seq_oss_midi.c

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/*
 * OSS compatible sequencer driver
 *
 * MIDI device handlers
 *
 * Copyright (C) 1998,99 Takashi Iwai <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <sound/asoundef.h>
#include "seq_oss_midi.h"
#include "seq_oss_readq.h"
#include "seq_oss_timer.h"
#include "seq_oss_event.h"
#include <sound/seq_midi_event.h>
#include "../seq_lock.h"
#include <linux/init.h>
#include <linux/slab.h>


/*
 * constants
 */
#define SNDRV_SEQ_OSS_MAX_MIDI_NAME 30

/*
 * definition of midi device record
 */
struct seq_oss_midi {
    int seq_device;     /* device number */
    int client;     /* sequencer client number */
    int port;       /* sequencer port number */
    unsigned int flags; /* port capability */
    int opened;     /* flag for opening */
    unsigned char name[SNDRV_SEQ_OSS_MAX_MIDI_NAME];
    struct snd_midi_event *coder;   /* MIDI event coder */
    struct seq_oss_devinfo *devinfo;    /* assigned OSSseq device */
    snd_use_lock_t use_lock;
};


/*
 * midi device table
 */
static int max_midi_devs;
static struct seq_oss_midi *midi_devs[SNDRV_SEQ_OSS_MAX_MIDI_DEVS];

static DEFINE_SPINLOCK(register_lock);

/*
 * prototypes
 */
static struct seq_oss_midi *get_mdev(int dev);
static struct seq_oss_midi *get_mididev(struct seq_oss_devinfo *dp, int dev);
static int send_synth_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int dev);
static int send_midi_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, struct seq_oss_midi *mdev);

/*
 * look up the existing ports
 * this looks a very exhausting job.
 */
int __init
snd_seq_oss_midi_lookup_ports(int client)
{
    struct snd_seq_client_info *clinfo;
    struct snd_seq_port_info *pinfo;

    clinfo = kzalloc(sizeof(*clinfo), GFP_KERNEL);
    pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
    if (! clinfo || ! pinfo) {
        kfree(clinfo);
        kfree(pinfo);
        return -ENOMEM;
    }
    clinfo->client = -1;
    while (snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_QUERY_NEXT_CLIENT, clinfo) == 0) {
        if (clinfo->client == client)
            continue; /* ignore myself */
        pinfo->addr.client = clinfo->client;
        pinfo->addr.port = -1;
        while (snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_QUERY_NEXT_PORT, pinfo) == 0)
            snd_seq_oss_midi_check_new_port(pinfo);
    }
    kfree(clinfo);
    kfree(pinfo);
    return 0;
}


/*
 */
static struct seq_oss_midi *
get_mdev(int dev)
{
    struct seq_oss_midi *mdev;
    unsigned long flags;

    spin_lock_irqsave(&register_lock, flags);
    mdev = midi_devs[dev];
    if (mdev)
        snd_use_lock_use(&mdev->use_lock);
    spin_unlock_irqrestore(&register_lock, flags);
    return mdev;
}

/*
 * look for the identical slot
 */
static struct seq_oss_midi *
find_slot(int client, int port)
{
    int i;
    struct seq_oss_midi *mdev;
    unsigned long flags;

    spin_lock_irqsave(&register_lock, flags);
    for (i = 0; i < max_midi_devs; i++) {
        mdev = midi_devs[i];
        if (mdev && mdev->client == client && mdev->port == port) {
            /* found! */
            snd_use_lock_use(&mdev->use_lock);
            spin_unlock_irqrestore(&register_lock, flags);
            return mdev;
        }
    }
    spin_unlock_irqrestore(&register_lock, flags);
    return NULL;
}


#define PERM_WRITE (SNDRV_SEQ_PORT_CAP_WRITE|SNDRV_SEQ_PORT_CAP_SUBS_WRITE)
#define PERM_READ (SNDRV_SEQ_PORT_CAP_READ|SNDRV_SEQ_PORT_CAP_SUBS_READ)
/*
 * register a new port if it doesn't exist yet
 */
int
snd_seq_oss_midi_check_new_port(struct snd_seq_port_info *pinfo)
{
    int i;
    struct seq_oss_midi *mdev;
    unsigned long flags;

    debug_printk(("check for MIDI client %d port %d\n", pinfo->addr.client, pinfo->addr.port));
    /* the port must include generic midi */
    if (! (pinfo->type & SNDRV_SEQ_PORT_TYPE_MIDI_GENERIC))
        return 0;
    /* either read or write subscribable */
    if ((pinfo->capability & PERM_WRITE) != PERM_WRITE &&
        (pinfo->capability & PERM_READ) != PERM_READ)
        return 0;

