Device

Data Structures
struct	iio_device
	Represents a device in the IIO context. More...
Functions
__api __pure struct iio_context *	iio_device_get_context (const struct iio_device *dev)
	Retrieve a pointer to the iio_context structure.
__api __pure const char *	iio_device_get_id (const struct iio_device *dev)
	Retrieve the device ID (e.g. iio:device0)
__api __pure const char *	iio_device_get_name (const struct iio_device *dev)
	Retrieve the device name (e.g. xadc)
__api __pure unsigned int	iio_device_get_channels_count (const struct iio_device *dev)
	Enumerate the channels of the given device.
__api __pure unsigned int	iio_device_get_attrs_count (const struct iio_device *dev)
	Enumerate the device-specific attributes of the given device.
__api __pure struct iio_channel *	iio_device_get_channel (const struct iio_device *dev, unsigned int index)
	Get the channel present at the given index.
__api __pure const char *	iio_device_get_attr (const struct iio_device *dev, unsigned int index)
	Get the device-specific attribute present at the given index.
__api __pure struct iio_channel *	iio_device_find_channel (const struct iio_device *dev, const char *name, bool output)
	Try to find a channel structure by its name of ID.
__api __pure const char *	iio_device_find_attr (const struct iio_device *dev, const char *name)
	Try to find a device-specific attribute by its name.
__api ssize_t	iio_device_attr_read (const struct iio_device *dev, const char *attr, char *dst, size_t len)
	Read the content of the given device-specific attribute.
__api int	iio_device_attr_read_all (struct iio_device *dev, int(*cb)(struct iio_device *dev, const char *attr, const char *value, size_t len, void *d), void *data)
	Read the content of all device-specific attributes.
__api int	iio_device_attr_read_bool (const struct iio_device *dev, const char *attr, bool *val)
	Read the content of the given device-specific attribute.
__api int	iio_device_attr_read_longlong (const struct iio_device *dev, const char *attr, long long *val)
	Read the content of the given device-specific attribute.
__api int	iio_device_attr_read_double (const struct iio_device *dev, const char *attr, double *val)
	Read the content of the given device-specific attribute.
__api ssize_t	iio_device_attr_write (const struct iio_device *dev, const char *attr, const char *src)
	Set the value of the given device-specific attribute.
__api ssize_t	iio_device_attr_write_raw (const struct iio_device *dev, const char *attr, const void *src, size_t len)
	Set the value of the given device-specific attribute.
__api int	iio_device_attr_write_all (struct iio_device *dev, ssize_t(*cb)(struct iio_device *dev, const char *attr, void *buf, size_t len, void *d), void *data)
	Set the values of all device-specific attributes.
__api int	iio_device_attr_write_bool (const struct iio_device *dev, const char *attr, bool val)
	Set the value of the given device-specific attribute.
__api int	iio_device_attr_write_longlong (const struct iio_device *dev, const char *attr, long long val)
	Set the value of the given device-specific attribute.
__api int	iio_device_attr_write_double (const struct iio_device *dev, const char *attr, double val)
	Set the value of the given device-specific attribute.
__api void	iio_device_set_data (struct iio_device *dev, void *data)
	Associate a pointer to an iio_device structure.
__api void *	iio_device_get_data (const struct iio_device *dev)
	Retrieve a previously associated pointer of an iio_device structure.
__api int	iio_device_get_trigger (const struct iio_device *dev, const struct iio_device **trigger)
	Retrieve the trigger of a given device.
__api int	iio_device_set_trigger (const struct iio_device *dev, const struct iio_device *trigger)
	Associate a trigger to a given device.
__api __pure bool	iio_device_is_trigger (const struct iio_device *dev)
	Return True if the given device is a trigger.
__api int	iio_device_set_kernel_buffers_count (const struct iio_device *dev, unsigned int nb_buffers)
	Configure the number of kernel buffers for a device.

---

Function Documentation

__api ssize_t iio_device_attr_read	(	const struct iio_device *	dev,
		const char *	attr,
		char *	dst,
		size_t	len
	)

Read the content of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
dst	A pointer to the memory area where the NULL-terminated string corresponding to the value read will be stored
len	The available length of the memory area, in bytes

Returns:

On success, the number of bytes written to the buffer

On error, a negative errno code is returned

NOTE:By passing NULL as the "attr" argument to iio_device_attr_read, it is now possible to read all of the attributes of a device.

