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rtc: pcf2127: fix reading uninitialized value on RTC_READ_VL ioctl 

The flag reported on the RTC_READ_VL ioctl is only initialized when the
date is read out. So the voltage low value doesn't represent reality but
the status at the time the date was read (or 0 if the date was not read
yet).

Moreover when userspace requests a value via an ioctl there is no added
benefit to also make a prosa representation of this (and other) values
appear in the kernel log so remove the calls to dev_info and the driver
data members to track their state.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
hifive-unleashed-5.1
Uwe Kleine-König 2015-10-02 11:17:19 +02:00 committed by Alexandre Belloni
parent 2441782993
commit f97cfddc88
1 changed files with 22 additions and 18 deletions
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40
drivers/rtc/rtc-pcf2127.c
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@ -24,7 +24,10 @@
#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)
@ -39,8 +42,6 @@ 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 */
};
/*
@ -49,7 +50,6 @@ 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 */
@ -59,18 +59,15 @@ 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, 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;
@ -107,7 +104,6 @@ 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;
@ -141,9 +137,6 @@ 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;
}
@ -151,17 +144,28 @@ 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, check/replace battery\n");
if (pcf2127->oscillator_failed)
dev_info(dev, "oscillator stop detected, date/time is not reliable\n");
ret = i2c_master_send(client, &buf, 1);
if (!ret)
ret = -EIO;
if (ret < 0)
return ret;
if (copy_to_user((void __user *)arg, &pcf2127->voltage_low,
sizeof(int)))
ret = i2c_master_recv(client, &buf, 1);
if (!ret)
ret = -EIO;
if (ret < 0)
return ret;
touser = buf & PCF2127_REG_CTRL3_BLF ? 1 : 0;
if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
return -EFAULT;
return 0;
default: