-/*++\r
-\r
-Copyright (c) 2005 - 2006, Intel Corporation \r
-All rights reserved. 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
-Module Name:\r
-\r
- Timer.c\r
-\r
-Abstract:\r
-\r
- Timer Architectural Protocol as defined in the DXE CIS\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
-VOID\r
-SetPitCount (\r
- IN UINT16 Count\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Sets the counter value for Timer #0 in a legacy 8254 timer.\r
-\r
-Arguments:\r
-\r
- Count - The 16-bit counter value to program into Timer #0 of the legacy 8254 timer.\r
-\r
-Returns: \r
-\r
- None\r
-\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
-VOID\r
-EFIAPI\r
-TimerInterruptHandler (\r
- IN EFI_EXCEPTION_TYPE InterruptType,\r
- IN EFI_SYSTEM_CONTEXT SystemContext\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- 8254 Timer #0 Interrupt Handler\r
-\r
-Arguments:\r
-\r
- InterruptType - The type of interrupt that occured\r
-\r
- SystemContext - A pointer to the system context when the interrupt occured\r
-\r
-Returns: \r
-\r
- None\r
-\r
---*/\r
-{\r
- EFI_TPL OriginalTPL;\r
-\r
- OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r
-\r
- mLegacy8259->EndOfInterrupt (mLegacy8259, Efi8259Irq0);\r
-\r
- if (mTimerNotifyFunction) {\r
- //\r
- // BUGBUG : This does not handle missed timer interrupts\r
- //\r
- mTimerNotifyFunction (mTimerPeriod);\r
- }\r
-\r
- gBS->RestoreTPL (OriginalTPL);\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
-Routine Description:\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
-Arguments:\r
-\r
- This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
-\r
- 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
-Returns: \r
-\r
- EFI_SUCCESS - The timer handler was registered.\r
-\r
- EFI_UNSUPPORTED - The platform does not support timer interrupts.\r
-\r
- EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already \r
- registered.\r
-\r
- EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not \r
- previously registered.\r
-\r
- EFI_DEVICE_ERROR - The timer handler could not be registered.\r
-\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
-EFI_STATUS\r
-EFIAPI\r
-TimerDriverSetTimerPeriod (\r
- IN EFI_TIMER_ARCH_PROTOCOL *This,\r
- IN UINT64 TimerPeriod\r
- )\r
-/*++\r
-\r
-Routine Description:\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
-Arguments:\r
-\r
- This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
-\r
- 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
-Returns: \r
-\r
- EFI_SUCCESS - The timer period was changed.\r
-\r
- EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt.\r
-\r
- EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.\r
-\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
-EFI_STATUS\r
-EFIAPI\r
-TimerDriverGetTimerPeriod (\r
- IN EFI_TIMER_ARCH_PROTOCOL *This,\r
- OUT UINT64 *TimerPeriod\r
- )\r
-/*++\r
-\r
-Routine Description:\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
-Arguments:\r
-\r
- This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
-\r
- 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
-Returns: \r
-\r
- EFI_SUCCESS - The timer period was returned in TimerPeriod.\r
-\r
- EFI_INVALID_PARAMETER - TimerPeriod is NULL.\r
-\r
---*/\r
-{\r
- if (TimerPeriod == NULL) {\r
- return EFI_INVALID_PARAMETER;\r
- }\r
-\r
- *TimerPeriod = mTimerPeriod;\r
-\r
- return EFI_SUCCESS;\r
-}\r
-\r
-EFI_STATUS\r
-EFIAPI\r
-TimerDriverGenerateSoftInterrupt (\r
- IN EFI_TIMER_ARCH_PROTOCOL *This\r
- )\r
-/*++\r
-\r
-Routine Description:\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
-Arguments:\r
-\r
- This - The EFI_TIMER_ARCH_PROTOCOL instance.\r
-\r
-Returns: \r
-\r
- EFI_SUCCESS - The soft timer interrupt was generated.\r
-\r
- EFI_UNSUPPORTEDT - The platform does not support the generation of soft timer interrupts.\r
-\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) {\r
- //\r
- // BUGBUG : 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
-EFI_STATUS\r
-EFIAPI\r
-TimerDriverInitialize (\r
- IN EFI_HANDLE ImageHandle,\r
- IN EFI_SYSTEM_TABLE *SystemTable\r
- )\r
-/*++\r
-\r
-Routine Description:\r
-\r
- Initialize the Timer Architectural Protocol driver\r
-\r
-Arguments:\r
-\r
- ImageHandle - ImageHandle of the loaded driver\r
-\r
- SystemTable - Pointer to the System Table\r
-\r
-Returns:\r
-\r
- EFI_SUCCESS - Timer Architectural Protocol created\r
-\r
- EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.\r
- \r
- EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.\r
-\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