iio: accel: Add driver for the BMA400 (465c811f) · Commits · 戴 / test

MAINTAINERS

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		@@ -3064,6 +3064,13 @@ S: Supported
		F: drivers/net/bonding/
		F: include/uapi/linux/if_bonding.h

		BOSCH SENSORTEC BMA400 ACCELEROMETER IIO DRIVER
		M: Dan Robertson <dan@dlrobertson.com>
		L: linux-iio@vger.kernel.org
		S: Maintained
		F: drivers/iio/accel/bma400*
		F: Documentation/devicetree/bindings/iio/accel/bosch,bma400.yaml

		BPF (Safe dynamic programs and tools)
		M: Alexei Starovoitov <ast@kernel.org>
		M: Daniel Borkmann <daniel@iogearbox.net>

drivers/iio/accel/Kconfig

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		@@ -112,6 +112,22 @@ config BMA220
		To compile this driver as a module, choose M here: the
		module will be called bma220_spi.

		config BMA400
		tristate "Bosch BMA400 3-Axis Accelerometer Driver"
		select REGMAP
		select BMA400_I2C if I2C
		help
		Say Y here if you want to build a driver for the Bosch BMA400
		triaxial acceleration sensor.

		To compile this driver as a module, choose M here: the
		module will be called bma400_core and you will also get
		bma400_i2c if I2C is enabled.

		config BMA400_I2C
		tristate
		depends on BMA400

		config BMC150_ACCEL
		tristate "Bosch BMC150 Accelerometer Driver"
		select IIO_BUFFER

drivers/iio/accel/Makefile

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		@@ -14,6 +14,8 @@ obj-$(CONFIG_ADXL372_I2C) += adxl372_i2c.o
		obj-$(CONFIG_ADXL372_SPI) += adxl372_spi.o
		obj-$(CONFIG_BMA180) += bma180.o
		obj-$(CONFIG_BMA220) += bma220_spi.o
		obj-$(CONFIG_BMA400) += bma400_core.o
		obj-$(CONFIG_BMA400_I2C) += bma400_i2c.o
		obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
		obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
		obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o

drivers/iio/accel/bma400.h

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		/* SPDX-License-Identifier: GPL-2.0-only */
		/*
		* Register constants and other forward declarations needed by the bma400
		* sources.
		*
		* Copyright 2019 Dan Robertson <dan@dlrobertson.com>
		*/

		#ifndef _BMA400_H_
		#define _BMA400_H_

		#include <linux/bits.h>
		#include <linux/regmap.h>

		/*
		* Read-Only Registers
		*/

		/* Status and ID registers */
		#define BMA400_CHIP_ID_REG 0x00
		#define BMA400_ERR_REG 0x02
		#define BMA400_STATUS_REG 0x03

		/* Acceleration registers */
		#define BMA400_X_AXIS_LSB_REG 0x04
		#define BMA400_X_AXIS_MSB_REG 0x05
		#define BMA400_Y_AXIS_LSB_REG 0x06
		#define BMA400_Y_AXIS_MSB_REG 0x07
		#define BMA400_Z_AXIS_LSB_REG 0x08
		#define BMA400_Z_AXIS_MSB_REG 0x09

		/* Sensor time registers */
		#define BMA400_SENSOR_TIME0 0x0a
		#define BMA400_SENSOR_TIME1 0x0b
		#define BMA400_SENSOR_TIME2 0x0c

		/* Event and interrupt registers */
		#define BMA400_EVENT_REG 0x0d
		#define BMA400_INT_STAT0_REG 0x0e
		#define BMA400_INT_STAT1_REG 0x0f
		#define BMA400_INT_STAT2_REG 0x10

		/* Temperature register */
		#define BMA400_TEMP_DATA_REG 0x11

		/* FIFO length and data registers */
		#define BMA400_FIFO_LENGTH0_REG 0x12
		#define BMA400_FIFO_LENGTH1_REG 0x13
		#define BMA400_FIFO_DATA_REG 0x14

		/* Step count registers */
		#define BMA400_STEP_CNT0_REG 0x15
		#define BMA400_STEP_CNT1_REG 0x16
		#define BMA400_STEP_CNT3_REG 0x17
		#define BMA400_STEP_STAT_REG 0x18

