forked from Minki/linux
135 lines
4.4 KiB
C
135 lines
4.4 KiB
C
/*
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* PCM I/O Plug-In Interface
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* Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
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*
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*
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* This library is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Library General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <sound/driver.h>
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#include <linux/time.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#include <sound/pcm_params.h>
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#include "pcm_plugin.h"
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#define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)
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#define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count,1)
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#define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)
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#define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count,1)
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/*
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* Basic io plugin
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*/
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static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,
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const struct snd_pcm_plugin_channel *src_channels,
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struct snd_pcm_plugin_channel *dst_channels,
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snd_pcm_uframes_t frames)
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{
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snd_assert(plugin != NULL, return -ENXIO);
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snd_assert(src_channels != NULL, return -ENXIO);
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if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
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return pcm_write(plugin->plug, src_channels->area.addr, frames);
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} else {
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int channel, channels = plugin->dst_format.channels;
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void **bufs = (void**)plugin->extra_data;
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snd_assert(bufs != NULL, return -ENXIO);
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for (channel = 0; channel < channels; channel++) {
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if (src_channels[channel].enabled)
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bufs[channel] = src_channels[channel].area.addr;
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else
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bufs[channel] = NULL;
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}
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return pcm_writev(plugin->plug, bufs, frames);
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}
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}
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static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,
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const struct snd_pcm_plugin_channel *src_channels,
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struct snd_pcm_plugin_channel *dst_channels,
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snd_pcm_uframes_t frames)
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{
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snd_assert(plugin != NULL, return -ENXIO);
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snd_assert(dst_channels != NULL, return -ENXIO);
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if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
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return pcm_read(plugin->plug, dst_channels->area.addr, frames);
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} else {
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int channel, channels = plugin->dst_format.channels;
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void **bufs = (void**)plugin->extra_data;
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snd_assert(bufs != NULL, return -ENXIO);
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for (channel = 0; channel < channels; channel++) {
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if (dst_channels[channel].enabled)
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bufs[channel] = dst_channels[channel].area.addr;
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else
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bufs[channel] = NULL;
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}
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return pcm_readv(plugin->plug, bufs, frames);
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}
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return 0;
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}
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static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,
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snd_pcm_uframes_t frames,
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struct snd_pcm_plugin_channel **channels)
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{
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int err;
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unsigned int channel;
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struct snd_pcm_plugin_channel *v;
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err = snd_pcm_plugin_client_channels(plugin, frames, &v);
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if (err < 0)
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return err;
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*channels = v;
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if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
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for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)
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v->wanted = 1;
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}
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return frames;
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}
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int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,
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struct snd_pcm_hw_params *params,
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struct snd_pcm_plugin **r_plugin)
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{
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int err;
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struct snd_pcm_plugin_format format;
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struct snd_pcm_plugin *plugin;
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snd_assert(r_plugin != NULL, return -ENXIO);
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*r_plugin = NULL;
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snd_assert(plug != NULL && params != NULL, return -ENXIO);
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format.format = params_format(params);
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format.rate = params_rate(params);
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format.channels = params_channels(params);
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err = snd_pcm_plugin_build(plug, "I/O io",
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&format, &format,
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sizeof(void *) * format.channels,
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&plugin);
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if (err < 0)
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return err;
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plugin->access = params_access(params);
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if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
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plugin->transfer = io_playback_transfer;
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if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)
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plugin->client_channels = io_src_channels;
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} else {
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plugin->transfer = io_capture_transfer;
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}
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*r_plugin = plugin;
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return 0;
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}
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