GNU Linux-libre 4.19.314-gnu1
[releases.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 <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 }