iio: adc: ti-adc161s626: 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: 4d671b71beef ("iio: adc: ti-adc161s626: add support for TI 1-channel differential ADCs")
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/20220508175712.647246-34-jic23@kernel.org

iio: adc: ti-adc161s626: Use devm managed functions for all of probe.

Simplifies error handling and allows us to drop remove entirely.

The regulator handling in this driver was unusual as it would try to
acquire the regulator, but if that failed with an error would continue.

We should get a stub regulator if one isn't provided in DT and an error
could indicate an actual problem preventing the device being powered
(perhaps a need to defer). So this handling is cleaned up (arguably
that might be a fix but given no one has run into it, I haven't broken
it out separately.

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: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210516172520.1398835-9-jic23@kernel.org

iio:adc:ti-adc161s626: Drop of_match_ptr protection.

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>

iio: Remove superfluous of_node assignments

If a driver does not assign an of_node to a IIO device to IIO core will
automatically assign the of_node of the parent device. This automatic
assignment is done in the iio_device_register() function.

There is a fair amount of drivers that currently manually assign the
of_node of the IIO device. All but 4 of them can make use of the automatic
assignment though.

The exceptions are:
* mxs-lradc-adc: Which uses the of_node of the parent of the parent.
* stm32-dfsdm-adc, stm32-adc and stm32-dac: Which reference the of_node
assigned to the IIO device before iio_device_register() is called.

All other drivers are updated to use automatic assignment. This reduces
the amount of boilerplate code involved in setting up the IIO device.

The patch has mostly been auto-generated with the following semantic patch

// <smpl>
@exists@
expression indio_dev;
expression parent;
@@
indio_dev = \(devm_iio_device_alloc\|iio_device_alloc\)(&parent, ...)
...
-indio_dev->dev.of_node = parent.of_node;

@exists@
expression indio_dev;
expression parent;
@@
indio_dev = \(devm_iio_device_alloc\|iio_device_alloc\)(parent, ...)
...
-indio_dev->dev.of_node = parent->of_node;
// </smpl>

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

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: 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:adc: 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: adc: ti-adc161s626: add regulator support

Allow IIO_CHAN_INFO_SCALE and IIO_CHAN_INFO_OFFSET attributes for
processing by checking voltage from a regulator.

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

iio: adc: ti-adc161s626: add support for TI 1-channel differential ADCs

Add support for Texas Instruments ADC141S626, and ADC161S626 chips.

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