staging: iio: sysfs abi documentation. Add _type and _index attrs
Also remove no unused precision attr.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio b/drivers/staging/iio/Documentation/sysfs-bus-iio
index c137020..62becc0 100644
--- a/drivers/staging/iio/Documentation/sysfs-bus-iio
+++ b/drivers/staging/iio/Documentation/sysfs-bus-iio
@@ -266,24 +266,41 @@
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
+What: /sys/.../device[n]/buffer/scan_elements/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.
+ Scan element control for triggered data capture.
-What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_precision
+What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_type
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.
+ Description of the scan element data storage within the buffer
+ and hence the form in which it is read from userspace.
+ Form is [s|u]bits/storagebits. s or u specifies if signed
+ (2's complement) or unsigned. bits is the number of bits of
+ data and storagebits is the space (after padding) that it
+ occupies in the buffer. Note that some devices will have
+ additional information in the unused bits so to get a clean
+ value, the bits value must be used to mask the buffer output
+ value appropriately. The storagebits value also specifies the
+ data alignment. So s48/64 will be a signed 48 bit integer
+ stored in a 64 bit location aligned to a a64 bit boundary.
+ For other storage combinations this attribute will be extended
+ appropriately.
+
+What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_index
+KernelVersion: 2.6.37
+Contact: linux-iio@vger.kernel.org
+Description:
+ A single positive integer specifying the position of this
+ scan element in the buffer. Note these are not dependant on
+ what is enabled and may not be contiguous. Thus for userspace
+ to establish the full layout these must be used in conjunction
+ with all _en attributes to establish which channels are present,
+ and the relevant _type attributes to establish the data storage
+ format.
What: /sys/.../device[n]/buffer/scan_elements/accel[_x0]_shift
KernelVersion: 2.6.37
@@ -291,4 +308,3 @@
Description:
A bit shift (to right) that must be applied prior to
extracting the bits specified by accel[_x0]_precision.
-
