Vlv2TbltDevicePkg/Metronome/LegacyMetronome.c

   1 /** @file
   2
   3   Copyright (c) 2004  - 2014, Intel Corporation. All rights reserved.<BR>
   4
   5   SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7
   8
   9 Module Name:
  10
  11
  12   LegacyMetronome.c
  13
  14 Abstract:
  15
  16   This contains the installation function for the driver.
  17
  18 --*/
  19
  20 #include "LegacyMetronome.h"
  21
  22 //
  23 // Handle for the Metronome Architectural Protocol instance produced by this driver
  24 //
  25 EFI_HANDLE                  mMetronomeHandle = NULL;
  26
  27 //
  28 // The Metronome Architectural Protocol instance produced by this driver
  29 //
  30 EFI_METRONOME_ARCH_PROTOCOL mMetronome = {
  31   WaitForTick,
  32   TICK_PERIOD
  33 };
  34
  35 //
  36 // The CPU I/O Protocol used to access system hardware
  37 //
  38 EFI_CPU_IO_PROTOCOL         *mCpuIo = NULL;
  39
  40 //
  41 // Worker Functions
  42 //
  43
  44 /**
  45   Write an 8 bit value to an I/O port and save it to the S3 script
  46
  47   @param Port  IO Port
  48   @param Data  Data in IO Port
  49
  50   @retval None.
  51
  52 **/
  53 VOID
  54 ScriptWriteIo8 (
  55   UINT16  Port,
  56   UINT8   Data
  57   )
  58 {
  59   mCpuIo->Io.Write (
  60                mCpuIo,
  61                EfiCpuIoWidthUint8,
  62                Port,
  63                1,
  64                &Data
  65                );
  66
  67 }
  68
  69 /**
  70
  71   Read the refresh bit from the REFRESH_PORT
  72
  73   @param None.
  74
  75   @retval Refresh bit.
  76
  77 **/
  78 UINT8
  79 ReadRefresh (
  80   VOID
  81   )
  82 {
  83   UINT8 Data;
  84
  85   mCpuIo->Io.Read (
  86                mCpuIo,
  87                EfiCpuIoWidthUint8,
  88                REFRESH_PORT,
  89                1,
  90                &Data
  91                );
  92   return (UINT8) (Data & REFRESH_ON);
  93 }
  94
  95 /**
  96
  97   Waits for the TickNumber of ticks from a known platform time source.
  98
  99   @param This                Pointer to the protocol instance.
 100   @param TickNumber          Tick Number to be waited
 101
 102
 103   @retval EFI_SUCCESS         If number of ticks occurred.
 104   @retval EFI_NOT_FOUND       Could not locate CPU IO protocol
 105
 106 **/
 107 EFI_STATUS
 108 EFIAPI
 109 WaitForTick (
 110   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
 111   IN UINT32                       TickNumber
 112   )
 113 {
 114   //
 115   // Wait for TickNumber toggles of the Refresh bit
 116   //
 117   for (; TickNumber != 0x00; TickNumber--) {
 118     while (ReadRefresh () == REFRESH_ON)
 119       ;
 120     while (ReadRefresh () == REFRESH_OFF)
 121       ;
 122   }
 123
 124   return EFI_SUCCESS;
 125 }
 126
 127 //
 128 // Driver Entry Point
 129 //
 130 /**
 131   Install the LegacyMetronome driver.  Loads a Metronome Arch Protocol based
 132   on the Port 61 timer.
 133
 134   @param ImageHandle      Handle for the image of this driver
 135   @param SystemTable      Pointer to the EFI System Table
 136
 137   @retval EFI_SUCCESS     Metronome Architectural Protocol Installed
 138
 139 **/
 140 EFI_STATUS
 141 EFIAPI
 142 InstallLegacyMetronome (
 143   IN EFI_HANDLE        ImageHandle,
 144   IN EFI_SYSTEM_TABLE  *SystemTable
 145   )
 146 {
 147   EFI_STATUS  Status;
 148
 149   //
 150   // Make sure the Metronome Architectural Protocol is not already installed in the system
 151   //
 152   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiMetronomeArchProtocolGuid);
 153
 154   //
 155   // Get the CPU I/O Protocol that this driver requires
 156   // If the CPU I/O Protocol is not found, then ASSERT because the dependency expression
 157   // should guarantee that it is present in the handle database.
 158   //
 159   Status = gBS->LocateProtocol (
 160                   &gEfiCpuIoProtocolGuid,
 161                   NULL,
 162                   (void **)&mCpuIo
 163                   );
 164   ASSERT_EFI_ERROR (Status);
 165
 166   //
 167   // Program port 61 timer 1 as refresh timer. We could use ACPI timer in the
 168   // future.
 169   //
 170   ScriptWriteIo8 (TIMER1_CONTROL_PORT, LOAD_COUNTER1_LSB);
 171   ScriptWriteIo8 (TIMER1_COUNT_PORT, COUNTER1_COUNT);
 172
 173   //
 174   // Install on a new handle
 175   //
 176   Status = gBS->InstallMultipleProtocolInterfaces (
 177                   &mMetronomeHandle,
 178                   &gEfiMetronomeArchProtocolGuid,
 179                   &mMetronome,
 180                   NULL
 181                   );
 182   ASSERT_EFI_ERROR (Status);
 183
 184   return Status;
 185 }