NAME¶

libiio-0.25 - introduction to libiio, a library for interacting with the Linux IIO subsystem and devices

SYNOPSIS¶

#include <iio.h>

cc file.c -liio

OPTIONS¶

The define IIO_CHECK_REG will warn if return values are not checked. Most libiio functions, if/when a failure occurs will return a negative error number. this warning will ensure these error numbers are looked at. There is nothing more frustraining than calling a function, debugging some hardware, and then eventually realizing there was a typo in an attribute name. This option will force libraries users to at least capture the return value.

cc file.c -DIIO_CHECK_REG -liio

DESCRIPTION¶

libiio is a library used to interface to the Linux Industrial Input/Output (IIO) Subsystem. The Linux IIO subsystem is intended to provide support for devices that in some sense are analog to digital or digital to analog converters (ADCs, DACs). This includes, but is not limited to ADCs, Accelerometers, Gyros, IMUs, Capacitance to Digital Converters (CDCs), Pressure Sensors, Color, Light and Proximity Sensors, Temperature Sensors, Magnetometers, DACs, DDS (Direct Digital Synthesis), PLLs (Phase Locked Loops), Variable/Programmable Gain Amplifiers (VGA, PGA), and RF transceivers. You can use libiio natively on an embedded Linux target (local mode), or use libiio to communicate remotely to that same target from a host Linux, Windows or MAC over USB, Ethernet or Serial.

DATA TYPES¶

The library makes use of C structures and typedefs to promote portability, and is known to run on various GNU/Linux distributions, macOS, Windows, and mbed (via tiny-iiod). The main C structures are:

iio_scan_context

The scanning context

iio_context_info

The information related to a discovered context

iio_context

Contains the representation of an IIO context

iio_device

Represents a device in the IIO context

iio_channel

Represents an input or output channel of a device

iio_buffer

An input or output buffer, used to read or write samples

iio_data_format

Contains the format of a data sample.

LIST OF ROUTINES¶

The following routines are part of the library. Consult the Doxygen pages for details on their operation (in the SEE ALSO section).

Scan Functions for scanning available contexts

Function

Description

iio_create_scan_context

Create a scan context

iio_scan_context_destroy

Destroy the given scan context

iio_scan_context_get_info_list

Enumerate available contexts

iio_context_info_list_free

Free a context info list

iio_context_info_get_description

Get a description of a discovered context

iio_context_info_get_uri

Get the URI of a discovered context

iio_create_scan_block

Create a scan block

iio_scan_block_destroy

Destroy the given scan block

iio_scan_block_scan

Enumerate available contexts via scan block

iio_scan_block_get_info

Get the iio_context_info for a particular context

TopLevel Top-level functions

Function

Description

iio_library_get_version

Get the version of the libiio library

iio_strerror

Get a string description of an error code

iio_has_backend

Check if the specified backend is available

iio_get_backends_count

Get the number of available backends

iio_get_backend

Retrieve the name of a given backend

Context Context

Function

Description

iio_create_default_context

Create a context from local or remote IIO devices

iio_create_local_context

Create a context from local IIO devices (Linux only)

