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62979904b0
This adds ability to control the oversampling ratio of the temperature and pressure measurement for both bmp180 and bmp280. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Vlad Dogaru <vlad.dogaru@intel.com> Cc: Christoph Mair <christoph.mair@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
923 lines
22 KiB
C
923 lines
22 KiB
C
/*
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* Copyright (c) 2014 Intel Corporation
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*
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* Driver for Bosch Sensortec BMP180 and BMP280 digital pressure sensor.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Datasheet:
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* https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP180-DS000-121.pdf
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* https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BMP280-DS001-12.pdf
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*/
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#define pr_fmt(fmt) "bmp280: " fmt
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#include <linux/module.h>
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#include <linux/i2c.h>
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#include <linux/acpi.h>
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#include <linux/regmap.h>
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#include <linux/delay.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/sysfs.h>
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/* BMP280 specific registers */
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#define BMP280_REG_TEMP_XLSB 0xFC
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#define BMP280_REG_TEMP_LSB 0xFB
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#define BMP280_REG_TEMP_MSB 0xFA
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#define BMP280_REG_PRESS_XLSB 0xF9
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#define BMP280_REG_PRESS_LSB 0xF8
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#define BMP280_REG_PRESS_MSB 0xF7
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#define BMP280_REG_CONFIG 0xF5
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#define BMP280_REG_STATUS 0xF3
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#define BMP280_REG_COMP_TEMP_START 0x88
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#define BMP280_COMP_TEMP_REG_COUNT 6
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#define BMP280_REG_COMP_PRESS_START 0x8E
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#define BMP280_COMP_PRESS_REG_COUNT 18
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#define BMP280_FILTER_MASK (BIT(4) | BIT(3) | BIT(2))
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#define BMP280_FILTER_OFF 0
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#define BMP280_FILTER_2X BIT(2)
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#define BMP280_FILTER_4X BIT(3)
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#define BMP280_FILTER_8X (BIT(3) | BIT(2))
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#define BMP280_FILTER_16X BIT(4)
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#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5))
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#define BMP280_OSRS_TEMP_SKIP 0
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#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5)
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#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1)
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#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2)
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#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3)
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#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4)
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#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5)
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#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2))
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#define BMP280_OSRS_PRESS_SKIP 0
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#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2)
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#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1)
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#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2)
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#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3)
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#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4)
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#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5)
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#define BMP280_MODE_MASK (BIT(1) | BIT(0))
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#define BMP280_MODE_SLEEP 0
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#define BMP280_MODE_FORCED BIT(0)
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#define BMP280_MODE_NORMAL (BIT(1) | BIT(0))
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/* BMP180 specific registers */
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#define BMP180_REG_OUT_XLSB 0xF8
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#define BMP180_REG_OUT_LSB 0xF7
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#define BMP180_REG_OUT_MSB 0xF6
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#define BMP180_REG_CALIB_START 0xAA
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#define BMP180_REG_CALIB_COUNT 22
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#define BMP180_MEAS_SCO BIT(5)
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#define BMP180_MEAS_TEMP (0x0E | BMP180_MEAS_SCO)
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#define BMP180_MEAS_PRESS_X(oss) ((oss) << 6 | 0x14 | BMP180_MEAS_SCO)
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#define BMP180_MEAS_PRESS_1X BMP180_MEAS_PRESS_X(0)
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#define BMP180_MEAS_PRESS_2X BMP180_MEAS_PRESS_X(1)
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#define BMP180_MEAS_PRESS_4X BMP180_MEAS_PRESS_X(2)
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#define BMP180_MEAS_PRESS_8X BMP180_MEAS_PRESS_X(3)
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/* BMP180 and BMP280 common registers */
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#define BMP280_REG_CTRL_MEAS 0xF4
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#define BMP280_REG_RESET 0xE0
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#define BMP280_REG_ID 0xD0
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#define BMP180_CHIP_ID 0x55
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#define BMP280_CHIP_ID 0x58
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#define BMP280_SOFT_RESET_VAL 0xB6
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struct bmp280_data {
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struct i2c_client *client;
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struct mutex lock;
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struct regmap *regmap;
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const struct bmp280_chip_info *chip_info;
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/* log of base 2 of oversampling rate */
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u8 oversampling_press;
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u8 oversampling_temp;
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/*
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* Carryover value from temperature conversion, used in pressure
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* calculation.
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*/
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s32 t_fine;
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};
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struct bmp280_chip_info {
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const struct regmap_config *regmap_config;
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const int *oversampling_temp_avail;
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int num_oversampling_temp_avail;
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const int *oversampling_press_avail;
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int num_oversampling_press_avail;
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int (*chip_config)(struct bmp280_data *);
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int (*read_temp)(struct bmp280_data *, int *);
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int (*read_press)(struct bmp280_data *, int *, int *);
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};
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/*
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* These enums are used for indexing into the array of compensation
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* parameters for BMP280.
