On Thu, 27 Jun 2024 13:25:19 +0300 Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> wrote: > Add documentation for adxl380 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> > Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx> > --- > changes in v3: > - performed docs build via `make htmldocs` and no warnings were > detected for adxl380 documentation. Great. I'm paranoid about this (and often forget to check myself!) This looks good to me except as with the DT binding, I think you want to tone down the marketting a little! Thanks, Jonathan > Documentation/iio/adxl380.rst | 238 ++++++++++++++++++++++++++++++++++ > Documentation/iio/index.rst | 1 + > 2 files changed, 239 insertions(+) > create mode 100644 Documentation/iio/adxl380.rst > > diff --git a/Documentation/iio/adxl380.rst b/Documentation/iio/adxl380.rst > new file mode 100644 > index 000000000000..a64e330a18ee > --- /dev/null > +++ b/Documentation/iio/adxl380.rst > @@ -0,0 +1,238 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +=============== > +ADXL380 driver > +=============== > + > +This driver supports Analog Device's ADXL380/382 on SPI/I2C bus. > + > +1. Supported devices > +==================== > + > +* `ADXL380 <https://www.analog.com/ADXL380>`_ > +* `ADXL382 <https://www.analog.com/ADXL382>`_ > + > +The ADXL380/ADXL382 is a low noise density, low power, 3-axis accelerometer with > +selectable measurement ranges. The ADXL380 supports the ±4 g, ±8 g, and ±16 g > +ranges, and the ADXL382 supports ±15 g, ±30 g, and ±60 g ranges. > + > +The ADXL380/ADXL382 offers industry leading noise, enabling precision > +applications with minimal calibration. This bit is marketting heavy. > The low noise, and low power > +ADXL380/ADXL382 enables accurate measurement in an environment with high > +vibration, heart sounds and audio. This is more reasonable as talking about where it might be used. > + > +2. Device attributes > +==================== > + > +Accelerometer measurements are always provided. > + > +Temperature data are also provided. This data can be used to monitor the > +internal system temperature or to improve the temperature stability of the > +device via calibration. > + > +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 adxl380 related device files, found in the > +specific device folder path ``/sys/bus/iio/devices/iio:deviceX``. > + > ++---------------------------------------------------+----------------------------------------------------------+ > +| 3-Axis Accelerometer related device files | Description | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_scale | Scale for the accelerometer channels. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_filter_high_pass_3db_frequency | Low pass filter bandwidth. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_filter_high_pass_3db_frequency_available | Available low pass filter bandwidth configurations. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_filter_low_pass_3db_frequency | High pass filter bandwidth. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_filter_low_pass_3db_frequency_available | Available high pass filter bandwidth configurations. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_x_calibbias | Calibration offset for the X-axis accelerometer channel. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_x_raw | Raw X-axis accelerometer channel value. | > ++---------------------------------------------------+----------------------------------------------------------+ > +| in_accel_y_calibbias | 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. | > ++---------------------------------------------------+----------------------------------------------------------+ > + > ++----------------------------------+--------------------------------------------+ > +| Temperature sensor related files | Description | > ++----------------------------------+--------------------------------------------+ > +| in_temp_raw | Raw temperature channel value. | > ++----------------------------------+--------------------------------------------+ > +| in_temp_offset | Offset for the temperature sensor channel. | > ++----------------------------------+--------------------------------------------+ > +| in_temp_scale | Scale for the temperature sensor channel. | > ++----------------------------------+--------------------------------------------+ > + > ++------------------------------+----------------------------------------------+ > +| Miscellaneous device files | Description | > ++------------------------------+----------------------------------------------+ > +| name | Name of the IIO device. | > ++------------------------------+----------------------------------------------+ > +| sampling_frequency | Currently selected sample rate. | > ++------------------------------+----------------------------------------------+ > +| sampling_frequency_available | Available sampling frequency configurations. | > ++------------------------------+----------------------------------------------+ > + > +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 adis16475 driver offers data for 2 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 | > ++-------------------------------------+---------------------------+ > +| Temperature | Millidegrees Celsius | > ++-------------------------------------+---------------------------+ > + > +Usage examples > +-------------- > + > +Show device name: > + > +.. code-block:: bash > + > + root:/sys/bus/iio/devices/iio:device0> cat name > + adxl382 > + > +Show accelerometer channels value: > + > +.. code-block:: bash > + > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_raw > + -1771 > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_y_raw > + 282 > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_z_raw > + -1523 > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_scale > + 0.004903325 > + > +- X-axis acceleration = in_accel_x_raw * in_accel_scale = −8.683788575 m/s^2 > +- Y-axis acceleration = in_accel_y_raw * in_accel_scale = 1.38273765 m/s^2 > +- Z-axis acceleration = in_accel_z_raw * in_accel_scale = -7.467763975 m/s^2 > + > +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 50 > in_accel_x_calibbias > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_x_calibbias > + 50 > + > +Set sampling frequency: > + > +.. code-block:: bash > + > + root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency > + 16000 > + root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency_available > + 16000 32000 64000 > + > + root:/sys/bus/iio/devices/iio:device0> echo 32000 > sampling_frequency > + root:/sys/bus/iio/devices/iio:device0> cat sampling_frequency > + 32000 > + > +Set low pass filter bandwidth for accelerometer channels: > + > +.. code-block:: bash > + > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency > + 32000 > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency_available > + 32000 8000 4000 2000 > + > + root:/sys/bus/iio/devices/iio:device0> echo 2000 > in_accel_filter_low_pass_3db_frequency > + root:/sys/bus/iio/devices/iio:device0> cat in_accel_filter_low_pass_3db_frequency > + 2000 > + > +3. Device buffers > +================= > + > +This driver supports IIO buffers. > + > +All devices support retrieving the raw acceleration and temperature measurements > +using buffers. > + > +Usage examples > +-------------- > + > +Select channels for buffer read: > + > +.. code-block:: bash > + > + root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_x_en > + root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_y_en > + root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_accel_z_en > + root:/sys/bus/iio/devices/iio:device0> echo 1 > scan_elements/in_temp_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 > + ... > + 002bc300 f7 e7 00 a8 fb c5 24 80 f7 e7 01 04 fb d6 24 80 |......$.......$.| > + 002bc310 f7 f9 00 ab fb dc 24 80 f7 c3 00 b8 fb e2 24 80 |......$.......$.| > + 002bc320 f7 fb 00 bb fb d1 24 80 f7 b1 00 5f fb d1 24 80 |......$...._..$.| > + 002bc330 f7 c4 00 c6 fb a6 24 80 f7 a6 00 68 fb f1 24 80 |......$....h..$.| > + 002bc340 f7 b8 00 a3 fb e7 24 80 f7 9a 00 b1 fb af 24 80 |......$.......$.| > + 002bc350 f7 b1 00 67 fb ee 24 80 f7 96 00 be fb 92 24 80 |...g..$.......$.| > + 002bc360 f7 ab 00 7a fc 1b 24 80 f7 b6 00 ae fb 76 24 80 |...z..$......v$.| > + 002bc370 f7 ce 00 a3 fc 02 24 80 f7 c0 00 be fb 8b 24 80 |......$.......$.| > + 002bc380 f7 c3 00 93 fb d0 24 80 f7 ce 00 d8 fb c8 24 80 |......$.......$.| > + 002bc390 f7 bd 00 c0 fb 82 24 80 f8 00 00 e8 fb db 24 80 |......$.......$.| > + 002bc3a0 f7 d8 00 d3 fb b4 24 80 f8 0b 00 e5 fb c3 24 80 |......$.......$.| > + 002bc3b0 f7 eb 00 c8 fb 92 24 80 f7 e7 00 ea fb cb 24 80 |......$.......$.| > + 002bc3c0 f7 fd 00 cb fb 94 24 80 f7 e3 00 f2 fb b8 24 80 |......$.......$.| > + ... > + > +See ``Documentation/iio/iio_devbuf.rst`` for more information about how buffered > +data is structured. > + > +4. IIO Interfacing Tools > +======================== > + > +See ``Documentation/iio/iio_tools.rst`` for the description of the available IIO > +interfacing tools. > diff --git a/Documentation/iio/index.rst b/Documentation/iio/index.rst > index 4c13bfa2865c..1ce5b24d40aa 100644 > --- a/Documentation/iio/index.rst > +++ b/Documentation/iio/index.rst > @@ -20,5 +20,6 @@ Industrial I/O Kernel Drivers > ad7944 > adis16475 > adis16480 > + adxl380 > bno055 > ep93xx_adc
