[mirror_edk2.git] / ArmPlatformPkg / Drivers / SP805WatchdogDxe / SP805Watchdog.c

/** @file\r
*\r
*  Copyright (c) 2011-2013, ARM Limited. All rights reserved.\r
*  Copyright (c) 2018, Linaro Limited. All rights reserved.\r
*\r
*  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/BaseMemoryLib.h>\r
#include <Library/DebugLib.h>\r
#include <Library/IoLib.h>\r
#include <Library/UefiBootServicesTableLib.h>\r
\r
#include <Protocol/WatchdogTimer.h>\r
\r
#include "SP805Watchdog.h"\r
\r
STATIC EFI_EVENT          mEfiExitBootServicesEvent;\r
\r
/**\r
  Make sure the SP805 registers are unlocked for writing.\r
\r
  Note: The SP805 Watchdog Timer supports locking of its registers,\r
  i.e. it inhibits all writes to avoid rogue software accidentally\r
  corrupting their contents.\r
**/\r
STATIC\r
VOID\r
SP805Unlock (\r
  VOID\r
  )\r
{\r
  if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_LOCKED) {\r
    MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_SPECIAL_UNLOCK_CODE);\r
  }\r
}\r
\r
/**\r
  Make sure the SP805 registers are locked and can not be overwritten.\r
\r
  Note: The SP805 Watchdog Timer supports locking of its registers,\r
  i.e. it inhibits all writes to avoid rogue software accidentally\r
  corrupting their contents.\r
**/\r
STATIC\r
VOID\r
SP805Lock (\r
  VOID\r
  )\r
{\r
  if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_UNLOCKED) {\r
    // To lock it, just write in any number (except the special unlock code).\r
    MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_LOCK_IS_LOCKED);\r
  }\r
}\r
\r
/**\r
  Stop the SP805 watchdog timer from counting down by disabling interrupts.\r
**/\r
STATIC\r
VOID\r
SP805Stop (\r
  VOID\r
  )\r
{\r
  // Disable interrupts\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) != 0) {\r
    MmioAnd32 (SP805_WDOG_CONTROL_REG, ~SP805_WDOG_CTRL_INTEN);\r
  }\r
}\r
\r
/**\r
  Starts the SP805 counting down by enabling interrupts.\r
  The count down will start from the value stored in the Load register,\r
  not from the value where it was previously stopped.\r
**/\r
STATIC\r
VOID\r
SP805Start (\r
  VOID\r
  )\r
{\r
  // Enable interrupts\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r
    MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_INTEN);\r
  }\r
}\r
\r
/**\r
    On exiting boot services we must make sure the SP805 Watchdog Timer\r
    is stopped.\r
**/\r
STATIC\r
VOID\r
EFIAPI\r
ExitBootServicesEvent (\r
  IN EFI_EVENT  Event,\r
  IN VOID       *Context\r
  )\r
{\r
  SP805Unlock ();\r
  SP805Stop ();\r
  SP805Lock ();\r
}\r
\r
/**\r
  This function registers the handler NotifyFunction so it is called every time\r
  the watchdog timer expires.  It also passes the amount of time since the last\r
  handler call to the NotifyFunction.\r
  If NotifyFunction is not NULL and a handler is not already registered,\r
  then the new handler is registered and EFI_SUCCESS is returned.\r
  If NotifyFunction is NULL, and a handler is already registered,\r
  then that handler is unregistered.\r
  If an attempt is made to register a handler when a handler is already registered,\r
  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.\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 watchdog timer handler was registered.\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
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805RegisterHandler (\r
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL         *This,\r
  IN EFI_WATCHDOG_TIMER_NOTIFY                NotifyFunction\r
  )\r
{\r
  // ERROR: This function is not supported.\r
  // The hardware watchdog will reset the board\r
  return EFI_INVALID_PARAMETER;\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
\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
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805SetTimerPeriod (\r
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL         *This,\r
