diff options
Diffstat (limited to 'drivers/iio/temperature/mlx90614.c')
| -rw-r--r-- | drivers/iio/temperature/mlx90614.c | 92 |
1 files changed, 89 insertions, 3 deletions
diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c index 5d033a5af615..a570c2e2aac3 100644 --- a/drivers/iio/temperature/mlx90614.c +++ b/drivers/iio/temperature/mlx90614.c @@ -3,6 +3,7 @@ * * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net> * Copyright (c) 2015 Essensium NV + * Copyright (c) 2015 Melexis * * 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 @@ -20,7 +21,6 @@ * always has a pull-up so we do not need an extra GPIO to drive it high. If * the "wakeup" GPIO is not given, power management will be disabled. * - * TODO: filter configuration */ #include <linux/err.h> @@ -32,6 +32,7 @@ #include <linux/pm_runtime.h> #include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> #define MLX90614_OP_RAM 0x00 #define MLX90614_OP_EEPROM 0x20 @@ -71,6 +72,7 @@ #define MLX90614_CONST_SCALE 20 /* Scale in milliKelvin (0.02 * 1000) */ #define MLX90614_CONST_RAW_EMISSIVITY_MAX 65535 /* max value for emissivity */ #define MLX90614_CONST_EMISSIVITY_RESOLUTION 15259 /* 1/65535 ~ 0.000015259 */ +#define MLX90614_CONST_FIR 0x7 /* Fixed value for FIR part of low pass filter */ struct mlx90614_data { struct i2c_client *client; @@ -79,6 +81,20 @@ struct mlx90614_data { unsigned long ready_timestamp; /* in jiffies */ }; +/* Bandwidth values for IIR filtering */ +static const int mlx90614_iir_values[] = {77, 31, 20, 15, 723, 153, 110, 86}; +static IIO_CONST_ATTR(in_temp_object_filter_low_pass_3db_frequency_available, + "0.15 0.20 0.31 0.77 0.86 1.10 1.53 7.23"); + +static struct attribute *mlx90614_attributes[] = { + &iio_const_attr_in_temp_object_filter_low_pass_3db_frequency_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group mlx90614_attr_group = { + .attrs = mlx90614_attributes, +}; + /* * Erase an address and write word. * The mutex must be locked before calling. @@ -117,6 +133,43 @@ static s32 mlx90614_write_word(const struct i2c_client *client, u8 command, return ret; } +/* + * Find the IIR value inside mlx90614_iir_values array and return its position + * which is equivalent to the bit value in sensor register + */ +static inline s32 mlx90614_iir_search(const struct i2c_client *client, + int value) +{ + int i; + s32 ret; + + for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) { + if (value == mlx90614_iir_values[i]) + break; + } + + if (i == ARRAY_SIZE(mlx90614_iir_values)) + return -EINVAL; + + /* + * CONFIG register values must not be changed so + * we must read them before we actually write + * changes + */ + ret = i2c_smbus_read_word_data(client, MLX90614_CONFIG); + if (ret < 0) + return ret; + + ret &= ~MLX90614_CONFIG_FIR_MASK; + ret |= MLX90614_CONST_FIR << MLX90614_CONFIG_FIR_SHIFT; + ret &= ~MLX90614_CONFIG_IIR_MASK; + ret |= i << MLX90614_CONFIG_IIR_SHIFT; + + /* Write changed values */ + ret = mlx90614_write_word(client, MLX90614_CONFIG, ret); + return ret; +} + #ifdef CONFIG_PM /* * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since @@ -236,6 +289,21 @@ static int mlx90614_read_raw(struct iio_dev *indio_dev, *val2 = ret * MLX90614_CONST_EMISSIVITY_RESOLUTION; } return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR setting with + FIR = 1024 */ + mlx90614_power_get(data, false); + mutex_lock(&data->lock); + ret = i2c_smbus_read_word_data(data->client, MLX90614_CONFIG); + mutex_unlock(&data->lock); + mlx90614_power_put(data); + + if (ret < 0) + return ret; + + *val = mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] / 100; + *val2 = (mlx90614_iir_values[ret & MLX90614_CONFIG_IIR_MASK] % 100) * + 10000; + return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } @@ -263,6 +331,18 @@ static int mlx90614_write_raw(struct iio_dev *indio_dev, mlx90614_power_put(data); return ret; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: /* IIR Filter setting */ + if (val < 0 || val2 < 0) + return -EINVAL; + + mlx90614_power_get(data, false); + mutex_lock(&data->lock); + ret = mlx90614_iir_search(data->client, + val * 100 + val2 / 10000); + mutex_unlock(&data->lock); + mlx90614_power_put(data); + + return ret; default: return -EINVAL; } @@ -275,6 +355,8 @@ static int mlx90614_write_raw_get_fmt(struct iio_dev *indio_dev, switch (mask) { case IIO_CHAN_INFO_CALIBEMISSIVITY: return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY: + return IIO_VAL_INT_PLUS_MICRO; default: return -EINVAL; } @@ -294,7 +376,8 @@ static const struct iio_chan_spec mlx90614_channels[] = { .modified = 1, .channel2 = IIO_MOD_TEMP_OBJECT, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | - BIT(IIO_CHAN_INFO_CALIBEMISSIVITY), + BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), }, @@ -305,7 +388,8 @@ static const struct iio_chan_spec mlx90614_channels[] = { .channel = 1, .channel2 = IIO_MOD_TEMP_OBJECT, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | - BIT(IIO_CHAN_INFO_CALIBEMISSIVITY), + BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | + BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), }, @@ -315,6 +399,7 @@ static const struct iio_info mlx90614_info = { .read_raw = mlx90614_read_raw, .write_raw = mlx90614_write_raw, .write_raw_get_fmt = mlx90614_write_raw_get_fmt, + .attrs = &mlx90614_attr_group, .driver_module = THIS_MODULE, }; @@ -569,5 +654,6 @@ 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_AUTHOR("Crt Mori <cmo@melexis.com>"); MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver"); MODULE_LICENSE("GPL"); |