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*/
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enum { T1, T2, T3 };
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enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
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static const struct iio_chan_spec bmp280_channels[] = {
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{
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.type = IIO_PRESSURE,
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
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BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
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},
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{
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.type = IIO_TEMP,
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.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
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BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
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},
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};
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static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case BMP280_REG_CONFIG:
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case BMP280_REG_CTRL_MEAS:
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case BMP280_REG_RESET:
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return true;
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default:
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return false;
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};
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}
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static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case BMP280_REG_TEMP_XLSB:
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case BMP280_REG_TEMP_LSB:
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case BMP280_REG_TEMP_MSB:
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case BMP280_REG_PRESS_XLSB:
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case BMP280_REG_PRESS_LSB:
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case BMP280_REG_PRESS_MSB:
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case BMP280_REG_STATUS:
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return true;
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default:
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return false;
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}
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}
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static const struct regmap_config bmp280_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = BMP280_REG_TEMP_XLSB,
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.cache_type = REGCACHE_RBTREE,
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.writeable_reg = bmp280_is_writeable_reg,
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.volatile_reg = bmp280_is_volatile_reg,
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};
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/*
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* Returns temperature in DegC, resolution is 0.01 DegC. Output value of
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* "5123" equals 51.23 DegC. t_fine carries fine temperature as global
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* value.
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*
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* Taken from datasheet, Section 3.11.3, "Compensation formula".
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*/
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static s32 bmp280_compensate_temp(struct bmp280_data *data,
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s32 adc_temp)
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{
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int ret;
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s32 var1, var2;
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__le16 buf[BMP280_COMP_TEMP_REG_COUNT / 2];
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ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_TEMP_START,
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buf, BMP280_COMP_TEMP_REG_COUNT);
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if (ret < 0) {
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dev_err(&data->client->dev,
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"failed to read temperature calibration parameters\n");
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return ret;
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}
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/*
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* The double casts are necessary because le16_to_cpu returns an
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* unsigned 16-bit value. Casting that value directly to a
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* signed 32-bit will not do proper sign extension.
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*
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* Conversely, T1 and P1 are unsigned values, so they can be
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* cast straight to the larger type.
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*/
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var1 = (((adc_temp >> 3) - ((s32)le16_to_cpu(buf[T1]) << 1)) *
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((s32)(s16)le16_to_cpu(buf[T2]))) >> 11;
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var2 = (((((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1]))) *
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((adc_temp >> 4) - ((s32)le16_to_cpu(buf[T1])))) >> 12) *
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((s32)(s16)le16_to_cpu(buf[T3]))) >> 14;
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data->t_fine = var1 + var2;
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return (data->t_fine * 5 + 128) >> 8;
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}
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/*
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* Returns pressure in Pa as unsigned 32 bit integer in Q24.8 format (24
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* integer bits and 8 fractional bits). Output value of "24674867"
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* represents 24674867/256 = 96386.2 Pa = 963.862 hPa
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*
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* Taken from datasheet, Section 3.11.3, "Compensation formula".
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*/
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static u32 bmp280_compensate_press(struct bmp280_data *data,
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s32 adc_press)
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{
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int ret;
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s64 var1, var2, p;
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__le16 buf[BMP280_COMP_PRESS_REG_COUNT / 2];
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ret = regmap_bulk_read(data->regmap, BMP280_REG_COMP_PRESS_START,
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buf, BMP280_COMP_PRESS_REG_COUNT);
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if (ret < 0) {
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dev_err(&data->client->dev,
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"failed to read pressure calibration parameters\n");
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return ret;
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}
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var1 = ((s64)data->t_fine) - 128000;
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var2 = var1 * var1 * (s64)(s16)le16_to_cpu(buf[P6]);
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var2 += (var1 * (s64)(s16)le16_to_cpu(buf[P5])) << 17;
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var2 += ((s64)(s16)le16_to_cpu(buf[P4])) << 35;
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var1 = ((var1 * var1 * (s64)(s16)le16_to_cpu(buf[P3])) >> 8) +
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((var1 * (s64)(s16)le16_to_cpu(buf[P2])) << 12);
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var1 = ((((s64)1) << 47) + var1) * ((s64)le16_to_cpu(buf[P1])) >> 33;
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if (var1 == 0)
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return 0;
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p = ((((s64)1048576 - adc_press) << 31) - var2) * 3125;
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p = div64_s64(p, var1);
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var1 = (((s64)(s16)le16_to_cpu(buf[P9])) * (p >> 13) * (p >> 13)) >> 25;
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var2 = (((s64)(s16)le16_to_cpu(buf[P8])) * p) >> 19;
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p = ((p + var1 + var2) >> 8) + (((s64)(s16)le16_to_cpu(buf[P7])) << 4);
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return (u32)p;
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}
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static int bmp280_read_temp(struct bmp280_data *data,
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int *val)
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{
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int ret;
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__be32 tmp = 0;
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s32 adc_temp, comp_temp;
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ret = regmap_bulk_read(data->regmap, BMP280_REG_TEMP_MSB,
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(u8 *) &tmp, 3);
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if (ret < 0) {
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dev_err(&data->client->dev, "failed to read temperature\n");
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return ret;
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}
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adc_temp = be32_to_cpu(tmp) >> 12;
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comp_temp = bmp280_compensate_temp(data, adc_temp);
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/*
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* val might be NULL if we're called by the read_press routine,
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* who only cares about the carry over t_fine value.
