OcRtcLib.c

Go to the documentation of this file.

 
#include <IndustryStandard/AppleRtc.h>
#include <Library/IoLib.h>
#include <Library/OcRtcLib.h>
#include "OcRtcLibInternal.h"
 
UINT8
OcRtcRead (
  IN  UINT8  Offset
  )
{
  UINT8  RtcIndexPort;
  UINT8  RtcDataPort;
  UINT8  RtcIndexNmi;
 
  if (Offset < RTC_BANK_SIZE) {
    RtcIndexPort = R_PCH_RTC_INDEX;
    RtcDataPort  = R_PCH_RTC_TARGET;
  } else {
    RtcIndexPort = R_PCH_RTC_EXT_INDEX;
    RtcDataPort  = R_PCH_RTC_EXT_TARGET;
  }
 
  RtcIndexNmi = IoRead8 (RtcIndexPort) & RTC_NMI_MASK;
  IoWrite8 (RtcIndexPort, (Offset & RTC_DATA_MASK) | RtcIndexNmi);
  return IoRead8 (RtcDataPort);
}
 
VOID
OcRtcWrite (
  IN UINT8  Offset,
  IN UINT8  Value
  )
{
  UINT8  RtcIndexPort;
  UINT8  RtcDataPort;
  UINT8  RtcIndexNmi;
 
  if (Offset < RTC_BANK_SIZE) {
    RtcIndexPort = R_PCH_RTC_INDEX;
    RtcDataPort  = R_PCH_RTC_TARGET;
  } else {
    RtcIndexPort = R_PCH_RTC_EXT_INDEX;
    RtcDataPort  = R_PCH_RTC_EXT_TARGET;
  }
 
  RtcIndexNmi = IoRead8 (RtcIndexPort) & RTC_NMI_MASK;
  IoWrite8 (RtcIndexPort, (Offset & RTC_DATA_MASK) | RtcIndexNmi);
  IoWrite8 (RtcDataPort, Value);
}
 
UINT16
OcRtcChecksumApple (
  IN CONST VOID  *Data,
  IN UINTN       Size
  )
{
  CONST UINT8  *Buffer;
  CONST UINT8  *BufferEnd;
  UINT16       Checksum;
  UINTN        Index;
 
  Buffer    = Data;
  BufferEnd = Buffer + Size;
  Checksum  = 0;
 
  while (Buffer < BufferEnd) {
    Checksum ^= *Buffer++;
    for (Index = 0; Index < APPLE_RTC_CHECKSUM_ROUNDS; ++Index) {
      if (Checksum & 1U) {
        Checksum >>= 1U;
        Checksum  ^= APPLE_RTC_CHECKSUM_POLYNOMIAL;
      } else {
        Checksum >>= 1U;
      }
    }
  }
 
  return Checksum;
}
 
UINT8
OcRtcReadIvy (
  IN  UINT8  Offset
  )
{
  UINT8  RtcIndexPort;
  UINT8  RtcDataPort;
 
  //
  // CMOS access registers (using alternative access not to handle NMI bit)
  //
  if (Offset < RTC_BANK_SIZE) {
    RtcIndexPort = R_PCH_RTC_INDEX_ALT;
    RtcDataPort  = R_PCH_RTC_TARGET_ALT;
  } else {
    RtcIndexPort = R_PCH_RTC_EXT_INDEX_ALT;
    RtcDataPort  = R_PCH_RTC_EXT_TARGET_ALT;
  }
 
  IoWrite8 (RtcIndexPort, Offset & RTC_DATA_MASK);
  return IoRead8 (RtcDataPort);
}
 
VOID
OcRtcWriteIvy (
  IN UINT8  Offset,
  IN UINT8  Value
  )
{
  UINT8  RtcIndexPort;
  UINT8  RtcDataPort;
 
  //
  // CMOS access registers (using alternative access not to handle NMI bit)
  //
  if (Offset < RTC_BANK_SIZE) {
    RtcIndexPort = R_PCH_RTC_INDEX_ALT;
    RtcDataPort  = R_PCH_RTC_TARGET_ALT;
  } else {
    RtcIndexPort = R_PCH_RTC_EXT_INDEX_ALT;
    RtcDataPort  = R_PCH_RTC_EXT_TARGET_ALT;
  }
 
  IoWrite8 (RtcIndexPort, Offset & RTC_DATA_MASK);
  IoWrite8 (RtcDataPort, Value);
}