mirror of
https://github.com/RGBCube/serenity
synced 2025-05-18 22:25:08 +00:00
fe2bd8e3dd
The APICTimer, HPET and RTC (the RTC timer is in the context of the PC RTC here) are timers that exist only in x86 platforms, therefore, we move the handling code and the initialization code to the Arch/x86/Time directory. Other related code patterns in the TimeManagement singleton and in the Random.cpp file are guarded with #ifdef to ensure they are only compiled for x86 builds.
89 lines
2.2 KiB
C++
89 lines
2.2 KiB
C++
/*
|
|
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <Kernel/Arch/InterruptDisabler.h>
|
|
#include <Kernel/Arch/x86/IO.h>
|
|
#include <Kernel/Arch/x86/Time/PIT.h>
|
|
#include <Kernel/Interrupts/GenericInterruptHandler.h>
|
|
#include <Kernel/Scheduler.h>
|
|
#include <Kernel/Sections.h>
|
|
#include <Kernel/Thread.h>
|
|
#include <Kernel/Time/TimeManagement.h>
|
|
|
|
#define IRQ_TIMER 0
|
|
namespace Kernel {
|
|
|
|
UNMAP_AFTER_INIT NonnullLockRefPtr<PIT> PIT::initialize(Function<void(RegisterState const&)> callback)
|
|
{
|
|
return adopt_lock_ref(*new PIT(move(callback)));
|
|
}
|
|
|
|
[[maybe_unused]] inline static void reset_countdown(u16 timer_reload)
|
|
{
|
|
IO::out8(PIT_CTL, TIMER0_SELECT | WRITE_WORD | MODE_COUNTDOWN);
|
|
IO::out8(TIMER0_CTL, LSB(timer_reload));
|
|
IO::out8(TIMER0_CTL, MSB(timer_reload));
|
|
}
|
|
|
|
PIT::PIT(Function<void(RegisterState const&)> callback)
|
|
: HardwareTimer(IRQ_TIMER, move(callback))
|
|
, m_periodic(true)
|
|
{
|
|
IO::out8(PIT_CTL, TIMER0_SELECT | WRITE_WORD | MODE_SQUARE_WAVE);
|
|
|
|
dmesgln("PIT: {} Hz, square wave ({:#08x})", OPTIMAL_TICKS_PER_SECOND_RATE, BASE_FREQUENCY / OPTIMAL_TICKS_PER_SECOND_RATE);
|
|
reset_to_default_ticks_per_second();
|
|
enable_irq();
|
|
}
|
|
|
|
size_t PIT::ticks_per_second() const
|
|
{
|
|
return m_frequency;
|
|
}
|
|
|
|
void PIT::set_periodic()
|
|
{
|
|
// FIXME: Implement it...
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
void PIT::set_non_periodic()
|
|
{
|
|
// FIXME: Implement it...
|
|
VERIFY_NOT_REACHED();
|
|
}
|
|
|
|
void PIT::reset_to_default_ticks_per_second()
|
|
{
|
|
InterruptDisabler disabler;
|
|
bool success = try_to_set_frequency(OPTIMAL_TICKS_PER_SECOND_RATE);
|
|
VERIFY(success);
|
|
}
|
|
|
|
bool PIT::try_to_set_frequency(size_t frequency)
|
|
{
|
|
InterruptDisabler disabler;
|
|
if (!is_capable_of_frequency(frequency))
|
|
return false;
|
|
disable_irq();
|
|
size_t reload_value = BASE_FREQUENCY / frequency;
|
|
IO::out8(TIMER0_CTL, LSB(reload_value));
|
|
IO::out8(TIMER0_CTL, MSB(reload_value));
|
|
m_frequency = frequency;
|
|
enable_irq();
|
|
return true;
|
|
}
|
|
bool PIT::is_capable_of_frequency(size_t frequency) const
|
|
{
|
|
VERIFY(frequency != 0);
|
|
return frequency <= BASE_FREQUENCY;
|
|
}
|
|
size_t PIT::calculate_nearest_possible_frequency(size_t frequency) const
|
|
{
|
|
VERIFY(frequency != 0);
|
|
return frequency;
|
|
}
|
|
|
|
}
|