seq_ports.h | Explore in Territory

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *   ALSA sequencer Ports 
 *   Copyright (c) 1998 by Frank van de Pol <[email protected]>
 */
#ifndef __SND_SEQ_PORTS_H
#define __SND_SEQ_PORTS_H

#include <sound/seq_kernel.h>
#include <sound/ump_convert.h>
#include "seq_lock.h"

/* list of 'exported' ports */

/* Client ports that are not exported are still accessible, but are
 anonymous ports. 
 
 If a port supports SUBSCRIPTION, that port can send events to all
 subscribersto a special address, with address
 (queue==SNDRV_SEQ_ADDRESS_SUBSCRIBERS). The message is then send to all
 recipients that are registered in the subscription list. A typical
 application for these SUBSCRIPTION events is handling of incoming MIDI
 data. The port doesn't 'know' what other clients are interested in this
 message. If for instance a MIDI recording application would like to receive
 the events from that port, it will first have to subscribe with that port.
 
*/

struct snd_seq_subscribers { … };

struct snd_seq_port_subs_info { … };

struct snd_seq_client_port { … };

struct snd_seq_client;

/* return pointer to port structure and lock port */
struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);

/* search for next port - port is locked if found */
struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
						       struct snd_seq_port_info *pinfo);

/* unlock the port */
#define snd_seq_port_unlock(port) …

/* create a port, port number or a negative error code is returned */
int snd_seq_create_port(struct snd_seq_client *client, int port_index,
			struct snd_seq_client_port **port_ret);

/* delete a port */
int snd_seq_delete_port(struct snd_seq_client *client, int port);

/* delete all ports */
int snd_seq_delete_all_ports(struct snd_seq_client *client);

/* set port info fields */
int snd_seq_set_port_info(struct snd_seq_client_port *port,
			  struct snd_seq_port_info *info);

/* get port info fields */
int snd_seq_get_port_info(struct snd_seq_client_port *port,
			  struct snd_seq_port_info *info);

/* add subscriber to subscription list */
int snd_seq_port_connect(struct snd_seq_client *caller,
			 struct snd_seq_client *s, struct snd_seq_client_port *sp,
			 struct snd_seq_client *d, struct snd_seq_client_port *dp,
			 struct snd_seq_port_subscribe *info);

/* remove subscriber from subscription list */ 
int snd_seq_port_disconnect(struct snd_seq_client *caller,
			    struct snd_seq_client *s, struct snd_seq_client_port *sp,
			    struct snd_seq_client *d, struct snd_seq_client_port *dp,
			    struct snd_seq_port_subscribe *info);

/* subscribe port */
int snd_seq_port_subscribe(struct snd_seq_client_port *port,
			   struct snd_seq_port_subscribe *info);

/* get matched subscriber */
int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
				  struct snd_seq_addr *dest_addr,
				  struct snd_seq_port_subscribe *subs);

#endif
linux/sound/core/seq/seq_ports.h
