diff mbox series

[v5,08/14] iio: imu: add Bosch Sensortec BNO055 core driver

Message ID 20220426131102.23966-9-andrea.merello@gmail.com
State New
Headers show
Series [v5,01/14] iio: add modifiers for linear acceleration | expand

Commit Message

Andrea Merello April 26, 2022, 1:10 p.m. UTC
From: Andrea Merello <andrea.merello@iit.it>

Add the core driver for the BNO055 IMU from Bosch. This IMU can be
connected via both serial and I2C busses; separate patches will add support
for them.

The driver supports "AMG" (Accelerometer, Magnetometer, Gyroscope) mode,
that provides raw data from the said internal sensors, and a couple of
"fusion" modes (i.e. the IMU also do calculations in order to provide euler
angles, quaternions, linear acceleration and gravity measurements).

In fusion modes the AMG data is still available (with some calibration
refinements done by the IMU), but certain settings such as low pass filters
cut-off frequency and sensors ranges are fixed, while in AMG mode they can
be customized; this is why AMG mode can still be interesting.

Signed-off-by: Andrea Merello <andrea.merello@iit.it>
---
 drivers/iio/imu/Kconfig         |    1 +
 drivers/iio/imu/Makefile        |    1 +
 drivers/iio/imu/bno055/Kconfig  |    4 +
 drivers/iio/imu/bno055/Makefile |    3 +
 drivers/iio/imu/bno055/bno055.c | 1710 +++++++++++++++++++++++++++++++
 drivers/iio/imu/bno055/bno055.h |   12 +
 6 files changed, 1731 insertions(+)
 create mode 100644 drivers/iio/imu/bno055/Kconfig
 create mode 100644 drivers/iio/imu/bno055/Makefile
 create mode 100644 drivers/iio/imu/bno055/bno055.c
 create mode 100644 drivers/iio/imu/bno055/bno055.h
diff mbox series

Patch

diff --git a/drivers/iio/imu/Kconfig b/drivers/iio/imu/Kconfig
index 001ca2c3ff95..f1d7d4b5e222 100644
--- a/drivers/iio/imu/Kconfig
+++ b/drivers/iio/imu/Kconfig
@@ -52,6 +52,7 @@  config ADIS16480
 	  ADIS16485, ADIS16488 inertial sensors.
 
 source "drivers/iio/imu/bmi160/Kconfig"
+source "drivers/iio/imu/bno055/Kconfig"
 
 config FXOS8700
 	tristate
diff --git a/drivers/iio/imu/Makefile b/drivers/iio/imu/Makefile
index c82748096c77..6eb612034722 100644
--- a/drivers/iio/imu/Makefile
+++ b/drivers/iio/imu/Makefile
@@ -15,6 +15,7 @@  adis_lib-$(CONFIG_IIO_ADIS_LIB_BUFFER) += adis_buffer.o
 obj-$(CONFIG_IIO_ADIS_LIB) += adis_lib.o
 
 obj-y += bmi160/
+obj-y += bno055/
 
 obj-$(CONFIG_FXOS8700) += fxos8700_core.o
 obj-$(CONFIG_FXOS8700_I2C) += fxos8700_i2c.o
diff --git a/drivers/iio/imu/bno055/Kconfig b/drivers/iio/imu/bno055/Kconfig
new file mode 100644
index 000000000000..d0ab3221fba5
--- /dev/null
+++ b/drivers/iio/imu/bno055/Kconfig
@@ -0,0 +1,4 @@ 
+# SPDX-License-Identifier: GPL-2.0
+
+config BOSCH_BNO055_IIO
+	tristate
diff --git a/drivers/iio/imu/bno055/Makefile b/drivers/iio/imu/bno055/Makefile
new file mode 100644
index 000000000000..56cc4de60a7e
--- /dev/null
+++ b/drivers/iio/imu/bno055/Makefile
@@ -0,0 +1,3 @@ 
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_BOSCH_BNO055_IIO) += bno055.o
diff --git a/drivers/iio/imu/bno055/bno055.c b/drivers/iio/imu/bno055/bno055.c
new file mode 100644
index 000000000000..4b79e1913b4c
--- /dev/null
+++ b/drivers/iio/imu/bno055/bno055.c
@@ -0,0 +1,1710 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * IIO driver for Bosch BNO055 IMU
+ *
+ * Copyright (C) 2021-2022 Istituto Italiano di Tecnologia
+ * Electronic Design Laboratory
+ * Written by Andrea Merello <andrea.merello@iit.it>
+ *
+ * Portions of this driver are taken from the BNO055 driver patch
+ * from Vlad Dogaru which is Copyright (c) 2016, Intel Corporation.
+ *
+ * This driver is also based on BMI160 driver, which is:
+ *	Copyright (c) 2016, Intel Corporation.
+ *	Copyright (c) 2019, Martin Kelly.
+ */
+
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/bitfield.h>
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/util_macros.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+
+#include "bno055.h"
+
+#define BNO055_FW_NAME "bno055-caldata"
+#define BNO055_FW_EXT ".dat"
+#define BNO055_FW_UID_NAME BNO055_FW_NAME "-%*phN" BNO055_FW_EXT
+#define BNO055_FW_GENERIC_NAME (BNO055_FW_NAME BNO055_FW_EXT)
+
+/* common registers */
+#define BNO055_PAGESEL_REG		0x7
+
+/* page 0 registers */
+#define BNO055_CHIP_ID_REG		0x0
+#define BNO055_CHIP_ID_MAGIC 0xA0
+#define BNO055_SW_REV_LSB_REG		0x4
+#define BNO055_SW_REV_MSB_REG		0x5
+#define BNO055_ACC_DATA_X_LSB_REG	0x8
+#define BNO055_ACC_DATA_Y_LSB_REG	0xA
+#define BNO055_ACC_DATA_Z_LSB_REG	0xC
+#define BNO055_MAG_DATA_X_LSB_REG	0xE
+#define BNO055_MAG_DATA_Y_LSB_REG	0x10
+#define BNO055_MAG_DATA_Z_LSB_REG	0x12
+#define BNO055_GYR_DATA_X_LSB_REG	0x14
+#define BNO055_GYR_DATA_Y_LSB_REG	0x16
+#define BNO055_GYR_DATA_Z_LSB_REG	0x18
+#define BNO055_EUL_DATA_X_LSB_REG	0x1A
+#define BNO055_EUL_DATA_Y_LSB_REG	0x1C
+#define BNO055_EUL_DATA_Z_LSB_REG	0x1E
+#define BNO055_QUAT_DATA_W_LSB_REG	0x20
+#define BNO055_LIA_DATA_X_LSB_REG	0x28
+#define BNO055_LIA_DATA_Y_LSB_REG	0x2A
+#define BNO055_LIA_DATA_Z_LSB_REG	0x2C
+#define BNO055_GRAVITY_DATA_X_LSB_REG	0x2E
+#define BNO055_GRAVITY_DATA_Y_LSB_REG	0x30
+#define BNO055_GRAVITY_DATA_Z_LSB_REG	0x32
+#define BNO055_SCAN_CH_COUNT ((BNO055_GRAVITY_DATA_Z_LSB_REG - BNO055_ACC_DATA_X_LSB_REG) / 2)
+#define BNO055_TEMP_REG			0x34
+#define BNO055_CALIB_STAT_REG		0x35
+#define BNO055_CALIB_STAT_MASK GENMASK(1, 0)
+#define BNO055_CALIB_STAT_MAGN_SHIFT 0
+#define BNO055_CALIB_STAT_ACCEL_SHIFT 2
+#define BNO055_CALIB_STAT_GYRO_SHIFT 4
+#define BNO055_CALIB_STAT_SYS_SHIFT 6
+#define BNO055_SYS_ERR_REG		0x3A
+#define BNO055_POWER_MODE_REG		0x3E
+#define BNO055_POWER_MODE_NORMAL 0
+#define BNO055_SYS_TRIGGER_REG		0x3F
+#define BNO055_SYS_TRIGGER_RST_SYS BIT(5)
+#define BNO055_SYS_TRIGGER_CLK_SEL BIT(7)
+#define BNO055_OPR_MODE_REG		0x3D
+#define BNO055_OPR_MODE_CONFIG 0x0
+#define BNO055_OPR_MODE_AMG 0x7
+#define BNO055_OPR_MODE_FUSION_FMC_OFF 0xB
+#define BNO055_OPR_MODE_FUSION 0xC
+#define BNO055_UNIT_SEL_REG		0x3B
+/* Android orientation mode means: pitch value decreases turning clockwise */
+#define BNO055_UNIT_SEL_ANDROID BIT(7)
+#define BNO055_UNIT_SEL_GYR_RPS BIT(1)
+#define BNO055_CALDATA_START		0x55
+#define BNO055_CALDATA_END		0x6A
+#define BNO055_CALDATA_LEN 22
+
+/*
+ * The difference in address between the register that contains the
+ * value and the register that contains the offset.  This applies for
+ * accel, gyro and magn channels.
