alsa-lib/src/rawmidi/rawmidi.c

/*
 *  RawMIDI Interface - main file
 *  Copyright (c) 2000 by Jaroslav Kysela <perex@suse.cz>
 *                        Abramo Bagnara <abramo@alsa-project.org>
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Library 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 Library General Public License for more details.
 *
 *   You should have received a copy of the GNU Library General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <dlfcn.h>
#include <asm/page.h>
#include "rawmidi_local.h"

static inline int snd_rawmidi_stream_ok(snd_rawmidi_t *rmidi, snd_rawmidi_stream_t stream)
{
	assert(rmidi);
	assert(stream == SND_RAWMIDI_STREAM_INPUT || 
	       stream == SND_RAWMIDI_STREAM_OUTPUT);
	return rmidi->streams & (1 << (snd_enum_to_int(stream)));
}

int snd_rawmidi_close(snd_rawmidi_t *rmidi)
{
	int err;
  	assert(rmidi);
	if ((err = rmidi->ops->close(rmidi)) < 0)
		return err;
	if (rmidi->name)
		free(rmidi->name);
	free(rmidi);
	return 0;
}

int snd_rawmidi_poll_descriptor(snd_rawmidi_t *rmidi,
				snd_rawmidi_stream_t stream ATTRIBUTE_UNUSED)
{
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	return rmidi->poll_fd;
}

int snd_rawmidi_nonblock(snd_rawmidi_t *rmidi, 
			 snd_rawmidi_stream_t stream ATTRIBUTE_UNUSED,
			 int nonblock)
{
	int err;
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	assert(!(rmidi->mode & SND_RAWMIDI_APPEND));
	if ((err = rmidi->ops->nonblock(rmidi, nonblock)) < 0)
		return err;
	if (nonblock)
		rmidi->mode |= SND_RAWMIDI_NONBLOCK;
	else
		rmidi->mode &= ~SND_RAWMIDI_NONBLOCK;
	return 0;
}

int snd_rawmidi_info(snd_rawmidi_t *rmidi,
		     snd_rawmidi_stream_t stream,
		     snd_rawmidi_info_t * info)
{
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	assert(info);
	info->stream = snd_enum_to_int(stream);
	return rmidi->ops->info(rmidi, info);
}

int snd_rawmidi_params(snd_rawmidi_t *rmidi, 
		       snd_rawmidi_stream_t stream,
		       snd_rawmidi_params_t * params)
{
	int err;
	snd_rawmidi_str_t *pstr;
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	assert(params);
	params->stream = snd_enum_to_int(stream);
	err = rmidi->ops->params(rmidi, params);
	if (err < 0)
		return err;
	pstr = &rmidi->stream[snd_enum_to_int(stream)];
	pstr->buffer_size = params->buffer_size;
	pstr->avail_min = params->avail_min;
	pstr->no_active_sensing = params->no_active_sensing;
	return 0;
}

int snd_rawmidi_status(snd_rawmidi_t *rmidi,
		       snd_rawmidi_stream_t stream,
		       snd_rawmidi_status_t * status)
{
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	assert(status);
	status->stream = snd_enum_to_int(stream);
	return rmidi->ops->status(rmidi, status);
}

int snd_rawmidi_drop(snd_rawmidi_t *rmidi, snd_rawmidi_stream_t stream)
{
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	return rmidi->ops->drop(rmidi, stream);
}

int snd_rawmidi_drain(snd_rawmidi_t *rmidi, snd_rawmidi_stream_t stream)
{
	assert(snd_rawmidi_stream_ok(rmidi, stream));
	return rmidi->ops->drain(rmidi, stream);
}

ssize_t snd_rawmidi_write(snd_rawmidi_t *rmidi, const void *buffer, size_t size)
{
	assert(snd_rawmidi_stream_ok(rmidi, SND_RAWMIDI_STREAM_OUTPUT));
	assert(buffer || size == 0);
	return rmidi->ops->write(rmidi, buffer, size);
}

ssize_t snd_rawmidi_read(snd_rawmidi_t *rmidi, void *buffer, size_t size)
{
	assert(snd_rawmidi_stream_ok(rmidi, SND_RAWMIDI_STREAM_INPUT));
	assert(buffer || size == 0);
	return rmidi->ops->read(rmidi, buffer, size);
}

int snd_rawmidi_params_current(snd_rawmidi_t *rmidi, snd_rawmidi_stream_t stream, snd_rawmidi_params_t *params)
{
	snd_rawmidi_str_t *pstr;
	assert(snd_rawmidi_stream_ok(rmidi, SND_RAWMIDI_STREAM_OUTPUT));
	assert(params);
	pstr = &rmidi->stream[snd_enum_to_int(stream)];
	params->buffer_size = pstr->buffer_size;
	params->avail_min = pstr->avail_min;
	params->no_active_sensing = pstr->no_active_sensing;
	return 0;
}