    /*
     * look for the identical slot
     */
    if ((mdev = find_slot(pinfo->addr.client, pinfo->addr.port)) != NULL) {
        /* already exists */
        snd_use_lock_free(&mdev->use_lock);
        return 0;
    }

    /*
     * allocate midi info record
     */
    if ((mdev = kzalloc(sizeof(*mdev), GFP_KERNEL)) == NULL) {
        snd_printk(KERN_ERR "can't malloc midi info\n");
        return -ENOMEM;
    }

    /* copy the port information */
    mdev->client = pinfo->addr.client;
    mdev->port = pinfo->addr.port;
    mdev->flags = pinfo->capability;
    mdev->opened = 0;
    snd_use_lock_init(&mdev->use_lock);

    /* copy and truncate the name of synth device */
    strlcpy(mdev->name, pinfo->name, sizeof(mdev->name));

    /* create MIDI coder */
    if (snd_midi_event_new(MAX_MIDI_EVENT_BUF, &mdev->coder) < 0) {
        snd_printk(KERN_ERR "can't malloc midi coder\n");
        kfree(mdev);
        return -ENOMEM;
    }
    /* OSS sequencer adds running status to all sequences */
    snd_midi_event_no_status(mdev->coder, 1);

    /*
     * look for en empty slot
     */
    spin_lock_irqsave(&register_lock, flags);
    for (i = 0; i < max_midi_devs; i++) {
        if (midi_devs[i] == NULL)
            break;
    }
    if (i >= max_midi_devs) {
        if (max_midi_devs >= SNDRV_SEQ_OSS_MAX_MIDI_DEVS) {
            spin_unlock_irqrestore(&register_lock, flags);
            snd_midi_event_free(mdev->coder);
            kfree(mdev);
            return -ENOMEM;
        }
        max_midi_devs++;
    }
    mdev->seq_device = i;
    midi_devs[mdev->seq_device] = mdev;
    spin_unlock_irqrestore(&register_lock, flags);

    return 0;
}

/*
 * release the midi device if it was registered
 */
int
snd_seq_oss_midi_check_exit_port(int client, int port)
{
    struct seq_oss_midi *mdev;
    unsigned long flags;
    int index;

    if ((mdev = find_slot(client, port)) != NULL) {
        spin_lock_irqsave(&register_lock, flags);
        midi_devs[mdev->seq_device] = NULL;
        spin_unlock_irqrestore(&register_lock, flags);
        snd_use_lock_free(&mdev->use_lock);
        snd_use_lock_sync(&mdev->use_lock);
        if (mdev->coder)
            snd_midi_event_free(mdev->coder);
        kfree(mdev);
    }
    spin_lock_irqsave(&register_lock, flags);
    for (index = max_midi_devs - 1; index >= 0; index--) {
        if (midi_devs[index])
            break;
    }
    max_midi_devs = index + 1;
    spin_unlock_irqrestore(&register_lock, flags);
    return 0;
}


/*
 * release the midi device if it was registered
 */
void
snd_seq_oss_midi_clear_all(void)
{
    int i;
    struct seq_oss_midi *mdev;
    unsigned long flags;

    spin_lock_irqsave(&register_lock, flags);
    for (i = 0; i < max_midi_devs; i++) {
        if ((mdev = midi_devs[i]) != NULL) {
            if (mdev->coder)
                snd_midi_event_free(mdev->coder);
            kfree(mdev);
            midi_devs[i] = NULL;
        }
    }
    max_midi_devs = 0;
    spin_unlock_irqrestore(&register_lock, flags);
}


/*
 * set up midi tables
 */
void
snd_seq_oss_midi_setup(struct seq_oss_devinfo *dp)
{
    dp->max_mididev = max_midi_devs;
}

/*
 * clean up midi tables
 */
void
snd_seq_oss_midi_cleanup(struct seq_oss_devinfo *dp)
{
    int i;
    for (i = 0; i < dp->max_mididev; i++)
        snd_seq_oss_midi_close(dp, i);
    dp->max_mididev = 0;
}


