[mirror_edk2.git] / EmbeddedPkg / TemplateTimerDxe / Timer.c

/** @file\r
  Template for Timer Architecture Protocol driver of the ARM flavor\r
\r
  Copyright (c) 2008-2009, Apple Inc. All rights reserved.\r
  \r
  All rights reserved. This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
\r
#include <PiDxe.h>\r
\r
#include <Library/BaseLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/BaseMemoryLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
#include <Library/UefiLib.h>\r
#include <Library/PcdLib.h>\r
#include <Library/IoLib.h>\r
\r
#include <Protocol/Timer.h>\r
#include <Protocol/HardwareInterrupt.h>\r
\r
//\r
// Get Base Address of timer block from platform .DSC file\r
//\r
#define TIMER_BASE ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00c0)\r
\r
\r
#define TIMER_CMD    ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000004)\r
#define TIMER_DATA   ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000008)\r
\r
//\r
// The notification function to call on every timer interrupt.\r
// A bug in the compiler prevents us from initializing this here.\r
//\r
volatile EFI_TIMER_NOTIFY mTimerNotifyFunction;\r
\r
//\r
// The current period of the timer interrupt\r
//\r
volatile UINT64           mTimerPeriod = 0;\r
\r
//\r
// Cached copy of the Hardware Interrupt protocol instance\r
//\r
EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;\r
\r
\r
/**\r
  C Interrupt Handler calledin the interrupt context when Source interrupt is active.\r
\r
  @param Source         Source of the interrupt. Hardware routing off a specific platform defines\r
                        what source means.\r
  @param SystemContext  Pointer to system register context. Mostly used by debuggers and will\r
                        update the system context after the return from the interrupt if \r
                        modified. Don't change these values unless you know what you are doing\r
\r
**/\r
VOID\r
EFIAPI\r
TimerInterruptHandler (\r
	IN HARDWARE_INTERRUPT_SOURCE		Source,\r
  IN  EFI_SYSTEM_CONTEXT          SystemContext     	\r
	)\r
{\r
	EFI_TPL							OriginalTPL;\r
\r
  // Mask all interrupts\r
	OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
  MmioWrite32 (TIMER_CMD, 0);\r
\r
	if (mTimerNotifyFunction) {\r
		mTimerNotifyFunction (mTimerPeriod);\r
	}\r
\r
  // restore state\r
	gBS->RestoreTPL (OriginalTPL);\r
}\r
\r
\r
\r
/**\r
  This function registers the handler NotifyFunction so it is called every time \r
  the timer interrupt fires.  It also passes the amount of time since the last \r
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the \r
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is \r
  returned.  If the CPU does not support registering a timer interrupt handler, \r
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler \r
  when a handler is already registered, then EFI_ALREADY_STARTED is returned.  \r
  If an attempt is made to unregister a handler when a handler is not registered, \r
  then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to \r
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR \r
  is returned.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  NotifyFunction   The function to call when a timer interrupt fires. This\r
                           function executes at TPL_HIGH_LEVEL. The DXE Core will\r
                           register a handler for the timer interrupt, so it can know\r
                           how much time has passed. This information is used to\r
                           signal timer based events. NULL will unregister the handler.\r
\r
  @retval EFI_SUCCESS           The timer handler was registered.\r
  @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.\r
  @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already\r
                                registered.\r
  @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not\r
                                previously registered.\r
  @retval EFI_DEVICE_ERROR      The timer handler could not be registered.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverRegisterHandler (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN EFI_TIMER_NOTIFY         NotifyFunction\r
