/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __SOUND_RAWMIDI_H
#define __SOUND_RAWMIDI_H

/*
 *  Abstract layer for MIDI v1.0 stream
 *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
 */

#include <sound/asound.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/device.h>

#if IS_ENABLED(CONFIG_SND_SEQUENCER)
#include <sound/seq_device.h>
#endif
#include <sound/info.h>

/*
 *  Raw MIDI interface
 */

#define SNDRV_RAWMIDI_DEVICES           8

#define SNDRV_RAWMIDI_LFLG_OUTPUT       (1<<0)
#define SNDRV_RAWMIDI_LFLG_INPUT        (1<<1)
#define SNDRV_RAWMIDI_LFLG_OPEN         (3<<0)
#define SNDRV_RAWMIDI_LFLG_APPEND       (1<<2)

struct snd_rawmidi;
struct snd_rawmidi_substream;
struct snd_seq_port_info;
struct pid;

struct snd_rawmidi_ops {
        int (*open) (struct snd_rawmidi_substream * substream);
        int (*close) (struct snd_rawmidi_substream * substream);
        void (*trigger) (struct snd_rawmidi_substream * substream, int up);
        void (*drain) (struct snd_rawmidi_substream * substream);
};

struct snd_rawmidi_global_ops {
        int (*dev_register) (struct snd_rawmidi * rmidi);
        int (*dev_unregister) (struct snd_rawmidi * rmidi);
        void (*get_port_info)(struct snd_rawmidi *rmidi, int number,
                              struct snd_seq_port_info *info);
        long (*ioctl)(struct snd_rawmidi *rmidi, unsigned int cmd,
                      void __user *argp);
        void (*proc_read)(struct snd_info_entry *entry,
                          struct snd_info_buffer *buf);
};

struct snd_rawmidi_runtime {
        struct snd_rawmidi_substream *substream;
        unsigned int drain: 1,  /* drain stage */
                     oss: 1;    /* OSS compatible mode */
        /* midi stream buffer */
        unsigned char *buffer;  /* buffer for MIDI data */
        size_t buffer_size;     /* size of buffer */
        size_t appl_ptr;        /* application pointer */
        size_t hw_ptr;          /* hardware pointer */
        size_t avail_min;       /* min avail for wakeup */
        size_t avail;           /* max used buffer for wakeup */
        size_t xruns;           /* over/underruns counter */
        size_t align;           /* alignment (0 = byte stream, 3 = UMP) */
        int buffer_ref;         /* buffer reference count */
        /* misc */
        wait_queue_head_t sleep;
        /* event handler (new bytes, input only) */
        void (*event)(struct snd_rawmidi_substream *substream);
        /* defers calls to event [input] or ops->trigger [output] */
        struct work_struct event_work;
        /* private data */
        void *private_data;
        void (*private_free)(struct snd_rawmidi_substream *substream);
};

struct snd_rawmidi_substream {
        struct list_head list;          /* list of all substream for given stream */
        int stream;                     /* direction */
        int number;                     /* substream number */
        bool opened;                    /* open flag */
        bool append;                    /* append flag (merge more streams) */
        bool active_sensing;            /* send active sensing when close */
        unsigned int framing;           /* whether to frame input data */
        unsigned int clock_type;        /* clock source to use for input framing */
        int use_count;                  /* use counter (for output) */
        bool inactive;                  /* inactive substream (for UMP legacy) */
        size_t bytes;
        spinlock_t lock;
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_str *pstr;
        char name[32];
        struct snd_rawmidi_runtime *runtime;
        struct pid *pid;
        /* hardware layer */
        const struct snd_rawmidi_ops *ops;
};

struct snd_rawmidi_file {
        struct snd_rawmidi *rmidi;
        struct snd_rawmidi_substream *input;
        struct snd_rawmidi_substream *output;
        unsigned int user_pversion;     /* supported protocol version */
};

struct snd_rawmidi_str {
        unsigned int substream_count;
        unsigned int substream_opened;
        struct list_head substreams;
};

struct snd_rawmidi {
        struct snd_card *card;
        struct list_head list;
        unsigned int device;            /* device number */
        unsigned int info_flags;        /* SNDRV_RAWMIDI_INFO_XXXX */
        unsigned int tied_device;
        char id[64];
        char name[80];

#ifdef CONFIG_SND_OSSEMUL
        int ossreg;
#endif

        const struct snd_rawmidi_global_ops *ops;

        struct snd_rawmidi_str streams[2];

        void *private_data;
        void (*private_free) (struct snd_rawmidi *rmidi);

        struct mutex open_mutex;
        wait_queue_head_t open_wait;

        struct device *dev;

        struct snd_info_entry *proc_entry;

#if IS_ENABLED(CONFIG_SND_SEQUENCER)
        struct snd_seq_device *seq_dev;
#endif
};

/* main rawmidi functions */

int snd_rawmidi_new(struct snd_card *card, char *id, int device,
                    int output_count, int input_count,
                    struct snd_rawmidi **rmidi);
void snd_rawmidi_set_ops(struct snd_rawmidi *rmidi, int stream,
                         const struct snd_rawmidi_ops *ops);

/* internal */
int snd_rawmidi_init(struct snd_rawmidi *rmidi,
                     struct snd_card *card, char *id, int device,
                     int output_count, int input_count,
                     unsigned int info_flags);
int snd_rawmidi_free(struct snd_rawmidi *rmidi);

/* callbacks */

int snd_rawmidi_receive(struct snd_rawmidi_substream *substream,
                        const unsigned char *buffer, int count);
int snd_rawmidi_transmit_empty(struct snd_rawmidi_substream *substream);
int snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream,
                              unsigned char *buffer, int count);
int snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count);
int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream,
                         unsigned char *buffer, int count);
int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream);

/* main midi functions */

int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info);
int snd_rawmidi_kernel_open(struct snd_rawmidi *rmidi, int subdevice,
                            int mode, struct snd_rawmidi_file *rfile);
int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile);
int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream,
                              struct snd_rawmidi_params *params);
int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream,
                             struct snd_rawmidi_params *params);
int snd_rawmidi_drop_output(struct snd_rawmidi_substream *substream);
int snd_rawmidi_drain_output(struct snd_rawmidi_substream *substream);
int snd_rawmidi_drain_input(struct snd_rawmidi_substream *substream);
long snd_rawmidi_kernel_read(struct snd_rawmidi_substream *substream,
                             unsigned char *buf, long count);
long snd_rawmidi_kernel_write(struct snd_rawmidi_substream *substream,
                              const unsigned char *buf, long count);

/* set up the tied devices */
static inline void snd_rawmidi_tie_devices(struct snd_rawmidi *r1,
                                           struct snd_rawmidi *r2)
{
        /* tied_device field keeps the device+1 (so that 0 being unknown) */
        r1->tied_device = r2->device + 1;
        r2->tied_device = r1->device + 1;
}

#endif /* __SOUND_RAWMIDI_H */