MdeModulePkg/Universal/WatchdogTimerDxe/WatchdogTimer.c

   1 /** @file
   2
   3   Generic watchdog timer services implemenetation using UEFI APIs and
   4   install watchdog timer architecture protocol.
   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 **/
  16
  17 #include "WatchdogTimer.h"
  18
  19 //
  20 // Handle for the Watchdog Timer Architectural Protocol instance produced by this driver
  21 //
  22 EFI_HANDLE                        mWatchdogTimerHandle = NULL;
  23
  24 //
  25 // The Watchdog Timer Architectural Protocol instance produced by this driver
  26 //
  27 EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  mWatchdogTimer = {
  28   WatchdogTimerDriverRegisterHandler,
  29   WatchdogTimerDriverSetTimerPeriod,
  30   WatchdogTimerDriverGetTimerPeriod
  31 };
  32
  33 //
  34 // The watchdog timer period in 100 nS units
  35 //
  36 UINT64                            mWatchdogTimerPeriod = 0;
  37
  38 //
  39 // The notification function to call if the watchdig timer fires
  40 //
  41 EFI_WATCHDOG_TIMER_NOTIFY         mWatchdogTimerNotifyFunction = NULL;
  42
  43 //
  44 // The one-shot timer event that is armed when the watchdog timer is enabled
  45 //
  46 EFI_EVENT                         mWatchdogTimerEvent;
  47
  48
  49 /**
  50   Notification function that is called if the watchdog timer is fired.  If a
  51   handler has been registered with the Watchdog Timer Architectural Protocol,
  52   then that handler is called passing in the time period that has passed that
  53   cause the watchdog timer to fire.  Then, a call to the Runtime Service
  54   ResetSystem() is made to reset the platform.
  55
  56
  57   @param  Timer     The one-shot timer event that was signaled when the watchdog timer
  58                          expired.
  59   @param  Context   The context that was registered when the event Timer was created.
  60
  61   @return None.
  62
  63 **/
  64 VOID
  65 EFIAPI
  66 WatchdogTimerDriverExpires (
  67   IN EFI_EVENT    Timer,
  68   IN VOID         *Context
  69   )
  70 {
  71   REPORT_STATUS_CODE (EFI_ERROR_CODE | EFI_ERROR_MINOR, PcdGet32 (PcdStatusCodeValueEfiWatchDogTimerExpired));
  72
  73   //
  74   // If a notification function has been registered, then call it
  75   //
  76   if (mWatchdogTimerNotifyFunction != NULL) {
  77     mWatchdogTimerNotifyFunction (mWatchdogTimerPeriod);
  78   }
  79   //
  80   // Reset the platform
  81   //
  82   gRT->ResetSystem (EfiResetCold, EFI_TIMEOUT, 0, NULL);
  83 }
  84
  85
  86 /**
  87   This function registers a handler that is to be invoked when the watchdog
  88   timer fires.  By default, the EFI_WATCHDOG_TIMER protocol will call the
  89   Runtime Service ResetSystem() when the watchdog timer fires.  If a
  90   NotifyFunction is registered, then the NotifyFunction will be called before
  91   the Runtime Service ResetSystem() is called.  If NotifyFunction is NULL, then
  92   the watchdog handler is unregistered.  If a watchdog handler is registered,
  93   then EFI_SUCCESS is returned.  If an attempt is made to register a handler
  94   when a handler is already registered, then EFI_ALREADY_STARTED is returned.
  95   If an attempt is made to uninstall a handler when a handler is not installed,
  96   then return EFI_INVALID_PARAMETER.
  97
  98   @param  This                  The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
  99   @param  NotifyFunction        The function to call when the watchdog timer fires.  If this
 100                                 is NULL, then the handler will be unregistered.
 101
 102   @return EFI_SUCCESS           The watchdog timer handler was registered or unregistered.
 103   @return EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already registered.
 104   @return EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not previously registered.
