linux.git/include/linux/iio, branch v6.11

iio: buffer-dma: Enable support for DMABUFs

2024-06-30T10:29:24+00:00

Implement iio_dma_buffer_attach_dmabuf(), iio_dma_buffer_detach_dmabuf()
and iio_dma_buffer_transfer_dmabuf(), which can then be used by the IIO
DMA buffer implementations.

Signed-off-by: Paul Cercueil 
Co-developed-by: Nuno Sa 
Signed-off-by: Nuno Sa 
Link: https://patch.msgid.link/20240620122726.41232-5-paul@crapouillou.net
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 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: imu: adis: remove legacy lock helpers

2024-06-25T20:04:50+00:00

Since all users were converted to the new cleanup based helper,
adis_dev_lock() and adis_dev_unlock() can now be removed from the lib.

Signed-off-by: Nuno Sa 
Link: https://patch.msgid.link/20240618-dev-iio-adis-cleanup-v1-9-bd93ce7845c7@analog.com
Signed-off-by: Jonathan Cameron

iio: imu: adis: add cleanup based lock helpers

2024-06-25T20:04:49+00:00

Add two new lock helpers that make use of the cleanup guard() and
scoped_guard() macros. Thus, users won't have to worry about unlocking
which is less prone to errors and allows for simpler error paths.

Signed-off-by: Nuno Sa 
Link: https://patch.msgid.link/20240618-dev-iio-adis-cleanup-v1-3-bd93ce7845c7@analog.com
Signed-off-by: Jonathan Cameron

iio: imu: adis: move to the cleanup magic

2024-06-25T20:04:49+00:00

This makes locking and handling error paths simpler.

Signed-off-by: Nuno Sa 
Link: https://patch.msgid.link/20240618-dev-iio-adis-cleanup-v1-2-bd93ce7845c7@analog.com
Signed-off-by: Jonathan Cameron

iio: adc: ad_sigma_delta: add disable_one callback

2024-06-25T20:04:32+00:00

Sigma delta ADCs with a sequencer need to disable the previously enabled
channel when reading using ad_sigma_delta_single_conversion(). This was
done manually in drivers for devices with sequencers.

This patch implements handling of single channel disabling after a
single conversion.

Reviewed-by: Nuno Sa 
Signed-off-by: Dumitru Ceclan 
Reviewed-by: David Lechner 
Link: https://patch.msgid.link/20240607-ad4111-v7-3-97e3855900a0@analog.com
Signed-off-by: Jonathan Cameron

iio: imu: adis_trigger: Allow level interrupts for FIFO readings

2024-06-04T18:53:09+00:00

Currently, adis library allows configuration only for edge interrupts,
needed for data ready sampling.
This patch removes the restriction for level interrupts for devices
which have FIFO support.
Furthermore, in case of devices which have FIFO support,
devm_request_threaded_irq is used for interrupt allocation, to avoid
flooding the processor with the FIFO watermark level interrupt, which
is active until enough data has been read from the FIFO.

Reviewed-by: Nuno Sa 
Signed-off-by: Ramona Gradinariu 
Link: https://lore.kernel.org/r/20240527142618.275897-7-ramona.bolboaca13@gmail.com
Signed-off-by: Jonathan Cameron

iio: imu: adis_buffer: Add buffer setup API with buffer attributes

2024-06-04T18:53:09+00:00

Add new API called devm_adis_setup_buffer_and_trigger_with_attrs() which
also takes buffer attributes as a parameter.
Rewrite devm_adis_setup_buffer_and_trigger() implementation such that it
calls devm_adis_setup_buffer_and_trigger_with_attrs() with buffer
attributes parameter NULL

Reviewed-by: Nuno Sa 
Signed-off-by: Ramona Gradinariu 
Link: https://lore.kernel.org/r/20240527142618.275897-4-ramona.bolboaca13@gmail.com
Signed-off-by: Jonathan Cameron

iio: add support for multiple scan types per channel

2024-06-04T18:53:08+00:00

This adds new fields to the iio_channel structure to support multiple
scan types per channel. This is useful for devices that support multiple
resolution modes or other modes that require different data formats of
the raw data.

To make use of this, drivers need to implement the new callback
get_current_scan_type() to resolve the scan type for a given channel
based on the current state of the driver. There is a new scan_type_ext
field in the iio_channel structure that should be used to store the
scan types for any channel that has more than one. There is also a new
flag has_ext_scan_type that acts as a type discriminator for the
scan_type/ext_scan_type union. A union is used so that we don't grow
the size of the iio_channel structure and also makes it clear that
scan_type and ext_scan_type are mutually exclusive.

The buffer code is the only code in the IIO core code that is using the
scan_type field. This patch updates the buffer code to use the new
iio_channel_validate_scan_type() function to ensure it is returning the
correct scan type for the current state of the device when reading the
sysfs attributes. The buffer validation code is also update to validate
any additional scan types that are set in the scan_type_ext field. Part
of that code is refactored to a new function to avoid duplication.

Some userspace tools may need to be updated to re-read the scan type
after writing any other attribute. During testing, we noticed that we
had to restart iiod to get it to re-read the scan type after enabling
oversampling on the ad7380 driver.

Signed-off-by: David Lechner 
Reviewed-by: Nuno Sa 
Link: https://lore.kernel.org/r/20240530-iio-add-support-for-multiple-scan-types-v3-3-cbc4acea2cfa@baylibre.com
Signed-off-by: Jonathan Cameron