max6620.c

/*
 * max6620.c - Linux Kernel module for hardware monitoring.
 *
 * (C) 2012 by L. Grunenberg <contact@lgrunenberg.de>
 *
 * based on code written by :
 * 2007 by Hans J. Koch <hjk@hansjkoch.de>
 * John Morris <john.morris@spirentcom.com>
 * Copyright (c) 2003 Spirent Communications
 * and Claus Gindhart <claus.gindhart@kontron.com>
 *
 * This module has only been tested with the MAX6620 chip.
 *
 * The datasheet was last seen at:
 *
 *        http://pdfserv.maxim-ic.com/en/ds/MAX6620.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>

/*
 * Insmod parameters
 */


/* clock: The clock frequency of the chip the driver should assume */
static int clock = 8192;

module_param(clock, int, S_IRUGO);

static const unsigned short normal_i2c[] = {0x0a, 0x1a, 0x2a, I2C_CLIENT_END};

/*
 * MAX 6620 registers
 */

#define MAX6620_REG_CONFIG	0x00
#define MAX6620_REG_FAULT	0x01
#define MAX6620_REG_CONF_FAN0	0x02
#define MAX6620_REG_CONF_FAN1	0x03
#define MAX6620_REG_CONF_FAN2	0x04
#define MAX6620_REG_CONF_FAN3	0x05
#define MAX6620_REG_DYN_FAN0	0x06
#define MAX6620_REG_DYN_FAN1	0x07
#define MAX6620_REG_DYN_FAN2	0x08
#define MAX6620_REG_DYN_FAN3	0x09
#define MAX6620_REG_TACH0	0x10
#define MAX6620_REG_TACH1	0x12
#define MAX6620_REG_TACH2	0x14
#define MAX6620_REG_TACH3	0x16
#define MAX6620_REG_VOLT0	0x18
#define MAX6620_REG_VOLT1	0x1A
#define MAX6620_REG_VOLT2	0x1C
#define MAX6620_REG_VOLT3	0x1E
#define MAX6620_REG_TAR0	0x20
#define MAX6620_REG_TAR1	0x22
#define MAX6620_REG_TAR2	0x24
#define MAX6620_REG_TAR3	0x26
#define MAX6620_REG_DAC0	0x28
#define MAX6620_REG_DAC1	0x2A
#define MAX6620_REG_DAC2	0x2C
#define MAX6620_REG_DAC3	0x2E

/*
 * Config register bits
 */

#define MAX6620_CFG_RUN			0x80
#define MAX6620_CFG_POR			0x40
#define MAX6620_CFG_TIMEOUT		0x20
#define MAX6620_CFG_FULLFAN		0x10
#define MAX6620_CFG_OSC			0x08
#define MAX6620_CFG_WD_MASK		0x06
#define MAX6620_CFG_WD_2		0x02
#define MAX6620_CFG_WD_6		0x04
#define MAX6620_CFG_WD10		0x06
#define MAX6620_CFG_WD			0x01


/*
 * Failure status register bits
 */

#define MAX6620_FAIL_TACH0	0x10
#define MAX6620_FAIL_TACH1	0x20
#define MAX6620_FAIL_TACH2	0x40
#define MAX6620_FAIL_TACH3	0x80
#define MAX6620_FAIL_MASK0	0x01
#define MAX6620_FAIL_MASK1	0x02
#define MAX6620_FAIL_MASK2	0x04
#define MAX6620_FAIL_MASK3	0x08


/* Minimum and maximum values of the FAN-RPM */
#define FAN_RPM_MIN 240
#define FAN_RPM_MAX 30000

#define DIV_FROM_REG(reg) (1 << ((reg & 0xE0) >> 5))

static int max6620_probe(struct i2c_client *client, const struct i2c_device_id *id);
static int max6620_init_client(struct i2c_client *client);
static int max6620_remove(struct i2c_client *client);
static struct max6620_data *max6620_update_device(struct device *dev);

static const u8 config_reg[] = {
	MAX6620_REG_CONF_FAN0,
	MAX6620_REG_CONF_FAN1,
	MAX6620_REG_CONF_FAN2,
	MAX6620_REG_CONF_FAN3,
};

static const u8 dyn_reg[] = {
	MAX6620_REG_DYN_FAN0,
	MAX6620_REG_DYN_FAN1,
	MAX6620_REG_DYN_FAN2,
	MAX6620_REG_DYN_FAN3,
};

