Commit 6742064a authored by Piotr Stankiewicz's avatar Piotr Stankiewicz Committed by Mark Brown
Browse files

ASoC: dapm: support user-defined stop condition in dai_get_connected_widgets 



Certain situations may warrant examining DAPM paths only to a certain
arbitrary point, as opposed to always following them to the end. For
instance, when establishing a connection between a front-end DAI link
and a back-end DAI link in a DPCM path, it does not make sense to walk
the DAPM graph beyond the first widget associated with a back-end link.

This patch introduces a mechanism which lets a user of
dai_get_connected_widgets supply a function which will be called for
every node during the graph walk. When invoked, this function can
execute arbitrary logic to decide whether the walk, given a DAPM widget
and walk direction, should be terminated at that point or continued
as normal.

Signed-off-by: default avatarPiotr Stankiewicz <piotrs@opensource.wolfsonmicro.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 1a695a90

include/sound/soc-dapm.h

+4 −1
Original line number Diff line number Diff line
@@ -358,6 +358,7 @@ struct snd_soc_dapm_context; 
struct regulator;

struct snd_soc_dapm_widget_list;

struct snd_soc_dapm_update;

enum snd_soc_dapm_direction;



int dapm_regulator_event(struct snd_soc_dapm_widget *w,

			 struct snd_kcontrol *kcontrol, int event);
@@ -451,7 +452,9 @@ void dapm_mark_endpoints_dirty(struct snd_soc_card *card); 


/* dapm path query */

int snd_soc_dapm_dai_get_connected_widgets(struct snd_soc_dai *dai, int stream,

	struct snd_soc_dapm_widget_list **list);

	struct snd_soc_dapm_widget_list **list,

	bool (*custom_stop_condition)(struct snd_soc_dapm_widget *,

				      enum snd_soc_dapm_direction));



struct snd_soc_dapm_context *snd_soc_dapm_kcontrol_dapm(

	struct snd_kcontrol *kcontrol);

sound/soc/soc-dapm.c

+45 −13
Original line number Diff line number Diff line
@@ -1073,7 +1073,11 @@ static int dapm_widget_list_create(struct snd_soc_dapm_widget_list **list, 
 */

static __always_inline int is_connected_ep(struct snd_soc_dapm_widget *widget,

	struct list_head *list, enum snd_soc_dapm_direction dir,

	int (*fn)(struct snd_soc_dapm_widget *, struct list_head *))

	int (*fn)(struct snd_soc_dapm_widget *, struct list_head *,

		  bool (*custom_stop_condition)(struct snd_soc_dapm_widget *,

						enum snd_soc_dapm_direction)),

	bool (*custom_stop_condition)(struct snd_soc_dapm_widget *,

				      enum snd_soc_dapm_direction))

{

	enum snd_soc_dapm_direction rdir = SND_SOC_DAPM_DIR_REVERSE(dir);

	struct snd_soc_dapm_path *path;
@@ -1088,6 +1092,9 @@ static __always_inline int is_connected_ep(struct snd_soc_dapm_widget *widget, 
	if (list)

		list_add_tail(&widget->work_list, list);



	if (custom_stop_condition && custom_stop_condition(widget, dir))

		return con;



	if ((widget->is_ep & SND_SOC_DAPM_DIR_TO_EP(dir)) && widget->connected) {

		widget->endpoints[dir] = snd_soc_dapm_suspend_check(widget);

		return widget->endpoints[dir];
@@ -1106,7 +1113,7 @@ static __always_inline int is_connected_ep(struct snd_soc_dapm_widget *widget, 


		if (path->connect) {

			path->walking = 1;

			con += fn(path->node[dir], list);

			con += fn(path->node[dir], list, custom_stop_condition);

			path->walking = 0;

		}

	}
@@ -1119,23 +1126,37 @@ static __always_inline int is_connected_ep(struct snd_soc_dapm_widget *widget, 
/*

 * Recursively check for a completed path to an active or physically connected

 * output widget. Returns number of complete paths.

 *

 * Optionally, can be supplied with a function acting as a stopping condition.

 * This function takes the dapm widget currently being examined and the walk

 * direction as an arguments, it should return true if the walk should be

 * stopped and false otherwise.

