mpipe_pad Struct Reference

Pad structure. More...

#include <mpipe_pad.h>

Data Fields
struct mpipe_object	object
	Base object.
enum mpipe_pad_direction	direction
	Pad direction, cannot change after creating the pad.
enum mpipe_pad_presence	presence
	Pad presence.
enum mpipe_pad_mode	mode
	Operating mode.
struct mpipe_pad *	peer
	Pointer to the peer pad this pad is linked to.
struct mpipe_structure	caps
	Pad's capability.
atomic_t	flushing
	Flushing gate.
int(*	process_fn )(struct mpipe_pad *pad, struct net_buf *in_buf, struct net_buf **out_buf)
	Process a buffer.
int(*	query_fn )(struct mpipe_pad *pad, struct mpipe_dispatch *query)
	Answer a query.
int(*	event_fn )(struct mpipe_pad *pad, struct mpipe_dispatch *event)
	Handle an event.
int(*	enum_caps_fn )(struct mpipe_pad *pad, uint32_t index, const struct mpipe_structure *filter, struct mpipe_structure *out)
	Produce one of the pad's supported capabilities.

Detailed Description

Pad structure.

The pad structure represents a connection point of an element. Pads are used to negotiate capabilities and transfer data between elements.

Field Documentation

caps

struct mpipe_structure mpipe_pad::caps

Pad's capability.

ANY until one is negotiated, reset back to ANY on PAUSED to READY

direction

enum mpipe_pad_direction mpipe_pad::direction

Pad direction, cannot change after creating the pad.

enum_caps_fn

int(* mpipe_pad::enum_caps_fn) (struct mpipe_pad *pad, uint32_t index, const struct mpipe_structure *filter, struct mpipe_structure *out)

Produce one of the pad's supported capabilities.

This is how an element says what it supports. The framework calls it with index 0, 1, 2 and so on, one capability per call, until it reports -ENOENT, so several formats live on the index rather than in a list. A capability known at build time is copied out of a static structure; one only known at run time is built by querying the driver. When filter is given, produce the capability narrowed by it, which mpipe_pad_enum_filter does, and report -EAGAIN when this index cannot satisfy it, so the walk moves on to the next one. The default produces the pad's own capability at index 0 and nothing past it.

Parameters

	pad	Pad to enumerate
	index	Zero-based index of the capability
	filter	Capability to narrow by, may be NULL
[out]	out	Caller storage for the capability

Return values

0	Success.
-EAGAIN	This index cannot satisfy filter
-ENOENT	Past the last capability

event_fn

int(* mpipe_pad::event_fn) (struct mpipe_pad *pad, struct mpipe_dispatch *event)

Handle an event.

Parameters

pad	Pad the event arrives on
event	Event to act on and forward

Returns

0 on success, negative errno on failure

flushing

atomic_t mpipe_pad::flushing

Flushing gate.

While set, buffers are dropped instead of processed

mode

enum mpipe_pad_mode mpipe_pad::mode

Operating mode.

object

struct mpipe_object mpipe_pad::object

Base object.

peer

struct mpipe_pad* mpipe_pad::peer

Pointer to the peer pad this pad is linked to.

presence

enum mpipe_pad_presence mpipe_pad::presence

Pad presence.

process_fn

int(* mpipe_pad::process_fn) (struct mpipe_pad *pad, struct net_buf *in_buf, struct net_buf **out_buf)

Process a buffer.

The element's processing function, called on its sink pad for every buffer pushed to it. It owns in_buf and releases it whether it succeeds or fails, and hands back what it produced: a new buffer from its pool, the same buffer transformed in place or passed through, or NULL when it consumed the input, which ends the push.

Parameters

	pad	Sink pad the buffer arrives on
	in_buf	Buffer to process
[out]	out_buf	Buffer produced, or NULL when the input was consumed

Returns

0 on success, negative errno on failure

query_fn

int(* mpipe_pad::query_fn) (struct mpipe_pad *pad, struct mpipe_dispatch *query)

Answer a query.

Parameters

pad	Pad the query arrives on
query	Query to answer in place

Returns

0 on success, negative errno on failure

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The documentation for this struct was generated from the following file:

• include/zephyr/mpipe/mpipe_pad.h