ArmEbPkg/Library/TimerLib/TimerLib.c

   1 /** @file
   2
   3   Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
   4
   5   This program and the accompanying materials
   6   are licensed and made available under the terms and conditions of the BSD License
   7   which accompanies this distribution.  The full text of the license may be found at
   8   http://opensource.org/licenses/bsd-license.php
   9
  10   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #include <Base.h>
  16
  17 #include <Library/BaseLib.h>
  18 #include <Library/TimerLib.h>
  19 #include <Library/DebugLib.h>
  20 #include <Library/PcdLib.h>
  21 #include <Library/IoLib.h>
  22
  23
  24 UINTN
  25 EFIAPI
  26 MicroSecondDelay (
  27   IN  UINTN MicroSeconds
  28   )
  29 {
  30   UINT64  NanoSeconds;
  31
  32   NanoSeconds = MultU64x32 (MicroSeconds, 1000);
  33
  34   while (NanoSeconds > (UINTN)-1) {
  35     NanoSecondDelay((UINTN)-1);
  36     NanoSeconds -= (UINTN)-1;
  37   }
  38
  39   NanoSecondDelay (NanoSeconds);
  40
  41   return MicroSeconds;
  42 }
  43
  44 UINTN
  45 EFIAPI
  46 NanoSecondDelay (
  47   IN  UINTN NanoSeconds
  48   )
  49 {
  50   UINT32  Delay;
  51   UINT32  StartTime;
  52   UINT32  CurrentTime;
  53   UINT32  ElapsedTime;
  54
  55
  56   Delay = (NanoSeconds / PcdGet32(PcdEmbeddedPerformanceCounterPeriodInNanoseconds)) + 1;
  57
  58   StartTime = MmioRead32 (0);
  59   do
  60   {
  61     CurrentTime = 0ULL;
  62     ElapsedTime = CurrentTime - StartTime;
  63   } while (ElapsedTime < Delay);
  64
  65   NanoSeconds = ElapsedTime * PcdGet32 (PcdEmbeddedPerformanceCounterPeriodInNanoseconds);
  66
  67   return NanoSeconds;
  68 }
  69
  70 UINT64
  71 EFIAPI
  72 GetPerformanceCounter (
  73   VOID
  74   )
  75 {
  76   return (UINT64)0ULL;
  77 }
  78
  79 UINT64
  80 EFIAPI
  81 GetPerformanceCounterProperties (
  82   OUT UINT64  *StartValue,  OPTIONAL
  83   OUT UINT64  *EndValue     OPTIONAL
  84   )
  85 {
  86   if (StartValue != NULL) {
  87     // Timer starts with the reload value
  88     *StartValue = (UINT64)0ULL;
  89   }
  90
  91   if (EndValue != NULL) {
  92     // Timer counts up to 0xFFFFFFFF
  93     *EndValue = 0xFFFFFFFF;
  94   }
  95
  96   return PcdGet64(PcdEmbeddedPerformanceCounterFrequencyInHz);
  97 }