 105
 106 **/
 107 EFI_STATUS
 108 EFIAPI
 109 WatchdogTimerDriverRegisterHandler (
 110   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 111   IN EFI_WATCHDOG_TIMER_NOTIFY         NotifyFunction
 112   )
 113 {
 114   if (NotifyFunction == NULL && mWatchdogTimerNotifyFunction == NULL) {
 115     return EFI_INVALID_PARAMETER;
 116   }
 117
 118   if (NotifyFunction != NULL && mWatchdogTimerNotifyFunction != NULL) {
 119     return EFI_ALREADY_STARTED;
 120   }
 121
 122   mWatchdogTimerNotifyFunction = NotifyFunction;
 123
 124   return EFI_SUCCESS;
 125 }
 126
 127 /**
 128   This function sets the amount of time to wait before firing the watchdog
 129   timer to TimerPeriod 100 nS units.  If TimerPeriod is 0, then the watchdog
 130   timer is disabled.
 131
 132   @param  This              The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
 133   @param  TimerPeriod       The amount of time in 100 nS units to wait before the watchdog
 134                             timer is fired.  If TimerPeriod is zero, then the watchdog
 135                             timer is disabled.
 136
 137   @return EFI_SUCCESS       The watchdog timer has been programmed to fire in Time
 138                             100 nS units.
 139   @return EFI_DEVICE_ERROR  A watchdog timer could not be programmed due to a device
 140                             error.
 141
 142 **/
 143 EFI_STATUS
 144 EFIAPI
 145 WatchdogTimerDriverSetTimerPeriod (
 146   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 147   IN UINT64                            TimerPeriod
 148   )
 149 {
 150   mWatchdogTimerPeriod = TimerPeriod;
 151
 152   return gBS->SetTimer (
 153                 mWatchdogTimerEvent,
 154                 (mWatchdogTimerPeriod == 0) ? TimerCancel : TimerRelative,
 155                 mWatchdogTimerPeriod
 156                 );
 157 }
 158
 159 /**
 160   This function retrieves the amount of time the system will wait before firing
 161   the watchdog timer.  This period is returned in TimerPeriod, and EFI_SUCCESS
 162   is returned.  If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
 163
 164   @param  This                    The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
 165   @param  TimerPeriod             A pointer to the amount of time in 100 nS units that the system
 166                                   will wait before the watchdog timer is fired.  If TimerPeriod of
 167                                   zero is returned, then the watchdog timer is disabled.
 168
 169   @return EFI_SUCCESS             The amount of time that the system will wait before
 170                                   firing the watchdog timer was returned in TimerPeriod.
 171   @return EFI_INVALID_PARAMETER   TimerPeriod is NULL.
 172
 173 **/
 174 EFI_STATUS
 175 EFIAPI
 176 WatchdogTimerDriverGetTimerPeriod (
 177   IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  *This,
 178   IN UINT64                            *TimerPeriod
 179   )
 180 {
 181   if (TimerPeriod == NULL) {
 182     return EFI_INVALID_PARAMETER;
 183   }
 184
 185   *TimerPeriod = mWatchdogTimerPeriod;
 186
 187   return EFI_SUCCESS;
 188 }
 189
 190 /**
 191   Initialize the Watchdog Timer Architectural Protocol driver.
 192
 193   @param  ImageHandle             ImageHandle of the loaded driver.
 194   @param  SystemTable             Pointer to the System Table.
 195
 196   @return EFI_SUCCESS             Timer Architectural Protocol created.
 197
 198 **/
 199 EFI_STATUS
 200 EFIAPI
 201 WatchdogTimerDriverInitialize (
 202   IN EFI_HANDLE        ImageHandle,
 203   IN EFI_SYSTEM_TABLE  *SystemTable
 204   )
 205 {
 206   EFI_STATUS  Status;
 207
 208   //
 209   // Make sure the Watchdog Timer Architectural Protocol is not already installed in the system
 210   //
 211   ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);
 212
 213   //
 214   // Create the timer event used to implement a simple watchdog timer
 215   //
 216   Status = gBS->CreateEvent (
 217                   EVT_TIMER | EVT_NOTIFY_SIGNAL,
 218                   TPL_NOTIFY,
 219                   WatchdogTimerDriverExpires,
 220                   NULL,
 221                   &mWatchdogTimerEvent
 222                   );
 223   ASSERT_EFI_ERROR (Status);
 224
 225   //
 226   // Install the Watchdog Timer Arch Protocol onto a new handle
 227   //
 228   Status = gBS->InstallMultipleProtocolInterfaces (
 229                   &mWatchdogTimerHandle,
 230                   &gEfiWatchdogTimerArchProtocolGuid,
 231                   &mWatchdogTimer,
 232                   NULL
 233                   );
 234   ASSERT_EFI_ERROR (Status);
 235
 236   return Status;
 237 }