/*
* ALSA <-> OSS PCM I/O plugin
*
* Copyright (c) 2005 by Takashi Iwai <tiwai@suse.de>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdio.h>
#include <sys/ioctl.h>
#include <alsa/asoundlib.h>
#include <alsa/pcm_external.h>
#include <linux/soundcard.h>
typedef struct snd_pcm_oss {
snd_pcm_ioplug_t io;
char *device;
int fd;
int fragment_set;
int caps;
int format;
unsigned int period_shift;
unsigned int periods;
unsigned int frame_bytes;
} snd_pcm_oss_t;
static snd_pcm_sframes_t oss_write(snd_pcm_ioplug_t *io,
const snd_pcm_channel_area_t *areas,
snd_pcm_uframes_t offset,
snd_pcm_uframes_t size)
{
snd_pcm_oss_t *oss = io->private_data;
const char *buf;
ssize_t result;
/* we handle only an interleaved buffer */
buf = (char *)areas->addr + (areas->first + areas->step * offset) / 8;
size *= oss->frame_bytes;
result = write(oss->fd, buf, size);
if (result <= 0)
return result;
return result / oss->frame_bytes;
}
static snd_pcm_sframes_t oss_read(snd_pcm_ioplug_t *io,
const snd_pcm_channel_area_t *areas,
snd_pcm_uframes_t offset,
snd_pcm_uframes_t size)
{
snd_pcm_oss_t *oss = io->private_data;
char *buf;
ssize_t result;
/* we handle only an interleaved buffer */
buf = (char *)areas->addr + (areas->first + areas->step * offset) / 8;
size *= oss->frame_bytes;
result = read(oss->fd, buf, size);
if (result <= 0)
return result;
return result / oss->frame_bytes;
}
static snd_pcm_sframes_t oss_pointer(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
struct count_info info;
int ptr;
if (ioctl(oss->fd, io->stream == SND_PCM_STREAM_PLAYBACK ?
SNDCTL_DSP_GETOPTR : SNDCTL_DSP_GETIPTR, &info) < 0) {
fprintf(stderr, "*** OSS: oss_pointer error\n");
return 0;
}
ptr = snd_pcm_bytes_to_frames(io->pcm, info.ptr);
return ptr;
}
static int oss_start(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
int tmp = io->stream == SND_PCM_STREAM_PLAYBACK ?
PCM_ENABLE_OUTPUT : PCM_ENABLE_INPUT;
if (ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &tmp) < 0) {
fprintf(stderr, "*** OSS: trigger failed\n");
if (io->stream == SND_PCM_STREAM_CAPTURE)
/* fake read to trigger */
read(oss->fd, &tmp, 0);
}
return 0;
}
static int oss_stop(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
int tmp = 0;
ioctl(oss->fd, SNDCTL_DSP_SETTRIGGER, &tmp);
return 0;
}
static int oss_drain(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
if (io->stream == SND_PCM_STREAM_PLAYBACK)
ioctl(oss->fd, SNDCTL_DSP_SYNC);
return 0;
}
static int oss_prepare(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
int tmp;
ioctl(oss->fd, SNDCTL_DSP_RESET);
tmp = io->channels;
if (ioctl(oss->fd, SNDCTL_DSP_CHANNELS, &tmp) < 0) {
perror("SNDCTL_DSP_CHANNELS");
return -EINVAL;
}
tmp = oss->format;
if (ioctl(oss->fd, SNDCTL_DSP_SETFMT, &tmp) < 0) {
perror("SNDCTL_DSP_SETFMT");
return -EINVAL;
}
tmp = io->rate;
if (ioctl(oss->fd, SNDCTL_DSP_SPEED, &tmp) < 0 ||
tmp > io->rate * 1.01 || tmp < io->rate * 0.99) {
perror("SNDCTL_DSP_SPEED");
return -EINVAL;
}
return 0;
}
static int oss_hw_params(snd_pcm_ioplug_t *io,
snd_pcm_hw_params_t *params ATTRIBUTE_UNUSED)
{
snd_pcm_oss_t *oss = io->private_data;
int i, tmp, err;
unsigned int period_bytes;
long oflags, flags;
oss->frame_bytes = (snd_pcm_format_physical_width(io->format) * io->channels) / 8;
