PcAtChipsetPkg/8254TimerDxe/Timer.h - third_party/edk2 - Git at Google

 /*++

 Copyright (c) 2005 - 2006, Intel Corporation
 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.


 Module Name:

  Timer.h

 Abstract:

   Private data structures

 --*/

 #ifndef _TIMER_H_
 #define _TIMER_H_

 #include <PiDxe.h>

 #include <Protocol/Cpu.h>
 #include <Protocol/Legacy8259.h>
 #include <Protocol/Timer.h>

 #include <Library/UefiBootServicesTableLib.h>
 #include <Library/BaseLib.h>
 #include <Library/DebugLib.h>
 #include <Library/IoLib.h>

 //
 // The PCAT 8253/8254 has an input clock at 1.193182 MHz and Timer 0 is
 // initialized as a 16 bit free running counter that generates an interrupt(IRQ0)
 // each time the counter rolls over.
 //
 //   65536 counts
 // ---------------- * 1,000,000 uS/S = 54925.4 uS = 549254 * 100 ns
 //   1,193,182 Hz
 //
 // The default timer tick duration is set to 10 ms = 100000 100 ns units
 //
 #define DEFAULT_TIMER_TICK_DURATION 100000
 #define TIMER_CONTROL_PORT          0x43
 #define TIMER0_COUNT_PORT           0x40

 //
 // Function Prototypes
 //
 EFI_STATUS
 EFIAPI
 TimerDriverInitialize (
   IN EFI_HANDLE        ImageHandle,
   IN EFI_SYSTEM_TABLE  *SystemTable
   )
 /*++

 Routine Description:

   Initialize the Timer Architectural Protocol driver

 Arguments:

   ImageHandle - ImageHandle of the loaded driver

   SystemTable - Pointer to the System Table

 Returns:

   EFI_SUCCESS           - Timer Architectural Protocol created

   EFI_OUT_OF_RESOURCES  - Not enough resources available to initialize driver.

   EFI_DEVICE_ERROR      - A device error occured attempting to initialize the driver.

 --*/
 ;

 EFI_STATUS
 EFIAPI
 TimerDriverRegisterHandler (
   IN EFI_TIMER_ARCH_PROTOCOL  *This,
   IN EFI_TIMER_NOTIFY         NotifyFunction
   )
 /*++

 Routine Description:

   This function registers the handler NotifyFunction so it is called every time
   the timer interrupt fires.  It also passes the amount of time since the last
   handler call to the NotifyFunction.  If NotifyFunction is NULL, then the
   handler is unregistered.  If the handler is registered, then EFI_SUCCESS is
   returned.  If the CPU does not support registering a timer interrupt handler,
   then EFI_UNSUPPORTED is returned.  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.  If an error occurs attempting to
   register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
   is returned.

 Arguments:

   This           - The EFI_TIMER_ARCH_PROTOCOL instance.

   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.

 Returns:

   EFI_SUCCESS           - The timer handler was registered.

   EFI_UNSUPPORTED       - The platform does not support timer interrupts.

   EFI_ALREADY_STARTED   - NotifyFunction is not NULL, and a handler is already
                           registered.

   EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
                           previously registered.

   EFI_DEVICE_ERROR      - The timer handler could not be registered.

 --*/
 ;

 EFI_STATUS
 EFIAPI
 TimerDriverSetTimerPeriod (
   IN EFI_TIMER_ARCH_PROTOCOL  *This,
   IN UINT64                   TimerPeriod
   )
 /*++

 Routine Description:

   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.

 Arguments:

   This        - The EFI_TIMER_ARCH_PROTOCOL instance.

   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.

 Returns:

   EFI_SUCCESS      - The timer period was changed.

   EFI_UNSUPPORTED  - The platform cannot change the period of the timer interrupt.

   EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.

 --*/
 ;

 EFI_STATUS
 EFIAPI
 TimerDriverGetTimerPeriod (
   IN EFI_TIMER_ARCH_PROTOCOL   *This,
   OUT UINT64                   *TimerPeriod
   )
 /*++

 Routine Description:

   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.

 Arguments:

   This        - The EFI_TIMER_ARCH_PROTOCOL instance.

   TimerPeriod - A pointer to the timer period to retrieve in 100 ns units.  If
                 0 is returned, then the timer is currently disabled.

 Returns:

   EFI_SUCCESS           - The timer period was returned in TimerPeriod.

   EFI_INVALID_PARAMETER - TimerPeriod is NULL.

 --*/
 ;

 EFI_STATUS
 EFIAPI
 TimerDriverGenerateSoftInterrupt (
   IN EFI_TIMER_ARCH_PROTOCOL  *This
   )
 /*++

 Routine Description:

   This function generates a soft timer interrupt. If the platform does not support soft
   timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
   If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
   service, then a soft timer interrupt will be generated. If the timer interrupt is
   enabled when this service is called, then the registered handler will be invoked. The
   registered handler should not be able to distinguish a hardware-generated timer
   interrupt from a software-generated timer interrupt.

 Arguments:

   This  -  The EFI_TIMER_ARCH_PROTOCOL instance.

 Returns:

   EFI_SUCCESS       - The soft timer interrupt was generated.

   EFI_UNSUPPORTEDT  - The platform does not support the generation of soft timer interrupts.

 --*/
 ;

 #endif
	/*++

	Copyright (c) 2005 - 2006, Intel Corporation
	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.