static const u8 tach_reg[] = {
	MAX6620_REG_TACH0,
	MAX6620_REG_TACH1,
	MAX6620_REG_TACH2,
	MAX6620_REG_TACH3,
};

static const u8 volt_reg[] = {
	MAX6620_REG_VOLT0,
	MAX6620_REG_VOLT1,
	MAX6620_REG_VOLT2,
	MAX6620_REG_VOLT3,
};

static const u8 target_reg[] = {
	MAX6620_REG_TAR0,
	MAX6620_REG_TAR1,
	MAX6620_REG_TAR2,
	MAX6620_REG_TAR3,
};

static const u8 dac_reg[] = {
	MAX6620_REG_DAC0,
	MAX6620_REG_DAC1,
	MAX6620_REG_DAC2,
	MAX6620_REG_DAC3,
};

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

static const struct i2c_device_id max6620_id[] = {
	{ "max6620", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, max6620_id);

static struct i2c_driver max6620_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "max6620",
	},
	.probe		= max6620_probe,
	.remove		= __devexit_p(max6620_remove),
	.id_table	= max6620_id,
	.address_list	= normal_i2c,
};

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

struct max6620_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	int nr_fans;
	char valid; /* zero until following fields are valid */
	unsigned long last_updated; /* in jiffies */

	/* register values */
	u8 speed[4];
	u8 config;
	u8 fancfg[4];
	u8 fandyn[4];
	u8 tach[4];
	u8 volt[4];
	u8 target[4];
	u8 dac[4];
	u8 fault;
};

static ssize_t get_fan(struct device *dev, struct device_attribute *devattr, char *buf) {
			
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = max6620_update_device(dev);
	int rpm;

	/*
	 * Calculation details:
	 *
	 * Each tachometer counts over an interval given by the "count"
	 * register (0.25, 0.5, 1 or 2 seconds). This module assumes
	 * that the fans produce two pulses per revolution (this seems
	 * to be the most common).
	 */
	if(data->tach[attr->index] == 0 || data->tach[attr->index] == 255) {
		rpm = 0;
	} else {	
		rpm = ((clock / (data->tach[attr->index] << 3)) * 30 * DIV_FROM_REG(data->fandyn[attr->index]));
	}
	
	return sprintf(buf, "%d\n", rpm);
}

static ssize_t get_target(struct device *dev, struct device_attribute *devattr, char *buf) {
				
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = max6620_update_device(dev);
	int kscale, ktach, rpm;

	/*
	 * Use the datasheet equation:
	 *
	 *    FanSpeed = KSCALE x fCLK / [256 x (KTACH + 1)]
	 *
	 * then multiply by 60 to give rpm.
	 */

	kscale = DIV_FROM_REG(data->fandyn[attr->index]);
	ktach = data->target[attr->index];
	if(ktach == 0) {
		rpm = 0;
	} else {
		rpm = ((60 * kscale * clock) / (ktach << 3)); 
	}
	return sprintf(buf, "%d\n", rpm);
}

static ssize_t set_target(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) {
				
	struct i2c_client *client = to_i2c_client(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = i2c_get_clientdata(client);
	int kscale, ktach;
	unsigned long rpm;
	int err;

	err = kstrtoul(buf, 10, &rpm);
	if (err)
		return err;

	rpm = SENSORS_LIMIT(rpm, FAN_RPM_MIN, FAN_RPM_MAX);

	/*
	 * Divide the required speed by 60 to get from rpm to rps, then
	 * use the datasheet equation:
	 *
	 *     KTACH = [(fCLK x KSCALE) / (256 x FanSpeed)] - 1
	 */

	mutex_lock(&data->update_lock);

	kscale = DIV_FROM_REG(data->fandyn[attr->index]);
	ktach = ((60 * kscale * clock) / rpm); 
	if (ktach < 0)
		ktach = 0;
	if (ktach > 255)
		ktach = 255;
	data->target[attr->index] = ktach;

	i2c_smbus_write_byte_data(client, target_reg[attr->index], data->target[attr->index]);
	i2c_smbus_write_byte_data(client, target_reg[attr->index]+0x01, 0x00);

	mutex_unlock(&data->update_lock);

	return count;
}

/*
 * Get/set the fan speed in open loop mode using pwm1 sysfs file.
 * Speed is given as a relative value from 0 to 255, where 255 is maximum
 * speed. Note that this is done by writing directly to the chip's DAC,
 * it won't change the closed loop speed set by fan1_target.
 * Also note that due to rounding errors it is possible that you don't read
 * back exactly the value you have set.
 */

static ssize_t get_pwm(struct device *dev, struct device_attribute *devattr, char *buf) {
			
	int pwm;
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = max6620_update_device(dev);

