staging: iio partial documentation update
Signed-off-by: Manuel Stahl <manuel.stahl@iis.fraunhofer.de> Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Manuel Stahl
Greg Kroah-Hartman
Родитель
bf32963cbe
Коммит
5770b8ffaf
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@ -47,10 +47,8 @@ request_update
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If parameters have changed that require reinitialization or configuration of
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the ring buffer this will trigger it.
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get_bpd, set_bpd
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Get/set the number of bytes for a given reading (single element, not sample set)
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The value of bps (bytes per set) is created from a combination of this and the
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enabled scan elements.
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get_bytes_per_datum, set_bytes_per_datum
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Get/set the number of bytes for a complete scan. (All samples + timestamp)
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get_length / set_length
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Get/set the number of sample sets that may be held by the buffer.
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@ -158,7 +158,7 @@ Contact: linux-iio@vger.kernel.org
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Description:
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Magnetic field along axis x, y or z (may be arbitrarily assigned)
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channel m (not present if only one magnetometer at this orientation).
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Data converted by application of offset then scale to Gauss
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Data converted by application of offset then scale to Gauss.
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Has all the equivalent modifiers as per in[m].
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What: /sys/.../device[n]/device[n]:event[m]
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@ -212,39 +212,6 @@ Description:
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The actual value of the threshold in raw device units obtained by
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reverse application of scale and offfset to the acceleration in m/s^2.
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What: /sys/.../device[n]/scan_elements
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KernelVersion: 2.6.35
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Contact: linux-iio@vger.kernel.org
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Description:
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Directory containing interfaces for elements that will be captured
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for a single triggered sample set in the buffer.
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What: /sys/.../device[n]/scan_elements/[m]_accel_x0_en
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KernelVersion: 2.6.35
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Contact: linux-iio@vger.kernel.org
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Description:
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Scan element control for triggered data capture. m implies the
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ordering within the buffer. Next the type is specified with
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modifier and channel number as per the sysfs single channel
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access above.
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What: /sys/.../device[n]/scan_elements/accel[_x0]_precision
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KernelVersion: 2.6.35
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Contact: linux-iio@vger.kernel.org
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Description:
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Scan element precision within the buffer. Note that the
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data alignment must restrictions must be read from within
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buffer to work out full data alignment for data read
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via buffer_access chrdev. _x0 dropped if shared across all
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acceleration channels.
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What: /sys/.../device[n]/scan_elements/accel[_x0]_shift
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KernelVersion: 2.6.35
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Contact: linux-iio@vger.kernel.org
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Description:
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A bit shift (to right) that must be applied prior to
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extracting the bits specified by accel[_x0]_precision.
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What: /sys/.../device[n]/device[n]:buffer:event/dev
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KernelVersion: 2.6.35
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Contact: linux-iio@vger.kernel.org
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@ -270,8 +237,8 @@ Contact: linux-iio@vger.kernel.org
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Description:
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Number of scans contained by the buffer.
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What: /sys/.../device[n]:buffer/bps
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KernelVersion: 2.6.35
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What: /sys/.../device[n]:buffer/bytes_per_datum
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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Bytes per scan. Due to alignment fun, the scan may be larger
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@ -292,3 +259,36 @@ Description:
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to the nearest power of 2 times this. (may not be true in weird
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hardware buffers that pack data well)
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What: /sys/.../device[n]/buffer/scan_elements
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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Directory containing interfaces for elements that will be captured
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for a single triggered sample set in the buffer.
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What: /sys/.../device[n]/buffer/scan_elements/[m]_accel_x0_en
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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Scan element control for triggered data capture. m implies the
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ordering within the buffer. Next the type is specified with
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modifier and channel number as per the sysfs single channel
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access above.
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What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_precision
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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Scan element precision within the buffer. Note that the
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data alignment must restrictions must be read from within
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buffer to work out full data alignment for data read
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via buffer_access chrdev. _x0 dropped if shared across all
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acceleration channels.
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What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_shift
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KernelVersion: 2.6.37
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Contact: linux-iio@vger.kernel.org
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Description:
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A bit shift (to right) that must be applied prior to
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extracting the bits specified by accel[_x0]_precision.
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@ -7,17 +7,14 @@ Typical sysfs entries (pruned for clarity)
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/sys/class/iio
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device0 - iio_dev related elements
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name - driver specific identifier (here lis3l02dq)
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accel_x - polled (or from ring) raw readout of acceleration
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accel_x_gain - hardware gain (calibration)
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accel_x_offset - hardware offset (calibration)
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available_sampling_frequency
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accel_x_raw - polled (or from ring) raw readout of acceleration
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accel_x_offset - offset to be applied to the raw reading
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accel_x_scale - scale to be applied to the raw reading and offset
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accel_x_calibbias - hardware offset (calibration)
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accel_x_calibscale - hardware gain (calibration)
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available_sampling_frequency - what options are there
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sampling_frequency_available - what options are there
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sampling_frequency - control of internal sampling frequency
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scan_elements - controls which channels will be stored in the ring buffer
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scan_en_accel_x
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scan_en_accel_y
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scan_en_timestamp
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device - link to underlying hardware device
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uevent - udev related element
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@ -30,23 +27,28 @@ Typical sysfs entries (pruned for clarity)
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dev - major:minor for the chrdev (note major allocation dynamic)
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trigger - consumer attachement
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current_trigger - name based association with a trigger
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ring_buffer0 - ring buffer interface
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bps - byptes per sample (read only), dependant on scan element selection
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device0:buffer0 - ring buffer interface
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bytes_per_datum - byptes per complete datum (read only),
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dependant on scan element selection
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length - (rw) specificy length fo software ring buffer (typically ro in hw case)
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ring_enable - turn the ring on. If its the first to be enabled attached to this
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trigger will also enable the trigger.
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ring_access0
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enable - turn the ring on. If its the first to be enabled attached to this
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trigger will also enable the trigger.
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device0:buffer0:access0
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dev - major:minor for ring buffer access chrdev
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ring_event_line0
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device0:buffer0:event0
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dev - major:minor for ring buffer event chrdev
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scan_elements - controls which channels will be stored in the ring buffer
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accel_x_en
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accel_y_en
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timestamp_en
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trigger0 - data ready trigger elements
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name - unqiue name of trigger
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Udev will create the following entries under /dev by default:
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ring_access0 - ring access chrdev
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ring_event0 - ring event chrdev
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device0:buffer0:access0 - ring access chrdev
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device0:buffer0:event0 - ring event chrdev
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event_line0 - general event chrdev.
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For the example code we assume the following rules have been used to ensure
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