diff options
Diffstat (limited to 'drivers/iio/pressure/bmp280-core.c')
| -rw-r--r-- | drivers/iio/pressure/bmp280-core.c | 968 |
1 files changed, 968 insertions, 0 deletions
diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c new file mode 100644 index 000000000000..83b96fe71f3b --- /dev/null +++ b/drivers/iio/pressure/bmp280-core.c @@ -0,0 +1,968 @@ +/* + * Copyright (c) 2014 Intel Corporation + * + * Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Datasheet: + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf + * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME280_DS001-11.pdf + */ + +#define pr_fmt(fmt) "bmp280: " fmt + +#include <linux/device.h> +#include <linux/regmap.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/gpio/consumer.h> +#include <linux/regulator/consumer.h> + +#include "bmp280.h" + +struct bmp280_data { + struct device *dev; + struct mutex lock; + struct regmap *regmap; + const struct bmp280_chip_info *chip_info; + struct regulator *vddd; + struct regulator *vdda; + unsigned int start_up_time; /* in milliseconds */ + + /* log of base 2 of oversampling rate */ + u8 oversampling_press; + u8 oversampling_temp; + u8 oversampling_humid; + + /* + * Carryover value from temperature conversion, used in pressure + * calculation. + */ + s32 t_fine; +}; + +struct bmp280_chip_info { + const int *oversampling_temp_avail; + int num_oversampling_temp_avail; + + const int *oversampling_press_avail; + int num_oversampling_press_avail; + + const int *oversampling_humid_avail; + int num_oversampling_humid_avail; + + int (*chip_config)(struct bmp280_data *); + int (*read_temp)(struct bmp280_data *, int *); + int (*read_press)(struct bmp280_data *, int *, int *); + int (*read_humid)(struct bmp280_data *, int *, int *); +}; + +/* + * These enums are used for indexing into the array of compensation + * parameters for BMP280. + */ +enum { T1, T2, T3 }; +enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 }; + +static const struct iio_chan_spec bmp280_channels[] = { + { + .type = IIO_PRESSURE, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | + BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), + }, + { + .type = IIO_TEMP, + .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), + }, +}; + +/* + * Returns humidity in percent, resolution is 0.01 percent. Output value of + * "47445" represents 47445/1024 = 46.333 %RH. + * + * Taken from BME280 datasheet, Section 4.2.3, "Compensation formula". + */ + +static u32 bmp280_compensate_humidity(struct bmp280_data *data, + s32 adc_humidity) +{ + struct device *dev = data->dev; + unsigned int H1, H3, tmp; + int H2, H4, H5, H6, ret, var; + + ret = regmap_read(data->regmap, BMP280_REG_COMP_H1, &H1); + if (ret < 0) { + dev_err(dev, "failed to read H1 comp value\n"); + return ret; + } + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H2, &tmp, 2); + if (ret < 0) { + dev_err(dev, "failed to read H2 comp value\n"); + return ret; + } + H2 = sign_extend32(le16_to_cpu(tmp), 15); + + ret = regmap_read(data->regmap, BMP280_REG_COMP_H3, &H3); + if (ret < 0) { + dev_err(dev, "failed to read H3 comp value\n"); + return ret; + } + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H4, &tmp, 2); + if (ret < 0) { + dev_err(dev, "failed to read H4 comp value\n"); + return ret; + } + H4 = sign_extend32(((be16_to_cpu(tmp) >> 4) & 0xff0) | + (be16_to_cpu(tmp) & 0xf), 11); + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_H5, &tmp, 2); + if (ret < 0) { + dev_err(dev, "failed to read H5 comp value\n"); + return ret; + } + H5 = sign_extend32(((le16_to_cpu(tmp) >> 4) & 0xfff), 11); + + ret = regmap_read(data->regmap, BMP280_REG_COMP_H6, &tmp); + if (ret < 0) { + dev_err(dev, "failed to read H6 comp value\n"); + return ret; + } + H6 = sign_extend32(tmp, 7); + + var = ((s32)data->t_fine) - 76800; + var = ((((adc_humidity << 14) - (H4 << 20) - (H5 * var)) + 16384) >> 15) + * (((((((var * H6) >> 10) * (((var * H3) >> 11) + 32768)) >> 10) + + 2097152) * H2 + 8192) >> 14); + var -= ((((var >> 15) * (var >> 15)) >> 7) * H1) >> 4; + + return var >> 12; +}; + +/* + * Returns temperature in DegC, resolution is 0.01 DegC. Output value of + * "5123" equals 51.23 DegC. t_fine carries fine temperature as global + * value. + * + * Taken from datasheet, Section 3.11.3, "Compensation formula". + */ +static s32 bmp280_compensate_temp(struct bmp280_data *data, + s32 adc_temp) +{ + int ret; + s32 var1, var2; + __le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2]; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START, + buf, BMP280_COMP_TEMP_REG_COUNT); + if (ret < 0) { + dev_err(data->dev, + "failed to read temperature calibration parameters\n"); + return ret; + } + + /* + * The double casts are necessary because le16_to_cpu returns an + * unsigned 16-bit value. Casting that value directly to a + * signed 32-bit will not do proper sign extension. + * + * Conversely, T1 and P1 are unsigned values, so they can be + * cast straight to the larger type. + */ + var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) * + ((s32)(s16)le16_to_cpu(buf[T2]))) >> 11; + var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) * + ((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) * + ((s32)(s16)le16_to_cpu(buf[T3]))) >> 14; + data->t_fine = var1 + var2; + + return (data->t_fine * 5 + 128) >> 8; +} + +/* + * Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24 + * integer bits and 8 fractional bits). Output value of "24674867" + * represents 24674867/256 = 96386.2 Pa = 963.862 hPa + * + * Taken from datasheet, Section 3.11.3, "Compensation formula". + */ +static u32 bmp280_compensate_press(struct bmp280_data *data, + s32 adc_press) +{ + int ret; + s64 var1, var2, p; + __le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2]; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START, + buf, BMP280_COMP_PRESS_REG_COUNT); + if (ret < 0) { + dev_err(data->dev, + "failed to read pressure calibration parameters\n"); + return ret; + } + + var1 = ((s64)data->t_fine) - 128000; + var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]); + var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17; + var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35; + var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) + + ((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12); + var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33; + + if (var1 == 0) + return 0; + + p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125; + p = div64_s64(p, var1); + var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25; + var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19; + p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4); + + return (u32)p; +} + +static int bmp280_read_temp(struct bmp280_data *data, + int *val) +{ + int ret; + __be32 tmp = 0; + s32 adc_temp, comp_temp; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB, + (u8 *) &tmp, 3); + if (ret < 0) { + dev_err(data->dev, "failed to read temperature\n"); + return ret; + } + + adc_temp = be32_to_cpu(tmp) >> 12; + comp_temp = bmp280_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) { + *val = comp_temp * 10; + return IIO_VAL_INT; + } + + return 0; +} + +static int bmp280_read_press(struct bmp280_data *data, + int *val, int *val2) +{ + int ret; + __be32 tmp = 0; + s32 adc_press; + u32 comp_press; + + /* Read and compensate temperature so we get a reading of t_fine. */ + ret = bmp280_read_temp(data, NULL); + if (ret < 0) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB, + (u8 *) &tmp, 3); + if (ret < 0) { + dev_err(data->dev, "failed to read pressure\n"); + return ret; + } + + adc_press = be32_to_cpu(tmp) >> 12; + comp_press = bmp280_compensate_press(data, adc_press); + + *val = comp_press; + *val2 = 256000; + + return IIO_VAL_FRACTIONAL; +} + +static int bmp280_read_humid(struct bmp280_data *data, int *val, int *val2) +{ + int ret; + __be16 tmp = 0; + s32 adc_humidity; + u32 comp_humidity; + + /* Read and compensate temperature so we get a reading of t_fine. */ + ret = bmp280_read_temp(data, NULL); + if (ret < 0) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP280_REG_HUMIDITY_MSB, + (u8 *) &tmp, 2); + if (ret < 0) { + dev_err(data->dev, "failed to read humidity\n"); + return ret; + } + + adc_humidity = be16_to_cpu(tmp); + comp_humidity = bmp280_compensate_humidity(data, adc_humidity); + + *val = comp_humidity; + *val2 = 1024; + + return IIO_VAL_FRACTIONAL; +} + +static int bmp280_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + int ret; + struct bmp280_data *data = iio_priv(indio_dev); + + mutex_lock(&data->lock); + + switch (mask) { + case IIO_CHAN_INFO_PROCESSED: + switch (chan->type) { + case IIO_HUMIDITYRELATIVE: + ret = data->chip_info->read_humid(data, val, val2); + break; + case IIO_PRESSURE: + ret = data->chip_info->read_press(data, val, val2); + break; + case IIO_TEMP: + ret = data->chip_info->read_temp(data, val); + break; + default: + ret = -EINVAL; + break; + } + break; + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + switch (chan->type) { + case IIO_HUMIDITYRELATIVE: + *val = 1 << data->oversampling_humid; + ret = IIO_VAL_INT; + break; + case IIO_PRESSURE: + *val = 1 << data->oversampling_press; + ret = IIO_VAL_INT; + break; + case IIO_TEMP: + *val = 1 << data->oversampling_temp; + ret = IIO_VAL_INT; + break; + default: + ret = -EINVAL; + break; + } + break; + default: + ret = -EINVAL; + break; + } + + mutex_unlock(&data->lock); + + return ret; +} + +static int bmp280_write_oversampling_ratio_humid(struct bmp280_data *data, + int val) +{ + int i; + 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) { + data->oversampling_humid = ilog2(val); + + return data->chip_info->chip_config(data); + } + } + return -EINVAL; +} + +static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data, + int val) +{ + int i; + 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) { + data->oversampling_temp = ilog2(val); + + return data->chip_info->chip_config(data); + } + } + return -EINVAL; +} + +static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data, + int val) +{ + int i; + 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) { + data->oversampling_press = ilog2(val); + + return data->chip_info->chip_config(data); + } + } + return -EINVAL; +} + +static int bmp280_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + int ret = 0; + struct bmp280_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_OVERSAMPLING_RATIO: + mutex_lock(&data->lock); + switch (chan->type) { + case IIO_HUMIDITYRELATIVE: + ret = bmp280_write_oversampling_ratio_humid(data, val); + break; + case IIO_PRESSURE: + ret = bmp280_write_oversampling_ratio_press(data, val); + break; + case IIO_TEMP: + ret = bmp280_write_oversampling_ratio_temp(data, val); + break; + default: + ret = -EINVAL; + break; + } + mutex_unlock(&data->lock); + break; + default: + return -EINVAL; + } + + return ret; +} + +static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n) +{ + size_t len = 0; + int i; + + for (i = 0; i < n; i++) + len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]); + + buf[len - 1] = '\n'; + + return len; +} + +static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev)); + + return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail, + data->chip_info->num_oversampling_temp_avail); +} + +static ssize_t