Allows sampling frequency and IIR filter coefficients configuration
using sysfs ABI.
The IIR filter coefficient is configurable using the sysfs attribute
"filter_low_pass_3db_frequency".
Signed-off-by: Angel Iglesias <[email protected]>
---
drivers/iio/pressure/bmp280-core.c | 324 ++++++++++++++++++++++++++---
drivers/iio/pressure/bmp280.h | 18 --
2 files changed, 294 insertions(+), 48 deletions(-)
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index fe171908a89c..39406f0f1e76 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -100,6 +100,27 @@ static const char *const bmp280_supply_names[] = {
"vddd", "vdda"
};
+enum bmp380_odr {
+ BMP380_ODR_200HZ,
+ BMP380_ODR_100HZ,
+ BMP380_ODR_50HZ,
+ BMP380_ODR_25HZ,
+ BMP380_ODR_12_5HZ,
+ BMP380_ODR_6_25HZ,
+ BMP380_ODR_3_125HZ,
+ BMP380_ODR_1_5625HZ,
+ BMP380_ODR_0_78HZ,
+ BMP380_ODR_0_39HZ,
+ BMP380_ODR_0_2HZ,
+ BMP380_ODR_0_1HZ,
+ BMP380_ODR_0_05HZ,
+ BMP380_ODR_0_02HZ,
+ BMP380_ODR_0_01HZ,
+ BMP380_ODR_0_006HZ,
+ BMP380_ODR_0_003HZ,
+ BMP380_ODR_0_0015HZ,
+};
+
#define BMP280_NUM_SUPPLIES ARRAY_SIZE(bmp280_supply_names)
struct bmp280_data {
@@ -121,6 +142,17 @@ struct bmp280_data {
u8 oversampling_press;
u8 oversampling_temp;
u8 oversampling_humid;
+ u8 iir_filter_coeff;
+
+ /*
+ * BMP380 devices introduce sampling frequency configuration. See
+ * datasheet sections 3.3.3. and 4.3.19 for more details.
+ *
+ * BMx280 devices allowed indirect configuration of sampling frequency
+ * changing the t_standby duration between measurements, as detailed on
+ * section 3.6.3 of the datasheet.
+ */
+ int sampling_freq;
/*
* Carryover value from temperature conversion, used in pressure
@@ -145,6 +177,7 @@ struct bmp280_data {
struct bmp280_chip_info {
unsigned int id_reg;
+ const struct iio_chan_spec *channels;
int num_channels;
unsigned int start_up_time;
@@ -160,6 +193,14 @@ struct bmp280_chip_info {
int num_oversampling_humid_avail;
int oversampling_humid_default;
+ const int *iir_filter_coeffs_avail;
+ int num_iir_filter_coeffs_avail;
+ int iir_filter_coeff_default;
+
+ const int (*sampling_freq_avail)[2];
+ int num_sampling_freq_avail;
+ int sampling_freq_default;
+
int (*chip_config)(struct bmp280_data *);
int (*read_temp)(struct bmp280_data *, int *);
int (*read_press)(struct bmp280_data *, int *, int *);
@@ -211,6 +252,30 @@ static const struct iio_chan_spec bmp280_channels[] = {
},
};
+static const struct iio_chan_spec bmp380_channels[] = {
+ {
+ .type = IIO_PRESSURE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+ },
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+ },
+ {
+ .type = IIO_HUMIDITYRELATIVE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ) |
+ BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+ },
+};
+
static int bmp280_read_calib(struct bmp280_data *data, unsigned int chip)
{
int ret;
@@ -526,6 +591,25 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
break;
}
break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ if (!data->chip_info->sampling_freq_avail) {
+ ret = -EINVAL;
+ break;
+ }
+
+ *val = data->chip_info->sampling_freq_avail[data->sampling_freq][0];
+ *val2 = data->chip_info->sampling_freq_avail[data->sampling_freq][1];
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ if (!data->chip_info->iir_filter_coeffs_avail) {
+ ret = -EINVAL;
+ break;
+ }
+
+ *val = data->chip_info->iir_filter_coeffs_avail[data->iir_filter_coeff];
