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SubjectRe: [PATCH 2/4] iio: imu: add Bosch Sensortec BNO055 core driver
Il giorno ven 16 lug 2021 alle ore 09:24 Alexandru Ardelean
<ardeleanalex@gmail.com> ha scritto:
>
> On Thu, Jul 15, 2021 at 5:21 PM Andrea Merello <andrea.merello@gmail.com> wrote:
> >
> > This patch adds a 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.
> >
>
> Hey,
>
> I tried to comment on the ones that Andy did not touch.
> I had a little trouble following all the locking.
> I'm not sure if I missed anything.

Hi,

Well, indeed (unless I did some mistake, which is very possible), here
the lock is simply around every access to the IMU. This is because
there are places (e.g. in_calibration_data_show() ) in which we switch
the IMU to configuration mode, we do something, and then we switch the
IMU back to normal operation mode. The lock prevent any other access
to the IMU during these procedures. The very same lock also guarantees
serialization for all IMU operations that comes in behalf of
userspace.

Note that putting the lock at a lower lever (e.g. in register access
functions) wouldn't suffice because of the configuration mode swich
said above.

> My notes are inline.
>
>
> > 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>
> > Cc: Andrea Merello <andrea.merello@gmail.com>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Matt Ranostay <matt.ranostay@konsulko.com>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Vlad Dogaru <vlad.dogaru@intel.com>
> > Cc: linux-kernel@vger.kernel.org
> > Cc: linux-iio@vger.kernel.org
> > ---
> > drivers/iio/imu/Kconfig | 1 +
> > drivers/iio/imu/Makefile | 1 +
> > drivers/iio/imu/bno055/Kconfig | 7 +
> > drivers/iio/imu/bno055/Makefile | 6 +
> > drivers/iio/imu/bno055/bno055.c | 1361 +++++++++++++++++++++++++++++++
> > drivers/iio/imu/bno055/bno055.h | 12 +
> > 6 files changed, 1388 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 --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..2bfed8df4554
> > --- /dev/null
> > +++ b/drivers/iio/imu/bno055/Kconfig
> > @@ -0,0 +1,7 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +#
> > +# driver for Bosh bmo055
> > +#
> > +
> > +config BOSH_BNO055_IIO
> > + tristate
> > diff --git a/drivers/iio/imu/bno055/Makefile b/drivers/iio/imu/bno055/Makefile
> > new file mode 100644
> > index 000000000000..15c5ddf8d648
> > --- /dev/null
> > +++ b/drivers/iio/imu/bno055/Makefile
> > @@ -0,0 +1,6 @@
> > +# SPDX-License-Identifier: GPL-2.0
> > +#
> > +# Makefile for bosh bno055
> > +#
> > +
> > +obj-$(CONFIG_BOSH_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..888a88bb13d5
> > --- /dev/null
> > +++ b/drivers/iio/imu/bno055/bno055.c
> > @@ -0,0 +1,1361 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * IIO driver for Bosh BNO055 IMU
> > + *
> > + * Copyright (C) 2021 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/clk.h>
> > +#include <linux/firmware.h>
> > +#include <linux/gpio/consumer.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 <linux/irq.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +#include <linux/regmap.h>
> > +#include <linux/util_macros.h>
> > +
> > +#include "bno055.h"
> > +
> > +#define BNO055_FW_NAME "bno055-caldata"
> > +#define BNO055_FW_EXT ".dat"
> > +
> > +/* 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_TEMP_REG 0x34
> > +#define BNO055_CALIB_STAT_REG 0x35
> > +#define BNO055_CALIB_STAT_MASK 3
> > +#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_TRIGGER_REG 0x3F
> > +#define BNO055_SYS_TRIGGER_RST_INT BIT(6)
> > +#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
> > +#define BNO055_UNIT_SEL_ANDROID BIT(7)
> > +#define BNO055_CALDATA_START 0x55
> > +#define BNO055_CALDATA_END 0x6A
> > +#define BNO055_CALDATA_LEN (BNO055_CALDATA_END - BNO055_CALDATA_START + 1)
> > +
> > +/*
> > + * 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 PG1(x) ((x) | 0x80)
> > +#define BNO055_ACC_CONFIG_REG PG1(0x8)
> > +#define BNO055_ACC_CONFIG_LPF_MASK 0x1C
> > +#define BNO055_ACC_CONFIG_LPF_SHIFT 0x2
> > +#define BNO055_ACC_CONFIG_RANGE_MASK 0x3
> > +#define BNO055_ACC_CONFIG_RANGE_SHIFT 0x0
> > +#define BNO055_MAG_CONFIG_REG PG1(0x9)
> > +#define BNO055_MAG_CONFIG_HIGHACCURACY 0x18
> > +#define BNO055_MAG_CONFIG_ODR_MASK 0x7
> > +#define BNO055_MAG_CONFIG_ODR_SHIFT 0
> > +#define BNO055_GYR_CONFIG_REG PG1(0xA)
> > +#define BNO055_GYR_CONFIG_RANGE_MASK 0x7
> > +#define BNO055_GYR_CONFIG_RANGE_SHIFT 0
> > +#define BNO055_GYR_CONFIG_LPF_MASK 0x38
> > +#define BNO055_GYR_CONFIG_LPF_SHIFT 3
> > +#define BNO055_INT_MSK PG1(0xF)
> > +#define BNO055_INT_EN PG1(0x10)
> > +#define BNO055_INT_ACC_BSX_DRDY BIT(0)
> > +#define BNO055_INT_MAG_DRDY BIT(1)
> > +#define BNO055_INT_GYR_DRDY BIT(4)
> > +#define BNO055_UID_REG PG1(0x50)
> > +#define BNO055_UID_LEN (0xF)
> > +
> > +static const int bno055_mag_odr_vals[] = {2, 6, 8, 10, 15, 20, 25, 30};
> > +static const int bno055_acc_lpf_vals[] = {781, 1563, 3125, 6250,
> > + 12500, 25000, 50000, 100000};
> > +static const int bno055_acc_ranges[] = {2, 4, 8, 16};
> > +static const int bno055_gyr_lpf_vals[] = {523, 230, 116, 47, 23, 12, 64, 32};
> > +static const int bno055_gyr_ranges[] = {2000, 1000, 500, 250, 125};
> > +
> > +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];
> > +};
> > +
> > +static int find_closest_unsorted(int val, const int arr[], int len)
> > +{
> > + int i;
> > + int best_idx, best_delta, delta;
> > + int first = 1;
> > +
> > + for (i = 0; i < len; i++) {
> > + delta = abs(arr[i] - val);
> > + if (first || delta < best_delta) {
> > + best_delta = delta;
