UnixPkg/MetronomeDxe/Metronome.c

   1 /*++
   2
   3 Copyright (c) 2006 - 2008, Intel Corporation
   4 All rights reserved. This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Metronome.c
  15
  16 Abstract:
  17
  18   UNIX Emulation Metronome Architectural Protocol Driver as defined in DXE CIS
  19
  20 --*/
  21 #include "PiDxe.h"
  22 #include "UnixDxe.h"
  23 #include <Protocol/Metronome.h>
  24 #include "Metronome.h"
  25
  26 #include <Library/BaseLib.h>
  27 #include <Library/DebugLib.h>
  28 #include <Library/UefiLib.h>
  29 #include <Library/UefiDriverEntryPoint.h>
  30 #include <Library/UnixLib.h>
  31 #include <Library/MemoryAllocationLib.h>
  32 #include <Library/UefiBootServicesTableLib.h>
  33
  34 //
  35 // Global Variables
  36 //
  37 EFI_METRONOME_ARCH_PROTOCOL mMetronome = {
  38   UnixMetronomeDriverWaitForTick,
  39   TICK_PERIOD
  40 };
  41
  42 //
  43 // Worker Functions
  44 //
  45
  46 EFI_STATUS
  47 EFIAPI
  48 UnixMetronomeDriverWaitForTick (
  49   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
  50   IN UINT32                       TickNumber
  51   )
  52 /*++
  53
  54 Routine Description:
  55
  56   The WaitForTick() function waits for the number of ticks specified by
  57   TickNumber from a known time source in the platform.  If TickNumber of
  58   ticks are detected, then EFI_SUCCESS is returned.  The actual time passed
  59   between entry of this function and the first tick is between 0 and
  60   TickPeriod 100 nS units.  If you want to guarantee that at least TickPeriod
  61   time has elapsed, wait for two ticks.  This function waits for a hardware
  62   event to determine when a tick occurs.  It is possible for interrupt
  63   processing, or exception processing to interrupt the execution of the
  64   WaitForTick() function.  Depending on the hardware source for the ticks, it
  65   is possible for a tick to be missed.  This function cannot guarantee that
  66   ticks will not be missed.  If a timeout occurs waiting for the specified
  67   number of ticks, then EFI_TIMEOUT is returned.
  68
  69 Arguments:
  70
  71   This       - The EFI_METRONOME_ARCH_PROTOCOL instance.
  72   TickNumber - Number of ticks to wait.
  73
  74 Returns:
  75
  76   EFI_SUCCESS - The wait for the number of ticks specified by TickNumber
  77                 succeeded.
  78
  79 --*/
  80 {
  81   UINT64  SleepTime;
  82
  83   //
  84   // Calculate the time to sleep.  Win API smallest unit to sleep is 1 millisec
  85   // Tick Period is in 100ns units, divide by 10000 to convert to ms
  86   //
  87   SleepTime = DivU64x32 (MultU64x32 ((UINT64) TickNumber, TICK_PERIOD) + 9999, 10000);
  88   gUnix->Sleep ((UINT32) SleepTime);
  89
  90   return EFI_SUCCESS;
  91 }
  92
  93
  94 EFI_STATUS
  95 EFIAPI
  96 UnixMetronomeDriverInitialize (
  97   IN EFI_HANDLE        ImageHandle,
  98   IN EFI_SYSTEM_TABLE  *SystemTable
  99   )
 100 /*++
 101
 102 Routine Description:
 103
 104   Initialize the Metronome Architectural Protocol driver
 105
 106 Arguments:
 107
 108   ImageHandle - ImageHandle of the loaded driver
 109
 110
 111   SystemTable - Pointer to the System Table
 112
 113 Returns:
 114
 115   EFI_SUCCESS           - Metronome Architectural Protocol created
 116
 117   EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.
 118
 119   EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.
 120
 121 --*/
 122 {
 123   EFI_STATUS  Status;
 124   EFI_HANDLE  Handle;
 125
 126
 127   //
 128   // Install the Metronome Architectural Protocol onto a new handle
 129   //
 130   Handle = NULL;
 131   DEBUG ((EFI_D_ERROR, "*******************file %d line %d\n", __FUNCTION__, __LINE__));
 132   Status = gBS->InstallProtocolInterface (
 133                   &Handle,
 134                   &gEfiMetronomeArchProtocolGuid,
 135                   EFI_NATIVE_INTERFACE,
 136                   &mMetronome
 137                   );
 138
 139   return Status;
 140 }