diff options
Diffstat (limited to 'sound/core/oss/io.c')
| -rw-r--r-- | sound/core/oss/io.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/sound/core/oss/io.c b/sound/core/oss/io.c new file mode 100644 index 000000000000..bb1c99a5b734 --- /dev/null +++ b/sound/core/oss/io.c @@ -0,0 +1,134 @@ +/* + * 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 + * + */ + +#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(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; +} |