diff options
Diffstat (limited to 'drivers/iio/chemical/bme680_core.c')
| -rw-r--r-- | drivers/iio/chemical/bme680_core.c | 1266 |
1 files changed, 1266 insertions, 0 deletions
diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c new file mode 100644 index 000000000000..70f81c4a96ba --- /dev/null +++ b/drivers/iio/chemical/bme680_core.c @@ -0,0 +1,1266 @@ +// 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 <himanshujha199640@gmail.com> + * + * Datasheet: + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf + */ +#include <linux/bitfield.h> +#include <linux/cleanup.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/pm.h> +#include <linux/pm_runtime.h> +#include <linux/regmap.h> +#include <linux/regulator/consumer.h> + +#include <linux/iio/buffer.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> + +#include <linux/unaligned.h> + +#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; +}; + +/* values of CTRL_MEAS register */ +enum bme680_op_mode { + BME680_MODE_SLEEP = 0, + BME680_MODE_FORCED = 1, +}; + +enum bme680_scan { + BME680_TEMP, + BME680_PRESS, + BME680_HUMID, + BME680_GAS, +}; + +static const char *const bme680_supply_names[] = { "vdd", "vddio" }; + +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; + u8 preheat_curr_mA; + u16 heater_dur; + u16 heater_temp; + + struct { + s32 chan[4]; + aligned_s64 ts; + } scan; + + union { + u8 buf[BME680_NUM_BULK_READ_REGS]; + 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_MAPLE, +}; +EXPORT_SYMBOL_NS(bme680_regmap_config, "IIO_BME680"); + +static const struct iio_chan_spec bme680_channels[] = { + { + .type = IIO_TEMP, + /* PROCESSED maintained for ABI backwards compatibility */ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .scan_index = 0, + .scan_type = { + .sign = 's', + .realbits = 16, + .storagebits = 16, + .endianness = IIO_CPU, + }, + }, + { + .type = IIO_PRESSURE, + /* PROCESSED maintained for ABI backwards compatibility */ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .scan_index = 1, + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + { + .type = IIO_HUMIDITYRELATIVE, + /* PROCESSED maintained for ABI backwards compatibility */ + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + .scan_index = 2, + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + { + .type = IIO_RESISTANCE, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + .scan_index = 3, + .scan_type = { + .sign = 'u', + .realbits = 32, + .storagebits = 32, + .endianness = IIO_CPU, + }, + }, + IIO_CHAN_SOFT_TIMESTAMP(4), + { + .type = IIO_CURRENT, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + .output = 1, + .scan_index = -1, + }, +}; + +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 lookup_table[16] = { + 2147483647u, 2147483647u, 2147483647u, 2147483647u, + 2147483647u, 2126008810u, 2147483647u, 2130303777u, + 2147483647u, 2147483647u, 2143188679u, 2136746228u, + 2147483647u, 2126008810u, 2147483647u, 2147483647u + }; + + var1 = ((1340LL + (5 * calib->range_sw_err)) * + (lookup_table[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; +} + +/* Taken from datasheet, section 5.3.3 */ +static u8 bme680_calc_heater_preheat_current(u8 curr) +{ + return 8 * curr - 1; +} + +static int bme680_set_mode(struct bme680_data *data, enum bme680_op_mode mode) +{ + struct device *dev = regmap_get_device(data->regmap); + int ret; + + ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, + BME680_MODE_MASK, mode); + if (ret < 0) { + dev_err(dev, "failed to set ctrl_meas register\n"); + return ret; + } + + 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); + + fsleep(wait_eoc_us); + + 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_preheat_curr_config(struct bme680_data *data, u8 val) +{ + struct device *dev = regmap_get_device(data->regmap); + u8 heatr_curr; + int ret; + + heatr_curr = bme680_calc_heater_preheat_current(val); + ret = regmap_write(data->regmap, BME680_REG_IDAC_HEAT_0, heatr_curr); + if (ret < 0) + dev_err(dev, "failed to write idac_heat_0 register\n"); + + return ret; +} + +static int bme680_gas_config(struct bme680_data *data) +{ + struct device *dev = regmap_get_device(data->regmap); + int ret; + u8 heatr_res, heatr_dur; + + ret = bme680_set_mode(data, BME680_MODE_SLEEP); + 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; + } + + ret = bme680_preheat_curr_config(data, data->preheat_curr_mA); + if (ret) + 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, s16 *comp_temp) +{ + int ret; + u32 adc_temp; + + ret = bme680_read_temp_adc(data, &adc_temp); + if (ret) + return ret; + + *comp_temp = bme680_compensate_temp(data, adc_temp); + return 0; +} + +static int bme680_read_press(struct bme680_data *data, u32 *comp_press) +{ + 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; + + *comp_press = bme680_compensate_press(data, adc_press, t_fine); + return 0; +} + +static int bme680_read_humid(struct bme680_data *data, u32 *comp_humidity) +{ + int ret; + u32 adc_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); + return 0; +} + +static int bme680_read_gas(struct bme680_data *data, int *comp_gas_res) +{ + 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); + *comp_gas_res = bme680_compensate_gas(data, adc_gas_res, gas_range); + return 0; +} + +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 chan_val, ret; + s16 temp_chan_val; + + guard(mutex)(&data->lock); + + ret = bme680_set_mode(data, BME680_MODE_FORCED); + 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: + ret = bme680_read_temp(data, &temp_chan_val); + if (ret) + return ret; + + *val = temp_chan_val * 10; + return IIO_VAL_INT; + case IIO_PRESSURE: + ret = bme680_read_press(data, &chan_val); + if (ret) + return ret; + + *val = chan_val; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + case IIO_HUMIDITYRELATIVE: + ret = bme680_read_humid(data, &chan_val); + if (ret) + return ret; + + *val = chan_val; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + case IIO_RESISTANCE: + ret = bme680_read_gas(data, &chan_val); + if (ret) + return ret; + + *val = chan_val; + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_RAW: + switch (chan->type) { + case IIO_TEMP: + ret = bme680_read_temp(data, &temp_chan_val); + if (ret) + return ret; + + *val = temp_chan_val; + return IIO_VAL_INT; + case IIO_PRESSURE: + ret = bme680_read_press(data, &chan_val); + if (ret) + return ret; + + *val = chan_val; + return IIO_VAL_INT; + case IIO_HUMIDITYRELATIVE: + ret = bme680_read_humid(data, &chan_val); + if (ret) + return ret; + + *val = chan_val; + return IIO_VAL_INT; + default: + return -EINVAL; + } + case IIO_CHAN_INFO_SCALE: + switch (chan->type) { + case IIO_TEMP: + *val = 10; + return IIO_VAL_INT; + case IIO_PRESSURE: + *val = 1; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + case IIO_HUMIDITYRELATIVE: + *val = 1; + *val2 = 1000; + return IIO_VAL_FRACTIONAL; + 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 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); + struct device *dev = regmap_get_device(data->regmap); + int ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return ret; + + ret = __bme680_read_raw(indio_dev, chan, val, val2, mask); + pm_runtime_put_autosuspend(dev); + + return ret; +} + +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); + } + case IIO_CHAN_INFO_PROCESSED: + { + switch (chan->type) { + case IIO_CURRENT: + return bme680_preheat_curr_config(data, (u8)val); + default: + return -EINVAL; + } + } + default: + return -EINVAL; + } +} + +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); + struct device *dev = regmap_get_device(data->regmap); + int ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret) + return ret; + + ret = __bme680_write_raw(indio_dev, chan, val, val2, mask); + pm_runtime_put_autosuspend(dev); + + return ret; +} + +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, +}; + +static const unsigned long bme680_avail_scan_masks[] = { + BIT(BME680_GAS) | BIT(BME680_HUMID) | BIT(BME680_PRESS) | BIT(BME680_TEMP), + 0 +}; + +static irqreturn_t bme680_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct bme680_data *data = iio_priv(indio_dev); + struct device *dev = regmap_get_device(data->regmap); + u32 adc_temp, adc_press, adc_humid; + u16 adc_gas_res, gas_regs_val; + u8 gas_range; + s32 t_fine; + int ret; + + guard(mutex)(&data->lock); + + ret = bme680_set_mode(data, BME680_MODE_FORCED); + if (ret < 0) + goto