[mirror_edk2.git] / ArmEbPkg / TimerDxe / Timer.c

/** @file
  Template for Timer Architecture Protocol driver of the ARM flavor

  Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
  
  This program and the accompanying materials                          
  are licensed and made available under the terms and conditions of the BSD License         
  which accompanies this distribution.  The full text of the license may be found at        
  http://opensource.org/licenses/bsd-license.php                                            

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

**/


#include <PiDxe.h>

#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/PcdLib.h>
#include <Library/IoLib.h>
#include <Library/OmapLib.h>

#include <Protocol/Timer.h>
#include <Protocol/HardwareInterrupt.h>

#include <ArmEb/ArmEb.h>


// The notification function to call on every timer interrupt.
volatile EFI_TIMER_NOTIFY      mTimerNotifyFunction   = (EFI_TIMER_NOTIFY)NULL;


// The current period of the timer interrupt
volatile UINT64 mTimerPeriod = 0;

// Cached copy of the Hardware Interrupt protocol instance
EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;

// Cached interrupt vector
UINTN  gVector;


/**

  C Interrupt Handler calledin the interrupt context when Source interrupt is active.


  @param Source         Source of the interrupt. Hardware routing off a specific platform defines
                        what source means.

  @param SystemContext  Pointer to system register context. Mostly used by debuggers and will
                        update the system context after the return from the interrupt if 
                        modified. Don't change these values unless you know what you are doing

**/
VOID
EFIAPI
TimerInterruptHandler (
  IN  HARDWARE_INTERRUPT_SOURCE   Source,
  IN  EFI_SYSTEM_CONTEXT          SystemContext       
  )
{
  EFI_TPL OriginalTPL;

  //
  // DXE core uses this callback for the EFI timer tick. The DXE core uses locks 
  // that raise to TPL_HIGH and then restore back to current level. Thus we need
  // to make sure TPL level is set to TPL_HIGH while we are handling the timer tick. 
  //
  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);

  // clear the periodic interrupt\r
  MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_INT_CLR_REG, 0);

  // signal end of interrupt early to help avoid losing subsequent ticks from long duration handlers
  gInterrupt->EndOfInterrupt (gInterrupt, Source);

  if (mTimerNotifyFunction) {
    mTimerNotifyFunction (mTimerPeriod);
  }

  gBS->RestoreTPL (OriginalTPL);
}


/**
  This function registers the handler NotifyFunction so it is called every time 
  the timer interrupt fires.  It also passes the amount of time since the last 
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the 
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is 
  returned.  If the CPU does not support registering a timer interrupt handler, 
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler 
  when a handler is already registered, then EFI_ALREADY_STARTED is returned.  
  If an attempt is made to unregister a handler when a handler is not registered, 
  then EFI_INVALID_PARAMETER is returned.  If an error occurs attempting to 
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR 
  is returned.

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  NotifyFunction   The function to call when a timer interrupt fires. This
                           function executes at TPL_HIGH_LEVEL. The DXE Core will
                           register a handler for the timer interrupt, so it can know
                           how much time has passed. This information is used to
                           signal timer based events. NULL will unregister the handler.
  @retval EFI_SUCCESS           The timer handler was registered.
  @retval EFI_UNSUPPORTED       The platform does not support timer interrupts.
  @retval EFI_ALREADY_STARTED   NotifyFunction is not NULL, and a handler is already
                                registered.
  @retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
                                previously registered.
  @retval EFI_DEVICE_ERROR      The timer handler could not be registered.

