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>
diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index c446485..db781f6 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -1073,7 +1073,11 @@
*/
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 @@
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 @@
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 @@
/*
* 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 @@
* @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 @@
}
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 @@
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 @@
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",