Commit 983b97be authored by Hartmut Knaack's avatar Hartmut Knaack Committed by Guenter Roeck
Browse files

hwmon: Driver for ADT7410 



This patch brings basic support for the Analog Devices ADT7410 temperature
sensor. The following functionality has been implemented:

  * get current temperature
  * get/set minimum, maximum and critical temperature
  * get/set hysteresis
  * get alarm events for minimum, maximum and critical temperature

All implemented sysfs attributes have been sucessfully tested at temperatures
of 15°C to 40°C.

Signed-off-by: default avatarHartmut Knaack <knaack.h@gmx.de>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 87432a2e

Documentation/hwmon/adt7410

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+51 −0
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Kernel driver adt7410

=====================



Supported chips:

  * Analog Devices ADT7410

    Prefix: 'adt7410'

    Addresses scanned: I2C 0x48 - 0x4B

    Datasheet: Publicly available at the Analog Devices website

               http://www.analog.com/static/imported-files/data_sheets/ADT7410.pdf



Author: Hartmut Knaack <knaack.h@gmx.de>



Description

-----------



The ADT7410 is a temperature sensor with rated temperature range of -55°C to

+150°C. It has a high accuracy of +/-0.5°C and can be operated at a resolution

of 13 bits (0.0625°C) or 16 bits (0.0078°C). The sensor provides an INT pin to

indicate that a minimum or maximum temperature set point has been exceeded, as

well as a critical temperature (CT) pin to indicate that the critical

temperature set point has been exceeded. Both pins can be set up with a common

hysteresis of 0°C - 15°C and a fault queue, ranging from 1 to 4 events. Both

pins can individually set to be active-low or active-high, while the whole

device can either run in comparator mode or interrupt mode. The ADT7410

supports continous temperature sampling, as well as sampling one temperature

value per second or even justget one sample on demand for power saving.

Besides, it can completely power down its ADC, if power management is

required.



Configuration Notes

-------------------



Since the device uses one hysteresis value, which is an offset to minimum,

maximum and critical temperature, it can only be set for temp#_max_hyst.

However, temp#_min_hyst and temp#_crit_hyst show their corresponding

hysteresis.

The device is set to 16 bit resolution and comparator mode.



sysfs-Interface

---------------



temp#_input		- temperature input

temp#_min		- temperature minimum setpoint

temp#_max		- temperature maximum setpoint

temp#_crit		- critical temperature setpoint

temp#_min_hyst		- hysteresis for temperature minimum (read-only)

temp#_max_hyst		- hysteresis for temperature maximum (read/write)

temp#_crit_hyst		- hysteresis for critical temperature (read-only)

temp#_min_alarm		- temperature minimum alarm flag

temp#_max_alarm		- temperature maximum alarm flag

temp#_crit_alarm	- critical temperature alarm flag

drivers/hwmon/Kconfig

+10 −0
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@@ -179,6 +179,16 @@ config SENSORS_ADM9240 
	  This driver can also be built as a module.  If so, the module

	  will be called adm9240.



config SENSORS_ADT7410

	tristate "Analog Devices ADT7410"

	depends on I2C && EXPERIMENTAL

	help

	  If you say yes here you get support for the Analog Devices

	  ADT7410 temperature monitoring chip.



	  This driver can also be built as a module. If so, the module

	  will be called adt7410.



config SENSORS_ADT7411

	tristate "Analog Devices ADT7411"

	depends on I2C && EXPERIMENTAL

drivers/hwmon/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ obj-$(CONFIG_SENSORS_ADM9240) += adm9240.o 
obj-$(CONFIG_SENSORS_ADS1015)	+= ads1015.o

obj-$(CONFIG_SENSORS_ADS7828)	+= ads7828.o

obj-$(CONFIG_SENSORS_ADS7871)	+= ads7871.o

obj-$(CONFIG_SENSORS_ADT7410)	+= adt7410.o

obj-$(CONFIG_SENSORS_ADT7411)	+= adt7411.o

obj-$(CONFIG_SENSORS_ADT7462)	+= adt7462.o

obj-$(CONFIG_SENSORS_ADT7470)	+= adt7470.o

drivers/hwmon/adt7410.c

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/*

 * adt7410.c - Part of lm_sensors, Linux kernel modules for hardware

 *	 monitoring

 * This driver handles the ADT7410 and compatible digital temperature sensors.