**/
EFI_STATUS
EFIAPI
TimerDriverRegisterHandler (
  IN EFI_TIMER_ARCH_PROTOCOL  *This,
  IN EFI_TIMER_NOTIFY         NotifyFunction
  )
{
  if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {
    return EFI_INVALID_PARAMETER;
  }

  if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {
    return EFI_ALREADY_STARTED;
  }

  mTimerNotifyFunction = NotifyFunction;

  return EFI_SUCCESS;
}

/**

  This function adjusts the period of timer interrupts to the value specified 
  by TimerPeriod.  If the timer period is updated, then the selected timer 
  period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned.  If 
  the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.  
  If an error occurs while attempting to update the timer period, then the 
  timer hardware will be put back in its state prior to this call, and 
  EFI_DEVICE_ERROR is returned.  If TimerPeriod is 0, then the timer interrupt 
  is disabled.  This is not the same as disabling the CPU's interrupts.  
  Instead, it must either turn off the timer hardware, or it must adjust the 
  interrupt controller so that a CPU interrupt is not generated when the timer 
  interrupt fires. 

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  TimerPeriod      The rate to program the timer interrupt in 100 nS units. If
                           the timer hardware is not programmable, then EFI_UNSUPPORTED is
                           returned. If the timer is programmable, then the timer period
                           will be rounded up to the nearest timer period that is supported
                           by the timer hardware. If TimerPeriod is set to 0, then the
                           timer interrupts will be disabled.


  @retval EFI_SUCCESS           The timer period was changed.
  @retval EFI_UNSUPPORTED       The platform cannot change the period of the timer interrupt.
  @retval EFI_DEVICE_ERROR      The timer period could not be changed due to a device error.

**/
EFI_STATUS
EFIAPI
TimerDriverSetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL  *This,
  IN UINT64                   TimerPeriod
  )
{
  EFI_STATUS  Status;
  UINT64      TimerTicks;\r
  
  // always disable the timer
  MmioAnd32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, ~SP804_TIMER_CTRL_ENABLE);

  if (TimerPeriod == 0) {
    // leave timer disabled from above, and...\r
    // disable timer 0/1 interrupt for a TimerPeriod of 0\r
    
    Status = gInterrupt->DisableInterruptSource (gInterrupt, gVector);    
  } else {  
    // Convert TimerPeriod into 1MHz clock counts (us units = 100ns units / 10)\r
    TimerTicks = DivU64x32 (TimerPeriod, 10, NULL);\r
   \r
    // if it's larger than 32-bits, pin to highest value\r
    if (TimerTicks > 0xffffffff) {\r
      TimerTicks = 0xffffffff;\r
    }\r
\r
    // Program the SP804 timer with the new count value\r
    MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_LOAD_REG, TimerTicks);\r
    \r
    // enable the timer\r
    MmioOr32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);\r
\r
    // enable timer 0/1 interrupts\r
    Status = gInterrupt->EnableInterruptSource (gInterrupt, gVector);    
  }

  //
  // Save the new timer period
  //
  mTimerPeriod = TimerPeriod;
  return Status;
}


/**
  This function retrieves the period of timer interrupts in 100 ns units, 
  returns that value in TimerPeriod, and returns EFI_SUCCESS.  If TimerPeriod 
  is NULL, then EFI_INVALID_PARAMETER is returned.  If a TimerPeriod of 0 is 
  returned, then the timer is currently disabled.

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.
  @param  TimerPeriod      A pointer to the timer period to retrieve in 100 ns units. If
                           0 is returned, then the timer is currently disabled.


  @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.
  @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.

**/
EFI_STATUS
EFIAPI
TimerDriverGetTimerPeriod (
  IN EFI_TIMER_ARCH_PROTOCOL   *This,
  OUT UINT64                   *TimerPeriod
  )
{
  if (TimerPeriod == NULL) {
    return EFI_INVALID_PARAMETER;
  }

  *TimerPeriod = mTimerPeriod;
  return EFI_SUCCESS;
}

/**
  This function generates a soft timer interrupt. If the platform does not support soft 
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned. 
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler() 
  service, then a soft timer interrupt will be generated. If the timer interrupt is 
  enabled when this service is called, then the registered handler will be invoked. The 
  registered handler should not be able to distinguish a hardware-generated timer 
  interrupt from a software-generated timer interrupt.

  @param  This             The EFI_TIMER_ARCH_PROTOCOL instance.

