libiio
Classes | Macros | Functions
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_deviceiio_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
chnA pointer to an iio_channel structure
attrA NULL-terminated string corresponding to the name of the attribute
ptrA 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
chnA pointer to an iio_channel structure
attrA NULL-terminated string corresponding to the name of the attribute
valThe 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
chnA pointer to an iio_channel structure
attra 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
chnA pointer to an iio_channel structure
attrA NULL-terminated string corresponding to the name of the attribute
dstA pointer to the memory area where the NULL-terminated string corresponding to the value read will be stored
lenThe 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
chnA pointer to an iio_channel structure
attrA NULL-terminated string corresponding to the name of the attribute
srcA pointer to the data to be written
lenThe 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
chnA pointer to an iio_channel structure
maskThe 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
chnA pointer to an iio_channel structure
maskThe 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
chnA pointer to an iio_channel structure
nameA 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
chnA pointer to an iio_channel structure
indexThe 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA 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
chnA pointer to an iio_channel structure
blockA pointer to an iio_block structure
dstA pointer to the memory area where the converted data will be stored
lenThe available length of the memory area, in bytes
rawTrue 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
chnA pointer to an iio_channel structure
dataThe 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
chnA pointer to an iio_channel structure
blockA pointer to an iio_block structure
srcA pointer to the memory area where the sequential data will be read from
lenThe length of the memory area, in bytes
rawTrue if the samples are already in hardware format, false if they need to be converted.
Returns
The number of bytes actually converted and multiplexed