This change attaches the life-cycle of the kfifo buffer & IRQ to the
parent-device. This in turn cleans up the exit & error paths, since we
don't need to explicitly cleanup these resources.

The main intent here is to remove the explicit cleanup of the
'indio_dev->buffer' via 'iio_kfifo_free(indio_dev->buffer);'.

As we want to add support for multiple buffers per IIO device, having it
exposed like this makes it tricky to consider a safe backwards compatible
approach for it.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change attaches the life-cycle of the channels array to the parent
device object that is attached to the IIO device.
This way we can remove from the cleanup code, the explicit
tiadc_channels_remove() which simply does a kfree() on the channels array.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Whilst it's unlikely this device will ever be instantiated using
ACPI, there is little advantage not assigning the of_device_id table in all
cases and it avoids providing an example that might be coppied into new
drivers.

Also include mod_devicetable.h whilst here as of_device_id is defined
in there so including the header is best practice.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Artur Rojek <contact@artur-rojek.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

These stop us using ACPI PRP0001 to instantiate the device.
I am slowly clearly out use of these in IIO to avoid this being coppied
into new drivers.

Here I also included mod_devicetable.h as we are using of_match_id
which is defined in there and hence it is best practice to include
it directly.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Phil Reid <preid@electromag.com.au>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Dropping this allows use of ACPI PRP0001.

I'm also looking to drop all of_match_ptr use in IIO in order to avoid
it getting cut and paste into new drivers in the future.

Also add a direct include of mod_devicetable.h to reflect the use
of struct of_device_id.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Allows ACPI PRP0001 to be used with this driver.
Also adds mod_devicetable.h header as the driver is directly using
struct of_device_id which is defined in that file.

I'm also trying to clear out of_match_ptr use in IIO to avoid it
being cut and paste into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Mårten Lindahl <martenli@axis.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

These just prevent the driver being used with ACPI PRP0001.

I am also trying to remove these from IIO in general to avoid
them being coppied into new drivers.

Also include the mod_devicetable.h header as we are using
of_device_id which is defined in there.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Whilst this driver already supports explicit ACPI bindings we
might as well also allow for PRP0001 based binding.

I'm also keen to remove of_match_ptr from IIO drivers to avoid
this (now) anti-pattern getting coppied into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Dropping of_match_ptr allows this driver to be used with ACPI.
The header includes are adjusted to include platform_device.h
and mod_devicetable.h instead of OF specific header as nothing
from that header itself is actually used.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

They stop the driver being used with ACPI PRP0001 and are something
I want to avoid being cut and paste into new drivers.
Also switch the include from of.h to mod_devicetable.h as we
struct of_device_id is defined in there and we don't use anything
actually in of.h.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Angelo Compagnucci <angelo.compagnucci@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

These just prevent the driver being used with ACPI PRP0001.
They also get cut and paste into new drivers and we want to discourage
this from happening by cleaning it out in general.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Oskar Andero <oskar.andero@gmail.com>
Cc: Søren Andersen <san@rosetechnology.dk>
Cc: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

These just stop the driver being used with ACPI PRP0001 and
we are trying to clear them out of IIO to avoid them getting copied
into new drivers.
Also add the mod_devicetable.h include as we are using
struct of_device_id which is defined in there.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Allows use of driver with ACPI PRP0001 base binding.
Mostly this is about trying to avoid cut and paste of this into new
drivers (it is a frequent review comment) rather than any
thought that this driver might get used on an ACPI platform.

The mod_devicetable.h include is to encourage best practice of including
any header directly used within the code (here for of_match_id)
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

This prevents the driver being used with ACPI PRP0001 based
bindings. Also switch include to mod_devicetable.h which devices
the used id structure.

Note this is most about removing something I don't want want cut
and paste into new driver rather than any thought that this particular
driver will be used in an ACPI system (though it might!)
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Part of a slow effort to avoid OF specific code in IIO.

Whilst the main advantages of this are not likely to be seen in this
particular driver (ACPI support via PRP0001) the change proposed
does make things a bit more maintainable and also ensures that
this particular (now) anti-patern is less likely to be cut and
paste into new drivers.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

The macro prevents use of driver with ACPI PRP0001 and
the of_match_id structure is defined in mod_devicetable.h so include
that directly rather than of.h.

Note this is mostly about removing something I don't want cut and
paste into new drivers rather than expectation that this particular
driver will be used on an ACPI platform.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

These just prevent the driver being used with ACPI PRP0001
and provide no major benefits.

Part of clearing these out in general in IIO to avoid cut and paste
repetition in new drivers.  Also include mod_devicetable.h as we
directly make use of of_device_id which is defined in there.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Philippe Reynes <tremyfr@yahoo.fr>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Allows driver to use ACPI PRP0001 binding and there was no particular
advantage in having the protections in this driver.

Mostly this part of an effort to remove as many OF specific bits
of handling from IIO and use the generic forms where possible.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Allows use of ACPI with PRP0001 and is generally something we are
trying to avoid having people cut and paste into new drivers without
thinking about it.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

I guess this is a left over from some earlier cleanup. Not used
currently.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

Whilst is unlikely anyone will be using this part with an ACPI PRP0001
based binding any time soon, we are getting a lot of cut and pasting
of this pattern so I am looking to remove it entirely from IIO.

