44 lines
845 B
C
44 lines
845 B
C
#include <types.h>
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#include <port_io.h>
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#include <stdio.h>
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#include <drivers/pit.h>
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#define PIT_CHANNEL0 0x40
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#define PIT_COMMAND 0x43
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#define PIT_IRQ_LINE 0
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#define PIT_FREQUENCY_BASE 1193182
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volatile uint64_t pit_ticks = 0;
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bool pit_initialized = false;
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void pit_init(void)
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{
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uint16_t divisor = (uint16_t)1193;
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/* Send command byte */
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outb(PIT_COMMAND, 0x36); /* Channel 0, low/high byte, mode 3 (square wave), binary */
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/* Send divisor low and high byte */
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outb(PIT_CHANNEL0, (uint8_t)(divisor & 0xFF)); /* Low byte */
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outb(PIT_CHANNEL0, (uint8_t)((divisor >> 8) & 0xFF)); /* High byte */
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pit_initialized = true;
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}
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void pit_handler(void)
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{
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pit_ticks++;
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}
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void pit_sleep(uint64_t ms)
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{
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uint64_t target = pit_ticks + ms;
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while (pit_ticks < target)
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{
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asm volatile ("hlt");
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}
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}
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