iio: pressure: bmp280: add support for BMP180
This adds support for the BMP180 to the bmp280 iio driver. The BMP180 has already been supported by misc/bmp085 driver but it doesn't use iio framework. This change adds the kconfig dependency not to be selected both of them in order to avoid any issues. 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>
This commit is contained in:
Akinobu Mita
Jonathan Cameron
parent
06ad7ea10e
commit
6dba72eca7
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@ -6,12 +6,13 @@
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menu "Pressure sensors"
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config BMP280
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tristate "Bosch Sensortec BMP280 pressure sensor driver"
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tristate "Bosch Sensortec BMP180 and BMP280 pressure sensor driver"
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depends on I2C
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depends on !(BMP085_I2C=y || BMP085_I2C=m)
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select REGMAP_I2C
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help
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Say yes here to build support for Bosch Sensortec BMP280
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pressure and temperature sensor.
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Say yes here to build support for Bosch Sensortec BMP180 and BMP280
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pressure and temperature sensors.
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To compile this driver as a module, choose M here: the module
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will be called bmp280.
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@ -1,12 +1,15 @@
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/*
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* Copyright (c) 2014 Intel Corporation
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*
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* Driver for Bosch Sensortec BMP280 digital pressure sensor.
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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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@ -15,9 +18,11 @@
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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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@ -26,10 +31,7 @@
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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_CTRL_MEAS 0xF4
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#define BMP280_REG_STATUS 0xF3
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#define BMP280_REG_RESET 0xE0
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#define BMP280_REG_ID 0xD0
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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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@ -65,6 +67,28 @@
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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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@ -72,6 +96,7 @@ 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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/*
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* Carryover value from temperature conversion, used in pressure
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@ -80,9 +105,17 @@ struct bmp280_data {
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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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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.
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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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@ -290,10 +323,10 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
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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 = bmp280_read_press(data, val, val2);
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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 = bmp280_read_temp(data, val);
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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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@ -315,7 +348,7 @@ static const struct iio_info bmp280_info = {
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.read_raw = &bmp280_read_raw,
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};
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static int bmp280_chip_init(struct bmp280_data *data)
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static int bmp280_chip_config(struct bmp280_data *data)
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{
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int ret;
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@ -344,6 +377,296 @@ static int bmp280_chip_init(struct bmp280_data *data)
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return ret;
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}
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static const struct bmp280_chip_info bmp280_chip_info = {
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.regmap_config = &bmp280_regmap_config,
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.chip_config = bmp280_chip_config,
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.read_temp = bmp280_read_temp,
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.read_press = bmp280_read_press,
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};
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static bool bmp180_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_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 bmp180_is_volatile_reg(struct device *dev, unsigned int reg)
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{
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switch (reg) {
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case BMP180_REG_OUT_XLSB:
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case BMP180_REG_OUT_LSB:
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case BMP180_REG_OUT_MSB:
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case BMP280_REG_CTRL_MEAS:
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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 bmp180_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = BMP180_REG_OUT_XLSB,
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.cache_type = REGCACHE_RBTREE,
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.writeable_reg = bmp180_is_writeable_reg,
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.volatile_reg = bmp180_is_volatile_reg,
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};
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static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
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{
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int ret;
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const int conversion_time_max[] = { 4500, 7500, 13500, 25500 };
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unsigned int delay_us;
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unsigned int ctrl;
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ret = regmap_write(data->regmap, BMP280_REG_CTRL_MEAS, ctrl_meas);
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if (ret)
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return ret;
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if (ctrl_meas == BMP180_MEAS_TEMP)
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delay_us = 4500;
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else
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delay_us = conversion_time_max[ilog2(8)];
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usleep_range(delay_us, delay_us + 1000);
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ret = regmap_read(data->regmap, BMP280_REG_CTRL_MEAS, &ctrl);
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if (ret)
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return ret;
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/* The value of this bit reset to "0" after conversion is complete */
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if (ctrl & BMP180_MEAS_SCO)
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return -EIO;
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return 0;
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}
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static int bmp180_read_adc_temp(struct bmp280_data *data, int *val)
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{
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int ret;
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__be16 tmp = 0;
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ret = bmp180_measure(data, BMP180_MEAS_TEMP);
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if (ret)
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return ret;
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ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 2);
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if (ret)
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return ret;
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*val = be16_to_cpu(tmp);
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return 0;
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}
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/*
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* These enums are used for indexing into the array of calibration
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* coefficients for BMP180.
