rtc.c

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#include "libk/serial.h"
#include <hal/timer/rtc.h>
#include <libk/io.h>
 
#define CMOS_ADDR 0x70
#define CMOS_DATA 0x71
 
static uint8_t cmos_read(uint8_t reg) {
    outb(CMOS_ADDR, reg);
    return inb(CMOS_DATA);
}
 
static bool rtc_is_updating() {
    outb(CMOS_ADDR, 0x0A);
    return inb(CMOS_DATA) & 0x80;
}
 
typedef struct {
    uint8_t second;
    uint8_t minute;
    uint8_t hour;
    uint8_t day;
    uint8_t month;
    uint8_t year;
 
} date_time;
 
static void rtc_read_time(date_time* dt) {
    while (rtc_is_updating())
        ; // tunggu UIP clear
    uint8_t sec = cmos_read(0x00);
    uint8_t min = cmos_read(0x02);
    uint8_t hour = cmos_read(0x04);
    uint8_t day = cmos_read(0x07);
    uint8_t month = cmos_read(0x08);
    uint8_t year = cmos_read(0x09);
 
    // BCD ke binary
    uint8_t regB = cmos_read(0x0B);
    if (!(regB & 0x04)) {
        sec = ((sec & 0x0F) + ((sec / 16) * 10));
        min = ((min & 0x0F) + ((min / 16) * 10));
        hour = ((hour & 0x0F) + (((hour / 16) * 10)));
        day = ((day & 0x0F) + ((day / 16) * 10));
        month = ((month & 0x0F) + ((month / 16) * 10));
        year = ((year & 0x0F) + ((year / 16) * 10));
    }
 
    // Format 12h ke 24h jika perlu
    if (!(regB & 0x02) && (hour & 0x80)) {
        hour = ((hour & 0x7F) + 12) % 24;
    }
    dt->second = sec;
    dt->minute = min;
    dt->hour = hour;
    dt->day = day;
    dt->month = month;
    dt->year = year;
}
 
// static void rtc_enable_periodic_interrupt() {
//  outb(CMOS_ADDR, 0x8A);
//  uint8_t prevA = inb(CMOS_DATA);
//  outb(CMOS_ADDR, 0x8A);
//  outb(CMOS_DATA, (prevA & 0xF0) | 0x06); // 1024 Hz misalnya
 
//  outb(CMOS_ADDR, 0x8B);
//  uint8_t prevB = inb(CMOS_DATA);
//  outb(CMOS_ADDR, 0x8B);
//  outb(CMOS_DATA, prevB | 0x40); // Set PIE
// }
 
// void rtc_isr() {
//  outb(CMOS_ADDR, 0x0C);
//  inb(CMOS_DATA); // wajib dibaca untuk clear IRQ
//          // ... lakukan hal lain seperti update jam global ...
// }
 
void rtc_initialize(void) {
    date_time dt;
    rtc_read_time(&dt);
    LOG_INFO("RTC", "sekarang hari %d/%d/%d jam %d:%d:%d", dt.day, dt.month,
         dt.year, dt.hour, dt.minute, dt.second);
}