The driver currently registers a pair of irq handlers using
request_threaded_irq(), however the synchronization mechanism between the
hardirq and the threadedirq handler is a regular spinlock.

Unfortunately, this breaks PREEMPT_RT builds, where a spinlock can sleep,
and is thus not able to be acquired from a hardirq handler. This patch gets
rid of the threaded handler and pushes all interrupt handling into the
hardirq context, and uses request_irq().

To validate that this change has no impact on RT performance, here are
cyclictest values with no processes running:

$ sudo cyclictest -S -m -p 98
policy: fifo: loadavg: 0.00 0.01 0.05 1/174 2539
T: 0 ( 1405) P:98 I:1000 C:167010520 Min: 9 Act: 12 Avg: 12 Max: 75
T: 1 ( 1862) P:98 I:1500 C:111340339 Min: 9 Act: 12 Avg: 12 Max: 73

Then, all xadc raw handles were accessed in a continuous loop via
/sys/bus/iio/devices/iio:device0:

$ sudo cyclictest -S -m -p 98
policy: fifo: loadavg: 7.84 7.70 7.63 3/182 4260
T: 0 ( 2559) P:98 I:1000 C:241557018 Min: 11 Act: 18 Avg: 21 Max: 74
T: 1 ( 2560) P:98 I:1500 C:161038006 Min: 10 Act: 21 Avg: 20 Max: 73
Signed-off-by: Xander Huff <xander.huff@ni.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Load the driver using the below command:
echo hmc5983 0x1e > /sys/bus/i2c/devices/i2c-?/new_device

In sysfs, the iio name is hmc5843, however the i2c name is hmc5983,
they are inconsistent.

With this patch, the iio name will be the same as the i2c device name
Signed-off-by: Yong Li <sdliyong@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This makes the error from iio_event_getfd() percolate up
to userspace properly so we can know for sure there is no
events on this device (-ENODEV returned). Before this patch
we would bail out looking for the unsupported events on the
erroneous (negative) file descriptor.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Currently if generic_buffer is invoked without first enabling any
channels in scan_elements/*_en, it will fail unable to enable the
buffer because bytes_per_datum inside the kernel will be zero if
no channels are available.

It is implied that the user of the program should enable channels
manually or with a script before executing generic_buffer.

Be more helpful by stopping execution if no enabled channels can
be found, and print a helptext that will tell you what is wrong
and what needs to be done.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This makes the event monitor bail out with a helpful error
message if a device does not support events, as a related
fix to iio core now makes it return -ENODEV properly.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This adds a debugfs hook to read/write registers in the ST
sensors using debugfs. Proved to be awesome help when trying
to debug why IRQs do not arrive.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This patch adds the documentation ABI for the remove_trigger
attribute, provided by the iio-trig-sysfs stand-alone driver.
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This patch adds the ABI documentation for the add_trigger
attribute, which is provided by the iio-trig-sysfs stand-alone driver.
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

i2c_get_clientdata() is specifically for i2c. Replace it with the
generic dev_get/set_drvdata() to support different protocols.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

i2c_client variable is not really used anymore in the core driver. It is
only used to get the device to make proper outputs.

This patch replaces all i2c_client usage through direct usage of the
device pointer.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This patch introduces regmap usage into the driver. This is done to
later easily support the SPI interface of this chip.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

For generic IIO trigger implementations we already have a sub-directory,
but the generic buffer implementations currently reside in the IIO
top-level directory. The main reason is that things have historically grown
into this form.

With more generic buffer implementations on its way now is the perfect time
to clean this up and introduce a sub-directory for generic buffer
implementations to avoid too much clutter in the top-level directory.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Currently the IIO callback buffer implementation is directly built into the
IIO core module when enabled. Given that the callback buffer module is
standalone functionallity there is really no reason to do this. So move it
to its own module.

