iio: adc: fsl-imx25-gcq: 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/20230919174931.1417681-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: fsl-imx25-gcq: initialize regulators as needed

The driver tries to initialize all possible regulators from the DT, then
match the external regulators with each channel and then release all unused
regulators.

We can change the logic a bit to initialize regulators only when at least
one channel needs them.

This change creates a mx25_gcq_ext_regulator_setup() function that is
called only for the external regulators. If there's already a reference to
an external regulator, the function will just exit early with no error.

This way, the driver doesn't need to keep any track of these regulators
during init.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210625074325.9237-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: fsl-imx25-gcq: adjust irq check to match docs and simplify code

For the function of platform_get_irq(), the example in platform.c is
* int irq = platform_get_irq(pdev, 0);
* if (irq < 0)
* return irq;
the return value of zero is unnecessary to check, so make the right
check and simplify code.

Note that platform_get_irq() is documented as never returning 0
so this is a minor optmization rather than a fix.

Co-developed-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20210802120929.33760-1-tangbin@cmss.chinamobile.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: fsl-imx25-gcq: Use the defined variable to clean code

Use the defined variable "dev" to make the code cleaner.

Co-developed-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20210720125945.11548-1-tangbin@cmss.chinamobile.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: fsl-imx25-gcq: Replace indio_dev->mlock with own device lock

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock, to protect against any other accesses during the
reading of sample. Reading a sample requires multiple consecutive regmap
operations and a completion callback, so this requires that no other
read occurs until it completes.

This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/

Signed-off-by: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20200916092928.78026-1-alexandru.ardelean@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: fsl-imx25-gcq: Use devm_platform_ioremap_resource

Use the helper function that wraps the calls to
platform_get_resource() and devm_ioremap_resource()
together. It reduces boilerplate and suggested by coccinelle.

Signed-off-by: Aishwarya Ramakrishnan <aishwaryarj100@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Remove dev_err() usage after platform_get_irq()

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@pmeerw.net>
Cc: linux-iio@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
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: imx25-gcq: Fix leak of device_node in mx25_gcq_setup_cfgs()

Leaving for_each_child_of_node loop we should release child device node,
if it is not stored for future use.

Found by Linux Driver Verification project (linuxtesting.org).

JC: I'm not sending this as a quick fix as it's been wrong for years,
but good to pick up for stable after the merge window.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 6df2e98c3ea56 ("iio: adc: Add imx25-gcq ADC driver")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: imx25-gcq: Fix module autoload

If the driver is built as a module, autoload won't work because the module
alias information is not filled. So user-space can't match the registered
device with the corresponding module.

Export the module alias information using the MODULE_DEVICE_TABLE() macro.

Before this patch:

$ modinfo drivers/iio/adc/fsl-imx25-gcq.ko | grep alias
$

After this patch:

$ modinfo drivers/iio/adc/fsl-imx25-gcq.ko | grep alias
alias: of:N*T*Cfsl,imx25-gcqC*
alias: of:N*T*Cfsl,imx25-gcq

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc/imx25-gcq: Move incorrect do_div

The newly added driver uses do_div() to device a 32-bit number, which now
provokes a warning:

drivers/iio/adc/fsl-imx25-gcq.c: In function 'mx25_gcq_setup_cfgs':
include/asm-generic/div64.h:207:28: warning: comparison of distinct pointer types lacks a cast
(void)(((typeof((n)) *)0) == ((uint64_t *)0)); \

This replaces the do_div() call with a straight division operator.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 6df2e98c3ea5 ("iio: adc: Add imx25-gcq ADC driver")
Signed-off-by: Lee Jones <lee.jones@linaro.org>

iio: adc: Add imx25-gcq ADC driver

This is a conversion queue driver for the mx25 SoC. It uses the central
ADC which is used by two seperate independent queues. This driver
prepares different conversion configurations for each possible input.
For a conversion it creates a conversionqueue of one item with the
correct configuration for the chosen channel. It then executes the queue
once and disables the conversion queue afterwards.

The reference voltages are configurable through devicetree subnodes,
depending on the connections of the ADC inputs.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Denis Carikli <denis@eukrea.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>