hpet.c File Reference

#include <kernel/cpu/cpu.h>
#include <kernel/log/log.h>
#include <kernel/log/panic.h>
#include <kernel/mem/vmm.h>
#include <kernel/module/module.h>
#include <kernel/sched/sched.h>
#include <kernel/sched/clock.h>
#include <kernel/sched/thread.h>
#include <kernel/sched/wait.h>
#include <kernel/sync/seqlock.h>
#include <kernel/utils/utils.h>
#include <modules/acpi/tables.h>

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Data Structures
struct	hpet_t
	High Precision Event Timer structure. More...

Macros
#define	HPET_CAP_COUNTER_CLK_PERIOD_SHIFT   32
	The bit offset of the clock period in the capabilities register.
#define	HPET_CONF_ENABLE_CNF_BIT   (1 << 0)
	The bit to set to enable the HPET in the configuration register.
#define	HPET_CONF_LEG_RT_CNF_BIT   (1 << 1)
	The bit to set to enable legacy replacement mode in the configuration register.
#define	HPET_ADDRESS_SPACE_MEMORY   0
	If hpet_t::addressSpaceId is equal to this, the address is in system memory space.
#define	HPET_ADDRESS_SPACE_IO   1
	If hpet_t::addressSpaceId is equal to this, the address is in system I/O space.
#define	HPET_FEMTOSECONDS_PER_SECOND   1000000000000000ULL
	The number of femtoseconds in one second.

Enumerations
enum	hpet_register_t {   HPET_REG_GENERAL_CAPABILITIES_ID = 0x000 , HPET_REG_GENERAL_CONFIG = 0x010 , HPET_REG_GENERAL_INTERRUPT = 0x020 , HPET_REG_MAIN_COUNTER_VALUE = 0x0F0 ,   HPET_REG_TIMER0_CONFIG_CAP = 0x100 , HPET_REG_TIMER0_COMPARATOR = 0x108 }
	HPET register offsets. More...

Functions
static void	hpet_write (hpet_register_t reg, uint64_t value)
	Write to an HPET register.
static uint64_t	hpet_read (hpet_register_t reg)
	Read from an HPET register.
static clock_t	hpet_ns_per_tick (void)
	Get the HPET clock period in nanoseconds.
static clock_t	hpet_read_ns_counter (void)
	Safely read the HPET counter value in nanoseconds.
static void	hpet_reset_counter (void)
	Reset the HPET main counter to zero and enable the HPET.
static void	hpet_overflow_thread (void *arg)
	Thread function that periodically accumulates the HPET counter to prevent overflow.
static uint64_t	hpet_init (void)
	Initialize the HPET.
static void	hpet_deinit (void)
	Deinitialize the HPET.
uint64_t	_module_procedure (const module_event_t *event)
	MODULE_INFO ("HPET Driver", "Kai Norberg", "A High Precision Event Timer driver", OS_VERSION, "MIT", "PNP0103")

Variables
static hpet_t *	hpet
	Pointer to the HPET ACPI table.
static uintptr_t	address
	Mapped virtual address of the HPET registers.
static uint64_t	period
	Main counter tick period in femtoseconds (10^-15 s).
static atomic_uint64_t	counter = ATOMIC_VAR_INIT(0)
	Accumulated nanosecond counter, used to avoid overflows.
static seqlock_t	counterLock = SEQLOCK_CREATE()
	Seqlock for the accumulated counter.
static tid_t	overflowThreadTid = 0
	Thread ID of the overflow thread.
static wait_queue_t	overflowQueue = WAIT_QUEUE_CREATE(overflowQueue)
	Wait queue for the overflow thread.
static atomic_bool	overflowShouldStop = ATOMIC_VAR_INIT(false)
	Flag to signal the overflow thread to stop.
static clock_source_t	source
	Structure to describe the HPET to the sys time subsystem.

Function Documentation

_module_procedure()

uint64_t _module_procedure

(

const module_event_t *

event

)

Definition at line 279 of file hpet.c.

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MODULE_INFO()

MODULE_INFO	(	"HPET Driver"	,
		"Kai Norberg"	,
		"A High Precision Event Timer driver"	,
		OS_VERSION	,
		"MIT"	,
		"PNP0103"
	)