Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / sound / core / oss / copy.c
1 /*
2  *  Linear conversion Plug-In
3  *  Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
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 "pcm_plugin.h"
26
27 static snd_pcm_sframes_t copy_transfer(struct snd_pcm_plugin *plugin,
28                              const struct snd_pcm_plugin_channel *src_channels,
29                              struct snd_pcm_plugin_channel *dst_channels,
30                              snd_pcm_uframes_t frames)
31 {
32         unsigned int channel;
33         unsigned int nchannels;
34
35         if (snd_BUG_ON(!plugin || !src_channels || !dst_channels))
36                 return -ENXIO;
37         if (frames == 0)
38                 return 0;
39         nchannels = plugin->src_format.channels;
40         for (channel = 0; channel < nchannels; channel++) {
41                 if (snd_BUG_ON(src_channels->area.first % 8 ||
42                                src_channels->area.step % 8))
43                         return -ENXIO;
44                 if (snd_BUG_ON(dst_channels->area.first % 8 ||
45                                dst_channels->area.step % 8))
46                         return -ENXIO;
47                 if (!src_channels->enabled) {
48                         if (dst_channels->wanted)
49                                 snd_pcm_area_silence(&dst_channels->area, 0, frames, plugin->dst_format.format);
50                         dst_channels->enabled = 0;
51                         continue;
52                 }
53                 dst_channels->enabled = 1;
54                 snd_pcm_area_copy(&src_channels->area, 0, &dst_channels->area, 0, frames, plugin->src_format.format);
55                 src_channels++;
56                 dst_channels++;
57         }
58         return frames;
59 }
60
61 int snd_pcm_plugin_build_copy(struct snd_pcm_substream *plug,
62                               struct snd_pcm_plugin_format *src_format,
63                               struct snd_pcm_plugin_format *dst_format,
64                               struct snd_pcm_plugin **r_plugin)
65 {
66         int err;
67         struct snd_pcm_plugin *plugin;
68         int width;
69
70         if (snd_BUG_ON(!r_plugin))
71                 return -ENXIO;
72         *r_plugin = NULL;
73
74         if (snd_BUG_ON(src_format->format != dst_format->format))
75                 return -ENXIO;
76         if (snd_BUG_ON(src_format->rate != dst_format->rate))
77                 return -ENXIO;
78         if (snd_BUG_ON(src_format->channels != dst_format->channels))
79                 return -ENXIO;
80
81         width = snd_pcm_format_physical_width(src_format->format);
82         if (snd_BUG_ON(width <= 0))
83                 return -ENXIO;
84
85         err = snd_pcm_plugin_build(plug, "copy", src_format, dst_format,
86                                    0, &plugin);
87         if (err < 0)
88                 return err;
89         plugin->transfer = copy_transfer;
90         *r_plugin = plugin;
91         return 0;
92 }