int snd_rawmidi_params_default(snd_rawmidi_t *rmidi, snd_rawmidi_stream_t stream, snd_rawmidi_params_t *params)
{
	assert(snd_rawmidi_stream_ok(rmidi, SND_RAWMIDI_STREAM_OUTPUT));
	assert(params);
	params->buffer_size = PAGE_SIZE;
	params->avail_min = 1;
	params->no_active_sensing = 0;
	return 0;
}

int snd_rawmidi_open(snd_rawmidi_t **rawmidip, char *name, 
		     int streams, int mode)
{
	char *str;
	int err;
	snd_config_t *rawmidi_conf, *conf, *type_conf;
	snd_config_iterator_t i;
	snd_rawmidi_params_t params;
	unsigned int stream;
	char *lib = NULL, *open = NULL;
	int (*open_func)(snd_rawmidi_t **rawmidip, char *name, snd_config_t *conf, 
			 int streams, int mode);
	void *h;
	assert(rawmidip && name);
	err = snd_config_update();
	if (err < 0)
		return err;
	err = snd_config_searchv(snd_config, &rawmidi_conf, "rawmidi", name, 0);
	if (err < 0) {
		int card, dev, subdev;
		err = sscanf(name, "hw:%d,%d,%d", &card, &dev, &subdev);
		if (err == 3)
			return snd_rawmidi_hw_open(rawmidip, name, card, dev, subdev, streams, mode);
		err = sscanf(name, "hw:%d,%d", &card, &dev);
		if (err == 2)
			return snd_rawmidi_hw_open(rawmidip, name, card, dev, -1, streams, mode);
		ERR("Unknown RAWMIDI %s", name);
		return -ENOENT;
	}
	if (snd_config_type(rawmidi_conf) != SND_CONFIG_TYPE_COMPOUND) {
		ERR("Invalid type for RAWMIDI %s definition", name);
		return -EINVAL;
	}
	err = snd_config_search(rawmidi_conf, "streams", &conf);
	if (err >= 0) {
		err = snd_config_string_get(conf, &str);
		if (err < 0) {
			ERR("Invalid type for %s", conf->id);
			return err;
		}
		if (strcmp(str, "output") == 0) {
			if (streams == SND_RAWMIDI_OPEN_INPUT)
				return -EINVAL;
		} else if (strcmp(str, "input") == 0) {
			if (streams == SND_RAWMIDI_OPEN_OUTPUT)
				return -EINVAL;
		} else if (strcmp(str, "duplex") == 0) {
			if (streams != SND_RAWMIDI_OPEN_DUPLEX)
				return -EINVAL;
		} else {
			ERR("Invalid value for %s", conf->id);
			return -EINVAL;
		}
	}
	err = snd_config_search(rawmidi_conf, "type", &conf);
	if (err < 0) {
		ERR("type is not defined");
		return err;
	}
	err = snd_config_string_get(conf, &str);
	if (err < 0) {
		ERR("Invalid type for %s", conf->id);
		return err;
	}
	err = snd_config_searchv(snd_config, &type_conf, "rawmiditype", str, 0);
	if (err < 0) {
		ERR("Unknown RAWMIDI type %s", str);
		return err;
	}
	snd_config_foreach(i, type_conf) {
		snd_config_t *n = snd_config_entry(i);
		if (strcmp(n->id, "comment") == 0)
			continue;
		if (strcmp(n->id, "lib") == 0) {
			err = snd_config_string_get(n, &lib);
			if (err < 0) {
				ERR("Invalid type for %s", n->id);
				return -EINVAL;
			}
			continue;
		}
		if (strcmp(n->id, "open") == 0) {
			err = snd_config_string_get(n, &open);
			if (err < 0) {
				ERR("Invalid type for %s", n->id);
				return -EINVAL;
			}
			continue;
			ERR("Unknown field %s", n->id);
			return -EINVAL;
		}
	}
	if (!open) {
		ERR("open is not defined");
		return -EINVAL;
	}
	if (!lib)
		lib = "libasound.so";
	h = dlopen(lib, RTLD_NOW);
	if (!h) {
		ERR("Cannot open shared library %s", lib);
		return -ENOENT;
	}
	open_func = dlsym(h, open);
	dlclose(h);
	if (!open_func) {
		ERR("symbol %s is not defined inside %s", open, lib);
		return -ENXIO;
	}
	err = open_func(rawmidip, name, rawmidi_conf, streams, mode);
	if (err < 0)
		return err;
	for (stream = 0; stream < 2; stream++) {
		if (!(streams & (1 << stream)))
			continue;
		snd_rawmidi_params_default(*rawmidip, snd_int_to_enum(stream), &params);
		err = snd_rawmidi_params(*rawmidip, snd_int_to_enum(stream), &params);
		assert(err >= 0);
	}
	return 0;
}