Remove kernel-doc keyword from function header comment.
It fixes issues spotted by scripts/kernel-doc like:
drivers/iio/<driver>.c:3: info: Scanning doc for function <component name>
drivers/iio/<driver>.c:X: warning: expecting prototype for <component name>.
  Prototype was for <function>() instead

To reproduce the errors:
scripts/kernel-doc -v -none $(find drivers/iio/ -name \*.c \
-exec head -2 {} \+ | grep -B2 -e '\*\*' | grep '==' | cut -d ' ' -f 2)

After, confirm these errors are gone with:
scripts/kernel-doc -v -none $(git show --name-only  | grep -e "^driver")
Signed-off-by: NGwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20210309234314.2208256-1-gwendal@chromium.orgSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

As pointed by Lars, this doesn't require a zero-check. Also, while looking
at this a little closer at it (again), the masking can be done later, as
there is a zero-check for 'mode_flags' anyway, which returns -EINVAL. And
we only need the 'mode_flags' later in the logic.

This change is more of a tweak.

Fixes: e36db6a0 ("iio: kfifo: add devm_iio_kfifo_buffer_setup() helper")
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NAlexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210306162834.7339-1-ardeleanalex@gmail.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Allow setting frequency below 1Hz or sub 1Hz precision.
Useful for slow sensors like ALS.

Test frequency is set properly:
modprobe iio-trig-hrtimer && \
mkdir /sys/kernel/config/iio/triggers/hrtimer/t1 && \
cd /sys/bus/iio/devices/triggerX ;
for i in 1 .1 .01 .001 ; do
  echo $i > sampling_frequency
  cat sampling_frequency
done
Signed-off-by: NGwendal Grignou <gwendal@chromium.org>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210226014733.2108544-1-gwendal@chromium.orgSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The ADI device-drivers-devel list no longer exists.

Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/69b3e45e7666a1dd74a83df0b84ef8a63bf090ea.1614082343.git.baruch@tkos.co.ilSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Improve readability by fixing indentation.
Signed-off-by: NSean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20210301080029.1974797-1-sean@geanix.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Add the proximity rate optional option and handling of it for
vishay vcnl3020.
Signed-off-by: NIvan Mikhaylov <i.mikhaylov@yadro.com>
Link: https://lore.kernel.org/r/20210225201444.12983-2-i.mikhaylov@yadro.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/Signed-off-by: NSergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: NMircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-3-mircea.caprioru@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/Signed-off-by: NSergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: NMircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-2-mircea.caprioru@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

As part of the general cleanup of indio_dev->mlock, this change replaces
it with a local lock on the device's state structure.

This is part of a bigger cleanup.
Link: https://lore.kernel.org/linux-iio/CA+U=Dsoo6YABe5ODLp+eFNPGFDjk5ZeQEceGkqjxXcVEhLWubw@mail.gmail.com/Signed-off-by: NSergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: NMircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-1-mircea.caprioru@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This control on the gain of a measurement used for time of flight sensing
is standard but the expected values for different enviroments may not be.
As we cannot have the same ABI element documented in two files, add a
generic version to sysfs-bus-iio-proximity and a note on the expected
value vs measuring environment for the as3935.

Fixes
$ scripts/get_abi.pl validate
Warning: /sys/bus/iio/devices/iio:deviceX/sensor_sensitivity is defined 2 times:  ./Documentation/ABI/testing/sysfs-bus-iio-distance-srf08:0  ./Documentation/ABI/testing/sysfs-bus-iio-proximity-as3935:8

Cc: Matt Ranostay <matt.ranostay@konsulko.com>
Reported-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: NMatt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210117153816.696693-7-jic23@kernel.orgSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

These contain only one entry for out_current_heater_raw (_available).
Document this in a new sysfs-bus-iio-humidity file, and make it a little
more generic by allowing for non 0/1 values.

Fixes
$ scripts/get_abi.pl validate
Warning: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw is defined 2 times:  ./Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010:0  ./Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x:0
Warning: /sys/bus/iio/devices/iio:deviceX/out_current_heater_raw_available is defined 2 times:  ./Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc2010:1  ./Documentation/ABI/testing/sysfs-bus-iio-humidity-hdc100x:1

Cc: Eugene Zaikonnikov <ez@norphonic.com>
Cc: Matt Ranostay <matt.ranostay@konsulko.com>
Reported-by: NMauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: NMatt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210117153816.696693-6-jic23@kernel.org

To get access to the big endian byte order parsing helpers
drivers need to include <asm/unaligned.h> and nothing else.