+ */
+#define BNO055_REG_OFFSET_ADDR		0x4D
+
+/* page 1 registers */
+#define BNO055_PG1(x) ((x) | 0x80)
+#define BNO055_ACC_CONFIG_REG		BNO055_PG1(0x8)
+#define BNO055_ACC_CONFIG_LPF_MASK GENMASK(4, 2)
+#define BNO055_ACC_CONFIG_RANGE_MASK GENMASK(1, 0)
+#define BNO055_MAG_CONFIG_REG		BNO055_PG1(0x9)
+#define BNO055_MAG_CONFIG_HIGHACCURACY 0x18
+#define BNO055_MAG_CONFIG_ODR_MASK GENMASK(2, 0)
+#define BNO055_GYR_CONFIG_REG		BNO055_PG1(0xA)
+#define BNO055_GYR_CONFIG_RANGE_MASK GENMASK(2, 0)
+#define BNO055_GYR_CONFIG_LPF_MASK GENMASK(5, 3)
+#define BNO055_GYR_AM_SET_REG		BNO055_PG1(0x1F)
+#define BNO055_UID_LOWER_REG		BNO055_PG1(0x50)
+#define BNO055_UID_HIGHER_REG		BNO055_PG1(0x5F)
+#define BNO055_UID_LEN 16
+
+struct bno055_sysfs_attr {
+	int *vals;
+	int len;
+	int *fusion_vals;
+	int *hw_xlate;
+	int type;
+};
+
+#define BNO055_ATTR_VALS(...)		\
+	.vals = (int[]){ __VA_ARGS__},	\
+	.len = ARRAY_SIZE(((int[]){__VA_ARGS__}))
+
+static struct bno055_sysfs_attr bno055_acc_lpf = {
+	BNO055_ATTR_VALS(7, 810000, 15, 630000,
+			 31, 250000, 62, 500000, 125, 0,
+			 250, 0, 500, 0, 1000, 0),
+	.fusion_vals = (int[]){62, 500000},
+	.type = IIO_VAL_INT_PLUS_MICRO
+};
+
+static struct bno055_sysfs_attr bno055_acc_range = {
+		     /* G:   2,    4,    8,    16 */
+	BNO055_ATTR_VALS(1962, 3924, 7848, 15696),
+	.fusion_vals = (int[]){3924}, /* 4G */
+	.type = IIO_VAL_INT
+};
+
+/*
+ * Theoretically the IMU should return data in a given (i.e. fixed) unit
+ * regardless the range setting. This happens for the accelerometer, but not for
+ * the gyroscope; the gyroscope range setting affects the scale.
+ * This is probably due to this[0] bug.
+ * For this reason we map the internal range setting onto the standard IIO scale
+ * attribute for gyro.
+ * Since the bug[0] may be fixed in future, we check for the IMU FW version and
+ * eventually warn the user.
+ * Currently we just don't care about "range" attributes for gyro.
+ *
+ * [0]  https://community.bosch-sensortec.com/t5/MEMS-sensors-forum/BNO055-Wrong-sensitivity-resolution-in-datasheet/td-p/10266
+ */
+static struct bno055_sysfs_attr bno055_gyr_scale = {
+	/*
+	 * dps = hwval * (dps_range/2^15)
+	 * rps = hwval * (rps_range/2^15)
+	 *     = hwval * (dps_range/(2^15 * k))
+	 * where k is rad-to-deg factor
+	 */
+	BNO055_ATTR_VALS(125, 1877467, 250, 1877467,
+			 500, 1877467, 1000, 1877467,
+			 2000, 1877467),
+	.fusion_vals = (int[]){1, 900},
+	.hw_xlate = (int[]){4, 3, 2, 1, 0},
+	.type = IIO_VAL_FRACTIONAL
+};
+
+static struct bno055_sysfs_attr bno055_gyr_lpf = {
+	BNO055_ATTR_VALS(12, 23, 32, 47, 64, 116, 230, 523),
+	.fusion_vals = (int[]){32},
+	.hw_xlate = (int[]){5, 4, 7, 3, 6, 2, 1, 0},
+	.type = IIO_VAL_INT
+};
+
+static struct bno055_sysfs_attr bno055_mag_odr = {
+	BNO055_ATTR_VALS(2, 6, 8, 10, 15, 20, 25, 30),
+	.fusion_vals = (int[]){20},
+	.type = IIO_VAL_INT
+};
+
+struct bno055_priv {
+	struct regmap *regmap;
+	struct device *dev;
+	struct clk *clk;
+	int operation_mode;
+	int xfer_burst_break_thr;
+	struct mutex lock;
+	u8 uid[BNO055_UID_LEN];
+	struct gpio_desc *reset_gpio;
+	bool sw_reset;
+	struct {
+		__le16 chans[BNO055_SCAN_CH_COUNT];
+		s64 timestamp __aligned(8);
+	} buf;
+#ifdef CONFIG_DEBUG_FS
+	struct dentry *debugfs;
+#endif
+};
+
+static bool bno055_regmap_volatile(struct device *dev, unsigned int reg)
+{
+	/* data and status registers */
+	if (reg >= BNO055_ACC_DATA_X_LSB_REG && reg <= BNO055_SYS_ERR_REG)
+		return true;
+
+	/* when in fusion mode, config is updated by chip */
+	if (reg == BNO055_MAG_CONFIG_REG ||
+	    reg == BNO055_ACC_CONFIG_REG ||
+	    reg == BNO055_GYR_CONFIG_REG)
+		return true;
+
+	/* calibration data may be updated by the IMU */
+	if (reg >= BNO055_CALDATA_START && reg <= BNO055_CALDATA_END)
+		return true;
+
+	return false;
+}
+
+static bool bno055_regmap_readable(struct device *dev, unsigned int reg)
+{
+	/* unnamed PG0 reserved areas */
+	if ((reg < BNO055_PG1(0) && reg > BNO055_CALDATA_END) ||
+	    reg == 0x3C)
+		return false;
+
+	/* unnamed PG1 reserved areas */
+	if (reg > BNO055_PG1(BNO055_UID_HIGHER_REG) ||
+	    (reg < BNO055_PG1(BNO055_UID_LOWER_REG) && reg > BNO055_PG1(BNO055_GYR_AM_SET_REG)) ||
+	    reg == BNO055_PG1(0xE) ||
+	    (reg < BNO055_PG1(BNO055_PAGESEL_REG) && reg >= BNO055_PG1(0x0)))
+		return false;
+	return true;
+}
+
+static bool bno055_regmap_writeable(struct device *dev, unsigned int reg)
+{
+	/*
+	 * Unreadable registers are indeed reserved; there are no WO regs
+	 * (except for a single bit in SYS_TRIGGER register)
+	 */
+	if (!bno055_regmap_readable(dev, reg))
+		return false;
+
+	/* data and status registers */
+	if (reg >= BNO055_ACC_DATA_X_LSB_REG && reg <= BNO055_SYS_ERR_REG)
+		return false;
+
+	/* ID areas */
+	if (reg < BNO055_PAGESEL_REG ||
+	    (reg <= BNO055_UID_HIGHER_REG && reg >= BNO055_UID_LOWER_REG))
+		return false;
+
+	return true;
+}
+
+static const struct regmap_range_cfg bno055_regmap_ranges[] = {
+	{
+		.range_min = 0,
+		.range_max = 0x7f * 2,
+		.selector_reg = BNO055_PAGESEL_REG,
+		.selector_mask = GENMASK(7, 0),
+		.selector_shift = 0,
+		.window_start = 0,
+		.window_len = 0x80
+	},
+};
+
+const struct regmap_config bno055_regmap_config = {
+	.name = "bno055",
+	.reg_bits = 8,
+	.val_bits = 8,
+	.ranges = bno055_regmap_ranges,
+	.num_ranges = 1,
+	.volatile_reg = bno055_regmap_volatile,
+	.max_register = 0x80 * 2,
+	.writeable_reg = bno055_regmap_writeable,
+	.readable_reg = bno055_regmap_readable,
+	.cache_type = REGCACHE_RBTREE,
+};
+EXPORT_SYMBOL_NS_GPL(bno055_regmap_config, IIO_BNO055);
+
+/* must be called in configuration mode */