Also rename the source to follow the standard IIO module naming convention
as well as add a license notice to the file.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Move the entry for the CC 10001 ADC driver in Kconfig and Makefile up to
maintain alphabetic order.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Sort the entry for bmc105_magn in Kconfig and Makefile to its correct
position. Also add the minor module information for completeness.

Fixes: c91746a2 ("iio: magn: Add support for BMC150 magnetometer")
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Adjust some indentation issues as spotted by checkpatch.pl --strict
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Reviewed-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Indicate the bit number of predefined states, make use of these names and
change the state type in _resume to u8 to avoid type casting.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Reviewed-by: Tiberiu Breana <tiberiu.a.breana@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Check for the following error cases:
  * lower boundary for val in _write_event
  * return value of regmap_(field_)read
  * possible values for chan->type
  * return value of stk3310_gpio_probe

Also add an error path in _probe to put the sensor back into stand-by mode
in case of serious errors.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Some adjustment of indentation to make checkpatch.pl happy in strict mode.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Move the call to enable channel interrupts into its _read() function to
have it protected by a mutex. This ensures that only one channel is
sampled at a time.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Make use of GENMASK for consecutive bitmasks and BIT for single bitmasks.
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Merge tag 'iio-for-4.3b-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of new device support, features and cleanup for the 4.3 cycle.
Take 2 also includes a fix set that was too late for the 4.2 cycle.

As we had a lot of tools and docs work in this set, I have broken those
out into their own categories in this description.

Fixes from the pull request '4th set of IIO fixes for the 4.2 cycle'.
* Poll functions for both event chardev and the buffer one were returning
  negative error codes (via a positive value).
* A recent change to lsiio adding some error handling that was wrong and
  stopped the tool working.
* bmg160 was missing some dependencies in Kconfig
* berlin2-adc had a misshandled register (wrote a value rather than a bitmap)

New device support
* TI opt3001 light sensor
* TXC PA12 ALS and proximity sensor.
* mcp3301 ADC support (in mcp320x driver)
* ST lsm303agr accelerometer and magnetometer drivers (plus some st-sensors
  common support to allow different WHOAMI register addresses, devices with
  fixed scale and allow interrupt equiped magnetometers).
* ADIS16305, ADIS16367, ADIS16445IMUs (in the adis16400 driver)
* ADIS16266 gyro (in the adis16260 driver)
* ADIS16137 gyro (in the adis16136 driver)

New functionality
* mmc35240 DT bindings.
* Inverse unit conversion macros to aid handing of values written to sysfs
  attributes.

Core cleanup
* Forward declaration of struct iio_trigger to avoid a compile warning.

Driver cleanup / fixes
* mxs-lradc
  - Clarify which parts are supported.
  - Fix spelling erorrs.
  - Missing/extra includes
  - reorder includes
  - add datasheet name listings for all usable channels (to allow them
    to be bound by name from consumer drivers)
* acpi-als - add some function prefixes as per general iio style.
* bmc150_magn - replace a magic value with the existing define.
* vf610 - determine possible sample frequencies taking into account the
  electrical characteristics (defining a minimum sample time)
* dht11
  - whitespace
  - additional docs
  - avoid mulitple assignments in one line
  - Use the new funciton ktime_get_resolution_ns to cleanup a nasty trick
    previously used for timing.
* Fix all drivers that consider 0 a valid IRQ for historical reasons.
* Export I2C module alias info where previously missing (to allow autoprobing)
* Export OF module alias info where previously missing.
* mmc35240 - switch some variables into arrays to improve readability.
* mlx90614 - define some magic numbers for readability.
* bmc150_magn
  - expand area locked by a mutex to cover all the use of the
    data->buffer.
  - use descriptive naming for a mask instead of a magic value.
* berin2-adc
  - pass up an error code rather that a generic error
  - constify the iio_chan_spec
  - some other little tidy ups.
* stk8312
  - fix a dependency on triggered buffers in kconfig
  - add a check for invalid attribute values
  - improve error handling by returning error codes where possible and
    return immediately where relevant
  - rework macro defs to use GENMASK etc
  - change some variable types to reduce unnecessary casting
  - clean up code style
  - drop a local buffer copy for bulk reads and use the one in data->buffer
     instead.
* adis16400 - the adis16448 gyroscope scale was wrong.
* adis16480 - some more wrong scales for various parts.
* adis16300 - has an undocumented product id and serial number registers so
  use them.
* iio_simple_dummy - fix some wrong code indentation.
* bmc150-accel - use the chip ID to detect the chip present rather than
  verifying the expected part was there.  This was in response to a wrong
  ACPI entry on the WinBook TW100.
* mma8452
  - fix _get_hp_filter_index
  - drop a double include
  - pass up an error code rather than rewriting it
  - range check input values to attribute writes
  - register defs tidy up using GENMASK and reordering them to be easier to
    follow.
  - various coding style cleanups
  - put the Kconfig entry in the write place (alphabetically).

