// SPDX-License-Identifier: GPL-2.0 /* * Bosch BME680 - Temperature, Pressure, Humidity & Gas Sensor * * Copyright (C) 2017 - 2018 Bosch Sensortec GmbH * Copyright (C) 2018 Himanshu Jha * * Datasheet: * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf */ #include #include #include #include #include #include #include #include #include #include #include "bme680.h" /* 1st set of calibration data */ enum { /* Temperature calib indexes */ T2_LSB = 0, T3 = 2, /* Pressure calib indexes */ P1_LSB = 4, P2_LSB = 6, P3 = 8, P4_LSB = 10, P5_LSB = 12, P7 = 14, P6 = 15, P8_LSB = 18, P9_LSB = 20, P10 = 22, }; /* 2nd set of calibration data */ enum { /* Humidity calib indexes */ H2_MSB = 0, H1_LSB = 1, H3 = 3, H4 = 4, H5 = 5, H6 = 6, H7 = 7, /* Stray T1 calib index */ T1_LSB = 8, /* Gas heater calib indexes */ GH2_LSB = 10, GH1 = 12, GH3 = 13, }; /* 3rd set of calibration data */ enum { RES_HEAT_VAL = 0, RES_HEAT_RANGE = 2, RANGE_SW_ERR = 4, }; struct bme680_calib { u16 par_t1; s16 par_t2; s8 par_t3; u16 par_p1; s16 par_p2; s8 par_p3; s16 par_p4; s16 par_p5; s8 par_p6; s8 par_p7; s16 par_p8; s16 par_p9; u8 par_p10; u16 par_h1; u16 par_h2; s8 par_h3; s8 par_h4; s8 par_h5; u8 par_h6; s8 par_h7; s8 par_gh1; s16 par_gh2; s8 par_gh3; u8 res_heat_range; s8 res_heat_val; s8 range_sw_err; }; struct bme680_data { struct regmap *regmap; struct bme680_calib bme680; struct mutex lock; /* Protect multiple serial R/W ops to device. */ u8 oversampling_temp; u8 oversampling_press; u8 oversampling_humid; u16 heater_dur; u16 heater_temp; union { u8 buf[3]; unsigned int check; __be16 be16; u8 bme680_cal_buf_1[BME680_CALIB_RANGE_1_LEN]; u8 bme680_cal_buf_2[BME680_CALIB_RANGE_2_LEN]; u8 bme680_cal_buf_3[BME680_CALIB_RANGE_3_LEN]; }; }; static const struct regmap_range bme680_volatile_ranges[] = { regmap_reg_range(BME680_REG_MEAS_STAT_0, BME680_REG_GAS_R_LSB), regmap_reg_range(BME680_REG_STATUS, BME680_REG_STATUS), regmap_reg_range(BME680_T2_LSB_REG, BME680_GH3_REG), }; static const struct regmap_access_table bme680_volatile_table = { .yes_ranges = bme680_volatile_ranges, .n_yes_ranges = ARRAY_SIZE(bme680_volatile_ranges), }; const struct regmap_config bme680_regmap_config = { .reg_bits = 8, .val_bits = 8, .max_register = 0xef, .volatile_table = &bme680_volatile_table, .cache_type = REGCACHE_RBTREE, }; EXPORT_SYMBOL_NS(bme680_regmap_config, IIO_BME680); static const struct iio_chan_spec bme680_channels[] = { { .type = IIO_TEMP, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), }, { .type = IIO_PRESSURE, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), }, { .type = IIO_HUMIDITYRELATIVE, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), }, { .type = IIO_RESISTANCE, .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), }, }; static int bme680_read_calib(struct bme680_data *data, struct bme680_calib *calib) { struct device *dev = regmap_get_device(data->regmap); unsigned int tmp_msb, tmp_lsb; int ret; ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG, data->bme680_cal_buf_1, sizeof(data->bme680_cal_buf_1)); if (ret < 0) { dev_err(dev, "failed to read 1st set of calib data;\n"); return ret; } calib->par_t2 = get_unaligned_le16(&data->bme680_cal_buf_1[T2_LSB]); calib->par_t3 = data->bme680_cal_buf_1[T3]; calib->par_p1 = get_unaligned_le16(&data->bme680_cal_buf_1[P1_LSB]); calib->par_p2 = get_unaligned_le16(&data->bme680_cal_buf_1[P2_LSB]); calib->par_p3 = data->bme680_cal_buf_1[P3]; calib->par_p4 = get_unaligned_le16(&data->bme680_cal_buf_1[P4_LSB]); calib->par_p5 = get_unaligned_le16(&data->bme680_cal_buf_1[P5_LSB]); calib->par_p7 = data->bme680_cal_buf_1[P7]; calib->par_p6 = data->bme680_cal_buf_1[P6]; calib->par_p8 = get_unaligned_le16(&data->bme680_cal_buf_1[P8_LSB]); calib->par_p9 = get_unaligned_le16(&data->bme680_cal_buf_1[P9_LSB]); calib->par_p10 = data->bme680_cal_buf_1[P10]; ret = regmap_bulk_read(data->regmap, BME680_H2_MSB_REG, data->bme680_cal_buf_2, sizeof(data->bme680_cal_buf_2)); if (ret < 0) { dev_err(dev, "failed to read 2nd set of calib data;\n"); return ret; } tmp_lsb = data->bme680_cal_buf_2[H1_LSB]; tmp_msb = data->bme680_cal_buf_2[H1_LSB + 1]; calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | (tmp_lsb & BME680_BIT_H1_DATA_MASK); tmp_msb = data->bme680_cal_buf_2[H2_MSB]; tmp_lsb = data->bme680_cal_buf_2[H2_MSB + 1]; calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | (tmp_lsb >> BME680_HUM_REG_SHIFT_VAL); calib->par_h3 = data->bme680_cal_buf_2[H3]; calib->par_h4 = data->bme680_cal_buf_2[H4]; calib->par_h5 = data->bme680_cal_buf_2[H5]; calib->par_h6 = data->bme680_cal_buf_2[H6]; calib->par_h7 = data->bme680_cal_buf_2[H7]; calib->par_t1 = get_unaligned_le16(&data->bme680_cal_buf_2[T1_LSB]); calib->par_gh2 = get_unaligned_le16(&data->bme680_cal_buf_2[GH2_LSB]); calib->par_gh1 = data->bme680_cal_buf_2[GH1]; calib->par_gh3 = data->bme680_cal_buf_2[GH3]; ret = regmap_bulk_read(data->regmap, BME680_REG_RES_HEAT_VAL, data->bme680_cal_buf_3, sizeof(data->bme680_cal_buf_3)); if (ret < 0) { dev_err(dev, "failed to read 3rd set of calib data;\n"); return ret; } calib->res_heat_val = data->bme680_cal_buf_3[RES_HEAT_VAL]; calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK, data->bme680_cal_buf_3[RES_HEAT_RANGE]); calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK, data->bme680_cal_buf_3[RANGE_SW_ERR]); return 0; } static int bme680_read_temp_adc(struct bme680_data *data, u32 *adc_temp) { struct device *dev = regmap_get_device(data->regmap); u32 value_temp; int ret; ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB, data->buf, BME680_TEMP_NUM_BYTES); if (ret < 0) { dev_err(dev, "failed to read temperature\n"); return ret; } value_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(data->buf)); if (value_temp == BME680_MEAS_SKIPPED) { /* reading was skipped */ dev_err(dev, "reading temperature skipped\n"); return -EINVAL; } *adc_temp = value_temp; return 0; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L876 * * Returns temperature measurement in DegC, resolutions is 0.01 DegC. Therefore, * output value of "3233" represents 32.33 DegC. */ static s32 bme680_calc_t_fine(struct bme680_data *data, u32 adc_temp) { struct bme680_calib *calib = &data->bme680; s64 var1, var2, var3; /* If the calibration is invalid, attempt to reload it */ if (!calib->par_t2) bme680_read_calib(data, calib); var1 = ((s32)adc_temp >> 3) - ((s32)calib->par_t1 << 1); var2 = (var1 * calib->par_t2) >> 11; var3 = ((var1 >> 1) * (var1 >> 1)) >> 12; var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14; return var2 + var3; /* t_fine = var2 + var3 */ } static int bme680_get_t_fine(struct bme680_data *data, s32 *t_fine) { u32 adc_temp; int ret; ret = bme680_read_temp_adc(data, &adc_temp); if (ret) return ret; *t_fine = bme680_calc_t_fine(data, adc_temp); return 0; } static s16 bme680_compensate_temp(struct bme680_data *data, u32 adc_temp) { return (bme680_calc_t_fine(data, adc_temp) * 5 + 128) / 256; } static int bme680_read_press_adc(struct bme680_data *data, u32 *adc_press) { struct device *dev = regmap_get_device(data->regmap); u32 value_press; int ret; ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB, data->buf, BME680_PRESS_NUM_BYTES); if (ret < 0) { dev_err(dev, "failed to read pressure\n"); return ret; } value_press = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(data->buf)); if (value_press == BME680_MEAS_SKIPPED) { /* reading was skipped */ dev_err(dev, "reading pressure skipped\n"); return -EINVAL; } *adc_press = value_press; return 0; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L896 * * Returns pressure measurement in Pa. Output value of "97356" represents * 97356 Pa = 973.56 hPa. */ static u32 bme680_compensate_press(struct bme680_data *data, u32 adc_press, s32 t_fine) { struct bme680_calib *calib = &data->bme680; s32 var1, var2, var3, press_comp; var1 = (t_fine >> 1) - 64000; var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2; var2 = var2 + (var1 * calib->par_p5 << 1); var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16); var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) * ((s32)calib->par_p3 << 5)) >> 3) + ((calib->par_p2 * var1) >> 1); var1 = var1 >> 18; var1 = ((32768 + var1) * calib->par_p1) >> 15; press_comp = 1048576 - adc_press; press_comp = ((press_comp - (var2 >> 12)) * 3125); if (press_comp >= BME680_MAX_OVERFLOW_VAL) press_comp = ((press_comp / (u32)var1) << 1); else press_comp = ((press_comp << 1) / (u32)var1); var1 = (calib->par_p9 * (((press_comp >> 3) * (press_comp >> 3)) >> 13)) >> 12; var2 = ((press_comp >> 2) * calib->par_p8) >> 13; var3 = ((press_comp >> 8) * (press_comp >> 8) * (press_comp >> 8) * calib->par_p10) >> 17; press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4; return press_comp; } static int bme680_read_humid_adc(struct bme680_data *data, u32 *adc_humidity) { struct device *dev = regmap_get_device(data->regmap); u32 value_humidity; int ret; ret = regmap_bulk_read(data->regmap, BME680_REG_HUMIDITY_MSB, &data->be16, BME680_HUMID_NUM_BYTES); if (ret < 0) { dev_err(dev, "failed to read humidity\n"); return ret; } value_humidity = be16_to_cpu(data->be16); if (value_humidity == BME680_MEAS_SKIPPED) { /* reading was skipped */ dev_err(dev, "reading humidity skipped\n"); return -EINVAL; } *adc_humidity = value_humidity; return 0; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L937 * * Returns humidity measurement in percent, resolution is 0.001 percent. Output * value of "43215" represents 43.215 %rH. */ static u32 bme680_compensate_humid(struct bme680_data *data, u16 adc_humid, s32 t_fine) { struct bme680_calib *calib = &data->bme680; s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum; temp_scaled = (t_fine * 5 + 128) >> 8; var1 = (adc_humid - (((s32)calib->par_h1 * 16))) - (((temp_scaled * calib->par_h3) / 100) >> 1); var2 = (calib->par_h2 * (((temp_scaled * calib->par_h4) / 100) + (((temp_scaled * ((temp_scaled * calib->par_h5) / 100)) >> 6) / 100) + (1 << 14))) >> 10; var3 = var1 * var2; var4 = (s32)calib->par_h6 << 7; var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4; var5 = ((var3 >> 14) * (var3 >> 14)) >> 10; var6 = (var4 * var5) >> 1; calc_hum = (((var3 + var6) >> 10) * 1000) >> 12; calc_hum = clamp(calc_hum, 0, 100000); /* clamp between 0-100 %rH */ return calc_hum; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L973 * * Returns gas measurement in Ohm. Output value of "82986" represent 82986 ohms. */ static u32 bme680_compensate_gas(struct bme680_data *data, u16 gas_res_adc, u8 gas_range) { struct bme680_calib *calib = &data->bme680; s64 var1; u64 var2; s64 var3; u32 calc_gas_res; /* Look up table for the possible gas range values */ static const u32 lookupTable[16] = {2147483647u, 2147483647u, 2147483647u, 2147483647u, 2147483647u, 2126008810u, 2147483647u, 2130303777u, 2147483647u, 2147483647u, 2143188679u, 2136746228u, 2147483647u, 2126008810u, 2147483647u, 2147483647u}; var1 = ((1340 + (5 * (s64) calib->range_sw_err)) * ((s64) lookupTable[gas_range])) >> 16; var2 = ((gas_res_adc << 15) - 16777216) + var1; var3 = ((125000 << (15 - gas_range)) * var1) >> 9; var3 += (var2 >> 1); calc_gas_res = div64_s64(var3, (s64) var2); return calc_gas_res; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1002 */ static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp) { struct bme680_calib *calib = &data->bme680; s32 var1, var2, var3, var4, var5, heatr_res_x100; u8 heatr_res; if (temp > 400) /* Cap temperature */ temp = 400; var1 = (((s32) BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256; var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) * temp * 5) / 100) + 3276800) / 10); var3 = var1 + (var2 / 2); var4 = (var3 / (calib->res_heat_range + 4)); var5 = 131 * calib->res_heat_val + 65536; heatr_res_x100 = ((var4 / var5) - 250) * 34; heatr_res = DIV_ROUND_CLOSEST(heatr_res_x100, 100); return heatr_res; } /* * Taken from Bosch BME680 API: * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1188 */ static u8 bme680_calc_heater_dur(u16 dur) { u8 durval, factor = 0; if (dur >= 0xfc0) { durval = 0xff; /* Max duration */ } else { while (dur > 0x3F) { dur = dur / 4; factor += 1; } durval = dur + (factor * 64); } return durval; } static int bme680_set_mode(struct bme680_data *data, bool mode) { struct device *dev = regmap_get_device(data->regmap); int ret; if (mode) { ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, BME680_MODE_MASK, BME680_MODE_FORCED); if (ret < 0) dev_err(dev, "failed to set forced mode\n"); } else { ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, BME680_MODE_MASK, BME680_MODE_SLEEP); if (ret < 0) dev_err(dev, "failed to set sleep mode\n"); } return ret; } static u8 bme680_oversampling_to_reg(u8 val) { return ilog2(val) + 1; } /* * Taken from Bosch BME680 API: * https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490 */ static int bme680_wait_for_eoc(struct bme680_data *data) { struct device *dev = regmap_get_device(data->regmap); int ret; /* * (Sum of oversampling ratios * time per oversampling) + * TPH measurement + gas measurement + wait transition from forced mode * + heater duration */ int wait_eoc_us = ((data->oversampling_temp + data->oversampling_press + data->oversampling_humid) * 1936) + (477 * 4) + (477 * 5) + 1000 + (data->heater_dur * 1000); usleep_range(wait_eoc_us, wait_eoc_us + 100); ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); if (ret) { dev_err(dev, "failed to read measurement status register.\n"); return ret; } if (data->check & BME680_MEAS_BIT) { dev_err(dev, "Device measurement cycle incomplete.\n"); return -EBUSY; } if (!(data->check & BME680_NEW_DATA_BIT)) { dev_err(dev, "No new data available from the device.\n"); return -ENODATA; } return 0; } static int bme680_chip_config(struct bme680_data *data) { struct device *dev = regmap_get_device(data->regmap); int ret; u8 osrs; osrs = FIELD_PREP( BME680_OSRS_HUMIDITY_MASK, bme680_oversampling_to_reg(data->oversampling_humid)); /* * Highly recommended to set oversampling of humidity before * temperature/pressure oversampling. */ ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_HUMIDITY, BME680_OSRS_HUMIDITY_MASK, osrs); if (ret < 0) { dev_err(dev, "failed to write ctrl_hum register\n"); return ret; } /* IIR filter settings */ ret = regmap_update_bits(data->regmap, BME680_REG_CONFIG, BME680_FILTER_MASK, BME680_FILTER_COEFF_VAL); if (ret < 0) { dev_err(dev, "failed to write config register\n"); return ret; } osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK, bme680_oversampling_to_reg(data->oversampling_temp)) | FIELD_PREP(BME680_OSRS_PRESS_MASK, bme680_oversampling_to_reg(data->oversampling_press)); ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK, osrs); if (ret < 0) { dev_err(dev, "failed to write ctrl_meas register\n"); return ret; } return 0; } static int bme680_gas_config(struct bme680_data *data) { struct device *dev = regmap_get_device(data->regmap); int ret; u8 heatr_res, heatr_dur; /* Go to sleep */ ret = bme680_set_mode(data, false); if (ret < 0) return ret; heatr_res = bme680_calc_heater_res(data, data->heater_temp); /* set target heater temperature */ ret = regmap_write(data->regmap, BME680_REG_RES_HEAT_0, heatr_res); if (ret < 0) { dev_err(dev, "failed to write res_heat_0 register\n"); return ret; } heatr_dur = bme680_calc_heater_dur(data->heater_dur); /* set target heating duration */ ret = regmap_write(data->regmap, BME680_REG_GAS_WAIT_0, heatr_dur); if (ret < 0) { dev_err(dev, "failed to write gas_wait_0 register\n"); return ret; } /* Enable the gas sensor and select heater profile set-point 0 */ ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1, BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK, FIELD_PREP(BME680_RUN_GAS_MASK, 1) | FIELD_PREP(BME680_NB_CONV_MASK, 0)); if (ret < 0) dev_err(dev, "failed to write ctrl_gas_1 register\n"); return ret; } static int bme680_read_temp(struct bme680_data *data, int *val) { int ret; u32 adc_temp; s16 comp_temp; ret = bme680_read_temp_adc(data, &adc_temp); if (ret) return ret; comp_temp = bme680_compensate_temp(data, adc_temp); *val = comp_temp * 10; /* Centidegrees to millidegrees */ return IIO_VAL_INT; } static int bme680_read_press(struct bme680_data *data, int *val, int *val2) { int ret; u32 adc_press; s32 t_fine; ret = bme680_get_t_fine(data, &t_fine); if (ret) return ret; ret = bme680_read_press_adc(data, &adc_press); if (ret) return ret; *val = bme680_compensate_press(data, adc_press, t_fine); *val2 = 1000; return IIO_VAL_FRACTIONAL; } static int bme680_read_humid(struct bme680_data *data, int *val, int *val2) { int ret; u32 adc_humidity, comp_humidity; s32 t_fine; ret = bme680_get_t_fine(data, &t_fine); if (ret) return ret; ret = bme680_read_humid_adc(data, &adc_humidity); if (ret) return ret; comp_humidity = bme680_compensate_humid(data, adc_humidity, t_fine); *val = comp_humidity; *val2 = 1000; return IIO_VAL_FRACTIONAL; } static int bme680_read_gas(struct bme680_data *data, int *val) { struct device *dev = regmap_get_device(data->regmap); int ret; u16 adc_gas_res, gas_regs_val; u8 gas_range; ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); if (data->check & BME680_GAS_MEAS_BIT) { dev_err(dev, "gas measurement incomplete\n"); return -EBUSY; } ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB, &data->be16, BME680_GAS_NUM_BYTES); if (ret < 0) { dev_err(dev, "failed to read gas resistance\n"); return ret; } gas_regs_val = be16_to_cpu(data->be16); adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val); /* * occurs if either the gas heating duration was insuffient * to reach the target heater temperature or the target * heater temperature was too high for the heater sink to * reach. */ if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) { dev_err(dev, "heater failed to reach the target temperature\n"); return -EINVAL; } gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val); *val = bme680_compensate_gas(data, adc_gas_res, gas_range); return IIO_VAL_INT; } static int bme680_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct bme680_data *data = iio_priv(indio_dev); int ret; guard(mutex)(&data->lock); /* set forced mode to trigger measurement */ ret = bme680_set_mode(data, true); if (ret < 0) return ret; ret = bme680_wait_for_eoc(data); if (ret) return ret; switch (mask) { case IIO_CHAN_INFO_PROCESSED: switch (chan->type) { case IIO_TEMP: return