iio: resolver: ad2s1210: move out of staging

This moves the ad2s1210 resolver driver out of staging. The driver has
been fixed up and is ready to graduate.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20231010-ad2s1210-mainline-v5-4-35a0f6ffa04a@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: meter: Drop ade7854 driver

This driver is so far from making correct use of the IIO infrastructure
and ABI that if someone wanted to make the driver suitable for moving
out of staging, they would more or less be starting from scratch.

As such there is little point in keeping the existing code in staging.

Note this was only user of the meter.h header so that is dropped.
There are no other drivers in the staging/iio/meter directory so drop
the build system files as well.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20230129160805.747745-1-jic23@kernel.org

iio: cdc: ad7746: Move driver out of staging.

All known major issues with this driver resolved so time to move
it out of staging. This also allows us to remove the now empty
staging/iio/cdc directory and build files.

Note this cleanup work was done using the roadtest framework.
https://lore.kernel.org/all/20220311162445.346685-1-vincent.whitchurch@axis.com/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

staging: iio: Drop ADIS16060 driver from staging

This part has been declared "not for new designs". It is now
difficult to obtain and we have had no-one come forward with hardware
making it difficult to proceed with the necessary work to move this
driver out of staging.

The device uses two separate chip selects and would require locking
between them which is thought to be difficult to enforce without
non trivial changes in the SPI subsystem. This work simply isn't worth
doing given the status of the part and the fact no one seems to have
gone for a similar hardware design since this one.

If anyone does have access to one of these and is willing to contribute
the time necessary then we can reevaluate dropping the driver.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: tsl2x7x/tsl2772: move out of staging

Move the tsl2772 driver out of staging and into mainline.

Signed-off-by: Brian Masney <masneyb@onstation.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: remove iio-trig-bfin-timer driver

The blackfin architecture is getting removed, so the timer trigger
driver is now obsolete. Since this is the last remaining iio trigger
driver in staging, I'm removing the entire directory.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Aaron Wu <aaron.wu@analog.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: hmc5843: Move hmc5843 out of staging

This patch moves hmc5843 driver from staging/iio/magnetometer
to iio/magnetometer, updates the corresponding Makefiles and
moves the hmc5843* entries to the 'Industrial I/O support ->
Magnetometer sensors' menu.

Signed-off-by: Cristina Moraru <cristina.moraru09@gmail.com>
Cc: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

staging:iio: Delete some commented out lines in Kconfig and Makefile.

These should have been removed with the driver move out of staging
but instead were commented out. This was missed in reviews at the
time so fixing it up now.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Move IIO Dummy Driver out of staging

This patch moves the reference IIO dummy driver from drivers/staging/iio
into a separate folder, drivers/iio/dummy and adds the proper Kconfig
and Makefile for it.

A new config menu entry called IIO dummy driver has also been added
in the Industrial I/O support menu, corresponding to this driver.

Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

hwmon: Move the IIO client driver for hwmon out of staging

This driver uses channel maps, defined either through device tree
or platform data, to create a hwmon driver which acts as a client
for the underlying IIO device channels. Thus a general purpose
IIO adc driver can be used to provide hardware monitoring using a subset
of its channels.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>

--
The only non move changes here concern the description and changes to the
dependencies to IIO explicit and hwmon implicit.

I'm proposing moving this into hwmon on the basis of placing drivers
based on what they provide rather than what their underlying hardware
is.

drivers/hwmon/Kconfig | 9 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/iio_hwmon.c | 196 ++++++++++++++++++++++++++++++++++++++++
drivers/staging/iio/Kconfig | 8 --
drivers/staging/iio/Makefile | 2 -
drivers/staging/iio/iio_hwmon.c | 196 ----------------------------------------
6 files changed, 206 insertions(+), 206 deletions(-)

staging:iio: drop sw_ring buffer implementation.

Whilst this is IIO's oldest buffer implementation it is messy, poorly
implemented and whilst it works, no one is entirely sure it always will.

