iio: event_monitor: Enable events before monitoring

After some painful sessions with a driver that register an
enable/disable sysfs knob (gp2ap002) and manually going
in and enabling the event before monitoring it:

  cd /sys/bus/iio/devices/iio\:device2/events
  # ls
  in_proximity_thresh_either_en
  # echo 1 > in_proximity_thresh_either_en

I realized that it's better if the iio_event_monitor is
smart enough to enable all events by itself and disable them
after use, if passed the -a flag familiar from the
iio_generic_buffer tool.

Auto-enabling events depend on the hardware being able
to handle all events at the same time which isn't
necessarily the case, so a command line option is required
for this.

Cc: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210319135301.542911-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: iio: adc: Add compatible for Mediatek MT8195

This commit adds dt-binding documentation of auxadc for Mediatek MT8195 SoC
Platform.

Signed-off-by: Seiya Wang <seiya.wang@mediatek.com>
Link: https://lore.kernel.org/r/20210319023427.16711-7-seiya.wang@mediatek.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:magnetometer: Add Support for ST IIS2MDC

Add support for ST magnetometer IIS2MDC,
an I2C/SPI interface 3-axis magnetometer.
The patch was tested on the instrument with IIS2MDC via I2C interface.

Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
Link: https://lore.kernel.org/r/20210317063902.19300-3-Qing-wu.Li@leica-geosystems.com.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: iio: st,st-sensors add IIS2MDC.

Add support for ST magnetometer IIS2MDC,
an I2C/SPI interface 3-axis magnetometer sensor.
The patch was tested on the instrument with IIS2MDC via I2C interface.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: LI Qingwu <Qing-wu.Li@leica-geosystems.com.cn>
Link: https://lore.kernel.org/r/20210317063902.19300-2-Qing-wu.Li@leica-geosystems.com.cn
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: ad9832: kernel-doc fixes

Fixes a W=1 warning.
-Added ``:`` to lock parameter in 'ad9832_state' description.
-It's a reference comment so removed /**

Signed-off-by: Mugilraj Dhavachelvan <dmugil2000@gmail.com>
Link: https://lore.kernel.org/r/20210315133711.26860-1-dmugil2000@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:dac:max517.c: Use devm_iio_device_register()

Use devm_iio_device_register() to avoid remove function and
drop explicit call to iio_device_unregister().

Signed-off-by: Mugilraj Dhavachelvan <dmugil2000@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314175709.34301-1-dmugil2000@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:cros_ec_sensors: Fix a wrong function name in kernel doc.

cros_ec_sensors_read_data_unsafe() had wrong function name in kernel-doc
This shows up with W=1 builds.

No fixes tag because I don't want to waste time on this being
backported.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Link: https://lore.kernel.org/r/20210313145341.116088-1-jic23@kernel.org

iio: buffer: kfifo_buf: kernel-doc, typo in function name.

Should have been _kfifo_ and was _fifo_

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314164655.408461-9-jic23@kernel.org

iio: accel: sca3000: kernel-doc fixes. Missing - and wrong function names.

All extremely obvious so nothing to add to patch title.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314164655.408461-8-jic23@kernel.org

iio: adc: adi-axi-adc: Drop false marking for kernel-doc

This comment block isn't in kernel-doc format so drop the /** marking.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210314164655.408461-7-jic23@kernel.org

iio: adc: cpcap-adc: kernel-doc fix - that should be _ in structure name

Fixes a W=1 warning.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314164655.408461-6-jic23@kernel.org

iio: dac: ad5504: fix wrong part number in kernel-doc structure name.