> > + best_idx = i;
> > + }
> > + first = 0;
> > + }
> > +
> > + return best_idx;
> > +}
> > +
> > +static bool bno055_regmap_volatile(struct device *dev, unsigned int reg)
> > +{
> > + if ((reg >= 0x8 && reg <= 0x3A) ||
> > + /* when in fusion mode, config is updated by chip */
> > + reg == BNO055_MAG_CONFIG_REG ||
> > + reg == BNO055_ACC_CONFIG_REG ||
> > + reg == BNO055_GYR_CONFIG_REG ||
> > + (reg >= BNO055_CALDATA_START && reg <= BNO055_CALDATA_END))
> > + return true;
> > + return false;
> > +}
> > +
> > +static bool bno055_regmap_readable(struct device *dev, unsigned int reg)
> > +{
> > + if ((reg <= 0x7F && reg >= 0x6B) ||
> > + reg == 0x3C ||
> > + (reg <= PG1(0x7F) && reg >= PG1(0x60)) ||
> > + (reg <= PG1(0x4F) && reg >= PG1(0x20)) ||
> > + reg == PG1(0xE) ||
> > + (reg <= PG1(0x6) && reg >= PG1(0x0)))
> > + return false;
> > + return true;
> > +}
> > +
> > +static bool bno055_regmap_writeable(struct device *dev, unsigned int reg)
> > +{
> > + if ((!bno055_regmap_readable(dev, reg)) ||
> > + (reg <= 0x3A && reg >= 0x8) ||
> > + reg <= 0x6 ||
> > + (reg <= PG1(0x5F) && reg >= PG1(0x50)))
> > + 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 = 0xff,
> > + .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_GPL(bno055_regmap_config);
> > +
> > +static int bno055_reg_read(struct bno055_priv *priv,
> > + unsigned int reg, unsigned int *val)
> > +{
> > + int res = regmap_read(priv->regmap, reg, val);
> > +
> > + if (res && res != -ERESTARTSYS) {
> > + dev_err(priv->dev, "Regmap read error. adr: 0x%x, res: %d",
> > + reg, res);
> > + }
> > +
> > + return res;
> > +}
> > +
> > +static int bno055_reg_write(struct bno055_priv *priv,
> > + unsigned int reg, unsigned int val)
> > +{
> > + int res = regmap_write(priv->regmap, reg, val);
> > +
> > + if (res && res != -ERESTARTSYS) {
> > + dev_err(priv->dev, "Regmap write error. adr: 0x%x, res: %d",
> > + reg, res);
> > + }
> > +
> > + return res;
> > +}
> > +
> > +static int bno055_reg_update_bits(struct bno055_priv *priv, unsigned int reg,
> > + unsigned int mask, unsigned int val)
> > +{
> > + int res = regmap_update_bits(priv->regmap, reg, mask, val);
> > +
> > + if (res && res != -ERESTARTSYS) {
> > + dev_err(priv->dev, "Regmap update_bits error. adr: 0x%x, res: %d",
> > + reg, res);
> > + }
> > +
> > + return res;
> > +}
> > +
> > +/* must be called in configuration mode */
> > +int bno055_calibration_load(struct bno055_priv *priv, const struct firmware *fw)
> > +{
> > + int i;
> > + unsigned int tmp;
> > + u8 cal[BNO055_CALDATA_LEN];
> > + int read, tot_read = 0;
> > + int ret = 0;
> > + char *buf = kmalloc(fw->size + 1, GFP_KERNEL);
> > +
> > + if (!buf)
> > + return -ENOMEM;
> > +
> > + memcpy(buf, fw->data, fw->size);
> > + buf[fw->size] = '\0';
> > + for (i = 0; i < BNO055_CALDATA_LEN; i++) {
> > + ret = sscanf(buf + tot_read, "%x%n",
> > + &tmp, &read);
> > + if (ret != 1 || tmp > 0xff) {
> > + ret = -EINVAL;
> > + goto exit;
> > + }
> > + cal[i] = tmp;
> > + tot_read += read;
> > + }
> > + dev_dbg(priv->dev, "loading cal data: %*ph", BNO055_CALDATA_LEN, cal);
> > + ret = regmap_bulk_write(priv->regmap, BNO055_CALDATA_START,
> > + cal, BNO055_CALDATA_LEN);
> > +exit:
> > + kfree(buf);
> > + return ret;
> > +}
> > +
> > +static int bno055_init(struct bno055_priv *priv, const struct firmware *caldata)
> > +{
> > + int res;
> > +
> > + res = bno055_reg_write(priv, BNO055_SYS_TRIGGER_REG,
> > + (priv->clk ? BNO055_SYS_TRIGGER_CLK_SEL : 0) |
> > + BNO055_SYS_TRIGGER_RST_INT);
> > + if (res)
> > + return res;
> > +
> > + msleep(100);
> > + res = bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + BNO055_OPR_MODE_CONFIG);
> > + if (res)
> > + return res;
> > +
> > + /* use standard SI units */
> > + res = bno055_reg_write(priv, BNO055_UNIT_SEL_REG,
> > + BNO055_UNIT_SEL_ANDROID);
> > + if (res)
> > + return res;
> > +
> > + if (caldata) {
> > + res = bno055_calibration_load(priv, caldata);
> > + if (res)
> > + dev_warn(priv->dev, "failed to load calibration data with error %d",
> > + res);
> > + }
> > +
> > + /*
> > + * Start in fusion mode (all data available), but with magnetometer auto
> > + * calibration switched off, in order not to overwrite magnetometer
> > + * calibration data in case one want to keep it untouched.
> > + */
> > + priv->operation_mode = BNO055_OPR_MODE_FUSION_FMC_OFF;
> > + return bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + priv->operation_mode);
> > +}
> > +
> > +static void bno055_uninit(void *arg)
> > +{
> > + struct bno055_priv *priv = arg;
> > +
> > + bno055_reg_write(priv, BNO055_INT_EN, 0);
> > +
> > + clk_disable_unprepare(priv->clk);
>
> devm_add_action_or_reset() callbacks should be used as one-per-each uninit;
> it's one of the rules for their usage; it also took me a while to get this;
>
> so, you would do:
>
> ..................
> static void bno055_clk_disable(void *clk)
> {
> clk_disable_unprepare(clk)
> }
>
> static void bno055_uninit(void *priv)
> {
> bno055_reg_write(priv, BNO055_INT_EN, 0);
> }
>
> .........................
>
> ret = clk_prepare_enable(priv->clk);
> if (ret)
> return ret;
> // also make sure to check return code for clk_prepare_enable
>
> ret = devm_add_action_or_reset(dev, bno055_clk_disable, priv->clk)
> if (ret)
> return ret;
>
> ............
>
> res = bno055_init(priv, caldata);
> if (res)
> return res;
>
> ret = devm_add_action_or_reset(dev, bno055_uninit, priv)
> if (ret)
> return ret;
>
> Right now, as bno055_uninit() does both, which is not recommended,
> as devm_ uninit actions should mirror the init actions (but in
> reverse).
>

