diff mbox series

[v2] iio: accel: Add support for the Bosch-Sensortec BMI088

Message ID 20200316073208.19715-1-mike.looijmans@topic.nl (mailing list archive)
State New, archived
Headers show
Series [v2] iio: accel: Add support for the Bosch-Sensortec BMI088 | expand

Commit Message

Mike Looijmans March 16, 2020, 7:32 a.m. UTC
The BMI088 is a combined module with both accelerometer and gyroscope.
This adds the accelerometer driver support for the SPI interface.
The gyroscope part is already supported by the BMG160 driver.

Signed-off-by: Mike Looijmans <mike.looijmans@topic.nl>
---
v2: Remove unused typedefs and variables
    Fix error return when iio_device_register fails

 drivers/iio/accel/Kconfig             |  17 +
 drivers/iio/accel/Makefile            |   2 +
 drivers/iio/accel/bmi088-accel-core.c | 655 ++++++++++++++++++++++++++
 drivers/iio/accel/bmi088-accel-spi.c  | 100 ++++
 drivers/iio/accel/bmi088-accel.h      |  11 +
 5 files changed, 785 insertions(+)
 create mode 100644 drivers/iio/accel/bmi088-accel-core.c
 create mode 100644 drivers/iio/accel/bmi088-accel-spi.c
 create mode 100644 drivers/iio/accel/bmi088-accel.h

Comments

Lars-Peter Clausen March 16, 2020, 2:54 p.m. UTC | #1
On 3/16/20 8:32 AM, Mike Looijmans wrote:
> The BMI088 is a combined module with both accelerometer and gyroscope.
> This adds the accelerometer driver support for the SPI interface.
> The gyroscope part is already supported by the BMG160 driver.
Looks very good, a few comments inline.
> [...]
> +static int bmi088_accel_get_temp(struct bmi088_accel_data *data, int *val)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +	int ret;
> +	u8 value[2];
> +	unsigned int temp;
> +
> +	mutex_lock(&data->mutex);
> +
> +	/* Read temp reg MSB */
> +	ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_REG_TEMP,
> +			       &value, sizeof(value));
> +	if (ret < 0) {
> +		dev_err(dev, "Error reading BMI088_ACCEL_REG_TEMP\n");
> +		mutex_unlock(&data->mutex);
> +		return ret;
> +	}
> +	temp = (unsigned int)value[0] << 3;
> +	temp |= (value[1] >> 5);
> +
> +	if (temp > 1023)
> +		*val = temp - 2028;

I would be highly surprised if this is not supposed to be 2048.

If it is you can simplify the expression to be able to work without the 
conditional by using

*val = sign_extend32(temp, 11);

I believe it is 11, better double check.

> +	else
> +		*val = temp;
> +
> +	mutex_unlock(&data->mutex);
> +
> +	return IIO_VAL_INT;
> +}
> [...]
> +static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
> +				 struct iio_chan_spec const *chan,
> +				 int *val, int *val2, long mask)
> +{
> +	struct bmi088_accel_data *data = iio_priv(indio_dev);
> +	int ret;
> +	unsigned int range;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_TEMP:
> +			return bmi088_accel_get_temp(data, val);
> +		case IIO_ACCEL:
> +			if (iio_buffer_enabled(indio_dev))
> +				return -EBUSY;

I think there is a race condition here. If the buffer is enabled after 
the check undefined behavior might occur. Jonathan already mentioned it 
in his review. Best is to use iio_device_{claim,release}_direct_mode().

