iio: adc: mcp3911: simplify code with guard macro

Use the guard(mutex) macro for handle mutex lock/unlocks.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20231206-mcp3911-guard-v4-1-30c3c5d4340f@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: add support for the whole MCP39xx family

Microchip does have many similar chips, add support for those.

The new supported chips are:
- microchip,mcp3910
- microchip,mcp3912
- microchip,mcp3913
- microchip,mcp3914
- microchip,mcp3918
- microchip,mcp3919

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230822192259.1125792-7-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: avoid ambiguity parameters in macros

Name macro parameters after what they represent instead of 'x'
and make sure the evaluation of that will have no side effects.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20230822192259.1125792-6-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: fix indentation

The whole file does not make use of indentation properly.
Do something about it.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20230822192259.1125792-5-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: simplify usage of spi->dev

Replace the usage of `adc->spi->dev` with `dev` to make the code prettier.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20230822192259.1125792-4-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: make use of dev_err_probe()

Simplify code by switch to dev_err_probe().

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20230822192259.1125792-3-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: add support to set PGA

Add support for setting the Programmable Gain Amplifiers by adjust the
scale value.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220922194639.1118971-1-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: mask out device ID in debug prints

The Device ID should not be included when printing register.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20221010194654.676525-1-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: use correct id bits

The device ID should be shifted 6 bits to left according to datasheet.

Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20221010194641.676484-1-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: return proper error code on failure to allocate trigger

smatch warnings:
drivers/iio/adc/mcp3911.c:441 mcp3911_probe() warn: passing zero to 'PTR_ERR'

Fixes: 08a65f61db69 ("iio: adc: mcp3911: add support for interrupts")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20220927092537.94663-1-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: fix sizeof() vs ARRAY_SIZE() bug

This code uses sizeof() instead of ARRAY_SIZE() so it reads beyond the
end of the mcp3911_osr_table[] array.

Fixes: 6d965885f4ea ("iio: adc: mcp3911: add support for oversampling ratio")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/YzFsjY3xLHUQMjVr@kili
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: add support for oversampling ratio

The chip supports oversampling ratio, so expose it to userspace.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220815061625.35568-9-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: add support for interrupts

Make it possible to read values upon interrupts.
Configure Data Ready Signal Output Pin to either HiZ or push-pull and
use it as interrupt source.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220815061625.35568-7-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: add support for buffers

Add support for buffers to make the driver fit for more use cases.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220815061625.35568-6-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: use resource-managed version of iio_device_register

Keep using managed resources as much as possible.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220815061625.35568-5-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: use correct formula for AD conversion

The ADC conversion is actually not rail-to-rail but with a factor 1.5.
Make use of this factor when calculating actual voltage.

Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220722130726.7627-4-marcus.folkesson@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: correct "microchip,device-addr" property

Go for the right property name that is documented in the bindings.

Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220722130726.7627-3-marcus.folkesson@gmail.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: mcp3911: make use of the sign bit

The device supports negative values as well.

Fixes: 3a89b289df5d ("iio: adc: add support for mcp3911")
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220722130726.7627-2-marcus.folkesson@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

spi: make remove callback a void function

The value returned by an spi driver's remove function is mostly ignored.
(Only an error message is printed if the value is non-zero that the
error is ignored.)

So change the prototype of the remove function to return no value. This
way driver authors are not tempted to assume that passing an error to
the upper layer is a good idea. All drivers are adapted accordingly.
There is no intended change of behaviour, all callbacks were prepared to
return 0 before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Claudius Heine <ch@denx.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Acked-by: Łukasz Stelmach <l.stelmach@samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20220123175201.34839-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>

iio:adc:mcp3911: Switch to generic firmware properties.

This allows use of the driver with other types of firmware such as ACPI
PRP0001 based probing.

Also part of a general attempt to remove direct use of of_ specific
accessors from IIO.

Added an include for mod_devicetable.h whilst here to cover the
struct of_device_id definition.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Kent Gustavsson <kent@minoris.se>
Reviewed-by: Marcus Folkesson <marcus.folkesson@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 left-over parent assignments

These were found by doing some shell magic:
------------
for file in $(git grep -w devm_iio_device_alloc | cut -d: -f1 | sort | uniq) ; do
if grep 'parent =' $file | grep -v trig | grep -vq devm_; then
echo "$file -> $(grep "parent =" $file)"
fi
done
-----------

The output is bearable [after the semantic patch is applied].
There is a mix of trigger assignments with some iio device parent
assignments that are removed via this patch.

JC: A few more added via inspection of all parent =
statements in drivers/iio. Some of these may just have crossed with this
series, others were less obvious to scripting due to some cross
file / module boundary calls.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: add support for mcp3911

MCP3911 is a dual channel Analog Front End (AFE) containing two
synchronous sampling delta-sigma Analog-to-Digital Converters (ADC).

Co-developed-by: Kent Gustavsson <kent@minoris.se>
Signed-off-by: Kent Gustavsson <kent@minoris.se>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>