iio: adc: ad7192: Add fast settling support

Add fast settling mode support for AD7193.

Add two new device specific attributes: oversampling_ratio and
oversampling_ratio_available.

For AD7193 the user can set the average factor by writing to
oversampling_ratio. The possible values are exposed when reading
oversampling_ratio_available.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20231010124927.143343-4-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Remove unused member

Remove extend_name from channel macro since it is not used anywhere.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20231010124927.143343-3-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Organize chip info

Move all chip specific data into chip_info structure.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20231010124927.143343-2-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Improve f_order computation

Instead of using the f_order member of ad7192_state, a function that
computes the f_order coefficient makes more sense. This coefficient is a
function of the sinc filter and chop filter states.

Remove f_order member of ad7192_state structure. Instead use
ad7192_compute_f_order function to compute the f_order coefficient
according to the sinc filter and chop filter states passed as
parameters.

Add ad7192_get_f_order function that returns the current f_order
coefficient of the device.

Add ad7192_compute_f_adc function that computes the f_adc value
according to the sinc filter and chop filter states passed as
parameters.

Add ad7192_get_f_adc function that returns the current f_adc value of
the device.

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20230924215148.102491-3-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Use bitfield access macros

Include bitfield.h and update driver to use bitfield access macros GENMASK,
FIELD_PREP and FIELD_GET.

Remove old macros in favor of using FIELD_PREP and masks.

Change %d to %ld to match the type of FIELD_GET().

Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Link: https://lore.kernel.org/r/20230924215148.102491-2-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Correct reference voltage

The avdd and the reference voltage are two different sources but the
reference voltage was assigned according to the avdd supply.

Add vref regulator structure and set the reference voltage according to
the vref supply from the devicetree.

In case vref supply is missing, reference voltage is set according to
the avdd supply for compatibility with old devicetrees.

Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging")
Signed-off-by: Alisa-Dariana Roman <alisa.roman@analog.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230924152149.41884-1-alisadariana@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20230714174628.4057920-1-robh@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Use sysfs_emit_at

Replace scnprintf with sysfs_emit_at which is the preferred alternative.

Also make sure each fractional digit is in its place by padding with
zeros up to 3 digits: "...%03d...".

Signed-off-by: Alisa Roman <alisa.roman@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230620163135.93780-1-alisa.roman@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adi: ad7192: Add error check and more debug log

Print read and expected device ID as debug warning.
Add error check for ad_sd_init() result.

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: Markus Burri <markus.burri@mt.com>
Link: https://lore.kernel.org/r/20230614073033.2497318-1-markus.burri@mt.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Simplify using devm_clk_get_optional_enabled()

If st->mclk is not NULL, then st->clock_sel is either AD7192_CLK_EXT_MCLK2
or AD7192_CLK_EXT_MCLK1_2.

So devm_clk_get_optional_enabled() can be used instead of hand writing it.
This saves some line of code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/7dbe973905f1fdae5d2f5ae5a3b01dd1d6a9925b.1686774340.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Fix ac excitation feature

AC excitation enable feature exposed to user on AD7192, allowing a bit
which should be 0 to be set. This feature is specific only to AD7195. AC
excitation attribute moved accordingly.

In the AD7195 documentation, the AC excitation enable bit is on position
22 in the Configuration register. ACX macro changed to match correct
register and bit.

Note that the fix tag is for the commit that moved the driver out of
staging.

Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging")
Signed-off-by: Alisa Roman <alisa.roman@analog.com>
Cc: stable@vger.kernel.org
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230614155242.160296-1-alisa.roman@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Fix internal/external clock selection

Fix wrong selection of internal clock when mclk is defined.

Resolve a logical inversion introduced in c9ec2cb328e3.

Fixes: c9ec2cb328e3 ("iio: adc: ad7192: use devm_clk_get_optional() for mclk")
Signed-off-by: Fabrizio Lamarque <fl.scratchpad@gmail.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230530075311.400686-3-fl.scratchpad@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Fix null ad7192_state pointer access

Pointer to indio_dev structure is obtained via spi_get_drvdata() at
the beginning of function ad7192_setup(), but the spi->dev->driver_data
member is not initialized, hence a NULL pointer is returned.

