Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  PCM I/O Plug-In Interface

 *  Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>

 *

 *

 *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 *

 */

#include <sound/driver.h>

#include <linux/time.h>

#include <sound/core.h>

#include <sound/pcm.h>

#include <sound/pcm_params.h>

#include "pcm_plugin.h"

#define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)

#define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count,1)

#define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)

#define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count,1)

/*

 *  Basic io plugin

 */

static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,

                                    const struct snd_pcm_plugin_channel *src_channels,

                                    struct snd_pcm_plugin_channel *dst_channels,

                                    snd_pcm_uframes_t frames)

{

        snd_assert(plugin != NULL, return -ENXIO);

        snd_assert(src_channels != NULL, return -ENXIO);

        if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {

                return pcm_write(plugin->plug, src_channels->area.addr, frames);

        } else {

                int channel, channels = plugin->dst_format.channels;

                void **bufs = (void**)plugin->extra_data;

                snd_assert(bufs != NULL, return -ENXIO);

                for (channel = 0; channel < channels; channel++) {

                        if (src_channels[channel].enabled)

                                bufs[channel] = src_channels[channel].area.addr;

                        else

                                bufs[channel] = NULL;

                }

                return pcm_writev(plugin->plug, bufs, frames);

        }

}

static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,

                                   const struct snd_pcm_plugin_channel *src_channels,

                                   struct snd_pcm_plugin_channel *dst_channels,

                                   snd_pcm_uframes_t frames)

{

        snd_assert(plugin != NULL, return -ENXIO);

        snd_assert(dst_channels != NULL, return -ENXIO);

        if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {

                return pcm_read(plugin->plug, dst_channels->area.addr, frames);

        } else {

                int channel, channels = plugin->dst_format.channels;

                void **bufs = (void**)plugin->extra_data;

                snd_assert(bufs != NULL, return -ENXIO);

                for (channel = 0; channel < channels; channel++) {

                        if (dst_channels[channel].enabled)

                                bufs[channel] = dst_channels[channel].area.addr;

                        else

                                bufs[channel] = NULL;

                }

                return pcm_readv(plugin->plug, bufs, frames);

        }

        return 0;

}

static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,

                             snd_pcm_uframes_t frames,

                             struct snd_pcm_plugin_channel **channels)

{

        int err;

        unsigned int channel;

        struct snd_pcm_plugin_channel *v;

        err = snd_pcm_plugin_client_channels(plugin, frames, &v);

        if (err < 0)

                return err;

        *channels = v;

        if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {

                for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)

                        v->wanted = 1;

        }

        return frames;

}

int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,

                            struct snd_pcm_hw_params *params,

                            struct snd_pcm_plugin **r_plugin)

{

        int err;

        struct snd_pcm_plugin_format format;

        struct snd_pcm_plugin *plugin;

        snd_assert(r_plugin != NULL, return -ENXIO);

        *r_plugin = NULL;

        snd_assert(plug != NULL && params != NULL, return -ENXIO);

        format.format = params_format(params);

        format.rate = params_rate(params);

        format.channels = params_channels(params);

        err = snd_pcm_plugin_build(plug, "I/O io",

                                   &format, &format,

                                   sizeof(void *) * format.channels,

                                   &plugin);

        if (err < 0)

                return err;

        plugin->access = params_access(params);

        if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {

                plugin->transfer = io_playback_transfer;

                if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)

                        plugin->client_channels = io_src_channels;

        } else {

                plugin->transfer = io_capture_transfer;

        }

        *r_plugin = plugin;

        return 0;

}