[PATCH 5/5] docs: iio: add documentation for adis16480 driver
From: Ramona Gradinariu
Date: Tue Apr 23 2024 - 04:45:12 EST
Add documentation for adis16480 driver which describes the driver
device files and shows how the user may use the ABI for various
scenarios (configuration, measurement, etc.).
Signed-off-by: Ramona Gradinariu <ramona.gradinariu@xxxxxxxxxx>
---
Documentation/iio/adis16480.rst | 461 ++++++++++++++++++++++++++++++++
Documentation/iio/index.rst | 1 +
2 files changed, 462 insertions(+)
create mode 100644 Documentation/iio/adis16480.rst
diff --git a/Documentation/iio/adis16480.rst b/Documentation/iio/adis16480.rst
new file mode 100644
index 000000000000..891865cfa712
--- /dev/null
+++ b/Documentation/iio/adis16480.rst
@@ -0,0 +1,461 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+================
+ADIS16480 driver
+================
+
+This driver supports Analog Device's IMUs on SPI bus.
+
+1. Supported devices
+====================
+
+* `ADIS16375 <https://www.analog.com/ADIS16375>`_
+* `ADIS16480 <https://www.analog.com/ADIS16480>`_
+* `ADIS16485 <https://www.analog.com/ADIS16485>`_
+* `ADIS16488 <https://www.analog.com/ADIS16488>`_
+* `ADIS16490 <https://www.analog.com/ADIS16490>`_
+* `ADIS16495 <https://www.analog.com/ADIS16495>`_
+* `ADIS16497 <https://www.analog.com/ADIS16497>`_
+* `ADIS16545 <https://www.analog.com/ADIS16545>`_
+* `ADIS16547 <https://www.analog.com/ADIS16547>`_
+
+Each supported device is a complete inertial system that includes a triaxial
+gyroscope and a triaxial accelerometer. Each inertial sensor in device combines
+with signal conditioning that optimizes dynamic performance. The factory
+calibration characterizes each sensor for sensitivity, bias, and alignment. As
+a result, each sensor has its own dynamic compensation formulas that provide
+accurate sensor measurements.
+
+2. Device attributes
+====================
+
+Accelerometer, gyroscope measurements are always provided. Furthermore, the
+driver offers the capability to retrieve the delta angle and the delta velocity
+measurements computed by the device.
+
+The delta angle measurements represent a calculation of angular displacement
+between each sample update, while the delta velocity measurements represent a
+calculation of linear velocity change between each sample update.
+
+Finally, temperature data are provided which show a coarse measurement of
+the temperature inside of the IMU device. This data is most useful for
+monitoring relative changes in the thermal environment.
+
+ADIS16480 and ADIS16488 also provide access to barometric pressure data and
+triaxial magnetometer measurements.
+
+Each IIO device, has a device folder under ``/sys/bus/iio/devices/iio:deviceX``,
+where X is the IIO index of the device. Under these folders reside a set of
+device files, depending on the characteristics and features of the hardware
+device in questions. These files are consistently generalized and documented in
+the IIO ABI documentation.
+
+The following tables show the adis16480 related device files, found in the
+specific device folder path ``/sys/bus/iio/devices/iio:deviceX``.
