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
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