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/*
* Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/NonnullRefPtr.h>
#include <AK/Types.h>
#include <Kernel/Time/HardwareTimer.h>
namespace Kernel {
/* Timer related ports */
#define TIMER0_CTL 0x40
#define TIMER1_CTL 0x41
#define TIMER2_CTL 0x42
#define PIT_CTL 0x43
/* Building blocks for PIT_CTL */
#define TIMER0_SELECT 0x00
#define TIMER1_SELECT 0x40
#define TIMER2_SELECT 0x80
#define MODE_COUNTDOWN 0x00
#define MODE_ONESHOT 0x02
#define MODE_RATE 0x04
#define MODE_SQUARE_WAVE 0x06
#define WRITE_WORD 0x30
#define BASE_FREQUENCY 1193182
class PIT final : public HardwareTimer<IRQHandler> {
public:
static NonnullRefPtr<PIT> initialize(Function<void(RegisterState const&)>);
virtual HardwareTimerType timer_type() const override { return HardwareTimerType::i8253; }
virtual StringView model() const override { return "i8254"sv; }
virtual size_t ticks_per_second() const override;
virtual bool is_periodic() const override { return m_periodic; }
virtual bool is_periodic_capable() const override { return true; }
virtual void set_periodic() override;
virtual void set_non_periodic() override;
virtual void disable() override { }
virtual void reset_to_default_ticks_per_second() override;
virtual bool try_to_set_frequency(size_t frequency) override;
virtual bool is_capable_of_frequency(size_t frequency) const override;
virtual size_t calculate_nearest_possible_frequency(size_t frequency) const override;
private:
explicit PIT(Function<void(RegisterState const&)>);
bool m_periodic { true };
};
}
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