seq_ports.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/*
  3 *   ALSA sequencer Ports 
  4 *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
  5 */
  6#ifndef __SND_SEQ_PORTS_H
  7#define __SND_SEQ_PORTS_H
  8
  9#include <sound/seq_kernel.h>
 10#include <sound/ump_convert.h>
 11#include "seq_lock.h"
 12
 13/* list of 'exported' ports */
 14
 15/* Client ports that are not exported are still accessible, but are
 16 anonymous ports. 
 17 
 18 If a port supports SUBSCRIPTION, that port can send events to all
 19 subscribersto a special address, with address
 20 (queue==SNDRV_SEQ_ADDRESS_SUBSCRIBERS). The message is then send to all
 21 recipients that are registered in the subscription list. A typical
 22 application for these SUBSCRIPTION events is handling of incoming MIDI
 23 data. The port doesn't 'know' what other clients are interested in this
 24 message. If for instance a MIDI recording application would like to receive
 25 the events from that port, it will first have to subscribe with that port.
 26 
 27*/
 28
 29struct snd_seq_subscribers {
 30	struct snd_seq_port_subscribe info;	/* additional info */
 31	struct list_head src_list;	/* link of sources */
 32	struct list_head dest_list;	/* link of destinations */
 33	atomic_t ref_count;
 34};
 35
 36struct snd_seq_port_subs_info {
 37	struct list_head list_head;	/* list of subscribed ports */
 38	unsigned int count;		/* count of subscribers */
 39	unsigned int exclusive: 1;	/* exclusive mode */
 40	struct rw_semaphore list_mutex;
 41	rwlock_t list_lock;
 42	int (*open)(void *private_data, struct snd_seq_port_subscribe *info);
 43	int (*close)(void *private_data, struct snd_seq_port_subscribe *info);
 44};
 45
 46struct snd_seq_client_port {
 47
 48	struct snd_seq_addr addr;	/* client/port number */
 49	struct module *owner;		/* owner of this port */
 50	char name[64];			/* port name */	
 51	struct list_head list;		/* port list */
 52	snd_use_lock_t use_lock;
 53
 54	/* subscribers */
 55	struct snd_seq_port_subs_info c_src;	/* read (sender) list */
 56	struct snd_seq_port_subs_info c_dest;	/* write (dest) list */
 57
 58	int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data,
 59			   int atomic, int hop);
 60	void (*private_free)(void *private_data);
 61	void *private_data;
 62	unsigned int closing : 1;
 63	unsigned int timestamping: 1;
 64	unsigned int time_real: 1;
 65	int time_queue;
 66	
 67	/* capability, inport, output, sync */
 68	unsigned int capability;	/* port capability bits */
 69	unsigned int type;		/* port type bits */
 70
 71	/* supported channels */
 72	int midi_channels;
 73	int midi_voices;
 74	int synth_voices;
 75		
 76	/* UMP direction and group */
 77	unsigned char direction;
 78	unsigned char ump_group;
 79
 80	bool is_midi1;	/* keep MIDI 1.0 protocol */
 81
 82#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
 83	struct ump_cvt_to_ump_bank midi2_bank[16]; /* per channel */
 84#endif
 85};
 86
 87struct snd_seq_client;
 88
 89/* return pointer to port structure and lock port */
 90struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);
 91
 92/* search for next port - port is locked if found */
 93struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
 94						       struct snd_seq_port_info *pinfo);
 95
 96/* unlock the port */
 97#define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)
 98
 99DEFINE_FREE(snd_seq_port, struct snd_seq_client_port *, if (!IS_ERR_OR_NULL(_T)) snd_seq_port_unlock(_T))
100
101/* create a port, port number or a negative error code is returned */
102int snd_seq_create_port(struct snd_seq_client *client, int port_index,
103			struct snd_seq_client_port **port_ret);
104
105/* delete a port */
106int snd_seq_delete_port(struct snd_seq_client *client, int port);
107
108/* delete all ports */
109int snd_seq_delete_all_ports(struct snd_seq_client *client);
110
111/* set port info fields */
112int snd_seq_set_port_info(struct snd_seq_client_port *port,
113			  struct snd_seq_port_info *info);
114
115/* get port info fields */
116int snd_seq_get_port_info(struct snd_seq_client_port *port,
117			  struct snd_seq_port_info *info);
118
119/* add subscriber to subscription list */
120int snd_seq_port_connect(struct snd_seq_client *caller,
121			 struct snd_seq_client *s, struct snd_seq_client_port *sp,
122			 struct snd_seq_client *d, struct snd_seq_client_port *dp,
123			 struct snd_seq_port_subscribe *info);
124
125/* remove subscriber from subscription list */ 
126int snd_seq_port_disconnect(struct snd_seq_client *caller,
127			    struct snd_seq_client *s, struct snd_seq_client_port *sp,
128			    struct snd_seq_client *d, struct snd_seq_client_port *dp,
129			    struct snd_seq_port_subscribe *info);
130
131/* subscribe port */
132int snd_seq_port_subscribe(struct snd_seq_client_port *port,
133			   struct snd_seq_port_subscribe *info);
134
135/* get matched subscriber */
136int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
137				  struct snd_seq_addr *dest_addr,
138				  struct snd_seq_port_subscribe *subs);
139
140#endif