	Module Name:

	Timer.h

	Abstract:

	Private data structures

	--*/

	#ifndef _TIMER_H_
	#define _TIMER_H_

	#include <PiDxe.h>

	#include <Protocol/Cpu.h>
	#include <Protocol/Legacy8259.h>
	#include <Protocol/Timer.h>

	#include <Library/UefiBootServicesTableLib.h>
	#include <Library/BaseLib.h>
	#include <Library/DebugLib.h>
	#include <Library/IoLib.h>

	//
	// The PCAT 8253/8254 has an input clock at 1.193182 MHz and Timer 0 is
	// initialized as a 16 bit free running counter that generates an interrupt(IRQ0)
	// each time the counter rolls over.
	//
	// 65536 counts
	// ---------------- * 1,000,000 uS/S = 54925.4 uS = 549254 * 100 ns
	// 1,193,182 Hz
	//
	// The default timer tick duration is set to 10 ms = 100000 100 ns units
	//
	#define DEFAULT_TIMER_TICK_DURATION 100000
	#define TIMER_CONTROL_PORT 0x43
	#define TIMER0_COUNT_PORT 0x40

	//
	// Function Prototypes
	//
	EFI_STATUS
	EFIAPI
	TimerDriverInitialize (
	IN EFI_HANDLE ImageHandle,
	IN EFI_SYSTEM_TABLE *SystemTable
	)
	/*++

	Routine Description:

	Initialize the Timer Architectural Protocol driver

	Arguments:

	ImageHandle - ImageHandle of the loaded driver

	SystemTable - Pointer to the System Table

	Returns:

	EFI_SUCCESS - Timer Architectural Protocol created

	EFI_OUT_OF_RESOURCES - Not enough resources available to initialize driver.

	EFI_DEVICE_ERROR - A device error occured attempting to initialize the driver.

	--*/
	;

	EFI_STATUS
	EFIAPI
	TimerDriverRegisterHandler (
	IN EFI_TIMER_ARCH_PROTOCOL *This,
	IN EFI_TIMER_NOTIFY NotifyFunction
	)
	/*++

	Routine Description:

	This function registers the handler NotifyFunction so it is called every time
	the timer interrupt fires. It also passes the amount of time since the last
	handler call to the NotifyFunction. If NotifyFunction is NULL, then the
	handler is unregistered. If the handler is registered, then EFI_SUCCESS is
	returned. If the CPU does not support registering a timer interrupt handler,
	then EFI_UNSUPPORTED is returned. 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. If an error occurs attempting to
	register the NotifyFunction with the timer interrupt, then EFI_DEVICE_ERROR
	is returned.

	Arguments:

	This - The EFI_TIMER_ARCH_PROTOCOL instance.

	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.

	Returns:

	EFI_SUCCESS - The timer handler was registered.

	EFI_UNSUPPORTED - The platform does not support timer interrupts.

	EFI_ALREADY_STARTED - NotifyFunction is not NULL, and a handler is already
	registered.

	EFI_INVALID_PARAMETER - NotifyFunction is NULL, and a handler was not
	previously registered.

	EFI_DEVICE_ERROR - The timer handler could not be registered.

	--*/
	;

	EFI_STATUS
	EFIAPI
	TimerDriverSetTimerPeriod (
	IN EFI_TIMER_ARCH_PROTOCOL *This,
	IN UINT64 TimerPeriod
	)
	/*++

	Routine Description:

	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.

	Arguments:

	This - The EFI_TIMER_ARCH_PROTOCOL instance.

	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.

	Returns:

	EFI_SUCCESS - The timer period was changed.

	EFI_UNSUPPORTED - The platform cannot change the period of the timer interrupt.

	EFI_DEVICE_ERROR - The timer period could not be changed due to a device error.

	--*/
	;

	EFI_STATUS
	EFIAPI
	TimerDriverGetTimerPeriod (
	IN EFI_TIMER_ARCH_PROTOCOL *This,
	OUT UINT64 *TimerPeriod
	)
	/*++

	Routine Description:

	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.

	Arguments:

	This - The EFI_TIMER_ARCH_PROTOCOL instance.

	TimerPeriod - A pointer to the timer period to retrieve in 100 ns units. If
	0 is returned, then the timer is currently disabled.

	Returns:

	EFI_SUCCESS - The timer period was returned in TimerPeriod.

	EFI_INVALID_PARAMETER - TimerPeriod is NULL.

	--*/
	;

	EFI_STATUS
	EFIAPI
	TimerDriverGenerateSoftInterrupt (
	IN EFI_TIMER_ARCH_PROTOCOL *This
	)
	/*++

	Routine Description:

	This function generates a soft timer interrupt. If the platform does not support soft
	timer interrupts, then EFI_UNSUPPORTED is returned. Otherwise, EFI_SUCCESS is returned.
	If a handler has been registered through the EFI_TIMER_ARCH_PROTOCOL.RegisterHandler()
	service, then a soft timer interrupt will be generated. If the timer interrupt is
	enabled when this service is called, then the registered handler will be invoked. The
	registered handler should not be able to distinguish a hardware-generated timer
	interrupt from a software-generated timer interrupt.

	Arguments:

	This - The EFI_TIMER_ARCH_PROTOCOL instance.

	Returns:

	EFI_SUCCESS - The soft timer interrupt was generated.

	EFI_UNSUPPORTEDT - The platform does not support the generation of soft timer interrupts.

	--*/
	;

	#endif