pcm.c

linux 内核源代码

{
	struct snd_pcm_substream *substream = entry->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (!runtime) {
		snd_iprintf(buffer, "closed\n");
		return;
	}
	if (runtime->status->state == SNDRV_PCM_STATE_OPEN) {
		snd_iprintf(buffer, "no setup\n");
		return;
	}
	snd_iprintf(buffer, "tstamp_mode: %s\n", snd_pcm_tstamp_mode_name(runtime->tstamp_mode));
	snd_iprintf(buffer, "period_step: %u\n", runtime->period_step);
	snd_iprintf(buffer, "sleep_min: %u\n", runtime->sleep_min);
	snd_iprintf(buffer, "avail_min: %lu\n", runtime->control->avail_min);
	snd_iprintf(buffer, "xfer_align: %lu\n", runtime->xfer_align);
	snd_iprintf(buffer, "start_threshold: %lu\n", runtime->start_threshold);
	snd_iprintf(buffer, "stop_threshold: %lu\n", runtime->stop_threshold);
	snd_iprintf(buffer, "silence_threshold: %lu\n", runtime->silence_threshold);
	snd_iprintf(buffer, "silence_size: %lu\n", runtime->silence_size);
	snd_iprintf(buffer, "boundary: %lu\n", runtime->boundary);
}

static void snd_pcm_substream_proc_status_read(struct snd_info_entry *entry,
					       struct snd_info_buffer *buffer)
{
	struct snd_pcm_substream *substream = entry->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_pcm_status status;
	int err;
	if (!runtime) {
		snd_iprintf(buffer, "closed\n");
		return;
	}
	memset(&status, 0, sizeof(status));
	err = snd_pcm_status(substream, &status);
	if (err < 0) {
		snd_iprintf(buffer, "error %d\n", err);
		return;
	}
	snd_iprintf(buffer, "state: %s\n", snd_pcm_state_name(status.state));
	snd_iprintf(buffer, "trigger_time: %ld.%09ld\n",
		status.trigger_tstamp.tv_sec, status.trigger_tstamp.tv_nsec);
	snd_iprintf(buffer, "tstamp      : %ld.%09ld\n",
		status.tstamp.tv_sec, status.tstamp.tv_nsec);
	snd_iprintf(buffer, "delay       : %ld\n", status.delay);
	snd_iprintf(buffer, "avail       : %ld\n", status.avail);
	snd_iprintf(buffer, "avail_max   : %ld\n", status.avail_max);
	snd_iprintf(buffer, "-----\n");
	snd_iprintf(buffer, "hw_ptr      : %ld\n", runtime->status->hw_ptr);
	snd_iprintf(buffer, "appl_ptr    : %ld\n", runtime->control->appl_ptr);
}

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
static void snd_pcm_xrun_debug_read(struct snd_info_entry *entry,
				    struct snd_info_buffer *buffer)
{
	struct snd_pcm_str *pstr = entry->private_data;
	snd_iprintf(buffer, "%d\n", pstr->xrun_debug);
}

static void snd_pcm_xrun_debug_write(struct snd_info_entry *entry,
				     struct snd_info_buffer *buffer)
{
	struct snd_pcm_str *pstr = entry->private_data;
	char line[64];
	if (!snd_info_get_line(buffer, line, sizeof(line)))
		pstr->xrun_debug = simple_strtoul(line, NULL, 10);
}
#endif

static int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr)
{
	struct snd_pcm *pcm = pstr->pcm;
	struct snd_info_entry *entry;
	char name[16];

	sprintf(name, "pcm%i%c", pcm->device, 
		pstr->stream == SNDRV_PCM_STREAM_PLAYBACK ? 'p' : 'c');
	if ((entry = snd_info_create_card_entry(pcm->card, name, pcm->card->proc_root)) == NULL)
		return -ENOMEM;
	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
	if (snd_info_register(entry) < 0) {
		snd_info_free_entry(entry);
		return -ENOMEM;
	}
	pstr->proc_root = entry;

	if ((entry = snd_info_create_card_entry(pcm->card, "info", pstr->proc_root)) != NULL) {
		snd_info_set_text_ops(entry, pstr, snd_pcm_stream_proc_info_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	pstr->proc_info_entry = entry;