/*
 * open all midi devices.  ignore errors.
 */
void
snd_seq_oss_midi_open_all(struct seq_oss_devinfo *dp, int file_mode)
{
    int i;
    for (i = 0; i < dp->max_mididev; i++)
        snd_seq_oss_midi_open(dp, i, file_mode);
}


/*
 * get the midi device information
 */
static struct seq_oss_midi *
get_mididev(struct seq_oss_devinfo *dp, int dev)
{
    if (dev < 0 || dev >= dp->max_mididev)
        return NULL;
    return get_mdev(dev);
}


/*
 * open the midi device if not opened yet
 */
int
snd_seq_oss_midi_open(struct seq_oss_devinfo *dp, int dev, int fmode)
{
    int perm;
    struct seq_oss_midi *mdev;
    struct snd_seq_port_subscribe subs;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return -ENODEV;

    /* already used? */
    if (mdev->opened && mdev->devinfo != dp) {
        snd_use_lock_free(&mdev->use_lock);
        return -EBUSY;
    }

    perm = 0;
    if (is_write_mode(fmode))
        perm |= PERM_WRITE;
    if (is_read_mode(fmode))
        perm |= PERM_READ;
    perm &= mdev->flags;
    if (perm == 0) {
        snd_use_lock_free(&mdev->use_lock);
        return -ENXIO;
    }

    /* already opened? */
    if ((mdev->opened & perm) == perm) {
        snd_use_lock_free(&mdev->use_lock);
        return 0;
    }

    perm &= ~mdev->opened;

    memset(&subs, 0, sizeof(subs));

    if (perm & PERM_WRITE) {
        subs.sender = dp->addr;
        subs.dest.client = mdev->client;
        subs.dest.port = mdev->port;
        if (snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &subs) >= 0)
            mdev->opened |= PERM_WRITE;
    }
    if (perm & PERM_READ) {
        subs.sender.client = mdev->client;
        subs.sender.port = mdev->port;
        subs.dest = dp->addr;
        subs.flags = SNDRV_SEQ_PORT_SUBS_TIMESTAMP;
        subs.queue = dp->queue;     /* queue for timestamps */
        if (snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_SUBSCRIBE_PORT, &subs) >= 0)
            mdev->opened |= PERM_READ;
    }

    if (! mdev->opened) {
        snd_use_lock_free(&mdev->use_lock);
        return -ENXIO;
    }

    mdev->devinfo = dp;
    snd_use_lock_free(&mdev->use_lock);
    return 0;
}

/*
 * close the midi device if already opened
 */
int
snd_seq_oss_midi_close(struct seq_oss_devinfo *dp, int dev)
{
    struct seq_oss_midi *mdev;
    struct snd_seq_port_subscribe subs;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return -ENODEV;
    if (! mdev->opened || mdev->devinfo != dp) {
        snd_use_lock_free(&mdev->use_lock);
        return 0;
    }

    debug_printk(("closing client %d port %d mode %d\n", mdev->client, mdev->port, mdev->opened));
    memset(&subs, 0, sizeof(subs));
    if (mdev->opened & PERM_WRITE) {
        subs.sender = dp->addr;
        subs.dest.client = mdev->client;
        subs.dest.port = mdev->port;
        snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, &subs);
    }
    if (mdev->opened & PERM_READ) {
        subs.sender.client = mdev->client;
        subs.sender.port = mdev->port;
        subs.dest = dp->addr;
        snd_seq_kernel_client_ctl(dp->cseq, SNDRV_SEQ_IOCTL_UNSUBSCRIBE_PORT, &subs);
    }

    mdev->opened = 0;
    mdev->devinfo = NULL;

    snd_use_lock_free(&mdev->use_lock);
    return 0;
}

/*
 * change seq capability flags to file mode flags
 */
int
snd_seq_oss_midi_filemode(struct seq_oss_devinfo *dp, int dev)
{
    struct seq_oss_midi *mdev;
    int mode;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return 0;

    mode = 0;
    if (mdev->opened & PERM_WRITE)
        mode |= SNDRV_SEQ_OSS_FILE_WRITE;
    if (mdev->opened & PERM_READ)
        mode |= SNDRV_SEQ_OSS_FILE_READ;

    snd_use_lock_free(&mdev->use_lock);
    return mode;
}

/*
 * reset the midi device and close it:
 * so far, only close the device.
 */
void
snd_seq_oss_midi_reset(struct seq_oss_devinfo *dp, int dev)
{
    struct seq_oss_midi *mdev;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return;
    if (! mdev->opened) {
        snd_use_lock_free(&mdev->use_lock);
        return;
    }

