/*
* An hwmon driver for the Analog Devices AD7414
*
* Copyright 2006 Stefan Roese <sr at denx.de>, DENX Software Engineering
*
* Copyright (c) 2008 PIKA Technologies
* Sean MacLennan <smaclennan@pikatech.com>
*
* Copyright (c) 2008 Spansion Inc.
* Frank Edelhaeuser <frank.edelhaeuser at spansion.com>
* (converted to "new style" I2C driver model, removed checkpatch.pl warnings)
*
* Based on ad7418.c
* Copyright 2006 Tower Technologies, Alessandro Zummo <a.zummo at towertech.it>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
/* AD7414 registers */
#define AD7414_REG_TEMP 0x00
#define AD7414_REG_CONF 0x01
#define AD7414_REG_T_HIGH 0x02
#define AD7414_REG_T_LOW 0x03
static u8 AD7414_REG_LIMIT[] = { AD7414_REG_T_HIGH, AD7414_REG_T_LOW };
struct ad7414_data {
struct i2c_client *client;
struct mutex lock; /* atomic read data updates */
char valid; /* !=0 if following fields are valid */
unsigned long next_update; /* In jiffies */
s16 temp_input; /* Register values */
s8 temps[ARRAY_SIZE(AD7414_REG_LIMIT)];
};
/* REG: (0.25C/bit, two's complement) << 6 */
static inline int ad7414_temp_from_reg(s16 reg)
{
/*
* use integer division instead of equivalent right shift to
* guarantee arithmetic shift and preserve the sign
*/
return ((int)reg / 64) * 250;
}
static inline int ad7414_read(struct i2c_client *client, u8 reg)
{
if (reg == AD7414_REG_TEMP)
return i2c_smbus_read_word_swapped(client, reg);
else
return i2c_smbus_read_byte_data(client, reg);
}
static inline int ad7414_write(struct i2c_client *client, u8 reg, u8 value)
{
return i2c_smbus_write_byte_data(client, reg, value);
}
static struct ad7414_data *ad7414_update_device(struct device *dev)
{
struct ad7414_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
mutex_lock(&data->lock);
if (time_after(jiffies, data->next_update) || !data->valid) {
int value, i;
dev_dbg(&client->dev, "starting ad7414 update\n");
value = ad7414_read(client, AD7414_REG_TEMP);
if (value < 0)
dev_dbg(&client->dev, "AD7414_REG_TEMP err %d\n",
value);
else
data->temp_input = value;
for (i = 0; i < ARRAY_SIZE(AD7414_REG_LIMIT); ++i) {
value = ad7414_read(client, AD7414_REG_LIMIT[i]);
if (value < 0)
dev_dbg(&client->dev, "AD7414 reg %d err %d\n",
AD7414_REG_LIMIT[i], value);
else
data->temps[i] = value;
}
data->next_update = jiffies + HZ + HZ / 2;
data->valid = 1;
}
mutex_unlock(&data->lock);
return data;
}
static ssize_t show_temp_input(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ad7414_data *data = ad7414_update_device(dev);
return sprintf(buf, "%d\n", ad7414_temp_from_reg(data->temp_input));
}
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL, 0);
static ssize_t show_max_min(struct device *dev, struct device_attribute *attr,
char *buf)
{
int index = to_sensor_dev_attr(attr)->index;
struct ad7414_data *data = ad7414_update_device(dev);
return sprintf(buf, "%d\n", data->temps[index] * 1000);
}
static ssize_t set_max_min(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct ad7414_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int index = to_sensor_dev_attr(attr)->index;
u8 reg = AD7414_REG_LIMIT[index];
long temp;
int ret = kstrtol(buf, 10, &temp);
if (ret < 0)
return ret;
temp = clamp_val(temp, -40000, 85000);
temp = (temp + (temp < 0 ? -500 : 500)) / 1000;
mutex_lock(&data->lock);
data->temps[index] = temp;
ad7414_write(client, reg, temp);
mutex_unlock(&data->lock);
return count;
}
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
show_max_min, set_max_min, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
show_max_min, set_max_min, 1);
static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
char *buf)
{
int bitnr = to_sensor_dev_attr(attr)->index;
struct ad7414_data *data = ad7414_update_device(dev);
int value = (data->temp_input >> bitnr) & 1;
return sprintf(buf, "%d\n", value);
}
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static struct attribute *ad7414_attrs[] = {
&sensor_dev_attr_temp1_input.dev_attr.attr,
&sensor_dev_attr_temp1_max.dev_attr.attr,
&sensor_dev_attr_temp1_min.dev_attr.attr,
&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
NULL
};
ATTRIBUTE_GROUPS(ad7414);
static int ad7414_probe(struct i2c_client *client,
const struct i2c_device_id *dev_id)
{
struct device *dev = &client->dev;
struct ad7414_data *data;
struct device *hwmon_dev;
int conf;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_READ_WORD_DATA))
return -EOPNOTSUPP;
data = devm_kzalloc(dev, sizeof(struct ad7414_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
mutex_init(&data->lock);
dev_info(&client->dev, "chip found\n");
/* Make sure the chip is powered up. */
conf = i2c_smbus_read_byte_data(client, AD7414_REG_CONF);
if (conf < 0)
dev_warn(dev, "ad7414_probe unable to read config register.\n");
else {
conf &= ~(1 << 7);
i2c_smbus_write_byte_data(client, AD7414_REG_CONF, conf);
}
hwmon_dev = devm_hwmon_device_register_with_groups(dev,
client->name,
data, ad7414_groups);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id ad7414_id[] = {
{ "ad7414", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, ad7414_id);
static struct i2c_driver ad7414_driver = {
.driver = {
.name = "ad7414",
},
.probe = ad7414_probe,
.id_table = ad7414_id,
};
module_i2c_driver(ad7414_driver);
MODULE_AUTHOR("Stefan Roese <sr at denx.de>, "
"Frank Edelhaeuser <frank.edelhaeuser at spansion.com>");
MODULE_DESCRIPTION("AD7414 driver");
MODULE_LICENSE("GPL");
