lunaix-os/hal/rtc.c

   1 #include <hal/rtc.h>
   2
   3 uint8_t
   4 rtc_read_reg(uint8_t reg_selector)
   5 {
   6     io_outb(RTC_INDEX_PORT, reg_selector);
   7     return io_inb(RTC_TARGET_PORT);
   8 }
   9
  10 uint8_t
  11 bcd2dec(uint8_t bcd)
  12 {
  13     return (bcd >> 4) * 10 + (bcd & 0x0f);
  14 }
  15
  16 void
  17 rtc_get_datetime(rtc_datetime* datetime)
  18 {
  19     datetime->year = rtc_read_reg(RTC_REG_YRS);
  20     datetime->month = rtc_read_reg(RTC_REG_MTH);
  21     datetime->day = rtc_read_reg(RTC_REG_DAY);
  22     datetime->weekday = rtc_read_reg(RTC_REG_WDY);
  23     datetime->hour = rtc_read_reg(RTC_REG_HRS);
  24     datetime->minute = rtc_read_reg(RTC_REG_MIN);
  25     datetime->second = rtc_read_reg(RTC_REG_SEC);
  26
  27     uint8_t regbv = rtc_read_reg(RTC_REG_B);
  28
  29     // Convert from bcd to binary when needed
  30     if (!RTC_BIN_ENCODED(regbv)) {
  31         datetime->year = bcd2dec(datetime->year);
  32         datetime->month = bcd2dec(datetime->month);
  33         datetime->day = bcd2dec(datetime->day);
  34         datetime->hour = bcd2dec(datetime->hour);
  35         datetime->minute = bcd2dec(datetime->minute);
  36         datetime->second = bcd2dec(datetime->second);
  37     }
  38
  39
  40     // To 24 hour format
  41     if (!RTC_24HRS_ENCODED(regbv)) {
  42         datetime->hour = (datetime->hour >> 7) ? (12 + datetime->hour & 0x80)
  43                                                : (datetime->hour & 0x80);
  44     }
  45
  46     datetime->year += RTC_CURRENT_CENTRY * 100;
  47 }