pcm_native.c

linux 内核源代码

 * @state: PCM state after stopping the stream
 *
 * Try to stop all running streams in the substream group.
 * The state of each stream is changed to the given value after that unconditionally.
 */
int snd_pcm_stop(struct snd_pcm_substream *substream, int state)
{
	return snd_pcm_action(&snd_pcm_action_stop, substream, state);
}

EXPORT_SYMBOL(snd_pcm_stop);

/**
 * snd_pcm_drain_done
 * @substream: the PCM substream
 *
 * Stop the DMA only when the given stream is playback.
 * The state is changed to SETUP.
 * Unlike snd_pcm_stop(), this affects only the given stream.
 */
int snd_pcm_drain_done(struct snd_pcm_substream *substream)
{
	return snd_pcm_action_single(&snd_pcm_action_stop, substream,
				     SNDRV_PCM_STATE_SETUP);
}

/*
 * pause callbacks
 */
static int snd_pcm_pre_pause(struct snd_pcm_substream *substream, int push)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (!(runtime->info & SNDRV_PCM_INFO_PAUSE))
		return -ENOSYS;
	if (push) {
		if (runtime->status->state != SNDRV_PCM_STATE_RUNNING)
			return -EBADFD;
	} else if (runtime->status->state != SNDRV_PCM_STATE_PAUSED)
		return -EBADFD;
	runtime->trigger_master = substream;
	return 0;
}

static int snd_pcm_do_pause(struct snd_pcm_substream *substream, int push)
{
	if (substream->runtime->trigger_master != substream)
		return 0;
	return substream->ops->trigger(substream,
				       push ? SNDRV_PCM_TRIGGER_PAUSE_PUSH :
					      SNDRV_PCM_TRIGGER_PAUSE_RELEASE);
}

static void snd_pcm_undo_pause(struct snd_pcm_substream *substream, int push)
{
	if (substream->runtime->trigger_master == substream)
		substream->ops->trigger(substream,
					push ? SNDRV_PCM_TRIGGER_PAUSE_RELEASE :
					SNDRV_PCM_TRIGGER_PAUSE_PUSH);
}

static void snd_pcm_post_pause(struct snd_pcm_substream *substream, int push)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_trigger_tstamp(substream);
	if (push) {
		runtime->status->state = SNDRV_PCM_STATE_PAUSED;
		if (substream->timer)
			snd_timer_notify(substream->timer,
					 SNDRV_TIMER_EVENT_MPAUSE,
					 &runtime->trigger_tstamp);
		snd_pcm_tick_set(substream, 0);
		wake_up(&runtime->sleep);
	} else {
		runtime->status->state = SNDRV_PCM_STATE_RUNNING;
		if (runtime->sleep_min)
			snd_pcm_tick_prepare(substream);
		if (substream->timer)
			snd_timer_notify(substream->timer,
					 SNDRV_TIMER_EVENT_MCONTINUE,
					 &runtime->trigger_tstamp);
	}
}

static struct action_ops snd_pcm_action_pause = {
	.pre_action = snd_pcm_pre_pause,
	.do_action = snd_pcm_do_pause,
	.undo_action = snd_pcm_undo_pause,
	.post_action = snd_pcm_post_pause
};

/*
 * Push/release the pause for all linked streams.
 */
static int snd_pcm_pause(struct snd_pcm_substream *substream, int push)
{
	return snd_pcm_action(&snd_pcm_action_pause, substream, push);
}

#ifdef CONFIG_PM
/* suspend */

static int snd_pcm_pre_suspend(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (runtime->status->state == SNDRV_PCM_STATE_SUSPENDED)
		return -EBUSY;
	runtime->trigger_master = substream;
	return 0;
}

static int snd_pcm_do_suspend(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (runtime->trigger_master != substream)
		return 0;
	if (! snd_pcm_running(substream))
		return 0;
	substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
	return 0; /* suspend unconditionally */
}

static void snd_pcm_post_suspend(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_trigger_tstamp(substream);
	if (substream->timer)
		snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MSUSPEND,
				 &runtime->trigger_tstamp);
	runtime->status->suspended_state = runtime->status->state;
	runtime->status->state = SNDRV_PCM_STATE_SUSPENDED;
	snd_pcm_tick_set(substream, 0);
	wake_up(&runtime->sleep);
}

static struct action_ops snd_pcm_action_suspend = {
	.pre_action = snd_pcm_pre_suspend,
	.do_action = snd_pcm_do_suspend,
	.post_action = snd_pcm_post_suspend
};

