diff options
Diffstat (limited to 'drivers/iio/pressure/bmp280.c')
| -rw-r--r-- | drivers/iio/pressure/bmp280.c | 922 |
1 files changed, 0 insertions, 922 deletions
diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c deleted file mode 100644 index 724452d61..000000000 --- a/drivers/iio/pressure/bmp280.c +++ /dev/null @@ -1,922 +0,0 @@ -/* - * 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 - */ - -#define pr_fmt(fmt) "bmp280: " fmt - -#include <linux/module.h> -#include <linux/i2c.h> -#include <linux/acpi.h> -#include <linux/regmap.h> -#include <linux/delay.h> -#include <linux/iio/iio.h> -#include <linux/iio/sysfs.h> - -/* BMP280 specific registers */ -#define BMP280_REG_TEMP_XLSB 0xFC -#define BMP280_REG_TEMP_LSB 0xFB -#define BMP280_REG_TEMP_MSB 0xFA -#define BMP280_REG_PRESS_XLSB 0xF9 -#define BMP280_REG_PRESS_LSB 0xF8 -#define BMP280_REG_PRESS_MSB 0xF7 - -#define BMP280_REG_CONFIG 0xF5 -#define BMP280_REG_STATUS 0xF3 - -#define BMP280_REG_COMP_TEMP_START 0x88 -#define BMP280_COMP_TEMP_REG_COUNT 6 - -#define BMP280_REG_COMP_PRESS_START 0x8E -#define BMP280_COMP_PRESS_REG_COUNT 18 - -#define BMP280_FILTER_MASK (BIT(4) | BIT(3) | BIT(2)) -#define BMP280_FILTER_OFF 0 -#define BMP280_FILTER_2X BIT(2) -#define BMP280_FILTER_4X BIT(3) -#define BMP280_FILTER_8X (BIT(3) | BIT(2)) -#define BMP280_FILTER_16X BIT(4) - -#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5)) -#define BMP280_OSRS_TEMP_SKIP 0 -#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5) -#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1) -#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2) -#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3) -#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4) -#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5) - -#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2)) -#define BMP280_OSRS_PRESS_SKIP 0 -#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2) -#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1) -#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2) -#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3) -#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4) -#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5) - -#define BMP280_MODE_MASK (BIT(1) | BIT(0)) -#define BMP280_MODE_SLEEP 0 -#define BMP280_MODE_FORCED BIT(0) -#define BMP280_MODE_NORMAL (BIT(1) | BIT(0)) - -/* BMP180 specific registers */ -#define BMP180_REG_OUT_XLSB 0xF8 -#define BMP180_REG_OUT_LSB 0xF7 -#define BMP180_REG_OUT_MSB 0xF6 - -#define BMP180_REG_CALIB_START 0xAA -#define BMP180_REG_CALIB_COUNT 22 - -#define BMP180_MEAS_SCO BIT(5) -#define BMP180_MEAS_TEMP (0x0E | BMP180_MEAS_SCO) -#define BMP180_MEAS_PRESS_X(oss) ((oss) << 6 | 0x14 | BMP180_MEAS_SCO) -#define BMP180_MEAS_PRESS_1X BMP180_MEAS_PRESS_X(0) -#define BMP180_MEAS_PRESS_2X BMP180_MEAS_PRESS_X(1) -#define BMP180_MEAS_PRESS_4X BMP180_MEAS_PRESS_X(2) -#define BMP180_MEAS_PRESS_8X BMP180_MEAS_PRESS_X(3) - -/* BMP180 and BMP280 common registers */ -#define BMP280_REG_CTRL_MEAS 0xF4 -#define BMP280_REG_RESET 0xE0 -#define BMP280_REG_ID 0xD0 - -#define BMP180_CHIP_ID 0x55 -#define BMP280_CHIP_ID 0x58 -#define BMP280_SOFT_RESET_VAL 0xB6 - -struct bmp280_data { - struct i2c_client *client; - struct mutex lock; - struct regmap *regmap; - const struct bmp280_chip_info *chip_info; - - /* log of base 2 of oversampling rate */ - u8 oversampling_press; - u8 oversampling_temp; - - /* - * Carryover value from temperature conversion, used in pressure - * calculation. - */ - s32 t_fine; -}; - -struct bmp280_chip_info { - const struct regmap_config *regmap_config; - - const int *oversampling_temp_avail; - int num_oversampling_temp_avail; - - const int *oversampling_press_avail; - int num_oversampling_press_avail; - - int (*chip_config)(struct bmp280_data *); - int (*read_temp)(struct bmp280_data *, int *); - int (*read_press)(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), - }, -}; - -static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg) -{ - switch (reg) { - case BMP280_REG_CONFIG: - case BMP280_REG_CTRL_MEAS: - case BMP280_REG_RESET: - return true; - default: - return false; - }; -} - -static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg) -{ - switch (reg) { - case BMP280_REG_TEMP_XLSB: - case BMP280_REG_TEMP_LSB: - case BMP280_REG_TEMP_MSB: - case BMP280_REG_PRESS_XLSB: - case BMP280_REG_PRESS_LSB: - case BMP280_REG_PRESS_MSB: - case BMP280_REG_STATUS: - return true; - default: - return false; - } -} - -static const struct regmap_config bmp280_regmap_config = { - .reg_bits = 8, - .val_bits = 8, - - .max_register = BMP280_REG_TEMP_XLSB, - .cache_type = REGCACHE_RBTREE, - - .writeable_reg = bmp280_is_writeable_reg, - .volatile_reg = bmp280_is_volatile_reg, -}; - -/* - * 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->client->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->client->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->client->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->client->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_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_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_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_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_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->client->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->client->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 = { - .regmap_config = &bmp280_regmap_config, - - .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 bool bmp180_is_writeable_reg(struct device *dev, unsigned int reg) -{ - switch (reg) { - case BMP280_REG_CTRL_MEAS: - case BMP280_REG_RESET: - return true; - default: - return false; - }; -} - -static bool bmp180_is_volatile_reg(struct device *dev, unsigned int reg) -{ - switch (reg) { - case BMP180_REG_OUT_XLSB: - case BMP180_REG_OUT_LSB: - case BMP180_REG_OUT_MSB: - case BMP280_REG_CTRL_MEAS: - return true; - default: - return false; - } -} - -static const struct regmap_config bmp180_regmap_config = { - .reg_bits = 8, - .val_bits = 8, - - .max_register = BMP180_REG_OUT_XLSB, - .cache_type = REGCACHE_RBTREE, - - .writeable_reg = bmp180_is_writeable_reg, - .volatile_reg = bmp180_is_volatile_reg, -}; - -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->client->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->client->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 = { - .regmap_config = &bmp180_regmap_config, - - .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, -}; - -static int bmp280_probe(struct i2c_client *client, - const struct i2c_device_id *id) -{ - int ret; - struct iio_dev *indio_dev; - struct bmp280_data *data; - unsigned int chip_id; - - indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); - if (!indio_dev) - return -ENOMEM; - - data = iio_priv(indio_dev); - mutex_init(&data->lock); - data->client = client; - - indio_dev->dev.parent = &client->dev; - indio_dev->name = id->name; - indio_dev->channels = bmp280_channels; - indio_dev->num_channels = ARRAY_SIZE(bmp280_channels); - indio_dev->info = &bmp280_info; - indio_dev->modes = INDIO_DIRECT_MODE; - - switch (id->driver_data) { - case BMP180_CHIP_ID: - data->chip_info = &bmp180_chip_info; - data->oversampling_press = ilog2(8); - data->oversampling_temp = ilog2(1); - break; - case BMP280_CHIP_ID: - data->chip_info = &bmp280_chip_info; - data->oversampling_press = ilog2(16); - data->oversampling_temp = ilog2(2); - break; - default: - return -EINVAL; - } - - data->regmap = devm_regmap_init_i2c(client, - data->chip_info->regmap_config); - if (IS_ERR(data->regmap)) { - dev_err(&client->dev, "failed to allocate register map\n"); - return PTR_ERR(data->regmap); - } - - ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id); - if (ret < 0) - return ret; - if (chip_id != id->driver_data) { - dev_err(&client->dev, "bad chip id. expected %lx got %x\n", - id->driver_data, chip_id); - return -EINVAL; - } - - ret = data->chip_info->chip_config(data); - if (ret < 0) - return ret; - - return devm_iio_device_register(&client->dev, indio_dev); -} - -static const struct acpi_device_id bmp280_acpi_match[] = { - {"BMP0280", BMP280_CHIP_ID }, - {"BMP0180", BMP180_CHIP_ID }, - {"BMP0085", BMP180_CHIP_ID }, - { }, -}; -MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match); - -static const struct i2c_device_id bmp280_id[] = { - {"bmp280", BMP280_CHIP_ID }, - {"bmp180", BMP180_CHIP_ID }, - {"bmp085", BMP180_CHIP_ID }, - { }, -}; -MODULE_DEVICE_TABLE(i2c, bmp280_id); - -static struct i2c_driver bmp280_driver = { - .driver = { - .name = "bmp280", - .acpi_match_table = ACPI_PTR(bmp280_acpi_match), - }, - .probe = bmp280_probe, - .id_table = bmp280_id, -}; -module_i2c_driver(bmp280_driver); - -MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>"); -MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor"); -MODULE_LICENSE("GPL v2"); |