OldMdePkg/Include/Dxe/ArchProtocol/Timer.h

   1 /** @file
   2   Timer Architectural Protocol as defined in the DXE CIS
   3
   4   This code is used to provide the timer tick for the DXE core.
   5
   6   Copyright (c) 2006, Intel Corporation
   7   All rights reserved. This program and the accompanying materials
   8   are licensed and made available under the terms and conditions of the BSD License
   9   which accompanies this distribution.  The full text of the license may be found at
  10   http://opensource.org/licenses/bsd-license.php
  11
  12   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  13   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  14
  15   Module Name:  Timer.h
  16
  17   @par Revision Reference:
  18   Version 0.91B.
  19
  20 **/
  21
  22 #ifndef __ARCH_PROTOCOL_TIMER_H__
  23 #define __ARCH_PROTOCOL_TIMER_H__
  24
  25 //
  26 // Global ID for the Timer Architectural Protocol
  27 //
  28 #define EFI_TIMER_ARCH_PROTOCOL_GUID \
  29   { 0x26baccb3, 0x6f42, 0x11d4, {0xbc, 0xe7, 0x0, 0x80, 0xc7, 0x3c, 0x88, 0x81 } }
  30
  31 //
  32 // Declare forward reference for the Timer Architectural Protocol
  33 //
  34 typedef struct _EFI_TIMER_ARCH_PROTOCOL   EFI_TIMER_ARCH_PROTOCOL;
  35
  36 /**
  37   This function of this type is called when a timer interrupt fires.  This
  38   function executes at TPL_HIGH_LEVEL.  The DXE Core will register a funtion
  39   of tyis type to be called for the timer interrupt, so it can know how much
  40   time has passed.  This information is used to signal timer based events.
  41
  42   @param  Time             Time since the last timer interrupt in 100 ns units. This will
  43                            typically be TimerPeriod, but if a timer interrupt is missed, and the
  44                            EFI_TIMER_ARCH_PROTOCOL driver can detect missed interrupts, then Time
  45                            will contain the actual amount of time since the last interrupt.
  46
  47   None.
  48
  49 **/
  50 typedef
  51 VOID
  52 (EFIAPI *EFI_TIMER_NOTIFY) (
  53   IN UINT64  Time
  54   );
  55
  56 /**
  57   This function registers the handler NotifyFunction so it is called every time
  58   the timer interrupt fires.  It also passes the amount of time since the last
  59   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
  60   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
  61   returned.  If the CPU does not support registering a timer interrupt handler,
  62   then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler
  63   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  64   If an attempt is made to unregister a handler when a handler is not registered,
  65   then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to
  66   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
  67   is returned.
  68
  69   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  70   @param  NotifyFunction   The function to call when a timer interrupt fires. This
  71                            function executes at TPL_HIGH_LEVEL. The DXE Core will
  72                            register a handler for the timer interrupt, so it can know
  73                            how much time has passed. This information is used to
  74                            signal timer based events. NULL will unregister the handler.
  75
  76   @retval EFI_SUCCESS           The timer handler was registered.
  77   @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
  78   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
  79                                 registered.
  80   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
  81                                 previously registered.
  82   @retval EFI_DEVICE_ERROR      The timer handler could not be registered.
  83
  84 **/
  85 typedef
  86 EFI_STATUS
  87 (EFIAPI *EFI_TIMER_REGISTER_HANDLER) (
  88   IN EFI_TIMER_ARCH_PROTOCOL    *This,
  89   IN EFI_TIMER_NOTIFY           NotifyFunction
  90 );
  91
  92 /**
  93   This function adjusts the period of timer interrupts to the value specified
  94   by TimerPeriod.  If the timer period is updated, then the selected timer
  95   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
  96   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
  97   If an error occurs while attempting to update the timer period, then the
  98   timer hardware will be put back in its state prior to this call, and
  99   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 100   is disabled.  This is not the same as disabling the CPU's interrupts.
 101   Instead, it must either turn off the timer hardware, or it must adjust the
 102   interrupt controller so that a CPU interrupt is not generated when the timer
 103   interrupt fires.
