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Justin C. Miller
f4cbb9498f
Calling `spinwait()` was hanging due to improper computation of the clock rate because justin did a dumb at math. Also the period can be greater than 1ns, so the clock's units were updated to microseconds.
47 lines
1.0 KiB
C++
47 lines
1.0 KiB
C++
#pragma once
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/// \file hpet.h
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/// Definitions for handling the HPET timer
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#include <stdint.h>
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/// Source function for the clock that takes a pointer to
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/// an hpet object.
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uint64_t hpet_clock_source(void *);
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/// Represents a single HPET timer
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class hpet
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{
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public:
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/// Constructor.
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/// \arg index The index of the HPET out of all HPETs
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/// \arg base The base address of the HPET for MMIO
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hpet(uint8_t index, uint64_t *base);
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/// Configure the timer and start it running.
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void enable();
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/// Get the timer rate in ticks per us
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inline uint64_t rate() const { return 1000000000/m_period; }
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/// Get the current timer value
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uint64_t value() const;
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private:
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friend void hpet_irq_callback(void *);
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friend uint64_t hpet_clock_source(void *);
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void setup_timer_interrupts(unsigned timer, uint8_t irq, uint64_t interval, bool periodic);
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void enable_timer(unsigned timer);
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void disable_timer(unsigned timer);
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void callback();
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uint8_t m_timers;
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uint8_t m_index;
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uint64_t m_period;
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volatile uint64_t *m_base;
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};
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