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 // The CPU I/O Protocol used to access system hardware
  38 //
  39 EFI_CPU_IO_PROTOCOL         *mCpuIo = NULL;
  40
  41 //
  42 // Worker Functions
  43 //
  44 VOID
  45 IoWrite8 (
  46   UINT16  Port,
  47   UINT8   Data
  48   )
  49 /*++
  50
  51 Routine Description:
  52
  53   Write an 8 bit value to an I/O port and save it to the S3 script
  54
  55 Arguments:
  56
  57 Returns:
  58
  59   None.
  60
  61 --*/
  62 // TODO:    Port - add argument and description to function comment
  63 // TODO:    Data - add argument and description to function comment
  64 {
  65   mCpuIo->Io.Write (
  66               mCpuIo,
  67               EfiCpuIoWidthUint8,
  68               Port,
  69               1,
  70               &Data
  71               );
  72
  73 }
  74
  75 UINT8
  76 ReadRefresh (
  77   VOID
  78   )
  79 /*++
  80
  81 Routine Description:
  82
  83   Read the refresh bit from the REFRESH_PORT
  84
  85 Arguments:
  86
  87 Returns:
  88
  89   None.
  90
  91 --*/
  92 {
  93   UINT8 Data;
  94
  95   mCpuIo->Io.Read (
  96               mCpuIo,
  97               EfiCpuIoWidthUint8,
  98               REFRESH_PORT,
  99               1,
 100               &Data
 101               );
 102   return (UINT8) (Data & REFRESH_ON);
 103 }
 104
 105 EFI_STATUS
 106 EFIAPI
 107 WaitForTick (
 108   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
 109   IN UINT32                       TickNumber
 110   )
 111 /*++
 112
 113 Routine Description:
 114
 115   Waits for the TickNumber of ticks from a known platform time source.
 116
 117 Arguments:
 118
 119   This                Pointer to the protocol instance.
 120
 121 Returns:
 122
 123   EFI_SUCCESS         If number of ticks occurred.
 124   EFI_NOT_FOUND       Could not locate CPU IO protocol
 125
 126 --*/
 127 // TODO:    TickNumber - add argument and description to function comment
 128 {
 129   //
 130   // Wait for TickNumber toggles of the Refresh bit
 131   //
 132   for (; TickNumber != 0x00; TickNumber--) {
 133     while (ReadRefresh () == REFRESH_ON)
 134       ;
 135     while (ReadRefresh () == REFRESH_OFF)
 136       ;
 137   }
 138
 139   return EFI_SUCCESS;
 140 }
 141
 142 EFI_STATUS
 143 EFIAPI
 144 InstallMetronome (
 145   IN EFI_HANDLE        ImageHandle,
 146   IN EFI_SYSTEM_TABLE  *SystemTable
 147   )
 148 /*++
 149
 150 Routine Description:
 151
 152   Install the LegacyMetronome driver.  Loads a Metronome Arch Protocol based
 153   on the Port 61 timer.
 154
 155 Arguments:
 156
 157   (Standard EFI Image entry - EFI_IMAGE_ENTRY_POINT)
 158
 159 Returns:
 160
 161   EFI_SUCCESS - Metronome Architectural Protocol Installed
 162
 163 --*/
 164 // TODO:    ImageHandle - add argument and description to function comment
 165 // TODO:    SystemTable - add argument and description to function comment
 166 {
 167   EFI_STATUS  Status;
 168
 169   //
 170   // Make sure the Metronome Architectural Protocol is not already installed in the system
 171   //
 172   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiMetronomeArchProtocolGuid);
 173
 174   //
 175   // Get the CPU I/O Protocol that this driver requires
 176   // If the CPU I/O Protocol is not found, then ASSERT because the dependency expression
 177   // should guarantee that it is present in the handle database.
 178   //
 179   Status = gBS->LocateProtocol (&gEfiCpuIoProtocolGuid, NULL, &mCpuIo);
 180   ASSERT_EFI_ERROR (Status);
 181
 182   //
 183   // Program port 61 timer 1 as refresh timer. We could use ACPI timer in the
 184   // future.
 185   //
 186   IoWrite8 (TIMER1_CONTROL_PORT, LOAD_COUNTER1_LSB);
 187   IoWrite8 (TIMER1_COUNT_PORT, COUNTER1_COUNT);
 188
 189   //
 190   // Install on a new handle
 191   //
 192   Status = gBS->InstallMultipleProtocolInterfaces (
 193                   &mMetronomeHandle,
 194                   &gEfiMetronomeArchProtocolGuid,
 195                   &mMetronome,
 196                   NULL
 197                   );
 198   ASSERT_EFI_ERROR (Status);
 199
 200   return Status;
 201 }