iio: add bmp280 pressure and temperature driver (d5c94568) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/iio/pressure/Kconfig

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		@@ -5,6 +5,17 @@

		menu "Pressure sensors"

		config BMP280
		tristate "Bosch Sensortec BMP280 pressure sensor driver"
		depends on I2C
		select REGMAP_I2C
		help
		Say yes here to build support for Bosch Sensortec BMP280
		pressure and temperature sensor.

		To compile this driver as a module, choose M here: the module
		will be called bmp280.

		config HID_SENSOR_PRESS
		depends on HID_SENSOR_HUB
		select IIO_BUFFER

drivers/iio/pressure/Makefile

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		@@ -3,6 +3,7 @@
		#

		# When adding new entries keep the list in alphabetical order
		obj-$(CONFIG_BMP280) += bmp280.o
		obj-$(CONFIG_HID_SENSOR_PRESS) += hid-sensor-press.o
		obj-$(CONFIG_MPL115) += mpl115.o
		obj-$(CONFIG_MPL3115) += mpl3115.o

drivers/iio/pressure/bmp280.c

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		/*
		* Copyright (c) 2014 Intel Corporation
		*
		* Driver for Bosch Sensortec 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.
		*
		*/

		#define pr_fmt(fmt) "bmp280: " fmt

		#include <linux/module.h>
		#include <linux/i2c.h>
		#include <linux/acpi.h>
		#include <linux/regmap.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>

		#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_CTRL_MEAS 0xF4
		#define BMP280_REG_STATUS 0xF3
		#define BMP280_REG_RESET 0xE0
		#define BMP280_REG_ID 0xD0

		#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_1X BIT(5)
		#define BMP280_OSRS_TEMP_2X BIT(6)
		#define BMP280_OSRS_TEMP_4X (BIT(6) \| BIT(5))
		#define BMP280_OSRS_TEMP_8X BIT(7)
		#define BMP280_OSRS_TEMP_16X (BIT(7) \| BIT(5))

		#define BMP280_OSRS_PRESS_MASK (BIT(4) \| BIT(3) \| BIT(2))
		#define BMP280_OSRS_PRESS_SKIP 0
		#define BMP280_OSRS_PRESS_1X BIT(2)
		#define BMP280_OSRS_PRESS_2X BIT(3)
		#define BMP280_OSRS_PRESS_4X (BIT(3) \| BIT(2))
		#define BMP280_OSRS_PRESS_8X BIT(4)
		#define BMP280_OSRS_PRESS_16X (BIT(4) \| BIT(2))

		#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))

		#define BMP280_CHIP_ID 0x58
		#define BMP280_SOFT_RESET_VAL 0xB6

		struct bmp280_data {
		struct i2c_client *client;
		struct mutex lock;
		struct regmap *regmap;

		/*
		* Carryover value from temperature conversion, used in pressure
		* calculation.
		*/
		s32 t_fine;
		};

		/* Compensation parameters. */
		struct bmp280_comp_temp {
		u16 dig_t1;
		s16 dig_t2, dig_t3;
		};

		struct bmp280_comp_press {
		u16 dig_p1;
		s16 dig_p2, dig_p3, dig_p4, dig_p5, dig_p6, dig_p7, dig_p8, dig_p9;
		};

		static const struct iio_chan_spec bmp280_channels[] = {
		{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		},
		{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		},
		};

		static bool bmp280_is_writeable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case BMP280_REG_CONFIG:
		case BMP280_REG_CTRL_MEAS:
		case BMP280_REG_RESET:
		return true;
		default:
		return false;
		};
		}

		static bool bmp280_is_volatile_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case BMP280_REG_TEMP_XLSB:
		case BMP280_REG_TEMP_LSB:
		case BMP280_REG_TEMP_MSB:
		case BMP280_REG_PRESS_XLSB:
		case BMP280_REG_PRESS_LSB:
		case BMP280_REG_PRESS_MSB:
		case BMP280_REG_STATUS:
		return true;
		default:
		return false;
		}
		}

		static const struct regmap_config bmp280_regmap_config = {
		.reg_bits = 8,
		.val_bits = 8,

		.max_register = BMP280_REG_TEMP_XLSB,
		.cache_type = REGCACHE_RBTREE,

		.writeable_reg = bmp280_is_writeable_reg,
		.volatile_reg = bmp280_is_volatile_reg,
		};

		static int bmp280_read_compensation_temp(struct bmp280_data *data,
		struct bmp280_comp_temp *comp)
		{
		int ret;
		__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;
		}

		comp->dig_t1 = (u16) le16_to_cpu(buf[0]);
		comp->dig_t2 = (s16) le16_to_cpu(buf[1]);
		comp->dig_t3 = (s16) le16_to_cpu(buf[2]);

		return 0;
		}

		static int bmp280_read_compensation_press(struct bmp280_data *data,
		struct bmp280_comp_press *comp)
		{
		int ret;
		__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;
		}

