/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * ALSA sequencer Ports * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl> */ #ifndef __SND_SEQ_PORTS_H #define __SND_SEQ_PORTS_H #include <sound/seq_kernel.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_subscribe info; /* additional info */ struct list_head src_list; /* link of sources */ struct list_head dest_list; /* link of destinations */ atomic_t ref_count; }; struct snd_seq_port_subs_info { struct list_head list_head; /* list of subscribed ports */ unsigned int count; /* count of subscribers */ unsigned int exclusive: 1; /* exclusive mode */ struct rw_semaphore list_mutex; rwlock_t list_lock; int (*open)(void *private_data, struct snd_seq_port_subscribe *info); int (*close)(void *private_data, struct snd_seq_port_subscribe *info); }; struct snd_seq_client_port { struct snd_seq_addr addr; /* client/port number */ struct module *owner; /* owner of this port */ char name[64]; /* port name */ struct list_head list; /* port list */ snd_use_lock_t use_lock; /* subscribers */ struct snd_seq_port_subs_info c_src; /* read (sender) list */ struct snd_seq_port_subs_info c_dest; /* write (dest) list */ int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data, int atomic, int hop); void (*private_free)(void *private_data); void *private_data; unsigned int closing : 1; unsigned int timestamping: 1; unsigned int time_real: 1; int time_queue; /* capability, inport, output, sync */ unsigned int capability; /* port capability bits */ unsigned int type; /* port type bits */ /* supported channels */ int midi_channels; int midi_voices; int synth_voices; }; 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) snd_use_lock_free(&(port)->use_lock) /* create a port, port number is returned (-1 on failure) */ struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client, int port_index); /* 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