Re: [PATCH] iio: orientation: Add BNO055 9-axis Absolute Orientation Sensor driver
From: Peter Meerwald-Stadler
Date: Tue Jul 26 2016 - 04:07:51 EST
> BNO055 provides the following motion sensors data:
>
> * Gyroscope
> * Accelerometer
> * Magnetometer
> * Absolute Orientation (Quaternion)
comments below
> Signed-off-by: navin patidar <navin.patidar@xxxxxxxxx>
> ---
> drivers/iio/orientation/Kconfig | 10 +
> drivers/iio/orientation/Makefile | 1 +
> drivers/iio/orientation/bno055.c | 422 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 433 insertions(+)
> create mode 100644 drivers/iio/orientation/bno055.c
>
> diff --git a/drivers/iio/orientation/Kconfig b/drivers/iio/orientation/Kconfig
> index e3aa1e5..9ac21ee 100644
> --- a/drivers/iio/orientation/Kconfig
> +++ b/drivers/iio/orientation/Kconfig
> @@ -28,4 +28,14 @@ config HID_SENSOR_DEVICE_ROTATION
> device rotation. The output of a device rotation sensor
> is presented using quaternion format.
>
> +config BNO055
> + tristate "BOSCH BNO055 Absolute Orientation"
> + depends on I2C
> + select REGMAP_I2C
> + help
> + Say yes here to build support for BOSCH BNO55 9-axis absolute orientation sensor
> + driver connected via I2C.
> + This driver can also be built as a module. If so, the module
> + will be called bno055.
> +
> endmenu
> diff --git a/drivers/iio/orientation/Makefile b/drivers/iio/orientation/Makefile
> index 4734dab..7d00037 100644
> --- a/drivers/iio/orientation/Makefile
> +++ b/drivers/iio/orientation/Makefile
> @@ -5,3 +5,4 @@
> # When adding new entries keep the list in alphabetical order
> obj-$(CONFIG_HID_SENSOR_INCLINOMETER_3D) += hid-sensor-incl-3d.o
> obj-$(CONFIG_HID_SENSOR_DEVICE_ROTATION) += hid-sensor-rotation.o
> +obj-$(CONFIG_BNO055) += bno055.o
> diff --git a/drivers/iio/orientation/bno055.c b/drivers/iio/orientation/bno055.c
> new file mode 100644
> index 0000000..48b9e93
> --- /dev/null
> +++ b/drivers/iio/orientation/bno055.c
> @@ -0,0 +1,422 @@
> +/*
> + * Copyright (c) 2016 Intel Corporation
> + *
> + * Driver for Bosch Sensortec BNO055 digital motion 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.
> + *
I find it useful to state the 7-bit i2c chip address here
> + */
> +
> +#define pr_fmt(fmt) "bno055: " 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>
> +
drop one newline
> +
> +#define BNO055_CHIP_ID 0xA0
> +#define REG_MAG_RADIUS_MSB 0x6A
please consistently prefix with BNO055_
> +
> +/* BNO055 configuration registers */
> +#define REG_PWR_MODE 0x3E
> +#define REG_OPR_MODE 0x3D
> +#define REG_UNIT_SEL 0x3B
> +#define REG_AXIS_MAP_SIGN 0x42
> +#define REG_AXIS_MAP_CONFIG 0x41
> +#define REG_UNIT_SEL 0x3B
> +#define REG_SYS_TRIGGER 0x3F
> +#define BNO055_REG_PAGE_ID 0x07
> +#define BNO055_REG_ID 0x00
> +
> +/* BNO055 status registers */
> +#define SYS_STATUS 0x39
> +#define INT_STATUS 0x37
> +#define CALIB_STATUS 0x35
> +
> +/* BNO055 data registers */
drop newline
> +
> +#define GRV_DATA_Z_MSB 0x33
> +#define GRV_DATA_Z_LSB 0x32
> +#define GRV_DATA_Y_MSB 0x31
> +#define GRV_DATA_Y_LSB 0x30
> +#define GRV_DATA_X_MSB 0x2F
> +#define GRV_DATA_X_LSB 0x2E
do we really need all those register #defines?
they are not used and noone wants to read just the LSB...