Fix by changing ad7192_setup() signature to take pointer to struct
iio_dev, and get ad7192_state pointer via st = iio_priv(indio_dev);

Fixes: bd5dcdeb3fd0 ("iio: adc: ad7192: convert to device-managed functions")
Signed-off-by: Fabrizio Lamarque <fl.scratchpad@gmail.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20230530075311.400686-2-fl.scratchpad@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Change "shorted" channels to differential

The AD7192 provides a specific channel configuration where both negative
and positive inputs are connected to AIN2. This was represented in the
ad7192 driver as a IIO channel with .channel = 2 and .extended_name set
to "shorted".

The problem with this approach, is that the driver provided two IIO
channels with the identifier .channel = 2; one "shorted" and the other
not. This goes against the IIO ABI, as a channel identifier should be
unique.

Address this issue by changing "shorted" channels to being differential
instead, with channel 2 vs. itself, as we're actually measuring AIN2 vs.
itself.

Note that the fix tag is for the commit that moved the driver out of
staging. The bug existed before that, but backporting would become very
complex further down and unlikely to happen.

Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Co-developed-by: Alisa Roman <alisa.roman@analog.com>
Signed-off-by: Alisa Roman <alisa.roman@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230330102100.17590-1-paul@crapouillou.net
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Simplify using devm_regulator_get_enable()

Use devm_regulator_get_enable() instead of open coded get, enable,
add-action-to-disable-at-detach - pattern. Also drop the seemingly unused
struct member 'dvdd'.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/9719c445c095d3d308e2fc9f4f93294f5806c41c.1660934107.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Silence no spi_device_id warnings

SPI devices use the spi_device_id for module autoloading even on
systems using device tree, after commit 5fa6863ba692 ("spi: Check
we have a spi_device_id for each DT compatible"), kernel warns as
follows since the spi_device_id is missing:

SPI driver ad7192 has no spi_device_id for adi,ad7190
SPI driver ad7192 has no spi_device_id for adi,ad7193
SPI driver ad7192 has no spi_device_id for adi,ad7195

Add spi_device_id entries to silence the warnings, and ensure driver
module autoloading works.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Link: https://lore.kernel.org/r/20220921163620.805879-5-weiyongjun@huaweicloud.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Replace strtobool() with kstrtobool()

strtobool() is deprecated and just a wrapper around kstrtobool().Replace
it with kstrtobool() so the deprecated function can be removed eventually.

Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220409105812.2113895-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: add sequencer support

Add sequencer support for AD7192.

Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Link: https://lore.kernel.org/r/20220322105029.86389-7-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Add update_scan_mode

The callback .set_channel cannot be used to enable multiple
channels at once, only one is allowed simultaneously.

By adding an update_scan_mode callback, every time the
continuous mode is activated, channels will be enabled/disabled
accordingly.

Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Link: https://lore.kernel.org/r/20220322105029.86389-4-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ad_sigma_delta: Move exports into IIO_AD_SIGMA_DELTA namespace

In order to avoid unnecessary pollution of the global symbol namespace
move the core/library functions into a specific namespace and import
that into the various specific device drivers that use them.

For more information see https://lwn.net/Articles/760045/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Renato Lui Geh <renatogeh@gmail.com>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20220130205701.334592-2-jic23@kernel.org

iio: ad7192: Use sysfs_emit()

sysfs_emit() is preferred over raw s*printf() for sysfs attributes since it
knows about the sysfs buffer specifics and has some built-in checks for
size and alignment.

Use sysfs_emit() to format the custom `ac_excitation` and `bridge_swtich`
attributes of the ad7192 driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20211216185217.1054495-4-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: expose shared parameter in IIO_ENUM_AVAILABLE

The shared parameter should be configurable based on its usage, and not
constrained to IIO_SHARED_BY_TYPE.

This patch aims to improve the flexibility in using the
IIO_ENUM_AVAILABLE define and avoid redefining custom iio enums that
expose the shared parameter.

An example is the ad5766.c driver where IIO_ENUM_AVAILABLE_SHARED was
defined in order to achieve `shared` parameter customization.

The current state of the IIO_ENUM_AVAILABLE implementation will imply
similar redefinitions each time a driver will require access to the
`shared` parameter. An example would be admv1013 driver which will
require custom device attribute for the frequency translation modes:
Quadrature I/Q mode and Intermediate Frequency mode.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20211119085627.6348-1-antoniu.miclaus@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: Add IRQ flag

IRQ type in ad_sigma_delta_info struct was missing.