switch (io->format) {
case SND_PCM_FORMAT_U8:
oss->format = AFMT_U8;
break;
case SND_PCM_FORMAT_S16_LE:
oss->format = AFMT_S16_LE;
break;
case SND_PCM_FORMAT_S16_BE:
oss->format = AFMT_S16_BE;
break;
default:
fprintf(stderr, "*** OSS: unsupported format %s\n", snd_pcm_format_name(io->format));
return -EINVAL;
}
period_bytes = io->period_size * oss->frame_bytes;
oss->period_shift = 0;
for (i = 31; i >= 4; i--) {
if (period_bytes & (1U << i)) {
oss->period_shift = i;
break;
}
}
if (! oss->period_shift) {
fprintf(stderr, "*** OSS: invalid period size %d\n", (int)io->period_size);
return -EINVAL;
}
oss->periods = io->buffer_size / io->period_size;
_retry:
tmp = oss->period_shift | (oss->periods << 16);
if (ioctl(oss->fd, SNDCTL_DSP_SETFRAGMENT, &tmp) < 0) {
if (! oss->fragment_set) {
perror("SNDCTL_DSP_SETFRAGMENT");
fprintf(stderr, "*** period shift = %d, periods = %d\n", oss->period_shift, oss->periods);
return -EINVAL;
}
/* OSS has no proper way to reinitialize the fragments */
/* try to reopen the device */
close(oss->fd);
oss->fd = open(oss->device, io->stream == SND_PCM_STREAM_PLAYBACK ?
O_WRONLY : O_RDONLY);
if (oss->fd < 0) {
err = -errno;
SNDERR("Cannot reopen the device %s", oss->device);
return err;
}
io->poll_fd = oss->fd;
io->poll_events = io->stream == SND_PCM_STREAM_PLAYBACK ?
POLLOUT : POLLIN;
snd_pcm_ioplug_reinit_status(io);
oss->fragment_set = 0;
goto _retry;
}
oss->fragment_set = 1;
if ((flags = fcntl(oss->fd, F_GETFL)) < 0) {
err = -errno;
perror("F_GETFL");
} else {
oflags = flags;
if (io->nonblock)
flags |= O_NONBLOCK;
else
flags &= ~O_NONBLOCK;
if (flags != oflags &&
fcntl(oss->fd, F_SETFL, flags) < 0) {
err = -errno;
perror("F_SETFL");
}
}
return 0;
}
#define ARRAY_SIZE(ary) (sizeof(ary)/sizeof(ary[0]))
static int oss_hw_constraint(snd_pcm_oss_t *oss)
{
snd_pcm_ioplug_t *io = &oss->io;
static const snd_pcm_access_t access_list[] = {
SND_PCM_ACCESS_RW_INTERLEAVED,
SND_PCM_ACCESS_MMAP_INTERLEAVED
};
unsigned int nformats;
unsigned int format[5];
unsigned int nchannels;
unsigned int channel[6];
/* period and buffer bytes must be power of two */
static const unsigned int bytes_list[] = {
1U<<8, 1U<<9, 1U<<10, 1U<<11, 1U<<12, 1U<<13, 1U<<14, 1U<<15,
1U<<16, 1U<<17, 1U<<18, 1U<<19, 1U<<20, 1U<<21, 1U<<22, 1U<<23
};
int i, err, tmp;
/* check trigger */
oss->caps = 0;
if (ioctl(oss->fd, SNDCTL_DSP_GETCAPS, &oss->caps) >= 0) {
if (! (oss->caps & DSP_CAP_TRIGGER))
fprintf(stderr, "*** OSS: trigger is not supported!\n");
}
/* access type - interleaved only */
if ((err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_ACCESS,
ARRAY_SIZE(access_list), access_list)) < 0)
return err;
/* supported formats */
tmp = 0;
ioctl(oss->fd, SNDCTL_DSP_GETFMTS, &tmp);
nformats = 0;
if (tmp & AFMT_U8)
format[nformats++] = SND_PCM_FORMAT_U8;
if (tmp & AFMT_S16_LE)
format[nformats++] = SND_PCM_FORMAT_S16_LE;
if (tmp & AFMT_S16_BE)
format[nformats++] = SND_PCM_FORMAT_S16_BE;
if (tmp & AFMT_MU_LAW)
format[nformats++] = SND_PCM_FORMAT_MU_LAW;
if (! nformats)
format[nformats++] = SND_PCM_FORMAT_S16;
if ((err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_FORMAT,
nformats, format)) < 0)
return err;
/* supported channels */
