iio: Make return value check for set_trigger_state() consistent

In `iio_trigger_detach_poll_func()` the return value from
`trig->ops->set_trigger_state(trig, false)` is checked with `if (ret)`.
However, in `iio_trigger_attach_poll_func()` it is checked with
`if (ret < 0)`. Resolve this mismatch by only checking for `if (ret)` in
both places.

Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://lore.kernel.org/r/pndv8eojdey.fsf@axis.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: Add simple trigger_validation helper

Some triggers can only be attached to the IIO device that corresponds to
the same physical device. Implement generic helper which can be used as
a validate_trigger callback for such devices.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/51cd3e3e74a6addf8d333f4a109fb9c5a11086ee.1683541225.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Rename iio_trigger_poll_chained and add kernel-doc

Rename the function to iio_trigger_poll_nested. Add kernel-doc with
a note on the context where the function is expected to be called.

Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
Link: https://lore.kernel.org/r/841b533cba28ca25a8e87280c44e45979166e8e2.1677761379.git.mehdi.djait.k@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Improve the kernel-doc of iio_trigger_poll

Move the kernel-doc of the function to industrialio-trigger.c
Add a note on the context where the function is expected to be called.

Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/bd84fc17e9d22eab998bf48720297f9a77689f45.1677761379.git.mehdi.djait.k@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: move 'mlock' to 'struct iio_dev_opaque'

Now that there are no more users accessing 'mlock' directly, we can move
it to the iio_dev private structure. Hence, it's now explicit that new
driver's should not directly use this lock.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20221012151620.1725215-5-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Add blank lines after declarations.

As reported by checkpatch.pl add blank lines after declarations.

Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220727181855.589052-2-joetalbott@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Be consistent with allocation result tests.

Make both allocation result tests use the same format

if (!ptr)

Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220718020348.32047-1-joetalbott@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Use parens with sizeof

Prefer 'sizeof(var)' over 'sizeof var' as reported by checkpatch.pl.

Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Link: https://lore.kernel.org/r/20220717153438.10800-1-joetalbott@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: move trig->owner init to trigger allocate() stage

To provide a new IIO trigger to the IIO core, usually driver executes the
following pipeline: allocate()/register()/get(). Before, IIO core assigned
trig->owner as a pointer to the module which registered this trigger at
the register() stage. But actually the trigger object is owned by the
module earlier, on the allocate() stage, when trigger object is
successfully allocated for the driver.

This patch moves trig->owner initialization from register()
stage of trigger initialization pipeline to allocate() stage to
eliminate all misunderstandings and time gaps between trigger object
creation and owner acquiring.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Link: https://lore.kernel.org/r/20220601174837.20292-1-ddrokosov@sberdevices.ru
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: warn about non-registered iio trigger getting attempt

As a part of patch series about wrong trigger register() and get()
calls order in the some IIO drivers trigger initialization path:

https://lore.kernel.org/all/20220524181150.9240-1-ddrokosov@sberdevices.ru/

runtime WARN_ONCE() is added to alarm IIO driver authors who make such
a mistake.

When an IIO driver allocates a new IIO trigger, it should register it
before calling the get() operation. In other words, each IIO driver
must abide by IIO trigger alloc()/register()/get() calls order.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
Link: https://lore.kernel.org/r/20220607183907.20017-1-ddrokosov@sberdevices.ru
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Use octal permissions and DEVICE_ATTR_{RO,RW}.

As reported by checkpatch.pl. Where possible use DEVICE_ATTR_RO(),
DEVICE_ATTR_RW(), and __ATTR_RO(). Change function names to be
<var>_show() for read and <var>_store() for write.

Suggested-by: Joe Perches <joe@perches.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Joe Simmons-Talbott <joetalbott@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220601185414.251571-1-joetalbott@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Directly use ida_alloc()/free()

Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu <liuke94@huawei.com>
Link: https://lore.kernel.org/r/20220527091739.2949426-1-liuke94@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Move the currentmode entry to the opaque structure

This entry should, under no situation, be modified by device
drivers. Now that we have limited its read access to device drivers
really needing it and did so through a dedicated helper, we can
easily move this variable to the opaque structure in order to
prevent any further modification from non-authorized code (out of the
core, basically).

