On 17 August 2015 at 15:29, Peter Meerwald <pmeerw@xxxxxxxxxx> wrote: > 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 > Thanks for checking. My replies inline 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 > ok, bad habbit of mine to use minimal stuff. >> + 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 > will change to something like 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); > > I'd rather do > if (ret < 0) > return ret; > thanks - slipped my view. >> + 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 > Except for splitting this up (fir shift and mask in separate variable) or as nested macro I doubt I can make it more readable. I also think compiler does handle this nicely without additional variables. I could add a comment up there which explains that we fix FIR to 1024, with that 0x7 and shift and application of FIR mask, then afterwards we apply IIR value with IIR mask. >> + } >> + 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 > OK, I thought point was to rely on operator precedence to avoid additional parenthesis. >> + 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) -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
