max1668.c

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/*
 * Copyright (c) 2011 David George <[email protected]>
 *
 * based on adm1021.c
 * some credit to Christoph Scheurer, but largely a rewrite
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.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>

/* Addresses to scan */
static unsigned short max1668_addr_list[] = {
    0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

/* max1668 registers */

#define MAX1668_REG_TEMP(nr)    (nr)
#define MAX1668_REG_STAT1   0x05
#define MAX1668_REG_STAT2   0x06
#define MAX1668_REG_MAN_ID  0xfe
#define MAX1668_REG_DEV_ID  0xff

/* limits */

/* write high limits */
#define MAX1668_REG_LIMH_WR(nr) (0x13 + 2 * (nr))
/* write low limits */
#define MAX1668_REG_LIML_WR(nr) (0x14 + 2 * (nr))
/* read high limits */
#define MAX1668_REG_LIMH_RD(nr) (0x08 + 2 * (nr))
/* read low limits */
#define MAX1668_REG_LIML_RD(nr) (0x09 + 2 * (nr))

/* manufacturer and device ID Constants */
#define MAN_ID_MAXIM        0x4d
#define DEV_ID_MAX1668      0x3
#define DEV_ID_MAX1805      0x5
#define DEV_ID_MAX1989      0xb

/* read only mode module parameter */
static bool read_only;
module_param(read_only, bool, 0);
MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");

enum chips { max1668, max1805, max1989 };

struct max1668_data {
    struct device *hwmon_dev;
    enum chips type;

    struct mutex update_lock;
    char valid;     /* !=0 if following fields are valid */
    unsigned long last_updated; /* In jiffies */

    /* 1x local and 4x remote */
    s8 temp_max[5];
    s8 temp_min[5];
    s8 temp[5];
    u16 alarms;
};

static struct max1668_data *max1668_update_device(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct max1668_data *data = i2c_get_clientdata(client);
    struct max1668_data *ret = data;
    s32 val;
    int i;

    mutex_lock(&data->update_lock);

    if (data->valid && !time_after(jiffies,
            data->last_updated + HZ + HZ / 2))
        goto abort;

    for (i = 0; i < 5; i++) {
        val = i2c_smbus_read_byte_data(client, MAX1668_REG_TEMP(i));
        if (unlikely(val < 0)) {
            ret = ERR_PTR(val);
            goto abort;
        }
        data->temp[i] = (s8) val;

        val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIMH_RD(i));
        if (unlikely(val < 0)) {
            ret = ERR_PTR(val);
            goto abort;
        }
        data->temp_max[i] = (s8) val;

        val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIML_RD(i));
        if (unlikely(val < 0)) {
            ret = ERR_PTR(val);
            goto abort;
        }
        data->temp_min[i] = (s8) val;
    }

    val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT1);
    if (unlikely(val < 0)) {
        ret = ERR_PTR(val);
        goto abort;
    }
    data->alarms = val << 8;

    val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT2);
    if (unlikely(val < 0)) {
        ret = ERR_PTR(val);
        goto abort;
    }
    data->alarms |= val;

    data->last_updated = jiffies;
    data->valid = 1;
abort:
    mutex_unlock(&data->update_lock);

    return ret;
}

static ssize_t show_temp(struct device *dev,
             struct device_attribute *devattr, char *buf)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct max1668_data *data = max1668_update_device(dev);

    if (IS_ERR(data))
        return PTR_ERR(data);

    return sprintf(buf, "%d\n", data->temp[index] * 1000);
}

static ssize_t show_temp_max(struct device *dev,
                 struct device_attribute *devattr, char *buf)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct max1668_data *data = max1668_update_device(dev);

    if (IS_ERR(data))
        return PTR_ERR(data);

    return sprintf(buf, "%d\n", data->temp_max[index] * 1000);
}

static ssize_t show_temp_min(struct device *dev,
                 struct device_attribute *devattr, char *buf)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct max1668_data *data = max1668_update_device(dev);

    if (IS_ERR(data))
        return PTR_ERR(data);

    return sprintf(buf, "%d\n", data->temp_min[index] * 1000);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    int index = to_sensor_dev_attr(attr)->index;
    struct max1668_data *data = max1668_update_device(dev);

    if (IS_ERR(data))
        return PTR_ERR(data);