  @retval EFI_SUCCESS           The soft timer interrupt was generated.
  @retval EFI_UNSUPPORTED       The platform does not support the generation of soft timer interrupts.

**/
EFI_STATUS
EFIAPI
TimerDriverGenerateSoftInterrupt (
  IN EFI_TIMER_ARCH_PROTOCOL  *This
  )
{
  return EFI_UNSUPPORTED;
}


/**
  Interface stucture for the Timer Architectural Protocol.

  @par Protocol Description:
  This protocol provides the services to initialize a periodic timer 
  interrupt, and to register a handler that is called each time the timer
  interrupt fires.  It may also provide a service to adjust the rate of the
  periodic timer interrupt.  When a timer interrupt occurs, the handler is 
  passed the amount of time that has passed since the previous timer 
  interrupt.

  @param RegisterHandler
  Registers a handler that will be called each time the 
  timer interrupt fires.  TimerPeriod defines the minimum 
  time between timer interrupts, so TimerPeriod will also 
  be the minimum time between calls to the registered 
  handler.

  @param SetTimerPeriod
  Sets the period of the timer interrupt in 100 nS units.  
  This function is optional, and may return EFI_UNSUPPORTED.  
  If this function is supported, then the timer period will 
  be rounded up to the nearest supported timer period.


  @param GetTimerPeriod
  Retrieves the period of the timer interrupt in 100 nS units.

  @param GenerateSoftInterrupt
  Generates a soft timer interrupt that simulates the firing of 
  the timer interrupt. This service can be used to invoke the   registered handler if the timer interrupt has been masked for 
  a period of time.

**/
EFI_TIMER_ARCH_PROTOCOL   gTimer = {
  TimerDriverRegisterHandler,
  TimerDriverSetTimerPeriod,
  TimerDriverGetTimerPeriod,
  TimerDriverGenerateSoftInterrupt
};


/**
  Initialize the state information for the Timer Architectural Protocol and
  the Timer Debug support protocol that allows the debugger to break into a
  running program.

  @param  ImageHandle   of the loaded driver
  @param  SystemTable   Pointer to the System Table

  @retval EFI_SUCCESS           Protocol registered
  @retval EFI_OUT_OF_RESOURCES  Cannot allocate protocol data structure
  @retval EFI_DEVICE_ERROR      Hardware problems

**/
EFI_STATUS
EFIAPI
TimerInitialize (
  IN EFI_HANDLE         ImageHandle,
  IN EFI_SYSTEM_TABLE   *SystemTable
  )
{
  EFI_HANDLE  Handle = NULL;
  EFI_STATUS  Status;
  UINT32      TimerBaseAddress;

  // configure free running timer (TIMER1) for 1MHz operation\r
  \r
  // AND disable clock, OR configure 1MHz clock\r
  MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER1_EN, SP810_SYS_CTRL_TIMER1_TIMCLK);  \r
\r
  // Renable timer\r
  MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER1_EN);  \r
    \r
\r
  // configure timer 1 for free running operation, 32 bits, no prescaler, interrupt disabled\r
  MmioWrite32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1);\r
\r
  // enable the free running timer\r
  MmioOr32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);\r
\r
  // record free running tick value (should be close to 0xffffffff)\r
  mLastTickCount = MmioRead32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CURRENT_REG);\r
\r
  // Disable the timer
  Status = TimerDriverSetTimerPeriod (&gTimer, 0);
  ASSERT_EFI_ERROR (Status);
\r
  // Install interrupt handler for SP804 timer 0/1 interrupts\r
  Status = mGic->RegisterInterruptHandler(mGic, EB_TIMER01_INTERRUPT_NUM, TimerInterruptHandler);\r
  ASSERT_EFI_ERROR (Status);\r

