Channel

Classes
struct	iio_channel
	Represents an input or output channel of a device. More...

Macros
#define	iio_channel_attr_read(chn, attr, ptr)
	Read the content of the given channel-specific attribute. More...
#define	iio_channel_attr_write(chn, attr, val)
	Set the value of the given channel-specific attribute. More...

Functions
__api __check_ret __pure const struct iio_device *	iio_channel_get_device (const struct iio_channel *chn)
	Retrieve a pointer to the iio_device structure. More...
__api __check_ret __pure const char *	iio_channel_get_id (const struct iio_channel *chn)
	Retrieve the channel ID (e.g. More...
__api __check_ret __pure const char *	iio_channel_get_name (const struct iio_channel *chn)
	Retrieve the channel name (e.g. More...
__api __check_ret __pure bool	iio_channel_is_output (const struct iio_channel *chn)
	Return True if the given channel is an output channel. More...
__api __check_ret __pure bool	iio_channel_is_scan_element (const struct iio_channel *chn)
	Return True if the given channel is a scan element. More...
__api __check_ret __pure unsigned int	iio_channel_get_attrs_count (const struct iio_channel *chn)
	Enumerate the channel-specific attributes of the given channel. More...
__api __check_ret __pure const char *	iio_channel_get_attr (const struct iio_channel *chn, unsigned int index)
	Get the channel-specific attribute present at the given index. More...
__api __check_ret __pure const char *	iio_channel_find_attr (const struct iio_channel *chn, const char *name)
	Try to find a channel-specific attribute by its name. More...
__api __check_ret __pure const char *	iio_channel_attr_get_filename (const struct iio_channel *chn, const char *attr)
	Retrieve the filename of an attribute. More...
__api __check_ret ssize_t	iio_channel_attr_read_raw (const struct iio_channel *chn, const char *attr, char *dst, size_t len)
	Read the content of the given channel-specific attribute. More...
__api __check_ret ssize_t	iio_channel_attr_write_raw (const struct iio_channel *chn, const char *attr, const void *src, size_t len)
	Set the value of the given channel-specific attribute. More...
__api void	iio_channel_enable (const struct iio_channel *chn, struct iio_channels_mask *mask)
	Enable the given channel. More...
__api void	iio_channel_disable (const struct iio_channel *chn, struct iio_channels_mask *mask)
	Disable the given channel. More...
__api __check_ret bool	iio_channel_is_enabled (const struct iio_channel *chn, const struct iio_channels_mask *mask)
	Returns True if the channel is enabled. More...
__api __check_ret size_t	iio_channel_read (const struct iio_channel *chn, const struct iio_block *block, void *dst, size_t len, bool raw)
	Demultiplex and convert the samples of a given channel. More...
__api __check_ret size_t	iio_channel_write (const struct iio_channel *chn, struct iio_block *block, const void *src, size_t len, bool raw)
	Convert and multiplex the samples of a given channel. More...
__api void	iio_channel_set_data (struct iio_channel *chn, void *data)
	Associate a pointer to an iio_channel structure. More...
__api void *	iio_channel_get_data (const struct iio_channel *chn)
	Retrieve a previously associated pointer of an iio_channel structure. More...
__api __check_ret __pure enum iio_chan_type	iio_channel_get_type (const struct iio_channel *chn)
	Get the type of the given channel. More...
__api __check_ret __pure enum iio_modifier	iio_channel_get_modifier (const struct iio_channel *chn)
	Get the modifier type of the given channel. More...

Detailed Description

Macro Definition Documentation

iio_channel_attr_read

#define iio_channel_attr_read	(		chn,
			attr,
			ptr
	)

Value:

_Generic((ptr),                     \
         bool *: iio_channel_attr_read_bool,        \
         long long *: iio_channel_attr_read_longlong,   \
         double *: iio_channel_attr_read_double)(chn, attr, ptr)

Read the content of the given channel-specific attribute.

Parameters

chn	A pointer to an iio_channel structure
attr	A NULL-terminated string corresponding to the name of the attribute
ptr	A pointer to the variable where the value should be stored

Returns

On success, 0 is returned

On error, a negative errno code is returned

iio_channel_attr_write

#define iio_channel_attr_write	(		chn,
			attr,
			val
	)

Value:

_Generic((val),                     \
         const char *: iio_channel_attr_write_string,   \
         char *: iio_channel_attr_write_string,     \
         bool: iio_channel_attr_write_bool,     \
         long long: iio_channel_attr_write_longlong,    \
         double: iio_channel_attr_write_double)(chn, attr, val)

Set the value of the given channel-specific attribute.

Parameters

chn	A pointer to an iio_channel structure
attr	A NULL-terminated string corresponding to the name of the attribute
val	The value to set the attribute to

Returns

On success, 0 is returned

On error, a negative errno code is returned

Function Documentation

iio_channel_attr_get_filename()

__api __check_ret __pure const char* iio_channel_attr_get_filename	(	const struct iio_channel *	chn,
		const char *	attr
	)

Retrieve the filename of an attribute.

Parameters

chn	A pointer to an iio_channel structure
attr	a NULL-terminated string corresponding to the name of the attribute

Returns

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

If the attribute name is unknown, NULL is returned

iio_channel_attr_read_raw()

__api __check_ret ssize_t iio_channel_attr_read_raw	(	const struct iio_channel *	chn,
		const char *	attr,
		char *	dst,
		size_t	len
	)

Read the content of the given channel-specific attribute.