+ ret = IIO_VAL_INT;
+ break;
default:
ret = -EINVAL;
break;
@@ -542,14 +626,22 @@ static int bmp280_write_oversampling_ratio_humid(struct bmp280_data *data,
int val)
{
int i;
+ int ret, prev;
const int *avail = data->chip_info->oversampling_humid_avail;
const int n = data->chip_info->num_oversampling_humid_avail;
for (i = 0; i < n; i++) {
if (avail[i] == val) {
+ prev = data->oversampling_humid;
data->oversampling_humid = ilog2(val);
- return data->chip_info->chip_config(data);
+ ret = data->chip_info->chip_config(data);
+ if (ret) {
+ data->oversampling_humid = prev;
+ data->chip_info->chip_config(data);
+ return ret;
+ }
+ return 0;
}
}
return -EINVAL;
@@ -559,14 +651,22 @@ static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
int val)
{
int i;
+ int ret, prev;
const int *avail = data->chip_info->oversampling_temp_avail;
const int n = data->chip_info->num_oversampling_temp_avail;
for (i = 0; i < n; i++) {
if (avail[i] == val) {
+ prev = data->oversampling_temp;
data->oversampling_temp = ilog2(val);
- return data->chip_info->chip_config(data);
+ ret = data->chip_info->chip_config(data);
+ if (ret) {
+ data->oversampling_temp = prev;
+ data->chip_info->chip_config(data);
+ return ret;
+ }
+ return 0;
}
}
return -EINVAL;
@@ -576,14 +676,72 @@ static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
int val)
{
int i;
+ int ret, prev;
const int *avail = data->chip_info->oversampling_press_avail;
const int n = data->chip_info->num_oversampling_press_avail;
for (i = 0; i < n; i++) {
if (avail[i] == val) {
+ prev = data->oversampling_press;
data->oversampling_press = ilog2(val);
- return data->chip_info->chip_config(data);
+ ret = data->chip_info->chip_config(data);
+ if (ret) {
+ data->oversampling_press = prev;
+ data->chip_info->chip_config(data);
+ return ret;
+ }
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static int bmp280_write_sampling_frequency(struct bmp280_data *data,
+ int val, int val2)
+{
+ int i;
+ int ret, prev;
+ const int (*avail)[2] = data->chip_info->sampling_freq_avail;
+ const int n = data->chip_info->num_sampling_freq_avail;
+
+ for (i = 0; i < n; i++) {
+ if (avail[i][0] == val && avail[i][1] == val2) {
+ prev = data->sampling_freq;
+ data->sampling_freq = i;
+
+ ret = data->chip_info->chip_config(data);
+ if (ret) {
+ data->sampling_freq = prev;
+ data->chip_info->chip_config(data);
+ return ret;
+ }
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static int bmp280_write_iir_filter_coeffs(struct bmp280_data *data, int val)
+{
+ int i;
+ int ret, prev;
+ const int *avail = data->chip_info->iir_filter_coeffs_avail;
+ const int n = data->chip_info->num_iir_filter_coeffs_avail;
+
+ for (i = 0; i < n; i++) {
+ if (avail[i] == val) {
+ prev = data->iir_filter_coeff;
+ data->iir_filter_coeff = i;
+
+ ret = data->chip_info->chip_config(data);
+ if (ret) {
+ data->iir_filter_coeff = prev;
+ data->chip_info->chip_config(data);
+ return ret;
+
+ }
+ return 0;
}
}
return -EINVAL;
@@ -596,6 +754,12 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
int ret = 0;
struct bmp280_data *data = iio_priv(indio_dev);
+ /*
+ * Helper functions to update sensor running configuration.
+ * If an error happens applying new settings, will try restore
+ * previous parameters to ensure the sensor is left in a known
+ * working configuration.