Ah, thank you for the explanation; I wasn't aware of this. I'll do this way.

>
>
> > +}
> > +
> > +#define BNO055_CHANNEL(_type, _axis, _index, _address, _sep, _sh) { \
> > + .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), \
> > + .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 bmi160_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_HEADING,
> > + 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,
> > +};
> > +
> > +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)),
> > + 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)),
> > + 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)),
> > + /* 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)),
> > + 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)),
> > + 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)),
> > + /* 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)),
> > + 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)),
> > + 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)),
> > + /* euler angle */
> > + BNO055_CHANNEL(IIO_ROT, X, BNO055_SCAN_HEADING,
> > + BNO055_EUL_DATA_X_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_ROT, Y, BNO055_SCAN_ROLL,
> > + BNO055_EUL_DATA_Y_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_ROT, Z, BNO055_SCAN_PITCH,
> > + BNO055_EUL_DATA_Z_LSB_REG, 0, 0),
> > + /* quaternion */
> > + BNO055_CHANNEL(IIO_ROT, QUATERNION, BNO055_SCAN_QUATERNION,
> > + BNO055_QUAT_DATA_W_LSB_REG, 0, 0),
> > +
> > + /* linear acceleration */
> > + BNO055_CHANNEL(IIO_ACCEL, ACCEL_LINEAR_X, BNO055_SCAN_LIA_X,
> > + BNO055_LIA_DATA_X_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_ACCEL, ACCEL_LINEAR_Y, BNO055_SCAN_LIA_Y,
> > + BNO055_LIA_DATA_Y_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_ACCEL, ACCEL_LINEAR_Z, BNO055_SCAN_LIA_Z,
> > + BNO055_LIA_DATA_Z_LSB_REG, 0, 0),
> > +
> > + /* gravity vector */
> > + BNO055_CHANNEL(IIO_GRAVITY, X, BNO055_SCAN_GRAVITY_X,
> > + BNO055_GRAVITY_DATA_X_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_GRAVITY, Y, BNO055_SCAN_GRAVITY_Y,
> > + BNO055_GRAVITY_DATA_Y_LSB_REG, 0, 0),
> > + BNO055_CHANNEL(IIO_GRAVITY, Z, BNO055_SCAN_GRAVITY_Z,
> > + BNO055_GRAVITY_DATA_Z_LSB_REG, 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, int shift,
> > + const int tbl[], int k)
> > +{
> > + int hwval, idx;
> > + int ret = bno055_reg_read(priv, reg, &hwval);
> > +
> > + if (ret)
> > + return ret;
> > + if (val2)
> > + *val2 = 0;
> > + idx = (hwval & mask) >> shift;
> > + *val = tbl[idx] / k;
> > +
> > + if (k == 1)
> > + return IIO_VAL_INT;
> > +
> > + *val2 = (tbl[idx] % k) * 10000;
> > + return IIO_VAL_INT_PLUS_MICRO;
> > +}
> > +
> > +static int bno055_set_regmask(struct bno055_priv *priv, int val, int val2,
> > + int reg, int mask, int shift,
> > + const int table[], int table_len, int k)
> > +
> > +{
> > + int ret;
> > + int hwval = find_closest_unsorted(val * k + val2 / 10000,
> > + table, table_len);
> > + /*
> > + * 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;
> > +
> > + dev_dbg(priv->dev, "WR config - reg, mask, val: 0x%x, 0x%x, 0x%x",
> > + reg, mask, hwval);
> > +
> > + ret = bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + BNO055_OPR_MODE_CONFIG);
> > + if (ret)
> > + return ret;
> > +
> > + ret = bno055_reg_update_bits(priv, reg, mask, hwval << shift);
> > +
> > + if (ret)
> > + return ret;
> > +
> > + return bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + BNO055_OPR_MODE_AMG);
> > + return 0;
>
> this return 0 statement looks unreachable;
> i wonder if the compiler would have caught this

