* https://cdn-shop.adafruit.com/datasheets/BST-BMP180-DS000-09.pdf
* https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp280-ds001.pdf
* https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme280-ds002.pdf
+ * https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bmp388-ds001.pdf
*
* Notice:
* The link to the bmp180 datasheet points to an outdated version missing these changes:
s8 H6;
};
+/* See datasheet Section 3.11.1. */
+struct bmp380_calib {
+ u16 T1;
+ u16 T2;
+ s8 T3;
+ s16 P1;
+ s16 P2;
+ s8 P3;
+ s8 P4;
+ u16 P5;
+ u16 P6;
+ s8 P7;
+ s8 P8;
+ s16 P9;
+ s8 P10;
+ s8 P11;
+};
+
static const char *const bmp280_supply_names[] = {
"vddd", "vdda"
};
union {
struct bmp180_calib bmp180;
struct bmp280_calib bmp280;
+ struct bmp380_calib bmp380;
} calib;
struct regulator_bulk_data supplies[BMP280_NUM_SUPPLIES];
unsigned int start_up_time; /* in microseconds */
/* Calibration data buffers */
__le16 bmp280_cal_buf[BMP280_CONTIGUOUS_CALIB_REGS / 2];
__be16 bmp180_cal_buf[BMP180_REG_CALIB_COUNT / 2];
+ u8 bmp380_cal_buf[BMP380_CALIB_REG_COUNT];
/* Miscellaneous, endianess-aware data buffers */
__le16 le16;
__be16 be16;
*/
enum { T1, T2, T3, P1, P2, P3, P4, P5, P6, P7, P8, P9 };
+enum {
+ /* Temperature calib indexes */
+ BMP380_T1 = 0,
+ BMP380_T2 = 2,
+ BMP380_T3 = 4,
+ /* Pressure calib indexes */
+ BMP380_P1 = 5,
+ BMP380_P2 = 7,
+ BMP380_P3 = 9,
+ BMP380_P4 = 10,
+ BMP380_P5 = 11,
+ BMP380_P6 = 13,
+ BMP380_P7 = 15,
+ BMP380_P8 = 16,
+ BMP380_P9 = 17,
+ BMP380_P10 = 19,
+ BMP380_P11 = 20,
+};
+
static const struct iio_chan_spec bmp280_channels[] = {
{
.type = IIO_PRESSURE,
.read_calib = bme280_read_calib,
};
+/*
+ * Helper function to send a command to BMP3XX sensors.
+ *
+ * Sensor processes commands written to the CMD register and signals
+ * execution result through "cmd_rdy" and "cmd_error" flags available on
+ * STATUS and ERROR registers.
+ */
+static int bmp380_cmd(struct bmp280_data *data, u8 cmd)
+{
+ unsigned int reg;
+ int ret;
+
+ /* Check if device is ready to process a command */
+ ret = regmap_read(data->regmap, BMP380_REG_STATUS, ®);
+ if (ret) {
+ dev_err(data->dev, "failed to read error register\n");
+ return ret;
+ }
+ if (!(reg & BMP380_STATUS_CMD_RDY_MASK)) {
+ dev_err(data->dev, "device is not ready to accept commands\n");
+ return -EBUSY;
+ }
+
+ /* Send command to process */
+ ret = regmap_write(data->regmap, BMP380_REG_CMD, cmd);
+ if (ret) {
+ dev_err(data->dev, "failed to send command to device\n");
+ return ret;
+ }
+ /* Wait for 2ms for command to be processed */
+ usleep_range(data->start_up_time, data->start_up_time + 100);
+ /* Check for command processing error */
+ ret = regmap_read(data->regmap, BMP380_REG_ERROR, ®);
+ if (ret) {
+ dev_err(data->dev, "error reading ERROR reg\n");
+ return ret;
+ }
+ if (reg & BMP380_ERR_CMD_MASK) {
+ dev_err(data->dev, "error processing command 0x%X\n", cmd);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Returns temperature in Celsius dregrees, resolution is 0.01º C. Output value of
+ * "5123" equals 51.2º C. t_fine carries fine temperature as global value.
+ *
+ * Taken from datasheet, Section Appendix 9, "Compensation formula" and repo
+ * https://github.com/BoschSensortec/BMP3-Sensor-API.
+ */
+static s32 bmp380_compensate_temp(struct bmp280_data *data, u32 adc_temp)
+{
+ s64 var1, var2, var3, var4, var5, var6, comp_temp;
+ struct bmp380_calib *calib = &data->calib.bmp380;
+
+ var1 = ((s64) adc_temp) - (((s64) calib->T1) << 8);
+ var2 = var1 * ((s64) calib->T2);
+ var3 = var1 * var1;
+ var4 = var3 * ((s64) calib->T3);
+ var5 = (var2 << 18) + var4;
+ var6 = var5 >> 32;
+ data->t_fine = (s32) var6;
+ comp_temp = (var6 * 25) >> 14;
+
+ comp_temp = clamp_val(comp_temp, BMP380_MIN_TEMP, BMP380_MAX_TEMP);
+ return (s32) comp_temp;
+}
+
+/*
+ * Returns pressure in Pa as an unsigned 32 bit integer in fractional Pascal.
