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 - 2008, 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   @par Revision Reference:
  16   Version 0.91B.
  17
  18 **/
  19
  20 #ifndef __ARCH_PROTOCOL_WATCHDOG_TIMER_H__
  21 #define __ARCH_PROTOCOL_WATCHDOG_TIMER_H__
  22
  23 //
  24 // Global ID for the Watchdog Timer Architectural Protocol
  25 //
  26 #define EFI_WATCHDOG_TIMER_ARCH_PROTOCOL_GUID \
  27   { 0x665E3FF5, 0x46CC, 0x11d4, {0x9A, 0x38, 0x00, 0x90, 0x27, 0x3F, 0xC1, 0x4D } }
  28
  29 //
  30 // Declare forward reference for the Timer Architectural Protocol
  31 //
  32 typedef struct _EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  EFI_WATCHDOG_TIMER_ARCH_PROTOCOL;
  33
  34 /**
  35   A function of this type is called when the watchdog timer fires if a
  36   handler has been registered.
  37
  38   @param  Time             The time in 100 ns units that has passed since the watchdog
  39                            timer was armed. For the notify function to be called, this
  40                            must be greater than TimerPeriod.
  41
  42   @return None.
  43
  44 **/
  45 typedef
  46 VOID
  47 (EFIAPI *EFI_WATCHDOG_TIMER_NOTIFY)(
  48   IN UINT64  Time
  49   );
  50
  51 /**
  52   This function registers a handler that is to be invoked when the watchdog
  53   timer fires.  By default, the EFI_WATCHDOG_TIMER protocol will call the
  54   Runtime Service ResetSystem() when the watchdog timer fires.  If a
  55   NotifyFunction is registered, then the NotifyFunction will be called before
  56   the Runtime Service ResetSystem() is called.  If NotifyFunction is NULL, then
  57   the watchdog handler is unregistered.  If a watchdog handler is registered,
  58   then EFI_SUCCESS is returned.  If an attempt is made to register a handler
  59   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  60   If an attempt is made to uninstall a handler when a handler is not installed,
  61   then return EFI_INVALID_PARAMETER.
  62
  63   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
  64   @param  NotifyFunction   The function to call when the watchdog timer fires. If this
  65                            is NULL, then the handler will be unregistered.
  66
  67   @retval EFI_SUCCESS           The watchdog timer handler was registered or
  68                                 unregistered.
  69   @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
  70                                 registered.
  71   @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
  72                                 previously registered.
  73
  74 **/
  75 typedef
  76 EFI_STATUS
  77 (EFIAPI *EFI_WATCHDOG_TIMER_REGISTER_HANDLER)(
  78   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
  79   IN EFI_WATCHDOG_TIMER_NOTIFY         NotifyFunction
  80   );
  81
  82 /**
  83   This function sets the amount of time to wait before firing the watchdog
  84   timer to TimerPeriod 100 nS units.  If TimerPeriod is 0, then the watchdog
  85   timer is disabled.
  86
  87   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
  88   @param  TimerPeriod      The amount of time in 100 nS units to wait before the watchdog
  89                            timer is fired. If TimerPeriod is zero, then the watchdog
  90                            timer is disabled.
  91
  92   @retval EFI_SUCCESS           The watchdog timer has been programmed to fire in Time
  93                                 100 nS units.
  94   @retval EFI_DEVICE_ERROR      A watchdog timer could not be programmed due to a device
  95                                 error.
  96
  97 **/
  98 typedef
  99 EFI_STATUS
 100 (EFIAPI *EFI_WATCHDOG_TIMER_SET_TIMER_PERIOD)(
 101   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 102   IN UINT64                            TimerPeriod
 103   );
 104
 105 /**
 106   This function retrieves the amount of time the system will wait before firing
 107   the watchdog timer.  This period is returned in TimerPeriod, and EFI_SUCCESS
 108   is returned.  If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
 109
 110   @param  This             The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
 111   @param  TimerPeriod      A pointer to the amount of time in 100 nS units that the system
 112                            will wait before the watchdog timer is fired. If TimerPeriod of
 113                            zero is returned, then the watchdog timer is disabled.
 114
 115   @retval EFI_SUCCESS           The amount of time that the system will wait before
 116                                 firing the watchdog timer was returned in TimerPeriod.
 117   @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
 118
 119 **/
 120 typedef
 121 EFI_STATUS
 122 (EFIAPI *EFI_WATCHDOG_TIMER_GET_TIMER_PERIOD)(
 123   IN  EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 124   OUT UINT64                            *TimerPeriod
 125   );
 126
 127
 128 /**
 129   Interface stucture for the Watchdog Timer Architectural Protocol.
 130
 131   @par Protocol Description:
 132   This protocol provides the services required to implement the Boot Service
 133   SetWatchdogTimer().  It provides a service to set the amount of time to wait
 134   before firing the watchdog timer, and it also provides a service to register
 135   a handler that is invoked when the watchdog timer fires.  This protocol can
 136   implement the watchdog timer by using the event and timer Boot Services, or
 137   it can make use of custom hardware.  When the watchdog timer fires, control
 138   will be passed to a handler if one has been registered.  If no handler has
 139   been registered, or the registered handler returns, then the system will be
 140   reset by calling the Runtime Service ResetSystem().
 141
 142   @param  RegisterHandler  Registers a handler that is invoked when the watchdog
 143                            timer fires.
 144
 145   @param  SetTimerPeriod   Sets the amount of time in 100 ns units to wait before the
 146                            watchdog timer is fired. If this function is supported,
 147                            then the watchdog timer period will be rounded up to the
 148                            nearest supported watchdog timer period.
 149
 150   @param  GetTimerPeriod   Retrieves the amount of time in 100 ns units that the
 151                            system will wait before the watchdog timer is fired.
 152
 153 **/
 154 struct _EFI_WATCHDOG_TIMER_ARCH_PROTOCOL {
 155   EFI_WATCHDOG_TIMER_REGISTER_HANDLER  RegisterHandler;
 156   EFI_WATCHDOG_TIMER_SET_TIMER_PERIOD  SetTimerPeriod;
 157   EFI_WATCHDOG_TIMER_GET_TIMER_PERIOD  GetTimerPeriod;
 158 };
 159
 160 extern EFI_GUID gEfiWatchdogTimerArchProtocolGuid;
 161
 162 #endif
 163