diff options
| author | oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524> | 2011-09-27 16:35:16 +0000 |
|---|---|---|
| committer | oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524> | 2011-09-27 16:35:16 +0000 |
| commit | da9675a241ab9856377b9bd63504b2d5333b3c7a (patch) | |
| tree | 15c8f64a5dbb56ef78dc059bbaa436c6e374ce2f /ArmPkg/Library/ArmArchTimerLib | |
| parent | 0c0e7ef451a3f74d6756d6ec65685114b3dacea8 (diff) | |
| download | edk2-platforms-da9675a241ab9856377b9bd63504b2d5333b3c7a.tar.xz | |
ArmPkg: Add ARM Architectural Timer support
ARM Architectural Timer support is defined by the ARM Generic Timer Specification.
git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12455 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'ArmPkg/Library/ArmArchTimerLib')
| -rw-r--r-- | ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c | 191 | ||||
| -rw-r--r-- | ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.inf | 46 |
2 files changed, 237 insertions, 0 deletions
diff --git a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c new file mode 100644 index 0000000000..d6f3f1b709 --- /dev/null +++ b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c @@ -0,0 +1,191 @@ +/** @file
+ Generic ARM implementation of TimerLib.h
+
+ Copyright (c) 2011, ARM Limited. All rights reserved.
+
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+#include <Base.h>
+#include <Library/BaseLib.h>
+#include <Library/TimerLib.h>
+#include <Library/DebugLib.h>
+#include <Library/PcdLib.h>
+#include <Library/ArmV7ArchTimerLib.h>
+#include <Chipset/ArmV7.h>
+
+#define TICKS_PER_MICRO_SEC (PcdGet32 (PcdArmArchTimerFreqInHz)/1000000U)
+
+RETURN_STATUS
+EFIAPI
+ArmArchTimerLibConstructor (
+ VOID
+ )
+{
+ // Check if the ARM Generic Timer Extension is implemented
+ if (ArmIsArchTimerImplemented ()) {
+
+ UINTN TimerFreq;
+
+ // Check if Architectural Timer frequency is valid number (should not be 0)
+ ASSERT (PcdGet32 (PcdArmArchTimerFreqInHz));
+
+ // Check if ticks/uS is not 0. The Architectural timer runs at constant
+ // frequency irrespective of CPU frequency. According to General Timer Ref
+ // manual lower bound of the frequency is in the range of 1-10MHz
+ ASSERT (TICKS_PER_MICRO_SEC);
+
+ // If the security extensions are not implemented set Timer Frequency
+ if ((ArmReadIdPfr1 () & 0xF0)) {
+ ArmArchTimerSetTimerFreq (PcdGet32 (PcdArmArchTimerFreqInHz));
+ }
+
+ // Architectural Timer Frequency must be set in the Secure privileged(if secure extensions are supported) mode.
+ // If the reset value (0) is returned just ASSERT.
+ TimerFreq = ArmArchTimerGetTimerFreq ();
+ ASSERT (TimerFreq);
+
+ } else {
+ DEBUG ((EFI_D_ERROR, "ARM Architectural Timer is not available in the CPU, Hence cann't use this library \n"));
+ ASSERT (0);
+ }
+
+ return RETURN_SUCCESS;
+}
+
+
+/**
+ Stalls the CPU for the number of microseconds specified by MicroSeconds.
+
+ @param MicroSeconds The minimum number of microseconds to delay.
+
+ @return The value of MicroSeconds inputted.
+
+**/
+UINTN
+EFIAPI
+MicroSecondDelay (
+ IN UINTN MicroSeconds
+ )
+{
+ UINT64 TimerTicks64;
+ UINT64 SystemCounterVal;
+
+ // Calculate counter ticks that can represent requsted delay
+ TimerTicks64 = MultU64x32 (MicroSeconds, TICKS_PER_MICRO_SEC);
+
+ // Read System Counter value
+ SystemCounterVal = ArmArchTimerGetSystemCount ();
+
+ TimerTicks64 += SystemCounterVal;
+
+ // Wait until delay count is expired.
+ while (SystemCounterVal < TimerTicks64) {
+ SystemCounterVal = ArmArchTimerGetSystemCount ();
+ }
+
+ return MicroSeconds;
+}
+
+
+/**
+ Stalls the CPU for at least the given number of nanoseconds.