		/*
		* Read-write configuration registers
		*/
		#define BMA400_ACC_CONFIG0_REG 0x19
		#define BMA400_ACC_CONFIG1_REG 0x1a
		#define BMA400_ACC_CONFIG2_REG 0x1b
		#define BMA400_CMD_REG 0x7e

		/* Chip ID of BMA 400 devices found in the chip ID register. */
		#define BMA400_ID_REG_VAL 0x90

		#define BMA400_LP_OSR_SHIFT 5
		#define BMA400_NP_OSR_SHIFT 4
		#define BMA400_SCALE_SHIFT 6

		#define BMA400_TWO_BITS_MASK GENMASK(1, 0)
		#define BMA400_LP_OSR_MASK GENMASK(6, 5)
		#define BMA400_NP_OSR_MASK GENMASK(5, 4)
		#define BMA400_ACC_ODR_MASK GENMASK(3, 0)
		#define BMA400_ACC_SCALE_MASK GENMASK(7, 6)

		#define BMA400_ACC_ODR_MIN_RAW 0x05
		#define BMA400_ACC_ODR_LP_RAW 0x06
		#define BMA400_ACC_ODR_MAX_RAW 0x0b

		#define BMA400_ACC_ODR_MAX_HZ 800
		#define BMA400_ACC_ODR_MIN_WHOLE_HZ 25
		#define BMA400_ACC_ODR_MIN_HZ 12

		#define BMA400_SCALE_MIN 38357
		#define BMA400_SCALE_MAX 306864

		extern const struct regmap_config bma400_regmap_config;

		int bma400_probe(struct device dev, struct regmap regmap, const char *name);

		int bma400_remove(struct device *dev);

		#endif

drivers/iio/accel/bma400_core.c

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		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Core IIO driver for Bosch BMA400 triaxial acceleration sensor.
		*
		* Copyright 2019 Dan Robertson <dan@dlrobertson.com>
		*
		* TODO:
		* - Support for power management
		* - Support events and interrupts
		* - Create channel for step count
		* - Create channel for sensor time
		*/

		#include <linux/bitops.h>
		#include <linux/device.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/sysfs.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/mutex.h>
		#include <linux/regmap.h>

		#include "bma400.h"

		/*
		* The G-range selection may be one of 2g, 4g, 8, or 16g. The scale may
		* be selected with the acc_range bits of the ACC_CONFIG1 register.
		* NB: This buffer is populated in the device init.
		*/
		static int bma400_scales[8];

		/*
		* See the ACC_CONFIG1 section of the datasheet.
		* NB: This buffer is populated in the device init.
		*/
		static int bma400_sample_freqs[14];

		static const int bma400_osr_range[] = { 0, 1, 3 };

		/* See the ACC_CONFIG0 section of the datasheet */
		enum bma400_power_mode {
		POWER_MODE_SLEEP = 0x00,
		POWER_MODE_LOW = 0x01,
		POWER_MODE_NORMAL = 0x02,
		POWER_MODE_INVALID = 0x03,
		};

		struct bma400_sample_freq {
		int hz;
		int uhz;
		};

		struct bma400_data {
		struct device *dev;
		struct regmap *regmap;
		struct mutex mutex; /* data register lock */
		struct iio_mount_matrix orientation;
		enum bma400_power_mode power_mode;
		struct bma400_sample_freq sample_freq;
		int oversampling_ratio;
		int scale;
		};

		static bool bma400_is_writable_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case BMA400_CHIP_ID_REG:
		case BMA400_ERR_REG:
		case BMA400_STATUS_REG:
		case BMA400_X_AXIS_LSB_REG:
		case BMA400_X_AXIS_MSB_REG:
		case BMA400_Y_AXIS_LSB_REG:
		case BMA400_Y_AXIS_MSB_REG:
		case BMA400_Z_AXIS_LSB_REG:
		case BMA400_Z_AXIS_MSB_REG:
		case BMA400_SENSOR_TIME0:
		case BMA400_SENSOR_TIME1:
		case BMA400_SENSOR_TIME2:
		case BMA400_EVENT_REG:
		case BMA400_INT_STAT0_REG:
		case BMA400_INT_STAT1_REG:
		case BMA400_INT_STAT2_REG:
		case BMA400_TEMP_DATA_REG:
		case BMA400_FIFO_LENGTH0_REG:
		case BMA400_FIFO_LENGTH1_REG:
		case BMA400_FIFO_DATA_REG:
		case BMA400_STEP_CNT0_REG:
		case BMA400_STEP_CNT1_REG:
		case BMA400_STEP_CNT3_REG:
		case BMA400_STEP_STAT_REG:
		return false;
		default:
		return true;
		}
		}

