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 "seq_lock.h"
11
12/* list of 'exported' ports */
13
14/* Client ports that are not exported are still accessible, but are
15 anonymous ports.
16
17 If a port supports SUBSCRIPTION, that port can send events to all
18 subscribersto a special address, with address
19 (queue==SNDRV_SEQ_ADDRESS_SUBSCRIBERS). The message is then send to all
20 recipients that are registered in the subscription list. A typical
21 application for these SUBSCRIPTION events is handling of incoming MIDI
22 data. The port doesn't 'know' what other clients are interested in this
23 message. If for instance a MIDI recording application would like to receive
24 the events from that port, it will first have to subscribe with that port.
25
26*/
27
28struct snd_seq_subscribers {
29 struct snd_seq_port_subscribe info; /* additional info */
30 struct list_head src_list; /* link of sources */
31 struct list_head dest_list; /* link of destinations */
32 atomic_t ref_count;
33};
34
35struct snd_seq_port_subs_info {
36 struct list_head list_head; /* list of subscribed ports */
37 unsigned int count; /* count of subscribers */
38 unsigned int exclusive: 1; /* exclusive mode */
39 struct rw_semaphore list_mutex;
40 rwlock_t list_lock;
41 int (*open)(void *private_data, struct snd_seq_port_subscribe *info);
42 int (*close)(void *private_data, struct snd_seq_port_subscribe *info);
43};
44
45/* context for converting from legacy control event to UMP packet */
46struct snd_seq_ump_midi2_bank {
47 bool rpn_set;
48 bool nrpn_set;
49 bool bank_set;
50 unsigned char cc_rpn_msb, cc_rpn_lsb;
51 unsigned char cc_nrpn_msb, cc_nrpn_lsb;
52 unsigned char cc_data_msb, cc_data_lsb;
53 unsigned char cc_bank_msb, cc_bank_lsb;
54};
55
56struct snd_seq_client_port {
57
58 struct snd_seq_addr addr; /* client/port number */
59 struct module *owner; /* owner of this port */
60 char name[64]; /* port name */
61 struct list_head list; /* port list */
62 snd_use_lock_t use_lock;
63
64 /* subscribers */
65 struct snd_seq_port_subs_info c_src; /* read (sender) list */
66 struct snd_seq_port_subs_info c_dest; /* write (dest) list */
67
68 int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data,
69 int atomic, int hop);
70 void (*private_free)(void *private_data);
71 void *private_data;
72 unsigned int closing : 1;
73 unsigned int timestamping: 1;
74 unsigned int time_real: 1;
75 int time_queue;
76
77 /* capability, inport, output, sync */
78 unsigned int capability; /* port capability bits */
79 unsigned int type; /* port type bits */
80
81 /* supported channels */
82 int midi_channels;
83 int midi_voices;
84 int synth_voices;
85
86 /* UMP direction and group */
87 unsigned char direction;
88 unsigned char ump_group;
89
90#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
91 struct snd_seq_ump_midi2_bank midi2_bank[16]; /* per channel */
92#endif
93};
94
95struct snd_seq_client;
96
97/* return pointer to port structure and lock port */
98struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);
99
100/* search for next port - port is locked if found */
101struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
102 struct snd_seq_port_info *pinfo);
103
104/* unlock the port */
105#define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)
106
107/* create a port, port number or a negative error code is returned */
108int snd_seq_create_port(struct snd_seq_client *client, int port_index,
109 struct snd_seq_client_port **port_ret);
110
111/* delete a port */
112int snd_seq_delete_port(struct snd_seq_client *client, int port);
113
114/* delete all ports */
115int snd_seq_delete_all_ports(struct snd_seq_client *client);
116
117/* set port info fields */
118int snd_seq_set_port_info(struct snd_seq_client_port *port,
119 struct snd_seq_port_info *info);
120
121/* get port info fields */
122int snd_seq_get_port_info(struct snd_seq_client_port *port,
123 struct snd_seq_port_info *info);
124
125/* add subscriber to subscription list */
126int snd_seq_port_connect(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/* remove subscriber from subscription list */
132int snd_seq_port_disconnect(struct snd_seq_client *caller,
133 struct snd_seq_client *s, struct snd_seq_client_port *sp,
134 struct snd_seq_client *d, struct snd_seq_client_port *dp,
135 struct snd_seq_port_subscribe *info);
136
137/* subscribe port */
138int snd_seq_port_subscribe(struct snd_seq_client_port *port,
139 struct snd_seq_port_subscribe *info);
140
141/* get matched subscriber */
142int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
143 struct snd_seq_addr *dest_addr,
144 struct snd_seq_port_subscribe *subs);
145
146#endif
147

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