Cc: Gene Chen <gene_chen@richtek.com>
Suggested-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210215153447.48457-1-linus.walleij@linaro.orgSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Add some helpers to lock and unlock the device. As this is such a simple
change, we update all the users that were using the lock already in this
patch.
Signed-off-by: NNuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-5-nuno.sa@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

`adi,scaled-output-hz` is no longer used by the driver.
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NNuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-4-nuno.sa@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

With this patch, we don't force users to define the IMU scaled internal
sampling rate once in the devicetree. Now it's dynamically calculated
at runtime depending on the desired output rate given by users.

Calculating the sync_scale dynamically gives us better chances of
achieving a perfect/integer value for DEC_RATE (thus giving more
flexibility). The math is:
 1. lcm of the input clock and the desired output rate.
 2. get the highest multiple of the previous result lower than the adis
    max rate.
 3. The last result becomes the IMU sample rate. Use that to calculate
    SYNC_SCALE and DEC_RATE (to get the user output rate).
Signed-off-by: NNuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-3-nuno.sa@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

When using PPS mode, the input clock needs to be scaled so that we have
an IMU sample rate between (optimally) 4000 and 4250. After this, we can
use the decimation filter to lower the sampling rate in order to get what
the user wants. Optimally, the user sample rate is a multiple of both the
IMU sample rate and the input clock. Hence, calculating the sync_scale
dynamically gives us better chances of achieving a perfect/integer value
for DEC_RATE. The math here is:
 1. lcm of the input clock and the desired output rate.
 2. get the highest multiple of the previous result lower than the adis
    max rate.
 3. The last result becomes the IMU sample rate. Use that to calculate
    SYNC_SCALE and DEC_RATE (to get the user output rate).

Fixes: 326e2357 ("iio: imu: adis16480: Add support for external clock")
Signed-off-by: NNuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-2-nuno.sa@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The channels are of type iio_chan_spec, not axi_adc_chan_spec. They were in
some earlier version, but forgot to rename in the doc-string.

Fixes: ef040706 ("iio: adc: adi-axi-adc: add support for AXI ADC IP core")
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210219090134.48057-1-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Since the new change to the IIO buffer infrastructure, the buffer/ and
scan_elements/ directories have been merged into bufferY/ to have some
attributes available per-buffer.

This change updates the ABI docs to reflect this change.

The hwfifo attributes are not updated, as for now these should be used
via the legacy buffer/ directory until they are moved into core.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210217083438.37865-2-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The AD5673R/AD5677R are low power, 16-channel, 12-/16-bit buffered voltage
output digital-to-analog converters (DACs). They include a 2.5 V internal
reference (enabled by default).

These devices are very similar to AD5674R/AD5679R, except that they
have an i2c interface.
Signed-off-by: NMircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210217074102.23148-1-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Some 2-in-1 laptops / convertibles with 360° (yoga-style) hinges,
have 2 accelerometers, 1 in their base and 1 in their display.

In many cases the kernel can detect the location of each accelerometer
based on e.g. information from the ACPI tables.

It is important for userspace to know the location of the 2 accelerometers.
Rather then adding a new sysfs-attribute for this we can relay this
information to userspace by using standardized label strings for this.
This mirrors how this is done for proximity sensors.

This commit documents 2 new standardized label strings for this purpose:
"accel-base"
"accel-display"

Note the "base" and "display" suffixes were chosen to match the values
used for the systemd/udev hwdb.d/60-sensor.hwdb file's ACCEL_LOCATION
property.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Pearson <mpearson@lenovo.com>
Cc: Bastien Nocera <hadess@hadess.net>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210215191003.698888-2-hdegoede@redhat.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Add an entry to Documentation/ABI/testing/sysfs-bus-iio for
the new device label sysfs-attribute support.

And document the standardized labels which may be used with proximity
sensors to hint userspace about the intended use of the sensor.

