kernel/linux.git/include/linux/iio/consumer.h, branch v6.19.11

iio: buffer: document that buffer callback must be context safe

2025-10-13T07:37:24+00:00

Document that the callback registered with iio_channel_get_all_cb() must be safe to call from any context since it is called from by iio_push_to_buffer() which can be called in any context. Signed-off-by: David Lechner Signed-off-by: Jonathan Cameron

iio: consumers: Add an iio_multiply_value() helper function

2025-09-10T18:47:04+00:00

The channel-scale handling in iio_convert_raw_to_processed() in essence does the following: processed = raw * caller-provided-scale * channel-scale Which can also be written as: multiplier = raw * caller-provided-scale iio-value = channel-scale processed = multiplier * iio-value Where iio-value is a set of IIO_VAL_* type + val + val2 integers, being able to handle multiplication of iio-values like this is something which is useful to have in general and, as previous bugfixes to iio_convert_raw_to_processed() have shown, also tricky to implement. Split the iio-value multiplication code from iio_convert_raw_to_processed() out into a new iio_multiply_value() helper. This serves multiple purposes: 1. Having this split out allows writing a KUnit test for this. 2. Having this split out allows re-use to get better precision when scaling values in iio_read_channel_processed_scale(). Reviewed-by: Andy Shevchenko Signed-off-by: Hans de Goede Link: https://patch.msgid.link/20250831104825.15097-4-hansg@kernel.org Signed-off-by: Jonathan Cameron

iio: consumers: ensure read buffers for labels and ext_info are page aligned

2024-12-11T19:20:49+00:00

Attributes of iio providers are exposed via sysfs. Typically, providers pass attribute values to the iio core, which handles formatting and printing to sysfs. However, some attributes, such as labels or extended info, are directly formatted and printed to sysfs by provider drivers using sysfs_emit() and sysfs_emit_at(). These helpers assume the read buffer, allocated by sysfs fop, is page-aligned. When these attributes are accessed by consumer drivers, the read buffer is allocated by the consumer and may not be page-aligned, leading to failures in the provider's callback that utilizes sysfs_emit*. Add a check to ensure that read buffers for labels and external info attributes are page-aligned. Update the prototype documentation as well. Signed-off-by: Matteo Martelli Link: https://patch.msgid.link/20241202-iio-kmalloc-align-v1-1-aa9568c03937@gmail.com Signed-off-by: Jonathan Cameron

iio: Add iio_read_channel_label to inkern API

2024-06-28T19:06:56+00:00

It can be convenient for other in-kernel drivers to reuse IIO channel labels. Export the iio_read_channel_label function to allow this. The signature is different depending on where we are calling it from, so the meat is moved to do_iio_read_channel_label. Signed-off-by: Sean Anderson Acked-by: Jonathan Cameron Link: https://patch.msgid.link/20240624174601.1527244-2-sean.anderson@linux.dev Signed-off-by: Jonathan Cameron

iio: inkern: Add a helper to query an available minimum raw value

2023-07-09T21:48:17+00:00

A helper, iio_read_max_channel_raw() exists to read the available maximum raw value of a channel but nothing similar exists to read the available minimum raw value. This new helper, iio_read_min_channel_raw(), fills the hole and can be used for reading the available minimum raw value of a channel. It is fully based on the existing iio_read_max_channel_raw(). Signed-off-by: Herve Codina Reviewed-by: Andy Shevchenko Acked-by: Jonathan Cameron Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/20230623085830.749991-11-herve.codina@bootlin.com Signed-off-by: Mark Brown

iio: consumer.h: Fix raw values documentation notes

2023-07-09T21:48:11+00:00

The raw values notes mention 'ADC counts' and are not fully accurate. Reword the notes in order to remove the 'ADC counts' and describe the conversion needed between a raw value and a value in the standard units. Signed-off-by: Herve Codina Acked-by: Jonathan Cameron Reviewed-by: Andy Shevchenko Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/20230623085830.749991-5-herve.codina@bootlin.com Signed-off-by: Mark Brown

iio: inkern: remove OF dependencies

2022-08-15T21:30:00+00:00

Since all users of the OF dependendent API are now converted to use the firmware agnostic alternative, we can drop OF dependencies from the IIO in kernel interface. Signed-off-by: Nuno Sá Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220715122903.332535-15-nuno.sa@analog.com Signed-off-by: Jonathan Cameron

iio: inkern: move to fwnode properties

2022-08-15T21:29:59+00:00

This moves the IIO in kernel interface to use fwnode properties and thus be firmware agnostic. Note that the interface is still not firmware agnostic. At this point we have both OF and fwnode interfaces so that we don't break any user. On top of this we also want to have a per driver conversion and that is the main reason we have both of_xlate() and fwnode_xlate() support. Signed-off-by: Nuno Sá Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20220715122903.332535-6-nuno.sa@analog.com Signed-off-by: Jonathan Cameron

iio: Provide iio_read_channel_processed_scale() API

2021-03-25T19:13:51+00:00

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 Cc: Chris Lesiak Cc: Jonathan Cameron 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 Link: https://lore.kernel.org/r/20210308100219.2732156-1-linus.walleij@linaro.org Signed-off-by: Jonathan Cameron

iio: provide of_iio_channel_get_by_name() and devm_ version it

2021-01-16T18:27:51+00:00

There might be cases when the IIO channel is attached to the device subnode instead of being attached to the main device node. Allow drivers to query IIO channels by using device tree nodes. Signed-off-by: Dmitry Baryshkov Link: https://lore.kernel.org/r/20201204025509.1075506-8-dmitry.baryshkov@linaro.org Signed-off-by: Jonathan Cameron