ASoC: audio-graph-card2: recommend to use auto select DAI format

"Simple Audio Card", "Audio Graph Card", "Audio Graph Card2" are
possible to set DAI format via DT.

OTOH, ASoC is supporting .auto_selectable_formats to select DAI
format automatically. Let's recommend to use it on "Audio Graph Card2".
One note is that it keeps supporting DAI format setting via DT.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://patch.msgid.link/87ik7s36k2.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: morimoto

sound/soc/generic/audio-graph-card2.c

@@ -778,6 +778,18 @@ static void graph_link_init(struct simple_util_priv *priv,
 	graph_parse_daifmt(ports_cpu,	&daifmt);
 	graph_parse_daifmt(ports_codec,	&daifmt);
 	graph_parse_daifmt(lnk,		&daifmt);
+	if (daifmt) {
+		struct device *dev = simple_priv_to_dev(priv);
+
+		/*
+		 * Recommend to use Auto Select by using .auto_selectable_formats.
+		 * linux/sound/soc/renesas/rcar/core.c can be good sample for it.
+		 *
+		 * One note is that Audio Graph Card2 still keeps compatible to set
+		 * DAI format via DT.
+		 */
+		dev_warn_once(dev, "use .auto_selectable_formats on each corresponding CPU/Codec driver");
+	}
 
 	graph_util_parse_link_direction(lnk,		&playback_only, &capture_only);
 	graph_util_parse_link_direction(ports_cpu,	&playback_only, &capture_only);