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| author | Olivier Martin <olivier.martin@arm.com> | 2014-08-27 10:12:00 +0000 |
|---|---|---|
| committer | oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524> | 2014-08-27 10:12:00 +0000 |
| commit | 33292af5f13b18ef5124f32a7bbf0b05b2d519c5 (patch) | |
| tree | c29b177431d691ee1e6ff0112f0d542605e0a5ee | |
| parent | 8f1cbb011faf2435fa976e61ba7e1ab46a5a09d0 (diff) | |
| download | edk2-platforms-33292af5f13b18ef5124f32a7bbf0b05b2d519c5.tar.xz | |
ArmPkg/TimerDxe: Changed calculation to allow 1KHz granularity frequency
Prior to this change the frequency was rounded to 1Mhz.
This change rounds the timer frequency to 1KHz.
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15921 6f19259b-4bc3-4df7-8a09-765794883524
| -rw-r--r-- | ArmPkg/Drivers/TimerDxe/TimerDxe.c | 11 | ||||
| -rw-r--r-- | ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c | 6 |
2 files changed, 10 insertions, 7 deletions
diff --git a/ArmPkg/Drivers/TimerDxe/TimerDxe.c b/ArmPkg/Drivers/TimerDxe/TimerDxe.c index 633876bea6..ccdb38c79b 100644 --- a/ArmPkg/Drivers/TimerDxe/TimerDxe.c +++ b/ArmPkg/Drivers/TimerDxe/TimerDxe.c @@ -141,12 +141,13 @@ TimerDriverSetTimerPeriod ( ArmArchTimerDisableTimer ();
if (TimerPeriod != 0) {
- // Convert TimerPeriod to micro sec units
- TimerTicks = DivU64x32 (TimerPeriod, 10);
+ // TimerTicks = TimerPeriod in 1ms unit x Frequency.10^-3
+ // = TimerPeriod.10^-4 x Frequency.10^-3
+ // = (TimerPeriod x Frequency) x 10^-7
+ TimerTicks = MultU64x32 (TimerPeriod, FixedPcdGet32 (PcdArmArchTimerFreqInHz));
+ TimerTicks = DivU64x32 (TimerTicks, 10000000U);
- TimerTicks = MultU64x32 (TimerTicks, (PcdGet32(PcdArmArchTimerFreqInHz)/1000000));
-
- ArmArchTimerSetTimerVal((UINTN)TimerTicks);
+ ArmArchTimerSetTimerVal ((UINTN)TimerTicks);
// Enable the timer
ArmArchTimerEnableTimer ();
diff --git a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c index d1cd0c8e6e..4fe7cb8d64 100644 --- a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c +++ b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c @@ -82,8 +82,10 @@ MicroSecondDelay ( UINT64 TimerTicks64;
UINT64 SystemCounterVal;
- // Calculate counter ticks that can represent requested delay
- TimerTicks64 = MultU64x32 (MicroSeconds, TICKS_PER_MICRO_SEC);
+ // Calculate counter ticks that can represent requested delay:
+ // = MicroSeconds x TICKS_PER_MICRO_SEC
+ // = MicroSeconds x Frequency.10^-6
+ TimerTicks64 = (MicroSeconds * PcdGet32 (PcdArmArchTimerFreqInHz)) / 1000000U;
// Read System Counter value
SystemCounterVal = ArmArchTimerGetSystemCount ();
|