iio: core: Add new DMABUF interface infrastructure

Add the necessary infrastructure to the IIO core to support a new
optional DMABUF based interface.

With this new interface, DMABUF objects (extern

iio: core: Add new DMABUF interface infrastructure

Add the necessary infrastructure to the IIO core to support a new
optional DMABUF based interface.

With this new interface, DMABUF objects (externally created) can be
attached to a IIO buffer, and subsequently used for data transfer.

A userspace application can then use this interface to share DMABUF
objects between several interfaces, allowing it to transfer data in a
zero-copy fashion, for instance between IIO and the USB stack.

The userspace application can also memory-map the DMABUF objects, and
access the sample data directly. The advantage of doing this vs. the
read() interface is that it avoids an extra copy of the data between the
kernel and userspace. This is particularly userful for high-speed
devices which produce several megabytes or even gigabytes of data per
second.

As part of the interface, 3 new IOCTLs have been added:

IIO_BUFFER_DMABUF_ATTACH_IOCTL(int fd):
Attach the DMABUF object identified by the given file descriptor to the
buffer.

IIO_BUFFER_DMABUF_DETACH_IOCTL(int fd):
Detach the DMABUF object identified by the given file descriptor from
the buffer. Note that closing the IIO buffer's file descriptor will
automatically detach all previously attached DMABUF objects.

IIO_BUFFER_DMABUF_ENQUEUE_IOCTL(struct iio_dmabuf *):
Request a data transfer to/from the given DMABUF object. Its file
descriptor, as well as the transfer size and flags are provided in the
"iio_dmabuf" structure.

These three IOCTLs have to be performed on the IIO buffer's file
descriptor, obtained using the IIO_BUFFER_GET_FD_IOCTL() ioctl.

Signed-off-by: Paul Cercueil <[email protected]>
Co-developed-by: Nuno Sa <[email protected]>
Signed-off-by: Nuno Sa <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: add the IIO backend framework

This is a Framework to handle complex IIO aggregate devices.

The typical architecture is to have one device as the frontend device which
can be "linked" against o

iio: add the IIO backend framework

This is a Framework to handle complex IIO aggregate devices.

The typical architecture is to have one device as the frontend device which
can be "linked" against one or multiple backend devices. All the IIO and
userspace interface is expected to be registers/managed by the frontend
device which will callback into the backends when needed (to get/set
some configuration that it does not directly control).

The basic framework interface is pretty simple:
- Backends should register themselves with @devm_iio_backend_register()
- Frontend devices should get backends with @devm_iio_backend_get()

Signed-off-by: Nuno Sa <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Andy Shevchenko <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: light: Add gain-time-scale helpers

Some light sensors can adjust both the HW-gain and integration time.
There are cases where adjusting the integration time has similar impact
to the scale of t

iio: light: Add gain-time-scale helpers

Some light sensors can adjust both the HW-gain and integration time.
There are cases where adjusting the integration time has similar impact
to the scale of the reported values as gain setting has.

IIO users do typically expect to handle scale by a single writable 'scale'
entry. Driver should then adjust the gain/time accordingly.

It however is difficult for a driver to know whether it should change
gain or integration time to meet the requested scale. Usually it is
preferred to have longer integration time which usually improves
accuracy, but there may be use-cases where long measurement times can be
an issue. Thus it can be preferable to allow also changing the
integration time - but mitigate the scale impact by also changing the gain
underneath. Eg, if integration time change doubles the measured values,
the driver can reduce the HW-gain to half.

The theory of the computations of gain-time-scale is simple. However,
some people (undersigned) got that implemented wrong for more than once.

Add some gain-time-scale helpers in order to not dublicate errors in all
drivers needing these computations.

Signed-off-by: Matti Vaittinen <[email protected]>
Link: https://lore.kernel.org/r/268d418e7cffcdaa2ece6738478bbc57692c213e.1680263956.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: add filter subfolder

Add filter subfolder for IIO devices that handle filter functionality.

Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Jonathan Cameron <Jonatha

iio: add filter subfolder

Add filter subfolder for IIO devices that handle filter functionality.

Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: add addac subdirectory

For IIO devices that expose both ADC and DAC functionality.

Signed-off-by: Cosmin Tanislav <[email protected]>
Link: https://lore.kernel.org/r/20211205114045.17

iio: add addac subdirectory

For IIO devices that expose both ADC and DAC functionality.

Signed-off-by: Cosmin Tanislav <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

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iio:cdc:ad7150: Move driver out of staging.

This capacitance to digital converter (CDC) driver is compliant with
the IIO ABI. Note, not all features supported (e.g. window event modes)
but the driv

iio:cdc:ad7150: Move driver out of staging.

This capacitance to digital converter (CDC) driver is compliant with
the IIO ABI. Note, not all features supported (e.g. window event modes)
but the driver should be in a useful functional state.

The cleanup was done against QEMU emulation of the device rather than
actual hardware. Whilst this was a bit of an experiment, it made it
easy to confirm that the driver remained in a consistent working state
through the various refactors. If it worked in the first place, it
should still be working after this cleanup.

