3 Copyright (c) 2004, 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 UNIX Emulation Timer Architectural Protocol Driver as defined in DXE CIS
20 This Timer module uses an UNIX Thread to simulate the timer-tick driven
21 timer service. In the future, the Thread creation should possibly be
22 abstracted by the CPU architectural protocol
29 // Pointer to the CPU Architectural Protocol instance
31 EFI_CPU_ARCH_PROTOCOL
*mCpu
;
34 // The Timer Architectural Protocol that this driver produces
36 EFI_TIMER_ARCH_PROTOCOL mTimer
= {
37 UnixTimerDriverRegisterHandler
,
38 UnixTimerDriverSetTimerPeriod
,
39 UnixTimerDriverGetTimerPeriod
,
40 UnixTimerDriverGenerateSoftInterrupt
44 // The notification function to call on every timer interrupt
46 EFI_TIMER_NOTIFY mTimerNotifyFunction
= NULL
;
49 // The current period of the timer interrupt
51 UINT64 mTimerPeriodMs
;
55 TimerCallback (UINT64 DeltaMs
)
60 TODO: Add function description
64 wTimerID - TODO: add argument description
65 msg - TODO: add argument description
66 dwUser - TODO: add argument description
67 dw1 - TODO: add argument description
68 dw2 - TODO: add argument description
72 TODO: add return values
77 EFI_TIMER_NOTIFY CallbackFunction
;
80 OriginalTPL
= gBS
->RaiseTPL (TPL_HIGH_LEVEL
);
82 if (OriginalTPL
< TPL_HIGH_LEVEL
) {
83 CallbackFunction
= mTimerNotifyFunction
;
86 // Only invoke the callback function if a Non-NULL handler has been
87 // registered. Assume all other handlers are legal.
89 if (CallbackFunction
!= NULL
) {
90 CallbackFunction ((UINT64
) (DeltaMs
* 10000));
94 gBS
->RestoreTPL (OriginalTPL
);
100 UnixTimerDriverRegisterHandler (
101 IN EFI_TIMER_ARCH_PROTOCOL
*This
,
102 IN EFI_TIMER_NOTIFY NotifyFunction
108 This function registers the handler NotifyFunction so it is called every time
109 the timer interrupt fires. It also passes the amount of time since the last
110 handler call to the NotifyFunction. If NotifyFunction is NULL, then the
111 handler is unregistered. If the handler is registered, then EFI_SUCCESS is
112 returned. If the CPU does not support registering a timer interrupt handler,
113 then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler
114 when a handler is already registered, then EFI_ALREADY_STARTED is returned.
115 If an attempt is made to unregister a handler when a handler is not registered,
116 then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to
117 register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
122 This - The EFI_TIMER_ARCH_PROTOCOL instance.
124 NotifyFunction - The function to call when a timer interrupt fires. This
125 function executes at TPL_HIGH_LEVEL. The DXE Core will
126 register a handler for the timer interrupt, so it can know
127 how much time has passed. This information is used to
128 signal timer based events. NULL will unregister the handler.
132 EFI_SUCCESS - The timer handler was registered.
134 EFI_UNSUPPORTED - The platform does not support timer interrupts.
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.
142 EFI_DEVICE_ERROR - The timer handler could not be registered.
147 // Check for invalid parameters
149 if (NotifyFunction
== NULL
&& mTimerNotifyFunction
== NULL
) {
150 return EFI_INVALID_PARAMETER
;
153 if (NotifyFunction
!= NULL
&& mTimerNotifyFunction
!= NULL
) {
154 return EFI_ALREADY_STARTED
;
157 if (NotifyFunction
== NULL
) {
159 gUnix
->SetTimer (0, TimerCallback
);
160 } else if (mTimerNotifyFunction
== NULL
) {
162 gUnix
->SetTimer (mTimerPeriodMs
, TimerCallback
);
164 mTimerNotifyFunction
= NotifyFunction
;
171 UnixTimerDriverSetTimerPeriod (
172 IN EFI_TIMER_ARCH_PROTOCOL
*This
,
173 IN UINT64 TimerPeriod
179 This function adjusts the period of timer interrupts to the value specified
180 by TimerPeriod. If the timer period is updated, then the selected timer
181 period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If
182 the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
183 If an error occurs while attempting to update the timer period, then the
184 timer hardware will be put back in its state prior to this call, and
185 EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt
186 is disabled. This is not the same as disabling the CPU's interrupts.