Right. Surprisingly, my compiler doesn't complain; I also would have
expected a warning to be spitted.

> > +}
> > +
> > +#define bno055_get_mag_odr(p, v, v2) \
> > + bno055_get_regmask(p, v, v2, \
> > + BNO055_MAG_CONFIG_REG, BNO055_MAG_CONFIG_ODR_MASK, \
> > + BNO055_MAG_CONFIG_ODR_SHIFT, bno055_mag_odr_vals, 1)
> > +
> > +#define bno055_set_mag_odr(p, v, v2) \
> > + bno055_set_regmask(p, v, v2, \
> > + BNO055_MAG_CONFIG_REG, BNO055_MAG_CONFIG_ODR_MASK, \
> > + BNO055_MAG_CONFIG_ODR_SHIFT, \
> > + bno055_mag_odr_vals, \
> > + ARRAY_SIZE(bno055_mag_odr_vals), 1)
> > +
> > +#define bno055_get_acc_lpf(p, v, v2) \
> > + bno055_get_regmask(p, v, v2, \
> > + BNO055_ACC_CONFIG_REG, BNO055_ACC_CONFIG_LPF_MASK, \
> > + BNO055_ACC_CONFIG_LPF_SHIFT, \
> > + bno055_acc_lpf_vals, 100)
> > +
> > +#define bno055_set_acc_lpf(p, v, v2) \
> > + bno055_set_regmask(p, v, v2, \
> > + BNO055_ACC_CONFIG_REG, BNO055_ACC_CONFIG_LPF_MASK, \
> > + BNO055_ACC_CONFIG_LPF_SHIFT, \
> > + bno055_acc_lpf_vals, \
> > + ARRAY_SIZE(bno055_acc_lpf_vals), 100)
> > +
> > +#define bno055_get_acc_range(p, v, v2) \
> > + bno055_get_regmask(priv, v, v2, \
> > + BNO055_ACC_CONFIG_REG, \
> > + BNO055_ACC_CONFIG_RANGE_MASK, \
> > + BNO055_ACC_CONFIG_RANGE_SHIFT, bno055_acc_ranges, 1)
> > +
> > +#define bno055_set_acc_range(p, v, v2) \
> > + bno055_set_regmask(p, v, v2, \
> > + BNO055_ACC_CONFIG_REG, \
> > + BNO055_ACC_CONFIG_RANGE_MASK, \
> > + BNO055_ACC_CONFIG_RANGE_SHIFT, \
> > + bno055_acc_ranges, ARRAY_SIZE(bno055_acc_ranges), 1)
> > +
> > +#define bno055_get_gyr_lpf(p, v, v2) \
> > + bno055_get_regmask(p, v, v2, \
> > + BNO055_GYR_CONFIG_REG, BNO055_GYR_CONFIG_LPF_MASK, \
> > + BNO055_GYR_CONFIG_LPF_SHIFT, bno055_gyr_lpf_vals, 1)
> > +
> > +#define bno055_set_gyr_lpf(p, v, v2) \
> > + bno055_set_regmask(p, v, v2, \
> > + BNO055_GYR_CONFIG_REG, BNO055_GYR_CONFIG_LPF_MASK, \
> > + BNO055_GYR_CONFIG_LPF_SHIFT, \
> > + bno055_gyr_lpf_vals, \
> > + ARRAY_SIZE(bno055_gyr_lpf_vals), 1)
> > +
> > +#define bno055_get_gyr_range(p, v, v2) \
> > + bno055_get_regmask(p, v, v2, \
> > + BNO055_GYR_CONFIG_REG, \
> > + BNO055_GYR_CONFIG_RANGE_MASK, \
> > + BNO055_GYR_CONFIG_RANGE_SHIFT, \
> > + bno055_gyr_ranges, 1)
> > +
> > +#define bno055_set_gyr_range(p, v, v2) \
> > + bno055_set_regmask(p, v, v2, \
> > + BNO055_GYR_CONFIG_REG, \
> > + BNO055_GYR_CONFIG_RANGE_MASK, \
> > + BNO055_GYR_CONFIG_RANGE_SHIFT, \
> > + bno055_gyr_ranges, ARRAY_SIZE(bno055_gyr_ranges), 1)
> > +
> > +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, 2);
> > + if (ret < 0)
> > + return ret;
> > + *val = (s16)le16_to_cpu(raw_val);
> > + *val2 = 0;
> > + 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, 2);
> > + if (ret < 0)
> > + return ret;
> > + *val = -(s16)le16_to_cpu(raw_val);
> > + }
> > + *val2 = 0;
> > + 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 */
> > + *val2 = 900;
> > + break;
> > + case IIO_ROT:
> > + /* Table 3-28: 1 degree = 16 LSB */
> > + *val2 = 16;
> > + break;
> > + default:
> > + return -EINVAL;
> > + }
> > + return IIO_VAL_FRACTIONAL;
> > + default:
> > + return -EINVAL;
> > +
> > + case IIO_CHAN_INFO_SAMP_FREQ:
> > + if (chan->type == IIO_MAGN)
> > + return bno055_get_mag_odr(priv, val, val2);
> > + else
> > + return -EINVAL;
> > +
> > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> > + switch (chan->type) {
> > + case IIO_ANGL_VEL:
> > + return bno055_get_gyr_lpf(priv, val, val2);
> > + case IIO_ACCEL:
> > + return bno055_get_acc_lpf(priv, val, val2);
> > + 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] = (s16)le16_to_cpu(raw_vals[i]);
> > + *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] = 1 << 14;
> > + return IIO_VAL_FRACTIONAL;
> > + 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)
> > +{
> > + 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)
> > +{
> > + int ret;
> > + struct bno055_priv *priv = iio_priv(indio_dev);
> > +
> > + 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_mag_odr(priv, val, val2);
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + break;
>
> This break looks unreachable.