In this case CONFIG_OF protections also removed and
mod_devicetable.h include added given direct use of struct of_device_id.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

The compatible for BMM150 should not have "_magn" suffix because, unlike
two other Bosch devices, it is only a magnetometer.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The driver supports also BMC156B and BMM150B.  Add existing compatibles
marking the BMM150B one as deprecated (due to redundant suffix "_magn"
because the device unlike two others is a magnetometer only).  Introduce
a new, proper compatible for the deprecated one.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

The value retrieved by `irqd_get_trigger_type()` is not an irq flag.
While the values are the same, the meaning is different.
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Drop the doubled word "struct".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: William Breathitt Gray <vilhelm.gray@gmail.com>
Cc: linux-iio@vger.kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Drop the doubled word "the".
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: linux-iio@vger.kernel.org
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Same as with other private fields, this moves the event interface reference
to the opaque IIO device object, to be invisible to drivers.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change moves the 'buffer_list' away from the public IIO device object
into the private part.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change bit straightforward and simple, since the
'channel_attr_list' & 'chan_attr_group' fields are only used in
'industrialio-core.c'.

This change moves to the private IIO device object
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

This change moves all iio_dev debugfs fields to the iio_dev_priv object.
It's not the biggest advantage yet (to the whole thing of abstractization)
but it's a start.

The iio_get_debugfs_dentry() function (which is moved in
industrialio-core.c) needs to also be guarded against the CONFIG_DEBUG_FS
symbol, when it isn't defined. We do want to keep the inline definition in
the iio.h header, so that the compiler can better infer when to compile out
debugfs code that is related to the IIO debugfs directory.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

There was a recent discussion about this code:
  https://lore.kernel.org/linux-iio/20200322165317.0b1f0674@archlinux/

This looks like a good time to removed this, since any issues about it
should pop-up under testing, because the iio_dev is having a bit of an
overhaul and stuff being moved to iio_dev_opaque.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

There are plenty of bad designs we want to discourage or not have to review
manually usually about accessing private (marked as [INTERN]) fields of
'struct iio_dev'.

Sometimes users copy drivers that are not always the best examples.

A better idea is to hide those fields into the framework.
For 'struct iio_dev' this is a 'struct iio_dev_opaque' which wraps a public
'struct iio_dev' object.

In the next series, some fields will be moved to this new struct, each with
it's own rework.

This rework will not be complete-able for a while, as many fields need some
drivers to be reworked in order to finalize them (e.g. 'indio_dev->mlock').

But some fields can already be moved, and in time, all of them may get
there (in the 'struct iio_dev_opaque' object).

Since a lot of drivers also call 'iio_priv()', in order to preserve
fast-paths (where this matters), the public iio_dev object will have a
'priv' field that will have the pointer to the private information already
computed. The reference returned by this field should be guaranteed to be
cacheline aligned.

The opaque parts will be moved into the 'include/linux/iio/iio-opaque.h'
header. Should the hidden information be required for some debugging or
some special needs, it can be made available via this header.
Otherwise, only the IIO core files should include this file.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

We may want to get rid of the iio_priv_to_dev() helper. The reason is that
we will hide some of the members of the iio_dev structure (to prevent
drivers from accessing them directly), and that will also mean hiding the
implementation of the iio_priv_to_dev() helper inside the IIO core.

Hiding the implementation of iio_priv_to_dev() implies that some fast-paths
may not be fast anymore, so a general idea is to try to get rid of the
iio_priv_to_dev() altogether.
The iio_priv() helper won't be affected by the rework, as the iio_dev
struct will keep a reference to the private information.

For this driver, not using iio_priv_to_dev(), means reworking some paths to
pass the iio device and using iio_priv() to access the private information,
and also keeping a reference to the iio device for some quirky paths.

One [quirky] path is the at91_adc_workq_handler() which requires the IIO
device & the state struct to push to buffers.
Since this requires the back-ref to the IIO device, the
at91_adc_touch_pos() also uses it. This simplifies the patch a bit. The
information required in this function is mostly for debugging purposes.
Replacing it with a reference to the IIO device would have been a slightly
bigger change, which may not be worth it (for just the debugging purpose
and given that we need the back-ref to the IIO device anyway).
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add SCD30 sensor binding file.
Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add serial interface driver for the SCD30 sensor.
Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add I2C interface driver for the SCD30 sensor.
Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add Sensirion SCD30 carbon dioxide core driver.
Signed-off-by: Tomasz Duszynski <tomasz.duszynski@octakon.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add MAINTAINERS entry for InvenSense ICM-426xx IMU device.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Document the ICM-426xxx devices devicetree bindings.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Add a timestamping mechanism for buffer that provides accurate
event timestamps when using watermark. This mechanism estimates
device internal clock by comparing FIFO interrupts delta time and
device elapsed time computed by parsing FIFO data.

Take interrupt timestamp in hard irq handler and add IIO device
specific timestamp structures in device private allocation.
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>