pcm_native.c

linux 内核源代码

	snd_pcm_uframes_t stop_threshold;
};

static int snd_pcm_drop(struct snd_pcm_substream *substream);

/*
 * Drain the stream(s).
 * When the substream is linked, sync until the draining of all playback streams
 * is finished.
 * After this call, all streams are supposed to be either SETUP or DRAINING
 * (capture only) state.
 */
static int snd_pcm_drain(struct snd_pcm_substream *substream)
{
	struct snd_card *card;
	struct snd_pcm_runtime *runtime;
	struct snd_pcm_substream *s;
	int result = 0;
	int i, num_drecs;
	struct drain_rec *drec, drec_tmp, *d;

	snd_assert(substream != NULL, return -ENXIO);
	card = substream->pcm->card;
	runtime = substream->runtime;

	if (runtime->status->state == SNDRV_PCM_STATE_OPEN)
		return -EBADFD;

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

	/* allocate temporary record for drain sync */
	down_read(&snd_pcm_link_rwsem);
	if (snd_pcm_stream_linked(substream)) {
		drec = kmalloc(substream->group->count * sizeof(*drec), GFP_KERNEL);
		if (! drec) {
			up_read(&snd_pcm_link_rwsem);
			snd_power_unlock(card);
			return -ENOMEM;
		}
	} else
		drec = &drec_tmp;

	/* count only playback streams */
	num_drecs = 0;
	snd_pcm_group_for_each_entry(s, substream) {
		runtime = s->runtime;
		if (s->stream == SNDRV_PCM_STREAM_PLAYBACK) {
			d = &drec[num_drecs++];
			d->substream = s;
			init_waitqueue_entry(&d->wait, current);
			add_wait_queue(&runtime->sleep, &d->wait);
			/* stop_threshold fixup to avoid endless loop when
			 * stop_threshold > buffer_size
			 */
			d->stop_threshold = runtime->stop_threshold;
			if (runtime->stop_threshold > runtime->buffer_size)
				runtime->stop_threshold = runtime->buffer_size;
		}
	}
	up_read(&snd_pcm_link_rwsem);

	snd_pcm_stream_lock_irq(substream);
	/* resume pause */
	if (substream->runtime->status->state == SNDRV_PCM_STATE_PAUSED)
		snd_pcm_pause(substream, 0);

	/* pre-start/stop - all running streams are changed to DRAINING state */
	result = snd_pcm_action(&snd_pcm_action_drain_init, substream, 0);
	if (result < 0) {
		snd_pcm_stream_unlock_irq(substream);
		goto _error;
	}

	for (;;) {
		long tout;
		if (signal_pending(current)) {
			result = -ERESTARTSYS;
			break;
		}
		/* all finished? */
		for (i = 0; i < num_drecs; i++) {
			runtime = drec[i].substream->runtime;
			if (runtime->status->state == SNDRV_PCM_STATE_DRAINING)
				break;
		}
		if (i == num_drecs)
			break; /* yes, all drained */

		set_current_state(TASK_INTERRUPTIBLE);
		snd_pcm_stream_unlock_irq(substream);
		snd_power_unlock(card);
		tout = schedule_timeout(10 * HZ);
		snd_power_lock(card);
		snd_pcm_stream_lock_irq(substream);
		if (tout == 0) {
			if (substream->runtime->status->state == SNDRV_PCM_STATE_SUSPENDED)
				result = -ESTRPIPE;
			else {
				snd_printd("playback drain error (DMA or IRQ trouble?)\n");
				snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
				result = -EIO;
			}
			break;
		}
	}

	snd_pcm_stream_unlock_irq(substream);

 _error:
	for (i = 0; i < num_drecs; i++) {
		d = &drec[i];
		runtime = d->substream->runtime;
		remove_wait_queue(&runtime->sleep, &d->wait);
		runtime->stop_threshold = d->stop_threshold;
	}

	if (drec != &drec_tmp)
		kfree(drec);
	snd_power_unlock(card);

	return result;
}

/*
 * drop ioctl
 *
 * Immediately put all linked substreams into SETUP state.
 */
static int snd_pcm_drop(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime;
	struct snd_card *card;
	int result = 0;
	
	snd_assert(substream != NULL, return -ENXIO);
	runtime = substream->runtime;
	card = substream->pcm->card;

	if (runtime->status->state == SNDRV_PCM_STATE_OPEN ||
	    runtime->status->state == SNDRV_PCM_STATE_DISCONNECTED)
		return -EBADFD;