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*/
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enum { AC1, AC2, AC3, AC4, AC5, AC6, B1, B2, MB, MC, MD };
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struct bmp180_calib {
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s16 AC1;
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s16 AC2;
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s16 AC3;
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u16 AC4;
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u16 AC5;
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u16 AC6;
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s16 B1;
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s16 B2;
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s16 MB;
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s16 MC;
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s16 MD;
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};
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static int bmp180_read_calib(struct bmp280_data *data,
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struct bmp180_calib *calib)
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{
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int ret;
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int i;
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__be16 buf[BMP180_REG_CALIB_COUNT / 2];
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ret = regmap_bulk_read(data->regmap, BMP180_REG_CALIB_START, buf,
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sizeof(buf));
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if (ret < 0)
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return ret;
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/* None of the words has the value 0 or 0xFFFF */
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for (i = 0; i < ARRAY_SIZE(buf); i++) {
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if (buf[i] == cpu_to_be16(0) || buf[i] == cpu_to_be16(0xffff))
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return -EIO;
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}
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calib->AC1 = be16_to_cpu(buf[AC1]);
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calib->AC2 = be16_to_cpu(buf[AC2]);
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calib->AC3 = be16_to_cpu(buf[AC3]);
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calib->AC4 = be16_to_cpu(buf[AC4]);
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calib->AC5 = be16_to_cpu(buf[AC5]);
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calib->AC6 = be16_to_cpu(buf[AC6]);
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calib->B1 = be16_to_cpu(buf[B1]);
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calib->B2 = be16_to_cpu(buf[B2]);
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calib->MB = be16_to_cpu(buf[MB]);
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calib->MC = be16_to_cpu(buf[MC]);
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calib->MD = be16_to_cpu(buf[MD]);
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return 0;
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}
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/*
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* Returns temperature in DegC, resolution is 0.1 DegC.
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* t_fine carries fine temperature as global value.
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*
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* Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
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*/
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static s32 bmp180_compensate_temp(struct bmp280_data *data, s32 adc_temp)
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{
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int ret;
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s32 x1, x2;
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struct bmp180_calib calib;
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ret = bmp180_read_calib(data, &calib);
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if (ret < 0) {
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dev_err(&data->client->dev,
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"failed to read calibration coefficients\n");
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return ret;
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}
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x1 = ((adc_temp - calib.AC6) * calib.AC5) >> 15;
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x2 = (calib.MC << 11) / (x1 + calib.MD);
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data->t_fine = x1 + x2;
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return (data->t_fine + 8) >> 4;
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}
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static int bmp180_read_temp(struct bmp280_data *data, int *val)
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{
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int ret;
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s32 adc_temp, comp_temp;
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ret = bmp180_read_adc_temp(data, &adc_temp);
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if (ret)
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return ret;
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comp_temp = bmp180_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 * 100;
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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 bmp180_read_adc_press(struct bmp280_data *data, int *val)
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{
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int ret;
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__be32 tmp = 0;
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u8 oss = ilog2(8);
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ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
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if (ret)
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return ret;
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ret = regmap_bulk_read(data->regmap, BMP180_REG_OUT_MSB, (u8 *)&tmp, 3);
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if (ret)
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return ret;
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*val = (be32_to_cpu(tmp) >> 8) >> (8 - oss);
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return 0;
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}
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/*
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* Returns pressure in Pa, resolution is 1 Pa.
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*
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* Taken from datasheet, Section 3.5, "Calculating pressure and temperature".