/**
 * snd_pcm_suspend
 * @substream: the PCM substream
 *
 * Trigger SUSPEND to all linked streams.
 * After this call, all streams are changed to SUSPENDED state.
 */
int snd_pcm_suspend(struct snd_pcm_substream *substream)
{
	int err;
	unsigned long flags;

	if (! substream)
		return 0;

	snd_pcm_stream_lock_irqsave(substream, flags);
	err = snd_pcm_action(&snd_pcm_action_suspend, substream, 0);
	snd_pcm_stream_unlock_irqrestore(substream, flags);
	return err;
}

EXPORT_SYMBOL(snd_pcm_suspend);

/**
 * snd_pcm_suspend_all
 * @pcm: the PCM instance
 *
 * Trigger SUSPEND to all substreams in the given pcm.
 * After this call, all streams are changed to SUSPENDED state.
 */
int snd_pcm_suspend_all(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	int stream, err = 0;

	if (! pcm)
		return 0;

	for (stream = 0; stream < 2; stream++) {
		for (substream = pcm->streams[stream].substream;
		     substream; substream = substream->next) {
			/* FIXME: the open/close code should lock this as well */
			if (substream->runtime == NULL)
				continue;
			err = snd_pcm_suspend(substream);
			if (err < 0 && err != -EBUSY)
				return err;
		}
	}
	return 0;
}

EXPORT_SYMBOL(snd_pcm_suspend_all);

/* resume */

static int snd_pcm_pre_resume(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (!(runtime->info & SNDRV_PCM_INFO_RESUME))
		return -ENOSYS;
	runtime->trigger_master = substream;
	return 0;
}

static int snd_pcm_do_resume(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (runtime->trigger_master != substream)
		return 0;
	/* DMA not running previously? */
	if (runtime->status->suspended_state != SNDRV_PCM_STATE_RUNNING &&
	    (runtime->status->suspended_state != SNDRV_PCM_STATE_DRAINING ||
	     substream->stream != SNDRV_PCM_STREAM_PLAYBACK))
		return 0;
	return substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_RESUME);
}

static void snd_pcm_undo_resume(struct snd_pcm_substream *substream, int state)
{
	if (substream->runtime->trigger_master == substream &&
	    snd_pcm_running(substream))
		substream->ops->trigger(substream, SNDRV_PCM_TRIGGER_SUSPEND);
}

static void snd_pcm_post_resume(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	snd_pcm_trigger_tstamp(substream);
	if (substream->timer)
		snd_timer_notify(substream->timer, SNDRV_TIMER_EVENT_MRESUME,
				 &runtime->trigger_tstamp);
	runtime->status->state = runtime->status->suspended_state;
	if (runtime->sleep_min)
		snd_pcm_tick_prepare(substream);
}

static struct action_ops snd_pcm_action_resume = {
	.pre_action = snd_pcm_pre_resume,
	.do_action = snd_pcm_do_resume,
	.undo_action = snd_pcm_undo_resume,
	.post_action = snd_pcm_post_resume
};

static int snd_pcm_resume(struct snd_pcm_substream *substream)
{
	struct snd_card *card = substream->pcm->card;
	int res;

	snd_power_lock(card);
	if ((res = snd_power_wait(card, SNDRV_CTL_POWER_D0)) >= 0)
		res = snd_pcm_action_lock_irq(&snd_pcm_action_resume, substream, 0);
	snd_power_unlock(card);
	return res;
}

#else

static int snd_pcm_resume(struct snd_pcm_substream *substream)
{
	return -ENOSYS;
}

#endif /* CONFIG_PM */

/*
 * xrun ioctl
 *
 * Change the RUNNING stream(s) to XRUN state.
 */
static int snd_pcm_xrun(struct snd_pcm_substream *substream)
{
	struct snd_card *card = substream->pcm->card;
	struct snd_pcm_runtime *runtime = substream->runtime;
	int result;

	snd_power_lock(card);
	if (runtime->status->state == SNDRV_PCM_STATE_SUSPENDED) {
		result = snd_power_wait(card, SNDRV_CTL_POWER_D0);
		if (result < 0)
			goto _unlock;
	}

	snd_pcm_stream_lock_irq(substream);
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_XRUN:
		result = 0;	/* already there */
		break;
	case SNDRV_PCM_STATE_RUNNING:
		result = snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
		break;
	default:
		result = -EBADFD;
	}
	snd_pcm_stream_unlock_irq(substream);
 _unlock:
	snd_power_unlock(card);
	return result;
}

