ArmPlatformPkg: Add SP805 Watchdog support

- Create SP805 Watchdog timer
- Enable this new driver on VExpress Cortex-A9x4 Core tile



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11794 6f19259b-4bc3-4df7-8a09-765794883524

2 files changed, 500 insertions, 0 deletions

diff --git a/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c
new file mode 100644
index 0000000000..0eb459303f
--- /dev/null
+++ b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805Watchdog.c
@@ -0,0 +1,450 @@
+/** @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;
+}
diff --git a/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805WatchdogDxe.inf b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805WatchdogDxe.inf
new file mode 100644
index 0000000000..b77320120c
--- /dev/null
+++ b/ArmPlatformPkg/Drivers/SP805WatchdogDxe/SP805WatchdogDxe.inf
@@ -0,0 +1,50 @@
+/** @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.             
+*
+**/
+
+[Defines]
+  INF_VERSION                    = 0x00010005
+  BASE_NAME                      = SP805WatchdogDxe
+  FILE_GUID                      = ebd705fb-fa92-46a7-b32b-7f566d944614 
+  MODULE_TYPE                    = DXE_DRIVER
+  VERSION_STRING                 = 1.0
+
+  ENTRY_POINT                    = SP805InstallProtocol
+
+[Sources.common]
+  SP805Watchdog.c
+
+[Packages]
+  MdePkg/MdePkg.dec
+  EmbeddedPkg/EmbeddedPkg.dec
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+
+[LibraryClasses]
+  BaseLib
+  UefiRuntimeServicesTableLib
+  UefiLib
+  UefiBootServicesTableLib
+  BaseMemoryLib
+  DebugLib
+  UefiDriverEntryPoint
+  IoLib
+
+[Guids]
+
+[Protocols]
+  gEfiWatchdogTimerArchProtocolGuid  
+
+
+[Depex]
+TRUE