 * Hartmut Knaack <knaack.h@gmx.de> 2012-07-22

 * based on lm75.c by Frodo Looijaard <frodol@dds.nl>

 * and adt7410.c from iio-staging by Sonic Zhang <sonic.zhang@analog.com>

 *

 * 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/delay.h>



/*

 * ADT7410 registers definition

 */



#define ADT7410_TEMPERATURE		0

#define ADT7410_STATUS			2

#define ADT7410_CONFIG			3

#define ADT7410_T_ALARM_HIGH		4

#define ADT7410_T_ALARM_LOW		6

#define ADT7410_T_CRIT			8

#define ADT7410_T_HYST			0xA



/*

 * ADT7410 status

 */

#define ADT7410_STAT_T_LOW		(1 << 4)

#define ADT7410_STAT_T_HIGH		(1 << 5)

#define ADT7410_STAT_T_CRIT		(1 << 6)

#define ADT7410_STAT_NOT_RDY		(1 << 7)



/*

 * ADT7410 config

 */

#define ADT7410_FAULT_QUEUE_MASK	(1 << 0 | 1 << 1)

#define ADT7410_CT_POLARITY		(1 << 2)

#define ADT7410_INT_POLARITY		(1 << 3)

#define ADT7410_EVENT_MODE		(1 << 4)

#define ADT7410_MODE_MASK		(1 << 5 | 1 << 6)

#define ADT7410_FULL			(0 << 5 | 0 << 6)

#define ADT7410_PD			(1 << 5 | 1 << 6)

#define ADT7410_RESOLUTION		(1 << 7)



/*

 * ADT7410 masks

 */

#define ADT7410_T13_VALUE_MASK			0xFFF8

#define ADT7410_T_HYST_MASK			0xF



/* straight from the datasheet */

#define ADT7410_TEMP_MIN (-55000)

#define ADT7410_TEMP_MAX 150000



enum adt7410_type {		/* keep sorted in alphabetical order */

	adt7410,

};



/* Addresses scanned */

static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,

					I2C_CLIENT_END };



static const u8 ADT7410_REG_TEMP[4] = {

	ADT7410_TEMPERATURE,		/* input */

	ADT7410_T_ALARM_HIGH,		/* high */

	ADT7410_T_ALARM_LOW,		/* low */

	ADT7410_T_CRIT,			/* critical */

};



/* Each client has this additional data */

struct adt7410_data {

	struct device		*hwmon_dev;

	struct mutex		update_lock;

	u8			config;

	u8			oldconfig;

	bool			valid;		/* true if registers valid */

	unsigned long		last_updated;	/* In jiffies */

	s16			temp[4];	/* Register values,

						   0 = input

						   1 = high

						   2 = low

						   3 = critical */

	u8			hyst;		/* hysteresis offset */

};



/*

 * adt7410 register access by I2C

 */

static int adt7410_temp_ready(struct i2c_client *client)

{

	int i, status;



	for (i = 0; i < 6; i++) {

		status = i2c_smbus_read_byte_data(client, ADT7410_STATUS);

		if (status < 0)

			return status;

		if (!(status & ADT7410_STAT_NOT_RDY))

			return 0;

		msleep(60);

	}

	return -ETIMEDOUT;

}



static struct adt7410_data *adt7410_update_device(struct device *dev)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct adt7410_data *data = i2c_get_clientdata(client);

	struct adt7410_data *ret = data;

	mutex_lock(&data->update_lock);



	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)

	    || !data->valid) {

		int i, status;



		dev_dbg(&client->dev, "Starting update\n");



		status = adt7410_temp_ready(client); /* check for new value */

		if (unlikely(status)) {

			ret = ERR_PTR(status);

			goto abort;

		}

		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {

			status = i2c_smbus_read_word_swapped(client,

							ADT7410_REG_TEMP[i]);

			if (unlikely(status < 0)) {

				dev_dbg(dev,

					"Failed to read value: reg %d, error %d\n",

					ADT7410_REG_TEMP[i], status);

				ret = ERR_PTR(status);

				goto abort;

			}

			data->temp[i] = status;

		}

		status = i2c_smbus_read_byte_data(client, ADT7410_T_HYST);

		if (unlikely(status < 0)) {

			dev_dbg(dev,

				"Failed to read value: reg %d, error %d\n",

				ADT7410_T_HYST, status);

			ret = ERR_PTR(status);

			goto abort;

		}

		data->hyst = status;

		data->last_updated = jiffies;

		data->valid = true;

