audk/EmbeddedPkg/TemplateTimerDxe/Timer.c

374 lines
12 KiB
C

/** @file
Template for Timer Architecture Protocol driver of the ARM flavor
Copyright (c) 2008-2009, Apple Inc. All rights reserved.
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.
**/
#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/DebugLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/UefiLib.h>
#include <Library/PcdLib.h>
#include <Library/IoLib.h>
#include <Protocol/Timer.h>
#include <Protocol/HardwareInterrupt.h>
//
// Get Base Address of timer block from platform .DSC file
//
#define TIMER_BASE ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00c0)
#define TIMER_CMD ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000004)
#define TIMER_DATA ((UINTN)FixedPcdGet32 (PcdTimerBaseAddress) + 0x00000008)
//
// The notification function to call on every timer interrupt.
// A bug in the compiler prevents us from initializing this here.
//
volatile EFI_TIMER_NOTIFY mTimerNotifyFunction;
//
// The current period of the timer interrupt
//
volatile UINT64 mTimerPeriod = 0;
//
// Cached copy of the Hardware Interrupt protocol instance
//
EFI_HARDWARE_INTERRUPT_PROTOCOL *gInterrupt = NULL;
/**
C Interrupt Handler calledin the interrupt context when Source interrupt is active.
@param Source Source of the interrupt. Hardware routing off a specific platform defines
what source means.
@param SystemContext Pointer to system register context. Mostly used by debuggers and will
update the system context after the return from the interrupt if
modified. Don't change these values unless you know what you are doing
**/
VOID
EFIAPI
TimerInterruptHandler (
IN HARDWARE_INTERRUPT_SOURCE Source,
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
EFI_TPL OriginalTPL;
// Mask all interrupts
OriginalTPL = gBS->RaiseTPL (TPL_HIGH_LEVEL);
MmioWrite32 (TIMER_CMD, 0);
if (mTimerNotifyFunction) {
mTimerNotifyFunction (mTimerPeriod);
}
// restore state
gBS->RestoreTPL (OriginalTPL);
}
/**
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.
@param This The EFI_TIMER_ARCH_PROTOCOL instance.
@param 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.
@retval EFI_SUCCESS The timer handler was registered.
@retval EFI_UNSUPPORTED The platform does not support timer interrupts.
@retval EFI_ALREADY_STARTED NotifyFunction is not NULL, and a handler is already
registered.
@retval EFI_INVALID_PARAMETER NotifyFunction is NULL, and a handler was not
previously registered.
@retval EFI_DEVICE_ERROR The timer handler could not be registered.
**/
EFI_STATUS
EFIAPI
TimerDriverRegisterHandler (
IN EFI_TIMER_ARCH_PROTOCOL *This,
IN EFI_TIMER_NOTIFY NotifyFunction
)
{
//
// Check for invalid parameters
//
if (NotifyFunction == NULL && mTimerNotifyFunction == NULL) {
return EFI_INVALID_PARAMETER;
}
if (NotifyFunction != NULL && mTimerNotifyFunction != NULL) {
return EFI_ALREADY_STARTED;
}
mTimerNotifyFunction = NotifyFunction;
return EFI_SUCCESS;
}
/**
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.
@param This The EFI_TIMER_ARCH_PROTOCOL instance.
@param 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.
@retval EFI_SUCCESS The timer period was changed.
@retval EFI_UNSUPPORTED The platform cannot change the period of the timer interrupt.
@retval EFI_DEVICE_ERROR The timer period could not be changed due to a device error.
**/
EFI_STATUS
EFIAPI
TimerDriverSetTimerPeriod (
IN EFI_TIMER_ARCH_PROTOCOL *This,
IN UINT64 TimerPeriod
)
{
EFI_STATUS Status;
UINT64 TimerCount;
if (TimerPeriod == 0) {
//
// Disable interrupt 0 and timer
//
MmioAnd32 (TIMER_DATA, 0);
Status = gInterrupt->DisableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector));
} else {
//
// Convert TimerPeriod into Timer F counts
//
TimerCount = DivU64x32 (TimerPeriod + 5, 10);
//
// Program Timer F with the new count value
//
MmioWrite32 (TIMER_DATA, (UINT32)TimerCount);
//
// Enable interrupt and initialize and enable timer.
