edk2-msm/Silicon/Qualcomm/QcomPkg/Library/VirtualRealTimeClockLib/VirtualRealTimeClockLib.c

/** @file
 *
 *  Implement dummy EFI RealTimeClock runtime services.
 *
 *  Copyright (c), 2018, Andrei Warkentin <andrey.warkentin@gmail.com>
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *
 *  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 http://opensource.org/licenses/bsd-license.php
 *
 *  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR
 *IMPLIED.
 *
 **/

#include <PiDxe.h>

#include <Library/ArmGenericTimerCounterLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
#include <Library/IoLib.h>
#include <Library/PcdLib.h>
#include <Library/RealTimeClockLib.h>
#include <Library/TimerLib.h>

#include <Configuration/Hob.h>

STATIC EFI_TIME BaseTime;

/**
Returns the current time and date information, and the time-keeping capabilities
of the virtual RTC.

For simplicity, this LibGetTime does not report Years/Months, instead it will
only report current Day, Hours, Minutes and Seconds starting from the begining
of CPU up-time. Otherwise, a more complex logic will be required to account for
leap years and days/month differences.

@param  Time                  A pointer to storage to receive a snapshot of the
current time.
@param  Capabilities          An optional pointer to a buffer to receive the
real time clock device's capabilities.

@retval EFI_SUCCESS           The operation completed successfully.
@retval EFI_INVALID_PARAMETER Time is NULL.
@retval EFI_DEVICE_ERROR      The time could not be retrieved due to hardware
error.

**/
EFI_STATUS
EFIAPI
LibGetTime(OUT EFI_TIME *Time, OUT EFI_TIME_CAPABILITIES *Capabilities)
{
  UINT32 Freq = ArmGenericTimerGetTimerFreq();

  if (Time == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  //
  // Depend on ARM generic timer to report date/time relative to the
  // start of CPU timer counting where date and time will always
  // be relative to the date/time 1/1/1900 00H:00M:00S
  //

  ASSERT(Freq != 0);
  if (Freq == 0) {
    return EFI_DEVICE_ERROR;
  }

  if (Capabilities) {
    Capabilities->Accuracy   = 0;
    Capabilities->Resolution = Freq;
    Capabilities->SetsToZero = FALSE;
  }

  UINT64 ElapsedSeconds = GetPerformanceCounter() / Freq;

  //
  // Don't report Year/Month since Leap Year logic is not implemented. This
  // should be fine since the sole purpose of this special implementation is to
  // be used for relative time measurement. e.g. Windows Boot Manager.
  //

  Time->Year  = BaseTime.Year;
  Time->Month = BaseTime.Month;

  const UINT64 SECONDS_PER_DAY = 24 * 60 * 60;
  Time->Day                    = (ElapsedSeconds / SECONDS_PER_DAY);
  ElapsedSeconds %= SECONDS_PER_DAY;

  const UINT64 SECONDS_PER_HOUR = 60 * 60;
  Time->Hour                    = (ElapsedSeconds / SECONDS_PER_HOUR);
  ElapsedSeconds %= SECONDS_PER_HOUR;

  const UINT64 SECONDS_PER_MINUTE = 60;
  Time->Minute                    = (ElapsedSeconds / SECONDS_PER_MINUTE);
  ElapsedSeconds %= SECONDS_PER_MINUTE;

  Time->Second = ElapsedSeconds;

  //
  // Not required to report in our special case
  //

  Time->Nanosecond = 0;
  Time->TimeZone   = 0;
  Time->Daylight   = 0;

  return EFI_SUCCESS;
}

/**
Sets the current local time and date information.

@param  Time                  A pointer to the current time.

@retval EFI_SUCCESS           The operation completed successfully.
@retval EFI_INVALID_PARAMETER A time field is out of range.
@retval EFI_DEVICE_ERROR      The time could not be set due due to hardware
error.

**/
EFI_STATUS
EFIAPI
LibSetTime(IN EFI_TIME *Time)
{
  //
  // The virtual clock is read-only.
  //
  return EFI_UNSUPPORTED;
}

/**
Returns the current wakeup alarm clock setting.

@param  Enabled               Indicates if the alarm is currently enabled or
disabled.
@param  Pending               Indicates if the alarm signal is pending and
requires acknowledgement.
@param  Time                  The current alarm setting.

@retval EFI_SUCCESS           The alarm settings were returned.
@retval EFI_INVALID_PARAMETER Any parameter is NULL.
@retval EFI_DEVICE_ERROR      The wakeup time could not be retrieved due to a
hardware error.

**/
EFI_STATUS
EFIAPI
LibGetWakeupTime(OUT BOOLEAN *Enabled, OUT BOOLEAN *Pending, OUT EFI_TIME *Time)
{
  return EFI_UNSUPPORTED;
}

/**
Sets the system wakeup alarm clock time.

@param  Enabled               Enable or disable the wakeup alarm.
@param  Time                  If Enable is TRUE, the time to set the wakeup
alarm for.

@retval EFI_SUCCESS           If Enable is TRUE, then the wakeup alarm was
enabled. If Enable is FALSE, then the wakeup alarm was disabled.
@retval EFI_INVALID_PARAMETER A time field is out of range.
@retval EFI_DEVICE_ERROR      The wakeup time could not be set due to a hardware
error.
@retval EFI_UNSUPPORTED       A wakeup timer is not supported on this platform.

**/
EFI_STATUS
EFIAPI
LibSetWakeupTime(IN BOOLEAN Enabled, OUT EFI_TIME *Time)
{
  return EFI_UNSUPPORTED;
}

/**
This is the declaration of an EFI image entry point. This can be the entry point
to an application written to this specification, an EFI boot service driver, or
an EFI runtime driver.

@param  ImageHandle           Handle that identifies the loaded image.
@param  SystemTable           System Table for this image.

@retval EFI_SUCCESS           The operation completed successfully.

**/
EFI_STATUS
EFIAPI
LibRtcInitialize(IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable)
{
  BaseTime.Year  = 2019;
  BaseTime.Month = 1;

  return EFI_SUCCESS;
}

/**
Fixup internal data so that EFI can be call in virtual mode.
Call the passed in Child Notify event and convert any pointers in
lib to virtual mode.

@param[in]    Event   The Event that is being processed
@param[in]    Context Event Context
**/
VOID EFIAPI LibRtcVirtualNotifyEvent(IN EFI_EVENT Event, IN VOID *Context)
{
  return;
}