path: root/sound/core/compress_offload.c

/*
 *  compress_core.c - compress offload core
 *
 *  Copyright (C) 2011 Intel Corporation
 *  Authors:	Vinod Koul <vinod.koul@linux.intel.com>
 *		Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
 *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  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; version 2 of the License.
 *
 *  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.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 */
#define FORMAT(fmt) "%s: %d: " fmt, __func__, __LINE__
#define pr_fmt(fmt) KBUILD_MODNAME ": " FORMAT(fmt)

#include <linux/file.h>
#include <linux/fs.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/uio.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/compress_params.h>
#include <sound/compress_offload.h>
#include <sound/compress_driver.h>

/* TODO:
 * - add substream support for multiple devices in case of
 *	SND_DYNAMIC_MINORS is not used
 * - Multiple node representation
 *	driver should be able to register multiple nodes
 */

static DEFINE_MUTEX(device_mutex);

struct snd_compr_file {
	unsigned long caps;
	struct snd_compr_stream stream;
};

/*
 * a note on stream states used:
 * we use follwing states in the compressed core
 * SNDRV_PCM_STATE_OPEN: When stream has been opened.
 * SNDRV_PCM_STATE_SETUP: When stream has been initialized. This is done by
 *	calling SNDRV_COMPRESS_SET_PARAMS. running streams will come to this
 *	state at stop by calling SNDRV_COMPRESS_STOP, or at end of drain.
 * SNDRV_PCM_STATE_RUNNING: When stream has been started and is
 *	decoding/encoding and rendering/capturing data.
 * SNDRV_PCM_STATE_DRAINING: When stream is draining current data. This is done
 *	by calling SNDRV_COMPRESS_DRAIN.
 * SNDRV_PCM_STATE_PAUSED: When stream is paused. This is done by calling
 *	SNDRV_COMPRESS_PAUSE. It can be stopped or resumed by calling
 *	SNDRV_COMPRESS_STOP or SNDRV_COMPRESS_RESUME respectively.
 */
static int snd_compr_open(struct inode *inode, struct file *f)
{
	struct snd_compr *compr;
	struct snd_compr_file *data;
	struct snd_compr_runtime *runtime;
	enum snd_compr_direction dirn;
	int maj = imajor(inode);
	int ret;

	if ((f->f_flags & O_ACCMODE) == O_WRONLY)
		dirn = SND_COMPRESS_PLAYBACK;
	else if ((f->f_flags & O_ACCMODE) == O_RDONLY)
		dirn = SND_COMPRESS_CAPTURE;
	else
		return -EINVAL;

	if (maj == snd_major)
		compr = snd_lookup_minor_data(iminor(inode),
					SNDRV_DEVICE_TYPE_COMPRESS);
	else
		return -EBADFD;

	if (compr == NULL) {
		pr_err("no device data!!!\n");
		return -ENODEV;
	}

	if (dirn != compr->direction) {
		pr_err("this device doesn't support this direction\n");
		snd_card_unref(compr->card);
		return -EINVAL;
	}

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
		snd_card_unref(compr->card);
		return -ENOMEM;
	}
	data->stream.ops = compr->ops;
	data->stream.direction = dirn;
	data->stream.private_data = compr->private_data;
	data->stream.device = compr;
	runtime = kzalloc(sizeof(*runtime), GFP_KERNEL);
	if (!runtime) {
		kfree(data);
		snd_card_unref(compr->card);
		return -ENOMEM;
	}
	runtime->state = SNDRV_PCM_STATE_OPEN;
	init_waitqueue_head(&runtime->sleep);
	data->stream.runtime = runtime;
	f->private_data = (void *)data;
	mutex_lock(&compr->lock);
	ret = compr->ops->open(&data->stream);
	mutex_unlock(&compr->lock);
	if (ret) {
		kfree(runtime);
		kfree(data);
	}
	snd_card_unref(compr->card);
	return 0;
}

static int snd_compr_free(struct inode *inode, struct file *f)
{
	struct snd_compr_file *data = f->private_data;
	struct snd_compr_runtime *runtime = data->stream.runtime;

	switch (runtime->state) {
	case SNDRV_PCM_STATE_RUNNING:
	case SNDRV_PCM_STATE_DRAINING:
	case SNDRV_PCM_STATE_PAUSED:
		data->stream.ops->trigger(&data->stream, SNDRV_PCM_TRIGGER_STOP);
		break;
	default:
		break;
	}

	data->stream.ops->free(&data->stream);
	kfree(data->stream.runtime->buffer);
	kfree(data->stream.runtime);
	kfree(data);
	return 0;
}

static int snd_compr_update_tstamp(struct snd_compr_stream *stream,
		struct snd_compr_tstamp *tstamp)
{
	if (!stream->ops->pointer)
		return -