Probably a bit of cut and paste where someone forgot to change the
part number.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314164655.408461-5-jic23@kernel.org

iio: dac: ad5770r: kernel-doc fix case of letter R wrong in structure name

Nothing useful to add beyond this causing a warning with W=1

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210314164655.408461-4-jic23@kernel.org

iio: adc: ti-adc084s021: kernel-doc fixes, missing function names

The documentation in this driver was nearly kernel-doc and was marked
as such. Unfortunately the format was wrong and function names were
missing. This patch puts them in with minor edits to keep the resulting
line short.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: Mårten Lindahl <martenli@axis.com>
Link: https://lore.kernel.org/r/20210314164655.408461-3-jic23@kernel.org

iio: pressure: zpa2326: kernel-doc fixes

Two comment blocks had wrong naming for function/structures that they
referred to.  Results in warnings when doing a W=1 build.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20210314164655.408461-2-jic23@kernel.org

counter: add IRQ or GPIO based counter

Add simple IRQ or GPIO base counter. This device is used to measure
rotation speed of some agricultural devices, so no high frequency on the
counter pin is expected.

The maximal measurement frequency depends on the CPU and system load. On
the idle iMX6S I was able to measure up to 20kHz without count drops.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Reviewed-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/20210301080401.22190-3-o.rempel@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: counter: add interrupt-counter binding

Add binding for the interrupt counter node

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210301080401.22190-2-o.rempel@pengutronix.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: ad9834: convert to device-managed functions in probe

This change converts the driver to use device-managed functions in the
probe function. For the clock and regulator disable, some
devm_add_action_or_reset() calls are required, and then
devm_iio_device_register() function can be used register the IIO device.

The final aim here would be for IIO to export only the device-managed
functions of it's API. That's a long way to go and this a small step in
that direction.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210310095131.47476-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: temperature: tmp007: use device-managed functions in probe

This change converts the driver to use device-managed functions in the
probe function. The power-down call is handled now via a
devm_add_action_or_reset() hook, and then devm_iio_device_register() can be
used to register the IIO device.

The final aim here would be for IIO to export only the device-managed
functions of it's API. That's a long way to go and this a small step in
that direction.

Signed-off-by: Alexandru Ardelean <aardelean@deviqon.com>
Link: https://lore.kernel.org/r/20210310093800.45822-1-aardelean@deviqon.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: fix use-after-free for attached_buffers array

Thanks to Lars for finding this.
The free of the 'attached_buffers' array should be done as late as
possible. This change moves it to iio_buffers_put(), which looks like
the best place for it, since it takes place right before the IIO device
data is free'd.
The free of this array will be handled by calling iio_device_free().
The iio_buffers_put() function is renamed to iio_device_detach_buffers()
since the role of this function changes a bit.

It looks like this issue was ocurring on the error path of
iio_buffers_alloc_sysfs_and_mask() and in
iio_buffers_free_sysfs_and_mask()

Added a comment in the doc-header of iio_device_attach_buffer() to
mention how this will be free'd in case anyone is reading the code
and becoming confused about it.

Fixes: ee708e6baacd ("iio: buffer: introduce support for attaching more IIO buffers")
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210307185444.32924-1-ardeleanalex@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

hwmon: (ntc_thermistor): try reading processed

Before trying the custom method of reading the sensor
as raw and then converting, we want to use
iio_read_channel_processed_scale() which first tries to
see if the ADC can provide a processed value directly,
else reads raw and applies scaling inside of IIO
using the scale attributes of the ADC. We need to
multiply the scaled value with 1000 to get to
microvolts from millivolts which is what processed
IIO channels returns.

Keep the code that assumes 12bit ADC around as a
fallback.

This gives correct readings on the AB8500 thermistor
inputs used in the Ux500 HREFP520 platform for reading
battery and board temperature.

Cc: Peter Rosin <peda@axentia.se>
Cc: Chris Lesiak <chris.lesiak@licor.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org
Link: https://lore.kernel.org/linux-iio/20201224011607.1059534-1-linus.walleij@linaro.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Tested-by: Chris Lesiak <chris.lesiak@licor.com>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210308100219.2732156-2-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Provide iio_read_channel_processed_scale() API

Since the old iio_read_channel_processed() would
lose precision if we fall back to reading raw and
scaling, we introduce a new API that will pass in
a scale factor when reading a processed channel:
iio_read_channel_processed_scale().

