/** @file
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FDT client library for ARM's PL031 RTC driver
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Copyright (c) 2016, 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 <Uefi.h>
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#include <Library/BaseLib.h>
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#include <Library/DebugLib.h>
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#include <Library/PcdLib.h>
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#include <Library/UefiBootServicesTableLib.h>
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#include <Protocol/FdtClient.h>
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RETURN_STATUS
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EFIAPI
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ArmVirtPL031FdtClientLibConstructor (
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VOID
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)
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{
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EFI_STATUS Status;
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FDT_CLIENT_PROTOCOL *FdtClient;
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INT32 Node;
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CONST UINT64 *Reg;
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UINT32 RegSize;
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UINT64 RegBase;
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RETURN_STATUS PcdStatus;
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Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL,
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(VOID **)&FdtClient);
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ASSERT_EFI_ERROR (Status);
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Status = FdtClient->FindCompatibleNode (FdtClient, "arm,pl031", &Node);
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if (EFI_ERROR (Status)) {
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DEBUG ((EFI_D_WARN, "%a: No 'arm,pl031' compatible DT node found\n",
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__FUNCTION__));
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return EFI_SUCCESS;
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}
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Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg",
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(CONST VOID **)&Reg, &RegSize);
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if (EFI_ERROR (Status)) {
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DEBUG ((EFI_D_WARN,
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"%a: No 'reg' property found in 'arm,pl031' compatible DT node\n",
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__FUNCTION__));
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return EFI_SUCCESS;
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}
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ASSERT (RegSize == 16);
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RegBase = SwapBytes64 (Reg[0]);
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ASSERT (RegBase < MAX_UINT32);
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PcdStatus = PcdSet32S (PcdPL031RtcBase, (UINT32)RegBase);
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ASSERT_RETURN_ERROR (PcdStatus);
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DEBUG ((EFI_D_INFO, "Found PL031 RTC @ 0x%Lx\n", RegBase));
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//
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// UEFI takes ownership of the RTC hardware, and exposes its functionality
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// through the UEFI Runtime Services GetTime, SetTime, etc. This means we
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// need to disable it in the device tree to prevent the OS from attaching
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// its device driver as well.
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//
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Status = FdtClient->SetNodeProperty (FdtClient, Node, "status",
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"disabled", sizeof ("disabled"));
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if (EFI_ERROR (Status)) {
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DEBUG ((EFI_D_WARN, "Failed to set PL031 status to 'disabled'\n"));
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}
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return EFI_SUCCESS;
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}
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