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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2015-10-02 12:17:19 +0300
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2015-11-08 16:12:27 +0300
commitf97cfddc886bc8f9d4302447f8773239bed854c1 (patch)
tree7a616bc4375f23432347448790baa4a6ead0fdf3 /drivers/rtc
parent24417829936d82b03b156e0d036c3b8f25aa93fd (diff)
downloadlinux-f97cfddc886bc8f9d4302447f8773239bed854c1.tar.xz
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>
Diffstat (limited to 'drivers/rtc')
-rw-r--r--drivers/rtc/rtc-pcf2127.c40
1 files changed, 22 insertions, 18 deletions
diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index a26bae60826c..d83b2d8e3c2b 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -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;
+
+ 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, &pcf2127->voltage_low,
- sizeof(int)))
+ if (copy_to_user((void __user *)arg, &touser, sizeof(int)))
return -EFAULT;
return 0;
default: