[1/1] docs: iio: add documentation for adis16475 driver
Commit Message
Add documentation for adis16475 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@analog.com>
---
Documentation/iio/adis16475.rst | 327 ++++++++++++++++++++++++++++++++
1 file changed, 327 insertions(+)
create mode 100644 Documentation/iio/adis16475.rst
new file mode 100644
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+.. SPDX-License-Identifier: GPL-2.0
+
+================
+ADIS16475 driver
+================
+
+This driver supports Analog Device's IMUs on SPI bus.
+
+1. Supported devices
+====================
+
+* `ADIS16465 <https://www.analog.com/ADIS16465>`_
+* `ADIS16467 <https://www.analog.com/ADIS16467>`_
+* `ADIS16470 <https://www.analog.com/ADIS16470>`_
+* `ADIS16475 <https://www.analog.com/ADIS16475>`_
+* `ADIS16477 <https://www.analog.com/ADIS16477>`_
+* `ADIS16500 <https://www.analog.com/ADIS16500>`_
+* `ADIS16505 <https://www.analog.com/ADIS16505>`_
+* `ADIS16507 <https://www.analog.com/ADIS16507>`_
+
+Each supported device is a precision, miniature microelectromechanical system
+(MEMS) inertial measurement unit (IMU) that includes a triaxial gyroscope and a
+triaxial accelerometer. Each inertial sensor in the IMU device combines with
+signal conditioning that optimizes dynamic performance. The factory calibration
+characterizes each sensor for sensitivity, bias, alignment, linear acceleration
+(gyroscope bias), and point of percussion (accelerometer location). As a result,
+each sensor has dynamic compensation formulas that provide accurate sensor
+measurements over a broad set of conditions.
+
+2. Device attributes
+====================
+
+Accelerometer, gyroscope measures 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.
+
+The signal chain of each inertial sensor (accelerometers and
+gyroscopes) includes the application of unique correction
+formulas, which are derived from extensive characterization
+of bias, sensitivity, alignment, response to linear acceleration
+(gyroscopes), and point of percussion (accelerometer location)
+over a temperature range of −40°C to +85°C, for each ADIS device.
+These correction formulas are not accessible, but users do have
+the opportunity to adjust the bias for each sensor individually
+through the calibbias attribute.
+
++-------------------------------------------+----------------------------------------------------------+
+| 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. |
++-------------------------------------------+----------------------------------------------------------+
+| accel_calibbias_x | x-axis acceleration offset correction |
++-------------------------------------------+----------------------------------------------------------+
+| in_accel_x_raw | Raw X-axis accelerometer channel value. |
++-------------------------------------------+----------------------------------------------------------+
+| accel_calibbias_y | y-axis acceleration offset correction |
++-------------------------------------------+----------------------------------------------------------+
+| 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_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. |
++---------------------------------------+------------------------------------------------------+
+| anglvel_calibbias_x | x-axis gyroscope offset correction |
++---------------------------------------+------------------------------------------------------+
+| in_anglvel_x_raw | Raw X-axis gyroscope channel value. |
++---------------------------------------+------------------------------------------------------+
+| anglvel_calibbias_y | y-axis gyroscope offset correction |
++---------------------------------------+------------------------------------------------------+
+| 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_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_scale | Scale for the temperature sensor channel. |
++----------------------------------+-------------------------------------------+
+
++-------------------------------+---------------------------------------------------------+
+| Miscellaneous device files | Description |
++-------------------------------+---------------------------------------------------------+
+| name | Name of the IIO device. |
++-------------------------------+---------------------------------------------------------+
+| sampling_frequency | Currently selected sample rate. |
++-------------------------------+---------------------------------------------------------+
+| filter_low_pass_3db_frequency | Bandwidth for the accelerometer and gyroscope channels. |
++-------------------------------+---------------------------------------------------------+
+
++----------------------+-------------------------------------------------------------------------+
+| Debugfs device files | Description |
++----------------------+-------------------------------------------------------------------------+
+| serial_number | The serial number of the chip in hexadecimal format. |
++----------------------+-------------------------------------------------------------------------+
+| product_id | Chip specific product id (e.g. 16475, 16500, 16505, 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. |
++----------------------+-------------------------------------------------------------------------+
+
+Usage examples
+--------------
+
+Show device name:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat name
+ adis16505-2
+
+Show accelerometer channels value:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw
+ -275924
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw
+ -30142222
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw
+ 261265769
+ root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale
+ 0.000000037
+
+- X-axis acceleration = in_accel_x_raw * in_accel_scale = −0.010209188 m/s^2
+- Y-axis acceleration = in_accel_y_raw * in_accel_scale = −1.115262214 m/s^2
+- Z-axis acceleration = in_accel_z_raw * in_accel_scale = 9.666833453 m/s^2
+
+Show gyroscope channels value:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_x_raw
+ -3324626
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_y_raw
+ 1336980
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_z_raw
+ -602983
+ root:/sys/bus/iio/devices/iio:device0> cat in_anglvel_scale
+ 0.000000006
+
+- X-axis angular velocity = in_anglvel_x_raw * in_anglvel_scale = −0.019947756 rad/s
+- Y-axis angular velocity = in_anglvel_y_raw * in_anglvel_scale = 0.00802188 rad/s
+- Z-axis angular velocity = in_anglvel_z_raw * in_anglvel_scale = −0.003617898 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
+ 2000.000000
+
+ root:/sys/bus/iio/devices/iio:device0> echo 1000 > sampling_frequency
+ 1000.000000
+
+Set bandwidth for accelerometer and gyroscope:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency
+ 720
+
+ root:/sys/bus/iio/devices/iio:device0> echo 360 > filter_low_pass_3db_frequency
+ root:/sys/bus/iio/devices/iio:device0> cat filter_low_pass_3db_frequency
+ 360
+
+Show serial number:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat serial_number
+ 0x04f9
+
+Show product id:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat product_id
+ 16505
+
+Show flash count:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat flash_count
+ 150
+
+Show firmware revision:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat firmware_revision
+ 1.6
+
+Show firmware date:
+
+.. code-block:: bash
+
+ root:/sys/kernel/debug/iio/iio:device0> cat firmware_date
+ 06-27-2019
+
+
+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:
+ - ADIS16477
+ - ADIS16500
+ - ADIS16505
+ - ADIS16507
+
+However, when retrieving acceleration or gyroscope data using buffers, delta readings will not be available and vice versa.
+
+Usage examples
+--------------
+
+Set trigger if not available:
+
+.. code-block:: bash
+
+ root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+
+ root:/sys/bus/iio/devices/iio:device0> echo adis16505-2-dev0 > trigger/current_trigger
+ root:/sys/bus/iio/devices/iio:device0> cat trigger/current_trigger
+ adis16505-2-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 /dev/iio\:device0
+ ...
+ 0044760 3901 0000 ffff f9fe ffff 29ee 0100 f79b
+ 0044770 3901 0000 ffff 98fe ffff 1aef 0100 439a
+ 0044780 3901 0000 ffff b4fe ffff 32ef 0100 c199
+ 0044790 3901 0000 ffff bdfe ffff 20ef 0100 5f9a
+ 00447a0 3901 0000 ffff 37ff ffff 1eef 0100 389b
+ 00447b0 3901 0000 ffff 7dff ffff 96ee 0100 5a9c
+ ...