//
MmioOr32 (TIMER_CMD, 0x11);
Status = gInterrupt->EnableInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector));
}
//
// Save the new timer period
//
mTimerPeriod = TimerPeriod;
return Status;
}
/**
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.
@param This The EFI_TIMER_ARCH_PROTOCOL instance.
@param TimerPeriod A pointer to the timer period to retrieve in 100 ns units. If
0 is returned, then the timer is currently disabled.
@retval EFI_SUCCESS The timer period was returned in TimerPeriod.
@retval EFI_INVALID_PARAMETER TimerPeriod is NULL.
**/
EFI_STATUS
EFIAPI
TimerDriverGetTimerPeriod (
IN EFI_TIMER_ARCH_PROTOCOL *This,
OUT UINT64 *TimerPeriod
)
{
if (TimerPeriod == NULL) {
return EFI_INVALID_PARAMETER;
}
*TimerPeriod = mTimerPeriod;
return EFI_SUCCESS;
}
/**
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.
@param This The EFI_TIMER_ARCH_PROTOCOL instance.
@retval EFI_SUCCESS The soft timer interrupt was generated.
@retval EFI_UNSUPPORTED The platform does not support the generation of soft timer interrupts.
**/
EFI_STATUS
EFIAPI
TimerDriverGenerateSoftInterrupt (
IN EFI_TIMER_ARCH_PROTOCOL *This
)
{
return EFI_UNSUPPORTED;
}
/**
Interface stucture for the Timer Architectural Protocol.
@par Protocol Description:
This protocol provides the services to initialize a periodic timer
interrupt, and to register a handler that is called each time the timer
interrupt fires. It may also provide a service to adjust the rate of the
periodic timer interrupt. When a timer interrupt occurs, the handler is
passed the amount of time that has passed since the previous timer
interrupt.
@param RegisterHandler
Registers a handler that will be called each time the
timer interrupt fires. TimerPeriod defines the minimum
time between timer interrupts, so TimerPeriod will also
be the minimum time between calls to the registered
handler.
@param SetTimerPeriod
Sets the period of the timer interrupt in 100 nS units.
This function is optional, and may return EFI_UNSUPPORTED.
If this function is supported, then the timer period will
be rounded up to the nearest supported timer period.
@param GetTimerPeriod
Retrieves the period of the timer interrupt in 100 nS units.
@param GenerateSoftInterrupt
Generates a soft timer interrupt that simulates the firing of
the timer interrupt. This service can be used to invoke the
registered handler if the timer interrupt has been masked for
a period of time.
**/
EFI_TIMER_ARCH_PROTOCOL gTimer = {
TimerDriverRegisterHandler,
TimerDriverSetTimerPeriod,
TimerDriverGetTimerPeriod,
TimerDriverGenerateSoftInterrupt
};
EFI_HANDLE gTimerHandle = NULL;
/**
Initialize the state information for the Timer Architectural Protocol
@param ImageHandle of the loaded driver
@param SystemTable Pointer to the System Table
@retval EFI_SUCCESS Protocol registered
@retval EFI_OUT_OF_RESOURCES Cannot allocate protocol data structure
@retval EFI_DEVICE_ERROR Hardware problems
**/
EFI_STATUS
EFIAPI
TimerInitialize (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
//
// Find the interrupt controller protocol. ASSERT if not found.
//
Status = gBS->LocateProtocol (&gHardwareInterruptProtocolGuid, NULL, ( VOID ** )&gInterrupt);
ASSERT_EFI_ERROR (Status);
MmioWrite32 (TIMER_CMD, 0x01);
//
// Force the timer to be disabled
//
Status = TimerDriverSetTimerPeriod (&gTimer, 0);
ASSERT_EFI_ERROR (Status);
//
// Install interrupt handler
//
Status = gInterrupt->RegisterInterruptSource (gInterrupt, FixedPcdGet32 (PcdTimerVector), TimerInterruptHandler);
ASSERT_EFI_ERROR (Status);
//
// Force the timer to be enabled at its default period
//
Status = TimerDriverSetTimerPeriod (&gTimer, FixedPcdGet32 (PcdTimerPeriod));
ASSERT_EFI_ERROR (Status);
//
// Install the Timer Architectural Protocol onto a new handle
//
Status = gBS->InstallMultipleProtocolInterfaces (
&gTimerHandle,
&gEfiTimerArchProtocolGuid, &gTimer,
NULL
);
ASSERT_EFI_ERROR (Status);
return Status;
}