    if (mdev->opened & PERM_WRITE) {
        struct snd_seq_event ev;
        int c;

        debug_printk(("resetting client %d port %d\n", mdev->client, mdev->port));
        memset(&ev, 0, sizeof(ev));
        ev.dest.client = mdev->client;
        ev.dest.port = mdev->port;
        ev.queue = dp->queue;
        ev.source.port = dp->port;
        if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_SYNTH) {
            ev.type = SNDRV_SEQ_EVENT_SENSING;
            snd_seq_oss_dispatch(dp, &ev, 0, 0);
        }
        for (c = 0; c < 16; c++) {
            ev.type = SNDRV_SEQ_EVENT_CONTROLLER;
            ev.data.control.channel = c;
            ev.data.control.param = MIDI_CTL_ALL_NOTES_OFF;
            snd_seq_oss_dispatch(dp, &ev, 0, 0);
            if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC) {
                ev.data.control.param =
                    MIDI_CTL_RESET_CONTROLLERS;
                snd_seq_oss_dispatch(dp, &ev, 0, 0);
                ev.type = SNDRV_SEQ_EVENT_PITCHBEND;
                ev.data.control.value = 0;
                snd_seq_oss_dispatch(dp, &ev, 0, 0);
            }
        }
    }
    // snd_seq_oss_midi_close(dp, dev);
    snd_use_lock_free(&mdev->use_lock);
}


/*
 * get client/port of the specified MIDI device
 */
void
snd_seq_oss_midi_get_addr(struct seq_oss_devinfo *dp, int dev, struct snd_seq_addr *addr)
{
    struct seq_oss_midi *mdev;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return;
    addr->client = mdev->client;
    addr->port = mdev->port;
    snd_use_lock_free(&mdev->use_lock);
}


/*
 * input callback - this can be atomic
 */
int
snd_seq_oss_midi_input(struct snd_seq_event *ev, int direct, void *private_data)
{
    struct seq_oss_devinfo *dp = (struct seq_oss_devinfo *)private_data;
    struct seq_oss_midi *mdev;
    int rc;

    if (dp->readq == NULL)
        return 0;
    if ((mdev = find_slot(ev->source.client, ev->source.port)) == NULL)
        return 0;
    if (! (mdev->opened & PERM_READ)) {
        snd_use_lock_free(&mdev->use_lock);
        return 0;
    }

    if (dp->seq_mode == SNDRV_SEQ_OSS_MODE_MUSIC)
        rc = send_synth_event(dp, ev, mdev->seq_device);
    else
        rc = send_midi_event(dp, ev, mdev);

    snd_use_lock_free(&mdev->use_lock);
    return rc;
}

/*
 * convert ALSA sequencer event to OSS synth event
 */
static int
send_synth_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, int dev)
{
    union evrec ossev;

    memset(&ossev, 0, sizeof(ossev));

    switch (ev->type) {
    case SNDRV_SEQ_EVENT_NOTEON:
        ossev.v.cmd = MIDI_NOTEON; break;
    case SNDRV_SEQ_EVENT_NOTEOFF:
        ossev.v.cmd = MIDI_NOTEOFF; break;
    case SNDRV_SEQ_EVENT_KEYPRESS:
        ossev.v.cmd = MIDI_KEY_PRESSURE; break;
    case SNDRV_SEQ_EVENT_CONTROLLER:
        ossev.l.cmd = MIDI_CTL_CHANGE; break;
    case SNDRV_SEQ_EVENT_PGMCHANGE:
        ossev.l.cmd = MIDI_PGM_CHANGE; break;
    case SNDRV_SEQ_EVENT_CHANPRESS:
        ossev.l.cmd = MIDI_CHN_PRESSURE; break;
    case SNDRV_SEQ_EVENT_PITCHBEND:
        ossev.l.cmd = MIDI_PITCH_BEND; break;
    default:
        return 0; /* not supported */
    }

    ossev.v.dev = dev;

