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: Piotr Stankiewicz <piotrs@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Piotr Stankiewicz 2016-05-13 17:03:55 +01:00 committed by Mark Brown
parent 1a695a905c
commit 6742064aef
3 changed files with 51 additions and 15 deletions

View File

@ -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);

View File

@ -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",

View File

@ -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");