ASoC: simple-card: fix probe failure on platform component

A previous change to simple-card resulted in asoc_simple_parse_dai
attempting to retrieve the dai_name for platform components, which are
unlikely to have a valid DAI name. This caused simple-card to fail to
probe when using the xlnx_formatter_pcm as the platform component, since
it does not register any DAI components.

Since the dai_name is not used for platform components, just skip trying
to retrieve it for those.

Fixes: f107294c64 ("ASoC: simple-card: support snd_soc_dai_link_component style for cpu")
Signed-off-by: Robert Hancock <robert.hancock@calian.com>
Link: https://lore.kernel.org/r/20220107214711.1100162-6-robert.hancock@calian.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/generic/simple-card.c

@@ -28,6 +28,30 @@ static const struct snd_soc_ops simple_ops = {
 	.hw_params	= asoc_simple_hw_params,
 };
 
+static int asoc_simple_parse_platform(struct device_node *node,
+				      struct snd_soc_dai_link_component *dlc)
+{
+	struct of_phandle_args args;
+	int ret;
+
+	if (!node)
+		return 0;
+
+	/*
+	 * Get node via "sound-dai = <&phandle port>"
+	 * it will be used as xxx_of_node on soc_bind_dai_link()
+	 */
+	ret = of_parse_phandle_with_args(node, DAI, CELL, 0, &args);
+	if (ret)
+		return ret;
+
+	/* dai_name is not required and may not exist for plat component */
+
+	dlc->of_node = args.np;
+
+	return 0;
+}
+
 static int asoc_simple_parse_dai(struct device_node *node,
 				 struct snd_soc_dai_link_component *dlc,
 				 int *is_single_link)
@@ -289,7 +313,7 @@ static int simple_dai_link_of(struct asoc_simple_priv *priv,
 	if (ret < 0)
 		goto dai_link_of_err;
 
-	ret = asoc_simple_parse_dai(plat, platforms, NULL);
+	ret = asoc_simple_parse_platform(plat, platforms);
 	if (ret < 0)
 		goto dai_link_of_err;