From 34d609402bfec75c51a02deac7733c9a0128f55d Mon Sep 17 00:00:00 2001
From: Akshay Behl <cap2k4@rivosinc.com>
Date: Sun, 8 Jun 2025 23:09:04 +0530
Subject: UefiCpuPkg/CpuTimerDxeRiscV64: Use DT based timer frequency in Timer
 driver

There is GetPerformanceCounterProperties() that relies
on Device Tree to fetch timer frequency and removes the
dependency from the PCDs, use that instead.

Signed-off-by: Akshay Behl <cap2k4@rivosinc.com>

Co-authored-by: Dhaval Sharma <dhaval@rivosinc.com>
---
 UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf | 2 +-
 UefiCpuPkg/CpuTimerDxeRiscV64/Timer.c                | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf b/UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf
index f2a2cf1..812b674 100644
--- a/UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf
+++ b/UefiCpuPkg/CpuTimerDxeRiscV64/CpuTimerDxeRiscV64.inf
@@ -32,6 +32,7 @@
   CpuLib
   UefiBootServicesTableLib
   UefiDriverEntryPoint
+  TimerLib
 
 [LibraryClasses.RISCV64]
   RiscVSbiLib
@@ -42,7 +43,6 @@
 
 [Pcd]
   gEfiMdePkgTokenSpaceGuid.PcdRiscVFeatureOverride           ## CONSUMES
-  gUefiCpuPkgTokenSpaceGuid.PcdCpuCoreCrystalClockFrequency  ## CONSUMES
 
 [Protocols]
   gEfiCpuArchProtocolGuid       ## CONSUMES
diff --git a/UefiCpuPkg/CpuTimerDxeRiscV64/Timer.c b/UefiCpuPkg/CpuTimerDxeRiscV64/Timer.c
index 216f48a..14780e4 100644
--- a/UefiCpuPkg/CpuTimerDxeRiscV64/Timer.c
+++ b/UefiCpuPkg/CpuTimerDxeRiscV64/Timer.c
@@ -10,6 +10,7 @@
 #include <Library/BaseLib.h>
 #include <Library/BaseRiscVSbiLib.h>
 #include <Library/UefiLib.h>
+#include <Library/TimerLib.h>
 #include "Timer.h"
 
 //
@@ -114,7 +115,7 @@ TimerInterruptHandler (
     mTimerNotifyFunction (
       DivU64x32 (
         EFI_TIMER_PERIOD_SECONDS (PeriodStart - mLastPeriodStart),
-        PcdGet64 (PcdCpuCoreCrystalClockFrequency)
+        GetPerformanceCounterProperties (NULL, NULL)
         )
       );
   }
@@ -129,7 +130,7 @@ TimerInterruptHandler (
   PeriodStart     += DivU64x32 (
                        MultU64x32 (
                          mTimerPeriod,
-                         PcdGet64 (PcdCpuCoreCrystalClockFrequency)
+                         GetPerformanceCounterProperties (NULL, NULL)
                          ),
                        1000000u
                        );  // convert to tick
@@ -232,7 +233,7 @@ TimerDriverSetTimerPeriod (
   PeriodStart     += DivU64x32 (
                        MultU64x32 (
                          mTimerPeriod,
-                         PcdGet64 (PcdCpuCoreCrystalClockFrequency)
+                         GetPerformanceCounterProperties (NULL, NULL)
                          ),
                        1000000u
                        ); // convert to tick
-- 
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