> +
> +			ret = regmap_read(data->regmap,
> +				BMI088_ACCEL_REG_ACC_RANGE, &range);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = bmi088_accel_get_axis(data, chan, val);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = (*val * 3 * 980 * (0x01 << range)) >> 15;
> +
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> [...]
> +}
> +
> +static int bmi088_accel_write_raw(struct iio_dev *indio_dev,
> +				  struct iio_chan_spec const *chan,
> +				  int val, int val2, long mask)
> +{
> +	struct bmi088_accel_data *data = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		mutex_lock(&data->mutex);
> +		ret = bmi088_accel_set_bw(data, val, val2);
> +		mutex_unlock(&data->mutex);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800 1600");
> +
> +static struct attribute *bmi088_accel_attributes[] = {
> +	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
> +	NULL,
> +};
> +
> +static const struct attribute_group bmi088_accel_attrs_group = {
> +	.attrs = bmi088_accel_attributes,
> +};
> +
> +#define BMI088_ACCEL_CHANNEL(_axis, bits) {				\
> +	.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_SCALE) |		\
> +				BIT(IIO_CHAN_INFO_SAMP_FREQ),		\
> +	.scan_index = AXIS_##_axis,					\
> +	.scan_type = {							\
> +		.sign = 's',						\
> +		.realbits = (bits),					\
> +		.storagebits = 16,					\
> +		.shift = 16 - (bits),					\
> +		.endianness = IIO_LE,					\
> +	},								\
> +}
> +
> +#define BMI088_ACCEL_CHANNELS(bits) {					\
> +	{								\
> +		.type = IIO_TEMP,					\
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
> +				      BIT(IIO_CHAN_INFO_SCALE) |	\
> +				      BIT(IIO_CHAN_INFO_OFFSET),	\
> +		.scan_index = -1,					\
> +	},								\
> +	BMI088_ACCEL_CHANNEL(X, bits),					\
> +	BMI088_ACCEL_CHANNEL(Y, bits),					\
> +	BMI088_ACCEL_CHANNEL(Z, bits),					\
> +	IIO_CHAN_SOFT_TIMESTAMP(3),					\
> +}
> +
> +static const struct iio_chan_spec bmi088_accel_channels[] =
> +	BMI088_ACCEL_CHANNELS(16);
> +
> +static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = {
> +	[0] = {
> +		.name = "BMI088A",
> +		.chip_id = 0x1E,
> +		.channels = bmi088_accel_channels,
> +		.num_channels = ARRAY_SIZE(bmi088_accel_channels),
> +		.scale_table = { {9610, BMI088_ACCEL_RANGE_3G},
> +				 {19122, BMI088_ACCEL_RANGE_6G},
> +				 {38344, BMI088_ACCEL_RANGE_12G},
> +				 {76590, BMI088_ACCEL_RANGE_24G} },
> +		},
> +};
> +
> +static const struct iio_info bmi088_accel_info = {
> +	.attrs		= &bmi088_accel_attrs_group,
> +	.read_raw	= bmi088_accel_read_raw,
> +	.write_raw	= bmi088_accel_write_raw,
> +};
> +
> +static const unsigned long bmi088_accel_scan_masks[] = {
> +				BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
> +				0};
> +
> +
> +
> +#ifdef CONFIG_PM
> +static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
> +	bool on)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +	int ret;
> +
> +	if (on) {
> +		ret = pm_runtime_get_sync(dev);
> +	} else {
> +		pm_runtime_mark_last_busy(dev);
> +		ret = pm_runtime_put_autosuspend(dev);
> +	}
> +
> +	if (ret < 0) {
> +		dev_err(dev, "Failed: %s(%d)\n", __func__, on);
> +		if (on)
> +			pm_runtime_put_noidle(dev);
> +
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +#else
> +static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
> +	bool on)
> +{
> +	return 0;
> +}
> +#endif
> +
> +static int bmi088_accel_chip_init(struct bmi088_accel_data *data)
> +{
> +	struct device *dev = regmap_get_device(data->regmap);
> +	int ret, i;
> +	unsigned int val;
> +
> +	/* Do a dummy read (of chip ID), to enable SPI interface */
> +	regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
> +
> +	/*
> +	 * Reset chip to get it in a known good state. A delay of 1ms after
> +	 * reset is required according to the data sheet
> +	 */
> +	regmap_write(data->regmap, BMI088_ACCEL_REG_RESET,
> +		     BMI088_ACCEL_RESET_VAL);
> +	usleep_range(1000, 2000);
> +
> +	/* Do a dummy read (of chip ID), to enable SPI interface after reset */
> +	regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
> +
> +	/* Read chip ID */
> +	ret = regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
> +	if (ret < 0) {
> +		dev_err(dev, "Error: Reading chip id\n");
> +		return ret;
> +	}
> +
> +	/* Validate chip ID */
> +	dev_dbg(dev, "Chip Id %x\n", val);
> +	for (i = 0; i < ARRAY_SIZE(bmi088_accel_chip_info_tbl); i++) {
> +		if (bmi088_accel_chip_info_tbl[i].chip_id == val) {
> +			data->chip_info = &bmi088_accel_chip_info_tbl[i];
> +			break;
> +		}
> +	}
> +
> +	if (!data->chip_info) {
> +		dev_err(dev, "Invalid chip %x\n", val);
> +		return -ENODEV;
> +	}
> +
> +	/* Set Active mode (and wait for 5ms) */
> +	ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
> +	if (ret < 0)
> +		return ret;
> +
> +	usleep_range(5000, 10000);
> +
> +	/* Enable accelerometer */
> +	ret = bmi088_accel_enable(data, true);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Set Bandwidth */
> +	ret = bmi088_accel_set_bw(data, BMI088_ACCEL_MODE_ODR_100,
> +		BMI088_ACCEL_MODE_OSR_NORMAL);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Set Default Range */
> +	ret = regmap_write(data->regmap, BMI088_ACCEL_REG_ACC_RANGE,
> +			   BMI088_ACCEL_RANGE_6G);
> +	if (ret < 0) {
> +		dev_err(dev, "Error writing ACC_RANGE\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap,
> +	int irq, const char *name, bool block_supported)
> +{
> +	struct bmi088_accel_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	dev_set_drvdata(dev, indio_dev);
> +
> +	data->regmap = regmap;
> +
> +	ret = bmi088_accel_chip_init(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	mutex_init(&data->mutex);
> +
> +	indio_dev->dev.parent = dev;
> +	indio_dev->channels = data->chip_info->channels;
> +	indio_dev->num_channels = data->chip_info->num_channels;
> +	indio_dev->name = name ? name : data->chip_info->name;
Considering that chip_info is chosen by the product ID register, 
regardless of what the compatible string was, maybe it is best to always 
use chip_info->name here.
> +	indio_dev->available_scan_masks = bmi088_accel_scan_masks;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->info = &bmi088_accel_info;
>
> diff --git a/drivers/iio/accel/bmi088-accel-spi.c b/drivers/iio/accel/bmi088-accel-spi.c
> new file mode 100644
> index 000000000000..920e146f07d3
> --- /dev/null
> +++ b/drivers/iio/accel/bmi088-accel-spi.c
> @@ -0,0 +1,100 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
> + *  - BMI088
> + *
> + * Copyright (c) 2018, Topic Embedded Products
> + */
> +
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/acpi.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/spi/spi.h>
> +#include <linux/regmap.h>
> +
> +#include "bmi088-accel.h"
> +
> +int bmi088_regmap_spi_write(void *context, const void *data, size_t count)
> +{
> +	struct spi_device *spi = context;
> +	u8 buf[count];
> +
> +	memcpy(buf, data, count);
> +
> +	dev_dbg(&spi->dev, "Write val: %x to reg: %x\n", buf[1], buf[0]);
> +
> +	/*
> +	 * The SPI register address (= full register address without bit 7)
> +	 * and the write command (bit7 = RW = '0')
> +	 */
> +	buf[0] &= ~0x80;
> +
> +	return spi_write(spi, buf, count);
> +}
> +
> +int bmi088_regmap_spi_read(void *context, const void *reg,
> +				size_t reg_size, void *val, size_t val_size)
> +{
> +	struct spi_device *spi = context;
> +	u8 addr[reg_size + 1];
I believe there is an effort to eliminate variable length arrays that 
are placed on the stack from the kernel. reg_size should have a very 
small upper limit you should be able to get away with a statically sized 
array.
> +
> +	addr[0] = *(u8 *)reg;
> +
> +	dev_dbg(&spi->dev, "Read reg: %x\n", addr[0]);
> +
> +	addr[0] |= 0x80; /* bit7 = RW = '1' */
> +
> +	/* Do a write of 2 to mimic the dummy byte (see datasheet) */
> +	return spi_write_then_read(spi, addr, sizeof(addr), val, val_size);
> +}
[...]
Mike Looijmans March 17, 2020, 1:58 p.m. UTC | #2
Thanks for the review, expect a v3 once I've had the cance to test it.