iio_create_xml_context

Create a context from XML data in memory

iio_create_xml_context_mem

Create a context from XML data in memory

iio_create_network_context

Create a context from the network

iio_create_context_from_uri

iio_context_clone

Duplicate a pre-existing IIO context

iio_context_destroy

Destroy the given context

iio_context_get_version

Get the version of the backend in use

iio_context_get_xml

Obtain a XML representation of the given context

iio_context_get_name

Get the name of the given context

iio_context_get_description

Get a description of the given context

iio_context_get_attrs_count

Get the number of context-specific attributes

iio_context_get_attr

Retrieve the value of a context-specific attribute

iio_context_get_attr_value

Retrieve the value of a context-specific attribute

iio_context_get_devices_count

Enumerate the devices found in the given context

iio_context_get_device

Get the device present at the given index

iio_context_find_device

Try to find a device structure by its ID, label or name

iio_context_set_timeout

Set a timeout for I/O operations

Device Device

Function

Description

iio_device_get_context

Retrieve a pointer to the iio_context structure

iio_device_get_id

Get whether or not the device is a hardware monitoring device

iio_device_get_name

Retrieve the device name

iio_device_get_label

Retrieve the device label

iio_device_get_channels_count

Enumerate the channels of the given device

iio_device_get_attrs_count

Enumerate the device-specific attributes of the given device

iio_device_get_buffer_attrs_count

Enumerate the buffer-specific attributes of the given device

iio_device_get_channel

Get the channel present at the given index

iio_device_get_attr

Get the device-specific attribute present at the given index

iio_device_get_buffer_attr

Get the buffer-specific attribute present at the given index

iio_device_find_channel

Try to find a channel structure by its name of ID

iio_device_find_attr

Try to find a device-specific attribute by its name

iio_device_find_buffer_attr

Try to find a buffer-specific attribute by its name

iio_device_attr_read

Read the content of the given device-specific attribute

iio_device_attr_read_all

Read the content of all device-specific attributes

iio_device_attr_read_bool

Read the content of the given device-specific attribute

iio_device_attr_read_longlong

Read the content of the given device-specific attribute

iio_device_attr_read_double

Read the content of the given device-specific attribute

iio_device_attr_write

Set the value of the given device-specific attribute

iio_device_attr_write_raw

Set the value of the given device-specific attribute

iio_device_attr_write_all

Set the values of all device-specific attributes

iio_device_attr_write_bool

Set the value of the given device-specific attribute

iio_device_attr_write_longlong

Set the value of the given device-specific attribute

iio_device_attr_write_double

Set the value of the given device-specific attribute

iio_device_buffer_attr_read

Read the content of the given buffer-specific attribute

iio_device_buffer_attr_read_all

Read the content of all buffer-specific attributes

iio_device_buffer_attr_read_bool

Read the content of the given buffer-specific attribute

iio_device_buffer_attr_read_longlong

Read the content of the given buffer-specific attribute

iio_device_buffer_attr_read_double

Read the content of the given buffer-specific attribute

iio_device_buffer_attr_write

Set the value of the given buffer-specific attribute

iio_device_buffer_attr_write_raw

Set the value of the given buffer-specific attribute

iio_device_buffer_attr_write_all

Set the values of all buffer-specific attributes

iio_device_buffer_attr_write_bool

Set the value of the given buffer-specific attribute

iio_device_buffer_attr_write_longlong

Set the value of the given buffer-specific attribute

iio_device_buffer_attr_write_double

Set the value of the given buffer-specific attribute

iio_device_set_data

Associate a pointer to an iio_device structure

iio_device_get_data

Retrieve a previously associated pointer of an iio_device structure

iio_device_get_trigger

Retrieve the trigger of a given device

iio_device_set_trigger

Associate a trigger to a given device

iio_device_is_trigger

Return True if the given device is a trigger

iio_device_set_kernel_buffers_count

Configure the number of kernel buffers for a device

Channel Channel

Function

Description

iio_channel_get_device

Retrieve a pointer to the iio_device structure

iio_channel_get_id

Retrieve the channel ID

iio_channel_get_name

Retrieve the channel name

iio_channel_is_output

Return True if the given channel is an output channel

iio_channel_is_scan_element

Return True if the given channel is a scan element

