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1/*2 * PCM I/O Plug-In Interface3 * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>4 *5 *6 * This library is free software; you can redistribute it and/or modify7 * it under the terms of the GNU Library General Public License as8 * published by the Free Software Foundation; either version 2 of9 * the License, or (at your option) any later version.10 *11 * This program is distributed in the hope that it will be useful,12 * but WITHOUT ANY WARRANTY; without even the implied warranty of13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the14 * GNU Library General Public License for more details.15 *16 * You should have received a copy of the GNU Library General Public17 * License along with this library; if not, write to the Free Software18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA19 *20 */21 22#include <linux/time.h>23#include <sound/core.h>24#include <sound/pcm.h>25#include <sound/pcm_params.h>26#include "pcm_plugin.h"27 28#define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)29#define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count)30#define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)31#define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count)32 33/*34 * Basic io plugin35 */36 37static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,38 const struct snd_pcm_plugin_channel *src_channels,39 struct snd_pcm_plugin_channel *dst_channels,40 snd_pcm_uframes_t frames)41{42 if (snd_BUG_ON(!plugin))43 return -ENXIO;44 if (snd_BUG_ON(!src_channels))45 return -ENXIO;46 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {47 return pcm_write(plugin->plug, src_channels->area.addr, frames);48 } else {49 int channel, channels = plugin->dst_format.channels;50 void **bufs = (void**)plugin->extra_data;51 if (snd_BUG_ON(!bufs))52 return -ENXIO;53 for (channel = 0; channel < channels; channel++) {54 if (src_channels[channel].enabled)55 bufs[channel] = src_channels[channel].area.addr;56 else57 bufs[channel] = NULL;58 }59 return pcm_writev(plugin->plug, bufs, frames);60 }61}62 63static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,64 const struct snd_pcm_plugin_channel *src_channels,65 struct snd_pcm_plugin_channel *dst_channels,66 snd_pcm_uframes_t frames)67{68 if (snd_BUG_ON(!plugin))69 return -ENXIO;70 if (snd_BUG_ON(!dst_channels))71 return -ENXIO;72 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {73 return pcm_read(plugin->plug, dst_channels->area.addr, frames);74 } else {75 int channel, channels = plugin->dst_format.channels;76 void **bufs = (void**)plugin->extra_data;77 if (snd_BUG_ON(!bufs))78 return -ENXIO;79 for (channel = 0; channel < channels; channel++) {80 if (dst_channels[channel].enabled)81 bufs[channel] = dst_channels[channel].area.addr;82 else83 bufs[channel] = NULL;84 }85 return pcm_readv(plugin->plug, bufs, frames);86 }87 return 0;88}89 90static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,91 snd_pcm_uframes_t frames,92 struct snd_pcm_plugin_channel **channels)93{94 int err;95 unsigned int channel;96 struct snd_pcm_plugin_channel *v;97 err = snd_pcm_plugin_client_channels(plugin, frames, &v);98 if (err < 0)99 return err;100 *channels = v;101 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {102 for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)103 v->wanted = 1;104 }105 return frames;106}107 108int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,109 struct snd_pcm_hw_params *params,110 struct snd_pcm_plugin **r_plugin)111{112 int err;113 struct snd_pcm_plugin_format format;114 struct snd_pcm_plugin *plugin;115 116 if (snd_BUG_ON(!r_plugin))117 return -ENXIO;118 *r_plugin = NULL;119 if (snd_BUG_ON(!plug || !params))120 return -ENXIO;121 format.format = params_format(params);122 format.rate = params_rate(params);123 format.channels = params_channels(params);124 err = snd_pcm_plugin_build(plug, "I/O io",125 &format, &format,126 sizeof(void *) * format.channels,127 &plugin);128 if (err < 0)129 return err;130 plugin->access = params_access(params);131 if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {132 plugin->transfer = io_playback_transfer;133 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)134 plugin->client_channels = io_src_channels;135 } else {136 plugin->transfer = io_capture_transfer;137 }138 139 *r_plugin = plugin;140 return 0;141}142