diff options
Diffstat (limited to 'drivers/rtc/rtc-pcf8563.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf8563.c | 44 |
1 files changed, 43 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c index bc0677de1996..97a3284bb7c6 100644 --- a/drivers/rtc/rtc-pcf8563.c +++ b/drivers/rtc/rtc-pcf8563.c @@ -64,6 +64,7 @@ struct pcf8563 { * 1970...2069. */ int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */ + int voltage_low; /* incicates if a low_voltage was detected */ }; /* @@ -86,9 +87,11 @@ static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm) return -EIO; } - if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) + if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) { + pcf8563->voltage_low = 1; dev_info(&client->dev, "low voltage detected, date/time is not reliable.\n"); + } dev_dbg(&client->dev, "%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, " @@ -173,6 +176,44 @@ static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm) return 0; } +#ifdef CONFIG_RTC_INTF_DEV +static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) +{ + struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev)); + struct rtc_time tm; + + switch (cmd) { + case RTC_VL_READ: + if (pcf8563->voltage_low) + dev_info(dev, "low voltage detected, date/time is not reliable.\n"); + + if (copy_to_user((void __user *)arg, &pcf8563->voltage_low, + sizeof(int))) + return -EFAULT; + return 0; + case RTC_VL_CLR: + /* + * Clear the VL bit in the seconds register in case + * the time has not been set already (which would + * have cleared it). This does not really matter + * because of the cached voltage_low value but do it + * anyway for consistency. + */ + if (pcf8563_get_datetime(to_i2c_client(dev), &tm)) + pcf8563_set_datetime(to_i2c_client(dev), &tm); + + /* Clear the cached value. */ + pcf8563->voltage_low = 0; + + return 0; + default: + return -ENOIOCTLCMD; + } +} +#else +#define pcf8563_rtc_ioctl NULL +#endif + static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm) { return pcf8563_get_datetime(to_i2c_client(dev), tm); @@ -184,6 +225,7 @@ static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm) } static const struct rtc_class_ops pcf8563_rtc_ops = { + .ioctl = pcf8563_rtc_ioctl, .read_time = pcf8563_rtc_read_time, .set_time = pcf8563_rtc_set_time, }; |