+ */
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
pm_runtime_get_sync(data->dev);
@@ -618,6 +782,22 @@ static int bmp280_write_raw(struct iio_dev *indio_dev,
pm_runtime_mark_last_busy(data->dev);
pm_runtime_put_autosuspend(data->dev);
break;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ pm_runtime_get_sync(data->dev);
+ mutex_lock(&data->lock);
+ ret = bmp280_write_sampling_frequency(data, val, val2);
+ mutex_unlock(&data->lock);
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
+ break;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ pm_runtime_get_sync(data->dev);
+ mutex_lock(&data->lock);
+ ret = bmp280_write_iir_filter_coeffs(data, val);
+ mutex_unlock(&data->lock);
+ pm_runtime_mark_last_busy(data->dev);
+ pm_runtime_put_autosuspend(data->dev);
+ break;
default:
return -EINVAL;
}
@@ -648,6 +828,17 @@ static int bmp280_read_avail(struct iio_dev *indio_dev,
}
*type = IIO_VAL_INT;
return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *vals = (const int *)data->chip_info->sampling_freq_avail;
+ *type = IIO_VAL_INT_PLUS_MICRO;
+ /* Values are stored in a 2D matrix */
+ *length = data->chip_info->num_sampling_freq_avail;
+ return IIO_AVAIL_LIST;
+ case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+ *vals = data->chip_info->iir_filter_coeffs_avail;
+ *type = IIO_VAL_INT;
+ *length = data->chip_info->num_iir_filter_coeffs_avail;
+ return IIO_AVAIL_LIST;
default:
return -EINVAL;
}
@@ -693,6 +884,7 @@ static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
static const struct bmp280_chip_info bmp280_chip_info = {
.id_reg = BMP280_REG_ID,
.start_up_time = 2000,
+ .channels = bmp280_channels,
.num_channels = 2,
.oversampling_temp_avail = bmp280_oversampling_avail,
@@ -740,6 +932,7 @@ static int bme280_chip_config(struct bmp280_data *data)
static const struct bmp280_chip_info bme280_chip_info = {
.id_reg = BMP280_REG_ID,
.start_up_time = 2000,
+ .channels = bmp280_channels,
.num_channels = 3,
.oversampling_temp_avail = bmp280_oversampling_avail,
@@ -978,18 +1171,39 @@ static int bmp380_read_calib(struct bmp280_data *data, unsigned int chip)
return 0;
}
+static const int bmp380_odr_table[][2] = {
+ [BMP380_ODR_200HZ] = {200, 0},
+ [BMP380_ODR_100HZ] = {100, 0},
+ [BMP380_ODR_50HZ] = {50, 0},
+ [BMP380_ODR_25HZ] = {25, 0},
+ [BMP380_ODR_12_5HZ] = {12, 500000},
+ [BMP380_ODR_6_25HZ] = {6, 250000},
+ [BMP380_ODR_3_125HZ] = {3, 125000},
+ [BMP380_ODR_1_5625HZ] = {1, 562500},
+ [BMP380_ODR_0_78HZ] = {0, 781250},
+ [BMP380_ODR_0_39HZ] = {0, 390625},
+ [BMP380_ODR_0_2HZ] = {0, 195313},
+ [BMP380_ODR_0_1HZ] = {0, 97656},
+ [BMP380_ODR_0_05HZ] = {0, 48828},
+ [BMP380_ODR_0_02HZ] = {0, 24414},
+ [BMP380_ODR_0_01HZ] = {0, 12207},
+ [BMP380_ODR_0_006HZ] = {0, 6104},
+ [BMP380_ODR_0_003HZ] = {0, 3052},
+ [BMP380_ODR_0_0015HZ] = {0, 1526},
+};
+
static int bmp380_chip_config(struct bmp280_data *data)
{
+ bool change = false, aux;
unsigned int tmp;
u8 osrs;
int ret;
/* configure power control register */
- ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
- BMP380_CTRL_SENSORS_MASK | BMP380_MODE_MASK,
- BMP380_CTRL_SENSORS_PRESS_EN |
- BMP380_CTRL_SENSORS_TEMP_EN |
- FIELD_PREP(BMP380_MODE_MASK, BMP380_MODE_NORMAL));
+ ret = regmap_update_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+ BMP380_CTRL_SENSORS_MASK,
