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path: root/drivers/iio/temperature/mlx90614.c
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Diffstat (limited to 'drivers/iio/temperature/mlx90614.c')
-rw-r--r--drivers/iio/temperature/mlx90614.c92
1 files changed, 89 insertions, 3 deletions
diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c
index 5d033a5af..a570c2e2a 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");