  )\r
{\r
  //\r
  // Check for invalid parameters\r
  //\r
  if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  mTimerNotifyFunction = NotifyFunction;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
\r
\r
/**\r
  This function adjusts the period of timer interrupts to the value specified \r
  by TimerPeriod.  If the timer period is updated, then the selected timer \r
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If \r
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.  \r
  If an error occurs while attempting to update the timer period, then the \r
  timer hardware will be put back in its state prior to this call, and \r
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt \r
  is disabled.  This is not the same as disabling the CPU's interrupts.  \r
  Instead, it must either turn off the timer hardware, or it must adjust the \r
  interrupt controller so that a CPU interrupt is not generated when the timer \r
  interrupt fires. \r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If\r
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
                           returned. If the timer is programmable, then the timer period\r
                           will be rounded up to the nearest timer period that is supported\r
                           by the timer hardware. If TimerPeriod is set to 0, then the\r
                           timer interrupts will be disabled.\r
\r
  @retval EFI_SUCCESS           The timer period was changed.\r
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.\r
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverSetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN UINT64                   TimerPeriod\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT64      TimerCount;\r
  \r
  if (TimerPeriod == 0) {\r
    //\r
    // Disable interrupt 0 and timer\r
    //\r
    MmioAnd32 (TIMER_DATA, 0);\r
\r
		Status = gInterrupt->DisableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector));    \r
  } else {\r
		//\r
		// Convert TimerPeriod into Timer F counts\r
		//\r
		TimerCount = DivU64x32 (TimerPeriod + 5, 10);\r
\r
		//\r
		// Program Timer F with the new count value\r
		//\r
		MmioWrite32 (TIMER_DATA, (UINT32)TimerCount);\r
\r
		//\r
		// Enable interrupt and initialize and enable timer.\r
		//\r
		MmioOr32 (TIMER_CMD, 0x11);\r
\r
		Status = gInterrupt->EnableInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector));    \r
  }\r
\r
	//\r
	// Save the new timer period\r
	//\r
	mTimerPeriod = TimerPeriod;\r
  return Status;\r
}\r
\r
\r
/**\r
  This function retrieves the period of timer interrupts in 100 ns units, \r
  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod \r
  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is \r
  returned, then the timer is currently disabled.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
  @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If\r
                           0 is returned, then the timer is currently disabled.\r
\r
  @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.\r
  @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL   *This,\r
  OUT UINT64                   *TimerPeriod\r
  )\r
{\r
  if (TimerPeriod == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *TimerPeriod = mTimerPeriod;\r
  return EFI_SUCCESS;\r
}\r
\r
\r
\r
/**\r
  This function generates a soft timer interrupt. If the platform does not support soft \r
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned. \r
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler() \r
  service, then a soft timer interrupt will be generated. If the timer interrupt is \r
  enabled when this service is called, then the registered handler will be invoked. The \r
  registered handler should not be able to distinguish a hardware-generated timer \r
  interrupt from a software-generated timer interrupt.\r
\r
  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  @retval EFI_SUCCESS           The soft timer interrupt was generated.\r