+static int bno055_calibration_load(struct bno055_priv *priv, const u8 *data, int len)
+{
+	if (len != BNO055_CALDATA_LEN) {
+		dev_dbg(priv->dev, "Invalid calibration file size %d (expected %d)",
+			len, BNO055_CALDATA_LEN);
+		return -EINVAL;
+	}
+
+	dev_dbg(priv->dev, "loading cal data: %*ph", BNO055_CALDATA_LEN, data);
+	return regmap_bulk_write(priv->regmap, BNO055_CALDATA_START,
+				 data, BNO055_CALDATA_LEN);
+}
+
+static int bno055_operation_mode_do_set(struct bno055_priv *priv,
+					int operation_mode)
+{
+	int ret;
+
+	ret = regmap_write(priv->regmap, BNO055_OPR_MODE_REG,
+			   operation_mode);
+	if (ret)
+		return ret;
+
+	msleep(20);
+
+	return 0;
+}
+
+static int bno055_system_reset(struct bno055_priv *priv)
+{
+	int ret;
+
+	if (priv->reset_gpio) {
+		gpiod_set_value_cansleep(priv->reset_gpio, 0);
+		usleep_range(5000, 10000);
+		gpiod_set_value_cansleep(priv->reset_gpio, 1);
+	} else {
+		if (!priv->sw_reset)
+			return 0;
+
+		ret = regmap_write(priv->regmap, BNO055_SYS_TRIGGER_REG,
+				   BNO055_SYS_TRIGGER_RST_SYS);
+		if (ret)
+			return ret;
+	}
+
+	regcache_drop_region(priv->regmap, 0x0, 0xff);
+	usleep_range(650000, 700000);
+
+	return 0;
+}
+
+static int bno055_init(struct bno055_priv *priv, const u8 *caldata, int len)
+{
+	int ret;
+
+	ret = bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_CONFIG);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, BNO055_POWER_MODE_REG,
+			   BNO055_POWER_MODE_NORMAL);
+	if (ret)
+		return ret;
+
+	ret = regmap_write(priv->regmap, BNO055_SYS_TRIGGER_REG,
+			   priv->clk ? BNO055_SYS_TRIGGER_CLK_SEL : 0);
+	if (ret)
+		return ret;
+
+	/* use standard SI units */
+	ret = regmap_write(priv->regmap, BNO055_UNIT_SEL_REG,
+			   BNO055_UNIT_SEL_ANDROID | BNO055_UNIT_SEL_GYR_RPS);
+	if (ret)
+		return ret;
+
+	if (caldata) {
+		ret = bno055_calibration_load(priv, caldata, len);
+		if (ret)
+			dev_warn(priv->dev, "failed to load calibration data with error %d",
+				 ret);
+	}
+
+	return 0;
+}
+
+static ssize_t bno055_operation_mode_set(struct bno055_priv *priv,
+					 int operation_mode)
+{
+	u8 caldata[BNO055_CALDATA_LEN];
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	ret = bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_CONFIG);
+	if (ret)
+		goto exit;
+
+	if (operation_mode == BNO055_OPR_MODE_FUSION ||
+	    operation_mode == BNO055_OPR_MODE_FUSION_FMC_OFF) {
+		/* for entering fusion mode, reset the chip to clear the algo state */
+		ret = regmap_bulk_read(priv->regmap, BNO055_CALDATA_START, caldata,
+				       BNO055_CALDATA_LEN);
+		if (ret)
+			goto exit;
+
+		ret = bno055_system_reset(priv);
+		if (ret)
+			goto exit;
+
+		ret = bno055_init(priv, caldata, BNO055_CALDATA_LEN);
+		if (ret)
+			goto exit;
+	}
+
+	ret = bno055_operation_mode_do_set(priv, operation_mode);
+	if (ret)
+		goto exit;
+
+	priv->operation_mode = operation_mode;
+
+exit:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static void bno055_uninit(void *arg)
+{
+	struct bno055_priv *priv = arg;
+
+	/* stop the IMU */
+	bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_CONFIG);
+}
+
+#define BNO055_CHANNEL(_type, _axis, _index, _address, _sep, _sh, _avail) {	\
+	.address = _address,							\
+	.type = _type,								\
+	.modified = 1,								\
+	.channel2 = IIO_MOD_##_axis,						\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | (_sep),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | (_sh),		\
+	.info_mask_shared_by_type_available = _avail,				\
+	.scan_index = _index,							\
+	.scan_type = {								\
+		.sign = 's',							\
+		.realbits = 16,							\
+		.storagebits = 16,						\
+		.endianness = IIO_LE,						\
+		.repeat = IIO_MOD_##_axis == IIO_MOD_QUATERNION ? 4 : 0		\
+	},									\
+}
+
+/* scan indexes follow DATA register order */
+enum bno055_scan_axis {
+	BNO055_SCAN_ACCEL_X,
+	BNO055_SCAN_ACCEL_Y,
+	BNO055_SCAN_ACCEL_Z,
+	BNO055_SCAN_MAGN_X,
+	BNO055_SCAN_MAGN_Y,
+	BNO055_SCAN_MAGN_Z,
+	BNO055_SCAN_GYRO_X,
+	BNO055_SCAN_GYRO_Y,
+	BNO055_SCAN_GYRO_Z,
+	BNO055_SCAN_YAW,
+	BNO055_SCAN_ROLL,
+	BNO055_SCAN_PITCH,
+	BNO055_SCAN_QUATERNION,
+	BNO055_SCAN_LIA_X,
+	BNO055_SCAN_LIA_Y,
+	BNO055_SCAN_LIA_Z,
+	BNO055_SCAN_GRAVITY_X,
+	BNO055_SCAN_GRAVITY_Y,
+	BNO055_SCAN_GRAVITY_Z,
+	BNO055_SCAN_TIMESTAMP,
+	_BNO055_SCAN_MAX
+};
+
+static const struct iio_chan_spec bno055_channels[] = {
+	/* accelerometer */
+	BNO055_CHANNEL(IIO_ACCEL, X, BNO055_SCAN_ACCEL_X,
+		       BNO055_ACC_DATA_X_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)),
+	BNO055_CHANNEL(IIO_ACCEL, Y, BNO055_SCAN_ACCEL_Y,
+		       BNO055_ACC_DATA_Y_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)),
+	BNO055_CHANNEL(IIO_ACCEL, Z, BNO055_SCAN_ACCEL_Z,
+		       BNO055_ACC_DATA_Z_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY)),
+	/* gyroscope */
+	BNO055_CHANNEL(IIO_ANGL_VEL, X, BNO055_SCAN_GYRO_X,
+		       BNO055_GYR_DATA_X_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |
+		       BIT(IIO_CHAN_INFO_SCALE)),
+	BNO055_CHANNEL(IIO_ANGL_VEL, Y, BNO055_SCAN_GYRO_Y,
+		       BNO055_GYR_DATA_Y_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |
+		       BIT(IIO_CHAN_INFO_SCALE)),
+	BNO055_CHANNEL(IIO_ANGL_VEL, Z, BNO055_SCAN_GYRO_Z,
+		       BNO055_GYR_DATA_Z_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),
+		       BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY) |
+		       BIT(IIO_CHAN_INFO_SCALE)),
+	/* magnetometer */
+	BNO055_CHANNEL(IIO_MAGN, X, BNO055_SCAN_MAGN_X,
+		       BNO055_MAG_DATA_X_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_SAMP_FREQ), BIT(IIO_CHAN_INFO_SAMP_FREQ)),
+	BNO055_CHANNEL(IIO_MAGN, Y, BNO055_SCAN_MAGN_Y,
