linux-kernel-test/Documentation/ABI
Greg Kroah-Hartman 9f827d8099 First round of new driver, new functionality and cleanups for IIO in the 4.4 cycle
New device support
 * APDS9960 ALS + proximity driver
 * bmg160 SPI devices.
 * HDC100x humidity sensors
 * Holt HI-8435 threshold detector
 * mma8453Q accelerometer added to the mma8452 driver
 * mma86452FC and mma8653FC accelerometers added to the mma8452 driver
 * mxc4005 accelerometer
 * PulsedLight LIDAR
 * SensorTech VZ89x volatile organic compound sensor
 * UPISEMI uS5182d ALS and proximity sensors
 
 New core functionality
 * triggered events - use triggers to check for changes in threshold type
   detectors on devices with out interrupt support.  First user is the holt
   comparator.
 * chemical concentration and resistance channel types.
 
 New driver functionality
 * vf610
   - buffer support.
   - followup coccinelle warning fix.
 
 Core rework
 * buffers
   - break out callback buffer to own module.
   - move buffer implementations to a new subdirectory
 * percolate the error code form iio_event_getfd out to userspace
   rather than giving a missleading error later on.
 
 Cleanups
 * adddac drivers
   - use BIT macro where appropriate.
 * meter drivers
   - use BIT macro where appropriate.
 
 * ad7303
  - add an OF match table to line up with the binding docs.
 * adc128s052
   - add an OF match table to line up with the binding docs.
 * adf4350
   - add an OF match table to line up with the binding docs
 * as3935
   - add an OF match table to line up with the binding docs.
 * berlin2-adc
   - use GENMASK and BIT for masks
   - prevent attempting to sample multiple channels at once by moving a
     mutex scop
   - coding style cleanups
 * bmg150_magn
   - kconfig sort order was wrong - fix it.
 * bmg160
   - use i2c regmap and drop all uses of i2c_client
   - separate i2c and core driver
 * cc10001_adc
   - kconfig sort order was wrong - fix it.
 * evgen (dummy driver helper module)
   - move interrupt generation to irq_work to reduce differences between
     the dummy driver and real hardware drivers.
 * hmc5843
   - set the name dynamically rather than to a fixed value for one of the
     suported parts.
   - export module alias information to allow autoprobing of module.
 * lpc32xx
   - on failure to get resource or irq return -ENXIO as uppose to -EBUSY
 * max1027
   - set .of_match_table to actually allow OF style matching.
 * max5821
   - add MODULE_DEVICE_TABLE for OF table.
 * mma8452
   - refactor to separate out chip specific data.
   - add freefall / motion interrupt source for devices that do their
     interrupts slightly differently.
   - update copywrite notice.
   - leave naming of events directory in sysfs to the core
 * mcp320x
   - set .of_match_table so that it can be use for OF style matching.
 * mlx90614
   - Implement filter configuration (note the datasheet changed as a result
     of the driver reviews to include the values we needed ;)
 * opt3001
   - drop .owner field as assigned by platform driver core.
 * si7020
   - replace a bitmask on the humidity values with a more correct range
     check.
 * stk310
   - improved error handling.
   - use BIT macro where appropriate and use the resulting defines
     instead of magic numbers in the code.
   - fix indentation
 * st-sensors
   - add debugfs register read hook
 * tsl4531
   - fix error handling in check_id
 * twl6030
   - fix module autoload for OF
 * iio-trig-sysfs
   - document add and remove attribute
 * trigger in staging
   - code alignment fixes.
   - braces on both branches of if statement if needed for one.
 * xilinx-xadc
   - push interrupts into hardirq context as there isn't much in them
     any more and it avoids breaking PREEMPT_RT builds due to the use
     of a spinlock between the hardirq and the thread.
 
 Tools
 * event-monitor
   - report unsupported events.  We keep expanding what can come from drivers
     so give a helpful error if one turns up in an out of date userspace
     program.
 * generic-buffer
   - helpful message about needing to enable a channel to start the buffer.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJWBDeHAAoJEFSFNJnE9BaIgSQP/183S1WJTqpsrz3APZY4qQLU
 m8Jv6VCvtSENpryUxn6MtfPuVeBa8LwhciAtelsJfVvu2O902VAOcsgMhgp3cz7Y
 daTXio/XhdA7YJvuOkycLD3CdWJ7Gb3+nieBmcEb0YMAMIgchMR+gI/LYR/htISz
 Req9EM8C/4sU5hn3r92mVZFMiV5XWsApCv61A6IzXdaz4YgiEjtFb8NF87IPlFq0
 Rpg3BG4/9Ka1tUaZs6a98sWXqudCzHSetKk9GLFbnhoo6xC+C33b06Z+fSinAZmn
 FsVGfQ/I6xhFJmCJLifLq/voN9gbDuebUQCPIYPfu7Oby29JcK95P60ZHM954s2M
 DGTCQ44GTReA2IqRvxlgQDU/TBUTwWKKDnuelw6+387t/wT0tnnfkwFrps1xPqGy
 k1qHVViofzf3iSKdDKeQyMjDoO+nMUv0DdkzYNz4xCPQIhGMRXA/Q+U81tJvJHZl
 rwhHVruFHyhI1/sTvTMJ/5+F7lL7LieFdCTVnzl0QblzMskGpLy5d/fMJn8OLVqa
 6PiA5x3799U2o67wtCYH+RoSdQj1U+qEFkg7Oe+nVvlpbs/vfdR2dI3wYfp8459l
 mjafTgW8R+7tXYKU+iSKA4660QIN9LR6byBqyxX97mjyYxn3ml3VWJ44ztqfhjZd
 1ZyZxsWa2y5b6L017kJN
 =E+jf
 -----END PGP SIGNATURE-----

