diff options
Diffstat (limited to 'drivers/iio/temperature/mlx90614.c')
| -rw-r--r-- | drivers/iio/temperature/mlx90614.c | 221 |
1 files changed, 221 insertions, 0 deletions
diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c new file mode 100644 index 000000000..a112fc9ab --- /dev/null +++ b/drivers/iio/temperature/mlx90614.c @@ -0,0 +1,221 @@ +/* + * 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"); |