/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *   ALSA sequencer Ports 
 *   Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
 */
#ifndef __SND_SEQ_PORTS_H
#define __SND_SEQ_PORTS_H

#include <sound/seq_kernel.h>
#include <sound/ump_convert.h>
#include "seq_lock.h"

/* list of 'exported' ports */

/* Client ports that are not exported are still accessible, but are
 anonymous ports. 
 
 If a port supports SUBSCRIPTION, that port can send events to all
 subscribersto a special address, with address
 (queue==SNDRV_SEQ_ADDRESS_SUBSCRIBERS). The message is then send to all
 recipients that are registered in the subscription list. A typical
 application for these SUBSCRIPTION events is handling of incoming MIDI
 data. The port doesn't 'know' what other clients are interested in this
 message. If for instance a MIDI recording application would like to receive
 the events from that port, it will first have to subscribe with that port.
 
*/

struct snd_seq_subscribers {
        struct snd_seq_port_subscribe info;     /* additional info */
        struct list_head src_list;      /* link of sources */
        struct list_head dest_list;     /* link of destinations */
        atomic_t ref_count;
};

struct snd_seq_port_subs_info {
        struct list_head list_head;     /* list of subscribed ports */
        unsigned int count;             /* count of subscribers */
        unsigned int exclusive: 1;      /* exclusive mode */
        struct rw_semaphore list_mutex;
        rwlock_t list_lock;
        int (*open)(void *private_data, struct snd_seq_port_subscribe *info);
        int (*close)(void *private_data, struct snd_seq_port_subscribe *info);
};

struct snd_seq_client_port {

        struct snd_seq_addr addr;       /* client/port number */
        struct module *owner;           /* owner of this port */
        char name[64];                  /* port name */ 
        struct list_head list;          /* port list */
        snd_use_lock_t use_lock;

        /* subscribers */
        struct snd_seq_port_subs_info c_src;    /* read (sender) list */
        struct snd_seq_port_subs_info c_dest;   /* write (dest) list */

        int (*event_input)(struct snd_seq_event *ev, int direct, void *private_data,
                           int atomic, int hop);
        void (*private_free)(void *private_data);
        void *private_data;
        unsigned int closing : 1;
        unsigned int timestamping: 1;
        unsigned int time_real: 1;
        int time_queue;
        
        /* capability, inport, output, sync */
        unsigned int capability;        /* port capability bits */
        unsigned int type;              /* port type bits */

        /* supported channels */
        int midi_channels;
        int midi_voices;
        int synth_voices;
                
        /* UMP direction and group */
        unsigned char direction;
        unsigned char ump_group;

        bool is_midi1;  /* keep MIDI 1.0 protocol */

#if IS_ENABLED(CONFIG_SND_SEQ_UMP)
        struct ump_cvt_to_ump_bank midi2_bank[16]; /* per channel */
#endif
};

struct snd_seq_client;

/* return pointer to port structure and lock port */
struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client, int num);

/* search for next port - port is locked if found */
struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
                                                       struct snd_seq_port_info *pinfo);

/* unlock the port */
#define snd_seq_port_unlock(port) snd_use_lock_free(&(port)->use_lock)

DEFINE_FREE(snd_seq_port, struct snd_seq_client_port *, if (!IS_ERR_OR_NULL(_T)) snd_seq_port_unlock(_T))

/* create a port, port number or a negative error code is returned */
int snd_seq_create_port(struct snd_seq_client *client, int port_index,
                        struct snd_seq_client_port **port_ret);

/* delete a port */
int snd_seq_delete_port(struct snd_seq_client *client, int port);

/* delete all ports */
int snd_seq_delete_all_ports(struct snd_seq_client *client);

/* set port info fields */
int snd_seq_set_port_info(struct snd_seq_client_port *port,
                          struct snd_seq_port_info *info);

/* get port info fields */
int snd_seq_get_port_info(struct snd_seq_client_port *port,
                          struct snd_seq_port_info *info);

/* add subscriber to subscription list */
int snd_seq_port_connect(struct snd_seq_client *caller,
                         struct snd_seq_client *s, struct snd_seq_client_port *sp,
                         struct snd_seq_client *d, struct snd_seq_client_port *dp,
                         struct snd_seq_port_subscribe *info);

/* remove subscriber from subscription list */ 
int snd_seq_port_disconnect(struct snd_seq_client *caller,
                            struct snd_seq_client *s, struct snd_seq_client_port *sp,
                            struct snd_seq_client *d, struct snd_seq_client_port *dp,
                            struct snd_seq_port_subscribe *info);

/* subscribe port */
int snd_seq_port_subscribe(struct snd_seq_client_port *port,
                           struct snd_seq_port_subscribe *info);

/* get matched subscriber */
int snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
                                  struct snd_seq_addr *dest_addr,
                                  struct snd_seq_port_subscribe *subs);

#endif