pcm_oss.c

LINUX 2.6.17.4的源码

			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(struct snd_pcm_substream *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
	{
		struct snd_pcm_runtime *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(struct snd_pcm_oss_file *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++) {
		struct snd_pcm_substream *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(struct snd_pcm_substream *substream, snd_pcm_uframes_t hw_ptr)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_uframes_t appl_ptr;
	appl_ptr = hw_ptr + runtime->buffer_size;
	appl_ptr %= runtime->boundary;
	runtime->control->appl_ptr = appl_ptr;
}

static int snd_pcm_oss_set_trigger(struct snd_pcm_oss_file *pcm_oss_file, int trigger)
{
	struct snd_pcm_runtime *runtime;
	struct snd_pcm_substream *psubstream = NULL, *csubstream = NULL;
	int err, cmd;

#ifdef OSS_DEBUG
	printk("pcm_oss: trigger = 0x%x\n", trigger);
#endif
	
	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 (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;
			if (atomic_read(&psubstream->runtime->mmap_count))
				snd_pcm_oss_simulate_fill(psubstream, runtime->hw_ptr_interrupt);
			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_ioctl(psubstream, cmd, NULL);
		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_ioctl(csubstream, cmd, NULL);
		if (err < 0)
			return err;
	}
 _skip2:
	return 0;
}

static int snd_pcm_oss_get_trigger(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *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(struct snd_pcm_oss_file *pcm_oss_file)
{
	struct snd_pcm_substream *substream;
	struct snd_pcm_runtime *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_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(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct count_info __user * _info)
{	
	struct snd_pcm_substream *substream;
	struct snd_pcm_runtime *runtime;
	snd_pcm_sframes_t delay;
	int fixup;
	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;
	}
	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
		err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &delay);
		if (err == -EPIPE || err == -ESTRPIPE || (! err && delay < 0)) {
			err = 0;
			delay = 0;
			fixup = 0;
		} else {
			fixup = runtime->oss.buffer_used;
		}
	} else {
		err = snd_pcm_oss_capture_position_fixup(substream, &delay);
		fixup = -runtime->oss.buffer_used;
	}
	if (err < 0)
		return err;
	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 = (delay = 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 = delay;
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			snd_pcm_oss_simulate_fill(substream, delay);
		info.bytes = snd_pcm_oss_bytes(substream, runtime->status->hw_ptr) & INT_MAX;
	} else {
		delay = snd_pcm_oss_bytes(substream, delay);
		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
			if (substream->oss.setup.buggyptr)
				info.blocks = (runtime->oss.buffer_bytes - delay - fixup) / runtime->oss.period_bytes;
			else
				info.blocks = (delay + fixup) / runtime->oss.period_bytes;
			info.bytes = (runtime->oss.bytes - delay) & INT_MAX;
		} else {
			delay += fixup;
			info.blocks = delay / runtime->oss.period_bytes;
			info.bytes = (runtime->oss.bytes + delay) & INT_MAX;
		}
	}
	if (copy_to_user(_info, &info, sizeof(info)))
		return -EFAULT;
	return 0;
}

static int snd_pcm_oss_get_space(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct audio_buf_info __user *_info)
{
	struct snd_pcm_substream *substream;
	struct snd_pcm_runtime *runtime;
	snd_pcm_sframes_t avail;
	int fixup;
	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;
	if (runtime->oss.prepare) {
		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
			info.bytes = runtime->oss.period_bytes * runtime->oss.periods;
			info.fragments = runtime->oss.periods;
		} else {
			info.bytes = 0;
			info.fragments = 0;
		}
	} else {
		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
			err = snd_pcm_kernel_ioctl(substream, SNDRV_PCM_IOCTL_DELAY, &avail);
			if (err == -EPIPE || err == -ESTRPIPE || (! err && avail < 0)) {
				avail = runtime->buffer_size;
				err = 0;
				fixup = 0;
			} else {
				avail = runtime->buffer_size - avail;
				fixup = -runtime->oss.buffer_used;
			}
		} else {
			err = snd_pcm_oss_capture_position_fixup(substream, &avail);
			fixup = runtime->oss.buffer_used;
		}
		if (err < 0)
			return err;
		info.bytes = snd_pcm_oss_bytes(substream, avail) + fixup;
		info.fragments = info.bytes / runtime->oss.period_bytes;
	}

#ifdef OSS_DEBUG
	printk("pcm_oss: space: bytes = %i, fragments = %i, fragstotal = %i, fragsize = %i\n", info.bytes, info.fragments, info.fragstotal, info.fragsize);
#endif
	if (copy_to_user(_info, &info, sizeof(info)))
		return -EFAULT;
	return 0;
}

static int snd_pcm_oss_get_mapbuf(struct snd_pcm_oss_file *pcm_oss_file, int stream, struct buffmem_desc __user * _info)
{
	// it won't be probably implemented
	// snd_printd("TODO: snd_pcm_oss_get_mapbuf\n");
	return -EINVAL;
}

static const char *strip_task_path(const char *path)
{
	const char *ptr, *ptrl = NULL;
	for (ptr = path; *ptr; ptr++) {
		if (*ptr == '/')
			ptrl = ptr + 1;
	}
	return ptrl;
}