		static bool bma400_is_volatile_reg(struct device *dev, unsigned int reg)
		{
		switch (reg) {
		case BMA400_ERR_REG:
		case BMA400_STATUS_REG:
		case BMA400_X_AXIS_LSB_REG:
		case BMA400_X_AXIS_MSB_REG:
		case BMA400_Y_AXIS_LSB_REG:
		case BMA400_Y_AXIS_MSB_REG:
		case BMA400_Z_AXIS_LSB_REG:
		case BMA400_Z_AXIS_MSB_REG:
		case BMA400_SENSOR_TIME0:
		case BMA400_SENSOR_TIME1:
		case BMA400_SENSOR_TIME2:
		case BMA400_EVENT_REG:
		case BMA400_INT_STAT0_REG:
		case BMA400_INT_STAT1_REG:
		case BMA400_INT_STAT2_REG:
		case BMA400_TEMP_DATA_REG:
		case BMA400_FIFO_LENGTH0_REG:
		case BMA400_FIFO_LENGTH1_REG:
		case BMA400_FIFO_DATA_REG:
		case BMA400_STEP_CNT0_REG:
		case BMA400_STEP_CNT1_REG:
		case BMA400_STEP_CNT3_REG:
		case BMA400_STEP_STAT_REG:
		return true;
		default:
		return false;
		}
		}

		const struct regmap_config bma400_regmap_config = {
		.reg_bits = 8,
		.val_bits = 8,
		.max_register = BMA400_CMD_REG,
		.cache_type = REGCACHE_RBTREE,
		.writeable_reg = bma400_is_writable_reg,
		.volatile_reg = bma400_is_volatile_reg,
		};
		EXPORT_SYMBOL(bma400_regmap_config);

		static const struct iio_mount_matrix *
		bma400_accel_get_mount_matrix(const struct iio_dev *indio_dev,
		const struct iio_chan_spec *chan)
		{
		struct bma400_data *data = iio_priv(indio_dev);

		return &data->orientation;
		}

		static const struct iio_chan_spec_ext_info bma400_ext_info[] = {
		IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, bma400_accel_get_mount_matrix),
		{ }
		};

		#define BMA400_ACC_CHANNEL(_axis) { \
		.type = IIO_ACCEL, \
		.modified = 1, \
		.channel2 = IIO_MOD_##_axis, \
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
		BIT(IIO_CHAN_INFO_SCALE) \| \
		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
		.info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
		BIT(IIO_CHAN_INFO_SCALE) \| \
		BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
		.ext_info = bma400_ext_info, \
		}

		static const struct iio_chan_spec bma400_channels[] = {
		BMA400_ACC_CHANNEL(X),
		BMA400_ACC_CHANNEL(Y),
		BMA400_ACC_CHANNEL(Z),
		{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ),
		},
		};

		static int bma400_get_temp_reg(struct bma400_data data, int val, int *val2)
		{
		unsigned int raw_temp;
		int host_temp;
		int ret;

		if (data->power_mode == POWER_MODE_SLEEP)
		return -EBUSY;

		ret = regmap_read(data->regmap, BMA400_TEMP_DATA_REG, &raw_temp);
		if (ret)
		return ret;

		host_temp = sign_extend32(raw_temp, 7);
		/*
		* The formula for the TEMP_DATA register in the datasheet
		* is: x * 0.5 + 23
		*/
		*val = (host_temp >> 1) + 23;
		val2 = (host_temp & 0x1) 500000;
		return IIO_VAL_INT_PLUS_MICRO;
		}

		static int bma400_get_accel_reg(struct bma400_data *data,
		const struct iio_chan_spec *chan,
		int *val)
		{
		__le16 raw_accel;
		int lsb_reg;
		int ret;

		if (data->power_mode == POWER_MODE_SLEEP)
		return -EBUSY;

		switch (chan->channel2) {
		case IIO_MOD_X:
		lsb_reg = BMA400_X_AXIS_LSB_REG;
		break;
		case IIO_MOD_Y:
		lsb_reg = BMA400_Y_AXIS_LSB_REG;
		break;
		case IIO_MOD_Z:
		lsb_reg = BMA400_Z_AXIS_LSB_REG;
		break;
		default:
		dev_err(data->dev, "invalid axis channel modifier\n");
		return -EINVAL;
		}

