DuetPkg/LegacyMetronome/Metronome.c

   1 /*++
   2
   3 Copyright (c) 2005, 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   LegacyMetronome.c
  14
  15 Abstract:
  16
  17   This contains the installation function for the driver.
  18
  19 --*/
  20
  21 #include "Metronome.h"
  22
  23 //
  24 // Handle for the Metronome Architectural Protocol instance produced by this driver
  25 //
  26 EFI_HANDLE                  mMetronomeHandle = NULL;
  27
  28 //
  29 // The Metronome Architectural Protocol instance produced by this driver
  30 //
  31 EFI_METRONOME_ARCH_PROTOCOL mMetronome = {
  32   WaitForTick,
  33   TICK_PERIOD
  34 };
  35
  36 //
  37 // Worker Functions
  38 //
  39 EFI_STATUS
  40 EFIAPI
  41 WaitForTick (
  42   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
  43   IN UINT32                       TickNumber
  44   )
  45 /*++
  46
  47 Routine Description:
  48
  49   Waits for the TickNumber of ticks from a known platform time source.
  50
  51 Arguments:
  52
  53   This                Pointer to the protocol instance.
  54
  55 Returns:
  56
  57   EFI_SUCCESS         If number of ticks occurred.
  58   EFI_NOT_FOUND       Could not locate CPU IO protocol
  59
  60 --*/
  61 // TODO:    TickNumber - add argument and description to function comment
  62 {
  63   //
  64   // Wait for TickNumber toggles of the Refresh bit
  65   //
  66   for (; TickNumber != 0x00; TickNumber--) {
  67     while ((IoRead8(REFRESH_PORT) & REFRESH_ON) == REFRESH_ON);
  68     while ((IoRead8(REFRESH_PORT) & REFRESH_ON) == REFRESH_OFF);
  69   }
  70
  71   return EFI_SUCCESS;
  72 }
  73
  74 EFI_STATUS
  75 EFIAPI
  76 InstallMetronome (
  77   IN EFI_HANDLE        ImageHandle,
  78   IN EFI_SYSTEM_TABLE  *SystemTable
  79   )
  80 /*++
  81
  82 Routine Description:
  83
  84   Install the LegacyMetronome driver.  Loads a Metronome Arch Protocol based
  85   on the Port 61 timer.
  86
  87 Arguments:
  88
  89   (Standard EFI Image entry - EFI_IMAGE_ENTRY_POINT)
  90
  91 Returns:
  92
  93   EFI_SUCCESS - Metronome Architectural Protocol Installed
  94
  95 --*/
  96 // TODO:    ImageHandle - add argument and description to function comment
  97 // TODO:    SystemTable - add argument and description to function comment
  98 {
  99   EFI_STATUS  Status;
 100
 101   //
 102   // Make sure the Metronome Architectural Protocol is not already installed in the system
 103   //
 104   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiMetronomeArchProtocolGuid);
 105
 106   //
 107   // Program port 61 timer 1 as refresh timer. We could use ACPI timer in the
 108   // future.
 109   //
 110   IoWrite8 (TIMER1_CONTROL_PORT, LOAD_COUNTER1_LSB);
 111   IoWrite8 (TIMER1_COUNT_PORT, COUNTER1_COUNT);
 112
 113   //
 114   // Install on a new handle
 115   //
 116   Status = gBS->InstallMultipleProtocolInterfaces (
 117                   &mMetronomeHandle,
 118                   &gEfiMetronomeArchProtocolGuid,
 119                   &mMetronome,
 120                   NULL
 121                   );
 122   ASSERT_EFI_ERROR (Status);
 123
 124   return Status;
 125 }