  @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGenerateSoftInterrupt (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This\r
  )\r
{\r
  return EFI_UNSUPPORTED;\r
}\r
\r
\r
/**\r
  Interface stucture for the Timer Architectural Protocol.\r
\r
  @par Protocol Description:\r
  This protocol provides the services to initialize a periodic timer \r
  interrupt, and to register a handler that is called each time the timer\r
  interrupt fires.  It may also provide a service to adjust the rate of the\r
  periodic timer interrupt.  When a timer interrupt occurs, the handler is \r
  passed the amount of time that has passed since the previous timer \r
  interrupt.\r
\r
  @param RegisterHandler\r
  Registers a handler that will be called each time the \r
  timer interrupt fires.  TimerPeriod defines the minimum \r
  time between timer interrupts, so TimerPeriod will also \r
  be the minimum time between calls to the registered \r
  handler.\r
\r
  @param SetTimerPeriod\r
  Sets the period of the timer interrupt in 100 nS units.  \r
  This function is optional, and may return EFI_UNSUPPORTED.  \r
  If this function is supported, then the timer period will \r
  be rounded up to the nearest supported timer period.\r
\r
  @param GetTimerPeriod\r
  Retrieves the period of the timer interrupt in 100 nS units.\r
\r
  @param GenerateSoftInterrupt\r
  Generates a soft timer interrupt that simulates the firing of \r
  the timer interrupt. This service can be used to invoke the \r
  registered handler if the timer interrupt has been masked for \r
  a period of time.\r
\r
**/\r
EFI_TIMER_ARCH_PROTOCOL   gTimer = {\r
  TimerDriverRegisterHandler,\r
  TimerDriverSetTimerPeriod,\r
  TimerDriverGetTimerPeriod,\r
  TimerDriverGenerateSoftInterrupt\r
};\r
\r
EFI_HANDLE  gTimerHandle = NULL;\r
\r
\r
/**\r
  Initialize the state information for the Timer Architectural Protocol\r
\r
  @param  ImageHandle   of the loaded driver\r
  @param  SystemTable   Pointer to the System Table\r
\r
  @retval EFI_SUCCESS           Protocol registered\r
  @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure\r
  @retval EFI_DEVICE_ERROR      Hardware problems\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerInitialize (\r
  IN EFI_HANDLE         ImageHandle,\r
  IN EFI_SYSTEM_TABLE   *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
\r
	//\r
	// Find the interrupt controller protocol.  ASSERT if not found.\r
	//\r
	Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, ( VOID ** )&gInterrupt);\r
	ASSERT_EFI_ERROR (Status);\r
\r
  MmioWrite32 (TIMER_CMD, 0x01);\r
\r
  //\r
  // Force the timer to be disabled\r
  //\r
  Status = TimerDriverSetTimerPeriod (&gTimer, 0);\r
	ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Install interrupt handler\r
  //\r
  Status = gInterrupt->RegisterInterruptSource (gInterrupt,  FixedPcdGet32 (PcdTimerVector), TimerInterruptHandler);\r
	ASSERT_EFI_ERROR (Status);\r
\r
	//\r
	// Force the timer to be enabled at its default period\r
	//\r
	Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32 (PcdTimerPeriod));\r
	ASSERT_EFI_ERROR (Status);\r
\r
\r
  //\r
  // Install the Timer Architectural Protocol onto a new handle\r
  //\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &gTimerHandle,\r
                  &gEfiTimerArchProtocolGuid,  &gTimer,\r
                  NULL\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r
\r
Commit	Line	Data
2ef2b01e A	1	/** @file\r
	2	Template for Timer Architecture Protocol driver of the ARM flavor\r
	3	\r
	4	Copyright (c) 2008-2009, Apple Inc. All rights reserved.\r
	5	\r
	6	All rights reserved. This program and the accompanying materials\r
	7	are licensed and made available under the terms and conditions of the BSD License\r
	8	which accompanies this distribution. The full text of the license may be found at\r
	9	http://opensource.org/licenses/bsd-license.php\r
	10	\r
	11	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	12	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	13	\r
	14	**/\r
	15	\r
	16	\r
	17	#include <PiDxe.h>\r
	18	\r