		/* bulk read two registers, with the base being the LSB register */
		ret = regmap_bulk_read(data->regmap, lsb_reg, &raw_accel,
		sizeof(raw_accel));
		if (ret)
		return ret;

		*val = sign_extend32(le16_to_cpu(raw_accel), 11);
		return IIO_VAL_INT;
		}

		static void bma400_output_data_rate_from_raw(int raw, unsigned int *val,
		unsigned int *val2)
		{
		*val = BMA400_ACC_ODR_MAX_HZ >> (BMA400_ACC_ODR_MAX_RAW - raw);
		if (raw > BMA400_ACC_ODR_MIN_RAW)
		*val2 = 0;
		else
		*val2 = 500000;
		}

		static int bma400_get_accel_output_data_rate(struct bma400_data *data)
		{
		unsigned int val;
		unsigned int odr;
		int ret;

		switch (data->power_mode) {
		case POWER_MODE_LOW:
		/*
		* Runs at a fixed rate in low-power mode. See section 4.3
		* in the datasheet.
		*/
		bma400_output_data_rate_from_raw(BMA400_ACC_ODR_LP_RAW,
		&data->sample_freq.hz,
		&data->sample_freq.uhz);
		return 0;
		case POWER_MODE_NORMAL:
		/*
		* In normal mode the ODR can be found in the ACC_CONFIG1
		* register.
		*/
		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
		if (ret)
		goto error;

		odr = val & BMA400_ACC_ODR_MASK;
		if (odr < BMA400_ACC_ODR_MIN_RAW \|\|
		odr > BMA400_ACC_ODR_MAX_RAW) {
		ret = -EINVAL;
		goto error;
		}

		bma400_output_data_rate_from_raw(odr, &data->sample_freq.hz,
		&data->sample_freq.uhz);
		return 0;
		case POWER_MODE_SLEEP:
		data->sample_freq.hz = 0;
		data->sample_freq.uhz = 0;
		return 0;
		default:
		ret = 0;
		goto error;
		}
		error:
		data->sample_freq.hz = -1;
		data->sample_freq.uhz = -1;
		return ret;
		}

		static int bma400_set_accel_output_data_rate(struct bma400_data *data,
		int hz, int uhz)
		{
		unsigned int idx;
		unsigned int odr;
		unsigned int val;
		int ret;

		if (hz >= BMA400_ACC_ODR_MIN_WHOLE_HZ) {
		if (uhz \|\| hz > BMA400_ACC_ODR_MAX_HZ)
		return -EINVAL;

		/* Note this works because MIN_WHOLE_HZ is odd */
		idx = __ffs(hz);

		if (hz >> idx != BMA400_ACC_ODR_MIN_WHOLE_HZ)
		return -EINVAL;

		idx += BMA400_ACC_ODR_MIN_RAW + 1;
		} else if (hz == BMA400_ACC_ODR_MIN_HZ && uhz == 500000) {
		idx = BMA400_ACC_ODR_MIN_RAW;
		} else {
		return -EINVAL;
		}

		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
		if (ret)
		return ret;

		/* preserve the range and normal mode osr */
		odr = (~BMA400_ACC_ODR_MASK & val) \| idx;

		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG, odr);
		if (ret)
		return ret;

		bma400_output_data_rate_from_raw(idx, &data->sample_freq.hz,
		&data->sample_freq.uhz);
		return 0;
		}

		static int bma400_get_accel_oversampling_ratio(struct bma400_data *data)
		{
		unsigned int val;
		unsigned int osr;
		int ret;