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*/
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static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
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{
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int ret;
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s32 x1, x2, x3, p;
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s32 b3, b6;
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u32 b4, b7;
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s32 oss = ilog2(8);
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struct bmp180_calib calib;
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ret = bmp180_read_calib(data, &calib);
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if (ret < 0) {
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dev_err(&data->client->dev,
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"failed to read calibration coefficients\n");
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return ret;
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}
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b6 = data->t_fine - 4000;
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x1 = (calib.B2 * (b6 * b6 >> 12)) >> 11;
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x2 = calib.AC2 * b6 >> 11;
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x3 = x1 + x2;
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b3 = ((((s32)calib.AC1 * 4 + x3) << oss) + 2) / 4;
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x1 = calib.AC3 * b6 >> 13;
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x2 = (calib.B1 * ((b6 * b6) >> 12)) >> 16;
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x3 = (x1 + x2 + 2) >> 2;
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b4 = calib.AC4 * (u32)(x3 + 32768) >> 15;
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b7 = ((u32)adc_press - b3) * (50000 >> oss);
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if (b7 < 0x80000000)
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p = (b7 * 2) / b4;
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else
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p = (b7 / b4) * 2;
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x1 = (p >> 8) * (p >> 8);
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x1 = (x1 * 3038) >> 16;
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x2 = (-7357 * p) >> 16;
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return p + ((x1 + x2 + 3791) >> 4);
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}
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static int bmp180_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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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 = bmp180_read_temp(data, NULL);
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if (ret)
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return ret;
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ret = bmp180_read_adc_press(data, &adc_press);
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if (ret)
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return ret;
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comp_press = bmp180_compensate_press(data, adc_press);
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*val = comp_press;
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*val2 = 1000;
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return IIO_VAL_FRACTIONAL;
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}
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static int bmp180_chip_config(struct bmp280_data *data)
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{
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return 0;
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}
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static const struct bmp280_chip_info bmp180_chip_info = {
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.regmap_config = &bmp180_regmap_config,
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.chip_config = bmp180_chip_config,
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.read_temp = bmp180_read_temp,
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.read_press = bmp180_read_press,
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};
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static int bmp280_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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@ -367,7 +690,19 @@ static int bmp280_probe(struct i2c_client *client,
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indio_dev->info = &bmp280_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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data->regmap = devm_regmap_init_i2c(client, &bmp280_regmap_config);
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switch (id->driver_data) {
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case BMP180_CHIP_ID:
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data->chip_info = &bmp180_chip_info;
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break;
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case BMP280_CHIP_ID:
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data->chip_info = &bmp280_chip_info;
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break;
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default:
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return -EINVAL;
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}
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data->regmap = devm_regmap_init_i2c(client,
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data->chip_info->regmap_config);
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if (IS_ERR(data->regmap)) {
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dev_err(&client->dev, "failed to allocate register map\n");
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return PTR_ERR(data->regmap);
|
||||
|
|
@ -376,13 +711,13 @@ static int bmp280_probe(struct i2c_client *client,
|
|||
ret = regmap_read(data->regmap, BMP280_REG_ID, &chip_id);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
if (chip_id != BMP280_CHIP_ID) {
|
||||
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 = bmp280_chip_init(data);
|
||||
ret = data->chip_info->chip_config(data);
|
||||
if (ret < 0)
|
||||
return ret;
|
||||
|
||||
|
|
@ -390,13 +725,17 @@ static int bmp280_probe(struct i2c_client *client,
|
|||
}
|
||||
|
||||
static const struct acpi_device_id bmp280_acpi_match[] = {
|
||||
{"BMP0280", 0},
|
||||
{"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", 0},
|
||||
{"bmp280", BMP280_CHIP_ID },
|
||||
{"bmp180", BMP180_CHIP_ID },
|
||||
{"bmp085", BMP180_CHIP_ID },
|
||||
{ },
|
||||
};
|
||||
MODULE_DEVICE_TABLE(i2c, bmp280_id);
|
||||
|
|
@ -412,5 +751,5 @@ static struct i2c_driver bmp280_driver = {
|
|||
module_i2c_driver(bmp280_driver);
|
||||
|
||||
MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
|
||||
MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP280 pressure and temperature sensor");
|
||||
MODULE_DESCRIPTION("Driver for Bosch Sensortec BMP180/BMP280 pressure and temperature sensor");
|
||||
MODULE_LICENSE("GPL v2");
|
||||
|
|
|
|||
Loading…
Reference in a new issue