Using labels to differentiate between the multiple proximity sensors
which a modern laptop/tablet may have was discussed in this thread:
https://lore.kernel.org/linux-iio/9f9b0ff6-3bf1-63c4-eb36-901cecd7c4d9@redhat.com/

As mentioned there the "proximity-wifi*" labels are already being used
in this manner on some chromebooks, see e.g.:
arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi
arch/arm64/boot/dts/qcom/sc7180-trogdor-lte-sku.dtsi

And the "proximity-palmrest" and "proximity-lap" labels are intended
to be used with the lap and palmrest sensors found in recent Lenovo
ThinkPad models.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Mark Pearson <mpearson@lenovo.com>
Cc: Bastien Nocera <hadess@hadess.net>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210215191003.698888-1-hdegoede@redhat.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Add relative hysteresis in ABI documentation for als sensor.
Signed-off-by: NYe Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210207070048.23935-4-xiang.ye@intel.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Hid sensor als use relative hysteresis, this patch adds the support.
Signed-off-by: NYe Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210207070048.23935-3-xiang.ye@intel.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Some hid sensors may use relative sensitivity such as als sensor.
This patch adds relative sensitivity checking for all hid sensors.
Signed-off-by: NYe Xiang <xiang.ye@intel.com>
Acked-by: NJiri Kosina <jkosina@suse.cz>
Link: https://lore.kernel.org/r/20210207070048.23935-2-xiang.ye@intel.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Before, when reading/writing the hysteresis of als, incli-3d, press, and
rotation sensor, we will get invalid argument error.

This patch add more sensitivity data fields for these sensors, so that
these sensors can get sensitivity index and return correct hysteresis
value.
Signed-off-by: NYe Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210201054921.18214-3-xiang.ye@intel.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

No functional change has been made with this patch. The main intent here
is to reduce code repetition of getting sensitivity attribute.

In the current implementation, sensor_hub_input_get_attribute_info() is
called from multiple drivers to get attribute info for sensitivity
field. Moving this to common place will avoid code repetition.
Signed-off-by: NYe Xiang <xiang.ye@intel.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210201054921.18214-2-xiang.ye@intel.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Show that this field is optional, just like the shift value.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-6-luca@lucaceresoli.netSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This 2nd-level bullet list is not properly ReST-formatted and thus it gets
rendered as a unique paragraph quite unreadable.  Fix by adding spaces as
needed.

While there also swap "shift" and "repeat" so they are in the correct
order.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-5-luca@lucaceresoli.netSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Two out of three attributes are documented, document the third one too.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-4-luca@lucaceresoli.netSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This directory is a, well, directory, not a file.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-3-luca@lucaceresoli.netSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This line is part of the code snippet, so it has to be nested in order
to be rendered correctly.
Signed-off-by: NLuca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-2-luca@lucaceresoli.netSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Use getter and setter functions, for a variety of data types.
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20210209211315.1261791-1-Julia.Lawall@inria.frSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This change makes use of the new IIO buffer API to read data from an IIO
buffer.
It doesn't read the /sys/bus/iio/devices/iio:deviceX/scan_elements dir
anymore, it reads /sys/bus/iio/devices/iio:deviceX/bufferY, where all the
scan_elements have been merged together with the old/classical buffer
attributes.

And it makes use of the new IIO_BUFFER_GET_FD_IOCTL ioctl to get an FD for
the IIO buffer for which to read data from.
It also does a quick sanity check to see that -EBUSY is returned if reading
the chardev after the ioctl() has succeeded.

This was tested with the following cases:
 1. Tested buffer0 works with ioctl()
 2. Tested that buffer0 can't be opened via /dev/iio:deviceX after ioctl()
    This check should be omitted under normal operation; it's being done
    here to check that the driver change is sane
 3. Moved valid buffer0 to be buffer1, and tested that data comes from it
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-25-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

Mostly a tidy-up.
But also helps to understand the limits of scope of these functions and
globals.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-24-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

This is a bit of a tidy-up, but also helps with extending the
iioutils_get_type() function a bit, as we don't need to use it outside of
the iio_utils.c file. So, we'll need to update it only in one place.

With this change, the 'unsigned' types are updated to 'unsigned int' in the
iioutils_get_type() function definition.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-23-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The 'dev' variable name usually refers to 'struct device' types. However in
iio_device_alloc() this was used for the 'struct iio_dev' type, which was
sometimes causing minor confusions.

This change renames the variable to 'indio_dev', which is the usual name
used around IIO for 'struct iio_dev' type objects.
It makes grepping a bit easier as well.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-22-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

With this change, an ioctl() call is added to open a character device for a
buffer. The ioctl() number is 'i' 0x91, which follows the
IIO_GET_EVENT_FD_IOCTL ioctl.

