Tools/Source/TianoTools/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
  71   @param  NotifyFunction The function to call when a timer interrupt fires.  This
  72   function executes at TPL_HIGH_LEVEL.  The DXE Core will
  73   register a handler for the timer interrupt, so it can know
  74   how much time has passed.  This information is used to
  75   signal timer based events.  NULL will unregister the handler.
  76
  77   @retval  EFI_SUCCESS The timer handler was registered.
  78
  79   @retval  EFI_UNSUPPORTED The platform does not support timer interrupts.
  80
  81   @retval  EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already
  82   registered.
  83
  84   @retval  EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
  85   previously registered.
  86
  87   @retval  EFI_DEVICE_ERROR The timer handler could not be registered.
  88
  89 **/
  90 typedef
  91 EFI_STATUS
  92 (EFIAPI *EFI_TIMER_REGISTER_HANDLER) (
  93   IN EFI_TIMER_ARCH_PROTOCOL    *This,
  94   IN EFI_TIMER_NOTIFY           NotifyFunction
  95 );
  96
  97 /**
  98   This function adjusts the period of timer interrupts to the value specified
  99   by TimerPeriod.  If the timer period is updated, then the selected timer
 100   period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If
 101   the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
 102   If an error occurs while attempting to update the timer period, then the
 103   timer hardware will be put back in its state prior to this call, and
 104   EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt
 105   is disabled.  This is not the same as disabling the CPU's interrupts.
 106   Instead, it must either turn off the timer hardware, or it must adjust the
 107   interrupt controller so that a CPU interrupt is not generated when the timer
 108   interrupt fires.
 109
 110   @param  This The EFI_TIMER_ARCH_PROTOCOL instance.
 111
 112   @param  TimerPeriod The rate to program the timer interrupt in 100 nS units.  If
 113   the timer hardware is not programmable, then EFI_UNSUPPORTED is
 114   returned.  If the timer is programmable, then the timer period
 115   will be rounded up to the nearest timer period that is supported
 116   by the timer hardware.  If TimerPeriod is set to 0, then the
 117   timer interrupts will be disabled.
 118
 119   @retval  EFI_SUCCESS The timer period was changed.
 120
 121   @retval  EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.
 122
 123   @retval  EFI_DEVICE_ERROR The timer period could not be changed due to a device error.
 124
 125 **/
 126 typedef
 127 EFI_STATUS
 128 (EFIAPI *EFI_TIMER_SET_TIMER_PERIOD) (
 129   IN EFI_TIMER_ARCH_PROTOCOL    *This,
 130   IN UINT64                     TimerPeriod
 131   );
 132
 133 /**
 134   This function retrieves the period of timer interrupts in 100 ns units,
 135   returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod
 136   is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is
 137   returned, then the timer is currently disabled.
 138
 139   @param  This The EFI_TIMER_ARCH_PROTOCOL instance.
 140
 141   @param  TimerPeriod A pointer to the timer period to retrieve in 100 ns units.  If
 142   0 is returned, then the timer is currently disabled.
 143
 144   @retval  EFI_SUCCESS The timer period was returned in TimerPeriod.
 145
 146   @retval  EFI_INVALID_PARAMETER TimerPeriod is NULL.
 147
 148 **/
 149 typedef
 150 EFI_STATUS
 151 (EFIAPI *EFI_TIMER_GET_TIMER_PERIOD) (
 152   IN EFI_TIMER_ARCH_PROTOCOL      *This,
 153   OUT UINT64                      *TimerPeriod
 154   );
 155
 156 /**
 157   This function generates a soft timer interrupt. If the platform does not support soft
 158   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
 159   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
 160   service, then a soft timer interrupt will be generated. If the timer interrupt is
 161   enabled when this service is called, then the registered handler will be invoked. The
 162   registered handler should not be able to distinguish a hardware-generated timer
 163   interrupt from a software-generated timer interrupt.
 164
 165   @param  This The EFI_TIMER_ARCH_PROTOCOL instance.
 166
 167   @retval  EFI_SUCCESS The soft timer interrupt was generated.
 168
 169   @retval  EFI_UNSUPPORTEDT The platform does not support the generation of soft timer interrupts.
 170
 171 **/
 172 typedef
 173 EFI_STATUS
 174 (EFIAPI *EFI_TIMER_GENERATE_SOFT_INTERRUPT) (
 175   IN EFI_TIMER_ARCH_PROTOCOL    *This
 176   );
 177
 178
 179 /**
 180   Interface stucture for the Timer Architectural Protocol.
 181
 182   @par Protocol Description:
 183   This protocol provides the services to initialize a periodic timer
 184   interrupt, and to register a handler that is called each time the timer
 185   interrupt fires.  It may also provide a service to adjust the rate of the
 186   periodic timer interrupt.  When a timer interrupt occurs, the handler is
 187   passed the amount of time that has passed since the previous timer
 188   interrupt.
 189
 190   @param RegisterHandler
 191   Registers a handler that will be called each time the
 192   timer interrupt fires.  TimerPeriod defines the minimum
 193   time between timer interrupts, so TimerPeriod will also
 194   be the minimum time between calls to the registered
 195   handler.
 196
 197   @param SetTimerPeriod
 198   Sets the period of the timer interrupt in 100 nS units.
 199   This function is optional, and may return EFI_UNSUPPORTED.
 200   If this function is supported, then the timer period will
 201   be rounded up to the nearest supported timer period.
 202
 203   @param GetTimerPeriod
 204   Retrieves the period of the timer interrupt in 100 nS units.
 205
 206   @param GenerateSoftInterrupt
 207   Generates a soft timer interrupt that simulates the firing of
 208   the timer interrupt. This service can be used to invoke the
 209   registered handler if the timer interrupt has been masked for
 210   a period of time.
 211
 212 **/
 213 struct _EFI_TIMER_ARCH_PROTOCOL {
 214   EFI_TIMER_REGISTER_HANDLER          RegisterHandler;
 215   EFI_TIMER_SET_TIMER_PERIOD          SetTimerPeriod;
 216   EFI_TIMER_GET_TIMER_PERIOD          GetTimerPeriod;
 217   EFI_TIMER_GENERATE_SOFT_INTERRUPT   GenerateSoftInterrupt;
 218 };
 219
 220 extern EFI_GUID gEfiTimerArchProtocolGuid;
 221
 222 #endif