Tools related
* Tools cleanup - drop an explicity NULL comparison, some unnecessary braces,
  use the ARRAY_SIZE macro, send error messages to stderr instead of dropping
  them in the middle of normal output.
* Fix tools to allow that scale and offset attributes are optional.
* More tools fixes including allowing true 32bit data (previously an overflow
  prevented more than 31bits)
* Drop a stray header guard that ended up in a c file.
* Make calc_digits static as it isn't exported or in the header.
* Set ci_array pointer to NULL after free as a protection against non safe
  usage of the tools core code.  Also convert a double pointer to a single
  one as the extra level of indirection was unnecessary.

Docs
* DocBook introduction by Daniel Baluta.  Glad we are beginning to
  draw together some more introductory docs to suplement the various
  tools / examples.
* Drop bytes_per_datum sysfs attribute docs as it no longer exists.
* A whole load of missing / fixing of kernel-doc for the core of IIO.
* Document the trigger name sysfs attribute in the ABI docs.
* Minor typos in the ABI docs related to power down modes.

Negative return values are not supported by iio_event_poll since
its return type is unsigned int.

Fixes: f18e7a06 ("iio: Return -ENODEV for file operations if the device has been unregistered")
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Change return value to 0 if no device is bound since
unsigned int cannot support negative error codes.

Fixes: f18e7a06 ("iio: Return -ENODEV for file operations if the
device has been unregistered")
Signed-off-by: Cristina Opriceana <cristina.opriceana@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

commit acf50b35
"tools:iio:lsiio: add error handling"
introduced error handling of errors returned from
read_sysfs_string(), but with a simple if (retval),
missing the fact that these functions return a positive
value if the read was successful.

As a result lsiio regresses and does not show any
devices on my filesystem. Fix this by checking for
only negative error codes.

Cc: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

This patch adds selects for IIO_BUFFER and IIO_TRIGGERED_BUFFER. Without
IIO_BUFFER, the driver does not compile.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Active channel number is stored in BERLIN2_SM_CTRL as value, instead of a
bit map.
The masks for channel interrupts and data ready are a 16 bits wide bit
map each, instead of just 4 bits.

Also correct the data mask for the temperature sensor, which was
Reported-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Acked-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Ozwpan is completely unmaintained and potentially a security problem. As
this is a staging driver, it should be removed, since it has been
abandoned.

Cc: Shigekatsu Tateno <shigekatsu.tateno@atmel.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We want the IIO and staging fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull input subsystem fixes from Dmitry Torokhov:
 "Just small ALPS and Elan touchpads, and other driver fixups"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: elantech - add special check for fw_version 0x470f01 touchpad
  Input: twl4030-vibra - fix ERROR: Bad of_node_put() warning
  Input: alps - only Dell laptops have separate button bits for v2 dualpoint sticks
  Input: axp20x-pek - add module alias
  Input: turbografx - fix potential out of bound access

Pull MIPS fixes from Ralf Baechle:
 "Another round of MIPS fixes for 4.2.  No area does particularly stand
  out but we have a two unpleasant ones:

   - Kernel ptes are marked with a global bit which allows the kernel to
     share kernel TLB entries between all processes.  For this to work
     both entries of an adjacent even/odd pte pair need to have the
     global bit set.  There has been a subtle race in setting the other
     entry's global bit since ~ 2000 but it take particularly
     pathological workloads that essentially do mostly vmalloc/vfree to
     trigger this.

