pcm_oss.c

是关于linux2.5.1的完全源码

}

static int snd_pcm_oss_get_rate(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.rate;
}

static int snd_pcm_oss_set_channels(snd_pcm_oss_file_t *pcm_oss_file, int channels)
{
	int idx;
	if (channels < 1)
		channels = 1;
	if (channels > 128)
		return -EINVAL;
	for (idx = 1; idx >= 0; --idx) {
		snd_pcm_substream_t *substream = pcm_oss_file->streams[idx];
		snd_pcm_runtime_t *runtime;
		if (substream == NULL)
			continue;
		runtime = substream->runtime;
		if (runtime->oss.channels != channels) {
			runtime->oss.params = 1;
			runtime->oss.channels = channels;
		}
	}
	return snd_pcm_oss_get_channels(pcm_oss_file);
}

static int snd_pcm_oss_get_channels(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.channels;
}

static int snd_pcm_oss_get_block_size(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.period_bytes;
}

static int snd_pcm_oss_get_formats(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	int err;
	int direct;
	snd_pcm_hw_params_t params;
	unsigned int formats = 0;
	unsigned int format_mask;
	int fmt;
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	if (atomic_read(&substream->runtime->mmap_count)) {
		direct = 1;
	} else {
		snd_pcm_oss_setup_t *setup = substream->oss.setup;
		direct = (setup != NULL && setup->direct);
	}
	if (!direct)
		return AFMT_MU_LAW | AFMT_U8 |
		       AFMT_S16_LE | AFMT_S16_BE |
		       AFMT_S8 | AFMT_U16_LE |
		       AFMT_U16_BE;
	_snd_pcm_hw_params_any(&params);
	err = snd_pcm_hw_refine(substream, &params);
	snd_assert(err >= 0, return err);
	format_mask = *hw_param_mask(&params, SNDRV_PCM_HW_PARAM_FORMAT); 
	for (fmt = 0; fmt < 32; ++fmt) {
		if (format_mask & (1 << fmt)) {
			int f = snd_pcm_oss_format_to(fmt);
			if (f >= 0)
				formats |= f;
		}
	}
	return formats;
}

static int snd_pcm_oss_set_format(snd_pcm_oss_file_t *pcm_oss_file, int format)
{
	int formats, idx;
	
	if (format != AFMT_QUERY) {
		formats = snd_pcm_oss_get_formats(pcm_oss_file);
		if (!(formats & format))
			format = AFMT_U8;
		for (idx = 1; idx >= 0; --idx) {
			snd_pcm_substream_t *substream = pcm_oss_file->streams[idx];
			snd_pcm_runtime_t *runtime;
			if (substream == NULL)
				continue;
			runtime = substream->runtime;
			if (runtime->oss.format != format) {
				runtime->oss.params = 1;
				runtime->oss.format = format;
			}
		}
	}
	return snd_pcm_oss_get_format(pcm_oss_file);
}

static int snd_pcm_oss_get_format(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	int err;
	
	if ((err = snd_pcm_oss_get_active_substream(pcm_oss_file, &substream)) < 0)
		return err;
	return substream->runtime->oss.format;
}

static int snd_pcm_oss_set_subdivide1(snd_pcm_substream_t *substream, int subdivide)
{
	snd_pcm_runtime_t *runtime;

	if (substream == NULL)
		return 0;
	runtime = substream->runtime;
	if (subdivide == 0) {
		subdivide = runtime->oss.subdivision;
		if (subdivide == 0)
			subdivide = 1;
		return subdivide;
	}
	if (runtime->oss.subdivision || runtime->oss.fragshift)
		return -EINVAL;
	if (subdivide != 1 && subdivide != 2 && subdivide != 4 &&
	    subdivide != 8 && subdivide != 16)
		return -EINVAL;
	runtime->oss.subdivision = subdivide;
	runtime->oss.params = 1;
	return subdivide;
}

static int snd_pcm_oss_set_subdivide(snd_pcm_oss_file_t *pcm_oss_file, int subdivide)
{
	int err = -EINVAL, idx;

	for (idx = 1; idx >= 0; --idx) {
		snd_pcm_substream_t *substream = pcm_oss_file->streams[idx];
		if (substream == NULL)
			continue;
		if ((err = snd_pcm_oss_set_subdivide1(substream, subdivide)) < 0)
			return err;
	}
	return err;
}

static int snd_pcm_oss_set_fragment1(snd_pcm_substream_t *substream, unsigned int val)
{
	snd_pcm_runtime_t *runtime;

	if (substream == NULL)
		return 0;
	runtime = substream->runtime;
	if (runtime->oss.subdivision || runtime->oss.fragshift)
		return -EINVAL;
	runtime->oss.fragshift = val & 0xffff;
	runtime->oss.maxfrags = (val >> 16) & 0xffff;
	if (runtime->oss.fragshift < 4)		/* < 16 */
		runtime->oss.fragshift = 4;
	if (runtime->oss.maxfrags < 2)
		runtime->oss.maxfrags = 2;
	runtime->oss.params = 1;
	return 0;
}