+ * Output value of "9528709" represents 9528709/100 = 95287.09 Pa = 952.8709 hPa.
+ *
+ * Taken from datasheet, Section 9.3. "Pressure compensation" and repository
+ * https://github.com/BoschSensortec/BMP3-Sensor-API.
+ */
+static u32 bmp380_compensate_press(struct bmp280_data *data, u32 adc_press)
+{
+ s64 var1, var2, var3, var4, var5, var6, offset, sensitivity;
+ struct bmp380_calib *calib = &data->calib.bmp380;
+ u32 comp_press;
+
+ var1 = (s64)data->t_fine * (s64)data->t_fine;
+ var2 = var1 >> 6;
+ var3 = (var2 * ((s64) data->t_fine)) >> 8;
+ var4 = ((s64)calib->P8 * var3) >> 5;
+ var5 = ((s64)calib->P7 * var1) << 4;
+ var6 = ((s64)calib->P6 * (s64)data->t_fine) << 22;
+ offset = ((s64)calib->P5 << 47) + var4 + var5 + var6;
+ var2 = ((s64)calib->P4 * var3) >> 5;
+ var4 = ((s64)calib->P3 * var1) << 2;
+ var5 = ((s64)calib->P2 - ((s64)1 << 14)) *
+ ((s64)data->t_fine << 21);
+ sensitivity = (((s64) calib->P1 - ((s64) 1 << 14)) << 46) +
+ var2 + var4 + var5;
+ var1 = (sensitivity >> 24) * (s64)adc_press;
+ var2 = (s64)calib->P10 * (s64)data->t_fine;
+ var3 = var2 + ((s64)calib->P9 << 16);
+ var4 = (var3 * (s64)adc_press) >> 13;
+
+ /*
+ * Dividing by 10 followed by multiplying by 10 to avoid
+ * possible overflow caused by (uncomp_data->pressure * partial_data4).
+ */
+ var5 = ((s64)adc_press * div_s64(var4, 10)) >> 9;
+ var5 *= 10;
+ var6 = (s64)adc_press * (s64)adc_press;
+ var2 = ((s64)calib->P11 * var6) >> 16;
+ var3 = (var2 * (s64)adc_press) >> 7;
+ var4 = (offset >> 2) + var1 + var5 + var3;
+ comp_press = ((u64)var4 * 25) >> 40;
+
+ comp_press = clamp_val(comp_press, BMP380_MIN_PRES, BMP380_MAX_PRES);
+ return comp_press;
+}
+
+static int bmp380_read_temp(struct bmp280_data *data, int *val)
+{
+ s32 comp_temp;
+ u32 adc_temp;
+ int ret;
+
+ ret = regmap_bulk_read(data->regmap, BMP380_REG_TEMP_XLSB,
+ data->buf, sizeof(data->buf));
+ if (ret) {
+ dev_err(data->dev, "failed to read temperature\n");
+ return ret;
+ }
+
+ adc_temp = get_unaligned_le24(data->buf);
+ if (adc_temp == BMP380_TEMP_SKIPPED) {
+ dev_err(data->dev, "reading temperature skipped\n");
+ return -EIO;
+ }
+ comp_temp = bmp380_compensate_temp(data, adc_temp);
+
+ /*
+ * Val might be NULL if we're called by the read_press routine,
+ * who only cares about the carry over t_fine value.
