kernel/git/stable/linux.git/drivers/iio/Kconfig, 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 new DMABUF interface infrastructure

2024-06-30T10:29:17+00:00

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 Co-developed-by: Nuno Sa Signed-off-by: Nuno Sa Link: https://patch.msgid.link/20240620122726.41232-4-paul@crapouillou.net 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: Kconfig: Provide title for IIO_TRIGGERED_EVENT symbol

2020-09-29T16:27:08+00:00

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 Link: https://lore.kernel.org/r/20200924111758.196367-3-alexandru.ardelean@analog.com 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