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Release 4.7 drivers/iio/pressure/bmp280.c

/*
 * 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; }; }

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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; } }

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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; }

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/* * 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; }

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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; }

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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; }

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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; }

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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; }

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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; }

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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; }

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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; }

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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); }

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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); }

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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; }

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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; }; }

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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; } }

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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; }

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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; }

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/* * 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; }

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/* * 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; }

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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; }

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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; }

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/* * 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); }

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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; }

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static int bmp180_chip_config(struct bmp280_data *data) { return 0; }

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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); }

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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");

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