git.oblomov.eu Git - linux-2.6/blob - sound/core/oss/io.c

   1 /*
   2  *  PCM I/O Plug-In Interface
   3  *  Copyright (c) 1999 by Jaroslav Kysela <perex@suse.cz>
   4  *
   5  *
   6  *   This library is free software; you can redistribute it and/or modify
   7  *   it under the terms of the GNU Library General Public License as
   8  *   published by the Free Software Foundation; either version 2 of
   9  *   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 of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU Library General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU Library General Public
  17  *   License along with this library; if not, write to the Free Software
  18  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  19  *
  20  */
  21
  22 #include <sound/driver.h>
  23
  24 #ifdef CONFIG_SND_PCM_OSS_PLUGINS
  25
  26 #include <linux/time.h>
  27 #include <sound/core.h>
  28 #include <sound/pcm.h>
  29 #include <sound/pcm_params.h>
  30 #include "pcm_plugin.h"
  31
  32 #define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1)
  33 #define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count,1)
  34 #define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1)
  35 #define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count,1)
  36
  37 /*
  38  *  Basic io plugin
  39  */
  40
  41 static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin,
  42                                     const struct snd_pcm_plugin_channel *src_channels,
  43                                     struct snd_pcm_plugin_channel *dst_channels,
  44                                     snd_pcm_uframes_t frames)
  45 {
  46         snd_assert(plugin != NULL, return -ENXIO);
  47         snd_assert(src_channels != NULL, return -ENXIO);
  48         if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
  49                 return pcm_write(plugin->plug, src_channels->area.addr, frames);
  50         } else {
  51                 int channel, channels = plugin->dst_format.channels;
  52                 void **bufs = (void**)plugin->extra_data;
  53                 snd_assert(bufs != NULL, return -ENXIO);
  54                 for (channel = 0; channel < channels; channel++) {
  55                         if (src_channels[channel].enabled)
  56                                 bufs[channel] = src_channels[channel].area.addr;
  57                         else
  58                                 bufs[channel] = NULL;
  59                 }
  60                 return pcm_writev(plugin->plug, bufs, frames);
  61         }
  62 }
  63
  64 static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin,
  65                                    const struct snd_pcm_plugin_channel *src_channels,
  66                                    struct snd_pcm_plugin_channel *dst_channels,
  67                                    snd_pcm_uframes_t frames)
  68 {
  69         snd_assert(plugin != NULL, return -ENXIO);
  70         snd_assert(dst_channels != NULL, return -ENXIO);
  71         if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
  72                 return pcm_read(plugin->plug, dst_channels->area.addr, frames);
  73         } else {
  74                 int channel, channels = plugin->dst_format.channels;
  75                 void **bufs = (void**)plugin->extra_data;
  76                 snd_assert(bufs != NULL, return -ENXIO);
  77                 for (channel = 0; channel < channels; channel++) {
  78                         if (dst_channels[channel].enabled)
  79                                 bufs[channel] = dst_channels[channel].area.addr;
  80                         else
  81                                 bufs[channel] = NULL;
  82                 }
  83                 return pcm_readv(plugin->plug, bufs, frames);
  84         }
  85         return 0;
  86 }
  87
  88 static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin,
  89                              snd_pcm_uframes_t frames,
  90                              struct snd_pcm_plugin_channel **channels)
  91 {
  92         int err;
  93         unsigned int channel;
  94         struct snd_pcm_plugin_channel *v;
  95         err = snd_pcm_plugin_client_channels(plugin, frames, &v);
  96         if (err < 0)
  97                 return err;
  98         *channels = v;
  99         if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) {
 100                 for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v)
 101                         v->wanted = 1;
 102         }
 103         return frames;
 104 }
 105
 106 int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug,
 107                             struct snd_pcm_hw_params *params,
 108                             struct snd_pcm_plugin **r_plugin)
 109 {
 110         int err;
 111         struct snd_pcm_plugin_format format;
 112         struct snd_pcm_plugin *plugin;
 113
 114         snd_assert(r_plugin != NULL, return -ENXIO);
 115         *r_plugin = NULL;
 116         snd_assert(plug != NULL && params != NULL, return -ENXIO);
 117         format.format = params_format(params);
 118         format.rate = params_rate(params);
 119         format.channels = params_channels(params);
 120         err = snd_pcm_plugin_build(plug, "I/O io",
 121                                    &format, &format,
 122                                    sizeof(void *) * format.channels,
 123                                    &plugin);
 124         if (err < 0)
 125                 return err;
 126         plugin->access = params_access(params);
 127         if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) {
 128                 plugin->transfer = io_playback_transfer;
 129                 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED)
 130                         plugin->client_channels = io_src_channels;
 131         } else {
 132                 plugin->transfer = io_capture_transfer;
 133         }
 134
 135         *r_plugin = plugin;
 136         return 0;
 137 }
 138
 139 #endif