+		       BNO055_MAG_DATA_Y_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_SAMP_FREQ), BIT(IIO_CHAN_INFO_SAMP_FREQ)),
+	BNO055_CHANNEL(IIO_MAGN, Z, BNO055_SCAN_MAGN_Z,
+		       BNO055_MAG_DATA_Z_LSB_REG, BIT(IIO_CHAN_INFO_OFFSET),
+		       BIT(IIO_CHAN_INFO_SAMP_FREQ), BIT(IIO_CHAN_INFO_SAMP_FREQ)),
+	/* euler angle */
+	BNO055_CHANNEL(IIO_ROT, YAW, BNO055_SCAN_YAW,
+		       BNO055_EUL_DATA_X_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_ROT, ROLL, BNO055_SCAN_ROLL,
+		       BNO055_EUL_DATA_Y_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_ROT, PITCH, BNO055_SCAN_PITCH,
+		       BNO055_EUL_DATA_Z_LSB_REG, 0, 0, 0),
+	/* quaternion */
+	BNO055_CHANNEL(IIO_ROT, QUATERNION, BNO055_SCAN_QUATERNION,
+		       BNO055_QUAT_DATA_W_LSB_REG, 0, 0, 0),
+
+	/* linear acceleration */
+	BNO055_CHANNEL(IIO_ACCEL, LINEAR_X, BNO055_SCAN_LIA_X,
+		       BNO055_LIA_DATA_X_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_ACCEL, LINEAR_Y, BNO055_SCAN_LIA_Y,
+		       BNO055_LIA_DATA_Y_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_ACCEL, LINEAR_Z, BNO055_SCAN_LIA_Z,
+		       BNO055_LIA_DATA_Z_LSB_REG, 0, 0, 0),
+
+	/* gravity vector */
+	BNO055_CHANNEL(IIO_GRAVITY, X, BNO055_SCAN_GRAVITY_X,
+		       BNO055_GRAVITY_DATA_X_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_GRAVITY, Y, BNO055_SCAN_GRAVITY_Y,
+		       BNO055_GRAVITY_DATA_Y_LSB_REG, 0, 0, 0),
+	BNO055_CHANNEL(IIO_GRAVITY, Z, BNO055_SCAN_GRAVITY_Z,
+		       BNO055_GRAVITY_DATA_Z_LSB_REG, 0, 0, 0),
+
+	{
+		.type = IIO_TEMP,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+		.scan_index = -1
+	},
+	IIO_CHAN_SOFT_TIMESTAMP(BNO055_SCAN_TIMESTAMP),
+};
+
+static int bno055_get_regmask(struct bno055_priv *priv, int *val, int *val2,
+			      int reg, int mask, struct bno055_sysfs_attr *attr)
+{
+	const int shift = __ffs(mask);
+	int hwval, idx;
+	int ret;
+	int i;
+
+	ret = regmap_read(priv->regmap, reg, &hwval);
+	if (ret)
+		return ret;
+
+	idx = (hwval & mask) >> shift;
+	if (attr->hw_xlate)
+		for (i = 0; i < attr->len; i++)
+			if (attr->hw_xlate[i] == idx) {
+				idx = i;
+				break;
+			}
+	if (attr->type == IIO_VAL_INT) {
+		*val = attr->vals[idx];
+	} else { /* IIO_VAL_INT_PLUS_MICRO or IIO_VAL_FRACTIONAL */
+		*val = attr->vals[idx * 2];
+		*val2 = attr->vals[idx * 2 + 1];
+	}
+
+	return attr->type;
+}
+
+static int bno055_set_regmask(struct bno055_priv *priv, int val, int val2,
+			      int reg, int mask, struct bno055_sysfs_attr *attr)
+{
+	const int shift = __ffs(mask);
+	int best_delta;
+	int req_val;
+	int tbl_val;
+	bool first;
+	int delta;
+	int hwval;
+	int ret;
+	int len;
+	int i;
+
+	/*
+	 * The closest value the HW supports is only one in fusion mode,
+	 * and it is autoselected, so don't do anything, just return OK,
+	 * as the closest possible value has been (virtually) selected
+	 */
+	if (priv->operation_mode != BNO055_OPR_MODE_AMG)
+		return 0;
+
+	len = attr->len;
+
+	/*
+	 * We always get a request in INT_PLUS_MICRO, but we
+	 * take care of the micro part only when we really have
+	 * non-integer tables. This prevents 32-bit overflow with
+	 * larger integers contained in integer tables.
+	 */
+	req_val = val;
+	if (attr->type != IIO_VAL_INT) {
+		if (val > 2147)
+			val = 2147;
+		len /= 2;
+		req_val = val * 1000000 + val2;
+	}
+
+	first = true;
+	for (i = 0; i < len; i++) {
+		switch (attr->type) {
+		case IIO_VAL_INT:
+			tbl_val = attr->vals[i];
+			break;
+		case IIO_VAL_INT_PLUS_MICRO:
+			WARN_ON(attr->vals[i * 2] > 2147);
+			tbl_val = attr->vals[i * 2] * 1000000 +
+				attr->vals[i * 2 + 1];
+			break;
+		case IIO_VAL_FRACTIONAL:
+			WARN_ON(attr->vals[i * 2] > 4294);
+			tbl_val = attr->vals[i * 2] * 1000000 /
+				attr->vals[i * 2 + 1];
+			break;
+		default:
+			return -EINVAL;
+		}
+		delta = abs(tbl_val - req_val);
+		if (first || delta < best_delta) {
+			best_delta = delta;
+			hwval = i;
+			first = false;
+		}
+	}
+
+	if (attr->hw_xlate)
+		hwval = attr->hw_xlate[hwval];
+
+	ret = bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_CONFIG);
+	if (ret)
+		return ret;
+
+	ret = regmap_update_bits(priv->regmap, reg, mask, hwval << shift);
+	if (ret)
+		return ret;
+
+	return bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_AMG);
+}
+
+static int bno055_read_simple_chan(struct iio_dev *indio_dev,
+				   struct iio_chan_spec const *chan,
+				   int *val, int *val2, long mask)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	__le16 raw_val;
+	int ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = regmap_bulk_read(priv->regmap, chan->address,
+				       &raw_val, sizeof(raw_val));
+		if (ret < 0)
+			return ret;
+		*val = sign_extend32(le16_to_cpu(raw_val), 15);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		if (priv->operation_mode != BNO055_OPR_MODE_AMG) {
+			*val = 0;
+		} else {
+			ret = regmap_bulk_read(priv->regmap,
+					       chan->address +
+					       BNO055_REG_OFFSET_ADDR,
+					       &raw_val, sizeof(raw_val));
+			if (ret < 0)
+				return ret;
+			/*
+			 * IMU reports sensor offests; IIO wants correction
+			 * offset, thus we need the 'minus' here.
+			 */
+			*val = -sign_extend32(le16_to_cpu(raw_val), 15);
+		}
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 1;
+		switch (chan->type) {
+		case IIO_GRAVITY:
+			/* Table 3-35: 1 m/s^2 = 100 LSB */
+		case IIO_ACCEL:
+			/* Table 3-17: 1 m/s^2 = 100 LSB */
+			*val2 = 100;
+			break;
+		case IIO_MAGN:
+			/*
+			 * Table 3-19: 1 uT = 16 LSB.  But we need
+			 * Gauss: 1G = 0.1 uT.
+			 */
+			*val2 = 160;
+			break;
+		case IIO_ANGL_VEL:
+			/*
+			 * Table 3-22: 1 Rps = 900 LSB
+			 * .. but this is not exactly true. See comment at the
+			 * beginning of this file.
