ASoC: soc-pcm: DPCM cares BE format

Current DPCM is caring only FE format. but it will be no sound
if FE/BE was below style, and user selects S24_LE format.

        FE: S16_LE/S24_LE
        BE: S16_LE

DPCM can rewrite the format, so basically we don't want to
constrain with the BE constraints. But sometimes it will be trouble.
This patch adds new .dpcm_merged_format on struct snd_soc_dai_link.
DPCM will use FE / BE merged format if .struct snd_soc_dai_link
has it. We can have other .dpcm_merged_xxx in the future

    .dpcm_merged_foramt
    .dpcm_merged_rate
    .dpcm_merged_chan

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Keita Kobayashi <keita.kobayashi.ym@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/soc.h

@@ -985,6 +985,9 @@ struct snd_soc_dai_link {
 	unsigned int dpcm_capture:1;
 	unsigned int dpcm_playback:1;
 
+	/* DPCM used FE & BE merged format */
+	unsigned int dpcm_merged_format:1;
+
 	/* pmdown_time is ignored at stop */
 	unsigned int ignore_pmdown_time:1;
 };

sound/soc/soc-pcm.c

@@ -1485,30 +1485,67 @@ int dpcm_be_dai_startup(struct snd_soc_pcm_runtime *fe, int stream)
 }
 
 static void dpcm_init_runtime_hw(struct snd_pcm_runtime *runtime,
-	struct snd_soc_pcm_stream *stream)
+				 struct snd_soc_pcm_stream *stream,
+				 u64 formats)
 {
 	runtime->hw.rate_min = stream->rate_min;
 	runtime->hw.rate_max = stream->rate_max;
 	runtime->hw.channels_min = stream->channels_min;
 	runtime->hw.channels_max = stream->channels_max;
 	if (runtime->hw.formats)
-		runtime->hw.formats &= stream->formats;
+		runtime->hw.formats &= formats & stream->formats;
 	else
-		runtime->hw.formats = stream->formats;
+		runtime->hw.formats = formats & stream->formats;
 	runtime->hw.rates = stream->rates;
 }
 
+static u64 dpcm_runtime_base_format(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *fe = substream->private_data;
+	struct snd_soc_dpcm *dpcm;
+	u64 formats = ULLONG_MAX;
+	int stream = substream->stream;
+
+	if (!fe->dai_link->dpcm_merged_format)
+		return formats;
+
+	/*
+	 * It returns merged BE codec format
+	 * if FE want to use it (= dpcm_merged_format)
+	 */
+
+	list_for_each_entry(dpcm, &fe->dpcm[stream].be_clients, list_be) {
+		struct snd_soc_pcm_runtime *be = dpcm->be;
+		struct snd_soc_dai_driver *codec_dai_drv;
+		struct snd_soc_pcm_stream *codec_stream;
+		int i;
+
+		for (i = 0; i < be->num_codecs; i++) {
+			codec_dai_drv = be->codec_dais[i]->driver;
+			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+				codec_stream = &codec_dai_drv->playback;
+			else
+				codec_stream = &codec_dai_drv->capture;
+
+			formats &= codec_stream->formats;
+		}
+	}
+
+	return formats;
+}
+
 static void dpcm_set_fe_runtime(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
+	u64 format = dpcm_runtime_base_format(substream);
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback);
+		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback, format);
 	else
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture);
+		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture, format);
 }
 
 static int dpcm_fe_dai_do_trigger(struct snd_pcm_substream *substream, int cmd);