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What: /sys/bus/iio/devices/device[n]
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Hardware chip or device accessed by on communication port.
Corresponds to a grouping of sensor channels.
What: /sys/bus/iio/devices/trigger[n]
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
An event driven driver of data capture to an in kernel buffer.
May be provided by a device driver that also has an IIO device
based on hardware generated events (e.g. data ready) or
provided by a separate driver for other hardware (e.g.
periodic timer, gpio or high resolution timer).
Contains trigger type specific elements. These do not
generalize well and hence are not documented in this file.
What: /sys/bus/iio/devices/device[n]:buffer
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Link to /sys/class/iio/device[n]/device[n]:buffer. n indicates the
device with which this buffer buffer is associated.
What: /sys/.../device[n]/name
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Description of the physical chip / device. Typically a part
number.
What: /sys/.../device[n]/sampling_frequency
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Some devices have internal clocks. This parameter sets the
resulting sampling frequency. In many devices this
parameter has an effect on input filters etc rather than
simply controlling when the input is sampled. As this
effects datardy triggers, hardware buffers and the sysfs
direct access interfaces, it may be found in any of the
relevant directories. If it effects all of the above
then it is to be found in the base device directory as here.
What: /sys/.../device[n]/sampling_frequency_available
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
When the internal sampling clock can only take a small
discrete set of values, this file lists those availale.
What: /sys/.../device[n]/in[_name][m]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Raw (unscaled no bias removal etc) voltage measurement from
channel m. name is used in special cases where this does
not correspond to externally available input (e.g. supply
voltage monitoring in which case the file is in_supply_raw).
What: /sys/.../device[n]/in[_name][m]_offset
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
If known for a device, offset to be added to in[m]_raw prior
to scaling by in[_name][m]_scale in order to obtain voltage in
millivolts. Not present if the offset is always 0 or unknown.
If m is not present, then voltage offset applies to all in
channels. May be writable if a variable offset is controlled
by the device. Note that this is different to calibbias which
is for devices that apply offsets to compensate for variation
between different instances of the part, typically adjusted by
using some hardware supported calibration procedure.
What: /sys/.../device[n]/in[_name][m]_offset_available
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
If a small number of discrete offset values are available, this
will be a space separated list. If these are independant (but
options the same) for individual offsets then m should not be
present.
What: /sys/.../device[n]/in[_name][m]_offset_[min|max]
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
If a more or less continuous range of voltage offsets are supported
then these specify the minimum and maximum. If shared by all
in channels then m is not present.
What: /sys/.../device[n]/in[_name][m]_calibbias
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Hardware applied calibration offset. (assumed to fix production
inaccuracies)
What /sys/.../device[n]/in[_name][m]_calibscale
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Hardware applied calibration scale factor. (assumed to fix production
inaccuracies)
What: /sys/.../device[n]/in[_name][m]_scale
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
If known for a device, scale to be applied to volt[m]_raw post
addition of in[_name][m]_offset in order to obtain the measured
voltage in millivolts. If shared across all in channels then m is not present.
What: /sys/.../device[n]/in[m]-in[o]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Raw (unscaled) differential voltage measurement equivalent to
channel m - channel o where these channel numbers apply to the physically
equivalent inputs when non differential readings are separately available.
In differential only parts, then all that is required is a consistent
labelling.
What: /sys/.../device[n]/accel[_x|_y|_z][m]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Acceleration in direction x, y or z (may be arbitrarily assigned
but should match other such assignments on device)
channel m (not present if only one accelerometer channel at
this orientation). Has all of the equivalent parameters as per in[m].
Units after application of scale and offset are m/s^2.
What: /sys/.../device[n]/gyro[_x|_y|_z][m]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Angular velocity about axis x, y or z (may be arbitrarily assigned)
channel m (not present if only one gyroscope at this orientation).
Data converted by application of offset then scale to
radians per second. Has all the equivalent parameters as per in[m].
What: /sys/.../device[n]/incli[_x|_y|_z][m]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Inclination raw reading about axis x, y or z (may be arbitarily
assigned) channel m (not present if only one inclinometer at
this orientation). Data converted by application of offset
and scale to Degrees.
What: /sys/.../device[n]/magn[_x|_y|_z][m]_raw
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Magnetic field along axis x, y or z (may be arbitrarily assigned)
channel m (not present if only one magnetometer at this orientation).
Data converted by application of offset then scale to Gauss
Has all the equivalent modifiers as per in[m].
What: /sys/.../device[n]/device[n]:event[m]
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Configuration of which hardware generated events are passed up to
userspace. Some of these are a bit complex to generalize so this
section is a work in progress.
What: /sys/.../device[n]:event[m]/dev
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
major:minor character device numbers for the event line.
Taking accel_x0 as an example
What: /sys/.../device[n]:event[m]/accel_x0_thresh[_high|_low]_en
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Event generated when accel_x0 passes a threshold in correction direction
(or stays beyond one). If direction isn't specified, either triggers it.
Note driver will assume last p events requested are enabled where p is
however many it supports. So if you want to be sure you have
set what you think you have, check the contents of these. Drivers
may have to buffer any parameters so that they are consistent when a
given event type is enabled a future point (and not those for whatever
alarm was previously enabled).
What: /sys/.../device[n]:event[m]/accel_x0_roc[_high|_low]_en
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Same as above but based on the first differential of the value.
What: /sys/.../device[n]:event[m]/accel_x0[_thresh|_roc][_high|_low]_period
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
A period of time (microsecs) for which the condition must be broken
before an interrupt is triggered. Applies to all alarms if type is not
specified.
What: /sys/.../device[n]:event[m]/accel_x0[_thresh|_roc][_high|_low]_value
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
The actual value of the threshold in raw device units obtained by
reverse application of scale and offfset to the acceleration in m/s^2.
What: /sys/.../device[n]/scan_elements
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Directory containing interfaces for elements that will be captured
for a single triggered sample set in the buffer.
What: /sys/.../device[n]/scan_elements/[m]_accel_x0_en
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Scan element control for triggered data capture. m implies the
ordering within the buffer. Next the type is specified with
modifier and channel number as per the sysfs single channel
access above.
What: /sys/.../device[n]/scan_elements/accel[_x0]_precision
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Scan element precision within the buffer. Note that the
data alignment must restrictions must be read from within
buffer to work out full data alignment for data read
via buffer_access chrdev. _x0 dropped if shared across all
acceleration channels.
What: /sys/.../device[n]/scan_elements/accel[_x0]_shift
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
A bit shift (to right) that must be applied prior to
extracting the bits specified by accel[_x0]_precision.
What: /sys/.../device[n]/device[n]:buffer:event/dev
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Buffer for device n event character device major:minor numbers.
What: /sys/.../device[n]/device[n]:buffer:access/dev
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Buffer for device n access character device o major:minor numbers.
What: /sys/.../device[n]:buffer/trigger
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
The name of the trigger source being used, as per string given
in /sys/class/iio/trigger[n]/name.
What: /sys/.../device[n]:buffer/length
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Number of scans contained by the buffer.
What: /sys/.../device[n]:buffer/bps
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Bytes per scan. Due to alignment fun, the scan may be larger
than implied directly by the scan_element parameters.
What: /sys/.../device[n]:buffer/enable
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Actually start the buffer capture up. Will start trigger
if first device and appropriate.
What: /sys/.../device[n]:buffer/alignment
KernelVersion: 2.6.35
Contact: linux-iio@vger.kernel.org
Description:
Minimum data alignment. Scan elements larger than this are aligned
to the nearest power of 2 times this. (may not be true in weird
hardware buffers that pack data well)
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