+
+ Stalls the CPU for the number of nanoseconds specified by NanoSeconds.
+
+ When the timer frequency is 1MHz, each tick corresponds to 1 microsecond.
+ Therefore, the nanosecond delay will be rounded up to the nearest 1 microsecond.
+
+ @param NanoSeconds The minimum number of nanoseconds to delay.
+
+ @return The value of NanoSeconds inputted.
+
+**/
+UINTN
+EFIAPI
+NanoSecondDelay (
+ IN UINTN NanoSeconds
+ )
+{
+ UINTN MicroSeconds;
+
+ // Round up to 1us Tick Number
+ MicroSeconds = NanoSeconds / 1000;
+ MicroSeconds += ((NanoSeconds % 1000) == 0) ? 0 : 1;
+
+ MicroSecondDelay (MicroSeconds);
+
+ return NanoSeconds;
+}
+
+/**
+ Retrieves the current value of a 64-bit free running performance counter.
+
+ The counter can either count up by 1 or count down by 1. If the physical
+ performance counter counts by a larger increment, then the counter values
+ must be translated. The properties of the counter can be retrieved from
+ GetPerformanceCounterProperties().
+
+ @return The current value of the free running performance counter.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounter (
+ VOID
+ )
+{
+ // Just return the value of system count
+ return ArmArchTimerGetSystemCount ();
+}
+
+/**
+ Retrieves the 64-bit frequency in Hz and the range of performance counter
+ values.
+
+ If StartValue is not NULL, then the value that the performance counter starts
+ with immediately after is it rolls over is returned in StartValue. If
+ EndValue is not NULL, then the value that the performance counter end with
+ immediately before it rolls over is returned in EndValue. The 64-bit
+ frequency of the performance counter in Hz is always returned. If StartValue
+ is less than EndValue, then the performance counter counts up. If StartValue
+ is greater than EndValue, then the performance counter counts down. For
+ example, a 64-bit free running counter that counts up would have a StartValue
+ of 0 and an EndValue of 0xFFFFFFFFFFFFFFFF. A 24-bit free running counter
+ that counts down would have a StartValue of 0xFFFFFF and an EndValue of 0.
+
+ @param StartValue The value the performance counter starts with when it
+ rolls over.
+ @param EndValue The value that the performance counter ends with before
+ it rolls over.
+
+ @return The frequency in Hz.
+
+**/
+UINT64
+EFIAPI
+GetPerformanceCounterProperties (
+ OUT UINT64 *StartValue, OPTIONAL
+ OUT UINT64 *EndValue OPTIONAL
+ )
+{
+ if (StartValue != NULL) {
+ // Timer starts with the reload value
+ *StartValue = (UINT64)0ULL ;
+ }
+
+ if (EndValue != NULL) {
+ // Timer counts down to 0x0
+ *EndValue = 0xFFFFFFFFFFFFFFFF;;
+ }
+
+ return (UINT64)ArmArchTimerGetTimerFreq ();
+}
diff --git a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.inf b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.inf new file mode 100644 index 0000000000..87548b4851 --- /dev/null +++ b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.inf @@ -0,0 +1,46 @@ +#/** @file
+#
+# Copyright (c) 2011, ARM Limited. All rights reserved.<BR>
+# This program and the accompanying materials
+# are licensed and made available under the terms and conditions of the BSD License
+# which accompanies this distribution. The full text of the license may be found at
+# http://opensource.org/licenses/bsd-license.php
+#
+# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+#
+#**/
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = ArmArchTimerLib
+ FILE_GUID = 82da1b44-d2d6-4a7d-bbf0-a0cb67964034
+ MODULE_TYPE = BASE
+ VERSION_STRING = 1.0
+ LIBRARY_CLASS = TimerLib
+ CONSTRUCTOR = ArmArchTimerLibConstructor
+
+[Sources.common]
+ ArmArchTimerLib.c
+
+[Packages]
+ MdePkg/MdePkg.dec
+ EmbeddedPkg/EmbeddedPkg.dec
+ ArmPkg/ArmPkg.dec
+
+
+[LibraryClasses]
+ DebugLib
+ IoLib
+ ArmLib
+ BaseLib
+
+[Protocols]
+
+[Guids]
+
+[Pcd]
+ gArmTokenSpaceGuid.PcdArmArchTimerFreqInHz
+
+[Depex]
+ gEfiCpuArchProtocolGuid
|