[PATCH 09/12] ASoC: doc: dapm: fix and improve section "Registering DAPM controls"

Luca Ceresoli
2024-04-16T05:57:01Z

Extend the first paragraph to mention the {,num_}dapm_routes fields just
like the widget conterparts. Mention the route fields also in the code
example. Fix "at build time", this really means "at probe time".

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
Documentation/sound/soc/dapm.rst | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/Documentation/sound/soc/dapm.rst b/Documentation/sound/soc/dapm.rst
index 3aca913c99fc..ab7d48582cf7 100644
--- a/Documentation/sound/soc/dapm.rst
+++ b/Documentation/sound/soc/dapm.rst
@@ -254,12 +254,17 @@ This can be used to merge two signal paths together in software.
Registering DAPM controls
=========================

-In many cases the DAPM widgets implemented statically in a ``static const
-struct snd_soc_dapm_widget`` array and the routes connecting them in a
-``static const struct snd_soc_dapm_route`` array in a codec driver, and
-simply declared via the ``dapm_widgets`` and ``num_dapm_widgets`` fields of
-the ``struct snd_soc_component_driver`` so the driver registration will
-take care of populating them::
+In many cases the DAPM widgets are implemented statically in a ``static
+const struct snd_soc_dapm_widget`` array in a codec driver, and simply
+declared via the ``dapm_widgets`` and ``num_dapm_widgets`` fields of the
+``struct snd_soc_component_driver``.
+
+Similarly, routes connecting them are implemented statically in a ``static
+const struct snd_soc_dapm_route`` array and declared via the
+``dapm_routes`` and ``num_dapm_routes`` fields of the same struct.
+
+With the above declared, the driver registration will take care of
+populating them::

static const struct snd_soc_dapm_widget wm2000_dapm_widgets[] = {
SND_SOC_DAPM_OUTPUT("SPKN"),
@@ -278,11 +283,13 @@ take care of populating them::
...
.dapm_widgets = wm2000_dapm_widgets,
.num_dapm_widgets = ARRAY_SIZE(wm2000_dapm_widgets),
+ .dapm_routes = wm2000_audio_map,
+ .num_dapm_routes = ARRAY_SIZE(wm2000_audio_map),
...
};

In more complex cases the list of DAPM widgets and/or routes can be only
-known at build time. This happens for example when a driver supports
+known at probe time. This happens for example when a driver supports
different models having a different set of features. In those cases
separate widgets and routes arrays implementing the case-specific features
can be registered programmatically by calling snd_soc_dapm_new_controls()

--
2.34.1