iio_channel_get_attrs_count

Enumerate the channel-specific attributes of the given channel

iio_channel_get_attr

Get the channel-specific attribute present at the given index

iio_channel_find_attr

Try to find a channel-specific attribute by its name

iio_channel_attr_get_filename

Retrieve the filename of an attribute

iio_channel_attr_read

Read the content of the given channel-specific attribute

iio_channel_attr_read_all

Read the content of all channel-specific attributes

iio_channel_attr_read_bool

Read the content of the given channel-specific attribute

iio_channel_attr_read_longlong

Read the content of the given channel-specific attribute

iio_channel_attr_read_double

Read the content of the given channel-specific attribute

iio_channel_attr_write

Set the value of the given channel-specific attribute

iio_channel_attr_write_raw

Set the value of the given channel-specific attribute

iio_channel_attr_write_all

Set the values of all channel-specific attributes

iio_channel_attr_write_bool

Set the value of the given channel-specific attribute

iio_channel_attr_write_longlong

Set the value of the given channel-specific attribute

iio_channel_attr_write_double

Set the value of the given channel-specific attribute

iio_channel_enable

Enable the given channel

iio_channel_disable

Disable the given channel

iio_channel_is_enabled

Returns True if the channel is enabled

iio_channel_read_raw

Demultiplex the samples of a given channel

iio_channel_read

Demultiplex and convert the samples of a given channel

iio_channel_write_raw

Multiplex the samples of a given channel

iio_channel_write

Convert and multiplex the samples of a given channel

iio_channel_set_data

Associate a pointer to an iio_channel structure

iio_channel_get_data

Get a pointer to a channel's data format structure

iio_channel_get_type

Get the type of the given hwmon channel

iio_channel_get_modifier

Get the modifier type of the given channel

Buffer Buffer

Function

Description

iio_buffer_get_device

Retrieve a pointer to the iio_device structure

iio_device_create_buffer

Create an input or output buffer associated to the given device

iio_buffer_destroy

Destroy the given buffer

iio_buffer_get_poll_fd

Get a pollable file descriptor

iio_buffer_set_blocking_mode

Make iio_buffer_refill() and iio_buffer_push() blocking or not

iio_buffer_refill

Cancel all buffer operations

iio_buffer_push

Cancel all buffer operations

iio_buffer_push_partial

Send a given number of samples to the hardware

iio_buffer_cancel

Cancel all buffer operations

iio_buffer_start

Get the start address of the buffer

iio_buffer_first

Find the first sample of a channel in a buffer

iio_buffer_step

Get the step size between two samples of one channel

iio_buffer_end

Get the address that follows the last sample in a buffer

iio_buffer_foreach_sample

Call the supplied callback for each sample found in a buffer

iio_buffer_set_data

Associate a pointer to an iio_buffer structure

iio_buffer_get_data

Retrieve a previously associated pointer of an iio_buffer structure

iio_device_get_sample_size

Get the current sample size

iio_channel_get_index

Get the index of the given channel

iio_channel_get_data_format

Get a pointer to a channel's data format structure

iio_channel_convert

Convert the sample from host format to hardware format

iio_channel_convert_inverse

Convert the sample from host format to hardware format

iio_device_get_debug_attrs_count

Enumerate the debug attributes of the given device

iio_device_get_debug_attr

Get the debug attribute present at the given index

iio_device_find_debug_attr

Try to find a debug attribute by its name

iio_device_debug_attr_read

Read the content of the given debug attribute

iio_device_debug_attr_read_all

Read the content of all debug attributes

iio_device_debug_attr_write

Set the value of the given debug attribute

iio_device_debug_attr_write_raw

Set the value of the given debug attribute

iio_device_debug_attr_write_all

Set the values of all debug attributes

iio_device_debug_attr_read_bool

Read the content of the given debug attribute

iio_device_debug_attr_read_longlong

Read the content of the given debug attribute

iio_device_debug_attr_read_double

Read the content of the given debug attribute

iio_device_debug_attr_write_bool

Set the value of the given debug attribute

iio_device_debug_attr_write_longlong

Set the value of the given debug attribute

iio_device_debug_attr_write_double

Set the value of the given debug attribute

iio_device_identify_filename

Identify the channel or debug attribute corresponding to a filename

iio_device_reg_write

Set the value of a hardware register

iio_device_reg_read

Get the value of a hardware register

Hwmon Compatibility with hardware monitoring (hwmon) devices