From 10ba8ea9bdad9cae23b555af38561f41e81e310a Mon Sep 17 00:00:00 2001 From: Jonathan Cameron Date: Tue, 21 Sep 2010 14:41:08 +0100 Subject: [PATCH] staging: iio: sysfs abi documentation. Add _type and _index attrs Also remove no unused precision attr. Signed-off-by: Jonathan Cameron Signed-off-by: Manuel Stahl Signed-off-by: Greg Kroah-Hartman --- .../staging/iio/Documentation/sysfs-bus-iio | 40 +++++++++++++------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/drivers/staging/iio/Documentation/sysfs-bus-iio b/drivers/staging/iio/Documentation/sysfs-bus-iio index c13702037b08..62becc0cdb76 100644 --- a/drivers/staging/iio/Documentation/sysfs-bus-iio +++ b/drivers/staging/iio/Documentation/sysfs-bus-iio @@ -266,24 +266,41 @@ 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 +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 @@ 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. -