  IN UINT64                                   TimerPeriod   // In 100ns units\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT64      Ticks64bit;\r
\r
  SP805Unlock ();\r
\r
  Status = EFI_SUCCESS;\r
\r
  if (TimerPeriod == 0) {\r
    // This is a watchdog stop request\r
    SP805Stop ();\r
  } else {\r
    // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds\r
    // The SP805 will count down to ZERO once, generate an interrupt and\r
    // then it will again reload the initial value and start again.\r
    // On the second time when it reaches ZERO, it will actually reset the board.\r
    // Therefore, we need to load half the required delay.\r
    //\r
    // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz) / 2 ;\r
    //\r
    // i.e.:\r
    //\r
    // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 20 MHz ;\r
\r
    Ticks64bit = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz));\r
    Ticks64bit = DivU64x32 (Ticks64bit, 20000000);\r
\r
    // The registers in the SP805 are only 32 bits\r
    if (Ticks64bit > MAX_UINT32) {\r
      // We could load the watchdog with the maximum supported value but\r
      // if a smaller value was requested, this could have the watchdog\r
      // triggering before it was intended.\r
      // Better generate an error to let the caller know.\r
      Status = EFI_DEVICE_ERROR;\r
      goto EXIT;\r
    }\r
\r
    // Update the watchdog with a 32-bit value.\r
    MmioWrite32 (SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);\r
\r
    // Start the watchdog\r
    SP805Start ();\r
  }\r
\r
EXIT:\r
  // Ensure the watchdog is locked before exiting.\r
  SP805Lock ();\r
  return Status;\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
\r
  @retval EFI_SUCCESS           The timer period was returned in TimerPeriod.\r
  @retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r
\r
**/\r
STATIC\r
EFI_STATUS\r
EFIAPI\r
SP805GetTimerPeriod (\r
  IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL         *This,\r
  OUT UINT64                                  *TimerPeriod\r
  )\r
{\r
  UINT64      ReturnValue;\r
\r
  if (TimerPeriod == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  // Check if the watchdog is stopped\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r
    // It is stopped, so return zero.\r
    ReturnValue = 0;\r
  } else {\r
    // Convert the Watchdog ticks into TimerPeriod\r
    // Ensure 64bit arithmetic throughout because the Watchdog ticks may already\r
    // be at the maximum 32 bit value and we still need to multiply that by 600.\r
    ReturnValue = MultU64x32 (MmioRead32 (SP805_WDOG_LOAD_REG), 600);\r
  }\r
\r
  *TimerPeriod = ReturnValue;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Interface structure for the Watchdog Architectural Protocol.\r
\r
  @par Protocol Description:\r
  This protocol provides a service to set the amount of time to wait\r
  before firing the watchdog timer, and it also provides a service to\r
  register a handler that is invoked when the watchdog timer fires.\r
\r
  @par When the watchdog timer fires, control will be passed to a handler\r
  if one has been registered.  If no handler has been registered,\r
  or the registered handler returns, then the system will be\r
  reset by calling the Runtime Service ResetSystem().\r
\r
  @param RegisterHandler\r
  Registers a handler that will be called each time the\r
  watchdogtimer 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
  NOTE: If the watchdog resets the system in hardware, then\r
        this function will not have any chance of executing.\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
**/\r
STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = {\r
  SP805RegisterHandler,\r
  SP805SetTimerPeriod,\r
  SP805GetTimerPeriod\r
};\r
\r
/**\r
  Initialize the state information for the Watchdog 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