In Sigma-Delta devices the SDO line is also used as an interrupt.
Leaving IRQ on level instead of falling might trigger a sample read
when the IRQ is enabled, as the SDO line is already low. Not sure
if SDO line will always immediately go high in ad_sd_buffer_postenable
before the IRQ is enabled.

Also the datasheet seem to explicitly say the falling edge of the SDO
should be used as an interrupt:
>From the AD7192 datasheet: "The DOUT/RDY falling edge can be used
as an interrupt to a processor,"

Fixes: da4d3d6bb9f6 ("iio: adc: ad-sigma-delta: Allow custom IRQ flags")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210906065630.16325-2-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: convert to device-managed functions

With the devm_ad_sd_setup_buffer_and_trigger() helper, it's a bit easier
now to convert the probe of the AD7192 driver to use device-managed
functions.

The regulators and the mclk requires devm_add_action_or_reset() callbacks
though.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210513120752.90074-11-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: use devm_clk_get_optional() for mclk

The devm_clk_get_optional() helper returns NULL when devm_clk_get() returns
-ENOENT.
This makes things slightly cleaner. The added benefit is mostly cosmetic.

Also, a minor detail with this call, is that the reference for the parent
device is taken as `spi->dev` instead of `&st->sd.spi->dev` (which looks a
little quirky).

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210513120752.90074-10-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7192: handle regulator voltage error first

This change fixes a corner-case, where for a zero regulator value, the
driver would exit early, initializing the driver only partially.
The driver would be in an unknown state.

This change reworks the code to check regulator_voltage() return value
for negative (error) first, and return early. This is the more common
idiom.

Also, this change is removing the 'voltage_uv' variable and using the 'ret'
value directly. The only place where 'voltage_uv' is being used is to
compute the internal reference voltage, and the type of this variable is
'int' (same are for 'ret'). Using only 'ret' avoids having to assign it on
the error path.

Fixes: ab0afa65bbc7 ("staging: iio: adc: ad7192: fail probe on get_voltage")
Cc: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: <Stable@vger.kernel.org>

iio: adc: ad7192: Avoid disabling a clock that was never enabled.

Found by inspection.

If the internal clock source is being used, the driver doesn't
call clk_prepare_enable() and as such we should not call
clk_disable_unprepare()

Use the same condition to protect the disable path as is used
on the enable one. Note this will all get simplified when
the driver moves over to a full devm_ flow, but that would make
backporting the fix harder.

Fix obviously predates move out of staging, but backporting will
become more complex (and is unlikely to happen), hence that patch
is given in the fixes tag.

Alexandru's sign off is here because he added this patch into
a larger series that Jonathan then applied.

Fixes: b581f748cce0 ("staging: iio: adc: ad7192: move out of staging")
Cc: Alexandru Tachici <alexandru.tachici@analog.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Cc: <Stable@vger.kernel.org>

iio: adc: ad7192: move ad7192_of_match table closer to the end of the file

The change is more cosmetic. There is no need to reference this table in
the probe function since 'of_device_get_match_data' is used, which obtains
this information from the driver object.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.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: ad7192: fix null pointer de-reference crash during probe

When the 'spi_device_id' table was removed, it omitted to cleanup/fix the
assignment:
'indio_dev->name = spi_get_device_id(spi)->name;'

After that patch 'spi_get_device_id(spi)' returns NULL, so this crashes
during probe with null de-ref.

This change fixes this by introducing an ad7192_chip_info struct, and
defines all part-names [that should be assigned to indio_dev->name] in a
'ad7192_chip_info_tbl' table.

With this change, the old 'st->devid' is also moved to be a
'chip_info->chip_id'. And the old 'ID_AD719X' macros have been renamed to
'CHIPID_AD719X'. Tld identifiers have been re-purposed to be enum/index
values in the new 'ad7192_chip_info_tbl'.

This should fix the bug, and maintain the ABI for the 'indio_dev->name'
field.

Fixes: 66614ab2be38 ("staging: iio: adc: ad7192: removed spi_device_id")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: adc: ad7192: Re-indent enum labels

Re-indent enum labels as per coding style guidelines. Problem
detected by checkpatch script.

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/5c6bef6462d135b748f58f8c2645c60234482f52.1584904896.git.mh12gx2825@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: iio: adc: ad7192: move out of staging

Move ad7192 ADC driver out of staging into mainline.

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