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
141

source code of linux/sound/core/seq/seq_ports.h