iio: dac: ad7303: 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'.

Fixes: f83478240e74 ("iio:dac: Add support for the AD7303")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-58-jic23@kernel.org

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: dac: ad7303: convert probe to full device-managed

For this conversion, the regulators need to have some cleanup hooks
registered with devm_add_action_or_reset() and then the
devm_io_device_register() call can be used.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210913115121.300082-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: dac: Convert powerdown read callbacks to sysfs_emit()

Update DAC drivers powerdown attribute show callback to use the new
sysfs_emit() function.

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

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210320071405.9347-5-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: dac: ad7303: remove platform data header

The information in the ad7303 platform_data header is unused, so it's dead
code.
This change removes it and it's inclusion from the driver.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20201001141004.53846-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: dac: ad7303: Complete 'struct ad7303_state' doc

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

drivers/iio/dac/ad7303.c:49: warning: Function parameter or member 'vdd_reg' not described in 'ad7303_state'
drivers/iio/dac/ad7303.c:49: warning: Function parameter or member 'vref_reg' not described in 'ad7303_state'
drivers/iio/dac/ad7303.c:49: warning: Function parameter or member 'lock' not described in 'ad7303_state'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Michael Hennerich <Michael.Hennerich@analog.com>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200716135928.1456727-31-lee.jones@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:dac:ad7303: Drop of_match_ptr protection

This prevents use of this driver with ACPI via PRP0001 and are
an example of an anti pattern I'm trying to remove from IIO.

Also add mod_devicetable.h include given struct of_device_id is
declared there.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Michael Hennerich <michael.hennerich@analog.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20200910173242.621168-13-jic23@kernel.org

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: dac: ad7303: use regulator get optional to check for ext supply

Previously, the code was using the of_read_property_bool() to check if
an external regulator was provided. However, this is redundant, as it's
more simple/direct to just ask the regulator is provided, via a
`devm_regulator_get_optional()` call.

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

iio: dac: ad7303: replace mlock with own lock

This change replaces indio_dev's mlock with the driver's own lock. The lock
is mostly needed to protect state when changing the `dac_cache` info.
The lock has been extended to `ad7303_read_raw()`, to make sure that the
cache is updated if an SPI-write is already in progress.

Signed-off-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:dac: drop assignment of iio_info.driver_module

The equivalent of this is now done via macro magic when
the relevant register call is made. The actual structure
element will shortly go away.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>

iio: dac: ad7303: fix channel description

realbits, storagebits and shift should be numbers, not ASCII characters.

Signed-off-by: Pavel Roskin <plroskin@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: <Stable@vger.kernel.org>
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: dac: ad7303: Add OF match table

The Documentation/devicetree/bindings/iio/dac/ad7303.txt DT binding doc
lists "adi,ad7303" as a compatible string but the corresponding driver
does not have an OF match table. Add the table to the driver so the SPI
core can do an OF style match.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: dac: ad7303: remove an unneeded check

"ret" is zero here. There is no need to check again.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: refactor info mask and ext_info attribute creation.

Introduce an enum to specify whether the attribute is separate or
shared.

Factor out the bitmap handling for loop into a separate function.

Tidy up error handling and add a NULL assignment to squish a false
positive warning from GCC.

Change ext_info shared type from boolean to enum and update in all
drivers.

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

iio: dac: ad7303: Use devm_* APIs

devm_* APIs are device managed and make code simpler.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio: dac: ad7303: fix error return code in ad7303_probe()

Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

iio:dac: Add support for the AD7303

This patch adds support for the AD7303. The AD7303 is a simple 2 channel 8 bit
DAC with an SPI interface.

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