| Message ID | 20220426131102.23966-1-andrea.merello@gmail.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | Add support for Bosch BNO055 IMU | expand |
On Tue, Apr 26, 2022 at 3:11 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: > > 1/14 to 6/14: 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 > > 7/14: fix binary attributes didn't work with IIO > > 8/14 to 11/14: add the core IIO BNO055 driver and documentation for sysfs > attributes and DT bindings > > 12/14: adds serdev BNO055 driver to actually use the IMU via serial line > > 13/14: adds I2C BNO055 driver to actually use the IMU via I2C wiring > > 14/14: add a documentation file that describe the bno055 driver and > specifically the calibration FWIW, Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> for non-commented patches (12 out of 14 AFAICS). > Differences wrt v4: > - be more tolerant wrt unrecognized chip IDs > - rename 'serial_number' attribute in 'serialnumber' > - fix missing NULL variable initialization > - use sign_extend32() instead of s16 casting where appropriate > - fix quaternion unit > - minor stuff (e.g. comments..) > - reduce (slightly) locking in serdev driver > - rework tracepoint support (e.g. remove dedicated config option) > > 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 "serialnumber" sysfs attribute > dt-bindings: iio/imu: Add Bosch BNO055 > 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 | 25 + > drivers/iio/imu/bno055/Makefile | 10 + > drivers/iio/imu/bno055/bno055.c | 1710 +++++++++++++++++ > drivers/iio/imu/bno055/bno055.h | 12 + > drivers/iio/imu/bno055/bno055_i2c.c | 57 + > drivers/iio/imu/bno055/bno055_ser_core.c | 560 ++++++ > drivers/iio/imu/bno055/bno055_ser_trace.h | 104 + > drivers/iio/industrialio-core.c | 10 +- > include/uapi/linux/iio/types.h | 7 +- > tools/iio/iio_event_monitor.c | 6 + > 17 files changed, 2718 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_core.c > create mode 100644 drivers/iio/imu/bno055/bno055_ser_trace.h > > -- > 2.17.1
On Wed, 27 Apr 2022 15:42:49 +0200 Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > On Tue, Apr 26, 2022 at 3:11 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: > > > > 1/14 to 6/14: 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 > > > > 7/14: fix binary attributes didn't work with IIO > > > > 8/14 to 11/14: add the core IIO BNO055 driver and documentation for sysfs > > attributes and DT bindings > > > > 12/14: adds serdev BNO055 driver to actually use the IMU via serial line > > > > 13/14: adds I2C BNO055 driver to actually use the IMU via I2C wiring > > > > 14/14: add a documentation file that describe the bno055 driver and > > specifically the calibration > > FWIW, > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > for non-commented patches (12 out of 14 AFAICS). > FWIW I'm fine with the series once you've tidied up the stuff Andy picked up on. Thanks Andy for the detailed reviewing btw. Jonathan > > Differences wrt v4: > > - be more tolerant wrt unrecognized chip IDs > > - rename 'serial_number' attribute in 'serialnumber' > > - fix missing NULL variable initialization > > - use sign_extend32() instead of s16 casting where appropriate > > - fix quaternion unit > > - minor stuff (e.g. comments..) > > - reduce (slightly) locking in serdev driver > > - rework tracepoint support (e.g. remove dedicated config option) > > > > 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 "serialnumber" sysfs attribute > > dt-bindings: iio/imu: Add Bosch BNO055 > > 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 | 25 + > > drivers/iio/imu/bno055/Makefile | 10 + > > drivers/iio/imu/bno055/bno055.c | 1710 +++++++++++++++++ > > drivers/iio/imu/bno055/bno055.h | 12 + > > drivers/iio/imu/bno055/bno055_i2c.c | 57 + > > drivers/iio/imu/bno055/bno055_ser_core.c | 560 ++++++ > > drivers/iio/imu/bno055/bno055_ser_trace.h | 104 + > > drivers/iio/industrialio-core.c | 10 +- > > include/uapi/linux/iio/types.h | 7 +- > > tools/iio/iio_event_monitor.c | 6 + > > 17 files changed, 2718 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_core.c > > create mode 100644 drivers/iio/imu/bno055/bno055_ser_trace.h > > > > -- > > 2.17.1 > > >
Il giorno dom 1 mag 2022 alle ore 18:54 Jonathan Cameron <jic23@kernel.org> ha scritto: > > On Wed, 27 Apr 2022 15:42:49 +0200 > Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > > On Tue, Apr 26, 2022 at 3:11 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: > > > > > > 1/14 to 6/14: 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 > > > > > > 7/14: fix binary attributes didn't work with IIO > > > > > > 8/14 to 11/14: add the core IIO BNO055 driver and documentation for sysfs > > > attributes and DT bindings > > > > > > 12/14: adds serdev BNO055 driver to actually use the IMU via serial line > > > > > > 13/14: adds I2C BNO055 driver to actually use the IMU via I2C wiring > > > > > > 14/14: add a documentation file that describe the bno055 driver and > > > specifically the calibration > > > > FWIW, > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > for non-commented patches (12 out of 14 AFAICS). > > > FWIW I'm fine with the series once you've tidied up the stuff Andy picked up > on. > > Thanks Andy for the detailed reviewing btw. > > Jonathan I'm very grateful to both of you and to everyone who commented on those patches. Thanks :). Beside the "Reviewed-by" tags where appropriate, is it usual/appropriate to put some tag like "Thanks-to .. [for comments]" ? BTW I have also gone through some kernel-robot reports; they also state "If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@intel.com>". I'd say that it would be OK to add this tag to a patch that just fixes what is reported, but I'm unsure whether it is appropriate to add this tag to the patches in my series, because they add the code and the fix at once. Any advice here? Andrea
On Mon, May 2, 2022 at 8:33 AM Andrea Merello <andrea.merello@gmail.com> wrote: > Il giorno dom 1 mag 2022 alle ore 18:54 Jonathan Cameron > <jic23@kernel.org> ha scritto: > > On Wed, 27 Apr 2022 15:42:49 +0200 > > Andy Shevchenko <andy.shevchenko@gmail.com> wrote: > > > On Tue, Apr 26, 2022 at 3:11 PM Andrea Merello <andrea.merello@gmail.com> wrote: ... > > > FWIW, > > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > > for non-commented patches (12 out of 14 AFAICS). > > > > > FWIW I'm fine with the series once you've tidied up the stuff Andy picked up > > on. > > > > Thanks Andy for the detailed reviewing btw. You/re welcome! > I'm very grateful to both of you and to everyone who commented on > those patches. Thanks :). Beside the "Reviewed-by" tags where > appropriate, is it usual/appropriate to put some tag like "Thanks-to > .. [for comments]" ? Nope, just mention that in the cover letter. > BTW I have also gone through some kernel-robot reports; they also > state "If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp@intel.com>". I'd say that it would > be OK to add this tag to a patch that just fixes what is reported, but > I'm unsure whether it is appropriate to add this tag to the patches in > my series, because they add the code and the fix at once. Any advice > here? For this we specifically amended the kernel documentation recently. https://www.kernel.org/doc/html/latest/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes "The tag is intended for bugs; please do not use it to credit feature requests."