I'll drop it.

> > + case IIO_ACCEL:
> > + switch (mask) {
> > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> > + return bno055_set_acc_lpf(priv, val, val2);
> > +
> > + default:
> > + return -EINVAL;
> > + }
> > + case IIO_ANGL_VEL:
> > + switch (mask) {
> > + case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> > + return bno055_set_gyr_lpf(priv, val, val2);
> > + }
>
> this looks like an implicit switch-case fall-through;
> sometimes the compiler complains about these

Here it doesn't, but I agree that it isn't so good-looking. I'd add
the default also for IIO_ANGL_VEL case.

> > + default:
> > + return -EINVAL;
> > + }
> > +
> > + return 0;
>
> This return also looks unreachable.

Indeed.. I'll drop it.

> > +}
> > +
> > +static int bno055_write_raw(struct iio_dev *iio_dev,
> > + struct iio_chan_spec const *chan,
> > + int val, int val2, long mask)
> > +{
> > + int ret;
> > + struct bno055_priv *priv = iio_priv(iio_dev);
> > +
> > + mutex_lock(&priv->lock);
> > + ret = _bno055_write_raw(iio_dev, chan, val, val2, mask);
> > + mutex_unlock(&priv->lock);
> > +
> > + return ret;
> > +}
> > +
> > +static ssize_t in_magn_sampling_frequency_available_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode != BNO055_OPR_MODE_AMG) ? "20" :
> > + "2 6 8 10 15 20 25 30");
> > +}
> > +
> > +static ssize_t in_accel_range_available_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode != BNO055_OPR_MODE_AMG) ? "4" :
> > + "2 4 8 16");
> > +}
> > +
> > +static ssize_t
> > +in_accel_filter_low_pass_3db_frequency_available_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode != BNO055_OPR_MODE_AMG) ? "62.5" :
> > + "7.81 15.63 31.25 62.5 125 250 500 1000");
> > +}
> > +
> > +static ssize_t in_anglvel_range_available_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode != BNO055_OPR_MODE_AMG) ? "2000" :
> > + "125 250 500 1000 2000");
> > +}
> > +
> > +static ssize_t
> > +in_anglvel_filter_low_pass_3db_frequency_available_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode != BNO055_OPR_MODE_AMG) ? "32" :
> > + "12 23 47 32 64 116 230 523");
> > +}
> > +
> > +static ssize_t bno055_operation_mode_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n",
> > + (priv->operation_mode == BNO055_OPR_MODE_AMG) ? "amg" :
> > + (priv->operation_mode == BNO055_OPR_MODE_FUSION) ?
> > + "fusion" : "fusion_fmc_off");
> > +}
> > +
> > +static ssize_t bno055_operation_mode_store(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t len)
> > +{
> > + int res;
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + if (sysfs_streq(buf, "amg"))
> > + priv->operation_mode = BNO055_OPR_MODE_AMG;
> > + else if (sysfs_streq(buf, "fusion"))
> > + priv->operation_mode = BNO055_OPR_MODE_FUSION;
> > + else if (sysfs_streq(buf, "fusion_fmc_off"))
> > + priv->operation_mode = BNO055_OPR_MODE_FUSION_FMC_OFF;
> > + else
> > + return -EINVAL;
> > +
> > + mutex_lock(&priv->lock);
> > + res = bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + BNO055_OPR_MODE_CONFIG);
> > + if (res) {
> > + mutex_unlock(&priv->lock);
> > + return res;
> > + }
> > +
> > + res = bno055_reg_write(priv, BNO055_OPR_MODE_REG, priv->operation_mode);
> > + mutex_unlock(&priv->lock);
> > +
> > + return res ? res : len;
> > +}
> > +
> > +static ssize_t bno055_in_accel_range_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + int val;
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + int res = bno055_get_acc_range(priv, &val, NULL);
> > +
> > + if (res < 0)
> > + return res;
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%d\n", val);
> > +}
> > +
> > +static ssize_t bno055_in_accel_range_store(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t len)
> > +{
> > + int ret;
> > + unsigned long val;
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + ret = kstrtoul(buf, 10, &val);
> > + if (ret)
> > + return ret;
> > +
> > + mutex_lock(&priv->lock);
> > + ret = bno055_set_acc_range(priv, val, 0);
> > + mutex_unlock(&priv->lock);
> > +
> > + return ret ? ret : len;
> > +}
> > +
