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 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 87 struct snd_seq_client; 88 89 /* return pointer to port structure and lock port */ 90 struct 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 */ 93 struct 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 99 /* create a port, port number or a negative error code is returned */ 100 int snd_seq_create_port(struct snd_seq_client *client, int port_index, 101 struct snd_seq_client_port **port_ret); 102 103 /* delete a port */ 104 int snd_seq_delete_port(struct snd_seq_client *client, int port); 105 106 /* delete all ports */ 107 int snd_seq_delete_all_ports(struct snd_seq_client *client); 108 109 /* set port info fields */ 110 int snd_seq_set_port_info(struct snd_seq_client_port *port, 111 struct snd_seq_port_info *info); 112 113 /* get port info fields */ 114 int snd_seq_get_port_info(struct snd_seq_client_port *port, 115 struct snd_seq_port_info *info); 116 117 /* add subscriber to subscription list */ 118 int snd_seq_port_connect(struct snd_seq_client *caller, 119 struct snd_seq_client *s, struct snd_seq_client_port *sp, 120 struct snd_seq_client *d, struct snd_seq_client_port *dp, 121 struct snd_seq_port_subscribe *info); 122 123 /* remove subscriber from subscription list */ 124 int snd_seq_port_disconnect(struct snd_seq_client *caller, 125 struct snd_seq_client *s, struct snd_seq_client_port *sp, 126 struct snd_seq_client *d, struct snd_seq_client_port *dp, 127 struct snd_seq_port_subscribe *info); 128 129 /* subscribe port */ 130 int snd_seq_port_subscribe(struct snd_seq_client_port *port, 131 struct snd_seq_port_subscribe *info); 132 133 /* get matched subscriber */ 134 int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp, 135 struct snd_seq_addr *dest_addr, 136 struct snd_seq_port_subscribe *subs); 137 138 #endif 139