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 snd_assert(plugin != NULL, return -ENXIO); 43 snd_assert(src_channels != NULL, return -ENXIO); 44 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 45 return pcm_write(plugin->plug, src_channels->area.addr, frames); 46 } else { 47 int channel, channels = plugin->dst_format.channels; 48 void **bufs = (void**)plugin->extra_data; 49 snd_assert(bufs != NULL, return -ENXIO); 50 for (channel = 0; channel < channels; channel++) { 51 if (src_channels[channel].enabled) 52 bufs[channel] = src_channels[channel].area.addr; 53 else 54 bufs[channel] = NULL; 55 } 56 return pcm_writev(plugin->plug, bufs, frames); 57 } 58 } 59 60 static snd_pcm_sframes_t io_capture_transfer(struct snd_pcm_plugin *plugin, 61 const struct snd_pcm_plugin_channel *src_channels, 62 struct snd_pcm_plugin_channel *dst_channels, 63 snd_pcm_uframes_t frames) 64 { 65 snd_assert(plugin != NULL, return -ENXIO); 66 snd_assert(dst_channels != NULL, return -ENXIO); 67 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 68 return pcm_read(plugin->plug, dst_channels->area.addr, frames); 69 } else { 70 int channel, channels = plugin->dst_format.channels; 71 void **bufs = (void**)plugin->extra_data; 72 snd_assert(bufs != NULL, return -ENXIO); 73 for (channel = 0; channel < channels; channel++) { 74 if (dst_channels[channel].enabled) 75 bufs[channel] = dst_channels[channel].area.addr; 76 else 77 bufs[channel] = NULL; 78 } 79 return pcm_readv(plugin->plug, bufs, frames); 80 } 81 return 0; 82 } 83 84 static snd_pcm_sframes_t io_src_channels(struct snd_pcm_plugin *plugin, 85 snd_pcm_uframes_t frames, 86 struct snd_pcm_plugin_channel **channels) 87 { 88 int err; 89 unsigned int channel; 90 struct snd_pcm_plugin_channel *v; 91 err = snd_pcm_plugin_client_channels(plugin, frames, &v); 92 if (err < 0) 93 return err; 94 *channels = v; 95 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) { 96 for (channel = 0; channel < plugin->src_format.channels; ++channel, ++v) 97 v->wanted = 1; 98 } 99 return frames; 100 } 101 102 int snd_pcm_plugin_build_io(struct snd_pcm_substream *plug, 103 struct snd_pcm_hw_params *params, 104 struct snd_pcm_plugin **r_plugin) 105 { 106 int err; 107 struct snd_pcm_plugin_format format; 108 struct snd_pcm_plugin *plugin; 109 110 snd_assert(r_plugin != NULL, return -ENXIO); 111 *r_plugin = NULL; 112 snd_assert(plug != NULL && params != NULL, return -ENXIO); 113 format.format = params_format(params); 114 format.rate = params_rate(params); 115 format.channels = params_channels(params); 116 err = snd_pcm_plugin_build(plug, "I/O io", 117 &format, &format, 118 sizeof(void *) * format.channels, 119 &plugin); 120 if (err < 0) 121 return err; 122 plugin->access = params_access(params); 123 if (snd_pcm_plug_stream(plug) == SNDRV_PCM_STREAM_PLAYBACK) { 124 plugin->transfer = io_playback_transfer; 125 if (plugin->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED) 126 plugin->client_channels = io_src_channels; 127 } else { 128 plugin->transfer = io_capture_transfer; 129 } 130 131 *r_plugin = plugin; 132 return 0; 133 } 134