> > +static ssize_t bno055_in_gyr_range_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + int val;
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > + int res = bno055_get_gyr_range(priv, &val, NULL);
> > +
> > + if (res < 0)
> > + return res;
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%d\n", val);
> > +}
> > +
> > +static ssize_t bno055_in_gyr_range_store(struct device *dev,
> > + struct device_attribute *attr,
> > + const char *buf, size_t len)
> > +{
> > + int ret;
> > + unsigned long val;
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + ret = kstrtoul(buf, 10, &val);
> > + if (ret)
> > + return ret;
> > +
> > + mutex_lock(&priv->lock);
> > + ret = bno055_set_gyr_range(priv, val, 0);
> > + mutex_unlock(&priv->lock);
> > +
> > + return ret ? ret : len;
> > +}
> > +
> > +static ssize_t bno055_get_calib_status(struct device *dev, char *buf, int which)
> > +{
> > + int val;
> > + int ret;
> > + const char *calib_str;
> > + static const char * const calib_status[] = {"bad", "barely enough",
> > + "fair", "good"};
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + if (priv->operation_mode == BNO055_OPR_MODE_AMG ||
> > + (priv->operation_mode == BNO055_OPR_MODE_FUSION_FMC_OFF &&
> > + which == BNO055_CALIB_STAT_MAGN_SHIFT)) {
> > + calib_str = "idle";
> > + } else {
> > + mutex_lock(&priv->lock);
> > + ret = bno055_reg_read(priv, BNO055_CALIB_STAT_REG, &val);
> > + mutex_unlock(&priv->lock);
> > +
> > + if (ret)
> > + return -EIO;
> > +
> > + val = (val >> which) & BNO055_CALIB_STAT_MASK;
> > + calib_str = calib_status[val];
> > + }
> > +
> > + return scnprintf(buf, PAGE_SIZE, "%s\n", calib_str);
> > +}
> > +
> > +static ssize_t in_calibration_data_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + int ret;
> > + int size;
> > + int i;
> > + u8 data[BNO055_CALDATA_LEN];
> > + struct bno055_priv *priv = iio_priv(dev_to_iio_dev(dev));
> > +
> > + mutex_lock(&priv->lock);
> > + ret = bno055_reg_write(priv, BNO055_OPR_MODE_REG,
> > + 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_reg_write(priv, BNO055_OPR_MODE_REG, priv->operation_mode);
> > + mutex_unlock(&priv->lock);
> > + if (ret)
> > + return ret;
> > +
> > + for (size = 0, i = 0; i < BNO055_CALDATA_LEN; i++) {
> > + ret = scnprintf(buf + size,
> > + PAGE_SIZE - size, "%02x%c", data[i],
> > + (i + 1 < BNO055_CALDATA_LEN) ? ' ' : '\n');
> > + if (ret < 0)
> > + return ret;
> > + size += ret;
> > + }
> > +
> > + return size;
> > +unlock:
> > + mutex_unlock(&priv->lock);
> > + return ret;
> > +}
> > +
> > +static ssize_t in_autocalibration_status_sys_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_autocalibration_status_accel_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_autocalibration_status_gyro_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_autocalibration_status_magn_show(struct device *dev,
> > + struct device_attribute *a,
> > + char *buf)
> > +{
> > + return bno055_get_calib_status(dev, buf, BNO055_CALIB_STAT_MAGN_SHIFT);
> > +}
> > +
> > +static IIO_DEVICE_ATTR_RO(in_magn_sampling_frequency_available,
> > + 0);
> > +
> > +static IIO_DEVICE_ATTR(operation_mode, 0644,
> > + bno055_operation_mode_show,
> > + bno055_operation_mode_store, 0);
> > +
> > +static IIO_CONST_ATTR(operation_mode_available,
> > + "amg fusion fusion_fmc_off");
> > +
> > +static IIO_DEVICE_ATTR(in_accel_range, 0644,
> > + bno055_in_accel_range_show,
> > + bno055_in_accel_range_store, 0);
> > +
> > +static IIO_DEVICE_ATTR_RO(in_accel_range_available, 0);
> > +static IIO_DEVICE_ATTR_RO(in_accel_filter_low_pass_3db_frequency_available, 0);
> > +
> > +static IIO_DEVICE_ATTR(in_anglvel_range, 0644,
> > + bno055_in_gyr_range_show,
> > + bno055_in_gyr_range_store, 0);
> > +
> > +static IIO_DEVICE_ATTR_RO(in_anglvel_range_available, 0);
> > +static IIO_DEVICE_ATTR_RO(in_anglvel_filter_low_pass_3db_frequency_available, 0);
> > +
> > +static IIO_DEVICE_ATTR_RO(in_autocalibration_status_sys, 0);
> > +static IIO_DEVICE_ATTR_RO(in_autocalibration_status_accel, 0);
> > +static IIO_DEVICE_ATTR_RO(in_autocalibration_status_gyro, 0);
