--- /dev/null
+/** @file
+*
+* Copyright (c) 2011, ARM Limited. All rights reserved.
+*
+* 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/UefiRuntimeServicesTableLib.h>
+#include <Library/UefiLib.h>
+#include <Library/IoLib.h>
+
+#include <Protocol/WatchdogTimer.h>
+#include <ArmPlatform.h>
+#include <Drivers/SP805Watchdog.h>
+
+/**
+ Interface structure for the Watchdog Architectural Protocol.
+
+ @par Protocol Description:
+ This protocol provides a service to set the amount of time to wait
+ before firing the watchdog timer, and it also provides a service to
+ register a handler that is invoked when the watchdog timer fires.
+
+ @par When the watchdog timer fires, control will be passed to a handler
+ if one has been registered. If no handler has been registered,
+ or the registered handler returns, then the system will be
+ reset by calling the Runtime Service ResetSystem().
+
+ @param RegisterHandler
+ Registers a handler that will be called each time the
+ watchdogtimer interrupt fires. TimerPeriod defines the minimum
+ time between timer interrupts, so TimerPeriod will also
+ be the minimum time between calls to the registered
+ handler.
+ NOTE: If the watchdog resets the system in hardware, then
+ this function will not have any chance of executing.
+
+ @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.
+
+**/
+EFI_WATCHDOG_TIMER_ARCH_PROTOCOL gWatchdogTimer = {
+ (EFI_WATCHDOG_TIMER_REGISTER_HANDLER) SP805RegisterHandler,
+ (EFI_WATCHDOG_TIMER_SET_TIMER_PERIOD) SP805SetTimerPeriod,
+ (EFI_WATCHDOG_TIMER_GET_TIMER_PERIOD) SP805GetTimerPeriod
+};
+
+EFI_EVENT EfiExitBootServicesEvent = (EFI_EVENT)NULL;
+
+BOOLEAN mSP805Initialized = FALSE;
+
+EFI_STATUS
+SP805Identify (
+ VOID
+ )
+{
+ // Check if this is a PrimeCell Peripheral
+ if( ( MmioRead8( SP805_WDOG_PCELL_ID0 ) != 0x0D )
+ || ( MmioRead8( SP805_WDOG_PCELL_ID1 ) != 0xF0 )
+ || ( MmioRead8( SP805_WDOG_PCELL_ID2 ) != 0x05 )
+ || ( MmioRead8( SP805_WDOG_PCELL_ID3 ) != 0xB1 ) ) {
+ return EFI_NOT_FOUND;
+ }
+
+ // Check if this PrimeCell Peripheral is the SP805 Watchdog Timer
+ if( ( MmioRead8( SP805_WDOG_PERIPH_ID0 ) != 0x05 )
+ || ( MmioRead8( SP805_WDOG_PERIPH_ID1 ) != 0x18 )
+ || (( MmioRead8( SP805_WDOG_PERIPH_ID2 ) & 0x0000000F) != 0x04 )
+ || ( MmioRead8( SP805_WDOG_PERIPH_ID3 ) != 0x00 ) ) {
+ return EFI_NOT_FOUND;
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Make sure the SP805 registers are unlocked for writing.
+
+ Note: The SP805 Watchdog Timer supports locking of its registers,
+ i.e. it inhibits all writes to avoid rogue software accidentally
+ corrupting their contents.
+**/
+inline
+VOID
+SP805Unlock (
+ VOID
+ )
+{
+ if( MmioRead32(SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_LOCKED ) {
+ MmioWrite32(SP805_WDOG_LOCK_REG, SP805_WDOG_SPECIAL_UNLOCK_CODE);
+ }
+}
+
+/**
+ Make sure the SP805 registers are locked and can not be overwritten.
+
+ Note: The SP805 Watchdog Timer supports locking of its registers,
+ i.e. it inhibits all writes to avoid rogue software accidentally
+ corrupting their contents.
