driver-api/iio/core.rst

8 :file:`drivers/iio/industrialio-*`
16 * iio_device_register() - register a device with the IIO subsystem
17 * iio_device_unregister() - unregister a device from the IIO
20 An IIO device usually corresponds to a single hardware sensor and it
22 Let's first have a look at the functionality embedded in an IIO device
23 then we will show how a device driver makes use of an IIO device.
25 There are two ways for a user space application to interact with an IIO driver.
27 1. :file:`/sys/bus/iio/devices/iio:device{X}/`, this represents a hardware sensor
29 2. :file:`/dev/iio:device{X}`, character device node interface used for
32 A typical IIO driver will register itself as an :doc:`I2C <../i2c>` or
37 1. Call iio_device_alloc(), which allocates memory for an IIO device.
38 2. Initialize IIO device fields with driver specific information (e.g.
41    IIO core. After this call the device is ready to accept requests from user
46 1. iio_device_unregister(), unregister the device from the IIO core.
47 2. iio_device_free(), free the memory allocated for the IIO device.
49 IIO device sysfs interface
54 index X, attributes can be found under /sys/bus/iio/devices/iio:deviceX/
59   :file:`/dev/iio:deviceX` node.
62 * Available standard attributes for IIO devices are described in the
63   :file:`Documentation/ABI/testing/sysfs-bus-iio` file in the Linux kernel
66 IIO device channels
71 An IIO device channel is a representation of a data channel. An IIO device can
80 An IIO channel is described by the struct iio_chan_spec.
143 * :file:`/sys/bus/iio/devices/iio:device{X}/in_intensity_ir_raw`
144 * :file:`/sys/bus/iio/devices/iio:device{X}/in_intensity_both_raw`
148 * :file:`/sys/bus/iio/devices/iio:device{X}/in_illuminance_input`
152 * :file:`/sys/bus/iio/devices/iio:device{X}/sampling_frequency`.
173 * :file:`/sys/bus/iio/devices/iio:device{X}/in_voltage0_raw`, representing
175 * :file:`/sys/bus/iio/devices/iio:device{X}/in_voltage1_raw`, representing
180 .. kernel-doc:: include/linux/iio/iio.h
181 .. kernel-doc:: drivers/iio/industrialio-core.c