  // Install interrupt handler
  gVector = EB_TIMER01_INTERRUPT_NUM;
  Status = gInterrupt->RegisterInterruptSource (gInterrupt, gVector, TimerInterruptHandler);
  ASSERT_EFI_ERROR (Status);
\r
\r
  // configure periodic timer (TIMER0) for 1MHz operation\r
  MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER0_EN, SP810_SYS_CTRL_TIMER0_TIMCLK);\r
\r
  // Renable timer\r
  MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER0_EN);  \r
\r
  // configure timer 0 for periodic operation, 32 bits, no prescaler, and interrupt enabled\r
  MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_PERIODIC | SP804_TIMER_CTRL_32BIT | SP804_PRESCALE_DIV_1 | SP804_TIMER_CTRL_INT_ENABLE);\r


  // Set up default timer
  Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD
  ASSERT_EFI_ERROR (Status);

  // Install the Timer Architectural Protocol onto a new handle
  Status = gBS->InstallMultipleProtocolInterfaces(
                  &Handle,
                  &gEfiTimerArchProtocolGuid,      &gTimer,
                  NULL
                  );
  ASSERT_EFI_ERROR(Status);

  return Status;
}
Commit	Line	Data
5f4dc6dd	1	/** @file
	2	Template for Timer Architecture Protocol driver of the ARM flavor
	3
	4	Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
	5
	6	This program and the accompanying materials
	7	are licensed and made available under the terms and conditions of the BSD License
	8	which accompanies this distribution. The full text of the license may be found at
	9	http://opensource.org/licenses/bsd-license.php
	10
	11	THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
	12	WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
	13
	14	**/
	15
	16
	17	#include <PiDxe.h>
	18
	19	#include <Library/BaseLib.h>
	20	#include <Library/DebugLib.h>
	21	#include <Library/BaseMemoryLib.h>
	22	#include <Library/UefiBootServicesTableLib.h>
	23	#include <Library/UefiLib.h>
	24	#include <Library/PcdLib.h>
	25	#include <Library/IoLib.h>
	26	#include <Library/OmapLib.h>
	27
	28	#include <Protocol/Timer.h>
	29	#include <Protocol/HardwareInterrupt.h>
	30
	31	#include <ArmEb/ArmEb.h>
	32
	33
	34	// The notification function to call on every timer interrupt.
	35	volatile EFI_TIMER_NOTIFY mTimerNotifyFunction = (EFI_TIMER_NOTIFY)NULL;
	36
	37
	38	// The current period of the timer interrupt
	39	volatile UINT64 mTimerPeriod = 0;
	40
	41	// Cached copy of the Hardware Interrupt protocol instance
	42	EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;
	43
	44	// Cached interrupt vector
	45	UINTN gVector;
	46
	47
	48	/**
	49
	50	C Interrupt Handler calledin the interrupt context when Source interrupt is active.
	51
	52
	53	@param Source Source of the interrupt. Hardware routing off a specific platform defines
	54	what source means.
	55
	56	@param SystemContext Pointer to system register context. Mostly used by debuggers and will
	57	update the system context after the return from the interrupt if
	58	modified. Don't change these values unless you know what you are doing
	59
	60	**/
	61	VOID
	62	EFIAPI
	63	TimerInterruptHandler (
	64	IN HARDWARE_INTERRUPT_SOURCE Source,
65	IN EFI_SYSTEM_CONTEXT SystemContext
66	)
67	{
68	EFI_TPL OriginalTPL;
69
70	//
71	// DXE core uses this callback for the EFI timer tick. The DXE core uses locks
72	// that raise to TPL_HIGH and then restore back to current level. Thus we need
73	// to make sure TPL level is set to TPL_HIGH while we are handling the timer tick.
74	//
75	OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
76
77	// clear the periodic interrupt\r
78	MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_INT_CLR_REG, 0);
79
80	// signal end of interrupt early to help avoid losing subsequent ticks from long duration handlers
81	gInterrupt->EndOfInterrupt (gInterrupt, Source);