Il giorno lun 2 mag 2022 alle ore 09:48 Andy Shevchenko <andy.shevchenko@gmail.com> ha scritto: > [ .. ] > > BTW I have also gone through some kernel-robot reports; they also > > state "If you fix the issue, kindly add following tag as appropriate > > Reported-by: kernel test robot <lkp@intel.com>". I'd say that it would > > be OK to add this tag to a patch that just fixes what is reported, but > > I'm unsure whether it is appropriate to add this tag to the patches in > > my series, because they add the code and the fix at once. Any advice > > here? > > For this we specifically amended the kernel documentation recently. > https://www.kernel.org/doc/html/latest/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes > > "The tag is intended for bugs; please do not use it to credit feature requests." Well, no any feature request to credit here; a bug and its fix are involved. Sounds more like a "yes" so far.. But it wouldn't be clear what the robot did report indeed (squashed bugs and fixes).. Maybe a "thank" in the cover letter also to it would suffice? > -- > With Best Regards, > Andy Shevchenko
On Mon, May 2, 2022 at 10:31 AM Andrea Merello <andrea.merello@gmail.com> wrote: > Il giorno lun 2 mag 2022 alle ore 09:48 Andy Shevchenko > <andy.shevchenko@gmail.com> ha scritto: ... > > > BTW I have also gone through some kernel-robot reports; they also > > > state "If you fix the issue, kindly add following tag as appropriate > > > Reported-by: kernel test robot <lkp@intel.com>". I'd say that it would > > > be OK to add this tag to a patch that just fixes what is reported, but > > > I'm unsure whether it is appropriate to add this tag to the patches in > > > my series, because they add the code and the fix at once. Any advice > > > here? > > > > For this we specifically amended the kernel documentation recently. > > https://www.kernel.org/doc/html/latest/process/submitting-patches.html#using-reported-by-tested-by-reviewed-by-suggested-by-and-fixes > > > > "The tag is intended for bugs; please do not use it to credit feature requests." > > Well, no any feature request to credit here; a bug and its fix are > involved. Sounds more like a "yes" so far.. But it wouldn't be clear > what the robot did report indeed (squashed bugs and fixes).. Maybe a > "thank" in the cover letter also to it would suffice? The reported from bots should be used when your patches.changes induced by those reports, it seems otherwise in your case.,
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: 1/14 to 6/14: 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 7/14: fix binary attributes didn't work with IIO 8/14 to 11/14: add the core IIO BNO055 driver and documentation for sysfs attributes and DT bindings 12/14: adds serdev BNO055 driver to actually use the IMU via serial line 13/14: adds I2C BNO055 driver to actually use the IMU via I2C wiring 14/14: add a documentation file that describe the bno055 driver and specifically the calibration Differences wrt v4: - be more tolerant wrt unrecognized chip IDs - rename 'serial_number' attribute in 'serialnumber' - fix missing NULL variable initialization - use sign_extend32() instead of s16 casting where appropriate - fix quaternion unit - minor stuff (e.g. comments..) - reduce (slightly) locking in serdev driver - rework tracepoint support (e.g. remove dedicated config option) 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 "serialnumber" sysfs attribute dt-bindings: iio/imu: Add Bosch BNO055 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 | 25 + drivers/iio/imu/bno055/Makefile | 10 + drivers/iio/imu/bno055/bno055.c | 1710 +++++++++++++++++ drivers/iio/imu/bno055/bno055.h | 12 + drivers/iio/imu/bno055/bno055_i2c.c | 57 + drivers/iio/imu/bno055/bno055_ser_core.c | 560 ++++++ drivers/iio/imu/bno055/bno055_ser_trace.h | 104 + drivers/iio/industrialio-core.c | 10 +- include/uapi/linux/iio/types.h | 7 +- tools/iio/iio_event_monitor.c | 6 + 17 files changed, 2718 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_core.c create mode 100644 drivers/iio/imu/bno055/bno055_ser_trace.h -- 2.17.1