#ifdef CONFIG_SND_PCM_XRUN_DEBUG
	if ((entry = snd_info_create_card_entry(pcm->card, "xrun_debug",
						pstr->proc_root)) != NULL) {
		entry->c.text.read = snd_pcm_xrun_debug_read;
		entry->c.text.write = snd_pcm_xrun_debug_write;
		entry->mode |= S_IWUSR;
		entry->private_data = pstr;
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	pstr->proc_xrun_debug_entry = entry;
#endif
	return 0;
}

static int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr)
{
#ifdef CONFIG_SND_PCM_XRUN_DEBUG
	snd_info_free_entry(pstr->proc_xrun_debug_entry);
	pstr->proc_xrun_debug_entry = NULL;
#endif
	snd_info_free_entry(pstr->proc_info_entry);
	pstr->proc_info_entry = NULL;
	snd_info_free_entry(pstr->proc_root);
	pstr->proc_root = NULL;
	return 0;
}

static int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream)
{
	struct snd_info_entry *entry;
	struct snd_card *card;
	char name[16];

	card = substream->pcm->card;

	sprintf(name, "sub%i", substream->number);
	if ((entry = snd_info_create_card_entry(card, name, substream->pstr->proc_root)) == NULL)
		return -ENOMEM;
	entry->mode = S_IFDIR | S_IRUGO | S_IXUGO;
	if (snd_info_register(entry) < 0) {
		snd_info_free_entry(entry);
		return -ENOMEM;
	}
	substream->proc_root = entry;

	if ((entry = snd_info_create_card_entry(card, "info", substream->proc_root)) != NULL) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_substream_proc_info_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_info_entry = entry;

	if ((entry = snd_info_create_card_entry(card, "hw_params", substream->proc_root)) != NULL) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_substream_proc_hw_params_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_hw_params_entry = entry;

	if ((entry = snd_info_create_card_entry(card, "sw_params", substream->proc_root)) != NULL) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_substream_proc_sw_params_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_sw_params_entry = entry;

	if ((entry = snd_info_create_card_entry(card, "status", substream->proc_root)) != NULL) {
		snd_info_set_text_ops(entry, substream,
				      snd_pcm_substream_proc_status_read);
		if (snd_info_register(entry) < 0) {
			snd_info_free_entry(entry);
			entry = NULL;
		}
	}
	substream->proc_status_entry = entry;

	return 0;
}

static int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream)
{
	snd_info_free_entry(substream->proc_info_entry);
	substream->proc_info_entry = NULL;
	snd_info_free_entry(substream->proc_hw_params_entry);
	substream->proc_hw_params_entry = NULL;
	snd_info_free_entry(substream->proc_sw_params_entry);
	substream->proc_sw_params_entry = NULL;
	snd_info_free_entry(substream->proc_status_entry);
	substream->proc_status_entry = NULL;
	snd_info_free_entry(substream->proc_root);
	substream->proc_root = NULL;
	return 0;
}
#else /* !CONFIG_SND_VERBOSE_PROCFS */
static inline int snd_pcm_stream_proc_init(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_stream_proc_done(struct snd_pcm_str *pstr) { return 0; }
static inline int snd_pcm_substream_proc_init(struct snd_pcm_substream *substream) { return 0; }
static inline int snd_pcm_substream_proc_done(struct snd_pcm_substream *substream) { return 0; }
#endif /* CONFIG_SND_VERBOSE_PROCFS */

/**
 * snd_pcm_new_stream - create a new PCM stream
 * @pcm: the pcm instance
 * @stream: the stream direction, SNDRV_PCM_STREAM_XXX
 * @substream_count: the number of substreams
 *
 * Creates a new stream for the pcm.
 * The corresponding stream on the pcm must have been empty before
 * calling this, i.e. zero must be given to the argument of
 * snd_pcm_new().
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_pcm_new_stream(struct snd_pcm *pcm, int stream, int substream_count)
{
	int idx, err;
	struct snd_pcm_str *pstr = &pcm->streams[stream];
	struct snd_pcm_substream *substream, *prev;

