linux.git/drivers/iio/Makefile, branch master

iio: flow: add Sensirion SLF3S liquid flow sensor driver

2026-08-04T23:03:28+00:00

Add a driver for the Sensirion SLF3S family of digital
liquid-flow sensors on I2C.  Currently supported variants are
SLF3S-0600F, SLF3S-1300F and SLF3S-4000B; they share the same
register map and differ only in flow-scale factor and calibrated
measurement range.  The variant (and therefore the scale) is
auto-detected from the product-information register at probe time;
a sensor reporting an unknown sub-type falls back to the variant
named in the device tree / I2C table, so a drop-in replacement part
keeps working on a kernel that does not know its sub-type yet.

Each measurement frame returns a 16-bit signed flow value, a
16-bit signed temperature reading and a status word, each
protected by a CRC-8 byte.  The driver exposes the flow rate as
IIO_VOLUMEFLOW and the temperature as IIO_TEMP via the standard
IIO read_raw / read_scale interface.

The volume-flow scale is reported in m^3/s.  As the per-LSB scale
is on the order of 1e-12 m^3/s, it is emitted as a 64-bit
fixed-point value with femto (1e-15) resolution
(IIO_VAL_DECIMAL64_FEMTO) so the small SI value keeps full
precision.  This relies on the IIO_VAL_DECIMAL64_FEMTO format type
added earlier in this series.

The active calibration medium can be switched at runtime between
the factory-calibrated water and isopropyl-alcohol modes via the
in_volumeflow_medium sysfs attribute; the sensor starts in water
mode after probe.

The sensor has no low-power state of its own, so system suspend
stops the measurement and disables the vdd supply; resume powers
the sensor back up, waits out the power-up time and restarts the
measurement with the previously active medium, following the
scd30/scd4x precedent.

This driver also creates the drivers/iio/flow/ subdirectory and
the corresponding Kconfig/Makefile glue.

Signed-off-by: Wadim Mueller 
Signed-off-by: Jonathan Cameron

iio: core: Add iio_read_acpi_mount_matrix() helper function

2024-04-29T19:53:25+00:00

The ACPI "ROTM" rotation matrix parsing code atm is already duplicated
between bmc150-accel-core.c and kxcjk-1013.c and a third user of this
is coming.

Add an iio_read_acpi_mount_matrix() helper function for this.
The 2 existing copies of the code are identical, except that
the kxcjk-1013.c has slightly better error logging.

To new helper is a 1:1 copy of the kxcjk-1013.c version, the only change
is the addition of a "char *acpi_method" parameter since some bmc150
dual-accel setups (360° hinges with 1 accel in kbd/base + 1 in display)
declare both accels in a single ACPI device with 2 different method names
for the 2 matrices. This new acpi_method parameter is not "const char *"
because the pathname parameter to acpi_evaluate_object() is not const.

The 2 existing copies of this function will be removed in further patches
in this series.

Acked-by: Rafael J. Wysocki 
Signed-off-by: Hans de Goede 
Link: https://lore.kernel.org/r/20240425125754.76010-2-hdegoede@redhat.com
Signed-off-by: Jonathan Cameron

iio: add the IIO backend framework

2024-02-19T19:32:22+00:00

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 
Link: https://lore.kernel.org/r/20240210-iio-backend-v11-5-f5242a5fb42a@analog.com
Reviewed-by: Andy Shevchenko 
Signed-off-by: Jonathan Cameron

iio: light: Add gain-time-scale helpers

2023-04-10T11:26:34+00:00

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 
Link: https://lore.kernel.org/r/268d418e7cffcdaa2ece6738478bbc57692c213e.1680263956.git.mazziesaccount@gmail.com
Signed-off-by: Jonathan Cameron

iio: add filter subfolder

2021-12-16T17:29:46+00:00

Add filter subfolder for IIO devices that handle filter functionality.

Signed-off-by: Antoniu Miclaus 
Signed-off-by: Jonathan Cameron

iio: add addac subdirectory

2021-12-12T17:09:11+00:00

For IIO devices that expose both ADC and DAC functionality.

Signed-off-by: Cosmin Tanislav 
Link: https://lore.kernel.org/r/20211205114045.173612-2-cosmin.tanislav@analog.com
Signed-off-by: Jonathan Cameron

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

2021-04-07T07:36:37+00:00

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 
Reviewed-by: Alexandru Ardelean 
Link: https://lore.kernel.org/r/20210314181511.531414-25-jic23@kernel.org

iio: Add basic unit test for iio_format_value()

2021-03-11T20:47:00+00:00

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 
Link: https://lore.kernel.org/r/20201215191743.2725-3-lars@metafoo.de
Signed-off-by: Jonathan Cameron

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

2020-03-27T08:25:59+00:00

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 
Reviewed-by: Jonathan Cameron 
Signed-off-by: Lee Jones

counter: stm32-lptimer: add counter device

2019-04-25T19:33:41+00:00

Add support for new counter device to stm32-lptimer.

Signed-off-by: Fabrice Gasnier 
Reviewed-by: Jonathan Cameron 
Signed-off-by: William Breathitt Gray 
Signed-off-by: Greg Kroah-Hartman