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