerHandle);
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}
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/**
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Stops a device controller or a bus controller.
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@param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL
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instance.
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@param[in] ControllerHandle A handle to the device being stopped. The handle
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must support a bus specific I/O protocol for the
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driver to use to stop the device.
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@param[in] NumberOfChildren The number of child device handles in
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ChildHandleBuffer.
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@param[in] ChildHandleBuffer An array of child handles to be freed. May be
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NULL if NumberOfChildren is 0.
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@retval EFI_SUCCESS The device was stopped.
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@retval EFI_DEVICE_ERROR The device could not be stopped due to a device
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error.
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**/
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EFI_STATUS
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EFIAPI
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I2cHwrngDriverBindingStop (
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IN EFI_DRIVER_BINDING_PROTOCOL *This,
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IN EFI_HANDLE ControllerHandle,
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IN UINTN NumberOfChildren,
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IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
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)
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{
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return AtSha204aRelease (This->DriverBindingHandle, ControllerHandle);
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}
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STATIC
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EFI_DRIVER_BINDING_PROTOCOL gI2cHwrngDriverBinding = {
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I2cHwrngDriverBindingSupported,
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I2cHwrngDriverBindingStart,
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I2cHwrngDriverBindingStop,
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0xa,
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NULL,
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NULL
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};
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/**
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The entry point of AtSha204a UEFI Driver.
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@param ImageHandle The image handle of the UEFI Driver.
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@param SystemTable A pointer to the EFI System Table.
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@retval EFI_SUCCESS The Driver or UEFI Driver exited normally.
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@retval EFI_INCOMPATIBLE_VERSION _gUefiDriverRevision is greater than
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SystemTable->Hdr.Revision.
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**/
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EFI_STATUS
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EFIAPI
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EntryPoint (
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IN EFI_HANDLE ImageHandle,
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IN EFI_SYSTEM_TABLE *SystemTable
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)
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{
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EFI_STATUS Status;
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//
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// Add the driver to the list of drivers
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//
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Status = EfiLibInstallDriverBindingComponentName2 (
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ImageHandle, SystemTable, &gI2cHwrngDriverBinding, ImageHandle,
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NULL, &gAtSha204aDriverComponentName2);
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ASSERT_EFI_ERROR (Status);
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DEBUG ((DEBUG_INIT | DEBUG_INFO, "*** Installed AtSha204a driver! ***\n"));
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return EFI_SUCCESS;
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}
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/**
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Unload function for the AtSha204a Driver.
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@param ImageHandle[in] The allocated handle for the EFI image
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@retval EFI_SUCCESS The driver was unloaded successfully
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@retval EFI_INVALID_PARAMETER ImageHandle is not a valid image handle.
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**/
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EFI_STATUS
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EFIAPI
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UnloadImage (
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IN EFI_HANDLE ImageHandle
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)
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{
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EFI_STATUS Status;
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EFI_HANDLE *HandleBuffer;
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UINTN HandleCount;
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UINTN Index;
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//
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// Retrieve all I2C I/O handles in the handle database
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//
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Status = gBS->LocateHandleBuffer (ByProtocol,
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&gEfiI2cIoProtocolGuid,
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NULL,
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&HandleCount,
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&HandleBuffer);
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if (EFI_ERROR (Status)) {
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return Status;
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}
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//
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// Disconnect the driver from the handles in the handle database
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//
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for (Index = 0; Index < HandleCount; Index++) {
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Status = gBS->DisconnectController (HandleBuffer[Index],
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gImageHandle,
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NULL);
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}
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//
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// Free the handle array
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//
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gBS->FreePool (HandleBuffer);
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//
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// Uninstall protocols installed by the driver in its entrypoint
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//
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Status = gBS->UninstallMultipleProtocolInterfaces (ImageHandle,
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&gEfiDriverBindingProtocolGuid,
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&gI2cHwrngDriverBinding,
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NULL
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);
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return EFI_SUCCESS;
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}
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