ASoC: Intel: Add DMIC channel constraint for bxt machine

Add channel and rate constraints for Refcap and dmiccap devices
respectively.

Signed-off-by: Yong Zhi <yong.zhi@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/bxt_da7219_max98357a.c

@@ -37,6 +37,7 @@ enum {
 	BXT_DPCM_AUDIO_PB = 0,
 	BXT_DPCM_AUDIO_CP,
 	BXT_DPCM_AUDIO_REF_CP,
+	BXT_DPCM_AUDIO_DMIC_CP,
 	BXT_DPCM_AUDIO_HDMI1_PB,
 	BXT_DPCM_AUDIO_HDMI2_PB,
 	BXT_DPCM_AUDIO_HDMI3_PB,
@@ -252,6 +253,52 @@ static struct snd_soc_ops broxton_da7219_ops = {
 	.hw_free = broxton_da7219_hw_free,
 };
 
+static int broxton_dmic_fixup(struct snd_soc_pcm_runtime *rtd,
+			struct snd_pcm_hw_params *params)
+{
+	struct snd_interval *channels = hw_param_interval(params,
+						SNDRV_PCM_HW_PARAM_CHANNELS);
+	channels->min = channels->max = DUAL_CHANNEL;
+
+	return 0;
+}
+
+static int broxton_dmic_startup(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	runtime->hw.channels_max = DUAL_CHANNEL;
+	snd_pcm_hw_constraint_list(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+			&constraints_channels);
+
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_RATE, &constraints_rates);
+}
+
+static const struct snd_soc_ops broxton_dmic_ops = {
+	.startup = broxton_dmic_startup,
+};
+
+static const unsigned int rates_16000[] = {
+	16000,
+};
+
+static const struct snd_pcm_hw_constraint_list constraints_16000 = {
+	.count = ARRAY_SIZE(rates_16000),
+	.list  = rates_16000,
+};
+
+static int broxton_refcap_startup(struct snd_pcm_substream *substream)
+{
+	return snd_pcm_hw_constraint_list(substream->runtime, 0,
+			SNDRV_PCM_HW_PARAM_RATE,
+			&constraints_16000);
+};
+
+static struct snd_soc_ops broxton_refcap_ops = {
+	.startup = broxton_refcap_startup,
+};
+
 /* broxton digital audio interface glue - connects codec <--> CPU */
 static struct snd_soc_dai_link broxton_dais[] = {
 	/* Front End DAI links */
@@ -299,6 +346,21 @@ static struct snd_soc_dai_link broxton_dais[] = {
 		.ignore_suspend = 1,
 		.nonatomic = 1,
 		.dynamic = 1,
+		.ops = &broxton_refcap_ops,
+	},
+	[BXT_DPCM_AUDIO_DMIC_CP]
+	{
+		.name = "Bxt Audio DMIC cap",
+		.stream_name = "dmiccap",
+		.cpu_dai_name = "DMIC Pin",
+		.codec_name = "snd-soc-dummy",
+		.codec_dai_name = "snd-soc-dummy-dai",
+		.platform_name = "0000:00:0e.0",
+		.init = NULL,
+		.dpcm_capture = 1,
+		.nonatomic = 1,
+		.dynamic = 1,
+		.ops = &broxton_dmic_ops,
 	},
 	[BXT_DPCM_AUDIO_HDMI1_PB]
 	{
@@ -382,6 +444,7 @@ static struct snd_soc_dai_link broxton_dais[] = {
 		.codec_dai_name = "dmic-hifi",
 		.platform_name = "0000:00:0e.0",
 		.ignore_suspend = 1,
+		.be_hw_params_fixup = broxton_dmic_fixup,
 		.dpcm_capture = 1,
 		.no_pcm = 1,
 	},