Parameters

chn	A pointer to an iio_channel 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

iio_channel_attr_write_raw()

__api __check_ret ssize_t iio_channel_attr_write_raw	(	const struct iio_channel *	chn,
		const char *	attr,
		const void *	src,
		size_t	len
	)

Set the value of the given channel-specific attribute.

Parameters

chn	A pointer to an iio_channel 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

iio_channel_disable()

__api void iio_channel_disable	(	const struct iio_channel *	chn,
		struct iio_channels_mask *	mask
	)

Disable the given channel.

Parameters

chn	A pointer to an iio_channel structure
mask	The channels mask to manipulate

iio_channel_enable()

__api void iio_channel_enable	(	const struct iio_channel *	chn,
		struct iio_channels_mask *	mask
	)

Enable the given channel.

Parameters

chn	A pointer to an iio_channel structure
mask	The channels mask to manipulate

iio_channel_find_attr()

__api __check_ret __pure const char* iio_channel_find_attr	(	const struct iio_channel *	chn,
		const char *	name
	)

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

Parameters

chn	A pointer to an iio_channel 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 channel, 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.

iio_channel_get_attr()

__api __check_ret __pure const char* iio_channel_get_attr	(	const struct iio_channel *	chn,
		unsigned int	index
	)

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

Parameters

chn	A pointer to an iio_channel 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

iio_channel_get_attrs_count()

__api __check_ret __pure unsigned int iio_channel_get_attrs_count

(

const struct iio_channel *

chn

)

Enumerate the channel-specific attributes of the given channel.

Parameters

chn	A pointer to an iio_channel structure

Returns

The number of channel-specific attributes found

iio_channel_get_data()

__api void* iio_channel_get_data

(

const struct iio_channel *

chn

)

Retrieve a previously associated pointer of an iio_channel structure.

Parameters

chn	A pointer to an iio_channel structure

Returns

The pointer previously associated if present, or NULL

iio_channel_get_device()

__api __check_ret __pure const struct iio_device* iio_channel_get_device

(

const struct iio_channel *

chn

)

Retrieve a pointer to the iio_device structure.

Parameters

chn	A pointer to an iio_channel structure

Returns

A pointer to an iio_device structure

iio_channel_get_id()

__api __check_ret __pure const char* iio_channel_get_id

(

const struct iio_channel *

chn

)

Retrieve the channel ID (e.g.

voltage0)

Parameters

chn	A pointer to an iio_channel structure

Returns

A pointer to a static NULL-terminated string

iio_channel_get_modifier()

__api __check_ret __pure enum iio_modifier iio_channel_get_modifier

(

const struct iio_channel *

chn

)

Get the modifier type of the given channel.

Parameters

chn	A pointer to an iio_channel structure

Returns

The modifier type of the channel

iio_channel_get_name()

__api __check_ret __pure const char* iio_channel_get_name

(

const struct iio_channel *

chn

)

Retrieve the channel name (e.g.

vccint)

Parameters

chn	A pointer to an iio_channel structure

Returns

A pointer to a static NULL-terminated string

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

iio_channel_get_type()

__api __check_ret __pure enum iio_chan_type iio_channel_get_type

(

const struct iio_channel *

chn

)

Get the type of the given channel.

Parameters

chn	A pointer to an iio_channel structure

Returns

The type of the channel

iio_channel_is_enabled()

__api __check_ret bool iio_channel_is_enabled	(	const struct iio_channel *	chn,
		const struct iio_channels_mask *	mask
	)

Returns True if the channel is enabled.

Parameters

chn	A pointer to an iio_channel structure

Returns

True if the channel is enabled, False otherwise

iio_channel_is_output()

__api __check_ret __pure bool iio_channel_is_output

(

const struct iio_channel *

chn

)

Return True if the given channel is an output channel.

Parameters

chn	A pointer to an iio_channel structure

Returns

True if the channel is an output channel, False otherwise

iio_channel_is_scan_element()

__api __check_ret __pure bool iio_channel_is_scan_element

(

const struct iio_channel *

chn

)

Return True if the given channel is a scan element.

Parameters

chn	A pointer to an iio_channel structure

Returns

True if the channel is a scan element, False otherwise

NOTE: a channel that is a scan element is a channel that can generate samples (for an input channel) or receive samples (for an output channel) after being enabled.

iio_channel_read()

__api __check_ret size_t iio_channel_read	(	const struct iio_channel *	chn,
		const struct iio_block *	block,
		void *	dst,
		size_t	len,
		bool	raw
	)

Demultiplex and convert the samples of a given channel.

Parameters

chn	A pointer to an iio_channel structure
block	A pointer to an iio_block structure
dst	A pointer to the memory area where the converted data will be stored
len	The available length of the memory area, in bytes
raw	True to read samples in the hardware format, false to read converted samples.

Returns

The size of the converted data, in bytes

iio_channel_set_data()

__api void iio_channel_set_data	(	struct iio_channel *	chn,
		void *	data
	)

Associate a pointer to an iio_channel structure.

Parameters

chn	A pointer to an iio_channel structure
data	The pointer to be associated

iio_channel_write()

__api __check_ret size_t iio_channel_write	(	const struct iio_channel *	chn,
		struct iio_block *	block,
		const void *	src,
		size_t	len,
		bool	raw
	)

Convert and multiplex the samples of a given channel.

Parameters

chn	A pointer to an iio_channel structure
block	A pointer to an iio_block structure
src	A pointer to the memory area where the sequential data will be read from
len	The length of the memory area, in bytes
raw	True if the samples are already in hardware format, false if they need to be converted.

Returns

The number of bytes actually converted and multiplexed