Refactor iio_read_channel_processed() as a special
case with scale factor 1.

Cc: Peter Rosin <peda@axentia.se>
Cc: Chris Lesiak <chris.lesiak@licor.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: linux-iio@vger.kernel.org
Link: https://lore.kernel.org/linux-iio/20201224011607.1059534-1-linus.walleij@linaro.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210308100219.2732156-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: xilinx-xadc: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

In xadc_alloc_trigger, given dev is indio_dev->dev.parent, and we call
devm_iio_trigger_alloc wit dev as argument,  we do not have to set
data->trig->dev.parent to indio_dev->dev.parent anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-9-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: as3935: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

Given we call devm_iio_trigger_alloc() and devm_iio_device_alloc() with
dev as parent, we do not have to set data->trig->dev.parent to
indio_dev->dev.parent anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-8-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: chemical: atlas: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

Given we call devm_iio_trigger_alloc() and devm_iio_device_alloc() with
&client->dev as parent, we do not have to set data->trig->dev.parent to
indio_dev->dev.parent anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-7-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: lmp91000: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

Given data->dev is dev, and we call devm_iio_trigger_alloc with
dev instead of data->dev, we do not have to set data->trig->dev.parent to
dev anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-6-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: gp2ap020a00f: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.

Given data->client is client, and we call devm_iio_trigger_alloc() with
&client->dev, we do not have to set data->trig->dev.parent to
&data->client->dev anymore.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-5-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adis_trigger: Remove code to set trigger parent

iio_trigger_set_drvdata() sets the trigger device parent to first
argument of viio_trigger_alloc(), no need to do it again in the driver
code.
Remove adis_trigger_setup() to match other drivers where setting the
trigger is usually done in the probe() routine.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-4-gwendal@chromium.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: set default trig->dev.parent

When allocated with [devm_]iio_trigger_alloc(), set trig device parent to
the device the trigger is allocated for by default.

It can always be reassigned in the probe routine.

Change iio_trigger_alloc() API to add the device pointer to be coherent
with devm_iio_trigger_alloc, using similar interface to
iio_device_alloc().

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210309193620.2176163-2-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: ad7124: allow more than 8 channels

Currently AD7124-8 driver cannot use more than 8 IIO channels
because it was assigning the channel configurations bijectively
to channels specified in the device-tree. This is not possible
to do when using more than 8 channels as AD7124-8 has only 8
configuration registers.

To allow the user to use all channels at once the driver
will keep in memory configurations for all channels but
will program only 8 of them at a time on the device.
If multiple channels have the same configuration, only
one configuration register will be used. If there
are more configurations than available registers only
the last 8 used configurations will be allowed to exist
on the device in a LRU fashion.

Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20210311091154.47785-2-alexandru.tachici@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: light: gp2ap002: Drop unneeded explicit casting

The unnecessary explicit casting is being used. Drop it for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210312134903.4296-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: st_lsm6dsx: Drop unneeded explicit castings

In a few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210312134743.4055-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: imu: fxos8700: Drop unneeded explicit castings

In a few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210312134538.3759-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: chemical: bmp680: Drop unneeded explicit castings

In few places the unnecessary explicit castings are being used.
Drop them for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210312134349.3472-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: proximity: Add a ChromeOS EC MKBP proximity driver

Add support for a ChromeOS EC proximity driver that exposes a "front"
proximity sensor via the IIO subsystem. The EC decides when front
proximity is near and sets an MKBP switch 'EC_MKBP_FRONT_PROXIMITY' to
notify the kernel of proximity. Similarly, when proximity detects
something far away it sets the switch bit to 0. For now this driver
exposes a single sensor, but it could be expanded in the future via more
MKBP bits if desired.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20210211024601.1963379-4-swboyd@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: iio: Add cros ec proximity yaml doc

Some cros ECs support a front proximity MKBP event via
'EC_MKBP_FRONT_PROXIMITY'. Add a DT binding to document this feature via
a node that is a child of the main cros_ec device node. Devices that
have this ability will describe this in firmware.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Cc: <devicetree@vger.kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210211024601.1963379-3-swboyd@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

platform/chrome: cros_ec: Add SW_FRONT_PROXIMITY MKBP define

Some cros ECs support a front proximity MKBP event via
'EC_MKBP_FRONT_PROXIMITY'. Add this define so it can be used in a
future patch.