out; + + ret = bme680_wait_for_eoc(data); + if (ret) + goto out; + + ret = regmap_bulk_read(data->regmap, BME680_REG_MEAS_STAT_0, + data->buf, sizeof(data->buf)); + if (ret) { + dev_err(dev, "failed to burst read sensor data\n"); + goto out; + } + if (data->buf[0] & BME680_GAS_MEAS_BIT) { + dev_err(dev, "gas measurement incomplete\n"); + goto out; + } + + /* Temperature calculations */ + adc_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[5])); + if (adc_temp == BME680_MEAS_SKIPPED) { + dev_err(dev, "reading temperature skipped\n"); + goto out; + } + data->scan.chan[0] = bme680_compensate_temp(data, adc_temp); + t_fine = bme680_calc_t_fine(data, adc_temp); + + /* Pressure calculations */ + adc_press = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[2])); + if (adc_press == BME680_MEAS_SKIPPED) { + dev_err(dev, "reading pressure skipped\n"); + goto out; + } + data->scan.chan[1] = bme680_compensate_press(data, adc_press, t_fine); + + /* Humidity calculations */ + adc_humid = get_unaligned_be16(&data->buf[8]); + if (adc_humid == BME680_MEAS_SKIPPED) { + dev_err(dev, "reading humidity skipped\n"); + goto out; + } + data->scan.chan[2] = bme680_compensate_humid(data, adc_humid, t_fine); + + /* Gas calculations */ + gas_regs_val = get_unaligned_be16(&data->buf[13]); + adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val); + if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) { + dev_err(dev, "heater failed to reach the target temperature\n"); + goto out; + } + gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val); + data->scan.chan[3] = bme680_compensate_gas(data, adc_gas_res, gas_range); + + iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan), + iio_get_time_ns(indio_dev)); +out: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +static int bme680_buffer_preenable(struct iio_dev *indio_dev) +{ + struct bme680_data *data = iio_priv(indio_dev); + struct device *dev = regmap_get_device(data->regmap); + + return pm_runtime_resume_and_get(dev); +} + +static int bme680_buffer_postdisable(struct iio_dev *indio_dev) +{ + struct bme680_data *data = iio_priv(indio_dev); + struct device *dev = regmap_get_device(data->regmap); + + pm_runtime_put_autosuspend(dev); + return 0; +} + +static const struct iio_buffer_setup_ops bme680_buffer_setup_ops = { + .preenable = bme680_buffer_preenable, + .postdisable = bme680_buffer_postdisable, +}; + +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->available_scan_masks = bme680_avail_scan_masks; + 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 */ + data->preheat_curr_mA = 0; + + ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(bme680_supply_names), + bme680_supply_names); + if (ret) + return dev_err_probe(dev, ret, + "failed to get and enable supplies.\n"); + + fsleep(BME680_STARTUP_TIME_US); + + 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"); + + fsleep(BME680_STARTUP_TIME_US); + + 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"); + + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, + iio_pollfunc_store_time, + bme680_trigger_handler, + &bme680_buffer_setup_ops); + if (ret) + return dev_err_probe(dev, ret, + "iio triggered buffer setup failed\n"); + + /* Enable runtime PM */ + pm_runtime_set_autosuspend_delay(dev, BME680_STARTUP_TIME_US); + pm_runtime_use_autosuspend(dev); + pm_runtime_set_active(dev); + ret = devm_pm_runtime_enable(dev); + if (ret) + return ret; + + return devm_iio_device_register(dev, indio_dev); +} +EXPORT_SYMBOL_NS_GPL(bme680_core_probe, "IIO_BME680"); + +static int bme680_runtime_suspend(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bme680_data *data = iio_priv(indio_dev); + + return bme680_set_mode(data, BME680_MODE_SLEEP); +} + +static int bme680_runtime_resume(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bme680_data *data = iio_priv(indio_dev); + int ret; + + ret = bme680_chip_config(data); + if (ret) + return ret; + + return bme680_gas_config(data); +} + +EXPORT_RUNTIME_DEV_PM_OPS(bme680_dev_pm_ops, bme680_runtime_suspend, + bme680_runtime_resume, NULL); + +MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>"); +MODULE_DESCRIPTION("Bosch BME680 Driver"); +MODULE_LICENSE("GPL v2"); |