> > +static IIO_DEVICE_ATTR_RO(in_autocalibration_status_magn, 0);
> > +static IIO_DEVICE_ATTR_RO(in_calibration_data, 0);
> > +
> > +static struct attribute *bno055_attrs[] = {
> > + &iio_dev_attr_in_magn_sampling_frequency_available.dev_attr.attr,
> > + &iio_dev_attr_in_accel_range_available.dev_attr.attr,
> > + &iio_dev_attr_in_accel_range.dev_attr.attr,
> > + &iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
> > + &iio_dev_attr_in_anglvel_range_available.dev_attr.attr,
> > + &iio_dev_attr_in_anglvel_range.dev_attr.attr,
> > + &iio_dev_attr_in_anglvel_filter_low_pass_3db_frequency_available.dev_attr.attr,
> > + &iio_const_attr_operation_mode_available.dev_attr.attr,
> > + &iio_dev_attr_operation_mode.dev_attr.attr,
> > + &iio_dev_attr_in_autocalibration_status_sys.dev_attr.attr,
> > + &iio_dev_attr_in_autocalibration_status_accel.dev_attr.attr,
> > + &iio_dev_attr_in_autocalibration_status_gyro.dev_attr.attr,
> > + &iio_dev_attr_in_autocalibration_status_magn.dev_attr.attr,
> > + &iio_dev_attr_in_calibration_data.dev_attr.attr,
> > + NULL,
> > +};
> > +
> > +static const struct attribute_group bno055_attrs_group = {
> > + .attrs = bno055_attrs,
> > +};
> > +
> > +static const struct iio_info bno055_info = {
> > + .read_raw_multi = bno055_read_raw_multi,
> > + .write_raw = bno055_write_raw,
> > + .attrs = &bno055_attrs_group,
> > +};
> > +
> > +/*
> > + * 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 xferred 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 inspite 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)
> > +{
> > + int buf_base = *buf_idx;
> > + const int base = BNO055_ACC_DATA_X_LSB_REG;
> > + int ret;
> > + int i, j, n;
> > + __le16 *dst, *src;
> > + bool quat_in_read = false;
> > + int offs_fixup = 0;
> > + int xfer_len = len;
> > +
> > + /* All chans are made up 1 16bit sample, except for quaternion
> > + * that is made up 4 16-bit values.
> > + * For us the quaternion CH is just like 4 regular CHs.
> > + * If out 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) {
> > + for (j = 0; j < n; j++)
> > + dst[j] = src[j];
> > + }
> > +
> > + *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);
> > + struct {
> > + __le16 chans[(BNO055_GRAVITY_DATA_Z_LSB_REG -
> > + BNO055_ACC_DATA_X_LSB_REG) / 2];
> > + s64 timestamp __aligned(8);
> > + } buf;
> > + bool thr_hit;
> > + int quat;
> > + int ret;
> > + int start, end, xfer_start, next = 0;
> > + int buf_idx = 0;
> > + bool finish = false;
> > + unsigned long mask;
> > +
> > + /* we have less than 32 chs, all masks fit in an ulong */
> > + start = find_first_bit(iio_dev->active_scan_mask, iio_dev->masklength);
> > + xfer_start = start;
> > + if (start == iio_dev->masklength)
> > + goto done;
> > +
> > + mutex_lock(&priv->lock);
> > + while (!finish) {
> > + end = find_next_zero_bit(iio_dev->active_scan_mask,
> > + iio_dev->masklength, start);
> > + if (end == iio_dev->masklength) {
> > + finish = true;
> > + } else {
> > + next = find_next_bit(iio_dev->active_scan_mask,
> > + iio_dev->masklength, end);
> > + if (next == iio_dev->masklength) {
> > + finish = true;
> > + } else {
> > + quat = ((next > BNO055_SCAN_QUATERNION) &&
> > + (end <= BNO055_SCAN_QUATERNION)) ? 3 : 0;
> > + thr_hit = (next - end + quat) >
> > + priv->xfer_burst_break_thr;
> > + }
> > + }
> > +
> > + if (thr_hit || finish) {
> > + mask = *iio_dev->active_scan_mask >> xfer_start;
> > + ret = bno055_scan_xfer(priv, xfer_start,
> > + end - xfer_start,
> > + mask, buf.chans, &buf_idx);
> > + if (ret)
> > + goto done;
> > + xfer_start = next;
> > + }
> > + start = next;
> > + }
> > + iio_push_to_buffers_with_timestamp(iio_dev, &buf, pf->timestamp);
> > +done:
> > + mutex_unlock(&priv->lock);
> > + iio_trigger_notify_done(iio_dev->trig);
> > + return IRQ_HANDLED;
> > +}
> > +
> > +int bno055_probe(struct device *dev, struct regmap *regmap, int irq,
> > + int xfer_burst_break_thr)
> > +{
> > + int ver, rev;
> > + int res;
> > + unsigned int val;
> > + struct gpio_desc *rst;
> > + struct iio_dev *iio_dev;
