MdeModulePkg/Universal/Metronome/Metronome.h

   1 /** @file
   2   Include file of Metronome driver.
   3
   4 Copyright (c) 2008, Intel Corporation. <BR>
   5 All rights reserved. This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 **/
  14
  15 #ifndef _METRONOME_H_
  16 #define _METRONOME_H_
  17
  18 #include <PiDxe.h>
  19 #include <Protocol/Metronome.h>
  20 #include <Library/UefiBootServicesTableLib.h>
  21 #include <Library/TimerLib.h>
  22 #include <Library/DebugLib.h>
  23
  24 /**
  25   Waits for the specified number of ticks.
  26
  27   This function implements EFI_METRONOME_ARCH_PROTOCOL.WaitForTick().
  28   The WaitForTick() function waits for the number of ticks specified by
  29   TickNumber from a known time source in the platform.  If TickNumber of
  30   ticks are detected, then EFI_SUCCESS is returned.  The actual time passed
  31   between entry of this function and the first tick is between 0 and
  32   TickPeriod 100 nS units.  If you want to guarantee that at least TickPeriod
  33   time has elapsed, wait for two ticks.  This function waits for a hardware
  34   event to determine when a tick occurs.  It is possible for interrupt
  35   processing, or exception processing to interrupt the execution of the
  36   WaitForTick() function.  Depending on the hardware source for the ticks, it
  37   is possible for a tick to be missed.  This function cannot guarantee that
  38   ticks will not be missed.  If a timeout occurs waiting for the specified
  39   number of ticks, then EFI_TIMEOUT is returned.
  40
  41   @param  This             The EFI_METRONOME_ARCH_PROTOCOL instance.
  42   @param  TickNumber       Number of ticks to wait.
  43
  44   @retval EFI_SUCCESS      The wait for the number of ticks specified by TickNumber
  45                            succeeded.
  46   @retval EFI_TIMEOUT      A timeout occurred waiting for the specified number of ticks.
  47
  48 **/
  49 EFI_STATUS
  50 EFIAPI
  51 WaitForTick (
  52   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
  53   IN UINT32                       TickNumber
  54   );
  55
  56 #endif