+**/
+inline
+VOID
+SP805Lock (
+ VOID
+ )
+{
+ if( MmioRead32(SP805_WDOG_LOCK_REG) == SP805_WDOG_LOCK_IS_UNLOCKED ) {
+ // To lock it, just write in any number (except the special unlock code).
+ MmioWrite32(SP805_WDOG_LOCK_REG, SP805_WDOG_LOCK_IS_LOCKED);
+ }
+}
+
+/**
+ Stop the SP805 watchdog timer from counting down by disabling interrupts.
+**/
+inline
+VOID
+SP805Stop (
+ VOID
+ )
+{
+ // Disable interrupts
+ if ( (MmioRead32(SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) != 0 ) {
+ MmioAnd32(SP805_WDOG_CONTROL_REG, ~SP805_WDOG_CTRL_INTEN);
+ }
+}
+
+/**
+ Starts the SP805 counting down by enabling interrupts.
+ The count down will start from the value stored in the Load register,
+ not from the value where it was previously stopped.
+**/
+inline
+VOID
+SP805Start (
+ VOID
+ )
+{
+ // Enable interrupts
+ if ( (MmioRead32(SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0 ) {
+ MmioOr32(SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_INTEN);
+ }
+}
+
+/**
+ On exiting boot services we must make sure the SP805 Watchdog Timer
+ is stopped.
+**/
+VOID
+EFIAPI
+ExitBootServicesEvent (
+ IN EFI_EVENT Event,
+ IN VOID *Context
+ )
+{
+ SP805Unlock();
+ SP805Stop();
+ SP805Lock();
+}
+
+/**
+ This function registers the handler NotifyFunction so it is called every time
+ the watchdog timer expires. It also passes the amount of time since the last
+ handler call to the NotifyFunction.
+ If NotifyFunction is not NULL and a handler is not already registered,
+ then the new handler is registered and EFI_SUCCESS is returned.
+ If NotifyFunction is NULL, and a handler is already registered,
+ then that handler is unregistered.
+ 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.
+
+ @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 watchdog timer handler was registered.
+ @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.
+
+**/
+EFI_STATUS
+EFIAPI
+SP805RegisterHandler (
+ IN CONST EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,
+ IN EFI_WATCHDOG_TIMER_NOTIFY NotifyFunction
+ )
+{
+ // ERROR: This function is not supported.
+ // The hardware watchdog will reset the board
+ return EFI_INVALID_PARAMETER;
+}
+
+/**
+
+ 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
+SP805SetTimerPeriod (
+ IN CONST EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,
+ IN UINT64 TimerPeriod // In 100ns units
+ )
+{
+ EFI_STATUS Status = EFI_SUCCESS;
+ UINT64 Ticks64bit;
+
+ // Initialize the hardware if not already done
+ if( !mSP805Initialized ) {
+ Status = SP805Initialize();
+ if (EFI_ERROR(Status)) {
+ goto EXIT;
+ }
+ }
+
+ SP805Unlock();
+
+ if( TimerPeriod == 0 ) {
+ // This is a watchdog stop request
+ SP805Stop();
+ goto EXIT;
+ } else {
+ // Calculate the Watchdog ticks required for a delay of (TimerTicks * 100) nanoseconds
+ // The SP805 will count down to ZERO once, generate an interrupt and
+ // then it will again reload the initial value and start again.
+ // On the second time when it reaches ZERO, it will actually reset the board.
+ // Therefore, we need to load half the required delay.
+ //
+ // WatchdogTicks = ((TimerPeriod * 100 * SP805_CLOCK_FREQUENCY) / 1GHz) / 2 ;
+ //
+ // i.e.:
+ //
+ // WatchdogTicks = (TimerPeriod * SP805_CLOCK_FREQUENCY) / 20 MHz ;
+
+ Ticks64bit = DivU64x32( MultU64x32( TimerPeriod, SP805_CLOCK_FREQUENCY ), 20000000 );
+
+ // The registers in the SP805 are only 32 bits
+ if( Ticks64bit > SP805_MAX_TICKS ) {
+ // We could load the watchdog with the maximum supported value but
+ // if a smaller value was requested, this could have the watchdog
+ // triggering before it was intended.