	/*
	 * Useful range for dac is 0-180 for 12V fans and 0-76 for 5V fans.
	 * Lower DAC values mean higher speeds.
	 */
	pwm = ((int)data->volt[attr->index]);

	if (pwm < 0)
		pwm = 0;

	return sprintf(buf, "%d\n", pwm);
}

static ssize_t set_pwm(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) {
				
	struct i2c_client *client = to_i2c_client(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = i2c_get_clientdata(client);
	unsigned long pwm;
	int err;

	err = kstrtoul(buf, 10, &pwm);
	if (err)
		return err;

	pwm = SENSORS_LIMIT(pwm, 0, 255);

	mutex_lock(&data->update_lock);

		data->dac[attr->index] = pwm;
	

	i2c_smbus_write_byte_data(client, dac_reg[attr->index], data->dac[attr->index]);
	i2c_smbus_write_byte_data(client, dac_reg[attr->index]+1, 0x00);

	mutex_unlock(&data->update_lock);

	return count;
}

/*
 * Get/Set controller mode:
 * Possible values:
 * 0 = Fan always on
 * 1 = Open loop, Voltage is set according to speed, not regulated.
 * 2 = Closed loop, RPM for all fans regulated by fan1 tachometer
 */

static ssize_t get_enable(struct device *dev, struct device_attribute *devattr, char *buf) {
				
	struct max6620_data *data = max6620_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int mode = (data->fancfg[attr->index] & 0x80 ) >> 7;
	int sysfs_modes[2] = {1, 2};

	return sprintf(buf, "%d\n", sysfs_modes[mode]);
}

static ssize_t set_enable(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) {
				
	struct i2c_client *client = to_i2c_client(dev);
	struct max6620_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	int max6620_modes[3] = {0, 1, 0};
	unsigned long mode;
	int err;

	err = kstrtoul(buf, 10, &mode);
	if (err)
		return err;

	if (mode > 2)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	data->fancfg[attr->index] = i2c_smbus_read_byte_data(client, config_reg[attr->index]);
	data->fancfg[attr->index] = (data->fancfg[attr->index] & ~0x80)
		       | (max6620_modes[mode] << 7);

	i2c_smbus_write_byte_data(client, config_reg[attr->index], data->fancfg[attr->index]);

	mutex_unlock(&data->update_lock);

	return count;
}

/*
 * Read/write functions for fan1_div sysfs file. The MAX6620 has no such
 * divider. We handle this by converting between divider and counttime:
 *
 * (counttime == k) <==> (divider == 2^k), k = 0, 1, 2, 3, 4 or 5
 *
 * Lower values of k allow to connect a faster fan without the risk of
 * counter overflow. The price is lower resolution. You can also set counttime
 * using the module parameter. Note that the module parameter "prescaler" also
 * influences the behaviour. Unfortunately, there's no sysfs attribute
 * defined for that. See the data sheet for details.
 */

static ssize_t get_div(struct device *dev, struct device_attribute *devattr, char *buf) {
			
	struct max6620_data *data = max6620_update_device(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

	return sprintf(buf, "%d\n", DIV_FROM_REG(data->fandyn[attr->index]));
}

static ssize_t set_div(struct device *dev, struct device_attribute *devattr, const char *buf, size_t count) {
	
	struct i2c_client *client = to_i2c_client(dev);
	struct max6620_data *data = i2c_get_clientdata(client);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	unsigned long div;
	int err;
	u8 div_bin;

	err = kstrtoul(buf, 10, &div);
	if (err)
		return err;

	mutex_lock(&data->update_lock);
	switch (div) {
	case 1:
		div_bin = 0;
		break;
	case 2:
		div_bin = 1;
		break;
	case 4:
		div_bin = 2;
		break;
	case 8:
		div_bin = 3;
		break;
	case 16:
		div_bin = 4;
		break;
	case 32:
		div_bin = 5;
		break;
	default:
		mutex_unlock(&data->update_lock);
		return -EINVAL;
	}
	data->fandyn[attr->index] &= 0x1F;
	data->fandyn[attr->index] |= div_bin << 5;
	i2c_smbus_write_byte_data(client, dyn_reg[attr->index], data->fandyn[attr->index]);
	mutex_unlock(&data->update_lock);

	return count;
}

/*
 * Get alarm stati:
 * Possible values:
 * 0 = no alarm
 * 1 = alarm
 */

static ssize_t get_alarm(struct device *dev, struct device_attribute *devattr, char *buf) {
				