+ BMP380_CTRL_SENSORS_PRESS_EN |
+ BMP380_CTRL_SENSORS_TEMP_EN);
if (ret < 0) {
dev_err(data->dev,
"failed to write operation control register\n");
@@ -1000,55 +1214,94 @@ static int bmp380_chip_config(struct bmp280_data *data)
osrs = FIELD_PREP(BMP380_OSRS_TEMP_MASK, data->oversampling_temp) |
FIELD_PREP(BMP380_OSRS_PRESS_MASK, data->oversampling_press);
- ret = regmap_write_bits(data->regmap, BMP380_REG_OSR,
- BMP380_OSRS_TEMP_MASK | BMP380_OSRS_PRESS_MASK,
- osrs);
+ ret = regmap_update_bits_check(data->regmap, BMP380_REG_OSR,
+ BMP380_OSRS_TEMP_MASK |
+ BMP380_OSRS_PRESS_MASK,
+ osrs, &aux);
if (ret < 0) {
dev_err(data->dev, "failed to write oversampling register\n");
return ret;
}
+ change = change || aux;
/* configure output data rate */
- ret = regmap_write_bits(data->regmap, BMP380_REG_ODR,
- BMP380_ODRS_MASK, BMP380_ODRS_50HZ);
+ ret = regmap_update_bits_check(data->regmap, BMP380_REG_ODR,
+ BMP380_ODRS_MASK, data->sampling_freq,
+ &aux);
if (ret < 0) {
dev_err(data->dev, "failed to write ODR selection register\n");
return ret;
}
+ change = change || aux;
/* set filter data */
- ret = regmap_update_bits(data->regmap, BMP380_REG_CONFIG,
- BMP380_FILTER_MASK,
- FIELD_PREP(BMP380_FILTER_MASK, BMP380_FILTER_3X));
+ ret = regmap_update_bits_check(data->regmap, BMP380_REG_CONFIG,
+ BMP380_FILTER_MASK,
+ FIELD_PREP(BMP380_FILTER_MASK, data->iir_filter_coeff),
+ &aux);
if (ret < 0) {
dev_err(data->dev, "failed to write config register\n");
return ret;
}
+ change = change || aux;
- /* wait startup_time before verifying config changes */
- usleep_range(data->start_up_time, data->start_up_time + 100);
+ if (change) {
+ /*
+ * The configurations errors are detected on the fly during a measurement
+ * cycle. If the sampling frequency is too low, it's faster to reset
+ * the measurement loop than wait until the next measurement is due.
+ *
+ * Resets sensor measurement loop toggling between sleep and normal
+ * operating modes.
+ */
+ ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+ BMP380_MODE_MASK,
+ FIELD_PREP(BMP380_MODE_MASK,
+ BMP380_MODE_SLEEP));
+ if (ret < 0) {
+ dev_err(data->dev, "failed to set sleep mode\n");
+ return ret;
+ }
+ usleep_range(2000, 2500);
+ ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+ BMP380_MODE_MASK,
+ FIELD_PREP(BMP380_MODE_MASK,
+ BMP380_MODE_NORMAL));
+ if (ret < 0) {
+ dev_err(data->dev, "failed to set normal mode\n");
+ return ret;
+ }
+ /*
+ * Waits for measurement before checking configuration error flag.
+ * Selected longest measure time indicated in section 3.9.1
+ * in the datasheet.
+ */
+ msleep(80);
- /* check config error flag */
- ret = regmap_read(data->regmap, BMP380_REG_ERROR, &tmp);
- if (ret < 0) {
- dev_err(data->dev,
- "failed to read error register\n");
- return ret;
- }
- if (tmp & BMP380_ERR_CONF_MASK) {
- dev_warn(data->dev,
- "sensor flagged configuration as incompatible\n");
- return -EINVAL;
+ /* check config error flag */
+ ret = regmap_read(data->regmap, BMP380_REG_ERROR, &tmp);
+ if (ret < 0) {
+ dev_err(data->dev,
+ "failed to read error register\n");
+ return ret;
+ }
+ if (tmp & BMP380_ERR_CONF_MASK) {
+ dev_warn(data->dev,
+ "sensor flagged configuration as incompatible\n");
+ return -EINVAL;
+ }
}
return 0;
}
static const int bmp380_oversampling_avail[] = { 1, 2, 4, 8, 16, 32 };
