| Message ID | 20220415130005.85879-1-andrea.merello@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add support for Bosch BNO055 IMU | expand |
On Fri, Apr 15, 2022 at 4:00 PM Andrea Merello <andrea.merello@gmail.com> wrote: > > From: Andrea Merello <andrea.merello@iit.it> > > This series (tries to) add support for Bosch BNO055 IMU to Linux IIO > subsystem. It is made up several patches: > > 1/13 to 7/12: add some IIO modifiers, and their documentation, to the IIO > core layer, in order to being able to expose the linear > acceleration and Euler angles among standard attributes. > Also update the IIO event monitor tool > > 7/13: fix binary attributes didn't work with IIO > > 8/13 to 11/13: add the core IIO BNO055 driver and documentation for sysfs > attributes and DT bindings > > 12/13: adds serdev BNO055 driver to actually use the IMU via serial line > > 13/13: adds I2C BNO055 driver to actually use the IMU via I2C wiring > > 14/13: add a documentation file that describe the bno055 driver and > specifically the calibration Thanks for a new version. So far I have noticed the issues with more than one patch: 1) missed commit message; 2) non-imperative mode of speaking in the commit messages. Please, take your time to refresh the Submitting Patches documentation and fix your series accordingly.
From: Andrea Merello <andrea.merello@iit.it> This series (tries to) add support for Bosch BNO055 IMU to Linux IIO subsystem. It is made up several patches: 1/13 to 7/12: add some IIO modifiers, and their documentation, to the IIO core layer, in order to being able to expose the linear acceleration and Euler angles among standard attributes. Also update the IIO event monitor tool 7/13: fix binary attributes didn't work with IIO 8/13 to 11/13: add the core IIO BNO055 driver and documentation for sysfs attributes and DT bindings 12/13: adds serdev BNO055 driver to actually use the IMU via serial line 13/13: adds I2C BNO055 driver to actually use the IMU via I2C wiring 14/13: add a documentation file that describe the bno055 driver and specifically the calibration Differences wrt v3: - use binary attribute for calibration data - introduce trace events (instead of dev_dbg()) for bno055 serial driver - changed serial driver name bno055_sl -> bno055_ser - fix quaternion unit - make the driver return error, instead of reading zeroes, when trying to access fusion data, but fusion is disabled - make serial driver code more readable and use more kernel helpers when possible - address issues found by 0day - fix accel range unit in doc - fix debugfs directory was not ever removed - add of_device_id table in I2C driver - use probe_new() instead of probe in I2C driver - some other trivial improvements and fixes Differences wrt other BNO055 drivers: Previously at least another driver for the very same chip has been posted to the Linux ML [0], but it has been never merged, and it seems no one cared of it since quite a long time. This driver differs from the above driver on the following aspects: - This driver supports also serial access (to be reliable, reset pin is required to be wired) - The above driver tried to support all IMU HW modes by allowing to choose one in the DT, and adapting IIO attributes accordingly. This driver does not rely on DT for this, instead settings are done via sysfs attributes. All IIO attributes are always exposed; more on this later on. This driver however supports only a subset of the HW-supported modes. - This driver has some support for managing the IMU calibration Supported operation modes: - AMG (accelerometer, magnetometer and gyroscope) mode, which provides raw (uncalibrated) measurements from the said sensors, and allows for setting some parameters about them (e.g. filter cut-off frequency, max sensor ranges, etc). - Fusion mode, which still provides AMG measures, while it also provides other data calculated by the IMU (e.g. rotation angles, linear acceleration, etc). In this mode user has no freedom to set any sensor parameter, since the HW locks them. Autocalibration and correction is performed by the IMU. IIO attributes exposing sensors parameters are always present, but in fusion modes the available values are constrained to just the one used by the HW. This is reflected in the '*_available' IIO attributes. Trying to set a not-supported value always falls back to the closest supported one, which in this case is just the one in use by the HW. IIO attributes for unavailable measurements (e.g. Euler angles in AMG mode) can't be read (return -EBUSY, or refuse to enable buffer). IMU calibration: The IMU supports for two sets of calibration parameters: - SIC matrix. user-provided; this driver doesn't currently support it - Offset and radius parameters. The IMU automatically finds out them when it is running in fusion mode; supported by this driver. The driver provides access to autocalibration flags (i.e. you can known if the IMU has successfully autocalibrated) and to 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 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 changes on each device). In AMG 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 and read as zero. Access protocols and serdev module: The serial protocol is quite simple, but there are tricks to make it really works. Those tricks and workarounds are documented in the driver source file. The core BNO055 driver tries to group readings in burst when appropriate, in order to optimize triggered buffer operation. The threshold for splitting a burst (i.e. max number of unused bytes in the middle of a burst that will be throw away) is provided to the core driver by the lowlevel access driver (either serdev or I2C) at probe time. [0] https://www.spinics.net/lists/linux-iio/msg25508.html Andrea Merello (14): iio: add modifiers for linear acceleration iio: document linear acceleration modifiers iio: event_monitor: add linear acceleration modifiers iio: add modifers for pitch, yaw, roll iio: document pitch, yaw, roll modifiers iio: event_monitor: add pitch, yaw and roll modifiers iio: add support for binary attributes iio: imu: add Bosch Sensortec BNO055 core driver iio: document bno055 private sysfs attributes iio: document "serial_number" sysfs attribute dt-bindings: iio: imu: add documentation for Bosch BNO055 bindings iio: imu: add BNO055 serdev driver iio: imu: add BNO055 I2C driver docs: iio: add documentation for BNO055 driver Documentation/ABI/testing/sysfs-bus-iio | 25 + .../ABI/testing/sysfs-bus-iio-bno055 | 81 + .../bindings/iio/imu/bosch,bno055.yaml | 59 + Documentation/iio/bno055.rst | 50 + Documentation/iio/index.rst | 2 + drivers/iio/imu/Kconfig | 1 + drivers/iio/imu/Makefile | 1 + drivers/iio/imu/bno055/Kconfig | 31 + drivers/iio/imu/bno055/Makefile | 7 + drivers/iio/imu/bno055/bno055.c | 1715 +++++++++++++++++ drivers/iio/imu/bno055/bno055.h | 12 + drivers/iio/imu/bno055/bno055_i2c.c | 56 + drivers/iio/imu/bno055/bno055_ser.c | 556 ++++++ drivers/iio/imu/bno055/bno055_ser_trace.h | 114 ++ drivers/iio/industrialio-core.c | 10 +- include/uapi/linux/iio/types.h | 7 +- tools/iio/iio_event_monitor.c | 6 + 17 files changed, 2731 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-bno055 create mode 100644 Documentation/devicetree/bindings/iio/imu/bosch,bno055.yaml create mode 100644 Documentation/iio/bno055.rst 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 create mode 100644 drivers/iio/imu/bno055/bno055_i2c.c create mode 100644 drivers/iio/imu/bno055/bno055_ser.c create mode 100644 drivers/iio/imu/bno055/bno055_ser_trace.h -- 2.17.1