	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
	struct max6620_data *data = max6620_update_device(dev);
	struct i2c_client *client = to_i2c_client(dev);
	int alarm = 0;

	if (data->fault & (1 << attr->index)) {
		mutex_lock(&data->update_lock);
		alarm = 1;
		data->fault &= ~(1 << attr->index);
		data->fault |= i2c_smbus_read_byte_data(client,
							MAX6620_REG_FAULT);
		mutex_unlock(&data->update_lock);
	}

	return sprintf(buf, "%d\n", alarm);
}

static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, get_fan, NULL, 0);
static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, get_fan, NULL, 1);
static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, get_fan, NULL, 2);
static SENSOR_DEVICE_ATTR(fan4_input, S_IRUGO, get_fan, NULL, 3);
static SENSOR_DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO, get_target, set_target, 0);
static SENSOR_DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_div, set_div, 0);
// static SENSOR_DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO, get_enable, set_enable, 0);
static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 0);
static SENSOR_DEVICE_ATTR(fan2_target, S_IWUSR | S_IRUGO, get_target, set_target, 1);
static SENSOR_DEVICE_ATTR(fan2_div, S_IWUSR | S_IRUGO, get_div, set_div, 1);
// static SENSOR_DEVICE_ATTR(pwm2_enable, S_IWUSR | S_IRUGO, get_enable, set_enable, 1);
static SENSOR_DEVICE_ATTR(pwm2, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 1);
static SENSOR_DEVICE_ATTR(fan3_target, S_IWUSR | S_IRUGO, get_target, set_target, 2);
static SENSOR_DEVICE_ATTR(fan3_div, S_IWUSR | S_IRUGO, get_div, set_div, 2);
// static SENSOR_DEVICE_ATTR(pwm3_enable, S_IWUSR | S_IRUGO, get_enable, set_enable, 2);
static SENSOR_DEVICE_ATTR(pwm3, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 2);
static SENSOR_DEVICE_ATTR(fan4_target, S_IWUSR | S_IRUGO, get_target, set_target, 3);
static SENSOR_DEVICE_ATTR(fan4_div, S_IWUSR | S_IRUGO, get_div, set_div, 3);
// static SENSOR_DEVICE_ATTR(pwm4_enable, S_IWUSR | S_IRUGO, get_enable, set_enable, 3);
static SENSOR_DEVICE_ATTR(pwm4, S_IWUSR | S_IRUGO, get_pwm, set_pwm, 3);

static struct attribute *max6620_attrs[] = {
	&sensor_dev_attr_fan1_input.dev_attr.attr,
	&sensor_dev_attr_fan2_input.dev_attr.attr,
	&sensor_dev_attr_fan3_input.dev_attr.attr,
	&sensor_dev_attr_fan4_input.dev_attr.attr,
	&sensor_dev_attr_fan1_target.dev_attr.attr,
	&sensor_dev_attr_fan1_div.dev_attr.attr,
//	&sensor_dev_attr_pwm1_enable.dev_attr.attr,
	&sensor_dev_attr_pwm1.dev_attr.attr,
	&sensor_dev_attr_fan2_target.dev_attr.attr,
	&sensor_dev_attr_fan2_div.dev_attr.attr,
//	&sensor_dev_attr_pwm2_enable.dev_attr.attr,
	&sensor_dev_attr_pwm2.dev_attr.attr,
	&sensor_dev_attr_fan3_target.dev_attr.attr,
	&sensor_dev_attr_fan3_div.dev_attr.attr,
//	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
	&sensor_dev_attr_pwm3.dev_attr.attr,
	&sensor_dev_attr_fan4_target.dev_attr.attr,
	&sensor_dev_attr_fan4_div.dev_attr.attr,
//	&sensor_dev_attr_pwm4_enable.dev_attr.attr,
	&sensor_dev_attr_pwm4.dev_attr.attr,
	NULL
};

static struct attribute_group max6620_attr_grp = {
	.attrs = max6620_attrs,
};


