1 /* 2 * PCM I/O Plug-In Interface 3 * Copyright (c) 1999 by Jaroslav Kysela <perex@perex.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 <linux/time.h> 23 #include <sound/core.h> 24 #include <sound/pcm.h> 25 #include <sound/pcm_params.h> 26 #include "pcm_plugin.h" 27 28 #define pcm_write(plug,buf,count) snd_pcm_oss_write3(plug,buf,count,1) 29 #define pcm_writev(plug,vec,count) snd_pcm_oss_writev3(plug,vec,count,1) 30 #define pcm_read(plug,buf,count) snd_pcm_oss_read3(plug,buf,count,1) 31 #define pcm_readv(plug,vec,count) snd_pcm_oss_readv3(plug,vec,count,1) 32 33 /* 34 * Basic io plugin 35 */ 36 37 static snd_pcm_sframes_t io_playback_transfer(struct snd_pcm_plugin *plugin, 38 const struct snd_pcm_plugin_channel *src_channels, 39 struct snd_pcm_plugin_channel *dst_channels, 40 snd_pcm_uframes_t frames) 41 { 42 if (snd_BUG_ON(!plugin)) 43 return -ENXIO; 44 if (snd_BUG_ON(!src_channels)) 45 return -ENXIO; 46 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 47 return pcm_write(plugin->plug, src_channels->area.addr, frames); 48 } else { 49 int channel, channels = plugin->dst_format.channels; 50 void **bufs = (void**)plugin->extra_data; 51 if (snd_BUG_ON(!bufs)) 52 return -ENXIO; 53 for (channel = 0; channel < channels; channel++) { 54 if (src_channels[channel].enabled) 55 bufs[channel] = src_channels[channel].area.addr; 56 else 57 bufs[channel] = NULL; 58 } 59 return pcm_writev(plugin->plug, bufs, frames); 60 } 61 } 62 63 static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin, 64 const struct snd_pcm_plugin_channel *src_channels, 65 struct snd_pcm_plugin_channel *dst_channels, 66 snd_pcm_uframes_t frames) 67 { 68 if (snd_BUG_ON(!plugin)) 69 return -ENXIO; 70 if (snd_BUG_ON(!dst_channels)) 71 return -ENXIO; 72 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 73 return pcm_read(plugin->plug, dst_channels->area.addr, frames); 74 } else { 75 int channel, channels = plugin->dst_format.channels; 76 void **bufs = (void**)plugin->extra_data; 77 if (snd_BUG_ON(!bufs)) 78 return -ENXIO; 79 for (channel = 0; channel < channels; channel++) { 80 if (dst_channels[channel].enabled) 81 bufs[channel] = dst_channels[channel].area.addr; 82 else 83 bufs[channel] = NULL; 84 } 85 return pcm_readv(plugin->plug, bufs, frames); 86 } 87 return 0; 88 } 89 90 static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin, 91 snd_pcm_uframes_t frames, 92 struct snd_pcm_plugin_channel **channels) 93 { 94 int err; 95 unsigned int channel; 96 struct snd_pcm_plugin_channel *v; 97 err = snd_pcm_plugin_client_channels(plugin, frames, &v); 98 if (err < 0) 99 return err; 100 *channels = v; 101 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 102 for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v) 103 v->wanted = 1; 104 } 105 return frames; 106 } 107 108 int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug, 109 struct snd_pcm_hw_params *params, 110 struct snd_pcm_plugin **r_plugin) 111 { 112 int err; 113 struct snd_pcm_plugin_format format; 114 struct snd_pcm_plugin *plugin; 115 116 if (snd_BUG_ON(!r_plugin)) 117 return -ENXIO; 118 *r_plugin = NULL; 119 if (snd_BUG_ON(!plug || !params)) 120 return -ENXIO; 121 format.format = params_format(params); 122 format.rate = params_rate(params); 123 format.channels = params_channels(params); 124 err = snd_pcm_plugin_build(plug, "I/O io", 125 &format, &format, 126 sizeof(void *) * format.channels, 127 &plugin); 128 if (err < 0) 129 return err; 130 plugin->access = params_access(params); 131 if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) { 132 plugin->transfer = io_playback_transfer; 133 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) 134 plugin->client_channels = io_src_channels; 135 } else { 136 plugin->transfer = io_capture_transfer; 137 } 138 139 *r_plugin = plugin; 140 return 0; 141 } 142