82
83	if (mTimerNotifyFunction) {
84	mTimerNotifyFunction (mTimerPeriod);
85	}
86
87	gBS->RestoreTPL (OriginalTPL);
88	}
89
90
91	/**
92	This function registers the handler NotifyFunction so it is called every time
93	the timer interrupt fires. It also passes the amount of time since the last
94	handler call to the NotifyFunction. If NotifyFunction is NULL, then the
95	handler is unregistered. If the handler is registered, then EFI_SUCCESS is
96	returned. If the CPU does not support registering a timer interrupt handler,
97	then EFI_UNSUPPORTED is returned. If an attempt is made to register a handler
98	when a handler is already registered, then EFI_ALREADY_STARTED is returned.
99	If an attempt is made to unregister a handler when a handler is not registered,
100	then EFI_INVALID_PARAMETER is returned. If an error occurs attempting to
101	register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
102	is returned.
103
104	@param This The EFI_TIMER_ARCH_PROTOCOL instance.
105	@param NotifyFunction The function to call when a timer interrupt fires. This
106	function executes at TPL_HIGH_LEVEL. The DXE Core will
107	register a handler for the timer interrupt, so it can know
108	how much time has passed. This information is used to
109	signal timer based events. NULL will unregister the handler.
110	@retval EFI_SUCCESS The timer handler was registered.
111	@retval EFI_UNSUPPORTED The platform does not support timer interrupts.
112	@retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already
113	registered.
114	@retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
115	previously registered.
116	@retval EFI_DEVICE_ERROR The timer handler could not be registered.
117
118	**/
119	EFI_STATUS
120	EFIAPI
121	TimerDriverRegisterHandler (
122	IN EFI_TIMER_ARCH_PROTOCOL *This,
123	IN EFI_TIMER_NOTIFY NotifyFunction
124	)
125	{
126	if ((NotifyFunction == NULL) && (mTimerNotifyFunction == NULL)) {
127	return EFI_INVALID_PARAMETER;
128	}
129
130	if ((NotifyFunction != NULL) && (mTimerNotifyFunction != NULL)) {
131	return EFI_ALREADY_STARTED;
132	}
133
134	mTimerNotifyFunction = NotifyFunction;
135
136	return EFI_SUCCESS;
137	}
138
139	/**
140
141	This function adjusts the period of timer interrupts to the value specified
142	by TimerPeriod. If the timer period is updated, then the selected timer
143	period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If
144	the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.
145	If an error occurs while attempting to update the timer period, then the
146	timer hardware will be put back in its state prior to this call, and
147	EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt
148	is disabled. This is not the same as disabling the CPU's interrupts.
149	Instead, it must either turn off the timer hardware, or it must adjust the
150	interrupt controller so that a CPU interrupt is not generated when the timer
151	interrupt fires.
152
153	@param This The EFI_TIMER_ARCH_PROTOCOL instance.
154	@param TimerPeriod The rate to program the timer interrupt in 100 nS units. If
155	the timer hardware is not programmable, then EFI_UNSUPPORTED is
156	returned. If the timer is programmable, then the timer period
157	will be rounded up to the nearest timer period that is supported
158	by the timer hardware. If TimerPeriod is set to 0, then the
159	timer interrupts will be disabled.
160
161
162	@retval EFI_SUCCESS The timer period was changed.
163	@retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.
164	@retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error.
165
166	**/
167	EFI_STATUS
168	EFIAPI
169	TimerDriverSetTimerPeriod (
170	IN EFI_TIMER_ARCH_PROTOCOL *This,
171	IN UINT64 TimerPeriod
172	)
173	{
174	EFI_STATUS Status;
175	UINT64 TimerTicks;\r
176
