iio: adc: ad7923: support extended range

By default the driver was always setting the RANGE bit which means that
the analog input goes from 0 to VREF. However, we might want to have 0
to 2xVREF. This change adds a new Firmware property to allow for the
extended range while keeping the default behavior if nothing is provided.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220912081223.173584-3-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: fix channel readings for some variants

Some of the supported devices have 4 or 2 LSB trailing bits that should
not be taken into account. Hence we need to shift these bits out which
fits perfectly on the scan type shift property. This change fixes both
raw and buffered reads.

Fixes: f2f7a449707e ("iio:adc:ad7923: Add support for the ad7904/ad7914/ad7924")
Fixes: 851644a60d20 ("iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220912081223.173584-2-nuno.sa@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: Fix alignment for DMA safety

____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_DMA_MINALIGN definition.

Update the comment to include 'may'.

Note that some other fixes have applied to this line of code
that may complicate automated backporting.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Fixes: 0eac259db28f ("IIO ADC support for AD7923")
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-19-jic23@kernel.org

iio: adc: ad7923: Fix undersized rx buffer.

Fixes tag is where the max channels became 8, but timestamp space was missing
before that.

Fixes: 851644a60d20 ("iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Daniel Junho <djunho@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210501165314.511954-3-jic23@kernel.org
Cc: <Stable@vger.kernel.org>

iio:adc: Drop false comment about lack of timestamp control

The timestamp control has been a function implemented in the core of
IIO for a long time, so this comment is incorrect and has clearly been
cut and paste into all these drivers.

The remainder of the comment added nothing and was confusing so dropped
that as well.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210401145410.226917-1-jic23@kernel.org

iio: adc: ad7923: register device with devm_iio_device_register

Registers the device using the devm variant.
This is the final step of converting the ad7923 to only use devm routines,
meaning that the ad7923_remove() function is no longer needed to release
resources on device detach.

Signed-off-by: Lucas Stankus <lucas.p.stankus@gmail.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/b0146465d52f4e259f5f95c83c71e72f065093da.1616966903.git.lucas.p.stankus@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: use device-managed function for triggered buffer

Converts the iio_triggered_buffer_setup() call to its device-managed
counterpart.
With this, the error handling routine in the ad7923_probe() function
becomes unnecessary as well as the iio_triggered_buffer_cleanup() call.

Signed-off-by: Lucas Stankus <lucas.p.stankus@gmail.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/fe46a45caaa788f333d78367968272de728f4a6e.1616966903.git.lucas.p.stankus@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: use devm_add_action_or_reset for regulator disable

Adds a device-managed action to handle disabling the driver's regulator on
device detach.
This slightly simplifies deinitialization and enables further conversion of
the driver to device-managed routines without breaking the init order.

Signed-off-by: Lucas Stankus <lucas.p.stankus@gmail.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/49a7c0436ca1186313dbccf3d810d0cf38cb5b37.1616966903.git.lucas.p.stankus@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: Demote obvious misuse of kerneldoc to standard comment blocks

No attempt has been made to document either of the demoted functions here

Fixes the following W=1 kernel build warning(s):

drivers/iio/adc/ad7923.c:159: warning: Function parameter or member 'indio_dev' not described in 'ad7923_update_scan_mode'
drivers/iio/adc/ad7923.c:159: warning: Function parameter or member 'active_scan_mask' not described in 'ad7923_update_scan_mode'
drivers/iio/adc/ad7923.c:202: warning: Function parameter or member 'irq' not described in 'ad7923_trigger_handler'
drivers/iio/adc/ad7923.c:202: warning: Function parameter or member 'p' not described in 'ad7923_trigger_handler'

Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.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>

iio: adc: ad7923: Add support for the ad7908/ad7918/ad7928

The ad7928 is software compatible with the ad7923.
The ad7908 and ad7918 are the 8 and 10-bit versions of the ad7928.

Signed-off-by: Daniel Junho <djunho@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: Add of_device_id table

Accomplish device tree compatibility to driver AD7923
by adding of_device_id table and making a subsequent call to
MODULE_DEVICE_TABLE.

Signed-off-by: Daniel Junho <djunho@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: Fix checkpatch warning

Fix checkpatch warning:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
+static int ad7923_scan_direct(struct ad7923_state *st, unsigned ch)

Signed-off-by: Daniel Junho <djunho@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7923: Remove the unused defines

Removes the unused define AD7923_CHANNEL_x from the code.

