hwmon: (ads1015) Fix build warning

The following build warning is seen in some configurations.

drivers/hwmon/ads1015.c: In function 'show_in':
drivers/hwmon/ads1015.c:129: warning: 'in' may be used uninitialized in this function

Fix by separating the register read function from the code converting the result
into mV.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Dirk Eibach <eibach@gdsys.de>
Reviewed-by: Robert Coulson <robert.coulson@ericsson.com>

diff --git a/drivers/hwmon/ads1015.c b/drivers/hwmon/ads1015.c
index 7765e4f74ec56177ad8cc39476320d6d2436f719..1958f03efd7aaa43f72416f809eb42fe569b413f 100644 (file)
--- a/drivers/hwmon/ads1015.c
+++ b/drivers/hwmon/ads1015.c
@@ -59,14 +59,11 @@ struct ads1015_data {
        struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
 };
 
-static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
-                             int *value)
+static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
 {
        u16 config;
-       s16 conversion;
        struct ads1015_data *data = i2c_get_clientdata(client);
        unsigned int pga = data->channel_data[channel].pga;
-       int fullscale;
        unsigned int data_rate = data->channel_data[channel].data_rate;
        unsigned int conversion_time_ms;
        int res;
@@ -78,7 +75,6 @@ static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
        if (res < 0)
                goto err_unlock;
        config = res;
-       fullscale = fullscale_table[pga];
        conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
 
        /* setup and start single conversion */
@@ -105,33 +101,36 @@ static int ads1015_read_value(struct i2c_client *client, unsigned int channel,
        }
 
        res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
-       if (res < 0)
-               goto err_unlock;
-       conversion = res;
-
-       mutex_unlock(&data->update_lock);
-
-       *value = DIV_ROUND_CLOSEST(conversion * fullscale, 0x7ff0);
-
-       return 0;
 
 err_unlock:
        mutex_unlock(&data->update_lock);
        return res;
 }
 
+static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
+                            s16 reg)
+{
+       struct ads1015_data *data = i2c_get_clientdata(client);
+       unsigned int pga = data->channel_data[channel].pga;
+       int fullscale = fullscale_table[pga];
+
+       return DIV_ROUND_CLOSEST(reg * fullscale, 0x7ff0);
+}
+
 /* sysfs callback function */
 static ssize_t show_in(struct device *dev, struct device_attribute *da,
        char *buf)
 {
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        struct i2c_client *client = to_i2c_client(dev);
-       int in;
        int res;
+       int index = attr->index;
 
-       res = ads1015_read_value(client, attr->index, &in);
+       res = ads1015_read_adc(client, index);
+       if (res < 0)
+               return res;
 
-       return (res < 0) ? res : sprintf(buf, "%d\n", in);
+       return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
 }
 
 static const struct sensor_device_attribute ads1015_in[] = {