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 <ang.iglesiasg@xxxxxxxxx>
---
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
