iio: Don't silently expect attribute types

The iio_triggered_buffer_setup_ext() and the
devm_iio_kfifo_buffer_setup_ext() were changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

When using IIO_CONST_ATTRs the added attribute "wrapping" does not copy
the pointer to stored string constant and when the sysfs file is read the
kernel will access to invalid location.

Change the function signatures to expect an array of iio_dev_attrs to
avoid similar errors in the future.

Merge conflict resolved whilst applying due to patch crossing with
two new drivers (kx022a accelerometer and ad4130 ADC).

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/63f54787a684eb1232f1c5d275a09c786987fe4a.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: Use IIO_STATIC_CONST_DEVICE_ATTR()

Slightly simplify by dropping open-coded constant data iio_dev_attr
functions and using the IIO_STATIC_CONST_DEVICE_ATTR() instead.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/3632af8849ef101c54ec1f739596f22c773b067c.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: Fix unsafe buffer attributes

The iio_triggered_buffer_setup_ext() was changed by
commit 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
to silently expect that all attributes given in buffer_attrs array are
device-attributes. This expectation was not forced by the API - and some
drivers did register attributes created by IIO_CONST_ATTR().

The added attribute "wrapping" does not copy the pointer to stored
string constant and when the sysfs file is read the kernel will access
to invalid location.

Change the IIO_CONST_ATTRs from the driver to IIO_DEVICE_ATTR in order
to prevent the invalid memory access.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Fixes: 15097c7a1adc ("iio: buffer: wrap all buffer attributes into iio_dev_attr")
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/19158499623cdf7f9c5efae1f13c9f1a918ff75f.1664782676.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:accel:adxl372: Move exports into IIO_ADXL372 namespace

To avoid unnecessary pollution of the global symbol namespace move the
driver core exports into their own namespace and import that into the two
bus modules.

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

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20220116180535.2367780-9-jic23@kernel.org

iio: triggered-buffer: extend support to configure output buffers

Now that output (kfifo) buffers are supported, we need to extend the
{devm_}iio_triggered_buffer_setup_ext() parameter list to take a direction
parameter.

This allows us to attach an output triggered buffer to a DAC device.
Unfortunately it's a bit difficult to add another macro to avoid changing 5
drivers where {devm_}iio_triggered_buffer_setup_ext() is used.
Well, it's doable, but may not be worth the trouble vs just updating all
these 5 drivers.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Mihail Chindris <mihail.chindris@analog.com>
Link: https://lore.kernel.org/r/20211007080035.2531-4-mihail.chindris@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

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: 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: accel: adxl372: use devm_iio_triggered_buffer_setup_ext()

This change switches to the new devm_iio_triggered_buffer_setup_ext()
function and removes the iio_buffer_set_attrs() call, for assigning the
HW FIFO attributes to the buffer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200929125949.69934-5-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: adxl372: Add support for FIFO peak mode

By default, if all three channels (x, y, z) are enabled, sample sets of
concurrent 3-axis data is stored in the FIFO. This patch adds the option
to configure the FIFO to store peak acceleration (x, y and z) of every
over-threshold event. When pushing to iio buffer we push only enabled
axis data.

Currently the driver configures adxl372 to work in loop mode.
The inactivity and activity timings decide how fast the chip
will loop through the awake and waiting states and the
thresholds on x,y,z axis decide when activity or inactivity
will be detected.

This patch adds standard events sysfs entries for the inactivity
and activity timings: thresh_falling_period/thresh_rising_period
and for the in_accel_x_thresh_falling/rising_value.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Link: https://lore.kernel.org/r/20200810093257.65929-2-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Move attach/detach of the poll func to the core

All devices using a triggered buffer need to attach and detach the trigger
to the device in order to properly work. Instead of doing this in each and
every driver by hand move this into the core.

At this point in time, all drivers should have been resolved to
attach/detach the poll-function in the same order.

This patch removes all explicit calls of iio_triggered_buffer_postenable()
& iio_triggered_buffer_predisable() in all drivers, since the core handles
now the pollfunc attach/detach.