+ */
+ if (val) {
+ /* IIO reports temperatures in milli Celsius */
+ *val = comp_temp * 10;
+ return IIO_VAL_INT;
+ }
+
+ return 0;
+}
+
+static int bmp380_read_press(struct bmp280_data *data, int *val, int *val2)
+{
+ s32 comp_press;
+ u32 adc_press;
+ int ret;
+
+ /* Read and compensate for temperature so we get a reading of t_fine */
+ ret = bmp380_read_temp(data, NULL);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap, BMP380_REG_PRESS_XLSB,
+ data->buf, sizeof(data->buf));
+ if (ret) {
+ dev_err(data->dev, "failed to read pressure\n");
+ return ret;
+ }
+
+ adc_press = get_unaligned_le24(data->buf);
+ if (adc_press == BMP380_PRESS_SKIPPED) {
+ dev_err(data->dev, "reading pressure skipped\n");
+ return -EIO;
+ }
+ comp_press = bmp380_compensate_press(data, adc_press);
+
+ *val = comp_press;
+ /* Compensated pressure is in cPa (centipascals) */
+ *val2 = 100000;
+
+ return IIO_VAL_FRACTIONAL;
+}
+
+static int bmp380_read_calib(struct bmp280_data *data)
+{
+ struct bmp380_calib *calib = &data->calib.bmp380;
+ int ret;
+
+ /* Read temperature and pressure calibration data */
+ ret = regmap_bulk_read(data->regmap, BMP380_REG_CALIB_TEMP_START,
+ data->bmp380_cal_buf, sizeof(data->bmp380_cal_buf));
+ if (ret) {
+ dev_err(data->dev,
+ "failed to read temperature calibration parameters\n");
+ return ret;
+ }
+
+ /* Toss the temperature calibration data into the entropy pool */
+ add_device_randomness(data->bmp380_cal_buf, sizeof(data->bmp380_cal_buf));
+
+ /* Parse calibration values */
+ calib->T1 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_T1]);
+ calib->T2 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_T2]);
+ calib->T3 = data->bmp380_cal_buf[BMP380_T3];
+ calib->P1 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_P1]);
+ calib->P2 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_P2]);
+ calib->P3 = data->bmp380_cal_buf[BMP380_P3];
+ calib->P4 = data->bmp380_cal_buf[BMP380_P4];
+ calib->P5 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_P5]);
+ calib->P6 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_P6]);
+ calib->P7 = data->bmp380_cal_buf[BMP380_P7];
+ calib->P8 = data->bmp380_cal_buf[BMP380_P8];
+ calib->P9 = get_unaligned_le16(&data->bmp380_cal_buf[BMP380_P9]);
+ calib->P10 = data->bmp380_cal_buf[BMP380_P10];
+ calib->P11 = data->bmp380_cal_buf[BMP380_P11];
+
+ return 0;
+}
+
+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_update_bits(data->regmap, BMP380_REG_POWER_CONTROL,
+ BMP380_CTRL_SENSORS_MASK,
+ BMP380_CTRL_SENSORS_PRESS_EN |
+ BMP380_CTRL_SENSORS_TEMP_EN);
+ if (ret) {
+ dev_err(data->dev,
+ "failed to write operation control register\n");
+ return ret;
+ }
+
+ /* Configure oversampling */
+ osrs = FIELD_PREP(BMP380_OSRS_TEMP_MASK, data->oversampling_temp) |
+ FIELD_PREP(BMP380_OSRS_PRESS_MASK, data->oversampling_press);
+
+ ret = regmap_update_bits_check(data->regmap, BMP380_REG_OSR,
+ BMP380_OSRS_TEMP_MASK |
+ BMP380_OSRS_PRESS_MASK,
+ osrs, &aux);
+ if (ret) {
+ dev_err(data->dev, "failed to write oversampling register\n");
+ return ret;
+ }
+ change = change || aux;
+
+ /* Configure output data rate */
+ ret = regmap_update_bits(data->regmap, BMP380_REG_ODR,
+ BMP380_ODRS_MASK, BMP380_ODRS_50HZ);
+ if (ret) {
+ dev_err(data->dev, "failed to write ODR selection register\n");
+ return ret;
+ }
+
+ /* Set filter data */
+ ret = regmap_update_bits(data->regmap, BMP380_REG_CONFIG,
+ BMP380_FILTER_MASK,
+ FIELD_PREP(BMP380_FILTER_MASK, BMP380_FILTER_3X));
+ if (ret) {
+ dev_err(data->dev, "failed to write config register\n");
+ return ret;
+ }
+
+ 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) {
+ 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) {
+ 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) {
+ 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 struct bmp280_chip_info bmp380_chip_info = {
+ .id_reg = BMP380_REG_ID,
+ .start_up_time = 2000,
+ .num_channels = 2,
+
