ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.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 #include <Drivers/SP804Timer.h>
  23 #include <ArmPlatform.h>
  24
  25 // Setup SP810's Timer2 for managing delay functions. And Timer3 for Performance counter
  26 // Note: ArmVE's Timer0 and Timer1 are used by TimerDxe.
  27 RETURN_STATUS
  28 EFIAPI
  29 TimerConstructor (
  30   VOID
  31   )
  32 {
  33   // Check if Timer 2 is already initialized
  34   if (MmioRead32(SP804_TIMER2_BASE + SP804_TIMER_CONTROL_REG) & SP804_TIMER_CTRL_ENABLE) {
  35     return RETURN_SUCCESS;
  36   } else {
  37     // Configure timer 2 for one shot operation, 32 bits, no prescaler, and interrupt disabled
  38     MmioOr32 (SP804_TIMER2_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ONESHOT | SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
  39
  40     // Preload the timer count register
  41     MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, 1);
  42
  43     // Enable the timer
  44     MmioOr32 (SP804_TIMER2_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
  45   }
  46
  47   // Check if Timer 3 is already initialized
  48   if (MmioRead32(SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG) & SP804_TIMER_CTRL_ENABLE) {
  49     return RETURN_SUCCESS;
  50   } else {
  51     // Configure timer 3 for free running operation, 32 bits, no prescaler, interrupt disabled
  52     MmioOr32 (SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
  53
  54     // Enable the timer
  55     MmioOr32 (SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
  56   }
  57
  58   return RETURN_SUCCESS;
  59 }
  60
  61 /**
  62   Stalls the CPU for at least the given number of microseconds.
  63
  64   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  65
  66   @param  MicroSeconds  The minimum number of microseconds to delay.
  67
  68   @return The value of MicroSeconds inputted.
  69
  70 **/
  71 UINTN
  72 EFIAPI
  73 MicroSecondDelay (
  74   IN  UINTN MicroSeconds
  75   )
  76 {
  77   // load the timer count register
  78   MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
  79
  80   while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
  81     ;
  82   }
  83
  84   return MicroSeconds;
  85 }
  86
  87 /**
  88   Stalls the CPU for at least the given number of nanoseconds.
  89
  90   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  91
  92   @param  NanoSeconds The minimum number of nanoseconds to delay.
  93
  94   @return The value of NanoSeconds inputted.
  95
  96 **/
  97 UINTN
  98 EFIAPI
  99 NanoSecondDelay (
 100   IN  UINTN NanoSeconds
 101   )
 102 {
 103   UINT32 MicroSeconds;
 104
 105   // Round up to 1us Tick Number
 106   MicroSeconds =   (UINT32)NanoSeconds / 1000;
 107   MicroSeconds += ((UINT32)NanoSeconds % 1000) == 0 ? 0 : 1;
 108
 109   // load the timer count register
 110   MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
 111
 112   while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
 113     ;
 114   }
 115
 116   return NanoSeconds;
 117 }
 118
 119 /**
 120   Retrieves the current value of a 64-bit free running performance counter.
 121
 122   The counter can either count up by 1 or count down by 1. If the physical
 123   performance counter counts by a larger increment, then the counter values
 124   must be translated. The properties of the counter can be retrieved from
 125   GetPerformanceCounterProperties().
 126
 127   @return The current value of the free running performance counter.
 128
 129 **/
 130 UINT64
 131 EFIAPI
 132 GetPerformanceCounter (
 133   VOID
 134   )
 135 {
 136   // Free running 64-bit/32-bit counter is needed here.
 137   // Don't think we need this to boot, just to do performance profile
 138   UINT64 Value;
 139   Value = MmioRead32 (SP804_TIMER3_BASE + SP804_TIMER_CURRENT_REG);
 140   ASSERT(Value > 0);
 141   return Value;
 142 }
 143
 144
 145 /**
 146   Retrieves the 64-bit frequency in Hz and the range of performance counter
 147   values.
 148
 149   If StartValue is not NULL, then the value that the performance counter starts
 150   with immediately after is it rolls over is returned in StartValue. If
 151   EndValue is not NULL, then the value that the performance counter end with
 152   immediately before it rolls over is returned in EndValue. The 64-bit
 153   frequency of the performance counter in Hz is always returned. If StartValue
 154   is less than EndValue, then the performance counter counts up. If StartValue
 155   is greater than EndValue, then the performance counter counts down. For
 156   example, a 64-bit free running counter that counts up would have a StartValue
 157   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 158   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 159
 160   @param  StartValue  The value the performance counter starts with when it
 161                       rolls over.
 162   @param  EndValue    The value that the performance counter ends with before
 163                       it rolls over.
 164
 165   @return The frequency in Hz.
 166
 167 **/
 168 UINT64
 169 EFIAPI
 170 GetPerformanceCounterProperties (
 171   OUT UINT64  *StartValue,  OPTIONAL
 172   OUT UINT64  *EndValue     OPTIONAL
 173   )
 174 {
 175   if (StartValue != NULL) {
 176     // Timer starts with the reload value
 177     *StartValue = (UINT64)0ULL;
 178   }
 179
 180   if (EndValue != NULL) {
 181     // Timer counts up to 0xFFFFFFFF
 182     *EndValue = 0xFFFFFFFF;
 183   }
 184
 185   return 1000000;
 186 }