/*
 * reset ioctl
 */
static int snd_pcm_pre_reset(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	switch (runtime->status->state) {
	case SNDRV_PCM_STATE_RUNNING:
	case SNDRV_PCM_STATE_PREPARED:
	case SNDRV_PCM_STATE_PAUSED:
	case SNDRV_PCM_STATE_SUSPENDED:
		return 0;
	default:
		return -EBADFD;
	}
}

static int snd_pcm_do_reset(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	int err = substream->ops->ioctl(substream, SNDRV_PCM_IOCTL1_RESET, NULL);
	if (err < 0)
		return err;
	// snd_assert(runtime->status->hw_ptr < runtime->buffer_size, );
	runtime->hw_ptr_base = 0;
	runtime->hw_ptr_interrupt = runtime->status->hw_ptr -
		runtime->status->hw_ptr % runtime->period_size;
	runtime->silence_start = runtime->status->hw_ptr;
	runtime->silence_filled = 0;
	return 0;
}

static void snd_pcm_post_reset(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	runtime->control->appl_ptr = runtime->status->hw_ptr;
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
	    runtime->silence_size > 0)
		snd_pcm_playback_silence(substream, ULONG_MAX);
}

static struct action_ops snd_pcm_action_reset = {
	.pre_action = snd_pcm_pre_reset,
	.do_action = snd_pcm_do_reset,
	.post_action = snd_pcm_post_reset
};

static int snd_pcm_reset(struct snd_pcm_substream *substream)
{
	return snd_pcm_action_nonatomic(&snd_pcm_action_reset, substream, 0);
}

/*
 * prepare ioctl
 */
/* we use the second argument for updating f_flags */
static int snd_pcm_pre_prepare(struct snd_pcm_substream *substream,
			       int f_flags)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
	    runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
		return -EBADFD;
	if (snd_pcm_running(substream))
		return -EBUSY;
	substream->f_flags = f_flags;
	return 0;
}

static int snd_pcm_do_prepare(struct snd_pcm_substream *substream, int state)
{
	int err;
	err = substream->ops->prepare(substream);
	if (err < 0)
		return err;
	return snd_pcm_do_reset(substream, 0);
}

static void snd_pcm_post_prepare(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	runtime->control->appl_ptr = runtime->status->hw_ptr;
	runtime->status->state = SNDRV_PCM_STATE_PREPARED;
}

static struct action_ops snd_pcm_action_prepare = {
	.pre_action = snd_pcm_pre_prepare,
	.do_action = snd_pcm_do_prepare,
	.post_action = snd_pcm_post_prepare
};

/**
 * snd_pcm_prepare
 * @substream: the PCM substream instance
 * @file: file to refer f_flags
 *
 * Prepare the PCM substream to be triggerable.
 */
static int snd_pcm_prepare(struct snd_pcm_substream *substream,
			   struct file *file)
{
	int res;
	struct snd_card *card = substream->pcm->card;
	int f_flags;

	if (file)
		f_flags = file->f_flags;
	else
		f_flags = substream->f_flags;

	snd_power_lock(card);
	if ((res = snd_power_wait(card, SNDRV_CTL_POWER_D0)) >= 0)
		res = snd_pcm_action_nonatomic(&snd_pcm_action_prepare,
					       substream, f_flags);
	snd_power_unlock(card);
	return res;
}

/*
 * drain ioctl
 */

static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream, int state)
{
	if (substream->f_flags & O_NONBLOCK)
		return -EAGAIN;
	substream->runtime->trigger_master = substream;
	return 0;
}

static int snd_pcm_do_drain_init(struct snd_pcm_substream *substream, int state)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		switch (runtime->status->state) {
		case SNDRV_PCM_STATE_PREPARED:
			/* start playback stream if possible */
			if (! snd_pcm_playback_empty(substream)) {
				snd_pcm_do_start(substream, SNDRV_PCM_STATE_DRAINING);
				snd_pcm_post_start(substream, SNDRV_PCM_STATE_DRAINING);
			}
			break;
		case SNDRV_PCM_STATE_RUNNING:
			runtime->status->state = SNDRV_PCM_STATE_DRAINING;
			break;
		default:
			break;
		}
	} else {
		/* stop running stream */
		if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) {
			int state = snd_pcm_capture_avail(runtime) > 0 ?
				SNDRV_PCM_STATE_DRAINING : SNDRV_PCM_STATE_SETUP;
			snd_pcm_do_stop(substream, state);
			snd_pcm_post_stop(substream, state);
		}
	}
	return 0;
}

static void snd_pcm_post_drain_init(struct snd_pcm_substream *substream, int state)
{
}

static struct action_ops snd_pcm_action_drain_init = {
	.pre_action = snd_pcm_pre_drain_init,
	.do_action = snd_pcm_do_drain_init,
	.post_action = snd_pcm_post_drain_init
};

struct drain_rec {
	struct snd_pcm_substream *substream;
	wait_queue_t wait;