+ // Better generate an error to let the caller know.
+ Status = EFI_DEVICE_ERROR;
+ goto EXIT;
+ }
+
+ // Update the watchdog with a 32-bit value.
+ MmioWrite32(SP805_WDOG_LOAD_REG, (UINT32)Ticks64bit);
+
+ // Start the watchdog
+ SP805Start();
+ }
+
+ EXIT:
+ // Ensure the watchdog is locked before exiting.
+ SP805Lock();
+ 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
+SP805GetTimerPeriod (
+ IN CONST EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This,
+ OUT UINT64 *TimerPeriod
+ )
+{
+ EFI_STATUS Status = EFI_SUCCESS;
+ UINT64 ReturnValue;
+
+ if (TimerPeriod == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ // Initialize the hardware if not already done
+ if( !mSP805Initialized ) {
+ Status = SP805Initialize();
+ if (EFI_ERROR(Status)) {
+ goto EXIT;
+ }
+ }
+
+ // Check if the watchdog is stopped
+ if ( (MmioRead32(SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_INTEN) == 0 ) {
+ // It is stopped, so return zero.
+ ReturnValue = 0;
+ } else {
+ // Convert the Watchdog ticks into TimerPeriod
+ // Ensure 64bit arithmetic throughout because the Watchdog ticks may already
+ // be at the maximum 32 bit value and we still need to multiply that by 600.
+ ReturnValue = MultU64x32( MmioRead32(SP805_WDOG_LOAD_REG), 600 );
+ }
+
+ *TimerPeriod = ReturnValue;
+
+ EXIT:
+ return Status;
+}
+
+/**
+ Initialize the state information for the Watchdog Timer Architectural Protocol.
+
+ @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
+SP805Initialize (
+ VOID
+ )
+{
+ EFI_STATUS Status;
+
+ // Check if the SP805 hardware watchdog module exists on board
+ Status = SP805Identify();
+ if (EFI_ERROR( Status )) {
+ Status = EFI_DEVICE_ERROR;
+ goto EXIT;
+ }
+
+ // Unlock access to the SP805 registers
+ SP805Unlock();
+
+ // Stop the watchdog from triggering unexpectedly
+ SP805Stop();
+
+ // Set the watchdog to reset the board when triggered
+ if ( (MmioRead32(SP805_WDOG_CONTROL_REG) & SP805_WDOG_CTRL_RESEN) == 0 ) {
+ MmioOr32(SP805_WDOG_CONTROL_REG, SP805_WDOG_CTRL_RESEN);
+ }
+
+ // Prohibit any rogue access to SP805 registers
+ SP805Lock();
+
+ mSP805Initialized = TRUE;
+
+ EXIT:
+ return Status;
+}
+
+EFI_STATUS
+EFIAPI
+SP805InstallProtocol (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+ EFI_HANDLE Handle;
+
+ //
+ // Make sure the Watchdog Timer Architectural Protocol has not been installed in the system yet.
+ // This will avoid conflicts with the universal watchdog
+ //
+ ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiWatchdogTimerArchProtocolGuid);
+
+ // Register for an ExitBootServicesEvent
+ Status = gBS->CreateEvent (EVT_SIGNAL_EXIT_BOOT_SERVICES, TPL_NOTIFY, ExitBootServicesEvent, NULL, &EfiExitBootServicesEvent);
+ if (EFI_ERROR(Status)) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto EXIT;
+ }
+
+ // Install the Timer Architectural Protocol onto a new handle
+ Handle = NULL;
+ Status = gBS->InstallMultipleProtocolInterfaces(
+ &Handle,
+ &gEfiWatchdogTimerArchProtocolGuid, &gWatchdogTimer,
+ NULL
+ );
+ if (EFI_ERROR(Status)) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto EXIT;
+ }
+
+ EXIT:
+ if(EFI_ERROR(Status)) {
+ // The watchdog failed to initialize
+ ASSERT(FALSE);
+ }
+ return Status;
+}
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