MC13XXX_RTCDAY
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);