[PATCH] ASoC: audio-graph-card2: add comment for format property

[Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>]

We don't need to have "format" property on DT any more if
CPU/Codec driver has .auto_selectable_formats settings
on snd_soc_dai_ops. The sample dtsi doesn't have it.
To avoid user confusion, this patch indicates it on comment.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
---
 .../soc/generic/audio-graph-card2-custom-sample.dtsi |  7 +++++++
 sound/soc/generic/audio-graph-card2.c                | 12 ++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/sound/soc/generic/audio-graph-card2-custom-sample.dtsi b/sound/soc/generic/audio-graph-card2-custom-sample.dtsi
index 2ac0de3c21da..8acaa2ddb335 100644
--- a/sound/soc/generic/audio-graph-card2-custom-sample.dtsi
+++ b/sound/soc/generic/audio-graph-card2-custom-sample.dtsi
@@ -34,6 +34,13 @@
  *		...
  *	};
  *
+ *
+ * Below sample doesn't use "format" property,
+ * because test-component driver (test-cpu/test-codec) is supporting
+ * snd_soc_dai_ops :: .auto_selectable_formats.
+ * see
+ *	snd_soc_runtime_get_dai_fmt()
+ *	linux/sound/soc/generic/test-component.c :: test_dai_formats
  */
 / {
 	/*
diff --git a/sound/soc/generic/audio-graph-card2.c b/sound/soc/generic/audio-graph-card2.c
index 542c4a114940..1fae810a2833 100644
--- a/sound/soc/generic/audio-graph-card2.c
+++ b/sound/soc/generic/audio-graph-card2.c
@@ -47,6 +47,18 @@
  see
 	graph_parse_daifmt().
 
+ "format" property is no longer needed on DT if both CPU/Codec drivers are
+ supporting snd_soc_dai_ops :: .auto_selectable_formats.
+ see
+	snd_soc_runtime_get_dai_fmt()
+
+	sample driver
+		linux/sound/soc/sh/rcar/core.c
+		linux/sound/soc/codecs/ak4613.c
+		linux/sound/soc/codecs/pcm3168a.c
+		linux/sound/soc/soc-utils.c
+		linux/sound/soc/generic/test-component.c
+
  ************************************
 	Normal Audio-Graph
  ************************************
-- 
2.25.1