The buffer is filled with one block of data per attribute of the device, by the order they appear in the iio_device structure.

The first four bytes of one block correspond to a 32-bit signed value in network order. If negative, it corresponds to the errno code that were returned when reading the attribute; if positive, it corresponds to the length of the data read. In that case, the rest of the block contains the data.

__api int iio_device_attr_read_all	(	struct iio_device *	dev,
		int(*)(struct iio_device *dev, const char *attr, const char *value, size_t len, void *d)	cb,
		void *	data
	)

Read the content of all device-specific attributes.

Parameters:

dev	A pointer to an iio_device structure
cb	A pointer to a callback function
data	A pointer that will be passed to the callback function

Returns:

On success, 0 is returned

On error, a negative errno code is returned

NOTE: This function is especially useful when used with the network backend, as all the device-specific attributes are read in one single command.

__api int iio_device_attr_read_bool	(	const struct iio_device *	dev,
		const char *	attr,
		bool *	val
	)

Read the content of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A pointer to a bool variable where the value should be stored

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api int iio_device_attr_read_double	(	const struct iio_device *	dev,
		const char *	attr,
		double *	val
	)

Read the content of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A pointer to a double variable where the value should be stored

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api int iio_device_attr_read_longlong	(	const struct iio_device *	dev,
		const char *	attr,
		long long *	val
	)

Read the content of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A pointer to a long long variable where the value should be stored

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api ssize_t iio_device_attr_write	(	const struct iio_device *	dev,
		const char *	attr,
		const char *	src
	)

Set the value of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
src	A NULL-terminated string to set the attribute to

Returns:

On success, the number of bytes written

On error, a negative errno code is returned

NOTE:By passing NULL as the "attr" argument to iio_device_attr_write, it is now possible to write all of the attributes of a device.

The buffer must contain one block of data per attribute of the device, by the order they appear in the iio_device structure.

The first four bytes of one block correspond to a 32-bit signed value in network order. If negative, the attribute is not written; if positive, it corresponds to the length of the data to write. In that case, the rest of the block must contain the data.

__api int iio_device_attr_write_all	(	struct iio_device *	dev,
		ssize_t(*)(struct iio_device *dev, const char *attr, void *buf, size_t len, void *d)	cb,
		void *	data
	)

Set the values of all device-specific attributes.

Parameters:

dev	A pointer to an iio_device structure
cb	A pointer to a callback function
data	A pointer that will be passed to the callback function

Returns:

On success, 0 is returned

On error, a negative errno code is returned

NOTE: This function is especially useful when used with the network backend, as all the device-specific attributes are written in one single command.

__api int iio_device_attr_write_bool	(	const struct iio_device *	dev,
		const char *	attr,
		bool	val
	)

Set the value of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A bool value to set the attribute to

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api int iio_device_attr_write_double	(	const struct iio_device *	dev,
		const char *	attr,
		double	val
	)

Set the value of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A double value to set the attribute to

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api int iio_device_attr_write_longlong	(	const struct iio_device *	dev,
		const char *	attr,
		long long	val
	)

Set the value of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	A long long value to set the attribute to

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api ssize_t iio_device_attr_write_raw	(	const struct iio_device *	dev,
		const char *	attr,
		const void *	src,
		size_t	len
	)

Set the value of the given device-specific attribute.

Parameters:

dev	A pointer to an iio_device structure
attr	A NULL-terminated string corresponding to the name of the attribute
src	A pointer to the data to be written
len	The number of bytes that should be written

Returns:

On success, the number of bytes written

On error, a negative errno code is returned

__api __pure const char* iio_device_find_attr	(	const struct iio_device *	dev,
		const char *	name
	)

Try to find a device-specific attribute by its name.

Parameters:

dev	A pointer to an iio_device structure
name	A NULL-terminated string corresponding to the name of the attribute

Returns:

On success, a pointer to a static NULL-terminated string

If the name does not correspond to any known attribute of the given device, NULL is returned

NOTE: This function is useful to detect the presence of an attribute. It can also be used to retrieve the name of an attribute as a pointer to a static string from a dynamically allocated string.