> +
> +#define LIA_DATA_Z_MSB 0x2D
> +#define LIA_DATA_Z_LSB 0x2C
> +#define LIA_DATA_Y_MSB 0x2B
> +#define LIA_DATA_Y_LSB 0x2A
> +#define LIA_DATA_X_MSB 0x29
> +#define LIA_DATA_X_LSB 0x28
> +
> +#define QUA_DATA_Z_MSB 0x27
> +#define QUA_DATA_Z_LSB 0x26
> +#define QUA_DATA_Y_MSB 0x25
> +#define QUA_DATA_Y_LSB 0x24
> +#define QUA_DATA_X_MSB 0x23
> +#define QUA_DATA_X_LSB 0x22
> +#define QUA_DATA_W_MSB 0x21
> +#define QUA_DATA_W_LSB 0x20
> +
> +#define EUL_PITCH_MSB 0x1F
> +#define EUL_PITCH_LSB 0x1E
> +#define EUL_ROLL_MSB 0x1D
> +#define EUL_ROLL_LSB 0x1C
> +#define EUL_HEADING_MSB 0x1B
> +#define EUL_HEADING_LSB 0x1A
> +
> +#define GYR_DATA_Z_MSB 0x19
> +#define GYR_DATA_Z_LSB 0x18
> +#define GYR_DATA_Y_MSB 0x17
> +#define GYR_DATA_Y_LSB 0x16
> +#define GYR_DATA_X_MSB 0x15
> +#define GYR_DATA_X_LSB 0x14
> +
> +#define MAG_DATA_Z_MSB 0x13
> +#define MAG_DATA_Z_LSB 0x12
> +#define MAG_DATA_Y_MSB 0x11
> +#define MAG_DATA_Y_LSB 0x10
> +#define MAG_DATA_X_MSB 0x0F
> +#define MAG_DATA_X_LSB 0x0E
> +
> +#define ACC_DATA_Z_MSB 0x0D
> +#define ACC_DATA_Z_LSB 0x0C
> +#define ACC_DATA_Y_MSB 0x0B
> +#define ACC_DATA_Y_LSB 0x0A
> +#define ACC_DATA_X_MSB 0x09
> +#define ACC_DATA_X_LSB 0x08
> +
> +/* operation modes */
> +#define FUSION_NDOF_MODE 0x0C
> +
> +/* power modes */
> +#define NORMAL_MODE 0x00
> +#define LOW_POWER_MODE BIT(0)
> +#define SUSPEND_MODE BIT(1)
> +
> +#define PROPER_CALIBRATION 0xFF
> +
> +#define BASE_REG 0x08
> +#define SENSOR_AXIS_TO_REG(sensor,axis) (BASE_REG + (sensor * 6) + (axis * 2))
> +
> +#define BNO055_CHANNEL(_type, _axis) { \
> + .type = IIO_##_type, \
> + .modified = 1, \
> + .channel2 = IIO_MOD_##_axis, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
in what unit is the data returned; please check with IIO ABI documentation
I think you will likely need _SCALE for some channels
> + .scan_index = AXIS_##_axis, \
.scan_index is a continuous counter over ALL channels, not just for one
channel type
the driver does not support buffered reads, so not scan_type/scan_index is
needed anyway
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 16, \
> + .storagebits = 16, \
> + .endianness = IIO_LE, \
> + }, \
> +}
> +
> +struct bno055_data {
> + struct i2c_client *client;
> + struct mutex lock;
> + struct regmap *regmap;
> +};
> +
> +enum bno055_axis {
> + AXIS_X,
> + AXIS_Y,
> + AXIS_Z,
> +};
> +
> +enum {ACC=0, MAG=1, GYR=2, EUL=3, QUA=4};
prefix!
