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#include "arch/devices/legacy_pit.hpp"
#include "kapi/devices.hpp"
#include "kapi/devices/device.hpp"
#include "kapi/interrupts.hpp"
#include "arch/device_io/port_io.hpp"
#include <cstddef>
#include <cstdint>
namespace arch::devices
{
namespace
{
using command_port = io::port<0x43, std::uint8_t, io::port_write>;
using channel_0_port = io::port<0x40, std::uint8_t, io::port_write>;
using channel_1_port = io::port<0x41, std::uint8_t, io::port_write>;
using channel_2_port = io::port<0x42, std::uint8_t, io::port_write>;
constexpr auto base_frequency = 1'193'182u;
constexpr auto square_wave_mode = 0x36;
} // namespace
legacy_pit::legacy_pit(std::size_t major, std::uint32_t frequency_in_hz)
: kapi::devices::device{major, 0, "legacy_pit"}
, m_irq_number{0}
, m_frequency_in_hz{frequency_in_hz}
{}
auto legacy_pit::init() -> bool
{
auto divisor = static_cast<std::uint16_t>(base_frequency / m_frequency_in_hz);
kapi::interrupts::register_handler(m_irq_number, *this);
command_port::write<std::uint8_t>(square_wave_mode);
io::wait();
channel_0_port::write<std::uint8_t>(divisor & 0xff);
io::wait();
channel_0_port::write<std::uint8_t>(divisor >> 8 & 0xff);
io::wait();
return true;
}
auto legacy_pit::handle_interrupt(std::uint32_t irq_number) -> kapi::interrupts::status
{
if (irq_number != m_irq_number)
{
return kapi::interrupts::status::unhandled;
}
++m_ticks;
return kapi::interrupts::status::handled;
}
} // namespace arch::devices
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