Commit e5a63942 authored by Peter Meerwald's avatar Peter Meerwald Committed by Jonathan Cameron
Browse files

iio: Add tmp006 IR temperature sensor 

the TI TMP006 is a non-contact temperature sensor with I2C interface;
it measures the surface temperature of a distance object using a
thermopile to absorb IR energy emitted from the object

the sensor has two channels: IR sensor voltage (16-bit) and reference
temperature of the chip (14-bit); datasheet is here:
http://www.ti.com/lit/ds/symlink/tmp006.pdf



v2 (thanks to Grygorii Strashko, Lars-Peter Clausen, Jonathan Cameron
for review comments):
* power down device on driver remove
* use sign_extend32()
* style cleanup
* add comments what channel raw LSBs mean
* spelling of thermopile

Signed-off-by: default avatarPeter Meerwald <pmeerw@pmeerw.net>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: LM Sensors <lm-sensors@lm-sensors.org>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 9c6cd3b3

drivers/iio/Kconfig

+1 −0
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@@ -73,5 +73,6 @@ if IIO_TRIGGER 
   source "drivers/iio/trigger/Kconfig"

endif #IIO_TRIGGER

source "drivers/iio/pressure/Kconfig"

source "drivers/iio/temperature/Kconfig"



endif # IIO

drivers/iio/Makefile

+1 −0
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@@ -21,5 +21,6 @@ obj-y += frequency/ 
obj-y += imu/

obj-y += light/

obj-y += magnetometer/

obj-y += temperature/

obj-y += trigger/

obj-y += pressure/

drivers/iio/temperature/Kconfig

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+16 −0
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#

# Temperature sensor drivers

#

menu "Temperature sensors"



config TMP006

	tristate "TMP006 infrared thermopile sensor"

	depends on I2C

	help

	  If you say yes here you get support for the Texas Instruments

	  TMP006 infrared thermopile sensor.



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

	  be called tmp006.



endmenu

drivers/iio/temperature/Makefile

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#

# Makefile for industrial I/O temperature drivers

#



obj-$(CONFIG_TMP006) += tmp006.o

drivers/iio/temperature/tmp006.c

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+291 −0
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/*

 * tmp006.c - Support for TI TMP006 IR thermopile sensor

 *

 * Copyright (c) 2013 Peter Meerwald <pmeerw@pmeerw.net>

 *

 * This file is subject to the terms and conditions of version 2 of

 * the GNU General Public License.  See the file COPYING in the main

 * directory of this archive for more details.

 *

 * Driver for the Texas Instruments I2C 16-bit IR thermopile sensor

 *

 * (7-bit I2C slave address 0x40, changeable via ADR pins)

 *

 * TODO: data ready irq

 */



#include <linux/err.h>

#include <linux/i2c.h>

#include <linux/delay.h>

#include <linux/module.h>

#include <linux/pm.h>

#include <linux/bitops.h>



#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>



#define TMP006_VOBJECT 0x00

#define TMP006_TAMBIENT 0x01

#define TMP006_CONFIG 0x02

#define TMP006_MANUFACTURER_ID 0xfe

#define TMP006_DEVICE_ID 0xff



#define TMP006_TAMBIENT_SHIFT 2



#define TMP006_CONFIG_RESET BIT(15)

#define TMP006_CONFIG_DRDY_EN BIT(8)

#define TMP006_CONFIG_DRDY BIT(7)



#define TMP006_CONFIG_MOD_MASK 0x7000



#define TMP006_CONFIG_CR_MASK 0x0e00

#define TMP006_CONFIG_CR_SHIFT 9



#define MANUFACTURER_MAGIC 0x5449

#define DEVICE_MAGIC 0x0067



struct tmp006_data {

	struct i2c_client *client;

	u16 config;

};



static int tmp006_read_measurement(struct tmp006_data *data, u8 reg)

{

	s32 ret;

	int tries = 50;



	while (tries-- > 0) {

		ret = i2c_smbus_read_word_swapped(data->client,

			TMP006_CONFIG);

		if (ret < 0)

			return ret;

		if (ret & TMP006_CONFIG_DRDY)

			break;

		msleep(100);

	}



	if (tries < 0)

		return -EIO;



	return i2c_smbus_read_word_swapped(data->client, reg);

}



static int tmp006_read_raw(struct iio_dev *indio_dev,

			    struct iio_chan_spec const *channel, int *val,

			    int *val2, long mask)

{

	struct tmp006_data *data = iio_priv(indio_dev);

	s32 ret;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (channel->type == IIO_VOLTAGE) {

			/* LSB is 156.25 nV */

			ret = tmp006_read_measurement(data, TMP006_VOBJECT);

			if (ret < 0)

				return ret;

			*val = sign_extend32(ret, 15);

		} else if (channel->type == IIO_TEMP) {

			/* LSB is 0.03125 degrees Celsius */

			ret = tmp006_read_measurement(data, TMP006_TAMBIENT);

			if (ret < 0)

				return ret;

			*val = sign_extend32(ret, 15) >> TMP006_TAMBIENT_SHIFT;

		} else {

			break;

		}

		return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:

		if (channel->type == IIO_VOLTAGE) {

			*val = 0;

			*val2 = 156250;

		} else if (channel->type == IIO_TEMP) {

			*val = 31;

