D03: enhance RTC lock acquiring

We would acquire I2C lock only when I2C status in CPLD shows idle,
however, acquiring lock will still fail for BMC might acquire the lock
at exactly the same time.
So we add additional check to see if we really get the lock. Timeout process
is also added to avoid system hang due to possible deadlock or device error.
Code style is improved as well.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Peicong Li <lipeicong@huawei.com>
Signed-off-by: Heyi Guo <heyi.guo@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>

3 files changed, 76 insertions, 19 deletions

diff --git a/Platforms/Hisilicon/D03/Include/Library/CpldD03.h b/Platforms/Hisilicon/D03/Include/Library/CpldD03.h
index 78aec2f..456bf4b 100644
--- a/Platforms/Hisilicon/D03/Include/Library/CpldD03.h
+++ b/Platforms/Hisilicon/D03/Include/Library/CpldD03.h
@@ -17,5 +17,9 @@
 #define __CPLD_D03_H__

 

 #define CPLD_BIOSINDICATE_FLAG  0x09

+#define CPLD_I2C_SWITCH_FLAG    0x17

+#define CPU_GET_I2C_CONTROL     BIT2

+#define BMC_I2C_STATUS          BIT3

+

 

 #endif

diff --git a/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.c b/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.c
index fa63027..91d7de1 100644
--- a/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.c
+++ b/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.c
@@ -38,6 +38,7 @@
 #include <Protocol/RealTimeClock.h>

 #include <Library/I2CLib.h>

 #include "DS3231RealTimeClock.h"

+#include <Library/CpldD03.h>

 #include <Library/CpldIoLib.h>

 

 extern I2C_DEVICE gDS3231RtcDevice;

@@ -56,6 +57,54 @@ IdentifyDS3231 (
 }

 

 EFI_STATUS

+SwitchRtcI2cChannelAndLock (

+  VOID

+  )

+{

+  UINT8   Temp;

+  UINT8   Count;

+

+  for (Count = 0; Count < 20; Count++) {

+    Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+

+    if ((Temp & BMC_I2C_STATUS) != 0) {

+      //The I2C channel is shared with BMC,

+      //Check if BMC has taken ownership of I2C.

+      //If so, wait 30ms, then try again.

+      //If not, start using I2C.

+      //And the CPLD_I2C_SWITCH_FLAG will be set to CPU_GET_I2C_CONTROL

+      //BMC will check this flag to decide to use I2C or not.

+      MicroSecondDelay (30000);

+      continue;

+    }

+

+    Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+    Temp = Temp | CPU_GET_I2C_CONTROL;

+    WriteCpldReg (CPLD_I2C_SWITCH_FLAG, Temp);

+

+    //This is empirical value,give cpld some time to make sure the

+    //value is wrote in

+    MicroSecondDelay (2);

+    Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+

+    if ((Temp & CPU_GET_I2C_CONTROL) == CPU_GET_I2C_CONTROL) {

+      return EFI_SUCCESS;

+    }

+

+    //There need 30ms to keep consistent with the previous loops if the CPU failed

+    //to get control of I2C

+    MicroSecondDelay (30000);

+  }

+

+  Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+  Temp = Temp & ~CPU_GET_I2C_CONTROL;

+  WriteCpldReg (CPLD_I2C_SWITCH_FLAG, Temp);

+

+  return EFI_NOT_READY;

+}

+

+

+EFI_STATUS

 InitializeDS3231 (

   VOID

   )

@@ -136,19 +185,17 @@ LibGetTime (
     return EFI_INVALID_PARAMETER;

   }

 

-

-

-  Temp = ReadCpldReg(0x17);

-  while( (Temp & BIT3) != 0)

-  {

-      Temp = ReadCpldReg(0x17);

+  Status = SwitchRtcI2cChannelAndLock();

+  if(EFI_ERROR (Status)) {

+    return Status;

   }

-  WriteCpldReg(0x17,0x4);

+

   // Initialize the hardware if not already done

   if (!mDS3231Initialized) {

     Status = InitializeDS3231 ();

     if (EFI_ERROR (Status)) {

-      return EFI_NOT_READY;

+      Status = EFI_NOT_READY;

+      goto GExit;

     }

   }

 

@@ -175,7 +222,8 @@ LibGetTime (
 

   BaseHour = 0;

   if((Temp&0x30) == 0x30){

-    return EFI_DEVICE_ERROR;

+    Status = EFI_DEVICE_ERROR;

+    goto GExit;

   }else if(Temp&0x20){

     BaseHour = 20;

   }else if(Temp&0x10){

@@ -196,11 +244,15 @@ LibGetTime (
   Time->TimeZone    = EFI_UNSPECIFIED_TIMEZONE;

 

   if((EFI_ERROR(Status)) || (!IsTimeValid(Time)) || ((Time->Year - BaseYear) > 99)) {

-    return EFI_DEVICE_ERROR;

+    Status = EFI_UNSUPPORTED;

   }

 

-  WriteCpldReg(0x17,0x0);

-  return EFI_SUCCESS;

+GExit:

+  Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+  Temp = Temp & ~CPU_GET_I2C_CONTROL;

+  WriteCpldReg (CPLD_I2C_SWITCH_FLAG, Temp);

+

+  return Status;

 

 }

 

@@ -234,13 +286,10 @@ LibSetTime (
     return EFI_INVALID_PARAMETER;

   }

 

-

-  Temp = ReadCpldReg(0x17);

-  while( (Temp & BIT3) != 0)

-  {

-      Temp = ReadCpldReg(0x17);

+  Status = SwitchRtcI2cChannelAndLock();

+  if(EFI_ERROR (Status)) {

+    return Status;

   }

-  WriteCpldReg(0x17,0x4);

 

   // Initialize the hardware if not already done

   if (!mDS3231Initialized) {

@@ -313,7 +362,9 @@ LibSetTime (
 

   EXIT:

 

-  WriteCpldReg(0x17,0x0);

+  Temp = ReadCpldReg (CPLD_I2C_SWITCH_FLAG);

+  Temp = Temp & ~CPU_GET_I2C_CONTROL;

+  WriteCpldReg (CPLD_I2C_SWITCH_FLAG, Temp);

 

   return Status;

 }

diff --git a/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.inf b/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.inf
index 8121f37..ae1b9b8 100644
--- a/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.inf
+++ b/Platforms/Hisilicon/D03/Library/DS3231RealTimeClockLib/DS3231RealTimeClockLib.inf
@@ -30,6 +30,7 @@
   MdePkg/MdePkg.dec

   EmbeddedPkg/EmbeddedPkg.dec

   OpenPlatformPkg/OpenPlatformPkg.dec

+  OpenPlatformPkg/Platforms/Hisilicon/D03/D03.dec

   OpenPlatformPkg/Chips/Hisilicon/HisiPkg.dec

 

 [LibraryClasses]

@@ -41,6 +42,7 @@
   TimerLib

 # Use EFiAtRuntime to check stage

   UefiRuntimeLib

+  CpldIoLib

   EfiTimeBaseLib

 

 [Pcd]