ASoC: soc-dai: set dai_link dpcm_ flags with a helper

Add a helper to walk through all the DAIs and set dpcm_playback and
dpcm_capture flags based on the DAIs capabilities, and use this helper
to avoid setting these flags arbitrarily in generic cards.

The commit referenced in the Fixes tag did not introduce the
configuration issue but will prevent the card from probing when
detecting invalid configurations.

Fixes: b73287f0b0 ('ASoC: soc-pcm: dpcm: fix playback/capture checks')
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200707210439.115300-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc-dai.h

@@ -161,6 +161,7 @@ void snd_soc_dai_resume(struct snd_soc_dai *dai);
 int snd_soc_dai_compress_new(struct snd_soc_dai *dai,
 			     struct snd_soc_pcm_runtime *rtd, int num);
 bool snd_soc_dai_stream_valid(struct snd_soc_dai *dai, int stream);
+void snd_soc_dai_link_set_capabilities(struct snd_soc_dai_link *dai_link);
 void snd_soc_dai_action(struct snd_soc_dai *dai,
 			int stream, int action);
 static inline void snd_soc_dai_activate(struct snd_soc_dai *dai,

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

@@ -317,8 +317,8 @@ static int graph_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 	if (ret < 0)
 		goto out_put_node;
 
-	dai_link->dpcm_playback		= 1;
-	dai_link->dpcm_capture		= 1;
+	snd_soc_dai_link_set_capabilities(dai_link);
+
 	dai_link->ops			= &graph_ops;
 	dai_link->init			= asoc_simple_dai_init;
 

sound/soc/generic/simple-card.c

@@ -231,8 +231,8 @@ static int simple_dai_link_of_dpcm(struct asoc_simple_priv *priv,
 	if (ret < 0)
 		goto out_put_node;
 
-	dai_link->dpcm_playback		= 1;
-	dai_link->dpcm_capture		= 1;
+	snd_soc_dai_link_set_capabilities(dai_link);
+
 	dai_link->ops			= &simple_ops;
 	dai_link->init			= asoc_simple_dai_init;
 

sound/soc/soc-dai.c

@@ -391,6 +391,44 @@ bool snd_soc_dai_stream_valid(struct snd_soc_dai *dai, int dir)
 	return stream->channels_min;
 }
 
+/*
+ * snd_soc_dai_link_set_capabilities() - set dai_link properties based on its DAIs
+ */
+void snd_soc_dai_link_set_capabilities(struct snd_soc_dai_link *dai_link)
+{
+	struct snd_soc_dai_link_component *cpu;
+	struct snd_soc_dai_link_component *codec;
+	struct snd_soc_dai *dai;
+	bool supported[SNDRV_PCM_STREAM_LAST + 1];
+	int direction;
+	int i;
+
+	for_each_pcm_streams(direction) {
+		supported[direction] = true;
+
+		for_each_link_cpus(dai_link, i, cpu) {
+			dai = snd_soc_find_dai(cpu);
+			if (!dai || !snd_soc_dai_stream_valid(dai, direction)) {
+				supported[direction] = false;
+				break;
+			}
+		}
+		if (!supported[direction])
+			continue;
+		for_each_link_codecs(dai_link, i, codec) {
+			dai = snd_soc_find_dai(codec);
+			if (!dai || !snd_soc_dai_stream_valid(dai, direction)) {
+				supported[direction] = false;
+				break;
+			}
+		}
+	}
+
+	dai_link->dpcm_playback = supported[SNDRV_PCM_STREAM_PLAYBACK];
+	dai_link->dpcm_capture  = supported[SNDRV_PCM_STREAM_CAPTURE];
+}
+EXPORT_SYMBOL_GPL(snd_soc_dai_link_set_capabilities);
+
 void snd_soc_dai_action(struct snd_soc_dai *dai,
 			int stream, int action)
 {