/*
 * Real code
 */

static int __devinit max6620_probe(struct i2c_client *client, const struct i2c_device_id *id) {
				
	struct max6620_data *data;
	int err;

	data = devm_kzalloc(&client->dev, sizeof(struct max6620_data), GFP_KERNEL);
	if (!data) {
		dev_err(&client->dev, "out of memory.\n");
		return -ENOMEM;
	}

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

	/*
	 * Initialize the max6620 chip
	 */
	dev_info(&client->dev, "About to initialize module\n");
	
	err = max6620_init_client(client);
	if (err)
		return err;
	dev_info(&client->dev, "Module initialized\n");

	err = sysfs_create_group(&client->dev.kobj, &max6620_attr_grp);
	if (err)
		return err;
dev_info(&client->dev, "Sysfs entries created\n");

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (!IS_ERR(data->hwmon_dev))
		return 0;

	err = PTR_ERR(data->hwmon_dev);
	dev_err(&client->dev, "error registering hwmon device.\n");

	sysfs_remove_group(&client->dev.kobj, &max6620_attr_grp);
	return err;
}

static int __devexit max6620_remove(struct i2c_client *client) {
	
	struct max6620_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);

	sysfs_remove_group(&client->dev.kobj, &max6620_attr_grp);
	return 0;
}

static int max6620_init_client(struct i2c_client *client) {
	
	struct max6620_data *data = i2c_get_clientdata(client);
	int config;
	int err = -EIO;
	int i;

	config = i2c_smbus_read_byte_data(client, MAX6620_REG_CONFIG);

	if (config < 0) {
		dev_err(&client->dev, "Error reading config, aborting.\n");
		return err;
	}

	


	if (i2c_smbus_write_byte_data(client, MAX6620_REG_CONFIG, config)) {
		dev_err(&client->dev, "Config write error, aborting.\n");
		return err;
	}

	data->config = config;
	for (i = 0; i < 4; i++) {
		data->fancfg[i] = i2c_smbus_read_byte_data(client, config_reg[i]);
		data->fancfg[i] |= 0x80;		// enable TACH monitoring
		i2c_smbus_write_byte_data(client, config_reg[i], data->fancfg[i]);
		data->fandyn[i] = i2c_smbus_read_byte_data(client, dyn_reg[i]);
		data-> fandyn[i] |= 0x1C;
		i2c_smbus_write_byte_data(client, dyn_reg[i], data->fandyn[i]);
		data->tach[i] = i2c_smbus_read_byte_data(client, tach_reg[i]);
		data->volt[i] = i2c_smbus_read_byte_data(client, volt_reg[i]);
		data->target[i] = i2c_smbus_read_byte_data(client, target_reg[i]);
		data->dac[i] = i2c_smbus_read_byte_data(client, dac_reg[i]);
	

		
	}
	
	

	return 0;
}




static struct max6620_data *max6620_update_device(struct device *dev)
{
	int i;
	struct i2c_client *client = to_i2c_client(dev);
	struct max6620_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
		
		for (i = 0; i < 4; i++) {
			data->fancfg[i] = i2c_smbus_read_byte_data(client, config_reg[i]);
			data->fandyn[i] = i2c_smbus_read_byte_data(client, dyn_reg[i]);
			data->tach[i] = i2c_smbus_read_byte_data(client, tach_reg[i]);
			data->volt[i] = i2c_smbus_read_byte_data(client, volt_reg[i]);
			data->target[i] = i2c_smbus_read_byte_data(client, target_reg[i]);
			data->dac[i] = i2c_smbus_read_byte_data(client, dac_reg[i]);
		}
	

		/*
		 * Alarms are cleared on read in case the condition that
		 * caused the alarm is removed. Keep the value latched here
		 * for providing the register through different alarm files.
		 */
		u8 fault_reg;
		fault_reg = i2c_smbus_read_byte_data(client, MAX6620_REG_FAULT);
		data->fault |= (fault_reg >> 4) & (fault_reg & 0x0F);

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

	mutex_unlock(&data->update_lock);

	return data;
}

module_i2c_driver(max6620_driver);

static int __init max6620_init(void)
{
	return i2c_add_driver(&max6620_driver);
}
module_init(max6620_init);

/**
 * sht21_init() - clean up driver
 *
 * Called when module is removed.
 */
static void __exit max6620_exit(void)
{
	i2c_del_driver(&max6620_driver);
}
module_exit(max6620_exit);

MODULE_AUTHOR("Lucas Grunenberg");
MODULE_DESCRIPTION("MAX6620 sensor driver");
MODULE_LICENSE("GPL");