X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=ArmPlatformPkg%2FDrivers%2FSP805WatchdogDxe%2FSP805Watchdog.c;h=12c2f0a1fe499688fc318e7b64c27a8dcf985ec6;hp=f8faab735de6c2fed4feecb5edeb3ae88aebd80a;hb=e3fa3d83e7c7e8830b31c9d916c0206a71bf2b48;hpb=3723a71a33d88307d96bca4facdce7d0120d922f diff --git a/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c index f8faab735d..12c2f0a1fe 100644 --- a/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c +++ b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c @@ -1,450 +1,389 @@ -/** @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 - -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include - -/** - 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, (UINTN)PcdGet32(PcdSP805WatchdogClockFrequencyInHz)), 20000000); - - // The registers in the SP805 are only 32 bits - if(Ticks64bit > (UINT64)0xFFFFFFFF) { - // 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; -} +/** @file +* +* Copyright (c) 2011-2013, ARM Limited. All rights reserved. +* Copyright (c) 2018, Linaro 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 + +#include +#include +#include +#include +#include + +#include + +#include "SP805Watchdog.h" + +STATIC EFI_EVENT mEfiExitBootServicesEvent; + +/** + 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. +**/ +STATIC +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. +**/ +STATIC +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. +**/ +STATIC +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. +**/ +STATIC +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. +**/ +STATIC +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. + +**/ +STATIC +EFI_STATUS +EFIAPI +SP805RegisterHandler ( + IN 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. + +**/ +STATIC +EFI_STATUS +EFIAPI +SP805SetTimerPeriod ( + IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, + IN UINT64 TimerPeriod // In 100ns units + ) +{ + EFI_STATUS Status; + UINT64 Ticks64bit; + + SP805Unlock (); + + Status = EFI_SUCCESS; + + if (TimerPeriod == 0) { + // This is a watchdog stop request + SP805Stop (); + } 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 = MultU64x32 (TimerPeriod, PcdGet32 (PcdSP805WatchdogClockFrequencyInHz)); + Ticks64bit = DivU64x32 (Ticks64bit, 20000000); + + // The registers in the SP805 are only 32 bits + if (Ticks64bit > MAX_UINT32) { + // 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. + +**/ +STATIC +EFI_STATUS +EFIAPI +SP805GetTimerPeriod ( + IN EFI_WATCHDOG_TIMER_ARCH_PROTOCOL *This, + OUT UINT64 *TimerPeriod + ) +{ + UINT64 ReturnValue; + + if (TimerPeriod == NULL) { + return EFI_INVALID_PARAMETER; + } + + // 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; + + return EFI_SUCCESS; +} + +/** + 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. + +**/ +STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = { + SP805RegisterHandler, + SP805SetTimerPeriod, + SP805GetTimerPeriod +}; + +/** + 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 +EFIAPI +SP805Initialize ( + IN EFI_HANDLE ImageHandle, + IN EFI_SYSTEM_TABLE *SystemTable + ) +{ + EFI_STATUS Status; + EFI_HANDLE Handle; + + // 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 (); + + // + // 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, &mEfiExitBootServicesEvent); + 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, &mWatchdogTimer, + NULL + ); + if (EFI_ERROR (Status)) { + Status = EFI_OUT_OF_RESOURCES; + goto EXIT; + } + +EXIT: + ASSERT_EFI_ERROR (Status); + return Status; +}