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20220207143840.707510-12-miquel.raynal@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: Fix a scheduling whilst atomic issue seen on tsc2046

IIO triggers are software IRQ chips that split an incoming IRQ into
separate IRQs routed to all devices using the trigger.
When all consumers are done then a trigger callback reenable() is
called. There are a few circumstances under which this can happen
in atomic context.

1) A single user of the trigger that calls the iio_trigger_done()
function from interrupt context.
2) A race between disconnecting the last device from a trigger and
the trigger itself sucessfully being disabled.

To avoid a resulting scheduling whilst atomic, close this second corner
by using schedule_work() to ensure the reenable is not done in atomic
context.

Note that drivers must be careful to manage the interaction of
set_state() and reenable() callbacks to ensure appropriate reference
counting if they are relying on the same hardware controls.

Deliberately taking this the slow path rather than via a fixes tree
because the error has hard to hit and I would like it to soak for a while
before hitting a release kernel.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211017172209.112387-1-jic23@kernel.org

iio: trigger: Fix reference counting

In viio_trigger_alloc() device_initialize() is used to set the initial
reference count of the trigger to 1. Then another get_device() is called on
trigger. This sets the reference count to 2 before the trigger is returned.

iio_trigger_free(), which is the matching API to viio_trigger_alloc(),
calls put_device() which decreases the reference count by 1. But the second
reference count acquired in viio_trigger_alloc() is never dropped.

As a result the iio_trigger_release() function is never called and the
memory associated with the trigger is never freed.

Since there is no reason for the trigger to start its lifetime with two
reference counts just remove the extra get_device() in
viio_trigger_alloc().

Fixes: 5f9c035cae18 ("staging:iio:triggers. Add a reference get to the core for triggers.")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20211024092700.6844-2-lars@metafoo.de
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: move @trig_readonly from struct iio_dev to struct iio_dev_opaque

This is only set via the iio_trig_set_immutable() call and later used
by the IIO core so there is no benefit in drivers being able to access
it.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-5-jic23@kernel.org

iio: core: move @driver_module from struct iio_dev to struct iio_dev_opaque

Continuing move to hide internal elements from drivers, move this structure
element over. It's only accessed from iio core files so this one was
straight forward and no accessor functions are needed.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-4-jic23@kernel.org

iio: trigger: simplify __devm_iio_trigger_register

Use devm_add_action_or_reset() instead of devres_alloc() and
devres_add(), which works the same. This will simplify the
code. There is no functional changes.

Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/1617881896-3164-7-git-send-email-yangyicong@hisilicon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: Fix strange (ladder-type) indentation

In some cases indentation looks a bit weird with starting from = sign
and being in a ladder-type style. Unify it across the module.

While at it, add blank line after definition block where it needed,

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210402174911.44408-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: trigger: Replace explicit casting and wrong specifier with proper one

By unknown reason device name is set with an index casted from int
to unsigned long while at the same time with "%ld" specifier. Both parts
seems wrong to me, thus replace replace explicit casting and wrong specifier
with proper one, i.e. "%d".

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210402174911.44408-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Use sysfs_emit() (trivial bits)

sysfs_emit() is preferred over raw s*printf() for sysfs attributes since it
knows about the sysfs buffer specifics and has some built-in sanity checks.

This patch converts the places in the iio core that follow the pattern of

return s*printf(...)

to

return sysfs_emit(...)

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210320071405.9347-2-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: set default trig->dev.parent

When allocated with [devm_]iio_trigger_alloc(), set trig device parent to
the device the trigger is allocated for by default.

It can always be reassigned in the probe routine.

Change iio_trigger_alloc() API to add the device pointer to be coherent
with devm_iio_trigger_alloc, using similar interface to
iio_device_alloc().