On 16-03-2020 15:54, Lars-Peter Clausen wrote:
> On 3/16/20 8:32 AM, Mike Looijmans wrote:
>> The BMI088 is a combined module with both accelerometer and gyroscope.
>> This adds the accelerometer driver support for the SPI interface.
>> The gyroscope part is already supported by the BMG160 driver.
> Looks very good, a few comments inline.
>> [...]
>> +static int bmi088_accel_get_temp(struct bmi088_accel_data *data, int 
>> *val)
>> +{
>> +    struct device *dev = regmap_get_device(data->regmap);
>> +    int ret;
>> +    u8 value[2];
>> +    unsigned int temp;
>> +
>> +    mutex_lock(&data->mutex);
>> +
>> +    /* Read temp reg MSB */
>> +    ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_REG_TEMP,
>> +                   &value, sizeof(value));
>> +    if (ret < 0) {
>> +        dev_err(dev, "Error reading BMI088_ACCEL_REG_TEMP\n");
>> +        mutex_unlock(&data->mutex);
>> +        return ret;
>> +    }
>> +    temp = (unsigned int)value[0] << 3;
>> +    temp |= (value[1] >> 5);
>> +
>> +    if (temp > 1023)
>> +        *val = temp - 2028;
> 
> I would be highly surprised if this is not supposed to be 2048.
> 
> If it is you can simplify the expression to be able to work without the 
> conditional by using
> 
> *val = sign_extend32(temp, 11);
> 
> I believe it is 11, better double check.

Yeah, the datasheet makes a big fuzz about it, but it's just a signed 
11-bit integer. See also my reply to Jonathan Cameron.


> 
>> +    else
>> +        *val = temp;
>> +
>> +    mutex_unlock(&data->mutex);
>> +
>> +    return IIO_VAL_INT;
>> +}
>> [...]
>> +static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
>> +                 struct iio_chan_spec const *chan,
>> +                 int *val, int *val2, long mask)
>> +{
>> +    struct bmi088_accel_data *data = iio_priv(indio_dev);
>> +    int ret;
>> +    unsigned int range;
>> +
>> +    switch (mask) {
>> +    case IIO_CHAN_INFO_RAW:
>> +        switch (chan->type) {
>> +        case IIO_TEMP:
>> +            return bmi088_accel_get_temp(data, val);
>> +        case IIO_ACCEL:
>> +            if (iio_buffer_enabled(indio_dev))
>> +                return -EBUSY;
> 
> I think there is a race condition here. If the buffer is enabled after 
> the check undefined behavior might occur. Jonathan already mentioned it 
> in his review. Best is to use iio_device_{claim,release}_direct_mode().

Fixed in v3.


