staging: iio partial documentation update (5770b8ff) · Commits · e / devices / android_kernel_teracube_2e

drivers/staging/iio/Documentation/ring.txt

+2 −4

Original line number	Diff line number	Diff line
		@@ -47,10 +47,8 @@ request_update
		If parameters have changed that require reinitialization or configuration of
		the ring buffer this will trigger it.

		get_bpd, set_bpd
		Get/set the number of bytes for a given reading (single element, not sample set)
		The value of bps (bytes per set) is created from a combination of this and the
		enabled scan elements.
		get_bytes_per_datum, set_bytes_per_datum
		Get/set the number of bytes for a complete scan. (All samples + timestamp)

		get_length / set_length
		Get/set the number of sample sets that may be held by the buffer.

drivers/staging/iio/Documentation/sysfs-class-iio

+36 −36

Original line number	Diff line number	Diff line
		@@ -158,7 +158,7 @@ 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
		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]
		@@ -212,39 +212,6 @@ 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
		@@ -270,8 +237,8 @@ Contact: linux-iio@vger.kernel.org
		Description:
		Number of scans contained by the buffer.

		What: /sys/.../device[n]:buffer/bps
		KernelVersion: 2.6.35
		What: /sys/.../device[n]:buffer/bytes_per_datum
		KernelVersion: 2.6.37
		Contact: linux-iio@vger.kernel.org
		Description:
		Bytes per scan. Due to alignment fun, the scan may be larger
		@@ -292,3 +259,36 @@ Description:
		to the nearest power of 2 times this. (may not be true in weird
		hardware buffers that pack data well)

		What: /sys/.../device[n]/buffer/scan_elements
		KernelVersion: 2.6.37
		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]/buffer/scan_elements/[m]_accel_x0_en
		KernelVersion: 2.6.37
		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]/buffer/scan_elements/accel[_x0]_precision
		KernelVersion: 2.6.37
		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]/buffer/scan_elements/accel[_x0]_shift
		KernelVersion: 2.6.37
		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.

drivers/staging/iio/Documentation/userspace.txt

+19 −17

Original line number	Diff line number	Diff line
		@@ -7,17 +7,14 @@ Typical sysfs entries (pruned for clarity)
		/sys/class/iio
		device0 - iio_dev related elements
		name - driver specific identifier (here lis3l02dq)
		accel_x - polled (or from ring) raw readout of acceleration
		accel_x_gain - hardware gain (calibration)
		accel_x_offset - hardware offset (calibration)
		available_sampling_frequency
		accel_x_raw - polled (or from ring) raw readout of acceleration
		accel_x_offset - offset to be applied to the raw reading
		accel_x_scale - scale to be applied to the raw reading and offset
		accel_x_calibbias - hardware offset (calibration)
		accel_x_calibscale - hardware gain (calibration)

		available_sampling_frequency - what options are there
		sampling_frequency_available - what options are there
		sampling_frequency - control of internal sampling frequency
		scan_elements - controls which channels will be stored in the ring buffer
		scan_en_accel_x
		scan_en_accel_y
		scan_en_timestamp
		device - link to underlying hardware device
		uevent - udev related element

		@@ -30,23 +27,28 @@ Typical sysfs entries (pruned for clarity)
		dev - major:minor for the chrdev (note major allocation dynamic)
		trigger - consumer attachement
		current_trigger - name based association with a trigger
		ring_buffer0 - ring buffer interface
		bps - byptes per sample (read only), dependant on scan element selection
		device0:buffer0 - ring buffer interface
		bytes_per_datum - byptes per complete datum (read only),
		dependant on scan element selection
		length - (rw) specificy length fo software ring buffer (typically ro in hw case)
		ring_enable - turn the ring on. If its the first to be enabled attached to this
		enable - turn the ring on. If its the first to be enabled attached to this
		trigger will also enable the trigger.
		ring_access0
		device0:buffer0:access0
		dev - major:minor for ring buffer access chrdev
		ring_event_line0
		device0:buffer0:event0
		dev - major:minor for ring buffer event chrdev
		scan_elements - controls which channels will be stored in the ring buffer
		accel_x_en
		accel_y_en
		timestamp_en

		trigger0 - data ready trigger elements
		name - unqiue name of trigger

		Udev will create the following entries under /dev by default:

		ring_access0 - ring access chrdev
		ring_event0 - ring event chrdev
		device0:buffer0:access0 - ring access chrdev
		device0:buffer0:event0 - ring event chrdev
		event_line0 - general event chrdev.

		For the example code we assume the following rules have been used to ensure