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/*++
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/CpuIo.h>
#include <Protocol/Legacy8259.h>
#include <Protocol/Timer.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.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
//
#define DEFAULT_TIMER_TICK_DURATION 549254
#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
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