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