+			 */
+			if (priv->operation_mode != BNO055_OPR_MODE_AMG) {
+				*val = bno055_gyr_scale.fusion_vals[0];
+				*val2 = bno055_gyr_scale.fusion_vals[1];
+				return IIO_VAL_FRACTIONAL;
+			}
+
+			return bno055_get_regmask(priv, val, val2,
+						  BNO055_GYR_CONFIG_REG,
+						  BNO055_GYR_CONFIG_RANGE_MASK,
+						  &bno055_gyr_scale);
+			break;
+		case IIO_ROT:
+			/* Table 3-28: 1 degree = 16 LSB */
+			*val2 = 16;
+			break;
+		default:
+			return -EINVAL;
+		}
+		return IIO_VAL_FRACTIONAL;
+
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (chan->type != IIO_MAGN)
+			return -EINVAL;
+		else
+			return bno055_get_regmask(priv, val, val2,
+						  BNO055_MAG_CONFIG_REG,
+						  BNO055_MAG_CONFIG_ODR_MASK,
+						  &bno055_mag_odr);
+
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			return bno055_get_regmask(priv, val, val2,
+						  BNO055_GYR_CONFIG_REG,
+						  BNO055_GYR_CONFIG_LPF_MASK,
+						  &bno055_gyr_lpf);
+		case IIO_ACCEL:
+			return bno055_get_regmask(priv, val, val2,
+						  BNO055_ACC_CONFIG_REG,
+						  BNO055_ACC_CONFIG_LPF_MASK,
+						  &bno055_acc_lpf);
+		default:
+			return -EINVAL;
+		}
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bno055_sysfs_attr_avail(struct bno055_priv *priv, struct bno055_sysfs_attr *attr,
+				   const int **vals, int *length)
+{
+	if (priv->operation_mode != BNO055_OPR_MODE_AMG) {
+		/* locked when fusion enabled */
+		*vals = attr->fusion_vals;
+		if (attr->type == IIO_VAL_INT)
+			*length = 1;
+		else
+			*length = 2; /* IIO_VAL_INT_PLUS_MICRO or IIO_VAL_FRACTIONAL*/
+	} else {
+		*vals = attr->vals;
+		*length = attr->len;
+	}
+
+	return attr->type;
+}
+
+static int bno055_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long mask)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*type = bno055_sysfs_attr_avail(priv, &bno055_gyr_scale,
+							vals, length);
+			return IIO_AVAIL_LIST;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*type = bno055_sysfs_attr_avail(priv, &bno055_gyr_lpf,
+							vals, length);
+			return IIO_AVAIL_LIST;
+		case IIO_ACCEL:
+			*type = bno055_sysfs_attr_avail(priv, &bno055_acc_lpf,
+							vals, length);
+			return IIO_AVAIL_LIST;
+		default:
+			return -EINVAL;
+		}
+
+		break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		switch (chan->type) {
+		case IIO_MAGN:
+			*type = bno055_sysfs_attr_avail(priv, &bno055_mag_odr,
+							vals, length);
+			return IIO_AVAIL_LIST;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bno055_read_temp_chan(struct iio_dev *indio_dev, int *val)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	unsigned int raw_val;
+	int ret;
+
+	ret = regmap_read(priv->regmap, BNO055_TEMP_REG, &raw_val);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Tables 3-36 and 3-37: one byte of priv, signed, 1 LSB = 1C.
+	 * ABI wants milliC.
+	 */
+	*val = raw_val * 1000;
+
+	return IIO_VAL_INT;
+}
+
+static int bno055_read_quaternion(struct iio_dev *indio_dev,
+				  struct iio_chan_spec const *chan,
+				  int size, int *vals, int *val_len,
+				  long mask)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	__le16 raw_vals[4];
+	int i, ret;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		if (size < 4)
+			return -EINVAL;
+		ret = regmap_bulk_read(priv->regmap,
+				       BNO055_QUAT_DATA_W_LSB_REG,
+				       raw_vals, sizeof(raw_vals));
+		if (ret < 0)
+			return ret;
+		for (i = 0; i < 4; i++)
+			vals[i] = sign_extend32(le16_to_cpu(raw_vals[i]), 15);
+		*val_len = 4;
+		return IIO_VAL_INT_MULTIPLE;
+	case IIO_CHAN_INFO_SCALE:
+		/* Table 3-31: 1 quaternion = 2^14 LSB */
+		if (size < 2)
+			return -EINVAL;
+		vals[0] = 1;
+		vals[1] = 14;
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static bool bno055_is_chan_readable(struct iio_dev *indio_dev,
+				    struct iio_chan_spec const *chan)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+
+	if (priv->operation_mode != BNO055_OPR_MODE_AMG)
+		return true;
+
+	switch (chan->type) {
+	case IIO_GRAVITY:
+	case IIO_ROT:
+		return false;
+	case IIO_ACCEL:
+		if (chan->channel2 == IIO_MOD_LINEAR_X ||
+		    chan->channel2 == IIO_MOD_LINEAR_Y ||
+		    chan->channel2 == IIO_MOD_LINEAR_Z)
+			return false;
+		return true;
+	default:
+		return true;
+	}
+}
+
+static int _bno055_read_raw_multi(struct iio_dev *indio_dev,
+				  struct iio_chan_spec const *chan,
+				  int size, int *vals, int *val_len,
+				  long mask)
+{
+	if (!bno055_is_chan_readable(indio_dev, chan))
+		return -EBUSY;
+
+	switch (chan->type) {
+	case IIO_MAGN:
+	case IIO_ACCEL:
+	case IIO_ANGL_VEL:
+	case IIO_GRAVITY:
+		if (size < 2)
+			return -EINVAL;
+		*val_len = 2;
+		return bno055_read_simple_chan(indio_dev, chan,
+					       &vals[0], &vals[1],
+					       mask);
+	case IIO_TEMP:
+		*val_len = 1;
+		return bno055_read_temp_chan(indio_dev, &vals[0]);
+	case IIO_ROT:
+		/*
+		 * Rotation is exposed as either a quaternion or three
+		 * Euler angles.
+		 */
+		if (chan->channel2 == IIO_MOD_QUATERNION)
+			return bno055_read_quaternion(indio_dev, chan,
+						      size, vals,
+						      val_len, mask);
+		if (size < 2)
+			return -EINVAL;
+		*val_len = 2;
+		return bno055_read_simple_chan(indio_dev, chan,
+					       &vals[0], &vals[1],
+					       mask);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bno055_read_raw_multi(struct iio_dev *indio_dev,
+				 struct iio_chan_spec const *chan,
+				 int size, int *vals, int *val_len,
+				 long mask)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = _bno055_read_raw_multi(indio_dev, chan, size,
+				     vals, val_len, mask);
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static int _bno055_write_raw(struct iio_dev *iio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct bno055_priv *priv = iio_priv(iio_dev);
+
+	switch (chan->type) {
+	case IIO_MAGN:
+		switch (mask) {
+		case IIO_CHAN_INFO_SAMP_FREQ:
+			return bno055_set_regmask(priv, val, val2,
+						  BNO055_MAG_CONFIG_REG,
+						  BNO055_MAG_CONFIG_ODR_MASK,
+						  &bno055_mag_odr);
+		default:
+			return -EINVAL;
+		}
+	case IIO_ACCEL:
+		switch (mask) {
+		case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+			return bno055_set_regmask(priv, val, val2,
+						  BNO055_ACC_CONFIG_REG,
+						  BNO055_ACC_CONFIG_LPF_MASK,
+						  &bno055_acc_lpf);
+
+		default:
+			return -EINVAL;
+		}
+	case IIO_ANGL_VEL:
+		switch (mask) {
+		case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
+			return bno055_set_regmask(priv, val, val2,
+						  BNO055_GYR_CONFIG_REG,
+						  BNO055_GYR_CONFIG_LPF_MASK,
+						  &bno055_gyr_lpf);
+		case IIO_CHAN_INFO_SCALE:
+			return bno055_set_regmask(priv, val, val2,
+						  BNO055_GYR_CONFIG_REG,
+						  BNO055_GYR_CONFIG_RANGE_MASK,
+						  &bno055_gyr_scale);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bno055_write_raw(struct iio_dev *iio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	struct bno055_priv *priv = iio_priv(iio_dev);
+	int ret;
+
+	mutex_lock(&priv->lock);
+	ret = _bno055_write_raw(iio_dev, chan, val, val2, mask);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static ssize_t in_accel_range_raw_available_show(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+	int len = 0;
+	int i;
+
+	if (priv->operation_mode != BNO055_OPR_MODE_AMG)
+		return sysfs_emit(buf, "%d\n", bno055_acc_range.fusion_vals[0]);
+
+	for (i = 0; i < bno055_acc_range.len; i++)
+		len += sysfs_emit_at(buf, len, "%d%c", bno055_acc_range.vals[i],
+				     (i == bno055_acc_range.len - 1) ? '\n' : ' ');
+	return len;
+}
+
+static ssize_t bno055_fusion_enable_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+
+	return sysfs_emit(buf, "%d\n",
+			  priv->operation_mode != BNO055_OPR_MODE_AMG);
+}
+
+static ssize_t bno055_fusion_enable_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	int ret = 0;
+
+	if (indio_dev->active_scan_mask &&
+	    !bitmap_empty(indio_dev->active_scan_mask, _BNO055_SCAN_MAX))
+		return -EBUSY;
+
+	if (sysfs_streq(buf, "0")) {
+		ret = bno055_operation_mode_set(priv, BNO055_OPR_MODE_AMG);
+	} else {
+		/*
+		 * Coming from AMG means the FMC was off, just switch to fusion
+		 * but don't change anything that doesn't belong to us (i.e let
+		 * FMC stay off.