	19	#include <Library/BaseLib.h>\r
	20	#include <Library/DebugLib.h>\r
	21	#include <Library/BaseMemoryLib.h>\r
	22	#include <Library/UefiBootServicesTableLib.h>\r
	23	#include <Library/UefiLib.h>\r
	24	#include <Library/PcdLib.h>\r
	25	#include <Library/IoLib.h>\r
	26	\r
	27	#include <Protocol/Timer.h>\r
	28	#include <Protocol/HardwareInterrupt.h>\r
	29	\r
	30	//\r
	31	// Get Base Address of timer block from platform .DSC file\r
	32	//\r
	33	#define TIMER_BASE ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00c0)\r
	34	\r
	35	\r
	36	#define TIMER_CMD ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000004)\r
	37	#define TIMER_DATA ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000008)\r
	38	\r
	39	//\r
	40	// The notification function to call on every timer interrupt.\r
	41	// A bug in the compiler prevents us from initializing this here.\r
	42	//\r
	43	volatile EFI_TIMER_NOTIFY mTimerNotifyFunction;\r
	44	\r
	45	//\r
	46	// The current period of the timer interrupt\r
	47	//\r
	48	volatile UINT64 mTimerPeriod = 0;\r
	49	\r
	50	//\r
	51	// Cached copy of the Hardware Interrupt protocol instance\r
	52	//\r
	53	EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;\r
	54	\r
	55	\r
	56	/**\r
	57	C Interrupt Handler calledin the interrupt context when Source interrupt is active.\r
	58	\r
	59	@param Source Source of the interrupt. Hardware routing off a specific platform defines\r
	60	what source means.\r
	61	@param SystemContext Pointer to system register context. Mostly used by debuggers and will\r
	62	update the system context after the return from the interrupt if \r
	63	modified. Don't change these values unless you know what you are doing\r
	64	\r
65	**/\r
66	VOID\r
67	EFIAPI\r
68	TimerInterruptHandler (\r
69	IN HARDWARE_INTERRUPT_SOURCE Source,\r
70	IN EFI_SYSTEM_CONTEXT SystemContext \r
71	)\r
72	{\r
73	EFI_TPL OriginalTPL;\r
74	\r
75	// Mask all interrupts\r
76	OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
77	\r
78	MmioWrite32 (TIMER_CMD, 0);\r
79	\r
80	if (mTimerNotifyFunction) {\r
81	mTimerNotifyFunction (mTimerPeriod);\r
82	}\r
83	\r
84	// restore state\r
85	gBS->RestoreTPL (OriginalTPL);\r
86	}\r
87	\r
88	\r
89	\r
90	/**\r
91	This function registers the handler NotifyFunction so it is called every time \r
92	the timer interrupt fires. It also passes the amount of time since the last \r
93	handler call to the NotifyFunction. If NotifyFunction is NULL, then the \r
94	handler is unregistered. If the handler is registered, then EFI_SUCCESS is \r
95	returned. If the CPU does not support registering a timer interrupt handler, \r
96	then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler \r
97	when a handler is already registered, then EFI_ALREADY_STARTED is returned. \r
98	If an attempt is made to unregister a handler when a handler is not registered, \r
99	then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to \r
100	register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR \r
101	is returned.\r
102	\r
103	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
104	@param NotifyFunction The function to call when a timer interrupt fires. This\r
105	function executes at TPL_HIGH_LEVEL. The DXE Core will\r
106	register a handler for the timer interrupt, so it can know\r
107	how much time has passed. This information is used to\r
108	signal timer based events. NULL will unregister the handler.\r
109	\r
110	@retval EFI_SUCCESS The timer handler was registered.\r
111	@retval EFI_UNSUPPORTED The platform does not support timer interrupts.\r
112	@retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already\r
113	registered.\r
114	@retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not\r
115	previously registered.\r
116	@retval EFI_DEVICE_ERROR The timer handler could not be registered.\r
117	\r
118	**/\r
119	EFI_STATUS\r
120	EFIAPI\r
121	TimerDriverRegisterHandler (\r
122	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
123	IN EFI_TIMER_NOTIFY NotifyFunction\r
124	)\r
125	{\r
126	//\r
127	// Check for invalid parameters\r
128	//\r
129	if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
