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path: root/kernel/drivers/rtc/rtc-pcf2127.c
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Diffstat (limited to 'kernel/drivers/rtc/rtc-pcf2127.c')
-rw-r--r--kernel/drivers/rtc/rtc-pcf2127.c62
1 files changed, 37 insertions, 25 deletions
diff --git a/kernel/drivers/rtc/rtc-pcf2127.c b/kernel/drivers/rtc/rtc-pcf2127.c
index 9bd842e97..629bfdf8c 100644
--- a/kernel/drivers/rtc/rtc-pcf2127.c
+++ b/kernel/drivers/rtc/rtc-pcf2127.c
@@ -20,11 +20,12 @@
#include <linux/module.h>
#include <linux/of.h>
-#define DRV_VERSION "0.0.1"
-
#define PCF2127_REG_CTRL1 (0x00) /* Control Register 1 */
#define PCF2127_REG_CTRL2 (0x01) /* Control Register 2 */
+
#define PCF2127_REG_CTRL3 (0x02) /* Control Register 3 */
+#define PCF2127_REG_CTRL3_BLF BIT(2)
+
#define PCF2127_REG_SC (0x03) /* datetime */
#define PCF2127_REG_MN (0x04)
#define PCF2127_REG_HR (0x05)
@@ -33,11 +34,12 @@
#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 */
};
/*
@@ -46,7 +48,6 @@ struct pcf2127 {
*/
static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
- struct pcf2127 *pcf2127 = i2c_get_clientdata(client);
unsigned char buf[10] = { PCF2127_REG_CTRL1 };
/* read registers */
@@ -56,10 +57,18 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
return -EIO;
}
- if (buf[PCF2127_REG_CTRL3] & 0x04) {
- pcf2127->voltage_low = 1;
+ if (buf[PCF2127_REG_CTRL3] & PCF2127_REG_CTRL3_BLF)
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
+ */
+ dev_warn(&client->dev,
+ "oscillator stop detected, date/time is not reliable\n");
+ return -EINVAL;
}
dev_dbg(&client->dev,
@@ -88,13 +97,7 @@ static int pcf2127_get_datetime(struct i2c_client *client, struct rtc_time *tm)
tm->tm_sec, tm->tm_min, tm->tm_hour,
tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
- /* the clock can give out invalid datetime, but we cannot return
- * -EINVAL otherwise hwclock will refuse to set the time on bootup.
- */
- if (rtc_valid_tm(tm) < 0)
- dev_err(&client->dev, "retrieved date/time is not valid.\n");
-
- return 0;
+ return rtc_valid_tm(tm);
}
static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
@@ -112,7 +115,7 @@ 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);
@@ -139,15 +142,28 @@ static int pcf2127_set_datetime(struct i2c_client *client, struct rtc_time *tm)
static int pcf2127_rtc_ioctl(struct device *dev,
unsigned int cmd, unsigned long arg)
{
- struct pcf2127 *pcf2127 = i2c_get_clientdata(to_i2c_client(dev));
+ struct i2c_client *client = to_i2c_client(dev);
+ unsigned char buf = PCF2127_REG_CTRL3;
+ int touser;
+ int ret;
switch (cmd) {
case RTC_VL_READ:
- if (pcf2127->voltage_low)
- dev_info(dev, "low voltage detected, date/time is not reliable.\n");
+ ret = i2c_master_send(client, &buf, 1);
+ if (!ret)
+ ret = -EIO;
+ if (ret < 0)
+ return ret;
+
+ ret = i2c_master_recv(client, &buf, 1);
+ if (!ret)
+ ret = -EIO;
+ if (ret < 0)
+ return ret;
- if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
- sizeof(int)))
+ touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;
+
+ if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
return -EFAULT;
return 0;
default:
@@ -189,8 +205,6 @@ static int pcf2127_probe(struct i2c_client *client,
if (!pcf2127)
return -ENOMEM;
- dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
-
i2c_set_clientdata(client, pcf2127);
pcf2127->rtc = devm_rtc_device_register(&client->dev,
@@ -217,7 +231,6 @@ MODULE_DEVICE_TABLE(of, pcf2127_of_match);
static struct i2c_driver pcf2127_driver = {
.driver = {
.name = "rtc-pcf2127",
- .owner = THIS_MODULE,
.of_match_table = of_match_ptr(pcf2127_of_match),
},
.probe = pcf2127_probe,
@@ -228,5 +241,4 @@ module_i2c_driver(pcf2127_driver);
MODULE_AUTHOR("Renaud Cerrato <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("NXP PCF2127 RTC driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE("GPL v2");