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.
89 // Report error code before exiting
92 EFI_ERROR_CODE
| EFI_ERROR_MINOR
,
93 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_CU_HP_EC_TIMER_EXPIRED
)
97 // If a notification function has been registered, then call it
99 if (mWatchdogTimerNotifyFunction
!= NULL
) {
100 mWatchdogTimerNotifyFunction (mWatchdogTimerPeriod
);
103 // Reset the platform
105 gRT
->ResetSystem (EfiResetCold
, EFI_TIMEOUT
, 0, NULL
);
110 WatchdogTimerDriverRegisterHandler (
111 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
112 IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction
118 This function registers a handler that is to be invoked when the watchdog
119 timer fires. By default, the EFI_WATCHDOG_TIMER protocol will call the
120 Runtime Service ResetSystem() when the watchdog timer fires. If a
121 NotifyFunction is registered, then the NotifyFunction will be called before
122 the Runtime Service ResetSystem() is called. If NotifyFunction is NULL, then
123 the watchdog handler is unregistered. If a watchdog handler is registered,
124 then EFI_SUCCESS is returned. If an attempt is made to register a handler
125 when a handler is already registered, then EFI_ALREADY_STARTED is returned.
126 If an attempt is made to uninstall a handler when a handler is not installed,
127 then return EFI_INVALID_PARAMETER.
131 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
133 NotifyFunction - The function to call when the watchdog timer fires. If this
134 is NULL, then the handler will be unregistered.
138 EFI_SUCCESS - The watchdog timer handler was registered or
141 EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already
144 EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
145 previously registered.
149 if (NotifyFunction
== NULL
&& mWatchdogTimerNotifyFunction
== NULL
) {
150 return EFI_INVALID_PARAMETER
;
153 if (NotifyFunction
!= NULL
&& mWatchdogTimerNotifyFunction
!= NULL
) {
154 return EFI_ALREADY_STARTED
;
157 mWatchdogTimerNotifyFunction
= NotifyFunction
;
164 WatchdogTimerDriverSetTimerPeriod (
165 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
166 IN UINT64 TimerPeriod
172 This function sets the amount of time to wait before firing the watchdog
173 timer to TimerPeriod 100 nS units. If TimerPeriod is 0, then the watchdog
178 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
180 TimerPeriod - The amount of time in 100 nS units to wait before the watchdog
181 timer is fired. If TimerPeriod is zero, then the watchdog
186 EFI_SUCCESS - The watchdog timer has been programmed to fire in Time
189 EFI_DEVICE_ERROR - A watchdog timer could not be programmed due to a device
194 mWatchdogTimerPeriod
= TimerPeriod
;
196 return gBS
->SetTimer (
198 (mWatchdogTimerPeriod
== 0) ? TimerCancel
: TimerRelative
,
205 WatchdogTimerDriverGetTimerPeriod (
206 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
207 IN UINT64
*TimerPeriod
213 This function retrieves the amount of time the system will wait before firing
214 the watchdog timer. This period is returned in TimerPeriod, and EFI_SUCCESS
215 is returned. If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
219 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
221 TimerPeriod - A pointer to the amount of time in 100 nS units that the system
222 will wait before the watchdog timer is fired. If TimerPeriod of
223 zero is returned, then the watchdog timer is disabled.
227 EFI_SUCCESS - The amount of time that the system will wait before
228 firing the watchdog timer was returned in TimerPeriod.
230 EFI_INVALID_PARAMETER - TimerPeriod is NULL.
234 if (TimerPeriod
== NULL
) {
235 return EFI_INVALID_PARAMETER
;
238 *TimerPeriod
= mWatchdogTimerPeriod
;
245 WatchdogTimerDriverInitialize (
246 IN EFI_HANDLE ImageHandle
,
247 IN EFI_SYSTEM_TABLE
*SystemTable
253 Initialize the Watchdog Timer Architectural Protocol driver
257 ImageHandle - ImageHandle of the loaded driver
259 SystemTable - Pointer to the System Table
263 EFI_SUCCESS - Timer Architectural Protocol created
265 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.
267 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.
275 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_SW_PC_INIT_BEGIN
)
278 // Make sure the Watchdog Timer Architectural Protocol is not already installed in the system
280 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL
, &gEfiWatchdogTimerArchProtocolGuid
);
283 // Create the timer event used to implement a simple watchdog timer
285 Status
= gBS
->CreateEvent (
286 EFI_EVENT_TIMER
| EFI_EVENT_NOTIFY_SIGNAL
,
288 WatchdogTimerDriverExpires
,
292 ASSERT_EFI_ERROR (Status
);
295 // Install the Watchdog Timer Arch Protocol onto a new handle
297 Status
= gBS
->InstallMultipleProtocolInterfaces (
298 &mWatchdogTimerHandle
,
299 &gEfiWatchdogTimerArchProtocolGuid
,
303 ASSERT_EFI_ERROR (Status
);
307 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_SW_PC_INIT_END
)