/* *  PCM I/O Plug-In Interface *  Copyright (c) 1999 by Jaroslav Kysela <perex@suse.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 * */  #define __NO_VERSION__#include <sound/driver.h>#include <linux/time.h>#include <sound/core.h>#include <sound/pcm.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(snd_pcm_plugin_t *plugin,				    const snd_pcm_plugin_channel_t *src_channels,				    snd_pcm_plugin_channel_t *dst_channels ATTRIBUTE_UNUSED,				    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(snd_pcm_plugin_t *plugin,				   const snd_pcm_plugin_channel_t *src_channels ATTRIBUTE_UNUSED,				   snd_pcm_plugin_channel_t *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(snd_pcm_plugin_t *plugin,			     snd_pcm_uframes_t frames,			     snd_pcm_plugin_channel_t **channels){	int err;	unsigned int channel;	snd_pcm_plugin_channel_t *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(snd_pcm_plug_t *plug,			    snd_pcm_hw_params_t *params,			    snd_pcm_plugin_t **r_plugin){	int err;	snd_pcm_plugin_format_t format;	snd_pcm_plugin_t *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;}