bmp280_show_press_oversampling_avail(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev)); + + return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail, + data->chip_info->num_oversampling_press_avail); +} + +static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available, + S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0); + +static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available, + S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0); + +static struct attribute *bmp280_attributes[] = { + &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr, + &iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr, + NULL, +}; + +static const struct attribute_group bmp280_attrs_group = { + .attrs = bmp280_attributes, +}; + +static const struct iio_info bmp280_info = { + .driver_module = THIS_MODULE, + .read_raw = &bmp280_read_raw, + .write_raw = &bmp280_write_raw, + .attrs = &bmp280_attrs_group, +}; + +static int bmp280_chip_config(struct bmp280_data *data) +{ + int ret; + u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) | + BMP280_OSRS_PRESS_X(data->oversampling_press + 1); + + ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS, + BMP280_OSRS_TEMP_MASK | + BMP280_OSRS_PRESS_MASK | + BMP280_MODE_MASK, + osrs | BMP280_MODE_NORMAL); + if (ret < 0) { + dev_err(data->dev, + "failed to write ctrl_meas register\n"); + return ret; + } + + ret = regmap_update_bits(data->regmap, BMP280_REG_CONFIG, + BMP280_FILTER_MASK, + BMP280_FILTER_4X); + if (ret < 0) { + dev_err(data->dev, + "failed to write config register\n"); + return ret; + } + + return ret; +} + +static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 }; + +static const struct bmp280_chip_info bmp280_chip_info = { + .oversampling_temp_avail = bmp280_oversampling_avail, + .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail), + + .oversampling_press_avail = bmp280_oversampling_avail, + .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail), + + .chip_config = bmp280_chip_config, + .read_temp = bmp280_read_temp, + .read_press = bmp280_read_press, +}; + +static int bme280_chip_config(struct bmp280_data *data) +{ + int ret = bmp280_chip_config(data); + u8 osrs = BMP280_OSRS_HUMIDITIY_X(data->oversampling_humid + 1); + + if (ret < 0) + return ret; + + return regmap_update_bits(data->regmap, BMP280_REG_CTRL_HUMIDITY, + BMP280_OSRS_HUMIDITY_MASK, osrs); +} + +static const struct bmp280_chip_info bme280_chip_info = { + .oversampling_temp_avail = bmp280_oversampling_avail, + .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail), + + .oversampling_press_avail = bmp280_oversampling_avail, + .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail), + + .oversampling_humid_avail = bmp280_oversampling_avail, + .num_oversampling_humid_avail = ARRAY_SIZE(bmp280_oversampling_avail), + + .chip_config = bme280_chip_config, + .read_temp = bmp280_read_temp, + .read_press = bmp280_read_press, + .read_humid = bmp280_read_humid, +}; + +static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas) +{ + int ret; + const int conversion_time_max[] = { 4500, 7500, 13500, 25500 }; + unsigned int delay_us; + unsigned int ctrl; + + ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas); + if (ret) + return ret; + + if (ctrl_meas == BMP180_MEAS_TEMP) + delay_us = 4500; + else + delay_us = conversion_time_max[data->oversampling_press]; + + usleep_range(delay_us, delay_us + 1000); + + ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl); + if (ret) + return ret; + + /* The value of this bit reset to "0" after conversion is complete */ + if (ctrl & BMP180_MEAS_SCO) + return -EIO; + + return 0; +} + +static int bmp180_read_adc_temp(struct bmp280_data *data, int *val) +{ + int ret; + __be16 tmp = 0; + + ret = bmp180_measure(data, BMP180_MEAS_TEMP); + if (ret) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2); + if (ret) + return ret; + + *val = be16_to_cpu(tmp); + + return 0; +} + +/* + * These enums are used for indexing into the array of calibration + * coefficients