--- /dev/null
+/*++\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
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