	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);
	/* resume pause */
	if (runtime->status->state == SNDRV_PCM_STATE_PAUSED)
		snd_pcm_pause(substream, 0);

	snd_pcm_stop(substream, SNDRV_PCM_STATE_SETUP);
	/* runtime->control->appl_ptr = runtime->status->hw_ptr; */
	snd_pcm_stream_unlock_irq(substream);
 _unlock:
	snd_power_unlock(card);
	return result;
}


/* WARNING: Don't forget to fput back the file */
static struct file *snd_pcm_file_fd(int fd)
{
	struct file *file;
	struct inode *inode;
	unsigned int minor;

	file = fget(fd);
	if (!file)
		return NULL;
	inode = file->f_path.dentry->d_inode;
	if (!S_ISCHR(inode->i_mode) ||
	    imajor(inode) != snd_major) {
		fput(file);
		return NULL;
	}
	minor = iminor(inode);
	if (!snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_PLAYBACK) &&
	    !snd_lookup_minor_data(minor, SNDRV_DEVICE_TYPE_PCM_CAPTURE)) {
		fput(file);
		return NULL;
	}
	return file;
}

/*
 * PCM link handling
 */
static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
{
	int res = 0;
	struct file *file;
	struct snd_pcm_file *pcm_file;
	struct snd_pcm_substream *substream1;

	file = snd_pcm_file_fd(fd);
	if (!file)
		return -EBADFD;
	pcm_file = file->private_data;
	substream1 = pcm_file->substream;
	down_write(&snd_pcm_link_rwsem);
	write_lock_irq(&snd_pcm_link_rwlock);
	if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN ||
	    substream->runtime->status->state != substream1->runtime->status->state) {
		res = -EBADFD;
		goto _end;
	}
	if (snd_pcm_stream_linked(substream1)) {
		res = -EALREADY;
		goto _end;
	}
	if (!snd_pcm_stream_linked(substream)) {
		substream->group = kmalloc(sizeof(struct snd_pcm_group), GFP_ATOMIC);
		if (substream->group == NULL) {
			res = -ENOMEM;
			goto _end;
		}
		spin_lock_init(&substream->group->lock);
		INIT_LIST_HEAD(&substream->group->substreams);
		list_add_tail(&substream->link_list, &substream->group->substreams);
		substream->group->count = 1;
	}
	list_add_tail(&substream1->link_list, &substream->group->substreams);
	substream->group->count++;
	substream1->group = substream->group;
 _end:
	write_unlock_irq(&snd_pcm_link_rwlock);
	up_write(&snd_pcm_link_rwsem);
	fput(file);
	return res;
}

static void relink_to_local(struct snd_pcm_substream *substream)
{
	substream->group = &substream->self_group;
	INIT_LIST_HEAD(&substream->self_group.substreams);
	list_add_tail(&substream->link_list, &substream->self_group.substreams);
}

static int snd_pcm_unlink(struct snd_pcm_substream *substream)
{
	struct snd_pcm_substream *s;
	int res = 0;

	down_write(&snd_pcm_link_rwsem);
	write_lock_irq(&snd_pcm_link_rwlock);
	if (!snd_pcm_stream_linked(substream)) {
		res = -EALREADY;
		goto _end;
	}
	list_del(&substream->link_list);
	substream->group->count--;
	if (substream->group->count == 1) {	/* detach the last stream, too */
		snd_pcm_group_for_each_entry(s, substream) {
			relink_to_local(s);
			break;
		}
		kfree(substream->group);
	}
	relink_to_local(substream);
       _end:
	write_unlock_irq(&snd_pcm_link_rwlock);
	up_write(&snd_pcm_link_rwsem);
	return res;
}

/*
 * hw configurator
 */
static int snd_pcm_hw_rule_mul(struct snd_pcm_hw_params *params,
			       struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	snd_interval_mul(hw_param_interval_c(params, rule->deps[0]),
		     hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_div(struct snd_pcm_hw_params *params,
			       struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	snd_interval_div(hw_param_interval_c(params, rule->deps[0]),
		     hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_muldivk(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	snd_interval_muldivk(hw_param_interval_c(params, rule->deps[0]),
			 hw_param_interval_c(params, rule->deps[1]),
			 (unsigned long) rule->private, &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_mulkdiv(struct snd_pcm_hw_params *params,
				   struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	snd_interval_mulkdiv(hw_param_interval_c(params, rule->deps[0]),
			 (unsigned long) rule->private,
			 hw_param_interval_c(params, rule->deps[1]), &t);
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