New IIO drivers have not been using this for some time and now all remaining
old users have been converted to use the kfifo based alternative.

Clearly a fifo isn't the same as a ring buffer but in many use cases it
really doesn't matter. We also loose the watershed based poll implementation.
However having poll effectively report data only when the buffer was half
full was at best an 'unusual' use of the interface.

At somepoint in the future we may bring watersheds back on a different
buffer implementation, but then we will think a lot more about how to do
the interface first.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>

staging:iio: Move adis16400 out of staging

This adis16400 driver is in pretty good shape now, so move it out of staging.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

staging:iio: Move DAC drivers out of staging

The IIO DAC drivers are in a reasonably good shape. They all make use of channel
spec and non of them provides non-documented sysfs attributes. Code style should
be OK as well, both checkpatch and coccicheck only report trivial issues.

So lets move the whole folder out of staging.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: Rename iio/dds to iio/frequency

Generalize naming to allow other frequency synthesis techniques as well.
No functional changes.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

IIO: Move the core files to drivers/iio

Take the core support + the kfifo buffer implentation out of
staging. Whilst we are far from done in improving this subsystem
it is now at a stage where the userspae interfaces (provided by
the core) can be considered stable.

Drivers will follow over a longer time scale.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging:iio::hwmon interface client driver.

Direct copy of version proposed for the non staging branch.
Needed here to allow testing of more advanced inkernel
interface code.

Minimal support of simple in, curr and temp attributes
so far.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging:iio:core add in kernel interface mapping and getting IIO channels.

Lifted from proposal for in kernel interface built on the out of staging
branch.

Two elements here:
* Map as defined in "inkern.h"
* Matching code to actually get the iio_dev and channel
that we want from the global list of IIO devices.
V4: Everything now built if iio is built (rather than being optional)
Removal race condition prevented by using info pointer as a check
of removal under a lock.
V3: Drop the option of registering / getting channels using dev pointer.
Stick to name only as suggested by Mark Brown (this has caused user
confusion in the regulator framework.)
V2: As per Greg KH suggestion, move over to registration by passing
the tables into the provider drivers (how regulator does it).
This does not prevent us using the original more flexible approach
if at a later date there is a usecase that demands it.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging:iio: Factor out event handling into its own file

The core iio file has gotten quite cluttered over time. This patch moves
the event handling code into its own file. Since the event handling code is
largely independent from the core code the only code changes necessary for
this are to make the moved iio_device_register_eventset,
iio_device_unregister_eventset and iio_event_getfd functions non static.

This has also the advantage that industrialio-core.c is now closer again to
its counterpart in the outofstaging branch.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: Relocate Capacitance to Digital Converters (CDC) into own subdir

No functional changes.
Fix Kconfig description.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio:dummy Add buffered reading support

Very simple buffered reading. Did not provide a trigger as
the sysfs trigger already meets that requirement.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio:dummy Add event support + fake event generator

The event generator is not very pretty but does the job and
allows this driver to look a lot more like a normal driver
than it otherwise would.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio:Documentation Simple dummy driver to explain the basics

The documenation explaining how to go about writing a driver is lagging
horribly, so here is another approach; an actual driver with
lots of explanatory comments.

Note it is currently minimal in that there are no events and no
buffer. With care they can probably be added in additional files
without messing up the clarity of what we have here.

V2: Addressed some of Manuel Stahl's feedback.

Fixed up kernel doc.
Added more general description.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio: replacing term ring with buffer in the IIO core.

They aren't always ring buffers, so just use buffer for all naming.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio: tree wide IIO_RING_BUFFER config symbol to IIO_BUFFER

Functionality is generic, so name is missleading.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

iio: impedance-analyzer: New driver for AD5933/4 Impedance Converter, Network Analyzer

The AD5933 is a high precision impedance converter system solution
that combines an on-board frequency generator with a 12-bit, 1 MSPS,
analog-to-digital converter (ADC). The frequency generator allows an
external complex impedance to be excited with a known frequency.