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-2-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: rework iio device group creation

Up until now, the device groups that an IIO device had were limited to 6.
Two of these groups would account for buffer attributes (the buffer/ and
scan_elements/ directories).

Since we want to add multiple buffers per IIO device, this number may not
be enough, when adding a second buffer. So, this change reallocates the
groups array whenever an IIO device group is added, via a
iio_device_register_sysfs_group() helper.

This also means that the groups array should be assigned to
'indio_dev.dev.groups' really late, right before {cdev_}device_add() is
called to do the entire setup.
And we also must take care to free this array when the sysfs resources are
being cleaned up.

With this change we can also move the 'groups' & 'groupcounter' fields to
the iio_dev_opaque object. Up until now, this didn't make a whole lot of
sense (especially since we weren't sure how multibuffer support would look
like in the end).
But doing it now kills one birds with one stone.

An alternative, would be to add a configurable Kconfig symbol
CONFIG_IIO_MAX_BUFFERS_PER_DEVICE (or something like that) and compute a
static maximum of the groups we can support per IIO device. But that would
probably annoy a few people since that would make the system less
configurable.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-11-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core-trigger: make iio_device_register_trigger_consumer() an int return

Oddly enough the noop function is an int-return. This one seems to be void.
This change converts it to int, because we want to change how groups are
registered. With that change this function could error out with -ENOMEM.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-10-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:trigger: rename try_reenable() to reenable() plus return void

As we no longer support a try again if we cannot reenable the trigger
rename the function to reflect this. Also we don't do anything with
the value returned so stop it returning anything. For the few drivers
that didn't already print an error message in this patch, add such
a print.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Christian Oder <me@myself5.de>
Cc: Eugen Hristev <eugen.hristev@microchip.com>
Cc: Nishant Malpani <nish.malpani25@gmail.com>
Cc: Daniel Baluta <daniel.baluta@oss.nxp.com>
Link: https://lore.kernel.org/r/20200920132548.196452-3-jic23@kernel.org

iio: Fix: Do not poll the driver again if try_reenable() callback returns non 0.

The original reason for this behaviour is long gone and no current
drivers are making use of this function correctly. Note however, that
you would be very unlucky to actually hit the problem as it would
require a bus comms failure in the callback.

This dates back a long way. The original board on which I did a lot
of early IIO development only supported edge interrupts, but some of the
sensors were level interrupt based. As such, the lis3l02dq driver did
a dance with checking a GPIO to identify if it should retrigger.
That was an unsustainable hack so we later just stopped supporting interrupts
for that particular combination.

There are a number of drivers where a fault on a bus read in the
try_reenable() callback will result in them returning non 0 and
incorrectly then causing iio_trigger_poll() to be called.

Anyhow, this handling is unused and causing issues so let us rip it out.
Link: https://lore.kernel.org/linux-iio/20200813075358.13310-1-lars@metafoo.de/

After this the try_reenable() naming makes no sense, so as a follow up
patch I'll rename it to simply reenable(). I haven't done that here
as it will add noise to the fix for backporting.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Christian Eggers <ceggers@arri.de>
Link: https://lore.kernel.org/r/20200920132548.196452-2-jic23@kernel.org

iio: Add __printf() attributes to various allocation functions

A partial set of these was added to IIO a long time back.
This fills in some gaps in coverage highlighted by building
with W=1

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200913132115.800131-3-jic23@kernel.org

iio: Move attach/detach of the poll func to the core

All devices using a triggered buffer need to attach and detach the trigger
to the device in order to properly work. Instead of doing this in each and
every driver by hand move this into the core.

At this point in time, all drivers should have been resolved to
attach/detach the poll-function in the same order.

This patch removes all explicit calls of iio_triggered_buffer_postenable()
& iio_triggered_buffer_predisable() in all drivers, since the core handles
now the pollfunc attach/detach.