	}



abort:

	mutex_unlock(&data->update_lock);

	return ret;

}



static s16 ADT7410_TEMP_TO_REG(long temp)

{

	return DIV_ROUND_CLOSEST(SENSORS_LIMIT(temp, ADT7410_TEMP_MIN,

					       ADT7410_TEMP_MAX) * 128, 1000);

}



static int ADT7410_REG_TO_TEMP(struct adt7410_data *data, s16 reg)

{

	/* in 13 bit mode, bits 0-2 are status flags - mask them out */

	if (!(data->config & ADT7410_RESOLUTION))

		reg &= ADT7410_T13_VALUE_MASK;

	/*

	 * temperature is stored in twos complement format, in steps of

	 * 1/128°C

	 */

	return DIV_ROUND_CLOSEST(reg * 1000, 128);

}



/*-----------------------------------------------------------------------*/



/* sysfs attributes for hwmon */



static ssize_t adt7410_show_temp(struct device *dev,

				 struct device_attribute *da, char *buf)

{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

	struct adt7410_data *data = adt7410_update_device(dev);



	if (IS_ERR(data))

		return PTR_ERR(data);



	return sprintf(buf, "%d\n", ADT7410_REG_TO_TEMP(data,

		       data->temp[attr->index]));

}



static ssize_t adt7410_set_temp(struct device *dev,

				struct device_attribute *da,

				const char *buf, size_t count)

{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

	struct i2c_client *client = to_i2c_client(dev);

	struct adt7410_data *data = i2c_get_clientdata(client);

	int nr = attr->index;

	long temp;

	int ret;



	ret = kstrtol(buf, 10, &temp);

	if (ret)

		return ret;



	mutex_lock(&data->update_lock);

	data->temp[nr] = ADT7410_TEMP_TO_REG(temp);

	ret = i2c_smbus_write_word_swapped(client, ADT7410_REG_TEMP[nr],

					   data->temp[nr]);

	if (ret)

		count = ret;

	mutex_unlock(&data->update_lock);

	return count;

}



static ssize_t adt7410_show_t_hyst(struct device *dev,

				   struct device_attribute *da,

				   char *buf)

{

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

	struct adt7410_data *data = adt7410_update_device(dev);

	int nr = attr->index;

	int hyst = (data->hyst & ADT7410_T_HYST_MASK) * 1000;



	/*

	 * hysteresis is stored as a 4 bit offset in the device, convert it

	 * to an absolute value

	 */

	if (nr == 2)	/* min has positive offset, others have negative */

		hyst = -hyst;

	return sprintf(buf, "%d\n",

		       ADT7410_REG_TO_TEMP(data, data->temp[nr]) - hyst);

}



static ssize_t adt7410_set_t_hyst(struct device *dev,

				  struct device_attribute *da,

				  const char *buf, size_t count)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct adt7410_data *data = i2c_get_clientdata(client);

	int limit, ret;

	long hyst;



	ret = kstrtol(buf, 10, &hyst);

	if (ret)

		return ret;

	/* convert absolute hysteresis value to a 4 bit delta value */

	limit = ADT7410_REG_TO_TEMP(data, data->temp[1]);

	hyst = SENSORS_LIMIT(hyst, ADT7410_TEMP_MIN, ADT7410_TEMP_MAX);

	data->hyst = SENSORS_LIMIT(DIV_ROUND_CLOSEST(limit - hyst, 1000),

				   0, ADT7410_T_HYST_MASK);

	ret = i2c_smbus_write_byte_data(client, ADT7410_T_HYST, data->hyst);

	if (ret)

		return ret;



	return count;

}



static ssize_t adt7410_show_alarm(struct device *dev,

				  struct device_attribute *da,

				  char *buf)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

	int ret;



	ret = i2c_smbus_read_byte_data(client, ADT7410_STATUS);

	if (ret < 0)

		return ret;



	return sprintf(buf, "%d\n", !!(ret & attr->index));

