Commit bcebd81d authored by Stefan Christ's avatar Stefan Christ Committed by Alexandre Belloni

rtc: m41t80: avoid out of range year values

Avoid saving an out of range year value to the RTC. Reading that value
from the RTC again returns a totally wrong time value. For Example

    $ timedatectl set-ntp no
    $ timedatectl set-time "1990-01-01 12:12:00"
    # Reboot
    rtc-m41t80 0-0068: setting system clock to 2090-01-01 12:12:35 UTC (3786955955)
Signed-off-by: default avatarStefan Christ <s.christ@phytec.de>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@free-electrons.com>
parent ae6e00b4
...@@ -176,7 +176,13 @@ static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm) ...@@ -176,7 +176,13 @@ static int m41t80_set_datetime(struct i2c_client *client, struct rtc_time *tm)
bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f); bin2bcd(tm->tm_mday) | (buf[M41T80_REG_DAY] & ~0x3f);
buf[M41T80_REG_MON] = buf[M41T80_REG_MON] =
bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f); bin2bcd(tm->tm_mon + 1) | (buf[M41T80_REG_MON] & ~0x1f);
/* assume 20YY not 19YY */ /* assume 20YY not 19YY */
if (tm->tm_year < 100 || tm->tm_year > 199) {
dev_err(&client->dev, "Year must be between 2000 and 2099. It's %d.\n",
tm->tm_year + 1900);
return -EINVAL;
}
buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100); buf[M41T80_REG_YEAR] = bin2bcd(tm->tm_year % 100);
if (i2c_transfer(client->adapter, msgs, 1) != 1) { if (i2c_transfer(client->adapter, msgs, 1) != 1) {
......
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