    switch (ev->type) {
    case SNDRV_SEQ_EVENT_NOTEON:
    case SNDRV_SEQ_EVENT_NOTEOFF:
    case SNDRV_SEQ_EVENT_KEYPRESS:
        ossev.v.code = EV_CHN_VOICE;
        ossev.v.note = ev->data.note.note;
        ossev.v.parm = ev->data.note.velocity;
        ossev.v.chn = ev->data.note.channel;
        break;
    case SNDRV_SEQ_EVENT_CONTROLLER:
    case SNDRV_SEQ_EVENT_PGMCHANGE:
    case SNDRV_SEQ_EVENT_CHANPRESS:
        ossev.l.code = EV_CHN_COMMON;
        ossev.l.p1 = ev->data.control.param;
        ossev.l.val = ev->data.control.value;
        ossev.l.chn = ev->data.control.channel;
        break;
    case SNDRV_SEQ_EVENT_PITCHBEND:
        ossev.l.code = EV_CHN_COMMON;
        ossev.l.val = ev->data.control.value + 8192;
        ossev.l.chn = ev->data.control.channel;
        break;
    }
    
    snd_seq_oss_readq_put_timestamp(dp->readq, ev->time.tick, dp->seq_mode);
    snd_seq_oss_readq_put_event(dp->readq, &ossev);

    return 0;
}

/*
 * decode event and send MIDI bytes to read queue
 */
static int
send_midi_event(struct seq_oss_devinfo *dp, struct snd_seq_event *ev, struct seq_oss_midi *mdev)
{
    char msg[32];
    int len;
    
    snd_seq_oss_readq_put_timestamp(dp->readq, ev->time.tick, dp->seq_mode);
    if (!dp->timer->running)
        len = snd_seq_oss_timer_start(dp->timer);
    if (ev->type == SNDRV_SEQ_EVENT_SYSEX) {
        if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) == SNDRV_SEQ_EVENT_LENGTH_VARIABLE)
            snd_seq_oss_readq_puts(dp->readq, mdev->seq_device,
                           ev->data.ext.ptr, ev->data.ext.len);
    } else {
        len = snd_midi_event_decode(mdev->coder, msg, sizeof(msg), ev);
        if (len > 0)
            snd_seq_oss_readq_puts(dp->readq, mdev->seq_device, msg, len);
    }

    return 0;
}


/*
 * dump midi data
 * return 0 : enqueued
 *        non-zero : invalid - ignored
 */
int
snd_seq_oss_midi_putc(struct seq_oss_devinfo *dp, int dev, unsigned char c, struct snd_seq_event *ev)
{
    struct seq_oss_midi *mdev;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return -ENODEV;
    if (snd_midi_event_encode_byte(mdev->coder, c, ev) > 0) {
        snd_seq_oss_fill_addr(dp, ev, mdev->client, mdev->port);
        snd_use_lock_free(&mdev->use_lock);
        return 0;
    }
    snd_use_lock_free(&mdev->use_lock);
    return -EINVAL;
}

/*
 * create OSS compatible midi_info record
 */
int
snd_seq_oss_midi_make_info(struct seq_oss_devinfo *dp, int dev, struct midi_info *inf)
{
    struct seq_oss_midi *mdev;

    if ((mdev = get_mididev(dp, dev)) == NULL)
        return -ENXIO;
    inf->device = dev;
    inf->dev_type = 0; /* FIXME: ?? */
    inf->capabilities = 0; /* FIXME: ?? */
    strlcpy(inf->name, mdev->name, sizeof(inf->name));
    snd_use_lock_free(&mdev->use_lock);
    return 0;
}


#ifdef CONFIG_PROC_FS
/*
 * proc interface
 */
static char *
capmode_str(int val)
{
    val &= PERM_READ|PERM_WRITE;
    if (val == (PERM_READ|PERM_WRITE))
        return "read/write";
    else if (val == PERM_READ)
        return "read";
    else if (val == PERM_WRITE)
        return "write";
    else
        return "none";
}

void
snd_seq_oss_midi_info_read(struct snd_info_buffer *buf)
{
    int i;
    struct seq_oss_midi *mdev;

    snd_iprintf(buf, "\nNumber of MIDI devices: %d\n", max_midi_devs);
    for (i = 0; i < max_midi_devs; i++) {
        snd_iprintf(buf, "\nmidi %d: ", i);
        mdev = get_mdev(i);
        if (mdev == NULL) {
            snd_iprintf(buf, "*empty*\n");
            continue;
        }
        snd_iprintf(buf, "[%s] ALSA port %d:%d\n", mdev->name,
                mdev->client, mdev->port);
        snd_iprintf(buf, "  capability %s / opened %s\n",
                capmode_str(mdev->flags),
                capmode_str(mdev->opened));
        snd_use_lock_free(&mdev->use_lock);
    }
}
#endif /* CONFIG_PROC_FS */