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)
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)
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
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