		/*
		* The oversampling ratio is stored in a different register
		* based on the power-mode. In normal mode the OSR is stored
		* in ACC_CONFIG1. In low-power mode it is stored in
		* ACC_CONFIG0.
		*/
		switch (data->power_mode) {
		case POWER_MODE_LOW:
		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val);
		if (ret) {
		data->oversampling_ratio = -1;
		return ret;
		}

		osr = (val & BMA400_LP_OSR_MASK) >> BMA400_LP_OSR_SHIFT;

		data->oversampling_ratio = osr;
		return 0;
		case POWER_MODE_NORMAL:
		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
		if (ret) {
		data->oversampling_ratio = -1;
		return ret;
		}

		osr = (val & BMA400_NP_OSR_MASK) >> BMA400_NP_OSR_SHIFT;

		data->oversampling_ratio = osr;
		return 0;
		case POWER_MODE_SLEEP:
		data->oversampling_ratio = 0;
		return 0;
		default:
		data->oversampling_ratio = -1;
		return -EINVAL;
		}
		}

		static int bma400_set_accel_oversampling_ratio(struct bma400_data *data,
		int val)
		{
		unsigned int acc_config;
		int ret;

		if (val & ~BMA400_TWO_BITS_MASK)
		return -EINVAL;

		/*
		* The oversampling ratio is stored in a different register
		* based on the power-mode.
		*/
		switch (data->power_mode) {
		case POWER_MODE_LOW:
		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG,
		&acc_config);
		if (ret)
		return ret;

		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG,
		(acc_config & ~BMA400_LP_OSR_MASK) \|
		(val << BMA400_LP_OSR_SHIFT));
		if (ret) {
		dev_err(data->dev, "Failed to write out OSR\n");
		return ret;
		}

		data->oversampling_ratio = val;
		return 0;
		case POWER_MODE_NORMAL:
		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG,
		&acc_config);
		if (ret)
		return ret;

		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG,
		(acc_config & ~BMA400_NP_OSR_MASK) \|
		(val << BMA400_NP_OSR_SHIFT));
		if (ret) {
		dev_err(data->dev, "Failed to write out OSR\n");
		return ret;
		}

		data->oversampling_ratio = val;
		return 0;
		default:
		return -EINVAL;
		}
		return ret;
		}

		static int bma400_accel_scale_to_raw(struct bma400_data *data,
		unsigned int val)
		{
		int raw;

		if (val == 0)
		return -EINVAL;

		/* Note this works because BMA400_SCALE_MIN is odd */
		raw = __ffs(val);

		if (val >> raw != BMA400_SCALE_MIN)
		return -EINVAL;

		return raw;
		}

		static int bma400_get_accel_scale(struct bma400_data *data)
		{
		unsigned int raw_scale;
		unsigned int val;
		int ret;

		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
		if (ret)
		return ret;

		raw_scale = (val & BMA400_ACC_SCALE_MASK) >> BMA400_SCALE_SHIFT;
		if (raw_scale > BMA400_TWO_BITS_MASK)
		return -EINVAL;

		data->scale = BMA400_SCALE_MIN << raw_scale;

		return 0;
		}

		static int bma400_set_accel_scale(struct bma400_data *data, unsigned int val)
		{
		unsigned int acc_config;
		int raw;
		int ret;

		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &acc_config);
		if (ret)
		return ret;

		raw = bma400_accel_scale_to_raw(data, val);
		if (raw < 0)
		return raw;

		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG,
		(acc_config & ~BMA400_ACC_SCALE_MASK) \|
		(raw << BMA400_SCALE_SHIFT));
		if (ret)
		return ret;

		data->scale = val;
		return 0;
		}

		static int bma400_get_power_mode(struct bma400_data *data)
		{
		unsigned int val;
		int ret;

		ret = regmap_read(data->regmap, BMA400_STATUS_REG, &val);
		if (ret) {
		dev_err(data->dev, "Failed to read status register\n");
		return ret;
		}

		data->power_mode = (val >> 1) & BMA400_TWO_BITS_MASK;
		return 0;
		}

		static int bma400_set_power_mode(struct bma400_data *data,
		enum bma400_power_mode mode)
		{
		unsigned int val;
		int ret;

		ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val);
		if (ret)
		return ret;

		if (data->power_mode == mode)
		return 0;

		if (mode == POWER_MODE_INVALID)
		return -EINVAL;

		/* Preserve the low-power oversample ratio etc */
		ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG,
		mode \| (val & ~BMA400_TWO_BITS_MASK));
		if (ret) {
		dev_err(data->dev, "Failed to write to power-mode\n");
		return ret;
		}

		data->power_mode = mode;