SP805Initialize (\r
  IN EFI_HANDLE         ImageHandle,\r
  IN EFI_SYSTEM_TABLE   *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
  EFI_HANDLE  Handle;\r
\r
  // Unlock access to the SP805 registers\r
  SP805Unlock ();\r
\r
  // Stop the watchdog from triggering unexpectedly\r
  SP805Stop ();\r
\r
  // Set the watchdog to reset the board when triggered\r
  if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_RESEN) == 0) {\r
    MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_RESEN);\r
  }\r
\r
  // Prohibit any rogue access to SP805 registers\r
  SP805Lock ();\r
\r
  //\r
  // Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet.\r
  // This will avoid conflicts with the universal watchdog\r
  //\r
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);\r
\r
  // Register for an ExitBootServicesEvent\r
  Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY,\r
                  ExitBootServicesEvent, NULL, &mEfiExitBootServicesEvent);\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto EXIT;\r
  }\r
\r
  // Install the Timer Architectural Protocol onto a new handle\r
  Handle = NULL;\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &Handle,\r
                  &gEfiWatchdogTimerArchProtocolGuid, &mWatchdogTimer,\r
                  NULL\r
                  );\r
  if (EFI_ERROR (Status)) {\r
    Status = EFI_OUT_OF_RESOURCES;\r
    goto EXIT;\r
  }\r
\r
EXIT:\r
  ASSERT_EFI_ERROR (Status);\r
  return Status;\r
}\r
Commit	Line	Data
1e57a462	1	/** @file\r
1e57a462	2	*\r
b2ce4a39	3	* Copyright (c) 2011-2013, ARM Limited. All rights reserved.\r
e3fa3d83	4	* Copyright (c) 2018, Linaro Limited. All rights reserved.\r
1e57a462	5	*\r
	6	* 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/BaseMemoryLib.h>\r
	21	#include <Library/DebugLib.h>\r
	22	#include <Library/IoLib.h>\r
1e57a462	23	#include <Library/UefiBootServicesTableLib.h>\r
1e57a462	24	\r
1e57a462	25	#include <Protocol/WatchdogTimer.h>\r
b9fddfb8 AB	26	\r
b9fddfb8 AB	27	#include "SP805Watchdog.h"\r
1e57a462	28	\r
e3fa3d83	29	STATIC EFI_EVENT mEfiExitBootServicesEvent;\r
1e57a462	30	\r
	31	/**\r
	32	Make sure the SP805 registers are unlocked for writing.\r
	33	\r
	34	Note: The SP805 Watchdog Timer supports locking of its registers,\r
	35	i.e. it inhibits all writes to avoid rogue software accidentally\r
	36	corrupting their contents.\r
	37	**/\r
b2ce4a39	38	STATIC\r
1e57a462	39	VOID\r
	40	SP805Unlock (\r
	41	VOID\r
	42	)\r
	43	{\r
e3fa3d83 AB	44	if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_LOCKED) {\r
e3fa3d83 AB	45	MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_SPECIAL_UNLOCK_CODE);\r
1e57a462	46	}\r
	47	}\r
	48	\r
	49	/**\r
	50	Make sure the SP805 registers are locked and can not be overwritten.\r
	51	\r
	52	Note: The SP805 Watchdog Timer supports locking of its registers,\r
	53	i.e. it inhibits all writes to avoid rogue software accidentally\r
	54	corrupting their contents.\r
	55	**/\r
b2ce4a39	56	STATIC\r
1e57a462	57	VOID\r
	58	SP805Lock (\r
	59	VOID\r
	60	)\r
	61	{\r
e3fa3d83	62	if (MmioRead32 (SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_UNLOCKED) {\r
1e57a462	63	// To lock it, just write in any number (except the special unlock code).\r
e3fa3d83	64	MmioWrite32 (SP805_WDOG_LOCK_REG, SP805_WDOG_LOCK_IS_LOCKED);\r
1e57a462	65	}\r
	66	}\r
	67	\r
	68	/**\r
	69	Stop the SP805 watchdog timer from counting down by disabling interrupts.\r
	70	**/\r
b2ce4a39	71	STATIC\r
1e57a462	72	VOID\r
	73	SP805Stop (\r
	74	VOID\r
	75	)\r
	76	{\r
	77	// Disable interrupts\r
e3fa3d83 AB	78	if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) != 0) {\r
e3fa3d83 AB	79	MmioAnd32 (SP805_WDOG_CONTROL_REG, ~SP805_WDOG_CTRL_INTEN);\r
1e57a462	80	}\r
	81	}\r
	82	\r
	83	/**\r
	84	Starts the SP805 counting down by enabling interrupts.\r
	85	The count down will start from the value stored in the Load register,\r
	86	not from the value where it was previously stopped.\r