+static const int bmp380_iir_filter_coeffs_avail[] = { 0, 1, 3, 7, 15, 31, 63, 127 };
static const struct bmp280_chip_info bmp380_chip_info = {
.id_reg = BMP380_REG_ID,
.start_up_time = 2000,
+ .channels = bmp380_channels,
.num_channels = 2,
.oversampling_temp_avail = bmp380_oversampling_avail,
@@ -1059,6 +1312,14 @@ static const struct bmp280_chip_info bmp380_chip_info = {
.num_oversampling_press_avail = ARRAY_SIZE(bmp380_oversampling_avail),
.oversampling_press_default = ilog2(4),
+ .sampling_freq_avail = bmp380_odr_table,
+ .num_sampling_freq_avail = ARRAY_SIZE(bmp380_odr_table) * 2,
+ .sampling_freq_default = BMP380_ODR_50HZ,
+
+ .iir_filter_coeffs_avail = bmp380_iir_filter_coeffs_avail,
+ .num_iir_filter_coeffs_avail = ARRAY_SIZE(bmp380_iir_filter_coeffs_avail),
+ .iir_filter_coeff_default = 2,
+
.chip_config = bmp380_chip_config,
.read_temp = bmp380_read_temp,
.read_press = bmp380_read_press,
@@ -1299,6 +1560,7 @@ static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
static const struct bmp280_chip_info bmp180_chip_info = {
.id_reg = BMP280_REG_ID,
.start_up_time = 2000,
+ .channels = bmp280_channels,
.num_channels = 2,
.oversampling_temp_avail = bmp180_oversampling_temp_avail,
@@ -1397,7 +1659,6 @@ int bmp280_common_probe(struct device *dev,
data->dev = dev;
indio_dev->name = name;
- indio_dev->channels = bmp280_channels;
indio_dev->info = &bmp280_info;
indio_dev->modes = INDIO_DIRECT_MODE;
@@ -1420,10 +1681,13 @@ int bmp280_common_probe(struct device *dev,
data->chip_info = chip_info;
/* apply initial values from chip info structure */
+ indio_dev->channels = chip_info->channels;
indio_dev->num_channels = chip_info->num_channels;
data->oversampling_press = chip_info->oversampling_press_default;
data->oversampling_humid = chip_info->oversampling_humid_default;
data->oversampling_temp = chip_info->oversampling_temp_default;
+ data->iir_filter_coeff = chip_info->iir_filter_coeff_default;
+ data->sampling_freq = chip_info->sampling_freq_default;
data->start_up_time = chip_info->start_up_time;
/* Bring up regulators */
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index 827bc6b7ca07..15ae3c32f168 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -54,24 +54,6 @@
#define BMP380_OSRS_PRESS_MASK GENMASK(2, 0)
#define BMP380_ODRS_MASK GENMASK(4, 0)
-#define BMP380_ODRS_200HZ 0x00
-#define BMP380_ODRS_100HZ 0x01
-#define BMP380_ODRS_50HZ 0x02
-#define BMP380_ODRS_25HZ 0x03
-#define BMP380_ODRS_12_5HZ 0x04
-#define BMP380_ODRS_6_25HZ 0x05
-#define BMP380_ODRS_3_1HZ 0x06
-#define BMP380_ODRS_1_5HZ 0x07
-#define BMP380_ODRS_0_78HZ 0x08
-#define BMP380_ODRS_0_39HZ 0x09
-#define BMP380_ODRS_0_2HZ 0x0A
-#define BMP380_ODRS_0_1HZ 0x0B
-#define BMP380_ODRS_0_05HZ 0x0C
-#define BMP380_ODRS_0_02HZ 0x0D
-#define BMP380_ODRS_0_01HZ 0x0E
-#define BMP380_ODRS_0_006HZ 0x0F
-#define BMP380_ODRS_0_003HZ 0x10
-#define BMP380_ODRS_0_0015HZ 0x11
#define BMP380_CTRL_SENSORS_MASK GENMASK(1, 0)
#define BMP380_CTRL_SENSORS_PRESS_EN BIT(0)
--
2.37.1
On Sun, Aug 7, 2022 at 2:44 PM Angel Iglesias <[email protected]> wrote:
>
> Allows sampling frequency and IIR filter coefficients configuration
> using sysfs ABI.
>
> The IIR filter coefficient is configurable using the sysfs attribute
> "filter_low_pass_3db_frequency".
...
> +static const int bmp380_odr_table[][2] = {
s32_fract ?