for BMP180. + */ +enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD }; + +struct bmp180_calib { + s16 AC1; + s16 AC2; + s16 AC3; + u16 AC4; + u16 AC5; + u16 AC6; + s16 B1; + s16 B2; + s16 MB; + s16 MC; + s16 MD; +}; + +static int bmp180_read_calib(struct bmp280_data *data, + struct bmp180_calib *calib) +{ + int ret; + int i; + __be16 buf[BMP180_REG_CALIB_COUNT / 2]; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf, + sizeof(buf)); + + if (ret < 0) + return ret; + + /* None of the words has the value 0 or 0xFFFF */ + for (i = 0; i < ARRAY_SIZE(buf); i++) { + if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff)) + return -EIO; + } + + calib->AC1 = be16_to_cpu(buf[AC1]); + calib->AC2 = be16_to_cpu(buf[AC2]); + calib->AC3 = be16_to_cpu(buf[AC3]); + calib->AC4 = be16_to_cpu(buf[AC4]); + calib->AC5 = be16_to_cpu(buf[AC5]); + calib->AC6 = be16_to_cpu(buf[AC6]); + calib->B1 = be16_to_cpu(buf[B1]); + calib->B2 = be16_to_cpu(buf[B2]); + calib->MB = be16_to_cpu(buf[MB]); + calib->MC = be16_to_cpu(buf[MC]); + calib->MD = be16_to_cpu(buf[MD]); + + return 0; +} + +/* + * Returns temperature in DegC, resolution is 0.1 DegC. + * t_fine carries fine temperature as global value. + * + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature". + */ +static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp) +{ + int ret; + s32 x1, x2; + struct bmp180_calib calib; + + ret = bmp180_read_calib(data, &calib); + if (ret < 0) { + dev_err(data->dev, + "failed to read calibration coefficients\n"); + return ret; + } + + x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15; + x2 = (calib.MC << 11) / (x1 + calib.MD); + data->t_fine = x1 + x2; + + return (data->t_fine + 8) >> 4; +} + +static int bmp180_read_temp(struct bmp280_data *data, int *val) +{ + int ret; + s32 adc_temp, comp_temp; + + ret = bmp180_read_adc_temp(data, &adc_temp); + if (ret) + return ret; + + comp_temp = bmp180_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) { + *val = comp_temp * 100; + return IIO_VAL_INT; + } + + return 0; +} + +static int bmp180_read_adc_press(struct bmp280_data *data, int *val) +{ + int ret; + __be32 tmp = 0; + u8 oss = data->oversampling_press; + + ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss)); + if (ret) + return ret; + + ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3); + if (ret) + return ret; + + *val = (be32_to_cpu(tmp) >> 8) >> (8 - oss); + + return 0; +} + +/* + * Returns pressure in Pa, resolution is 1 Pa. + * + * Taken from datasheet, Section 3.5, "Calculating pressure and temperature". + */ +static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press) +{ + int ret; + s32 x1, x2, x3, p; + s32 b3, b6; + u32 b4, b7; + s32 oss = data->oversampling_press; + struct bmp180_calib calib; + + ret = bmp180_read_calib(data, &calib); + if (ret < 0) { + dev_err(data->dev, + "failed to read calibration coefficients\n"); + return ret; + } + + b6 = data->t_fine - 4000; + x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11; + x2 = calib.AC2 * b6 >> 11; + x3 = x1 + x2; + b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4; + x1 = calib.AC3 * b6 >> 13; + x2 = (calib.B1 * ((b6 * b6) >> 12)) >> 16; + x3 = (x1 + x2 + 2) >> 2; + b4 = calib.AC4 * (u32)(x3 + 32768) >> 15; + b7 = ((u32)adc_press - b3) * (50000 >> oss); + if (b7 < 0x80000000) + p = (b7 * 2) / b4; + else + p = (b7 / b4) * 2; + + x1 = (p >> 8) * (p >> 8); + x1 = (x1 * 3038) >> 16; + x2 = (-7357 * p) >> 16; + + return p + ((x1 + x2 + 3791) >> 4); +} + +static int bmp180_read_press(struct bmp280_data *data, + int *val, int *val2) +{ + int ret; + s32 adc_press; + u32 comp_press; + + /* Read and compensate temperature so we get a reading of t_fine. */ + ret = bmp180_read_temp(data, NULL); + if (ret) + return ret; + + ret = bmp180_read_adc_press(data, &adc_press); + if (ret) + return ret; + + comp_press = bmp180_compensate_press(data, adc_press); + + *val = comp_press; + *val2 = 1000; + + return IIO_VAL_FRACTIONAL; +} + +static int bmp180_chip_config(struct bmp280_data *data) +{ + return 0; +} + +static const int bmp180_oversampling_temp_avail[] = { 1 }; +static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 }; + +static const struct bmp280_chip_info bmp180_chip_info = { + .oversampling_temp_avail = bmp180_oversampling_temp_avail, + .num_oversampling_temp_avail = + ARRAY_SIZE(bmp180_oversampling_temp_avail), + + .oversampling_press_avail = bmp180_oversampling_press_avail, + .num_oversampling_press_avail = + ARRAY_SIZE(bmp180_oversampling_press_avail), + + .chip_config = bmp180_chip_config, + .read_temp = bmp180_read_temp, + .read_press = bmp180_read_press, +}; + +int bmp280_common_probe(struct device *dev, + struct regmap *regmap, + unsigned int chip, + const char *name) +{ + int ret; + struct iio_dev *indio_dev; + struct bmp280_data *data; + unsigned int chip_id; + struct gpio_desc *gpiod; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + mutex_init(&data->lock); + data->dev = dev; + + indio_dev->dev.parent = dev; + indio_dev->name = name; + indio_dev->channels = bmp280_channels; + indio_dev->info = &bmp280_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + switch (chip) { + case BMP180_CHIP_ID: + indio_dev->num_channels = 2; + data->chip_info = &bmp180_chip_info; + data->oversampling_press = ilog2(8); + data->oversampling_temp = ilog2(1); + data->start_up_time = 10; + break; + case BMP280_CHIP_ID: + indio_dev->num_channels = 2; + data->chip_info = &bmp280_chip_info; + data->oversampling_press = ilog2(16); + data->oversampling_temp = ilog2(2); + data->start_up_time = 2; + break; + case BME280_CHIP_ID: + indio_dev->num_channels = 3; + data->chip_info = &bme280_chip_info; + data->oversampling_press = ilog2(16); + data->oversampling_humid = ilog2(16); + data->oversampling_temp = ilog2(2); + data->start_up_time = 2; + break; + default: + return -EINVAL; + } + + /* Bring up regulators */ + data->vddd = devm_regulator_get(dev, "vddd"); + if (IS_ERR(data->vddd)) { + dev_err(dev, "failed to get VDDD regulator\n"); + return PTR_ERR(data->vddd); + } + ret = regulator_enable(data->vddd); + if (ret) { + dev_err(dev, "failed to enable VDDD regulator\n"); + return ret; + } + data->vdda = devm_regulator_get(dev, "vdda"); + if (IS_ERR(data->vdda)) { + dev_err(dev, "failed to get VDDA regulator\n"); + ret = PTR_ERR(data->vddd); + goto out_disable_vddd; + } + ret = regulator_enable(data->vdda); + if (ret) { + dev_err(dev, "failed to enable VDDA regulator\n"); + goto out_disable_vddd; + } + /* Wait to make sure we started up properly */ + mdelay(data->start_up_time); + + /* Bring chip out of reset if there is an assigned GPIO line */ + gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH); + /* Deassert the signal */ + if (!IS_ERR(gpiod)) { + dev_info(dev, "release reset\n"); + gpiod_set_value(gpiod, 0); + } + + data->regmap = regmap; + ret = regmap_read(regmap, BMP280_REG_ID, &chip_id); + if (ret < 0) + goto out_disable_vdda; + if (chip_id != chip) { + dev_err(dev, "bad chip id: expected %x got %x\n", + chip, chip_id); + ret = -EINVAL; + goto out_disable_vdda; + } + + ret = data->chip_info->chip_config(data); + if (ret < 0) + goto out_disable_vdda; + + dev_set_drvdata(dev, indio_dev); + + ret = iio_device_register(indio_dev); + if (ret) + goto out_disable_vdda; + + return 0; + +out_disable_vdda: + regulator_disable(data->vdda); +out_disable_vddd: + regulator_disable(data->vddd); + return ret; +} + +int bmp280_common_remove(struct device *dev) +{ + struct iio_dev *indio_dev = dev_get_drvdata(dev); + struct bmp280_data *data = iio_priv(indio_dev); + + iio_device_unregister(indio_dev); + regulator_disable(data->vdda); + regulator_disable(data->vddd); + return 0; +} |