xref: /linux/sound/core/seq/seq_ports.h (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
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 
29 struct 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 
36 struct 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 
46 struct 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 #if IS_ENABLED(CONFIG_SND_SEQ_UMP)
81 	struct ump_cvt_to_ump_bank midi2_bank[16]; /* per channel */
82 #endif
83 };
84 
85 struct snd_seq_client;
86 
87 /* return pointer to port structure and lock port */
88 struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);
89 
90 /* search for next port - port is locked if found */
91 struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
92 						       struct snd_seq_port_info *pinfo);
93 
94 /* unlock the port */
95 #define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)
96 
97 /* create a port, port number or a negative error code is returned */
98 int snd_seq_create_port(struct snd_seq_client *client, int port_index,
99 			struct snd_seq_client_port **port_ret);
100 
101 /* delete a port */
102 int snd_seq_delete_port(struct snd_seq_client *client, int port);
103 
104 /* delete all ports */
105 int snd_seq_delete_all_ports(struct snd_seq_client *client);
106 
107 /* set port info fields */
108 int snd_seq_set_port_info(struct snd_seq_client_port *port,
109 			  struct snd_seq_port_info *info);
110 
111 /* get port info fields */
112 int snd_seq_get_port_info(struct snd_seq_client_port *port,
113 			  struct snd_seq_port_info *info);
114 
115 /* add subscriber to subscription list */
116 int snd_seq_port_connect(struct snd_seq_client *caller,
117 			 struct snd_seq_client *s, struct snd_seq_client_port *sp,
118 			 struct snd_seq_client *d, struct snd_seq_client_port *dp,
119 			 struct snd_seq_port_subscribe *info);
120 
121 /* remove subscriber from subscription list */
122 int snd_seq_port_disconnect(struct snd_seq_client *caller,
123 			    struct snd_seq_client *s, struct snd_seq_client_port *sp,
124 			    struct snd_seq_client *d, struct snd_seq_client_port *dp,
125 			    struct snd_seq_port_subscribe *info);
126 
127 /* subscribe port */
128 int snd_seq_port_subscribe(struct snd_seq_client_port *port,
129 			   struct snd_seq_port_subscribe *info);
130 
131 /* get matched subscriber */
132 int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
133 				  struct snd_seq_addr *dest_addr,
134 				  struct snd_seq_port_subscribe *subs);
135 
136 #endif
137