+		 * Coming from any other fusion mode means we don't need to do
+		 * anything.
+		 */
+		if (priv->operation_mode == BNO055_OPR_MODE_AMG)
+			ret = bno055_operation_mode_set(priv, BNO055_OPR_MODE_FUSION_FMC_OFF);
+	}
+	if (ret)
+		return ret;
+	return len;
+}
+
+static ssize_t bno055_fmc_enable_show(struct device *dev,
+				      struct device_attribute *attr,
+				      char *buf)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+
+	return sysfs_emit(buf, "%d\n",
+			  priv->operation_mode == BNO055_OPR_MODE_FUSION);
+}
+
+static ssize_t bno055_fmc_enable_store(struct device *dev,
+				       struct device_attribute *attr,
+				       const char *buf, size_t len)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	int ret;
+
+	if (indio_dev->active_scan_mask &&
+	    !bitmap_empty(indio_dev->active_scan_mask, _BNO055_SCAN_MAX))
+		return -EBUSY;
+
+	if (sysfs_streq(buf, "0")) {
+		if (priv->operation_mode == BNO055_OPR_MODE_FUSION) {
+			ret = bno055_operation_mode_set(priv, BNO055_OPR_MODE_FUSION_FMC_OFF);
+			if (ret)
+				return ret;
+		}
+	} else {
+		if (priv->operation_mode == BNO055_OPR_MODE_AMG)
+			return -EINVAL;
+
+		if (priv->operation_mode != BNO055_OPR_MODE_FUSION) {
+			ret = bno055_operation_mode_set(priv, BNO055_OPR_MODE_FUSION);
+			if (ret)
+				return ret;
+		}
+	}
+
+	return len;
+}
+
+static ssize_t bno055_in_accel_range_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+	int val;
+	int ret;
+
+	ret = bno055_get_regmask(priv, &val, NULL,
+				 BNO055_ACC_CONFIG_REG,
+				 BNO055_ACC_CONFIG_RANGE_MASK,
+				 &bno055_acc_range);
+	if (ret < 0)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", val);
+}
+
+static ssize_t bno055_in_accel_range_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t len)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+	unsigned long val;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret)
+		return ret;
+
+	mutex_lock(&priv->lock);
+	ret = bno055_set_regmask(priv, val, 0,
+				 BNO055_ACC_CONFIG_REG,
+				 BNO055_ACC_CONFIG_RANGE_MASK,
+				 &bno055_acc_range);
+	mutex_unlock(&priv->lock);
+
+	return ret ?: len;
+}
+
+static ssize_t bno055_get_calib_status(struct device *dev, char *buf, int which)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+	int calib;
+	int ret;
+	int val;
+
+	if (priv->operation_mode == BNO055_OPR_MODE_AMG ||
+	    (priv->operation_mode == BNO055_OPR_MODE_FUSION_FMC_OFF &&
+	     which == BNO055_CALIB_STAT_MAGN_SHIFT)) {
+		calib = 0;
+	} else {
+		mutex_lock(&priv->lock);
+		ret = regmap_read(priv->regmap, BNO055_CALIB_STAT_REG, &val);
+		mutex_unlock(&priv->lock);
+
+		if (ret)
+			return -EIO;
+
+		calib = ((val >> which) & BNO055_CALIB_STAT_MASK) + 1;
+	}
+
+	return sysfs_emit(buf, "%d\n", calib);
+}
+
+static ssize_t serialnumber_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
+
+	return sysfs_emit(buf, "%*ph\n", BNO055_UID_LEN, priv->uid);
+}
+
+static ssize_t calibration_data_read(struct file *filp, struct kobject *kobj,
+				     struct bin_attribute *bin_attr, char *buf,
+				     loff_t pos, size_t count)
+{
+	struct bno055_priv *priv = iio_priv(dev_to_iio_dev(kobj_to_dev(kobj)));
+	u8 data[BNO055_CALDATA_LEN];
+	int ret;
+
+	/*
+	 * Calibration data is volatile; reading it in chunks will possibly
+	 * results in inconsistent data. We require the user to read the whole
+	 * blob in a single chunk
+	 */
+	if (count < BNO055_CALDATA_LEN || pos != 0)
+		return -EINVAL;
+
+	mutex_lock(&priv->lock);
+	ret = bno055_operation_mode_do_set(priv, BNO055_OPR_MODE_CONFIG);
+	if (ret)
+		goto unlock;
+
+	ret = regmap_bulk_read(priv->regmap, BNO055_CALDATA_START, data,
+			       BNO055_CALDATA_LEN);
+	if (ret)
+		goto unlock;
+
+	ret = bno055_operation_mode_do_set(priv, priv->operation_mode);
+	if (ret)
+		goto unlock;
+
+	memcpy(buf, data, BNO055_CALDATA_LEN);
+
+	ret = BNO055_CALDATA_LEN;
+unlock:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+
+static ssize_t sys_calibration_auto_status_show(struct device *dev,
+						struct device_attribute *a,
+						char *buf)
+{
+	return bno055_get_calib_status(dev, buf, BNO055_CALIB_STAT_SYS_SHIFT);
+}
+
+static ssize_t in_accel_calibration_auto_status_show(struct device *dev,
+						     struct device_attribute *a,
+						     char *buf)
+{
+	return bno055_get_calib_status(dev, buf, BNO055_CALIB_STAT_ACCEL_SHIFT);
+}
+
+static ssize_t in_gyro_calibration_auto_status_show(struct device *dev,
+						    struct device_attribute *a,
+						    char *buf)
+{
+	return bno055_get_calib_status(dev, buf, BNO055_CALIB_STAT_GYRO_SHIFT);
+}
+
+static ssize_t in_magn_calibration_auto_status_show(struct device *dev,
+						    struct device_attribute *a,
+						    char *buf)
+{
+	return bno055_get_calib_status(dev, buf, BNO055_CALIB_STAT_MAGN_SHIFT);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static int bno055_debugfs_reg_access(struct iio_dev *iio_dev, unsigned int reg,
+				     unsigned int writeval, unsigned int *readval)
+{
+	struct bno055_priv *priv = iio_priv(iio_dev);
+
+	if (readval)
+		return regmap_read(priv->regmap, reg, readval);
+	else
+		return regmap_write(priv->regmap, reg, writeval);
+}
+
+static ssize_t bno055_show_fw_version(struct file *file, char __user *userbuf,
+				      size_t count, loff_t *ppos)
+{
+	struct bno055_priv *priv = file->private_data;
+	int rev, ver;
+	char *buf;
+	int ret;
+
+	ret = regmap_read(priv->regmap, BNO055_SW_REV_LSB_REG, &rev);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(priv->regmap, BNO055_SW_REV_MSB_REG, &ver);
+	if (ret)
+		return ret;
+
+	buf = kasprintf(GFP_KERNEL, "ver: 0x%x, rev: 0x%x\n", ver, rev);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = simple_read_from_buffer(userbuf, count, ppos, buf, strlen(buf));
+	kfree(buf);
+
+	return ret;
+}
+
+static const struct file_operations bno055_fw_version_ops = {
+	.open = simple_open,
+	.read = bno055_show_fw_version,