187 Instead, it must either turn off the timer hardware, or it must adjust the
188 interrupt controller so that a CPU interrupt is not generated when the timer
193 This - The EFI_TIMER_ARCH_PROTOCOL instance.
195 TimerPeriod - The rate to program the timer interrupt in 100 nS units. If
196 the timer hardware is not programmable, then EFI_UNSUPPORTED is
197 returned. If the timer is programmable, then the timer period
198 will be rounded up to the nearest timer period that is supported
199 by the timer hardware. If TimerPeriod is set to 0, then the
200 timer interrupts will be disabled.
204 EFI_SUCCESS - The timer period was changed.
206 EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt.
208 EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.
214 // If TimerPeriod is 0, then the timer thread should be canceled
215 // If the TimerPeriod is valid, then create and/or adjust the period of the timer thread
218 || ((TimerPeriod
> TIMER_MINIMUM_VALUE
)
219 && (TimerPeriod
< TIMER_MAXIMUM_VALUE
))) {
220 mTimerPeriodMs
= DivU64x32 (TimerPeriod
+ 5000, 10000);
222 gUnix
->SetTimer (mTimerPeriodMs
, TimerCallback
);
230 UnixTimerDriverGetTimerPeriod (
231 IN EFI_TIMER_ARCH_PROTOCOL
*This
,
232 OUT UINT64
*TimerPeriod
238 This function retrieves the period of timer interrupts in 100 ns units,
239 returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod
240 is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is
241 returned, then the timer is currently disabled.
245 This - The EFI_TIMER_ARCH_PROTOCOL instance.
247 TimerPeriod - A pointer to the timer period to retrieve in 100 ns units. If
248 0 is returned, then the timer is currently disabled.
252 EFI_SUCCESS - The timer period was returned in TimerPeriod.
254 EFI_INVALID_PARAMETER - TimerPeriod is NULL.
258 if (TimerPeriod
== NULL
) {
259 return EFI_INVALID_PARAMETER
;
262 *TimerPeriod
= mTimerPeriodMs
* 10000;
269 UnixTimerDriverGenerateSoftInterrupt (
270 IN EFI_TIMER_ARCH_PROTOCOL
*This
276 This function generates a soft timer interrupt. If the platform does not support soft
277 timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
278 If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
279 service, then a soft timer interrupt will be generated. If the timer interrupt is
280 enabled when this service is called, then the registered handler will be invoked. The
281 registered handler should not be able to distinguish a hardware-generated timer
282 interrupt from a software-generated timer interrupt.
286 This - The EFI_TIMER_ARCH_PROTOCOL instance.
290 EFI_SUCCESS - The soft timer interrupt was generated.
292 EFI_UNSUPPORTEDT - The platform does not support the generation of soft timer interrupts.
296 return EFI_UNSUPPORTED
;
301 UnixTimerDriverInitialize (
302 IN EFI_HANDLE ImageHandle
,
303 IN EFI_SYSTEM_TABLE
*SystemTable
309 Initialize the Timer Architectural Protocol driver
313 ImageHandle - ImageHandle of the loaded driver
315 SystemTable - Pointer to the System Table
319 EFI_SUCCESS - Timer Architectural Protocol created
321 EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.
323 EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.
331 // Make sure the Timer Architectural Protocol is not already installed in the system
333 ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL
, &gEfiTimerArchProtocolGuid
);
336 // Get the CPU Architectural Protocol instance
338 Status
= gBS
->LocateProtocol (&gEfiCpuArchProtocolGuid
, NULL
, (void *)&mCpu
);
339 ASSERT_EFI_ERROR (Status
);
342 // Install the Timer Architectural Protocol onto a new handle
345 Status
= gBS
->InstallProtocolInterface (
347 &gEfiTimerArchProtocolGuid
,
348 EFI_NATIVE_INTERFACE
,
351 if (EFI_ERROR (Status
)) {
356 // Start the timer thread at the default timer period
358 Status
= mTimer
.SetTimerPeriod (&mTimer
, DEFAULT_TIMER_TICK_DURATION
);
359 if (EFI_ERROR (Status
)) {