Correct Include style to pass GCC build.

[mirror_edk2.git] / PcAtChipsetPkg / 8254TimerDxe / Timer.c

/** @file\r
  Timer Architectural Protocol as defined in the DXE CIS\r
\r
Copyright (c) 2005 - 2010, Intel Corporation. All rights reserved.<BR>\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
#include "Timer.h"\r
\r
//\r
// The handle onto which the Timer Architectural Protocol will be installed\r
//\r
EFI_HANDLE                mTimerHandle = NULL;\r
\r
//\r
// The Timer Architectural Protocol that this driver produces\r
//\r
EFI_TIMER_ARCH_PROTOCOL   mTimer = {\r
  TimerDriverRegisterHandler,\r
  TimerDriverSetTimerPeriod,\r
  TimerDriverGetTimerPeriod,\r
  TimerDriverGenerateSoftInterrupt\r
};\r
\r
//\r
// Pointer to the CPU Architectural Protocol instance\r
//\r
EFI_CPU_ARCH_PROTOCOL     *mCpu;\r
\r
//\r
// Pointer to the Legacy 8259 Protocol instance\r
//\r
EFI_LEGACY_8259_PROTOCOL  *mLegacy8259;\r
\r
//\r
// The notification function to call on every timer interrupt.\r
// A bug in the compiler prevents us from initializing this here.\r
//\r
EFI_TIMER_NOTIFY mTimerNotifyFunction;\r
\r
//\r
// The current period of the timer interrupt\r
//\r
volatile UINT64           mTimerPeriod = 0;\r
\r
//\r
// Worker Functions\r
//\r
/**\r
  Sets the counter value for Timer #0 in a legacy 8254 timer.\r
\r
  @param Count    The 16-bit counter value to program into Timer #0 of the legacy 8254 timer.\r
**/\r
VOID\r
SetPitCount (\r
  IN UINT16  Count\r
  )\r
{\r
  IoWrite8 (TIMER_CONTROL_PORT, 0x36);\r
  IoWrite8 (TIMER0_COUNT_PORT, (UINT8)(Count & 0xff));\r
  IoWrite8 (TIMER0_COUNT_PORT, (UINT8)((Count >> 8) & 0xff));\r
}\r
\r
/**\r
  8254 Timer #0 Interrupt Handler.\r
\r
  @param InterruptType    The type of interrupt that occured\r
  @param SystemContext    A pointer to the system context when the interrupt occured\r
**/\r
VOID\r
EFIAPI\r
TimerInterruptHandler (\r
  IN EFI_EXCEPTION_TYPE   InterruptType,\r
  IN EFI_SYSTEM_CONTEXT   SystemContext\r
  )\r
{\r
  EFI_TPL OriginalTPL;\r
\r
  OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
  mLegacy8259->EndOfInterrupt (mLegacy8259, Efi8259Irq0);\r
\r
  if (mTimerNotifyFunction != NULL) {\r
    //\r
    // @bug : This does not handle missed timer interrupts\r
    //\r
    mTimerNotifyFunction (mTimerPeriod);\r
  }\r
\r
  gBS->RestoreTPL (OriginalTPL);\r
}\r
\r
/**\r
\r
  This function registers the handler NotifyFunction so it is called every time\r
  the timer interrupt fires.  It also passes the amount of time since the last\r
  handler call to the NotifyFunction.  If NotifyFunction is NULL, then the\r
  handler is unregistered.  If the handler is registered, then EFI_SUCCESS is\r
  returned.  If the CPU does not support registering a timer interrupt handler,\r
  then EFI_UNSUPPORTED is returned.  If an attempt is made to register a handler\r
  when a handler is already registered, 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.  If an error occurs attempting to\r
  register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR\r
  is returned.\r
\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 timer handler was registered.\r
  @retval        EFI_UNSUPPORTED        The platform does not support timer interrupts.\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
  @retval        EFI_DEVICE_ERROR       The timer handler could not be registered.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverRegisterHandler (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN EFI_TIMER_NOTIFY         NotifyFunction\r
  )\r
{\r
  //\r
  // Check for invalid parameters\r
  //\r
  if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {\r
    return EFI_ALREADY_STARTED;\r
  }\r
\r
  mTimerNotifyFunction = NotifyFunction;\r
\r
  return EFI_SUCCESS;\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
\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
  @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
EFI_STATUS\r
EFIAPI\r
TimerDriverSetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This,\r
  IN UINT64                   TimerPeriod\r
  )\r
{\r
  UINT64  TimerCount;\r
\r
  //\r
  //  The basic clock is 1.19318 MHz or 0.119318 ticks per 100 ns.\r
  //  TimerPeriod * 0.119318 = 8254 timer divisor. Using integer arithmetic\r
  //  TimerCount = (TimerPeriod * 119318)/1000000.\r
  //\r
  //  Round up to next highest integer. This guarantees that the timer is\r
  //  equal to or slightly longer than the requested time.\r
  //  TimerCount = ((TimerPeriod * 119318) + 500000)/1000000\r
  //\r
  // Note that a TimerCount of 0 is equivalent to a count of 65,536\r
  //\r
  // Since TimerCount is limited to 16 bits for IA32, TimerPeriod is limited\r
  // to 20 bits.\r
  //\r
  if (TimerPeriod == 0) {\r
    //\r
    // Disable timer interrupt for a TimerPeriod of 0\r
    //\r
    mLegacy8259->DisableIrq (mLegacy8259, Efi8259Irq0);\r
  } else {\r
\r
    //\r
    // Convert TimerPeriod into 8254 counts\r
    //\r
    TimerCount = DivU64x32 (MultU64x32 (119318, (UINT32) TimerPeriod) + 500000, 1000000);\r
\r
    //\r
    // Check for overflow\r
    //\r
    if (TimerCount >= 65536) {\r
