267 lines
6.9 KiB
C
267 lines
6.9 KiB
C
/*
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* An hwmon driver for the Analog Devices AD7414
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*
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* Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
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*
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* Copyright (c) 2008 PIKA Technologies
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* Sean MacLennan <smaclennan@pikatech.com>
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*
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* Copyright (c) 2008 Spansion Inc.
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* Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
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* (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
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*
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* Based on ad7418.c
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* Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/jiffies.h>
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#include <linux/i2c.h>
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#include <linux/hwmon.h>
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#include <linux/hwmon-sysfs.h>
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/sysfs.h>
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#include <linux/slab.h>
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/* AD7414 registers */
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#define AD7414_REG_TEMP 0x00
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#define AD7414_REG_CONF 0x01
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#define AD7414_REG_T_HIGH 0x02
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#define AD7414_REG_T_LOW 0x03
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static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
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struct ad7414_data {
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struct device *hwmon_dev;
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struct mutex lock; /* atomic read data updates */
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char valid; /* !=0 if following fields are valid */
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unsigned long next_update; /* In jiffies */
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s16 temp_input; /* Register values */
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s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
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};
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/* REG: (0.25C/bit, two's complement) << 6 */
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static inline int ad7414_temp_from_reg(s16 reg)
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{
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/*
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* use integer division instead of equivalent right shift to
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* guarantee arithmetic shift and preserve the sign
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*/
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return ((int)reg / 64) * 250;
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}
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static inline int ad7414_read(struct i2c_client *client, u8 reg)
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{
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if (reg == AD7414_REG_TEMP)
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return i2c_smbus_read_word_swapped(client, reg);
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else
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return i2c_smbus_read_byte_data(client, reg);
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}
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static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
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{
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return i2c_smbus_write_byte_data(client, reg, value);
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}
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static struct ad7414_data *ad7414_update_device(struct device *dev)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct ad7414_data *data = i2c_get_clientdata(client);
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mutex_lock(&data->lock);
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if (time_after(jiffies, data->next_update) || !data->valid) {
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int value, i;
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dev_dbg(&client->dev, "starting ad7414 update\n");
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value = ad7414_read(client, AD7414_REG_TEMP);
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if (value < 0)
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dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
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value);
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else
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data->temp_input = value;
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for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
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value = ad7414_read(client, AD7414_REG_LIMIT[i]);
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if (value < 0)
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dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
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AD7414_REG_LIMIT[i], value);
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else
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data->temps[i] = value;
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}
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data->next_update = jiffies + HZ + HZ / 2;
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data->valid = 1;
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}
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mutex_unlock(&data->lock);
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return data;
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}
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static ssize_t show_temp_input(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct ad7414_data *data = ad7414_update_device(dev);
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return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
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}
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static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
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static ssize_t show_max_min(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int index = to_sensor_dev_attr(attr)->index;
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struct ad7414_data *data = ad7414_update_device(dev);
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return sprintf(buf, "%d\n", data->temps[index] * 1000);
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}
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static ssize_t set_max_min(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct i2c_client *client = to_i2c_client(dev);
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struct ad7414_data *data = i2c_get_clientdata(client);
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int index = to_sensor_dev_attr(attr)->index;
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u8 reg = AD7414_REG_LIMIT[index];
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long temp;
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int ret = kstrtol(buf, 10, &temp);
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if (ret < 0)
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return ret;
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temp = SENSORS_LIMIT(temp, -40000, 85000);
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temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
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mutex_lock(&data->lock);
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data->temps[index] = temp;
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ad7414_write(client, reg, temp);
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mutex_unlock(&data->lock);
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return count;
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}
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static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
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show_max_min, set_max_min, 0);
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static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
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show_max_min, set_max_min, 1);
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static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
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char *buf)
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{
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int bitnr = to_sensor_dev_attr(attr)->index;
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struct ad7414_data *data = ad7414_update_device(dev);
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int value = (data->temp_input >> bitnr) & 1;
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return sprintf(buf, "%d\n", value);
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}
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static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
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static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
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static struct attribute *ad7414_attributes[] = {
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&sensor_dev_attr_temp1_input.dev_attr.attr,
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&sensor_dev_attr_temp1_max.dev_attr.attr,
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&sensor_dev_attr_temp1_min.dev_attr.attr,
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&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
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&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
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NULL
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};
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static const struct attribute_group ad7414_group = {
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.attrs = ad7414_attributes,
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};
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static int ad7414_probe(struct i2c_client *client,
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const struct i2c_device_id *dev_id)
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{
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struct ad7414_data *data;
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int conf;
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int err;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_READ_WORD_DATA)) {
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err = -EOPNOTSUPP;
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goto exit;
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}
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data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
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if (!data) {
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err = -ENOMEM;
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goto exit;
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}
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i2c_set_clientdata(client, data);
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mutex_init(&data->lock);
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dev_info(&client->dev, "chip found\n");
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/* Make sure the chip is powered up. */
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conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
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if (conf < 0)
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dev_warn(&client->dev,
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"ad7414_probe unable to read config register.\n");
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else {
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conf &= ~(1 << 7);
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i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
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}
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/* Register sysfs hooks */
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err = sysfs_create_group(&client->dev.kobj, &ad7414_group);
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if (err)
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goto exit_free;
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data->hwmon_dev = hwmon_device_register(&client->dev);
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if (IS_ERR(data->hwmon_dev)) {
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err = PTR_ERR(data->hwmon_dev);
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goto exit_remove;
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}
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return 0;
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exit_remove:
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sysfs_remove_group(&client->dev.kobj, &ad7414_group);
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exit_free:
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kfree(data);
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exit:
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return err;
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}
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static int __devexit ad7414_remove(struct i2c_client *client)
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{
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struct ad7414_data *data = i2c_get_clientdata(client);
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hwmon_device_unregister(data->hwmon_dev);
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sysfs_remove_group(&client->dev.kobj, &ad7414_group);
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kfree(data);
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return 0;
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}
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static const struct i2c_device_id ad7414_id[] = {
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{ "ad7414", 0 },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, ad7414_id);
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static struct i2c_driver ad7414_driver = {
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.driver = {
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.name = "ad7414",
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},
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.probe = ad7414_probe,
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.remove = __devexit_p(ad7414_remove),
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.id_table = ad7414_id,
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};
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module_i2c_driver(ad7414_driver);
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MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
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"Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
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MODULE_DESCRIPTION("AD7414 driver");
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MODULE_LICENSE("GPL");
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