ad7418.c

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/*
 * An hwmon driver for the Analog Devices AD7416/17/18
 * Copyright (C) 2006-07 Tower Technologies
 *
 * Author: Alessandro Zummo <[email protected]>
 *
 * Based on lm75.c
 * Copyright (C) 1998-99 Frodo Looijaard <[email protected]>
 *
 * 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 - version 2.
 */

#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/delay.h>
#include <linux/slab.h>

#include "lm75.h"

#define DRV_VERSION "0.4"

enum chips { ad7416, ad7417, ad7418 };

/* AD7418 registers */
#define AD7418_REG_TEMP_IN  0x00
#define AD7418_REG_CONF     0x01
#define AD7418_REG_TEMP_HYST    0x02
#define AD7418_REG_TEMP_OS  0x03
#define AD7418_REG_ADC      0x04
#define AD7418_REG_CONF2    0x05

#define AD7418_REG_ADC_CH(x)    ((x) << 5)
#define AD7418_CH_TEMP      AD7418_REG_ADC_CH(0)

static const u8 AD7418_REG_TEMP[] = { AD7418_REG_TEMP_IN,
                    AD7418_REG_TEMP_HYST,
                    AD7418_REG_TEMP_OS };

struct ad7418_data {
    struct device       *hwmon_dev;
    struct attribute_group  attrs;
    enum chips      type;
    struct mutex        lock;
    int         adc_max;    /* number of ADC channels */
    char            valid;
    unsigned long       last_updated;   /* In jiffies */
    s16         temp[3];    /* Register values */
    u16         in[4];
};

static int ad7418_probe(struct i2c_client *client,
            const struct i2c_device_id *id);
static int ad7418_remove(struct i2c_client *client);

static const struct i2c_device_id ad7418_id[] = {
    { "ad7416", ad7416 },
    { "ad7417", ad7417 },
    { "ad7418", ad7418 },
    { }
};
MODULE_DEVICE_TABLE(i2c, ad7418_id);

static struct i2c_driver ad7418_driver = {
    .driver = {
        .name   = "ad7418",
    },
    .probe      = ad7418_probe,
    .remove     = ad7418_remove,
    .id_table   = ad7418_id,
};

static void ad7418_init_client(struct i2c_client *client)
{
    struct ad7418_data *data = i2c_get_clientdata(client);

    int reg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
    if (reg < 0) {
        dev_err(&client->dev, "cannot read configuration register\n");
    } else {
        dev_info(&client->dev, "configuring for mode 1\n");
        i2c_smbus_write_byte_data(client, AD7418_REG_CONF, reg & 0xfe);

        if (data->type == ad7417 || data->type == ad7418)
            i2c_smbus_write_byte_data(client,
                        AD7418_REG_CONF2, 0x00);
    }
}

static struct ad7418_data *ad7418_update_device(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct ad7418_data *data = i2c_get_clientdata(client);

    mutex_lock(&data->lock);

    if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
        || !data->valid) {
        u8 cfg;
        int i, ch;

        /* read config register and clear channel bits */
        cfg = i2c_smbus_read_byte_data(client, AD7418_REG_CONF);
        cfg &= 0x1F;

        i2c_smbus_write_byte_data(client, AD7418_REG_CONF,
                        cfg | AD7418_CH_TEMP);
        udelay(30);

        for (i = 0; i < 3; i++) {
            data->temp[i] =
                i2c_smbus_read_word_swapped(client,
                        AD7418_REG_TEMP[i]);
        }

        for (i = 0, ch = 4; i < data->adc_max; i++, ch--) {
            i2c_smbus_write_byte_data(client,
                    AD7418_REG_CONF,
                    cfg | AD7418_REG_ADC_CH(ch));

            udelay(15);
            data->in[data->adc_max - 1 - i] =
                i2c_smbus_read_word_swapped(client,
                        AD7418_REG_ADC);
        }

        /* restore old configuration value */
        i2c_smbus_write_word_swapped(client, AD7418_REG_CONF, cfg);

        data->last_updated = jiffies;
        data->valid = 1;
    }

    mutex_unlock(&data->lock);

    return data;
}

static ssize_t show_temp(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);
    return sprintf(buf, "%d\n",
        LM75_TEMP_FROM_REG(data->temp[attr->index]));
}

static ssize_t show_adc(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);

    return sprintf(buf, "%d\n",
        ((data->in[attr->index] >> 6) * 2500 + 512) / 1024);
}

static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
            const char *buf, size_t count)
{
    struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
    struct i2c_client *client = to_i2c_client(dev);
    struct ad7418_data *data = i2c_get_clientdata(client);
    long temp;
    int ret = kstrtol(buf, 10, &temp);

    if (ret < 0)
        return ret;

    mutex_lock(&data->lock);
    data->temp[attr->index] = LM75_TEMP_TO_REG(temp);
    i2c_smbus_write_word_swapped(client,
                     AD7418_REG_TEMP[attr->index],
                     data->temp[attr->index]);
    mutex_unlock(&data->lock);
    return count;
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
                show_temp, set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
                show_temp, set_temp, 2);

static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, show_adc, NULL, 0);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, show_adc, NULL, 1);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, show_adc, NULL, 2);
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, show_adc, NULL, 3);

static struct attribute *ad7416_attributes[] = {
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp1_input.dev_attr.attr,
    NULL
};

static struct attribute *ad7417_attributes[] = {
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_in1_input.dev_attr.attr,
    &sensor_dev_attr_in2_input.dev_attr.attr,
    &sensor_dev_attr_in3_input.dev_attr.attr,
    &sensor_dev_attr_in4_input.dev_attr.attr,
    NULL
};

static struct attribute *ad7418_attributes[] = {
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_in1_input.dev_attr.attr,
    NULL
};

static int ad7418_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    struct i2c_adapter *adapter = client->adapter;
    struct ad7418_data *data;
    int err;

    if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
                    I2C_FUNC_SMBUS_WORD_DATA))
        return -EOPNOTSUPP;

    data = devm_kzalloc(&client->dev, sizeof(struct ad7418_data),
                GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    i2c_set_clientdata(client, data);

    mutex_init(&data->lock);
    data->type = id->driver_data;

    switch (data->type) {
    case ad7416:
        data->adc_max = 0;
        data->attrs.attrs = ad7416_attributes;
        break;

    case ad7417:
        data->adc_max = 4;
        data->attrs.attrs = ad7417_attributes;
        break;

    case ad7418:
        data->adc_max = 1;
        data->attrs.attrs = ad7418_attributes;
        break;
    }

    dev_info(&client->dev, "%s chip found\n", client->name);

    /* Initialize the AD7418 chip */
    ad7418_init_client(client);

    /* Register sysfs hooks */
    err = sysfs_create_group(&client->dev.kobj, &data->attrs);
    if (err)
        return err;

    data->hwmon_dev = hwmon_device_register(&client->dev);
    if (IS_ERR(data->hwmon_dev)) {
        err = PTR_ERR(data->hwmon_dev);
        goto exit_remove;
    }

    return 0;

exit_remove:
    sysfs_remove_group(&client->dev.kobj, &data->attrs);
    return err;
}

static int ad7418_remove(struct i2c_client *client)
{
    struct ad7418_data *data = i2c_get_clientdata(client);
    hwmon_device_unregister(data->hwmon_dev);
    sysfs_remove_group(&client->dev.kobj, &data->attrs);
    return 0;
}

module_i2c_driver(ad7418_driver);

MODULE_AUTHOR("Alessandro Zummo <[email protected]>");
MODULE_DESCRIPTION("AD7416/17/18 driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);