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: proximity: as3935: Fix alignment for DMA safety

____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_DMA_MINALIGN definition.

Fixes: 24ddb0e4bba4 ("iio: Add AS3935 lightning sensor support")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Matt Ranostay <mranostay@gmail.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-87-jic23@kernel.org

iio:proximity:as3935: Switch from CONFIG_PM_SLEEP guards to pm_sleep_ptr() etc

Letting the compiler remove these functions when the kernel is built
without CONFIG_PM_SLEEP support is simpler and less error prone than the
use of #ifdef based config guards.

Removing instances of this approach from IIO also stops them being
copied into new drivers.

Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20220130193147.279148-34-jic23@kernel.org

iio: as3935: Use devm_delayed_work_autocancel()

Use devm_delayed_work_autocancel() instead of hand writing it.
It saves a few lines of code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/8d5c50f191bd8f751849d72127f83b14a7636d64.1644755396.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: as3935: Use sysfs_emit()

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

Use sysfs_emit() to format the custom `noise_level_tripped` device
attribute of the as3935 driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211216185217.1054495-6-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: as3935: Remove unnecessary cast

`buf` is cast to a const char *, but `buf` is already a const char *, so
the case is unnecessary.

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

iio: as3935: Remove no-op trigger ops

The IIO core handles a trigger ops with all NULL callbacks the
same as if the trigger ops itself was NULL.

Remove the empty trigger ops from the interrupt trigger driver to slightly
reduce the boilerplate code. Object size of the driver module is also
slightly reduced.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211031142130.20791-6-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: prox: as3935: Fix buffer alignment in iio_push_to_buffers_with_timestamp()

To make code more readable, use a structure to express the channel
layout and ensure the timestamp is 8 byte aligned.

Found during an audit of all calls of uses of
iio_push_to_buffers_with_timestamp()

Fixes: 37b1ba2c68cf ("iio: proximity: as3935: fix buffer stack trashing")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Matt Ranostay <matt.ranostay@konsulko.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501170121.512209-15-jic23@kernel.org

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

Continuing from Alexandru Ardelean's introduction of the split between
driver modifiable fields and those that should only be set by the core.

This could have been done in two steps to make the actual move after
introducing iio_device_id() but there seemed limited point to that
given how mechanical the majority of the patch is.

Includes fixup from Alex for missing mxs-lradc-adc conversion.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-2-jic23@kernel.org

iio: as3935: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

Given we call devm_iio_trigger_alloc() and devm_iio_device_alloc() with
dev as parent, we do not have to set data->trig->dev.parent to
indio_dev->dev.parent anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-8-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:proximity:as3935: Drop of_match_ptr and use generic fw accessors

This change allows the driver to be used with ACPI PRP0001 and removes
an antipattern that I want to avoid being copied into new IIO drivers.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20200910173242.621168-33-jic23@kernel.org

iio:proximity:as3935: Use local struct device pointer to simplify code.

This makes the existing code easier to read and will make the following
patch a little simpler.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20200910173242.621168-32-jic23@kernel.org

iio: remove explicit IIO device parent assignment

This patch applies the semantic patch:
@@
expression I, P, SP;
@@
I = devm_iio_device_alloc(P, SP);
...
- I->dev.parent = P;

It updates 302 files and does 307 deletions.
This semantic patch also removes some comments like
'/* Establish that the iio_dev is a child of the i2c device */'

But this is is only done in case where the block is left empty.

The patch does not seem to cover all cases. It looks like in some cases a
different variable is used in some cases to assign the parent, but it
points to the same reference.
In other cases, the block covered by ... may be just too big to be covered
by the semantic patch.

However, this looks pretty good as well, as it does cover a big bulk of the
drivers that should remove the parent assignment.

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

iio: as3935: Drop GPIO includes

The driver includes <linux/gpio.h> and <linux/of_gpio.h> yet
fails to use symbols from any of the include files, so drop
these includes.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: proximity: as3935: fix use-after-free on device remove

This driver's probe() uses a mix of devm_ and non-devm_ functions. This
means that the remove order will not be the exact opposite of the probe
order.

Remove order:
1. remove() executes:
iio_device_unregister
iio_triggered_buffer_cleanup
iio_trigger_unregister
(A)
2. core frees devm resources in reverse order:
free_irq
iio_trigger_free
iio_device_free

In (A) the trigger has been unregistered, but the irq handler is still
registered and active, so the trigger may still be touched via
interrupt -> as3935_event_work. This is a potential use-after-unregister.

Given that the delayed work is never canceled explicitly, it may run even
after iio_device_free. This is a potential use-after-free.

Solution: convert all probe functions to their devm_ equivalents.
Add a devm callback, called by the core on remove right after irq_free,
which explicitly cancels the delayed work. This will guarantee that all
resources are freed in the correct order.

As an added bonus, some boilerplate code can be removed.

Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: add SPDX identifier for various drivers

Add GPLv2+ SPDX identifier and update email for author's drivers.

Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: proximity: as3935: noise detection + threshold changes

Most applications are too noisy to allow the default noise and
watchdog settings, and thus need to be configurable via DT
properties.