	87	**/\r
b2ce4a39	88	STATIC\r
1e57a462	89	VOID\r
	90	SP805Start (\r
	91	VOID\r
	92	)\r
	93	{\r
	94	// Enable interrupts\r
e3fa3d83 AB	95	if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r
e3fa3d83 AB	96	MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_INTEN);\r
1e57a462	97	}\r
	98	}\r
	99	\r
	100	/**\r
	101	On exiting boot services we must make sure the SP805 Watchdog Timer\r
	102	is stopped.\r
	103	**/\r
e3fa3d83	104	STATIC\r
1e57a462	105	VOID\r
	106	EFIAPI\r
	107	ExitBootServicesEvent (\r
	108	IN EFI_EVENT Event,\r
	109	IN VOID *Context\r
	110	)\r
	111	{\r
e3fa3d83 AB	112	SP805Unlock ();\r
	113	SP805Stop ();\r
	114	SP805Lock ();\r
1e57a462	115	}\r
	116	\r
	117	/**\r
	118	This function registers the handler NotifyFunction so it is called every time\r
	119	the watchdog timer expires. It also passes the amount of time since the last\r
	120	handler call to the NotifyFunction.\r
	121	If NotifyFunction is not NULL and a handler is not already registered,\r
	122	then the new handler is registered and EFI_SUCCESS is returned.\r
	123	If NotifyFunction is NULL, and a handler is already registered,\r
	124	then that handler is unregistered.\r
	125	If an attempt is made to register a handler when a handler is already registered,\r
	126	then EFI_ALREADY_STARTED is returned.\r
	127	If an attempt is made to unregister a handler when a handler is not registered,\r
	128	then EFI_INVALID_PARAMETER is returned.\r
	129	\r
	130	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
	131	@param NotifyFunction The function to call when a timer interrupt fires. This\r
	132	function executes at TPL_HIGH_LEVEL. The DXE Core will\r
	133	register a handler for the timer interrupt, so it can know\r
	134	how much time has passed. This information is used to\r
	135	signal timer based events. NULL will unregister the handler.\r
	136	\r
	137	@retval EFI_SUCCESS The watchdog timer handler was registered.\r
	138	@retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already\r
	139	registered.\r
	140	@retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not\r
	141	previously registered.\r
	142	\r
	143	**/\r
e3fa3d83	144	STATIC\r
1e57a462	145	EFI_STATUS\r
	146	EFIAPI\r
	147	SP805RegisterHandler (\r
e3fa3d83	148	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r
1e57a462	149	IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction\r
	150	)\r
	151	{\r
	152	// ERROR: This function is not supported.\r
	153	// The hardware watchdog will reset the board\r
	154	return EFI_INVALID_PARAMETER;\r
	155	}\r
	156	\r
	157	/**\r
	158	\r
	159	This function adjusts the period of timer interrupts to the value specified\r
	160	by TimerPeriod. If the timer period is updated, then the selected timer\r
	161	period is stored in EFI_TIMER.TimerPeriod, and EFI_SUCCESS is returned. If\r
	162	the timer hardware is not programmable, then EFI_UNSUPPORTED is returned.\r
	163	If an error occurs while attempting to update the timer period, then the\r
	164	timer hardware will be put back in its state prior to this call, and\r
	165	EFI_DEVICE_ERROR is returned. If TimerPeriod is 0, then the timer interrupt\r
	166	is disabled. This is not the same as disabling the CPU's interrupts.\r
	167	Instead, it must either turn off the timer hardware, or it must adjust the\r
	168	interrupt controller so that a CPU interrupt is not generated when the timer\r
	169	interrupt fires.\r
	170	\r
	171	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
	172	@param TimerPeriod The rate to program the timer interrupt in 100 nS units. If\r
	173	the timer hardware is not programmable, then EFI_UNSUPPORTED is\r
	174	returned. If the timer is programmable, then the timer period\r
	175	will be rounded up to the nearest timer period that is supported\r
	176	by the timer hardware. If TimerPeriod is set to 0, then the\r
	177	timer interrupts will be disabled.\r
	178	\r
	179	\r