			*val2 = 250000;

		} else {

			break;

		}

		return IIO_VAL_INT_PLUS_MICRO;

	default:

		break;

	}



	return -EINVAL;

}



static const char * const tmp006_freqs[] = { "4", "2", "1", "0.5", "0.25" };



static ssize_t tmp006_show_freq(struct device *dev,

				struct device_attribute *attr, char *buf)

{

	struct tmp006_data *data = iio_priv(dev_to_iio_dev(dev));

	int cr = (data->config & TMP006_CONFIG_CR_MASK)

		>> TMP006_CONFIG_CR_SHIFT;

	return sprintf(buf, "%s\n", tmp006_freqs[cr]);

}



static ssize_t tmp006_store_freq(struct device *dev,

				 struct device_attribute *attr,

				 const char *buf, size_t len)

{

	struct iio_dev *indio_dev = dev_to_iio_dev(dev);

	struct tmp006_data *data = iio_priv(indio_dev);

	int i;

	bool found = false;



	for (i = 0; i < ARRAY_SIZE(tmp006_freqs); i++)

		if (sysfs_streq(buf, tmp006_freqs[i])) {

			found = true;

			break;

		}

	if (!found)

		return -EINVAL;



	data->config &= ~TMP006_CONFIG_CR_MASK;

	data->config |= i << TMP006_CONFIG_CR_SHIFT;



	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,

		data->config);

}



static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR,

			tmp006_show_freq, tmp006_store_freq);



static IIO_CONST_ATTR(sampling_frequency_available, "4 2 1 0.5 0.25");



static struct attribute *tmp006_attributes[] = {

	&iio_dev_attr_sampling_frequency.dev_attr.attr,

	&iio_const_attr_sampling_frequency_available.dev_attr.attr,

	NULL

};



static const struct attribute_group tmp006_attribute_group = {

	.attrs = tmp006_attributes,

};



static const struct iio_chan_spec tmp006_channels[] = {

	{

		.type = IIO_VOLTAGE,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

			BIT(IIO_CHAN_INFO_SCALE),

	},

	{

		.type = IIO_TEMP,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

			BIT(IIO_CHAN_INFO_SCALE),

	}

};



static const struct iio_info tmp006_info = {

	.read_raw = tmp006_read_raw,

	.attrs = &tmp006_attribute_group,

	.driver_module = THIS_MODULE,

};



static bool tmp006_check_identification(struct i2c_client *client)

{

	int mid, did;



	mid = i2c_smbus_read_word_swapped(client, TMP006_MANUFACTURER_ID);

	if (mid < 0)

		return false;



	did = i2c_smbus_read_word_swapped(client, TMP006_DEVICE_ID);

	if (did < 0)

		return false;



	return mid == MANUFACTURER_MAGIC && did == DEVICE_MAGIC;

}



static int tmp006_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	struct iio_dev *indio_dev;

	struct tmp006_data *data;

	int ret;



	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))

		return -ENODEV;



	if (!tmp006_check_identification(client)) {

		dev_err(&client->dev, "no TMP006 sensor\n");

		return -ENODEV;

	}



	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));

	if (!indio_dev)

		return -ENOMEM;



	data = iio_priv(indio_dev);

	i2c_set_clientdata(client, indio_dev);

	data->client = client;



	indio_dev->dev.parent = &client->dev;

	indio_dev->name = dev_name(&client->dev);

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = &tmp006_info;



	indio_dev->channels = tmp006_channels;

	indio_dev->num_channels = ARRAY_SIZE(tmp006_channels);



	ret = i2c_smbus_read_word_swapped(data->client, TMP006_CONFIG);

	if (ret < 0)

		return ret;

	data->config = ret;



	return iio_device_register(indio_dev);

}



static int tmp006_powerdown(struct tmp006_data *data)

{

	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,

		data->config & ~TMP006_CONFIG_MOD_MASK);

}



static int tmp006_remove(struct i2c_client *client)

{

	struct iio_dev *indio_dev = i2c_get_clientdata(client);



	iio_device_unregister(indio_dev);

	tmp006_powerdown(iio_priv(indio_dev));



	return 0;

}



#ifdef CONFIG_PM_SLEEP

static int tmp006_suspend(struct device *dev)

{

	return tmp006_powerdown(iio_priv(dev_to_iio_dev(dev)));

}



static int tmp006_resume(struct device *dev)

{

	struct tmp006_data *data = iio_priv(dev_to_iio_dev(dev));

	return i2c_smbus_write_word_swapped(data->client, TMP006_CONFIG,

		data->config | TMP006_CONFIG_MOD_MASK);

}

#endif



static SIMPLE_DEV_PM_OPS(tmp006_pm_ops, tmp006_suspend, tmp006_resume);



static const struct i2c_device_id tmp006_id[] = {

	{ "tmp006", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, tmp006_id);



static struct i2c_driver tmp006_driver = {

	.driver = {

		.name	= "tmp006",

		.pm	= &tmp006_pm_ops,

		.owner	= THIS_MODULE,

	},

	.probe = tmp006_probe,

	.remove = tmp006_remove,

	.id_table = tmp006_id,

};

module_i2c_driver(tmp006_driver);



MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");

MODULE_DESCRIPTION("TI TMP006 IR thermopile sensor driver");

MODULE_LICENSE("GPL");