1 /** @file 2 FDT client library for ARM's PL031 RTC driver 3 4 Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR> 5 6 This program and the accompanying materials 7 are licensed and made available under the terms and conditions of the BSD License 8 which accompanies this distribution. The full text of the license may be found at 9 http://opensource.org/licenses/bsd-license.php 10 11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 13 14 **/ 15 16 #include <Uefi.h> 17 18 #include <Library/BaseLib.h> 19 #include <Library/DebugLib.h> 20 #include <Library/PcdLib.h> 21 #include <Library/UefiBootServicesTableLib.h> 22 23 #include <Protocol/FdtClient.h> 24 25 RETURN_STATUS 26 EFIAPI 27 ArmVirtPL031FdtClientLibConstructor ( 28 VOID 29 ) 30 { 31 EFI_STATUS Status; 32 FDT_CLIENT_PROTOCOL *FdtClient; 33 INT32 Node; 34 CONST UINT64 *Reg; 35 UINT32 RegSize; 36 UINT64 RegBase; 37 RETURN_STATUS PcdStatus; 38 39 Status = gBS->LocateProtocol (&gFdtClientProtocolGuid, NULL, 40 (VOID **)&FdtClient); 41 ASSERT_EFI_ERROR (Status); 42 43 Status = FdtClient->FindCompatibleNode (FdtClient, "arm,pl031", &Node); 44 if (EFI_ERROR (Status)) { 45 DEBUG ((EFI_D_WARN, "%a: No 'arm,pl031' compatible DT node found\n", 46 __FUNCTION__)); 47 return EFI_SUCCESS; 48 } 49 50 Status = FdtClient->GetNodeProperty (FdtClient, Node, "reg", 51 (CONST VOID **)&Reg, &RegSize); 52 if (EFI_ERROR (Status)) { 53 DEBUG ((EFI_D_WARN, 54 "%a: No 'reg' property found in 'arm,pl031' compatible DT node\n", 55 __FUNCTION__)); 56 return EFI_SUCCESS; 57 } 58 59 ASSERT (RegSize == 16); 60 61 RegBase = SwapBytes64 (Reg[0]); 62 ASSERT (RegBase < MAX_UINT32); 63 64 PcdStatus = PcdSet32S (PcdPL031RtcBase, (UINT32)RegBase); 65 ASSERT_RETURN_ERROR (PcdStatus); 66 67 DEBUG ((EFI_D_INFO, "Found PL031 RTC @ 0x%Lx\n", RegBase)); 68 69 if (!FeaturePcdGet (PcdPureAcpiBoot)) { 70 // 71 // UEFI takes ownership of the RTC hardware, and exposes its functionality 72 // through the UEFI Runtime Services GetTime, SetTime, etc. This means we 73 // need to disable it in the device tree to prevent the OS from attaching 74 // its device driver as well. 75 // 76 Status = FdtClient->SetNodeProperty (FdtClient, Node, "status", 77 "disabled", sizeof ("disabled")); 78 if (EFI_ERROR (Status)) { 79 DEBUG ((EFI_D_WARN, "Failed to set PL031 status to 'disabled'\n")); 80 } 81 } 82 83 return EFI_SUCCESS; 84 } 85