> 
>> +
>> +            ret = regmap_read(data->regmap,
>> +                BMI088_ACCEL_REG_ACC_RANGE, &range);
>> +            if (ret < 0)
>> +                return ret;
>> +
>> +            ret = bmi088_accel_get_axis(data, chan, val);
>> +            if (ret < 0)
>> +                return ret;
>> +
>> +            *val = (*val * 3 * 980 * (0x01 << range)) >> 15;
>> +
>> +            return IIO_VAL_INT;
>> +        default:
>> +            return -EINVAL;
>> +        }
>> [...]
>> +}
>> +
>> +static int bmi088_accel_write_raw(struct iio_dev *indio_dev,
>> +                  struct iio_chan_spec const *chan,
>> +                  int val, int val2, long mask)
>> +{
>> +    struct bmi088_accel_data *data = iio_priv(indio_dev);
>> +    int ret;
>> +
>> +    switch (mask) {
>> +    case IIO_CHAN_INFO_SAMP_FREQ:
>> +        mutex_lock(&data->mutex);
>> +        ret = bmi088_accel_set_bw(data, val, val2);
>> +        mutex_unlock(&data->mutex);
>> +        break;
>> +    default:
>> +        ret = -EINVAL;
>> +    }
>> +
>> +    return ret;
>> +}
>> +
>> +static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800 
>> 1600");
>> +
>> +static struct attribute *bmi088_accel_attributes[] = {
>> +    &iio_const_attr_sampling_frequency_available.dev_attr.attr,
>> +    NULL,
>> +};
>> +
>> +static const struct attribute_group bmi088_accel_attrs_group = {
>> +    .attrs = bmi088_accel_attributes,
>> +};
>> +
>> +#define BMI088_ACCEL_CHANNEL(_axis, bits) {                \
>> +    .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_SCALE) |        \
>> +                BIT(IIO_CHAN_INFO_SAMP_FREQ),        \
>> +    .scan_index = AXIS_##_axis,                    \
>> +    .scan_type = {                            \
>> +        .sign = 's',                        \
>> +        .realbits = (bits),                    \
>> +        .storagebits = 16,                    \
>> +        .shift = 16 - (bits),                    \
>> +        .endianness = IIO_LE,                    \
>> +    },                                \
>> +}
>> +
>> +#define BMI088_ACCEL_CHANNELS(bits) {                    \
>> +    {                                \
>> +        .type = IIO_TEMP,                    \
>> +        .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |        \
>> +                      BIT(IIO_CHAN_INFO_SCALE) |    \
>> +                      BIT(IIO_CHAN_INFO_OFFSET),    \
>> +        .scan_index = -1,                    \
>> +    },                                \
>> +    BMI088_ACCEL_CHANNEL(X, bits),                    \
>> +    BMI088_ACCEL_CHANNEL(Y, bits),                    \
>> +    BMI088_ACCEL_CHANNEL(Z, bits),                    \
>> +    IIO_CHAN_SOFT_TIMESTAMP(3),                    \
>> +}
>> +
>> +static const struct iio_chan_spec bmi088_accel_channels[] =
>> +    BMI088_ACCEL_CHANNELS(16);
>> +
>> +static const struct bmi088_accel_chip_info 
>> bmi088_accel_chip_info_tbl[] = {
>> +    [0] = {
>> +        .name = "BMI088A",
>> +        .chip_id = 0x1E,
>> +        .channels = bmi088_accel_channels,
>> +        .num_channels = ARRAY_SIZE(bmi088_accel_channels),
>> +        .scale_table = { {9610, BMI088_ACCEL_RANGE_3G},
>> +                 {19122, BMI088_ACCEL_RANGE_6G},
>> +                 {38344, BMI088_ACCEL_RANGE_12G},
>> +                 {76590, BMI088_ACCEL_RANGE_24G} },
>> +        },
>> +};
>> +
>> +static const struct iio_info bmi088_accel_info = {
>> +    .attrs        = &bmi088_accel_attrs_group,
>> +    .read_raw    = bmi088_accel_read_raw,
>> +    .write_raw    = bmi088_accel_write_raw,
>> +};
>> +
>> +static const unsigned long bmi088_accel_scan_masks[] = {
>> +                BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
>> +                0};
>> +
>> +
>> +
>> +#ifdef CONFIG_PM
>> +static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
>> +    bool on)
>> +{
>> +    struct device *dev = regmap_get_device(data->regmap);
>> +    int ret;
>> +
>> +    if (on) {
>> +        ret = pm_runtime_get_sync(dev);
>> +    } else {
>> +        pm_runtime_mark_last_busy(dev);
>> +        ret = pm_runtime_put_autosuspend(dev);
>> +    }
>> +
>> +    if (ret < 0) {
>> +        dev_err(dev, "Failed: %s(%d)\n", __func__, on);
>> +        if (on)
>> +            pm_runtime_put_noidle(dev);
>> +
>> +        return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +#else
>> +static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
>> +    bool on)
>> +{
>> +    return 0;
>> +}
>> +#endif
>> +
>> +static int bmi088_accel_chip_init(struct bmi088_accel_data *data)
>> +{
>> +    struct device *dev = regmap_get_device(data->regmap);
>> +    int ret, i;
>> +    unsigned int val;
>> +
>> +    /* Do a dummy read (of chip ID), to enable SPI interface */
>> +    regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
>> +
>> +    /*
>> +     * Reset chip to get it in a known good state. A delay of 1ms after
>> +     * reset is required according to the data sheet
>> +     */
>> +    regmap_write(data->regmap, BMI088_ACCEL_REG_RESET,
>> +             BMI088_ACCEL_RESET_VAL);
>> +    usleep_range(1000, 2000);
>> +
>> +    /* Do a dummy read (of chip ID), to enable SPI interface after 
>> reset */
>> +    regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
>> +
>> +    /* Read chip ID */
>> +    ret = regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
>> +    if (ret < 0) {
>> +        dev_err(dev, "Error: Reading chip id\n");
>> +        return ret;
>> +    }
>> +
>> +    /* Validate chip ID */
>> +    dev_dbg(dev, "Chip Id %x\n", val);
>> +    for (i = 0; i < ARRAY_SIZE(bmi088_accel_chip_info_tbl); i++) {
>> +        if (bmi088_accel_chip_info_tbl[i].chip_id == val) {
>> +            data->chip_info = &bmi088_accel_chip_info_tbl[i];
>> +            break;
>> +        }
>> +    }
>> +
>> +    if (!data->chip_info) {
>> +        dev_err(dev, "Invalid chip %x\n", val);
>> +        return -ENODEV;
>> +    }
>> +
>> +    /* Set Active mode (and wait for 5ms) */
>> +    ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    usleep_range(5000, 10000);
>> +
>> +    /* Enable accelerometer */
>> +    ret = bmi088_accel_enable(data, true);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    /* Set Bandwidth */
>> +    ret = bmi088_accel_set_bw(data, BMI088_ACCEL_MODE_ODR_100,
>> +        BMI088_ACCEL_MODE_OSR_NORMAL);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    /* Set Default Range */
>> +    ret = regmap_write(data->regmap, BMI088_ACCEL_REG_ACC_RANGE,
>> +               BMI088_ACCEL_RANGE_6G);
>> +    if (ret < 0) {
>> +        dev_err(dev, "Error writing ACC_RANGE\n");
>> +        return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap,
>> +    int irq, const char *name, bool block_supported)
>> +{
>> +    struct bmi088_accel_data *data;
>> +    struct iio_dev *indio_dev;
>> +    int ret;
>> +
>> +    indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
>> +    if (!indio_dev)
>> +        return -ENOMEM;
>> +
>> +    data = iio_priv(indio_dev);
>> +    dev_set_drvdata(dev, indio_dev);
>> +
>> +    data->regmap = regmap;
>> +
>> +    ret = bmi088_accel_chip_init(data);
>> +    if (ret < 0)
>> +        return ret;
>> +
>> +    mutex_init(&data->mutex);
>> +
>> +    indio_dev->dev.parent = dev;
>> +    indio_dev->channels = data->chip_info->channels;
>> +    indio_dev->num_channels = data->chip_info->num_channels;
>> +    indio_dev->name = name ? name : data->chip_info->name;
> Considering that chip_info is chosen by the product ID register, 
> regardless of what the compatible string was, maybe it is best to always 
> use chip_info->name here.

Copied from other driver actually. I'd be glad to replace it and get rid 
of the name parameter. I have no clue what purpose this serves.