Also default settings to POR defaults on a reset, and register
distuber interrupts as noise since it prevents proper usage.

Cc: devicetree@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:proximity: drop assign iio_info.driver_module and iio_trigger_ops.owner

The equivalent of both of these are now done via macro magic when
the relevant register calls are made. The actual structure
elements will shortly go away.

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

iio: proximity: as3935: fix iio_trigger_poll issue

Using iio_trigger_poll() can oops when multiple interrupts
happen before the first is handled.

Use iio_trigger_poll_chained() instead and use the timestamp
when processed, since it will be in theory be 2 ms max latency.

Fixes: 24ddb0e4bba4 ("iio: Add AS3935 lightning sensor support")
Cc: stable@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: fix AS3935_INT mask

AS3935 interrupt mask has been incorrect so valid lightning events
would never trigger an buffer event. Also noise interrupt should be
BIT(0).

Fixes: 24ddb0e4bba4 ("iio: Add AS3935 lightning sensor support")
CC: stable@vger.kernel.org
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: move storm out of range check

Move out of storm check to apply to IIO_CHAN_INFO_RAW so the reported
results are constant between the former and the IIO_CHAN_INFO_PROCESSED

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

iio: proximity: as3935: recalibrate RCO after resume

According to the datasheet the RCO must be recalibrated
on every power-on-reset. Also remove mutex locking in the
calibration function since callers other than the probe
function (which doesn't need it) will have a lock.

Fixes: 24ddb0e4bba4 ("iio: Add AS3935 lightning sensor support")
Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: fix as3935_write

AS3935_WRITE_DATA macro bit is incorrect and the actual write
sequence is two leading zeros.

Cc: George McCollister <george.mccollister@gmail.com>
Signed-off-by: Matt Ranostay <matt.ranostay@konsulko.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: constify attribute_group structures

Check for attribute_group structures that are only stored in the
attrs filed of iio_info structure. As the attrs field of iio_info
structures is constant, so these attribute_group structures can also be
declared constant.
Done using coccinelle:

@r1 disable optional_qualifier @
identifier i;
position p;
@@
static struct attribute_group i@p = {...};

@ok1@
identifier r1.i;
position p;
struct iio_info x;
@@
x.attrs=&i@p;

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
static
+const
struct attribute_group i={...};

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct attribute_group i;

File size before:
text data bss dec hex filename
4037 288 0 4325 10e5 drivers/iio/proximity/as3935.o

File size after:
text data bss dec hex filename
4101 256 0 4357 1105 drivers/iio/proximity/as3935.o

Signed-off-by: simran singhal <singhalsimran0@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: set up buffer timestamps for non-zero values

Use the iio_pollfunc_store_time parameter during triggered buffer
set-up to get valid timestamps.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Cc: Daniel Baluta <daniel.baluta@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: remove redundant zeroing of tune_cap

This is redundant as the containing stucture is allocated as part of
iio_device_alloc using kzalloc and hence is already 0.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: as3935: improve error reporting in as3935_event_work

gcc warns about a potentially uninitialized variable use
in as3935_event_work:

drivers/iio/proximity/as3935.c: In function ‘as3935_event_work’:
drivers/iio/proximity/as3935.c:231:6: error: ‘val’ may be used uninitialized in this function [-Werror=maybe-uninitialized]

This case specifically happens when spi_w8r8() fails with a
negative return code. We check all other users of this function
except this one.

As the error is rather unlikely to happen after the device
has already been initialized, this just adds a dev_warn().
Another warning already exists in the same function, but is
missing a trailing '\n' character, so I'm fixing that too.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: remove redundant MODULE_ALIAS

MODULE_ALIAS isn't needed since the module name is the same as the alias
defined.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: fix buffer stack trashing

Buffer wasn't of a valid size to allow the timestamp, and correct padding.
This patchset also moves the buffer off the stack, and onto the heap.

Cc: george.mccollister@gmail.com
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: remove triggered buffer processing

Triggered buffers shouldn't return processed data, and the respective
conversion was overflowing the defined .realbits for the channel.

Cc: george.mccollister@gmail.com
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: proximity: as3935: correct IIO_CHAN_INFO_RAW output

IIO_CHAN_INFO_RAW was returning processed data which was incorrect.
This also adds the IIO_CHAN_INFO_SCALE value to convert to a processed value.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

spi: Drop owner assignment from spi_drivers

An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

iio: as3935: Add OF match table

The Documentation/devicetree/bindings/iio/proximity/as3935.txt DT binding
doc lists "ams,as3935" as a compatible string but the corresponding driver
does not have an OF match table. Add the table to the driver so the SPI
core can do an OF style match.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: as3935: Switch to PM ops

Switch from the legacy suspend/resume callbacks to device pm ops.

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

iio: as3935: allocate correct iio_device size

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: as3935: Remove unnecessary semicolons

Signed-off-by: George McCollister <george.mccollister@gmail.com>
Acked-by: Hartmut Knaack <knaack.h@gmx.de>
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: Add AS3935 lightning sensor support

AS3935 chipset can detect lightning strikes and reports those back as
events and the estimated distance to the storm.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>