      TimerCount = 0;\r
      if (TimerPeriod >= DEFAULT_TIMER_TICK_DURATION) {\r
        TimerPeriod = DEFAULT_TIMER_TICK_DURATION;\r
      }\r
    }\r
    //\r
    // Program the 8254 timer with the new count value\r
    //\r
    SetPitCount ((UINT16) TimerCount);\r
\r
    //\r
    // Enable timer interrupt\r
    //\r
    mLegacy8259->EnableIrq (mLegacy8259, Efi8259Irq0, FALSE);\r
  }\r
  //\r
  // Save the new timer period\r
  //\r
  mTimerPeriod = TimerPeriod;\r
\r
  return EFI_SUCCESS;\r
}\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
\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
  @retval EFI_SUCCESS            The timer period was returned in TimerPeriod.\r
  @retval EFI_INVALID_PARAMETER  TimerPeriod is NULL.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGetTimerPeriod (\r
  IN EFI_TIMER_ARCH_PROTOCOL   *This,\r
  OUT UINT64                   *TimerPeriod\r
  )\r
{\r
  if (TimerPeriod == NULL) {\r
    return EFI_INVALID_PARAMETER;\r
  }\r
\r
  *TimerPeriod = mTimerPeriod;\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
\r
  This function generates a soft timer interrupt. If the platform does not support soft\r
  timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.\r
  If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()\r
  service, then a soft timer interrupt will be generated. If the timer interrupt is\r
  enabled when this service is called, then the registered handler will be invoked. The\r
  registered handler should not be able to distinguish a hardware-generated timer\r
  interrupt from a software-generated timer interrupt.\r
\r
\r
  @param This              The EFI_TIMER_ARCH_PROTOCOL instance.\r
\r
  @retval EFI_SUCCESS       The soft timer interrupt was generated.\r
  @retval EFI_UNSUPPORTEDT  The platform does not support the generation of soft timer interrupts.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverGenerateSoftInterrupt (\r
  IN EFI_TIMER_ARCH_PROTOCOL  *This\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT16      IRQMask;\r
  EFI_TPL     OriginalTPL;\r
  \r
  //\r
  // If the timer interrupt is enabled, then the registered handler will be invoked.\r
  //\r
  Status = mLegacy8259->GetMask (mLegacy8259, NULL, NULL, &IRQMask, NULL);\r
  ASSERT_EFI_ERROR (Status);\r
  if ((IRQMask & 0x1) == 0) {\r
    //\r
    // Invoke the registered handler\r
    //\r
    OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
\r
    if (mTimerNotifyFunction != NULL) {\r
      //\r
      // @bug : This does not handle missed timer interrupts\r
      //\r
      mTimerNotifyFunction (mTimerPeriod);\r
    }\r
   \r
    gBS->RestoreTPL (OriginalTPL);\r
  } else {\r
    return EFI_UNSUPPORTED;\r
  }\r
\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Initialize the Timer Architectural Protocol driver\r
\r
  @param ImageHandle     ImageHandle of the loaded driver\r
  @param SystemTable     Pointer to the System Table\r
\r
  @retval EFI_SUCCESS            Timer Architectural Protocol created\r
  @retval EFI_OUT_OF_RESOURCES   Not enough resources available to initialize driver.\r
  @retval EFI_DEVICE_ERROR       A device error occured attempting to initialize the driver.\r
\r
**/\r
EFI_STATUS\r
EFIAPI\r
TimerDriverInitialize (\r
  IN EFI_HANDLE        ImageHandle,\r
  IN EFI_SYSTEM_TABLE  *SystemTable\r
  )\r
{\r
  EFI_STATUS  Status;\r
  UINT32      TimerVector;\r
\r
  //\r
  // Initialize the pointer to our notify function.\r
  //\r
  mTimerNotifyFunction = NULL;\r
\r
  //\r
  // Make sure the Timer Architectural Protocol is not already installed in the system\r
  //\r
  ASSERT_PROTOCOL_ALREADY_INSTALLED (NULL, &gEfiTimerArchProtocolGuid);\r
\r
  //\r
  // Find the CPU architectural protocol.\r
  //\r
  Status = gBS->LocateProtocol (&gEfiCpuArchProtocolGuid, NULL, (VOID **) &mCpu);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Find the Legacy8259 protocol.\r
  //\r
  Status = gBS->LocateProtocol (&gEfiLegacy8259ProtocolGuid, NULL, (VOID **) &mLegacy8259);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Force the timer to be disabled\r
  //\r
  Status = TimerDriverSetTimerPeriod (&mTimer, 0);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Get the interrupt vector number corresponding to IRQ0 from the 8259 driver\r
  //\r
  TimerVector = 0;\r
  Status      = mLegacy8259->GetVector (mLegacy8259, Efi8259Irq0, (UINT8 *) &TimerVector);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Install interrupt handler for 8254 Timer #0 (ISA IRQ0)\r
  //\r
  Status = mCpu->RegisterInterruptHandler (mCpu, TimerVector, TimerInterruptHandler);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Force the timer to be enabled at its default period\r
  //\r
  Status = TimerDriverSetTimerPeriod (&mTimer, DEFAULT_TIMER_TICK_DURATION);\r
  ASSERT_EFI_ERROR (Status);\r
\r
  //\r
  // Install the Timer Architectural Protocol onto a new handle\r
  //\r
  Status = gBS->InstallMultipleProtocolInterfaces (\r
                  &mTimerHandle,\r
                  &gEfiTimerArchProtocolGuid, &mTimer,\r
                  NULL\r
                  );\r
  ASSERT_EFI_ERROR (Status);\r
\r
  return Status;\r
}\r
\r