 104
 105   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 106   @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
 107                            the timer hardware is not programmable, then EFI_UNSUPPORTED is
 108                            returned. If the timer is programmable, then the timer period
 109                            will be rounded up to the nearest timer period that is supported
 110                            by the timer hardware. If TimerPeriod is set to 0, then the
 111                            timer interrupts will be disabled.
 112
 113   @retval EFI_SUCCESS           The timer period was changed.
 114   @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
 115   @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.
 116
 117 **/
 118 typedef
 119 EFI_STATUS
 120 (EFIAPI *EFI_TIMER_SET_TIMER_PERIOD) (
 121   IN EFI_TIMER_ARCH_PROTOCOL    *This,
 122   IN UINT64                     TimerPeriod
 123   );
 124
 125 /**
 126   This function retrieves the period of timer interrupts in 100 ns units,
 127   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 128   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 129   returned, then the timer is currently disabled.
 130
 131   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 132   @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
 133                            0 is returned, then the timer is currently disabled.
 134
 135   @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.
 136   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 137
 138 **/
 139 typedef
 140 EFI_STATUS
 141 (EFIAPI *EFI_TIMER_GET_TIMER_PERIOD) (
 142   IN EFI_TIMER_ARCH_PROTOCOL      *This,
 143   OUT UINT64                      *TimerPeriod
 144   );
 145
 146 /**
 147   This function generates a soft timer interrupt. If the platform does not support soft
 148   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 149   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 150   service, then a soft timer interrupt will be generated. If the timer interrupt is
 151   enabled when this service is called, then the registered handler will be invoked. The
 152   registered handler should not be able to distinguish a hardware-generated timer
 153   interrupt from a software-generated timer interrupt.
 154
 155   @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
 156
 157   @retval EFI_SUCCESS           The soft timer interrupt was generated.
 158   @retval EFI_UNSUPPORTEDT      The platform does not support the generation of soft timer interrupts.
 159
 160 **/
 161 typedef
 162 EFI_STATUS
 163 (EFIAPI *EFI_TIMER_GENERATE_SOFT_INTERRUPT) (
 164   IN EFI_TIMER_ARCH_PROTOCOL    *This
 165   );
 166
 167
 168 /**
 169   Interface stucture for the Timer Architectural Protocol.
 170
 171   @par Protocol Description:
 172   This protocol provides the services to initialize a periodic timer
 173   interrupt, and to register a handler that is called each time the timer
 174   interrupt fires.  It may also provide a service to adjust the rate of the
 175   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 176   passed the amount of time that has passed since the previous timer
 177   interrupt.
 178
 179   @param RegisterHandler
 180   Registers a handler that will be called each time the
 181   timer interrupt fires.  TimerPeriod defines the minimum
 182   time between timer interrupts, so TimerPeriod will also
 183   be the minimum time between calls to the registered
 184   handler.
 185
 186   @param SetTimerPeriod
 187   Sets the period of the timer interrupt in 100 nS units.
 188   This function is optional, and may return EFI_UNSUPPORTED.
 189   If this function is supported, then the timer period will
 190   be rounded up to the nearest supported timer period.
 191
 192   @param GetTimerPeriod
 193   Retrieves the period of the timer interrupt in 100 nS units.
 194
 195   @param GenerateSoftInterrupt
 196   Generates a soft timer interrupt that simulates the firing of
 197   the timer interrupt. This service can be used to invoke the
 198   registered handler if the timer interrupt has been masked for
 199   a period of time.
 200
 201 **/
 202 struct _EFI_TIMER_ARCH_PROTOCOL {
 203   EFI_TIMER_REGISTER_HANDLER          RegisterHandler;
 204   EFI_TIMER_SET_TIMER_PERIOD          SetTimerPeriod;
 205   EFI_TIMER_GET_TIMER_PERIOD          GetTimerPeriod;
 206   EFI_TIMER_GENERATE_SOFT_INTERRUPT   GenerateSoftInterrupt;
 207 };
 208
 209 extern EFI_GUID gEfiTimerArchProtocolGuid;
 210
 211 #endif