static int snd_pcm_oss_set_fragment(snd_pcm_oss_file_t *pcm_oss_file, unsigned int val)
{
	int err = -EINVAL, idx;

	for (idx = 1; idx >= 0; --idx) {
		snd_pcm_substream_t *substream = pcm_oss_file->streams[idx];
		if (substream == NULL)
			continue;
		if ((err = snd_pcm_oss_set_fragment1(substream, val)) < 0)
			return err;
	}
	return err;
}

static int snd_pcm_oss_nonblock(struct file * file)
{
	file->f_flags |= O_NONBLOCK;
	return 0;
}

static int snd_pcm_oss_get_caps1(snd_pcm_substream_t *substream, int res)
{

	if (substream == NULL) {
		res &= ~DSP_CAP_DUPLEX;
		return res;
	}
#ifdef DSP_CAP_MULTI
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		if (substream->pstr->substream_count > 1)
			res |= DSP_CAP_MULTI;
#endif
	/* DSP_CAP_REALTIME is set all times: */
	/* all ALSA drivers can return actual pointer in ring buffer */
#if defined(DSP_CAP_REALTIME) && 0
	{
		snd_pcm_runtime_t *runtime = substream->runtime;
		if (runtime->info & (SNDRV_PCM_INFO_BLOCK_TRANSFER|SNDRV_PCM_INFO_BATCH))
			res &= ~DSP_CAP_REALTIME;
	}
#endif
	return res;
}

static int snd_pcm_oss_get_caps(snd_pcm_oss_file_t *pcm_oss_file)
{
	int result, idx;
	
	result = DSP_CAP_TRIGGER | DSP_CAP_MMAP	| DSP_CAP_DUPLEX | DSP_CAP_REALTIME;
	for (idx = 0; idx < 2; idx++) {
		snd_pcm_substream_t *substream = pcm_oss_file->streams[idx];
		result = snd_pcm_oss_get_caps1(substream, result);
	}
	result |= 0x0001;	/* revision - same as SB AWE 64 */
	return result;
}

static void snd_pcm_oss_simulate_fill(snd_pcm_substream_t *substream)
{
	snd_pcm_runtime_t *runtime = substream->runtime;
	snd_pcm_uframes_t appl_ptr;
	appl_ptr = runtime->hw_ptr_interrupt + runtime->buffer_size;
	appl_ptr %= runtime->boundary;
	runtime->control->appl_ptr = appl_ptr;
}

static int snd_pcm_oss_set_trigger(snd_pcm_oss_file_t *pcm_oss_file, int trigger)
{
	snd_pcm_runtime_t *runtime;
	snd_pcm_substream_t *psubstream = NULL, *csubstream = NULL;
	int err, cmd;
	
	psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];

	if (psubstream) {
		if ((err = snd_pcm_oss_make_ready(psubstream)) < 0)
			return err;
		if (atomic_read(&psubstream->runtime->mmap_count))
			snd_pcm_oss_simulate_fill(psubstream);
	}
	if (csubstream) {
		if ((err = snd_pcm_oss_make_ready(csubstream)) < 0)
			return err;
	}
      	if (psubstream) {
      		runtime = psubstream->runtime;
		if (trigger & PCM_ENABLE_OUTPUT) {
			if (runtime->oss.trigger)
				goto _skip1;
			runtime->oss.trigger = 1;
			runtime->start_threshold = 1;
			cmd = SNDRV_PCM_IOCTL_START;
		} else {
			if (!runtime->oss.trigger)
				goto _skip1;
			runtime->oss.trigger = 0;
			runtime->start_threshold = runtime->boundary;
			cmd = SNDRV_PCM_IOCTL_DROP;
			runtime->oss.prepare = 1;
		}
		err = snd_pcm_kernel_playback_ioctl(psubstream, cmd, 0);
		if (err < 0)
			return err;
	}
 _skip1:
	if (csubstream) {
      		runtime = csubstream->runtime;
		if (trigger & PCM_ENABLE_INPUT) {
			if (runtime->oss.trigger)
				goto _skip2;
			runtime->oss.trigger = 1;
			runtime->start_threshold = 1;
			cmd = SNDRV_PCM_IOCTL_START;
		} else {
			if (!runtime->oss.trigger)
				goto _skip2;
			runtime->oss.trigger = 0;
			runtime->start_threshold = runtime->boundary;
			cmd = SNDRV_PCM_IOCTL_DROP;
			runtime->oss.prepare = 1;
		}
		err = snd_pcm_kernel_capture_ioctl(csubstream, cmd, 0);
		if (err < 0)
			return err;
	}
 _skip2:
	return 0;
}