Given some IIO drivers require expensive hardware setups, (not particularly
true with this one) the use of QEMU may provide a viable way forward
for providing testing during code changes where previously we'd had
to rely on sharp eyes and crossed fingers.

Note, no explicit MAINTAINERS entry as it will be covered by the
generic catch-alls for ADI and IIO drivers which are sufficient.

Signed-off-by: Jonathan Cameron <[email protected]>
Reviewed-by: Alexandru Ardelean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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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
funct

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: Kconfig: Provide title for IIO_TRIGGERED_EVENT symbol

For some embedded systems, a workflow involving external kernel modules
that implement IIO devices is more practical than working with in-t

iio: Kconfig: Provide title for IIO_TRIGGERED_EVENT symbol

For some embedded systems, a workflow involving external kernel modules
that implement IIO devices is more practical than working with in-tree
sources.

Kconfig symbols without any titles do not show up in menuconfig, and as
such are more difficult to configure granularly, as they need to be
selected by potentially unused/un-needed drivers.

Albeit, the IIO_TRIGGERED_EVENT is used by a single mainline driver, this
could allow for some out-of-tree drivers to use this kmod.

This change adds a title to the IIO_TRIGGERED_EVENT Kconfig symbol.

Signed-off-by: Alexandru Ardelean <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: position: Add support for Azoteq IQS624/625 angle sensors

This patch adds support for the Azoteq IQS624 and IQS625 angular position
sensors, capable of reporting the angle of a rotating shaft d

iio: position: Add support for Azoteq IQS624/625 angle sensors

This patch adds support for the Azoteq IQS624 and IQS625 angular position
sensors, capable of reporting the angle of a rotating shaft down to 1 and
10 degrees of accuracy, respectively.

This patch also introduces a home for linear and angular position sensors.
Unlike resolvers, they are typically contactless and use the Hall effect.

Signed-off-by: Jeff LaBundy <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Signed-off-by: Lee Jones <[email protected]>

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docs: iio: convert to ReST

Rename the iio documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let

docs: iio: convert to ReST

Rename the iio documentation files to ReST, add an
index for them and adjust in order to produce a nice html
output via the Sphinx build system.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project

treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

- Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

GPL-2.0-only

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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counter: stm32-lptimer: add counter device

Add support for new counter device to stm32-lptimer.

Signed-off-by: Fabrice Gasnier <[email protected]>
Reviewed-by: Jonathan Cameron <Jonathan.Camer

counter: stm32-lptimer: add counter device

Add support for new counter device to stm32-lptimer.

Signed-off-by: Fabrice Gasnier <[email protected]>
Reviewed-by: Jonathan Cameron <[email protected]>
Signed-off-by: William Breathitt Gray <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <[email protected]>
Signed-off-by:

Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code and pidfd code.

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <[email protected]>
[[email protected]: adapt commit message to mention pidfds]
Signed-off-by: Christian Brauner <[email protected]>

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drivers: iio: Kconfig: pedantic cleanup

Formatting of Kconfig files doesn't look so pretty, so just
take damp cloth and clean it up.

Signed-off-by: Enrico Weigelt, metux IT consult <[email protected]>

drivers: iio: Kconfig: pedantic cleanup

Formatting of Kconfig files doesn't look so pretty, so just
take damp cloth and clean it up.

Signed-off-by: Enrico Weigelt, metux IT consult <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code.

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <viro@z

Make anon_inodes unconditional

Make the anon_inodes facility unconditional so that it can be used by core
VFS code.

Signed-off-by: David Howells <[email protected]>
Signed-off-by: Al Viro <[email protected]>

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staging: iio: ad2s1200: Move driver out of staging

Move the iio driver for the ad2s1200 and ad2s1205 resolver-to-digital
converter out of staging, into mainline iio subsystems.

Signed-off-by: David

staging: iio: ad2s1200: Move driver out of staging

Move the iio driver for the ad2s1200 and ad2s1205 resolver-to-digital
converter out of staging, into mainline iio subsystems.

Signed-off-by: David Veenstra <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: afe: rescale: new driver

If an ADC channel measures the midpoint of a voltage divider, the
interesting voltage is often the voltage over the full resistance.
E.g. if the full voltage is too big

iio: afe: rescale: new driver

If an ADC channel measures the midpoint of a voltage divider, the
interesting voltage is often the voltage over the full resistance.
E.g. if the full voltage is too big for the ADC to handle.
Likewise, if an ADC channel measures the voltage across a shunt
resistor, with or without amplification, the interesting value is
often the current through the resistor.

This driver solves these problems by allowing to linearly scale a channel
and/or by allowing changes to the type of the channel.

Signed-off-by: Peter Rosin <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: multiplexer: new iio category and iio-mux driver

When a multiplexer changes how an iio device behaves (for example
by feeding different signals to an ADC), this driver can be used
to create one

iio: multiplexer: new iio category and iio-mux driver

When a multiplexer changes how an iio device behaves (for example
by feeding different signals to an ADC), this driver can be used
to create one virtual iio channel for each multiplexer state.