static int snd_pcm_hw_rule_format(struct snd_pcm_hw_params *params,
				  struct snd_pcm_hw_rule *rule)
{
	unsigned int k;
	struct snd_interval *i = hw_param_interval(params, rule->deps[0]);
	struct snd_mask m;
	struct snd_mask *mask = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
	snd_mask_any(&m);
	for (k = 0; k <= SNDRV_PCM_FORMAT_LAST; ++k) {
		int bits;
		if (! snd_mask_test(mask, k))
			continue;
		bits = snd_pcm_format_physical_width(k);
		if (bits <= 0)
			continue; /* ignore invalid formats */
		if ((unsigned)bits < i->min || (unsigned)bits > i->max)
			snd_mask_reset(&m, k);
	}
	return snd_mask_refine(mask, &m);
}

static int snd_pcm_hw_rule_sample_bits(struct snd_pcm_hw_params *params,
				       struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	unsigned int k;
	t.min = UINT_MAX;
	t.max = 0;
	t.openmin = 0;
	t.openmax = 0;
	for (k = 0; k <= SNDRV_PCM_FORMAT_LAST; ++k) {
		int bits;
		if (! snd_mask_test(hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT), k))
			continue;
		bits = snd_pcm_format_physical_width(k);
		if (bits <= 0)
			continue; /* ignore invalid formats */
		if (t.min > (unsigned)bits)
			t.min = bits;
		if (t.max < (unsigned)bits)
			t.max = bits;
	}
	t.integer = 1;
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}

#if SNDRV_PCM_RATE_5512 != 1 << 0 || SNDRV_PCM_RATE_192000 != 1 << 12
#error "Change this table"
#endif

static unsigned int rates[] = { 5512, 8000, 11025, 16000, 22050, 32000, 44100,
                                 48000, 64000, 88200, 96000, 176400, 192000 };

const struct snd_pcm_hw_constraint_list snd_pcm_known_rates = {
	.count = ARRAY_SIZE(rates),
	.list = rates,
};

static int snd_pcm_hw_rule_rate(struct snd_pcm_hw_params *params,
				struct snd_pcm_hw_rule *rule)
{
	struct snd_pcm_hardware *hw = rule->private;
	return snd_interval_list(hw_param_interval(params, rule->var),
				 snd_pcm_known_rates.count,
				 snd_pcm_known_rates.list, hw->rates);
}		

static int snd_pcm_hw_rule_buffer_bytes_max(struct snd_pcm_hw_params *params,
					    struct snd_pcm_hw_rule *rule)
{
	struct snd_interval t;
	struct snd_pcm_substream *substream = rule->private;
	t.min = 0;
	t.max = substream->buffer_bytes_max;
	t.openmin = 0;
	t.openmax = 0;
	t.integer = 1;
	return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}		

int snd_pcm_hw_constraints_init(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_pcm_hw_constraints *constrs = &runtime->hw_constraints;
	int k, err;

	for (k = SNDRV_PCM_HW_PARAM_FIRST_MASK; k <= SNDRV_PCM_HW_PARAM_LAST_MASK; k++) {
		snd_mask_any(constrs_mask(constrs, k));
	}

	for (k = SNDRV_PCM_HW_PARAM_FIRST_INTERVAL; k <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL; k++) {
		snd_interval_any(constrs_interval(constrs, k));
	}

	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_CHANNELS));
	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_SIZE));
	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_BUFFER_BYTES));
	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_SAMPLE_BITS));
	snd_interval_setinteger(constrs_interval(constrs, SNDRV_PCM_HW_PARAM_FRAME_BITS));

	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FORMAT,
				   snd_pcm_hw_rule_format, NULL,
				   SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
				  snd_pcm_hw_rule_sample_bits, NULL,
				  SNDRV_PCM_HW_PARAM_FORMAT, 
				  SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, 
				  snd_pcm_hw_rule_div, NULL,
				  SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
				  snd_pcm_hw_rule_mul, NULL,
				  SNDRV_PCM_HW_PARAM_SAMPLE_BITS, SNDRV_PCM_HW_PARAM_CHANNELS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
				  SNDRV_PCM_HW_PARAM_PERIOD_BYTES, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_FRAME_BITS, 
				  snd_pcm_hw_rule_mulkdiv, (void*) 8,
				  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS, 
				  snd_pcm_hw_rule_div, NULL,
				  SNDRV_PCM_HW_PARAM_FRAME_BITS, SNDRV_PCM_HW_PARAM_SAMPLE_BITS, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
				  SNDRV_PCM_HW_PARAM_PERIOD_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_TIME, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE, 
				  snd_pcm_hw_rule_mulkdiv, (void*) 1000000,
				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_BUFFER_TIME, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIODS, 
				  snd_pcm_hw_rule_div, NULL,
				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1);
	if (err < 0)
		return err;
	err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 
				  snd_pcm_hw_rule_div, NULL,
				  SNDRV_PCM_HW_PARAM_BUFFER_SIZE, SNDRV_PCM_HW_PARAM_PERIODS, -1);
	if (err < 0)
		return err;