MdeModulePkg/Universal/Metronome/Metronome.h

   1 /** @file
   2   Include file of Metronome driver.
   3
   4 Copyright (c) 2008 - 2018, Intel Corporation. All rights reserved.<BR>
   5 SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8
   9 #ifndef _METRONOME_H_
  10 #define _METRONOME_H_
  11
  12 #include <PiDxe.h>
  13 #include <Protocol/Metronome.h>
  14 #include <Library/UefiBootServicesTableLib.h>
  15 #include <Library/TimerLib.h>
  16 #include <Library/DebugLib.h>
  17 #include <Library/UefiDriverEntryPoint.h>
  18
  19 /**
  20   Waits for the specified number of ticks.
  21
  22   This function implements EFI_METRONOME_ARCH_PROTOCOL.WaitForTick().
  23   The WaitForTick() function waits for the number of ticks specified by
  24   TickNumber from a known time source in the platform.  If TickNumber of
  25   ticks are detected, then EFI_SUCCESS is returned.  The actual time passed
  26   between entry of this function and the first tick is between 0 and
  27   TickPeriod 100 nS units.  If you want to guarantee that at least TickPeriod
  28   time has elapsed, wait for two ticks.  This function waits for a hardware
  29   event to determine when a tick occurs.  It is possible for interrupt
  30   processing, or exception processing to interrupt the execution of the
  31   WaitForTick() function.  Depending on the hardware source for the ticks, it
  32   is possible for a tick to be missed.  This function cannot guarantee that
  33   ticks will not be missed.  If a timeout occurs waiting for the specified
  34   number of ticks, then EFI_TIMEOUT is returned.
  35
  36   @param  This             The EFI_METRONOME_ARCH_PROTOCOL instance.
  37   @param  TickNumber       Number of ticks to wait.
  38
  39   @retval EFI_SUCCESS      The wait for the number of ticks specified by TickNumber
  40                            succeeded.
  41   @retval EFI_TIMEOUT      A timeout occurred waiting for the specified number of ticks.
  42
  43 **/
  44 EFI_STATUS
  45 EFIAPI
  46 WaitForTick (
  47   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
  48   IN UINT32                       TickNumber
  49   );
  50
  51 #endif