/** @file
*  Generic Timer Description Table (GTDT)
*
*  Copyright (c) 2018, Linaro Limited. All rights reserved.
*  Copyright (c) 2012 - 2016, ARM Limited. All rights reserved.
*
*  SPDX-License-Identifier: BSD-2-Clause-Patent
*
**/

#include "ArmPlatform.h"
#include <Library/AcpiLib.h>
#include <Library/PcdLib.h>
#include <IndustryStandard/Acpi.h>

#define GTDT_GLOBAL_FLAGS_MAPPED      EFI_ACPI_5_0_GTDT_GLOBAL_FLAG_MEMORY_MAPPED_BLOCK_PRESENT
#define GTDT_GLOBAL_FLAGS_NOT_MAPPED  0
#define GTDT_GLOBAL_FLAGS_EDGE        EFI_ACPI_5_0_GTDT_GLOBAL_FLAG_INTERRUPT_MODE
#define GTDT_GLOBAL_FLAGS_LEVEL       0

// Note: We could have a build flag that switches between memory mapped/non-memory mapped timer
#ifdef SYSTEM_TIMER_BASE_ADDRESS
  #define GTDT_GLOBAL_FLAGS             (GTDT_GLOBAL_FLAGS_MAPPED | GTDT_GLOBAL_FLAGS_LEVEL)
#else
  #define GTDT_GLOBAL_FLAGS             (GTDT_GLOBAL_FLAGS_NOT_MAPPED | GTDT_GLOBAL_FLAGS_LEVEL)
  #define SYSTEM_TIMER_BASE_ADDRESS     0xFFFFFFFFFFFFFFFF
#endif

#define GTDT_TIMER_EDGE_TRIGGERED   EFI_ACPI_5_0_GTDT_TIMER_FLAG_TIMER_INTERRUPT_MODE
#define GTDT_TIMER_LEVEL_TRIGGERED  0
#define GTDT_TIMER_ACTIVE_LOW       EFI_ACPI_5_0_GTDT_TIMER_FLAG_TIMER_INTERRUPT_POLARITY
#define GTDT_TIMER_ACTIVE_HIGH      0

#define GTDT_GTIMER_FLAGS           (GTDT_TIMER_ACTIVE_LOW | GTDT_TIMER_LEVEL_TRIGGERED)

#define EFI_ACPI_ARM_OEM_ID           'A','R','M','L','T','D'   // OEMID 6 bytes long
#define EFI_ACPI_ARM_OEM_TABLE_ID     SIGNATURE_64('A','R','M','-','J','U','N','O') // OEM table id 8 bytes long
#define EFI_ACPI_ARM_OEM_REVISION     0x20140727
#define EFI_ACPI_ARM_CREATOR_ID       SIGNATURE_32('A','R','M',' ')
#define EFI_ACPI_ARM_CREATOR_REVISION 0x00000099

#define ARM_ACPI_HEADER(Signature, Type, Revision) {              \
      Signature,		      /* UINT32  Signature */	    \
      sizeof (Type),		      /* UINT32  Length */	    \
      Revision, 		      /* UINT8	 Revision */	    \
      0,			      /* UINT8	 Checksum */	    \
      { EFI_ACPI_ARM_OEM_ID },	      /* UINT8	 OemId[6] */	    \
      EFI_ACPI_ARM_OEM_TABLE_ID,      /* UINT64  OemTableId */	    \
      EFI_ACPI_ARM_OEM_REVISION,      /* UINT32  OemRevision */     \
      EFI_ACPI_ARM_CREATOR_ID,	      /* UINT32  CreatorId */	    \
      EFI_ACPI_ARM_CREATOR_REVISION   /* UINT32  CreatorRevision */ \
    }

#pragma pack (1)

typedef struct {
  EFI_ACPI_5_1_GENERIC_TIMER_DESCRIPTION_TABLE          Gtdt;
} GENERIC_TIMER_DESCRIPTION_TABLE;

#pragma pack ()

GENERIC_TIMER_DESCRIPTION_TABLE Gtdt = {
  {
    ARM_ACPI_HEADER(
      EFI_ACPI_5_1_GENERIC_TIMER_DESCRIPTION_TABLE_SIGNATURE,
      GENERIC_TIMER_DESCRIPTION_TABLE,
      EFI_ACPI_5_1_GENERIC_TIMER_DESCRIPTION_TABLE_REVISION
    ),
    SYSTEM_TIMER_BASE_ADDRESS,                    // UINT64  PhysicalAddress
    0,                                            // UINT32  Reserved
    FixedPcdGet32 (PcdArmArchTimerSecIntrNum),    // UINT32  SecurePL1TimerGSIV
    GTDT_GTIMER_FLAGS,                            // UINT32  SecurePL1TimerFlags
    FixedPcdGet32 (PcdArmArchTimerIntrNum),       // UINT32  NonSecurePL1TimerGSIV
    GTDT_GTIMER_FLAGS,                            // UINT32  NonSecurePL1TimerFlags
    FixedPcdGet32 (PcdArmArchTimerVirtIntrNum),   // UINT32  VirtualTimerGSIV
    GTDT_GTIMER_FLAGS,                            // UINT32  VirtualTimerFlags
    FixedPcdGet32 (PcdArmArchTimerHypIntrNum),    // UINT32  NonSecurePL2TimerGSIV
    GTDT_GTIMER_FLAGS,                            // UINT32  NonSecurePL2TimerFlags
    0xFFFFFFFFFFFFFFFF,                           // UINT64  CntReadBasePhysicalAddress
    0,                          // UINT32  PlatformTimerCount
  },
};

//
// Reference the table being generated to prevent the optimizer
// from removing the data structure from the executable
//
VOID* CONST ReferenceAcpiTable = &Gtdt;