seq_oss_midi.c

Archos AVX Linux Sound driver source code

/*
 * OSS compatible sequencer driver
 *
 * MIDI device handlers
 *
 * Copyright (C) 1998,99 Takashi Iwai <[e-mail]>
 *
 * 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 "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>


/*
 * constants
 */
#define SNDRV_SEQ_OSS_MAX_MIDI_NAME	30

/*
 * definition of midi device record
 */
struct seq_oss_midi_t {
	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];
	snd_midi_event_t *coder;	/* MIDI event coder */
	seq_oss_devinfo_t *devinfo;	/* assigned OSSseq device */
	snd_use_lock_t use_lock;
};


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

static spinlock_t register_lock = SPIN_LOCK_UNLOCKED;

/*
 * prototypes
 */
static seq_oss_midi_t *get_mdev(int dev);
static seq_oss_midi_t *get_mididev(seq_oss_devinfo_t *dp, int dev);
static int send_synth_event(seq_oss_devinfo_t *dp, snd_seq_event_t *ev, int dev);
static int send_midi_event(seq_oss_devinfo_t *dp, snd_seq_event_t *ev, seq_oss_midi_t *mdev);

/*
 * look up the existing ports
 * this looks a very exhausting job.
 */
int __init
snd_seq_oss_midi_lookup_ports(int client)
{
	snd_seq_system_info_t sysinfo;
	snd_seq_client_info_t clinfo;
	snd_seq_port_info_t pinfo;
	int rc;

	rc = snd_seq_kernel_client_ctl(client, SNDRV_SEQ_IOCTL_SYSTEM_INFO, &sysinfo);
	if (rc < 0)
		return rc;
	
	memset(&clinfo, 0, sizeof(clinfo));
	memset(&pinfo, 0, sizeof(pinfo));
	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);
	}
	return 0;
}


/*
 */
static seq_oss_midi_t *
get_mdev(int dev)
{
	seq_oss_midi_t *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 seq_oss_midi_t *
find_slot(int client, int port)
{
	int i;
	seq_oss_midi_t *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(snd_seq_port_info_t *pinfo)
{
	int i;
	seq_oss_midi_t *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 = kcalloc(1, 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)
{
	seq_oss_midi_t *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;
	seq_oss_midi_t *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(seq_oss_devinfo_t *dp)
{
	dp->max_mididev = max_midi_devs;
}

/*
 * clean up midi tables
 */
void
snd_seq_oss_midi_cleanup(seq_oss_devinfo_t *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(seq_oss_devinfo_t *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 seq_oss_midi_t *
get_mididev(seq_oss_devinfo_t *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(seq_oss_devinfo_t *dp, int dev, int fmode)
{
	int perm;
	seq_oss_midi_t *mdev;
	snd_seq_port_subscribe_t 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);