     This pull request fixes the 64-bit case but leaves the case of 32
     bit CPUs with 64 bit ptes unsolved for now.  The unfixed cases
     affect hardware that is not available in the field yet.

   - Instruction emulation requires loading instructions from user space
     but the current fast but simplistic approach will fail on pages
     that are PROT_EXEC but !PROT_READ.  For this reason we temporarily
     do not permit this permission and will map pages with PROT_EXEC |
     PROT_READ.

  The remainder of this pull request is more or less across the field
  and the short log explains them well"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: Make set_pte() SMP safe.
  MIPS: Replace add and sub instructions in relocate_kernel.S with addiu
  MIPS: Flush RPS on kernel entry with EVA
  Revert "MIPS: BCM63xx: Provide a plat_post_dma_flush hook"
  MIPS: BMIPS: Delete unused Kconfig symbol
  MIPS: Export get_c0_perfcount_int()
  MIPS: show_stack: Fix stack trace with EVA
  MIPS: do_mcheck: Fix kernel code dump with EVA
  MIPS: SMP: Don't increment irq_count multiple times for call function IPIs
  MIPS: Partially disable RIXI support.
  MIPS: Handle page faults of executable but unreadable pages correctly.
  MIPS: Malta: Don't reinitialise RTC
  MIPS: unaligned: Fix build error on big endian R6 kernels
  MIPS: Fix sched_getaffinity with MT FPAFF enabled
  MIPS: Fix build with CONFIG_OF=y for non OF-enabled targets
  CPUFREQ: Loongson2: Fix broken build due to incorrect include.

Pull btrfs fix from Chris Mason:
 "We have a btrfs quota regression fix.

  I merged this one on Thursday and have run it through tests against
  current master.

  Normally I wouldn't have sent this while you were finalizing rc6, but
  I'm feeding mosquitoes in the adirondacks next week, so I wanted to
  get this one out before leaving.  I'll leave longer tests running and
  check on things during the week, but I don't expect any problems"

* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: qgroup: Fix a regression in qgroup reserved space.

Pull thermal management fixes from Zhang Rui:
 "Specifics:

   - fix an error that "weight_attr" sysfs attribute is not removed
     while unbinding.  From: Viresh Kumar.

   - fix power allocator governor tracing to return the real request.
     From Javi Merino.

   - remove redundant owner assignment of hisi platform thermal driver.
     From Krzysztof Kozlowski.

   - a couple of small fixes of Exynos thermal driver.  From Krzysztof
     Kozlowski and Chanwoo Choi"

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  thermal: Drop owner assignment from platform_driver
  thermal: exynos: Remove unused code related to platform_data on probe()
  thermal: exynos: Add the dependency of CONFIG_THERMAL_OF instead of CONFIG_OF
  thermal: exynos: Disable the regulator on probe failure
  thermal: power_allocator: trace the real requested power
  thermal: remove dangling 'weight_attr' device file

Fixed global integer initialization issue.
Global variables should not be explicitly initialized to 0 or NULL.
Signed-off-by: Daniel Machon <dmachon.dev@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed coding style issues where statement should be on the next line
Signed-off-by: Daniel Machon <dmachon.dev@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixed spelling error
Signed-off-by: Daniel Machon <dmachon.dev@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes the checkpatch.pl warning - braces {} are not necessary for any arm
of this statement
Signed-off-by: Chandra S Gorentla <csgorentla@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fixes the checkpatch.pl warning -
'unnecessary whitespace before a quoted newline'.
Signed-off-by: Chandra S Gorentla <csgorentla@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>