__api __pure struct iio_channel* iio_device_find_channel	(	const struct iio_device *	dev,
		const char *	name,
		bool	output
	)		[read]

Try to find a channel structure by its name of ID.

Parameters:

dev	A pointer to an iio_device structure
name	A NULL-terminated string corresponding to the name or the ID of the channel to search for
output	True if the searched channel is output, False otherwise

Returns:

On success, a pointer to an iio_channel structure

If the name or ID does not correspond to any known channel of the given device, NULL is returned

__api __pure const char* iio_device_get_attr	(	const struct iio_device *	dev,
		unsigned int	index
	)

Get the device-specific attribute present at the given index.

Parameters:

dev	A pointer to an iio_device structure
index	The index corresponding to the attribute

Returns:

On success, a pointer to a static NULL-terminated string

If the index is invalid, NULL is returned

__api __pure unsigned int iio_device_get_attrs_count

(

const struct iio_device *

dev

)

Enumerate the device-specific attributes of the given device.

Parameters:

dev	A pointer to an iio_device structure

Returns:

The number of device-specific attributes found

__api __pure struct iio_channel* iio_device_get_channel	(	const struct iio_device *	dev,
		unsigned int	index
	)		[read]

Get the channel present at the given index.

Parameters:

dev	A pointer to an iio_device structure
index	The index corresponding to the channel

Returns:

On success, a pointer to an iio_channel structure

If the index is invalid, NULL is returned

__api __pure unsigned int iio_device_get_channels_count

(

const struct iio_device *

dev

)

Enumerate the channels of the given device.

Parameters:

dev	A pointer to an iio_device structure

Returns:

The number of channels found

__api __pure struct iio_context* iio_device_get_context

(

const struct iio_device *

dev

)

[read]

Retrieve a pointer to the iio_context structure.

Parameters:

dev	A pointer to an iio_device structure

Returns:

A pointer to an iio_context structure

__api void* iio_device_get_data

(

const struct iio_device *

dev

)

Retrieve a previously associated pointer of an iio_device structure.

Parameters:

dev	A pointer to an iio_device structure

Returns:

The pointer previously associated if present, or NULL

__api __pure const char* iio_device_get_id

(

const struct iio_device *

dev

)

Retrieve the device ID (e.g. iio:device0)

Parameters:

dev	A pointer to an iio_device structure

Returns:

A pointer to a static NULL-terminated string

__api __pure const char* iio_device_get_name

(

const struct iio_device *

dev

)

Retrieve the device name (e.g. xadc)

Parameters:

dev	A pointer to an iio_device structure

Returns:

A pointer to a static NULL-terminated string

NOTE: if the device has no name, NULL is returned.

__api int iio_device_get_trigger	(	const struct iio_device *	dev,
		const struct iio_device **	trigger
	)

Retrieve the trigger of a given device.

Parameters:

dev	A pointer to an iio_device structure
trigger	a pointer to a pointer of an iio_device structure. The pointed pointer will be set to the address of the iio_device structure corresponding to the associated trigger device.

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api __pure bool iio_device_is_trigger

(

const struct iio_device *

dev

)

Return True if the given device is a trigger.

Parameters:

dev	A pointer to an iio_device structure

Returns:

True if the device is a trigger, False otherwise

__api void iio_device_set_data	(	struct iio_device *	dev,
		void *	data
	)

Associate a pointer to an iio_device structure.

Parameters:

dev	A pointer to an iio_device structure
data	The pointer to be associated

__api int iio_device_set_kernel_buffers_count	(	const struct iio_device *	dev,
		unsigned int	nb_buffers
	)

Configure the number of kernel buffers for a device.

This function allows to change the number of buffers on kernel side.

Parameters:

dev	A pointer to an iio_device structure
nb_buffers	The number of buffers

Returns:

On success, 0 is returned

On error, a negative errno code is returned

__api int iio_device_set_trigger	(	const struct iio_device *	dev,
		const struct iio_device *	trigger
	)

Associate a trigger to a given device.

Parameters:

dev	A pointer to an iio_device structure
trigger	a pointer to the iio_device structure corresponding to the trigger that should be associated.

Returns:

On success, 0 is returned

On error, a negative errno code is returned