[ALSA] Changed Jaroslav Kysela's e-mail from perex@suse.cz to perex@perex.cz
[linux-2.6.git] / sound / core / oss / io.c
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 <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 }