    return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1);
}

static ssize_t show_fault(struct device *dev,
              struct device_attribute *devattr, char *buf)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct max1668_data *data = max1668_update_device(dev);

    if (IS_ERR(data))
        return PTR_ERR(data);

    return sprintf(buf, "%u\n",
               (data->alarms & (1 << 12)) && data->temp[index] == 127);
}

static ssize_t set_temp_max(struct device *dev,
                struct device_attribute *devattr,
                const char *buf, size_t count)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct i2c_client *client = to_i2c_client(dev);
    struct max1668_data *data = i2c_get_clientdata(client);
    long temp;
    int ret;

    ret = kstrtol(buf, 10, &temp);
    if (ret < 0)
        return ret;

    mutex_lock(&data->update_lock);
    data->temp_max[index] = SENSORS_LIMIT(temp/1000, -128, 127);
    if (i2c_smbus_write_byte_data(client,
                    MAX1668_REG_LIMH_WR(index),
                    data->temp_max[index]))
        count = -EIO;
    mutex_unlock(&data->update_lock);

    return count;
}

static ssize_t set_temp_min(struct device *dev,
                struct device_attribute *devattr,
                const char *buf, size_t count)
{
    int index = to_sensor_dev_attr(devattr)->index;
    struct i2c_client *client = to_i2c_client(dev);
    struct max1668_data *data = i2c_get_clientdata(client);
    long temp;
    int ret;

    ret = kstrtol(buf, 10, &temp);
    if (ret < 0)
        return ret;

    mutex_lock(&data->update_lock);
    data->temp_min[index] = SENSORS_LIMIT(temp/1000, -128, 127);
    if (i2c_smbus_write_byte_data(client,
                    MAX1668_REG_LIML_WR(index),
                    data->temp_max[index]))
        count = -EIO;
    mutex_unlock(&data->update_lock);

    return count;
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_max,
                set_temp_max, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp_min,
                set_temp_min, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO, show_temp_max,
                set_temp_max, 1);
static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO, show_temp_min,
                set_temp_min, 1);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO, show_temp_max,
                set_temp_max, 2);
static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO, show_temp_min,
                set_temp_min, 2);
static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO, show_temp_max,
                set_temp_max, 3);
static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO, show_temp_min,
                set_temp_min, 3);
static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp, NULL, 4);
static SENSOR_DEVICE_ATTR(temp5_max, S_IRUGO, show_temp_max,
                set_temp_max, 4);
static SENSOR_DEVICE_ATTR(temp5_min, S_IRUGO, show_temp_min,
                set_temp_min, 4);

static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 14);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 13);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 7);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 6);
static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 5);
static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp5_min_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 0);

static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_fault, NULL, 4);

/* Attributes common to MAX1668, MAX1989 and MAX1805 */
static struct attribute *max1668_attribute_common[] = {
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_min.dev_attr.attr,
    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_temp2_max.dev_attr.attr,
    &sensor_dev_attr_temp2_min.dev_attr.attr,
    &sensor_dev_attr_temp2_input.dev_attr.attr,
    &sensor_dev_attr_temp3_max.dev_attr.attr,
    &sensor_dev_attr_temp3_min.dev_attr.attr,
    &sensor_dev_attr_temp3_input.dev_attr.attr,

    &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp3_min_alarm.dev_attr.attr,

    &sensor_dev_attr_temp2_fault.dev_attr.attr,
    &sensor_dev_attr_temp3_fault.dev_attr.attr,
    NULL
};

/* Attributes not present on MAX1805 */
static struct attribute *max1668_attribute_unique[] = {
    &sensor_dev_attr_temp4_max.dev_attr.attr,
    &sensor_dev_attr_temp4_min.dev_attr.attr,
    &sensor_dev_attr_temp4_input.dev_attr.attr,
    &sensor_dev_attr_temp5_max.dev_attr.attr,
    &sensor_dev_attr_temp5_min.dev_attr.attr,
    &sensor_dev_attr_temp5_input.dev_attr.attr,

    &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
    &sensor_dev_attr_temp5_min_alarm.dev_attr.attr,

