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ArmPlatformPkg/SP804Timer: Introduce gArmPlatformTokenSpaceGuid.PcdSP804FrequencyInMHz

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This PCD defines the speed of the SP804 timer. The default value is 1MHz.



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11745 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
oliviermartin
2011-06-03 09:33:35 +00:00
parent 23792dea0c
commit ce9cc403bd
5 changed files with 32 additions and 11 deletions
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29
ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.c
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@@ -74,11 +74,16 @@ MicroSecondDelay (
IN UINTN MicroSeconds
)
{
// load the timer count register
MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
UINTN Index;
while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
;
// Reload the counter for each 1Mhz to avoid an overflow in the load value
for (Index = 0; Index < (UINTN)PcdGet32(PcdSP804FrequencyInMHz); Index++) {
// load the timer count register
MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
;
}
}
return MicroSeconds;
@@ -100,17 +105,21 @@ NanoSecondDelay (
IN UINTN NanoSeconds
)
{
UINT32 MicroSeconds;
UINTN Index;
UINT32 MicroSeconds;
// Round up to 1us Tick Number
MicroSeconds = (UINT32)NanoSeconds / 1000;
MicroSeconds += ((UINT32)NanoSeconds % 1000) == 0 ? 0 : 1;
// load the timer count register
MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
// Reload the counter for each 1Mhz to avoid an overflow in the load value
for (Index = 0; Index < (UINTN)PcdGet32(PcdSP804FrequencyInMHz); Index++) {
// load the timer count register
MmioWrite32 (SP804_TIMER2_BASE + SP804_TIMER_LOAD_REG, MicroSeconds);
while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
;
while (MmioRead32 (SP804_TIMER2_BASE + SP804_TIMER_CURRENT_REG) > 0) {
;
}
}
return NanoSeconds;
@@ -182,5 +191,5 @@ GetPerformanceCounterProperties (
*EndValue = 0xFFFFFFFF;
}
return 1000000;
return PcdGet64 (PcdEmbeddedPerformanceCounterFrequencyInHz);
}