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*/
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if (val) {
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*val = comp_temp * 10;
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return IIO_VAL_INT;
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}
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return 0;
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}
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static int bmp280_read_press(struct bmp280_data *data,
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int *val, int *val2)
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{
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int ret;
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__be32 tmp = 0;
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s32 adc_press;
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u32 comp_press;
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/* Read and compensate temperature so we get a reading of t_fine. */
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ret = bmp280_read_temp(data, NULL);
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if (ret < 0)
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return ret;
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ret = regmap_bulk_read(data->regmap, BMP280_REG_PRESS_MSB,
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(u8 *) &tmp, 3);
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if (ret < 0) {
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dev_err(&data->client->dev, "failed to read pressure\n");
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return ret;
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}
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adc_press = be32_to_cpu(tmp) >> 12;
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comp_press = bmp280_compensate_press(data, adc_press);
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*val = comp_press;
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*val2 = 256000;
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return IIO_VAL_FRACTIONAL;
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}
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static int bmp280_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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int ret;
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struct bmp280_data *data = iio_priv(indio_dev);
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mutex_lock(&data->lock);
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switch (mask) {
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case IIO_CHAN_INFO_PROCESSED:
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switch (chan->type) {
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case IIO_PRESSURE:
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ret = data->chip_info->read_press(data, val, val2);
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break;
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case IIO_TEMP:
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ret = data->chip_info->read_temp(data, val);
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break;
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default:
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ret = -EINVAL;
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break;
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}
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break;
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case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
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switch (chan->type) {
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case IIO_PRESSURE:
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*val = 1 << data->oversampling_press;
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ret = IIO_VAL_INT;
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break;
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case IIO_TEMP:
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*val = 1 << data->oversampling_temp;
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ret = IIO_VAL_INT;
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break;
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default:
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ret = -EINVAL;
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break;
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}
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break;
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default:
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ret = -EINVAL;
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break;
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}
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mutex_unlock(&data->lock);
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return ret;
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}
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static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
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int val)
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{
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int i;
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const int *avail = data->chip_info->oversampling_temp_avail;
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const int n = data->chip_info->num_oversampling_temp_avail;
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for (i = 0; i < n; i++) {
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if (avail[i] == val) {
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data->oversampling_temp = ilog2(val);
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return data->chip_info->chip_config(data);
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}
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}
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return -EINVAL;
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}
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static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
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int val)
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{
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int i;
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const int *avail = data->chip_info->oversampling_press_avail;
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const int n = data->chip_info->num_oversampling_press_avail;
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for (i = 0; i < n; i++) {
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if (avail[i] == val) {
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data->oversampling_press = ilog2(val);
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return data->chip_info->chip_config(data);
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}
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}
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return -EINVAL;
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}
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static int bmp280_write_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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int ret = 0;
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struct bmp280_data *data = iio_priv(indio_dev);
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switch (mask) {
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case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
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mutex_lock(&data->lock);
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switch (chan->type) {
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case IIO_PRESSURE:
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ret = bmp280_write_oversampling_ratio_press(data, val);
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break;
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case IIO_TEMP:
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ret = bmp280_write_oversampling_ratio_temp(data, val);
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break;
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default:
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ret = -EINVAL;
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break;
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}
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mutex_unlock(&data->lock);
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break;
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default:
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return -EINVAL;
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}
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return ret;
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}
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static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
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{
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size_t len = 0;
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int i;
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for (i = 0; i < n; i++)
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len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
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buf[len - 1] = '\n';
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return len;
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}
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static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
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return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
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data->chip_info->num_oversampling_temp_avail);
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}
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static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
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return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
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data->chip_info->num_oversampling_press_avail);
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}
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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;
|
|
}
|
|
|
|
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 %x got %x\n",
|
|
BMP280_CHIP_ID, 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");
|