RYRCNT
RDAYCNT, RMONCNT, RYRCNT };
ret = ret ? ret : write_reg(dev, RYRCNT, bin2bcd(dt->tm_year - 100));
yr = readw(rtc->regbase + RYRCNT);
yr = readb(rtc->regbase + RYRCNT);
writew(year, rtc->regbase + RYRCNT);
writeb(bin2bcd(year), rtc->regbase + RYRCNT);