bme680_read_temp(data, val); case IIO_PRESSURE: return bme680_read_press(data, val, val2); case IIO_HUMIDITYRELATIVE: return bme680_read_humid(data, val, val2); case IIO_RESISTANCE: return bme680_read_gas(data, val); default: return -EINVAL; } case IIO_CHAN_INFO_OVERSAMPLING_RATIO: switch (chan->type) { case IIO_TEMP: *val = data->oversampling_temp; return IIO_VAL_INT; case IIO_PRESSURE: *val = data->oversampling_press; return IIO_VAL_INT; case IIO_HUMIDITYRELATIVE: *val = data->oversampling_humid; return IIO_VAL_INT; default: return -EINVAL; } default: return -EINVAL; } } static bool bme680_is_valid_oversampling(int rate) { return (rate > 0 && rate <= 16 && is_power_of_2(rate)); } static int bme680_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct bme680_data *data = iio_priv(indio_dev); guard(mutex)(&data->lock); if (val2 != 0) return -EINVAL; switch (mask) { case IIO_CHAN_INFO_OVERSAMPLING_RATIO: { if (!bme680_is_valid_oversampling(val)) return -EINVAL; switch (chan->type) { case IIO_TEMP: data->oversampling_temp = val; break; case IIO_PRESSURE: data->oversampling_press = val; break; case IIO_HUMIDITYRELATIVE: data->oversampling_humid = val; break; default: return -EINVAL; } return bme680_chip_config(data); } default: return -EINVAL; } } static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16"; static IIO_CONST_ATTR(oversampling_ratio_available, bme680_oversampling_ratio_show); static struct attribute *bme680_attributes[] = { &iio_const_attr_oversampling_ratio_available.dev_attr.attr, NULL, }; static const struct attribute_group bme680_attribute_group = { .attrs = bme680_attributes, }; static const struct iio_info bme680_info = { .read_raw = &bme680_read_raw, .write_raw = &bme680_write_raw, .attrs = &bme680_attribute_group, }; int bme680_core_probe(struct device *dev, struct regmap *regmap, const char *name) { struct iio_dev *indio_dev; struct bme680_data *data; int ret; indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); if (!indio_dev) return -ENOMEM; data = iio_priv(indio_dev); mutex_init(&data->lock); dev_set_drvdata(dev, indio_dev); data->regmap = regmap; indio_dev->name = name; indio_dev->channels = bme680_channels; indio_dev->num_channels = ARRAY_SIZE(bme680_channels); indio_dev->info = &bme680_info; indio_dev->modes = INDIO_DIRECT_MODE; /* default values for the sensor */ data->oversampling_humid = 2; /* 2X oversampling rate */ data->oversampling_press = 4; /* 4X oversampling rate */ data->oversampling_temp = 8; /* 8X oversampling rate */ data->heater_temp = 320; /* degree Celsius */ data->heater_dur = 150; /* milliseconds */ ret = regmap_write(regmap, BME680_REG_SOFT_RESET, BME680_CMD_SOFTRESET); if (ret < 0) return dev_err_probe(dev, ret, "Failed to reset chip\n"); usleep_range(BME680_STARTUP_TIME_US, BME680_STARTUP_TIME_US + 1000); ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check); if (ret < 0) return dev_err_probe(dev, ret, "Error reading chip ID\n"); if (data->check != BME680_CHIP_ID_VAL) { dev_err(dev, "Wrong chip ID, got %x expected %x\n", data->check, BME680_CHIP_ID_VAL); return -ENODEV; } ret = bme680_read_calib(data, &data->bme680); if (ret < 0) { return dev_err_probe(dev, ret, "failed to read calibration coefficients at probe\n"); } ret = bme680_chip_config(data); if (ret < 0) return dev_err_probe(dev, ret, "failed to set chip_config data\n"); ret = bme680_gas_config(data); if (ret < 0) return dev_err_probe(dev, ret, "failed to set gas config data\n"); return devm_iio_device_register(dev, indio_dev); } EXPORT_SYMBOL_NS_GPL(bme680_core_probe, IIO_BME680); MODULE_AUTHOR("Himanshu Jha "); MODULE_DESCRIPTION("Bosch BME680 Driver"); MODULE_LICENSE("GPL v2");