}



static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adt7410_show_temp, NULL, 0);

static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,

			  adt7410_show_temp, adt7410_set_temp, 1);

static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,

			  adt7410_show_temp, adt7410_set_temp, 2);

static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,

			  adt7410_show_temp, adt7410_set_temp, 3);

static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,

			  adt7410_show_t_hyst, adt7410_set_t_hyst, 1);

static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO,

			  adt7410_show_t_hyst, NULL, 2);

static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,

			  adt7410_show_t_hyst, NULL, 3);

static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, adt7410_show_alarm,

			  NULL, ADT7410_STAT_T_LOW);

static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adt7410_show_alarm,

			  NULL, ADT7410_STAT_T_HIGH);

static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, adt7410_show_alarm,

			  NULL, ADT7410_STAT_T_CRIT);



static struct attribute *adt7410_attributes[] = {

	&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_crit.dev_attr.attr,

	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,

	&sensor_dev_attr_temp1_min_hyst.dev_attr.attr,

	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,

	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,

	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,

	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,

	NULL

};



static const struct attribute_group adt7410_group = {

	.attrs = adt7410_attributes,

};



/*-----------------------------------------------------------------------*/



/* device probe and removal */



static int adt7410_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	struct adt7410_data *data;

	int ret;



	if (!i2c_check_functionality(client->adapter,

			I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))

		return -ENODEV;



	data = devm_kzalloc(&client->dev, sizeof(struct adt7410_data),

			    GFP_KERNEL);

	if (!data)

		return -ENOMEM;



	i2c_set_clientdata(client, data);

	mutex_init(&data->update_lock);



	/* configure as specified */

	ret = i2c_smbus_read_byte_data(client, ADT7410_CONFIG);

	if (ret < 0) {

		dev_dbg(&client->dev, "Can't read config? %d\n", ret);

		return ret;

	}

	data->oldconfig = ret;

	/*

	 * Set to 16 bit resolution, continous conversion and comparator mode.

	 */

	data->config = ret | ADT7410_FULL | ADT7410_RESOLUTION |

			ADT7410_EVENT_MODE;

	if (data->config != data->oldconfig) {

		ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,

						data->config);

		if (ret)

			return ret;

	}

	dev_dbg(&client->dev, "Config %02x\n", data->config);



	/* Register sysfs hooks */

	ret = sysfs_create_group(&client->dev.kobj, &adt7410_group);

	if (ret)

		goto exit_restore;



	data->hwmon_dev = hwmon_device_register(&client->dev);

	if (IS_ERR(data->hwmon_dev)) {

		ret = PTR_ERR(data->hwmon_dev);

		goto exit_remove;

	}



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



	return 0;



exit_remove:

	sysfs_remove_group(&client->dev.kobj, &adt7410_group);

exit_restore:

	i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->oldconfig);

	return ret;

}



static int adt7410_remove(struct i2c_client *client)

{

	struct adt7410_data *data = i2c_get_clientdata(client);



	hwmon_device_unregister(data->hwmon_dev);

	sysfs_remove_group(&client->dev.kobj, &adt7410_group);

	if (data->oldconfig != data->config)

		i2c_smbus_write_byte_data(client, ADT7410_CONFIG,

					  data->oldconfig);

	return 0;

}



static const struct i2c_device_id adt7410_ids[] = {

	{ "adt7410", adt7410, },

	{ /* LIST END */ }

};

MODULE_DEVICE_TABLE(i2c, adt7410_ids);



#ifdef CONFIG_PM

static int adt7410_suspend(struct device *dev)

{

	int ret;

	struct i2c_client *client = to_i2c_client(dev);

	struct adt7410_data *data = i2c_get_clientdata(client);



	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG,

					data->config | ADT7410_PD);

	return ret;

}



static int adt7410_resume(struct device *dev)

{

	int ret;

	struct i2c_client *client = to_i2c_client(dev);

	struct adt7410_data *data = i2c_get_clientdata(client);



	ret = i2c_smbus_write_byte_data(client, ADT7410_CONFIG, data->config);

	return ret;

}



static const struct dev_pm_ops adt7410_dev_pm_ops = {

	.suspend	= adt7410_suspend,

	.resume		= adt7410_resume,

};

#define ADT7410_DEV_PM_OPS (&adt7410_dev_pm_ops)

#else

#define ADT7410_DEV_PM_OPS NULL

#endif /* CONFIG_PM */



static struct i2c_driver adt7410_driver = {

	.class		= I2C_CLASS_HWMON,

	.driver = {

		.name	= "adt7410",

		.pm	= ADT7410_DEV_PM_OPS,

	},

	.probe		= adt7410_probe,

	.remove		= adt7410_remove,

	.id_table	= adt7410_ids,

	.address_list	= normal_i2c,

};



module_i2c_driver(adt7410_driver);



MODULE_AUTHOR("Hartmut Knaack");

MODULE_DESCRIPTION("ADT7410 driver");

MODULE_LICENSE("GPL");

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