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Benson Leung <bleung@chromium.org>
Cc: Guenter Roeck <groeck@chromium.org>
Cc: Douglas Anderson <dianders@chromium.org>
Cc: Gwendal Grignou <gwendal@chromium.org>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20210211024601.1963379-2-swboyd@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Remove kernel-doc keyword in file header comment

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: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20210309234314.2208256-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: kfifo: mask flags without zero-check in devm_iio_kfifo_buffer_setup()

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: e36db6a06937 ("iio: kfifo: add devm_iio_kfifo_buffer_setup() helper")
Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>
Link: https://lore.kernel.org/r/20210306162834.7339-1-ardeleanalex@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: hrtimer: Allow sub Hz granularity

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: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20210226014733.2108544-1-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

staging: iio: remove mention of defunct list

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

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

iio: accel: mma8452: fix indentation

Improve readability by fixing indentation.

Signed-off-by: Sean Nyekjaer <sean@geanix.com>
Link: https://lore.kernel.org/r/20210301080029.1974797-1-sean@geanix.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: proximity: vcnl3020: add proximity rate

Add the proximity rate optional option and handling of it for
vishay vcnl3020.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Link: https://lore.kernel.org/r/20210225201444.12983-2-i.mikhaylov@yadro.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: npcm_adc: Replace indio_dev->mlock with own device lock

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: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-3-mircea.caprioru@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: palmas_gpadc: Replace indio_dev->mlock with own device lock

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: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-2-mircea.caprioru@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: spear_adc: Replace indio_dev->mlock with own device lock

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: Sergiu Cuciurean <sergiu.cuciurean@analog.com>
Signed-off-by: Mircea Caprioru <mircea.caprioru@analog.com>
Link: https://lore.kernel.org/r/20200928131333.36646-1-mircea.caprioru@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio:ABI docs: Combine the two instances of docs for sensor_sensitivity

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

iio:ABI docs: Combine sysfs-bus-iio-humidity-hdc2010/hdc100x into one file

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: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20210117153816.696693-6-jic23@kernel.org

iio: adc: mt6360: Include right header

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: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210215153447.48457-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adis: add helpers for locking

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: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-5-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

dt-bindings: adis16475: remove property

`adi,scaled-output-hz` is no longer used by the driver.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-4-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adis16475: improve sync scale mode handling

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: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-3-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adis16480: fix pps mode sampling frequency math

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: 326e2357553d3 ("iio: imu: adis16480: Add support for external clock")

Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20210218114039.216091-2-nuno.sa@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: adc: adi-axi-adc: fix typo in doc-string

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: ef04070692a21 ("iio: adc: adi-axi-adc: add support for AXI ADC IP core")
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210219090134.48057-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Documentation: update definitions for bufferY and scan_elements

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210217083438.37865-2-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: dac: ad5686: Add support for AD5673R/AD5677R

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: Mircea Caprioru <mircea.caprioru@analog.com>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210217074102.23148-1-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: documentation: Document accelerometer label use

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: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210215191003.698888-2-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: documentation: Document proximity sensor label use

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: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210215191003.698888-1-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Add relative hysteresis in ABI documentation

Add relative hysteresis in ABI documentation for als sensor.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210207070048.23935-4-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: hid-sensor-als: Add relative hysteresis support

Hid sensor als use relative hysteresis, this patch adds the support.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210207070048.23935-3-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Add relative sensitivity support

Some hid sensors may use relative sensitivity such as als sensor.
This patch adds relative sensitivity checking for all hid sensors.

