linux/Documentation/ABI
Linus Torvalds 19b344efa3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID updates from Jiri Kosina:

 - hid driver transport cleanup, finalizing the long-desired decoupling
   of core from transport layers, by Benjamin Tissoires and Henrik
   Rydberg

 - support for hybrid finger/pen multitouch HID devices, by Benjamin
   Tissoires

 - fix for long-standing issue in Logitech unifying driver sometimes not
   inializing properly due to device specifics, by Andrew de los Reyes

 - Wii remote driver updates to support 2nd generation of devices, by
   David Herrmann

 - support for Apple IR remote

 - roccat driver now supports new devices (Roccat Kone Pure, IskuFX), by
   Stefan Achatz

 - debugfs locking fixes in hid debug interface, by Jiri Kosina

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (43 commits)
  HID: protect hid_debug_list
  HID: debug: break out hid_dump_report() into hid-debug
  HID: Add PID for Japanese version of NE4K keyboard
  HID: hid-lg4ff add support for new version of DFGT wheel
  HID: icade: u16 which never < 0
  HID: clarify Magic Mouse Kconfig description
  HID: appleir: add support for Apple ir devices
  HID: roccat: added media key support for Kone
  HID: hid-lenovo-tpkbd: remove doubled hid_get_drvdata
  HID: i2c-hid: fix length for set/get report in i2c hid
  HID: wiimote: parse reduced status reports
  HID: wiimote: add 2nd generation Wii Remote IDs
  HID: wiimote: use unique battery names
  HID: hidraw: warn if userspace headers are outdated
  HID: multitouch: force BTN_STYLUS for pen devices
  HID: multitouch: append " Pen" to the name of the stylus input
  HID: multitouch: add handling for pen in dual-sensors device
  HID: multitouch: change touch sensor detection in mt_input_configured()
  HID: multitouch: do not map usage from non used reports
  HID: multitouch: breaks out touch handling in specific functions
  ...
2013-04-30 09:37:55 -07:00
..
obsolete Merge branches 'for-3.7/upstream-fixes', 'for-3.8/hidraw', 'for-3.8/i2c-hid', 'for-3.8/multitouch', 'for-3.8/roccat', 'for-3.8/sensors' and 'for-3.8/upstream' into for-linus 2012-12-12 21:41:55 +01:00
removed netfilter: remove ip_queue support 2012-05-08 20:25:42 +02:00
stable tpm: add documentation for sysfs interfaces 2013-02-05 09:38:21 -06:00
testing Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid 2013-04-30 09:37:55 -07:00
README Documentation: remove reference to feature-removal-schedule.txt 2012-12-17 17:15:12 -08:00

This directory attempts to document the ABI between the Linux kernel and
userspace, and the relative stability of these interfaces.  Due to the
everchanging nature of Linux, and the differing maturity levels, these
interfaces should be used by userspace programs in different ways.

We have four different levels of ABI stability, as shown by the four
different subdirectories in this location.  Interfaces may change levels
of stability according to the rules described below.

The different levels of stability are:

  stable/
	This directory documents the interfaces that the developer has
	defined to be stable.  Userspace programs are free to use these
	interfaces with no restrictions, and backward compatibility for
	them will be guaranteed for at least 2 years.  Most interfaces
	(like syscalls) are expected to never change and always be
	available.

  testing/
	This directory documents interfaces that are felt to be stable,
	as the main development of this interface has been completed.
	The interface can be changed to add new features, but the
	current interface will not break by doing this, unless grave
	errors or security problems are found in them.  Userspace
	programs can start to rely on these interfaces, but they must be
	aware of changes that can occur before these interfaces move to
	be marked stable.  Programs that use these interfaces are
	strongly encouraged to add their name to the description of
	these interfaces, so that the kernel developers can easily
	notify them if any changes occur (see the description of the
	layout of the files below for details on how to do this.)

  obsolete/
  	This directory documents interfaces that are still remaining in
	the kernel, but are marked to be removed at some later point in
	time.  The description of the interface will document the reason
	why it is obsolete and when it can be expected to be removed.

  removed/
	This directory contains a list of the old interfaces that have
	been removed from the kernel.

Every file in these directories will contain the following information:

What:		Short description of the interface
Date:		Date created
KernelVersion:	Kernel version this feature first showed up in.
Contact:	Primary contact for this interface (may be a mailing list)
Description:	Long description of the interface and how to use it.
Users:		All users of this interface who wish to be notified when
		it changes.  This is very important for interfaces in
		the "testing" stage, so that kernel developers can work
		with userspace developers to ensure that things do not
		break in ways that are unacceptable.  It is also
		important to get feedback for these interfaces to make
		sure they are working in a proper way and do not need to
		be changed further.


How things move between levels:

Interfaces in stable may move to obsolete, as long as the proper
notification is given.

Interfaces may be removed from obsolete and the kernel as long as the
documented amount of time has gone by.

Interfaces in the testing state can move to the stable state when the
developers feel they are finished.  They cannot be removed from the
kernel tree without going through the obsolete state first.

It's up to the developer to place their interfaces in the category they
wish for it to start out in.