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/*
* mlx90614.c - Support for Melexis MLX90614 contactless IR temperature sensor
*
* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
* Copyright (c) 2015 Essensium NV
*
* 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 Melexis MLX90614 I2C 16-bit IR thermopile sensor
*
* (7-bit I2C slave address 0x5a, 100KHz bus speed only!)
*
* TODO: sleep mode, configuration EEPROM
*/
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#define MLX90614_OP_RAM 0x00
#define MLX90614_OP_EEPROM 0x20
#define MLX90614_OP_SLEEP 0xff
/* RAM offsets with 16-bit data, MSB first */
#define MLX90614_RAW1 (MLX90614_OP_RAM | 0x04) /* raw data IR channel 1 */
#define MLX90614_RAW2 (MLX90614_OP_RAM | 0x05) /* raw data IR channel 2 */
#define MLX90614_TA (MLX90614_OP_RAM | 0x06) /* ambient temperature */
#define MLX90614_TOBJ1 (MLX90614_OP_RAM | 0x07) /* object 1 temperature */
#define MLX90614_TOBJ2 (MLX90614_OP_RAM | 0x08) /* object 2 temperature */
/* EEPROM offsets with 16-bit data, MSB first */
#define MLX90614_EMISSIVITY (MLX90614_OP_EEPROM | 0x04) /* emissivity correction coefficient */
#define MLX90614_CONFIG (MLX90614_OP_EEPROM | 0x05) /* configuration register */
/* Control bits in configuration register */
#define MLX90614_CONFIG_IIR_SHIFT 0 /* IIR coefficient */
#define MLX90614_CONFIG_IIR_MASK (0x7 << MLX90614_CONFIG_IIR_SHIFT)
#define MLX90614_CONFIG_DUAL_SHIFT 6 /* single (0) or dual (1) IR sensor */
#define MLX90614_CONFIG_DUAL_MASK (1 << MLX90614_CONFIG_DUAL_SHIFT)
#define MLX90614_CONFIG_FIR_SHIFT 8 /* FIR coefficient */
#define MLX90614_CONFIG_FIR_MASK (0x7 << MLX90614_CONFIG_FIR_SHIFT)
#define MLX90614_CONFIG_GAIN_SHIFT 11 /* gain */
#define MLX90614_CONFIG_GAIN_MASK (0x7 << MLX90614_CONFIG_GAIN_SHIFT)
/* Timings (in ms) */
#define MLX90614_TIMING_EEPROM 20 /* time for EEPROM write/erase to complete */
#define MLX90614_TIMING_WAKEUP 34 /* time to hold SDA low for wake-up */
#define MLX90614_TIMING_STARTUP 250 /* time before first data after wake-up */
struct mlx90614_data {
struct i2c_client *client;
};
static int mlx90614_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct mlx90614_data *data = iio_priv(indio_dev);
u8 cmd;
s32 ret;
switch (mask) {
case IIO_CHAN_INFO_RAW: /* 0.02K / LSB */
switch (channel->channel2) {
case IIO_MOD_TEMP_AMBIENT:
cmd = MLX90614_TA;
break;
case IIO_MOD_TEMP_OBJECT:
switch (channel->channel) {
case 0:
cmd = MLX90614_TOBJ1;
break;
case 1:
cmd = MLX90614_TOBJ2;
break;
default:
return -EINVAL;
}
break;
default:
return -EINVAL;
}
ret = i2c_smbus_read_word_data(data->client, cmd);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OFFSET:
*val = 13657;
*val2 = 500000;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SCALE:
*val = 20;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static const struct iio_chan_spec mlx90614_channels[] = {
{
.type = IIO_TEMP,
.modified = 1,
.channel2 = IIO_MOD_TEMP_AMBIENT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
},
{
.type = IIO_TEMP,
.modified = 1,
.channel2 = IIO_MOD_TEMP_OBJECT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
},
{
.type = IIO_TEMP,
.indexed = 1,
.modified = 1,
.channel = 1,
.channel2 = IIO_MOD_TEMP_OBJECT,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
BIT(IIO_CHAN_INFO_SCALE),
},
};
static const struct iio_info mlx90614_info = {
.read_raw = mlx90614_read_raw,
.driver_module = THIS_MODULE,
};
/* Return 0 for single sensor, 1 for dual sensor, <0 on error. */
static int mlx90614_probe_num_ir_sensors(struct i2c_client *client)
{
s32 ret;
ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG);
if (ret < 0)
return ret;
return (ret & MLX90614_CONFIG_DUAL_MASK) ? 1 : 0;
}
static int mlx90614_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct iio_dev *indio_dev;
struct mlx90614_data *data;
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
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 = id->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &mlx90614_info;
ret = mlx90614_probe_num_ir_sensors(client);
switch (ret) {
case 0:
dev_dbg(&client->dev, "Found single sensor");
indio_dev->channels = mlx90614_channels;
indio_dev->num_channels = 2;
break;
case 1:
dev_dbg(&client->dev, "Found dual sensor");
indio_dev->channels = mlx90614_channels;
indio_dev->num_channels = 3;
break;
default:
return ret;
}
return iio_device_register(indio_dev);
}
static int mlx90614_remove(struct i2c_client *client)
{
iio_device_unregister(i2c_get_clientdata(client));
return 0;
}
static const struct i2c_device_id mlx90614_id[] = {
{ "mlx90614", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, mlx90614_id);
static struct i2c_driver mlx90614_driver = {
.driver = {
.name = "mlx90614",
.owner = THIS_MODULE,
},
.probe = mlx90614_probe,
.remove = mlx90614_remove,
.id_table = mlx90614_id,
};
module_i2c_driver(mlx90614_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@essensium.com>");
MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver");
MODULE_LICENSE("GPL");
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