		comp->dig_p1 = (s16) le16_to_cpu(buf[0]);
		comp->dig_p2 = (u16) le16_to_cpu(buf[1]);
		comp->dig_p3 = (u16) le16_to_cpu(buf[2]);
		comp->dig_p4 = (u16) le16_to_cpu(buf[3]);
		comp->dig_p5 = (u16) le16_to_cpu(buf[4]);
		comp->dig_p6 = (u16) le16_to_cpu(buf[5]);
		comp->dig_p7 = (u16) le16_to_cpu(buf[6]);
		comp->dig_p8 = (u16) le16_to_cpu(buf[7]);
		comp->dig_p9 = (u16) le16_to_cpu(buf[8]);

		return 0;
		}

		/*
		* 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,
		struct bmp280_comp_temp *comp,
		s32 adc_temp)
		{
		s32 var1, var2, t;

		var1 = (((adc_temp >> 3) - ((s32) comp->dig_t1 << 1)) *
		((s32) comp->dig_t2)) >> 11;
		var2 = (((((adc_temp >> 4) - ((s32) comp->dig_t1)) *
		((adc_temp >> 4) - ((s32) comp->dig_t1))) >> 12) *
		((s32) comp->dig_t3)) >> 14;

		data->t_fine = var1 + var2;
		t = (data->t_fine * 5 + 128) >> 8;

		return t;
		}

		/*
		* 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,
		struct bmp280_comp_press *comp,
		s32 adc_press)
		{
		s64 var1, var2, p;

		var1 = ((s64) data->t_fine) - 128000;
		var2 = var1 * var1 * (s64) comp->dig_p6;
		var2 = var2 + ((var1 * (s64) comp->dig_p5) << 17);
		var2 = var2 + (((s64) comp->dig_p4) << 35);
		var1 = ((var1 * var1 * (s64) comp->dig_p3) >> 8) +
		((var1 * (s64) comp->dig_p2) << 12);
		var1 = (((((s64) 1) << 47) + var1)) * ((s64) comp->dig_p1) >> 33;

		if (var1 == 0)
		return 0;

		p = ((((s64) 1048576 - adc_press) << 31) - var2) * 3125;
		do_div(p, var1);
		var1 = (((s64) comp->dig_p9) * (p >> 13) * (p >> 13)) >> 25;
		var2 = (((s64) comp->dig_p8) * p) >> 19;
		p = ((p + var1 + var2) >> 8) + (((s64) comp->dig_p7) << 4);

		return (u32) p;
		}

		static int bmp280_read_temp(struct bmp280_data *data,
		int *val)
		{
		int ret;
		__be32 tmp = 0;
		s32 adc_temp, comp_temp;
		struct bmp280_comp_temp comp;

		ret = bmp280_read_compensation_temp(data, &comp);
		if (ret < 0)
		return ret;

		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, &comp, adc_temp);

		/*
		* val might be NULL if we're called by the read_press routine,
		* who only cares about the carry over t_fine value.
		*/
		if (val) {
		val = comp_temp 10;
		return IIO_VAL_INT;
		}

		return 0;
		}

		static int bmp280_read_press(struct bmp280_data *data,
		int val, int val2)
		{
		int ret;
		__be32 tmp = 0;
		s32 adc_press;
		u32 comp_press;
		struct bmp280_comp_press comp;

		ret = bmp280_read_compensation_press(data, &comp);
		if (ret < 0)
		return ret;

		/* 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, &comp, adc_press);

		*val = comp_press / 256000;
		val2 = comp_press 1000000 / 256000;

		return IIO_VAL_INT_PLUS_MICRO;
		}

		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 = bmp280_read_press(data, val, val2);
		break;
		case IIO_TEMP:
		ret = bmp280_read_temp(data, val);
		break;
		default:
		ret = -EINVAL;
		break;
		}
		break;
		default:
		ret = -EINVAL;
		break;
		}

		mutex_unlock(&data->lock);

		return ret;
		}

		static const struct iio_info bmp280_info = {
		.driver_module = THIS_MODULE,
		.read_raw = &bmp280_read_raw,
		};

		static int bmp280_chip_init(struct bmp280_data *data)
		{
		int ret;

		ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
		BMP280_OSRS_TEMP_MASK \|
		BMP280_OSRS_PRESS_MASK \|
		BMP280_MODE_MASK,
		BMP280_OSRS_TEMP_2X \|
		BMP280_OSRS_PRESS_16X \|
		BMP280_MODE_NORMAL);
		if (ret < 0) {
		dev_err(&data->client->dev,
		"failed to write config 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 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;

		i2c_set_clientdata(client, indio_dev);
		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;

		data->regmap = devm_regmap_init_i2c(client, &bmp280_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 != BMP280_CHIP_ID) {
		dev_err(&client->dev, "bad chip id. expected %x got %x\n",
		BMP280_CHIP_ID, chip_id);
		return -EINVAL;
		}

		ret = bmp280_chip_init(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", 0},
		{ },
		};
		MODULE_DEVICE_TABLE(acpi, bmp280_acpi_match);

		static const struct i2c_device_id bmp280_id[] = {
		{"bmp280", 0},
		{ },
		};
		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 BMP280 pressure and temperature sensor");
		MODULE_LICENSE("GPL v2");