Signed-off-by: Ye Xiang <xiang.ye@intel.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Link: https://lore.kernel.org/r/20210207070048.23935-2-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

hid-sensors: Add more data fields for sensitivity checking

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: Ye Xiang <xiang.ye@intel.com>
Link: https://lore.kernel.org/r/20210201054921.18214-3-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: hid-sensors: Move get sensitivity attribute to hid-sensor-common

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: Ye Xiang <xiang.ye@intel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20210201054921.18214-2-xiang.ye@intel.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: iio: mark "repeat" sysfs attribute as optional

Show that this field is optional, just like the shift value.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-6-luca@lucaceresoli.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: iio: fix bullet list formatting

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: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-5-luca@lucaceresoli.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: iio: document the 'index' attribute too

Two out of three attributes are documented, document the third one too.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-4-luca@lucaceresoli.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: iio: fix directory naming

This directory is a, well, directory, not a file.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-3-luca@lucaceresoli.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: iio: fix example formatting

This line is part of the code snippet, so it has to be nested in order
to be rendered correctly.

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Link: https://lore.kernel.org/r/20210215143511.25471-2-luca@lucaceresoli.net
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: use getter/setter functions

Use getter and setter functions, for a variety of data types.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Link: https://lore.kernel.org/r/20210209211315.1261791-1-Julia.Lawall@inria.fr
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

tools: iio: convert iio_generic_buffer to use new IIO buffer API

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-25-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

tools: iio: privatize globals and functions in iio_generic_buffer.c file

Mostly a tidy-up.
But also helps to understand the limits of scope of these functions and
globals.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-24-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

tools: iio: make iioutils_get_type() private in iio_utils

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-23-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: rename 'dev' -> 'indio_dev' in iio_device_alloc()

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-22-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: add ioctl() to support opening extra buffers for IIO device

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-21-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: introduce support for attaching more IIO buffers

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-20-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: dummy: iio_simple_dummy_buffer: use triggered buffer core calls

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-19-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: move __iio_buffer_free_sysfs_and_mask() before alloc

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: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-18-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: wrap iio device & buffer into struct for character devices

In order to keep backwards compatibility with the current chardev
mechanism, and in order to add support for multiple buffers per IIO device,
we need to pass both the IIO device & IIO buffer to the chardev.

This is particularly needed for the iio_buffer_read_outer() function, where
we need to pass another buffer object than 'indio_dev->buffer'.

Since we'll also open some chardevs via anon inodes, we can pass extra
buffers in that function by assigning another object to the
iio_dev_buffer_pair object.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-17-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: dmaengine: obtain buffer object from attribute

The reference to the IIO buffer object is stored on the attribute object.
So we need to unwind it to obtain it.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-16-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: wrap all buffer attributes into iio_dev_attr

This change wraps all buffer attributes into iio_dev_attr objects, and
assigns a reference to the IIO buffer they belong to.

With the addition of multiple IIO buffers per one IIO device, we need a way
to know which IIO buffer is being enabled/disabled/controlled.

We know that all buffer attributes are device_attributes. So we can wrap
them with a iio_dev_attr types. In the iio_dev_attr type, we can also hold
a reference to an IIO buffer.
So, we end up being able to allocate wrapped attributes for all buffer
attributes (even the one from other drivers).

The neat part with this mechanism, is that we don't need to add any extra
cleanup, because these attributes are being added to a dynamic list that
will get cleaned up via iio_free_chan_devattr_list().

With this change, the 'buffer->scan_el_dev_attr_list' list is being renamed
to 'buffer->buffer_attr_list', effectively merging (or finalizing the
merge) of the buffer/ & scan_elements/ attributes internally.

Accessing these new buffer attributes can now be done via
'to_iio_dev_attr(attr)->buffer' inside the show/store handlers.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-15-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: add reference to iio buffer on iio_dev_attr

This change adds a reference to a 'struct iio_buffer' object on the
iio_dev_attr object. This way, we can use the created iio_dev_attr objects
on per-buffer basis (since they're allocated anyway).