The more peculiar change is for the 'at91-sama5d2_adc' driver, since it's
not immediately obvious that removing the hooks doesn't break anything.
Eugen was able to test on at91-sama5d2-adc driver, sama5d2-xplained board.
All seems to be fine.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com> #for at91-sama5d2-adc
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: drop devm_iio_trigger_free() API call

It's unused so far, so it can be removed. Also makes sense to remove it
to discourage weird uses of this call during review.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: drop devm_iio_trigger_unregister() API call

It's unused so far, so it can be removed. Also makes sense to remove it
to discourage weird uses of this call during review.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: trigger: Print an error if there is no available irq

If there are more trigger consumers than
CONFIG_IIO_CONSUMERS_PER_TRIGGER, iio_trigger_attach_poll_func will
silently fail. Add an error message to inform the user that
CONFIG_IIO_CONSUMERS_PER_TRIGGER limit might be exceeded.

Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:trigger: Remove necessity to have a trig->ops structure.

There are a few cases where none of the callbacks are supplied and the
ops structure purely existed to provide the driver module.

Given that is done differently now, we don't need to have a trig_ops structure.
Allow for it not being there required a few additional sanity checks when
trying check if particular callbacks are set.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: triggers: Use macros to avoid boilerplate assignment of owner.

This trig_ops.owner assignment occurs in all trigger drivers and
can be simply automated using a macro as has been done in many
other places in the kernel.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: Use macro magic to avoid manual assign of driver_module

Starting point in boiler plate reduction similar to that done for
many similar cases elsewhere in the kernel.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: trigger: fix NULL pointer dereference in iio_trigger_write_current()

In case oldtrig == trig == NULL (which happens when we set none
trigger, when there is already none set) there is a NULL pointer
dereference during iio_trigger_put(trig). Below is kernel output when
this occurs:

[ 26.741790] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 26.750179] pgd = cacc0000
[ 26.752936] [00000000] *pgd=8adc6835, *pte=00000000, *ppte=00000000
[ 26.759531] Internal error: Oops: 17 [#1] SMP ARM
[ 26.764261] Modules linked in: usb_f_ncm u_ether usb_f_acm u_serial usb_f_fs libcomposite configfs evbug
[ 26.773844] CPU: 0 PID: 152 Comm: synchro Not tainted 4.12.0-rc1 #2
[ 26.780128] Hardware name: Freescale i.MX6 Ultralite (Device Tree)
[ 26.786329] task: cb1de200 task.stack: cac92000
[ 26.790892] PC is at iio_trigger_write_current+0x188/0x1f4
[ 26.796403] LR is at lock_release+0xf8/0x20c
[ 26.800696] pc : [<c0736f34>] lr : [<c016efb0>] psr: 600d0013
[ 26.800696] sp : cac93e30 ip : cac93db0 fp : cac93e5c
[ 26.812193] r10: c0e64fe8 r9 : 00000000 r8 : 00000001
[ 26.817436] r7 : cb190810 r6 : 00000010 r5 : 00000001 r4 : 00000000
[ 26.823982] r3 : 00000000 r2 : 00000000 r1 : cb1de200 r0 : 00000000
[ 26.830528] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 26.837683] Control: 10c5387d Table: 8acc006a DAC: 00000051
[ 26.843448] Process synchro (pid: 152, stack limit = 0xcac92210)
[ 26.849475] Stack: (0xcac93e30 to 0xcac94000)
[ 26.853857] 3e20: 00000001 c0736dac c054033c cae6b680
[ 26.862060] 3e40: cae6b680 00000000 00000001 cb3f8610 cac93e74 cac93e60 c054035c c0736db8
[ 26.870264] 3e60: 00000001 c054033c cac93e94 cac93e78 c029bf34 c0540348 00000000 00000000
[ 26.878469] 3e80: cb3f8600 cae6b680 cac93ed4 cac93e98 c029b320 c029bef0 00000000 00000000
[ 26.886672] 3ea0: 00000000 cac93f78 cb2d41fc caed3280 c029b214 cac93f78 00000001 000e20f8
[ 26.894874] 3ec0: 00000001 00000000 cac93f44 cac93ed8 c0221dcc c029b220 c0e1ca39 cb2d41fc
[ 26.903079] 3ee0: cac93f04 cac93ef0 c0183ef0 c0183ab0 cb2d41fc 00000000 cac93f44 cac93f08
[ 26.911282] 3f00: c0225eec c0183ebc 00000001 00000000 c0223728 00000000 c0245454 00000001
[ 26.919485] 3f20: 00000001 caed3280 000e20f8 cac93f78 000e20f8 00000001 cac93f74 cac93f48
[ 26.927690] 3f40: c0223680 c0221da4 c0246520 c0245460 caed3283 caed3280 00000000 00000000
[ 26.935893] 3f60: 000e20f8 00000001 cac93fa4 cac93f78 c0224520 c02235e4 00000000 00000000
[ 26.944096] 3f80: 00000001 000e20f8 00000001 00000004 c0107f84 cac92000 00000000 cac93fa8
[ 26.952299] 3fa0: c0107de0 c02244e8 00000001 000e20f8 0000000e 000e20f8 00000001 fbad2484
[ 26.960502] 3fc0: 00000001 000e20f8 00000001 00000004 beb6b698 00064260 0006421c beb6b4b4
[ 26.968705] 3fe0: 00000000 beb6b450 b6f219a0 b6e2f268 800d0010 0000000e cac93ff4 cac93ffc
[ 26.976896] Backtrace:
[ 26.979388] [<c0736dac>] (iio_trigger_write_current) from [<c054035c>] (dev_attr_store+0x20/0x2c)
[ 26.988289] r10:cb3f8610 r9:00000001 r8:00000000 r7:cae6b680 r6:cae6b680 r5:c054033c
[ 26.996138] r4:c0736dac r3:00000001
[ 26.999747] [<c054033c>] (dev_attr_store) from [<c029bf34>] (sysfs_kf_write+0x50/0x54)
[ 27.007686] r5:c054033c r4:00000001
[ 27.011290] [<c029bee4>] (sysfs_kf_write) from [<c029b320>] (kernfs_fop_write+0x10c/0x224)
[ 27.019579] r7:cae6b680 r6:cb3f8600 r5:00000000 r4:00000000
[ 27.025271] [<c029b214>] (kernfs_fop_write) from [<c0221dcc>] (__vfs_write+0x34/0x120)
[ 27.033214] r10:00000000 r9:00000001 r8:000e20f8 r7:00000001 r6:cac93f78 r5:c029b214
[ 27.041059] r4:caed3280
[ 27.043622] [<c0221d98>] (__vfs_write) from [<c0223680>] (vfs_write+0xa8/0x170)
[ 27.050959] r9:00000001 r8:000e20f8 r7:cac93f78 r6:000e20f8 r5:caed3280 r4:00000001
[ 27.058731] [<c02235d8>] (vfs_write) from [<c0224520>] (SyS_write+0x44/0x98)
[ 27.065806] r9:00000001 r8:000e20f8 r7:00000000 r6:00000000 r5:caed3280 r4:caed3283
[ 27.073582] [<c02244dc>] (SyS_write) from [<c0107de0>] (ret_fast_syscall+0x0/0x1c)
[ 27.081179] r9:cac92000 r8:c0107f84 r7:00000004 r6:00000001 r5:000e20f8 r4:00000001
[ 27.088947] Code: 1a000009 e1a04009 e3a06010 e1a05008 (e5943000)
[ 27.095244] ---[ end trace 06d1dab86d6e6bab ]---

To fix that problem call iio_trigger_put(trig) only when trig is not
NULL.

Fixes: d5d24bcc0a10 ("iio: trigger: close race condition in acquiring trigger reference")
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: clean up viio_trigger_alloc()

1) Reverse the test for kmalloc() failure so we can pull everything
back one tab.
2) Use gotos for unwinding.
3) Some of the extra line breaks for the 80 character limit are no
longer needed so we can remove them.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: industrialio-trigger: constify device_type structures

Declare device_type structure as const as it is only stored in the
type field of a device structure. This field is of type const, so add
const to declaration of device_type structure.