	180	@retval EFI_SUCCESS The timer period was changed.\r
	181	@retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.\r
	182	@retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error.\r
	183	\r
	184	**/\r
e3fa3d83	185	STATIC\r
1e57a462	186	EFI_STATUS\r
	187	EFIAPI\r
	188	SP805SetTimerPeriod (\r
e3fa3d83	189	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r
1e57a462	190	IN UINT64 TimerPeriod // In 100ns units\r
	191	)\r
	192	{\r
e3fa3d83	193	EFI_STATUS Status;\r
1e57a462	194	UINT64 Ticks64bit;\r
1e57a462	195	\r
e3fa3d83	196	SP805Unlock ();\r
1e57a462	197	\r
e3fa3d83 AB	198	Status = EFI_SUCCESS;\r
	199	\r
	200	if (TimerPeriod == 0) {\r
1e57a462	201	// This is a watchdog stop request\r
e3fa3d83	202	SP805Stop ();\r
1e57a462	203	} else {\r
	204	// Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds\r
	205	// The SP805 will count down to ZERO once, generate an interrupt and\r
	206	// then it will again reload the initial value and start again.\r
	207	// On the second time when it reaches ZERO, it will actually reset the board.\r
	208	// Therefore, we need to load half the required delay.\r
	209	//\r
	210	// WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz) / 2 ;\r
	211	//\r
	212	// i.e.:\r
	213	//\r
	214	// WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 20 MHz ;\r
	215	\r
e3fa3d83 AB	216	Ticks64bit = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz));\r
e3fa3d83 AB	217	Ticks64bit = DivU64x32 (Ticks64bit, 20000000);\r
1e57a462	218	\r
1e57a462	219	// The registers in the SP805 are only 32 bits\r
e3fa3d83	220	if (Ticks64bit > MAX_UINT32) {\r
1e57a462	221	// We could load the watchdog with the maximum supported value but\r
	222	// if a smaller value was requested, this could have the watchdog\r
	223	// triggering before it was intended.\r
	224	// Better generate an error to let the caller know.\r
	225	Status = EFI_DEVICE_ERROR;\r
	226	goto EXIT;\r
	227	}\r
	228	\r
	229	// Update the watchdog with a 32-bit value.\r
e3fa3d83	230	MmioWrite32 (SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);\r
1e57a462	231	\r
1e57a462	232	// Start the watchdog\r
e3fa3d83	233	SP805Start ();\r
1e57a462	234	}\r
1e57a462	235	\r
e3fa3d83	236	EXIT:\r
1e57a462	237	// Ensure the watchdog is locked before exiting.\r
e3fa3d83	238	SP805Lock ();\r
1e57a462	239	return Status;\r
	240	}\r
	241	\r
	242	/**\r
	243	This function retrieves the period of timer interrupts in 100 ns units,\r
	244	returns that value in TimerPeriod, and returns EFI_SUCCESS. If TimerPeriod\r
	245	is NULL, then EFI_INVALID_PARAMETER is returned. If a TimerPeriod of 0 is\r
	246	returned, then the timer is currently disabled.\r
	247	\r
	248	@param This The EFI_TIMER_ARCH_PROTOCOL instance.\r
	249	@param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If\r
	250	0 is returned, then the timer is currently disabled.\r
	251	\r
	252	\r
	253	@retval EFI_SUCCESS The timer period was returned in TimerPeriod.\r
	254	@retval EFI_INVALID_PARAMETER TimerPeriod is NULL.\r
	255	\r
	256	**/\r
e3fa3d83	257	STATIC\r
1e57a462	258	EFI_STATUS\r
	259	EFIAPI\r
	260	SP805GetTimerPeriod (\r
e3fa3d83	261	IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,\r
1e57a462	262	OUT UINT64 *TimerPeriod\r
	263	)\r
	264	{\r
1e57a462	265	UINT64 ReturnValue;\r
	266	\r
	267	if (TimerPeriod == NULL) {\r
	268	return EFI_INVALID_PARAMETER;\r
	269	}\r
	270	\r
	271	// Check if the watchdog is stopped\r
e3fa3d83	272	if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0) {\r
1e57a462	273	// It is stopped, so return zero.\r
	274	ReturnValue = 0;\r
	275	} else {\r
	276	// Convert the Watchdog ticks into TimerPeriod\r
	277	// Ensure 64bit arithmetic throughout because the Watchdog ticks may already\r
	278	// be at the maximum 32 bit value and we still need to multiply that by 600.\r
e3fa3d83	279	ReturnValue = MultU64x32 (MmioRead32 (SP805_WDOG_LOAD_REG), 600);\r
1e57a462	280	}\r
	281	\r
	282	*TimerPeriod = ReturnValue;\r