#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
	mutex_init(&pstr->oss.setup_mutex);
#endif
	pstr->stream = stream;
	pstr->pcm = pcm;
	pstr->substream_count = substream_count;
	if (substream_count > 0) {
		err = snd_pcm_stream_proc_init(pstr);
		if (err < 0) {
			snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
			return err;
		}
	}
	prev = NULL;
	for (idx = 0, prev = NULL; idx < substream_count; idx++) {
		substream = kzalloc(sizeof(*substream), GFP_KERNEL);
		if (substream == NULL) {
			snd_printk(KERN_ERR "Cannot allocate PCM substream\n");
			return -ENOMEM;
		}
		substream->pcm = pcm;
		substream->pstr = pstr;
		substream->number = idx;
		substream->stream = stream;
		sprintf(substream->name, "subdevice #%i", idx);
		snprintf(substream->latency_id, sizeof(substream->latency_id),
			 "ALSA-PCM%d-%d%c%d", pcm->card->number, pcm->device,
			 (stream ? 'c' : 'p'), idx);
		substream->buffer_bytes_max = UINT_MAX;
		if (prev == NULL)
			pstr->substream = substream;
		else
			prev->next = substream;
		err = snd_pcm_substream_proc_init(substream);
		if (err < 0) {
			snd_printk(KERN_ERR "Error in snd_pcm_stream_proc_init\n");
			if (prev == NULL)
				pstr->substream = NULL;
			else
				prev->next = NULL;
			kfree(substream);
			return err;
		}
		substream->group = &substream->self_group;
		spin_lock_init(&substream->self_group.lock);
		INIT_LIST_HEAD(&substream->self_group.substreams);
		list_add_tail(&substream->link_list, &substream->self_group.substreams);
		spin_lock_init(&substream->timer_lock);
		atomic_set(&substream->mmap_count, 0);
		prev = substream;
	}
	return 0;
}				

EXPORT_SYMBOL(snd_pcm_new_stream);

/**
 * snd_pcm_new - create a new PCM instance
 * @card: the card instance
 * @id: the id string
 * @device: the device index (zero based)
 * @playback_count: the number of substreams for playback
 * @capture_count: the number of substreams for capture
 * @rpcm: the pointer to store the new pcm instance
 *
 * Creates a new PCM instance.
 *
 * The pcm operators have to be set afterwards to the new instance
 * via snd_pcm_set_ops().
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_pcm_new(struct snd_card *card, char *id, int device,
		int playback_count, int capture_count,
	        struct snd_pcm ** rpcm)
{
	struct snd_pcm *pcm;
	int err;
	static struct snd_device_ops ops = {
		.dev_free = snd_pcm_dev_free,
		.dev_register =	snd_pcm_dev_register,
		.dev_disconnect = snd_pcm_dev_disconnect,
	};

	snd_assert(rpcm != NULL, return -EINVAL);
	*rpcm = NULL;
	snd_assert(card != NULL, return -ENXIO);
	pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
	if (pcm == NULL) {
		snd_printk(KERN_ERR "Cannot allocate PCM\n");
		return -ENOMEM;
	}
	pcm->card = card;
	pcm->device = device;
	if (id)
		strlcpy(pcm->id, id, sizeof(pcm->id));
	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_PLAYBACK, playback_count)) < 0) {
		snd_pcm_free(pcm);
		return err;
	}
	if ((err = snd_pcm_new_stream(pcm, SNDRV_PCM_STREAM_CAPTURE, capture_count)) < 0) {
		snd_pcm_free(pcm);
		return err;
	}
	mutex_init(&pcm->open_mutex);
	init_waitqueue_head(&pcm->open_wait);
	if ((err = snd_device_new(card, SNDRV_DEV_PCM, pcm, &ops)) < 0) {
		snd_pcm_free(pcm);
		return err;
	}
	*rpcm = pcm;
	return 0;
}

EXPORT_SYMBOL(snd_pcm_new);

static void snd_pcm_free_stream(struct snd_pcm_str * pstr)
{
	struct snd_pcm_substream *substream, *substream_next;
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
	struct snd_pcm_oss_setup *setup, *setupn;
#endif
	substream = pstr->substream;
	while (substream) {
		substream_next = substream->next;
		snd_pcm_timer_done(substream);
		snd_pcm_substream_proc_done(substream);
		kfree(substream);
		substream = substream_next;
	}
	snd_pcm_stream_proc_done(pstr);
#if defined(CONFIG_SND_PCM_OSS) || defined(CONFIG_SND_PCM_OSS_MODULE)
	for (setup = pstr->oss.setup_list; setup; setup = setupn) {
		setupn = setup->next;
		kfree(setup->task_name);
		kfree(setup);
	}
#endif
}

static int snd_pcm_free(struct snd_pcm *pcm)
{
	struct snd_pcm_notify *notify;

	snd_assert(pcm != NULL, return -ENXIO);
	list_for_each_entry(notify, &snd_pcm_notify_list, list) {
		notify->n_unregister(pcm);
	}