3 Copyright (c) 2006, Intel Corporation
4 All rights reserved. This program and the accompanying materials
5 are licensed and made available under the terms and conditions of the BSD License
6 which accompanies this distribution. The full text of the license may be found at
7 http://opensource.org/licenses/bsd-license.php
9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
18 Generic watchdog timer implemenetation using EFI APIs
24 #include "WatchDogTimer.h"
27 // Handle for the Watchdog Timer Architectural Protocol instance produced by this driver
29 EFI_HANDLE mWatchdogTimerHandle
= NULL
;
32 // The Watchdog Timer Architectural Protocol instance produced by this driver
34 EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer
= {
35 WatchdogTimerDriverRegisterHandler
,
36 WatchdogTimerDriverSetTimerPeriod
,
37 WatchdogTimerDriverGetTimerPeriod
41 // The watchdog timer period in 100 nS units
43 UINT64 mWatchdogTimerPeriod
= 0;
46 // The notification function to call if the watchdig timer fires
48 EFI_WATCHDOG_TIMER_NOTIFY mWatchdogTimerNotifyFunction
= NULL
;
51 // The one-shot timer event that is armed when the watchdog timer is enabled
53 EFI_EVENT mWatchdogTimerEvent
;
61 WatchdogTimerDriverExpires (
69 Notification function that is called if the watchdog timer is fired. If a
70 handler has been registered with the Watchdog Timer Architectural Protocol,
71 then that handler is called passing in the time period that has passed that
72 cause the watchdog timer to fire. Then, a call to the Runtime Service
73 ResetSystem() is made to reset the platform.
77 Timer - The one-shot timer event that was signaled when the watchdog timer
80 Context - The context that was registered when the event Timer was created.
88 REPORT_STATUS_CODE (EFI_ERROR_CODE
| EFI_ERROR_MINOR
, PcdGet32 (PcdStatusCodeValueEfiWatchDogTimerExpired
));
91 // If a notification function has been registered, then call it
93 if (mWatchdogTimerNotifyFunction
!= NULL
) {
94 mWatchdogTimerNotifyFunction (mWatchdogTimerPeriod
);
99 gRT
->ResetSystem (EfiResetCold
, EFI_TIMEOUT
, 0, NULL
);
105 WatchdogTimerDriverRegisterHandler (
106 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
107 IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction
113 This function registers a handler that is to be invoked when the watchdog
114 timer fires. By default, the EFI_WATCHDOG_TIMER protocol will call the
115 Runtime Service ResetSystem() when the watchdog timer fires. If a
116 NotifyFunction is registered, then the NotifyFunction will be called before
117 the Runtime Service ResetSystem() is called. If NotifyFunction is NULL, then
118 the watchdog handler is unregistered. If a watchdog handler is registered,
119 then EFI_SUCCESS is returned. If an attempt is made to register a handler
120 when a handler is already registered, then EFI_ALREADY_STARTED is returned.
121 If an attempt is made to uninstall a handler when a handler is not installed,
122 then return EFI_INVALID_PARAMETER.
126 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
128 NotifyFunction - The function to call when the watchdog timer fires. If this
129 is NULL, then the handler will be unregistered.
133 EFI_SUCCESS - The watchdog timer handler was registered or
136 EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already
139 EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
140 previously registered.
144 if (NotifyFunction
== NULL
&& mWatchdogTimerNotifyFunction
== NULL
) {
145 return EFI_INVALID_PARAMETER
;
148 if (NotifyFunction
!= NULL
&& mWatchdogTimerNotifyFunction
!= NULL
) {
149 return EFI_ALREADY_STARTED
;
152 mWatchdogTimerNotifyFunction
= NotifyFunction
;
159 WatchdogTimerDriverSetTimerPeriod (
160 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
161 IN UINT64 TimerPeriod
167 This function sets the amount of time to wait before firing the watchdog
168 timer to TimerPeriod 100 nS units. If TimerPeriod is 0, then the watchdog
173 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
175 TimerPeriod - The amount of time in 100 nS units to wait before the watchdog
176 timer is fired. If TimerPeriod is zero, then the watchdog
181 EFI_SUCCESS - The watchdog timer has been programmed to fire in Time
184 EFI_DEVICE_ERROR - A watchdog timer could not be programmed due to a device
189 mWatchdogTimerPeriod
= TimerPeriod
;
191 return gBS
->SetTimer (
193 (mWatchdogTimerPeriod
== 0) ? TimerCancel
: TimerRelative
,
200 WatchdogTimerDriverGetTimerPeriod (
201 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
202 IN UINT64
*TimerPeriod
208 This function retrieves the amount of time the system will wait before firing
209 the watchdog timer. This period is returned in TimerPeriod, and EFI_SUCCESS
210 is returned. If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
214 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
216 TimerPeriod - A pointer to the amount of time in 100 nS units that the system
217 will wait before the watchdog timer is fired. If TimerPeriod of
218 zero is returned, then the watchdog timer is disabled.
222 EFI_SUCCESS - The amount of time that the system will wait before
223 firing the watchdog timer was returned in TimerPeriod.
225 EFI_INVALID_PARAMETER - TimerPeriod is NULL.
229 if (TimerPeriod
== NULL
) {
230 return EFI_INVALID_PARAMETER
;
233 *TimerPeriod
= mWatchdogTimerPeriod
;
240 WatchdogTimerDriverInitialize (
241 IN EFI_HANDLE ImageHandle
,
242 IN EFI_SYSTEM_TABLE
*SystemTable
248 Initialize the Watchdog Timer Architectural Protocol driver
252 ImageHandle - ImageHandle of the loaded driver
254 SystemTable - Pointer to the System Table
258 EFI_SUCCESS - Timer Architectural Protocol created
260 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.
262 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.
269 // Make sure the Watchdog Timer Architectural Protocol is not already installed in the system
271 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL
, &gEfiWatchdogTimerArchProtocolGuid
);
274 // Create the timer event used to implement a simple watchdog timer
276 Status
= gBS
->CreateEvent (
277 EVT_TIMER
| EVT_NOTIFY_SIGNAL
,
279 WatchdogTimerDriverExpires
,
283 ASSERT_EFI_ERROR (Status
);
286 // Install the Watchdog Timer Arch Protocol onto a new handle
288 Status
= gBS
->InstallMultipleProtocolInterfaces (
289 &mWatchdogTimerHandle
,
290 &gEfiWatchdogTimerArchProtocolGuid
,
294 ASSERT_EFI_ERROR (Status
);