+	.llseek = default_llseek,
+	.owner = THIS_MODULE,
+};
+
+static void bno055_debugfs_remove(void *debugfs)
+{
+	debugfs_remove((struct dentry *)debugfs);
+}
+
+static void bno055_debugfs_init(struct iio_dev *iio_dev)
+{
+	struct bno055_priv *priv = iio_priv(iio_dev);
+
+	priv->debugfs = debugfs_create_file("firmware_version", 0400,
+					    iio_get_debugfs_dentry(iio_dev),
+					    priv, &bno055_fw_version_ops);
+
+	devm_add_action_or_reset(priv->dev, bno055_debugfs_remove, priv->debugfs);
+}
+#else
+static void bno055_debugfs_init(struct iio_dev *iio_dev)
+{
+}
+
+int bno055_debugfs_reg_access(struct iio_dev *iio_dev, unsigned int reg,
+			      unsigned int writeval, unsigned int *readval)
+{
+	return 0;
+}
+#endif
+
+static IIO_DEVICE_ATTR(fusion_enable, 0644,
+		       bno055_fusion_enable_show,
+		       bno055_fusion_enable_store, 0);
+
+static IIO_DEVICE_ATTR(in_magn_calibration_fast_enable, 0644,
+		       bno055_fmc_enable_show,
+		       bno055_fmc_enable_store, 0);
+
+static IIO_DEVICE_ATTR(in_accel_range_raw, 0644,
+		       bno055_in_accel_range_show,
+		       bno055_in_accel_range_store, 0);
+
+static IIO_DEVICE_ATTR_RO(in_accel_range_raw_available, 0);
+
+static IIO_DEVICE_ATTR_RO(sys_calibration_auto_status, 0);
+static IIO_DEVICE_ATTR_RO(in_accel_calibration_auto_status, 0);
+static IIO_DEVICE_ATTR_RO(in_gyro_calibration_auto_status, 0);
+static IIO_DEVICE_ATTR_RO(in_magn_calibration_auto_status, 0);
+
+static IIO_DEVICE_ATTR_RO(serialnumber, 0);
+
+static struct attribute *bno055_attrs[] = {
+	&iio_dev_attr_in_accel_range_raw_available.dev_attr.attr,
+	&iio_dev_attr_in_accel_range_raw.dev_attr.attr,
+	&iio_dev_attr_fusion_enable.dev_attr.attr,
+	&iio_dev_attr_in_magn_calibration_fast_enable.dev_attr.attr,
+	&iio_dev_attr_sys_calibration_auto_status.dev_attr.attr,
+	&iio_dev_attr_in_accel_calibration_auto_status.dev_attr.attr,
+	&iio_dev_attr_in_gyro_calibration_auto_status.dev_attr.attr,
+	&iio_dev_attr_in_magn_calibration_auto_status.dev_attr.attr,
+	&iio_dev_attr_serialnumber.dev_attr.attr,
+	NULL
+};
+
+static BIN_ATTR_RO(calibration_data, BNO055_CALDATA_LEN);
+
+static struct bin_attribute *bno055_bin_attrs[] = {
+	&bin_attr_calibration_data,
+	NULL
+};
+
+static const struct attribute_group bno055_attrs_group = {
+	.attrs = bno055_attrs,
+	.bin_attrs = bno055_bin_attrs,
+};
+
+static const struct iio_info bno055_info = {
+	.read_raw_multi = bno055_read_raw_multi,
+	.read_avail = bno055_read_avail,
+	.write_raw = bno055_write_raw,
+	.attrs = &bno055_attrs_group,
+	.debugfs_reg_access = bno055_debugfs_reg_access,
+};
+
+/*
+ * Reads len samples from the HW, stores them in buf starting from buf_idx,
+ * and applies mask to cull (skip) unneeded samples.
+ * Updates buf_idx incrementing with the number of stored samples.
+ * Samples from HW are transferred into buf, then in-place copy on buf is
+ * performed in order to cull samples that need to be skipped.
+ * This avoids copies of the first samples until we hit the 1st sample to skip,
+ * and also avoids having an extra bounce buffer.
+ * buf must be able to contain len elements in spite of how many samples we are
+ * going to cull.
+ */
+static int bno055_scan_xfer(struct bno055_priv *priv,
+			    int start_ch, int len, unsigned long mask,
+			    __le16 *buf, int *buf_idx)
+{
+	const int base = BNO055_ACC_DATA_X_LSB_REG;
+	bool quat_in_read = false;
+	int buf_base = *buf_idx;
+	__le16 *dst, *src;
+	int offs_fixup = 0;
+	int xfer_len = len;
+	int ret;
+	int i, n;
+
+	if (!mask)
+		return 0;
+
+	/*
+	 * All chans are made up 1 16-bit sample, except for quaternion that is
+	 * made up 4 16-bit values.
+	 * For us the quaternion CH is just like 4 regular CHs.
+	 * If our read starts past the quaternion make sure to adjust the
+	 * starting offset; if the quaternion is contained in our scan then make
+	 * sure to adjust the read len.
+	 */
+	if (start_ch > BNO055_SCAN_QUATERNION) {
+		start_ch += 3;
+	} else if ((start_ch <= BNO055_SCAN_QUATERNION) &&
+		 ((start_ch + len) > BNO055_SCAN_QUATERNION)) {
+		quat_in_read = true;
+		xfer_len += 3;
+	}
+
+	ret = regmap_bulk_read(priv->regmap,
+			       base + start_ch * sizeof(__le16),
+			       buf + buf_base,
+			       xfer_len * sizeof(__le16));
+	if (ret)
+		return ret;
+
+	for_each_set_bit(i, &mask, len) {
+		if (quat_in_read && ((start_ch + i) > BNO055_SCAN_QUATERNION))
+			offs_fixup = 3;
+
+		dst = buf + *buf_idx;
+		src = buf + buf_base + offs_fixup + i;
+
+		n = (start_ch + i == BNO055_SCAN_QUATERNION) ? 4 : 1;
+
+		if (dst != src)
+			memcpy(dst, src, n * sizeof(__le16));
+
+		*buf_idx += n;
+	}
+	return 0;
+}
+
+static irqreturn_t bno055_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *iio_dev = pf->indio_dev;
+	struct bno055_priv *priv = iio_priv(iio_dev);
+	int xfer_start, start, end, prev_end;
+	unsigned long mask;
+	int quat_extra_len;
+	bool first = true;
+	int buf_idx = 0;
+	bool thr_hit;
+	int ret;
+
+	mutex_lock(&priv->lock);
+
+	/*
+	 * Walk the bitmap and eventually perform several transfers.
+	 * Bitmap ones-fileds that are separated by gaps <= xfer_burst_break_thr
+	 * will be included in same transfer.
+	 * Every time the bitmap contains a gap wider than xfer_burst_break_thr
+	 * then we split the transfer, skipping the gap.
+	 */
+	for_each_set_bitrange(start, end, iio_dev->active_scan_mask,
+			      iio_dev->masklength) {
+		/*
+		 * First transfer will start from the beginnig of the first
+		 * ones-field in the bitmap
+		 */
+		if (first)
+			xfer_start = start;
+
+		/*
+		 * We found the next ones-field; check whether to include it in
+		 * the current transfer or not (i.e. let's perform the current
+		 * transfer and prepare for another one).
+		 */
+		if (!first) {
+			/*
+			 * In case the zeros-gap contains the quaternion bit,
+			 * then its length is actually 4 words instead of 1
+			 * (i.e. +3 wrt other channels).
