Commit 45034e48 authored by Brandon Maier's avatar Brandon Maier Committed by Guenter Roeck
Browse files

hwmon: (ad7418) Catch I2C errors 



If there is an i2c failure, the ad7416 reports its temperature as 0C.
Return an error code so users can properly detect errors.

Signed-off-by: default avatarBrandon Maier <brandon.maier@rockwellcollins.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent e9b95485

drivers/hwmon/ad7418.c

+48 −15
Original line number Diff line number Diff line
@@ -54,10 +54,11 @@ struct ad7418_data { 
	u16			in[4];

};



static struct ad7418_data *ad7418_update_device(struct device *dev)

static int ad7418_update_device(struct device *dev)

{

	struct ad7418_data *data = dev_get_drvdata(dev);

	struct i2c_client *client = data->client;

	s32 val;



	mutex_lock(&data->lock);
@@ -67,47 +68,74 @@ static struct ad7418_data *ad7418_update_device(struct device *dev) 
		int i, ch;



		/* read config register and clear channel bits */

		cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);

		val = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);

		if (val < 0)

			goto abort;



		cfg = val;

		cfg &= 0x1F;



		i2c_smbus_write_byte_data(client, AD7418_REG_CONF,

		val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,

						cfg | AD7418_CH_TEMP);

		if (val < 0)

			goto abort;



		udelay(30);



		for (i = 0; i < 3; i++) {

			data->temp[i] =

				i2c_smbus_read_word_swapped(client,

			val = i2c_smbus_read_word_swapped(client,

							  AD7418_REG_TEMP[i]);

			if (val < 0)

				goto abort;



			data->temp[i] = val;

		}



		for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {

			i2c_smbus_write_byte_data(client,

					AD7418_REG_CONF,

			val = i2c_smbus_write_byte_data(client, AD7418_REG_CONF,

					cfg | AD7418_REG_ADC_CH(ch));

			if (val < 0)

				goto abort;



			udelay(15);

			data->in[data->adc_max - 1 - i] =

				i2c_smbus_read_word_swapped(client,

			val = i2c_smbus_read_word_swapped(client,

							  AD7418_REG_ADC);

			if (val < 0)

				goto abort;



			data->in[data->adc_max - 1 - i] = val;

		}



		/* restore old configuration value */

		i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);

		val = i2c_smbus_write_word_swapped(client, AD7418_REG_CONF,

						   cfg);

		if (val < 0)

			goto abort;



		data->last_updated = jiffies;

		data->valid = 1;

	}



	mutex_unlock(&data->lock);

	return 0;



	return data;

abort:

	data->valid = 0;

	mutex_unlock(&data->lock);

	return val;

}



static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,

			 char *buf)

{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	struct ad7418_data *data = ad7418_update_device(dev);

	struct ad7418_data *data = dev_get_drvdata(dev);

	int ret;



	ret = ad7418_update_device(dev);

	if (ret < 0)

		return ret;



	return sprintf(buf, "%d\n",

		LM75_TEMP_FROM_REG(data->temp[attr->index]));

}
@@ -116,7 +144,12 @@ static ssize_t adc_show(struct device *dev, struct device_attribute *devattr, 
			char *buf)

{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	struct ad7418_data *data = ad7418_update_device(dev);

	struct ad7418_data *data = dev_get_drvdata(dev);

	int ret;



	ret = ad7418_update_device(dev);

	if (ret < 0)

		return ret;



	return sprintf(buf, "%d\n",

		((data->in[attr->index] >> 6) * 2500 + 512) / 1024);