iio: adc: ad7292: Add explicit include for of.h

With linux/acpi.h no longer implicitly including of.h, add an explicit
include of of.h to fix the following error:

drivers/iio/adc/ad7292.c:307:9: error: implicit declaration of function 'for_each_available_child_of_node'; did you mean 'fwnode_for_each_available_child_node'? [-Werror=implicit-function-declaration]

Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

iio: ad7292: Prevent regulator double disable

The ad7292 tries to add an devm_action for disabling a regulator at
device detach using devm_add_action_or_reset(). The
devm_add_action_or_reset() does call the release function should adding
action fail. The driver inspects the value returned by
devm_add_action_or_reset() and manually calls regulator_disable() if
adding the action has failed. This leads to double disable and messes
the enable count for regulator.

Do not manually call disable if devm_add_action_or_reset() fails.

Fixes: 506d2e317a0a ("iio: adc: Add driver support for AD7292")
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/Yv9O+9sxU7gAv3vM@fedora
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7292: 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: 506d2e317a0a ("iio: adc: Add driver support for AD7292")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-12-jic23@kernel.org

iio: adc: ad7292: Modify the bool initialization assignment

A bool initializer is best assigned to false rather than 0.

Signed-off-by: Guoqing Chi <chiguoqing@yulong.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20210319062706.5135-1-chi962464zy@163.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7292: remove unneeded spi_set_drvdata()

This seems to have been copied from a driver that calls spi_set_drvdata()
but doesn't call spi_get_drvdata().
Setting a private object on the SPI device's object isn't necessary if it
won't be accessed.
This change removes the spi_set_drvdata() call.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Tested-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Reviewed-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Link: https://lore.kernel.org/r/20201119142720.86326-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: ad7292: Fix of_node refcounting

When returning or breaking early from a
`for_each_available_child_of_node()` loop, we need to explicitly call
`of_node_put()` on the child node to possibly release the node.

Fixes: 506d2e317a0a0 ("iio: adc: Add driver support for AD7292")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200925091045.302-2-nuno.sa@analog.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: adc: ad9292: Use new structure for SPI transfer delays

In a recent change to the SPI subsystem [1], a new `delay` struct was added
to replace the `delay_usecs`. This change replaces the current
`delay_usecs` with `delay` for this driver.

The `spi_transfer_delay_exec()` function [in the SPI framework] makes sure
that both `delay_usecs` & `delay` are used (in this order to preserve
backwards compatibility).

[1] commit bebcfd272df6 ("spi: introduce `delay` field for
`spi_transfer` + spi_transfer_delay_exec()")

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: Add driver support for AD7292

The AD7292 is a 10-bit monitor and control system with ADC, DACs,
temperature sensor, and GPIOs.

Configure AD7292 devices in direct access mode, enabling single-ended
ADC readings.

Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf

Signed-off-by: Marcelo Schmitt <marcelo.schmitt1@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>