diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-07-13 02:26:08 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-08-31 18:21:34 +0200 |
| commit | 50d6c0ea8111100a102c03b4410ba1e45fa8b771 (patch) | |
| tree | e118f6f86d3ff9df9c36223bcbea76f4fa3fb193 /drivers/rtc/rtc-ds1307.c | |
| parent | 59e5e70c9516a0ba34dd5a1a44ed89518cd5eda9 (diff) | |
rtc: ds1307: fix century bit support
Add an option to properly support the century bit of ds1337 and compatibles
and ds1340.
Because the driver had a bug until now, it is not possible to switch users
to the fixed code directly as RTCs in the field will wrongly have the
century bit set.
Acked-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers/rtc/rtc-ds1307.c')
| -rw-r--r-- | drivers/rtc/rtc-ds1307.c | 48 |
1 files changed, 43 insertions, 5 deletions
diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c index 8e1c5cb6ece6..712e221d2415 100644 --- a/drivers/rtc/rtc-ds1307.c +++ b/drivers/rtc/rtc-ds1307.c @@ -382,10 +382,25 @@ static int ds1307_get_time(struct device *dev, struct rtc_time *t) t->tm_mday = bcd2bin(ds1307->regs[DS1307_REG_MDAY] & 0x3f); tmp = ds1307->regs[DS1307_REG_MONTH] & 0x1f; t->tm_mon = bcd2bin(tmp) - 1; - - /* assume 20YY not 19YY, and ignore DS1337_BIT_CENTURY */ t->tm_year = bcd2bin(ds1307->regs[DS1307_REG_YEAR]) + 100; +#ifdef CONFIG_RTC_DRV_DS1307_CENTURY + switch (ds1307->type) { + case ds_1337: + case ds_1339: + case ds_3231: + if (ds1307->regs[DS1307_REG_MONTH] & DS1337_BIT_CENTURY) + t->tm_year += 100; + break; + case ds_1340: + if (ds1307->regs[DS1307_REG_HOUR] & DS1340_BIT_CENTURY) + t->tm_year += 100; + break; + default: + break; + } +#endif + dev_dbg(dev, "%s secs=%d, mins=%d, " "hours=%d, mday=%d, mon=%d, year=%d, wday=%d\n", "read", t->tm_sec, t->tm_min, @@ -409,6 +424,27 @@ 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); +#ifdef CONFIG_RTC_DRV_DS1307_CENTURY + if (t->tm_year < 100) + return -EINVAL; + + switch (ds1307->type) { + case ds_1337: + case ds_1339: + case ds_3231: + case ds_1340: + if (t->tm_year > 299) + return -EINVAL; + default: + if (t->tm_year > 199) + return -EINVAL; + break; + } +#else + if (t->tm_year < 100 || t->tm_year > 199) + return -EINVAL; +#endif + buf[DS1307_REG_SECS] = bin2bcd(t->tm_sec); buf[DS1307_REG_MIN] = bin2bcd(t->tm_min); buf[DS1307_REG_HOUR] = bin2bcd(t->tm_hour); @@ -424,11 +460,13 @@ static int ds1307_set_time(struct device *dev, struct rtc_time *t) case ds_1337: case ds_1339: case ds_3231: - buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY; + if (t->tm_year > 199) + buf[DS1307_REG_MONTH] |= DS1337_BIT_CENTURY; break; case ds_1340: - buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN - | DS1340_BIT_CENTURY; + buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY_EN; + if (t->tm_year > 199) + buf[DS1307_REG_HOUR] |= DS1340_BIT_CENTURY; break; case mcp794xx: /* |