Depends on the generic multiplexer subsystem.

Cache any ext_info values from the parent iio channel, creating a private
copy of the ext_info attributes for each multiplexer state/channel.

Reviewed-by: Jonathan Cameron <[email protected]>
Signed-off-by: Peter Rosin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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iio: 104-quad-8: Add IIO support for the ACCES 104-QUAD-8

The ACCES 104-QUAD-8 is a general purpose quadrature encoder
counter/interface board. The 104-QUAD-8 is capable of monitoring the
outputs of

iio: 104-quad-8: Add IIO support for the ACCES 104-QUAD-8

The ACCES 104-QUAD-8 is a general purpose quadrature encoder
counter/interface board. The 104-QUAD-8 is capable of monitoring the
outputs of eight encoders via four on-board LSI/CSI LS7266R1 24-bit
dual-axis quadrature counter chips. Core functions handled by the
LS7266R1, such as direction and total count, are available.

Performing a write to a counter's IIO_CHAN_INFO_RAW sets the counter and
also clears the counter's respective error flag. Although the counters
have a 25-bit range, only the lower 24 bits may be set, either directly
or via a counter's preset attribute. Interrupts are not supported by
this driver.

This driver adds IIO support for the ACCES 104-QUAD-8 and ACCES
104-QUAD-4. The base port addresses for the devices may be configured
via the base array module parameter.

Signed-off-by: William Breathitt Gray <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: potentiostat: add LMP91000 support

Add support for the LMP91000 potentiostat which is used for chemical
sensing applications.

Signed-off-by: Matt Ranostay <[email protected]>
Signed-off

iio: potentiostat: add LMP91000 support

Add support for the LMP91000 potentiostat which is used for chemical
sensing applications.

Signed-off-by: Matt Ranostay <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: Add support for creating IIO devices via configfs

This is similar with support for creating triggers via configfs.
Devices will be hosted under:
* /config/iio/devices

We allow users to regist

iio: Add support for creating IIO devices via configfs

This is similar with support for creating triggers via configfs.
Devices will be hosted under:
* /config/iio/devices

We allow users to register "device types" under:
* /config/iio/devices/<device_types>/

Signed-off-by: Daniel Baluta <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: light: add MAX30100 oximeter driver support

MAX30100 is an heart rate and pulse oximeter sensor that works using
two LEDS of different wavelengths, and detecting the light reflected
back.

This

iio: light: add MAX30100 oximeter driver support

MAX30100 is an heart rate and pulse oximeter sensor that works using
two LEDS of different wavelengths, and detecting the light reflected
back.

This patchset adds support for both IR and RED LED channels which can
be processed in userspace to determine heart rate and blood oxygen
levels.

Signed-off-by: Matt Ranostay <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: core: Introduce IIO software triggers

A software trigger associates an IIO device trigger with a software
interrupt source (e.g: timer, sysfs). This patch adds the generic
infrastructure for ha

iio: core: Introduce IIO software triggers

A software trigger associates an IIO device trigger with a software
interrupt source (e.g: timer, sysfs). This patch adds the generic
infrastructure for handling software triggers.

Software interrupts sources are kept in a iio_trigger_types_list and
registered separately when the associated kernel module is loaded.

Software triggers can be created directly from drivers or from user
space via configfs interface.

To sum up, this dynamically creates "triggers" group to be found under
/config/iio/triggers and offers the possibility of dynamically
creating trigger types groups. The first supported trigger type is
"hrtimer" found under /config/iio/triggers/hrtimer.

Signed-off-by: Daniel Baluta <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: core: Introduce IIO configfs support

This patch creates the IIO configfs root group. The group
will appear under <mount-point>/iio/, usually /config/iio.

We introduce configfs support in IIO i

iio: core: Introduce IIO configfs support

This patch creates the IIO configfs root group. The group
will appear under <mount-point>/iio/, usually /config/iio.

We introduce configfs support in IIO in order to be able to easily
create IIO objects from userspace. The first supported IIO objects
are triggers introduced with next patches.

Signed-off-by: Daniel Baluta <[email protected]>
Tested-by: Matt Ranostay <matt.ranostay@intel>
Signed-off-by: Jonathan Cameron <[email protected]>

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iio: Move IIO Dummy Driver out of staging

This patch moves the reference IIO dummy driver from drivers/staging/iio
into a separate folder, drivers/iio/dummy and adds the proper Kconfig
and Makefile

iio: Move IIO Dummy Driver out of staging

This patch moves the reference IIO dummy driver from drivers/staging/iio
into a separate folder, drivers/iio/dummy and adds the proper Kconfig
and Makefile for it.

A new config menu entry called IIO dummy driver has also been added
in the Industrial I/O support menu, corresponding to this driver.

Signed-off-by: Cristina Opriceana <[email protected]>
Signed-off-by: Jonathan Cameron <[email protected]>

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