File size before:
text data bss dec hex filename
5389 208 48 5645 160d iio/industrialio-trigger.o

File size after:
text data bss dec hex filename
5453 176 48 5677 162d iio/industrialio-trigger.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: close race condition in acquiring trigger reference

In iio_trigger_write_current() we find the trigger we want while
holding mutex on the list of triggers, but we don't actually do a
get on it while holding mutex. We wait until further validations
are completed and we're sure it's the one we want. Race condition
is that it could be freed by the time we do the get.

Solution is to grab the trigger (iio_trigger_get) as soon as we
find it while holding mutex on the list of triggers. If later
we decide it's not the right one, put it back. (iio_trigger_put).

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Suggested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: Add helper function to verify that a trigger belongs to the same device

Some triggers can only be attached to the IIO device that corresponds to
the same physical device. Currently each driver that requires this
implements its own trigger validation function.

Introduce a new helper function called iio_trigger_validate_own_device()
that can be used to do this check. Having a common implementation avoids
code duplication and unnecessary boiler-plate code.

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

iio: trigger: helpers to determine own trigger

This adds a helper function to the IIO trigger framework:

iio_trigger_using_own(): for an IIO device, this tells
whether the device is using itself as a trigger.
This is true if the indio device:
(A) supplies a trigger and
(B) has assigned its own buffer poll function to use this
trigger.

This helper function is good when constructing triggered,
buffered drivers that can either use its own hardware *OR*
an external trigger such as a HRTimer or even the trigger from
a totally different sensor.

Under such circumstances it is important to know for example
if the timestamp from the same trigger hardware should be used
when populating the buffer: if iio_trigger_using_own() is true,
we can use this timestamp, else we need to pick a unique
timestamp directly in the trigger handler.

For this to work of course IIO devices registering hardware
triggers must follow the convention to set the parent device
properly, as as well as setting the parent of the IIO device
itself.

When a new poll function is attached, we check if the parent
device of the IIO of the poll function is the same as the
parent device of the trigger and in that case we conclude that
the hardware is using itself as trigger.

Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Cc: Crestez Dan Leonard <leonard.crestez@intel.com>
Cc: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: add resource managed (un)register

Add resource managed devm_iio_trigger_register() and
devm_iio_triger_unregister() to automatically clean up registered triggers
allocated by IIO drivers, thus leading to simplified IIO drivers code.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: allow immutable triggers to be assigned

There are times when an assigned trigger to a device shouldn't ever
change after intialization.

Examples of this being used is when an provider device has a trigger
that is assigned to an ADC, which uses it populate data into a callback
buffer.

Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:core: timestamping clock selection support

Adds a new per-device sysfs attribute "current_timestamp_clock" to allow
userspace to select a particular POSIX clock for buffered samples and
events timestamping.

Following clocks, as listed in clock_gettime(2), are supported:
CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW,
CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_COARSE, CLOCK_BOOTTIME and
CLOCK_TAI.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Acked-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Refuse to register triggers with duplicate names

The trigger name is documented as unique but drivers are currently
allowed to register triggers with duplicate names. This should be
considered a bug since it makes the 'current_trigger' interface
unusable.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Fix error handling in iio_trigger_attach_poll_func

When attaching a pollfunc iio_trigger_attach_poll_func will allocate a
virtual irq and call the driver's set_trigger_state function. Fix error
handling to undo previous steps if any fails.

In particular this fixes handling errors from a driver's
set_trigger_state function. When using triggered buffers a failure to
enable the trigger used to make the buffer unusable.

Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: triggers: Make trigger ops structure explicitly non optional.

This structure has not been optional for a long time (if ever) but the
code implies that it is. As we then use it later in a fashion that would
crash if it was in fact NULL, it's inconsistent so fix it up by removing
unnecessary checks.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Support triggered events

Support triggered events.

This is useful for chips that don't have their own interrupt sources.
It allows to use generic/standalone iio triggers for those drivers.

Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: Add missing fields in kernel docs

Fix kernel docs warnings by adding the missing description
for each of the existing function parameters.

