linux-kernel - [PATCH 2/4] hwmon: (lm75) Create function from code to write into registers

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Date:   Tue,  6 Aug 2019 10:11:05 +0100
From:   Iker Perez <iker.perez@...ethink.co.uk>
To:     linux-hwmon@...r.kernel.org, linux@...ck-us.net
Cc:     jdelvare@...e.com, linux-kernel@...r.kernel.org,
        Iker Perez del Palomar Sustatxa 
        <iker.perez@...ethink.co.uk>
Subject: [PATCH 2/4] hwmon: (lm75) Create function from code to write into registers

From: Iker Perez del Palomar Sustatxa <iker.perez@...ethink.co.uk>

Wrap the existing code to write configurations into registers in
a function.

Added error handling to the function.

Signed-off-by: Iker Perez del Palomar Sustatxa <iker.perez@...ethink.co.uk>
---
 drivers/hwmon/lm75.c | 34 +++++++++++++++++++++++++++-------
 1 file changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c
index 1c012301b6ca..477ac0732ddf 100644
--- a/drivers/hwmon/lm75.c
+++ b/drivers/hwmon/lm75.c
@@ -228,6 +228,27 @@ static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
 	return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
 }
 
+static int lm75_write_config(struct lm75_data *data, u8 set_mask,
+			     u8 clr_mask)
+{
+	u8 value;
+
+	clr_mask |= LM75_SHUTDOWN;
+	value = data->current_conf & ~clr_mask;
+	value |= set_mask;
+
+	if (data->current_conf != value) {
+		s32 err;
+
+		err = i2c_smbus_write_byte_data(data->client, LM75_REG_CONF,
+						value);
+		if (err)
+			return err;
+		data->current_conf = value;
+	}
+	return 0;
+}
+
 static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
 		     u32 attr, int channel, long *val)
 {
@@ -389,7 +410,6 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	struct device *hwmon_dev;
 	struct lm75_data *data;
 	int status, err;
-	int new;
 	enum lm75_type kind;
 
 	if (client->dev.of_node)
@@ -429,16 +449,16 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		return status;
 	}
 	data->orig_conf = status;
-	new = status & ~(data->params->clr_mask | LM75_SHUTDOWN);
-	new |= data->params->set_mask;
-	if (status != new)
-		i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
+	data->current_conf = status;
 
-	err = devm_add_action_or_reset(dev, lm75_remove, data);
+	err = lm75_write_config(data, data->params->set_mask,
+				data->params->clr_mask);
 	if (err)
 		return err;
 
-	dev_dbg(dev, "Config %02x\n", new);
+	err = devm_add_action_or_reset(dev, lm75_remove, data);
+	if (err)
+		return err;
 
 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 data, &lm75_chip_info,
-- 
2.11.0