+ .oversampling_temp_avail = bmp380_oversampling_avail,
+ .num_oversampling_temp_avail = ARRAY_SIZE(bmp380_oversampling_avail),
+ .oversampling_temp_default = ilog2(1),
+
+ .oversampling_press_avail = bmp380_oversampling_avail,
+ .num_oversampling_press_avail = ARRAY_SIZE(bmp380_oversampling_avail),
+ .oversampling_press_default = ilog2(4),
+
+ .chip_config = bmp380_chip_config,
+ .read_temp = bmp380_read_temp,
+ .read_press = bmp380_read_press,
+ .read_calib = bmp380_read_calib,
+};
+
static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
{
const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
case BME280_CHIP_ID:
chip_info = &bme280_chip_info;
break;
+ case BMP380_CHIP_ID:
+ chip_info = &bmp380_chip_info;
+ break;
default:
return -EINVAL;
}
return -EINVAL;
}
+ /* BMP3xx requires soft-reset as part of initialization */
+ if (chip_id == BMP380_CHIP_ID) {
+ ret = bmp380_cmd(data, BMP380_CMD_SOFT_RESET);
+ if (ret < 0)
+ return ret;
+ }
+
ret = data->chip_info->chip_config(data);
if (ret < 0)
return ret;
#include <linux/device.h>
#include <linux/regmap.h>
+/* BMP380 specific registers */
+#define BMP380_REG_CMD 0x7E
+#define BMP380_REG_CONFIG 0x1F
+#define BMP380_REG_ODR 0x1D
+#define BMP380_REG_OSR 0x1C
+#define BMP380_REG_POWER_CONTROL 0x1B
+#define BMP380_REG_IF_CONFIG 0x1A
+#define BMP380_REG_INT_CONTROL 0x19
+#define BMP380_REG_INT_STATUS 0x11
+#define BMP380_REG_EVENT 0x10
+#define BMP380_REG_STATUS 0x03
+#define BMP380_REG_ERROR 0x02
+#define BMP380_REG_ID 0x00
+
+#define BMP380_REG_FIFO_CONFIG_1 0x18
+#define BMP380_REG_FIFO_CONFIG_2 0x17
+#define BMP380_REG_FIFO_WATERMARK_MSB 0x16
+#define BMP380_REG_FIFO_WATERMARK_LSB 0x15
+#define BMP380_REG_FIFO_DATA 0x14
+#define BMP380_REG_FIFO_LENGTH_MSB 0x13
+#define BMP380_REG_FIFO_LENGTH_LSB 0x12
+
+#define BMP380_REG_SENSOR_TIME_MSB 0x0E
+#define BMP380_REG_SENSOR_TIME_LSB 0x0D
+#define BMP380_REG_SENSOR_TIME_XLSB 0x0C
+
+#define BMP380_REG_TEMP_MSB 0x09
+#define BMP380_REG_TEMP_LSB 0x08
+#define BMP380_REG_TEMP_XLSB 0x07
+
+#define BMP380_REG_PRESS_MSB 0x06
+#define BMP380_REG_PRESS_LSB 0x05
+#define BMP380_REG_PRESS_XLSB 0x04
+
+#define BMP380_REG_CALIB_TEMP_START 0x31
+#define BMP380_CALIB_REG_COUNT 21
+
+#define BMP380_FILTER_MASK GENMASK(3, 1)
+#define BMP380_FILTER_OFF 0
+#define BMP380_FILTER_1X 1
+#define BMP380_FILTER_3X 2
+#define BMP380_FILTER_7X 3
+#define BMP380_FILTER_15X 4
+#define BMP380_FILTER_31X 5
+#define BMP380_FILTER_63X 6
+#define BMP380_FILTER_127X 7
+
+#define BMP380_OSRS_TEMP_MASK GENMASK(5, 3)
+#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)
+#define BMP380_CTRL_SENSORS_TEMP_EN BIT(1)
+#define BMP380_MODE_MASK GENMASK(5, 4)
+#define BMP380_MODE_SLEEP 0
+#define BMP380_MODE_FORCED 1
+#define BMP380_MODE_NORMAL 3
+
+#define BMP380_MIN_TEMP -4000
+#define BMP380_MAX_TEMP 8500
+#define BMP380_MIN_PRES 3000000
+#define BMP380_MAX_PRES 12500000
+
+#define BMP380_CMD_NOOP 0x00
+#define BMP380_CMD_EXTMODE_EN_MID 0x34
+#define BMP380_CMD_FIFO_FLUSH 0xB0
+#define BMP380_CMD_SOFT_RESET 0xB6
+
+#define BMP380_STATUS_CMD_RDY_MASK BIT(4)
+#define BMP380_STATUS_DRDY_PRESS_MASK BIT(5)
+#define BMP380_STATUS_DRDY_TEMP_MASK BIT(6)
+
+#define BMP380_ERR_FATAL_MASK BIT(0)
+#define BMP380_ERR_CMD_MASK BIT(1)
+#define BMP380_ERR_CONF_MASK BIT(2)
+
+#define BMP380_TEMP_SKIPPED 0x800000
+#define BMP380_PRESS_SKIPPED 0x800000
+
/* BMP280 specific registers */
#define BMP280_REG_HUMIDITY_LSB 0xFE
#define BMP280_REG_HUMIDITY_MSB 0xFD
#define BMP280_REG_RESET 0xE0
#define BMP280_REG_ID 0xD0
+#define BMP380_CHIP_ID 0x50
#define BMP180_CHIP_ID 0x55
#define BMP280_CHIP_ID 0x58
#define BME280_CHIP_ID 0x60
/* Regmap configurations */
extern const struct regmap_config bmp180_regmap_config;
extern const struct regmap_config bmp280_regmap_config;
+extern const struct regmap_config bmp380_regmap_config;
/* Probe called from different transports */
int bmp280_common_probe(struct device *dev,
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