130	return EFI_INVALID_PARAMETER;\r
131	}\r
132	\r
133	if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
134	return EFI_ALREADY_STARTED;\r
135	}\r
136	\r
137	mTimerNotifyFunction = NotifyFunction;\r
138	\r
139	return EFI_SUCCESS;\r
140	}\r
141	\r
142	\r
143	\r
144	/**\r
145	This function adjusts the period of timer interrupts to the value specified \r
146	by TimerPeriod. If the timer period is updated, then the selected timer \r
147	period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If \r
148	the timer hardware is not programmable, then EFI_UNSUPPORTED is returned. \r
149	If an error occurs while attempting to update the timer period, then the \r
150	timer hardware will be put back in its state prior to this call, and \r
151	EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt \r
152	is disabled. This is not the same as disabling the CPU's interrupts. \r
153	Instead, it must either turn off the timer hardware, or it must adjust the \r
154	interrupt controller so that a CPU interrupt is not generated when the timer \r
155	interrupt fires. \r
156	\r
157	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
158	@param TimerPeriod The rate to program the timer interrupt in 100 nS units. If\r
159	the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
160	returned. If the timer is programmable, then the timer period\r
161	will be rounded up to the nearest timer period that is supported\r
162	by the timer hardware. If TimerPeriod is set to 0, then the\r
163	timer interrupts will be disabled.\r
164	\r
165	@retval EFI_SUCCESS The timer period was changed.\r
166	@retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.\r
167	@retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error.\r
168	\r
169	**/\r
170	EFI_STATUS\r
171	EFIAPI\r
172	TimerDriverSetTimerPeriod (\r
173	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
174	IN UINT64 TimerPeriod\r
175	)\r
176	{\r
177	EFI_STATUS Status;\r
178	UINT64 TimerCount;\r
179	\r
180	if (TimerPeriod == 0) {\r
181	//\r
182	// Disable interrupt 0 and timer\r
183	//\r
184	MmioAnd32 (TIMER_DATA, 0);\r
185	\r
186	Status = gInterrupt->DisableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector)); \r
187	} else {\r
188	//\r
189	// Convert TimerPeriod into Timer F counts\r
190	//\r
191	TimerCount = DivU64x32 (TimerPeriod + 5, 10);\r
192	\r
193	//\r
194	// Program Timer F with the new count value\r
195	//\r
196	MmioWrite32 (TIMER_DATA, (UINT32)TimerCount);\r
197	\r
198	//\r
199	// Enable interrupt and initialize and enable timer.\r
200	//\r
201	MmioOr32 (TIMER_CMD, 0x11);\r
202	\r
203	Status = gInterrupt->EnableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector)); \r
204	}\r
205	\r
206	//\r
207	// Save the new timer period\r
208	//\r
209	mTimerPeriod = TimerPeriod;\r
210	return Status;\r
211	}\r
212	\r
213	\r
214	/**\r
215	This function retrieves the period of timer interrupts in 100 ns units, \r
216	returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod \r
217	is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is \r
218	returned, then the timer is currently disabled.\r
219	\r
220	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
221	@param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If\r
222	0 is returned, then the timer is currently disabled.\r
223	\r
224	@retval EFI_SUCCESS The timer period was returned in TimerPeriod.\r
225	@retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r
226	\r
227	**/\r
228	EFI_STATUS\r
229	EFIAPI\r
230	TimerDriverGetTimerPeriod (\r
231	IN EFI_TIMER_ARCH_PROTOCOL *This,\r
232	OUT UINT64 *TimerPeriod\r
233	)\r
234	{\r
235	if (TimerPeriod == NULL) {\r
236	return EFI_INVALID_PARAMETER;\r
237	}\r
238	\r
239	*TimerPeriod = mTimerPeriod;\r
240	return EFI_SUCCESS;\r
241	}\r
242	\r
243	\r
244	\r
245	/**\r
246	This function generates a soft timer interrupt. If the platform does not support soft \r
247	timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned. \r
248	If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler() \r
249	service, then a soft timer interrupt will be generated. If the timer interrupt is \r