> + [BMP380_ODR_200HZ] = {200, 0},
> + [BMP380_ODR_100HZ] = {100, 0},
> + [BMP380_ODR_50HZ] = {50, 0},
> + [BMP380_ODR_25HZ] = {25, 0},
> + [BMP380_ODR_12_5HZ] = {12, 500000},
> + [BMP380_ODR_6_25HZ] = {6, 250000},
> + [BMP380_ODR_3_125HZ] = {3, 125000},
> + [BMP380_ODR_1_5625HZ] = {1, 562500},
> + [BMP380_ODR_0_78HZ] = {0, 781250},
> + [BMP380_ODR_0_39HZ] = {0, 390625},
> + [BMP380_ODR_0_2HZ] = {0, 195313},
> + [BMP380_ODR_0_1HZ] = {0, 97656},
> + [BMP380_ODR_0_05HZ] = {0, 48828},
> + [BMP380_ODR_0_02HZ] = {0, 24414},
> + [BMP380_ODR_0_01HZ] = {0, 12207},
> + [BMP380_ODR_0_006HZ] = {0, 6104},
> + [BMP380_ODR_0_003HZ] = {0, 3052},
> + [BMP380_ODR_0_0015HZ] = {0, 1526},
> +};
...
> + ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
> + BMP380_MODE_MASK,
> + FIELD_PREP(BMP380_MODE_MASK,
> + BMP380_MODE_SLEEP));
One line?
...
> + ret = regmap_write_bits(data->regmap, BMP380_REG_POWER_CONTROL,
> + BMP380_MODE_MASK,
> + FIELD_PREP(BMP380_MODE_MASK,
> + BMP380_MODE_NORMAL));
Ditto.
...
> +static const int bmp380_iir_filter_coeffs_avail[] = { 0, 1, 3, 7, 15, 31, 63, 127 };
This seems like a power of two - 1, can it be replaced by a formula in the code?
--
With Best Regards,
Andy Shevchenko
On Mon, 2022-08-08 at 11:13 +0200, Andy Shevchenko wrote:
> On Sun, Aug 7, 2022 at 2:44 PM Angel Iglesias <[email protected]> wrote:
> >
> > Allows sampling frequency and IIR filter coefficients configuration
> > using sysfs ABI.
> >
> > The IIR filter coefficient is configurable using the sysfs attribute
> > "filter_low_pass_3db_frequency".
>
> ...
>
> > +static const int bmp380_odr_table[][2] = {
>
> s32_fract ?
I modeled this bit and other ODR representations after the adxl355 driver. I see
that s32_fract would be a bit cleaner than having arrays inside arrays, but I'm
failing to see which additional advantages would provide.
Also, technically, these are precomputed frequencies, the first index is the
integer part and the second is the fractional part. The fractions would be
200/1, 200/2, 200/4 ... 200/131072
> > + [BMP380_ODR_200HZ] = {200, 0},
> > + [BMP380_ODR_100HZ] = {100, 0},
> > + [BMP380_ODR_50HZ] = {50, 0},
> > + [BMP380_ODR_25HZ] = {25, 0},
> > + [BMP380_ODR_12_5HZ] = {12, 500000},
> > + [BMP380_ODR_6_25HZ] = {6, 250000},
> > + [BMP380_ODR_3_125HZ] = {3, 125000},
> > + [BMP380_ODR_1_5625HZ] = {1, 562500},
> > + [BMP380_ODR_0_78HZ] = {0, 781250},
> > + [BMP380_ODR_0_39HZ] = {0, 390625},
> > + [BMP380_ODR_0_2HZ] = {0, 195313},
> > + [BMP380_ODR_0_1HZ] = {0, 97656},
> > + [BMP380_ODR_0_05HZ] = {0, 48828},
> > + [BMP380_ODR_0_02HZ] = {0, 24414},
> > + [BMP380_ODR_0_01HZ] = {0, 12207},
> > + [BMP380_ODR_0_006HZ] = {0, 6104},
> > + [BMP380_ODR_0_003HZ] = {0, 3052},
> > + [BMP380_ODR_0_0015HZ] = {0, 1526},
> > +};
>
> ...