>> +    indio_dev->available_scan_masks = bmi088_accel_scan_masks;
>> +    indio_dev->modes = INDIO_DIRECT_MODE;
>> +    indio_dev->info = &bmi088_accel_info;
>>
>> diff --git a/drivers/iio/accel/bmi088-accel-spi.c 
>> b/drivers/iio/accel/bmi088-accel-spi.c
>> new file mode 100644
>> index 000000000000..920e146f07d3
>> --- /dev/null
>> +++ b/drivers/iio/accel/bmi088-accel-spi.c
>> @@ -0,0 +1,100 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * 3-axis accelerometer driver supporting following Bosch-Sensortec 
>> chips:
>> + *  - BMI088
>> + *
>> + * Copyright (c) 2018, Topic Embedded Products
>> + */
>> +
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/acpi.h>
>> +#include <linux/iio/iio.h>
>> +#include <linux/iio/sysfs.h>
>> +#include <linux/spi/spi.h>
>> +#include <linux/regmap.h>
>> +
>> +#include "bmi088-accel.h"
>> +
>> +int bmi088_regmap_spi_write(void *context, const void *data, size_t 
>> count)
>> +{
>> +    struct spi_device *spi = context;
>> +    u8 buf[count];
>> +
>> +    memcpy(buf, data, count);
>> +
>> +    dev_dbg(&spi->dev, "Write val: %x to reg: %x\n", buf[1], buf[0]);
>> +
>> +    /*
>> +     * The SPI register address (= full register address without bit 7)
>> +     * and the write command (bit7 = RW = '0')
>> +     */
>> +    buf[0] &= ~0x80;
>> +
>> +    return spi_write(spi, buf, count);
>> +}
>> +
>> +int bmi088_regmap_spi_read(void *context, const void *reg,
>> +                size_t reg_size, void *val, size_t val_size)
>> +{
>> +    struct spi_device *spi = context;
>> +    u8 addr[reg_size + 1];
> I believe there is an effort to eliminate variable length arrays that 
> are placed on the stack from the kernel. reg_size should have a very 
> small upper limit you should be able to get away with a statically sized 
> array.
>> +
>> +    addr[0] = *(u8 *)reg;
>> +
>> +    dev_dbg(&spi->dev, "Read reg: %x\n", addr[0]);
>> +
>> +    addr[0] |= 0x80; /* bit7 = RW = '1' */
>> +
>> +    /* Do a write of 2 to mimic the dummy byte (see datasheet) */
>> +    return spi_write_then_read(spi, addr, sizeof(addr), val, val_size);
>> +}
> [...]
> 
>
diff mbox series

Patch

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 5d91a6dda894..7ed9c82b731b 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -151,6 +151,23 @@  config BMC150_ACCEL_SPI
 	tristate
 	select REGMAP_SPI
 
