MdePkg/Include/Protocol/WatchdogTimer.h

   1 /** @file
   2   Watchdog Timer Architectural Protocol as defined in the DXE CIS
   3
   4   Used to provide system watchdog timer services
   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:  WatchdogTimer.h
  16
  17   @par Revision Reference:
  18   Version 0.91B.
  19
  20 **/
  21
  22 #ifndef __ARCH_PROTOCOL_WATCHDOG_TIMER_H__
  23 #define __ARCH_PROTOCOL_WATCHDOG_TIMER_H__
  24
  25 //
  26 // Global ID for the Watchdog Timer Architectural Protocol
  27 //
  28 #define EFI_WATCHDOG_TIMER_ARCH_PROTOCOL_GUID \
  29   { 0x665E3FF5, 0x46CC, 0x11d4, {0x9A, 0x38, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D } }
  30
  31 //
  32 // Declare forward reference for the Timer Architectural Protocol
  33 //
  34 typedef struct _EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  EFI_WATCHDOG_TIMER_ARCH_PROTOCOL;
  35
  36 /**
  37   A function of this type is called when the watchdog timer fires if a
  38   handler has been registered.
  39
  40   @param  Time             The time in 100 ns units that has passed since the watchdog
  41                            timer was armed. For the notify function to be called, this
  42                            must be greater than TimerPeriod.
  43
  44   @return None.
  45
  46 **/
  47 typedef
  48 VOID
  49 (EFIAPI *EFI_WATCHDOG_TIMER_NOTIFY) (
  50   IN UINT64  Time
  51   );
  52
  53 /**
  54   This function registers a handler that is to be invoked when the watchdog
  55   timer fires.  By default, the EFI_WATCHDOG_TIMER protocol will call the
  56   Runtime Service ResetSystem() when the watchdog timer fires.  If a
  57   NotifyFunction is registered, then the NotifyFunction will be called before
  58   the Runtime Service ResetSystem() is called.  If NotifyFunction is NULL, then
  59   the watchdog handler is unregistered.  If a watchdog handler is registered,
  60   then EFI_SUCCESS is returned.  If an attempt is made to register a handler
  61   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  62   If an attempt is made to uninstall a handler when a handler is not installed,
  63   then return EFI_INVALID_PARAMETER.
  64
  65   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
  66   @param  NotifyFunction   The function to call when the watchdog timer fires. If this
  67                            is NULL, then the handler will be unregistered.
  68
  69   @retval EFI_SUCCESS           The watchdog timer handler was registered or
  70                                 unregistered.
  71   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
  72                                 registered.
  73   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
  74                                 previously registered.
  75
  76 **/
  77 typedef
  78 EFI_STATUS
  79 (EFIAPI *EFI_WATCHDOG_TIMER_REGISTER_HANDLER) (
  80   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
  81   IN EFI_WATCHDOG_TIMER_NOTIFY         NotifyFunction
  82   );
  83
  84 /**
  85   This function sets the amount of time to wait before firing the watchdog
  86   timer to TimerPeriod 100 nS units.  If TimerPeriod is 0, then the watchdog
  87   timer is disabled.
  88
  89   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
  90   @param  TimerPeriod      The amount of time in 100 nS units to wait before the watchdog
  91                            timer is fired. If TimerPeriod is zero, then the watchdog
  92                            timer is disabled.
  93
  94   @retval EFI_SUCCESS           The watchdog timer has been programmed to fire in Time
  95                                 100 nS units.
  96   @retval EFI_DEVICE_ERROR      A watchdog timer could not be programmed due to a device
  97                                 error.
  98
  99 **/
 100 typedef
 101 EFI_STATUS
 102 (EFIAPI *EFI_WATCHDOG_TIMER_SET_TIMER_PERIOD) (
 103   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 104   IN UINT64                            TimerPeriod
 105   );
 106
 107 /**
 108   This function retrieves the amount of time the system will wait before firing
 109   the watchdog timer.  This period is returned in TimerPeriod, and EFI_SUCCESS
 110   is returned.  If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
 111
 112   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
 113   @param  TimerPeriod      A pointer to the amount of time in 100 nS units that the system
 114                            will wait before the watchdog timer is fired. If TimerPeriod of
 115                            zero is returned, then the watchdog timer is disabled.
 116
 117   @retval EFI_SUCCESS           The amount of time that the system will wait before
 118                                 firing the watchdog timer was returned in TimerPeriod.
 119   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 120
 121 **/
 122 typedef
 123 EFI_STATUS
 124 (EFIAPI *EFI_WATCHDOG_TIMER_GET_TIMER_PERIOD) (
 125   IN  EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 126   OUT UINT64                            *TimerPeriod
 127   );
 128
 129
 130 /**
 131   Interface stucture for the Watchdog Timer Architectural Protocol.
 132
 133   @par Protocol Description:
 134   This protocol provides the services required to implement the Boot Service
 135   SetWatchdogTimer().  It provides a service to set the amount of time to wait
 136   before firing the watchdog timer, and it also provides a service to register
 137   a handler that is invoked when the watchdog timer fires.  This protocol can
 138   implement the watchdog timer by using the event and timer Boot Services, or
 139   it can make use of custom hardware.  When the watchdog timer fires, control
 140   will be passed to a handler if one has been registered.  If no handler has
 141   been registered, or the registered handler returns, then the system will be
 142   reset by calling the Runtime Service ResetSystem().
 143
 144   @param  RegisterHandler  Registers a handler that is invoked when the watchdog
 145                            timer fires.
 146
 147   @param  SetTimerPeriod   Sets the amount of time in 100 ns units to wait before the
 148                            watchdog timer is fired. If this function is supported,
 149                            then the watchdog timer period will be rounded up to the
 150                            nearest supported watchdog timer period.
 151
 152   @param  GetTimerPeriod   Retrieves the amount of time in 100 ns units that the
 153                            system will wait before the watchdog timer is fired.
 154
 155 **/
 156 struct _EFI_WATCHDOG_TIMER_ARCH_PROTOCOL {
 157   EFI_WATCHDOG_TIMER_REGISTER_HANDLER  RegisterHandler;
 158   EFI_WATCHDOG_TIMER_SET_TIMER_PERIOD  SetTimerPeriod;
 159   EFI_WATCHDOG_TIMER_GET_TIMER_PERIOD  GetTimerPeriod;
 160 };
 161
 162 extern EFI_GUID gEfiWatchdogTimerArchProtocolGuid;
 163
 164 #endif
 165