> > + struct bno055_priv *priv;
> > + /* base name + separator + UID + ext + zero */
> > + char fw_name_buf[sizeof(BNO055_FW_NAME BNO055_FW_EXT) +
> > + BNO055_UID_LEN * 2 + 1 + 1];
> > + const struct firmware *caldata;
> > +
> > + iio_dev = devm_iio_device_alloc(dev, sizeof(*priv));
> > + if (!iio_dev)
> > + return -ENOMEM;
> > +
> > + iio_dev->name = "bno055";
> > + priv = iio_priv(iio_dev);
> > + memset(priv, 0, sizeof(*priv));
> > + mutex_init(&priv->lock);
> > + priv->regmap = regmap;
> > + priv->dev = dev;
> > + priv->xfer_burst_break_thr = xfer_burst_break_thr;
> > + rst = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
> > + if (IS_ERR(rst) && (PTR_ERR(rst) != -EPROBE_DEFER)) {
> > + dev_err(dev, "Failed to get reset GPIO");
> > + return PTR_ERR(rst);
> > + }
> > +
> > + priv->clk = devm_clk_get_optional(dev, "clk");
> > + if (IS_ERR(priv->clk) && (PTR_ERR(priv->clk) != -EPROBE_DEFER)) {
> > + dev_err(dev, "Failed to get CLK");
> > + return PTR_ERR(priv->clk);
> > + }
> > +
> > + clk_prepare_enable(priv->clk);
> > +
> > + if (rst) {
> > + usleep_range(5000, 10000);
> > + gpiod_set_value_cansleep(rst, 0);
> > + usleep_range(650000, 750000);
> > + }
> > +
> > + res = devm_add_action_or_reset(dev, bno055_uninit, priv);
> > + if (res)
> > + return res;
> > +
> > + res = bno055_reg_read(priv, BNO055_CHIP_ID_REG, &val);
> > + if (res)
> > + return res;
> > +
> > + if (val != BNO055_CHIP_ID_MAGIC) {
> > + dev_err(dev, "Unrecognized chip ID 0x%x", val);
> > + return -ENODEV;
> > + }
> > + dev_dbg(dev, "Found BMO055 chip");
> > +
> > + res = regmap_bulk_read(priv->regmap, BNO055_UID_REG,
> > + priv->uid, BNO055_UID_LEN);
> > + if (res)
> > + return res;
> > +
> > + dev_info(dev, "unique ID: %*ph", BNO055_UID_LEN, priv->uid);
> > +
> > + /*
> > + * This has nothing to do with the IMU firmware, this is for sensor
> > + * calibration data.
> > + */
> > + sprintf(fw_name_buf, BNO055_FW_NAME "-%*phN" BNO055_FW_EXT,
> > + BNO055_UID_LEN, priv->uid);
> > + res = request_firmware(&caldata, fw_name_buf, dev);
> > + if (res)
> > + res = request_firmware(&caldata,
> > + BNO055_FW_NAME BNO055_FW_EXT, dev);
> > +
> > + if (res) {
> > + dev_notice(dev, "Failed to load calibration data firmware file; this has nothing to do with IMU main firmware.");
> > + dev_notice(dev, "You can calibrate your IMU (look for 'in_autocalibration_status*' files in sysfs) and then copy 'in_calibration_data' to your firmware file");
> > + caldata = NULL;
> > + }
> > +
> > + res = bno055_init(priv, caldata);
> > + if (res)
> > + return res;
> > +
> > + if (caldata)
> > + release_firmware(caldata);
> > +
> > + res = regmap_read(priv->regmap,
> > + BNO055_SW_REV_LSB_REG, &rev);
> > + if (res)
> > + return res;
> > +
> > + res = regmap_read(priv->regmap,
> > + BNO055_SW_REV_MSB_REG, &ver);
> > + if (res)
> > + return res;
> > +
> > + dev_info(dev, "Firmware version %x.%x", ver, rev);
> > +
> > + iio_dev->channels = bno055_channels;
> > + iio_dev->num_channels = ARRAY_SIZE(bno055_channels);
> > + iio_dev->info = &bno055_info;
> > + iio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > + res = devm_iio_triggered_buffer_setup(dev, iio_dev,
> > + iio_pollfunc_store_time,
> > + bno055_trigger_handler, NULL);
> > + if (res)
> > + return res;
> > +
> > + return devm_iio_device_register(dev, iio_dev);
> > +}
> > +EXPORT_SYMBOL_GPL(bno055_probe);
> > +
> > +MODULE_AUTHOR("Andrea Merello <andrea.merello@iit.it>");
> > +MODULE_DESCRIPTION("Bosch BNO055 driver");
> > +MODULE_LICENSE("GPL v2");
> > diff --git a/drivers/iio/imu/bno055/bno055.h b/drivers/iio/imu/bno055/bno055.h
> > new file mode 100644
> > index 000000000000..163ab8068e7c
> > --- /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/device.h>
> > +#include <linux/regmap.h>
> > +
> > +int bno055_probe(struct device *dev, struct regmap *regmap, int irq,
> > + int xfer_burst_break_thr);
> > +extern const struct regmap_config bno055_regmap_config;
> > +
> > +#endif
> > --
> > 2.17.1
> >

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