From: <andrea.merello@iit.it>
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: [v6 14/14] docs: iio: add documentation for BNO055 driver
Date: Mon, 13 Jun 2022 14:05:34 +0200 [thread overview]
Message-ID: <20220613120534.36991-15-andrea.merello@iit.it> (raw)
In-Reply-To: <20220613120534.36991-1-andrea.merello@iit.it>
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>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---
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:[~2022-06-14 12:35 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-13 12:05 [v6 00/14] Add support for Bosch BNO055 IMU andrea.merello
2022-06-13 12:05 ` [v6 01/14] iio: add modifiers for linear acceleration andrea.merello
2022-06-13 12:05 ` [v6 02/14] iio: document linear acceleration modifiers andrea.merello
2022-06-13 12:05 ` [v6 03/14] iio: event_monitor: add " andrea.merello
2022-06-13 12:05 ` [v6 04/14] iio: add modifers for pitch, yaw, roll andrea.merello
2022-06-13 12:05 ` [v6 05/14] iio: document pitch, yaw, roll modifiers andrea.merello
2022-06-13 12:05 ` [v6 06/14] iio: event_monitor: add pitch, yaw and " andrea.merello
2022-06-13 12:05 ` [v6 07/14] iio: add support for binary attributes andrea.merello
2022-06-13 12:05 ` [v6 08/14] iio: imu: add Bosch Sensortec BNO055 core driver andrea.merello
2022-06-13 16:44 ` Andy Shevchenko
2022-06-14 9:11 ` Andrea Merello
2022-06-14 10:58 ` Andy Shevchenko
2022-06-14 12:15 ` Andrea Merello
2022-06-14 15:10 ` Andy Shevchenko
2022-06-14 15:27 ` Andrea Merello
2022-06-18 17:26 ` Jonathan Cameron
2022-06-13 12:05 ` [v6 09/14] iio: document bno055 private sysfs attributes andrea.merello
2022-06-13 12:05 ` [v6 10/14] iio: document "serialnumber" sysfs attribute andrea.merello
2022-06-13 12:05 ` [v6 11/14] dt-bindings: iio/imu: Add Bosch BNO055 andrea.merello
2022-06-13 12:05 ` [v6 12/14] iio: imu: add BNO055 serdev driver andrea.merello
2022-06-13 16:52 ` Andy Shevchenko
2022-06-15 20:57 ` kernel test robot
2022-06-15 21:13 ` Andy Shevchenko
2022-06-15 21:15 ` Andy Shevchenko
2022-07-03 1:52 ` kernel test robot
2022-06-13 12:05 ` [v6 13/14] iio: imu: add BNO055 I2C driver andrea.merello
2022-06-13 12:05 ` andrea.merello [this message]
2022-07-03 7:58 ` [v6 14/14] docs: iio: add documentation for BNO055 driver kernel test robot
2022-07-03 13:11 ` Bagas Sanjaya
2022-07-03 14:00 ` Andy Shevchenko
2022-07-04 1:21 ` Bagas Sanjaya
2022-07-04 3:40 ` [PATCH v2] Documentation: bno055: separate SPDX identifier and page title Bagas Sanjaya
2022-07-04 19:49 ` Andy Shevchenko
2022-07-05 1:13 ` Bagas Sanjaya
2022-07-05 9:02 ` Andy Shevchenko
2022-07-13 16:09 ` Jonathan Cameron
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