		/*
		* Update our cached osr and odr based on the new
		* power-mode.
		*/
		bma400_get_accel_output_data_rate(data);
		bma400_get_accel_oversampling_ratio(data);
		return 0;
		}

		static void bma400_init_tables(void)
		{
		int raw;
		int i;

		for (i = 0; i + 1 < ARRAY_SIZE(bma400_sample_freqs); i += 2) {
		raw = (i / 2) + 5;
		bma400_output_data_rate_from_raw(raw, &bma400_sample_freqs[i],
		&bma400_sample_freqs[i + 1]);
		}

		for (i = 0; i + 1 < ARRAY_SIZE(bma400_scales); i += 2) {
		raw = i / 2;
		bma400_scales[i] = 0;
		bma400_scales[i + 1] = BMA400_SCALE_MIN << raw;
		}
		}

		static int bma400_init(struct bma400_data *data)
		{
		unsigned int val;
		int ret;

		/* Try to read chip_id register. It must return 0x90. */
		ret = regmap_read(data->regmap, BMA400_CHIP_ID_REG, &val);
		if (ret) {
		dev_err(data->dev, "Failed to read chip id register\n");
		goto out;
		}

		if (val != BMA400_ID_REG_VAL) {
		dev_err(data->dev, "Chip ID mismatch\n");
		ret = -ENODEV;
		goto out;
		}

		ret = bma400_get_power_mode(data);
		if (ret) {
		dev_err(data->dev, "Failed to get the initial power-mode\n");
		goto out;
		}

		if (data->power_mode != POWER_MODE_NORMAL) {
		ret = bma400_set_power_mode(data, POWER_MODE_NORMAL);
		if (ret) {
		dev_err(data->dev, "Failed to wake up the device\n");
		goto out;
		}
		/*
		* TODO: The datasheet waits 1500us here in the example, but
		* lists 2/ODR as the wakeup time.
		*/
		usleep_range(1500, 2000);
		}

		bma400_init_tables();

		ret = bma400_get_accel_output_data_rate(data);
		if (ret)
		goto out;

		ret = bma400_get_accel_oversampling_ratio(data);
		if (ret)
		goto out;

		ret = bma400_get_accel_scale(data);
		if (ret)
		goto out;

		/*
		* Once the interrupt engine is supported we might use the
		* data_src_reg, but for now ensure this is set to the
		* variable ODR filter selectable by the sample frequency
		* channel.
		*/
		return regmap_write(data->regmap, BMA400_ACC_CONFIG2_REG, 0x00);

		out:
		return ret;
		}

		static int bma400_read_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const chan, int val,
		int *val2, long mask)
		{
		struct bma400_data *data = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_PROCESSED:
		mutex_lock(&data->mutex);
		ret = bma400_get_temp_reg(data, val, val2);
		mutex_unlock(&data->mutex);
		return ret;
		case IIO_CHAN_INFO_RAW:
		mutex_lock(&data->mutex);
		ret = bma400_get_accel_reg(data, chan, val);
		mutex_unlock(&data->mutex);
		return ret;
		case IIO_CHAN_INFO_SAMP_FREQ:
		switch (chan->type) {
		case IIO_ACCEL:
		if (data->sample_freq.hz < 0)
		return -EINVAL;

		*val = data->sample_freq.hz;
		*val2 = data->sample_freq.uhz;
		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_TEMP:
		/*
		* Runs at a fixed sampling frequency. See Section 4.4
		* of the datasheet.
		*/
		*val = 6;
		*val2 = 250000;
		return IIO_VAL_INT_PLUS_MICRO;
		default:
		return -EINVAL;
		}
		case IIO_CHAN_INFO_SCALE:
		*val = 0;
		*val2 = data->scale;
		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		/*
		* TODO: We could avoid this logic and returning -EINVAL here if
		* we set both the low-power and normal mode OSR registers when
		* we configure the device.
		*/
		if (data->oversampling_ratio < 0)
		return -EINVAL;

