ArmPlatformPkg/SP804Timer: Introduce gArmPlatformTokenSpaceGuid.PcdSP804FrequencyInMHz

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

2 files changed, 25 insertions, 11 deletions

diff --git a/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.c b/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.c
index 96c43aa042..2508897391 100644
--- a/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.c
+++ b/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.c
@@ -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);
 }
diff --git a/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.inf b/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.inf
index 7481236c2f..1cbb32ecb6 100644
--- a/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.inf
+++ b/ArmPlatformPkg/Library/SP804TimerLib/SP804TimerLib.inf
@@ -2,7 +2,7 @@
 # Timer library implementation
 #  
 #  
-#  Copyright (c) 2010, ARM Ltd. All rights reserved.<BR>
+#  Copyright (c) 2011, ARM Ltd. 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
@@ -30,8 +30,13 @@
   MdePkg/MdePkg.dec
   ArmPkg/ArmPkg.dec
   ArmPlatformPkg/ArmPlatformPkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
 
 [LibraryClasses]
   DebugLib
   IoLib
   BaseLib
+
+[Pcd]
+  gArmPlatformTokenSpaceGuid.PcdSP804FrequencyInMHz
+  gEmbeddedTokenSpaceGuid.PcdEmbeddedPerformanceCounterFrequencyInHz