Vlv2TbltDevicePkg/Metronome/LegacyMetronome.c

   1 /** @file
   2
   3   Copyright (c) 2004  - 2014, Intel Corporation. All rights reserved.<BR>
   4
   5   This program and the accompanying materials are licensed and made available under
   6   the terms and conditions of the BSD License that accompanies this distribution.
   7   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 Module Name:
  15
  16
  17   LegacyMetronome.c
  18
  19 Abstract:
  20
  21   This contains the installation function for the driver.
  22
  23 --*/
  24
  25 #include "LegacyMetronome.h"
  26
  27 //
  28 // Handle for the Metronome Architectural Protocol instance produced by this driver
  29 //
  30 EFI_HANDLE                  mMetronomeHandle = NULL;
  31
  32 //
  33 // The Metronome Architectural Protocol instance produced by this driver
  34 //
  35 EFI_METRONOME_ARCH_PROTOCOL mMetronome = {
  36   WaitForTick,
  37   TICK_PERIOD
  38 };
  39
  40 //
  41 // The CPU I/O Protocol used to access system hardware
  42 //
  43 EFI_CPU_IO_PROTOCOL         *mCpuIo = NULL;
  44
  45 //
  46 // Worker Functions
  47 //
  48
  49 /**
  50   Write an 8 bit value to an I/O port and save it to the S3 script
  51
  52   @param Port  IO Port
  53   @param Data  Data in IO Port
  54
  55   @retval None.
  56
  57 **/
  58 VOID
  59 ScriptWriteIo8 (
  60   UINT16  Port,
  61   UINT8   Data
  62   )
  63 {
  64   mCpuIo->Io.Write (
  65                mCpuIo,
  66                EfiCpuIoWidthUint8,
  67                Port,
  68                1,
  69                &Data
  70                );
  71
  72 }
  73
  74 /**
  75
  76   Read the refresh bit from the REFRESH_PORT
  77
  78   @param None.
  79
  80   @retval Refresh bit.
  81
  82 **/
  83 UINT8
  84 ReadRefresh (
  85   VOID
  86   )
  87 {
  88   UINT8 Data;
  89
  90   mCpuIo->Io.Read (
  91                mCpuIo,
  92                EfiCpuIoWidthUint8,
  93                REFRESH_PORT,
  94                1,
  95                &Data
  96                );
  97   return (UINT8) (Data & REFRESH_ON);
  98 }
  99
 100 /**
 101
 102   Waits for the TickNumber of ticks from a known platform time source.
 103
 104   @param This                Pointer to the protocol instance.
 105   @param TickNumber          Tick Number to be waited
 106
 107
 108   @retval EFI_SUCCESS         If number of ticks occurred.
 109   @retval EFI_NOT_FOUND       Could not locate CPU IO protocol
 110
 111 **/
 112 EFI_STATUS
 113 EFIAPI
 114 WaitForTick (
 115   IN EFI_METRONOME_ARCH_PROTOCOL  *This,
 116   IN UINT32                       TickNumber
 117   )
 118 {
 119   //
 120   // Wait for TickNumber toggles of the Refresh bit
 121   //
 122   for (; TickNumber != 0x00; TickNumber--) {
 123     while (ReadRefresh () == REFRESH_ON)
 124       ;
 125     while (ReadRefresh () == REFRESH_OFF)
 126       ;
 127   }
 128
 129   return EFI_SUCCESS;
 130 }
 131
 132 //
 133 // Driver Entry Point
 134 //
 135 /**
 136   Install the LegacyMetronome driver.  Loads a Metronome Arch Protocol based
 137   on the Port 61 timer.
 138
 139   @param ImageHandle      Handle for the image of this driver
 140   @param SystemTable      Pointer to the EFI System Table
 141
 142   @retval EFI_SUCCESS     Metronome Architectural Protocol Installed
 143
 144 **/
 145 EFI_STATUS
 146 EFIAPI
 147 InstallLegacyMetronome (
 148   IN EFI_HANDLE        ImageHandle,
 149   IN EFI_SYSTEM_TABLE  *SystemTable
 150   )
 151 {
 152   EFI_STATUS  Status;
 153
 154   //
 155   // Make sure the Metronome Architectural Protocol is not already installed in the system
 156   //
 157   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiMetronomeArchProtocolGuid);
 158
 159   //
 160   // Get the CPU I/O Protocol that this driver requires
 161   // If the CPU I/O Protocol is not found, then ASSERT because the dependency expression
 162   // should guarantee that it is present in the handle database.
 163   //
 164   Status = gBS->LocateProtocol (
 165                   &gEfiCpuIoProtocolGuid,
 166                   NULL,
 167                   (void **)&mCpuIo
 168                   );
 169   ASSERT_EFI_ERROR (Status);
 170
 171   //
 172   // Program port 61 timer 1 as refresh timer. We could use ACPI timer in the
 173   // future.
 174   //
 175   ScriptWriteIo8 (TIMER1_CONTROL_PORT, LOAD_COUNTER1_LSB);
 176   ScriptWriteIo8 (TIMER1_COUNT_PORT, COUNTER1_COUNT);
 177
 178   //
 179   // Install on a new handle
 180   //
 181   Status = gBS->InstallMultipleProtocolInterfaces (
 182                   &mMetronomeHandle,
 183                   &gEfiMetronomeArchProtocolGuid,
 184                   &mMetronome,
 185                   NULL
 186                   );
 187   ASSERT_EFI_ERROR (Status);
 188
 189   return Status;
 190 }