iio: Rename iio_trigger_poll_chained and add kernel-doc

Rename the function to iio_trigger_poll_nested. Add kernel-doc with
a note on the context where the function is expected to be called.

Signed-off-by: Mehdi Djait <mehdi.djait.k@gmail.com>
Link: https://lore.kernel.org/r/841b533cba28ca25a8e87280c44e45979166e8e2.1677761379.git.mehdi.djait.k@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: gyro: fxas210002c: Move exports to IIO_FXAS210002C namespace.

Includes using EXPORT_NS_GPL_DEV_PM_OPS() and the simplifications that
brings by allowing the compiler to remove unused struct dev_pm_ops
and callbacks without needing explicit __maybe_unused markings.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

--
Dropped Rui's tag on basis this is rather different from v1 due to
the different macro implementation.

v2: Switch to Paul's more flexible approach to EXPORT_NS_GPL_DEV_PM_OPS()
Acked-by: Rui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/r/20220925155719.3316280-4-jic23@kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: gyro: fxas210002c: 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.

Updated the comment to 'may' require.

Fixes: a0701b6263ae ("iio: gyro: add core driver for fxas21002c")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-76-jic23@kernel.org

iio: gyro: fxas21002c: Make use of device properties

Convert the module to be property provider agnostic and allow
it to be used on non-OF platforms.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Rui Miguel Silva <rmfrfs@gmail.com>
Link: https://lore.kernel.org/r/20220413131513.59258-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: gyro: fxa21002c: Balance runtime pm + use pm_runtime_resume_and_get().

In both the probe() error path and remove() pm_runtime_put_noidle()
is called which will decrement the runtime pm reference count.
However, there is no matching function to have raised the reference count.
Not this isn't a fix as the runtime pm core will stop the reference count
going negative anyway.

An alternative would have been to raise the count in these paths, but
it is not clear why that would be necessary.

Whilst we are here replace some boilerplate with pm_runtime_resume_and_get()
Found using coccicheck script under review at:
https://lore.kernel.org/lkml/20210427141946.2478411-1-Julia.Lawall@inria.fr/

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rui Miguel Silva <rui.silva@linaro.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210509113354.660190-2-jic23@kernel.org

iio: core: move @id from struct iio_dev to struct iio_dev_opaque

Continuing from Alexandru Ardelean's introduction of the split between
driver modifiable fields and those that should only be set by the core.

This could have been done in two steps to make the actual move after
introducing iio_device_id() but there seemed limited point to that
given how mechanical the majority of the patch is.

Includes fixup from Alex for missing mxs-lradc-adc conversion.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210426174911.397061-2-jic23@kernel.org

iio: gyro: fxas21002c: balance runtime power in error path

If we fail to read temperature or axis we need to decrement the
runtime pm reference count to trigger autosuspend.

Add the call to pm_put to do that in case of error.

Fixes: a0701b6263ae ("iio: gyro: add core driver for fxas21002c")
Suggested-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Link: https://lore.kernel.org/linux-iio/CBBZA9T1OY9C.2611WSV49DV2G@arch-thunder/
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: fix devm_iio_trigger_alloc with parent.cocci

Use cocci semantic patch:
@@
expression trigger, P;
@@
trigger = devm_iio_trigger_alloc(P, ...);
...
- trigger->dev.parent = P;

To remove trigger->dev.parent, since it is set by default.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-3-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: gyro: fxas21002c: Move 'fxas21002c_reg_fields' to the only file its used

'fxas21002c_reg_fields' is only used in '*core*', meaning that '*i2c*'
and '*spi*' complain of a defined but not used const variable. Let's
move it into the source file.

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

In file included from drivers/iio/gyro/fxas21002c_i2c.c:14:
drivers/iio/gyro/fxas21002c.h:79:31: warning: ‘fxas21002c_reg_fields’ defined but not used [-Wunused-const-variable=]
79 | static const struct reg_field fxas21002c_reg_fields[] = {
| ^~~~~~~~~~~~~~~~~~~~~
In file included from drivers/iio/gyro/fxas21002c_spi.c:14:
drivers/iio/gyro/fxas21002c.h:79:31: warning: ‘fxas21002c_reg_fields’ defined but not used [-Wunused-const-variable=]
79 | static const struct reg_field fxas21002c_reg_fields[] = {
| ^~~~~~~~~~~~~~~~~~~~~

Cc: Rui Miguel Silva <rmfrfs@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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: gyro: add core driver for fxas21002c

Add core support for the NXP fxas21002c Tri-axis gyroscope,
using the iio subsystem. It supports PM operations, axis reading,
temperature, scale factor of the axis, high pass and low pass
filtering, and sampling frequency selection.

It will have extras modules to support the communication over i2c and
spi.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>