[PATCH] It assume 20xx not 19xx.

[Linkui]

From: Linkui Xiao <xiaolin...@kylinos.cn>

If we settime between 1970 and 2000.
for example:
root# date 052915571978
root# hwclock -w

It will be wrong, this patch fix the bug.

Signed-off-by: Linkui Xiao <xiaolin...@kylinos.cn>
---
 drivers/rtc/rtc-ds1307.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
index a13e59e..8c218a1 100644
--- a/drivers/rtc/rtc-ds1307.c
+++ b/drivers/rtc/rtc-ds1307.c
@@ -425,7 +425,9 @@ static int ds1307_get_time(struct device *dev, struct 
rtc_time *t)
        t->tm_mday = bcd2bin(regs[DS1307_REG_MDAY] & 0x3f);
        tmp = regs[DS1307_REG_MONTH] & 0x1f;
        t->tm_mon = bcd2bin(tmp) - 1;
-       t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]) + 100;
+       t->tm_year = bcd2bin(regs[DS1307_REG_YEAR]);
+       if (t->tm_year >= 0 && t->tm_year <= 69)
+               t->tm_year += 100;
 
        if (regs[chip->century_reg] & chip->century_bit &&
            IS_ENABLED(CONFIG_RTC_DRV_DS1307_CENTURY))
@@ -454,7 +456,7 @@ static int ds1307_set_time(struct device *dev, struct 
rtc_time *t)
                t->tm_hour, t->tm_mday,
                t->tm_mon, t->tm_year, t->tm_wday);
 
-       if (t->tm_year < 100)
+       if (t->tm_year < 0)
                return -EINVAL;
 
 #ifdef CONFIG_RTC_DRV_DS1307_CENTURY
@@ -472,8 +474,9 @@ static int ds1307_set_time(struct device *dev, struct 
rtc_time *t)
        regs[DS1307_REG_MDAY] = bin2bcd(t->tm_mday);
        regs[DS1307_REG_MONTH] = bin2bcd(t->tm_mon + 1);
 
-       /* assume 20YY not 19YY */
-       tmp = t->tm_year - 100;
+       tmp = t->tm_year;
+       if (tmp >= 100 && tmp <= 169)
+               tmp -= 100;
        regs[DS1307_REG_YEAR] = bin2bcd(tmp);
 
        if (chip->century_enable_bit)
-- 
2.7.4