>
> > + ret = regmap_write_bits(data->regmap,
> > BMP380_REG_POWER_CONTROL,
> > + BMP380_MODE_MASK,
>
> > + FIELD_PREP(BMP380_MODE_MASK,
> > + BMP380_MODE_SLEEP));
>
> One line?
>
> ...
>
> > + ret = regmap_write_bits(data->regmap,
> > BMP380_REG_POWER_CONTROL,
> > + BMP380_MODE_MASK,
>
> > + FIELD_PREP(BMP380_MODE_MASK,
> > + BMP380_MODE_NORMAL));
>
> Ditto.
>
> ...
>
> > +static const int bmp380_iir_filter_coeffs_avail[] = { 0, 1, 3, 7, 15, 31,
> > 63, 127 };
>
> This seems like a power of two - 1, can it be replaced by a formula in the
> code?
>
On Mon, 12 Sep 2022 02:53:06 +0200
Angel Iglesias <[email protected]> wrote:
> On Mon, 2022-08-08 at 11:13 +0200, Andy Shevchenko wrote:
> > On Sun, Aug 7, 2022 at 2:44 PM Angel Iglesias <[email protected]> wrote:
> > >
> > > Allows sampling frequency and IIR filter coefficients configuration
> > > using sysfs ABI.
> > >
> > > The IIR filter coefficient is configurable using the sysfs attribute
> > > "filter_low_pass_3db_frequency".
> >
> > ...
> >
> > > +static const int bmp380_odr_table[][2] = {
> >
> > s32_fract ?
>
> I modeled this bit and other ODR representations after the adxl355 driver. I see
> that s32_fract would be a bit cleaner than having arrays inside arrays, but I'm
> failing to see which additional advantages would provide.
> Also, technically, these are precomputed frequencies, the first index is the
> integer part and the second is the fractional part. The fractions would be
> 200/1, 200/2, 200/4 ... 200/131072
>
Agreed. Don't use s32_fract for this. It would be misleading.
Jonathan
> > > + [BMP380_ODR_200HZ] = {200, 0},
> > > + [BMP380_ODR_100HZ] = {100, 0},
> > > + [BMP380_ODR_50HZ] = {50, 0},
> > > + [BMP380_ODR_25HZ] = {25, 0},
> > > + [BMP380_ODR_12_5HZ] = {12, 500000},
> > > + [BMP380_ODR_6_25HZ] = {6, 250000},
> > > + [BMP380_ODR_3_125HZ] = {3, 125000},
> > > + [BMP380_ODR_1_5625HZ] = {1, 562500},
> > > + [BMP380_ODR_0_78HZ] = {0, 781250},
> > > + [BMP380_ODR_0_39HZ] = {0, 390625},
> > > + [BMP380_ODR_0_2HZ] = {0, 195313},
> > > + [BMP380_ODR_0_1HZ] = {0, 97656},
> > > + [BMP380_ODR_0_05HZ] = {0, 48828},
> > > + [BMP380_ODR_0_02HZ] = {0, 24414},
> > > + [BMP380_ODR_0_01HZ] = {0, 12207},
> > > + [BMP380_ODR_0_006HZ] = {0, 6104},
> > > + [BMP380_ODR_0_003HZ] = {0, 3052},
> > > + [BMP380_ODR_0_0015HZ] = {0, 1526},
> > > +};
> >
> > ...
> >
> > > + ret = regmap_write_bits(data->regmap,
> > > BMP380_REG_POWER_CONTROL,
> > > + BMP380_MODE_MASK,
> >
> > > + FIELD_PREP(BMP380_MODE_MASK,
> > > + BMP380_MODE_SLEEP));
> >
> > One line?
> >
> > ...
> >
> > > + ret = regmap_write_bits(data->regmap,
> > > BMP380_REG_POWER_CONTROL,
> > > + BMP380_MODE_MASK,
> >
> > > + FIELD_PREP(BMP380_MODE_MASK,
> > > + BMP380_MODE_NORMAL));
> >
> > Ditto.
> >
> > ...
> >
> > > +static const int bmp380_iir_filter_coeffs_avail[] = { 0, 1, 3, 7, 15, 31,
> > > 63, 127 };
> >
> > This seems like a power of two - 1, can it be replaced by a formula in the
> > code?
> >
>