From: Andrea Merello <andrea.merello@gmail.com>
To: jic23@kernel.org, mchehab+huawei@kernel.org,
linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
devicetree@vger.kernel.org
Cc: lars@metafoo.de, robh+dt@kernel.org, andy.shevchenko@gmail.com,
matt.ranostay@konsulko.com, ardeleanalex@gmail.com,
jacopo@jmondi.org, Andrea Merello <andrea.merello@iit.it>
Subject: [v4 14/14] docs: iio: add documentation for BNO055 driver
Date: Fri, 15 Apr 2022 15:00:05 +0200 [thread overview]
Message-ID: <20220415130005.85879-15-andrea.merello@gmail.com> (raw)
In-Reply-To: <20220415130005.85879-1-andrea.merello@gmail.com>
From: Andrea Merello <andrea.merello@iit.it>
The bno055 driver is rather complex and have some oddities and not-obvious
things that worth to document (e.g. calibration files)
Signed-off-by: Andrea Merello <andrea.merello@iit.it>
---
Documentation/iio/bno055.rst | 50 ++++++++++++++++++++++++++++++++++++
Documentation/iio/index.rst | 2 ++
2 files changed, 52 insertions(+)
create mode 100644 Documentation/iio/bno055.rst
diff --git a/Documentation/iio/bno055.rst b/Documentation/iio/bno055.rst
new file mode 100644
index 000000000000..af21376d7a25
--- /dev/null
+++ b/Documentation/iio/bno055.rst
@@ -0,0 +1,50 @@
+.. SPDX-License-Identifier: GPL-2.0
+==============================
+BNO055 driver
+==============================
+
+1. Overview
+===========
+
+This driver supports Bosch BNO055 IMUs (on both serial and I2C busses).
+
+Accelerometer, magnetometer and gyroscope measures are always provided.
+When "fusion_enable" sysfs attribute is set to 1, orientation (both Euler
+angles and quaternion), linear velocity and gravity vector are also
+provided, but some sensor settings (e.g. low pass filtering and range)
+became locked (the IMU firmware controls them).
+
+This driver supports also IIO buffers.
+
+2. Calibration
+==============
+
+The IMU continuously performs an autocalibration procedure if (and only if)
+operating in fusion mode. The magnetometer autocalibration can however be
+disabled writing 0 in the sysfs in_magn_calibration_fast_enable attribute.
+
+The driver provides access to autocalibration flags (i.e. you can known if
+the IMU has successfully autocalibrated) and to the calibration data blob.
+
+The user can save this blob in a firmware file (i.e. in /lib/firmware) that
+the driver looks for at probe time. If found, then the IMU is initialized
+with this calibration data. This saves the user from performing the
+calibration procedure every time (which consist of moving the IMU in
+various way).
+
+The driver looks for calibration data file using two different names: first
+a file whose name is suffixed with the IMU unique ID (exposed in sysfs as
+serial_number) is searched for; this is useful when there is more than one
+IMU instance. If this file is not found, then a "generic" calibration file
+is searched for (which can be used when only one IMU is present, without
+struggling with fancy names, that change on each device).
+
+Valid calibration file names would be e.g.
+ bno055-caldata-0e7c26a33541515120204a35342b04ff.dat
+ bno055-caldata.dat
+
+In non-fusion mode the IIO 'offset' attributes provide access to the
+offsets from calibration data (if any), so that the user can apply them to
+the accel, angvel and magn IIO attributes. In fusion mode they are not
+needed (the IMU firmware internally applies those corrections) and they
+read as zero.
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index 58b7a4ebac51..1b7292c58cd0 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -10,3 +10,5 @@ Industrial I/O
iio_configfs
ep93xx_adc
+
+ bno055
--
2.17.1
next prev parent reply other threads:[~2022-04-15 13:01 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-15 12:59 [v4 00/14] Add support for Bosch BNO055 IMU Andrea Merello
2022-04-15 12:59 ` [v4 01/14] iio: add modifiers for linear acceleration Andrea Merello
2022-04-15 12:59 ` [v4 02/14] iio: document linear acceleration modifiers Andrea Merello
2022-04-15 12:59 ` [v4 03/14] iio: event_monitor: add " Andrea Merello
2022-04-16 8:37 ` Andy Shevchenko
2022-04-15 12:59 ` [v4 04/14] iio: add modifers for pitch, yaw, roll Andrea Merello
2022-04-16 8:38 ` Andy Shevchenko
2022-04-15 12:59 ` [v4 05/14] iio: document pitch, yaw, roll modifiers Andrea Merello
2022-04-15 12:59 ` [v4 06/14] iio: event_monitor: add pitch, yaw and " Andrea Merello
2022-04-15 12:59 ` [v4 07/14] iio: add support for binary attributes Andrea Merello
2022-04-15 12:59 ` [v4 08/14] iio: imu: add Bosch Sensortec BNO055 core driver Andrea Merello
2022-04-15 17:43 ` Jonathan Cameron
2022-04-19 7:10 ` Andrea Merello
2022-04-24 17:45 ` Jonathan Cameron
2022-04-26 9:28 ` Andrea Merello
2022-04-28 18:45 ` Jonathan Cameron
2022-04-15 13:00 ` [v4 09/14] iio: document bno055 private sysfs attributes Andrea Merello
2022-04-15 13:00 ` [v4 10/14] iio: document "serial_number" sysfs attribute Andrea Merello
2022-04-19 7:41 ` Lars-Peter Clausen
2022-04-24 17:46 ` Jonathan Cameron
2022-04-15 13:00 ` [v4 11/14] dt-bindings: iio: imu: add documentation for Bosch BNO055 bindings Andrea Merello
2022-04-25 22:08 ` Rob Herring
2022-04-15 13:00 ` [v4 12/14] iio: imu: add BNO055 serdev driver Andrea Merello
2022-04-15 16:48 ` Jonathan Cameron
2022-04-16 8:44 ` Andy Shevchenko
2022-04-19 7:48 ` Andrea Merello
2022-04-19 8:29 ` Andy Shevchenko
2022-04-20 7:22 ` Andrea Merello
2022-04-15 13:00 ` [v4 13/14] iio: imu: add BNO055 I2C driver Andrea Merello
2022-04-15 16:49 ` Jonathan Cameron
2022-04-15 13:00 ` Andrea Merello [this message]
2022-04-16 8:40 ` [v4 00/14] Add support for Bosch BNO055 IMU Andy Shevchenko
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