pr_debug("read time %02x.%02x.%02x %02x/%02x/%02x\n",
rtc_tm->tm_year, rtc_tm->tm_mon, rtc_tm->tm_mday,
rtc_tm->tm_hour, rtc_tm->tm_min, rtc_tm->tm_sec); // 转化为二进制存储
rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
rtc_tm->tm_year += 100; //因为存储器中存放的是从1900年开始的时间,所有加上100(这是2000年开始,自己改变这个值)
rtc_tm->tm_mon -= 1;
return 0;
}
同理,下面看设置时钟函数
static int s3c_rtc_settime(struct device *dev, struct rtc_time *tm)
{
void __iomem *base = s3c_rtc_base;
int year = tm->tm_year - 100; //理由如上
pr_debug("set time %02d.%02d.%02d %02d/%02d/%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
/* we get around y2k by simply not supporting it */
if (year < 0 || year >= 100) { //由于寄存器的限制,RTC实时时钟只支持100年时间
dev_err(dev, "rtc only supports 100 years\n");
return -EINVAL;
}
//转化为BCD码写到相应的寄存器
writeb(bin2bcd(tm->tm_sec), base + S3C2410_RTCSEC);
writeb(bin2bcd(tm->tm_min), base + S3C2410_RTCMIN);
writeb(bin2bcd(tm->tm_hour), base + S3C2410_RTCHOUR);
writeb(bin2bcd(tm->tm_mday), base + S3C2410_RTCDATE);
writeb(bin2bcd(tm->tm_mon + 1), base + S3C2410_RTCMON);
writeb(bin2bcd(year), base + S3C2410_RTCYEAR);
return 0;
} |