250	enabled when this service is called, then the registered handler will be invoked. The \r
251	registered handler should not be able to distinguish a hardware-generated timer \r
252	interrupt from a software-generated timer interrupt.\r
253	\r
254	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
255	\r
256	@retval EFI_SUCCESS The soft timer interrupt was generated.\r
257	@retval EFI_UNSUPPORTED The platform does not support the generation of soft timer interrupts.\r
258	\r
259	**/\r
260	EFI_STATUS\r
261	EFIAPI\r
262	TimerDriverGenerateSoftInterrupt (\r
263	IN EFI_TIMER_ARCH_PROTOCOL *This\r
264	)\r
265	{\r
266	return EFI_UNSUPPORTED;\r
267	}\r
268	\r
269	\r
270	/**\r
271	Interface stucture for the Timer Architectural Protocol.\r
272	\r
273	@par Protocol Description:\r
274	This protocol provides the services to initialize a periodic timer \r
275	interrupt, and to register a handler that is called each time the timer\r
276	interrupt fires. It may also provide a service to adjust the rate of the\r
277	periodic timer interrupt. When a timer interrupt occurs, the handler is \r
278	passed the amount of time that has passed since the previous timer \r
279	interrupt.\r
280	\r
281	@param RegisterHandler\r
282	Registers a handler that will be called each time the \r
283	timer interrupt fires. TimerPeriod defines the minimum \r
284	time between timer interrupts, so TimerPeriod will also \r
285	be the minimum time between calls to the registered \r
286	handler.\r
287	\r
288	@param SetTimerPeriod\r
289	Sets the period of the timer interrupt in 100 nS units. \r
290	This function is optional, and may return EFI_UNSUPPORTED. \r
291	If this function is supported, then the timer period will \r
292	be rounded up to the nearest supported timer period.\r
293	\r
294	@param GetTimerPeriod\r
295	Retrieves the period of the timer interrupt in 100 nS units.\r
296	\r
297	@param GenerateSoftInterrupt\r
298	Generates a soft timer interrupt that simulates the firing of \r
299	the timer interrupt. This service can be used to invoke the \r
300	registered handler if the timer interrupt has been masked for \r
301	a period of time.\r
302	\r
303	**/\r
304	EFI_TIMER_ARCH_PROTOCOL gTimer = {\r
305	TimerDriverRegisterHandler,\r
306	TimerDriverSetTimerPeriod,\r
307	TimerDriverGetTimerPeriod,\r
308	TimerDriverGenerateSoftInterrupt\r
309	};\r
310	\r
311	EFI_HANDLE gTimerHandle = NULL;\r
312	\r
313	\r
314	/**\r
315	Initialize the state information for the Timer Architectural Protocol\r
316	\r
317	@param ImageHandle of the loaded driver\r
318	@param SystemTable Pointer to the System Table\r
319	\r
320	@retval EFI_SUCCESS Protocol registered\r
321	@retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure\r
322	@retval EFI_DEVICE_ERROR Hardware problems\r
323	\r
324	**/\r
325	EFI_STATUS\r
326	EFIAPI\r
327	TimerInitialize (\r
328	IN EFI_HANDLE ImageHandle,\r
329	IN EFI_SYSTEM_TABLE *SystemTable\r
330	)\r
331	{\r
332	EFI_STATUS Status;\r
333	\r
334	//\r
335	// Find the interrupt controller protocol. ASSERT if not found.\r
336	//\r
337	Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, ( VOID ** )&gInterrupt);\r
338	ASSERT_EFI_ERROR (Status);\r
339	\r
340	MmioWrite32 (TIMER_CMD, 0x01);\r
341	\r
342	//\r
343	// Force the timer to be disabled\r
344	//\r
345	Status = TimerDriverSetTimerPeriod (&gTimer, 0);\r
346	ASSERT_EFI_ERROR (Status);\r
347	\r
348	//\r
349	// Install interrupt handler\r
350	//\r
351	Status = gInterrupt->RegisterInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector), TimerInterruptHandler);\r
352	ASSERT_EFI_ERROR (Status);\r
353	\r
354	//\r
355	// Force the timer to be enabled at its default period\r
356	//\r
357	Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32 (PcdTimerPeriod));\r
358	ASSERT_EFI_ERROR (Status);\r
359	\r
360	\r
361	//\r
362	// Install the Timer Architectural Protocol onto a new handle\r
363	//\r
364	Status = gBS->InstallMultipleProtocolInterfaces (\r
365	&gTimerHandle,\r
366	&gEfiTimerArchProtocolGuid, &gTimer,\r
367	NULL\r
368	);\r
369	ASSERT_EFI_ERROR (Status);\r
370	\r
371	return Status;\r
372	}\r
373	\r