		*val = data->oversampling_ratio;
		return IIO_VAL_INT;
		default:
		return -EINVAL;
		}
		}

		static int bma400_read_avail(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		const int *vals, int type, int *length,
		long mask)
		{
		switch (mask) {
		case IIO_CHAN_INFO_SCALE:
		*type = IIO_VAL_INT_PLUS_MICRO;
		*vals = bma400_scales;
		*length = ARRAY_SIZE(bma400_scales);
		return IIO_AVAIL_LIST;
		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		*type = IIO_VAL_INT;
		*vals = bma400_osr_range;
		*length = ARRAY_SIZE(bma400_osr_range);
		return IIO_AVAIL_RANGE;
		case IIO_CHAN_INFO_SAMP_FREQ:
		*type = IIO_VAL_INT_PLUS_MICRO;
		*vals = bma400_sample_freqs;
		*length = ARRAY_SIZE(bma400_sample_freqs);
		return IIO_AVAIL_LIST;
		default:
		return -EINVAL;
		}
		}

		static int bma400_write_raw(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan, int val, int val2,
		long mask)
		{
		struct bma400_data *data = iio_priv(indio_dev);
		int ret;

		switch (mask) {
		case IIO_CHAN_INFO_SAMP_FREQ:
		/*
		* The sample frequency is readonly for the temperature
		* register and a fixed value in low-power mode.
		*/
		if (chan->type != IIO_ACCEL)
		return -EINVAL;

		mutex_lock(&data->mutex);
		ret = bma400_set_accel_output_data_rate(data, val, val2);
		mutex_unlock(&data->mutex);
		return ret;
		case IIO_CHAN_INFO_SCALE:
		if (val != 0 \|\| val2 > BMA400_SCALE_MAX)
		return -EINVAL;

		mutex_lock(&data->mutex);
		ret = bma400_set_accel_scale(data, val2);
		mutex_unlock(&data->mutex);
		return ret;
		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		mutex_lock(&data->mutex);
		ret = bma400_set_accel_oversampling_ratio(data, val);
		mutex_unlock(&data->mutex);
		return ret;
		default:
		return -EINVAL;
		}
		}

		static int bma400_write_raw_get_fmt(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		long mask)
		{
		switch (mask) {
		case IIO_CHAN_INFO_SAMP_FREQ:
		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CHAN_INFO_SCALE:
		return IIO_VAL_INT_PLUS_MICRO;
		case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		return IIO_VAL_INT;
		default:
		return -EINVAL;
		}
		}

		static const struct iio_info bma400_info = {
		.read_raw = bma400_read_raw,
		.read_avail = bma400_read_avail,
		.write_raw = bma400_write_raw,
		.write_raw_get_fmt = bma400_write_raw_get_fmt,
		};

		int bma400_probe(struct device dev, struct regmap regmap, const char *name)
		{
		struct iio_dev *indio_dev;
		struct bma400_data *data;
		int ret;

		indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
		if (!indio_dev)
		return -ENOMEM;

		data = iio_priv(indio_dev);
		data->regmap = regmap;
		data->dev = dev;

		ret = bma400_init(data);
		if (ret)
		return ret;

		ret = iio_read_mount_matrix(dev, "mount-matrix", &data->orientation);
		if (ret)
		return ret;

		mutex_init(&data->mutex);
		indio_dev->dev.parent = dev;
		indio_dev->name = name;
		indio_dev->info = &bma400_info;
		indio_dev->channels = bma400_channels;
		indio_dev->num_channels = ARRAY_SIZE(bma400_channels);
		indio_dev->modes = INDIO_DIRECT_MODE;

		dev_set_drvdata(dev, indio_dev);

		return iio_device_register(indio_dev);
		}
		EXPORT_SYMBOL(bma400_probe);

		int bma400_remove(struct device *dev)
		{
		struct iio_dev *indio_dev = dev_get_drvdata(dev);
		struct bma400_data *data = iio_priv(indio_dev);
		int ret;

		mutex_lock(&data->mutex);
		ret = bma400_set_power_mode(data, POWER_MODE_SLEEP);
		mutex_unlock(&data->mutex);

		iio_device_unregister(indio_dev);

		return ret;
		}
		EXPORT_SYMBOL(bma400_remove);

		MODULE_AUTHOR("Dan Robertson <dan@dlrobertson.com>");
		MODULE_DESCRIPTION("Bosch BMA400 triaxial acceleration sensor core");
		MODULE_LICENSE("GPL");

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