177	// always disable the timer
178	MmioAnd32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, ~SP804_TIMER_CTRL_ENABLE);
179
180	if (TimerPeriod == 0) {
181	// leave timer disabled from above, and...\r
182	// disable timer 0/1 interrupt for a TimerPeriod of 0\r
183
184	Status = gInterrupt->DisableInterruptSource (gInterrupt, gVector);
185	} else {
186	// Convert TimerPeriod into 1MHz clock counts (us units = 100ns units / 10)\r
187	TimerTicks = DivU64x32 (TimerPeriod, 10, NULL);\r
188	\r
189	// if it's larger than 32-bits, pin to highest value\r
190	if (TimerTicks > 0xffffffff) {\r
191	TimerTicks = 0xffffffff;\r
192	}\r
193	\r
194	// Program the SP804 timer with the new count value\r
195	MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_LOAD_REG, TimerTicks);\r
196	\r
197	// enable the timer\r
198	MmioOr32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);\r
199	\r
200	// enable timer 0/1 interrupts\r
201	Status = gInterrupt->EnableInterruptSource (gInterrupt, gVector);
202	}
203
204	//
205	// Save the new timer period
206	//
207	mTimerPeriod = TimerPeriod;
208	return Status;
209	}
210
211
212	/**
213	This function retrieves the period of timer interrupts in 100 ns units,
214	returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod
215	is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is
216	returned, then the timer is currently disabled.
217
218	@param This The EFI_TIMER_ARCH_PROTOCOL instance.
219	@param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If
220	0 is returned, then the timer is currently disabled.
221
222
223	@retval EFI_SUCCESS The timer period was returned in TimerPeriod.
224	@retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
225
226	**/
227	EFI_STATUS
228	EFIAPI
229	TimerDriverGetTimerPeriod (
230	IN EFI_TIMER_ARCH_PROTOCOL *This,
231	OUT UINT64 *TimerPeriod
232	)
233	{
234	if (TimerPeriod == NULL) {
235	return EFI_INVALID_PARAMETER;
236	}
237
238	*TimerPeriod = mTimerPeriod;
239	return EFI_SUCCESS;
240	}
241
242	/**
243	This function generates a soft timer interrupt. If the platform does not support soft
244	timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
245	If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
246	service, then a soft timer interrupt will be generated. If the timer interrupt is
247	enabled when this service is called, then the registered handler will be invoked. The
248	registered handler should not be able to distinguish a hardware-generated timer
249	interrupt from a software-generated timer interrupt.
250
251	@param This The EFI_TIMER_ARCH_PROTOCOL instance.
252
253	@retval EFI_SUCCESS The soft timer interrupt was generated.
254	@retval EFI_UNSUPPORTED The platform does not support the generation of soft timer interrupts.
255
256	**/
257	EFI_STATUS
258	EFIAPI
259	TimerDriverGenerateSoftInterrupt (
260	IN EFI_TIMER_ARCH_PROTOCOL *This
261	)
262	{
263	return EFI_UNSUPPORTED;
264	}
265
266
267
268	/**
269	Interface stucture for the Timer Architectural Protocol.
270
271	@par Protocol Description:
272	This protocol provides the services to initialize a periodic timer
273	interrupt, and to register a handler that is called each time the timer
274	interrupt fires. It may also provide a service to adjust the rate of the
275	periodic timer interrupt. When a timer interrupt occurs, the handler is
276	passed the amount of time that has passed since the previous timer
277	interrupt.
278
279	@param RegisterHandler
280	Registers a handler that will be called each time the
281	timer interrupt fires. TimerPeriod defines the minimum
282	time between timer interrupts, so TimerPeriod will also
283	be the minimum time between calls to the registered
284	handler.
285
286	@param SetTimerPeriod
287	Sets the period of the timer interrupt in 100 nS units.