> +
> +static const struct iio_chan_spec bno055_channels[] = {
> + BNO055_CHANNEL(ANGL_VEL, X),
> + BNO055_CHANNEL(ANGL_VEL, Y),
> + BNO055_CHANNEL(ANGL_VEL, Z),
> + BNO055_CHANNEL(MAGN, X),
> + BNO055_CHANNEL(MAGN, Y),
> + BNO055_CHANNEL(MAGN, Z),
> + BNO055_CHANNEL(ACCEL, X),
> + BNO055_CHANNEL(ACCEL, Y),
> + BNO055_CHANNEL(ACCEL, Z),
> + {
> + .type = IIO_ROT,
> + .modified = 1,
> + .channel2 = IIO_MOD_QUATERNION,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + }
> +};
> +
> +static bool bno055_is_writeable_reg(struct device *dev, unsigned int reg)
> +{
> + switch (reg) {
> + case REG_PWR_MODE:
> + case REG_OPR_MODE:
> + case REG_UNIT_SEL:
> + case REG_AXIS_MAP_SIGN:
> + case REG_AXIS_MAP_CONFIG:
> + case REG_SYS_TRIGGER:
> + return true;
> + default:
> + return false;
> + };
> +}
> +
> +static bool bno055_is_volatile_reg(struct device *dev, unsigned int reg)
> +{
> + if ((reg >= ACC_DATA_X_LSB) && (reg <= QUA_DATA_Z_MSB))
> + return true;
> + else
> + return false;
> +}
> +
> +static const struct regmap_config bno055_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 8,
> +
> + .max_register = REG_MAG_RADIUS_MSB,
> + .cache_type = REGCACHE_RBTREE,
> +
> + .writeable_reg = bno055_is_writeable_reg,
> + .volatile_reg = bno055_is_volatile_reg,
> +};
> +
drop newline
> +
> +static int read_bno055(struct bno055_data *data, int sensor, int axis, int *val)
bno055 prefix please
> +{
> + int ret;
> + __le16 raw_val;
> + int reg;
> +
> + reg = SENSOR_AXIS_TO_REG(sensor, axis);
you can use .address in channel spec for that
> +
> + ret = regmap_bulk_read(data->regmap, reg, &raw_val,
> + sizeof(raw_val));
> + if (ret < 0) {
> + dev_err(&data->client->dev, "Error reading axis %d\n", axis);
> + return ret;
> + }
> +
> + *val = sign_extend32(le16_to_cpu(raw_val), 15);
> + return IIO_VAL_INT;
> +}
> +
> +/* Read raw quaternion values W,X,Y and Z.
> + * Raw values needs to be divied by the 16384 to get the exact quaternion values.
> + */
> +
> +static int read_rot(struct bno055_data *data, int *vals, int *val_len)
> +{
> + int ret, i;
> + __le16 raw_val[4];
> +
> + ret = regmap_bulk_read(data->regmap, QUA_DATA_W_LSB, &raw_val,
> + sizeof(raw_val));
> + if (ret < 0) {
> + dev_err(&data->client->dev, "Error reading Orientation \n");
lowercase orientation
delete space before \n
> + return ret;
> + }
> +
> + for (i = 0; i < 4; ++i)
> + vals[i] = sign_extend32(le16_to_cpu(raw_val[i]), 15);
> +
> + *val_len = 4;
> + return IIO_VAL_INT_MULTIPLE;
> +}
> +
> +static int bno055_read_raw_multi(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int size,
> + int *val, int *val2, long mask)
> +{
> + int ret = -EINVAL;
> + struct bno055_data *data = iio_priv(indio_dev);
> +
> + mutex_lock(&data->lock);
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + switch (chan->type) {
> + case IIO_ROT:
> + ret = read_rot(data, val, val2);
> + break;
> + case IIO_ANGL_VEL:
> + /* Gyroscope unit degrees per second */
> + /* Raw value needs to be divied by the 16 to get the exact value.*/
comment style, not a proper multi-line comment
use _SCALE, it is not about 'exact' but correct scaling/unit
typo: divided
wording: divided by 16
> + ret = read_bno055(data, GYR, chan->scan_index, val);
> + break;
> + case IIO_ACCEL:
> + /* Accelerometer Unit m/s2 */
> + /* Raw value needs to be divied by the 100 to get the exact value.*/
> + ret = read_bno055(data, ACC, chan->scan_index, val);
> + break;
> + case IIO_MAGN:
> + /* Magnetometer Unit microTesla */
> + /* Raw value needs to be divied by the 16 to get the exact value. */
> + ret = read_bno055(data, MAG, chan->scan_index, val);
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> + break;
> +
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + mutex_unlock(&data->lock);
> +
> + return ret;
> +}
> +
> +static const struct iio_info bno055_info = {
> + .driver_module = THIS_MODULE,
> + .read_raw_multi = &bno055_read_raw_multi,
> +};
> +
drop newline
> +
> +static int bno055_chip_init(struct bno055_data *data)
> +{
