linux/sound/core/oss/io.c
Tim Bird 65ff3a8d0b ALSA: core: Add SPDX license id to files
Add an SPDX id of LGPL-2.0+ to files in the
sound core sub-system that are missing ids.  Remove
boilerplate text.

These files were originally submitted in a big commit
for the ALSA sound system for kernel version 2.5.4,
by Jaroslav Kysela, in Feb 2002.

Signed-off-by: Tim Bird <tim.bird@sony.com>
Link: https://patch.msgid.link/20260212183103.3720788-1-tim.bird@sony.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2026-02-18 08:52:08 +01:00

127 lines
3.6 KiB
C

// SPDX-License-Identifier: LGPL-2.0+
/*
* PCM I/O Plug-In Interface
* Copyright (c) 1999 by Jaroslav Kysela <perex@perex.cz>
*/
#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)
#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)
/*
* 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)
{
if (snd_BUG_ON(!plugin))
return -ENXIO;
if (snd_BUG_ON(!src_channels))
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;
if (snd_BUG_ON(!bufs))
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)
{
if (snd_BUG_ON(!plugin))
return -ENXIO;
if (snd_BUG_ON(!dst_channels))
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;
if (snd_BUG_ON(!bufs))
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;
if (snd_BUG_ON(!r_plugin))
return -ENXIO;
*r_plugin = NULL;
if (snd_BUG_ON(!plug || !params))
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;
}