On Mon, 17 Aug 2015, Crt Mori wrote: > Implemented Low pass 3db frequency filter which configures > FIR and IIR values within the configuration register of EEPROM. > For more standardized interface we have fixed the FIR value > to 1024, while changes in IIR value are directly connected to > filter responses. The new datasheet version will provide a > simplified table (also in reStructured text format below) with > this change, to provide quick overview of possible settings. see comment below > Below sensor timings (bandwidth) are calculated for 3db frequency > low pass filter. > > +--------------------+-----------------+ > | Filter setting (%) | Band width (Hz) | > | (rounded to 1.0) | | > +====================+=================+ > | 13 | 0.15 | > +--------------------+-----------------+ > | 17 | 0.20 | > +--------------------+-----------------+ > | 25 | 0.31 | > +--------------------+-----------------+ > | 50 | 0.77 | > +--------------------+-----------------+ > | 57 | 0.86 | > +--------------------+-----------------+ > | 67 | 1.10 | > +--------------------+-----------------+ > | 80 | 1.53 | > +--------------------+-----------------+ > | 100 | 7.23 | > +--------------------+-----------------+ > > The diff is made towards togreg branch. Added myself to MAINTAINERS and > authors as per discussion with Jonathan. > > Signed-off-by: Crt Mori <cmo@xxxxxxxxxxx> > --- > MAINTAINERS | 7 +++ > drivers/iio/temperature/mlx90614.c | 89 ++++++++++++++++++++++++++++++++++++-- > 2 files changed, 93 insertions(+), 3 deletions(-) > > diff --git a/MAINTAINERS b/MAINTAINERS > index 8133cef..f658890 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -6739,6 +6739,13 @@ S: Supported > F: include/linux/mlx5/ > F: drivers/infiniband/hw/mlx5/ > > +MELEXIS MLX90614 DRIVER > +M: Crt Mori <cmo@xxxxxxxxxxx> > +L: linux-iio@xxxxxxxxxxxxxxx > +W: http://www.melexis.com > +S: Supported > +F: drivers/iio/temperature/mlx90614.c > + > MN88472 MEDIA DRIVER > M: Antti Palosaari <crope@xxxxxx> > L: linux-media@xxxxxxxxxxxxxxx > diff --git a/drivers/iio/temperature/mlx90614.c b/drivers/iio/temperature/mlx90614.c > index 5d033a5..08e2bbf 100644 > --- a/drivers/iio/temperature/mlx90614.c > +++ b/drivers/iio/temperature/mlx90614.c > @@ -3,6 +3,7 @@ > * > * Copyright (c) 2014 Peter Meerwald <pmeerw@xxxxxxxxxx> > * 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 > @@ -79,6 +80,20 @@ 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 +132,41 @@ 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) > +{ > + u8 i; I'd rather use int for the loop variable > + s32 ret; > + > + for (i = 0; i < ARRAY_SIZE(mlx90614_iir_values); ++i) { > + if (value == mlx90614_iir_values[i]) > + break; > + } > + > + if (value != mlx90614_iir_values[i]) this is an out-of-bound access beyond _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); I'd rather do if (ret < 0) return ret; > + if (ret >= 0) { > + /* Write changed values */ > + ret = mlx90614_write_word(client, MLX90614_CONFIG, > + (i << MLX90614_CONFIG_IIR_SHIFT) | > + (((u16) ((0x7 << MLX90614_CONFIG_FIR_SHIFT) | > + ((u16) ret & (~((u16) MLX90614_CONFIG_FIR_MASK))))) & > + (~(u16) MLX90614_CONFIG_IIR_MASK))); this is still a mess, ehm, not very readable > + } > + return ret; > +} > + > #ifdef CONFIG_PM > /* > * If @startup is true, make sure MLX90614_TIMING_STARTUP ms have elapsed since > @@ -236,6 +286,21 @@ 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 * probably add parenthesis and don't rely on operator precedence for clarity > + 10000; > + return IIO_VAL_INT_PLUS_MICRO; > default: > return -EINVAL; > } > @@ -263,6 +328,18 @@ 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 +352,8 @@ 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 +373,8 @@ 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 +385,8 @@ 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 +396,7 @@ 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 +651,6 @@ module_i2c_driver(mlx90614_driver); > > MODULE_AUTHOR("Peter Meerwald <pmeerw@xxxxxxxxxx>"); > MODULE_AUTHOR("Vianney le Clément de Saint-Marcq <vianney.leclement@xxxxxxxxxxxxx>"); > +MODULE_AUTHOR("Crt Mori <cmo@xxxxxxxxxxx>"); > MODULE_DESCRIPTION("Melexis MLX90614 contactless IR temperature sensor driver"); > MODULE_LICENSE("GPL"); > -- Peter Meerwald +43-664-2444418 (mobile)