+
+**Available only for ADIS16480 and ADIS16488:**
+
++------------------------------------------+---------------------------------------------------------+
+| 3-Axis Magnetometer related device files | Description |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_scale | Scale for the magnetometer channels. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_x_calibbias | Calibration offset for the X-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_x_raw | Raw X-axis magnetometer channel value. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_y_calibbias | Calibration offset for the Y-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_y_raw | Raw Y-axis magnetometer channel value. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_z_calibbias | Calibration offset for the Z-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis magnetometer channel. |
++------------------------------------------+---------------------------------------------------------+
+| in_magn_z_raw | Raw Z-axis magnetometer channel value. |
++------------------------------------------+---------------------------------------------------------+
+
++------------------------------------------+-----------------------------------------------------+
+| Barometric pressure sensor related files | Description |
++------------------------------------------+-----------------------------------------------------+
+| in_pressure0_calibbias | Calibration offset for barometric pressure channel. |
++------------------------------------------+-----------------------------------------------------+
+| in_pressure0_raw | Raw barometric pressure channel value. |
++------------------------------------------+-----------------------------------------------------+
+| in_pressure0_scale | Scale for the barometric pressure sensor channel. |
++------------------------------------------+-----------------------------------------------------+
+
+**Available for all supported devices:**
+
++-------------------------------------------+----------------------------------------------------------+
+| 3-Axis Accelerometer related device files | Description |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_scale | Scale for the accelerometer channels. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_calibbias | Calibration offset for the X-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_calibscale | Calibration scale for the X-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_raw | Raw X-axis accelerometer channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_y_calibbias | Calibration offset for the Y-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_y_calibscale | Calibration scale for the Y-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_y_raw | Raw Y-axis accelerometer channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_calibbias | Calibration offset for the Z-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_calibscale | Calibration scale for the Z-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis accelerometer channel. |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_z_raw | Raw Z-axis accelerometer channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_scale | Scale for delta velocity channels. |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_x_raw | Raw X-axis delta velocity channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_y_raw | Raw Y-axis delta velocity channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| in_deltavelocity_z_raw | Raw Z-axis delta velocity channel value. |
++-------------------------------------------+----------------------------------------------------------+
+
++--------------------------------------------+------------------------------------------------------+
+| 3-Axis Gyroscope related device files | Description |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_scale | Scale for the gyroscope channels. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_x_calibbias | Calibration offset for the X-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_x_calibscale | Calibration scale for the X-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_x_filter_low_pass_3db_frequency | Bandwidth for the X-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_x_raw | Raw X-axis gyroscope channel value. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_y_calibbias | Calibration offset for the Y-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_y_calibscale | Calibration scale for the Y-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_y_filter_low_pass_3db_frequency | Bandwidth for the Y-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_y_raw | Raw Y-axis gyroscope channel value. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_z_calibbias | Calibration offset for the Z-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_z_calibscale | Calibration scale for the Z-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_z_filter_low_pass_3db_frequency | Bandwidth for the Z-axis gyroscope channel. |
++--------------------------------------------+------------------------------------------------------+
+| in_anglvel_z_raw | Raw Z-axis gyroscope channel value. |
++--------------------------------------------+------------------------------------------------------+
+| in_deltaangl_scale | Scale for delta angle channels. |
++--------------------------------------------+------------------------------------------------------+
+| in_deltaangl_x_raw | Raw X-axis delta angle channel value. |
++--------------------------------------------+------------------------------------------------------+
+| in_deltaangl_y_raw | Raw Y-axis delta angle channel value. |
++--------------------------------------------+------------------------------------------------------+
+| in_deltaangl_z_raw | Raw Z-axis delta angle channel value. |
++--------------------------------------------+------------------------------------------------------+
+
++----------------------------------+-------------------------------------------+
+| Temperature sensor related files | Description |
++----------------------------------+-------------------------------------------+
+| in_temp0_raw | Raw temperature channel value. |
++----------------------------------+-------------------------------------------+
+| in_temp0_offset | Offset for the temperature sensor channel.|
++----------------------------------+-------------------------------------------+
+| in_temp0_scale | Scale for the temperature sensor channel. |
++----------------------------------+-------------------------------------------+
+
++-------------------------------+---------------------------------------------------------+
+| Miscellaneous device files | Description |
++-------------------------------+---------------------------------------------------------+
+| name | Name of the IIO device. |
++-------------------------------+---------------------------------------------------------+
+| sampling_frequency | Currently selected sample rate. |
++-------------------------------+---------------------------------------------------------+
+
+The following table shows the adis16480 related device debug files, found in the
+specific device debug folder path ``/sys/kernel/debug/iio/iio:deviceX``.