nchannels = 0;
for (i = 0; i < 6; i++) {
tmp = i + 1;
if (ioctl(oss->fd, SNDCTL_DSP_CHANNELS, &tmp) >= 0)
channel[nchannels++] = tmp;
}
if (! nchannels) /* assume 2ch stereo */
err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_CHANNELS,
2, 2);
else
err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_CHANNELS,
nchannels, channel);
if (err < 0)
return err;
/* supported rates */
/* FIXME: should query? */
err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_RATE, 8000, 480000);
if (err < 0)
return err;
/* period size (in power of two) */
err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_PERIOD_BYTES,
ARRAY_SIZE(bytes_list), bytes_list);
if (err < 0)
return err;
/* periods */
err = snd_pcm_ioplug_set_param_minmax(io, SND_PCM_IOPLUG_HW_PERIODS, 2, 1024);
if (err < 0)
return err;
/* buffer size (in power of two) */
err = snd_pcm_ioplug_set_param_list(io, SND_PCM_IOPLUG_HW_BUFFER_BYTES,
ARRAY_SIZE(bytes_list), bytes_list);
if (err < 0)
return err;
return 0;
}
static int oss_close(snd_pcm_ioplug_t *io)
{
snd_pcm_oss_t *oss = io->private_data;
close(oss->fd);
free(oss->device);
free(oss);
return 0;
}
static const snd_pcm_ioplug_callback_t oss_playback_callback = {
.start = oss_start,
.stop = oss_stop,
.transfer = oss_write,
.pointer = oss_pointer,
.close = oss_close,
.hw_params = oss_hw_params,
.prepare = oss_prepare,
.drain = oss_drain,
};
static const snd_pcm_ioplug_callback_t oss_capture_callback = {
.start = oss_start,
.stop = oss_stop,
.transfer = oss_read,
.pointer = oss_pointer,
.close = oss_close,
.hw_params = oss_hw_params,
.prepare = oss_prepare,
.drain = oss_drain,
};
SND_PCM_PLUGIN_DEFINE_FUNC(oss)
{
snd_config_iterator_t i, next;
const char *device = "/dev/dsp";
int err;
snd_pcm_oss_t *oss;
snd_config_for_each(i, next, conf) {
snd_config_t *n = snd_config_iterator_entry(i);
const char *id;
if (snd_config_get_id(n, &id) < 0)
continue;
if (strcmp(id, "comment") == 0 || strcmp(id, "type") == 0 || strcmp(id, "hint") == 0)
continue;
if (strcmp(id, "device") == 0) {
if (snd_config_get_string(n, &device) < 0) {
SNDERR("Invalid type for %s", id);
return -EINVAL;
}
continue;
}
SNDERR("Unknown field %s", id);
return -EINVAL;
}
oss = calloc(1, sizeof(*oss));
if (! oss) {
SNDERR("cannot allocate");
return -ENOMEM;
}
oss->device = strdup(device);
if (oss->device == NULL) {
SNDERR("cannot allocate");
free(oss);
return -ENOMEM;
}
oss->fd = open(device, stream == SND_PCM_STREAM_PLAYBACK ?
O_WRONLY : O_RDONLY);
if (oss->fd < 0) {
err = -errno;
SNDERR("Cannot open device %s", device);
goto error;
}
oss->io.version = SND_PCM_IOPLUG_VERSION;
oss->io.name = "ALSA <-> OSS PCM I/O Plugin";
oss->io.poll_fd = oss->fd;
oss->io.poll_events = stream == SND_PCM_STREAM_PLAYBACK ? POLLOUT : POLLIN;
oss->io.mmap_rw = 0;
oss->io.callback = stream == SND_PCM_STREAM_PLAYBACK ?
&oss_playback_callback : &oss_capture_callback;
oss->io.private_data = oss;
err = snd_pcm_ioplug_create(&oss->io, name, stream, mode);
if (err < 0)
goto error;
if ((err = oss_hw_constraint(oss)) < 0) {
snd_pcm_ioplug_delete(&oss->io);
return err;
}
*pcmp = oss->io.pcm;
return 0;
error:
if (oss->fd >= 0)
close(oss->fd);
free(oss->device);
free(oss);
return err;
}
SND_PCM_PLUGIN_SYMBOL(oss);