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path: root/drivers/rtc/rtc-pcf2127.c
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Diffstat (limited to 'drivers/rtc/rtc-pcf2127.c')
-rw-r--r--drivers/rtc/rtc-pcf2127.c26
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 350c5c7cb678..baf45c9ca65e 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -33,11 +33,14 @@
#define PCF2127_REG_MO (0x08)
#define PCF2127_REG_YR (0x09)
+#define PCF2127_OSF BIT(7) /* Oscillator Fail flag */
+
static struct i2c_driver pcf2127_driver;
struct pcf2127 {
struct rtc_device *rtc;
int voltage_low; /* indicates if a low_voltage was detected */
+ int oscillator_failed; /* OSF was detected and date is unreliable */
};
/*
@@ -59,7 +62,18 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
if (buf[PCF2127_REG_CTRL3] & 0x04) {
pcf2127->voltage_low = 1;
dev_info(&client->dev,
- "low voltage detected, date/time is not reliable.\n");
+ "low voltage detected, check/replace RTC battery.\n");
+ }
+
+ if (buf[PCF2127_REG_SC] & PCF2127_OSF) {
+ /*
+ * no need clear the flag here,
+ * it will be cleared once the new date is saved
+ */
+ pcf2127->oscillator_failed = 1;
+ dev_warn(&client->dev,
+ "oscillator stop detected, date/time is not reliable\n");
+ return -EINVAL;
}
dev_dbg(&client->dev,
@@ -93,6 +107,7 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
+ struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
unsigned char buf[8];
int i = 0, err;
@@ -106,7 +121,7 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
buf[i++] = PCF2127_REG_SC;
/* hours, minutes and seconds */
- buf[i++] = bin2bcd(tm->tm_sec);
+ buf[i++] = bin2bcd(tm->tm_sec); /* this will also clear OSF flag */
buf[i++] = bin2bcd(tm->tm_min);
buf[i++] = bin2bcd(tm->tm_hour);
buf[i++] = bin2bcd(tm->tm_mday);
@@ -126,6 +141,9 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
return -EIO;
}
+ /* clear OSF flag in client data */
+ pcf2127->oscillator_failed = 0;
+
return 0;
}
@@ -138,7 +156,9 @@ static int pcf2127_rtc_ioctl(struct device *dev,
switch (cmd) {
case RTC_VL_READ:
if (pcf2127->voltage_low)
- dev_info(dev, "low voltage detected, date/time is not reliable.\n");
+ dev_info(dev, "low voltage detected, check/replace battery\n");
+ if (pcf2127->oscillator_failed)
+ dev_info(dev, "oscillator stop detected, date/time is not reliable\n");
if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
sizeof(int)))