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
;
60 WatchdogTimerDriverExpires (
68 Notification function that is called if the watchdog timer is fired. If a
69 handler has been registered with the Watchdog Timer Architectural Protocol,
70 then that handler is called passing in the time period that has passed that
71 cause the watchdog timer to fire. Then, a call to the Runtime Service
72 ResetSystem() is made to reset the platform.
76 Timer - The one-shot timer event that was signaled when the watchdog timer
79 Context - The context that was registered when the event Timer was created.
88 // Report error code before exiting
91 EFI_ERROR_CODE
| EFI_ERROR_MINOR
,
92 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_CU_HP_EC_TIMER_EXPIRED
)
96 // If a notification function has been registered, then call it
98 if (mWatchdogTimerNotifyFunction
!= NULL
) {
99 mWatchdogTimerNotifyFunction (mWatchdogTimerPeriod
);
102 // Reset the platform
104 gRT
->ResetSystem (EfiResetCold
, EFI_TIMEOUT
, 0, NULL
);
109 WatchdogTimerDriverRegisterHandler (
110 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
111 IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction
117 This function registers a handler that is to be invoked when the watchdog
118 timer fires. By default, the EFI_WATCHDOG_TIMER protocol will call the
119 Runtime Service ResetSystem() when the watchdog timer fires. If a
120 NotifyFunction is registered, then the NotifyFunction will be called before
121 the Runtime Service ResetSystem() is called. If NotifyFunction is NULL, then
122 the watchdog handler is unregistered. If a watchdog handler is registered,
123 then EFI_SUCCESS is returned. If an attempt is made to register a handler
124 when a handler is already registered, then EFI_ALREADY_STARTED is returned.
125 If an attempt is made to uninstall a handler when a handler is not installed,
126 then return EFI_INVALID_PARAMETER.
130 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
132 NotifyFunction - The function to call when the watchdog timer fires. If this
133 is NULL, then the handler will be unregistered.
137 EFI_SUCCESS - The watchdog timer handler was registered or
140 EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already
143 EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
144 previously registered.
148 if (NotifyFunction
== NULL
&& mWatchdogTimerNotifyFunction
== NULL
) {
149 return EFI_INVALID_PARAMETER
;
152 if (NotifyFunction
!= NULL
&& mWatchdogTimerNotifyFunction
!= NULL
) {
153 return EFI_ALREADY_STARTED
;
156 mWatchdogTimerNotifyFunction
= NotifyFunction
;
163 WatchdogTimerDriverSetTimerPeriod (
164 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
165 IN UINT64 TimerPeriod
171 This function sets the amount of time to wait before firing the watchdog
172 timer to TimerPeriod 100 nS units. If TimerPeriod is 0, then the watchdog
177 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
179 TimerPeriod - The amount of time in 100 nS units to wait before the watchdog
180 timer is fired. If TimerPeriod is zero, then the watchdog
185 EFI_SUCCESS - The watchdog timer has been programmed to fire in Time
188 EFI_DEVICE_ERROR - A watchdog timer could not be programmed due to a device
193 mWatchdogTimerPeriod
= TimerPeriod
;
195 return gBS
->SetTimer (
197 (mWatchdogTimerPeriod
== 0) ? TimerCancel
: TimerRelative
,
204 WatchdogTimerDriverGetTimerPeriod (
205 IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL
*This
,
206 IN UINT64
*TimerPeriod
212 This function retrieves the amount of time the system will wait before firing
213 the watchdog timer. This period is returned in TimerPeriod, and EFI_SUCCESS
214 is returned. If TimerPeriod is NULL, then EFI_INVALID_PARAMETER is returned.
218 This - The EFI_WATCHDOG_TIMER_ARCH_PROTOCOL instance.
220 TimerPeriod - A pointer to the amount of time in 100 nS units that the system
221 will wait before the watchdog timer is fired. If TimerPeriod of
222 zero is returned, then the watchdog timer is disabled.
226 EFI_SUCCESS - The amount of time that the system will wait before
227 firing the watchdog timer was returned in TimerPeriod.
229 EFI_INVALID_PARAMETER - TimerPeriod is NULL.
233 if (TimerPeriod
== NULL
) {
234 return EFI_INVALID_PARAMETER
;
237 *TimerPeriod
= mWatchdogTimerPeriod
;
244 WatchdogTimerDriverInitialize (
245 IN EFI_HANDLE ImageHandle
,
246 IN EFI_SYSTEM_TABLE
*SystemTable
252 Initialize the Watchdog Timer Architectural Protocol driver
256 ImageHandle - ImageHandle of the loaded driver
258 SystemTable - Pointer to the System Table
262 EFI_SUCCESS - Timer Architectural Protocol created
264 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.
266 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.
274 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_SW_PC_INIT_BEGIN
)
277 // Make sure the Watchdog Timer Architectural Protocol is not already installed in the system
279 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL
, &gEfiWatchdogTimerArchProtocolGuid
);
282 // Create the timer event used to implement a simple watchdog timer
284 Status
= gBS
->CreateEvent (
285 EFI_EVENT_TIMER
| EFI_EVENT_NOTIFY_SIGNAL
,
287 WatchdogTimerDriverExpires
,
291 ASSERT_EFI_ERROR (Status
);
294 // Install the Watchdog Timer Arch Protocol onto a new handle
296 Status
= gBS
->InstallMultipleProtocolInterfaces (
297 &mWatchdogTimerHandle
,
298 &gEfiWatchdogTimerArchProtocolGuid
,
302 ASSERT_EFI_ERROR (Status
);
306 (EFI_COMPUTING_UNIT_HOST_PROCESSOR
| EFI_SW_PC_INIT_END
)