> + int ret;
> +
> + ret = regmap_write(data->regmap, REG_PWR_MODE,
> + NORMAL_MODE);
> + if (ret < 0) {
> + dev_err(&data->client->dev,
> + "failed to write power mode register\n");
> + return ret;
> + }
> +
> + ret = regmap_write(data->regmap, REG_OPR_MODE,
> + FUSION_NDOF_MODE);
> + if (ret < 0)
> + dev_err(&data->client->dev,
> + "failed to write operation mode register\n");
> +
> + return ret;
> +}
> +
> +static ssize_t show_calibration_status(struct device *dev, struct device_attribute *attr,
> + char *buf){
this is private API which needs to be documented
> + struct bno055_data *data;
> + int ret;
> + unsigned int calib_stat;
> +
> + data = dev->driver_data;
> +
> + ret = regmap_read(data->regmap, CALIB_STATUS, &calib_stat);
> +
> + if (ret){
space before {
> + dev_err(dev, "Failed to read calibration status.\n");
> + return ret;
> + }
> +
> + if (calib_stat != PROPER_CALIBRATION)
> + dev_info(dev, "bad calibration. expected %x got %x\n",
two spaces before 'expected'
> + PROPER_CALIBRATION, calib_stat);
> +
> + return scnprintf(buf, PAGE_SIZE, "0x%x\n", calib_stat);
> +}
> +
> +static DEVICE_ATTR(calib_status, 0444, show_calibration_status, NULL);
> +
> +static int bno055_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + int ret;
> + struct iio_dev *indio_dev;
> + struct bno055_data *data;
> + unsigned int chip_id;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + data = iio_priv(indio_dev);
> + mutex_init(&data->lock);
> + data->client = client;
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->name = id->name;
> + indio_dev->channels = bno055_channels;
> + indio_dev->num_channels = ARRAY_SIZE(bno055_channels);
> + indio_dev->info = &bno055_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + data->regmap = devm_regmap_init_i2c(client, &bno055_regmap_config);
> + if (IS_ERR(data->regmap)) {
> + dev_err(&client->dev, "Failed to allocate register map.\n");
> + return PTR_ERR(data->regmap);
> + }
> +
> + indio_dev->dev.driver_data = data;
> + i2c_set_clientdata(client, indio_dev);
> +
> + ret = regmap_read(data->regmap, BNO055_REG_ID, &chip_id);
> + if (ret < 0)
> + return ret;
> + if (chip_id != BNO055_CHIP_ID) {
> + dev_err(&client->dev, "bad chip id. expected %x got %x\n",
> + BNO055_CHIP_ID, chip_id);
> + return -EINVAL;
> + }
> +
> + ret = bno055_chip_init(data);
> + if (ret < 0)
> + return ret;
> +
> + ret = devm_iio_device_register(&client->dev, indio_dev);
> + if (ret){
space before {
> + dev_err(&client->dev, "failed to register IIO device.\n");
> + return ret;
> + }
> +
> + ret = device_create_file(&indio_dev->dev, &dev_attr_calib_status);
needs to be done BEFORE devm_iio_device_register()
IIO has specific mechanisms to create custom sysfs entries...
> + if (ret){
space before {
> + dev_err(&client->dev, "failed to create sysfs entry.\n");
> + devm_iio_device_unregister(&client->dev, indio_dev);
no need to call devm_iio_device_unregister
> + return ret;
> + }
> +
> + return ret;
> +}
> +
> +static int bno055_remove(struct i2c_client *client)
> +{
> + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> + device_remove_file(&indio_dev->dev, &dev_attr_calib_status);
> + devm_iio_device_unregister(&client->dev, indio_dev);
> + return 0;
> +}
> +
> +static const struct acpi_device_id bno055_acpi_match[] = {
> + {"bno055", 0},
> + { },
> +};
> +MODULE_DEVICE_TABLE(acpi, bno055_acpi_match);
> +
> +static const struct i2c_device_id bno055_id[] = {
> + {"bno055", 0},
> + { },
> +};
> +MODULE_DEVICE_TABLE(i2c, bno055_id);
> +
> +static struct i2c_driver bno055_driver = {
> + .driver = {
> + .name = "bno055",
> + .acpi_match_table = ACPI_PTR(bno055_acpi_match),
> + },
> + .probe = bno055_probe,
> + .remove = bno055_remove,
> + .id_table = bno055_id,
> +};
> +module_i2c_driver(bno055_driver);
> +
> +MODULE_AUTHOR("navin patidar <navin.patidar@xxxxxxxxx>");
> +MODULE_DESCRIPTION("Driver for Bosch Sensortec BNO055 orientation sensor");
> +MODULE_LICENSE("GPL v2");
>
--
Peter Meerwald-Stadler
+43-664-2444418 (mobile)