From a47b308ad40334e12c90d1f11c6b5e9847a4ad7a Mon Sep 17 00:00:00 2001
From: gikidy <gikidy@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Fri, 5 Jun 2009 06:42:00 +0000
Subject: [PATCH] Enhance the RTC driver to not reserve the CMOS century
 register MSB.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@8476 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../PcatRealTimeClockRuntimeDxe/PcRtc.c       | 45 ++-----------------
 .../PcatRealTimeClockRuntimeDxe/PcRtc.h       | 10 -----
 2 files changed, 3 insertions(+), 52 deletions(-)

diff --git a/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.c b/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.c
index e9367fb737..c6b58b394e 100644
--- a/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.c
+++ b/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.c
@@ -158,11 +158,7 @@ PcRtcInit (
   Time.Month  = RtcRead (RTC_ADDRESS_MONTH);
   Time.Year   = RtcRead (RTC_ADDRESS_YEAR);
 
-  if (RtcTestCenturyRegister () == EFI_SUCCESS) {
-    Century = (UINT8) (RtcRead (RTC_ADDRESS_CENTURY) & 0x7f);
-  } else {
-    Century = RtcRead (RTC_ADDRESS_CENTURY);
-  }
+  Century = BcdToDecimal8 (RtcRead (RTC_ADDRESS_CENTURY));
 
   //
   // Set RTC configuration after get original time
@@ -285,11 +281,7 @@ PcRtcGetTime (
   Time->Month   = RtcRead (RTC_ADDRESS_MONTH);
   Time->Year    = RtcRead (RTC_ADDRESS_YEAR);
 
-  if (RtcTestCenturyRegister () == EFI_SUCCESS) {
-    Century = (UINT8) (RtcRead (RTC_ADDRESS_CENTURY) & 0x7f);
-  } else {
-    Century = RtcRead (RTC_ADDRESS_CENTURY);
-  }
+  Century = BcdToDecimal8 (RtcRead (RTC_ADDRESS_CENTURY));
 
   //
   // Release RTC Lock.
@@ -401,10 +393,6 @@ PcRtcSetTime (
   RtcWrite (RTC_ADDRESS_DAY_OF_THE_MONTH, RtcTime.Day);
   RtcWrite (RTC_ADDRESS_MONTH, RtcTime.Month);
   RtcWrite (RTC_ADDRESS_YEAR, (UINT8) RtcTime.Year);
-  if (RtcTestCenturyRegister () == EFI_SUCCESS) {
-    Century = (UINT8) ((Century & 0x7f) | (RtcRead (RTC_ADDRESS_CENTURY) & 0x80));
-  }
-
   RtcWrite (RTC_ADDRESS_CENTURY, Century);
 
   //
@@ -520,11 +508,7 @@ PcRtcGetWakeupTime (
     Time->Year    = RtcRead (RTC_ADDRESS_YEAR);
   }
 
-  if (RtcTestCenturyRegister () == EFI_SUCCESS) {
-    Century = (UINT8) (RtcRead (RTC_ADDRESS_CENTURY) & 0x7f);
-  } else {
-    Century = RtcRead (RTC_ADDRESS_CENTURY);
-  }
+  Century = BcdToDecimal8 (RtcRead (RTC_ADDRESS_CENTURY));
 
   //
   // Release RTC Lock.
@@ -663,29 +647,6 @@ PcRtcSetWakeupTime (
   return EFI_SUCCESS;
 }
 
-/**
-  See if century register of RTC is valid.
-
-  @retval  EFI_SUCCESS       Century register is valid.
-  @retval  EFI_DEVICE_ERROR  Century register is NOT valid.
-**/
-EFI_STATUS
-RtcTestCenturyRegister (
-  VOID
-  )
-{
-  UINT8 Century;
-  UINT8 Temp;
-
-  Century = RtcRead (RTC_ADDRESS_CENTURY);
-  Temp = (UINT8) (RtcRead (RTC_ADDRESS_CENTURY) & 0x7f);
-  RtcWrite (RTC_ADDRESS_CENTURY, Century);
-  if (Temp == 0x19 || Temp == 0x20) {
-    return EFI_SUCCESS;
-  }
-
-  return EFI_DEVICE_ERROR;
-}
 
 /**
   Checks an 8-bit BCD value, and converts to an 8-bit value if valid.
diff --git a/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.h b/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.h
index 5beb075691..90cfa39634 100644
--- a/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.h
+++ b/MdeModulePkg/Universal/PcatRealTimeClockRuntimeDxe/PcRtc.h
@@ -296,16 +296,6 @@ ConvertEfiTimeToRtcTime (
   OUT    UINT8           *Century
   );
 
-/**
-  See if centry register of RTC is valid.
-
-  @retval  EFI_SUCCESS       Century register is valid.
-  @retval  EFI_DEVICE_ERROR  Century register is NOT valid.
-**/
-EFI_STATUS
-RtcTestCenturyRegister (
-  VOID
-  );
 
 /**
   Converts time read from RTC to EFI_TIME format defined by UEFI spec.
-- 
2.39.2