Signed-off-by: Daniel Junho <djunho@gmail.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 177

Based on 1 normalized pattern(s):

licensed under the gpl 2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 135 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170026.071193225@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

iio:adc:ad7923: Rewrite comparison to NULL

Solves checkpath.pl's message:

CHECK: Comparison to NULL could be written "!indio_dev"

Signed-off-by: Bárbara Fernandes <barbara.fernandes@usp.br>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ad7923: Put macro argument between ()'s

Put macro argument between parenthesis in order to avoid precedence
issues. Solves the following checkpath.pl's messages:

CHECK: Macro argument 'mode' may be better as '(mode)' to avoid
precedence issues
CHECK: Macro argument 'channel' may be better as '(channel)' to
avoid precedence issues
CHECK: Macro argument reuse 'sequence' - possible side-effects?
CHECK: Macro argument 'sequence' may be better as '(sequence)' to
avoid precedence issues
CHECK: Macro argument 'val' may be better as '(val)' to avoid
precedence issues
CHECK: Macro argument 'dec' may be better as '(dec)' to avoid precedence
issues
CHECK: Macro argument 'bits' may be better as '(bits)' to avoid
precedence issues

Signed-off-by: Bárbara Fernandes <barbara.fernandes@usp.br>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ad7923: Use BIT macro instead of bitshift

Replace use of the operation '<<' by the BIT macro. Solves checkpath.pl's
message:

CHECK: Prefer using the BIT macro

Signed-off-by: Bárbara Fernandes <barbara.fernandes@usp.br>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adc:ad7923: Align broken line to parenthesis

Get broken line aligned with parenthesis on upper line. Solves
checkpatch.pl's message:

CHECK: Alignment should match open parenthesis

Signed-off-by: Bárbara Fernandes <barbara.fernandes@usp.br>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers: iio: Update MODULE AUTHOR email address

no functional changes

Signed-off-by: Michael Hennerich <michael.hennerich@analog.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 missing of_node references to iio_dev

Adding missing indio_dev->dev.of_node references to allow iio consumers
to access the device channels.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:core: timestamping clock selection support

Adds a new per-device sysfs attribute "current_timestamp_clock" to allow
userspace to select a particular POSIX clock for buffered samples and
events timestamping.

Following clocks, as listed in clock_gettime(2), are supported:
CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW,
CLOCK_REALTIME_COARSE, CLOCK_MONOTONIC_COARSE, CLOCK_BOOTTIME and
CLOCK_TAI.

Signed-off-by: Gregor Boirie <gregor.boirie@parrot.com>
Acked-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: ad7923: use iio helper function to guarantee direct mode

Replace the code that guarantees the device stays in direct mode
with iio_device_claim_direct_mode() which does same.

Signed-off-by: Alison Schofield <amsfield22@gmail.com>
Acked-by: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

spi: Drop owner assignment from spi_drivers

An spi_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Andrew F. Davis <afd@ti.com>
Acked-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

iio:ad7923: Use iio_push_to_buffers_with_timestamp()

Makes the code a bit shorter and less ugly.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: Remove unnecessary casts for iio_push_to_buffers()

Now that iio_push_to_buffers() takes a void pointer for the data parameter we
can remove those casts to u8*.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: adc: ad7923: Use devm_* APIs

devm_* APIs are device managed and make code simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:ad7923: Add support for the ad7904/ad7914/ad7924

The ad7924 is software compatible with the ad7923. The ad7904 and ad7914 are the
8 and 10 bit version of the ad7924.

While we are at it also drop the "with temperature sensor" from the Kconfig
entry, since the chips do not have a temperature sensor.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:ad7923: Implement scale reporting

The driver already claims to support scale reporting in its channel spec, but
doesn't actually implement this yet. This patch uses the regulator API to get
the reference voltage and calculates the scale based on that. The patch also
moves the global configuration bits into a field in the ad7923_state struct,
since depending on the RANGE bit, the range goes either from 0 to VREF or from 0
to 2 * VREF. So we need to know the setting of the RANGE bit when calculating
the scale.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:ad7923: Return error if we didn't get the expected result

Instead of leaving 'val' uninitialized return an error if the result's address
did not match that of the channel we were trying to read.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:adc:ad7923 move to info_mask_(shared_by_type/separate)

The original info_mask is going away in favour of the broken out versions.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
cc: Patrick Vasseur <patrick.vasseur@c-s.fr>
cc: Christophe Leroy <christophe.leroy@c-s.fr>

IIO ADC support for AD7923

This patch adds support for Analog Devices AD7923 ADC in the IIO Subsystem.

Signed-off-by: Patrick Vasseur <patrick.vasseur@c-s.fr>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>