 */

static int is_connected_output_ep(struct snd_soc_dapm_widget *widget,

	struct list_head *list)

	struct list_head *list,

	bool (*custom_stop_condition)(struct snd_soc_dapm_widget *i,

				      enum snd_soc_dapm_direction))

{

	return is_connected_ep(widget, list, SND_SOC_DAPM_DIR_OUT,

			is_connected_output_ep);

			is_connected_output_ep, custom_stop_condition);

}



/*

 * Recursively check for a completed path to an active or physically connected

 * input widget. Returns number of complete paths.

 *

 * Optionally, can be supplied with a function acting as a stopping condition.

 * This function takes the dapm widget currently being examined and the walk

 * direction as an arguments, it should return true if the walk should be

 * stopped and false otherwise.

 */

static int is_connected_input_ep(struct snd_soc_dapm_widget *widget,

	struct list_head *list)

	struct list_head *list,

	bool (*custom_stop_condition)(struct snd_soc_dapm_widget *i,

				      enum snd_soc_dapm_direction))

{

	return is_connected_ep(widget, list, SND_SOC_DAPM_DIR_IN,

			is_connected_input_ep);

			is_connected_input_ep, custom_stop_condition);

}



/**
@@ -1143,15 +1164,24 @@ static int is_connected_input_ep(struct snd_soc_dapm_widget *widget, 
 * @dai: the soc DAI.

 * @stream: stream direction.

 * @list: list of active widgets for this stream.

 * @custom_stop_condition: (optional) a function meant to stop the widget graph

 *                         walk based on custom logic.

 *

 * Queries DAPM graph as to whether an valid audio stream path exists for

 * the initial stream specified by name. This takes into account

 * current mixer and mux kcontrol settings. Creates list of valid widgets.

 *

 * Optionally, can be supplied with a function acting as a stopping condition.

 * This function takes the dapm widget currently being examined and the walk

 * direction as an arguments, it should return true if the walk should be

 * stopped and false otherwise.

 *

 * Returns the number of valid paths or negative error.

 */

int snd_soc_dapm_dai_get_connected_widgets(struct snd_soc_dai *dai, int stream,

	struct snd_soc_dapm_widget_list **list)

	struct snd_soc_dapm_widget_list **list,

	bool (*custom_stop_condition)(struct snd_soc_dapm_widget *,

				      enum snd_soc_dapm_direction))

{

	struct snd_soc_card *card = dai->component->card;

	struct snd_soc_dapm_widget *w;
@@ -1171,9 +1201,11 @@ int snd_soc_dapm_dai_get_connected_widgets(struct snd_soc_dai *dai, int stream, 
	}



	if (stream == SNDRV_PCM_STREAM_PLAYBACK)

		paths = is_connected_output_ep(dai->playback_widget, &widgets);

		paths = is_connected_output_ep(dai->playback_widget, &widgets,

				custom_stop_condition);

	else

		paths = is_connected_input_ep(dai->capture_widget, &widgets);

		paths = is_connected_input_ep(dai->capture_widget, &widgets,

				custom_stop_condition);



	/* Drop starting point */

	list_del(widgets.next);
@@ -1268,8 +1300,8 @@ static int dapm_generic_check_power(struct snd_soc_dapm_widget *w) 


	DAPM_UPDATE_STAT(w, power_checks);



	in = is_connected_input_ep(w, NULL);

	out = is_connected_output_ep(w, NULL);

	in = is_connected_input_ep(w, NULL, NULL);

	out = is_connected_output_ep(w, NULL, NULL);

	return out != 0 && in != 0;

}
@@ -1928,8 +1960,8 @@ static ssize_t dapm_widget_power_read_file(struct file *file, 
		in = 0;

		out = 0;

	} else {

		in = is_connected_input_ep(w, NULL);

		out = is_connected_output_ep(w, NULL);

		in = is_connected_input_ep(w, NULL, NULL);

		out = is_connected_output_ep(w, NULL, NULL);

	}



	ret = snprintf(buf, PAGE_SIZE, "%s: %s%s  in %d out %d",

sound/soc/soc-pcm.c

+2 −1
Original line number Diff line number Diff line
@@ -1294,7 +1294,8 @@ int dpcm_path_get(struct snd_soc_pcm_runtime *fe, 
	int paths;



	/* get number of valid DAI paths and their widgets */

	paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, list);

	paths = snd_soc_dapm_dai_get_connected_widgets(cpu_dai, stream, list,

			NULL);



	dev_dbg(fe->dev, "ASoC: found %d audio %s paths\n", paths,

			stream ? "capture" : "playback");

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