iio: adc: rn5t618: Re-use generic struct u16_fract

Instead of custom data type re-use generic struct u16_fract.
No changes intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220126135353.24007-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: rn5t618-adc: use devm_iio_map_array_register() function

This driver already hooks a similar unwind callback via
devm_add_action_or_reset().

They pretty much do the same thing, so this change converts it to the
devm_iio_map_array_register().

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Reviewed-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/20210926162859.3567685-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: rn5t618: Add iio map

Add iio map to allow power driver to read out values as a consumer.
This approach does not block later addition of devicetree support
which would be helpful if there is an in-kernel consumer for AIN0/1.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.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: rn5t618: Add ADC driver for RN5T618/RC5T619

Both chips have an A/D converter capable of measuring
things like VBAT, VUSB and analog inputs.

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>