max1619.c

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/*
 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
 *             monitoring
 * Copyright (C) 2003-2004 Oleksij Rempel <[email protected]>
 *                         Jean Delvare <[email protected]>
 *
 * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
 * It reports up to two temperatures (its own plus up to
 * one external one). Complete datasheet can be
 * obtained from Maxim's website at:
 *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
 *
 * 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>
#include <linux/sysfs.h>

static const unsigned short normal_i2c[] = {
    0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

/*
 * The MAX1619 registers
 */

#define MAX1619_REG_R_MAN_ID        0xFE
#define MAX1619_REG_R_CHIP_ID       0xFF
#define MAX1619_REG_R_CONFIG        0x03
#define MAX1619_REG_W_CONFIG        0x09
#define MAX1619_REG_R_CONVRATE      0x04
#define MAX1619_REG_W_CONVRATE      0x0A
#define MAX1619_REG_R_STATUS        0x02
#define MAX1619_REG_R_LOCAL_TEMP    0x00
#define MAX1619_REG_R_REMOTE_TEMP   0x01
#define MAX1619_REG_R_REMOTE_HIGH   0x07
#define MAX1619_REG_W_REMOTE_HIGH   0x0D
#define MAX1619_REG_R_REMOTE_LOW    0x08
#define MAX1619_REG_W_REMOTE_LOW    0x0E
#define MAX1619_REG_R_REMOTE_CRIT   0x10
#define MAX1619_REG_W_REMOTE_CRIT   0x12
#define MAX1619_REG_R_TCRIT_HYST    0x11
#define MAX1619_REG_W_TCRIT_HYST    0x13

/*
 * Conversions
 */

static int temp_from_reg(int val)
{
    return (val & 0x80 ? val-0x100 : val) * 1000;
}

static int temp_to_reg(int val)
{
    return (val < 0 ? val+0x100*1000 : val) / 1000;
}

/*
 * Functions declaration
 */

static int max1619_probe(struct i2c_client *client,
             const struct i2c_device_id *id);
static int max1619_detect(struct i2c_client *client,
              struct i2c_board_info *info);
static void max1619_init_client(struct i2c_client *client);
static int max1619_remove(struct i2c_client *client);
static struct max1619_data *max1619_update_device(struct device *dev);

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id max1619_id[] = {
    { "max1619", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c, max1619_id);

static struct i2c_driver max1619_driver = {
    .class      = I2C_CLASS_HWMON,
    .driver = {
        .name   = "max1619",
    },
    .probe      = max1619_probe,
    .remove     = max1619_remove,
    .id_table   = max1619_id,
    .detect     = max1619_detect,
    .address_list   = normal_i2c,
};

/*
 * Client data (each client gets its own)
 */

struct max1619_data {
    struct device *hwmon_dev;
    struct mutex update_lock;
    char valid; /* zero until following fields are valid */
    unsigned long last_updated; /* in jiffies */

    /* registers values */
    u8 temp_input1; /* local */
    u8 temp_input2, temp_low2, temp_high2; /* remote */
    u8 temp_crit2;
    u8 temp_hyst2;
    u8 alarms;
};

/*
 * Sysfs stuff
 */

#define show_temp(value) \
static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
                char *buf) \
{ \
    struct max1619_data *data = max1619_update_device(dev); \
    return sprintf(buf, "%d\n", temp_from_reg(data->value)); \
}
show_temp(temp_input1);
show_temp(temp_input2);
show_temp(temp_low2);
show_temp(temp_high2);
show_temp(temp_crit2);
show_temp(temp_hyst2);