288	This function is optional, and may return EFI_UNSUPPORTED.
289	If this function is supported, then the timer period will
290	be rounded up to the nearest supported timer period.
291
292
293	@param GetTimerPeriod
294	Retrieves the period of the timer interrupt in 100 nS units.
295
296	@param GenerateSoftInterrupt
297	Generates a soft timer interrupt that simulates the firing of
298	the timer interrupt. This service can be used to invoke the registered handler if the timer interrupt has been masked for
299	a period of time.
300
301	**/
302	EFI_TIMER_ARCH_PROTOCOL gTimer = {
303	TimerDriverRegisterHandler,
304	TimerDriverSetTimerPeriod,
305	TimerDriverGetTimerPeriod,
306	TimerDriverGenerateSoftInterrupt
307	};
308
309
310	/**
311	Initialize the state information for the Timer Architectural Protocol and
312	the Timer Debug support protocol that allows the debugger to break into a
313	running program.
314
315	@param ImageHandle of the loaded driver
316	@param SystemTable Pointer to the System Table
317
318	@retval EFI_SUCCESS Protocol registered
319	@retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure
320	@retval EFI_DEVICE_ERROR Hardware problems
321
322	**/
323	EFI_STATUS
324	EFIAPI
325	TimerInitialize (
326	IN EFI_HANDLE ImageHandle,
327	IN EFI_SYSTEM_TABLE *SystemTable
328	)
329	{
330	EFI_HANDLE Handle = NULL;
331	EFI_STATUS Status;
332	UINT32 TimerBaseAddress;
333
334	// configure free running timer (TIMER1) for 1MHz operation\r
335	\r
336	// AND disable clock, OR configure 1MHz clock\r
337	MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER1_EN, SP810_SYS_CTRL_TIMER1_TIMCLK); \r
338	\r
339	// Renable timer\r
340	MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER1_EN); \r
341	\r
342	\r
343	// configure timer 1 for free running operation, 32 bits, no prescaler, interrupt disabled\r
344	MmioWrite32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_32BIT \| SP804_PRESCALE_DIV_1);\r
345	\r
346	// enable the free running timer\r
347	MmioOr32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_ENABLE);\r
348	\r
349	// record free running tick value (should be close to 0xffffffff)\r
350	mLastTickCount = MmioRead32 (EB_SP804_TIMER1_BASE + SP804_TIMER_CURRENT_REG);\r
351	\r
352	// Disable the timer
353	Status = TimerDriverSetTimerPeriod (&gTimer, 0);
354	ASSERT_EFI_ERROR (Status);
355	\r
356	// Install interrupt handler for SP804 timer 0/1 interrupts\r
357	Status = mGic->RegisterInterruptHandler(mGic, EB_TIMER01_INTERRUPT_NUM, TimerInterruptHandler);\r
358	ASSERT_EFI_ERROR (Status);\r
359
360	// Install interrupt handler
361	gVector = EB_TIMER01_INTERRUPT_NUM;
362	Status = gInterrupt->RegisterInterruptSource (gInterrupt, gVector, TimerInterruptHandler);
363	ASSERT_EFI_ERROR (Status);
364	\r
365	\r
366	// configure periodic timer (TIMER0) for 1MHz operation\r
367	MmioAndThenOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, ~SP810_SYS_CTRL_TIMER0_EN, SP810_SYS_CTRL_TIMER0_TIMCLK);\r
368	\r
369	// Renable timer\r
370	MmioOr32 (EB_SP810_CTRL_BASE + SP810_SYS_CTRL_REG, SP810_SYS_CTRL_TIMER0_EN); \r
371	\r
372	// configure timer 0 for periodic operation, 32 bits, no prescaler, and interrupt enabled\r
373	MmioWrite32 (EB_SP804_TIMER0_BASE + SP804_TIMER_CONTROL_REG, SP804_TIMER_CTRL_PERIODIC \| SP804_TIMER_CTRL_32BIT \| SP804_PRESCALE_DIV_1 \| SP804_TIMER_CTRL_INT_ENABLE);\r
374
375
376	// Set up default timer
377	Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32(PcdTimerPeriod)); // TIMER_DEFAULT_PERIOD
378	ASSERT_EFI_ERROR (Status);
379
380	// Install the Timer Architectural Protocol onto a new handle
381	Status = gBS->InstallMultipleProtocolInterfaces(
382	&Handle,
383	&gEfiTimerArchProtocolGuid, &gTimer,
384	NULL
385	);
386	ASSERT_EFI_ERROR(Status);
387
388	return Status;
389	}
390