The response signal from the impedance is sampled by the on-board ADC
and a discrete Fourier transform (DFT) is processed by an on-chip DSP engine.
The DFT algorithm returns a real (R) and imaginary (I) data-word at each
output frequency.

Changes since V1:

Apply list review feedback:
Consistently use poll_time_jiffies.
Use be|le cpu endian helpers where applicable.
Add various comments.

Changes since V2:

Fix KernelVersion tag in Documentation.
Declare ad5933_default_pdata static.
Fix typos.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio:kfifo buffer implementation

A very simple use of a kfifo as an alternative for the ring_sw

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Tested-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: resolver: new driver for AD2S90 devices

This also kicks off the new resolver subsection.

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: meter: new driver for ADE7753/6 devices

This also kicks off the new meter subsection.

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: dds: new driver for AD5930/2 devices

This is the initial driver in the new Direct Digital Synthesis section.

Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: dac: new driver for AD5624R devices

This is used to convert digital streams into voltages.

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: new ADT7316/7/8 and ADT7516/7/9 driver

IIO driver for temperature sensor, ADC and DAC devices over SPI and I2C.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: iio: add digital compass hmc5843 driver

Adding support for the Honeywell HMC5843. The interface to the device is
i2c

TODO:
Adding the documentation

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: iio: standardize kconfig/makefile spacing/style

Standardize the spacing/style across the IIO build files:
- comment block in Kconfigs
- newlines at ends of files
- trailing lines at ends of files
- indent with one tab, not spaces or mixed

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: iio: adis16260 digital gyro driver

Signed-off-by: Barry Song <Barry.Song@analog.com>
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging:iio:imu ADIS16300 driver

Signed-off-by: Barry Song <Barry.Song@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: Periodic timer based trigger

The original posting of this driver led to a discussion in
which it was commented that a better system was needed
for dealing with the many possible periodic interrupt
sources available on some SoCs. Unfortunately that is
a big task and as far as I know, no-one has taken it
on as yet. So in the meantime this driver is still
in here.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: Ring buffer: Initial pass at rarely locked ring buffer

Please note this ring buffer implementation is very much a
work in progress (and hence RFC). In it's current form
it is stable and reasonably efficient. There are a couple
of unlikely cases that will lead to more data being lost
that is strictly necessary. The target was for the case
of requiring regular sampling even during user space reads.

All comments welcome.

The intention is to make this only one of several
implementations with run time selection. For now there
is only one, so it is hard coded into the drivers using it.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: Trigger support added to core.

Add general registration support for IIO triggers. These
are currently only used to initialize a 'poll' of a given
device. Examples include the lis3l02dq's data ready signal
being used to initialize a read and gpio triggers being
used to allow externally synchronized sensor reading.

Each trigger can cause any number of 'consumer' devices
to be polled with each storing data into a related ring
buffer.

Two stage triggering is supported with 'fast' and 'slow'
paths. The first is used for things like pulling a data
hold line high and the second for actual read which
may take far longer.

Changes since V2:
* As with IIO triggers now use a registration approach
much closer to that of input leading to cleaner code.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: Add generic ring buffer support to the IIO core

This provides a unified interface for hardware and software
ring buffers.

Changes since V2:
* Moved to a more consistent structure. Now the ring buffer
has an associated struct device which is a child of the
relevant iio_dev. This in turn has two children, one
for the event interface and one for the access interface.
These two interfaces are now managed via cdev structures.

* Numerous minor cleanups

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: lis3l02dq accelerometer core support

A later patch in the series will add data ready triggering
and ring buffer support.

This core patch provides an event interface and sysfs
based reading of values.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: tsl2561 digital light sensor core support

This is a pretty minimalist example of an IIO driver.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: max1363 ADC driver

Core support for MAX1361, MAX1362, MAX1363, MAX1364,
MAX1136, MAX1137, MAX1138, MAX1139, MAX1236, MAX1237,
MAX1238, MAX1239.

Ring buffer support later in series.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Staging: IIO: core support for device registration and management

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>