	283	\r
e3fa3d83	284	return EFI_SUCCESS;\r
1e57a462	285	}\r
	286	\r
	287	/**\r
	288	Interface structure for the Watchdog Architectural Protocol.\r
	289	\r
	290	@par Protocol Description:\r
	291	This protocol provides a service to set the amount of time to wait\r
	292	before firing the watchdog timer, and it also provides a service to\r
	293	register a handler that is invoked when the watchdog timer fires.\r
	294	\r
	295	@par When the watchdog timer fires, control will be passed to a handler\r
	296	if one has been registered. If no handler has been registered,\r
	297	or the registered handler returns, then the system will be\r
	298	reset by calling the Runtime Service ResetSystem().\r
	299	\r
	300	@param RegisterHandler\r
	301	Registers a handler that will be called each time the\r
	302	watchdogtimer interrupt fires. TimerPeriod defines the minimum\r
	303	time between timer interrupts, so TimerPeriod will also\r
	304	be the minimum time between calls to the registered\r
	305	handler.\r
	306	NOTE: If the watchdog resets the system in hardware, then\r
	307	this function will not have any chance of executing.\r
	308	\r
	309	@param SetTimerPeriod\r
	310	Sets the period of the timer interrupt in 100 nS units.\r
	311	This function is optional, and may return EFI_UNSUPPORTED.\r
	312	If this function is supported, then the timer period will\r
	313	be rounded up to the nearest supported timer period.\r
	314	\r
	315	@param GetTimerPeriod\r
	316	Retrieves the period of the timer interrupt in 100 nS units.\r
	317	\r
	318	**/\r
e3fa3d83 AB	319	STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = {\r
	320	SP805RegisterHandler,\r
	321	SP805SetTimerPeriod,\r
	322	SP805GetTimerPeriod\r
1e57a462	323	};\r
	324	\r
	325	/**\r
	326	Initialize the state information for the Watchdog Timer Architectural Protocol.\r
	327	\r
	328	@param ImageHandle of the loaded driver\r
	329	@param SystemTable Pointer to the System Table\r
	330	\r
	331	@retval EFI_SUCCESS Protocol registered\r
	332	@retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure\r
	333	@retval EFI_DEVICE_ERROR Hardware problems\r
	334	\r
	335	**/\r
	336	EFI_STATUS\r
	337	EFIAPI\r
	338	SP805Initialize (\r
	339	IN EFI_HANDLE ImageHandle,\r
	340	IN EFI_SYSTEM_TABLE *SystemTable\r
	341	)\r
	342	{\r
	343	EFI_STATUS Status;\r
	344	EFI_HANDLE Handle;\r
	345	\r
	346	// Unlock access to the SP805 registers\r
	347	SP805Unlock ();\r
	348	\r
	349	// Stop the watchdog from triggering unexpectedly\r
	350	SP805Stop ();\r
	351	\r
	352	// Set the watchdog to reset the board when triggered\r
e3fa3d83	353	if ((MmioRead32 (SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_RESEN) == 0) {\r
1e57a462	354	MmioOr32 (SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_RESEN);\r
	355	}\r
	356	\r
	357	// Prohibit any rogue access to SP805 registers\r
e3fa3d83	358	SP805Lock ();\r
3402aac7	359	\r
1e57a462	360	//\r
	361	// Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet.\r
	362	// This will avoid conflicts with the universal watchdog\r
	363	//\r
	364	ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);\r
	365	\r
	366	// Register for an ExitBootServicesEvent\r
e3fa3d83 AB	367	Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY,\r
	368	ExitBootServicesEvent, NULL, &mEfiExitBootServicesEvent);\r
	369	if (EFI_ERROR (Status)) {\r
1e57a462	370	Status = EFI_OUT_OF_RESOURCES;\r
	371	goto EXIT;\r
	372	}\r
	373	\r
	374	// Install the Timer Architectural Protocol onto a new handle\r
	375	Handle = NULL;\r
e3fa3d83	376	Status = gBS->InstallMultipleProtocolInterfaces (\r
1e57a462	377	&Handle,\r
e3fa3d83	378	&gEfiWatchdogTimerArchProtocolGuid, &mWatchdogTimer,\r
1e57a462	379	NULL\r
1e57a462	380	);\r
e3fa3d83	381	if (EFI_ERROR (Status)) {\r
1e57a462	382	Status = EFI_OUT_OF_RESOURCES;\r
	383	goto EXIT;\r
	384	}\r
	385	\r
	386	EXIT:\r
e3fa3d83	387	ASSERT_EFI_ERROR (Status);\r
1e57a462	388	return Status;\r
1e57a462	389	}\r