The more peculiar change is for the 'at91-sama5d2_adc' driver, since it's
not immediately obvious that removing the hooks doesn't break anything.
Eugen was able to test on at91-sama5d2-adc driver, sama5d2-xplained board.
All seems to be fine.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Tested-by: Eugen Hristev <eugen.hristev@microchip.com> #for at91-sama5d2-adc
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: accel: adxl372: Set iio_chan BE

Data stored in the iio-buffer is BE and this
should be specified in the iio_chan_spec struct.

Fixes: f4f55ce38e5f8 ("iio:adxl372: Add FIFO and interrupts support")
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: adxl372: Perform a reset at start up

We need to perform a reset a start up to make sure that the chip is in a
consistent state. This reset also disables all the interrupts which
should only be enabled together with the iio buffer. Not doing this, was
sometimes causing unwanted interrupts to trigger.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Fixes: f4f55ce38e5f ("iio:adxl372: Add FIFO and interrupts support")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: adxl372: Fix push to buffers lost samples

One in two sample sets was lost by multiplying fifo_set_size with
sizeof(u16). Also, the double number of available samples were pushed to
the iio buffers.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Fixes: f4f55ce38e5f ("iio:adxl372: Add FIFO and interrupts support")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: adxl372: Fix/remove limitation for FIFO samples

Currently, the driver sets the FIFO_SAMPLES register with the number of
sample sets (maximum of 170 for 3 axis data, 256 for 2-axis and 512 for
single axis). However, the FIFO_SAMPLES register should store the number
of samples, regardless of how the FIFO format is configured.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Fixes: f4f55ce38e5f ("iio:adxl372: Add FIFO and interrupts support")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: fix iio_triggered_buffer_{pre,post}enable positions

The iio_triggered_buffer_{predisable,postenable} functions attach/detach
the poll functions.

For the predisable hook, the disable code should occur before detaching
the poll func, and for the postenable hook, the poll func should be
attached before the enable code.

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

iio: adxl372: Add support for I2C communication

The adxl372 is designed to communicate in either SPI or I2C protocol. It
autodetects the format being used, requiring no configuration control to
select the format.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: Refactor the driver

This patch restructures the existing adxl372 driver by adding a module for
SPI and a header file, while the baseline module deals with the chip-logic.

This is a necessary step, as this driver should support in the future
a similar device which differs only in the type of interface used (I2C
instead of SPI).

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adxl372: Add filter bandwidth support

This patch adds the option for the user to select the filter bandwidth. The
user can also read the available bandwidths which are always adjusted to be
at most half of the sampling frequency. Furthermore, the currently selected
bandwidth can be read via the read_raw function, while the write_raw sets a
new bandwidth value.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adxl372: Add sampling frequency support

This patch adds the option for the user to select the sampling frequency.
Also, the user can read the available frequencies and read the currently
set frequency via the read_raw function. The frequency can be set via the
write_raw function.

When the frequency is set, the bandwidth is also checked and ensured
that it is constrained to at most half of the sampling frequency. Also, the
activity and inactivity timers have to be updated because they depend on
the selected ODR.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: Provide validate_trigger and validate_device callbacks

This patch provides a validate_device callback for the trigger which makes
sure that other devices are rejected.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:adxl372: Add FIFO and interrupts support

This patch adds support for the adxl372 FIFO. In order to accomplish this,
triggered buffers were used.

The number of FIFO samples which trigger the watermark interrupt can be
configured by using the buffer watermark. The FIFO format is determined by
configuring the scan elements for each axis. The FIFO data is pushed to the
IIO device's buffer.

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adxl372: New driver for Analog Devices ADXL372 Accelerometer

This patch adds basic support for Analog Devices ADXL372 SPI-Bus
Three-Axis Digital Accelerometer.

The device is probed and configured the with some initial default
values. With this basic driver, it is possible to read raw acceleration
data.

Datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/ADXL372.pdf

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>