static void snd_pcm_oss_look_for_setup(struct snd_pcm *pcm, int stream,
				      const char *task_name,
				      struct snd_pcm_oss_setup *rsetup)
{
	struct snd_pcm_oss_setup *setup;

	mutex_lock(&pcm->streams[stream].oss.setup_mutex);
	do {
		for (setup = pcm->streams[stream].oss.setup_list; setup;
		     setup = setup->next) {
			if (!strcmp(setup->task_name, task_name))
				goto out;
		}
	} while ((task_name = strip_task_path(task_name)) != NULL);
 out:
	if (setup)
		*rsetup = *setup;
	mutex_unlock(&pcm->streams[stream].oss.setup_mutex);
}

static void snd_pcm_oss_release_substream(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;
	runtime = substream->runtime;
	vfree(runtime->oss.buffer);
	runtime->oss.buffer = NULL;
#ifdef CONFIG_SND_PCM_OSS_PLUGINS
	snd_pcm_oss_plugin_clear(substream);
#endif
	substream->oss.oss = 0;
}

static void snd_pcm_oss_init_substream(struct snd_pcm_substream *substream,
				       struct snd_pcm_oss_setup *setup,
				       int minor)
{
	struct snd_pcm_runtime *runtime;

	substream->oss.oss = 1;
	substream->oss.setup = *setup;
	if (setup->nonblock)
		substream->ffile->f_flags |= O_NONBLOCK;
	else if (setup->block)
		substream->ffile->f_flags &= ~O_NONBLOCK;
	runtime = substream->runtime;
	runtime->oss.params = 1;
	runtime->oss.trigger = 1;
	runtime->oss.rate = 8000;
	switch (SNDRV_MINOR_OSS_DEVICE(minor)) {
	case SNDRV_MINOR_OSS_PCM_8:
		runtime->oss.format = AFMT_U8;
		break;
	case SNDRV_MINOR_OSS_PCM_16:
		runtime->oss.format = AFMT_S16_LE;
		break;
	default:
		runtime->oss.format = AFMT_MU_LAW;
	}
	runtime->oss.channels = 1;
	runtime->oss.fragshift = 0;
	runtime->oss.maxfrags = 0;
	runtime->oss.subdivision = 0;
	substream->pcm_release = snd_pcm_oss_release_substream;
}

static int snd_pcm_oss_release_file(struct snd_pcm_oss_file *pcm_oss_file)
{
	int cidx;
	snd_assert(pcm_oss_file != NULL, return -ENXIO);
	for (cidx = 0; cidx < 2; ++cidx) {
		struct snd_pcm_substream *substream = pcm_oss_file->streams[cidx];
		if (substream)
			snd_pcm_release_substream(substream);
	}
	kfree(pcm_oss_file);
	return 0;
}

static int snd_pcm_oss_open_file(struct file *file,
				 struct snd_pcm *pcm,
				 struct snd_pcm_oss_file **rpcm_oss_file,
				 int minor,
				 struct snd_pcm_oss_setup *setup)
{
	int idx, err;
	struct snd_pcm_oss_file *pcm_oss_file;
	struct snd_pcm_substream *substream;
	unsigned int f_mode = file->f_mode;

	snd_assert(rpcm_oss_file != NULL, return -EINVAL);
	*rpcm_oss_file = NULL;

	pcm_oss_file = kzalloc(sizeof(*pcm_oss_file), GFP_KERNEL);
	if (pcm_oss_file == NULL)
		return -ENOMEM;

	if ((f_mode & (FMODE_WRITE|FMODE_READ)) == (FMODE_WRITE|FMODE_READ) &&
	    (pcm->info_flags & SNDRV_PCM_INFO_HALF_DUPLEX))
		f_mode = FMODE_WRITE;

	for (idx = 0; idx < 2; idx++) {
		if (setup[idx].disable)
			continue;
		if (! pcm->streams[idx].substream_count)
			continue; /* no matching substream */
		if (idx == SNDRV_PCM_STREAM_PLAYBACK) {
			if (! (f_mode & FMODE_WRITE))
				continue;
		} else {
			if (! (f_mode & FMODE_READ))
				continue;
		}
		err = snd_pcm_open_substream(pcm, idx, file, &substream);
		if (err < 0) {
			snd_pcm_oss_release_file(pcm_oss_file);
			return err;
		}

		pcm_oss_file->streams[idx] = substream;
		substream->file = pcm_oss_file;
		snd_pcm_oss_init_substream(substream, &setup[idx], minor);
	}
	
	if (!pcm_oss_file->streams[0] && !pcm_oss_file->streams[1]) {
		snd_pcm_oss_release_file(pcm_oss_file);
		return -EINVAL;
	}

	file->private_data = pcm_oss_file;
	*rpcm_oss_file = pcm_oss_file;
	return 0;
}


static int snd_task_name(struct task_struct *task, char *name, size_t size)
{
	unsigned int idx;

	snd_assert(task != NULL && name != NULL && size >= 2, return -EINVAL);
	for (idx = 0; idx < sizeof(task->comm) && idx + 1 < size; idx++)