hwmon: (lm90) Move 16-bit value read to a separate function (6388a388) · Commits · 戴 / test

drivers/hwmon/lm90.c

+43 −29

Original line number	Diff line number	Diff line
		/*
		* lm90.c - Part of lm_sensors, Linux kernel modules for hardware
		* monitoring
		* Copyright (C) 2003-2006 Jean Delvare <khali@linux-fr.org>
		* Copyright (C) 2003-2008 Jean Delvare <khali@linux-fr.org>
		*
		* Based on the lm83 driver. The LM90 is a sensor chip made by National
		* Semiconductor. It reports up to two temperatures (its own plus up to
		@@ -736,6 +736,38 @@ static int lm90_remove(struct i2c_client *client)
		return 0;
		}

		static int lm90_read16(struct i2c_client client, u8 regh, u8 regl, u16 value)
		{
		int err;
		u8 oldh, newh, l;

		/*
		* There is a trick here. We have to read two registers to have the
		* sensor temperature, but we have to beware a conversion could occur
		* inbetween the readings. The datasheet says we should either use
		* the one-shot conversion register, which we don't want to do
		* (disables hardware monitoring) or monitor the busy bit, which is
		* impossible (we can't read the values and monitor that bit at the
		* exact same time). So the solution used here is to read the high
		* byte once, then the low byte, then the high byte again. If the new
		* high byte matches the old one, then we have a valid reading. Else
		* we have to read the low byte again, and now we believe we have a
		* correct reading.
		*/
		if ((err = lm90_read_reg(client, regh, &oldh))
		\|\| (err = lm90_read_reg(client, regl, &l))
		\|\| (err = lm90_read_reg(client, regh, &newh)))
		return err;
		if (oldh != newh) {
		err = lm90_read_reg(client, regl, &l);
		if (err)
		return err;
		}
		*value = (newh << 8) \| l;

		return 0;
		}

		static struct lm90_data lm90_update_device(struct device dev)
		{
		struct i2c_client *client = to_i2c_client(dev);
		@@ -744,7 +776,7 @@ static struct lm90_data lm90_update_device(struct device dev)
		mutex_lock(&data->update_lock);

		if (time_after(jiffies, data->last_updated + HZ * 2) \|\| !data->valid) {
		u8 oldh, newh, l;
		u8 h, l;

		dev_dbg(&client->dev, "Updating lm90 data.\n");
		lm90_read_reg(client, LM90_REG_R_LOCAL_TEMP, &data->temp8[0]);
		@@ -754,39 +786,21 @@ static struct lm90_data lm90_update_device(struct device dev)
		lm90_read_reg(client, LM90_REG_R_REMOTE_CRIT, &data->temp8[4]);
		lm90_read_reg(client, LM90_REG_R_TCRIT_HYST, &data->temp_hyst);

		/*
		* There is a trick here. We have to read two registers to
		* have the remote sensor temperature, but we have to beware
		* a conversion could occur inbetween the readings. The
		* datasheet says we should either use the one-shot
		* conversion register, which we don't want to do (disables
		* hardware monitoring) or monitor the busy bit, which is
		* impossible (we can't read the values and monitor that bit
		* at the exact same time). So the solution used here is to
		* read the high byte once, then the low byte, then the high
		* byte again. If the new high byte matches the old one,
		* then we have a valid reading. Else we have to read the low
		* byte again, and now we believe we have a correct reading.
		*/
		if (lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &oldh) == 0
		&& lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0
		&& lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPH, &newh) == 0
		&& (newh == oldh
		\|\| lm90_read_reg(client, LM90_REG_R_REMOTE_TEMPL, &l) == 0))
		data->temp11[0] = (newh << 8) \| l;

		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &newh) == 0
		lm90_read16(client, LM90_REG_R_REMOTE_TEMPH,
		LM90_REG_R_REMOTE_TEMPL, &data->temp11[0]);

		if (lm90_read_reg(client, LM90_REG_R_REMOTE_LOWH, &h) == 0
		&& lm90_read_reg(client, LM90_REG_R_REMOTE_LOWL, &l) == 0)
		data->temp11[1] = (newh << 8) \| l;
		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &newh) == 0
		data->temp11[1] = (h << 8) \| l;
		if (lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHH, &h) == 0
		&& lm90_read_reg(client, LM90_REG_R_REMOTE_HIGHL, &l) == 0)
		data->temp11[2] = (newh << 8) \| l;
		data->temp11[2] = (h << 8) \| l;
		if (data->kind != max6657) {
		if (lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSH,
		&newh) == 0
		&h) == 0
		&& lm90_read_reg(client, LM90_REG_R_REMOTE_OFFSL,
		&l) == 0)
		data->temp11[3] = (newh << 8) \| l;
		data->temp11[3] = (h << 8) \| l;
		}
		lm90_read_reg(client, LM90_REG_R_STATUS, &data->alarms);

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