A minor downside of this change is that the number of parameters on
__iio_add_chan_devattr() grows by 1. This looks like it could do with a bit
of a re-think.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-14-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: merge buffer/ & scan_elements/ attributes

With this change, we create a new directory for the IIO device called
buffer0, under which both the old buffer/ and scan_elements/ are stored.

This is done to simplify the addition of multiple IIO buffers per IIO
device. Otherwise we would need to add a bufferX/ and scan_elementsX/
directory for each IIO buffer.
With the current way of storing attribute groups, we can't have directories
stored under each other (i.e. scan_elements/ under buffer/), so the best
approach moving forward is to merge their attributes.

The old/legacy buffer/ & scan_elements/ groups are not stored on the opaque
IIO device object. This way the IIO buffer can have just a single
attribute_group object, saving a bit of memory when adding multiple IIO
buffers.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-13-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer: group attr count and attr alloc

If we want to merge the attributes of the buffer/ and scan_elements/
directories, we'll need to count all attributes first, then (depending on
the attribute group) either allocate 2 attribute groups, or a single one.
Historically an IIO buffer was described by 2 subdirectories under
/sys/bus/iio/iio:devicesX (i.e. buffer/ and scan_elements/); these subdirs
were actually 2 separate attribute groups on the iio_buffer object.

Moving forward, if we want to allow more than one buffer per IIO device,
keeping 2 subdirectories for each IIO buffer is a bit cumbersome
(especially for userpace ABI). So, we will merge the attributes of these 2
subdirs under a /sys/bus/iio/iio:devicesX/bufferY subdirectory. To do this,
we need to count all attributes first, and then distribute them based on
which buffer this is. For the first buffer, we'll need to also allocate the
legacy 2 attribute groups (for buffer/ and scan_elements/), and also a
/sys/bus/iio/iio:devicesX/buffer0 attribute group.

For buffer1 and above, just a single attribute group will be allocated (the
merged one).

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-12-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: rework iio device group creation

Up until now, the device groups that an IIO device had were limited to 6.
Two of these groups would account for buffer attributes (the buffer/ and
scan_elements/ directories).

Since we want to add multiple buffers per IIO device, this number may not
be enough, when adding a second buffer. So, this change reallocates the
groups array whenever an IIO device group is added, via a
iio_device_register_sysfs_group() helper.

This also means that the groups array should be assigned to
'indio_dev.dev.groups' really late, right before {cdev_}device_add() is
called to do the entire setup.
And we also must take care to free this array when the sysfs resources are
being cleaned up.

With this change we can also move the 'groups' & 'groupcounter' fields to
the iio_dev_opaque object. Up until now, this didn't make a whole lot of
sense (especially since we weren't sure how multibuffer support would look
like in the end).
But doing it now kills one birds with one stone.

An alternative, would be to add a configurable Kconfig symbol
CONFIG_IIO_MAX_BUFFERS_PER_DEVICE (or something like that) and compute a
static maximum of the groups we can support per IIO device. But that would
probably annoy a few people since that would make the system less
configurable.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-11-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core-trigger: make iio_device_register_trigger_consumer() an int return

Oddly enough the noop function is an int-return. This one seems to be void.
This change converts it to int, because we want to change how groups are
registered. With that change this function could error out with -ENOMEM.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-10-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: register chardev only if needed

We only need a chardev if we need to support buffers and/or events.

With this change, a chardev will be created only if an IIO buffer is
attached OR an event_interface is configured.

Otherwise, no chardev will be created, and the IIO device will get
registered with the 'device_add()' call.

Quite a lot of IIO devices don't really need a chardev, so this is a minor
improvement to the IIO core, as the IIO device will take up (slightly)
fewer resources.

