/*      $OpenBSD: midivar.h,v 1.15 2024/10/14 00:47:36 jsg Exp $        */

/*
 * Copyright (c) 2003, 2004 Alexandre Ratchov
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef _SYS_DEV_MIDIVAR_H_
#define _SYS_DEV_MIDIVAR_H_

#include <dev/midi_if.h>
#include <sys/device.h>
#include <sys/event.h>
#include <sys/timeout.h>

#define MIDI_RATE       3125    /* midi uart baud rate in bytes/second */

/*
 * simple ring buffer
 */
#define MIDIBUF_SIZE            (1 << 10)
#define MIDIBUF_MASK            (MIDIBUF_SIZE - 1)

struct midi_buffer {
        struct        klist klist;      /* to record & wakeup poll(2) */
        int           blocking;         /* read/write blocking */
        unsigned char data[MIDIBUF_SIZE]; 
        unsigned      start, used;
};

#define MIDIBUF_START(buf)      ((buf)->start)
#define MIDIBUF_END(buf)        (((buf)->start + (buf)->used) & MIDIBUF_MASK)
#define MIDIBUF_USED(buf)       ((buf)->used)
#define MIDIBUF_AVAIL(buf)      (MIDIBUF_SIZE - (buf)->used)
#define MIDIBUF_ISFULL(buf)     ((buf)->used >= MIDIBUF_SIZE)
#define MIDIBUF_ISEMPTY(buf)    ((buf)->used == 0)
#define MIDIBUF_WRITE(buf, byte)                                \
        do {                                                    \
                (buf)->data[MIDIBUF_END(buf)] = (byte);         \
                (buf)->used++;                                  \
        } while(0)
#define MIDIBUF_READ(buf, byte)                                 \
        do {                                                    \
                (byte) = (buf)->data[(buf)->start++];           \
                (buf)->start &= MIDIBUF_MASK;                   \
                (buf)->used--;                                  \
        } while(0)
#define MIDIBUF_REMOVE(buf, count)                              \
        do {                                                    \
                (buf)->start += (count);                        \
                (buf)->start &= MIDIBUF_MASK;                   \
                (buf)->used  -= (count);                        \
        } while(0)
#define MIDIBUF_INIT(buf)                                       \
        do {                                                    \
                (buf)->start = (buf)->used = 0;                 \
        } while(0)
        

struct midi_softc {
        struct device       dev;
        const struct midi_hw_if *hw_if;
        void               *hw_hdl;
        int                 isbusy;             /* concerns only the output */
        int                 flags;              /* open flags */
        int                 props;              /* midi hw proprieties */
        struct timeout      timeo;
        struct midi_buffer  inbuf;
        struct midi_buffer  outbuf;
};

#endif /* _SYS_DEV_MIDIVAR_H_ */