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