In order to not create a chardev, we mostly just need to not initialize the
indio_dev->dev.devt field. If that is un-initialized, cdev_device_add()
behaves like device_add().

This change has a small chance of breaking some userspace ABI, because it
removes un-needed chardevs. While these chardevs (that are being removed)
have always been unusable, it is likely that some scripts may check their
existence (for whatever logic).
And we also hope that before opening these chardevs, userspace would have
already checked for some pre-conditions to make sure that opening these
chardevs makes sense.
For the most part, there is also the hope that it would be easier to change
userspace code than revert this. But in the case that reverting this is
required, it should be easy enough to do it.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-9-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

docs: ioctl-number.rst: reserve IIO subsystem ioctl() space

Currently, only the 'i' 0x90 ioctl() actually exists and is defined in
'include/uapi/linux/iio/events.h'.

It's the IIO_GET_EVENT_FD_IOCTL, which is used to retrieve and FD for
reading events from an IIO device.
We will want to add more ioct() numbers, so with this change the 'i'
0x90-0x9F space is reserved for IIO ioctl() calls.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-8-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: buffer-dma,adi-axi-adc: introduce devm_iio_dmaengine_buffer_setup()

This change does a conversion of the devm_iio_dmaengine_buffer_alloc() to
devm_iio_dmaengine_buffer_setup(). This will allocate an IIO DMA buffer and
attach it to the IIO device, similar to devm_iio_triggered_buffer_setup()
(though the underlying code is different, the final logic is the same).

Since the only user of the devm_iio_dmaengine_buffer_alloc() was the
adi-axi-adc driver, this change does the replacement in a single go in the
driver.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-7-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: kfifo: un-export devm_iio_kfifo_allocate() function

At this point all drivers should use devm_iio_kfifo_buffer_setup() instead
of manually allocating via devm_iio_kfifo_allocate() and assigning ops and
modes.

With this change, the devm_iio_kfifo_allocate() will be made private to the
IIO core, since all drivers should call either
devm_iio_kfifo_buffer_setup() or devm_iio_triggered_buffer_setup() to
create a kfifo buffer.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-6-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: sca3000: use devm_iio_kfifo_buffer_setup() helper

This change makes use of the devm_iio_kfifo_buffer_setup() helper, however
the unwind order is changed.
The life-time of the kfifo object is attached to the parent device object.
This is to make the driver a bit more consistent with the other IIO
drivers, even though (as it is now before this change) it shouldn't be a
problem.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-5-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: make use of devm_iio_kfifo_buffer_setup() helper

All drivers that already call devm_iio_kfifo_allocate() &
iio_device_attach_buffer() are simple to convert to
iio_device_attach_kfifo_buffer() in a single go.

This change does that; the unwind order is preserved.
What is important, is that the devm_iio_kfifo_buffer_setup() be called
after the indio_dev->modes is assigned, to make sure that
INDIO_BUFFER_SOFTWARE flag is set and not overridden by the assignment to
indio_dev->modes.

Also, the INDIO_BUFFER_SOFTWARE has been removed from the assignments of
'indio_dev->modes' because it is set by devm_iio_kfifo_buffer_setup().

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Matt Ranostay <matt.ranostay@konsulko.com>x
Link: https://lore.kernel.org/r/20210215104043.91251-4-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: kfifo: add devm_iio_kfifo_buffer_setup() helper

This change adds the devm_iio_kfifo_buffer_setup() helper/short-hand,
which groups the simple routine of allocating a kfifo buffers via
devm_iio_kfifo_allocate() and calling iio_device_attach_buffer().

The mode_flags parameter is required, as the IIO kfifo supports 2 modes:
INDIO_BUFFER_SOFTWARE & INDIO_BUFFER_TRIGGERED.
The setup_ops parameter is optional.

This function will be a bit more useful when needing to define multiple
buffers per IIO device.