static int snd_pcm_oss_get_trigger(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *psubstream = NULL, *csubstream = NULL;
	int result = 0;

	psubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	csubstream = pcm_oss_file->streams[SNDRV_PCM_STREAM_CAPTURE];
	if (psubstream && psubstream->runtime && psubstream->runtime->oss.trigger)
		result |= PCM_ENABLE_OUTPUT;
	if (csubstream && csubstream->runtime && csubstream->runtime->oss.trigger)
		result |= PCM_ENABLE_INPUT;
	return result;
}

static int snd_pcm_oss_get_odelay(snd_pcm_oss_file_t *pcm_oss_file)
{
	snd_pcm_substream_t *substream;
	snd_pcm_runtime_t *runtime;
	snd_pcm_sframes_t delay;
	int err;

	substream = pcm_oss_file->streams[SNDRV_PCM_STREAM_PLAYBACK];
	if (substream == NULL)
		return -EINVAL;
	if ((err = snd_pcm_oss_make_ready(substream)) < 0)
		return err;
	runtime = substream->runtime;
	if (runtime->oss.params || runtime->oss.prepare)
		return 0;
	err = snd_pcm_kernel_playback_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
	if (err == -EPIPE)
		delay = 0;	/* hack for broken OSS applications */
	else if (err < 0)
		return err;
	return snd_pcm_oss_bytes(substream, delay);
}

static int snd_pcm_oss_get_ptr(snd_pcm_oss_file_t *pcm_oss_file, int stream, struct count_info * _info)
{	
	snd_pcm_substream_t *substream;
	snd_pcm_runtime_t *runtime;
	snd_pcm_status_t status;
	struct count_info info;
	int err;

	if (_info == NULL)
		return -EFAULT;
	substream = pcm_oss_file->streams[stream];
	if (substream == NULL)
		return -EINVAL;
	if ((err = snd_pcm_oss_make_ready(substream)) < 0)
		return err;
	runtime = substream->runtime;
	if (runtime->oss.params || runtime->oss.prepare) {
		memset(&info, 0, sizeof(info));
		if (copy_to_user(_info, &info, sizeof(info)))
			return -EFAULT;
		return 0;
	}
	memset(&status, 0, sizeof(status));
	err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_STATUS, &status);
	if (err < 0)
		return err;
	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		info.bytes = runtime->oss.bytes - snd_pcm_oss_bytes(substream, runtime->buffer_size - status.avail);
	} else {
		info.bytes = runtime->oss.bytes + snd_pcm_oss_bytes(substream, status.avail);
	}
	info.ptr = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr % runtime->buffer_size);
	if (atomic_read(&runtime->mmap_count)) {
		snd_pcm_sframes_t n;
		n = runtime->hw_ptr_interrupt - runtime->oss.prev_hw_ptr_interrupt;
		if (n < 0)
			n += runtime->boundary;
		info.blocks = n / runtime->period_size;
		runtime->oss.prev_hw_ptr_interrupt = runtime->hw_ptr_interrupt;
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			snd_pcm_oss_simulate_fill(substream);
	} else {
		if (stream == SNDRV_PCM_STREAM_PLAYBACK)
			info.blocks = (runtime->buffer_size - status.avail) / runtime->period_size;
		else
			info.blocks = status.avail / runtime->period_size;
	}
	if (copy_to_user(_info, &info, sizeof(info)))
		return -EFAULT;
	return 0;
}

static int snd_pcm_oss_get_space(snd_pcm_oss_file_t *pcm_oss_file, int stream, struct audio_buf_info *_info)
{
	snd_pcm_substream_t *substream;
	snd_pcm_runtime_t *runtime;
	snd_pcm_status_t status;
	struct audio_buf_info info;
	int err;

	if (_info == NULL)
		return -EFAULT;
	substream = pcm_oss_file->streams[stream];
	if (substream == NULL)
		return -EINVAL;
	runtime = substream->runtime;

	if (runtime->oss.params &&
	    (err = snd_pcm_oss_change_params(substream)) < 0)
		return err;

	info.fragsize = runtime->oss.period_bytes;
	info.fragstotal = runtime->periods;
	memset(&status, 0, sizeof(status));
	if (runtime->oss.prepare) {
		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
			info.bytes = runtime->oss.period_bytes * runtime->periods;
			info.fragments = runtime->periods;
		} else {
			info.bytes = 0;
			info.fragments = 0;
		}
	} else {
		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_STATUS, &status);
		if (err < 0)
			return err;
		info.bytes = snd_pcm_oss_bytes(substream, status.avail);
		info.fragments = status.avail / runtime->period_size;
	}

#if 0
	/* very experimental stuff to get Quake2 working */
	runtime->oss.period = (info.periods - 1) << 16;
	for (tmp = info.fragsize; tmp > 1; tmp >>= 1)
		runtime->oss.period++;