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
37static 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
63static 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
90static 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
108int 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