rtc: pcf8523: don't return invalid date when battery is low (ecb4a353) · Commits · 戴 / test

drivers/rtc/rtc-pcf8523.c

+24 −8

Original line number	Original line	Diff line number	Diff line
	@@ -85,6 +85,18 @@ static int pcf8523_write(struct i2c_client *client, u8 reg, u8 value)
	return 0;		return 0;
	}		}

			static int pcf8523_voltage_low(struct i2c_client *client)
			{
			u8 value;
			int err;

			err = pcf8523_read(client, REG_CONTROL3, &value);
			if (err < 0)
			return err;

			return !!(value & REG_CONTROL3_BLF);
			}

	static int pcf8523_select_capacitance(struct i2c_client *client, bool high)		static int pcf8523_select_capacitance(struct i2c_client *client, bool high)
	{		{
	u8 value;		u8 value;
	@@ -167,6 +179,14 @@ static int pcf8523_rtc_read_time(struct device dev, struct rtc_time tm)
	struct i2c_msg msgs[2];		struct i2c_msg msgs[2];
	int err;		int err;

			err = pcf8523_voltage_low(client);
			if (err < 0) {
			return err;
			} else if (err > 0) {
			dev_err(dev, "low voltage detected, time is unreliable\n");
			return -EINVAL;
			}

	msgs[0].addr = client->addr;		msgs[0].addr = client->addr;
	msgs[0].flags = 0;		msgs[0].flags = 0;
	msgs[0].len = 1;		msgs[0].len = 1;
	@@ -251,17 +271,13 @@ static int pcf8523_rtc_ioctl(struct device *dev, unsigned int cmd,
	unsigned long arg)		unsigned long arg)
	{		{
	struct i2c_client *client = to_i2c_client(dev);		struct i2c_client *client = to_i2c_client(dev);
	u8 value;		int ret;
	int ret = 0, err;

	switch (cmd) {		switch (cmd) {
	case RTC_VL_READ:		case RTC_VL_READ:
	err = pcf8523_read(client, REG_CONTROL3, &value);		ret = pcf8523_voltage_low(client);
	if (err < 0)		if (ret < 0)
	return err;		return ret;

	if (value & REG_CONTROL3_BLF)
	ret = 1;

	if (copy_to_user((void __user *)arg, &ret, sizeof(int)))		if (copy_to_user((void __user *)arg, &ret, sizeof(int)))
	return -EFAULT;		return -EFAULT;

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