+
++----------------------+-------------------------------------------------------------------------+
+| Debugfs device files | Description |
++----------------------+-------------------------------------------------------------------------+
+| serial_number | The serial number of the chip in hexadecimal format. |
++----------------------+-------------------------------------------------------------------------+
+| product_id | Chip specific product id (e.g. 16480, 16488, 16545, etc.). |
++----------------------+-------------------------------------------------------------------------+
+| flash_count | The number of flash writes performed on the device. |
++----------------------+-------------------------------------------------------------------------+
+| firmware_revision | String containing the firmware revision in the following format ##.##. |
++----------------------+-------------------------------------------------------------------------+
+| firmware_date | String containing the firmware date in the following format mm-dd-yyyy. |
++----------------------+-------------------------------------------------------------------------+
+
+Channels processed values
+-------------------------
+
+A channel value can be read from its _raw attribute. The value returned is the
+raw value as reported by the devices. To get the processed value of the channel,
+apply the following formula:
+
+.. code-block:: bash
+
+ processed value = (_raw + _offset) * _scale
+
+Where _offset and _scale are device attributes. If no _offset attribute is
+present, simply assume its value is 0.
+
+The adis16480 driver offers data for 7 types of channels, the table below shows
+the measurement units for the processed value, which are defined by the IIO
+framework:
+
++--------------------------------------+---------------------------+
+| Channel type | Measurement unit |
++--------------------------------------+---------------------------+
+| Acceleration on X, Y, and Z axis | Meters per Second squared |
++--------------------------------------+---------------------------+
+| Angular velocity on X, Y and Z axis | Radians per second |
++--------------------------------------+---------------------------+
+| Delta velocity on X. Y, and Z axis | Meters per Second |
++--------------------------------------+---------------------------+
+| Delta angle on X, Y, and Z axis | Radians |
++--------------------------------------+---------------------------+
+| Temperature | Millidegrees Celsius |
++--------------------------------------+---------------------------+
+| Magnetic field along X, Y and Z axis | Gauss |
++--------------------------------------+---------------------------+
+| Barometric pressure | kilo Pascal |
++--------------------------------------+---------------------------+
+
+Usage examples
+--------------
+
+Show device name:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat name
+ adis16545-1
+
+Show accelerometer channels value:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw
+ 1376728
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw
+ 4487621
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw
+ 262773792
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale
+ 0.000000037
+
+- X-axis acceleration = in_accel_x_raw * in_accel_scale = 0.050938936 m/s^2
+- Y-axis acceleration = in_accel_y_raw * in_accel_scale = 0.166041977 m/s^2
+- Z-axis acceleration = in_accel_z_raw * in_accel_scale = 9.722630304 m/s^2
+
+Show gyroscope channels value:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_x_raw
+ -1041702
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_raw
+ -273013
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_z_raw
+ 2745116
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_scale
+ 0.000000001
+
+- X-axis angular velocity = in_anglvel_x_raw * in_anglvel_scale = −0.001041702 rad/s
+- Y-axis angular velocity = in_anglvel_y_raw * in_anglvel_scale = −0.000273013 rad/s
+- Z-axis angular velocity = in_anglvel_z_raw * in_anglvel_scale = 0.002745116 rad/s
+
+Set calibration offset for accelerometer channels:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
+ 0
+
+ root:/sys/bus/iio/devices/iio:device0> echo 5000 > in_accel_x_calibbias
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias
+ 5000
+
+Set calibration offset for gyroscope channels:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
+ 0
+
+ root:/sys/bus/iio/devices/iio:device0> echo -5000 > in_anglvel_y_calibbias
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_calibbias
+ -5000
+
+Set sampling frequency:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency
+ 4250.000000
+
+ root:/sys/bus/iio/devices/iio:device0> echo 1000 > sampling_frequency
+ 1062.500000
+
+Set bandwidth for accelerometer channels:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_filter_low_pass_3db_frequency
+ 0
+
+ root:/sys/bus/iio/devices/iio:device0> echo 300 > in_accel_x_filter_low_pass_3db_frequency
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_filter_low_pass_3db_frequency
+ 300
+
+Show serial number:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat serial_number
+ 0x000c
+
+Show product id:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat product_id
+ 16545
+
+Show flash count:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat flash_count
+ 88
+
+Show firmware revision:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat firmware_revision
+ 1.4
+
+Show firmware date:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat firmware_date
+ 09-23-2023
+
+3. Device buffers
+=================
+
+This driver supports IIO buffers.