+			 */
+			quat_extra_len = ((start > BNO055_SCAN_QUATERNION) &&
+					  (prev_end <= BNO055_SCAN_QUATERNION)) ? 3 : 0;
+
+			/* If the gap is wider than xfer_burst_break_thr then.. */
+			thr_hit = (start - prev_end + quat_extra_len) >
+				priv->xfer_burst_break_thr;
+
+			/*
+			 * .. transfer all the data up to the gap. Then set the
+			 * next transfer start index at right after the gap
+			 * (i.e. at the start of this ones-field).
+			 */
+			if (thr_hit) {
+				mask = *iio_dev->active_scan_mask >> xfer_start;
+				ret = bno055_scan_xfer(priv, xfer_start,
+						       prev_end - xfer_start,
+						       mask, priv->buf.chans, &buf_idx);
+				if (ret)
+					goto done;
+				xfer_start = start;
+			}
+		}
+		first = false;
+		prev_end = end;
+	}
+
+	/*
+	 * We finished walking the bitmap; no more gaps to check for. Just
+	 * perform the current transfer.
+	 */
+	mask = *iio_dev->active_scan_mask >> xfer_start;
+	ret = bno055_scan_xfer(priv, xfer_start,
+			       prev_end - xfer_start,
+			       mask, priv->buf.chans, &buf_idx);
+
+	iio_push_to_buffers_with_timestamp(iio_dev, &priv->buf, pf->timestamp);
+done:
+	mutex_unlock(&priv->lock);
+	iio_trigger_notify_done(iio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+static int bno055_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct bno055_priv *priv = iio_priv(indio_dev);
+	const unsigned long fusion_mask =
+		BIT(BNO055_SCAN_YAW) |
+		BIT(BNO055_SCAN_ROLL) |
+		BIT(BNO055_SCAN_PITCH) |
+		BIT(BNO055_SCAN_QUATERNION) |
+		BIT(BNO055_SCAN_LIA_X) |
+		BIT(BNO055_SCAN_LIA_Y) |
+		BIT(BNO055_SCAN_LIA_Z) |
+		BIT(BNO055_SCAN_GRAVITY_X) |
+		BIT(BNO055_SCAN_GRAVITY_Y) |
+		BIT(BNO055_SCAN_GRAVITY_Z);
+
+	if (priv->operation_mode == BNO055_OPR_MODE_AMG &&
+	    bitmap_intersects(indio_dev->active_scan_mask, &fusion_mask,
+			      _BNO055_SCAN_MAX))
+		return -EBUSY;
+	return 0;
+}
+
+static const struct iio_buffer_setup_ops bno055_buffer_setup_ops = {
+	.preenable = bno055_buffer_preenable,
+};
+
+static void bno055_clk_disable(void *arg)
+{
+	clk_disable_unprepare((struct clk *)arg);
+}
+
+int bno055_probe(struct device *dev, struct regmap *regmap,
+		 int xfer_burst_break_thr, bool sw_reset)
+{
+	const struct firmware *caldata = NULL;
+	const u8 *caldata_data = NULL;
+	struct bno055_priv *priv;
+	struct iio_dev *iio_dev;
+	int caldata_size = 0;
+	char *fw_name_buf;
+	unsigned int val;
+	int rev, ver;
+	int ret;
+
+	iio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
+	if (!iio_dev)
+		return -ENOMEM;
+
+	iio_dev->name = "bno055";
+	priv = iio_priv(iio_dev);
+	mutex_init(&priv->lock);
+	priv->regmap = regmap;
+	priv->dev = dev;
+	priv->xfer_burst_break_thr = xfer_burst_break_thr;
+	priv->sw_reset = sw_reset;
+
+	priv->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(priv->reset_gpio), "Failed to get reset GPIO");
+
+	priv->clk = devm_clk_get_optional(dev, "clk");
+	if (IS_ERR(priv->clk))
+		return dev_err_probe(dev, PTR_ERR(priv->clk), "Failed to get CLK");
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, bno055_clk_disable, priv->clk);
+	if (ret)
+		return ret;
+
+	if (priv->reset_gpio) {
+		usleep_range(5000, 10000);
+		gpiod_set_value_cansleep(priv->reset_gpio, 1);
+		usleep_range(650000, 750000);
+	} else {
+		if (!sw_reset)
+			dev_warn(dev, "No usable reset method; IMU may be unreliable");
+	}
+
+	ret = regmap_read(priv->regmap, BNO055_CHIP_ID_REG, &val);
+	if (ret)
+		return ret;
+
+	if (val != BNO055_CHIP_ID_MAGIC)
+		dev_warn(dev, "Unrecognized chip ID 0x%x", val);
+
+	/*
+	 * In case we haven't a HW reset pin, we can still reset the chip via
+	 * register write. This is probably nonsense in case we can't even
+	 * communicate with the chip or the chip isn't the one we expect (i.e.
+	 * we don't write to unknown chips), so we perform SW reset only after
+	 * chip magic ID check
+	 */
+	if (!priv->reset_gpio) {
+		ret = bno055_system_reset(priv);
+		if (ret)
+			return ret;
+	}
+
+	ret = regmap_read(priv->regmap, BNO055_SW_REV_LSB_REG, &rev);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(priv->regmap, BNO055_SW_REV_MSB_REG, &ver);
+	if (ret)
+		return ret;
+
+	/*
+	 * Seems that stock FW version conains a bug (see comment at the
+	 * beginning of this file) that causes the anglvel scale to be changed
+	 * depending by the chip range setting. We workaround this, but we don't
+	 * know what other FW version might do..
+	 */
+	if (ver != 0x3 || rev != 0x11)
+		dev_warn(dev, "Untested firmware version. Anglvel scale may not work as expected");
+
+	ret = regmap_bulk_read(priv->regmap, BNO055_UID_LOWER_REG,
+			       priv->uid, BNO055_UID_LEN);
+	if (ret)
+		return ret;
+
+	/* Sensor calibration data */
+	fw_name_buf = kasprintf(GFP_KERNEL,
+				BNO055_FW_UID_NAME,
+				BNO055_UID_LEN, priv->uid);
+	if (!fw_name_buf)
+		return -ENOMEM;
+
+	ret = request_firmware(&caldata, fw_name_buf, dev);
+	kfree(fw_name_buf);
+	if (ret)
+		ret = request_firmware(&caldata, BNO055_FW_GENERIC_NAME, dev);
+
+	if (ret)
+		dev_notice(dev, "Calibration file load failed. See instruction in kernel Documentation/iio/bno055.rst");
+
+	if (caldata) {
+		caldata_data = caldata->data;
+		caldata_size = caldata->size;
+	}
+	ret = bno055_init(priv, caldata_data, caldata_size);
+	if (caldata)
+		release_firmware(caldata);
+	if (ret)
+		return ret;
+
+	priv->operation_mode = BNO055_OPR_MODE_FUSION;
+	ret = bno055_operation_mode_do_set(priv, priv->operation_mode);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(dev, bno055_uninit, priv);
+	if (ret)
+		return ret;
+
+	iio_dev->channels = bno055_channels;
+	iio_dev->num_channels = ARRAY_SIZE(bno055_channels);
+	iio_dev->info = &bno055_info;
+	iio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = devm_iio_triggered_buffer_setup(dev, iio_dev,
+					      iio_pollfunc_store_time,
+					      bno055_trigger_handler,
+					      &bno055_buffer_setup_ops);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_device_register(dev, iio_dev);
+	if (ret)
+		return ret;
+
+	bno055_debugfs_init(iio_dev);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(bno055_probe, IIO_BNO055);
+
+MODULE_AUTHOR("Andrea Merello <andrea.merello@iit.it>");
+MODULE_DESCRIPTION("Bosch BNO055 driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/imu/bno055/bno055.h b/drivers/iio/imu/bno055/bno055.h
new file mode 100644
index 000000000000..2ccb373c61cd
--- /dev/null
+++ b/drivers/iio/imu/bno055/bno055.h
@@ -0,0 +1,12 @@ 
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __BNO055_H__
+#define __BNO055_H__
+
+#include <linux/regmap.h>
+
+struct device;
+int bno055_probe(struct device *dev, struct regmap *regmap,
+		 int xfer_burst_break_thr, bool sw_reset);
+extern const struct regmap_config bno055_regmap_config;
+
+#endif