Nt32Pkg: Replace BSD License with BSD+Patent License

[mirror_edk2.git] / Nt32Pkg / MetronomeDxe / Metronome.c

/**@file\r
\r
Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>\r
SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
Module Name:\r
\r
  Metronome.c\r
\r
Abstract:\r
\r
  NT Emulation Metronome Architectural Protocol Driver as defined in DXE CIS\r
\r
**/\r
\r
#include "Metronome.h"\r
\r
//\r
// Global Variables\r
//\r
EFI_METRONOME_ARCH_PROTOCOL mMetronome = {\r
  WinNtMetronomeDriverWaitForTick,\r
  TICK_PERIOD\r
};\r
\r
//\r
// Worker Functions\r
//\r
\r
EFI_STATUS\r
EFIAPI\r
WinNtMetronomeDriverWaitForTick (\r
  IN EFI_METRONOME_ARCH_PROTOCOL  *This,\r
  IN UINT32                       TickNumber\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  The WaitForTick() function waits for the number of ticks specified by\r
  TickNumber from a known time source in the platform.  If TickNumber of\r
  ticks are detected, then EFI_SUCCESS is returned.  The actual time passed\r
  between entry of this function and the first tick is between 0 and\r
  TickPeriod 100 nS units.  If you want to guarantee that at least TickPeriod\r
  time has elapsed, wait for two ticks.  This function waits for a hardware\r
  event to determine when a tick occurs.  It is possible for interrupt\r
  processing, or exception processing to interrupt the execution of the\r
  WaitForTick() function.  Depending on the hardware source for the ticks, it\r
  is possible for a tick to be missed.  This function cannot guarantee that\r
  ticks will not be missed.  If a timeout occurs waiting for the specified\r
  number of ticks, then EFI_TIMEOUT is returned.\r
\r
Arguments:\r
\r
  This       - The EFI_METRONOME_ARCH_PROTOCOL instance.\r
  TickNumber - Number of ticks to wait.\r
\r
Returns:\r
\r
  EFI_SUCCESS - The wait for the number of ticks specified by TickNumber\r
                succeeded.\r
\r
--*/\r
{\r
  UINT64  SleepTime;\r
\r
  //\r
  // Calculate the time to sleep.  Win API smallest unit to sleep is 1 millisec\r
  // Tick Period is in 100ns units, divide by 10000 to convert to ms\r
  //\r
  SleepTime = DivU64x32 (MultU64x32 ((UINT64) TickNumber, TICK_PERIOD) + 9999, 10000);\r
  gWinNt->Sleep ((UINT32) SleepTime);\r
\r
  return EFI_SUCCESS;\r
}\r
\r
\r
EFI_STATUS\r
EFIAPI\r
WinNtMetronomeDriverInitialize (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
/*++\r
\r
Routine Description:\r
\r
  Initialize the Metronome Architectural Protocol driver\r
\r
Arguments:\r
\r
  ImageHandle - ImageHandle of the loaded driver\r
\r
\r
  SystemTable - Pointer to the System Table\r
\r
Returns:\r
\r
  EFI_SUCCESS           - Metronome Architectural Protocol created\r
\r
  EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.\r
\r
  EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.\r
\r
--*/\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
\r
  //\r
  // Install the Metronome Architectural Protocol onto a new handle\r
  //\r
  Handle = NULL;\r
  Status = gBS->InstallProtocolInterface (\r
                  &Handle,\r
                  &gEfiMetronomeArchProtocolGuid,\r
                  EFI_NATIVE_INTERFACE,\r
                  &mMetronome\r
                  );\r
\r
  return Status;\r
}\r