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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/Assertions.h>
#include <Kernel/Debug.h>
#include <Kernel/Time/HPETComparator.h>
#include <Kernel/Time/TimeManagement.h>
namespace Kernel {
UNMAP_AFTER_INIT NonnullRefPtr<HPETComparator> HPETComparator::create(u8 number, u8 irq, bool periodic_capable)
{
auto timer = adopt(*new HPETComparator(number, irq, periodic_capable));
timer->register_interrupt_handler();
return timer;
}
UNMAP_AFTER_INIT HPETComparator::HPETComparator(u8 number, u8 irq, bool periodic_capable)
: HardwareTimer(irq)
, m_periodic(false)
, m_periodic_capable(periodic_capable)
, m_enabled(false)
, m_comparator_number(number)
{
}
void HPETComparator::disable()
{
if (!m_enabled)
return;
m_enabled = false;
HPET::the().disable(*this);
}
void HPETComparator::set_periodic()
{
VERIFY(m_periodic_capable);
m_periodic = true;
m_enabled = true;
HPET::the().enable_periodic_interrupt(*this);
}
void HPETComparator::set_non_periodic()
{
VERIFY(m_periodic_capable);
m_periodic = false;
m_enabled = true;
HPET::the().disable_periodic_interrupt(*this);
}
void HPETComparator::handle_irq(const RegisterState& regs)
{
HardwareTimer::handle_irq(regs);
if (!is_periodic())
set_new_countdown();
}
void HPETComparator::set_new_countdown()
{
VERIFY_INTERRUPTS_DISABLED();
VERIFY(m_frequency <= HPET::the().frequency());
HPET::the().update_non_periodic_comparator_value(*this);
}
size_t HPETComparator::ticks_per_second() const
{
return m_frequency;
}
void HPETComparator::reset_to_default_ticks_per_second()
{
dbgln("reset_to_default_ticks_per_second");
m_frequency = OPTIMAL_TICKS_PER_SECOND_RATE;
if (!is_periodic())
set_new_countdown();
else
try_to_set_frequency(m_frequency);
}
bool HPETComparator::try_to_set_frequency(size_t frequency)
{
InterruptDisabler disabler;
if (!is_capable_of_frequency(frequency)) {
dbgln("HPETComparator: not cable of frequency: {}", frequency);
return false;
}
auto hpet_frequency = HPET::the().frequency();
VERIFY(frequency <= hpet_frequency);
m_frequency = frequency;
m_enabled = true;
dbgln_if(HPET_COMPARATOR_DEBUG, "HPET Comparator: Max frequency {} Hz, want to set {} Hz, periodic: {}", hpet_frequency, frequency, is_periodic());
if (is_periodic()) {
HPET::the().update_periodic_comparator_value();
} else {
HPET::the().update_non_periodic_comparator_value(*this);
}
enable_irq(); // Enable if we haven't already
return true;
}
bool HPETComparator::is_capable_of_frequency(size_t frequency) const
{
if (frequency > HPET::the().frequency())
return false;
// HPET::update_periodic_comparator_value and HPET::update_non_periodic_comparator_value
// calculate the best counter based on the desired frequency.
return true;
}
size_t HPETComparator::calculate_nearest_possible_frequency(size_t frequency) const
{
if (frequency > HPET::the().frequency())
return HPET::the().frequency();
// HPET::update_periodic_comparator_value and HPET::update_non_periodic_comparator_value
// calculate the best counter based on the desired frequency.
return frequency;
}
u64 HPETComparator::current_raw() const
{
return HPET::the().read_main_counter();
}
u64 HPETComparator::raw_to_ns(u64 raw_delta) const
{
return HPET::the().raw_counter_ticks_to_ns(raw_delta);
}
}
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