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 SP810 to use 1MHz clock and disable
  38         MmioAndThenOr32 (SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER2_EN, SP810_SYS_CTRL_TIMER2_TIMCLK);
  39
  40         // configure timer 2 for one shot operation, 32 bits, no prescaler, and interrupt disabled
  41         MmioOr32 (SP804_TIMER2_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ONESHOT | SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
  42
  43         // preload the timer count register
  44         MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, 1);
  45
  46         // enable the timer
  47         MmioOr32 (SP804_TIMER2_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
  48     }
  49
  50     // Check if Timer 3 is already initialized
  51     if (MmioRead32(SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG) & SP804_TIMER_CTRL_ENABLE) {
  52         return RETURN_SUCCESS;
  53     } else {
  54         // configure SP810 to use 1MHz clock and disable
  55         MmioAndThenOr32 (SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER3_EN, SP810_SYS_CTRL_TIMER3_TIMCLK);
  56
  57         // configure timer 3 for free running operation, 32 bits, no prescaler, interrupt disabled
  58         MmioOr32 (SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);
  59
  60         // enable the timer
  61         MmioOr32 (SP804_TIMER3_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);
  62     }
  63
  64     return RETURN_SUCCESS;
  65 }
  66
  67 /**
  68   Stalls the CPU for at least the given number of microseconds.
  69
  70   Stalls the CPU for the number of microseconds specified by MicroSeconds.
  71
  72   @param  MicroSeconds  The minimum number of microseconds to delay.
  73
  74   @return The value of MicroSeconds inputted.
  75
  76 **/
  77 UINTN
  78 EFIAPI
  79 MicroSecondDelay (
  80   IN  UINTN MicroSeconds
  81   )
  82 {
  83   // load the timer count register
  84   MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
  85
  86   while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
  87     ;
  88   }
  89
  90   return MicroSeconds;
  91 }
  92
  93 /**
  94   Stalls the CPU for at least the given number of nanoseconds.
  95
  96   Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
  97
  98   @param  NanoSeconds The minimum number of nanoseconds to delay.
  99
 100   @return The value of NanoSeconds inputted.
 101
 102 **/
 103 UINTN
 104 EFIAPI
 105 NanoSecondDelay (
 106   IN  UINTN NanoSeconds
 107   )
 108 {
 109   UINT32 MicroSeconds;
 110
 111   // Round up to 1us Tick Number
 112   MicroSeconds =   (UINT32)NanoSeconds / 1000;
 113   MicroSeconds += ((UINT32)NanoSeconds % 1000) == 0 ? 0 : 1;
 114
 115   // load the timer count register
 116   MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
 117
 118   while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
 119     ;
 120   }
 121
 122   return NanoSeconds;
 123 }
 124
 125 /**
 126   Retrieves the current value of a 64-bit free running performance counter.
 127
 128   The counter can either count up by 1 or count down by 1. If the physical
 129   performance counter counts by a larger increment, then the counter values
 130   must be translated. The properties of the counter can be retrieved from
 131   GetPerformanceCounterProperties().
 132
 133   @return The current value of the free running performance counter.
 134
 135 **/
 136 UINT64
 137 EFIAPI
 138 GetPerformanceCounter (
 139   VOID
 140   )
 141 {
 142   // Free running 64-bit/32-bit counter is needed here.
 143   // Don't think we need this to boot, just to do performance profile
 144   // ASSERT (FALSE);
 145   UINT32 val = MmioRead32 (SP804_TIMER3_BASE + SP804_TIMER_CURRENT_REG);
 146   ASSERT(val > 0);
 147
 148   return (UINT64)val;
 149 }
 150
 151
 152 /**
 153   Retrieves the 64-bit frequency in Hz and the range of performance counter
 154   values.
 155
 156   If StartValue is not NULL, then the value that the performance counter starts
 157   with immediately after is it rolls over is returned in StartValue. If
 158   EndValue is not NULL, then the value that the performance counter end with
 159   immediately before it rolls over is returned in EndValue. The 64-bit
 160   frequency of the performance counter in Hz is always returned. If StartValue
 161   is less than EndValue, then the performance counter counts up. If StartValue
 162   is greater than EndValue, then the performance counter counts down. For
 163   example, a 64-bit free running counter that counts up would have a StartValue
 164   of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
 165   that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
 166
 167   @param  StartValue  The value the performance counter starts with when it
 168                       rolls over.
 169   @param  EndValue    The value that the performance counter ends with before
 170                       it rolls over.
 171
 172   @return The frequency in Hz.
 173
 174 **/
 175 UINT64
 176 EFIAPI
 177 GetPerformanceCounterProperties (
 178   OUT UINT64  *StartValue,  OPTIONAL
 179   OUT UINT64  *EndValue     OPTIONAL
 180   )
 181 {
 182   if (StartValue != NULL) {
 183     // Timer starts with the reload value
 184     *StartValue = (UINT64)0ULL;
 185   }
 186
 187   if (EndValue != NULL) {
 188     // Timer counts up to 0xFFFFFFFF
 189     *EndValue = 0xFFFFFFFF;
 190   }
 191
 192   return 1000000;
 193 }