+config BMI088_ACCEL
+	tristate "Bosch BMI088 Accelerometer Driver"
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
+	select REGMAP
+	select BMI088_ACCEL_SPI
+	help
+	  Say yes here to build support for the Bosch BMI088 accelerometer.
+
+	  This is a combo module with both accelerometer and gyroscope.
+	  This driver is only implementing accelerometer part, which has
+	  its own address and register map.
+
+config BMI088_ACCEL_SPI
+	tristate
+	select REGMAP_SPI
+
 config DA280
 	tristate "MiraMEMS DA280 3-axis 14-bit digital accelerometer driver"
 	depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 3a051cf37f40..f44613103ae5 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -19,6 +19,8 @@  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
+obj-$(CONFIG_BMI088_ACCEL) += bmi088-accel-core.o
+obj-$(CONFIG_BMI088_ACCEL_SPI) += bmi088-accel-spi.o
 obj-$(CONFIG_DA280)	+= da280.o
 obj-$(CONFIG_DA311)	+= da311.o
 obj-$(CONFIG_DMARD06)	+= dmard06.o
diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c
new file mode 100644
index 000000000000..3acac15701c6
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel-core.c
@@ -0,0 +1,655 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
+ *  - BMI088
+ *
+ * Copyright (c) 2018, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/regmap.h>
+
+#include "bmi088-accel.h"
+
+#define BMI088_ACCEL_DRV_NAME	"bmi088_accel"
+#define BMI088_ACCEL_IRQ_NAME	"bmi088_accel_event"
+
+#define BMI088_ACCEL_REG_CHIP_ID			0x00
+
+#define BMI088_ACCEL_REG_INT_STATUS			0x1D
+#define BMI088_ACCEL_INT_STATUS_BIT_DRDY		BIT(7)
+
+#define BMI088_ACCEL_REG_RESET				0x7E
+#define BMI088_ACCEL_RESET_VAL				0xB6
+
+#define BMI088_ACCEL_REG_PWR_CTRL			0x7D
+#define BMI088_ACCEL_REG_PWR_CONF			0x7C
+
+#define BMI088_ACCEL_REG_INT_MAP_DATA			0x58
+#define BMI088_ACCEL_INT_MAP_DATA_BIT_INT1_DRDY		BIT(2)
+#define BMI088_ACCEL_INT_MAP_DATA_BIT_INT2_FWM		BIT(5)
+
+#define BMI088_ACCEL_REG_INT1_IO_CONF			0x53
+#define BMI088_ACCEL_INT1_IO_CONF_BIT_ENABLE_OUT	BIT(3)
+#define BMI088_ACCEL_INT1_IO_CONF_BIT_LVL		BIT(1)
+
+#define BMI088_ACCEL_REG_INT2_IO_CONF			0x54
+#define BMI088_ACCEL_INT2_IO_CONF_BIT_ENABLE_OUT	BIT(3)
+#define BMI088_ACCEL_INT2_IO_CONF_BIT_LVL		BIT(1)
+
+#define BMI088_ACCEL_REG_ACC_CONF			0x40
+#define BMI088_ACCEL_REG_ACC_RANGE			0x41
+#define BMI088_ACCEL_RANGE_3G				0x00
+#define BMI088_ACCEL_RANGE_6G				0x01
+#define BMI088_ACCEL_RANGE_12G				0x02
+#define BMI088_ACCEL_RANGE_24G				0x03
+
+#define BMI088_ACCEL_REG_TEMP				0x22
+#define BMI088_ACCEL_TEMP_CENTER_VAL			23
+#define BMI088_ACCEL_TEMP_UNIT				125
+
+#define BMI088_ACCEL_REG_XOUT_L				0x12
+#define BMI088_ACCEL_AXIS_TO_REG(axis) \
+	(BMI088_ACCEL_REG_XOUT_L + (axis * 2))
+
+#define BMI088_ACCEL_MAX_STARTUP_TIME_MS		1
+
+#define BMI088_ACCEL_REG_FIFO_STATUS			0x0E
+#define BMI088_ACCEL_REG_FIFO_CONFIG0			0x48
+#define BMI088_ACCEL_REG_FIFO_CONFIG1			0x49
+#define BMI088_ACCEL_REG_FIFO_DATA			0x3F
+#define BMI088_ACCEL_FIFO_LENGTH			100
+
+#define BMI088_ACCEL_FIFO_MODE_FIFO			0x40
+#define BMI088_ACCEL_FIFO_MODE_STREAM			0x80
+
+enum bmi088_accel_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+	AXIS_MAX,
+};
+
+enum bmi088_power_modes {
+	BMI088_ACCEL_MODE_ACTIVE,
+	BMI088_ACCEL_MODE_SUSPEND,
+};
+
+/* Available OSR (over sampling rate) */
+enum bmi088_osr_modes {
+	BMI088_ACCEL_MODE_OSR_NORMAL = 0xA,
+	BMI088_ACCEL_MODE_OSR_2 = 0x9,
+	BMI088_ACCEL_MODE_OSR_4 = 0x8,
+};
+
+/* Available ODR (output data rates) in Hz */
+enum bmi088_odr_modes {
+	BMI088_ACCEL_MODE_ODR_12_5 = 0x5,
+	BMI088_ACCEL_MODE_ODR_25 = 0x6,
+	BMI088_ACCEL_MODE_ODR_50 = 0x7,
+	BMI088_ACCEL_MODE_ODR_100 = 0x8,
+	BMI088_ACCEL_MODE_ODR_200 = 0x9,
+	BMI088_ACCEL_MODE_ODR_400 = 0xa,
+	BMI088_ACCEL_MODE_ODR_800 = 0xb,
+	BMI088_ACCEL_MODE_ODR_1600 = 0xc,
+};
+
+struct bmi088_scale_info {
+	int scale;
+	u8 reg_range;
+};
+
+struct bmi088_accel_chip_info {
+	const char *name;
+	u8 chip_id;
+	const struct iio_chan_spec *channels;
+	int num_channels;
+	const struct bmi088_scale_info scale_table[4];
+};
+
+struct bmi088_accel_data {
+	struct regmap *regmap;
+	struct mutex mutex;
+	const struct bmi088_accel_chip_info *chip_info;
+};
+
+const struct regmap_config bmi088_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x7E,
+};
+EXPORT_SYMBOL_GPL(bmi088_regmap_conf);
+
+
+static int bmi088_accel_enable(struct bmi088_accel_data *data,
+				bool on_off)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CTRL,
+				on_off ? 0x4 : 0x0);
+	if (ret < 0) {
+		dev_err(dev, "Error writing ACC_PWR_CTRL reg\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bmi088_accel_set_mode(struct bmi088_accel_data *data,
+				enum bmi088_power_modes mode)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CONF,
+			   mode == BMI088_ACCEL_MODE_SUSPEND ? 0x3 : 0x0);
+	if (ret < 0) {
+		dev_err(dev, "Error writing ACCEL_PWR_CONF reg\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bmi088_accel_set_bw(struct bmi088_accel_data *data,
+				enum bmi088_odr_modes odr_mode,
+				enum bmi088_osr_modes osr_mode)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 value = (osr_mode << 4) | (odr_mode & 0xF);
+
+	ret = regmap_write(data->regmap, BMI088_ACCEL_REG_ACC_CONF, value);
+	if (ret < 0) {
+		dev_err(dev, "Error writing ACCEL_PWR_CONF reg\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static int bmi088_accel_get_bw(struct bmi088_accel_data *data, int *val,
+			       int *val2)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	unsigned int value;
+
+	ret = regmap_read(data->regmap, BMI088_ACCEL_REG_ACC_CONF,
+			  &value);
+	if (ret < 0) {
+		dev_err(dev, "Error reading ACC_CONF reg\n");
+		mutex_unlock(&data->mutex);
+		return ret;
+	}
+
+	*val = (value & 0xF); /* ODR */
+	*val2 = (value >> 4); /* OSR */
+
+	return 0;
+}
+
+static int bmi088_accel_get_temp(struct bmi088_accel_data *data, int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	u8 value[2];
+	unsigned int temp;
+
+	mutex_lock(&data->mutex);
+
+	/* Read temp reg MSB */
+	ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_REG_TEMP,
+			       &value, sizeof(value));
+	if (ret < 0) {
+		dev_err(dev, "Error reading BMI088_ACCEL_REG_TEMP\n");