The naming for this function has been inspired from
iio_triggered_buffer_setup() since that one does a kfifo alloc + a pollfunc
alloc. So, this should have a more familiar ring to what it is.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210215104043.91251-3-alexandru.ardelean@analog.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: Add basic unit test for iio_format_value()

The IIO core provides a function to do formatting of fixedpoint numbers.

In the past there have been some issues with the implementation of the
function where for example negative numbers were not handled correctly.

Introduce a basic unit test based on kunit that tests the function and
ensures that the generated output matches the expected output.

This gives us some confidence that future modifications to the function
implementation will not break ABI compatibility.

To run the unit tests follow the kunit documentation and add

  CONFIG_IIO=y
  CONFIG_IIO_TEST_FORMAT=y

to the .kunitconfig and run

  > ./tools/testing/kunit/kunit.py run
  Configuring KUnit Kernel ...
  Building KUnit Kernel ...
  Starting KUnit Kernel ...
  ============================================================
  ======== [PASSED] iio-format ========
  [PASSED] iio_test_iio_format_value_integer
  [PASSED] iio_test_iio_format_value_fixedpoint
  [PASSED] iio_test_iio_format_value_fractional
  [PASSED] iio_test_iio_format_value_fractional_log2
  [PASSED] iio_test_iio_format_value_multiple
  ============================================================
  Testing complete. 21 tests run. 0 failed. 0 crashed.
  Elapsed time: 8.242s total, 0.001s configuring, 3.865s building, 0.000s running

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201215191743.2725-3-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: iio_format_value(): Fix IIO_VAL_FRACTIONAL_LOG2 values between -1.0 and 0.0

When formatting a value using IIO_VAL_FRACTIONAL_LOG2 and the values is
between -1 and 0 the sign is omitted.

We need the same trick as for IIO_VAL_FRACTIONAL to make sure this gets
formatted correctly.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201215191743.2725-2-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: iio_format_value(): Use signed temporary for IIO_VAL_FRACTIONAL_LOG2

IIO_VAL_FRACTIONAL_LOG2 works with signed values, yet the temporary we use
is unsigned. This works at the moment because the variable is implicitly
cast to signed everywhere where it is used.

But it will certainly be cleaner to use a signed variable in the first
place.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Link: https://lore.kernel.org/r/20201215191743.2725-1-lars@metafoo.de
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: proximity: sx9500: Fix a spelling postive to positive

s/postive/positive/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://lore.kernel.org/r/20210210085704.1228068-1-unixbhaskar@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: kxcjk-1013: Set label based on accel-location on 2-accel yoga-style 2-in-1s

Some 2-in-1 laptops / convertibles with 360° (yoga-style) hinges,
use 2 KXCJ91008 accelerometers:
1 in their display using an ACPI HID of "KIOX010A"; and
1 in their base    using an ACPI HID of "KIOX020A"

Since in this case we know the location of each accelerometer,
set the label for the accelerometers to the standardized
"accel-display" resp. "accel-base" labels. This way userspace
can use the labels to get the location.

This was tested on a Medion Akoya E2228T MD60250.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210207160901.110643-4-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: accel: bmc150: Set label based on accel-location on 2-accel yoga-style 2-in-1s

Some 2-in-1 laptops / convertibles with 360° (yoga-style) hinges,
use 2 bmc150 accelerometers, defined by a single BOSC0200 ACPI
device node (1 in their base and 1 in their display).

Since in this case we know the location of each accelerometer,
set the label for the accelerometers to the standardized
"accel-display" resp. "accel-base" labels. This way userspace
can use the labels to get the location.

This was tested on a Lenovo ThinkPad Yoga 11e 4th gen (N3450 CPU).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210207160901.110643-3-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: core: Allow drivers to specify a label without it coming from of

Only set indio_dev->label from of/dt if there actually is a label
specified in of.

This allows drivers to set a label without this being overwritten with
NULL when there is no label specified in of. This is esp. useful on
devices where of is not used at all, such as your typical x86/ACPI device.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Link: https://lore.kernel.org/r/20210207160901.110643-2-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>