Merge tag 'iio-for-4.4a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First round of new driver, new functionality and cleanups for IIO in the 4.4 cycle

New device support
* APDS9960 ALS + proximity driver
* bmg160 SPI devices.
* HDC100x humidity sensors
* Holt HI-8435 threshold detector
* mma8453Q accelerometer added to the mma8452 driver
* mma86452FC and mma8653FC accelerometers added to the mma8452 driver
* mxc4005 accelerometer
* PulsedLight LIDAR
* SensorTech VZ89x volatile organic compound sensor
* UPISEMI uS5182d ALS and proximity sensors

New core functionality
* triggered events - use triggers to check for changes in threshold type
  detectors on devices with out interrupt support.  First user is the holt
  comparator.
* chemical concentration and resistance channel types.

New driver functionality
* vf610
  - buffer support.
  - followup coccinelle warning fix.

Core rework
* buffers
  - break out callback buffer to own module.
  - move buffer implementations to a new subdirectory
* percolate the error code form iio_event_getfd out to userspace
  rather than giving a missleading error later on.

Cleanups
* adddac drivers
  - use BIT macro where appropriate.
* meter drivers
  - use BIT macro where appropriate.

* ad7303
 - add an OF match table to line up with the binding docs.
* adc128s052
  - add an OF match table to line up with the binding docs.
* adf4350
  - add an OF match table to line up with the binding docs
* as3935
  - add an OF match table to line up with the binding docs.
* berlin2-adc
  - use GENMASK and BIT for masks
  - prevent attempting to sample multiple channels at once by moving a
    mutex scop
  - coding style cleanups
* bmg150_magn
  - kconfig sort order was wrong - fix it.
* bmg160
  - use i2c regmap and drop all uses of i2c_client
  - separate i2c and core driver
* cc10001_adc
  - kconfig sort order was wrong - fix it.
* evgen (dummy driver helper module)
  - move interrupt generation to irq_work to reduce differences between
    the dummy driver and real hardware drivers.
* hmc5843
  - set the name dynamically rather than to a fixed value for one of the
    suported parts.
  - export module alias information to allow autoprobing of module.
* lpc32xx
  - on failure to get resource or irq return -ENXIO as uppose to -EBUSY
* max1027
  - set .of_match_table to actually allow OF style matching.
* max5821
  - add MODULE_DEVICE_TABLE for OF table.
* mma8452
  - refactor to separate out chip specific data.
  - add freefall / motion interrupt source for devices that do their
    interrupts slightly differently.
  - update copywrite notice.
  - leave naming of events directory in sysfs to the core
* mcp320x
  - set .of_match_table so that it can be use for OF style matching.
* mlx90614
  - Implement filter configuration (note the datasheet changed as a result
    of the driver reviews to include the values we needed ;)
* opt3001
  - drop .owner field as assigned by platform driver core.
* si7020
  - replace a bitmask on the humidity values with a more correct range
    check.
* stk310
  - improved error handling.
  - use BIT macro where appropriate and use the resulting defines
    instead of magic numbers in the code.
  - fix indentation
* st-sensors
  - add debugfs register read hook
* tsl4531
  - fix error handling in check_id
* twl6030
  - fix module autoload for OF
* iio-trig-sysfs
  - document add and remove attribute
* trigger in staging
  - code alignment fixes.
  - braces on both branches of if statement if needed for one.
* xilinx-xadc
  - push interrupts into hardirq context as there isn't much in them
    any more and it avoids breaking PREEMPT_RT builds due to the use
    of a spinlock between the hardirq and the thread.

Tools
* event-monitor
  - report unsupported events.  We keep expanding what can come from drivers
    so give a helpful error if one turns up in an out of date userspace
    program.
* generic-buffer
  - helpful message about needing to enable a channel to start the buffer.
2015-09-30 03:37:48 +02:00
..
obsolete zram: deprecate zram attrs sysfs nodes 2015-04-15 16:35:21 -07:00
removed net_dma: simple removal 2014-09-28 07:05:16 -07:00
stable Drivers: hv: vmbus: document the VMBus sysfs files 2015-08-05 11:44:29 -07:00
testing First round of new driver, new functionality and cleanups for IIO in the 4.4 cycle 2015-09-30 03:37:48 +02:00
README

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.


Notable bits of non-ABI, which should not under any circumstances be considered
stable:

- Kconfig.  Userspace should not rely on the presence or absence of any
  particular Kconfig symbol, in /proc/config.gz, in the copy of .config
  commonly installed to /boot, or in any invocation of the kernel build
  process.

- Kernel-internal symbols.  Do not rely on the presence, absence, location, or
  type of any kernel symbol, either in System.map files or the kernel binary
  itself.  See Documentation/stable_api_nonsense.txt.