The ioctl() will return an FD for the requested buffer index. The indexes
are the same from the /sys/iio/devices/iio:deviceX/bufferY (i.e. the Y
variable).

Since there doesn't seem to be a sane way to return the FD for buffer0 to
be the same FD for the /dev/iio:deviceX, this ioctl() will return another
FD for buffer0 (or the first buffer). This duplicate FD will be able to
access the same buffer object (for buffer0) as accessing directly the
/dev/iio:deviceX chardev.

Also, there is no IIO_BUFFER_GET_BUFFER_COUNT ioctl() implemented, as the
index for each buffer (and the count) can be deduced from the
'/sys/bus/iio/devices/iio:deviceX/bufferY' folders (i.e the number of
bufferY folders).

Used following C code to test this:
-------------------------------------------------------------------

 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
 #include <fcntl.h"
 #include <errno.h>

 #define IIO_BUFFER_GET_FD_IOCTL      _IOWR('i', 0x91, int)

int main(int argc, char *argv[])
{
        int fd;
        int fd1;
        int ret;

        if ((fd = open("/dev/iio:device0", O_RDWR))<0) {
                fprintf(stderr, "Error open() %d errno %d\n",fd, errno);
                return -1;
        }

        fprintf(stderr, "Using FD %d\n", fd);

        fd1 = atoi(argv[1]);

        ret = ioctl(fd, IIO_BUFFER_GET_FD_IOCTL, &fd1);
        if (ret < 0) {
                fprintf(stderr, "Error for buffer %d ioctl() %d errno %d\n", fd1, ret, errno);
                close(fd);
                return -1;
        }

        fprintf(stderr, "Got FD %d\n", fd1);

        close(fd1);
        close(fd);

        return 0;
}
-------------------------------------------------------------------

Results are:
-------------------------------------------------------------------
 # ./test 0
 Using FD 3
 Got FD 4

 # ./test 1
 Using FD 3
 Got FD 4

 # ./test 2
 Using FD 3
 Got FD 4

 # ./test 3
 Using FD 3
 Got FD 4

 # ls /sys/bus/iio/devices/iio\:device0
 buffer  buffer0  buffer1  buffer2  buffer3  dev
 in_voltage_sampling_frequency  in_voltage_scale
 in_voltage_scale_available
 name  of_node  power  scan_elements  subsystem  uevent
-------------------------------------------------------------------

iio:device0 has some fake kfifo buffers attached to an IIO device.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-21-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

With this change, calling iio_device_attach_buffer() will actually attach
more buffers.
Right now this doesn't do any validation of whether a buffer is attached
twice; maybe that can be added later (if needed). Attaching a buffer more
than once should yield noticeably bad results.

The first buffer is the legacy buffer, so a reference is kept to it.

At this point, accessing the data for the extra buffers (that are added
after the first one) isn't possible yet.

The iio_device_attach_buffer() is also changed to return an error code,
which for now is -ENOMEM if the array could not be realloc-ed for more
buffers.
To adapt to this new change iio_device_attach_buffer() is called last in
all place where it's called. The realloc failure is a bit difficult to
handle during un-managed calls when unwinding, so it's better to have this
as the last error in the setup_buffer calls.

At this point, no driver should call iio_device_attach_buffer() directly,
it should call one of the {devm_}iio_triggered_buffer_setup() or
devm_iio_kfifo_buffer_setup() or devm_iio_dmaengine_buffer_setup()
functions. This makes iio_device_attach_buffer() a bit easier to handle.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-20-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The iio_simple_dummy_configure_buffer() function is essentially a
re-implementation of the iio_triggered_buffer_setup() function.

This change makes use of the iio_triggered_buffer_setup() function. The
reason is so that we don't have to modify the iio_device_attach_buffer()
function in this driver as well.

One minor drawback is that the pollfunc name may not be 100% identical
with the one in the original code, but since it's an example, it should be
a big problem.

This change does a minor re-arranging of the included iio headers, as a
minor tidy-up.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-19-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>

The __iio_buffer_free_sysfs_and_mask() function will be used in
iio_buffer_alloc_sysfs_and_mask() when multiple buffers will be attached to
the IIO device.
This will need to be used to cleanup resources on each buffer, when the
buffers cleanup unwind will occur on the error path.

The move is done in this patch to make the patch that adds multiple buffers
per IIO device a bit cleaner.
Signed-off-by: NAlexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-18-alexandru.ardelean@analog.comSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>