#define set_temp2(value, reg) \
static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
               const char *buf, \
    size_t count) \
{ \
    struct i2c_client *client = to_i2c_client(dev); \
    struct max1619_data *data = i2c_get_clientdata(client); \
    long val; \
    int err = kstrtol(buf, 10, &val); \
    if (err) \
        return err; \
\
    mutex_lock(&data->update_lock); \
    data->value = temp_to_reg(val); \
    i2c_smbus_write_byte_data(client, reg, data->value); \
    mutex_unlock(&data->update_lock); \
    return count; \
}

set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);

static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
               char *buf)
{
    struct max1619_data *data = max1619_update_device(dev);
    return sprintf(buf, "%d\n", data->alarms);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
              char *buf)
{
    int bitnr = to_sensor_dev_attr(attr)->index;
    struct max1619_data *data = max1619_update_device(dev);
    return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
}

static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
    set_temp_low2);
static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
    set_temp_high2);
static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
    set_temp_crit2);
static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
    set_temp_hyst2);
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);

static struct attribute *max1619_attributes[] = {
    &dev_attr_temp1_input.attr,
    &dev_attr_temp2_input.attr,
    &dev_attr_temp2_min.attr,
    &dev_attr_temp2_max.attr,
    &dev_attr_temp2_crit.attr,
    &dev_attr_temp2_crit_hyst.attr,

    &dev_attr_alarms.attr,
    &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_fault.dev_attr.attr,
    &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
    &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
    NULL
};

static const struct attribute_group max1619_group = {
    .attrs = max1619_attributes,
};

/*
 * Real code
 */

/* Return 0 if detection is successful, -ENODEV otherwise */
static int max1619_detect(struct i2c_client *client,
              struct i2c_board_info *info)
{
    struct i2c_adapter *adapter = client->adapter;
    u8 reg_config, reg_convrate, reg_status, man_id, chip_id;

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

    /* detection */
    reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
    reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
    reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
    if ((reg_config & 0x03) != 0x00
     || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
        dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
            client->addr);
        return -ENODEV;
    }

    /* identification */
    man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
    chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
    if (man_id != 0x4D || chip_id != 0x04) {
        dev_info(&adapter->dev,
             "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
             man_id, chip_id);
        return -ENODEV;
    }

    strlcpy(info->type, "max1619", I2C_NAME_SIZE);

    return 0;
}

static int max1619_probe(struct i2c_client *new_client,
             const struct i2c_device_id *id)
{
    struct max1619_data *data;
    int err;

    data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
                GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    i2c_set_clientdata(new_client, data);
    data->valid = 0;
    mutex_init(&data->update_lock);

    /* Initialize the MAX1619 chip */
    max1619_init_client(new_client);

    /* Register sysfs hooks */
    err = sysfs_create_group(&new_client->dev.kobj, &max1619_group);
    if (err)
        return err;

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

    return 0;

exit_remove_files:
    sysfs_remove_group(&new_client->dev.kobj, &max1619_group);
    return err;
}

static void max1619_init_client(struct i2c_client *client)
{
    u8 config;

    /*
     * Start the conversions.
     */
    i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
                  5); /* 2 Hz */
    config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
    if (config & 0x40)
        i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
                      config & 0xBF); /* run */
}

static int max1619_remove(struct i2c_client *client)
{
    struct max1619_data *data = i2c_get_clientdata(client);

    hwmon_device_unregister(data->hwmon_dev);
    sysfs_remove_group(&client->dev.kobj, &max1619_group);

    return 0;
}

static struct max1619_data *max1619_update_device(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct max1619_data *data = i2c_get_clientdata(client);

    mutex_lock(&data->update_lock);

    if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
        dev_dbg(&client->dev, "Updating max1619 data.\n");
        data->temp_input1 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_LOCAL_TEMP);
        data->temp_input2 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_REMOTE_TEMP);
        data->temp_high2 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_REMOTE_HIGH);
        data->temp_low2 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_REMOTE_LOW);
        data->temp_crit2 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_REMOTE_CRIT);
        data->temp_hyst2 = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_TCRIT_HYST);
        data->alarms = i2c_smbus_read_byte_data(client,
                    MAX1619_REG_R_STATUS);

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

    mutex_unlock(&data->update_lock);

    return data;
}

module_i2c_driver(max1619_driver);

MODULE_AUTHOR("Oleksij Rempel <[email protected]> and "
    "Jean Delvare <[email protected]>");
MODULE_DESCRIPTION("MAX1619 sensor driver");
MODULE_LICENSE("GPL");