iio: adc: axp20x: Convert to platform remove callback returning void

The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230919174931.1417681-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: Replace adc_en2 flag with adc_en2_mask field

The adc_en2 flag is essentially specific to axp20x-compatible devices
because it hardcodes register values. Replace it with a mask field
so the register value can be specified in device match data.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20230217153404.32481-2-aidanmacdonald.0x0@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: Minor code cleanups

The code may be clearer if parameters are not re-purposed to hold
temporary results like register values, so introduce local variables
as necessary to avoid that. Regroup macros based on chip type, and
use the FIELD_PREP() macro instead of a hand-rolled version.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Link: https://lore.kernel.org/r/20230217153404.32481-1-aidanmacdonald.0x0@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:axp20x: add support for NTC thermistor

Most AXPxxx-based reference designs place a 10k NTC thermistor on a
TS pin. When appropriately configured, AXP PMICs will inject fixed
current (80uA by default) into TS pin and measure the voltage across a
thermistor. The PMIC itself will by default compare this voltage with
predefined thresholds and disable battery charging whenever
the battery is too hot or too cold.

Alternatively, the TS pin can be configured as general-purpose
ADC input. This mode is not supported by the driver.

This patch allows reading the voltage on the TS pin. It can be then
either processed by userspace or used by kernel consumer like hwmon
ntc thermistor driver.

Signed-off-by: Evgeny Boger <boger@wirenboard.com>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Quentin Schulz <foss+kernel@0leil.net>
Link: https://lore.kernel.org/r/20211118141233.247907-2-boger@wirenboard.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: fix charging current reporting on AXP22x

Both the charging and discharging currents on AXP22x are stored as
12-bit integers, in accordance with the datasheet.
It's also confirmed by vendor BSP (axp20x_adc.c:axp22_icharge_to_mA).

The scale factor of 0.5 is never mentioned in datasheet, nor in the
vendor source code. I think it was here to compensate for
erroneous addition bit in register width.

Tested on custom A40i+AXP221s board with external ammeter as
a reference.

Fixes: 0e34d5de961d ("iio: adc: add support for X-Powers AXP20X and AXP22X PMICs ADCs")
Signed-off-by: Evgeny Boger <boger@wirenboard.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20211116213746.264378-1-boger@wirenboard.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:axp20x: Convert from OF to generic fw / device properties

Whilst fairly unlikely anyone will ever use this driver with anything
other than DT, we are trying to move IIO over to the generic interfaces
where easy to do so.

In this case this involved moving to generic check on presence
of fwnode, generic device_get_match_data() and dropping the of_match_ptr
protection. Also relevant header changes to have property.h and
mod_devicetable.h only.

Also drop the casting away of a const in favour of retaining
the const throughout.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Quentin Schulz <quentin.schulz@bootlin.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>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio: adc: axp20x_adc: remove !! in favor of ternary condition

!!'s behaviour isn't that obvious and sparse complained about it, so
let's replace it with a ternary condition.

Signed-off-by: Quentin Schulz <quentin.schulz@bootlin.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: add support for AXP813 ADC

The X-Powers AXP813 PMIC is really close to what is already done for
AXP20X/AXP22X.

There are two pairs of bits to set the rate (one for Voltage and Current
measurements and one for TS/GPIO0 voltage measurements) instead of one.

The register to set the ADC rates is different from the one for
AXP20X/AXP22X.

GPIO0 can be used as an ADC (measuring Volts) unlike for AXP22X.

The scales to apply to the different inputs are unlike the ones from
AXP20X and AXP22X.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: make it possible to probe from DT

To prepare for a future patch that will add a DT node for the ADC, make
axp20x_adc able to probe from DT and get the per-variant data from
of_device_id.data since platform_device_id.driver_data won't be set when
probing by DT.

Leave the ability to probe via platform for driver compatibility with
old DTs.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: axp20x_adc: put ADC rate setting in a per-variant function

To prepare for a new comer that set a different register with different
values, move rate setting in a function that is specific to each AXP
variant.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.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: add support for X-Powers AXP20X and AXP22X PMICs ADCs

The X-Powers AXP20X and AXP22X PMICs have multiple ADCs. They expose the
battery voltage, battery charge and discharge currents, AC-in and VBUS
voltages and currents, 2 GPIOs muxable in ADC mode and PMIC temperature.

This adds support for most of AXP20X and AXP22X ADCs.

Signed-off-by: Quentin Schulz <quentin.schulz@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>