+		mutex_unlock(&data->mutex);
+		return ret;
+	}
+	temp = (unsigned int)value[0] << 3;
+	temp |= (value[1] >> 5);
+
+	if (temp > 1023)
+		*val = temp - 2028;
+	else
+		*val = temp;
+
+	mutex_unlock(&data->mutex);
+
+	return IIO_VAL_INT;
+}
+
+static int bmi088_accel_get_axis(struct bmi088_accel_data *data,
+				 struct iio_chan_spec const *chan,
+				 int *val)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+	int axis = chan->scan_index;
+	__le16 raw_val;
+
+	mutex_lock(&data->mutex);
+
+	ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_AXIS_TO_REG(axis),
+			       &raw_val, sizeof(raw_val));
+	if (ret < 0) {
+		dev_err(dev, "Error reading axis %d\n", axis);
+		mutex_unlock(&data->mutex);
+		return ret;
+	}
+	*val = sign_extend32(le16_to_cpu(raw_val) >> chan->scan_type.shift,
+			     chan->scan_type.realbits - 1);
+
+	mutex_unlock(&data->mutex);
+
+	return IIO_VAL_INT;
+}
+
+static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int *val, int *val2, long mask)
+{
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+	int ret;
+	unsigned int range;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_TEMP:
+			return bmi088_accel_get_temp(data, val);
+		case IIO_ACCEL:
+			if (iio_buffer_enabled(indio_dev))
+				return -EBUSY;
+
+			ret = regmap_read(data->regmap,
+				BMI088_ACCEL_REG_ACC_RANGE, &range);
+			if (ret < 0)
+				return ret;
+
+			ret = bmi088_accel_get_axis(data, chan, val);
+			if (ret < 0)
+				return ret;
+
+			*val = (*val * 3 * 980 * (0x01 << range)) >> 15;
+
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = BMI088_ACCEL_TEMP_CENTER_VAL;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		*val = 0;
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = BMI088_ACCEL_TEMP_UNIT;
+			return IIO_VAL_INT;
+		case IIO_ACCEL:
+		{
+			ret = regmap_read(data->regmap,
+					BMI088_ACCEL_REG_ACC_RANGE, val);
+			if (ret < 0) {
+				dev_err(&indio_dev->dev,
+					"%s(): Read from device failed(%d)\n",
+					__func__, ret);
+				return -EINVAL;
+			}
+
+			return IIO_VAL_INT;
+		}
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&data->mutex);
+		ret = bmi088_accel_get_bw(data, val, val2);
+		mutex_unlock(&data->mutex);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bmi088_accel_write_raw(struct iio_dev *indio_dev,
+				  struct iio_chan_spec const *chan,
+				  int val, int val2, long mask)
+{
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		mutex_lock(&data->mutex);
+		ret = bmi088_accel_set_bw(data, val, val2);
+		mutex_unlock(&data->mutex);
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800 1600");
+
+static struct attribute *bmi088_accel_attributes[] = {
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bmi088_accel_attrs_group = {
+	.attrs = bmi088_accel_attributes,
+};
+
+#define BMI088_ACCEL_CHANNEL(_axis, bits) {				\
+	.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_SCALE) |		\
+				BIT(IIO_CHAN_INFO_SAMP_FREQ),		\
+	.scan_index = AXIS_##_axis,					\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = (bits),					\
+		.storagebits = 16,					\
+		.shift = 16 - (bits),					\
+		.endianness = IIO_LE,					\
+	},								\
+}
+
+#define BMI088_ACCEL_CHANNELS(bits) {					\
+	{								\
+		.type = IIO_TEMP,					\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+				      BIT(IIO_CHAN_INFO_SCALE) |	\
+				      BIT(IIO_CHAN_INFO_OFFSET),	\
+		.scan_index = -1,					\
+	},								\
+	BMI088_ACCEL_CHANNEL(X, bits),					\
+	BMI088_ACCEL_CHANNEL(Y, bits),					\
+	BMI088_ACCEL_CHANNEL(Z, bits),					\
+	IIO_CHAN_SOFT_TIMESTAMP(3),					\
+}
+
+static const struct iio_chan_spec bmi088_accel_channels[] =
+	BMI088_ACCEL_CHANNELS(16);
+
+static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = {
+	[0] = {
+		.name = "BMI088A",
+		.chip_id = 0x1E,
+		.channels = bmi088_accel_channels,
+		.num_channels = ARRAY_SIZE(bmi088_accel_channels),
+		.scale_table = { {9610, BMI088_ACCEL_RANGE_3G},
+				 {19122, BMI088_ACCEL_RANGE_6G},
+				 {38344, BMI088_ACCEL_RANGE_12G},
+				 {76590, BMI088_ACCEL_RANGE_24G} },
+		},
+};
+
+static const struct iio_info bmi088_accel_info = {
+	.attrs		= &bmi088_accel_attrs_group,
+	.read_raw	= bmi088_accel_read_raw,
+	.write_raw	= bmi088_accel_write_raw,
+};
+
+static const unsigned long bmi088_accel_scan_masks[] = {
+				BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
+				0};
+
+
+
+#ifdef CONFIG_PM
+static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
+	bool on)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret;
+
+	if (on) {
+		ret = pm_runtime_get_sync(dev);
+	} else {
+		pm_runtime_mark_last_busy(dev);
+		ret = pm_runtime_put_autosuspend(dev);
+	}
+
+	if (ret < 0) {
+		dev_err(dev, "Failed: %s(%d)\n", __func__, on);
+		if (on)
+			pm_runtime_put_noidle(dev);
+
+		return ret;
+	}
+
+	return 0;
+}
+#else
+static int bmi088_accel_set_power_state(struct bmi088_accel_data *data,
+	bool on)
+{
+	return 0;
+}
+#endif
+
+static int bmi088_accel_chip_init(struct bmi088_accel_data *data)
+{
+	struct device *dev = regmap_get_device(data->regmap);
+	int ret, i;
+	unsigned int val;
+
+	/* Do a dummy read (of chip ID), to enable SPI interface */
+	regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
+
+	/*
+	 * Reset chip to get it in a known good state. A delay of 1ms after
+	 * reset is required according to the data sheet
+	 */
+	regmap_write(data->regmap, BMI088_ACCEL_REG_RESET,
+		     BMI088_ACCEL_RESET_VAL);
+	usleep_range(1000, 2000);
+
+	/* Do a dummy read (of chip ID), to enable SPI interface after reset */
+	regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
+
+	/* Read chip ID */
+	ret = regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
+	if (ret < 0) {
+		dev_err(dev, "Error: Reading chip id\n");
+		return ret;
+	}
+
+	/* Validate chip ID */
+	dev_dbg(dev, "Chip Id %x\n", val);
+	for (i = 0; i < ARRAY_SIZE(bmi088_accel_chip_info_tbl); i++) {
+		if (bmi088_accel_chip_info_tbl[i].chip_id == val) {
+			data->chip_info = &bmi088_accel_chip_info_tbl[i];
+			break;
+		}
+	}
+
+	if (!data->chip_info) {
+		dev_err(dev, "Invalid chip %x\n", val);
+		return -ENODEV;
+	}
+
+	/* Set Active mode (and wait for 5ms) */
