iio: adc: lpc18xx: Benefit from devm_clk_get_enabled() to simplify

Make use of devm_clk_get_enabled() to replace some code that effectively
open codes this new function.

Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20220808204740.307667-5-u.kleine-koenig@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: lpc18xx_adc: Switch from of headers to mod_devicetable.h

There is nothing directly using of specific interfaces in this driver,
so lets not include the headers.

While at it, drop dependency to OF, which currently makes no sense.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220531212218.72189-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: lpc18xx_adc: Reorder clk_get_rate() function call

clk_get_rate() is not guaranteed to work if called before
clk_prepare_enable().

Reorder clk_get_rate(), so it's called after clk_prepare_enable() and
after devm_add_action_or_reset() of lpc18xx_clk_disable().

Not that this is not a problem on this particular device, but it is
good to remove a case that might get copied elsewhere.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>
Link: https://lore.kernel.org/r/YXag5l4xBkGQH3tq@Andryuu.br
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: lpc18xx_adc: Make use of the helper function dev_err_probe()

When possible use dev_err_probe help to properly deal with the
PROBE_DEFER error, the benefit is that DEFER issue will be logged
in the devices_deferred debugfs file.
Using dev_err_probe() can reduce code size, and the error value
gets printed.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20211008092858.495-3-caihuoqing@baidu.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: lpc18xx_adc: Convert probe to device managed version

The remove function and the goto sections are not necessary if devm
functions are used.

Convert device register to devm version. Add hook functions to release
device resources, and use them inside probe with devm_add_action,
which will release resources on driver detach.

To maintain the order of which device resources were released/reseted,
register the hook functions as soon as resources are obtained/initialized.
Since devres actions are called on driver detach, the remove
function and the error-handling goto sections are no longer necessary.

Signed-off-by: André Gustavo Nakagomi Lopez <andregnl@usp.br>
Link: https://lore.kernel.org/r/YWnMsGlc/I35gYvy@Andryuu.br
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: lpc18xx: use devm_platform_ioremap_resource

Avoid local boilerplate.
Identified by coccinelle

CHECK drivers/iio/adc/lpc18xx_adc.c
drivers/iio/adc/lpc18xx_adc.c:137:1-10: WARNING: Use devm_platform_ioremap_resource for adc -> base

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Joachim Eastwood <manabian@gmail.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: 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 NXP LPC18xx ADC driver

Add base support for the 10-bit SAR ADC peripheral found
on NXP LPC18xx/43xx SoCs.

This is a minimal driver that does not support burst mode,
interrupts, DMA or hardware triggers.

User manual with register description can be found on:
LPC18xx: www.nxp.com/documents/user_manual/UM10430.pdf
LPC43xx: www.nxp.com/documents/user_manual/UM10503.pdf

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>