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

iio: Remove timestamp argument from iio_trigger_poll() and iio_trigger_poll_chained()

argument has been ignored; adjust drivers accordingly

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio get rid of unneccessary error_ret

Get rid of obsolete uses of goto error_ret and some empty lines.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: Convert to use ATTRIBUTE_GROUPS

Use new ATTRIBUTE_GROUPS macro to declare attribute groups.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Remove redundant check that new trigger is different from old

same check is performed a new lines above

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Minor kerneldoc fix for iio_trigger_write_current()

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: core: Move kernel doc to the right location

Documentation related to function should be placed above
its implementation. Move it accordingly.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: trigger: implement devm_iio_trigger_alloc/devm_iio_triger_free

Add a resource managed devm_iio_trigger_alloc()/devm_iio_triger_free()
to automatically clean up triggers allocated by IIO drivers, thus
leading to simplified IIO drivers code.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Signed-off-by: Kyunmin Park <kyungmin.park@samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: Fix use_count race condition

When using more than one trigger consumer it can happen that multiple threads
perform a read-modify-update cycle on 'use_count' concurrently. This can cause
updates to be lost and use_count can get stuck at non-zero value, in which case
the IIO core assumes that at least one thread is still running and will wait for
it to finish before running any trigger handlers again. This effectively renders
the trigger disabled and a reboot is necessary before it can be used again. To
fix this make use_count an atomic variable. Also set it to the number of
consumers before starting the first consumer, otherwise it might happen that
use_count drops to 0 even though not all consumers have been run yet.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: device_unregister->device_del to avoid double free

iio_trigger unregistration and freeing has been separated in this
code for some time, but it looks like the calls to the device
handling were not appropriately updated.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reported-by: Otavio Salvador <otavio@ossystems.com.br>
Tested-by: Otavio Salvador <otavio@ossystems.com.br>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: tweak language in industrialio-trigger comments

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: Register sysfs file statically

The name sysfs attribute is the same for all triggers, so there is no need to
register them dynamically at runtime. Create a attribute group for it and set it
up for the bus attribute group. This also avoids a possible race condition
where the uevent for the device is sent before the name sysfs attribute has been
added.

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

iio: fix spelling of detach in static func

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:trigger: Use to_iio_trigger() instead of dev_get_drvdata()

Use to_iio_trigger(dev) instead of dev_get_drvdata(dev). Both will return the
trigger which belongs to the device, but the the first on is a bit more
lightweight.

Since this is the last location where we used dev_get_drvdata() for retrieving
the trigger there is no need anymore to assign the the trigger to the devices
drvdata, so we can remove that as well.

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: Use dev_to_iio_dev()

Replace open-coded instances of getting a iio_dev struct from a device struct
with dev_to_iio_dev().

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>

staging:iio: Streamline API function naming

Currently we use two different naming schemes in the IIO API, iio_verb_object
and iio_object_verb. E.g iio_device_register and iio_allocate_device. This
patches renames instances of the later to the former. The patch also renames allocate to
alloc as this seems to be the preferred form throughout the kernel.

In particular the following renames are performed by the patch:
iio_put_device -> iio_device_put
iio_allocate_device -> iio_device_alloc
iio_free_device -> iio_device_free
iio_get_trigger -> iio_trigger_get
iio_put_trigger -> iio_trigger_put
iio_allocate_trigger -> iio_trigger_alloc
iio_free_trigger -> iio_trigger_free

The conversion was done with the following coccinelle patch with manual fixes to
comments and documentation.

<smpl>
@@
@@
-iio_put_device
+iio_device_put
@@
@@
-iio_allocate_device
+iio_device_alloc
@@
@@
-iio_free_device
+iio_device_free
@@
@@
-iio_get_trigger
+iio_trigger_get
@@
@@
-iio_put_trigger
+iio_trigger_put
@@
@@
-iio_allocate_trigger
+iio_trigger_alloc
@@
@@
-iio_free_trigger
+iio_trigger_free
</smpl>

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: 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>