+	ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(5000, 10000);
+
+	/* Enable accelerometer */
+	ret = bmi088_accel_enable(data, true);
+	if (ret < 0)
+		return ret;
+
+	/* Set Bandwidth */
+	ret = bmi088_accel_set_bw(data, BMI088_ACCEL_MODE_ODR_100,
+		BMI088_ACCEL_MODE_OSR_NORMAL);
+	if (ret < 0)
+		return ret;
+
+	/* Set Default Range */
+	ret = regmap_write(data->regmap, BMI088_ACCEL_REG_ACC_RANGE,
+			   BMI088_ACCEL_RANGE_6G);
+	if (ret < 0) {
+		dev_err(dev, "Error writing ACC_RANGE\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap,
+	int irq, const char *name, bool block_supported)
+{
+	struct bmi088_accel_data *data;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	dev_set_drvdata(dev, indio_dev);
+
+	data->regmap = regmap;
+
+	ret = bmi088_accel_chip_init(data);
+	if (ret < 0)
+		return ret;
+
+	mutex_init(&data->mutex);
+
+	indio_dev->dev.parent = dev;
+	indio_dev->channels = data->chip_info->channels;
+	indio_dev->num_channels = data->chip_info->num_channels;
+	indio_dev->name = name ? name : data->chip_info->name;
+	indio_dev->available_scan_masks = bmi088_accel_scan_masks;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &bmi088_accel_info;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(dev, "Unable to register iio device\n");
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(bmi088_accel_core_probe);
+
+int bmi088_accel_core_remove(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+	pm_runtime_put_noidle(dev);
+
+	mutex_lock(&data->mutex);
+	bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(bmi088_accel_core_remove);
+
+#ifdef CONFIG_PM_SLEEP
+static int bmi088_accel_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+	bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+
+static int bmi088_accel_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+	mutex_lock(&data->mutex);
+	bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
+	mutex_unlock(&data->mutex);
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM
+static int bmi088_accel_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+	int ret;
+
+	dev_dbg(dev,  __func__);
+	ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+	if (ret < 0)
+		return -EAGAIN;
+
+	return 0;
+}
+
+static int bmi088_accel_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = dev_get_drvdata(dev);
+	struct bmi088_accel_data *data = iio_priv(indio_dev);
+	int ret;
+
+	dev_dbg(dev,  __func__);
+
+	ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(BMI088_ACCEL_MAX_STARTUP_TIME_MS * 1000,
+		BMI088_ACCEL_MAX_STARTUP_TIME_MS * 1000 * 2);
+
+	return 0;
+}
+#endif
+
+const struct dev_pm_ops bmi088_accel_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(bmi088_accel_suspend, bmi088_accel_resume)
+	SET_RUNTIME_PM_OPS(bmi088_accel_runtime_suspend,
+			   bmi088_accel_runtime_resume, NULL)
+};
+EXPORT_SYMBOL_GPL(bmi088_accel_pm_ops);
+
+MODULE_AUTHOR("Niek van Agt <niek.van.agt@topicproducts.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMI088 accelerometer driver (core)");
diff --git a/drivers/iio/accel/bmi088-accel-spi.c b/drivers/iio/accel/bmi088-accel-spi.c
new file mode 100644
index 000000000000..920e146f07d3
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel-spi.c
@@ -0,0 +1,100 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
+ *  - BMI088
+ *
+ * Copyright (c) 2018, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+
+#include "bmi088-accel.h"
+
+int bmi088_regmap_spi_write(void *context, const void *data, size_t count)
+{
+	struct spi_device *spi = context;
+	u8 buf[count];
+
+	memcpy(buf, data, count);
+
+	dev_dbg(&spi->dev, "Write val: %x to reg: %x\n", buf[1], buf[0]);
+
+	/*
+	 * The SPI register address (= full register address without bit 7)
+	 * and the write command (bit7 = RW = '0')
+	 */
+	buf[0] &= ~0x80;
+
+	return spi_write(spi, buf, count);
+}
+
+int bmi088_regmap_spi_read(void *context, const void *reg,
+				size_t reg_size, void *val, size_t val_size)
+{
+	struct spi_device *spi = context;
+	u8 addr[reg_size + 1];
+
+	addr[0] = *(u8 *)reg;
+
+	dev_dbg(&spi->dev, "Read reg: %x\n", addr[0]);
+
+	addr[0] |= 0x80; /* bit7 = RW = '1' */
+
+	/* Do a write of 2 to mimic the dummy byte (see datasheet) */
+	return spi_write_then_read(spi, addr, sizeof(addr), val, val_size);
+}
+
+static struct regmap_bus bmi088_regmap_bus = {
+	.write = bmi088_regmap_spi_write,
+	.read = bmi088_regmap_spi_read,
+	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
+	.val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static int bmi088_accel_probe(struct spi_device *spi)
+{
+	struct regmap *regmap;
+	const struct spi_device_id *id = spi_get_device_id(spi);
+
+	regmap = devm_regmap_init(&spi->dev, &bmi088_regmap_bus,
+			spi, &bmi088_regmap_conf);
+
+	if (IS_ERR(regmap)) {
+		dev_err(&spi->dev, "Failed to initialize spi regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	return bmi088_accel_core_probe(&spi->dev, regmap, spi->irq, id->name,
+				       true);
+}
+
+static int bmi088_accel_remove(struct spi_device *spi)
+{
+	return bmi088_accel_core_remove(&spi->dev);
+}
+
+static const struct spi_device_id bmi088_accel_id[] = {
+	{"bmi088_accel", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(spi, bmi088_accel_id);
+
+static struct spi_driver bmi088_accel_driver = {
+	.driver = {
+		.name	= "bmi088_accel_spi",
+	},
+	.probe		= bmi088_accel_probe,
+	.remove		= bmi088_accel_remove,
+	.id_table	= bmi088_accel_id,
+};
+module_spi_driver(bmi088_accel_driver);
+
+MODULE_AUTHOR("Niek van Agt <niek.van.agt@topicproducts.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMI088 accelerometer driver (SPI)");
diff --git a/drivers/iio/accel/bmi088-accel.h b/drivers/iio/accel/bmi088-accel.h
new file mode 100644
index 000000000000..540993647c75
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel.h
@@ -0,0 +1,11 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BMI088_ACCEL_H
+#define BMI088_ACCEL_H
+
+extern const struct regmap_config bmi088_regmap_conf;
+
+int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap, int irq,
+			    const char *name, bool block_supported);
+int bmi088_accel_core_remove(struct device *dev);
+
+#endif /* BMI088_ACCEL_H */