    &sensor_dev_attr_temp4_fault.dev_attr.attr,
    &sensor_dev_attr_temp5_fault.dev_attr.attr,
    NULL
};

static umode_t max1668_attribute_mode(struct kobject *kobj,
                     struct attribute *attr, int index)
{
    umode_t ret = S_IRUGO;
    if (read_only)
        return ret;
    if (attr == &sensor_dev_attr_temp1_max.dev_attr.attr ||
        attr == &sensor_dev_attr_temp2_max.dev_attr.attr ||
        attr == &sensor_dev_attr_temp3_max.dev_attr.attr ||
        attr == &sensor_dev_attr_temp4_max.dev_attr.attr ||
        attr == &sensor_dev_attr_temp5_max.dev_attr.attr ||
        attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
        attr == &sensor_dev_attr_temp2_min.dev_attr.attr ||
        attr == &sensor_dev_attr_temp3_min.dev_attr.attr ||
        attr == &sensor_dev_attr_temp4_min.dev_attr.attr ||
        attr == &sensor_dev_attr_temp5_min.dev_attr.attr)
        ret |= S_IWUSR;
    return ret;
}

static const struct attribute_group max1668_group_common = {
    .attrs = max1668_attribute_common,
    .is_visible = max1668_attribute_mode
};

static const struct attribute_group max1668_group_unique = {
    .attrs = max1668_attribute_unique,
    .is_visible = max1668_attribute_mode
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int max1668_detect(struct i2c_client *client,
              struct i2c_board_info *info)
{
    struct i2c_adapter *adapter = client->adapter;
    const char *type_name;
    int man_id, dev_id;

    if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
        return -ENODEV;

    /* Check for unsupported part */
    man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
    if (man_id != MAN_ID_MAXIM)
        return -ENODEV;

    dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
    if (dev_id < 0)
        return -ENODEV;

    type_name = NULL;
    if (dev_id == DEV_ID_MAX1668)
        type_name = "max1668";
    else if (dev_id == DEV_ID_MAX1805)
        type_name = "max1805";
    else if (dev_id == DEV_ID_MAX1989)
        type_name = "max1989";

    if (!type_name)
        return -ENODEV;

    strlcpy(info->type, type_name, I2C_NAME_SIZE);

    return 0;
}

static int max1668_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    struct i2c_adapter *adapter = client->adapter;
    struct max1668_data *data;
    int err;

    if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
        return -ENODEV;

    data = devm_kzalloc(&client->dev, sizeof(struct max1668_data),
                GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    i2c_set_clientdata(client, data);
    data->type = id->driver_data;
    mutex_init(&data->update_lock);

    /* Register sysfs hooks */
    err = sysfs_create_group(&client->dev.kobj, &max1668_group_common);
    if (err)
        return err;

    if (data->type == max1668 || data->type == max1989) {
        err = sysfs_create_group(&client->dev.kobj,
                     &max1668_group_unique);
        if (err)
            goto error_sysrem0;
    }

    data->hwmon_dev = hwmon_device_register(&client->dev);
    if (IS_ERR(data->hwmon_dev)) {
        err = PTR_ERR(data->hwmon_dev);
        goto error_sysrem1;
    }

    return 0;

error_sysrem1:
    if (data->type == max1668 || data->type == max1989)
        sysfs_remove_group(&client->dev.kobj, &max1668_group_unique);
error_sysrem0:
    sysfs_remove_group(&client->dev.kobj, &max1668_group_common);
    return err;
}

static int max1668_remove(struct i2c_client *client)
{
    struct max1668_data *data = i2c_get_clientdata(client);

    hwmon_device_unregister(data->hwmon_dev);
    if (data->type == max1668 || data->type == max1989)
        sysfs_remove_group(&client->dev.kobj, &max1668_group_unique);

    sysfs_remove_group(&client->dev.kobj, &max1668_group_common);

    return 0;
}

static const struct i2c_device_id max1668_id[] = {
    { "max1668", max1668 },
    { "max1805", max1805 },
    { "max1989", max1989 },
    { }
};
MODULE_DEVICE_TABLE(i2c, max1668_id);

/* This is the driver that will be inserted */
static struct i2c_driver max1668_driver = {
    .class = I2C_CLASS_HWMON,
    .driver = {
          .name = "max1668",
          },
    .probe = max1668_probe,
    .remove = max1668_remove,
    .id_table = max1668_id,
    .detect = max1668_detect,
    .address_list = max1668_addr_list,
};

module_i2c_driver(max1668_driver);

MODULE_AUTHOR("David George <[email protected]>");
MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
MODULE_LICENSE("GPL");