+
+All devices support retrieving the raw acceleration, gyroscope and temperature
+measurements using buffers.
+
+The following device families also support retrieving the delta velocity, delta
+angle and temperature measurements using buffers:
+
+- ADIS16545
+- ADIS16547
+
+However, when retrieving acceleration or gyroscope data using buffers, delta
+readings will not be available and vice versa.
+
+Usage examples
+--------------
+
+Set device trigger in current_trigger, if not already set:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+
+ root:/sys/bus/iio/devices/iio:device0> echo adis16545-1-dev0 > trigger/current_trigger
+ root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+ adis16545-1-dev0
+
+Select channels for buffer read:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_x_en
+ root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_y_en
+ root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_deltavelocity_z_en
+ root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp0_en
+
+Set the number of samples to be stored in the buffer:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> echo 10 > buffer/length
+
+Enable buffer readings:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> echo 1 > buffer/enable
+
+Obtain buffered data:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> hexdump -C /dev/iio\:device0
+ ...
+ 00006aa0 09 62 00 00 ff ff fc a4 00 00 01 69 00 03 3c 08 |.b.........i..<.|
+ 00006ab0 09 61 00 00 00 00 02 96 00 00 02 8f 00 03 37 50 |.a............7P|
+ 00006ac0 09 61 00 00 00 00 12 3d 00 00 0b 89 00 03 2c 0b |.a.....=......,.|
+ 00006ad0 09 61 00 00 00 00 1e dc 00 00 16 dd 00 03 25 bf |.a............%.|
+ 00006ae0 09 61 00 00 00 00 1e e3 00 00 1b bf 00 03 27 0b |.a............'.|
+ 00006af0 09 61 00 00 00 00 15 50 00 00 19 44 00 03 30 fd |.a.....P...D..0.|
+ 00006b00 09 61 00 00 00 00 09 0e 00 00 14 41 00 03 3d 7f |.a.........A..=.|
+ 00006b10 09 61 00 00 ff ff ff f0 00 00 0e bc 00 03 48 d0 |.a............H.|
+ 00006b20 09 63 00 00 00 00 00 9f 00 00 0f 37 00 03 4c fe |.c.........7..L.|
+ 00006b30 09 64 00 00 00 00 0b f6 00 00 18 92 00 03 43 22 |.d............C"|
+ 00006b40 09 64 00 00 00 00 18 df 00 00 22 33 00 03 33 ab |.d........"3..3.|
+ 00006b50 09 63 00 00 00 00 1e 81 00 00 26 be 00 03 29 60 |.c........&...)`|
+ 00006b60 09 63 00 00 00 00 1b 13 00 00 22 2f 00 03 23 91 |.c........"/..#.|
+ ...
+
+See ``Documentation/iio/iio_devbuf.rst`` for more information about how buffered
+data is structured.
+
+4. IIO Interfacing Tools
+========================
+
+Linux Kernel Tools
+------------------
+
+Linux Kernel provides some userspace tools that can be used to retrieve data
+from IIO sysfs:
+
+* lsiio: example application that provides a list of IIO devices and triggers
+* iio_event_monitor: example application that reads events from an IIO device
+ and prints them
+* iio_generic_buffer: example application that reads data from buffer
+* iio_utils: set of APIs, typically used to access sysfs files.
+
+LibIIO
+------
+
+LibIIO is a C/C++ library that provides generic access to IIO devices. The
+library abstracts the low-level details of the hardware, and provides a simple
+yet complete programming interface that can be used for advanced projects.
+
+For more information about LibIIO, please see:
+https://github.com/analogdevicesinc/libiio
diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst
index fb6f9d743211..79c348a0284b 100644
--- a/Documentation/iio/index.rst
+++ b/Documentation/iio/index.rst
@@ -18,5 +18,6 @@ Industrial I/O Kernel Drivers
ad7944
adis16475
+ adis16480
bno055
ep93xx_adc
--
2.34.1